Section 4 Part 2

Members of the public have raised the issue of a criticality-caused explosion at a Yucca Mountain repository, where circumstances are thought to being analogous to the Mayak Chemical Complex near Kyshtym, Russia, where a chemical explosion involving a radioactive liquid waste storage tank occurred in 1957.
Members of the public have raised the concern that degradation of the waste package in the period following closure of the repository may lead to reconfiguring the spent nuclear fuel and high-level radioactive waste into potentially critical geometries. This long-term degradation of the waste form and package raises the concern that postclosure criticality may occur without appropriate design controls.
The concern members of the public have raised over the possibility of an explosive nuclear criticality originates from a report by two DOE scientists at the Los Alamos National Laboratory, Dr. C.D. Bowman and Dr. F. Venneri, which concluded that an explosive nuclear criticality was credible [Bowman, C.D. and Venneri, F. 1995. "Underground Autocatalytic Criticality from Plutonium and Other Fissile Materials." LA-UR-94-4022. Albuquerque, New Mexico: Los Alamos National Laboratory. ACC: HQO.19950314.0027.].
Members of the public have raised the concern that enhanced material migration resulting from natural (earthquake, volcanism) external events could increase the likelihood of a criticality event.

Response

As stated in Section 4.3.3.2 of the S&ER Rev. 1, there is no potential event sequence in the preclosure period of the repository that would result in a criticality at a repository at Yucca Mountain. A criticality event would require the configuration of fuel with sufficient fissionable material to sustain a chain reaction. For the 10,000-year postclosure period., nuclear criticality is screened out from the TSPA nominal case analysis based on its probability being below that required for inclusion in the TSPA analysis. Nevertheless, because of significant interest in this topic, the DOE investigated the potential consequences of a criticality event. The results of the investigation indicate that a nuclear criticality would not have a significant impact on repository performance.

Limiting the potential for, and consequences of, criticality during the postclosure phase of the geologic repository relies on multiple barriers, natural and engineered. The natural barrier system consists of the rock formations of the repository and includes the geologic, mechanical, chemical, and hydrological properties of the site. As defined in the NRC's licensing regulation at 10 CFR Part 63 [66 FR 55732], the engineered barrier system comprises the waste packages and the underground facility in which they are emplaced. A waste package is the generic term for describing the waste form (radioactive waste and any encapsulating or stabilizing matrix) and any containers, shielding, packing, and other absorbent materials immediately surrounding an individual package. The underground facility consists of the underground structure and openings that penetrate the underground structure (e.g., ramps, shafts, and boreholes, including their seals). The engineered barrier system would minimize the potential for conditions that would be conducive to a criticality event after the repository has been permanently closed.

It is recognized that defense-in-depth (a design strategy based on a system of multiple, independent, and redundant barriers, designed to ensure that failure in any one barrier does not result in failure of the entire system) is needed against criticality events even if, as currently expected, the forecasted consequences of such events for the repository's performance and for the health and safety of the public would be very small. Therefore, scenarios and conditions that contribute significantly to the overall postclosure criticality risk would be examined, with an intent to incorporate reasonable measures (add or strengthen diverse or redundant barriers to criticality) to reduce the risk. Risk-informed, performance-based analysis would be used to determine the effectiveness of the measures [YMP (Yucca Mountain Site Characterization Project) 2000. "Disposal Criticality Analysis Methodology Topical Report." YMP/TR-004Q, Rev. 01. Las Vegas, Nevada: Yucca Mountain Site Characterization Office. ACC: MOL.20001214.0001.].

An important aspect of defense-in-depth involves taking advantage of the many natural and engineered features of the site and repository to make the probability and consequences of postclosure criticality as low as feasible. The engineered barriers would collectively make the probability of a postclosure criticality low. For a criticality to occur, multiple changes in conditions (waste package breach, water intrusion and retention, removal of neutron absorbers) must occur. Should a criticality occur, however, the confining features of the underground natural barriers would protect against releases of radionuclides to the accessible environment. The features eventually implemented are expected to provide barriers to postclosure criticality that are both diverse (dissimilar methods to limit susceptibility to common-mode failures) and redundant (multiple barriers performing the same function that reduces the probability of criticality). Examples of diverse barriers are the waste package inner barrier, neutron-absorbing materials in the basket, and the steel (which displaces moderator) in the basket materials. Similarly, the use of two separate barriers (waste package and drip shield) to impede entry of water into the waste form is an example of the use of redundant barriers. The waste package itself impedes entry of water into the waste form, and the drip shield limits or prevents damage to the waste package from dripping water or rockfall [Ibid.].

Appendix H of the FEIS examines repository safety by evaluating a spectrum of credible radiological accidents and estimating their impacts. Section 5 and Appendix H, Section 2, deal specifically with the issue of criticality for repository operations and after repository closure, respectively. In both cases, the analysis concludes that criticality accidents would be extremely unlikely, and if they occurred, the impacts would not be significant.

The report by Bowman and Venneri [Bowman, C.D. and Venneri, F. 1995. "Underground Autocatalytic Criticality from Plutonium and Other Fissile Materials." LA-UR-94-4022. Albuquerque, New Mexico: Los Alamos National Laboratory. ACC: HQO.19950314.0027.] dealt with autocatalytic criticality. As reported in Section 4.3.3.2.3 of the S&ER Rev. 1, this type of criticality has been found to be not credible [Paperiello, C.J.1995. "Review of Potential for Underground Autocatalytic Criticality." Letter from C.J. Paperiello (NRC) to L. Barrett (DOE/OCRWM), August 7, 1995, with enclosure. ACC: HQO.19950912.0002.]. Autocatalytic criticality is not possible for low-enriched waste forms like commercial spent nuclear fuel, nor is it possible for the waste form inside the waste package. Even for highly enriched waste forms or those containing nearly pure plutonium-239 (which excludes commercial spent nuclear fuel), achieving a critical mass outside a waste package would require the entire fissile content of the waste package to be spread uniformly in a nearly spherical shape. In addition, it would require the extremely unlikely commingling of large amounts of transported fissile material from at least two waste packages containing highly enriched waste forms [Canavan, G.H.; Colgate, S.A.; Judd, O.P.; Petschek, A.G.; and Stratton, T.F. 1995. "Comments on Nuclear Excursions and Criticality Issues." LA-UR: 95 0851. Los Alamos, New Mexico: Los Alamos National Laboratory. ACC: HQO.19950314.0028.] [CRWMS M&O 1996. "Probabilistic External Criticality Evaluation." BB0000000-01717-2200-00037 REV 00. Las Vegas, Nevada: CRWMS M&O. ACC: MOL.19961029.0024.]. Because the igneous rock at Yucca Mountain is not likely to contain deposits that can efficiently accumulate fissile material, the probability of creating such a critical mass from a single or multiple waste packages containing highly enriched waste forms is so low as to be not credible [Kastenberg, W.E.; Peterson, P.F.; Ahn, J.; Burch, J.; Casher, G.; Chambre, P.L.; Greenspan, E.; Olander, D.R.; Vujic, J.L.; Bessinger, B.; Cook. N.G.W.; Doyle, F.M.; and Hilbert, L.B., Jr. 1996. "Considerations of Autocatalytic Criticality of Fissile Materials in Geologic Repositories." Nuclear Technology," volume 115, pages 298-308. Hinsdale, Illinois: American Nuclear Society. TIC: 247504.].

There have been a number of criticality accidents in Russia since 1953 resulting in a total of seven worker deaths (no deaths to members of the public). However, none of these involved handling or burial of radioactive waste. The event that occurred at the Mayak Chemical Complex near Kyshtym, Russia, in the Ural Mountains, on September 29, 1957, was a chemical explosion involving a radioactive liquid waste storage tank, not a criticality accident. There are no liquid radioactive wastes or explosive chemicals allowed for disposal at the proposed Yucca Mountain repository. Therefore, events similar to this one are not possible at Yucca Mountain and this event is not relevant to repository safety.

The potential impact of disruptive natural events (e.g., seismic or igneous intrusion) on the risk of criticality in the repository has been studied. Seismic events can produce a rapid change in the configurations of waste forms and waste packages. If the resulting configuration has a neutron multiplication factor, k-effective, above the critical limit, the seismic event has provided a rapid reactivity insertion mechanism that could lead to a transient criticality. The identification of the initial, pre-insertion configurations has been incorporated into the repository criticality analysis methodology.

4.6.2 Accident Event Sequences

4.6.2 (8)

An issue has been raised about the reliability of the accident probabilities.

The DOE has established criteria for the consideration of possible events associated with a repository at Yucca Mountain that are consistent with relevant regulations, and consequences of event sequences applicable to a repository at Yucca Mountain have been calculated.

As discussed in Chapter 2 of the SSE, event sequences determined to be applicable to a repository at Yucca Mountain cover a full range of probable events, from normal operational events that might be reasonably anticipated to occur during the design life of the facility to very low-probability events that are not expected to occur. The probability of a preclosure operational event sequence is based on the frequency of occurrence. Event sequences are categorized as Category 1 or Category 2, as described in 10 CFR 63.2 as referenced in 10 CFR 963. Category 1 event sequences are expected to occur one or more times before permanent closure of the repository. Based on a preclosure operating period of 100 years, the Category 1 event sequence frequency is 0.01 events per year or higher. Other event sequences that have at least one chance in 10,000 of occurring before permanent closure are defined as Category 2. Based on a preclosure operating period of 100 years, the frequency range is between 0.01 and 0.000001 per year. Event sequences that are expected to occur at a frequency of less than once in 10,000 events, based on a 100-year preclosure operational period, are considered to be not credible. Category 2 event sequences are low probability events and the radiological consequences of these events have been calculated as described in Chapter 2 of the SSE.

The Category 1 and Category 2 event sequence frequencies were calculated based on a 100-year preclosure operational period. If the closure of the repository extended to 325 years, the use of a 100-year preclosure period to screen event sequences would be unchanged since the surface fuel handling operations would be completed after approximately 24 years. There would be no waste forms in the surface facility after the waste package subsurface emplacement operations are completed. Chapter 2 of the SSE notes that extension of the preclosure operations to 325 years would impact the screening criteria for subsurface event sequences; but no new event sequences have been identified that would impact the selection of bounding event sequences that could result in a radioactive release.

The DOE calculation method of event sequence probabilities indicates that a repository at Yucca Mountain would be likely to be below the NRC's radiation protection standards.

4.6.2 (18060)

Summary Comment

An issue has been raised concerning the effects of earthquakes on surface dry storage containers, fuel storage pools, and underground tunnels.

Response

Spent fuel storage casks may be employed to accommodate the inventory of spent fuel required to meet operating requirements with regard to the thermal load of waste packages. These casks would be required to meet all applicable NRC criteria, including the ability to adequately cool the fuel in the event of an earthquake and subsequent tipover.

The Pool Fuel Blending Inventory Building and the associated fuel blending inventory pools were described in Section 2.2.4.2.2 of the S&ER and Section 2.2.4.2.2 of the S&ER Rev. 1. The potential hazards from the fuel blending inventory pools and the surface aging facility (i.e., design options to support a range of thermal operating modes) were evaluated in Sections 5.3.2.1 and 5.3.2.3 of the S&ER Rev. 1, and were found to have no effect on the selection of bounding event sequences that result in radionuclide release.

Accidents involving the spent fuel storage modules in a surface aging facility are evaluated in Appendix H of the FEIS. An earthquake event could cause the modules to tip over, but the storage canisters and welded seams would withstand such tipovers without damage. A tipover of a storage module would not block all cooling vents, and the spent nuclear fuel would not overheat. A surface aging facility would comply with all applicable NRC licensing requirements, which would include seismic design criteria specific to the repository.

The DOE and others have determined the design basis vibratory ground motion frequency and fault displacement appropriate for design of a repository at Yucca Mountain. Structures, systems, and components important to radiological safety would be designed to withstand the effects of a design basis earthquake without posing a threat to public health and safety.

Seismic design basis vibratory ground motion frequency and fault displacement in the vicinity of the Yucca Mountain site have been the focus of a great deal of study by the DOE and others. As stated in Chapter 2 of the SSE, the DOE seismic design methodology and the earthquake occurrence frequencies, fault displacement, and vibratory ground motion hazards in the Yucca Mountain vicinity to be used for design of structures, systems, and components determined to be important to radiological safety and waste isolation was established by "Preclosure Seismic Design Methodology for a Geologic Repository at Yucca Mountain" [Yucca Mountain Site Characterization Project 1997. "Preclosure Seismic Design Methodology for a Geologic Repository at Yucca Mountain." Topical Report YMP/TR-003-NP, Rev. 2. Las Vegas, Nevada: Yucca Mountain Site Characterization Office. ACC: MOL.19971009.0412.].

As described in Chapter 2 of the SSE, the structures, systems, and components important to radiological safety would be designed to withstand the effects of a design basis earthquake. For licensing the NRC requires in 10 CFR Part 63 that a repository be designed and constructed to withstand a design basis earthquake without posing a threat to public health and safety. The design and construction attributes necessary to ensure that structures, systems, and components would not be compromised during a seismic event are well understood and would be applied to the repository. In addition, in Chapter 2 of the SSE, it is noted that earthquake ground motion at the repository level would be significantly less than on the ground surface, and underground repository structures would be designed for appropriate ground motion levels. The repository would be designed and constructed to comply with applicable codes, standards, and NRC regulations for licensing to withstand the design basis earthquake. For example, Chapter 2 of the S&ER Rev. 1 states that the emplacement gantry would be designed to prevent the drop of a waste package as a result of a design basis earthquake; and that the cranes and hoists in the canister transfer system would be designed to remain on their rails during and following a design basis earthquake.

4.6.3 Terrorist Attack and Sabotage Impacts

4.6.3 (55)

Members of the public have raised the concern that there exists the potential for sabotage at a repository at Yucca Mountain. This concern is raised for both the preclosure and postclosure periods. Members of the public have expressed the concern that a repository would represent a possible target for terrorists given the inventory of radioactive material stored. They have expressed the concern that the DOE failed to analyze the potential for a terrorist attack utilizing nuclear weapons on Yucca Mountain. Members of the public have expressed the concern that a nuclear warhead could be placed in a waste package and made to detonate after the waste has been permanently stored. In addition, they have expressed the concern that high-level radioactive waste and spent nuclear fuel stored on the surface at the a repository at Yucca Mountain could become targets for air attacks.

Spent nuclear fuel and high-level radioactive waste would be permanently entombed in a sealed geologic repository at Yucca Mountain, a remote location in an area of low population density. Postclosure access to the material by intruders would be extraordinarily difficult. In addition, for licensing, the NRC (10 CFR 63.21 and 10 CFR 73.51) requires any repository at Yucca Mountain to have preclosure physical protection. These regulations specify a performance objective, which provides "high assurance that activities involving spent nuclear fuel and high-level waste do not constitute an unreasonable risk to public health and safety." The regulation requires that spent nuclear fuel and high-level radioactive waste be stored in a protected area such that: (1) access to the material would require passage through or penetration of two physical barriers: the outer barrier would have isolation zones on each side to facilitate observation and threat assessment, would be continually monitored, and would be protected by an active alarm system; (2) adequate illumination would be provided for observation and threat assessment; (3) the area would be monitored by random patrol; and (4) access would be controlled by a lock system and personnel identification would be used to limit access to authorized persons.

A trained, equipped, and qualified security force would be required to conduct surveillance, assessment, access control, and communications to ensure adequate response to any security threat. Liaison with a response force would be required to permit timely response to unauthorized entry or activities.

In addition, 10 CFR Part 63 requires (by reference to 10 CFR Part 72) that comprehensive receipt, periodic inventory, and disposal records be kept for spent nuclear fuel and high-level waste in storage. The DOE would comply with any revisions to the licensing-related regulations concerning proposed protection and security.

Although it is not possible to predict whether sabotage events would occur, and if they did, the nature of such events, the DOE examined various accident scenarios, which provide an approximation of the types of consequences that could occur (see FEIS, Appendix H).

4.6.4 External Hazard Impacts

4.6.4 (10)

Members of the public have raised a concern that possible resumption of underground nuclear weapons testing or other operations at the Nevada Test Site could adversely affect repository operations or long-term isolation of spent nuclear fuel and high-level radioactive waste. In addition, members of the public are concerned that other nearby military or industrial activity may also affect repository operations.

NRC guidance typically requires applicants to include in their submittals a section addressing "nearby military and industrial activities." The purpose of this section is to identify such activities that might pose a risk to the safe operation of the facility for which a license is sought.

Operations on the Nevada Test Site and Nellis Air Force Range, and operations at nearby facilities outside the Nevada Test Site were found to include no activities that would impact the preclosure or postclosure safety.

No military or commercial industrial activities would be conducted within 8 kilometers (5 miles) of the Yucca Mountain site. The NRC guidance in NUREG-0800 [NRC 1987. "Design of Structures, Components, Equipment, and Systems." Chapter 3 of "Standard Review Plan for the Review of Safety Analysis Reports for Nuclear Power Plants." NUREG-0800. Washington, D.C.: U.S. Nuclear Regulatory Commission. TIC: 203894.] specifies that facilities and activities at distances greater than 8 kilometers (5 miles) should be considered for consequence analysis if these activities have the potential for affecting nuclear safety-related features. The area surrounding an 8-kilometer (5-mile) radius of a repository at Yucca Mountain would include the balance of the Nevada Test Site, land owned or controlled by the U.S. Air Force and the U.S. Bureau of Land Management, and the balance of any land withdrawal for a repository.

Chapter 8 of the FEIS contains an evaluation of the military or industrial activities that are conducted at distances greater than 8 kilometers (5 miles) from the Yucca Mountain site to determine their potential impact on a repository at Yucca Mountain. The Nevada Test Site and Nellis Air Force Range and were found to have no activities that would impact preclosure or postclosure safety. The remote location of a repository at Yucca Mountain (more than 8 kilometers [5 miles] from Nevada Test Site facilities, more than 20 kilometers [13 miles] from nearby commercial industrial operations and U.S. Highway 95, and more than 32 kilometers [20 miles] from Nellis Air Force Range facilities) is the major reason there would be no impacts to a repository. Proposed activities (e.g., Kistler Aerospace Corporation Launch Operations) at the Nevada Test Site cannot be fully evaluated because of a lack of design information. When these operations are further developed and information becomes available, an evaluation of potential event sequences from these operations would be performed.

The "Final Environmental Impact Statement for the Nevada Test Site and Off-Site Locations in the State of Nevada" [DOE 1996. "Final Environmental Impact Statement for the Nevada Test Site and Off-Site Locations in the State of Nevada." DOE/EIS 0243. Las Vegas, Nevada: U.S. Department of Energy, Nevada Operations Office. MOL.20010727.0190 through MOL.20010727.0191.] was used to identify current and future planned facilities and activities on the Nevada Test Site. Projects and activities covered in the environmental impact statement include the defense, waste management, environmental restoration, nondefense research and development, work for others programs, and Nevada Test Site support activities.

Nuclear stockpile stewardship at the Nevada Test Site includes no nuclear yield (sub-critical) nuclear weapons testing and science-based weapons experimentation. The locations for these tests are within either the Nuclear Test Zones or the Nuclear and High Explosive Test Zones. The closest point of these zones to the repository is approximately 24 kilometers (15 miles). Weapons testing is conducted either in vertical drill holes or in underground tunnels located in the general area of past weapons tests.

The environmental impact statement evaluation of potential impacts from underground testing at the Nevada Test Site [Ibid.] concluded that the only impact such testing could impose on a repository at Yucca Mountain would be ground motion associated with the energy released from the detonation of conventional high explosives. Even if nuclear weapon testing were to resume, the ground motion effects were determined not to exceed the seismic design criteria. In other words, the design basis earthquake for a repository was determined to provide the greatest ground motion effects. Therefore, since a repository would be designed to survive the design basis earthquake, it would also survive ground motion from any nuclear tests.

Some military aircraft participating in activities at the Nellis Air Force Range and the Tonopah Test Range carry explosive ordnance. However, this ordnance is not armed until the aircraft arrives at the test range. Any ordnance that was armed but was not dropped cannot be carried over the Nevada Test Site. Consequently, an aircraft crash near the repository would not be expected to detonate any ordnance carried by the aircraft.

No event sequences that could cause a radiological release as a result of any military sorties flying out of Nellis Air Force Range and the Tonopah Test Range were determined to be within a Category 1 or Category 2 event sequence. However, many of the parameters used to quantify the frequency of these events (e.g., fraction of flights that would pass near the Waste Handling Building and probability of objects or armament dropping from an aircraft) would be reevaluated during the preparation of any license application.

The existing analyses of potential military or industrial hazards to a repository sited at Yucca Mountain have provided an understanding of the potential risks and any further analyses that may be needed to adequately support a license application. If an aircraft crash is subsequently determined to be within a Category 1 or Category 2 event sequence, or if there are any new industrial developments that warrant consideration, the potential consequences would be calculated considering all pertinent conditions (e.g., explosives or quantity of jet fuel carried on the aircraft), and applicable design measures would be evaluated during the preparation of any license application.

Operations on the Nevada Test Site and Nellis Air Force Range, operations at nearby facilities outside the Nevada Test Site, and transportation routes were examined in "Industrial/Military Activity-Initiated Accident Screening Analysis" [CRWMS M&O 1999. "Industrial/Military Activity-Initiated Accident Screening Analysis." ANL-WHS-SE-000004 REV 00. Las Vegas, Nevada: CRWMS M&O. Sections 7 and 8. ACC: MOL.20000307.0381.] and found to have no events that would impact preclosure or postclosure safety.

4.6.4 (46)

Summary Comment

Members of the public have expressed concerns about why the DOE would accept foreign research reactor spent nuclear fuel and other spent nuclear fuels from foreign commercial reactors that would be disposed at a repository at Yucca Mountain.

Response

Consistent with the Nuclear Non-Proliferation Act and as described in the "Final Environmental Impact Statement on a Proposed Nuclear Weapons Nonproliferation Policy Concerning Foreign Research Reactor Spent Nuclear Fuels" [DOE 1996. "Final Environmental Impact Statement on a Proposed Nuclear Weapons Nonproliferation Policy Concerning Foreign Research Reactor Spent Nuclear Fuel." DOE/EIS-0218F. Washington, D.C.: U.S. Department of Energy. MOL.20010727.0195 and MOL.20010727.0196.], the United States has begun bringing back highly enriched uranium created in the United States and leased to other countries in the 1950s. The purpose of bringing the material back to the United States is to support the nuclear weapons nonproliferation policy. The only foreign research reactor spent nuclear fuel that may be emplaced at Yucca Mountain would be material for which the United States retains ownership.

The Nuclear Non-Proliferation Act also addresses the need to increase the effectiveness of international safeguards and controls on peaceful nuclear activities to prevent proliferation. In addition, the United States can accept limited quantities of foreign spent nuclear fuel without Congressional approval if the President determines that an emergency situation requires acceptance and is in the national interest, and notifies Congress with a detailed explanation and justification.

4.6.4 (15711)

Summary Comment

An issue has been raised concerning the Waste Handling Building Ventilation system and its quality safety classification.

Response

The Waste Handling Building confinement area ventilation and the emergency power source and distribution systems are classified as Quality Level-2.

The quality classification process for a repository is applied to structures, systems, and components that are "important to safety" and "important to waste isolation." The Waste Handling Building confinement area ventilation and the emergency power source and distribution systems have been determined to be important to safety. Structures, systems, and components are assigned quality level classifications that represent the relative importance of a structure, system, or component to the health and safety of the public or to the radiological safety of workers. Because the NRC developed the licensing regulation for a repository at Yucca Mountain (i.e., 10 CFR Part 63) as a risk-informed, performance-based rule, the quality classification criteria are derived in a risk-informed framework. 10 CFR Part 63 allows the DOE to categorize (or assign different levels of quality assurance to) structures, systems, or components whose failure to function has different risk of dose implications. Part of the classification criteria for licensing is quantitative and is derived from the 10 CFR Part 63 preclosure criteria for offsite doses and worker doses. Limiting dose criteria are imposed on different categories of event frequencies such that they become risk-informed performance criteria. These risk-informed regulatory criteria are an essential element in the quality classification. Models and results of the preclosure safety analysis are used to assess the change in frequency and/or consequences that occur when a given structure, system, or component is assumed unavailable (e.g., failed).

Proposed 10 CFR Part 63 used the term "design basis events." The S&ER and the SSE referred to Category 1 and Category 2 design basis events. The final version of 10 CFR Part 63 has replaced the term "design basis events" with "event sequences." There is no difference between Category 1 and 2 design basis events and Category 1 and 2 event sequences.

Category 1 event sequences are expected to occur one or more times before permanent closure of the repository. Category 2 event sequences have at least 1 chance in 10,000 of occurring before permanent closure. The DOE has assumed a 100-year preclosure operating period, although the preclosure period may be up to 325 years.

Important to safety, with reference to structures, systems, or components, means those engineered features of a geologic repository operations area whose function is (1) to provide reasonable assurance that high-level waste can be received, handled, packaged, stored, emplaced, and retrieved without exceeding the licensing requirements of 10 CFR 63.111(b)(1) for Category 1 event sequences (i.e., 15 millirem total effective dose equivalent); or (2) to prevent or mitigate Category 2 event sequences that could result in radiological doses exceeding the values specified at 10 CFR 63.111(b)(2) to any individual located on or beyond any point on the boundary of the site (i.e., 5 rem total effective dose equivalent).

The potential dose for Category 1 event sequences is calculated as if the structure, system, or component being evaluated fails when called upon to mitigate consequences. The unmitigated dose resulting from the removal of the structure, system, or component is added to aggregate offsite doses for Category 1 event sequences. This approach provides a risk-informed basis for classifying each structure, system, or component. If the revised dose exceeds 15 millirem per year total effective dose equivalent but is less than 100 millirem per year total effective dose equivalent, the structure, system, or component is classified as Quality Level-2. If the revised dose exceeds 100 millirem per year total effective dose equivalent, the structure, system, or component is classified as Quality Level-1.

The rationale for classifying the Waste Handling Building ventilation system as Quality Level-2 includes (1) the 15-millirem per year limit is a constraint on this potential source of radiation exposure, and (2) compliance would be monitored during any repository operations (i.e., practices that produce doses in excess of the 15-millirem limit may be subject to corrective actions).

Compliance analyses for Category 2 event sequences would demonstrate, for each event sequence assessed individually, that the offsite dose is less than 5 rem total effective dose equivalent. The classification analyses reassess the dose after a structure, system, or component functional failure is performed. If the dose exceeds 5 rem, the structure, system, or component is classified Quality Level-1; if the dose is less than 5 rem but greater than 100 millirem the structure, system, and component is classified Quality Level-2; if the dose is less than 100 millirem but greater than 15 millirem, the structure, system, or component is classified Quality Level-3; otherwise the structure, system, or component is not subject to the requirements of the quality assurance program and is classified as conventional quality.

No event sequence has been identified that would exceed the 100 millirem total effective dose equivalent classification guidance for the Waste Handling Building ventilation system; therefore, the ventilation system is not required to mitigate or prevent event sequences that could exceed 100 millirem without use of the building's ventilation system. Portions of the ventilation system are conservatively classified as Quality Level-2 based on preventing an offsite dose greater than 15 millirem per year.

As noted in the previous paragraphs, the Waste Handling Building ventilation system is classified as Quality Level-2. Therefore, the emergency power source and distribution system is also correctly classified as Quality Level-2 because its function is to support the Waste Handling Building ventilation system and failure of the emergency power source and distribution system would not result in an offsite dose that exceeds 100 millirem total effective dose equivalent classification guidance.

4.6.4 (11810)

Summary Comment

An issue has been raised concerning whether the DOE would notify the community in the event of a radioactive release.

Response

In accordance with NRC licensing regulations, an emergency response plan would be developed for a repository at Yucca Mountain that would include provisions for notification of the public of radiological releases to the environment. The design of a repository would include radiological monitoring systems to ensure the radiological safety of the public and the environment. Operational controls that would be implemented include a radiological environmental monitoring and surveillance program that would provide assurance that the facility is functioning as intended to limit releases to the environment and evidence that the public dose is as low as is reasonably achievable. The program would measure radiation and concentrations of radionuclides from facility operations including those that are most likely to result in exposure to members of the public.

4.7 postCLOSURE SAFETY and total system performance assessment

4.7.01 Waste Package and Drip Shield Degradation

4.7.01 (43)

Issues have been raised by members of the public regarding the chemical environment around the waste package and drip shield. These issues are grouped into three categories and include: concern that the DOE does not understand the chemical environment around the waste packages which impacts waste package materials testing and the ability to predict long term waste package performance; the potential for microbial attack of the waste package from microorganisms in the water; and the potential long term release of chromium into the environment following waste package corrosion.

Issues were raised by members of the general public that the DOE does not fully understand the chemical environment in the repository that should be utilized for waste package materials testing, including the presence of salts that could come in contact with the waste packages.

The chemistries of waters chosen for testing have a broad range that duplicate the most challenging environmental conditions expected within the repository.

The environment of the waste packages changes with time. Upon emplacement, the waste packages would still be fairly warm and the air would be low in relative humidity, assisted through the use of active ventilation. Just prior to repository closure, the drip shields would be inserted. Thereafter, the waste packages would continue to cool and the relative humidity would rise to near 100 percent. Thus, moisture is likely to condense on the drip shields and the waste packages, although the drip shields would prevent water from dripping directly from the roofs of the emplacement drifts onto the packages for thousands of years. This dripping water could be concentrated in its contained salts due to evaporative condensation processes or by the presence of deliquescent salts brought in by the ventilation system. Two types of water were evaluated (S&ER Rev. 1, Section 4.2.4.2.4) which cover the major sources of water potentially contacting the waste packages. These include the J-13 well water (a bicarbonate water) and rock pore water (a chloride-sulfate water). Analytical modeling as well as evaporation tests were conducted to estimate the compositions of the waters and salts as dryness was approached. The J-13 water formed salts containing chlorides, nitrates, carbonates and silicates. Calcium, as well as magnesium, precipitates as carbonates early in the evaporation process, while chlorides and nitrates, being more soluble, precipitate when evaporation is nearly complete. These salts have a deliquescent (liquefying by water absorption from air) point of about 50 percent relative humidity at 120 degrees Celsius (248 degrees Fahrenheit) with a resulting concentrated solution pH of about 12. The rock pore water was also evaluated using this process. Here chloride and sulfate salts predominated with a lower deliquescent point and a concentrated solution pH of about 6, which is near neutral.

Thus, the water chemistry resulting from the near evaporation of J-13 water was used as a basis for subsequent corrosion testing because this chemistry is considered to be more aggressive than that of the concentrated pore water. However, testing with pore-type waters is planned. The likely concentrations of heavy metals were also included in the testing program. Although it is recognized that at very long repository times, the waters contacting the waste package would be more dilute, the use of concentrated solutions throughout the entire period results in conservative estimates.

Several topics were identified and addressed during discussions between the DOE and the NRC on the effects of corrosion processes on the lifetimes of the containers. The topics include the credible range of brine water chemistry, the effect of introduced materials, the concentration and effect of minor (or trace) elements, the characteristics of the evolution of the types of brine waters, and an evaluation of periodic water drip evaporation.

The DOE has agreed to update documentation regarding these chemistry issues in a revision to the analysis model reports on environment on the surfaces of the drip shield and waste package outer barrier and on general and localized corrosion of the drip shield.

Issue

An issue has been raised by a member of the general public regarding the extent of de-alloying and corrosion enhancement due to the presence of microbes in Yucca Mountain.

Response

Microbial corrosion, also called microbially influenced corrosion, is possible if the right combination of microbes, nutrients, temperature and relative humidity exist. Microbially influenced corrosion has been studied by the DOE by utilizing combinations of microbes found at Yucca Mountain. Microcosm tests were conducted to determine which nutrients limited the growth of microbes. The low level of phosphate in J-13 well water, the water assumed representative of that contacting the waste packages, appears to be the principal nutrient-limiting factor to microbial growth.

In corrosion tests, the nickel-base alloy, Alloy 22, has shown very good resistance to attack against a consortium of Yucca Mountain microbes. Thus, the microbes would not cause accelerated corrosion of the waste packages. However, some evidence for de-alloying, or selective dissolution, perhaps from welded areas, has been observed. Thus, for conservatism, a multiplying factor of two was added to general and localized corrosion rates. For further detail, see Section 4.2.4.3.3 of the S&ER Rev. 1.

As a result of discussion between the DOE and the NRC on the effects of corrosion on the life times of waste packages, the DOE would provide documentation on microbial effects and the enhancement factor in a revision to the analysis model report on general and localized corrosion of waste package outer barrier.

Issue

Issues have been raised by members of the public regarding the analysis performed by the DOE on the potential release of chromium from the waste packages to the environment.

Response

The DOE has evaluated the potential for release of chromium from the dissolution of the chromium-containing Alloy 22 waste package and the stainless steel inner container materials. Corrosion testing has shown the dissolution rate of Alloy 22 and stainless steel under a wide range of conditions is very low, less than one micron per year. However, as a result of the dissolution process, a small amount of hexavalent chromium is put into solution that ultimately could reach the accessible environment.

The concentrations of chromium released from waste packages that potentially could reach the accessible environment have been calculated utilizing conservative assumptions. These have yielded concentrations well below EPA's maximum contaminant level goal.

4.7.01 (44)

Summary Comment

Issues have been raised by members of the public regarding the forecast of long term waste package performance. These issues are grouped into four categories and include: using short-term data for making long-term performance forecasts; calculations for forecasting long-term waste package performance; confidence in making long-term performance forecasts; and the differences in long-term waste package performance under hot or cold repository operating conditions. (For the purposes of describing testing programs, "long term" refers to tests that may be conducted over a period of tens of years through closure of a repository. For all other purposes, the term "long term" refers to durations of 5,000 to 10,000 years or greater.)

Issue

An issue has been raised by the public that long-term forecasts were inappropriately based on short-term data and questioning how the DOE would augment the existing database to provide some credibility for long-term lifetime forecasts.

Response

The DOE recognizes that forecasts are based on short-term data. Thus, the DOE would support the forecast of the long-term performance by continuing tests as performance confirmation tests. These efforts would be augmented by the consideration of natural and engineering analogues. For the purposes of describing testing programs, "long term" refers to tests that may be conducted over a period of tens of years through closure of a repository. For all other purposes, the term "long term" refers to durations of 5,000 to 10,000 years or greater.)

The DOE recognizes that current forecasts of the lifetime of containers are based upon its short-term and ongoing long-term test data, as well as data in the literature. Very long-term data under Yucca Mountain conditions are not yet available. Thus, the DOE intends to support forecasts of lifetimes of container materials by a combination of long-term testing, in situ and other performance confirmation tests, and the use of analogues, consistent with the guidance provided in the American Society for Testing Materials C 1174-97 standard. [ASTM C 1174-97. 1998 "Standard Practice for Prediction of the Long-Term Behavior of Materials, Including Waste Forms, Used in Engineered Barrier Systems (EBS) for Geological Disposal of High-Level Radioactive Waste." West Conshohocken, Pennsylvania: American Society for Testing and Materials. TIC: 246015.]. Testing would continue during waste emplacement and preclosure to collect long-term test data under conditions prototypical of those expected at Yucca Mountain. The data generated would continue to go to the scientists and engineers who determine the long-term performance of the materials as part of the determination of total system performance.

The DOE would actively monitor the waste packages and the conditions within the drifts following the start of emplacement operations to detect any significant changes from baseline conditions, to confirm that subsurface conditions are consistent with the assumptions used in performance analyses, and to confirm that barrier systems and components are operating as expected. Coupons of container materials, as well as waste packages, could be retrieved and examined, if necessary. Details of the performance confirmation program can be found in Section 4.6.1.1 of the S&ER Rev. 1. The DOE is exploring analogues of Alloy 22 to provide additional confidence in its performance. One such analogue is josephinite, a nickel-iron mineral found in some streambeds. While this material contains no chromium, an important element in Alloy 22, it does have a stable passive film. A general discussion of natural analogues can be found in the S&ER Rev. 1, Section 2.1.5.4.

These efforts plus the further development of a long-term mechanistic model for long-term general and localized corrosion and passive film stability provide confidence in the DOE's ability to forecast the long-term performance of waste package materials and, hence, the long-term container lifetime.

Issue

Issues have been raised by members of the public regarding the expected lifetime of the waste packages and how that expected lifetime was calculated.

Response

A key element in the prediction of the long-term performance of the waste package outer barrier, and hence the lifetime of the waste package, is the waste package degradation code. The Waste Package Degradation code integrates the individual material degradation models and corrosion test data. The code is described in the S&ER Rev. 1, Section 4.2.4. Both conservative and realistic versions have been developed. The most conservative case analysis was to evaluate the effects of the conservative model abstractions of several key corrosion model parameters. Those parameters are stress corrosion cracking-related parameters and general corrosion parameters, along with corrosion rate bias to account for silicate deposits. This case represents the worst case combination of those parameters from the perspective of time to first waste package failure.

As shown in the S&ER Rev. 1, Section 4.2.4.4, the results of this case indicate the earliest possible failure time of a waste package for the upper bound profile is about 12,000 years (based on the TSPA-SR model), much earlier than the more realistic median profile (about 50,000 years). The time to fail 10 percent of waste packages for the upper bound profile is about 22,000 years. Uncertainty and variability are accounted for in the Waste Package Degradation code. Sensitivity analyses were also performed considering a number of failures prior to 10,000 years, as shown in Section 4.5.4, of the S&ER Rev. 1.

A more recent analysis, contained in Section 3.2.8.2 of the SSE, assumed that a few (3 or less) waste packages could fail prior to 10,000 years due to assumed, undetected, improper heat treatment of the final closure weld. [BSC (Bechtel SAIC Company) 2001. "Total System Performance Assessment—Analyses for Disposal of Commercial and DOE Waste Inventories at Yucca Mountain—Input to Final Environmental Impact Statement and Site Suitability Evaluation." SL986M3 REV 00 ICN 01. Las Vegas, Nevada: Bechtel SAIC Company. ACC: MOL.20011114.0246. Section 5.2.4.2.]. The remaining waste packages would have lifetimes of about 80,000 years to over one million years.

Issue

Issues have been raised by members of the public regarding the difficulty in estimating long-term performance and how the DOE would provide confidence in its forecasts.

Response

The combination of long-term and short-term tests, the use of analogues, information gathered during in situ monitoring, plus the further development of a long-term mechanistic model for passive film stability provide confidence in the DOE's ability to forecast the long-term performance of waste package materials.

It is recognized that the forecasting of performance of an engineered system for thousands of years is unprecedented. However, the DOE has chosen to follow the guidance provided in the ASTM C 1174-97 standard. [ASTM C 1174-97. 1998. "Standard Practice for Prediction of the Long-Term Behavior of Materials, Including Waste Forms, Used in Engineered Barrier Systems (EBS) for Geological Disposal of High-Level Radioactive Waste." West Conshohocken, Pennsylvania: American Society for Testing and Materials. TIC: 246015.]. This practice utilizes a combination of experiments, including short-term and long-term tests under both service and accelerated conditions, and models along with analogue information. Testing at conditions expected at Yucca Mountain is referred to as service-condition testing. Testing outside of the range is considered to be aggressive and is thus categorized as accelerated testing. It should be noted that for accelerated testing to be meaningful, the corrosion mechanism must not be changed from that which is active under the service conditions. The DOE would also take advantage of information gathered during in situ monitoring.

Issue

Issues have been raised by members of the public about the difference in waste package performance with the hot versus cold scenarios and whether the higher repository temperatures would be a concern for rockfall.

Response

Although a range of thermal operating modes was investigated, waste package performance as evaluated by the expected maximum dose to the public did not vary greatly with repository temperatures.

The performance of repository system under a lower-temperature operating mode was discussed in detail in Section 2.1.5 of the S&ER Rev. 1. At lower temperatures, the overall amount of rockfall is likely to be lower, but the localized amount of rockfall could be greater due to nonuniform temperatures along the drift. In addition, if the ventilation period is extended, the potential for preclosure rockfall would increase. Another result of lower temperatures is that corrosion susceptibility is lowered and uncertainty is reduced. However, aqueous processes are initiated sooner in contrast to the higher operating mode where the initiation of corrosion is delayed. Each of the degradation mechanisms utilized to forecast the performance of the waste package includes temperature as a variable. Thus, the response of the waste package to a range of thermal conditions is built into the models. See the S&ER Rev. 1, Section 4.4.5.1.2, for further detail.

4.7.02 Waste Form Degradation and Radionuclide Release

4.7.02 (38)

Issues have been raised by members of the public regarding the types of nuclear materials that would be stored in the repository, the initial condition of these waste forms upon receipt, the assumptions and methods for forecasting degradation of these waste forms over time, the need for additional testing of waste form degradation, and geophysical and chemical processes related to the solubility of radionuclides.

The high-level radioactive waste forms the DOE would place in the repository consist primarily of commercial light water reactor spent nuclear fuel, high-level waste glasses containing the radioactive residues from nuclear weapons production, and DOE spent nuclear fuel. The great majority of waste received consists of assemblies that contain uranium oxide fuel pellets encased in intact zirconium alloy tubes. All waste forms will be in a solid form. Materials that could ignite or react chemically at a level that would compromise containment or isolation would be emplaced in canisters which are designed such that they could not be breached during preclosure repository operation. Neither the waste forms nor the waste packages would contain free liquids that could compromise waste containment. Materials that are regulated as hazardous waste under the RCRA would not be disposed in a repository.

Waste form degradation affects the repository performance analysis after the waste package has been breached or otherwise failed. Water contact with the waste form is the primary cause of degradation after the waste package no longer provides for isolation of the waste form. Waste form degradation occurs in the TSPA only after the waste package container breaches, exposing the waste form to the air or water or both environments of the Engineered Barrier System. Breach of the waste package container is conservatively assumed to result in direct exposure of the DOE spent nuclear fuel and high-level waste glass forms to the repository air and water environment. In the cases of the high-level waste glass and DOE spent fuel, no radionuclide containment credit is taken in TSPA for their canisters. In this way, the DOE conservatively accounts for waste form degradation as a source of radionuclide release.

The application of the waste form degradation models involves the extrapolation over periods of time that are orders of magnitude greater than the experimental test periods used to generate the degradation models. The DOE model development conformed to an American Society for Testing and Materials standard [ASTM C 1174-97. 1998. "Standard Practice for Prediction of the Long-Term Behavior of Materials, Including Waste Forms, Used in Engineered Barrier Systems (EBS) for Geologic Disposal of High-Level Radioactive Waste." American Society for Testing and Materials." West Conshohocken, Pa. TIC: 246015. Sections 19 and 20.] in developing waste form degradation models. Since TSPA analyses (S&ER Rev. 1, Section 4.2.6.3.6) have shown that the overall performance of the repository is very insensitive to the degradation rate of the DOE spent fuel, the emphasis, whenever possible, is on the application of upper-limit or bounding-degradation models for the spent fuel degradation. Confirmation testing of materials behavior models (e.g., the commercial spent fuel degradation model) could be required for the repository, where many years might pass from the time a decision is made to proceed until the repository is closed. The DOE expects that additional investigations would continue throughout the entire project period and the repository design, or decisions regarding the repository, may be changed to reflect newly identified information (S&ER Rev. 1, Sections 4.6.1 and 4.6.1.1.1).

Confirmation testing of key materials behavior models would be performed as necessary for the repository. This could include testing that would be required to establish the corrosion characteristics of the high-level waste pour canister. The DOE expects these investigations could continue throughout the entire project period and that the repository design or decisions regarding the repository would be changed to reflect newly identified information (S&ER Rev. 1, Section 4.6.1).

The DOE has considered the geochemistry of the system by evaluating the solubilities of key radionuclides. The solubilities of a number of radionuclide-bearing solids were measured as a function of water composition and temperature (S&ER Rev. 1, Section 4.2.6.2.7). Uranyl minerals would precipitate under the oxidation conditions expected when waste package breach exposes the waste forms to incoming water. Laboratory tests and field observations on natural analogue materials suggest the most common secondary uranyl phases to form under repository conditions would be schoepite, soddyite, uranophane, and sodium boltwoodite. Additionally, because carbonate levels tend to be higher at high pH and lower at low pH, the formation of soluble complexes of uranium and plutonium carbonates tend to increase at high pH (S&ER Rev. 1, Section 4.2.6.3.2). Neptunium solubilities are similar at pH 7 and pH 8.5 and are observed to decrease with increasing temperature; neptunium solubilities at pH 6 are one to two orders of magnitude higher than at pH 7 to 8.5. In general plutonium solubility is about three orders of magnitude lower, and is less affected by pH than that of neptunium. Increasing temperature decreases the solubility of plutonium.

Under conservative assumptions of oxidizing repository conditions, both laboratory measurements and thermodynamic analysis indicate that no insoluble salts of technetium, chlorine, or cesium form. Each form is relatively large monovalent ions, which are exceedingly soluble. Therefore, the solubility of each is set in TSPA to 1.0 moles per liter, which lets their inventory in the waste form determine their release rate. Carbon and strontium both form less soluble metal carbonate minerals. Rather than perform a complex prediction of carbon and strontium solubility, their solubility was conservatively set at 1.0 moles per liter. In this way the DOE does account, albeit conservatively, for the solubilities of key radionuclides in the TSPA.

4.7.03 Unsaturated Zone Transport

4.7.03 (66)

Comments involved the effects of climatic changes, rapid water movement, fast pathways, fractured rock, radionuclide releases, and general analyses of fluid flow and radionuclide transport in the unsaturated zone surrounding a repository at Yucca Mountain.

The DOE believes that any radionuclide releases reaching the accessible environment through the unsaturated and saturated zones during the 10,000 year postclosure period would likely be below the NRC's radiation protection standards for licensing.

Section 1.4 of the S&ER Rev. 1 describes the geologic settings of Yucca Mountain and the surrounding region in detail. The DOE believes that the information in the S&ER Rev. 1 and the FEIS on the amount and type of contaminants that would be released over time from a repository and from other sources in the region have been adequately described and analyzed.

Percolating water at the waste-emplacement horizon is unlikely to contact the waste packages because the excavation of the waste-emplacement drifts creates a capillary barrier that tends to divert water around the drift opening. This phenomenon limits the amount of water that can contact the waste packages.

Section 4.2.1.4 of the S&ER Rev. 1 discusses the breakthrough time required for a nonsorbing tracer to reach the water table from the repository horizon. The breakthrough time of a nonsorbing tracer is not equivalent to travel time of water in the unsaturated zone. Breakthrough times are related to concentration limits that constitute a "significant arrival" while travel times in the unsaturated zone are related to the arrival of "significant volume" of water. Because both properties are difficult to measure, they must be calculated. The breakthrough time of a radionuclide is usually less than the travel time of water. The arrival of the first radionuclides represent a very low probability event. Breakthrough times can vary from 400 years to 600,000 years depending on the upper and lower infiltration rates. Section 4.2.8.3.3 of the S&ER Rev. 1 provides related discussion about both field measurements and numerical predictions of the movement of radionuclides from a repository horizon to the water table. Importantly, scientists consider travel time of water in the unsaturated zone to be probabilistic, with a range of values reflecting uncertainty associated with flow and transport, in all rock units regardless of type or location.

In addition to travel time of water in the unsaturated zone as a measure of performance, chemical processes would tend to retard transport of radionuclides. Section 4.2.8.3.3 of the S&ER Rev. 1 provides related discussion about both field measurements and numerical predictions of the movement of radionuclides from the repository horizon to the water table. Chemical transport characteristics measured in boreholes suggest that the vitric and zeolitic rock units between the repository and the water table would effectively inhibit transport of sorbing radionuclides.

The S&ER Rev. 1, Sections 4.1, 4.2, and 4.4 included an evaluation of climate change and its effects on long-term performance. These effects included increased infiltration, increased flux at depth, increased radioactive material transport at depth after waste package failure, and a shortened path to the water table because of changes in water table elevation. The evaluations also considered three climate scenarios: present day, a monsoon climate, and a glacial-transition climate during and beyond the 10,000-year postclosure period. Section 3.3.2.1 of the SSE included an evaluation of post 10,000-year climate change including glacial climates and its effects on unsaturated zone flow characteristics and long-term performance.

Extreme precipitation events discussed in Section 4.2.1 of the S&ER Rev. 1 do not greatly influence the infiltration rates. This is because the subsurface tends to "damp" the extreme events (particularly in the Paintbrush nonwelded stratigraphic unit) to produce a nearly uniform infiltration rate with time at depth. Extreme precipitation events are more closely associated with surface runoff events. Locality-based infiltration rates were used (not whole-mountain averages) to derive infiltration rates for repository zones modeled in the performance analysis.

The measured corrosion rate for the waste package outer barrier material, Alloy 22, is very small. The waste packages would eventually corrode and release radionuclides into the groundwater. However, dose estimates are below applicable NRC radiation protection standards for licensing in 10 CFR Part 63 (S&ER Rev. 1, Sections 4.4 and SSE, Sections 4.1 and 4.2).

In summary, the DOE recognizes that some radionuclides would eventually enter the accessible environment outside a repository. Dose estimates are below applicable NRC radiation protection standards for licensing in 10 CFR Part 63 (SSE, Sections 3.1.2 and 4.2).

4.7.03 (2018)

Summary Comment

An issue was raised by the public regarding heater testing. The second heater test has not been completed, and there is to date no serious evaluation of how the combined stresses of excavation and intense heating will affect the hydraulic properties of the surrounding rock. However, seepage into the drift is sensitive to the size of fracture openings, which is likely to be sensitive to excavation and heating stresses. Simply put, thermally stressed rock may show more seepage than unstressed rock. Given this uncertainty concerning a critical aspect of site performance, it seems premature to proceed with a site recommendation.

Response

The DOE believes that it sufficiently understands the relationship between thermally induced stresses and changes in permeability.

The DOE has evaluated the effects of thermal loading as it pertains to fracture deformation impact to permeability. A recent study considered the effect of fracture deformation on permeability in the rock mass surrounding an emplacement drift in a repository [BSC (Bechtel SAIC Company) 2001. "Coupled Thermal-Hydrologic-Mechanical Effects on Permeability Analysis and Models Report." ANL-NBS-HS-000037 REV 00. Las Vegas, Nevada: Bechtel SAIC Company. ACC: MOL.20010822.0092.]. As discussed in Section 7.1 of this report, the analysis indicates that the overall permeability would be significantly reduced in vertical fractures, while the permeability of horizontal fractures would remain relatively unchanged. These findings are pertinent because many fractures are orientated vertically. Note that the second heater test (Drift Scale Test) was used to assist with the validation of the model used in the report cited above.

4.7.03 (2020)

Summary Comment

An issue was raised by the public regarding the treatment of radionuclide diffusion within the rock matrix.

Response

Matrix diffusion can be a major element of radionuclide retardation in unwelded tuffs or in transitional welded/nonwelded tuffs. However, for geologic units at Yucca Mountain comprised of either densely welded tuffs or tuffs with significant secondary mineralization, the pore connections are unusually "tight" which severely restricts movement of water from the fractures into the matrix. This observation is based on the difficulty of extracting pore water for analysis and the lack of equilibration between matrix water and fracture water in the perched water zones. This "tight" condition has led to the modeling of those zones as having reduced matrix diffusion. Therefore, matrix diffusion in welded tuffs is believed to be sufficiently understood and properly implemented into the performance assessment of the repository (S&ER Rev. 1, Sections 4.2.1 and 4.2.8, and SSE, Section 3.3.7.1.3).

4.7.03 (10282)

Summary Comment

An issue was raised by the public regarding the treatment of fracture porosity and fracture sealing.

Response

The DOE has analyzed the effects of fracture porosity and fracture sealing. The DOE has determined that the magnitude of the porosity changes is related to the initial fracture porosity and the presence of heterogeneities in fracture properties. Changes in porosity of less than 10 percent were obtained with an earlier model that did not account for as large a precipitation rate during final dryout. Using a heterogeneous fracture permeability distribution, changes in porosity of several percent can occur locally, however because there is already a range of at least 4 orders of magnitude in fracture permeability and 2-3 orders of magnitude variation in aperture, changes due to mineral precipitation are generally within this initial variability. The model results are, however, based on average properties and therefore local effects may be greater or less than the model simulations forecast (SSE, Section 3.3, and S&ER Rev. 1, Section 4.2.8).

As per discussion in Section 3.3 of the SSE, chloride concentrations calculated for the high-temperature case, were checked as part of the review process. The reported values are those obtained by the model simulations. Note that the plotted chloride concentrations are those from distinct times which may not in all cases correspond to those concentrations used in the abstractions (i.e., the concentration during the dryout period is higher than that during the highest period on the graph of chloride concentration versus time).

4.7.03 (10895)

Summary Comment

An issue was raised by the public regarding the influence of heat on the movement of water in the rock.

Response

An in-depth understanding of thermally driven coupled processes, including hydrological, mechanical, and chemical behavior, has been developed from the thermal testing program at Yucca Mountain. As discussed in Section 4.2.2.2.3 of the S&ER Rev. 1, the DOE has completed several in situ thermal tests, and the largest of these continues underground at Yucca Mountain. In addition, other comparable thermal tests have been conducted internationally to investigate geologic disposal of heat-producing waste. All of the thermal tests conducted at Yucca Mountain have included observation and measurement of thermal-hydrological-mechanical-chemical behavior. These measurements are compared to numerical simulations of the respective tests to validate thermal-hydrological, thermal-hydrological-mechanical, and thermal-hydrological-chemical models. Consequently, much work has been done at Yucca Mountain and elsewhere to better understand coupled processes.

With regard to the inherent uncertainty associated with coupled processes including thermal, hydrological, mechanical, and chemical analyses, as they pertain to performance assessment, Sections 4.2.1, 4.2.2, 4.2.8, and 4.4.1 of the S&ER Rev. 1 describe how the DOE addressed these issues. The DOE recognizes that the acquisition of additional data could further reduce these uncertainties. Studies are planned to gather additional information. Section 4.6 of the S&ER Rev. 1 describes the types of tests, experiments, and analyses that the DOE would conduct during the performance confirmation and monitoring phases under the umbrella of an integrated test and evaluation program (S&ER Rev. 1, Section 5.4). The performance confirmation program could continue for as long as 300 years after waste emplacement operations have been completed. The purpose of the performance confirmation program is to evaluate the adequacy of the information used to demonstrate compliance with the licensing performance objectives in Subpart E of 10 CFR Part 63 through various tests, experiments, and analyses.

4.7.04 Saturated Zone Transport

4.7.04 (68)

Issues have been raised by members of the public regarding fluid flow and radionuclide transport in the saturated zone underlying a repository at Yucca Mountain including general analyses of fluid flow, radionuclide transport, the potential existence of fast pathways, and the impact of seismic activity.

The flow of groundwater from Yucca Mountain would be limited to the Death Valley flow system in southern California and would not intersect surrounding areas, including the Las Vegas Valley or other areas of southern California. Any releases of radionuclides during the 10,000-year postclosure period.

The objective of the saturated zone flow and transport process model and the corresponding components of a repository's performance assessment (see S&ER Rev. 1, Section 4.4) is to evaluate the migration of radionuclides from their introduction at the water table below Yucca Mountain to the location at which releases and doses must be assessed. Consistent with NRC licensing regulations, the RMEI is assumed to live at a point above the highest concentration of radionuclides in the simulated plume of contamination where the plume crosses the southernmost boundary of the controlled area (at a latitude of 36 degrees 40 minutes 13.6661 seconds North). This distance is approximately 18 kilometers (11 miles) from within the repository footprint. The main output of the saturated zone flow and transport process models used directly by the TSPA is an assessment of the concentration of radionuclides in groundwater and the time it takes for various radionuclides to be transported from areas beneath a repository to the accessible environment.

As described in Section 4.2.9 of the S&ER Rev. 1 and Section 3.3.8 of the SSE, the DOE has conducted an extensive program to characterize the direction and nature of groundwater movement and radionuclide transport from a repository at Yucca Mountain. This characterization has determined that the very small amount of water that percolates through Yucca Mountain to the water table would then travel southward. The groundwater beneath Yucca Mountain merges and mixes with groundwater beneath Fortymile Wash. This groundwater then flows toward, and mixes with, the large groundwater reservoir beneath the Amargosa Desert. The natural discharge point of this groundwater occurs farther south in Franklin Lake Playa, an area of extensive evapotranspiration. A minor volume may flow south toward Tecopa into the southern Death Valley area. A fraction of the groundwater may flow through fractures in the relatively impermeable Precambrian rocks at the southeastern end of the Funeral Mountains toward springs in the Furnace Creek area of Death Valley. Potentiometric data indicate that a divide could exist in the Funeral Mountains between the Amargosa Desert and Death Valley. This divide would limit discharge from the shallow flow system but would not necessarily affect the flow from the deeper carbonate aquifer that may contribute discharge to springs in the Furnace Creek area.

Geochemical, isotopic, and temperature data indicate that water discharging from springs in the Furnace Creek area is a mixture of water from basin-fill aquifers in the northwestern Amargosa Desert and from deeper flow in the regional carbonate aquifer. Groundwater in the northwestern Amargosa Desert originates in Oasis Valley and from the eastern slope of the Funeral Mountains, both of which are west of the flow paths that extend southward from Yucca Mountain. Even if part of the flow from Yucca Mountain mixes with the carbonate pathway that supplies the springs in Furnace Creek, it would be too little to noticeably affect the water quality of these springs. Considering the small amount of water that would infiltrate through a repository compared to the total amount of water moving through the basin (approximately 0.2 percent or less), and the large distances involved (more than 60 kilometers [37 miles] from the source), any component of flow from Yucca Mountain that traveled along this long and complicated flow path would be significantly diluted.

Section 1.4 of the S&ER Rev. 1 describes the geologic setting of Yucca Mountain and the surrounding region. Section 4.4 of the S&ER Rev. 1 and Sections 8.2 and 8.3 of the FEIS consider the cumulative impacts to groundwater from a repository, the Nevada Test Site, and other activities in the area that could contribute to long-term groundwater pollution. The amount and type of contaminants released over time from a repository and from other sources in the region have been adequately described and analyzed in the S&ER Rev. 1 and the FEIS. Estimated releases to the accessible environment after 10,000 years would be limited geographically to the groundwater movement system described in Section 4.2.9 of the S&ER Rev. 1; contaminants from a repository could not reach the Las Vegas Valley, the Colorado River, or any other parts of Nevada and California outside of the Death Valley groundwater system.

Based on discussion in Section 4.3.2.2 of the S&ER Rev. 1 and Section 3.3.10.2 of the SSE, seismic/earthquake activity would not significantly alter the performance assessment of a repository. In addition, monitoring of contemporary seismicity indicates that earthquake activity continues in the Yucca Mountain vicinity. Consequently, seismic activity is treated in the TSPA as an expected event within the nominal (rather than disruptive) scenario, but with an uncertain magnitude and frequency. Because an earthquake could have consequences on the repository's underground facilities and hydrologic system, the DOE has performed an in-depth analysis to provide ground motion and fault displacement hazard results for both preclosure design determination and for postclosure performance assessment at both the surface and the repository level. During an earthquake, the underground portion of the repository, located at a depth of about 300 meters (1,000 feet), would experience significantly less vibratory ground motion than the surface facilities.

Section 4.3.3.1 of the S&ER Rev. 1 discusses several views regarding fluctuations in the elevation of the water table. According to one assertion, the water table at Yucca Mountain has risen in the past to elevations that are higher than the waste emplacement horizon beneath Yucca Mountain. Based on the results of analyses reported in Section 4.3.3.1 of the S&ER Rev. 1, the DOE does not believe that any credible combination of future climate change, earthquakes, and volcanic eruptions could raise the water table sufficiently high enough to inundate the waste emplacement horizon. The National Research Council established a panel that reviewed the pertinent literature and data available up to 1992. This panel consulted with scientists involved in related field and laboratory studies. The panel concluded that none of the evidence offered as proof of groundwater upwelling in and around Yucca Mountain could reasonably be attributed to that process.

In summary, the DOE recognizes that some radionuclides could eventually enter the environment outside a repository. However, TSPA dose estimates are below applicable NRC radiation protection standards for licensing in 10 CFR Part 63, (S&ER Rev. 1, Section 4.4, and SSE, Sections 4.1 and 4.2).

4.7.05 Biosphere Performance—Nominal Performance

4.7.05 (28)

Issues were raised by members of the public regarding potential leakage of radioactive material from a repository at Yucca Mountain into the groundwater and the associated consequences. The issues are grouped in four general categories: the likelihood and need to prevent releases; the potential for and extent of effects on people and the environment, including farm products; potential radiation doses and health consequences, and whether the radiation protection standards will be met; and protection of groundwater as a resource.

Issues have been raised by members of the public regarding the possibility of a Yucca Mountain repository contaminating the groundwater with radioactive material. Various concerns have been expressed regarding the likelihood, and the need for prevention of release and transport of this material to the groundwater in the vicinity.

The DOE is aware of the consequences of potential releases of radioactive material from a Yucca Mountain repository entering the environment through the groundwater pathway. The DOE's design and evaluation of the repository reflects an effort to minimize these potential consequences. Thus, the DOE's conceptual design incorporates a system of multiple engineered and natural barriers working together to keep water away from the waste and to protect public health and the environment for thousands of years.

The DOE's goal for geologic disposal at Yucca Mountain would be to isolate radioactive wastes in a relatively small area for a very long time. The repository safety strategy is built upon four key attributes that would minimize the risk of radioactive contamination of groundwater: limited water entering emplacement drifts, long-lived waste package and drip shield, limited release of radioactive material from engineered barriers, and delayed and diluted radioactive material concentrations provided by natural barriers.

This approach to design—employing multiple barriers that are developed using careful evaluation of the repository system's retention capabilities—is how the DOE is dealing with the potential for radioactive contamination of groundwater at a repository.

Issues have been raised by members of the public regarding the potential for people and the environment to be affected by the transport of groundwater contaminated with radioactive material in the regional aquifer. Concerns have been expressed about the extent of the area potentially affected, and consequences if local farm products are exported.

The DOE includes groundwater contamination with radioactive material in its analyses of potential public health risks associated with a repository at Yucca Mountain. The largest potential risk to groundwater users is to the people of Amargosa Valley because groundwater in the saturated zone beneath Yucca Mountain flows in a generally southerly direction toward this community (FEIS, Section 3.1.4). As indicated in Chapter 5 of the FEIS, overall human health impacts to area residents would be small, and would not occur until the far future. As explained in the S&ER Rev. 1 and the SSE, the hypothetical person studied to calculate dose would live year-round above the highest concentration of radionuclides in the groundwater contamination plume approximately 18 kilometers (11 miles) from within the repository footprint. The RMEI would annually consume or use 3,000 acre-feet of groundwater taken from potentially contaminated sources. RMEI is defined in the NRC licensing regulations 10 CFR 63.312 (66 FR 55814).

The DOE has conducted an extensive program to characterize the direction and nature of groundwater movement from the Yucca Mountain site. The results are described in the S&ER Rev. 1, Section 4.2.9. The general path of water that percolates through Yucca Mountain is southward toward Amargosa Valley, then beneath the area around Death Valley Junction in the southern Amargosa Desert. The groundwater beneath Yucca Mountain merges and mixes with groundwater beneath Fortymile Wash. This groundwater then flows toward, and mixes with, the large groundwater reservoir in the Amargosa Desert. The major natural discharge point of this groundwater is farther south in Franklin Lake Playa, an area of extensive evapotranspiration.

Issue

Issues have been raised by members of the public regarding whether, despite efforts to the contrary, radioactive material would be released from a repository at Yucca Mountain over time and contaminate groundwater in the vicinity. Issues also address the amount of potential radiation doses that could be incurred as a result of people using this groundwater, the health consequences of those doses, and whether health protection standards would be met.

Response

Although engineered and natural systems eventually degrade or change, the DOE has shown that a repository can be designed, constructed, operated, monitored, and eventually closed so that radiation protection standards established by the NRC for licensing would not likely be exceeded. These standards (10 CFR Part 63 [66 FR 55732]) prescribe radiation dose limits that a repository must meet during the 10,000-year postclosure period.

Section 3.1.2 of the SSE discusses the DOE's recent (September 2001) estimate of annual doses from groundwater potentially contaminated with radioactive material released from the repository [BSC (Bechtel SAIC Company) 2001. "Total System Performance Assessment—Analyses for Disposal of Commercial and DOE Waste Inventories at Yucca Mountain—Input to the Final Environmental Impact Statement and Site Suitability Evaluation." REV 00 ICN 01. Las Vegas, Nevada: Bechtel SAIC Company. ACC: MOL.20011114.0246.]. These doses were calculated for the RMEI located approximately 18 kilometers (11 miles) from within a repository footprint. In summarizing the analyses results, the SSE states that the peak mean dose calculated over the 10,000-year postclosure period is 1.7 x 10E-5 millirem per year for the higher-temperature repository operating mode and 1.1 x 10E-5 millirem per year for the lower-temperature operating mode. These estimated doses are extremely low (SSE, Section 3.1.2).

As described in the FEIS, the DOE has determined that there would be essentially no radiation-related health impacts to the population around Yucca Mountain caused by contaminated groundwater. The results of analyses presented in the SSE, Section 3.1.2, and the FEIS, Section 5.4, show that the annual radiation dose for the nominal scenario is extremely low for more than 10,000 years after closure of the repository.

Issue

Issues have been raised by members of the public regarding protection of groundwater from potential leakage of radioactive material from a repository at Yucca Mountain.

Response

Section 801 of the Energy Policy Act of 1992 requires the EPA (not DOE) to set standards for the protection of public health and safety from releases of radioactive materials stored or disposed of at Yucca Mountain. For licensing, the NRC groundwater protection standards follow the EPA's groundwater protection standards in 40 CFR Part 197 (66 FR 32074), which are compatible with relevant EPA drinking water standards for the entire United States. For licensing, the NRC groundwater protection standard is 4 millirem per year. This is low compared to the average radiation exposure from natural sources of radiation of 300 millirem per year.

To address the NRC groundwater protection standards for licensing, the revised supplemental TSPA model evaluated groundwater concentrations of radionuclides released from the disposal system into the accessible environment consistent with 10 CFR 63.331 and 10 CFR 63.332 (66 FR 55814). Section 3.1.2.5 of the SSE discusses the results of these analyses. A description of the revised supplemental model can be found in "Total System Performance Assessment—Analyses for Disposal of Commercial and DOE Waste Inventories at Yucca Mountain—Input to Final Environmental Impact Statement and Site Suitability Evaluation" [Williams, N.H. 2001. "Contract No. DE-AC08-01RW12101—Total System Performance Assessment—Analyses for Disposal of Commercial and DOE Waste Inventories at Yucca Mountain—Input to Final Environmental Impact Statement and Site Suitability Evaluation REV 00 ICN 02." Letter from N.H. Williams (BSC) to J.R. Summerson (DOE/YMSCO), December 11, 2001, RWA:cs-1204010670, with enclosure. ACC: MOL.20011213.0056.].

The calculated peak mean activity concentration for alpha-emitting radionuclides for the 10,000-year postclosure period is 1.8 x 10E-8 picocuries per liter, from a repository at Yucca Mountain that operates at higher temperatures and 3.3 x 10E-8 picocuries per liter for lower-temperature operation. These gross alpha concentrations do not include 1.1 picocuries per liter from natural background. The NRC groundwater protection standard for licensing, in 10 CFR Part 63, limits gross alpha concentration to 15 picocuries per liter, which includes natural background.

The calculated peak mean activity concentration for combined radium-226 and radium-228 activity for the 10,000-year postclosure period is less than 1 x 10E-10 picocuries per liter for both the higher- and the lower-temperature operating mode. These radium concentrations do not include 1.04 picocuries per liter from natural background. The NRC groundwater protection standards for licensing, in 10 CFR Part 63, limit total radium concentration to 5 picocuries per liter, which includes natural background.

The revised supplemental model also calculated the mean annual dose from the combined beta- and photon-emitting radionuclides based on consuming 2 liters of groundwater per day. For beta- and photon-emitting radionuclides, the model forecasts 2.3 x 10E-5 millirem per year from a repository at Yucca Mountain operating at higher temperatures and 1.3 x 10E-5 millirem per year for operating at lower temperatures. Both calculations consider the whole body and any organ. The NRC groundwater protection standard for licensing, in 10 CFR Part 63, limits exposures from consuming two liters of water per day from the representative volume of groundwater to 4 millirem per year to the whole body or any organ.

4.7.05 (29)

Summary Comment

This summary comment addresses issues raised by members of the public regarding the radiation dose and associated health impacts due to potential leakage of radioactive material from a repository at Yucca Mountain into the groundwater. The issues are grouped in these five general categories: effects of potential releases of radioactive material to the groundwater, including radiation doses and health consequences; potential effects on plants and animals; potential harm to Native Americans; population groups potentially more exposed than the RMEI, and changes over time that could produce worst case scenarios; and lastly, concerns that the EPA's groundwater protection standards might be relaxed for a Yucca Mountain repository.

Issue

Issues have been raised by members of the public regarding the effects of potential releases of radioactive material from a repository at Yucca Mountain, including the potential for contaminating groundwater in the vicinity, the radiation doses that could be incurred as people use this groundwater, and the health consequences of those doses.

Response

As described in the FEIS, the DOE has determined that there would be essentially no radiation-related health impacts to the population around Yucca Mountain caused by releases from the disposal system into groundwater. The results of analyses presented in the SSE, Section 3.1.2, and the FEIS, Section 5.4, forecast that for 10,000 years, the radionuclide concentrations in groundwater and radiological exposures from using and consuming this groundwater would fall well below the groundwater and individual protection standards issued by the EPA and the NRC.

Section 801 of the Energy Policy Act of 1992 requires the EPA (not the DOE) to set standards for the protection of public health and safety from releases of radioactive materials stored or disposed of at Yucca Mountain. For licensing, the NRC's groundwater and individual protection licensing standards, in 10 CFR Part 63, implement the corresponding EPA standards in 40 CFR Part 197 (66 FR 32074). The groundwater protection standards are compatible with relevant EPA drinking water standards for the entire United States, and the individual protection standard is 15 millirem per year. The dose standards are low compared to the average radiation exposure from natural sources of radiation of 300 millirem per year.

To address the NRC individual protection standard for licensing, the revised supplemental model calculated the radiological exposure that the RMEI would receive from using groundwater (including irrigation and consumption). The RMEI would be located approximately 18 kilometers (11 miles) from within the repository footprint, above the highest concentration of radionuclides in the predominant direction of groundwater flow. The model forecasts a peak mean dose, calculated over the 10,000-year postclosure period, for a nominal scenario and a probability-weighted peak mean dose for the disruptive scenario. The nominal scenario includes both seismic activity and the assumed premature failure of up to three waste packages. The disruptive scenario includes igneous activity.

For the nominal scenario during the 10,000-year postclosure period, the revised supplemental model forecasts a peak mean dose of 1.7 x 10E-5 millirem per year for the higher-temperature operating mode and 1.1 x 10E-5 millirem per year for the lower-temperature operating mode. The doses are attributed to the assumed failure of a few (3 or less) waste packages, due to assumed, undetected, improper heat treatment of the final closure weld. Figure 3-4 of the SSE shows mean annual dose results from the TSPA-SR model, supplemental model, and revised supplemental model that were developed to forecast nominal performance. These doses would be approximately one-third lower using an annual water demand of 3,000 acre-feet as specified in the NRC licensing regulations. Additionally, Figures 3-7 and 3-8 of the SSE show that groundwater contamination does not occur before 1,000 to 2,000 years, assuming these early waste package failures.

For the disruptive scenario during the 10,000-year postclosure period, the revised supplemental model forecasts a probability-weighted peak mean dose of 0.1 millirem per year for both the higher- and lower-temperature operating modes. The disruptive scenario includes igneous eruption and intrusive events. In an eruptive event, it is assumed that magma would destroy some waste packages and bring this waste to the surface. In an intrusive event, it is assumed that the magma destroys some waste packages, but increases the potential for the waste to contaminate groundwater rather than bringing the waste to the surface. The mean annual probability of an igneous event is approximately 1 in 60 million per year. Although highly improbable, this event was not excluded from TSPA because its probability is greater than the screening threshold of 1 in 100 million per year, consistent with the NRC's licensing regulations at 10 CFR 63.342.

The DOE combined the forecasted doses for the nominal and disruptive scenarios consistent with the NRC's guidance [NRC (U.S. Nuclear Regulatory Commission) 2000. "Issue Resolution Status Report, Key Technical Issue: Total System Performance Assessment and Integration." Rev. 3. Washington, D.C.: U.S. Nuclear Regulatory Commission. TIC: 249045.]. This produced a forecasted probability-weighted peak mean annual dose of 0.1 millirem per year. The NRC individual protection standard for licensing, in 10 CFR Part 63, is 15 millirem per year to the RMEI.

Regarding concern that the estimated doses might affect future generations, the FEIS presents the results of analyses pertinent to this matter in Section 5.4.2. Table 5-7 of the FEIS shows the added risk of latent cancer fatality if an individual received the dose calculated for the RMEI modeled during the maximum dose year in the 10,000-year postclosure period. The incremental lifetime risk from exposure, during the maximum year, would be 6 x 10E-10 (i.e., one chance in approximately 1.7 billion). For perspective, cancer from all other sources is fatal to about one in four persons.

Issue

Issues have been raised by members of the public regarding whether radioactively contaminated groundwater would contaminate desert soil and result in harm to plants and animals, including endangered species.

Response

The DOE has determined that it is unlikely that there would be any adverse radiation-related impacts to the environment around Yucca Mountain caused by contaminated groundwater.

Section 5.4 of the FEIS indicates that forecasted long-term levels of radioactive material concentration in groundwater and the resulting dose levels at the forecasted discharge area in Amargosa Valley would be low. More specifically, the SSE, Section 3.1.2, Figure 3-3, shows a very small dose (1.7 x 10E-5 millirem per year for the higher-temperature repository operating mode, and 1.1 x 10E-5 millirem per year for the lower-temperature operating mode) to the RMEI during the 10,000-year postclosure period for the nominal groundwater scenario. The DOE concludes that the dose rates to plants and animals in Amargosa Valley would be unlikely to cause measurable detrimental effects in populations of any species. This result is based on dose response information developed by the International Atomic Energy Agency for terrestrial ecosystems including the most radiosensitive species [IAEA (International Atomic Energy Agency) 1992. "Effects of Ionizing Radiation on Plants and Animals at Levels Implied by Current Radiation Protection Standards." Technical Reports Series No. 332. Vienna, Austria: International Atomic Energy Agency. TIC: 243768. Page 53.].

Issue

Issues have been raised by members of the public regarding concern that Native Americans would be harmed due to potential exposure to groundwater contaminated with radioactive material leaking from a repository at Yucca Mountain.

Response

The analyses of potential groundwater-related exposures, performed by modeling a RMEI in accordance with EPA's standards in 40 CFR Part 197 and NRC's licensing regulations in 10 CFR Part 63, provide conservative dose estimates.

The EPA has specifically considered the Paiute and Shoshone Tribes' traditional and customary uses of the area around Yucca Mountain to determine whether the RMEI's location used in the EPA's standard (40 CFR Part 197) prescribes a higher exposure than these Native Americans are likely to receive. The EPA states "...we conclude, after considering their description of tribal uses of the area, that the rural-residential RMEI (the EPA's regulatory receptor) is fully protective of tribal resources" (66 FR 32090).

The EPA discusses the basis for this conclusion. First, tribal use of natural springs involves water that would have lower contamination levels as a result of repository releases than would wells at the location specified in 40 CFR Part 197, which tap aquifers closer and more directly affected. Second, "...tribal use of wildlife and non-irrigated vegetation should not contribute significantly to total individual dose estimates. Gaseous releases from the repository are not a significant contributor to individual doses...through inhalation or rainfall, and should contribute less to contamination of wildlife and non-irrigated vegetation than the use [by the RMEI] of contaminated well water for raising crops and animals for food consumption" (66 FR 32090).

The EPA provides another reason to conclude the receptor prescribed in 40 CFR Part 197 is more conservative than, and thus protective of, Native Americans. The EPA states that the RMEI "...is assumed to be a full-time resident continually exposed to radiation coming from the disposal system. It appears that the tribal uses are intermittent and involve resources which are less likely to be contaminated, resulting in lower doses...." (66 FR 32091).

Issue

Issues have been raised by members of the public indicating that there are better choices among the potentially exposed population (for example, subsistence farmers) to use as the model receptor because they could receive much higher radiation doses in worst case scenarios. Comment input recommends that the DOE employ these alternatives in order to perform more conservative assessments.

Response

The RMEI used in the DOE's assessments is consistent with the EPA's standards in 40 CFR Part 197 and NRC's licensing regulations in 10 CFR Part 63. Thus, the use of alternative model receptors would be inappropriate.

The DOE has developed its biosphere model using the RMEI prescribed by the EPA and the NRC (40 CFR Part 197 and 10 CFR Part 63 [66 FR 55732], respectively). The RMEI lives in the accessible environment above the highest concentration of radionuclides in the plume of contamination; has a diet and living style representative of the people who now reside in the town of Amargosa Valley; uses well water with concentrations of radionuclides based on an annual water demand of 3,000 acre-feet; drinks two liters of water per day from a groundwater well at that location; and is an adult. The regulations detail methods to be followed in arriving at the diet and living styles for the RMEI. The RMEI is specified to behave in a way that is expected to incur high exposure from groundwater potentially contaminated with radioactivity released from the repository. Because of location and lifestyle, the RMEI would be expected to receive higher dose from a repository than other members of the public who might be exposed, for example, by a portion of their diet being food or dairy products produced in Amargosa Valley.

Comment input suggested that there are people who might be more exposed than the RMEI, and the DOE should use their characteristics in the dose assessments. An alternative provided is subsistence farmers, which is discussed below. This discussion may also apply to other possible alternatives.

The EPA states, "...we could not find nor did any other party demonstrate that there is the subsistence-farmer lifestyle at, or downgradient from, Yucca Mountain" (66 FR 32089). The EPA also discusses subsistence farming in its support document [EPA (U.S. Environmental Protection Agency) 2001. 40 CFR Part 197. "Technical Support Document: Characterization and Comparison of Alternative Dose Receptors for Individual Radiation Protection for a Repository at Yucca Mountain." Washington, D.C.: U.S. Environmental Protection Agency. TIC: 250266.]. It states, "Past attempts to achieve subsistence farming in the Yucca Mountain region, even with incentives and subsidies... have failed." In the absence of current residents with this lifestyle in the vicinity of Yucca Mountain, including subsistence farming, the EPA states, "Any future projection involves speculation" (66 FR 32091). Such projection is not pursued because the EPA is "...following NAS's [National Academy of Sciences] recommendation to use current technology and living patterns because speculation upon future society and lifestyle variations can be endless and not scientifically supportable..." [Ibid.].

The EPA sums up these issues by stating, "...we believe that the RMEI [reasonably maximally exposed individual] approach is sufficiently conservative and that it is fully protective of the general population (including women and children, the very young, the elderly, and the infirm)" (66 FR 32089). The NRC has adopted the RMEI approach in its licensing regulations, 10 CFR Part 63 (66 FR 55732).

Issue

Issues have been raised by members of the public regarding the methods and rationale used to select values for the parameters that describe the characteristics and behaviors of the model receptor. The commenter advised the DOE that these assigned values are significant to the correctness of exposure analyses and dose calculations.

Response

The RMEI is consistent with the EPA's and the NRC's prescriptions of diet and living style characteristics for assessments to assure the public is adequately protected.

The RMEI that the DOE uses in the TSPA dose assessment model is prescribed by NRC licensing regulations. The EPA's standard (40 CFR Part 197) and the NRC's licensing regulation (10 CFR Part 63 [66 FR 55732]) prescribe the diet and living style for the RMEI. These attributes are based on the diet and living style of current residents of Amargosa Valley. These regulations also prescribe additional conservatism.

The diet and living style attributes of the RMEI that are most important to radiation exposure from the contaminated groundwater pathway are consuming locally grown food irrigated with potentially contaminated groundwater and drinking that water. The values used in the model for food ingestion are based on data obtained in a 1997 survey of the Amargosa Valley area conducted by the DOE [DOE (U.S. Department of Energy) 1997. "The 1997 Biosphere Food Consumption Survey Summary Findings and Technical Documentation." Las Vegas, NV: U.S. Department of Energy. Office of Civilian Radioactive Waste Management. ACC: MOL.19981021.0301.]. This detailed information for the RMEI is used in concert with diet patterns obtained from currently available census information in model receptor development.

Issue

Issues have been raised by members of the public regarding concern that some worst case scenarios are not used in analyzing potential radiation doses due to the groundwater pathway. These commenters indicate that such things as climate change, extreme cultural swings and economic scenarios should be included in analyzing potential exposure from groundwater over the long time periods after closure of a repository at Yucca Mountain.

Response

In developing its assessments for the groundwater pathway, the DOE has complied with the EPA standards and NRC licensing regulations for incorporating changes over time. The DOE has considered features, events, and processes (FEPs) that could affect the repository's performance over the 10,000-year postclosure period. The FEPs include climate change, volcanic activity, and seismic events among others.

The DOE has performed analyses of potential exposures related to groundwater by modeling the RMEI in accordance with the EPA's standards in 40 CFR Part 197 and NRC's licensing regulations in 10 CFR Part 63. In explaining its regulatory decisions, the EPA states, "Extremes of behavior are not used as the basis for protection...Instead, cautious, but reasonable, assumptions would be used to establish the individual(s) most highly exposed" [EPA (U.S. Environmental Protection Agency) 2001. 40 CFR Part 197. "Technical Support Document: Characterization and Comparison of Alternative Dose Receptors for Individual Radiation Protection for a Repository at Yucca Mountain." Washington, D.C.: U.S. Environmental Protection Agency. TIC: 250266.]. The EPA also states, "The objective is to project doses that are within reason rather than extreme, but well above the average for the exposed population. This approach will estimate a level of exposure that is protective of the vast majority of exposed persons but is still within a reasonable range and not highly speculative" [Ibid., page 11.].

Regarding societal changes over long time periods, the National Academy of Sciences [National Research Council 1995. "Technical Bases for Yucca Mountain Standards." Washington, D.C.: National Academy Press. TIC: 217588. Page 122.], the NRC (66 FR 55757), and the EPA (66 FR 32091) have determined that speculation about future states of society can be almost unlimited. These organizations conclude that assumptions should be used for regulatory compliance calculations, and these assumptions should reflect current living patterns.

The EPA's standard (40 CFR 197.15) states, "The DOE should not project changes in society, the biosphere (other than climate), human biology, or increases or decreases of human knowledge or technology...DOE must assume that all of those factors remain constant...However, DOE must vary factors related to the geology, hydrology, and climate based upon cautious, but reasonable assumptions of the changes in these factors that could affect the Yucca Mountain disposal system over the next 10,000 years." The NRC has adopted the EPA's RMEI approach in its licensing regulations, 10 CFR Part 63 (66 FR 55732).

The DOE has conducted its analyses consistent with these and EPA and NRC provisions for the groundwater pathway, and has considered all features, events, and processes that could affect the repository's performance.

Issue

Issues have been raised by members of the public indicating that because of the long time periods involved in assessing potential impacts to people, possible increases in numbers of people living in the vicinity of Yucca Mountain over time should be addressed.

Response

The DOE's performance assessments specifically address societal changes over time, including population changes. Due to the method that the NRC prescribes to calculate dose to the RMEI, the regulatory standard is independent of changes to population. In addition, as described in the SSE, the DOE has determined that the RMEI would receive an annual probability-weighted peak mean dose of 0.1 millirem.

The DOE recognizes that forecasting societal changes, one of which is population change, over the long-term is speculative and not scientifically supportable. The DOE has followed the licensing related regulatory requirements of the NRC and the EPA regarding incorporation in performance assessments of future human-related changes. This precludes attempting to forecast population changes.

One specific comment expressed concern that the distance from the repository at which the RMEI is assumed to reside is arbitrary, and that future population growth would cause residents to move closer. The EPA standards and NRC licensing regulations prescribe that the RMEI reside "...in the accessible environment above the highest concentration of radionuclides in the plume of contamination" (10 CFR 197.21, and 10 CFR 63.312 [66 FR 55814]). The EPA states, "We consider it improbable that the rural-residential RMEI would occupy locations significantly north of U.S. Route 95, because the rough terrain and increasing depth to groundwater nearer Yucca Mountain would likely discourage settlement by individuals because access to water is more difficult than it would be a few kilometers farther south...Therefore, the exposure for a RMEI located approximately 18 kilometers (11 miles) south of the repository (where ingestion of locally grown contaminated food is a reasonable assumption) actually would be more conservative than a RMEI located much closer to the repository who is exposed primarily through drinking water" (66 FR 32093).

The DOE has determined that there would be essentially no radiation-related environmental or health impacts to the RMEI. This is based on the results of analyses presented in the SSE, Section 3.1.2. The annual radiation dose for the nominal groundwater scenario is extremely low for more than 10,000 years after closure of the repository (SSE, Section 3.1.2).

Issue

An issue has been raised by the public regarding whether the EPA's groundwater protection standards might be relaxed for a Yucca Mountain repository.

Response

Section 801 of the Energy Policy Act of 1992 requires the EPA (not DOE) to set standards for the protection of public health and safety from releases of radioactive materials stored or disposed of at Yucca Mountain. For licensing, the NRC groundwater protection standards follow the EPA's groundwater protection standards in 40 CFR Part 197 (66 FR 32074), which are compatible with relevant EPA drinking water standards for the entire United States. For licensing, the NRC individual protection standard is 15 millirem per year. This is low compared to the average radiation exposure from natural sources of radiation of 300 millirem per year.

On the subject of groundwater protection standards for a repository at Yucca Mountain, the EPA states "Regarding the protectiveness of the [groundwater protection] standards, 40 CFR Part 197 incorporates the current MCLs [maximum concentration limits]" (66 FR 32108). The EPA also states "We commonly apply MCLs to water treatment facilities to assure that exposures to the subsequent users of the water are acceptable and the users are protected" (66 FR 32109). "We see no reason why we should not apply the same approach to protection for the Yucca Mountain disposal facility" (66 FR 32108). "We also included groundwater protection requirements in our certification process for WIPP, which is the only deep geologic disposal facility in the country that has actually gone through a regulatory review and approval process" (66 FR 32108). The NRC has stated, regarding development of 10 CFR Part 63 (66 FR 55732), "NRC has adopted the EPA's (40 CFR Part 197 [66 FR 55733]) ground-water protection standards and the associated requirements for determining compliance with the standards." "The Commission has imported the EPA standards into its final 10 CFR Part 63 regulations in as transparent a manner as possible" (66 FR 55733).

4.7.05 (932)

Summary Comment

An issue has been raised by the public that the cancer risk factor reported by the DOE in the DEIS is different than the value established in the existing policy under the Comprehensive Environmental Response, Compensation and Liability Act; and more recently, the Food Quality Protection Act.

Response

The EPA used "...an average risk for a member of the U.S. population of 5.75 in 100 (5.75 x 10E-2) fatal cancers per sievert (Sv) (5.75 x 10E-4 fatal cancers per rem) delivered at low dose rates..." in developing its regulation 40 CFR Part 197. EPA refers to chapter 6.3 of the Background Information Document [EPA (U.S. Environmental Protection Agency) 1999. "Background Information Document for 40 CFR Part 197, Environmental Radiation Protection Standards for Yucca Mountain, Nevada." Washington, D.C.: U.S. Environmental Protection Agency, Office of Radiation and Indoor Air. TIC: 246926.] as a source of information on this risk factor. The EPA's risk factor (5.75 x 10E-4) is larger (i.e., more conservative) than the highest risk factor (1 x 10E-4) that the comment indicates should be used (66 FR 32081).

The DEIS and the FEIS used 5 x 10E-4 fatal cancers per rem, as recommended by the National Council on Radiation Protection and Measurements [NCRP (National Council on Radiation Protection and Measurements) 1993. "Limitation of Exposure to Ionizing Radiation." NCRP Report No. 116. Bethesda, Maryland: National Council on Radiation Protection and Measurements. TIC: 207090.] in performing calculations converting estimated doses to risks reported in Tables 5-7 and 5-8. The peak annual receptor and peak lifetime population doses during the 10,000-year postclosure period result in estimated latent cancer fatality probabilities of 6 x 10E-10 and 2.2 x 10E-6, respectively. The risk factor used in these calculations (5 x 10E-4) is larger (i.e., more conservative) than the highest risk factor (1 x 10E-4) attributed to the Comprehensive Environmental Response, Compensation and Liability Act; and more recently, the Food Quality Protection Act by the comment.

4.7.05 (1240)

Summary Comment

An issue has been raised by the public that radioactive gases could leak into the air from waste packages causing illnesses or possible death.

Response

The DOE has analyzed the level of risk associated with the atmospheric pathway for a repository at Yucca Mountain. The results of this work are documented for the preclosure period in the FEIS, Section 4.1.7, and for postclosure in Section 5.5.

The FEIS estimates the risk during the preclosure period to the maximally exposed individual, assumed to reside for a 70-year lifetime at 20 kilometers (12 miles) from within a repository footprint. This individual would have a probability of latent cancer fatality of approximately one in 30,000 or less from exposure to radionuclides released to the atmosphere from the repository. Population doses and risks are also discussed in the FEIS, Section 4.1.7.5.3. Other potential health impacts to the public in the preclosure period are due to airborne cristobalite and erionite due to mining the repository. The estimated concentrations of cristobalite are such that health impacts to the public would be unlikely. For the lower concentrations of erionite, health impacts would be very small (FEIS, Section 4.1.7).

Regarding the risk of contracting cancer as a result of any radioactive releases to the atmosphere from a repository at Yucca Mountain after permanent closure, the FEIS, Section 5.5, shows that the maximum dose from atmospheric exposure to the total population within 80 kilometers (50 miles) of Yucca Mountain would be 1.5 x 10E-8 person-rem per year. The dose corresponds to less than one chance in 100 billion of a latent cancer fatality in the entire regional population of 76,000 (in 2035) during each year at the maximum postclosure atmospheric release rate. For perspective, this dose would raise the statistical chances of an individual incurring cancer (i.e., approximately one in four) from 0.24 to 0.2400000000000064 and would add significantly less than 1 additional latent cancer fatality to the 139 cancer-related fatalities per year that would occur within the regional population from other cancer-causing mechanisms (at the 1995 rate of cancer caused deaths in Nevada). Nonradiological potential health impacts to the public in the postclosure period are due to metals (vanadium, chromium, nickel and molybdenum) entering the groundwater. These are not an atmospheric release hazard.

4.7.05 (1795)

Summary Comment

An issue has been raised by the public regarding the need for the DOE's performance assessment to account for the potential effects of animals, insects and plants digging, burrowing and rooting over long periods of time.

Response

The DOE has concluded that the assessment of potential radiation dose impacts to people that are associated with mixing and buildup of radioactivity in surface soil has been addressed. In addition, any animal, insect and plant impacts on the repository are precluded by the fact that it is located at least 200 meters below the surface.

The impact of bioturbation is accounted for in the biosphere model of the groundwater contamination case that supports the performance assessment. In that model, the radioactive material potentially delivered to the land surface by contaminated groundwater used for irrigation is assumed to be mixed into the top 15 centimeters (6 inches) of soil (through periodic plowing). This assumption models the radioactive material to be available to the entire root of plants being grown as food for people or as animal feed, thereby enhancing the material's availability for incorporation in the edible portion of the plant. Consuming locally grown food and drinking the water are the most important means of potential radiation exposure for the model receptor.

4.7.05 (1984)

Summary Comment

An issue has been raised by the public regarding the need for the DOE's performance assessment to include ingestion of nuts grown in the Amargosa Valley using irrigation water potentially contaminated with radioactive material from a repository at Yucca Mountain and the Nevada Test Site.

Response

The NRC's licensing regulation (10 CFR Part 63 [66 FR 55732]) prescribes that the diet and living style for the RMEI are to be representative for current residents in the Town of Amargosa Valley. Specifically, the DOE includes consumption of nuts in the fruit portion of the diet of the RMEI used in assessing potential radiation doses due to a repository at Yucca Mountain.

The diet and living style attributes of the RMEI that are most important to potential radiation exposure from the contaminated groundwater pathway are consuming locally grown food irrigated with potentially contaminated groundwater and drinking that water. The values used in the model for these important personal attributes are based on data obtained in a 1997 survey of the Amargosa Valley area conducted by the DOE [DOE (U.S. Department of Energy) 1997. "The 1997 Biosphere Food Consumption Survey Summary Findings and Technical Documentation." Las Vegas, NV: U.S. Department of Energy, Office of Civilian Radioactive Waste Management. ACC: MOL.19981021.0301.]. This detailed information for the receptor is consistent with the EPA's standards in 40 CFR Part 197 and NRC's licensing regulations in 10 CFR Part 63, and is used in concert with diet patterns obtained from currently available census information in model RMEI development.

The DOE has performed analyses of potential exposures related to groundwater by modeling the RMEI in accordance with regulatory licensing requirements (the EPA's 40 CFR Part 197, and the NRC's 10 CFR Part 63 [66 FR 55732]). In explaining its regulatory decisions, the EPA states, "Extremes of behavior are not used as the basis for protection...Instead, cautious, but reasonable, assumptions would be used to establish the individual(s) most highly exposed" [EPA (U.S. Environmental Protection Agency) 2001. 40 CFR Part 197. "Technical Support Document: Characterization and Comparison of Alternative Dose Receptors for Individual Radiation Protection for a Repository at Yucca Mountain." Washington, D.C.: U.S. Environmental Protection Agency. TIC: 250266. Page 5.]. The EPA also states, "The objective is to project doses that are within reason rather than extreme, but well above the average for the exposed population. This approach would estimate a level of exposure that is protective of the vast majority of exposed persons but is still within a reasonable range and not highly speculative" [Ibid., page 11.].

As described in the FEIS, the DOE has determined that there would be essentially no radiation-related health impacts to the RMEI. The results of analyses presented in the SSE, Section 3.1.2, and the FEIS, Section 5.4, show that the annual radiation dose for the nominal scenario is extremely low for more than 10,000 years after closure of the repository. Section 8.3 of the FEIS discusses cumulative impacts of past activities at the Nevada Test Site and the Beatty Low-Level Radioactive Waste Disposal Facility. The analysis shows that even considering the Nevada Test Site or the Beatty Facility in addition to a repository at Yucca Mountain, the cumulative dose impacts would not exceed the NRC regulated radiation protection standards.

4.7.05 (4003)

Summary Comment

An issue has been raised by the public regarding the need for the DOE to specifically address the linear threshold theory and explicitly discuss the probability of major events that could occur at the repository and the associated implications.

Response

The DOE recognizes that there are uncertainties regarding the relationship of radiation dose and health effects at low doses and low dose rates. Scientific advisory groups, including the National Academy of Sciences, National Council on Radiation Protection and Measurements, and the International Commission on Radiological Protection have reviewed the research and population dose data and recommended methods for calculating dose and estimating dose effects. These organizations recognize that the use of dose-to-risk conversion factors based on the linear no-threshold hypothesis to estimate stochastic effects (latent cancer fatalities, nonfatal cancer incidence, and hereditary effects) from very low exposures to ionizing radiation may overestimate the actual risk.

The DOE also recognizes that experts in the scientific community are reviewing the merits of the linear no-threshold hypothesis. However, because of uncertainties in the low dose and low dose rate region of the dose-to-health effect curve, the dose-to-risk factors recommended by the National Council on Radiation Protection and Measurements [NCRP (National Council on Radiation Protection and Measurements) 1993. "Limitation of Exposure to Ionizing Radiation." NCRP Report No. 116. Bethesda, Maryland: National Council on Radiation Protection and Measurements. TIC: 207090. Page 29.] and the International Commission on Radiological Protection [ICRP (International Commission on Radiological Protection) 1991. "1990 Recommendations of the International Commission on Radiological Protection." Volume 21, No. 1-3 of "Annals of the ICRP." ICRP Publication 60. New York, New York: Pergamon Press. TIC: 235864. Page 18.] for estimating the risk from exposure to ionizing radiation are based on the linear no-threshold hypothesis. These organizations have been careful to point out over the years that the use of the linear no-threshold-derived risk factors will provide reasonable assurance that the actual effect will not be underestimated. For these reasons, the linear no-threshold hypothesis has been accepted for use by federal agencies-including the DOE, the EPA, and the NRC-for radiation protection and for estimating risk from exposure to ionizing radiation.

4.7.05 (9224)

Summary Comment

An issue has been raised by the public regarding the potential for contaminated dairy products produced in the vicinity of Yucca Mountain to cause harm to the general population.

Response

The DOE includes groundwater contamination with radioactive material in its analyses of potential public health risks associated with a repository at Yucca Mountain. The largest potential risk to groundwater users would be to the people of Amargosa Valley because groundwater in the saturated zone beneath the repository flows in a generally southerly direction toward this community (FEIS, Section 3.1.4). As indicated in Chapter 5 of the FEIS, overall human health impacts to Amargosa Valley residents may never occur and in any event would be very small. The hypothetical person studied to calculate human health impacts (i.e., the RMEI) would live year-round above the highest concentration of radionuclides in the plume of groundwater contamination, eat locally produced foods, and drink water from potentially contaminated sources. The characteristics of the RMEI are defined in the NRC licensing regulations 10 CFR 63.312 (66 FR 55814).

Because of location and lifestyle, the RMEI would be expected to receive higher dose from a repository than other members of the general population who might be exposed, for example, by a portion of their diet being food or dairy products produced in Amargosa Valley.

The DOE has conducted an extensive program to characterize the direction and nature of groundwater movement from the Yucca Mountain site. The results are described in the S&ER Rev. 1, Section 4.2.9, and the FEIS, Section 3.1.4. The general path of water that percolates through Yucca Mountain is southward toward Amargosa Valley, then beneath the area around Death Valley Junction in the southern Amargosa Desert. The groundwater beneath Yucca Mountain merges and mixes with groundwater beneath Fortymile Wash. This groundwater then flows toward, and mixes with, the large groundwater reservoir in the Amargosa Desert. The major natural discharge point of this groundwater is farther south in Franklin Lake Playa, an area of extensive evapotranspiration.

Although engineered and natural systems eventually degrade or change, the DOE has shown that a repository can be designed, constructed, operated, monitored, and eventually closed so that radiation protection standards established by the NRC, for licensing, would be met. These standards (10 CFR Part 63 [66 FR 55732]) prescribe radiation dose limits that a repository must meet during the 10,000-year period after closure.

Section 3.1.2 of the SSE discusses the DOE's recent (September 2001) estimate of annual doses from groundwater potentially contaminated with radioactive material released from the repository [Williams, N.H. 2001. "Contract No. DE-AC08-01RW12101—Total System Performance Assessment—Analyses for Disposal of Commercial and DOE Waste Inventories at Yucca Mountain—Input to Final Environmental Impact Statement and Site Suitability Evaluation REV 00 ICN 02." Letter from N.H. Williams (BSC) to J.R. Summerson (DOE/YMSCO), December 11, 2001, RWA:cs-1204010670, with enclosure. ACC: MOL.20011213.0056.]. These doses were calculated for the RMEI located approximately 18 kilometers (11 miles) from within a repository footprint, and are presented in Table 6-1. In summarizing the analyses results, the SSE states that the peak mean dose calculated over the 10,000-year postclosure period is 1.7 x 10E-5 millirem per year for the higher-temperature repository operating mode and 1.1 x 10E-5 millirem per year for the lower-temperature operating mode. These estimated doses are extremely low (SSE, Section 3.1.2).

Regarding concern that the estimated doses might cause health consequences, the FEIS presents the results of analysis of this matter in Section 5.4.2. Table 5-7 shows that the incremental lifetime risk of latent cancer fatality if an individual received the dose calculated for the RMEI is less than one chance in a billion.

The comment raises the issue of potential contribution to radiation dose due to the dairy in the Amargosa Valley area. The consumption of locally produced milk by the RMEI was included in the analysis discussed above. The amount consumed was determined by data obtained in a 1997 survey of the Amargosa Valley area conducted by the DOE [DOE (U.S. Department of Energy) 1997. "The 1997 Biosphere Food Consumption Survey Summary Findings and Technical Documentation." Las Vegas, NV: U.S. Department of Energy. Office of Civilian Radioactive Waste Management. ACC: MOL.19981021.0301.] used in concert with regional diet patterns obtained from currently available U.S. Department of Agriculture information.

As described in the SSE, the DOE has determined that there would be essentially no radiation-related health impacts to the RMEI. The results of analyses presented in the SSE, Section 3.1.2, and the FEIS, Section 5.4, show that the annual radiation dose for the nominal groundwater scenario is extremely low for more than 10,000 years after closure of the repository.

4.7.05 (9506)

Summary Comment

An issue has been raised by the public regarding the need for the DOE to present worst case scenarios.

Response

The DOE has analyzed worst-case scenarios. These scenarios have been developed for preclosure accidents and postclosure events. These scenarios are discussed in detail as follows:

Preclosure accidents—The process and results for the preclosure radiological accident analysis are described in the FEIS, Section 4.1.8.1. In summary, this includes examining the initiating events that could lead to facility accidents, which can include human-caused situations such as aircraft crashes and facility worker human error, and natural phenomena like seismic disturbances and extreme weather. Probabilities of the events were estimated and accident sequences were analyzed to estimate overall probability. The potential radiation dose and radiological impacts were estimated for the postulated accident scenarios based on the current facility design. Impacts to the public were the result of inhalation of airborne radionuclides, external radiation from the passing plume, and long-term exposure to radionuclides deposited on the soil during plume passage via external exposure, ingestion of contaminated food and inhalation of resuspended particles. The most severe accident scenario for the 95-percent weather conditions (producing conservative, high dose estimates) would result in an estimated 0.007 latent cancer fatalities for the affected population. The more conservative summation of all potential accidents presented results in less than 0.01 latent cancer fatalities for the exposed population. Thus, the estimated number of latent fatalities from preclosure accidents would be small (FEIS, Section 4.1.8.1).

Postclosure events—The EPA standard and the NRC licensing regulations require developing performance assessments that includes features, events and processes (FEPs) that might affect repository performance. The DOE has identified the possible FEPs, assessed their probability or consequence, and has included those that could affect repository performance in the performance assessments. The analyses of the nominal case scenario and disruptive events scenarios demonstrate that the repository would not exceed the radiation protection standards that are contained in the NRC's licensing regulation (SSE, Section 3.1) (10 CFR 63.102(j) [66 FR 55805]).

The repository's capability to isolate nuclear waste is thoroughly treated in the TSPA-SR by modeling scenarios of the most plausible evolution of the geologic system and the occurrence of unlikely adverse conditions. Using a systematic procedure, earth scientists and engineers have developed scenarios of future system evolution and unlikely adverse conditions. These scenarios, which were developed by combining FEPs relevant to the site, are grouped into two basic categories: nominal scenarios and disruptive scenarios (S&ER Rev. 1, Section 4.3.2).

The nominal scenario includes the most likely FEPs expected to occur in the future (e.g., climate change, and repository heating). The disruptive scenario category includes adverse conditions that are very unlikely (e.g., volcanism), but that could, if they were to happen, significantly reduce the capability of the repository to isolate waste. In addition to analyses of scenarios in these two categories, the TSPA analyzes a separate scenario for human intrusion that, consistent with NRC licensing regulations, assumes a drill hole penetrating the repository (S&ER Rev. 1, Section 4.3.2).

A comprehensive set of potentially disruptive events, ranging from meteor or comet impacts to unexpected flooding of the repository, has been identified and evaluated. Similarly, a wide variety of potentially harmful processes, such as unanticipated failure of the waste packages and damage to repository systems by seismic activity, have been identified and evaluated. Depending on the results of this analysis, the events and processes have been treated in one of three ways: (1) events or processes with less than one chance in 10,000 of occurring in 10,000 years (e.g., meteor impacts) or very small consequences (i.e., events resulting in releases or doses whose omission would not change the results significantly) have been screened out and not analyzed further; (2) events or processes that are uncommon, but have probabilities greater than one chance in 10,000 of occurring in 10,000 years (e.g., igneous intrusion activity), have been included in the performance assessment; and (3) events or processes expected to occur during the period of regulatory compliance, such as climate change or ground shaking associated with earthquakes, have been included directly in models of the performance of the repository (S&ER Rev. 1, Section 4.1.1.3).

By recognizing and explicitly analyzing all identified events and processes that could affect repository performance, the DOE has provided a sound basis for evaluating the performance of the repository system (S&ER Rev. 1, Section 4.1.1.3). The analyses of the nominal case scenario and the disruptive events scenarios demonstrate that the postclosure repository would not exceed the radiation protection standards that are contained in the NRC's licensing regulation, 15 millirem per year (10 CFR Part 63.311 and 63.321(b)(1) [66 FR 55814]), for at least 10,000 years after repository closure.

4.7.05 (10437)

Summary Comment

An issue has been raised by the public regarding the potential for plutonium poisoning from a repository at Yucca Mountain.

Response

Nominal performance—Figure 3-4 of the SSE shows that nominal performance releases from the repository would not exceed NRC licensing radiation protection standards (15 millirem per year in 10 CFR 63.311 [66 FR 55814]) within 10,000 years of repository closure.

The SSPA Volume 2, Section 4.1.2, discusses the contribution to dose of various radionuclides potentially released from a repository at Yucca Mountain performing nominally. Figures 4.1-5 and 4.1-6 show that plutonium-239 first becomes available at approximately 100,000 years after closure and causes about 2 x 10E-4 millirem per year at its peak concentration. Plutonium-242 first appears at about 120,000 years, but is present in concentrations that begins to add dose (greater than 1 x 10E-5 millirem per year) after approximately 200,000 years. No other isotopes of plutonium contribute dose greater than 1 x 10E-6 millirem per year in the first 1,000,000 years after closure (SSPA, Vol. 2, Section 4.1.2).

These times are beyond the 10,000-year postclosure period specified in the NRC's licensing regulation (10 CFR Part 63.311 [66 FR 55814]).

FEIS, Section 5.1.2, states that a chemically toxic material inventory screening analysis showed that the only chemical materials of concern for the 10,000-year postclosure period would be those released as the external wall of the waste package and waste package support pallet materials corrode. These are made of Alloy 22 and stainless steel 316NG. The chemicals of concern listed do not include plutonium (FEIS, Section 5.1.2).

Disruptive performance—The SSPA Volume 2, Section 4.3.2, discusses the contribution to dose of various radionuclides potentially released from a repository at Yucca Mountain if it is impacted by an igneous disruption at 100 years after closure. Figures 4.3-5a and 4.3-5b show the probability-weighted doses due to plutonium-238, 239, 240, and 242, among the other principal dose-producing radionuclides. Plutonium-240 is present in concentrations in volcanic ash that cause approximately 2 x 10E-2 millirem per year at its peak. Concentrations in ash of plutonium-239 would result in about 4 x 10E-2 millirem per year at its peak. Concentrations of plutonium-238 and 242 would result in about 1 x 10E-2 and 5 x 10E-4 millirem per year, respectively, at their peaks (SSPA Vol. 2, Section 4.3.2).

The total dose from igneous activity (approximately 0.1 millirem per year), including the dose contributions from the plutonium radioisotopes, are below the 15 millirem per year dose limit specified in the NRC's regulation (10 CFR Part 63.311 [66 FR 55814]) that is designed to ensure protection of public safety.

Therefore, it is not likely for plutonium poisoning to occur for any of the conditions postulated for this repository.

4.7.06 Disruptive Events

4.7.06 (48)

Issues raised by members of the public reflect a concern over the seismic and volcanic activity that is possible in the area. There is concern on how such activity may affect repository performance and whether waste packages would be damaged from earthquakes. There is also concern that uncertainty exists in available data.

No comments received or comments addressed elsewhere.

The DOE considered disruptive events including seismic activity, volcanic (magmatic) intrusion and volcanic eruption as part of their assessment of the repository performance. Seismic activity occurs in the region and is an important criterion in the repository design considerations. Seismic effects were also considered in the assessment of radionuclide release scenarios. Volcanic events at the Yucca Mountain site are considered unlikely (about 1 chance in 62,500,000 of occurring per year) (S&ER Rev. 1, Section 4.3.2.1.2). However, the radiological consequences of such events were included in the TSPA estimate of doses. The results of the TSPA indicated dose values at levels that were below the NRC radiation protection standards contained in NRC licensing regulations (10 CFR Part 63).

Section 1.3.2 of the S&ER Rev. 1 describes the geologic setting of Yucca Mountain and the surrounding region. In addition, Sections 4 and 12 of the YMSD describe the geology, seismology, and volcanology of the region in extensive detail. Section 4.3.2 of the S&ER Rev. 1 describes the seismic scenarios used to assess the possible impacts to the repository and their effects on the long-term performance. Based on these studies and assessments, the DOE has concluded that the information provided in the S&ER Rev. 1 and the YMSD on geology, geologic hazards, and the effects of these hazards on the repository, adequately describe and analyze the Yucca Mountain site. The inherent uncertainty associated with geologic data, analyses, models, and the confidence in estimates of potential impacts due to future seismic events are described in Section 4.3 of the S&ER Rev. 1. In addition, the "Disruptive Events Process Model Report" [CRWMS M&O 2000. "Disruptive Events Process Model Report." TDR-NBS-MD-000002 REV 00 ICN 02. Las Vegas, Nevada: CRWMS M&O. ACC: MOL.20001220.0047.] discusses the evaluation of seismic hazards analysis in greater detail.

Over a two year period ending in 1998, 25 experts from industry, academia, and government conducted the probabilistic seismic hazard analysis [Wong, I.G. and Stepp, C. 1998. "Probabilistic Seismic Hazard Analyses for Fault Displacement and Vibratory Ground Motion at Yucca Mountain, Nevada." Milestone SP32IM3, September 23, 1998. Three volumes. Oakland, California: U.S. Geological Survey. ACC: MOL.19981207.0393.] for Yucca Mountain. The experts assessed the potential hazard at Yucca Mountain from vibratory ground motion from possible earthquakes along local and regional faults. These assessments would be used as a basis for seismic design of repository facilities. The assessment was based on available geologic, paleoseismic, historic seismicity, and geophysical data. Also assessed was the hazard at Yucca Mountain from displacement on local faults.

As discussed in Section 4.3.2.2.2 of the S&ER Rev. 1, the major effect of an earthquake at Yucca Mountain would be ground motion (shaking) rather than direct offset along a fault. Studies indicate that movement during the past approximately 2,000,000 years has been along existing faults, and the probability of new faults forming is negligible. Studies of the faults and seismic potential at Yucca Mountain indicate there is little chance that displacement of greater than 0.1 centimeter (0.04 inches) would occur within the emplacement drifts.

Repository facilities that are important to safety would be designed to withstand ground motions with an estimated annual frequency of exceedance of 1 x 10E-4. The results of the seismic hazard analysis indicate that the ground motion hazard at this probability level is dominated by moderate-sized (magnitude 5.5 to 6.5) earthquakes occurring near the site and larger (magnitude 7 and higher) earthquakes occurring more distant from the site [Ibid.].

Seismically induced rockfalls within the waste emplacement drifts were also considered. An analysis of potential rockfall block size was performed based on mapping of rock fractures and study of their geometries within the repository block (S&ER Rev. 1, Section 4.2.3.3.5).

Effects of repository heating and earthquake stresses were also considered. Based on these analyses, a range of rock sizes, weighing up to 10 metric tons, was derived. The 10-metric ton block represents the estimated maximum size that would potentially strike a single drip shield.

Larger block sizes would strike more than one shield, which would lessen the overall force because the load would be shared by more than one shield. Therefore, the 10-metric ton size is considered the maximum credible load from a rockfall (S&ER Rev. 1, Section 4.2.3.3.5).

Based on stress analyses the drip shields would be able to withstand the impact of a 10-metric ton rockfall with minimal effect. In the worst-case analysis, the drip shield would be dented, but would not be dented in such a way that it touched the waste package. The drip shield may be stress cracked from the impact. However, because of the properties of the titanium material, the aperture (spread) of the crack is estimated to not exceed 0.1-millimeter (0.004-inch) wide, which is not large enough to allow flow of seepage water. Therefore, the function of the drip shield would not be compromised, even in the event of stress cracking (S&ER Rev. 1, Section 4.2.4.3.4). The study also showed that most potential rockfalls would be much smaller (2 metric tons or less). Rockfalls involving blocks of these smaller sizes would result in minimal drip shield damage (S&ER Rev. 1, Section 4.2.3.3.5).

The drip shields (which are installed over the waste packages) are estimated to be able to retain their integrity for at least 20,000 years (S&ER Rev. 1, Section 4.4.2.2). As long as the drip shields remain intact, water would not come in contact with the packages nor would the packages be susceptible to rockfall damage. After the 20,000-year period, some of the drip shields are expected to breach. After that time, if seepage enters the repository it could come in contact with the waste packages. It is also possible that some of the packages could be damaged by rockfall.

The DOE has also evaluated the long-term geologic stability due to volcanic activity at Yucca Mountain, including the potential for volcanoes. For the disruptive scenario during the 10,000-year postclosure period, the revised supplemental model forecasts a probability-weighted peak mean dose of 0.1 millirem per year for both the higher- and lower-temperature operating modes. The disruptive scenario includes igneous eruption and intrusive events. In an eruptive event, it is assumed that magma would destroy some waste packages and bring this waste to the surface. In an intrusive event, it is assumed that the magma destroys some waste packages, but increases the potential for the waste to contaminate groundwater rather than bringing the waste to the surface. The mean annual probability of an igneous event is approximately 1 in 60 million per year. Although highly improbable, this event was not excluded from TSPA because its probability is greater than the screening threshold of 1 in 100 million per year, consistent with the NRC's licensing regulations at 10 CFR 63.342.

The DOE presents an analysis of the effects of both a volcanic eruption (emitting ash through the repository and into the atmosphere) and the intrusion of magma into the emplacement drifts.

Volcanic activity has been waning in the recent geologic past. The last basaltic eruption occurred approximately 80,000 years ago and formed the Lathrop Wells Cone (S&ER Rev. 1, Section 4.3.2.1.1), about 18 kilometers (11 miles) south of the site. A panel of outside experts examined the data and models and concluded that the probability of a volcanic dike disrupting the repository during the first 10,000 years after closure is 1 chance in 62,500,000 annually. The chance of a basaltic intrusion that continues to the surface and results in a volcanic eruption is 1 in 77,000,000 per year (S&ER Rev. 1, Section 4.3.2.1.2). It is assumed, if the intrusion event were to occur, breaching of all the waste packages that came in contact with magma would result. This in turn may result in radionuclide release to the unsaturated zone and would be available for transport via groundwater. In the event an eruption occurred, the radionuclides would be entrained in ash and exposure could occur via inhalation and ingestion. Both of these scenarios were included in the TSPA estimate of dose. The probability weighted peak mean dose estimate from these two scenarios is below NRC radiation protection standards for licensing (10 CFR Part 63).

The possibility of a silicic (Mount Saint Helens type) eruption was also studied. It was concluded that this type of volcanic eruption has not occurred in the Yucca Mountain region in the past 7.5 million years and is considered to no longer be credible in the region (S&ER Rev. 1, Section 4.3.2.1.1) because the conditions that produce silicic volcanoes no longer exist. Therefore, this type of volcanic event was not studied further.

4.7.06 (50)

Summary Comment

Issues were raised by the public regarding the appropriateness of the human intrusion event scenarios used by the DOE.

Response

In the "Total System Performance Assessment for the Site Recommendation" and "Preliminary Site Suitability Evaluation," the DOE projected that a stylized human intrusion scenario, based on proposed regulations of the NRC, would expose the RMEI to less than 0.01 millirem per year. At that time the NRC performance objective for human intrusion was 25 millirem per year, and it prescribed a scenario in which human intrusion would occur at 100 years after repository closure (64 FR 8676). However, in the final regulations (10 CFR 63.321), the NRC requires DOE to first determine when the waste packages would degrade sufficiently that a human intrusion could occur without recognition by the driller. If human intrusion without recognition by the driller could not occur at or before the 10,000-year compliance period, then that analysis of the human intrusion scenario must be presented in the Yucca Mountain environmental impact statement and the dose limits for the human intrusion standards would not apply.

Based on an analysis in Appendix A of the "FY01 Supplemental Science and Performance Analyses", the DOE has determined that the earliest time after disposal that the waste packages would degrade sufficiently that a human intrusion could occur without recognition by the drillers is 30,000 years. Before that time, drillers would recognize that they had drilled into waste packages because the compressive strength and ductility of the metals from which they and the drip shields are fabricated differ significantly from the rock that would surround them. Drillers would notice these differences. For example, the drilling assembly would buckle and bend when the bit attempts to penetrate the titanium drip shield and waste package (drill bits that are designed for rock do not easily penetrate metal, particularly titanium). The drillers should, therefore, recognize that they have attempted to drill into some material other than rock for at least as long as the drip shield or packages are intact, which is approximately 30,000 years. Although the supplemental TSPA model projects that a few waste packages may fail prematurely, these failures caused by localized corrosion that would not weaken the overall structural integrity of the waste packages. Consequently, the waste packages would resist drilling even after they have failed.

In formulating the regulatory approach to the human intrusion scenario, the EPA considered the advice given by "Technical Bases for Yucca Mountain Standards" [National Research Council 1995. "Technical Bases for Yucca Mountain Standards." Washington, D.C.: National Academy Press. TIC: 217588. Chapter 4.]. This report suggests there are three types of intrusions: inadvertent and where the intruder does not recognize that a hazard has been created, inadvertent but where the driller recognizes the hazard and takes corrective action, and intentional [Ibid., page 114.]. The last category would include terrorists or saboteurs, but it could also include a society needing to access the material for its energy content. The members of the National Research Council committee decided to recommend that only the first category be addressed, because the second category, if corrective measures are ineffective, would have the same consequences as the first. The third category was an imponderable given the unpredictability of future human society. There is no way to absolutely ensure that, if a future society wished to reenter the repository, it would not be able to do so.

For the analysis presented in "Total System Performance Assessment—Analyses for Disposal of Commercial and DOE Waste Inventories at Yucca Mountain—Input to Final Environmental Impact Statement and Site Suitability Evaluation" [Williams, N.H. 2001. "Contract No. DE-AC08-01RW12101—Total System Performance Assessment—Analyses for Disposal of Commercial and DOE Waste Inventories at Yucca Mountain—Input to Final Environmental Impact Statement and Site Suitability Evaluation REV 00 ICN 02." Letter from N.H. Williams (BSC) to J.R. Summerson (DOE/YMSCO), December 11, 2001, RWA:cs-1204010670, with enclosure. ACC: MOL.20011213.0056.], the DOE made a more conservative assumption that the intrusion event would occur at about 100 years after final closure. This assumption would tend to overestimate the consequences because the waste materials would become less toxic with time (due to radioactive decay). "Total System Performance Assessment—Analyses for Disposal of Commercial and DOE Waste Inventories at Yucca Mountain—Input to Final Environmental Impact Statement and Site Suitability Evaluation" [Ibid., Section 6.4.] contains results for an intrusion occurring at 30,000 years to simulate an intrusion at a time when the intruder might not detect the waste package because of its weakened state consistent with 10 CFR Part 63 (66 FR 55732). It should also be noted that, over time, as more waste packages failed (and potential doses rose toward a peak dose from the overall system), the consequences of intrusion would become less, not more due to radioactive decay. This is because the more waste packages that have failed, the less the additional waste package failure from human intrusion would contribute to the overall risk.

4.7.06 (11472)

Summary Comment

An issue has been raised by the public that new research on nearby volcanoes suggests that due to faults, some areas within the drifts of the repository would be more vulnerable to an igneous intrusion than others. The results of such intrusions would damage waste packages causing the loss of radioactive material.

Response

The YMSD details the locations and the known histories of movement along faults in the Yucca Mountain region. The intrusion of volcanic dikes along faults and within extensional zones is not uncommon in the geologic record; Section 6.4.1.5 of "Characterize Framework for Igneous Activity at Yucca Mountain, Nevada" [CRWMS M&O 2000. "Characterize Framework for Igneous Activity at Yucca Mountain, Nevada." ANL-MGR-GS-000001 REV 00 ICN 01. Las Vegas, Nevada: CRWMS M&O. ACC: MOL.20001221.0001.] discusses how this has been recognized in the Yucca Mountain region in Crater Flat, where there is a close spatial and temporal relationship between sites of extension and volcanism. However, the restriction of several episodes of post-Miocene volcanism to the extensional zone in the Crater Flat basin suggests that volcanism is less likely to occur at Yucca Mountain, which lies outside the zone, in an area where no post-Miocene volcanism has occurred. Also, the repository drifts would be located away from the larger faults which bound the repository block, thereby reducing the likelihood of a potential volcanic dike along these faults interacting with the subsurface facilities.

The interactions between a dike (magma) intrusion and the subsurface facilities and the waste packages has been investigated by the DOE; S&ER Rev. 1, Section 4.3.2.1.3, addresses these interactions and discusses the consequences that were modeled in the performance assessment. A horizontal break-out of a magmatic intrusion is the least likely of scenarios because the repository level is several hundred meters (hundreds of feet) beneath the surface. The DOE is doing additional investigation of the physical processes impacting a repository during a dike intrusion at depth. The DOE would continue to evaluate the possible effects of subsurface repository structures on the localization and evolution of a potential magmatic intrusion into the repository and an eruption on the surface. The issues include two scales of investigation: (1) how the topographic relief of the Yucca Mountain area affects the stresses in the upper kilometer or so of rock and the effects this may have on the direction and velocity (that is, propagation) of ascending magmatic dikes; and (2) how the mined drifts affect the direction of dike ascent and conduit formation on the surface above the repository. The evaluation would assess the effects of stress accumulation on geologic structures from the heat generated by high-level waste, and the response of these structures during an igneous event. The evaluation would also include how the presence of engineered repository structures could affect magma flow inside the drifts and above the repository level. The mechanical strength and durability of natural or engineered barriers are important parameters to consider when evaluating how these materials might restrict magma flow within the intersected drifts. Other important factors to evaluate are the rapid exsolution of gases and resulting fragmentation of the basaltic magma when entering the mined drifts, and the effects on waste packages.

The effects of repository structures on magma ascent have been the subject of discussion between the DOE and the NRC staff during technical meetings. The NRC staff has expressed confidence that the DOE proposed approach to the topic, together with DOE agreements to provide the NRC with additional information, should result in satisfactory resolution of the topic.

4.7.07 Human Intrusion Events—Other

4.7.08 Biosphere Performance Events

4.7.08 (64)

An issue was raised by the public regarding the radiation dose consequences that might result if an igneous event disrupts a repository at Yucca Mountain.

Information is presented below on radiation doses following potential disruption of a repository at Yucca Mountain by a volcanic eruption or igneous intrusion. This information is based on the results of extensive studies and modeling of the processes that lead to people receiving radiation doses if a volcano or intrusion disrupts a repository at Yucca Mountain.

One important consideration in calculating the radiation dose from erupted volcanic ash is the amount of ash at the location of the people receiving the dose. A "model receptor" location for groundwater is prescribed by the licensing regulations, 10 CFR Part 63 (66 FR 55732). The wind direction during the eruption is important to the transport of ash in the plume to the receptor. For the TSPA-SR, results are calculated assuming that the wind blows to the south toward the receptor location during any volcanic eruption. This assumption results in more ash at the receptor location than would occur if the wind direction were varied in the calculations, consistent with nature. This assumption results in increased exposure to contaminated ash, and higher (conservative) radiation doses. This assumption also compensates for the possibility that contaminated ash deposited elsewhere due to winds blowing in directions other than south might later be redistributed (for example, by wind or rain runoff) to the location of the receptor (S&ER Rev. 1, Section 4.4.3).

The SSE, Section 3.1.2, and the FEIS, Section 5.7, present the results of radiation dose calculations for the RMEI location, approximately 18 kilometers (11 miles) from within a repository footprint, for the igneous disruptive events (i.e., volcanic eruption and igneous intrusion). In performing these calculations, a random time of occurrence of the disruptive event in the first 10,000 years after repository closure was utilized. For the 10,000-year postclosure period, the effects of a volcanic eruption dominate the annual dose, with the igneous intrusion not contributing significantly. The SSE states that the probability-weighted mean annual dose during this period reaches a peak of approximately 0.1 millirem per year at about 300 years after closure of the repository (SSE, Section 3.1.2). This is well below the NRC's radiation protection standards for licensing.

The probability weighting is used to develop a combined dose that represents the expected risk for a repository at Yucca Mountain. This disruptive event dose, when combined with the dose for nominal performance, is used for comparison to the licensing radiation protection standards (15 millirem per year). Section 3.1.2 of the SSE discusses the comparison of these combined doses with the radiation protection standards, which are established to assure protection of the public from potential radiation hazards associated with a repository after closure (SSE, Section 3.1.2).

4.7.08 (11589)

Summary Comment

An issue has been raised by the public that an accident at the repository at Yucca Mountain could have Chernobyl like implications.

Response

There are no legitimate comparisons to be made between hypothetical accident scenarios at a Yucca Mountain repository and the Chernobyl reactor accident. The DOE has analyzed the level of risk associated with the atmospheric pathway for a repository at Yucca Mountain. The results of this work are documented for the preclosure period in the FEIS, Section 4.1.7.5.3, and for postclosure in Section 5.5.

4.7.09 Uncertainty in Total System Performance Assessment

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Issues were raised by members of the public regarding uncertainty in the Performance Assessment. These issues included: questions about data sufficiency and uncertainties; lack of confidence in the 10,000 year and 1 million year dose calculations, the need for more analysis and integration to reduce uncertainty; the reliability of the data models; and the need to continue to collect more data.

Issues were also raised by members of the public regarding: performance monitoring of the repository; the duration of the process monitoring program; calibration of and incorporation of new data into models; and access to waste packages.

Issues were raised by members of the public regarding the uncertainty in the assessment of performance. These issues were related to uncertainty in data and models used in the analyses and that these uncertainties would make the results of the analyses useless over the long term.

No comments received or comments addressed elsewhere.

The DOE has developed an approach to compensate for uncertainty in data, processes, and models, and this approach results in a performance assessment that bounds the possible behavior of the repository. The approach provides the DOE with confidence that the repository could be designed, constructed, operated, and closed while protecting the health and safety of the public. The range of results from performance assessment described in the S&ER Rev. 1, the SSPA Volumes 1 and 2, "Total System Performance Assessment—Analyses for Disposal of Commercial and DOE Waste Inventories at Yucca Mountain—Input to Final Environmental Impact Statement and Site Suitability Evaluation." [BSC (Bechtel SAIC Company) 2001. "Total System Performance Assessment—Analyses for Disposal of Commercial and DOE Waste Inventories at Yucca Mountain—Input to Final Environmental Impact Statement and Site Suitability Evaluation." SL986M3 REV 00 ICN 01. Las Vegas, Nevada: Bechtel SAIC Company. ACC: MOL.20011114.0246.], and the NRC Regulations Letter Report [Williams, N.H. 2001. "Contract No. DE-AC08-01RW12101—Total System Performance Assessment Sensitivity Analyses for Final Nuclear Regulatory Commission Regulations, Rev 00 ICN 01." Letter from N.H. Williams (BSC) to S.J. Brocoum (DOE/YMSCO), December 11, 2001, RWA:cs-1204010669, with enclosure. ACC: MOL.20011213.0057.] provide assurance that the effects of the repository would be below regulatory licensing standards (SSE, Section 4.2).

It is not possible to forecast with certainty what would occur hundreds or thousands of years into the future. The National Academy of Sciences, the EPA, and the NRC also recognize the difficulty of understanding the behavior of complex systems over long time periods. In its licensing regulation 10 CFR Part 63 (66 FR 55732), the NRC acknowledges that "[P]roof that the geologic repository will conform with the objectives for postclosure performance is not to be had in the ordinary sense of the word because of the uncertainties inherent in the understanding of the evolution of the geologic setting, biosphere and engineered barrier system." What is required for licensing is reasonable expectation for such long-term performance (consistent with 40 CFR Part 197). In Subpart B, 40 CFR 197.30, the EPA establishes "reasonable expectation" as a test of compliance, with diminished "weight of evidence" with time. The EPA also recognizes the potential need for expert judgment in assigning scenario probabilities, selecting simulation models, and assigning parameter distributions. Consistent with National Academy of Sciences observations, the DOE has conducted performance assessments based on a combination of mathematical modeling, site data and information, laboratory and literature data, and natural analogues (SSPA Vol. 1, Sections 1 and 2).

The DOE confidence in the waste disposal system is based on defense-in-depth that relies upon both natural and engineered barriers. The DOE has adopted an assessment approach that explicitly considers the spatial and temporal variability and inherent uncertainties in geologic and biological components. Confidence in the outcome of performance assessment modeling is provided for through reliance upon multiple barriers that ensure overall performance, despite the failure of one or more components to perform as expected. For example, the potential of the physical properties of the geologic medium to provide natural barriers that retard radionuclide transport is included in the assessment of overall performance. The DOE believes this process results in a reasonable estimation of dose and is sufficient for comparing the relative merits of the various repository scenarios (SSPA Vol. 1, Section 2).

The DOE has conducted a comprehensive quantitative analysis of the possible future behavior of a Yucca Mountain repository (TSPA-SR; S&ER Rev. 1, Section 4; SSPA Vols. 1 and 2; "Total System Performance Assessment—Analyses for Disposal of Commercial and DOE Waste Inventories at Yucca Mountain—Input to Final Environmental Impact Statement and Site Suitability Evaluation." SL986M3 REV 00 ICN 01. Las Vegas, Nevada: Bechtel SAIC Company. ACC: MOL.20011114.0246.]; and "Total System Performance Assessment Sensitivity Analyses for Final Nuclear Regulatory Commission Regulations" [Williams, N.H. 2001. "Contract No. DE-AC08-01RW12101—Total System Performance Assessment Sensitivity Analyses for Final Nuclear Regulatory Commission Regulations, Rev 00 ICN 01." Letter from N.H. Williams (BSC) to S.J. Brocoum (DOE/YMSCO), December 11, 2001, RWA:cs-1204010669, with enclosure. ACC: MOL.20011213.0057.]). This analysis combined the results of detailed conceptual and numerical models of each of the individual and coupled processes in a single probabilistic model that can be used to assess how a repository might perform over long periods of time.

Despite the extensive scientific studies described in the S&ER Rev. 1, the DOE has always recognized that significant uncertainties would remain in any assessment of the performance of a repository over thousands of years, as discussed in the S&ER Rev. 1, Sections 1.5, 4.1, and 4.4. These uncertainties are attributable to a variety of causes, ranging from uncertainty regarding the fundamental processes that may affect radionuclide migration to uncertainty related to the preliminary design and operation of the repository. For this reason, one part of the DOE approach to dealing with uncertainty relies on multiple lines of evidence that may contribute to the understanding of the performance of the repository. Another part of the DOE approach is a commitment to continued testing, monitoring, and analysis beyond the possible recommendation of the site.

An important aspect of the TSPA-SR model is the presence of unquantified uncertainties. These are uncertainties for which a realistic distribution of parameters is not identified, but rather a very conservative bounding value or bounding range is chosen. Additional studies have been conducted to investigate effects of unquantified uncertainties and sensitivities in the model. Part of the additional studies was to add several features to the performance assessment to better quantify uncertainties and the affected processes. An additional performance assessment, the SSPA Volumes 1 and 2, was prepared discussing this additional research and describing the modifications to the TSPA-SR model (SSPA Vol. 2, Sections 3 and 4). These sections summarize areas in which the supplemental model benefited from these additional uncertainty studies.

The DOE has adopted an assessment approach that explicitly considers the spatial and temporal variability and inherent uncertainties in geologic and biological components. The bases of the approach are summarized as follows:

The site description is based on extensive underground exploratory studies and investigations of the surface environment.
The preliminary design is based on laboratory investigations and conceptual engineering studies.
Features, events, and processes that could effect the long-term safety of the repository are identified.
Evaluation of a wide range of exposure scenarios, including the normal evolution of the disposal system under the expected thermal, hydrologic, chemical, and mechanical conditions; altered conditions due to natural processes such as changes in climate; or actions such as use of water supply wells and irrigation of crops; and low-probability events such as volcanoes, earthquakes, and nuclear criticality.
Development of alternative conceptual and numerical models to represent the FEPs of a particular scenario and to simulate system performance for that scenario.
Parameter distributions to represent the possible change of the system over the long term, and use of conservative assessments that lead to over estimation of impacts when there is insufficient information for use of a probability distribution.
Performance of sensitivity analyses.
Extensive peer review and oversight of the performance assessment approach and results.

This approach combined with extensive sensitivity analyses and broad peer review and oversight ensures that the effects of the repository are bounded. The DOE has demonstrated that this process results in a reasonable estimation of dose and is sufficient for comparing the relative merits of the various repository scenarios.

Issue

Issues were raised by members of the public that monitoring of the waste should continue and that new technology should be applied to the assessment as it develops.

Response

The DOE understands that ensuring public safety at Yucca Mountain requires continued stewardship and has developed a monitoring program that accomplishes multiple goals related to the DOE's obligation to protect public health and safety and the environment. Specifically, these programs would include long-term performance monitoring of the site and maintaining the integrity and security of the repository. Performance monitoring for the repository is subdivided into three categories, which comport with licensing regulatory requirements: preclosure safety monitoring, performance confirmation program, and post-permanent closure monitoring (S&ER Rev. 1, Section 4.6.1).

The performance confirmation program is designed to provide data on engineered and natural systems important to both preclosure and postclosure repository performance. Comparison of these data to the expected response (i.e., to performance predictions) would enable the DOE to provide reasonable expectation, during the preclosure period, that the repository would protect health and safety during the postclosure period.

Performance confirmation is the set of testing, monitoring, and analysis activities initiated during site characterization and continue until repository closure. The focus of this monitoring is to gather and analyze data on conditions and systems that would affect the performance of the facility after closure and to evaluate their impacts on postclosure performance. As stated in the S&ER Rev. 1, Section 4.6.1.1, key geologic, hydrologic, geomechanical, and other physical processes or "factors" would be monitored and tested throughout construction, emplacement and operation. These data would be compared to the expected response (performance predictions) to confirm both that subsurface conditions are consistent with the assumptions used in performance analyses and that barrier systems and components are operating within the expected bounds.

Briefly, the overall approach to performance confirmation can be divided into eight steps: (1) Identify key performance confirmation processes (factors) and parameters; (2) Establish the performance confirmation baseline database and forecast the performance of the key factors and parameters; (3) Establish tolerances and bounds for the key factors and parameters; (4) Establish the completion criteria (which define when there is no longer a need for a test or monitoring activity) and guidelines for corrective actions to be used when data exceed tolerances or bounds; (5) Plan and set up the performance confirmation test and monitoring program; (6) Monitor, test, and collect data; (7) Analyze, evaluate, and assess data; and (8) Recommend corrective actions and implement changes to the performance confirmation program, as required (S&ER Rev. 1, Section 4.6.1.1).

During the licensing process, reports on performance confirmation data and comparison to the expected response would be provided periodically to the NRC and the public (S&ER Rev. 1, Section 4.6.1.1). In addition, the data from performance confirmation data would provide input for updates to total system performance assessments, when performed.

If a variance is noted in performance confirmation data (i.e., if data fall above or below the defined tolerance bounds), the DOE would take appropriate measures to address the variance as approved by the regulator, the NRC. Such measures can include (at the extreme) the complete waste retrieval from the site.

The DOE understands that it has a responsibility to retrieve spent nuclear fuel and high-level waste from the repository in the event that new information indicates a need to do so. In fact, Section 122 of the NWPA, as amended in 1987 (42 U.S.C. 10142), requires the DOE to maintain the ability to retrieve emplaced spent nuclear fuel and high-level radioactive waste during an appropriate period of operation of the facility. Nuclear Regulatory Commission licensing regulations [10 CFR Part 63, particularly Section 63.111(e)] require that the repository be designed so that any or all of the waste could be retrieved on a reasonable schedule starting at any time up to 50 years after the start of waste emplacement. In accordance with these provisions, the operational plan for the Yucca Mountain Repository provides a design and management approach that would isolate wastes from the public in the future while allowing flexibility to preserve options for modifying emplacement and retrieving the waste. This design would maintain the ability to retrieve emplaced materials for up to 300 years after completion of emplacement to protect the public health and safety or the environment or to recover resources from spent nuclear fuel (see S&ER Rev. 1, Section 3.5.4.3).

After waste emplacement, the performance confirmation program would monitor waste packages to detect any corrosion or breach, and thereby prevent any waste from being dissolved and transported. Remote inspection technology would be employed to conduct inspections of the waste packages in the emplacement drifts. In particular, remotely operated inspection gantries that can conduct remote visual, thermal, and radiological inspection of the waste packages, as well as collect and place material samples or coupons, would be used. These vehicles would be remotely operated from a control center, and would periodically inspect each emplacement drift and all accessible waste packages. They would be able to inspect the upper and lower surfaces of the waste packages, and would operate within the high-temperature and high- radiation environment of the emplacement drifts. If corrosion or breach of the package is noted, the incident would be reported to the NRC and recommendations would be made to investigate the cause(s) of the condition, with the investigation to be approved by the NRC (S&ER Rev. 1, Section 4.6.1.1).

In addition, any waste package found to be breached or otherwise in questionable condition (i.e., out-of-specification) would be transferred to the waste package remediation system at the surface. This system would be housed in a multipurpose cell inside the Waste Handling Building. The out-of-specification waste package would then be repaired. After the waste packages have been examined, repaired or, if necessary, unsealed and repackaged, the remediation system would deliver them back to the disposal container handling system to be stored underground (S&ER Rev. 1, Section 2.2.4.2.7).

The provisions applicable to a postclosure monitoring program are derived from a variety of sources, including the NRC licensing regulations and the DOE policies. All parts of this program would contribute to the DOE's overall goal of building a repository that would provide for the containment and isolation of waste. A post-permanent closure monitoring program would include the monitoring activities that would be conducted in the vicinity of the repository after the facility has been closed and sealed. A license amendment submitted for permanent closure of the repository is to provide a description of this post-permanent closure monitoring program. The details of this program would be defined during processing of a license amendment. Deferring the definition of this program to the closure period allows for the identification of appropriate technology, including technology that may not be currently available (S&ER Rev. 1, Section 4.6.1).

4.7.09 (10902)

Summary Comment

An issue has been raised by the public that the abstractions of process model chemistry phenomena does not appear to capture important uncertainties in chemistry which control the release and transport of the important radionuclides.

Response

The DOE has taken a conservative approach in modeling the behavior of commercial spent fuel and other waste forms in the repository. Test data collected to date has demonstrated the conservatism inherent in using the model for the dissolution rate for uranium-dioxide based spent nuclear fuel.

In the repository performance assessment, the uranium-dioxide fuel releases radionuclides to the engineered barrier system only after the cladding has been breached and has exposed the fuel pellets to air and water. Volatile or gaseous materials become available for release while other radionuclides become available through aqueous dissolution of the fuel. Many tests have been performed to evaluate the mechanisms and rates of degradation of the uranium dioxide fuel under various conditions. These tests have been summarized in the S&ER Rev. 1, Section 4.2.6.2.4. These tests include oxidation tests, batch immersion tests, unsaturated drip tests, electrochemical tests, and flow-through tests. A commercial spent nuclear fuel degradation model has been generated as a result of this testing. The model for the degradation rate of uranium-dioxide spent fuel was derived from dissolution tests using the logic recommended by an American Society for Testing and Materials standard [ASTM C 1174-97. 1998. "Standard Practice for Prediction of the Long-Term Behavior of Materials, Including Waste Forms, Used in Engineered Barrier Systems (EBS) for Geologic Disposal of High-Level Radioactive Waste." West Conshohocken, Pennsylvania: American Society for Testing and Materials TIC: 246015.]. These tests represented the maximum forward-dissolution-reaction rate for the material with no back reactions that would inhibit dissolution. The fact that the dissolution reaction represented the maximum rate was verified by the observations of congruent dissolution and the lack of precipitated alteration phases on the test specimens during the tests. Vapor-phase tests were also performed on samples of the commercial reactor spent fuel. These tests indicated that alteration phases could form on the spent fuel, and these phases would inhibit the overall dissolution rate (S&ER Rev. 1, Section 4.2.6.3.4).

The DOE has factored the effect of altered waste package water chemistry on waste form degradation into the waste form performance analysis.

Outputs of the in-package chemistry model, such as pH and ionic strength, are used as inputs to several other models that describe processes dependent on the chemistry of in-package water, including degradation of commercial spent nuclear fuel cladding, degradation of the high-level waste glass and DOE spent nuclear fuel waste forms, the dissolved concentration of radionuclides, and the stability of colloids. For those waste packages containing commercial spent nuclear fuel, the model forecasts a decrease in pH caused by the dissolution of the low-carbon steel of the internal basket structure followed by: (1) a subsequent increase in pH due to the dissolution of the uranium dioxide fuel; (2) the oxidation of any aluminum; and (3) the inflow of additional water. In the codisposal waste packages the moderately alkaline pH of the in-flowing water is maintained, controlled by the dissolution of the low-carbon steel until it is exhausted. After this, the pH increases to a value around ten due to the dissolution of the high-level waste glass. Many of the input parameters in the model are sampled from broad ranges or conservatively bounded to accommodate uncertainties. The in-package chemistry model is described in the S&ER Rev. 1, Sections 4.2.6.3.2 and 4.2.6.4.2.

The solubilities of a number of radionuclide-bearing solids were measured as a function of water composition and temperature (S&ER Rev. 1, Section 4.2.6.2.7). Uranyl minerals would precipitate under the oxidation conditions expected when waste package breach exposes the waste forms to incoming water. Laboratory tests and field observations on natural analogue materials suggest the most common secondary uranyl phases to form under repository conditions would be schoepite, soddyite, uranophane, and sodium boltwoodite. Additionally, because carbonate levels tend to be higher at high pH and lower at low pH, the formation of soluble complexes of uranium and plutonium carbonates tend to increase at high pH (S&ER Rev. 1, Section 4.2.6.3.2).

Neptunium solubilities are similar at pH 7 and pH 8.5 and are observed to decrease with increasing temperature; neptunium solubilities at pH 6 are one to two orders of magnitude higher than at pH 7 to 8.5. In general plutonium solubility is about three orders of magnitude lower, and is less affected by pH than that of neptunium. Increasing temperature decreases the solubility of plutonium.

Under conservative assumptions of oxidizing repository conditions, both laboratory measurements and thermodynamic analysis indicate that no insoluble salts of technetium, chlorine, or cesium form. Each form is relatively large monovalent ions that are exceedingly soluble. Therefore, the solubility of each is set in the TSPA to 1.0 moles per liter, which lets their inventory in the waste form determine their release rate. Carbon and strontium both form less soluble metal carbonate minerals. Rather than perform a complex prediction of carbon and strontium solubility, their solubility was conservatively set at 1.0 moles per liter.

The DOE has demonstrated the conservatism inherent in using the models for the dissolution rate for the commercial uranium dioxide-based spent fuel and the high-level waste glass waste form. The DOE spent fuel is assumed to dissolve instantaneously at the time of waste package breach. The release of radionuclides from a failed waste package, for all waste forms is controlled by solubility rather than dissolution rate.

4.7.10 Postclosure Safety—Other

4.7.10 (15342)

An issue has been raised by a member of the public that the quantitative estimates in the Yucca Mountain Preliminary Site Suitability Evaluation (PSSE) Report are scientifically implausible.

Response

The DOE believes that the quantitative estimates provided in the PSSE are appropriate and certain claims to the contrary by members of the public appear to be based on a report, which is not applicable to the situation that would exist at Yucca Mountain.

4.7.11 Engineered Barriers and Near Field Environment Performance

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An issue has been raised by the public that the DOE lacks sufficient understanding of the potential effects of groundwater, groundwater minerals, and micro-organisms on waste packages that would be placed within a repository at Yucca Mountain.

The DOE has studied the Yucca Mountain seepage water, its chemistry, and the microbes associated with it. The results of the study have been used in the waste package performance assessment.

In a desert environment, the total amount of available water is small. A repository at Yucca Mountain would be designed to complement the hydrologic environment by diverting the small flow of water that would occur away from the waste packages. Multiple natural and engineered barriers are expected to limit contact between water and waste forms, and retard radionuclide migration (S&ER Rev. 1, Section 4.2.1.1). The chemistry of waters in the host rock would act as a boundary condition on the in-drift chemical environment. During the thermal period, water vapor would move away from the heated drifts, while liquid water would percolate downward and replace the water that evaporates, in a thermal refluxing process. The percolation water would contain dissolved chemical species, such as sodium, calcium, sulfate, chloride, carbonate, and silica. When evaporation occurs, the chemical species would be left behind in the rock as precipitated minerals and salts (S&ER Rev. 1, Section 4.2.3.1.1). The analytical and experimental studies conducted to date have examined these heat effects in detail, but with emphasis on the more severe environmental conditions associated with the higher-temperature operating mode described in Section 2.1.2 of the S&ER Rev. 1 (S&ER Rev. 1, Section 4.2.2).

The starting waters present at Yucca Mountain are classified into two types: (1) bicarbonate-type water, and (2) chloride-sulfate-type water. Chemical modeling and laboratory testing of these water compositions have shown that the bicarbonate-type water evolves by evaporative concentration to a high-pH brine, whereas the chloride-sulfate-type water evolves to a brine with a nearly neutral pH. Several test solutions have been developed for laboratory corrosion testing of titanium, Alloy 22, and other materials. These solutions were selected to represent a range of dilute and concentrated conditions, pH, and temperature that could result from evaporative concentration in the repository. The chemistry of the waters that contact the drip shield and waste package surfaces would vary in the repository, and the test solutions described above represent a range of possible conditions (S&ER Rev. 1, Section 4.2.3.3.4).

The exposure environments have been established, and the most important and relevant degradation processes have been identified, which in turn have been used for selecting engineered materials for the drip shield and the waste package. Titanium alloy was selected for construction of the drip shield because of its high resistance to corrosion. Alloy 22 (UNS N06022) was selected for construction of the waste package outer barrier. This material is one of the most corrosion-resistant nickel alloys for the expected range of repository environments (S&ER Rev. 1, Section 4.2.4.1). Even at the highest corrosion rate measured, the maximum penetration in the Alloy 22 outer barrier would be less than 0.001 meter (0.04 inches) over a 10,000-year postclosure period. The largest measured corrosion rate of the titanium alloy would not lead to failure of the drip shield during the first 10,000 year of its lifetime (S&ER Rev. 1, Section 4.2.4.3.3).

It has been observed that corrosion rates of Alloy 22 could be enhanced by microbially influenced corrosion by a factor of about 2. The argumentation of corrosion rates due to microbially influenced corrosion is accounted for in the model analysis of the corrosion rate of Alloy 22, as shown above (S&ER Rev. 1, Section 4.2.4.3.3). Although the microbial effects are important uncertainties in radionuclide transport, the in-drift microbial communities model has addressed enough of the uncertainties that they would not significantly change the results of the total system performance assessment for site recommendation. As an example, the new microbial model would not affect the conclusions of the total system performance assessment for site recommendation because sorption was conservatively excluded from the calculations (SSPA Vol. 1, Section 6.3.3.8.3).

4.7.12 Total System Performance Assessment

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An issue has been raised by the public that as the natural barriers provide little in the way of containment of radionuclides and that the containment is provided primarily by the engineered barriers, the DOE cannot guarantee containment for thousands of years and the resulting releases will contaminate groundwater in the Amargosa valley.

In the supplemental analyses, the releases in the first 10,000 years are extremely small (peak mean dose rates are approximately 10,000 times less than the regulatory standards) and are due to the very unlikely event of a failure of a few (3 or less) waste packages prior to 10,000 years due to assumed, undetected, improper heat treatment of the final closure weld. [BSC (Bechtel SAIC Company) 2001. "Total System Performance Assessment—Analyses for Disposal of Commercial and DOE Waste Inventories at Yucca Mountain—Input to Final Environmental Impact Statement and Site Suitability Evaluation." SL986M3 REV 00 ICN 01. Las Vegas, Nevada: Bechtel SAIC Company. ACC: MOL.20011114.0246. Section 5.2.4.2.]. These low doses are due to the protection provided by both the engineered and natural barriers. It is the environment of the natural barrier that provides conditions that allow the development of long-lived engineered barriers. The arrival of small doses at the receptor occurs at about 1,000 to 2,000 years using the supplemental model and beyond 10,000 years using the TSPA-SR model (SSPA Vol. 2, Section 4.1).

There are two natural barriers above the repository that contribute to the long-term performance of the repository system: (1) the surficial soils and topography, which limit the amount of water that infiltrates into the rock; and (2) the unsaturated rocks, which limit the amount of water that seeps into the repository. A description of barrier-importance analyses for each of these barriers can be found in S&ER Rev. 1, Section 4.5.3.

The net surficial infiltration flux into Yucca Mountain is affected by future climate states and surficial processes. The TSPA-SR analyses considered a range of infiltration rates. In partially degrading the surficial barrier, the assumption applied was that the maximum possible infiltration rate corresponding to the maximum anticipated climate state (the glacial-transition climate) prevailed throughout the duration of the 100,000-year simulated time period. In order to evaluate the consequences of a more positively performing surficial barrier, a separate scenario was analyzed, extrapolating the present-day climate's minimum infiltration rate throughout the entire duration of the simulated time period. The results of partial degradations of the surficial barrier show that the surficial infiltration rate over the range of likely conditions does not significantly affect the long-term performance of the repository system (S&ER Rev. 1, Section 4.5.3).

The net seepage into the repository drifts is affected by the percolation flux through the host rock and the rock properties around the emplacement drifts. In order to investigate the significance of seepage to system performance, a scenario was constructed that fixed (1) the infiltration rate at the maximum value of the three distributions, (2) the flow-focusing factor at its maximum to allow a greater fraction of the total percolation to come into contact with the repository drifts, (3) the seepage fraction at its maximum value, and (4) the seepage flow rate at its maximum value. All of these changes tend to maximize the fraction of the total percolation flux that seeps into the repository emplacement drifts. The above values were also fixed at their minimum values of the distribution (S&ER Rev. 1, Section 4.5.3) to evaluate the consequences of a more positively performing seepage barrier.

The results of this partial degradation of the seepage barrier show that, for the first 40,000 years, the degradation (or improvement) of this barrier has little net consequence (S&ER Rev. 1, Section 4.5.3). This is because the waste packages are intact for most of this period, and even when waste packages are breached, the drip shield remains intact for a portion of this time (S&ER Rev. 1, Section 4.5.3). Even if both these barriers are breached, the dominant radionuclide contributing to dose is the mobile technetium-99, which can diffuse through surface water films relatively rapidly (even in the absence of significant advective flux) because of its extremely high solubility. Because the solubility-limited radionuclides, like neptunium-237, are the radionuclides most affected by seepage; the significance of seepage to overall performance does not become pronounced until this radionuclide becomes the dominant dose contributor, at about 40,000 years (S&ER Rev. 1, Section 4.5.3).

There are two additional natural barriers below the repository block: the unsaturated zone rock units and the saturated zone rock units. Both affect the transport of dissolved and colloidal radionuclides from the engineered barriers to the point where such radionuclides could be extracted with the groundwater (S&ER Rev. 1, Section 4.5.3).

The significance of the unsaturated zone transport barrier was evaluated by fixing the transport parameters within the transport model to minimize retention in the unsaturated zone. This was accomplished by using the 5th percentile on sorption parameters for aqueous and colloid-borne radionuclides, the 95th percentiles on fracture apertures, and the 5th percentile on the matrix diffusion coefficient. In order to investigate the more optimistic end of the range of uncertainty, a similar analysis was conducted with the distributions at the opposite extremes. The results of degrading the unsaturated zone transport barrier decreases the transport time of neptunium-237 through the geologic media and, therefore, increases the dose rate at the receptor for a period from 20,000 to 40,000 years (S&ER Rev. 1, Section 4.5.3).

The significance of the saturated zone transport barrier is affected by several flow and transport parameters. In addition to the transport parameters described above for unsaturated zone transport, the saturated zone flow fields are also uncertain, as are the possible flow path lengths through the alluvium and the alluvium transport characteristics. In order to investigate the significance of the saturated zone transport barrier, all realizations used the 95th percentile breakthrough curve (i.e., that distribution of mass flux that for a given release rate to the water table causes the 95th percentile mass flux at the receptor). The results indicate that the saturated zone barrier has minimal significance when it is degraded, since the mean dose response correlates closely to the more conservative portion of the saturated zone transport characteristics. However, at the more optimistic end of the barrier performance, the saturated zone is found to significantly delay the transport of neptunium-237, and would therefore lower the expected dose to the receptor during the compliance period (S&ER Rev. 1, Section 4.5.3).

Results of the supplemental model show that small doses to the receptor could begin as early as about 1,000 to 2,000 years after repository closure. These doses are from premature failure of a few (3 or less) waste packages prior to 10,000 years due to assumed, undetected, improper heat treatment of the final closure weld. [Ibid., Section 5.2.4.2.] The doses continue to remain small until the drip shields and more waste packages begin to fail at about 80,000 years (SSE, Section 3.1.2).

The effects of disruptive events (seismic events and igneous activity) have also been considered. The effects of seismic events are factored into the results of the nominal case discussed above. The dose from volcanism (provided in SSE, Section 4.2) is largely due to the airborne pathway rather than the groundwater pathway (S&ER Rev. 1, Section 4.4.3.3).

4.7.12 (23)

Summary Comment

An issue was raised by the public that the understanding of colloidal transport is inadequate and that in the absence of scientific information on colloidal transport the site recommendation is premature.

Response

The DOE has used existing information as a basis for development of a colloidal transport model. This information is sufficient when combined with conservative assumptions to demonstrate that colloidal transport is not the major contributor to the dose to the receptor. Analyses of dose during the 10,000-year postclosure period show that dose to the receptor is likely to be below the NRC radiation protection standards used for licensing (SSE, Section 4.2). The DOE has presented a vast amount of information and analyses in the S&ER Rev. 1, the SSPA Volumes 1 and 2, "Total System Performance Assessment—Analyses for Disposal of Commercial and DOE Waste Inventories at Yucca Mountain—Input to the Final Environmental Impact Statement and Site Suitability Evaluation." [BSC (Bechtel SAIC Company) 2001. "Total System Performance Assessment—Analyses for Disposal of Commercial and DOE Waste Inventories at Yucca Mountain—Input to the Final Environmental Impact Statement and Site Suitability Evaluation." SL986M3 REV 00 ICN 01. Las Vegas, Nevada: Bechtel SAIC Company. ACC: MOL.20011114.0246.], and the NRC Regulations Letter Report [Williams, N.H. 2001. "Contract No. DE-AC08-01RW12101. "Total System Performance Assessment—Sensitivity Analyses for Final Nuclear Regulatory Commission Regulations, Rev 00 ICN 01." Letter from N.H. Williams (BSC) to S.J. Brocoum (DOE/YMSCO), December 11, 2001, RWA:cs-1204010669, with enclosure. ACC: MOL.20011213.0057.] that are sufficient to support any site recommendation.

Existing information on colloidal transport of radionuclides from a Yucca Mountain repository is sufficient to serve as the basis for performance assessment calculations due to conservative assumptions built into the colloidal transport model (SSPA Vol. 2, Section 3.2.7.4). The results of these calculations show that colloidal transport would contribute a small fraction of the annual dose to groundwater users in the future (see S&ER Rev. 1, Section 4.4.2.2; SSPA Vol. 2, Section 3.2.7.4). The models used for colloidal transport were developed based on laboratory testing, field evidence, and natural analogues (SSPA Vol. 2, Section 3.2.10.2.5). The use of existing information from field sites similar to or near Yucca Mountain represent analogues of colloidal transport.

For radionuclide-bearing colloids to affect repository performance, the colloidal particles must be stable for the duration of transport, and must transport greater concentrations of radionuclides than are transported as dissolved constituents. Transport times out of a failed waste package can range from days to years after the package is first breached, and transport times to the receptor can be up to hundreds of thousands of years. Some relatively unstable colloids generated at the waste form may persist long enough to be transported out of the waste package but not long enough to be transported a significant distance away from the repository. More stable colloids, however, may remain suspended for years and travel a much greater distance (S&ER Rev. 1, Section 4.2.7.2.3). Some colloids present along transport pathways, such as those consisting of natural silica, have relatively low affinity for radionuclides and do not result in significant radionuclide concentrations. Other types of colloids, such as waste-form colloids or those consisting of hydrous iron-oxide minerals, are more important and are included in the models for colloidal transport.

It is plausible that the plutonium from weapons tests was transported a short distance at the Nevada Test Site, irreversibly attached to colloids. This underscores the significance of the irreversibility of radionuclide attachment to smectite (clay) colloids observed in Argonne National Laboratory glass waste form corrosion experiments (S&ER Rev. 1, Section 4.2.6.3.11).

4.7.12 (25)

Summary Comment

An issue was raised by members of the public that the PSSE shows that there would be no releases, from the waste package for the 10,000-year postclosure period. To make such a claim based on a few years of simulations casts doubt on any potential for scientific credibility.

Response

The TSPA-SR model indicated that there would be zero release during the 10,000-year postclosure period. Since that time the DOE has completed the S&ER Rev. 1 and the SSPA Volumes 1 and 2. The results of the supplemental model (SSPA Vol. 2, Section 4.1) show small doses to the receptor during the compliance period from early failures of a few (3 or less) waste packages prior to 10,000 years due to assumed, undetected, improper heat treatment of the final closure weld. [BSC (Bechtel SAIC Company) 2001. "Total System Performance Assessment—Analyses for Disposal of Commercial and DOE Waste Inventories at Yucca Mountain—Input to Final Environmental Impact Statement and Site Suitability Evaluation." SL986M3 REV 00 ICN 01. Las Vegas, Nevada: Bechtel SAIC Company. ACC: MOL.20011114.0246. Section 5.2.4.2.].

The waste package, in combination with the other engineered barriers and the natural barriers, forms a barrier system that would limit the release of radionuclides to ensure public health and safety. Both the natural barriers and engineered barriers would work together to contribute to the overall performance of a repository. Natural barriers limit the amount of water that could contact the waste and provide a geochemical environment that prevents mobilization and transport of most species of radionuclides. Equally important, there would be little percolation of water down through the rock layers to the repository block even during cooler, wetter periods. Engineered barriers would also limit the amount of water that could contact the waste; moreover, the waste package would contain many species of radionuclides until they decay away. For example, strontium-90 and cesium-137 would have decayed away after the first 1,000 years. Far in the future, should the waste package breach and water dissolve the cladding and waste form, the movement of the long-lived radionuclides would be retarded by the physical and chemical properties of the geologic setting. Additionally, of those few species that are mobile, natural conditions of the unsaturated rock, as well as zeolites in the rock layers underlying the repository, would retard the migration of many species of radionuclides. Many species would sorb onto the zeolites and thus provide additional delay to allow additional time for these species of radionuclides to decay away. Thus, the natural and engineered barriers working together would prevent the vast majority of radionuclide species from reaching the accessible environment.

The repository performance assessment does not begin with the assumption that the repository would allow releases. Rather, the assessment assigns probability-of-occurrence values (referred to as probability distributions) to various parameter and process features. These values have consideration of the uncertainty associated with them built into the parameter distribution. When multiple simulations of repository performance (realizations) are computed, the results indicate which of the various outcomes are more likely to occur. However, in addition to the most likely outcome, the distributions also show extreme cases referred to as the 5th- and 95th-percentile values, which provide a measure of the uncertainty associated with a particular outcome. In response to the observation that the analysis appears to assume that the repository would allow releases, it should be noted that, although not likely, there were a number of realizations that produced no releases for extremely long periods.

The goal of geologic disposal is to concentrate and isolate high-level radioactive wastes in a relatively small area for a very long time. The DOE intends to achieve isolation of the wastes in the repository by using a system of engineered barriers and natural barriers, that is, the geologic setting of Yucca Mountain. However, it is always possible to conceive of circumstances (both man-made and natural) that, given the inherent uncertainties associated with long-term projections, could result in the release of radioactive materials to the accessible environment. In other words, the eventual release of some material is inevitable because all systems would degrade given sufficient time.

The DOE acknowledges that it cannot build a containment system that can provide perfect containment forever. The SSPA Volume 2, Section 4, provides the realistic estimate of the impacts that could occur when the containment system inevitably degrades. The results confirm that the repository would likely result in greater release of radioactive contamination to the environment beginning sometime after the 10,000-year postclosure period. The SSE, Section 4.2, shows that the releases within the 10,000-year postclosure period would likely be below the NRC's radiation protection standards for licensing would not exceed the EPA standards These standards are specifically enacted to ensure the safety of future generations.

In addition to the 10,000-year postclosure period, the DOE has evaluated potential impacts for the period of geologic stability at the repository (i.e., 1 million years). This evaluation was performed consistent with 40 CFR Part 197 to gain insight into the very long-term performance of the repository and thus provide information for the decision-makers in making site recommendation and potential design and licensing decisions. These results show a mean peak dose rate that is much lower than current background levels (see FEIS, Chapter 5, and SSE, Section 4.2).

The EPA, in promulgating the Yucca Mountain environmental protection standards (40 CFR Part 197), recognized that with the current state of technology it is impossible to provide certainty/reasonable expectation that there would be no releases over 10,000 years or longer. Therefore, standards have been established by the EPA that provide comparable protections to those of other activities related to radioactive and nonradioactive wastes. These standards do not require complete isolation of the wastes over the compliance period (i.e., 10,000 years) or the period of geologic stability (1 million years). The goal of a performance assessment for Yucca Mountain to support any site recommendation decision is to evaluate how the repository would perform relative to the standards of the EPA and as implemented by the NRC.

In the event that the site is approved the DOE would continue with the detailed design and licensing efforts necessary for construction, operation and maintenance, and eventual closure of the repository utilizing the best science and construction techniques available.

4.7.12 (26)

Summary Comment

An issue was raised by the public related to the transport of radionuclides and the sorption of radionuclides on mineral surfaces along the transport pathway.

Response

The DOE has used conservative values for sorption coefficients of radionuclides that contribute significantly to total dose from the repository. The effects of nonradioactive metals from corrosion of engineered barriers would be small for the significant contributors to dose (e.g., neptunium-237, technetium-99, and iodine-129). Sensitivity analyses of variation in transport path length through the alluvium show little effect on dose history.

There are three radionuclides that contribute significantly to the peak dose from the repository. These are neptunium-237, technetium-99, and iodine-129 (SSPA Vol. 2, Section 4.1). Of these radionuclides, technetium-99 and iodine-129 are not sorbed and travel with the groundwater. Other nonradioactive metals or the alluvium would not affect the transport of these radionuclides. For neptunium-237 the sorption coefficient is considered to range from 0 to 1.0 in the nonzeolitic tuff and from 0 to 3 in the zeolitic tuff (S&ER Rev. 1, Section 4.2.8). Because the values of sorption coefficient for neptunium are small reducing it to zero would have little influence on total dose. In fact the peak dose would remain the same, but would occur somewhat earlier.

A sensitivity analysis was conducted to investigate the effects of the path length of alluvium in the saturated-zone transport model. There is uncertainty in the model that encompasses the area where flow paths from the repository might enter alluvial deposits in southern Jackass Flats. The alluvium is approximately 5 kilometers wide by 8 kilometers long in the north-south direction. The path length of the alluvium, for this sensitivity study, was set to zero in the model; but there still was approximately 1 kilometer of flow path length in alluvium prior to reaching the dose receptor. This sensitivity study is meant to address the impact of the alluvium on the results of the total-system model. The length of the flow path in the alluvium could affect the performance of the repository, because of the slower transport of radionuclides in this unit relative to the volcanic units. The results of mean annual dose, calculated with minimal alluvium, show only a slight difference (generally less than 10 percent difference) in the dose result (SSPA Vol. 2, Section 3.2.10.2.4).

Based on field evidence of colloidal transport, the presence of natural colloids in groundwater at the Nevada Test Site, and the laboratory formation of colloids in waste form corrosion studies, the DOE has included colloidal transport of radionuclides in its performance assessment models. Even though colloidal transport makes a contribution to the annual dose to the receptor, the results of the performance assessment models, combining all modes of radionuclide transport, are within regulatory limits (SSE, Section 4.2).

There is field evidence that suggests that colloid-facilitated transport of radionuclides has occurred at a low-level waste site where plutonium and americium were detected more than 30 meters (100 feet) in unsaturated tuff after approximately 30 years of transport time. At the Nevada test site, the isotopic ratio of plutonium-240 to plutonium-239 suggests that plutonium may have been transported as colloids for as much as 1.3 kilometers (0.8 miles) over a 30-year period. At Los Alamos National Laboratory, detectable amounts of plutonium and americium have been observed in monitoring wells up to about 3.4 kilometers (2.1 miles) downgradient from the discharge point of treated liquid waste. At these locations (above), the radionuclides involved are strongly sorbed and the transport of the radionuclides involved as dissolved species over these distances (above) would not be expected. This strongly indicates transport by colloids. Additional details concerning recent evidence of colloidal transport of radionuclides are found in Sections 4.2.6.3.11 and 4.2.7.2.3 of the S&ER Rev. 1.

4.7.12 (33)

Summary Comment

Issues were raised by members of the public that the waste packages would fail and release gaseous and dissolved radionuclides, which would contaminate the groundwater and environment.

Response

The waste package, in combination with the other engineered barriers and the natural barriers, forms a barrier system that would limit the release of gaseous or dissolved radionuclides to the groundwater and ensure public health and safety. In more recent analyses, it is assumed that a few (3 or less) waste packages could fail prior to 10,000 years due to assumed, undetected, improper heat treatment of the final closure weld [BSC (Bechtel SAIC Company) 2001. "Total System Performance Assessment—Analyses for Disposal of Commercial and DOE Waste Inventories at Yucca Mountain—Input to Final Environmental Impact Statement and Site Suitability Evaluation." SL986M3 REV 00 ICN 01. Las Vegas, Nevada: Bechtel SAIC Company. ACC: MOL.20011114.0246. Section 5.2.4.2.]. When failure of a waste package occurs the gaseous components of the waste are released. The DOE has updated Section 5.5 of the FEIS to reflect impacts of atmospheric releases resulting from these waste package failures.

The consequences of gas-phase radionuclides are a function of their inventory and release rate at the time of waste package failure (most notably carbon-14). The reported impacts to the local population from such releases are exceedingly low. There is a negligible risk according to a National Research Council panel that reported its own investigation of this issue [National Research Council 1995. "Technical Bases for Yucca Mountain Standards." Washington, D.C.: National Academy Press. TIC: 217588. Pages 38-39.]. The National Research Council advised the EPA not to require controlling such a tiny potential release. The EPA also calculated the risk, and agreed with the National Academy that this risk was too low to regulate. For this reason the analyses of gas-phase risks are not included in the TSPA-SR, the S&ER Rev. 1, the SSPA Volumes 1 and 2, or the SSE.

There could be releases of carbon-14 to the air from a repository after closure. In fact, all of the very small carbon-14 releases, estimated in Section 5.5 of the FEIS were forecasted to occur after repository closure. In addition to these analyses, Chapters 5 and 8 of the FEIS include analyses of atmospheric releases.

Inherent uncertainties would exist in any projections of the future performance of a deep geologic repository. These uncertainties must be addressed in a way that is clear and understandable, to ensure technical credibility and sound decision-making. The uncertainties are quantified and addressed in the TSPA. Examples include potential changes in climate, seismicity, and other processes over the compliance period (10,000 years); variability and uncertainty of the properties of geologic media over large spatial scales; and incomplete knowledge about the long-term material behavior of engineered components (e.g., corrosion of metals over many thousands of years) (S&ER Rev. 1, Section 4.1.1.2).

The EPA, in promulgating the Yucca Mountain environmental protection standards (40 CFR Part 197), recognized that with the current state of technology it is impossible to provide a reasonable expectation that there would be "zero" releases over 10,000 years or longer. Therefore, standards have been established by the EPA that provide comparable protections to those of other activities related to radioactive and nonradioactive wastes. These standards do not require complete isolation of the wastes over the compliance period (i.e., 10,000 years) or the period of geologic stability (1 million years). The goal of a performance assessment for Yucca Mountain supporting a site recommendation is to evaluate whether the repository would be likely to meet the NRC's radiation protection standards applicable at licensing.

In addition to the 10,000-year postclosure period, the DOE has evaluated potential impacts for the period of geologic stability at the repository (i.e., 1 million years). This evaluation was performed in accordance with 40 CFR Part 197 to gain insight into the very long-term performance of the repository and thus provide information for the decision-makers in making the site recommendation and potential design and licensing decisions. These results show a mean peak dose rate that is much lower than current background levels (see FEIS, Chapter 5, and the SSE, Section 4.2).

4.7.12 (34)

Summary Comment

An issue was raised by the public regarding the performance assessment model including both questioning the models reliability and indicating that the system was adequate to protect public health and safety.

Response

Analysis of the future performance of a repository at Yucca Mountain is fundamental to the DOE understanding of the Yucca Mountain site. Therefore, the first element of developing a safety case is an analysis of how the repository could behave in the future. The methods used and the results of the TSPA for Yucca Mountain are described in Sections 4.3 and 4.4 of the TSPA-SR (S&ER Rev. 1, Section 4.1.1).

Performance assessment is a method or tool defined and specified by the EPA and the NRC for the evaluation of a Yucca Mountain repository. The objective of the TSPA-SR for Yucca Mountain and the supplemental analyses (SSPA Vols. 1 and 2) is to provide a basis for evaluating whether the safety of the general public would be protected. In the supplemental analyses the releases in the first 10,000 years are extremely small (mean doses are approximately 10,000 times less than the licensing standard) and are due to the very unlikely event of a few (0-3) packages failing due to improper heat treatment (SSE, Section 4.2). This comparison shows that the dose to the receptor within the 10,000-year postclosure period is well below the NRC radiation protection standards used in licensing. The DOE also used the performance assessment for broader purposes during site characterization. For instance, it was used as a tool to evaluate the effects of uncertainty on total system performance and to identify areas where further work is needed (S&ER Rev. 1, Section 4.1.1). Additional analyses of uncertainty are presented in Volumes 1 and 2 of the SSPA.

The TSPA is a systematic analysis that synthesizes information (e.g., data, analyses, and expert judgment) about the site and region with the design attributes of the engineered barriers of the repository system. As defined by licensing regulations at 10 CFR Part 63 (66 FR 55732), performance assessment is a probabilistic analysis that (1) identifies the features, events and processes that might affect the performance of the geologic repository; (2) examines the effects of such FEPs on the performance of the geologic repository; and (3) estimates the expected annual dose to the receptor as a result of the releases from the geologic repository (S&ER Rev. 1, Section 4.1.1.1).

Features are the physical components of the total repository system, including the natural system (e.g., the geologic setting) and the engineered system (e.g., the waste package). Processes typically act more or less continuously on the features (e.g., moisture flow through the geologic medium and corrosion of the waste package). Events also act on the features, but at discrete times. Examples include seismic and volcanic events (S&ER Rev. 1, Section 4.1.1.1). The FEPs process is designed to consider all FEPs that could potentially affect the repository, to screen out those that do not, and to identify those that are expected to effect the repository and are considered in the performance assessment.

The TSPA examines the performance of a repository at Yucca Mountain for a broad range of potential subsurface and surface conditions (e.g., hydrologic, geologic, climatic, and biosphere), and evaluates potential radiation doses to future generations. The radiation protection standards that apply, during licensing, to the postclosure performance of a Yucca Mountain repository are found in 10 CFR Part 63 (66 FR 55732). Specific technical requirements for a comprehensive TSPA are prescribed in the NRC regulation. The regulations specify two separate performance assessments: (1) a TSPA of the geologic repository that considers the evolution of the geologic setting (e.g., repository heating, climate change, seismicity, and igneous activity), including potentially disruptive conditions, but without human intrusion; and (2) a TSPA of the geologic repository that considers limited human intrusion, but excludes unlikely natural processes and events (S&ER Rev. 1, Section 4.1.1.1).

To present the assessment results clearly, the first case (without human intrusion) is further subdivided into (1) a nominal scenario composed of the likely FEPs representing the most plausible evolution of the repository system, without the occurrence of unlikely disruptive FEPs; and (2) disruptive scenarios that include unlikely features, events, and processes that could diminish the waste isolation capability of the repository system (e.g., igneous activity) (S&ER Rev. 1, Section 4.1.1.1). Features and processes are incorporated into the models. For example, faults are incorporated into the groundwater movement and transport models while seismicity is incorporated into the nominal case performance. Here a seismic event would damage spent fuel cladding which leads to more radionuclides being available for release from a failed waste package. Thus the "flaws" (features, events, and processes) at the site are incorporated into the analyses through the FEPs that are included in the nominal case and the disruptive case models.

The result of a TSPA analysis is a distribution (range) of possible outcomes of future performance. The mean of this distribution is the regulatory criterion. The 95th percentile is considered to be the upper bound of the dose to the receptor. Because of the probabilistic nature of the method, the TSPA results can capture and display much of the uncertainty associated with complex models and unknown future conditions. For this reason, however, the results should be regarded as indicative of future performance, not predictive (S&ER Rev. 1, Section 4.1.1.1).

The TSPA methodology for Yucca Mountain is very similar to that used in the compliance certification application for the Waste Isolation Pilot Plant, a bedded salt repository in southern New Mexico. The Waste Isolation Pilot Plant was certified by the EPA in 1998, and began receiving and disposing of transuranic nuclear waste in March 1999. The TSPA approach is also similar to approaches adopted by other countries currently conducting detailed siting studies for geologic repositories. In addition, the computer techniques used in performance assessments to address uncertainties are rooted in the probabilistic risk assessment method applied in the safety assessments for commercial nuclear reactors (S&ER Rev. 1, Section 4.1.1.1).

The TSPA methodology (i.e., approach and models) described in the S&ER Rev. 1 and in the SSPA Volumes 1 and 2 is the culmination of research and development conducted over more than a decade. These models rely on data and information developed during site characterization.

4.7.12 (35)

Summary Comment

An issue was raised by the public both questioning the TSPA results including such factors as seismicity, corrosion rate of the waste packages, and predictability of the models and stating the scientific evidence meets or exceeds all requirements.

Response

The potential for seismic events has been factored into the TSPA nominal case. At licensing, the DOE must show to the satisfaction of the NRC that the site meets the NRC's individual and groundwater protection requirements for licensing at 10 CFR Part 63 (66 FR 55732) which must consider likely features, events, and processes, including seismic events. The groundwater transport pathway has been evaluated in accordance with the licensing criteria specified in 10 CFR Part 63, including seismic events. The estimated dose during the 10,000-year postclosure period is a small fraction of the environmental radiation protection standards set by the NRC for licensing.

The difference in the dose at a particular time between the results of the TSPA-SR model and the supplemental model are largely due to waste package failure rate (SSE, Section 3.1). The difference in the timing of the peak dose from the two models is largely caused by the time dependent corrosion rate for the Alloy 22 in the supplemental model and the likelihood of stress corrosion cracking of the waste package would be less than forecasted by the TSPA-SR model. This causes a slower rate of waste package failure in the supplemental model resulting in the peak dose to move out in time and be somewhat lower. The comparison at 100,000 years would be between a considerable number of failed packages for the TSPA-SR model and a few early packages for the supplemental model. Thus, for a comparison of the two results at a specific time there is a significant difference in the number of failed packages and comparison of peak dose is a better indicator of model differences. Seismic events are represented in the nominal case for the TSPA-SR model and for the supplemental model.

During the 10,000-year postclosure period, the TSPA-SR model produces results that show zero release while the supplemental model results show a small dose to the receptor (SSE, Section 4.2). The DOE views the results of the supplemental model to be more realistic than those of the TSPA-SR model. The small dose during the 10,000-year postclosure period from the supplemental model (and the revised supplemental model) is caused by an assumed failure of a few waste packages (3 or less) due to assumed, undetected improper heat treatment of the waste package closure weld. [BSC (Bechtel SAIC Company) 2001. "Total System Performance Assessment—Analyses for Disposal of Commercial and DOE Waste Inventories at Yucca Mountain—Input to Final Environmental Impact Statement and Site Suitability Evaluation." SL986M3 REV 00 ICN 01. Las Vegas, Nevada: Bechtel SAIC Company. ACC: MOL.20011114.0246. Section 5.2.4.2.].

The DOE has evaluated the uncertainty of these analyses both in the S&ER Rev. 1, Section 4.4.1.2, and in the SSPA Volume 1, Section 2.1, and the SSPA Volume 2, Section 2.2). The extensive set of analyses contained in the S&ER Rev. 1 and the SSPA Volumes 1 and 2 give the DOE confidence that the repository would not unduly burden future generations.

4.7.12 (3054)

Summary Comment

An issue was raised by the public that there is no basis for assuming the proposed system will work flawlessly for the next ten thousand years under real-world conditions.

Response

The performance of a repository at Yucca Mountain is evaluated against regulatory requirements, not "zero release." Consistent with 10 CFR Part 63 the DOE uses a performance assessment to demonstrate that there is a reasonable expectation that for 10,000 years following disposal, the RMEI would receive no more than an annual dose of 15 millirem from releases from the undisturbed Yucca Mountain disposal system (S&ER, Section 1.2.2.2, pp. 1-7 to 1-8).

Consistent with NRC licensing requirements at 10 CFR Part 63 the DOE uses the presence of multiple barriers to show, by conducting performance assessment, that a repository at Yucca Mountain would meet the NRC's radiation protection standards for licensing for a 10,000-year postclosure period (S&ER, Section 1.2.2.3, pages 1-8).

4.7.12 (12812)

Summary Comment

An issue has been raised by the public that the DOE estimates of peak doses from a repository at Yucca Mountain are much smaller that those estimated by the National Academy of Sciences in 1983.

Response

There are significant differences between the National Academy of Sciences analyses of 1983 and the current DOE assessment of performance of a Yucca Mountain repository. In the 1983 analyses, the National Academy of Sciences did not include any engineered barriers to contain the waste and the repository analyzed by the National Academy of Sciences was located in the saturated zone. The current understanding of the unsaturated zone hydrology and the inclusion of the engineered barriers in the analyses are largely responsible for the differences in results.

4.8 NATIONAL AND NEVADA TRANSPORTATION

4.8.1 General Transportation

4.8.1 (102)

Several comments stated that spent nuclear fuel and high-level waste could be transported safely to Yucca Mountain with negligible radiological impacts to public health and safety and the environment. Cited in the comments were such things as the safe record of nuclear materials transport over 50 years; stringent shipping regulations; testing and certification of casks; cask construction; driver training; shipment tracking; and communications.

The results of the analysis presented in Chapter 6 and Appendix J of the FEIS are consistent with the observations of these comments.

The DOE believes that adequate preventative, protective, and mitigative measures would be in place to ensure that the shipments pose no undue risks to the public, workers, and environment.

4.8.1 (103)

Summary Comment

Members of the public have expressed concern and opposition to the transport of nuclear waste to Yucca Mountain. Opposition has been expressed to the transportation of nuclear waste nationally and in Nevada, by either rail, heavy-haul truck, or legal-weight truck.

Response

In 1987, Congress amended the NWPA and directed the DOE to focus its site characterization activities solely on Yucca Mountain. If Yucca Mountain were designated as the nation's first geologic repository for spent nuclear fuel and high-level radioactive waste, these materials would have to be transported to Yucca Mountain from each of the 72 commercial and 5 DOE sites throughout the country.

Based on the results of the impact analyses presented in Chapter 6 and Appendix J of the FEIS, as well as the results published in numerous other studies and environmental impact analyses cited in Chapter 6 and Appendix J, the DOE is confident that spent nuclear fuel and high-level radioactive waste can be safely transported to Yucca Mountain. The DOE also concludes, as the FEIS reports, that the potential impacts of incident free transport would be so low for individuals who live and work along the routes that these individual impacts would not be discernible even if the corresponding doses from such transportation could be measured. The analysis presented in the FEIS factored in the characteristics of spent nuclear fuel and high-level radioactive waste, the integrity of shipping casks that would be used in transport, and the regulatory and programmatic controls that would be imposed on shipping operations (see FEIS, Appendix M). The FEIS analytical results are supported by numerous technical and scientific studies which have been compiled through decades of research and development by the DOE and other Federal agencies of the United States, including the NRC and the U.S. Department of Transportation, as well as by the international community, including the International Atomic Energy Agency.

Transportation of hazardous materials in the United States is a very highly regulated activity, and transportation of spent nuclear fuel and high-level nuclear radioactive waste to a repository would be conducted under the umbrella of the NRC and Department of Transportation regulations with oversight, as applicable, by various local, Native American tribal, state, and Federal agencies. This would ensure that all shipments would be made safely (FEIS, Appendix M, Section M.2).

Spent nuclear fuel and high-level radioactive waste can be harmful to human health and the environment because they emit radiation as the radionuclides decay. For this reason, the NRC and the U.S. Department of Transportation regulations, as well as the DOE internal orders, specify containment, shielding, thermal, and nuclear safety requirements for shipping containers (casks). These regulations are designed to minimize the probability of direct exposure. Furthermore, spent nuclear fuel and high-level radioactive waste are not easily spilled or leaked, and, radiation from them does not make other materials radioactive. Spent nuclear fuel and high-level radioactive waste are solids. They are hard and dense ceramics, metals, or glasses contained within robust metal barriers.

The shipping casks used to transport these materials are massive, with design features that comply with regulatory requirements to ensure that the casks perform their safety functions even when damaged. Numerous tests and extensive analyses, using the most advanced analytical methods available, have demonstrated that these types of shipping casks would provide containment and shielding even under the most severe kinds of accidents. Since the publication of the DEIS, the NRC published "Reexamination of Spent Fuel Shipment Risk Estimates" [Sprung, J.L.; Ammerman, D.J.; Breivik, N.L.; Dukart, R.J.; Kanipe, F.L.; Koski, J.A.; Mills, G.S.; Neuhauser, K.S.; Radloff, H.D.; Weiner, R.F.; and Yoshimura, H.R. 2000. "Reexamination of Spent Fuel Shipment Risk Estimates." NUREG/CR-6672. Two volumes. Washington, D.C.: U.S. Nuclear Regulatory Commission. ACC: MOL.200001010.0217.], a study completed by Sandia National Laboratories. Based on the revised analyses, the DOE has concluded that casks would continue to contain spent nuclear fuel fully in more than 99.99 percent of all accidents. This means that of the approximately 53,000 truck shipments over 24 years in a "mostly truck" scenario, an estimated 66 accidents nationwide could occur, each having less than a 0.01 percent chance that radioactive materials would be released. The chance of a rail accident that would cause a release from a cask would be even less. The corresponding chance that such an accident would occur in any particular locale would be extremely low. Section J.1.4.2.1 of the FEIS reports potential consequences for accidents that could release radioactive materials.

Although the risk of releasing radioactive materials from a shipping cask in an accident would be small, the U.S. Department of Transportation requires highway shipments use preferred routes that reduce time in transit (49 CFR 397.101). The U.S. Department of Transportation regulations provides for states and tribes to designate alternate preferred routes. These regulations require a state to consider overall public safety in designating routes that would be in lieu of or in addition to routes specified by the U.S. Department of Transportation regulations. The U.S. Department of Transportation requirements and the planned completion of the Las Vegas beltway led the DOE to assume, for purposes of analysis in the FEIS, that legal-weight truck shipments would not enter the Spaghetti Bowl interchange of I-15 and U.S. 95. Nonetheless, to assess how potential impacts would be different from those of using the Las Vegas beltway, the DOE analyzed the impacts of legal-weight trucks travelling through the Spaghetti Bowl interchange (see Section J.3.1.3 of the FEIS for an analysis of the impacts of using different routes in Nevada). The DOE did not analyze transport by heavy-haul trucks through the Spaghetti Bowl interchange because use of the interchange would not be practical. The high volume of traffic through the interchange combined with the slow progression of the trucks through the turns and the over-length configurations of the vehicles would create excessive disruptions of traffic flow.

The U.S. Department of Transportation routing requirements along with regulatory requirements to limit radiation dose external to a shipping cask, would help to ensure that radiation dose to persons who live along routes would be low. The analysis in Chapter 6 of the FEIS for the mostly legal-weight truck scenario estimates the dose to persons who would drive alongside the trucks as they travel on the highways, who would be stopped in locales where truck shipments stop, and who live along the routes that would be used. In response to public comments, the DOE forecasted growth in populations along routes to estimate potential impacts that could occur in the future when shipments would occur. However, the estimated dose to an individual living along a route would not change with changes in population—only the integrated dose to the whole population would change. The dose to a maximally exposed individual who lived along a route would be about 0.25 millirem per year.

U.S. Department of Transportation regulations (49 CFR Part 172, 176, and 177) also provide additional requirements that add further measures of safety in transporting spent nuclear fuel and high-level radioactive waste by truck. Included are requirements for training of transportation personnel who are responsible for the safety of shipments, safety of vehicles, shipping documentation, financial responsibility of transportation carriers, emergency response notification, driving and parking, and other requirements (see FEIS, Appendix M).

NRC (10 CFR Part 73) and U.S. Department of Transportation (49 CFR Part 397) regulations both include requirements to ensure the physical security and protection of shipments from diversion and attack. For the FEIS, the DOE reexamined, for both rail and truck casks, the consequences of an attack that results in a release of material (in other words, the cask's shield wall is penetrated) (see FEIS, Section 6.2.4.2.3), and estimated consequences exceeded those presented in the DEIS. Differences in the consequences between the DEIS and the FEIS are due to using "representative" spent nuclear fuel isotopics (versus "typical" in the DEIS) and an escalation of impacts to represent population growth to the year 2035.

In the FEIS, the DOE estimated the greatest consequences assuming a sabotage event occurred in the center of a highly populated metropolitan area. The dose from such an event to a maximally exposed individual (about 110 rem over the person's lifetime) would increase his or her lifetime risk of a fatal cancer from about 23 percent (the current risk of incurring a fatal cancer from all other causes) to about 29 percent. However, doses to most affected individuals would be much lower than that to the maximally exposed individual; these individuals' increased risk of a latent fatal cancer would also be lower. It was not predicted that there would be any prompt fatalities from very high levels of exposure, and immediate health consequences from radiation doses would be unlikely, but by combining the large number of small individual risks in the population of a metropolitan area, the DOE estimated that a sabotage event could lead to as many as 48 latent fatal cancers. Although not estimated in the analysis, injuries and deaths from blast effects of a device that might be used would be expected for individuals who would be as close to the event as the hypothesized maximally exposed individual. The DOE designed the analyses to identify the maximum consequences that a severe accident could reasonably be expected to produce (reasonably expected is defined as a likelihood greater than, but on the order of, 1 in 10 million in a year), but the analysis did not make extreme assumptions that would identify the worst possible consequences that could be imagined.

In addition, the DOE would employ satellite tracking and in accordance with NRC regulations for licensing, provide advanced notification to state, tribal (subject to NRC approval), and local officials for each shipment of spent nuclear fuel. The DOE also maintains a national radiological emergency response capability that is available to assist states and tribes in the event of a transportation accident (FEIS, Appendix M).

Section 180(c) of the NWPA requires the DOE to provide technical assistance and funds to states for training of public safety officials of appropriate units of local government and Native American tribes through whose jurisdictions the DOE would transport spent nuclear fuel and high-level radioactive waste. The training shall cover procedures required for safe routine transportation of these materials, as well as procedures for addressing emergency response situations. The DOE would provide the assistance based on the training needs of the states and tribes, as they determined using a planning grant and based on availability of funds in annual budgets specified by Congress. Additional Federal response capabilities, such as expert services from the Radiological Assistance Program Team, could be activated, as requested by states and tribes. The schedule in the proposed policy and procedures for implementation of Section 180(c) of the NWPA (63 FR 23753) is designed to provide adequate time for training of first responders in advance of the first shipments. If there was a decision to proceed with the development of a repository at Yucca Mountain, shipping routes would be identified approximately 5 years before shipments began and Section 180(c) assistance would be made available approximately 4 years prior to shipments being made through a jurisdiction (see FEIS, Section M.6, for a discussion of the DOE Section 180(c) policy and procedures).

The Price–Anderson Act (42 U.S.C. 2210 et seq.) provides for indemnification of liability up to $9.43 billion to cover claims that might arise from a nuclear accident, in which radioactive material is released or one in which an authorized precautionary evacuation is made, regardless of who causes the damage (see FEIS, Appendix M, Section M.8, for a more complete discussion of the Price–Anderson Act). If the damage from a nuclear incident appeared likely to exceed that amount, the Price–Anderson Act contains a Congressional commitment to thoroughly review the particular incident and take whatever action is determined necessary to provide full and prompt compensation to the public.

The DOE also investigated the potential impacts transporting spent nuclear fuel and high-level radioactive waste to Yucca Mountain would have on multiple resource areas not related to human health and safety: land use; air quality; biological resources and soils; hydrology; cultural resources; socioeconomics; noise; aesthetic; waste management; utilities, energy and materials; and environmental justice (see FEIS, Chapter 6). The DOE concluded the impacts in these resource areas from national transportation (outside Nevada) would not be discernible because shipments would use existing highways and railroads and would contribute only minimally to national transportation (0.007 percent of railcar kilometers and 0.008 percent of truck kilometers). Although radiological health and traffic fatality impacts would be adverse, because these potential impacts nationwide would not be high for any individual or identifiable group, including Native American tribes, the DOE also concluded that the transportation of these materials would not raise environmental justice concerns. For the mostly legal-weight truck scenario, the population within 800 meters (0.5 miles) of routes would be about 10 million based on projections to 2035, where there could be 3 latent cancer fatalities. Of that 10 million population, about 2.3 million would likely incur fatal cancers from other causes. For the mostly rail scenario, the population within 800 meters (0.5 miles) would be about 16.4 million with about 1 latent cancer fatality from the shipment of spent nuclear fuel and high-level radioactive waste. Of that 16.4 million, about 3.8 million would likely incur fatal cancers from all other causes.

4.8.1 (500)

Summary Comment

An issue was raised by the public concerning the shipment of hazardous waste from the foreign countries to a repository at Yucca Mountain.

Response

Based on the results of the impact analyses presented in Chapter 6 and Appendix J of the FEIS, as well as the results published in numerous other studies and environmental impact analyses cited in the FEIS, the DOE is confident spent nuclear fuel and high-level radioactive waste could be safely transported to Yucca Mountain. The DOE also believes, as the FEIS reports that the potential impacts of this transportation would be so low for individuals who live and work along the routes that these individual impacts would not be discernible even if the corresponding doses from such transportation could be measured. The analysis presented in the FEIS factored in the characteristics of spent nuclear fuel and high-level radioactive waste, the integrity of shipping casks that would be used for transportation, and the regulatory and programmatic controls that would be imposed on shipping operations (see FEIS, Appendix M). The FEIS analytic results are supported by numerous technical and scientific studies that have been compiled through decades of research and development by the DOE and other federal agencies, including the NRC and the U.S. Department of Transportation, as well as by the international community, including the International Atomic Energy Agency.

The spent fuel coming back to the United States from overseas was part of the Atoms for Peace Program started by President Eisenhower with the intent that the fuel be returned to the U.S. There have been a number of these Foreign Research Reactor Fuel shipments safely made already from both Europe and the Far East. There is no intent for the United States to accept any other type of foreign reactor spent nuclear fuel.

4.8.2 Transportation in the State of Nevada

4.8.2 (95)

An issue has been raised by members of the public about the limitations that construction of a rail branch line would have on land use in the area of the branch line. A concern was also expressed regarding condemnation of private property for the branch line. In addition, a member of the public expressed concern about waste contamination (non-nuclear) from rail branch line construction.

Members of the public raised a concern that there has been insufficient information regarding the disposal of expected wastes that would be generated during the construction and operation of a rail line.

Waste generated from the construction of rail lines or intermodal transfer station would fall into several categories: waste soil and rock material; general construction waste, such as wood, excess rebar, rail ties, and track material; solid waste generated by workers indirect to construction, such as trash; hazardous wastes, such as used paints, resins and lubricants; and sanitary waste. For all waste types, the DOE likely would use the nearest available authorized disposal facilities having sufficient capacity. In some instances, the DOE recognizes that wastes might need to be transported either by use of a partially completed rail line or by truck. The DOE would identify disposal facilities during final design and construction of a rail line.

The FEIS provides the environmental impact information necessary to make certain broad transportation-related decisions, namely the choice of a national mode of transportation outside Nevada (mostly rail or mostly legal-weight truck), the choice among alternative transportation modes in Nevada (mostly rail, mostly legal-weight truck, or heavy-haul truck with use of an associated intermodal transfer station), and the choice among alternative rail corridors or heavy-haul truck routes with use of an associated intermodal transfer station in Nevada. However, follow-on implementing decisions, such as the selection of a specific rail alignment in a corridor would require additional field surveys, State and local government and Native American tribal consultations, environmental and engineering analyses, and regulatory reviews.

Issue

Members of the public have questioned how much land would be obtained and what type and to what extent would a rail branch line be fenced.

Response

If the site were approved, transportation system specifications would be developed during detailed design activities. Specifications for items such as administration and maintenance facility and any associated remote water supply and sanitation needs, train control systems, and road crossing signals would be developed during these activities. Detailed field studies and geotechnical work would be required for development of specifications for seismic, flood platform dimensions, ditch dimensions, bench dimensions, ballast requirements, and sub-ballast requirements. Specifications for grade crossings, road crossings, fencing locations and fencing type would be developed in conjunction with government agency consultations, environmental analyses, and any necessary regulatory reviews that would also be conducted at the time of detailed design activities.

The FEIS analyzes the potential environmental impacts that could result from the construction, operation and monitoring, and eventual closure of a repository at Yucca Mountain and provides the environmental impact information necessary to make certain broad transportation-related decisions, namely the choice of a national mode of transportation outside Nevada (mostly rail or mostly legal-weight truck), the choice among alternative transportation modes in Nevada (mostly rail, mostly legal-weight truck, or heavy-haul truck with use of an associated intermodal transfer station), and the choice among alternative rail corridors. However, follow-on implementing decisions, such as the selection of a specific rail alignment in a corridor, would require additional field surveys, State and local government and Native American tribal consultations, environmental and engineering analyses, and regulatory reviews. An analysis of impacts associated with rail branch line construction activities is found in the FEIS, Section 6.3.2.

Issue

Members of the public have expressed concern relating to the impacts to land use along the corridors; some specific concerns include impacts to recreation, mining and mineral resource; grazing allotment access, road access, and private property.

Response

Analyses in Section 6.3 and Appendix J.3 of the FEIS considered information that included planning and zoning designations in completed land-use planning documents prepared by public entities with jurisdiction over potential transportation routes in Nevada. The FEIS, Section 6.3, discusses the scope of land-use information deemed appropriate for assessing potential impacts on land use of transportation implementing alternatives in Nevada. Information is needed to identify the current ownership of the land that would be disturbed, and the present and anticipated future uses of the land. The region of influence for land-use and ownership impacts consists of land areas that would be disturbed or whose ownership or use would be changed as a result of the construction and use of a branch rail line. These disturbances in land use would include camping, hiking, fishing, hunting, nature study, back-country travel, sightseeing, mining, ranching, timber, and wilderness areas.

In its assessment of potential land-use impacts, the DOE considered the differences between land-use types, land disturbances, land ownership, and the creation of barriers. The assessment compared proposed use of land for Yucca Mountain transportation purposes to existing or other proposed land uses to estimate the magnitude and context of potential conflicts. If an action would result in continuing a current land use either due to little or no impact or through mitigation, the effects were considered insignificant or small. For example, as discussed in Section 6.3.2.1 of the FEIS, the impacts to livestock and Bureau of Land Management grazing allotments could be mitigated through the use of fencing, overpasses/underpasses, and could provide a water source to animals cut off from current sources. With these mitigating measures, the impacts would be lessened and considered small. If an action could result in departures from existing uses, and mitigation could not remedy the conflict, the effects could be more substantial. For example, as discussed in the Carlin and Caliente Corridor sections of Chapter 6 (Sections 6.3.2.2.1 and 6.3.2.2.2), the Bonnie Claire Alternate passes directly through the portion of the newly established Timbisha Shoshone Trust near Scotty's Junction. If this alternate is chosen, the construction of a branch line could limit or enhance economic development in the Timbisha Shoshone Trust Lands parcel and could limit the use for housing by restricting access. Factors considered included the uniqueness of a geographic area; presence of historic, scientific, and cultural resources; potential effects on endangered species; and compliance with Federal, State, or local law. Based on information available, potential land-use impacts associated with Yucca Mountain transportation activities could be minimized through judicious alignment of the rail line or through mitigation. Overall, the land-use impacts would not be substantial because of the use of various optional and alternate routes within the corridor, mitigation measures, and the judicious routing of the rail line within the corridor.

Additional information about impact-reduction features, procedures and safeguards, and mitigation measures under consideration are included in Chapter 9 of the FEIS. Chapter 9 identifies ongoing studies that could eventually influence mitigation measures related to the project plan and design. For example, Section 9.3 of the FEIS discusses mitigation measures intended to address impacts from the possible construction of a branch line or an intermodal transfer station in Nevada; construction of other transportation routes; upgrading of existing Nevada highways to accommodate heavy-haul vehicles; transportation of spent nuclear fuel and high-level radioactive waste from existing storage sites to the repository; and fabrication of casks and canisters. As suggested in the Foreword to the FEIS, if the DOE pursued consideration of a specific rail alignment within a corridor or a specific location of an intermodal transfer station or the need to upgrade the associated heavy-haul truck routes, more detailed field surveys, government consultation, analyses, and regulatory reviews would be conducted that would help ensure potential land-use conflicts associated with Yucca Mountain transportation activities were minimized.

Issue

Members of the public questioned if private property would be condemned in the vicinity of any rail line.

Response

In its assessment of potential land-use impacts, the DOE considered the differences between land-use types, land disturbances, land ownership, and the creation of barriers. The assessment compared proposed use of land for Yucca Mountain transportation purposes to existing or other proposed land uses to estimate the magnitude and context of potential conflicts. If an action would result in continuing a current land use either due to little or no impact or through mitigation, the effects were considered insignificant or small. For example, as discussed in Section 6.3.2.1 of the FEIS, impacts to livestock and Bureau of Land Management grazing allotments could be mitigated through the use of fencing, overpasses, and underpasses, which could provide a water source to animals cut off from current sources. With these mitigating measures, the impacts would be lessened and considered small. If an action could result in departures from existing uses, and mitigation could not remedy the conflict, the effects could be more substantial. For example, as discussed in the Carlin and Caliente Corridor sections of Chapter 6 (Sections 6.3.2.2.1 and 6.3.2.2.2), the Bonnie Claire alternate passes directly through the portion of the newly established Timbisha Shoshone Trust near Scotty's Junction. If this alternate is chosen, the construction of a branch line could limit or enhance economic development in the Timbisha Shoshone Trust Lands parcel and could limit the use for housing by restricting access. Factors considered included the uniqueness of a geographic area; presence of historic, scientific, and cultural resources; potential effects on endangered species; and compliance with Federal, State, or local law. Based on information available, potential land-use impacts associated with Yucca Mountain transportation activities could be minimized through judicious alignment of the rail line or through mitigation. Overall, the land-use impacts would not be substantial because of the use of various optional and alternate routes within the corridor, mitigation measures, and the judicious routing of the rail line within the corridor.

Regarding private property along the rail corridor, the DOE is required to use fair market value in the acquisition of real property. The DOE must comply with the policies contained in the Uniform Relocation Assistance and Real Property Acquisition Policies Act, Title III, which includes the provision that the Agency (DOE) offer just compensation.

4.8.2 (15935)

Summary Comment

Comments were expressed concerning highway impacts of heavy-haul transport, both to the road and traffic. Another concern was expressed regarding the dose impacts along the heavy-haul routes.

Issue

Members of the public expressed concern about the damage that heavy-haul vehicles transporting spent nuclear fuel and high-level radioactive waste would cause to the infrastructure in Nevada.

Response

The DOE has identified in the FEIS mostly rail as the preferred mode for transportation of spent nuclear fuel and high-level waste both nationally and in the State of Nevada.

At this time, the heavy-haul truck alternatives for transporting spent nuclear fuel and high-level radioactive waste to a repository are in the conceptual stages of development, although preliminary design and engineering studies have been conducted for the heavy-haul truck options [CRWMS M&O 1998. "Road Upgrades for Heavy Haul Truck Routes." BCBI00000-01717-0200-00008 REV00. Las Vegas, Nevada: CRWMS M&O. ACC: MOL.19981207.0254.] and [Ridilla, J.; Kiser, P.D.; Soule, R.; and Alvi, S. 1997. "Supplemental Transportation Analysis." Las Vegas, Nevada: TRW Environmental Safety Systems. ACC: MOL.19990324.0276.]. These studies identify potential upgrades for mitigating impacts of the heavy-haul truck concept shown in Figure 2-29 of the FEIS.

Based on the analysis mentioned above, heavy-haul truck transportation is technically feasible and its cost would be comparable to those for rail transportation. Sections of the Caliente route, such as Hancock Summit and affected communities, as well as the 90 degree turns in Hiko and Tonopah, and the intersection in Beatty, have been evaluated and are feasible routes if the recommended road upgrades were completed.

Issue

Members of the public expressed concern about the incident free radiological impacts associated with heavy-haul truck transport of spent nuclear fuel and high-level radioactive waste would cause in Nevada. Of particular concern was the increased dose due to slow vehicle speed.

Response

The DOE has received input from heavy-haul truck companies on the estimated speed of the heavy-haul vehicle identified in the FEIS. The speed depends on the highway grade. At 0-percent grade, the estimated speed is 68 kilometers (42 miles) per hour and at 4-percent grade, 24 kilometers (15 miles) per hour. Thus, the DOE analyses estimated an average speed, depending upon the route, of 32 to 48 kilometers (20 to 30 miles) per hour for an entire trip. The State of Nevada restricts heavy-haul truck transport to daylight hours only. Thus, intermediate overnight stops would be necessary for the longest of the heavy-haul truck routes. Sections 6.3.3.2.1 through 6.3.3.2.3 of the FEIS identify the heavy-haul truck routes that would require an overnight stop. The trucks would carry sufficient fuel to travel the entire one-way distance before refueling.

The DOE calculated heavy-haul truck impacts using the primary road rates in "State-Level Accident Rates of Surface Freight Transportation: A Reexamination" [Saricks, C.L. and Tompkins, M.M. 1999. "State-Level Accident Rates of Surface Freight Transportation: A Reexamination." ANL/ESD/TM-150. Argonne, Illinois: Argonne National Laboratory. TIC: 243751.]. Although the document does not explicitly address heavy-haul truck accident rates, the DOE believes it provides the latest reasonably available data, as relevant to heavy-haul truck as it is to legal-weight truck transport. The accident rates used in the analysis are conservative because the analysis does not consider the effects of the special precautions taken with heavy-haul truck shipments to prevent accidents, such as restricting travel to daylight hours and providing escort vehicles in front and behind the trucks. The heavy-haul trucks could affect the accident rates for other vehicles. However, the additional precautions described above in addition to the potential road improvements would mitigate these effects.

Incident-free impacts to hypothetical maximally exposed individuals would be similar among the Nevada heavy-haul truck transportation implementing alternatives. Table 6-88 lists the impacts to maximally exposed individuals including a Nevada-specific individual exposed to heavy-haul truck shipments. Appendix J.1.3.2.2 describes assumptions for estimating doses to maximally exposed individuals along the routes in Nevada. The estimated dose to a maximally exposed Nevada resident along a heavy-haul route is 0.53 rem during 24 years of operation which corresponds to a probability of latent fatal cancer of 0.00027. This is a small probability in comparison to the probability that an individual could contract a fatal cancer from all potential causes (0.22, according to the American Cancer Society [American Cancer Society 1998. "Cancer Facts and Figures—1998." Atlanta, Georgia: American Cancer Society. TIC: 242284. Page 10.]), including carcinogens in the environment, natural background radiation, and all other radiation sources.

Issue

Members of the public expressed concern about the traffic congestion impacts that heavy-haul truck would cause in Nevada.

Response

Section 6.3.3.1 of the FEIS states that most of the highways that heavy-haul truck shipments would use are classified as having freely flowing traffic without delays and that the addition of 11 round trips per week should not affect the level of service. The FEIS also states that the slow-moving heavy-haul trucks could present a traffic obstruction that increased congestion, delayed other vehicles, and caused short queues to form between turnout areas, even after the shipment passed. However, given the low frequency of heavy-haul truck shipments, congestion would occur predominantly on relatively short segments of the heavy-haul truck routes and mitigation measures could be implemented to alleviate congestion concerns.

4.8.2 (11802)

Summary Comment

An issue was raised by the public regarding the cost and responsibility of upgrading public highways.

Response

With the exception of the Nevada heavy-haul scenarios, the DOE believes existing highway infrastructure, as well as its maintenance and public safety services, would be adequate for the safe transportation of spent nuclear fuel and high-level radioactive waste to Yucca Mountain. In addition, the infrastructure would be minimally impacted by the transportation. Because estimated impacts on public safety would be small and because the estimates are based on present-day transportation conditions, it would not be necessary to upgrade infrastructure to support any shipments to a repository at Yucca Mountain.

The DOE would be responsible for making the funding available for the upgrades if it selected heavy-haul truck transport, and for working with the State of Nevada and tribes to ensure funding was available for the road upgrades necessary to provide infrastructure for transporting spent nuclear fuel and high-level radioactive waste using heavy-haul trucks on Nevada roads. For purposes of analysis in the FEIS, the DOE assumed funding to upgrade routes in Nevada for heavy haul transport would originate from a source or sources outside the state.

Cost estimates developed for highway upgrades associated with the heavy-haul truck transport implementing alternatives include cost for design and construction of road upgrades for public roads and for annual maintenance of the roads that would be used [Ahmer, D. 1998. "Cost Estimate for the Heavy Haul Truck Transport Design." EIS AR-TR-80036. Las Vegas, Nevada: Morrison Knudsen Corporation. ACC: MOL.19981207.0257.]. The estimated costs discussed in the FEIS, Section 6.3.3, for each potential route are based on detailed estimates, which include lane widening, truck lane and turnout construction, pavement upgrades, intersection upgrades, pavement type, and shoulder upgrades.

4.8.3 Transportation Mode and Routing

4.8.3 (14)

Concerns have been raised by the public expressing opposition to routing shipments of spent nuclear fuel and high-level radioactive waste through high population centers and along congested freeways and rail lines in the United States. An issue has been raised stating that the DOE should coordinate closely with state and local governments to minimize transportation routing through highly populated areas.

A concern has been expressed by the public that the DOE would route spent nuclear fuel and high-level waste with no effort to avoid high population centers. In addition, an issue has been raised by the public that recommends the DOE provide for an equitable distribution of shipping routes among a large number of possible routes.

The DOE would route shipments of spent nuclear fuel and high-level radioactive waste in accordance with Federal regulations (for highway) and Federal Railroad Administration Guidance.

Highway routes used for transportation of spent nuclear fuel and high-level radioactive waste must conform to U.S. Department of Transportation regulations, 49 CFR 397.101. These regulations, developed for transport of Highway Route-Controlled Quantities of Radioactive Materials, require the highway shipments to be made on preferred routes to reduce the time in transit. A preferred route is an interstate system highway, interstate system bypass or beltway, or a state-designated route selected by a state routing agency (defined in the regulations to include Native American tribal agencies). Alternative routes could be designated by states and tribes following U.S. Department of Transportation regulations, 49 CFR 397.103 that require consideration of the overall risk to the public and prior consultation with local jurisdictions and states. As of December 2000, 14 states had designated such preferred routes.

Federal regulations do not specifically restrict the routing of rail shipments transporting spent nuclear fuel and high-level radioactive waste; however, such routing of spent nuclear fuel does require prior approval of the NRC. The DOE transportation contractors would rely on rail carriers to provide primary and secondary route recommendations consistent with safe railroad operating practices. Guidelines provided to the transportation contractors would include consideration of track classification to ensure use of the highest rated track to the greatest extent possible, and the maximum use of key routes as described in the "Recommended Railroad Operating Practices for Transportation of Hazardous Materials" [AAR (Association of American Railroads) 2000. "Recommended Railroad Operating Practices for Transportation of Hazardous Materials." Circular No. OT-55-C. Washington, D.C.: Association of American Railroads. TIC: 250387.], which requires specific inspection maintenance, and operating procedures for key routes.

If Yucca Mountain were approved as the site for a repository, the DOE would begin the process of detailed transportation planning. This planning would include working with the states and tribes after preliminary routes are identified. Transportation protocols discussed in Appendix M of the FEIS would be used to determine actual routes, including routes to be used in the event of transportation emergencies or other conditions that require deviation from regular routes.

4.8.3 (15)

Summary Comment

Issues were raised by the public on how to select the safest and most efficient mode of transport for delivery of spent nuclear fuel and high-level radioactive waste to a repository at Yucca Mountain. The issues encompassed rail, highway, air, and barge modes. There was a consensus that rail transport should be used but trains need to be operated in a more controlled mode than regular freight trains, and, therefore, dedicated (special) trains should be used rather than general freight service.

Issue

An issue was raised by the public suggesting that the DOE should build a new national, high-speed rail transportation system specifically for the transport of spent nuclear fuel and high-level radioactive waste.

Response

The DOE did not consider a new national rail system dedicated for shipment of spent nuclear fuel and high-level radioactive waste from the 77 sites to a repository at Yucca Mountain because the potential impacts identified from rail and truck transport using the existing infrastructure from analysis in the FEIS and would be small (and much less than from constructing a new rail system), the cost for a new national rail line would be high and such new construction would increase impacts.

Issue

An issue was raised by the public stating that trucks should not be used for transportation of spent nuclear fuel and high-level radioactive waste.

Response

The DOE has identified mostly rail as its preferred mode of transportation, both nationally and in the State of Nevada. At this time, however, the DOE has not identified a preference among the five candidate rail corridors in Nevada.

The DOE expects that some spent nuclear fuel would be transported by the highway mode (truck). Prior transportation analyses provide substantial evidence that the environmental impacts for truck, rail, and barge modes of transportation that might be used would be small (see FEIS, Table 1-1).

If the Yucca Mountain site was recommended and approved, at some future date the DOE would issue a Record of Decision to select a mode of transportation. If, for example, mostly rail was selected (both nationally and in Nevada), the DOE would identify a preference for one of the rail corridors in consultation with affected stakeholders, particularly the State of Nevada. In this example, the DOE would announce a preferred corridor in the Federal Register and other media. No sooner than 30 days after the announcement of a preference, the DOE would publish its selection of a rail corridor in a Record of Decision. A similar process would occur in the event that the DOE selected heavy-haul truck as its mode of transportation in the State of Nevada. Other transportation decisions, such as the selection of a specific rail alignment within a corridor, would require additional field surveys, State and local government and Native American tribal consultations, environmental and engineering analyses, and regulatory reviews.

Issue

An issue was raised by the public recommending that air transportation should be used and expressing the belief that impacts would be less from air transport than from rail or truck transport.

Response

The DOE considers air transport an impractical mode for shipping spent nuclear fuel or high-level radioactive waste to a repository.

The weight of spent nuclear fuel and heavily shielded shipping casks would make transportation by air very expensive. In addition, use of air transportation would not eliminate use of land transportation. Shipments would still have to travel from generator and storage sites to nearby airports and from an airport in Nevada to Yucca Mountain by a land transportation mode. Also, regulatory requirements in 10 CFR Part 71 may preclude air transportation of spent nuclear fuel as designing a cask for air shipment of a practical quantity of spent nuclear fuel might not be feasible.

Issue

An issue was raised by the public stating that for transport of spent nuclear fuel and high-level radioactive waste dedicated (special) train service should be used over general freight service to assure greater safety.

Response

The DOE has not determined the commercial arrangements the DOE and its transportation contractors would request from the railroads, including the use of dedicated or general freight trains.

The DOE recognizes the different attributes of dedicated trains versus general freight service. General freight rail service, as well as dedicated train service, are capable of meeting the performance objectives of 10 CFR 73.37(a)(I) for physical protection based on successful completion of past shipments of spent nuclear fuel by rail. The DOE-revised draft request for proposal entitled "Acquisition of Waste Acceptance and Transportation Services for the Office of Civilian Radioactive Waste Management" [Ibid], encourages the "...maximum use of special train service and advanced rail equipment features where this type of service can be demonstrated to enhance operating efficiency, dependability, and cost effectiveness or lessen the potential of adverse railroad equipment incidents." The revised draft request for proposal can be accessed at the DOE Office of Radioactive Waste Management website at www.rw.doe.gov/wasteaccept/ wasteaccept.htm.

Section J.2.3 of Appendix J of the FEIS presents an impact assessment of using dedicated trains to transport spent nuclear fuel and high-level radioactive waste. Considering studies by the Department of Transportation and the Association of American Railroads [DOT (U.S. Department of Transportation) 1998. "Final Report, Identification of Factors for Selecting Modes and Routes for Shipping High-Level Radioactive Waste and Spent Nuclear Fuel." Washington, D.C.: U.S. Department of Transportation. ACC: MOL.20010721.0044.], the DOE concluded that there is no clear advantage between using either dedicated trains or general freight service.

4.8.3 (86)

Summary Comment

An issue has been raised by the public asserting that the DOE has not identified preferred transportation routes or the maximum number of shipments that would pass through or near specific areas across the United States. An assertion has also been made that because route-specific information is lacking, communities that would be affected by waste transport cannot begin emergency planning and preparedness and do not understand the impacts and costs to local programs.

Issue

An issue has been raised by the public regarding the identification of specific national transportation routes analyzed for the transport of spent nuclear fuel and high-level waste to Yucca Mountain.

Response

The DOE has identified rail as its preferred mode for transporting spent nuclear fuel and high-level radioactive waste to a repository, both nationally and in the State of Nevada.

The DOE has added maps of the representative routes analyzed in the FEIS and the potential number of shipments through each state to Appendix J.4 of the FEIS. At this time, many years before shipments could begin, it is impossible to accurately predict with a reasonable degree of accuracy which highway or rail lines would be used. For example, in the interim, state or Native American tribal governments might designate alternate preferred highway routes, and new highways and rail lines could be constructed or modified. Therefore, for purposes of analysis in the FEIS, the DOE identified representative highway routes for analysis in accordance with Department of Transportation regulations, which require the use of preferred routes (Interstate system highway, beltway or bypass, and state or tribal designated alternate) that reduce time in transit. The DOE identified representative rail lines for analysis based on current rail practices, as there are no comparable federal regulations applicable to the selection of rail lines for the shipment of radioactive materials. As discussed in Appendix M of the FEIS, the DOE would provide a draft transportation plan for review and comment, identifying proposed transportation routes to the states and tribes through whose jurisdictions spent nuclear fuel would be shipped. After consideration of stakeholder comments the DOE would finalize route selections and submit them to the NRC for approval. To support emergency response training activities, the DOE would identify preliminary shipping routes approximately five years before the shipments would begin. Actual route selection and submission to the NRC would occur one or more years before a route's use for shipments.

Issue

An issue has been raised by the public asserting that the DOE has not provided sufficient route-specific information on national routes and this failure to identify likely routes means that the impacts on specific communities, as well as states, have not been adequately evaluated.

Response

With respect to national transportation impacts, Appendix J.4 in the FEIS identifies the representative highway routes and rail lines analyzed for each state and the potential health and safety impacts associated with the transportation of spent nuclear fuel and high-level radioactive waste for each state through which the shipments would pass.

For purposes of analysis in the FEIS, the DOE identified representative highway routes for analysis in accordance with Department of Transportation regulations, which require the use of preferred routes (Interstate system highway, beltway or a bypass, and state or tribal designated alternate) that reduce time in transit. The DOE identified representative rail lines for analysis based on current rail practices, as there are no comparable federal regulations applicable to the selection of rail lines for the shipment of radioactive materials. However, the DOE has developed operational protocols (FEIS, Appendix M), which include guidelines for selecting rail routes based on current best practice. The DOE applied the guidelines in identifying representative routes for analysis in the FEIS.

The DOE does not believe it necessary to consider population characteristics on a community-by-community basis to determine potential public health and safety impacts from the transportation of spent nuclear fuel and high-level radioactive waste. The use of widely accepted analytical tools, latest reasonably available information, and cautious but reasonable assumptions if there are uncertainties, offer the most appropriate means to arrive at conservative estimates of transportation-related public health impacts. To ensure that the FEIS analyses reflect the latest reasonably available information, the DOE has either incorporated information that has become available since the publication of the DEIS or modified existing information to accommodate conditions likely to be encountered over the life of a repository at Yucca Mountain. For example, the analysis in the DEIS relied on population information from the 1990 Census. In the FEIS, the DOE has scaled impacts upward to reflect the relative state-by-state population growth to 2035, using 2000 Census data.

As discussed in Appendix M of the FEIS, the preliminary routes to be used would be identified approximately five years before shipments occur. Sections 6.2 and 6.3 of the FEIS address the potential impacts of transporting spent nuclear fuel and high-level radioactive waste from facilities where it is generated to Yucca Mountain. Appendix J of the FEIS discusses the methods and data that the DOE used for these analyses. The DOE based the analyses on representative routes, identified for the purpose of analysis. Analyses in the FEIS, Appendices J.2 and J.3, demonstrate that the total transportation impacts would be essentially the same regardless of the routes used. The analyses indicate that because all shipments must comply with regulatory limits, the impacts would be principally proportional to the number of shipment miles. Accidents that would release radioactivity from the casks would be extremely unlikely regardless of the routes because applicable transportation requirements prescribe that the casks must be able to withstand virtually all types of accidents without releasing their contents.

The FEIS adequately analyzes the potential environmental impacts that could result from transporting spent nuclear fuel and high-level radioactive waste to a repository at Yucca Mountain. This is based on the level of information and analysis, the analytical methods and approaches used to represent conservatively the reasonably foreseeable impacts that could occur, and the use of bounding assumptions where information is incomplete or unavailable, or where uncertainties exist.

4.8.3 (101)

Summary Comment

Issues have been raised by the public regarding shipments of spent nuclear fuel and high-level waste on specific Nevada routes, such as over Hoover Dam, and through Boulder City, Las Vegas, and the Spaghetti Bowl interchange of I-15/515 and U.S. 93/95, during peak travel times. A related issue suggested that the DOE should consider additional transportation corridors through Nevada, such as the routes identified by the Nevada Department of Transportation in 1989 for the transport of spent nuclear fuel and high-level radioactive waste. In addition, issues were raised regarding the DOE position that the Chalk Mountain rail route and the Chalk Mountain heavy-haul route were non-preferred alternatives. Commenters stated that the DOE position was based simply on opposition from the U.S. Air Force to routes passing through the Nellis Air Force Range; and stated that the Chalk Mountain routes were environmentally preferable because military security at Nellis Air Force Base would protect waste shipments, the lengths of these routes were the shortest of all alternatives under consideration, and they would avoid many communities in Nevada.

Issue

An issue has been raised by the public that the DOE has not revealed the process or a timetable for selecting a preferred rail, truck or heavy-haul corridor in Nevada for the transport of spent nuclear fuel and high-level waste.

Response

The DOE has now identified mostly rail as the preferred mode for transportation of spent nuclear fuel and high-level waste both nationally and in the State of Nevada. The DOE has not identified a preference among the five potential rail corridors in Nevada.

For legal-weight or heavy-haul truck transportation of spent nuclear fuel and high-level radioactive waste in Nevada, a motor carrier would use only routes that comply with the requirements contained in U.S. Department of Transportation regulations (49 CFR 397.101). These U.S. Department of Transportation regulations require use of routes designated as preferred routes that reduce the time in transit; these preferred routes are interstate system highways, interstate system beltways and bypasses, and state-designated preferred routes. There are exceptions for pick-up and delivery routes used to travel to and from a nearest preferred route.

The State of Nevada and Native American tribal governments can designate alternate preferred routes. To designate alternate preferred routes, Nevada or tribal governments must conduct a routing analysis; show how the alternative minimizes radiological risk or improves overall public safety; and undertake substantive consultation with affected jurisdictions. The DOE recognizes that heavy-haul highway shipments must also comply with the permit regulations of the State of Nevada and that these permits would specify conditions of travel.

The DOE believes that the FEIS provides the environmental impact information necessary to make certain broad transportation-related decisions including the choice among alternative transportation modes in Nevada (mostly rail, mostly legal-weight truck, or heavy-haul truck with use of an associated intermodal transfer station), and the choice among alternate rail corridors or heavy-haul truck routes with an associated intermodal transfer station in Nevada.

If the Yucca Mountain site was recommended and approved, at some future date the DOE would issue a Record of Decision to select a mode of transportation. If, for example, mostly rail was selected (both nationally and in Nevada), the DOE would identify a preference for one of the rail corridors in consultation with affected stakeholders, including the State of Nevada and affected counties. In this example, the DOE would announce a preferred corridor in the Federal Register and other media. No sooner than 30 days after the announcement of a preference, the DOE would publish its selection of a rail corridor in a Record of Decision. Other transportation decisions, such as the selection of a specific rail alignment within a corridor, would require additional field surveys, state and local government and Native American tribal consultations, environmental and engineering analyses, and regulatory reviews.

Issue

An issue has been raised by the public regarding routing of shipments of radioactive materials over Hoover Dam.

Response

Unless, in accordance with 49 CFR 397.103, the State of Nevada and the State of Arizona both designated U.S. 93 as a preferred route, from Kingman, Arizona, to Las Vegas, Nevada, the routes for transport of spent nuclear fuel and high level radioactive waste to Yucca Mountain would not cross Hoover Dam.

Issue

An issue has been raised by the public regarding the safety of routing shipments through the Spaghetti Bowl, U.S. 93/95 and I-15 interchange, and on US 93/95, during peak travel times.

Response

Truck shipments of spent nuclear fuel or high-level waste would only be by preferred highway routes of the U.S. Department of Transportation that are so designated at the time of shipment, unless the State of Nevada had selected, by then, alternate routes in accordance with 49 CFR 397.103.

Because the DOE assumed the Las Vegas beltway would be available when it is assumed that shipments would begin in 2010, the analysis presented in the FEIS, Chapter 6, Sections 6.3.1 and 6.3.3, did not use highway routing that would pass through the Spaghetti Bowl interchange for I-15/515, U.S. 93/95 in Las Vegas. However, to evaluate the sensitivity of impacts to potential alternative routing of highway shipments in southern Nevada, the DOE evaluated impacts that could occur if shipments traveled through the Spaghetti Bowl interchange. This evaluation is presented in the FEIS, Appendix J, Section 3.1.3.

Federal regulations for highway routing of shipments do not include time of day travel restrictions. However, the DOE protocols would include consideration of time of day travel through urban areas. For additional information regarding the DOE policies, procedures, and protocols for transportation, see Appendix M of the FEIS.

Issue

An issue has been raised by the public that alternative routes previously identified by the Nevada Department of Transportation were not analyzed in the DEIS.

Response

The DOE has evaluated the alternate routes identified by the Nevada Department of Transportation in 1989.

For completeness, the FEIS, Section J.3.1.3, evaluated all six of the Nevada Department of Transportation routes as sensitivity analyses to provide comparisons with the currently allowed preferred routes. Table J-48 of the FEIS presents the results of the sensitivity evaluations based upon the mostly legal-weight scenario. The various impacts are generally small for all cases but two of the Nevada routes are about a factor of 1.5 higher than the impacts for the route used in the FEIS analysis.

Issue

An issue has been raised by the public regarding the consideration and evaluation of additional Nevada transportation corridors in the vicinity of Nevada communities.

Response

The FEIS, Appendix J, Section J.3.1.2, lists studies of potential rail alignments from which the DOE identified the five rail corridors analyzed in the FEIS. Section J.3 of the FEIS Nevada Transportation also discusses the screening approach for the five identified corridors, and why the DOE chose to analyze them. Other routes and corridors through Nevada, including Nellis Air Force Range, were considered in the selection of the routes analyzed. Section J.3.1 provides the results of impact sensitivity studies performed for the various routes.

For truck transportation of spent nuclear fuel and high-level radioactive waste to Yucca Mountain, a motor carrier would use only routes that comply with the requirements contained in U.S. Department of Transportation regulations (49 CFR 397.101). The U.S. Department of Transportation regulations require use of routes designated as preferred routes; these preferred routes are interstate system highways, interstate system beltways and bypasses, and state-designated preferred routes. To designate alternate preferred routes, State and Native American tribal governments must conduct a routing analysis (49 CFR 397.103); show how the alternative minimizes radiological risk or improves overall public safety; and undertake substantive consultation with affected jurisdictions. The FEIS, Appendix J, Section 6.3.3, identifies the process used to identify heavy-haul routes for evaluation.

Issue

The issue has been raised by the public that Chalk Mountain routes (rail and heavy-haul) are preferable routes for shipment of spent nuclear fuel and high-level waste because of environmental and security reasons and should not be designated by the DOE as non-preferred alternatives.

Response

The DOE has continued to use the category of "non-preferred alternatives" in the FEIS for those routes with national security concerns.

Public comments during the environmental impact statement scoping period requested that the DOE evaluate routes through the Nellis Air Force Range (now called the Nellis Test and Training Range) to Yucca Mountain. In response, the DOE added an implementing alternative for the transportation of spent nuclear fuel and high-level radioactive waste by rail or by heavy-haul truck to the Yucca Mountain site across the Nellis Air Force Range (the Caliente-Chalk Mountain Corridor and heavy-haul truck route analyzed in the DEIS).

During preparation of the DEIS, the DOE consulted with various organizations and agencies, including the Air Force. In a letter dated March 1999, F. Whitten Peters, Acting Secretary of the Air Force [Peters, F.W. 1999. "Request to Move the Alternative for Any Transportation Route Through the Range to the 'Alternatives Considered but Not Carried Forward' Section in the Yucca Mountain Environmental Impact Statement." Letter from F.W. Peters (Department of the Air Force) to E.J. Moniz (DOE), March 8, 1999, with attachments. ACC: HQO.19991025.0008; HQO.19991025.0009; HQO.19991025.0010; HQO.19991025.0011.], commented that the Air Force believes that there is no route through the Nellis Air Force Range that could avoid adversely affecting classified national security activities, leading to the imposition of flight restrictions and affecting the ability for testing and training. As a consequence, the DOE listed the Caliente-Chalk Mountain Corridor and heavy-haul truck route in the DEIS as "non-preferred alternatives."

In comments on the DEIS, the Air Force restated its position that routes across the Nevada Test and Training Range would not be consistent with its national security uses. The Air Force concluded that use of such a corridor or route could adversely affect critical and sensitive national security activities. The U.S. Air Force has stated that it knows of no route across the Nevada Test and Training Range that would avoid the military sensitive areas and thus not affect the heavy volume of testing and training that occurs daily. The Nevada Test and Training Range is the nation's premier range for training of operational flying units and development and operational testing of weapons systems. The transportation of spent nuclear fuel and high-level radioactive waste would lead to the imposition of flight restrictions that would severely degrade the ability to test existing and evolving systems, as well as train U.S. and allied air crews. Therefore, the Air Force believes that such a route would be inconsistent with the national security uses of the Nevada Test and Training Range.

In response, the DOE reevaluated whether it should eliminate the Caliente-Chalk Mountain Corridor and the Caliente/Chalk Mountain heavy-haul truck routes from further evaluation. The DOE met with the Air Force (FEIS, Section C.2.1.6), considered the information the Air Force provided, and concluded that the Caliente-Chalk Mountain Corridor and the Caliente/Chalk Mountain heavy-haul truck route implementing alternatives should remain identified as "non-preferred alternatives" in the FEIS.

The DOE in designating the corridor/route as "non-preferred alternatives" recognized the implications of this corridor/route on national security uses of the Nevada Test and Training Range. At this time, the DOE is not aware of any modifications to the corridor or route that would mitigate the concerns of the Air Force. The DOE has been able to obtain sufficient information for the corridor and route to estimate the environmental impacts that could occur from the construction and operation of a branch rail line or heavy-haul truck route.

The DOE has not identified a particular rail corridor or heavy-haul route as environmentally preferable. If the Yucca Mountain site was recommended and approved and a mode of transportation (rail or heavy-haul truck in Nevada) selected in a Record of Decision, the DOE would then identify an environmentally preferable corridor or route in a subsequent Record of Decision. In making such a determination, the DOE would consider a variety of environmental factors, including many raised by commenters.

4.8.3 (10122)

Summary Comment

An issue was raised by the public regarding use of a rail route on the old Eureka Palisade railroad from Palisade through Pine Valley.

Response

In the report, "Preliminary Rail Access Study" [YMP (Yucca Mountain Site Characterization Project) 1990. "Preliminary Rail Access Study." YMP/89-16. Las Vegas, Nevada: Yucca Mountain Site Characterization Office. ACC: MOL.19980817.0094.], the DOE evaluated a number of potential rail routes from existing mainline railroads to Yucca Mountain. An evaluation of the 13 routes in Nevada is included in the report. In addition, the Eureka Board of County Commissioners issued a report, "Issues Identification Report for the Carlin Rail Route Option," [Planning Information Corporation 1993. "Issues Identification Report for Carlin Rail Route Option." Pahrump, Nevada: Eureka County Board of Commissioners. TIC: 246417.], the report discusses the issues associated with the route that goes from the Union Pacific Mainline in Palisades through the Pine Creek and Monitor Valleys south to Eureka. As identified in "Nevada Potential Repository Preliminary Transportation Strategy Study 2," 1996 [CRWMS M&O 1996. "Nevada Potential Repository Preliminary Transportation Strategy, Study 2," B00000000-0717-4600-00050, Revision 01. Two Volumes, Las Vegas, Nevada: CRWMS M&O. ACC: MOL.19960724.0199; MOL.19960724.0200.], the connection to the Union Pacific mainline at Palisades is very limited due to the close confines of the Palisade Canyon and the arrangement used originally for that line would not be acceptable today. In discussions with the personnel from both Eureka and Lander counties, it was determined that a branch rail line leaving the Union Pacific mainline in the vicinity of Beowawe, west of Palisades would be more preferable. Based on a number of positive attributes for an alignment exiting the Union Pacific mainline in the vicinity of Beowawe, negative attributes of the alignment exiting the Union Pacific mainline at Palisades, and suggestions of the local personnel, the Beowawe alignment was considered more desirable and recommended for further study. The Palisades alignment was then no longer considered. In addition, the FEIS, Section 2.3.3, discusses the other transportation alternatives that were considered but eliminated from detailed study and Figure 2-37 shows the potential rail routes from a mainline railroad to Yucca Mountain that were eliminated.

4.8.3 (13471)

Summary Comment

An issue was raised that the EIS must define how a cost reduction to the Yucca Mountain Program can be achieved with rail and what the projected cost is to construct and operate an intermodal facility in Nevada.

Response

The DOE has analyzed the cost of construction of a rail branch line and construction of an intermodal transfer station and associated road upgrades for heavy-haul transport within Nevada. Cost estimates for each of the transportation implementing alternatives within Nevada are discussed in Section S.5.2.2 of the FEIS Summary.

The DOE has identified mostly rail as the preferred mode for transportation of spent nuclear fuel and high-level waste both nationally and in the State of Nevada. The cost of a transportation-implementing alternative is only one factor in the selection of a mode within Nevada. The DOE would consider the overall impacts associated with any implementing alternative in its selection.

4.8.4 Transportation Cask Design and Performance

4.8.4 (90)

An issue has been raised by the public concerning the physical testing and analysis of casks. Some issues indicated there was no physical testing of shipping casks and there was a lack of information on the possibility of leakage in a severe transportation accident. Another issue stated that the cask testing program was exhaustive and rigorous. Several comments dealt with testing for fires, including the need to test for longer and hotter fires. Other comments advocated testing beyond the design regulatory requirements. Other issues included the effects of a tornado on a cask and the ability to withstand the collapse of Yucca Mountain on a cask in a tunnel.

Based on the results of the analysis presented in Chapter 6 and Appendix J of the FEIS, as well as the results of the studies and environmental impact analyses cited in Chapter 6 and Appendix J, the DOE is confident that transportation casks used to transport spent nuclear fuel and high level radioactive waste can perform their safety functions.

The following discussion presents the safety and accident basis for spent fuel shipping casks. This section is necessary to establish a context for the subsequent discussion on full scale testing.

Spent nuclear fuel casks are robust pieces of equipment, which are designed to safety standards set by the NRC. They are passive devices that require no moving parts to perform their safety functions. Human factors do not ordinarily affect the operation of a cask. Where human factors could affect cask safety, that is, design, fabrication, testing, maintenance, and preparation for use, effective practices, and industry and regulatory standards have evolved over the past half-century to ensure cask safety.

The government and private industry have both contributed to the ongoing improvement of cask safety. They have done so through their continued commitment of resources to research and development, and the development of consensus codes and standards at the national and international levels.

The shipping casks are also extensively tested prior to first use, including radiographic and ultrasonic inspections of welds, load testing of lifting trunnions, pressure testing of the cask containment boundary, gamma scans of the shield, and other tests. Trained and qualified personnel must conduct all testing. The shipping casks are also subjected to periodic in-service testing and maintenance, such as seal replacement, visual inspections of seals and sealing surfaces, and leakage testing. In addition, all shipping cask handling, loading, unloading, testing, and maintenance operations are required to be conducted in accordance with detailed written procedures and by trained and qualified personnel. All these activities are subject to periodic NRC inspection to ensure compliance. The DOE believes the testing, maintenance, procedural, and personnel training requirements would minimize the likelihood and consequences of errors during cask fabrication, testing, and operation.

The NWPA, as amended, (42 U.S.C. 10101 et seq.) requires that the DOE use casks certified by the NRC when transporting spent nuclear fuel and high-level radioactive waste to a repository. The NRC certifies that a cask meets the requirements of 10 CFR Part 71 that prescribes Normal Conditions for Transport (See 10 CFR 71.71) and Hypothetical Accident Conditions (See 10 CFR 71.73). These conditions represent the kinds of forces that a cask would encounter in a severe transportation accident. These conditions have been adopted as international safety standards by the member states of the International Atomic Energy Agency.

A cask's ability to survive the conditions prescribed by 10 CFR Part 71 can be demonstrated in several ways. These options include an appropriate combination of analysis and component, scale-model, and full-scale tests to confirm the performance of the casks. As part of its detailed technical review, the NRC approves the level of physical testing and analysis proposed by the licensee that is appropriate and necessary for each cask design. If the applicant for a certificate fails to demonstrate compliance with the regulations, including the normal and accident conditions, the NRC would not issue a certificate. For a further discussion of cask testing, see Appendix M of the FEIS.

The DOE has the option of evaluating the need for a full-scale cask test. If the DOE chooses to perform full-scale testing, the NRC would review all aspects of the full-scale testing program. For a massive, stiff object like a cask, detailed modeling and computer analysis of the cask's performance in the areas of structural loading, heat transfer, subcriticality, radiation shielding, and containment would still be needed and would require NRC review and certification. Modern computer codes provide more detailed information on the cask's remaining margin to failure at many different locations in the cask, information that cannot be readily obtained through a physical test.

Quarter-scale tests are useful for determining the nonlinear response of the impact limiters to drops and slapdown. This impact limiter testing can be accurately accomplished by scaling.

The following discussion relates to the ability of casks to perform their required safety functions of radiation shielding, maintenance of subcriticality, decay heat removal and radioactive material containment under severe accident conditions, which exceed the design and licensing basis for the cask.

In March 2000, the NRC published "Reexamination of Spent Fuel Shipment Risk Estimates" [Sprung, J.L.; Ammerman, D.J.; Breivik, N.L.; Dukart, R.J.; Kanipe, F.L.; Koski, J.A.; Mills, G.S.; Neuhauser, K.S.; Radloff, H.D.; Weiner, R.F.; and Yoshimura, H.R. 2000. "Reexamination of Spent Fuel Shipment Risk Estimates." NUREG/CR-6672. Two volumes. Washington, D.C.: U.S. Nuclear Regulatory Commission. ACC: MOL.20001010.0217.], a study completed by Sandia National Laboratories. The stated purpose of the study was to reexamine the risks associated with the transport of spent nuclear fuel by truck and rail and to compare the results to those published in the 1977 NRC environmental impact statement on transportation [NRC 1977. "Final Environmental Impact Statement on the Transportation of Radioactive Materials by Air and Other Modes." NUREG-0170. Two volumes. Washington, D.C.: U.S. Nuclear Regulatory Commission. TIC: 221616.] and the 1987 Modal Study [Fischer, L.E.; Chou, C.K.; Gerhard, M.A.; Kimura, C.Y.; Martin, R.W.; Mensing, R.W.; Mount, M.E.; and Witte, M.C. 1987. "Shipping Container Response to Severe Highway and Railway Accident Conditions." NUREG/CR-4829. Two volumes. Washington, D.C.: U.S. Nuclear Regulatory Commission. ACC: NNA.19900827.0230; NNA.19900827.0231.]. The DEIS used techniques and assumptions based on the Modal Study. The new NRC study concluded that both the 1977 NRC environmental impact statement on transportation and the Modal Study made a number of very conservative assumptions about spent nuclear fuel and cask response to accident conditions, which caused their estimate of accident source terms, accident frequencies, and accident consequences to be very conservative. The new NRC study also concluded (p. 9-3):

Based on this more detailed analysis, cask leakage is found to be even less likely than the estimates of the Modal Study, and retention of particles and condensable vapors by deposition onto cask interior surfaces is found to be substantial. Accordingly, both source term probabilities and magnitudes decrease further, and consequently accident population dose risks are reduced further by factors of 10 to 100.

The DOE has updated the FEIS transportation impact analysis to incorporate some of the new findings of the updated NRC analysis [Sprung et al. "Reexamination of Spent Fuel Shipment Risk Estimates."]. Section 6.2.4 and Section J.1.4 of Appendix J of the FEIS concerning analysis of transportation accidents have been revised. This revision incorporates data from the new NRC study and no longer relies on the data from the Modal Study. The new NRC study contains revised estimates of probable releases from spent nuclear fuel casks during severe transportation accidents, that involve long duration fires accompanied by high impact forces, which are beyond regulatory design requirements.

The NRC is also conducting its Package Performance Study to assess the performance of spent nuclear fuel packages during transportation accidents and to verify assumptions used in the new NRC study [Ibid.].

Risk analyses, such as the ones mentioned above, contain a spectrum of accident severity, from the ordinary to the severe. The most severe accidents are highly unlikely. The DOE has used the best and most current analyses reasonably available, and has concluded that the risk from the repository shipping campaign is neither overly conservative, nor unacceptably high. Based on the results of the analysis presented in Chapter 6 and Appendix J of the FEIS, as well as the results of the studies and environmental impact analyses cited in Chapter 6 and Appendix J, the DOE is confident spent nuclear fuel and high level radioactive waste can be transported to a repository safely.

The transportation regulations of the NRC include shipping cask design requirements for normal and accident conditions of transport (10 CFR Part 71). The regulations do not specifically address natural disasters such as earthquakes, floods, or tornadoes. However, if a shipment to Yucca Mountain was involved in any of these natural disasters, the impact on the cask would be within the bounds of the hypothetical accident defined in 10 CFR Part 71. The DOE transportation contractors, as part of the preshipment planning, would obtain weather forecasts. Forecasts for rain, snow, fog or high winds and tornado warnings would be considered in the determination of the shipment schedule. Shipments would not travel when severe weather conditions along routes or adverse road conditions would make highway travel too hazardous.

4.8.4 (91)

Summary Comment

An issue has been raised by the public regarding spent fuel shipping cask designs. Comments indicated concern with additional radiation shielding, possible cask leakage after an accident, and NRC regulatory design limits. Other issues were the release of radioactive materials after a crash or a fire, the disruption to a community that would result from an accident, possible lead shielding slump following a fire, and the ability of shipping casks to safely contain large amounts of radioactivity.

Issue

Members of the public expressed concern that shipping casks used in the transportation of spent nuclear fuel and high-level radioactive waste would not be safe.

Response

Casks used to transport spent nuclear fuel and high-level radioactive waste are robust pieces of equipment that are designed to safety standards set by the NRC. They are passive devices that require no moving parts to perform their safety functions. As passive devices, human errors do not normally affect the operation of a cask. However, human errors could affect cask safety during design, fabrication, maintenance, and preparation for use. Effective practices, and industry and regulatory standards have evolved over the past half-century to reduce human error to assure cask safety. The DOE would use casks certified by the NRC for shipments of spent nuclear fuel and high-level radioactive waste to a repository. The regulations, which must be met prior to certification of these casks, are the radiological performance standards that ensure public health and safety. Furthermore, the transportation activities would be done under a quality assurance program that is approved by the NRC. Cask design and quality assurance certifications are the two important types of approvals issued by the NRC that apply to transportation activities. Although the DOE would use casks designed by others, the NRC would certify the designs and require applicable quality assurance provisions.

The shipping casks that the DOE would use to transport spent nuclear fuel and high-level radioactive waste would be massive, with design features that comply with regulatory requirements that ensure the casks would perform their safety functions even when damaged. The cask safety functions, which must be maintained both during normal conditions or following an accident, are: decay heat removal, radiation shielding, maintenance of subcriticality within required shutdown margins, and containment of the radioactive contents within regulatory limits. Numerous tests and extensive analyses have demonstrated that casks would provide containment and shielding even under the most severe kinds of accidents. In addition, the NRC published a report, [Sprung, J.L.; Ammerman, D.J.; Breivik, N.L.; Dukart, R.J.; Kanipe, F.L.; Koski, J.A.; Mills, G.S.; Neuhauser, K.S.; Radloff, H.D.; Weiner, R.F.; and Yoshimura, H.R. 2000. "Reexamination of Spent Fuel Shipment Risk Estimates." NUREG/CR-6672. Two volumes. Washington, D.C.: U.S. Nuclear Regulatory Commission. ACC: MOL.20001010.0217.], a study completed by Sandia National Laboratories. Based on the revised analyses, the DOE has concluded in the FEIS that casks would fully contain spent nuclear fuel in more than 99.99 percent of all accidents. This means that of the approximately 53,000 truck shipments over 24 years in a "mostly truck" scenario, an estimated 66 accidents nationwide could occur, each having less than a 0.01 percent chance that radioactive materials would be released. The chance of a rail accident that would cause a release from a cask would be even less. The corresponding chance that such an accident would occur in any particular locale would be extremely low. Section J.1.4.2.1 of the FEIS presents radiological impacts for accidents that could release radioactive materials.

Unlike many hazardous materials routinely transported on our nation's roads and rails, spent nuclear fuel and high-level radioactive waste are solids. This fact is an inherent contributor to the demonstrated safety record of high-level radioactive waste transport in the U.S. during the last 30-plus years. The cask's shielding and structural integrity protect the public from harmful levels of radiation emitting from the spent nuclear fuel or high-level radioactive waste contained within the cask during transport. While there have been seven transport accidents involving spent nuclear fuel [FEMA (Federal Emergency Management Agency) 2000. "Guidance for Developing State, Tribal, and Local Radiological Emergency Response Planning and Preparedness for Transportation Accidents." FEMA REP-5, Rev. 02. Washington, D.C.: Federal Emergency Management Agency.], none of these accidents has resulted in the release of its radioactive contents. In the unlikely event of a transportation accident so severe that the cask seals are damaged, volatile elements, crud, and fission product gasses could be released into the air. Nevertheless, the transportation cask would still safely contain the solid spent nuclear fuel assemblies and high-level radioactive waste forms.

Because shipping casks are passive devices, human actions are not necessary to maintain the safety functions of a cask once it has been properly loaded and prepared for shipment. Human factors could affect cask safety in the design, fabrication, maintenance, and preparation for use. Effective practices promoted by a safety culture, strong regulatory oversight, quality assurance, and industry and regulatory standards provide a high degree of assurance that shipping casks meet the performance requirements of the regulations of the NRC and U.S. Department of Transportation. In addition, through continued commitment of resources to research and development, and development of consensus codes and standards, the Federal Government and private industry have contributed to ongoing improvement of cask safety.

Spent fuel shipping casks are not highly complex mechanisms. They are passive structures composed of well-characterized materials that are assembled to form relatively simple, massive structures that are within the scope of current fabrication technology. Manufacture of the cask is accomplished using many standardized processes. The resulting cask's quality is ensured through application of comprehensive NRC approved quality assurance programs, which covers fabrication of casks and requires that measures be established to ensure processes, including welding, heat treating, and nondestructive testing; are controlled and accomplished by qualified personnel using qualified procedures. These procedures are written in accordance with applicable codes, standards, specifications, criteria, and other requirements (see 10 CFR Part 71, Subparts D and H). The NWPA requires the DOE to use NRC certified shipping casks. NRC certified casks would be designed, manufactured, operated, and maintained under an NRC-approved quality assurance program (10 CFR Part 71, Subpart H). The NRC would perform independent regulatory oversight of the activities performed under the quality assurance program. The NRC oversight role typically includes periodic inspection at cask designers, fabricators, and reactor sites to verify proper implementation of required standards, fabrication practices, and quality control inspections.

As stated, spent nuclear fuel and high-level radioactive waste would be properly packaged for shipment in Type B shipping casks certified by the NRC to comply with the performance standards contained in 10 CFR Part 71, as required by NRC and U.S. Department of Transportation regulations. An accident, cited by some comments, occurred in Massachusetts in 1991 and involved Type A packaging. Type A containers have less stringent requirements than for Type B. The DOE would not use Type A containers to ship spent nuclear fuel or high-level radioactive waste.

The DOE has added Appendix M to the FEIS, which presents information on cask safety (FEIS, Section M.4). The DOE is confident that by implementing NRC licensing regulations and by using NRC-certified casks, transportation would be carried out in a safe manner.

"Real life" transportation accidents involve collisions of many kinds, such as with other vehicles and obstacles, which could result in fires and explosions, inundation, or burial of a cask containing spent nuclear fuel and high-level radioactive waste. These accidents are caused in turn by a variety of initiating events including human error, mechanical failure, and natural causes such as earthquakes. Accidents occur in many different kinds of places including mountain passes and urban areas, rural freeways in open landscapes, and rail switching yards.

The combinations of accident conditions, initiating events and locations is very large. Analyzing an extensive array of accident scenarios is neither practical nor meaningful. However, it is meaningful to analyze a range of reasonably foreseeable accident scenarios that consider, in effect, common initiating events and conditions having similar characteristics. Thus, for example, the FEIS analyzes the impacts of various collision accidents in which a cask would be exposed to a range of impact velocities (see FEIS, Section J.1.4.2.1).

The FEIS also analyzes a maximum reasonable foreseeable accident, an accident with a probability of occurrence of about 3 in 10 million per year. To put this in perspective, this accident would occur once in the course of about 5 billion legal-weight truck shipments (under a mostly legal-weight truck scenario there would be approximately 53,000 shipments). In this scenario, a truck cask, not involved in a collision, would be engulfed in a fire with temperatures between 750 degrees Celsius and 1,000 degrees Celsius (1,400 degrees Fahrenheit to 1,800 degrees Fahrenheit) (see FEIS, Section 6.2.4.2). The conditions of the maximum reasonably foreseeable accident analyzed in the FEIS envelope conditions reported for the Baltimore Tunnel fire (a train derailment and fire that occurred in July 2001 in a tunnel in Baltimore, Maryland).

It should be noted that transportation casks would not be placed in Yucca Mountain. Section 3.5.3.3 of the S&ER Rev. 1 contains a discussion of rockfall structural evaluations performed on waste package designs.

4.8.4 (2547)

Summary Comment

An issue has been raised by the public regarding cleaning of transportation casks.

Response

The issue could be referring to either of two common operational activities, which are performed on spent fuel shipping casks. The first possibility would be the cleaning of road dirt from the casks before they are placed in a spent fuel pool. This cleaning is necessary to prevent unnecessary amounts of dirt from entering the spent fuel pool, where it can become contaminated and would increase the loading on the pool filters. The second possibility would be the decontamination (sometimes called cleaning) of the cask after it is removed from a spent fuel pool and before it is released from a site for transport on public road or railways. Both these "cleaning" activities are common operational activities that must be accomplished carefully and controlled within licensed limits.

4.8.4 (13021)

Summary Comment

An issue has been raised by the public concerning the effect of irradiation on metal fatigue and the shipping casks.

Response

The issue raised is not correct in stating that metal fatigue in cask components would be caused by radiation from the cask's contents, and that metal fatigue would occur sooner due to increased heat.

Embrittlement of carbon steels is a design consideration for nuclear reactor vessels, where the fast neutron flux is very large, and impinges upon the reactor vessel at a high, steady rate over many years. In contrast, in a spent fuel cask, the fast neutron flux is many orders of magnitude lower than in a reactor, and the cask is exposed to that small flux for discontinuous periods of a few days, not enough flux or time to induce significant neutron embrittlement. So, neither neutron embrittlement nor radiation-induced metal fatigue is a compelling design issue for spent fuel casks.

The heat generation rate of spent nuclear fuel is not sufficient to alter the material properties during its design lifetime. Cask structural performance, fuel integrity, shield integrity, and cask surface temperature (a personnel safety issue) all depend on the fuel heat generation rate and the cask's ability to transfer that heat to the atmosphere. Cask designers set limits on the maximum allowed heat generation rate for the contents, and demonstrate that cask temperature limits are maintained for both normal and accident conditions, which are specified in the applicable NRC regulation, 10 CFR Part 71. The NRC reviews the cask designer's thermal analysis in detail, before granting a certificate allowing cask construction and use.

The DOE has added Appendix M to the FEIS, which presents information on cask safety (see Section M.4). The DOE would be required to follow NRC and U.S. Department of Transportation regulations and use NRC-certified casks when transporting spent nuclear fuel and high-level radioactive waste to a repository. The DOE is confident that by implementing these regulations and using NRC-certified casks, transportation would be carried out in a safe manner.

4.8.5 Transportation Operational Policies and Procedures

4.8.5 (9)

An issue was raised by the public about privatization of the transportation system. A common theme was that the DOE should not privatize or delegate to a contractor any key transportation responsibilities because of conflicts between transportation safety and the profit motivation of the private industry. Comments indicated a need for assuring that the transportation contractors conduct business properly and only permit transport on the safest rails or roads. A concern was that many critical policy decisions would be improperly delegated to a contractor, such as the responsibility for selecting modes, routes, and casks, as well as the development of institutional plans and the preparation of an environmental impact statement addressing transportation. Additionally, consideration should be given to shared use of any new branch rail line in Nevada for its contribution to the regional economic benefit.

An issue has been raised by the public recommending that the DOE not privatize or delegate to a contractor any key transportation responsibilities because of conflicts between transportation safety and the profit motivation of the private industry.

With the controls noted below, the DOE would be able to effectively utilize the experience and expertise of private transportation contractors while not degrading the safety of the shipments of spent nuclear fuel and high-level waste.

Transporting spent nuclear fuel and high-level radioactive waste is regulated to protect public health and safety. The NRC and the U.S. Department of Transportation share primary responsibility for establishing and enforcing requirements for the safe transportation of spent nuclear fuel and high-level radioactive waste. Shipments are regulated from both the safety and physical security standpoints. Transportation to a repository would be conducted under the regulations existing at the time of shipment with oversight by various local, tribal, state, and federal agencies.

The NWPA, in Section 137(a)(2) (42 U.S.C. 10157(a)(2)), requires the Secretary of Energy to utilize private industry to the fullest extent possible in each aspect of transportation of spent nuclear fuel and high-level radioactive waste under the Act. At present, the DOE plans to implement this requirement by contracting with private industry to provide equipment such as casks and transport vehicles, to provide training of utility personnel in the use of the equipment, and to provide the transportation of the loaded and unloaded casks between the waste generator and storage sites and Yucca Mountain. The exact form of the contracts with private industry continues to be studied.

The DOE would retain responsibility for policy decisions, stakeholder relations, and approval of routes to be proposed to the NRC in consultation with affected states and tribes. The DOE would implement and administer programs that implement the NWPA Section 180(c) (42 U.S.C. 10175(c)) for routine transportation and emergency response planning and training.

Prospective transportation contractors would be evaluated on their past performance and the degree to which their technical approach addresses the safety, operational, and logistical requirements of the program. The DOE would award contracts for waste acceptance and transportation services to bidders whose proposals are considered to be most advantageous to the DOE, with cost being only one of a variety of selection factors.

The DOE transportation contractors would be required to have quality assurance programs approved by the NRC under 10 CFR 71, Subpart H. The DOE would review and approve the transportation contractors' NRC-approved quality assurance programs and subsequently monitor and oversee the transportation contractors' activities through audits and surveillance. This oversight by the DOE would be in addition to that performed by the NRC on its 10 CFR Part 71 licensees.

The DOE would work with states and tribes to develop communication, training, and security plans. Should additional regulatory reviews for NWPA transportation activities be necessary, the DOE would be the responsible agency.

Appendix M of the FEIS contains additional information on the regulations that govern spent nuclear fuel and high-level waste transportation, the proposed process that the DOE would use to acquire commercial transportation services and the expected operational details and protocols that would be followed. Refer also to the DOE revised draft request for proposal for the "Acquisition of Waste Acceptance and Transportation Services for the Office of Civilian Radioactive Waste Management" [DOE (U.S. Department of Energy) 1998. "Acquisition of Waste Acceptance and Transportation Services for the Office of Civilian Radioactive Waste Management." Draft RFP # DE-RP01-98RW00320. Washington, D.C.: U.S. Department of Energy. ACC: MOL.19981007.0005.]. The revised draft request for proposal is available on the website for the DOE Office of Civilian Radioactive Waste Management at www.rw.doe.gov/wasteaccept/wasteaccept.htm.

Issue

The issue has been raised by the public that in the interest of safety, the DOE should not use a low-bidder strategy for transportation contracting.

Response

The DOE would award contracts for waste acceptance and transportation services to bidders whose proposals are considered to be most advantageous to the DOE, with cost being only one of the selection factors. All transportation of spent nuclear fuel and high-level radioactive waste would be in accordance with NRC and Department of Transportation regulations.

Prospective transportation contractors would be evaluated on their past performance and the degree to which their technical approach addressed the safety, operational, and logistical requirements of the program. One of the criterion that must be met by a successful bidder would be to have safely performed a major transportation and logistics coordination project involving railroad, truck, and/or intermodal carriage of radioactive, toxic, or other types of hazardous materials within the last 10 years. Most important, the DOE would continually assess the performance of each of the transportation contractors.

The qualification and evaluation criteria for the award of contracts to the private transportation contractors are identified in Section M of the "Acquisition of Waste Acceptance and Transportation Services for the Office of Civilian Radioactive Waste Management" [DOE (U.S. Department of Energy) 1998. "Acquisition of Waste Acceptance and Transportation Services for the Office of Civilian Radioactive Waste Management." Draft RFP # DE-RP01-98RW00320. Washington, D.C.: U.S. Department of Energy. ACC: MOL.19981007.0005.]. To qualify for consideration, the Offeror must provide in the submittal of a proposal evidence of demonstrated NRC approved Quality Assurance capability in accordance with the requirements of 10 CFR 71, Subpart H. The evaluation criteria include the degree to which the Offeror's proposed approach demonstrated the ability to implement and manage an effective Quality Assurance Program.

Issue

An issue has been raised by the public stating that shared use of a rail branch line in Nevada would produce economic and multiuse benefits as such use could enhance access to mining and mineral resource areas.

Response

The DOE identified the potential for shared use in Section 8.4.2 of the FEIS as a reasonably foreseeable future action. This section of the FEIS states "DOE would have to consider these impacts [of shared use] in any decision it made to allow shared use of the branch rail line."

Decisions on a Nevada rail route and its operation would not be made until the site approval process is complete. If the site were recommended and approved, there would be significant opportunities for input by the state, tribes and local jurisdictions, and other interested parties.

If the Yucca Mountain site was approved, the DOE believes that the FEIS provides the environmental impact information necessary to make certain broad transportation-related decisions, namely, the choice of a national mode of transportation outside Nevada (mostly rail or mostly legal-weight truck, or heavy-haul truck with use of an associated intermodal transfer station), and the choice among alternative rail corridors or heavy-haul truck routes with the use of an associated intermodal transfer station in Nevada. However, follow-on implementing decision, such as the selection of a specific rail alignment in a corridor would require additional field surveys, State and local government and Native American tribal consultation, environmental and engineering analyses, and regulatory reviews. Consequently, discussions with stakeholders regarding the specific alignment of a branch rail line within a corridor and the possibility of its shared use would be premature at this time.

4.8.5 (13)

Summary Comment

Issues were raised by the public regarding which guidelines would govern the movement of waste and what activities would be done to assure the safe transportation of the spent nuclear fuel and high-level radioactive waste under routine conditions of transport. Specific issues include notification of routes; condition of the highways, railroads and transport vehicles; inspection of roads, bridges and vehicles; training and qualifications of transport personnel; and consideration of weather and driver behavior.

Issue

An issue was raised by the public that requires identification of the regulations that would govern the shipments of spent nuclear fuel and high-level radioactive waste to a repository.

Response

The regulatory requirements of the NRC and the U.S. Department of Transportation govern shipments of spent nuclear fuel and high-level radioactive waste and are discussed in Appendix M of the FEIS.

The U.S. Department of Transportation and the NRC share primary responsibility for establishing and enforcing requirements for safe transportation of radioactive materials, including spent nuclear fuel and high-level radioactive waste. The regulations are contained in Titles 49 and 10, respectively, of the Code of Federal Regulations. The DOE would comply with these regulations when transporting spent nuclear fuel and high-level radioactive waste to Yucca Mountain.

U.S. Department of Transportation regulations set the standards for highway route selection, packaging, transporting, and handling radioactive materials, including labeling, shipping papers, placarding, loading, and unloading requirements. U.S. Department of Transportation regulations also specify the training required for personnel who perform handling and transport of radioactive materials.

NRC licensing regulations establish the standards for shipping casks to be used for transport of spent nuclear fuel and high-level radioactive waste to a repository at Yucca Mountain. The NWPA requires that the DOE use casks certified by the NRC when transporting spent nuclear fuel and high-level radioactive waste to a repository. The NRC certifies that a cask meets the requirements of 10 CFR Part 71, which prescribes the radiological performance standards for the casks subjected to specific test conditions. These test conditions represent the kind of forces that a cask could encounter in a severe transportation accident.

Issue

An issue was raised by the public regarding the need for clear identification of state and federal regulations that would have to be adhered to for rail shipments, especially for track maintenance, of spent nuclear fuel and high-level radioactive waste under the NWPA.

Response

A discussion of many of the transportation regulations and the operational protocols the DOE transportation contractors would be required to follow is in the FEIS, Appendix M.

The requirements for maintenance of rail lines are prescribed by Federal Railroad Administration regulations (49 CFR Part 213, "Track Safety Standards"). Rail shipments would be inspected according to the Federal Railroad Administration policy as described in the "High-Level Nuclear Waste Rail Transportation Inspection Policy" [FRA (Federal Railroad Administration) 2001. "High-Level Nuclear Waste Rail Transportation Inspection Policy." Washington, D.C.: U.S. Department of Transportation. Accessed August 2, 2001. ACC: MOL.20011009.0011. http://www.fra.dot.gov/o/safety/hazmat/hlvwste.htm].

Oversight of branch line operations in Nevada, if a decision is made to build such a line, has not been defined at this time; however, the Federal Railroad Safety Act of 1970, as amended, (49 U.S.C. 20101 et seq.) allows state participation in investigative and surveillance duties.

Issue

An issue was raised by the public regarding who would determine the suitability of the vehicle tractors and trailers or railcars used in transport.

Response

A discussion of many of the transportation regulations and operational protocols the contractors would be required to follow is found in FEIS Appendix M.

Inspections of the vehicles, loads, and drivers, at the point of origin and elsewhere as required, would be conducted, in accordance with procedures developed by the Commercial Vehicle Safety Alliance [CVSA (Commercial Vehicle Safety Alliance) 1999. "North American Standard Out-of-Service Criteria and Enhanced North American Standard Inspection Procedures and Out-of-Service Criteria for Commercial Highway Vehicles Transporting Transuranics, Spent Nuclear Fuel, and High-Level Radioactive Waste." Bethesda, Maryland: Commercial Vehicle Safety Alliance. TIC: 243776.] (home page at http://www.cvsa.org/). Rail shipments would be inspected according to the Federal Railroad Administration policy as described in the High-Level Nuclear Waste Rail Transportation Inspection Policy [FRA (Federal Railroad Administration) 2001. "High-Level Nuclear Waste Rail Transportation Inspection Policy." Washington, D.C.: U.S. Department of Transportation. Accessed August 2, 2001. ACC: MOL.20011009.0011. http://www.fra.dot.gov/o/safety/haxmat/hlvwste.htm].

Issue

An issue was raised by the public that careful plans that would minimize risk and ensure safe transport of radioactive materials must be developed and implemented.

Response

Each of the DOE transportation contractors would be required to prepare a comprehensive transportation plan that describes the operational strategy and delineates steps to be implemented to ensure compliance with all regulatory and DOE requirements. Adherence to these regulations has proven to minimize risk. Each plan would include identification of proposed routes and associated routing considerations, coordination and communication with all participating organizations and agencies, and interactions with appropriate federal and state organizations. The DOE would make the plans available to states and tribes for comment.

Issue

An issue was raised by the public that the DOE could enhance safe routine transport of shipments by working closer with local and state communities and national organizations.

Response

The DOE agrees that detailed, comprehensive planning would be required prior to the start of shipments to a repository. However, it would be useful only when carried out closer to the time any rail or truck transportation would be scheduled to begin. Otherwise, the information upon which such planning was based would be likely to change before shipments could begin. Operational protocols for transporting spent nuclear fuel and high-level radioactive waste to Yucca Mountain are presented in the draft Request for Proposal, "Acquisition of Waste Acceptance and Transportation Services for the Office of Civilian Radioactive Waste Management" [DOE (U.S. Department of Energy) 1998. "Acquisition of Waste Acceptance and Transportation Services for the Office of Civilian Radioactive Waste Management." Draft RFP # DE-RP01-98RW00320. Washington, D.C., U.S. Department of Energy, ACC: MOV.19981007.0005.]. They are also summarized in the Section M.3 of the FEIS. The "Waste Isolation Pilot Plant Transportation Safety Program Implementation Guide" [WGA (Western Governors' Association) 1995. "Waste Isolation Pilot Plant Transportation Safety Program Implementation Guide." Washington, D.C.: Western Governors' Association, Technical Advisory Group for WIPP Transport. ACC: HQO.20000922.0020.] protocols were used as a model for Yucca Mountain-related protocols. The DOE expects to interact with affected stakeholders on routing and related local issues if the repository site were approved.

Issue

An issue was raised by the public regarding the recent significant derailments involving hazardous, but not radioactive, materials.

Response

Actions would be taken during preparation for shipments to minimize the possibility of derailments.

The Federal Railroad Administration has developed its "Safety Compliance Oversight Plan for Rail Transportation of High-level Radioactive Waste and Spent Nuclear Fuel" [DOT (U.S. Department of Transportation) 1998. "Safety Compliance Oversight Plan for Rail Transportation of High-Level Radioactive Waste and Spent Nuclear Fuel, Ensuring the Safe, Routine Rail Transportation of Foreign Research Reactor Spent Nuclear Fuel." Washington, D.C.: U.S. Department of Transportation, Federal Railroad Administration. ACC: MOL.20011212.0115.]. That plan sets forth the Federal Railroad Administration policy to address the safety of rail shipments of spent nuclear fuel and high-level radioactive waste. The plan includes the current Federal Railroad Administration policy on planning, inspection, training and oversight activities and can be accessed at the U.S. Department of Transportation website, www.fra.dot.gov.

The DOE would require the transportation contractor to provide for maximum use of dedicated train service and advanced rail service features where this type of service or equipment can be demonstrated to enhance operating efficiency, dependability, cost effectiveness, or lessen the potential for adverse railroad equipment incidents. The requirements for maintenance of rail lines are prescribed by Federal Railroad Administration regulations (49 CFR Part 213, "Track Safety Standards"). The Federal Railroad Administration would check rail line maintenance in accordance with its "Safety Compliance Oversight Plan" [Ibid].

In Appendix M 3.2 of the FEIS, the DOE has added information regarding selection of rail routes for the transportation of spent nuclear fuel and high-level radioactive waste to a repository at Yucca Mountain.

Issue

An issue was raised by the public regarding possible human error in preparing the casks and transporters for shipment. The specific issue is the responsibility for assuring quality in transportation activities.

Response

The DOE has provided information on the potential operational aspects of transportation activities in Appendix M.3 of the FEIS.

Casks would be prepared for shipment under the quality assurance procedures approved by the NRC and, as a minimum, the DOE transportation contractor and the carrier would inspect the transporters and casks prior to shipment. A shipment would not be allowed to leave the generation or storage site until it complied with the quality assurance requirements. Inspections also could be conducted en route and at the repository destination.

The DOE transportation contractors would be required to have quality assurance (QA) programs approved by the NRC under 10 CFR 71, Subpart H. The DOE would review and approve the transportation contractors' NRC-approved quality assurance programs and, subsequently, would monitor and oversee the transportation contractors' activities through audits and surveillance. This oversight by the DOE would be in addition to that performed by the NRC on its 10 CFR Part 71 licensees.

Issue

A concern was raised by the public regarding driver behavior and whether relief drivers should be considered for safer transportation of the waste under routine conditions.

Response

The rules governing the amount of time a commercial driver can operate a vehicle are in 49 CFR Part 395 of the U.S. Department of Transportation, Federal Motor Carrier Safety Administration. These rules would guide the DOE transportation contractors in their transportation planning.

The DOE transportation contractors would be required to consider appropriate places for rest, vehicle refueling, and vehicle repair in their transportation plans. The DOE would make these plans available to states and tribes for comment before the shipments took place. Additional information can be found under the discussion of operational protocols in Appendix M of the FEIS.

Issue

An issue was raised by the public that, for safe routine transport of spent nuclear fuel and high-level radioactive waste, the drivers and crew need more than the regulatory minimum of training.

Response

Carriers are required to develop and maintain driver and crew-training programs that meet the U.S. Department of Transportation requirements of 49 CFR 172.600. Drivers are required to complete the training called for in 49 CFR 177.816, while locomotive engineers must meet the certification requirements of 49 CFR Part 240. See Appendix M of the FEIS for additional information.

The DOE contractors providing transportation services would be required to prepare a transportation plan that would discuss the various steps the contractor would take to ensure the shipments would be conducted in a safe and efficient manner. Among other things, the plan would provide for the training applicable to the transport of spent nuclear fuel and high-level radioactive waste. The training of drivers and crews would include, as appropriate, operation of specific package tie-down systems, cask recovery procedures, use of radiation detection instruments, use of the satellite communications system, adverse weather and safe parking procedures, first responder awareness training, and radiation worker training.

Issue

An issue was raised by the public that for safe routine transport of spent nuclear fuel and high-level radioactive waste the drivers and crew need more than the regulatory minimum qualifications, including a verification of a lack of past violations.

Response

The drivers and crew for shipments would not be federal employees nor would they have security clearances but they would, as indicated below, be required to have qualifications beyond the extensive requirements of the Department of Transportation regulations.

Drivers would be required to meet the qualifications specified in the U.S. Department of Transportation regulations 49 CFR Part 391. They would also be required to complete the training called for in the U.S. Department of Transportation regulations 49 CFR 177.816. Locomotive engineers must meet the certification requirements of 49 CFR Part 240. This includes training on the properties and hazards of the materials of radioactive material and procedures to be followed in the event of an emergency. In addition to these requirements, driver and crew training would cover the following: operation of specific package tie-downs, cask recovery procedures, use of radiation detection instruments, use of a satellite-based tracking system and other communications equipment, adverse weather and safe parking procedures, first responder awareness, enhanced inspection standards, and security requirements.

Each of the DOE transportation contractors would be required to develop, for review and approval of the DOE, a Carrier Management Plan that details the steps that the contractor and its carrier would implement to ensure compliance with all regulatory and other requirements of the DOE. The Carrier Management Plan would include, along with other requirements, the carrier's policy for: driver and crew screening and hiring, the imposition of specific driver and crew penalties, and the carrier's substance abuse policy (including screening tests).

Issue

An issue was raised by the public regarding the action that would be taken to ensure that severe weather or natural disasters would not endanger the shipments.

Response

The DOE would monitor weather forecasts to ensure shipments would not occur in areas where, and at the times when, the potential for severe weather could compromise safety.

The DOE would temporarily discontinue shipments of spent nuclear fuel and high-level radioactive waste that would use a highway or rail line where severe weather could compromise safety. Appendix M of the FEIS provides a discussion of the protocols and procedures to be implemented by DOE transportation contractors under adverse weather or road conditions.

The DOE and the transportation contractors would use a satellite-based system, for providing continuous real-time position tracking and communication for all shipments of spent nuclear fuel and high-level radioactive waste. The truck drivers or rail crew would be able to communicate to the dispatch center and others through various means of communication that would enable the carrier to immediately communicate potential problems, even in remote areas. If unanticipated severe weather or adverse road conditions were encountered, the driver and crew would coordinate with the control center routing to a safe parking area, if it became necessary to delay the shipment until conditions improved. Appendix M.3 of the FEIS provides detailed information on the selection of safe parking areas to be used in the event a shipment would have to be delayed.

Issue

An issue was raised by the public regarding how a person could identify shipments of spent nuclear fuel and high-level radioactive waste and how authorities could locate these shipments.

Response

Vehicles (trucks and railcars) carrying spent nuclear fuel or high-level radioactive waste would be placarded in accordance with U.S. Department of Transportation regulations in 49 CFR 172 Subpart F. Packages (casks) would be marked and labeled in accordance with NRC regulations for licensing in 10 CFR 71.59. Additional information on these marking requirements is provided in Appendix M.2.2 of the FEIS.

The DOE and the DOE transportation contractors would use the latest version of TRANSCOM or a similar satellite-based system, to provide continuous real-time position tracking and communication for all shipments of the trucks and railcars carrying spent nuclear fuel and high-level radioactive waste.

Issue

An issue was raised by the public that the DEIS did not address the provision for state notification regarding routes and mode of transportation.

Response

Information on the notification process is included in Appendix M 2.5 of the FEIS.

The DOE would comply with applicable federal regulations for providing notification to the states of spent nuclear fuel shipments. NRC regulations in 10 CFR 73.37(f) require notification by mail or messenger to the governor or the governor's designee. Governors should notify state and local safety officials, as appropriate, of the pending shipments. NRC physical security regulations apply only to shipments of spent nuclear fuel. Notification is not required for shipments of high-level radioactive waste. However, the DOE intends to follow the same procedures for high-level radioactive waste shipments, and for unclassified shipments of DOE-owned spent nuclear fuel and other material, that might be shipped to Yucca Mountain. Native American tribes would receive notification also, if the NRC amends the regulation to allow this.

Issue

An issue was raised by the public that the DOE should provide ways to monitor shipments so that states, tribes and individuals would know the location of shipments at all times.

Response

The DOE and the transportation contractors would use the latest version of TRANSCOM, or a similar satellite-based system, for providing continuous real-time position tracking for all shipments. The carrier would be able to communicate to its dispatch center and others through various means of communication, including the Transportation Tracking and Communication system. This system would enable the carrier to communicate, even in remote areas.

The DOE intends to make the TRANSCOM system information available to the states and tribes (if authorized by the NRC). Thus, there would be information upon which to base requests for aid to local law enforcement or emergency response personnel as needed.

The DOE would comply with the NRC regulations requiring notification to the governor or the governor's designee by mail or messenger (10 CFR 73.37(f)). Governors should notify state and local public safety officials, as appropriate, of the pending shipments. Therefore, these local law enforcement agencies would have access to the sensitive safeguards information and would know when a shipment is scheduled to be in their jurisdiction. Note that the NRC has a proposed regulatory change under consideration that would include the appropriate Native American tribes in the notification.

Not all information regarding shipments of spent nuclear fuel and high-level nuclear waste would be released to the general public because of security reasons. The NRC publishes the routes that shipments would take. NRC regulations (10 CFR Part 73) require the schedules to be held as sensitive safeguards information. The DOE transportation contractors must make prior arrangements with local law enforcement agencies along the routes for potential response to an emergency or a call for assistance. These local law enforcement agencies would have access to the confidential Safeguards Information and would know when shipments are scheduled to be in their area.

Issue

An issue was raised by the public that the DOE should identify the inspections that would be required for transport of spent nuclear fuel and high-level radioactive waste on the highways and rail lines. In addition, an issue was raised by the public that these inspections should be conducted by entities other than the DOE.

Response

Appendix M of the FEIS provides additional information on pretrip, en route, and posttrip inspections.

The DOE contractors providing transportation services would be required to prepare comprehensive transportation plans that discuss the various steps that the DOE and the carrier would take to ensure the shipments are conducted in a safe and efficient manner. These plans would identify pretrip, en route, and posttrip inspection requirements.

Rail shipments would be inspected in accordance with Federal Railroad Administration policy as described in "Safety Compliance Oversight Plan for Transportation of High-Level Radioactive Waste and Spent Nuclear Fuel" [DOT (U.S. Department of Transportation) 1998. "Safety Compliance Oversight Plan for Rail Transportation of High-Level Radioactive Waste and Spent Nuclear Fuel, Ensuring the Safe, Routine Rail Transportation of Foreign Research Reactor Spent Nuclear Fuel." Washington, D.C.: U.S. Department of Transportation, Federal Railroad Administration, ACC: MOL.20011212.0115.].

Funding under the NWPA allows the states and tribes to train public safety officials to conduct inspections on NWPA shipments. Inspections of the highway vehicle, load, and driver, at point of origin and elsewhere as required, would be conducted in accordance with procedures developed by the Commercial Vehicle Safety Alliance. Rail shipments would be inspected according to the Federal Railroad Administration policy as described in the "High-Level Nuclear Waste Rail Transportation Inspection Policy." [FRA (Federal Railroad Administration) 2001. "High-Level Nuclear Waste Rail Transportation Inspection Policy." Washington, D.C.: U.S. Department of Transportation. Accessed August 2, 2001 ACC: MOL.20011009.0011.].

The DOE has published a "Notice of Revised Proposed Policy and Procedures," which discusses the plans for implementation of Section 180 (c)(42 U.S.C.10175(a)) of the NWPA. One of the proposed policies is to provide each eligible state and tribe the funding and technical assistance to prepare for safety and enforcement inspections of NWPA highway shipments and for rail measures that complement Federal Railroad Administration inspection procedures. The Commercial Vehicle Safety Alliance conducts special training for state personnel who inspect highway vehicles transporting spent nuclear fuel and high-level radioactive waste. States and tribes may use Section 180(c) funds to receive Commercial Vehicle Safety Alliance training. The Federal Railroad Administration of the Department of Transportation provides funds to states for track and train inspectors. Section 180(c) funding would be available approximately four years before the DOE commences shipping to a repository. See Appendix M.3 of the FEIS for additional information.

4.8.5 (87)

Summary Comment

Issues were raised by members of the public regarding emergency response capabilities, protocols for response, potential mitigation measures, and who would implement them. A question was raised concerning how the DOE could measure health and safety impacts and emergency management mitigation needs if it is not clear how the DOE plans to communicate with local entities.

Issue

An issue has been raised by the public questioning who would respond in the event of an accident involving shipments of spent fuel or high-level radioactive waste to a repository.

Response

Response to accidents involving shipments of spent nuclear fuel or high-level waste would be by local public safety personnel assisted by the shipment escorts, the DOE transportation contractor and the carrier. Federal resources would be available to respond when requested.

As with any transportation accident, state and tribal governments have primary responsibility to respond and to protect the public health and safety in their jurisdictions when accidents involve radioactive or other materials. In addition, under U.S. Department of Transportation regulations, shippers and transporters also have responsibilities for emergency response and cleanup.

The DOE transportation contractors would be contractually required to provide detailed written procedures on how they would respond to an incident and arrange for repair or replacement of equipment or recovery, as appropriate. In accordance with American National Standards Institute N14.27-1986 (R1993), "Carrier and Shipper Responsibilities and Emergency Response Procedures for Highway Transportation Accidents," the highway carrier would be expected to provide appropriate resources for dealing with the consequences of an accident.

Additionally, the DOE has radiological emergency response resources available to assist, when requested. The DOE assistance is regionally based and staffed 24 hours a day, 365 days a year.

Issue

An issue has been raised by the public regarding how the DOE could measure emergency management mitigation needs if it is not clear how the DOE plans to communicate with local entities.

Response

NRC regulations (10 CFR 73.37(b)(6)) require that arrangements have been made prior to shipments with local law enforcement agencies along the routes of road and rail shipments, and at U.S. ports where vessels carrying spent nuclear fuel shipments are docked, for their response to an emergency or a call for assistance. This requirement is designed to provide for rapid local law enforcement agency assistance in the event of an emergency or a call for assistance. It also is intended to assure that the selected local law enforcement agencies along the route are familiar with the types of situations to expect when responding to such calls. It should be noted that 10 CFR 73.37(b)(6) does not require that notification be given by the DOE transportation contractors to each local law enforcement agency along the route for specific shipments either immediately prior to the shipment or during the shipment; it requires only that arrangements have been made some time prior to the first shipment along the NRC approved route.

The DOE and its transportation contractors would use a satellite tracking and communication system for providing continuous real-time position tracking for all shipments of spent nuclear fuel and high-level radioactive waste. The satellite tracking and communication system would allow messages to be sent from the drivers and crew directly to a control center. With regard to such communications, the DOE would intend to provide satellite tracking information to the states and tribes through whose jurisdictions the DOE would ship NWPA spent nuclear fuel and high-level waste (note that the NRC must approve this DOE proposal before it can be implemented).

The DOE transportation contractors would provide a backup telephone system in case the satellite tracking and communication system is temporarily not available. The transportation contractors would also provide satellite telephones and 40-channel, two-way citizen band radios in tractors and rail escort cars. Any unusual or unexpected situations encountered or any problems with the cask or other equipment would be immediately communicated to the control center.

Issue

An issue has been raised by the public regarding what potential mitigation measures would be available for transportation accidents, who would implement them, and what protocols would be followed in the event of a spill or leak.

Response

The DOE, along with other federal agencies, has the ability to quickly respond to radiological emergencies in any state, if requested. Response to an accident or incident would be in accordance with pre-established protocols.

The DOE agrees that transportation accidents could occur during the transport of spent nuclear fuel and high-level radioactive waste to a repository. However, the shipping casks used to transport these materials are massive with design features that comply with strict NRC regulatory requirements that ensure the casks perform their safety functions even when damaged. Numerous tests and extensive analyses have demonstrated that the casks would provide containment and shielding even under the most severe kinds of accidents. Furthermore, it should be noted that all such wastes are solids that would not be easily dispersed. Based upon a study completed by Sandia National Laboratories for the NRC in April 2000 [Sprung, J.L.; Ammerman, D.J.; Breivik, N.L.; Dukart, R.J.; Kanipe, F.L.; Koski, J.A.; Mills, G.S.; Neuhauser, K.S.; Radloff, H.D.; Weiner, R.F.; and Yoshimura, H.R. 2000. "Reexamination of Spent Fuel Shipment Risk Estimates." NUREG/CR-6672. Two volumes. Washington, D.C.: U.S. Nuclear Regulatory Commission. ACC: MOL.20001010.0217.]. The DOE concluded that such casks would continue to fully contain the radioactivity in more than 99.99 percent of all accidents.

Inspections of the highway vehicle and load, at point of origin, destination, and elsewhere, as required, would be conducted in accordance with the enhanced inspection procedures developed by the Commercial Vehicle Safety Alliance [CVSA (Commercial Vehicle Safety Alliance) 1999. "North American Standard Out-of-Service Criteria and Enhanced North American Standard Inspection Procedures and Out-of-Service Criteria (Shaded Items) for Commercial Highway Vehicles Transporting Transuranics, Spent Nuclear Fuel, and High-Level Radioactive Waste." Bethesda, Maryland: Commercial Vehicle Safety Alliance. TIC: 243776.]. Rail shipments would be inspected according to 49 CFR 174.92 and the Federal Railroad Administration's High-Level Nuclear Waste Rail Transportation Inspection Policy. The DOE transportation contractors and, as applicable, representatives of the states and tribes through which the shipments would be made would perform these inspections. See Appendix M.3 of the FEIS for additional information.

As with any transportation accident, a state government via the local jurisdiction has primary responsibility to respond and to protect the public health and safety in its jurisdiction when accidents involve radioactive or other materials.

The DOE transportation contractors would be contractually required to provide detailed written procedures on how it would respond to an incident and arrange for repair or replacement of equipment or recovery, as appropriate. In accordance with American National Standards Institute N14.27-1986 (R1993), "Carrier and Shipper Responsibilities and Emergency Response Procedures for Highway Transportation Accidents," the highway carrier would be expected to provide appropriate resources for dealing with the consequences of an accident, isolating and cleaning up contamination, and maintaining working contact with the responsible governmental authority until the latter has declared the incident to be satisfactorily resolved.

The DOE transportation contractors would be required to provide the DOE with Carrier Management Plans that address compliance with transportation requirements, including inspection requirements and driver and crew training in operations and safety.

Further, a state can request assistance from federal agencies as it judges what would be appropriate and needed to effectively respond to an accident. The DOE, along with other federal agencies, has the ability to quickly respond to radiological emergencies in any state, if requested. As the lead Federal agency for initial offsite radiological monitoring and assessment of major accidents, the DOE maintains the Radiological Assistance Program. Radiological Assistance Program resources include specialized staff and equipment, on call 24 hours a day at eight regional coordinating offices. Radiological Assistance Program resources are deployed in measured response to requests for technical advice or assistance from other federal agencies, states, tribes, or local governments.

4.8.6 Transportation Impact Analyses

4.8.6 (96)

Claims were made that the DOE transportation analyses are inadequate and significantly underestimates risk. Various reasons for inadequacy were cited by members of the public, among them were, use of the 1987 NRC Modal Study, lack of updated Nevada population data, inadequate consideration of human factors, inadequate consideration of cask weeping, inadequate consideration of impacts other than deaths, inadequate consideration of community issues, and an inadequate consideration of possible modal mixes. Members of the public stated the conclusion that transportation impacts were not significant was based on averaging transportation impacts across the country.

Assertions were made by the public that the DOE's transportation risk analyses underestimated the true risk to the public.

The FEIS analyzes the potential environmental impacts that could result from transporting spent nuclear fuel and high-level radioactive waste to Yucca Mountain. This is based on the level of information and analysis, the analytical methods and approaches used to represent conservatively the reasonably foreseeable impacts that could occur, and the use of bounding assumptions where information is incomplete or unavailable, or where uncertainties exist. The use of widely accepted analytical tools, the latest reasonably available information, and cautious but reasonable assumptions offer the most appropriate means to arrive at conservative estimates of transportation-related impacts.

To ensure that the FEIS analyses reflect the latest reasonably available information, the DOE has either incorporated information that has become available since the publication of the DEIS or modified existing information to accommodate conditions likely to be encountered over the life of a repository at Yucca Mountain. For example, the analysis in the DEIS relied on population information from the 1990 Census. In the FEIS, the DOE has scaled impacts upward to reflect the relative state-by-state population growth to 2035, using 2000 Census data.

Although the FEIS analyses are based on the latest reasonably available information and state-of-the-art analytical tools, not all aspects of incident-free transportation or accident conditions can be known with absolute certainty. In such instances, the DOE has relied on conservative assumptions that tend to overestimate impacts. For instance, the DOE assumed that the radiation dose external to each vehicle carrying a cask during routine transportation would be the maximum allowed by U.S. Department of Transportation regulations. Similarly, the DOE assumed that an individual, the "maximally exposed individual," would be a resident living 30 meters (100 feet) from a point where all truck shipments would pass. Under these circumstances, the maximally exposed individual would receive a dose of about 6 millirem from exposure to all truck shipments (6 millirem represents an increased probability of contracting a fatal cancer of 3 in 1 million). Although it can be argued that individuals could live closer to these shipments, it is highly unlikely that an individual would be exposed to all shipments over the 24-year period of shipments to a repository, even though the DOE incorporated this highly conservative assumption in the analysis.

Sections J.1.1 and J.1.4 of the FEIS present the approach the DOE used to estimate the number of accidents and the associated impacts that would occur in transporting spent nuclear fuel and high-level radioactive waste to a repository at Yucca Mountain. As requested by public comments, the DOE has included maps showing the representative routes used in the analysis and estimates of the state-by-state impacts based on these routes (see FEIS, Section J.4). The approach uses U.S. Department of Transportation state-by-state accident and fatality statistics for highway, rail, and barge transportation. The statistics were compiled from accidents that occurred during all four seasons from 1994 through 1996 [Saricks, C.L. and Tompkins, M.M. 1999. "State-Level Accident Rates of Surface Freight Transportation: A Reexamination." ANL/ESD/TM-150. Argonne, Illinois: Argonne National Laboratory. TIC: 243751.], which is the most current information of this type available. The approach includes the assumption that the number of potential accidents and impacts are proportional to the number of total kilometers that shipments would travel in each state (number of cask shipments times distance traveled). Annual accident data were used and routes were assumed not to change with season. Total incident-free impacts for 24 years that are also dependent on the total number of shipment kilometers. Because accident rate data are not available for specialized logistical arrangements, such as convoys and dedicated trains, the DOE assumed the industry-wide accident rates for individual truck, railcar, and barge shipments used in the FEIS would apply. Because incident-free impacts would be proportional to the number of cask shipments over 24 years, transporting casks in multiples in convoys or dedicated trains also would not affect these impacts. Because accidents at intermodal transfer facilities would not exceed cask design requirements, the DOE estimated radiological impacts would not occur for these facilities (see FEIS, Section J.3.3).

Section 6.3.3 of the FEIS presents estimates for industrial safety impacts from operations at an intermodal transfer station in Nevada. The approach for estimating the number and severity of accidents relies on historical experience. It assumes spent nuclear fuel and high-level radioactive waste would be properly packaged for shipment in Type B shipping casks certified by the NRC to comply with the performance standards contained in 10 CFR Part 71. The approach also assumes transport carriers' operations and vehicles would comply with applicable federal, state, Native American tribal, and local regulations; be conducted during all four seasons of the year; and resemble those used for other commodities transported in interstate commerce. The DOE would ensure shipments of spent nuclear fuel and high-level radioactive waste to a repository and return of empty shipping casks for further use fully complied with applicable Federal, state, and local regulations, including those of the NRC and U.S. Department of Transportation (see FEIS, Section 2.1.3). These regulations include, among other things, requirements for operator training, vehicle safety, records, communications and tracking, and security. These measures are implemented to minimize potential human errors and other conditions that could lead to accidents.

The analyses used "fatality" as the measure of impacts to the public because it is an easily understood objective measure used historically in environmental impact statements prepared by the DOE.

As discussed in Section F.1.1 of the FEIS, cancer is the principal potential risk to human health from exposure to low or chronic levels of radiation. It is well accepted within the risk assessment and health physics community to use latent cancer fatalities as the measure of impacts from radiation exposure. However, other health effects, such as nonfatal cancers and genetic effects, can occur as a result of chronic exposure to radiation and are discussed in Section F.1.1.5 of the FEIS.

The transportation analyses in the FEIS present the total impacts of the transportation of spent nuclear fuel and high-level nuclear waste to a repository at Yucca Mountain. Fatalities were used as the measure of the total impact because non-radiation-related traffic fatalities may be combined with radiation-related latent cancer fatalities to yield an estimate of the total number of fatalities for transportation. In contrast, combining non-radiation-related measures of impact, such as traffic related injuries, illnesses, and other environmental impacts with radiation-related latent cancer fatalities, would not yield an easily understandable estimate of total impacts. For this same reason, genetic effects, nonfatal cancers, and other radiation effects were not included in the estimates of the total impact.

Issue

An issue has been raised by the public regarding the perception that the DOE did not consider community issues, and reference documents submitted by affected county agencies in Nevada.

Response

To analyze the potential for impacts that could affect environmental resources, the DOE collected and considered large amounts of information including information provided by the State of Nevada and Nevada counties. For the analyses, the DOE used information that it judged to be relevant and reasonable. For example, based on comments submitted during scoping hearings for the DEIS, the DOE added consideration of the Caliente/Chalk Mountain rail corridor and highway route for heavy-haul trucks. The DOE used projections of population growth in Nevada provided by Clark and Nye counties and the Nevada State Demographer for updated information presented in the FEIS. The DOE also reviewed many documents produced by Lincoln County and other county and state agencies. The transportation-related information contained in those documents was considered for inclusion in the FEIS. Nevada highway traffic information was collected from the Nevada Department of Transportation [Nevada Department of Transportation n.d. "The Annual Traffic Report." Carson City, Nevada: Nevada Department of Transportation. TIC: 242973.]. The DOE obtained and used accident rates for Nevada highways from the Department of Motor Vehicles and Public Safety, State of Nevada (see FEIS, Section J.1.4.2.3.3). The DOE also used information contained in a report prepared for the City of North Las Vegas [Louis Berger Group, Inc. 2000. "Assessment of the Hazards of Transporting Spent Nuclear Fuel and High Level Radioactive Waste to the Proposed Yucca Mountain Repository using the Proposed Northern Las Vegas beltway." Las Vegas, Nevada: The Louis Berger Group. TIC: 250165.]. The information in this report provided the DOE with an estimate of the cost of advancing completion of the Las Vegas beltway for use by heavy-haul trucks, an estimate of the populations that might live along the beltway, and a basis for estimating the dose to a maximally exposed individual in a Nevada community from transportation of spent nuclear fuel and high-level radioactive waste to Yucca Mountain. The DOE also used information contained in "Statewide Radioactive Materials Transportation Plan, Phase II" to identify potential alternative highway routes for shipments of spent nuclear fuel and high-level radioactive waste that the State of Nevada has considered in the past [Ardila-Coulson, M.V. 1989. "The Statewide Radioactive Materials Transportation Plan." Phase II. Reno, Nevada: University of Nevada, Reno. ACC: NNA.19900301.0061.].

To calculate the potential impacts to a maximally exposed individual, the DOE used information and assumptions from the same report sponsored by the City of North Las Vegas, Nevada, because the DOE believes it to be the only source of the information [Louis Berger Group, Inc. "Assessment of the Hazards of Transporting Spent Nuclear Fuel and High Level Radioactive Waste to the Proposed Yucca Mountain Repository using the Proposed Northern Las Vegas beltway."]. However, the DOE considers the exposure assumptions presented in the report to be extreme and very unlikely to occur. The DOE analysis of dose, using information and assumptions presented in the report, estimated a maximally exposed individual in Nevada would receive a dose of about 530 millirem over 24 years. This is an annual dose of about 22 millirem, which is about 6 percent of a one year exposure to natural background radiation, and 22 percent of the limit for members of the public listed in NRC regulations (10 CFR Part 20). A dose of 530 millirem over the 24 years would increase an individual's risk of a fatal cancer by about 1 chance in 4,000 over the person's lifetime. For perspective, an individual's lifetime risk of a fatal cancer from all other causes is about 1 in 4. So, even using the unlikely exposure assumptions contained in the Berger report, the dose to a maximally exposed individual would be well below that received from natural background radiation, would not be discernible, and would not add measurably to other impacts that an individual could incur.

Issue

Members of the public have raised an issue that the DEIS failed to evaluate the impacts of the worst possible modal (e.g., truck, rail) combinations of transportation scenarios.

Response

The DOE has analyzed the effects of different mixes of rail and truck shipments. The results of this analysis confirm the DOE's estimate that the mostly rail and mostly legal-weight truck scenarios represent a reasonable range (lower and upper bound) of potential environmental impacts from the transportation of spent nuclear fuel and high-level radioactive waste.

The DOE believes that the mostly rail case, in which more than 95 percent of spent nuclear fuel and high-level radioactive waste would be shipped by rail, would most closely approximate the actual mix of truck and rail shipments. In reaching this conclusion, the DOE has assessed the capabilities of the sites to handle larger (rail) casks, the distances to suitable railheads, and historic experience in actual shipments of nuclear fuel, waste, or other large reactor-related components. In addition, the DOE considered relevant information published by sources such as the Nuclear Energy Institute and the State of Nevada.

Issue

An issue has been raised by the public questioning the DOE practice of averaging transportation impacts of transporting spent nuclear fuel and high-level radioactive waste across the entire nation. It was stated that the DOE conclusion that transportation impacts were not significant was a result of this practice of averaging transportation impacts across the country.

Response

The impacts reported in the FEIS are the estimated impacts summed over the specific routes used for analysis in the FEIS over the period necessary to ship the spent nuclear fuel and high-level radioactive waste to a repository at Yucca Mountain, not the average impact across the nation. The transportation impacts in the FEIS were evaluated over the entire shipping period. The total impacts to exposed populations over that period were calculated. The techniques used best reflect the actual potential for radiological exposure from the proposed activities associated with each of the alternatives. Appendix J of the FEIS has been expanded to include additional information on the state-specific route maps, and impact data (see FEIS, Section J.4).

Issue

Members of the public expressed concern over cask weeping during transport, citing various contamination events in the U.S. and Europe. It was stated that the DOE incident free transportation analysis was inadequate because the DOE did not account for contamination on the exterior of the cask.

Response

The phenomenon of cask weeping can be described as follows: a cask that has been loaded or unloaded in a spent nuclear fuel storage pool becomes contaminated with radioactivity on its surface. Before shipment, the external surface of the cask is decontaminated to levels specified by regulations, but when the cask is inspected on arrival at its destination, contamination above the levels allowed by regulations is found. This is probably the result of the cask being repeatedly placed into water-filled spent nuclear fuel storage pools so that it becomes contaminated over time, with the contamination penetrating deeper into the pores of the cask body. The cleaning removes the surface contamination, but the contamination that is deep in the pores remains. During transportation of a loaded cask, the surface can become contaminated again as the deep contamination is driven out of the pores by the heat of the spent nuclear fuel.

The levels of contamination associated with the weeping phenomenon are not high enough to be factored into the risk assessment for transportation, and procedures would be used to effectively preclude this problem during shipments. For example, wrapping the cask in plastic before entry into spent nuclear fuel storage pools is an effective practice that is currently used. Therefore, weeping is not expected to be a significant contributor to risk during spent nuclear fuel transportation.

Issue

Members of the public have raised an issue that the DOE analysis of transportation impact analysis was flawed because it did not include a community specific analysis of transportation routes.

Response

Although the FEIS analyses are based on the latest reasonably available information and state-of-the-art analytical tools, not all aspects of incident-free transportation or accident conditions can be known with absolute certainty. In such instances, the DOE has relied on conservative assumptions that tend to overestimate impacts. For instance, the DOE assumed that the radiation dose external to each vehicle carrying a cask during routine transportation would be the maximum allowed by U.S. Department of Transportation regulations. Similarly, the DOE assumed that an individual, the "maximally exposed individual," would be a resident living 30 meters (100 feet) from a point where all truck shipments would pass. Under these circumstances, the maximally exposed individual would receive a dose of about 6 millirem from exposure to all truck shipments (6 millirem represents an increased probability of contracting a fatal cancer of 3 in 1 million). Although it can be argued that individuals could live closer to these shipments, it is highly unlikely that an individual would be exposed to all shipments over the 24-year period of shipments to a repository at Yucca Mountain, even though the DOE incorporated this highly conservative assumption in the analysis.

Appendix J, Section 4, of the FEIS has been revised to include a state-by-state analysis of transportation impacts.

Issue

Members of the public have raised an issue that the DOE analysis of transportation impact analysis was flawed because it relied on the 1987 NRC Modal Study.

Response

The DOE has updated the transportation impact analysis to incorporate new findings of an updated NRC analysis.

In March 2000, the NRC published a study completed by Sandia National Laboratories, "Reexamination of Spent Fuel Shipment Risk Estimates" [Sprung, J.L.; Ammerman, D.J.; Breivik, N.L.; Dukart, R.J.; Kanipe, F.L.; Koski, J.A.; Mills, G.S.; Neuhauser, K.S.; Radloff, H.D.; Weiner, R.F.; and Yoshimura, H.R. 2000. "Reexamination of Spent Fuel Shipment Risk Estimates." NUREG/CR-6672. Two volumes. Washington, D.C.: U.S. Nuclear Regulatory Commission. ACC: MOL.20001010.0217.], an analysis on spent fuel shipment risk. The purpose of the study was to reexamine the risks associated with the transport of spent nuclear fuel by truck and rail, and compare the results to those published in the 1977 NRC environmental impact statement on transportation [NRC (U.S. Nuclear Regulatory Commission) 1977. "Final Environmental Impact Statement on the Transportation of Radioactive Materials by Air and Other Modes." NUREG-0170. Two volumes. Washington, D.C.: U.S. Nuclear Regulatory Commission. TIC: 221616.] and the 1987 Modal Study [Fischer, L.E.; Chou, C.K.; Gerhard, M.A.; Kimura, C.Y.; Martin, R.W.; Mensing, R.W.; Mount, M.E.; and Witte, M.C. 1987. "Shipping Container Response to Severe Highway and Railway Accident Conditions." NUREG/CR-4829. Two volumes. Washington, D.C.: U.S. Nuclear Regulatory Commission. ACC: NNA.19900827.0230; NNA.19900827.0231.]. The DEIS used techniques and assumptions based on the earlier Modal Study [Ibid.]. The new NRC study [Sprung et al. "Reexamination of Spent Fuel Shipment Risk Estimates."] concluded that both the NRC transportation environmental impact statement and the Modal Study [Fisher et al. "Shipping Container Response to Severe Highway and Railway Accident Conditions."] made a number of very conservative assumptions about spent nuclear fuel and cask response to accident conditions that caused their estimate of accident source terms, accident frequencies, and accident consequences to be very conservative. The new NRC study [Sprung et al. "Reexamination of Spent Fuel Shipment Risk Estimates." Page 9-3.] also concluded:

Based on this more detailed analysis, cask leakage is found to be even less likely than the estimates of the Modal Study, and retention of particles and condensible vapors by deposition onto cask interior surfaces is found to be substantial. Accordingly, both source term probabilities and magnitudes decrease further, and consequently accident population dose risks are reduced further by factors of 10 to 100.

The DOE has updated the FEIS transportation impact analysis to incorporate the relevant new findings of the updated NRC analysis. Section 6.2.4 and Section J.1.4, of the FEIS, concerning analysis of transportation accidents, have been revised. This revision incorporates data from the "Reexamination of Spent Fuel Shipment Risk Estimates," [Ibid.] and no longer relies on the data from the 1987 Modal Study [Fisher, L.E. et al. "Shipping Container Response to Severe Highway and Railway Accident Conditions."], with the exceptions of data used within the new NRC study. NUREG/CR-6672 [Sprung, J.L. et al. "Reexamination of Spent Fuel Shipment Risk Estimates."] contains revised estimates of probable releases from spent nuclear fuel casks during severe transportation accidents, which involve long duration fires accompanied by high impact forces, which are beyond regulatory limits.

Issue

Members of the public have raised an issue that the DOE does not adequately address human factors and organizational behavior in the transportation system. Specifically, the DOE does not consider the effects of human factors on accident rates and the privatization of the DOE transportation system.

Response

The impacts presented in the FEIS are based on reasonable consideration of the effects of human factors, often discounting certain benefits that could be reasonably expected.

Appendix J, Section 1.4, of the FEIS discusses potential effects of human error on accident probabilities and impacts. In addition, that section discusses how effects of human factors and errors are included in the risk. For example, the truck and rail accident rates used in the FEIS include accidents involving all causes, thus human error is factored into the accident rates and ultimately transportation risk. The accident rates used in the analysis are based on national transportation statistics, although use of highly trained and qualified personnel in transporting spent nuclear fuel and high-level radioactive waste, and preferred routes for highway shipments would tend to mitigate the number and severity of transportation accidents. Use of preferred routes for highway shipments and expeditious routing for rail shipments (see FEIS, Appendix J, Section 1.2) would also result in use of transportation infrastructure that minimizes radiological risk and time in transit. The analysis of transportation impacts did not take credit for these factors. In addition, the effects of emphasizing training and qualification of personnel, who would be employed by the DOE and contractors to transport spent nuclear fuel and high-level radioactive waste were not given credit in the assessment. Therefore, the DOE believes that the accident rates used for analyses may tend to overestimate the risk.

4.8.6 (99)

Summary Comment

Members of the public have raised questions about the frequency, type and both health and economic consequences of transportation accidents as evaluated by the DOE.

Issue

Members of the public questioned how many accidents would be expected each year.

Response

The DOE recognizes that accidents could occur during transportation of spent nuclear fuel and high-level radioactive waste to a repository. The DOE estimates that 66 shipping accidents could occur during the 24 years that spent nuclear fuel and high-level radioactive waste is being shipped to a repository at Yucca Mountain. However, the shipping casks that would be used to transport these materials would be massive with design features that comply with strict regulatory requirements that ensured the casks performed their safety functions even when damaged. Numerous tests and extensive analyses have demonstrated that casks would provide containment and shielding even under the most severe kinds of accidents. In addition, since the publication of the DEIS, the NRC published "Reexamination of Spent Fuel Shipment Risk Estimates" [Sprung, J.L.; Ammerman, D.J.; Breivik, N.L.; Dukart, R.J.; Kanipe, F.L.; Koski, J.A.; Mills, G.S.; Neuhauser, K.S.; Radloff, H.D.; Weiner, R.F.; and Yoshimura, H.R. 2000. "Reexamination of Spent Fuel Shipment Risk Estimates." NUREG/CR-6672. Two volumes. Washington, D.C.: U.S. Nuclear Regulatory Commission. ACC: MOL.20001010.0217.], a study completed by Sandia National Laboratories. Based on the revised analyses, the DOE has concluded in the FEIS that casks would continue to contain spent nuclear fuel fully in more than 99.99 percent of all accidents. This means that of the approximately 53,000 truck shipments over 24 years in a "mostly truck" scenario, an estimated 66 accidents nationwide could occur, each having less than a 0.01 percent chance that radioactive materials would be released. The chance of a rail accident that would cause a release from a cask would be even less. The corresponding chance that such an accident would occur in any particular locale would be extremely low. Section J.1.4.2.1 of the FEIS presents consequences for accidents that could release radioactive materials.

Special requirements imposed on the transportation of spent nuclear fuel and high-level waste, as discussed in Section M.2 of the FEIS, would be expected to reduce the accident rates for shipments to Yucca Mountain to below those assumed in the FEIS and those experienced by routine hazardous waste shipment.

Issue

Members of the public have raised an issue that the numerous accidents would occur in Nevada and especially in Las Vegas.

Response

Of the approximately 53,000 truck shipments over 24 years in a "mostly truck" scenario, it is estimated that 66 accidents nationwide could occur, each having less than a 0.01 percent chance that radioactive materials would be released. Because accident rates are based on the shipment miles traveled during the estimated 24-year duration of the shipment campaign and because total shipment miles outside the State of Nevada greatly exceed the total shipment miles inside Nevada, a proportionally larger number of the estimated accidents would occur outside the State of Nevada.

Based on revised analyses, the DOE has concluded in the FEIS that casks would continue to contain spent nuclear fuel fully in more than 99.99 percent of all accidents. This means that of the approximately 53,000 truck shipments over 24 years in a "mostly truck" scenario, an estimated 66 accidents nationwide could occur, each having less than a 0.01 percent chance that radioactive materials would be released. The chance of a rail accident that would cause a release from a cask would be even less. The corresponding chance that such an accident would occur in any particular locale would be extremely low. Section J.1.4.2.1 of the FEIS presents consequences for accidents that could release radioactive materials.

The text box in Section 6.3.1.3.2 of the FEIS discusses the likelihood of the maximum reasonably foreseeable accident occurring in the State of Nevada. This is an extremely unlikely accident with a likelihood of occurrence of about 3 in 10 million per year for the national transportation routes. The likelihood of this accident is directly related to the total number of shipment miles during the estimated 24-year duration of the shipment campaign. Total shipment miles outside the State of Nevada greatly exceed the total shipment miles inside Nevada. Therefore, as the FEIS states it is more likely that this type of accident would occur outside the State of Nevada than inside the State, and even more unlikely for any specific location in Nevada.

Issue

Members of the public have raised an issue that the DOE does not provide a description of a maximum reasonably foreseeable accident.

Response

The DOE has revised Section J.1.4.2 of the FEIS to include a description of the maximum reasonably foreseeable accident. As in "Reexamination of Spent Fuel Shipment Risk Estimates" [Sprung, J.L.; Ammerman, D.J.; Breivik, N.L.; Dukart, R.J.; Kanipe, F.L.; Koski, J.A.; Mills, G.S.; Neuhauser, K.S.; Radloff, H.D.; Weiner, R.F.; and Yoshimura, H.R. 2000. "Reexamination of Spent Fuel Shipment Risk Estimates." NUREG/CR-6672. Two volumes. Washington, D.C.: U.S. Nuclear Regulatory Commission. ACC: MOL.20001010.0217.], accidents are not described in terms of specific circumstances, because various accidents could lead to the same combination of cask failure mechanism, impact velocity range, and temperature range. However, detailed "event trees" are presented for truck and rail accidents as in Figures 7.3 and 7.4 of Sprung et al. [Ibid.]. These event trees illustrate the different combinations of events that occur during an accident. This approach to accident analysis precludes the necessity for analyzing numerous specific cases involving various collisions, various natural disasters, specific locations, or various infrastructure accidents. They are all covered by the considerations of impact velocities and temperatures on a cask.

Issue

Members of the public raised an issue concerning the response of a transportation cask to a collision.

Response

The shipping casks that would be used to transport these materials would be massive with design features that comply with strict regulatory requirements that ensured the casks performed their safety functions even when damaged. Numerous tests and extensive analyses have demonstrated that casks would provide containment and shielding even under the most severe kinds of accidents. In addition, since the publication of the DEIS, NRC published "Reexamination of Spent Fuel Shipment Risk Estimates" [Sprung, J.L.; Ammerman, D.J.; Breivik, N.L.; Dukart, R.J.; Kanipe, F.L.; Koski, J.A.; Mills, G.S.; Neuhauser, K.S.; Radloff, H.D.; Weiner, R.F.; and Yoshimura, H.R. 2000. "Reexamination of Spent Fuel Shipment Risk Estimates." NUREG/CR-6672. Two volumes. Washington, D.C.: U.S. Nuclear Regulatory Commission. ACC: MOL.20001010.0217.], a study completed by Sandia National Laboratories. Based on the revised analyses, the DOE has concluded in the FEIS that casks would continue to contain spent nuclear fuel fully in more than 99.99 percent of all accidents. This means that of the approximately 53,000 truck shipments over 24 years in a "mostly truck" scenario, an estimated 66 accidents nationwide could occur, each having less than a 0.01 percent chance that radioactive materials would be released. The chance of a rail accident that would cause a release from a cask would be even less. The corresponding chance that such an accident would occur in any particular locale would be extremely low. Section J.1.4.2.1 of the FEIS presents consequences for accidents that could release radioactive materials.

The DOE has revised Section J.1.4.2 of the FEIS to include a description of the maximum reasonably foreseeable accident. As in "Reexamination of Spent Fuel Shipment Risk Estimates" [Ibid.], accidents are not described in terms of specific circumstances, because various accidents could lead to the same combination of cask failure mechanism, impact velocity range, and temperature range. However, detailed "event trees" are presented for truck and rail accidents as in Figures 7.3 and 7.4 of Sprung et al. [Ibid.]. These event trees illustrate the different combinations of events that occur during an accident. This approach to accident analysis precludes the necessity for analyzing numerous specific cases involving various collisions, various natural disasters, specific locations (such as mountain passes), or various infrastructure accidents. They are all covered by the considerations of impact velocities and temperatures on a cask.

Issue

Members of the public observed that transportation accidents are a frequent occurrence on the nation's highways and railways and that some of these accidents result in extreme damage to the vehicles involved from both the force of the impact or fires or explosions of other hazardous material. Cited as an example, is the accident in July 2001 when a freight train hauling hazardous chemicals derailed in a rail tunnel near Baltimore.

Response

"Real life" transportation accidents involve collisions of many kinds, such as with other vehicles and obstacles, that could result in fires and explosions, inundation, or burial of a cask containing spent nuclear fuel and high-level radioactive waste. These accidents are caused, in turn, by a variety of initiating events including human error, mechanical failure, and natural causes such as earthquakes. Accidents occur in many different kinds of places including mountain passes and urban areas, rural freeways in open landscapes, and rail switching yards.

The FEIS also analyzes a maximum reasonable foreseeable accident, an accident with a probability of occurrence of about 3 in 10 million per year. To put this in perspective, this accident would occur once in the course of about 5 billion legal-weight truck shipments (even under a mostly legal-weight truck scenario there would only be approximately 53,000 shipments). In this scenario, a truck cask, not involved in a collision, would be engulfed in a fire with temperatures between 750 degrees Celsius and 1,000 degrees Celsius (1,400 degrees Fahrenheit to 1,800 degrees Fahrenheit) (see FEIS Section 6.2.4.2). The conditions of the maximum reasonably foreseeable accident analyzed in the FEIS envelope conditions reported for the Baltimore Tunnel fire (a train derailment and fire that occurred in July 2001 in a tunnel in Baltimore, Maryland). Temperatures in that fire were reported to be as high as 820 degrees Celsius (1,500 degrees Fahrenheit).

Issue

The issue of concern was raised by members of the public due to the recent significant derailments involving hazardous, but not radioactive, materials.

Response

Actions would be taken during preparation for shipments to minimize the possibility of derailments.

The Federal Railroad Administration has developed its "Safety Compliance Oversight Plan for Rail Transportation of High-Level Radioactive Waste and Spent Nuclear Fuel, Ensuring the Safe, Routine Rail Transportation of Foreign Research Reactor Spent Nuclear Fuel" [DOT (U.S. Department of Transportation) 1998. "Safety Compliance Oversight Plan for Rail Transportation of High-Level Radioactive Waste and Spent Nuclear Fuel, Ensuring the Safe, Routine Rail Transportation of Foreign Research Reactor Spent Nuclear Fuel." Washington, D.C.: U.S. Department of Transportation, Federal Railroad Administration, ACC: MOL.20011212.0115.]. That plan sets forth the Federal Railroad Administration policy to address the safety of rail shipments of spent nuclear fuel and high-level radioactive waste. The plan includes the current Federal Railroad Administration policy on planning, inspection, training and oversight activities and can be accessed at the U.S. Department of Transportation website, www.fra.dot.gov.

Issue

Members of the public have raised the question of how large an area could be affected by a severe accident and what would be the cost of cleanup.

Response

The DOE has included a discussion on the range of potential area of contamination and the resultant costs of cleanup following a severe transportation accident in Appendix J, Section J.1.4.2.5 of the FEIS. That discussion reviews calculations of land area contaminated and costs for cleanup presented in past studies, including a report used in the 1986 Environmental Assessments [Sandquist, G.M.; Rogers, V.C.; Sutherland, A.A.; and Merrell, G.B. 1985. "Exposures and Health Effects from Spent Fuel Transportation." RAE-8339/12-1. Salt Lake City, Utah: Rogers and Associates Engineering. TIC: 200593.] that shows a contaminated area of 110 square kilometers (42 square miles). The extreme high estimates of contaminated land area contained in the report are based on assumptions that all factors combine in the most disadvantageous way to create a "worst case" (e.g., a hypothetical rail cask accident postulated in the report "Exposures and Health Effects from Spent Fuel Transportation" [Ibid.] estimates a release of radioactive isotopes that would cause land contamination approximately two orders of magnitude greater than the FEIS estimated for a maximally reasonably foreseeable accident for a mostly rail scenario). Such worst cases are not reasonably foreseeable.

More than 99.99 percent of transportation accidents would not result in a release of radioactive materials from a shipping cask [Sprung, J.L.; Ammerman, D.J.; Breivik, N.L.; Dukart, R.J.; Kanipe, F.L.; Koski, J.A.; Mills, G.S.; Neuhauser, K.S.; Radloff, H.D.; Weiner, R.F.; and Yoshimura, H.R. 2000. "Reexamination of Spent Fuel Shipment Risk Estimates." NUREG/CR-6672. Two volumes. Washington, D.C.: U.S. Nuclear Regulatory Commission. ACC: MOL.20001010.0217.], although these accidents could lead to traffic fatalities and economic loss. Economic losses from nonrelease accidents would be similar to those losses associated with other transportation accidents that occur and would be compensated through normal commercial vehicle insurance and legal processes. In the unlikely case of an accident causing a release of radioactive materials from a cask to the environment, additional costs would be incurred associated with actions to decontaminate, or otherwise remediate and restore contaminated land (e.g., cleaning up). Such costs would be fully compensated under the provisions established by the Price–Anderson Amendments Act, which provides for recovery costs up to $9.43 billion (see FEIS, Appendix M).

The DOE anticipates that the economic costs of accidents where there is no release of radioactive material would not be substantial. The health and safety consequences of a maximum reasonably foreseeable transportation accident are discussed in Section 6.2.4.2 of the FEIS. The FEIS analysis did not include the restorative effects of postaccident recovery, remediation, or cleanup in estimating the health and safety impacts, and would, therefore, tend to overestimate, rather than underestimate, actual radiological impacts.

The DOE has included a discussion on the range of potential area of contamination and the resultant costs of cleanup following a severe transportation accident in Appendix J, Section J.1.4.2.5 of the FEIS. That discussion reviews calculations of land area contaminated and costs for cleanup presented in past studies, including a report used in the 1986 Environmental Assessments [Sandquist, G.M; Rogers, V.C.; Sutherland, A.A.; and Merrell, G. B. 1985. "Exposures and Health Effects from Spent Fuel Transportation." RAE-8339/12-1. Salt Lake City, Utah: Rogers and Associates Engineering. TIC: 200593.] which shows a contaminated area of 110 square kilometers (42 square miles). The extreme high estimates of contaminated land area contained in the report are based on assumptions that all factors combine in the most disadvantageous way to create a "worst case" (e.g., a hypothetical rail cask accident postulated in the report "Exposures and Health Effects from Spent Fuel Transportation" [Ibid.] estimates a release of radioactive isotopes that would cause land contamination approximately two orders of magnitude greater than the FEIS estimated for a maximally reasonably foreseeable accident for a mostly rail scenario). Such worst cases are not reasonably foreseeable.

Cost data used in the studies reviewed in Section J.1.4.2.5 of Appendix J, of the FEIS included data compiled from case studies involving actual cleanup of radioactive materials contamination. The studies also address consequences for releases of radioactive materials in communities.

Although the studies project high costs for cleanup following severe accidents, the accidents evaluated would be very unlikely and, as a consequence, the DOE believes the economic risks of transportation accidents are very small. The shipping casks used to transport spent nuclear fuel and high-level radioactive waste would be massive with design features that comply with strict regulatory requirements that would ensure the casks performed their safety functions even when damaged. Furthermore, the high-level radioactive waste would be in a solid form that would not be easily dispersed (ceramics, metals, or glasses).

Issue

Members of the public have expressed concern about detrimental health affects, other than latent cancer fatalities, that might result from a transportation accident.

Response

As discussed in Section F.1.1.5 of the FEIS, cancer is the principal potential risk to human health from exposure to low or chronic levels of radiation. It is well accepted within the risk assessment and health physics community to use latent cancer fatalities as the measure of impact from radiation exposure. However, other health effects such as nonfatal cancers and genetic effects can occur as a result of chronic exposure to radiation.

Fatalities were used as the measure of the total impact because non-radiation-related traffic fatalities can be combined with radiation-related latent cancer fatalities to yield an estimate of the total number of fatalities. In contrast, combining non-radiation-related measures of impact such as traffic-related injuries, illnesses, and other environmental impacts with radiation-related latent cancer fatalities would not yield an easily understandable estimate of total impacts. For the same reason, genetic effects, nonfatal cancers, and other radiation effects were not included in the estimates of the total impact.

Issue

Members of the public have raised an issue regarding the effect on water resources, which might be impacted by releases to the surface and groundwater bodies from transportation accidents.

Response

The shipping casks used to transport spent nuclear fuel and high-level radioactive waste would be massive with design features that comply with strict regulatory requirements that would ensure the casks performed their safety functions even when damaged. The casks would be designed to be watertight even after a severe accident. Furthermore, the high-level radioactive waste would be in a solid form that would not be easily dispersed (ceramics, metals, or glasses).

Numerous tests and extensive analyses, using the most advanced analytical methods available, have demonstrated that casks would provide containment and shielding even under the most severe kinds of accidents. Since the publication of the DEIS, the NRC published "Reexamination of Spent Fuel Shipment Risk Estimates" [Sprung, J.L.; Ammerman, D.J.; Breivik, N.L.; Dukart, R.J.; Kanipe, F.L.; Koski, J.A.; Mills, G.S.; Neuhauser, K.S.; Radloff, H.D.; Weiner, R.F.; and Yoshimura, H.R. 2000. "Reexamination of Spent Fuel Shipment Risk Estimates." NUREG/CR-6672. Two volumes. Washington, D.C.: U.S. Nuclear Regulatory Commission. ACC: MOL.20001010.0217.], a study completed by Sandia National Laboratories. Based on the revised analyses, the DOE has concluded in the FEIS that casks would continue to contain spent nuclear fuel fully in more than 99.99 percent of all accidents. This means that of the approximately 53,000 truck shipments over 24 years in a "mostly truck" scenario, an estimated 66 accidents nationwide could occur, each having less than a 0.01 percent chance that radioactive materials would be released. The chance of a rail accident that would cause a release from a cask would be even less. The corresponding chance that such an accident would occur in any particular locale would be extremely low. Section J.1.4.2.1 of the FEIS presents consequences for accidents that could release radioactive materials.

The FEIS does not specifically analyze a transportation accident involving contamination of surface water or groundwater. Analyses performed in previous environmental impact statements (see FEIS, Section 1.5.3 and Table 1-1) have consistently shown that the airborne pathway has the greatest potential for exposing large numbers of people in the event of a release of radioactive materials during a severe transportation accident. An analysis of the potential importance of water pathway contamination for spent nuclear fuel transportation accident risk using a worst-case water contamination scenario [Ostmeyer, R.M. 1986. "A Revised Rail-Stop Exposure Model for Incident-Free Transport of Nuclear Waste." SAND85-2149. Albuquerque, New Mexico: Sandia National Laboratories. ACC: HQZ.19870615.6381.] showed that the impacts of the water contamination scenario were about one-fiftieth of the impacts of a comparable accident in an urban area. Thus, it is extremely unlikely that an accident that resulted in a cask falling into any body of water would result in surface-water contamination, let alone groundwater contamination.

4.8.6 (100)

Summary Comment

Members of the public have expressed concern over worker radiation exposure during transportation cask loading activities. In addition, concern was expressed that the DOE did not adequately address the procedures that would be used in transferring casks from waste generators to the DOE transportation contractors.

Issue

Members of the public expressed concern about the dose to workers during cask loading operations.

Response

The FEIS, Section 6.2.2.1, presents the DOE analysis of the radiological impacts of routine loading operations at commercial sites. The DOE based its estimates of impacts of loading spent nuclear fuel and high-level radioactive waste on "Analysis of Radiation Doses from Operation of Postulated Commercial Spent Fuel Systems" [Schneider, K.J.; Ross, W.A.; Smith, R.I.; Daling, P.M.; Grinde, R.B.; Hostick, C.J.; Peterson, R.W.; Stiles, D.L.; Weakley, S.A.; and Young, J.R. 1987. "Analysis of Radiation Doses from Operation of Postulated Commercial Spent Fuel Transportation Systems." DOE-CH/TPO-001. Argonne, Illinois: U.S. Department of Energy, Chicago Operations Office. ACC: MOL.20010727.0163.]. The information in the report is based on analysis of loading procedures and risks experienced at commercial nuclear facilities for shipping spent nuclear fuel using truck casks and rail casks. The DOE believes this report provides the latest reasonable information for estimating impacts of loading spent nuclear fuel and high-level radioactive waste at generator facilities. The FEIS, Table 6-6, lists the estimated involved worker impacts from loading spent nuclear fuel and high-level radioactive waste. The DOE estimated that the maximum individual dose would be 12 rem over the 24 years of loading operations for individuals who worked the entire duration of repository operations (see FEIS, Section 6.2.2.1). The estimated probability of a latent cancer fatality for an involved worker from this dose would be about 0.005 (5 chances in 1,000). For perspective, an individual's lifetime risk of a fatal cancer from all other causes is about 1 in 4.

Issue

Members of the public have raised an issue that the DOE did not adequately address procedures or protocols to transfer transportation casks containing spent nuclear fuel and high-level waste from a waste generator to a carrier.

Response

Casks would be prepared for shipment by the operators of the waste generator or storage site under the quality assurance procedures approved by the NRC. The casks and transporter would be inspected prior to shipment. Truck shipments would not be allowed to leave the waste generator site unless found to be free of safety-related defects, as required by the Commercial Vehicle Safety Alliance inspection procedures. Rail shipments would be subjected to railroad hazardous materials inspections prior to being accepted by a railroad for transportation. Inspections would also occur along the route and at the repository destination. More information on inspection activities is provided in Section M.3.2.2.2 of the FEIS.

At present, the DOE intends to purchase services and equipment from DOE transportation contractors who would perform waste acceptance and transportation operations. Operational protocols and procedures would be developed with each generator by the DOE transportation contractors as part of the planning process to be completed prior to initiation of transport of spent nuclear fuel or high-level radioactive waste from generators to the repository. Section M.3 of the FEIS contains more information on operational protocols required of the DOE transportation contractors.

4.8.6 (105)

Summary Comment

Members of the public expressed concern about incident free impacts of transporting spent nuclear fuel and high-level radioactive waste to Yucca Mountain. Members of the public asserted that the exposed population across the nation from incident free transportation was 50 million individuals, and expressed concern that the chronic radiation exposure associated with incident free transportation would cause adverse health affects to members of the exposed public.

Issue

An issue has been raised expressing concern about the impacts to an individual member of the public along a transportation route from incident free transport of spent nuclear fuel and high-level radioactive waste to Yucca Mountain.

Response

The U.S. Department of Transportation routing requirements, along with NRC regulatory licensing requirements to limit radiation dose external to a shipping cask, would help to ensure that radiation doses to an individual residing along the routes would be low. The analysis in Chapter 6 of the FEIS for the mostly legal-weight truck scenario estimates the dose to persons who would drive alongside the trucks as they traveled on the highways, who would be stopped in locales where truck shipments stopped, and who lived along the routes that could be used. The DOE forecasted growth in populations along routes to estimate potential impacts that could occur in the future when shipments would occur. However, the estimated dose to an individual living along a route would not change with changes in population—only the integrated dose to the whole population would change. The dose for a maximally exposed individual who lived along a route would be about 0.25 millirem per year. The estimated dose to a maximally exposed individual living along a rail route would be even lower in a mostly rail scenario (see FEIS, Section 6.2.3).

The impacts reported in the FEIS are the estimated impacts summed over the specific routes used for analysis in the FEIS over the period necessary to ship the spent nuclear fuel and high-level radioactive waste. The transportation impacts in the FEIS were evaluated over the entire shipping period. The total impacts to exposed populations over that period were calculated. The analysis in the FEIS did not estimate an exposed population of 50 million, as asserted. The transportation impacts, analyzed in the FEIS, were integrated over the exposed population along the transportation routes and extrapolated to 2035. As discussed in Sections 6.2.3.1 and 6.2.3.2 of the FEIS, the estimated exposed population ranged from 10 million for truck shipments to 16 million for rail shipments. For perspective, the population of the United States was about 250 million in 1990 and 280 million in 2000.

The FEIS analysis includes estimated public health impacts along transportation routes. This analysis accounts for factors such as the locations of intersections, commercial establishments and residences, and traffic signals. The impacts of incident-free transportation would be so low for individuals who lived and worked along the routes that these individual impacts would not be discernible even if the corresponding doses from such transportation could be measured. The total impacts of transportation would be similar for different routes that could be used.

To calculate the potential impacts to a maximally exposed individual in Nevada, the DOE used information and assumptions from a report sponsored by the City of North Las Vegas, Nevada, [The Louis Berger Group, Inc. 2000. "Assessment of the Hazards of Transporting Spent Nuclear Fuel and High Level Radioactive Waste to the Proposed Yucca Mountain Repository using the Proposed Northern Las Vegas beltway." Las Vegas, Nevada: The Louis Berger Group. TIC: 250165.], because the DOE believes it to be the only source of the information. However, the DOE considers the exposure assumptions presented in the report to be extreme and very unlikely to occur. The DOE analysis of dose, using information and assumptions presented in the report, estimated a maximally exposed individual in Nevada would receive a dose of about 530 millirem over 24 years. This is an annual dose of about 22 millirem, which is about 6 percent of a 1-year exposure to natural background radiation, and 22 percent of the limit for members of the public as established by NRC regulations (10 CFR Part 20). A dose of 530 millirem would increase an individual's risk of a fatal cancer by about 1 chance in 4,000 over the person's lifetime. For perspective, an individual's lifetime risk of a fatal cancer from all other causes is about 1 in 4. So, even using the unlikely exposure assumptions contained in the Berger report, the dose to a maximally exposed individual would be well below that received from natural background radiation, would not be discernible, and would not add measurably to other impacts that an individual could incur.

The DOE also investigated the potential impacts of transporting spent nuclear fuel and high-level radioactive waste to Yucca Mountain would have on multiple resource areas not related to human health and safety: land use; air quality; biological resources and soils; hydrology; cultural resources; socioeconomics; noise; aesthetics; waste management; utilities, energy, and materials; and environmental justice (see FEIS, Chapter 6). The DOE concluded that the impacts in these resource areas from nationwide transportation (outside Nevada) would not be discernible because shipments would use existing highways and railroads and would contribute only minimally to the volume of national transportation (0.007 percent of railcar kilometers and 0.008 percent of truck kilometers). Although radiological health and traffic fatality impacts would be adverse, because these potential impacts nationwide would not be high for any individual or identifiable group, including Native American tribes, the DOE also concluded that transportation of these materials would not raise environmental justice concerns.

Based on the results of the impact analyses presented in Chapter 6 and Appendix J of the FEIS, as well as the results published in numerous other studies and environmental impact analyses cited in the FEIS, the DOE is confident spent nuclear fuel and high-level radioactive waste would be safely transported to Yucca Mountain. The DOE also believes, as the FEIS reports that the potential impacts of this transportation would be so low for individuals who live and work along the routes that these individual impacts would not be discernible even if the corresponding doses from such transportation could be measured. The analysis presented in the FEIS factored in the characteristics of spent nuclear fuel and high-level radioactive waste, the integrity of shipping casks that would be used for transportation, and the regulatory and programmatic controls that would be imposed on shipping operations (see FEIS, Appendix M). The FEIS analytical results are supported by numerous technical and scientific studies that have been compiled through decades of research and development by the DOE and other federal agencies, including the NRC and the U.S. Department of Transportation, as well as by the international community, including the International Atomic Energy Agency.

Issue

Members of the public questioned how much waste would be shipped and how many shipments of spent nuclear fuel and high-level radioactive waste would be made.

Response

The DOE estimates that 70,000 MTHM of spent nuclear fuel and high-level radioactive waste would be transported from commercial and DOE sites to Yucca Mountain using some combination of highway and railroad transport (modal-mix). The FEIS considers two modal-mix scenarios for national transportation, which for simplicity are referred to as the mostly legal weight truck scenario and the mostly rail scenario. For the mostly legal-weight truck scenario, during a 24-year period approximately 53,000 shipments would travel on the national highways and approximately 300 shipments of naval spent nuclear fuel would travel by rail/heavy-haul truck. Although this would imply that approximately six truck shipments would be arriving at a repository at Yucca Mountain on any given day, they would be arriving from different locations in the country, taking different routes, and their passage at any individual location along the route would require a minimal amount of time. For the mostly rail scenario, during a period of 24-years, approximately 1,000 legal weight truck shipments would occur together with approximately 9,000 to 10,000 railcar shipments (FEIS, Section 2.1.3).

4.8.6 (11142)

Summary Comment

An issue was raised by the public considering the tracking of shipments of hazardous materials other than spent nuclear fuel and high-level radioactive waste to a repository at Yucca Mountain.

Response

The tracking of shipments of hazardous materials other than spent nuclear fuel and high-level radioactive wastes is not a part of the Site Suitability evaluation. Moreover, the tracking of other hazardous materials is not necessary for safe transport of spent nuclear fuel and high-level radioactive waste.

The DOE intends to use the latest version of TRANSCOM, or a similar satellite tracking system, that would track and communicate continually with shipments of spent nuclear fuel and high-level radioactive waste to the repository. Currently, the DOE intends to purchase services and equipment from Regional Servicing Contractors who would perform waste acceptance and transportation operations. The Regional Servicing Contractor would be required to provide detailed written procedures for how it would respond to an incident and arrange for repair/replacement of equipment or recovery, as appropriate. In accordance with the national standard ANSI N14-27, the carrier is expected to provide appropriate resources for addressing the consequences of an accident, isolating and cleaning up contamination, and maintaining working contact with the responsible governmental authority until the latter has declared the incident to be satisfactorily resolved and closed. Information on TRANSCOM and federal response capabilities is found in Appendix M of the FEIS.

The DOE could decide to use either a dedicated train that carried only the material being shipped to Yucca Mountain, or could elect to move the spent nuclear fuel and high-level radioactive waste in general freight. If the material were shipped as general freight, the position of the spent nuclear fuel or high-level radioactive waste car in the train would be regulated by 49 CFR 174.85. This regulation requires that rail cars placarded "radioactive" must be separated from a locomotive, occupied caboose, or carload of undeveloped film by at least one nonplacarded car, and it may not be placed next to other placarded railcars of other hazard classes. Section J.2.3 of the FEIS presents an assessment of impacts of using dedicated trains or general freight to transport spent nuclear fuel and high-level radioactive waste. Based on current information from the U.S. Department of Transportation and the Association of American Railroads, it is the DOE's opinion that there is no clear advantage for using either dedicated trains or general freight service.

4.8.7 Transportation Impacts of Terrorist Attack and Sabotage

4.8.7 (97)

Members of the public have raised issues pertaining to the risks, nature, and severity of the consequences of a successful sabotage of spent nuclear fuel and high-level radioactive waste shipping casks. In question were methods for estimating the consequences of severe sabotage-induced accidents, along with provisions for sabotage prevention and emergency response.

Members of the public have raised an issue that shipments of spent nuclear fuel and high-level radioactive waste would present a possible target for saboteurs. Publicized events of terrorism are cited for the concern. In addition, the fact that spent nuclear fuel and high-level radioactive waste shipments would be frequent and involve a known destination suggests that they could be a target. Members of the public also expressed concern that there is an increased risk of sabotage in Utah due to the potential Private Fuel Storage facility in Skull Valley.

The physical security measures already in place by the NRC and the exceptional strength and durability of the transportation casks would protect shipments of radioactive waste from acts of terrorism or sabotage. The same design features that make transportation casks capable of surviving severe accidents also limit their vulnerability to sabotage. Also, programs and processes to guard against potential sabotage would be developed by the DOE and submitted to the NRC for review and approval before any spent nuclear fuel or high-level radioactive waste is transported to Yucca Mountain.

Shipments of spent nuclear fuel and high-level radioactive waste would be subject to physical protection regulations of the NRC (10 CFR 73.37). The NRC establishes regulations to minimize the possibility of sabotage events. Security measures include armed escorts, tracking, safeguarding schedule and itinerary information, security arrangements for the shipments, and arrangements with law enforcement agencies. In addition, transportation casks are massive metal containers designed to contain their radioactive contents following a severe accident sequence (e.g., drop, puncture, fire, and immersion in water). If the regulations for safeguards and security measures that apply to spent nuclear fuel transport were revised, the DOE would comply with the revised regulations in place at the time of shipments.

For the purpose of analysis in the FEIS, the DOE assumes that a sabotage event occurs, and considers the consequences. As discussed in the FEIS, a successful sabotage attempt would not likely release significant quantities of radioactive materials. Casks are designed and built to prevent release of their contents under severe accident conditions. Most types of sabotage events would not likely result in more damage to the casks than the severe transportation accident for which the casks were intended to survive.

The NRC is reviewing their security regulations and procedures (NRC press release No. 01-112). If the regulations for safeguards and security measures that apply to spent nuclear fuel transport were revised, the DOE would comply with the revised regulations in place at the time of shipments. For the purpose of analysis in the FEIS, the DOE assumes that a sabotage event occurs, and considers the consequence. A successful sabotage attempt would not likely release significant quantities of radioactive materials. Casks are designed and built to prevent release of their contents under severe accident conditions. Most types of sabotage events would not likely result in more damage to the casks than the severe transportation accidents for which the casks were intended to survive.

Even though the likelihood of successful penetration of a cask is very low in a sabotage attempt, the DOE estimated maximum releases of radioactive material from a sabotage attempt against a shipping cask containing spent nuclear fuel [Luna, R.E.; Neuhauser, K.S.; and Vigil, M.G. 1999. "Projected Source Terms for Potential Sabotage Events Related to Spent Fuel Shipments." SAND99-0963. Albuquerque, New Mexico: Sandia National Laboratories. ACC: MOL.19990609.0160.]. Sabotage analysis results are discussed in Section 6.2.4 of the FEIS and are summarized below. The supporting calculations used assumptions about the concentrations of radioisotopes in spent nuclear fuel, population densities, and average weather conditions to evaluate maximum reasonably foreseeable events.

For legal weight truck shipments, the analysis estimated that a sabotage event occurring in an urbanized area could result in a population dose of 96,000 person-rem. This dose would cause an estimated 48 fatal cancers among the population of exposed individuals. A maximally exposed individual could receive lifetime-committed dose of 110 rem, which would increase the risk of a fatal cancer from about 23 percent from all other causes to about 29 percent. The analysis estimated that this individual would be located between 100 to 330 meters (330 to 1,080 feet) from the event.

For rail shipments, the analysis estimated that a sabotage event in an urbanized area could result in a population dose of 17,000 person-rem. This dose would be likely to cause 9 fatal cancers among the population of exposed individuals. A maximally exposed individual could receive a lifetime-committed dose of 40 rem, which would increase the risk of fatal cancer from about 23 percent (national average) from all other causes to about 25 percent. The analysis estimated that this individual would be located between 100 to 330 meters (330 to 1,115 feet) from the event.

Issue

Members of the public have raised an issue that questioned protecting shipments at stopping points on the transportation route. The assertion was made that protection is likely to be inadequate compared to in-transit safeguards. Specifically, it was noted that the DOE does not address potential acts of sabotage at intermodal transfer stations.

Response

Casks are designed and built to prevent release of their contents. Most types of sabotage events would not likely result in more damage to the casks than the severe transportation accidents for which the casks were designed to survive.

Shipments of spent nuclear fuel and high-level radioactive waste would be subject to physical protection regulations of the NRC (10 CFR 73.37) that are designed to minimize the potential for successful sabotage attacks. Over the last 30 years, approximately 2,700 shipments of spent nuclear fuel have been transported safely over U.S. highways, waterways, and railroads. During that time, the overwhelming focus of transportation security for spent nuclear fuel has been radiological sabotage. The NRC establishes regulations to minimize the possibility of these events. Security measures include armed escorts in heavily populated areas, tracking, safeguarding schedule and itinerary information, security arrangements for the shipments, and arrangements with law enforcement agencies. In addition, as a part of the NRC required physical protection program for shipments of spent nuclear fuel, routes must be approved in advance by the NRC (see 10 CFR 73.37(b)). Routes would be reviewed by the NRC from a safeguards and security standpoint. Furthermore, transportation casks are massive metal containers designed to contain their radioactive contents following a severe accident sequence (drop, puncture, fire, and immersion in water). Additional information on the physical protection of spent nuclear fuel during transportation can be found in the Appendix M of the FEIS.

Issue

Members of the public have stated that based on policy, state law enforcement agencies would provide armed escorts while the shipments of spent nuclear fuel and high level waste are within the state's boundaries, and questioned who would pay for the escorts. The comments were that the costs of security measures should have been delineated, along with the responsible parties, in the DEIS. In addition, comments asked for the definition of "heavy-populated" areas in the context of armed security requirements.

Response

The DOE would comply with the NRC safeguards requirements in place at the time of the shipments. The costs associated with meeting the safeguards requirements, including those for DOE escorts, would be borne by the generators and owners of spent nuclear fuel and high-level radioactive waste. If states or tribes determine that they wish to provide escorts in addition to those provided by the DOE, the cost of these additional escorts would be borne by the state or tribe. As stated in 10 CFR Part 73, armed escorts are required in heavily populated areas. A heavily populated area is defined by the NRC as: "Certain areas within United States territory are designated as heavily populated for the purposes of regulation of spent fuel shipments. Heavily populated areas are characterized in terms of urbanized areas, as defined by the Bureau of the Census, having total populations of one hundred thousand persons or more" [NRC (U.S. Nuclear Regulatory Commission) 1980. "Physical Protection of Shipments of Irradiated Reactor Fuel, Interim Guidance." NUREG-0561, Rev. 1. Washington, D.C.: U.S. Nuclear Regulatory Commission. TIC: 231207. Section 2.3.].

Issue

Members of the public raised an issue over sabotage against shipments of spent nuclear fuel and high-level radioactive waste. Commenters summarized the State of Nevada's petition to the NRC to modify 10 CFR Part 73 that would increase the level of security for these shipments. Commenters noted that neither the DEIS nor the supporting Sandia National Laboratories report acknowledges Nevada's petition for rulemaking. The commenters also asked if waste shipments would have armed escorts along the entire shipment route rather than just urban or high-population areas. The comments recommended that armed escorts are required for the entire route and that the DOE should go beyond NRC regulations for licensing that prescribe safeguards for fuel shipments.

Response

NRC regulations (10 CFR Part 73) prescribe safeguards and security measures for spent nuclear fuel shipments. These measures have been developed to reduce the likelihood of successful sabotage. The DOE shipments to a repository would comply with these regulations. NRC regulations (10 CFR Part 73) require, in part, armed guards in heavily populated areas. Escorts are required in areas not considered heavily populated. The State of Nevada's petition to the NRC (docket number PRM-73-10, Notice of Receipt published in 64 FR 49410) requests that such a distinction based on population density be eliminated from the regulations. If the regulations for safeguards and security measures that apply to spent nuclear fuel transport were revised, the DOE would comply with the revised regulations. Likewise, for shipments other than spent nuclear fuel, which is addressed in 10 CFR 73.37, the DOE would comply with all applicable NRC safeguards and security requirements.

Issue

Members of the public have raised an issue that a serious transportation sabotage event could overwhelm emergency response resources, and disrupt commerce and economic activity.

Response

Estimating the economic risks and environmental consequences would depend on many factors associated with accidents that cannot be known in advance and, therefore, would require speculation. Moreover, more than 99.99 percent of transportation accidents would not result in a release of radioactive materials from a shipping cask [Sprung, J.L.; Ammerman, D.J.; Breivik, N.L.; Dukart, R.J.; Kanipe, F.L.; Koski, J.A.; Mills, G.S.; Neuhauser, K.S.; Radloff, H.D.; Weiner, R.F.; and Yoshimura, H.R. 2000. "Reexamination of Spent Fuel Shipment Risk Estimates." NUREG/CR-6672. Two volumes. Washington, D.C.: U.S. Nuclear Regulatory Commission. ACC: MOL.20001010.0217.], although these accidents could lead to traffic fatalities and economic loss. Economic losses from nonrelease accidents would be similar to those associated with other transportation accidents that occur. In the unlikely case of an accident that caused a release of radioactive materials from a cask to the environment, additional costs could be incurred that would be associated with personal or property damage. Such costs would be compensated under the provisions established by the Price–Anderson Act.

As required by Section 180(c) of the NWPA, the DOE would provide technical assistance and funds to states for training of public safety officials of appropriate units of government and Native American tribes through whose jurisdiction the DOE would transport spent-nuclear fuel and high-level radioactive waste. Training would include procedures required for safe, routine transportation of these materials, as well as procedures for dealing with emergencies. Additionally, Section 116(c)(2)(A) and 117(c)(5) of the NWPA sets forth assistance guidelines covering a number of issues including emergency preparedness and response. A discussion of Section 180(c) can be found in Appendix M of the FEIS.

In the event of sabotage or an accident involving radioactive materials, states, tribes, and local governments can also request assistance from the federal government under the Federal Radiological Emergency Response Plan. Different types of needed assistance are available from seventeen different agencies. In addition, the DOE maintains eight regional coordinating offices, which are ready at all times to provide assistance. Information concerning these resources can also be found in Appendix M of the FEIS. Transportation services contractors that the DOE may use would be required to provide drivers and crews with specific written procedures that clearly define actions to be taken in the event of an emergency or incident. Carrier and shipper responsibilities regarding emergency situations also are discussed in Appendix M of the FEIS.

Issue

Members of the public expressed a disbelief in the DOE's projected sabotage consequence saying it was underestimated by at least a factor of 10. The critique centered on assumptions regarding weapons used, and disagreement with analysis methodologies and computer codes used.

Response

The DOE believes the analysis discussed in Section 6.2.4.2.3 of the FEIS provides appropriately modeled, conservative, estimates of releases of radioactive material that could result from a sabotage attempt, and the consequences of such an attempt. Although the impacts from the potential sabotage attack estimated in the FEIS have increased from those reported in the DEIS, this was not due to an error in the analysis, but rather to revised spent nuclear fuel characteristics used in the analysis and the use of population projections to 2035.

The analysis estimated maximum releases of radioactive material from a sabotage attempt against a shipping cask containing spent nuclear fuel [Luna, R.E.; Neuhauser, K.S.; and Vigil, M.G. 1999. "Projected Source Terms for Potential Sabotage Events Related to Spent Fuel Shipments." SAND99-0963. Albuquerque, New Mexico: Sandia National Laboratories. ACC: MOL.19990609.0160.]. A variety of devices were considered and two were considered for detailed analyses.

The model used in the analysis has been benchmarked against experiments for estimating depth of penetration. As indicated in the recent Sandia National Laboratories study, the SCAP computer program code was tested against several experiments involving device interactions with material configurations not unlike spent nuclear fuel casks. The results show penetration of one cask wall and the spent nuclear fuel, but do not show penetration completely through the cask. Because the model may underestimate the volume of material affected, scientists have developed a method for correcting the estimates of swept volume. Although incorrectly described in an equation in the analysis report, swept volume was explicitly defined in the laboratory analysis.

The DOE used the RISKIND computer program and the results of the Sandia National Laboratories analysis to estimate the human health consequences of releases of radioactive materials that might result from an act of sabotage. The RISKIND code has been used widely and is generally accepted as appropriate for estimating the consequences of radioactive material transportation accidents that could release radioactive materials.

4.8.8 Emergency Response for Transportation Incidents

4.8.8 (88)

Issues were raised by the public that expressed concern about the funding, planning, equipment, capabilities, and personnel of local communities to train and equip their emergency responders. It was requested that no waste be transported until the proper measures for safe routine transportation and emergency response capability are in place.
Communities and counties, especially in either rural or remote areas, located along transportation routes questioned whether the necessary equipment, trained personnel, or funding would be available to respond to an accident involving radioactive waste. Some contended that the DOE did not adequately evaluate the demands on affected local government related to public health and safety with respect to the potential activities. They stated that a credible evaluation would identify the adequacy or inadequacy of emergency response capacity along routes and allow the state and local authorities to deploy the necessary resources. It was recommended that the federal government encourage the development of, and help fund communication centers in, transportation corridors to enhance emergency preparedness and response along routes.

An issue has been raised by the public questioning whether the DOE would train and equip first responders and encourage and fund state or local emergency management centers in the transportation corridors.

First responses to accidents are the responsibility of the jurisdiction where the accident occurs. However, the DOE would help the states and tribes develop effective emergency response capabilities relative to the shipments of spent nuclear fuel and high-level radioactive waste to a repository. The DOE would provide technical assistance and funds so the appropriate states and tribes can adequately train first responders.

Although the DOE would develop its own emergency response plans, the preparation and implementation of emergency response, evacuation and contingency plans, for their jurisdictions, is a state and tribal responsibility. Section 180(c) of the NWPA, as amended (42 U.S.C. 10175(c)), requires the DOE to provide technical assistance and funds to states for training of public safety officials of appropriate units of local government and Native American tribes through whose jurisdictions the DOE plans to transport spent nuclear fuel and high-level radioactive waste. As part of this program, eligible states and tribes would receive an up-front planning grant to determine their needs for technical assistance and funds to train public safety officials in procedures required for safe routine transportation and emergency response situations. Subsequently, eligible states and tribes would receive annual funding and technical assistance for planning, coordinating and implementing training in a timely manner. Although the DOE would provide the funding, each state and tribe would determine how it would administer that funding. In accordance with the draft Section 180(c), policy and procedures, jurisdictions may use a certain percentage of their financial assistance to purchase equipment that would be used for emergency management, as well as for training.

The DOE published "Notice of Revised Proposed Policy and Procedures," in the Federal Register on April 30, 1998 (63 FR 23753), that sets forth the draft proposed mechanisms for implementing the requirements of Section 180(c). The schedule in the proposed policy and procedures for implementation of Section 180(c) is designed to provide adequate time for training of first responders in advance of the first shipments. Should a decision be made to proceed with the development of a repository at Yucca Mountain, preliminary shipping routes would be identified approximately 5 years before shipments begin and Section 180(c) assistance would be made available approximately 4 years prior to shipments being made through a jurisdiction. Using this information, the DOE would notify those jurisdictions about their eligibility for the Section 180(c) program funds. The DOE plans to notify the governor and the Native American tribal leader of each eligible jurisdiction by letter and include an information packet and an application package.

With regards to communications, the DOE intends to use a satellite tracking system to monitor shipments to Yucca Mountain. If approved by the NRC under regulations contained in 10 CFR Part 73, the DOE would provide training on and equipment for states and tribes to track and communicate about shipments under the NWPA.

Additional federal response capabilities, such as expert services from the Radiological Assistance Program Team, could be activated, as requested by states and tribes.

The DOE has several programs available to provide assistance to the state, local and Native American tribal governments in response to radioactive material accidents. The Radiological Assistance Program, for example, provides trained personnel with equipment to evaluate, assess, advise and assist in the mitigation and monitoring of potential immediate hazards associated with a transportation accident. As part of the Program, the DOE maintains eight Regional Coordinating Offices across the country. These are staffed 24 hours per day, 365 days per year. The staff consists of nuclear engineers, health physicists, industrial hygienists, public affairs specialists, and other personnel who provide field monitoring, sampling, decontamination, communications, and other services as requested. In addition, the DOE Radiation Emergency Assistance Center/Training Site can provide rapid medical attention to persons involved in radiation accidents. The Radiation Emergency Assistance Center/Training Site maintains a 24-hour response center to provide direct or consultative support, including deployable equipment and personnel trained and experience in the treatment of radiation doses.

Additional information has been provided in Appendix M.6 of the FEIS on the DOE funding and assistance for improvements in local emergency response training and capabilities along the routes for spent nuclear fuel and high-level radioactive waste.

Issue

An issue has been raised by the public stating that the DOE analysis is inadequate because there is no analysis of potential activities and costs of emergency management including preparedness, response and recovery. The issue stated that for public safety, the DOE must examine what emergency response personnel, training, and equipment would be needed along routes for the shipping of spent nuclear fuel and high-level radioactive waste. Further, state, tribal, and local jurisdiction should be involved in the development of emergency preparedness plans.

Response

A recent NRC study [Sprung, J.L.; Ammerman, D.J.; Breivik, N.L.; Dukart, R.J.; Kanipe, F.L.; Koski, J.A.; Mills, G.S.; Neuhauser, K.S.; Radloff, H.D.; Weiner, R.F.; and Yoshimura, H.R. 2000. "Reexamination of Spent Fuel Shipment Risk Estimates." NUREG/CR-6672. Two volumes. Washington, D.C.: U.S. Nuclear Regulatory Commission. ACC: MOL.20001010.0217.] concluded that casks would continue to fully contain spent nuclear fuel in more than 99.99 percent of all accidents. After initial safety precautions had been taken, the cask would be recovered and removed from the accident scene. Because no radioactive material would be released, the economic costs of these accidents would be minimal.

Based on the above stated statistics, the DOE does not expect an accident to occur that would result in a radiological release and subsequent environmental cleanup. However, a discussion is presented in the FEIS, Appendix J, Section J.1.4.2.5, on the cost of cleanup and ecological restoration following an unlikely release of radioactive materials resulting from a transportation accident.

Although the DOE would develop its own emergency response plans, the preparation and implementation of emergency response, evacuation and contingency plans is a state and tribal responsibility for lands within their jurisdictions.

Funding in accordance with Section 180(c) of the NWPA, as amended (42 U.S.C. 10175(c)), would be provided to eligible jurisdictions for the preparation of these plans, as well as emergency response and safe routine transportation training and coordination activities. Under this program, every eligible jurisdiction would receive a one-time planning grant to determine their specific needs to provide an additional increment of preparedness specific to the shipments. Subsequently, eligible states and tribes would receive annual funding and technical assistance for planning, coordinating and implementing training in a timely manner.

Additional information has been provided in Appendix M.6 of the FEIS on the DOE funding for improvements in emergency response training and capabilities along the routes. Appendix M.8 of the FEIS describes the Price–Anderson Act (42 U.S.C. 2210), the federal law enacted to ensure prompt and equitable compensation in the event of a nuclear incident.

Issue

An issue has been raised by the public questioning whether communities or counties in rural or remote areas would have equipment, funding, or trained personnel to respond adequately to an accident that releases radioactivity.

Response

It is the DOE policy that each responsible jurisdiction would have the training necessary for safe routine transportation of shipments under the NWPA and to respond to transportation incidents or accidents. Further DOE resources would be deployed as requested to minimize the risk from accidents in rural areas.

As discussed in Section 6.2 of the FEIS, accidents involving the transport of spent nuclear fuel and high-level radioactive waste could occur. However, of an approximately 53,000 potential truck shipments, there would be an estimated 66 accidents nationwide, each having less than a 0.01 percent chance that radioactive materials would be released. The chance that a rail accident would cause a release from a cask would be even less. Consequently the likelihood that a first responder or other emergency personnel would become contaminated, even in a severe accident, is remote.

Although the DOE would develop its own emergency response plans, the preparation and implementation of emergency response, evacuation, and contingency plans for their jurisdictions is a state or tribal responsibility. Funding in accordance with Section 180(c) of the NWPA, as amended (42 U.S.C. 10175(c)), would be provided to eligible states and tribes for the preparation of these plans, as well as emergency response and safe routine transportation planning and coordination activities. Under this program, every eligible jurisdiction would receive an up-front planning grant to determine their specific needs to provide an additional increment of preparedness specific to the shipments under the NWPA. Subsequently, eligible states and tribes would receive annual funding and technical assistance for planning, coordinating, and implementing training in a timely manner.

The DOE transportation contractors would be required to provide the DOE with Carrier Management Plans that address compliance with all transportation requirements, including inspection requirements and driver and crew training in operations and safety.

Furthermore, each of the DOE transportation contractors, including the shipment escorts, would be required to provide detailed written procedures, to the DOE for approval, that describe how it would respond to an incident and arrangements that would be made for repair or replacement of equipment or recovery, as appropriate. The DOE intends to use the latest version of TRANSCOM, or a similar satellite tracking system, that would track and communicate continually with shipments to the repository. Also, the carriers are required by U.S. Department of Transportation regulations (49 CFR Part 387) to provide resources for: dealing with the consequences of an accident; isolating and cleaning up contamination; and maintaining working contact with the responsible governmental authority until the latter has declared the incident to be satisfactorily resolved and closed. Information on Section 180(c) (42 U.S.C.10175(c)), TRANSCOM and federal response capabilities is found in Appendix M of the FEIS.

Issue

An issue has been raised by the public questioning how first responders to accidents involving spent nuclear fuel or high-level radioactive waste would be notified of the potential life threatening exposures to which they could be exposed.

Response

The U.S. Department of Transportation requires the carriers of hazardous materials (which include radioactive materials) to uniquely placard the transport vehicle with signs that would identify to the first responder what material is being transported. In addition, drivers or train crews are trained in emergency response. NRC regulations (10 CFR 73.37) require escorts for in-transit physical protection of shipments of spent nuclear fuel. The DOE transportation contractors would be required to provide the DOE with Carrier Management Plans that address compliance with all transportation requirements, including driver and crew training in operations and safety.

The DOE published "Notice of Revised Proposed Policy and Procedures" in the Federal Register on April 30, 1998 (63 FR 23753), that sets forth the proposed mechanisms for implementing the requirements of Section 180(c) of the NWPA, as amended (42 U.S.C. 10175(c)). In accordance with the draft Section 180(c), policy and procedures, jurisdictions may use a certain percentage of their financial assistance to purchase equipment that can be used for training and for emergency response. This could include radiation detection equipment. See Appendix M.6 of the FEIS for a discussion of the DOE Section 180(c), policy and procedures and also a discussion of the placards used for these shipments.

Issue

An issue has been raised by the public questioning whether the DOE analysis adequately assessed the increased exposure of and health risks to emergency first responders.

Response

Risks to first responders are evaluated in the FEIS. The DOE has modified Section 6.2.4.2 of the FEIS to include estimated radiological impacts to emergency personnel who would respond to transportation accidents. The analysis assumed a first responder would be trained and would follow guidance in the "2000 Emergency Response Guidebook" [DOT (U.S. Department of Transportation) 2000. "2000 Emergency Response Guidebook." ERG2000. Washington, D.C.: U.S. Department of Transportation. ACC: MOL.20011009.0004.] when responding to transportation accidents involving shipments of radioactive materials. The maximum estimated dose to a first responder to a rail accident would be 830 millirem. This dose, which is about 40-percent of the limit for annual dose to radiation workers at DOE facilities, would lead to an increase of about 0.03-percent in the individual's lifetime risk of a latent fatal cancer. For perspective, an individual's lifetime risk of a fatal cancer from all other causes is about 1 in 4. Additional information on emergency response following an accident is also provided in Appendix M of the FEIS.

Issue

An issue has been raised by the public questioning the ability and training of hospitals and their personnel to handle and treat persons contaminated with radioactivity as a result of an accident involving the shipments of spent nuclear fuel and high-level radioactive waste.

Response

As discussed in Section 6.2 of the FEIS, accidents involving the transport of spent nuclear fuel and high-level radioactive waste could occur. However, of the approximately 53,000 potential truck shipments, there would be an estimated 66 accidents, each having less than a 0.01 percent chance that radioactive materials would be released. The chance that a rail accident would cause a release from a cask would be even less. Consequently the likelihood that a first responder or any other emergency response individual would become contaminated, even in a severe accident, would be remote.

However, in the unlikely event that someone becomes radioactively contaminated, emergency assistance is available. Major hospitals are equipped to deal with radioactive contamination because they routinely handle medical radioisotopes.

In addition, immediate assistance could be obtained from the DOE Radiation Emergency Assistance Center/Training Site where a team of specially trained physicians, nurses, heath physicists, radiobiologists, and emergency coordinators is on call 24 hours a day to provide direct or consultative help with cases where persons have been involved in a radiation accident.

Issue

An issue has been raised by the public questioning what provisions would be provided for families of first responders to compensate for their loss of income as the accident victim recuperated.

Response

A compensation system (the Price–Anderson Act [42 U.S.C. 2210]) exists for persons injured in nuclear accidents.

With respect to compensation for losses associated with an accident involving shipments of spent nuclear fuel or high-level radioactive waste, the Price–Anderson Act (42 U.S.C. 2210) establishes a system of financial protection for persons liable for and for persons injured by a nuclear accident or incident. The Price–Anderson Act establishes a system of private insurance and federal indemnification that generally ensures that up to $9.43 billion is available to compensate for damages suffered by the public from a nuclear accident, regardless of who causes the damages. Beyond that level, Congress would consider further action that it considered necessary to provide full and prompt compensation to the public. Price–Anderson indemnification is discussed in Section M.8 of the FEIS.

4.8.9 Other Transportation Concerns

4.8.9 (16)

An issue was raised by the public asserting that local ordinances prohibit the transport of spent nuclear fuel and high-level radioactive waste through some towns and counties.

An issue was raised by the public asserting that local ordinances prohibit the transport of spent nuclear fuel and high-level radioactive waste through some towns and counties.

Although some counties, towns, and cities have ordinances in place prohibiting the transportation of high-level nuclear waste, these ordinances, in order to be officially recognized by the Federal Highway Administration, a person, State, or political subdivision thereof, or Native American tribe directly affected by a highway routing designation, must submit an application for preemption determination to the Administrator of the Federal Highway Administration, to determine if the route designation can be preempted as defined by 49 U.S.C. 5125 and 49 CFR 397, Subpart E. After review of the application, the Administrator may grant a waiver of preemption, if the preemption standards of 49 CFR 397.203 are met. Highway routing designation includes any regulation, limitation, curfew, time of travel, restriction, lane restriction, routing ban, port-of-entry designation, or route weight restriction applicable to the highway transportation of hazardous materials (including class 7 radioactive waste) over a specific highway route or portion of a route.

The DOE would adhere to all applicable ordinances that have been granted a waiver of preemption by the Administrator of the Federal Highway Administration when transporting high-level nuclear waste or spent nuclear fuel.

4.8.9 (17)

Summary Comment

An issue was raised by the public regarding the cumulative risks and impacts from past, present, and future transport in Nevada of all radioactive and hazardous materials to the repository, to the Nevada Test Site, and to the Waste Isolation Pilot Plant in New Mexico.

Response

The DOE did consider, in the FEIS, the cumulative impacts of transportation in Nevada.

Section 8.4. of the FEIS describes the cumulative transportation impacts of past, present, and reasonably foreseeable shipments of radioactive materials throughout the nation and Nevada. Tables 8-58 and 8-60 of the FEIS summarize the estimates for collective worker-dose, the general-population dose, and traffic fatalities from these actions, between 1943 and 2047. These tables include shipments of low-level waste to the Nevada Test Site. This includes the reasonably foreseeable designation of the Nevada Test Site as a regional DOE low-level waste disposal site. Shipments of transuranic waste to the Waste Isolation Pilot Plant in New Mexico and shipments of spent nuclear fuel and high-level radioactive waste to various storage sites throughout the nation are also included. The DOE concluded in Section 8.4 of the FEIS that the cumulative health and safety impacts (latent cancer fatalities) from the transport of different types of waste would be indistinguishable from the natural fluctuations from either a national standpoint or to people in the region near Yucca Mountain.

4.8.9 (98)

Summary Comment

Several comments expressed concern about improvements to the transportation infrastructure for national and Nevada highway and rail routes for shipments of spent nuclear fuel and high level waste and the cost for these improvements. Comments expressed the idea that the DOE is responsible to assure that all needed infrastructure improvements are done.

Response

With the exception of the heavy-haul truck road upgrades or construction of a rail branch line in Nevada the DOE believes it would not be necessary to upgrade infrastructure to support shipments to Yucca Mountain.

With regards to road and rail improvements outside the State of Nevada, the shipment of radioactive materials requires no special transportation infrastructure that is not also necessary for safe transport of commodities in the United States today. The U.S. Department of Transportation is the regulatory agency responsible for establishing and enforcing the standards for the transportation infrastructure. Adequate highways, rail lines, crossings, bridges, and tunnels exist to support the transportation of materials described in the FEIS. Within the State of Nevada, upgrades to roads for heavy-haul shipments or the construction of a rail line to the repository are discussed in Chapter 6 and Appendix J of the FEIS. For purposes of analysis in the FEIS, the DOE assumed infrastructure and practices, including maintenance and enforcement of safety standards, used in transporting spent nuclear fuel and high-level radioactive waste to Yucca Mountain via rail would be comparable to that in current service.

The DOE would be responsible for making the funding available for road upgrades should it select heavy-haul truck transport and for working with the State of Nevada and tribes to ensure funding is made available for the road upgrades necessary to provide infrastructure for transporting spent nuclear fuel and high-level radioactive waste using heavy-haul trucks over Nevada roads. Likewise, the DOE would be responsible for funding and construction of a rail branch line in Nevada, if that option is used. For purposes of analysis in the FEIS the DOE assumed that funding for heavy-haul road upgrades and an associated intermodal transfer station and for rail branch line construction in Nevada came from sources outside Nevada.

With the exception of the heavy-haul truck scenario in Nevada, the shipments would use vehicles (trucks, railcars, and barges) similar in weight, size, and operation to vehicles that transport other commodities. As a result, potential impacts on transportation infrastructure (infrastructure typically includes bridges, roadways, railroad track, switchyards, locks, navigation aids, etc.) of a vehicle used in transporting spent nuclear fuel and high-level radioactive waste across the United States would be similar to the impacts of other commercial vehicles that use the nation's transportation systems. Because there would be few vehicles transporting spent nuclear fuel and high-level radioactive waste in comparison to other vehicles using the transportation system, the impacts on transportation infrastructure of shipments to Yucca Mountain would not be discernible. In addition, because the annual number of shipments that would be made to Yucca Mountain is less than 0.001 percent of the more than 300 million annual shipments of hazardous materials in the United States, impacts on state, local, and Native American tribal law enforcement and emergency response resources would be small.

National impacts estimated in the FEIS use data that incorporate statistics compiled from accidents in localities across the United States. The statistics include those for accidents where transportation infrastructure was a contributing factor. Thus, potential impacts in any locality, even one having transportation infrastructure with unusual hazards, would be much less than for the entire transportation system. Consequently, with the exception of the heavy-haul truck road upgrades or construction of a rail branch line in Nevada, the DOE believes existing highway and rail infrastructure, as well as its maintenance and public safety services, would be adequate for the safe transportation of spent nuclear fuel and high-level radioactive waste to Yucca Mountain. The DOE also believes the potential impacts to infrastructure and public safety services from transportation would be minimal. Because the estimates are based on present-day transportation conditions, the DOE believes it would not be necessary to upgrade infrastructure to support shipments to Yucca Mountain.

4.8.9 (11626)

Summary Comment

An issue has been raised by the public regarding the effect of different repository design options on the age of spent nuclear fuel that would be transported to a repository.

Response

The DOE developed the flexible design for the repository to allow flexibility in the emplacement of spent nuclear fuel and high-level radioactive waste that the DOE projects it would receive, not to promote or accommodate receipt of younger, hotter spent nuclear fuel. The DOE does not anticipate that the flexible design would have any effect on the characteristics of spent nuclear fuel that would be shipped to a repository or, consequently, on the casks and modes of transport that would be used for shipment. Therefore, the DOE does not expect that the health and safety risks of transporting spent nuclear fuel and high-level radioactive waste to Yucca Mountain, or the consequences of maximum reasonably foreseeable transportation accidents, would be different for the flexible design from those associated with the design presented in the DEIS.

Chapter 6 of the FEIS describes the changes made in the environmental analysis of transportation impacts since the publication of the DEIS. Among these changes are consideration of the effects of transporting hotter (less decayed) fuel. For incident free transportation, the radiological impacts did not change, since the analysis had assumed that the casks had been emitting maximum radiation levels permitted by the regulations. All real shipments are surveyed to ensure the casks remain below these NRC and Department of Transportation limits. The modeling assumption to use the regulatory dose rate limits as representative of actual values emanating from the casks is conservative.

The radionuclide inventory contained in spent nuclear fuel is presented in Appendix A of the FEIS. As discussed in Appendix A, Section 2.1 of the FEIS, the revised spent nuclear fuel characteristics are pressurized water reactor (i.e., 15 years old, 50 gigawatt day per metric ton of uranium burnup, 4.5 percent enrichment); and boiling water reactor (i.e., 14 years old, 40 gigawatt day per metric ton of uranium burnup, 3.5 percent enrichment). The DOE derived these characteristics through a dose-based hazard index analysis using the radionuclide inventory of the spent fuel assemblies and the screening models in "Screening Models for Releases of Radionuclides to Atmosphere, Surface Water, and Ground" [NCRP (National Council on Radiation Protection and Measurements) 1996. "Screening Models for Releases of Radionuclides to Atmosphere, Surface Water, and Ground." NCRP Report No. 123 I. Bethesda, Maryland: National Council on Radiation Protection and Measurements. TIC: 225158.]. These screening models account for all exposure pathways. Accidents modeled with these spent nuclear fuel characteristics provide a conservative estimate of the impacts of transportation accidents (see FEIS, Chapter 6). While some fuel could be slightly more radioactive; most would be considerably less radioactive.

For the analysis of transportation accidents, the FEIS describes a revised analysis in which two factors changed the results in opposite directions. The source term increased due to the hotter fuel. However, the risk analysis described in "Reexamination of Spent Fuel Shipment Risk Estimates" [Sprung, J.L.; Ammerman, D.J.; Breivik, N.L.; Dukart, R.J.; Kanipe, F.L.; Koski, J.A.; Mills, G.S.; Neuhauser, K.S.; Radloff, H.D.; Weiner, R.F.; and Yoshimura, H.R. 2000. Reexamination of Spent Fuel Shipment Risk Estimates. NUREG/CR-6672. Two volumes. Washington, D.C.: U.S. Nuclear Regulatory Commission. ACC: MOL.20001010.0217.] contained lower probabilities of occurrence for severe transportation accidents. The net effect is lower risk (accident dose times probability) for the revised FEIS analysis for hotter fuel.

The commenter claimed that current rail casks are designed to ship spent fuel older than ten years. The Certificates of Compliance for approved spent fuel rail casks have a variety of minimum cooling time limits, which are often coupled with a limit on maximum fuel burnup. Many of these minimum cooling times are less than ten years. The NRC publishes copies of Certificates of Compliance for each Type B package, including truck and rail spent fuel casks, in the 1996 directory [NRC (U.S. Nuclear Regulatory Commission) 1996. "Directory of Certificates of Compliance for Radioactive Materials Packages: Report of NRC-Approved Packages." NUREG-0383. Washington, D.C.: U.S. Nuclear Regulatory Commission. TIC: 8578.].

4.9 SOCIAL, ECONOMIC, AND QUALITY OF LIFE

4.9.0 (2531)

An issue has been raised that $15 million for socioeconomic studies went out of the State of Nevada.

Under Section 116(c)(1)(B) of the NWPA, the DOE has provided grants to the State of Nevada and affected units of local government "for purposes of determining any potential economic, social, public health and safety, and environmental impacts of a repository." Funds are spent at the discretion of these governmental organizations, as long as they meet the requirements of the NWPA. As such, the funds need not be spent within the State of Nevada.

4.9.1 General Socioeconomic Impacts

No comments received or comments addressed elsewhere.

4.9.2 Perceived Economic Impacts

4.9.2 (107)

Commenters stated that the DOE should analyze the impacts of stigma or risk perception and "special effects" on the State of Nevada and surrounding states. Commenters stated that people would avoid places and products associated with nuclear risk or stigma, resulting in decreased property values along transportation routes and near the storage site; reduction in tourism, reduced income for existing businesses; loss of new investments and businesses; decreased crop, product, and service prices, including effects on the marketability of agricultural products such as milk, vegetables, and organic products; decreased business diversification; loss of private land; and loss of existing population. The impact of this would be to destroy the welfare and standard of living, including affecting children and elderly people, in Nevada since the tax base would be affected. Commenters stated there could also be an effect on Death Valley and other scenic areas. Commenters cited as an example the effect on the Las Vegas economy of the September 11th events. Commenters also stated that the perceived risk of serious harm from the repository or transportation activities related to the repository would affect people's quality of life and psychological well-being.
Some commenters stated they did not believe there would be risk perception or stigma effects and cited examples such as no economic impacts from nuclear weapons testing at the Nevada Test Site or in France near nuclear waste shipment routes.

Regarding potential property value reductions, the DOE recognizes that nuclear facilities could be perceived to be either positive or negative, depending on the underlying value systems of the individual forming the perception. Perception-based impacts would not necessarily depend on the actual physical impacts or risks from repository operations or transportation. Further, people do not consistently act in accordance with negative perceptions, and thus the connection between public perception of risk and future behavior would be uncertain or speculative at best.

However, in light of the comments received on the DEIS concerning this subject, the DOE examined relevant studies and literature on perceived risk and stigmatization of communities to determine whether the state of the science in identified future behavior based on perceptions had advanced sufficiently to allow the DOE to quantify the impact of public risk perception on economic development or property values in potentially affected communities. Of particular interest were those scientific and social studies carried out in the past few years that directly relate to either Yucca Mountain or to DOE actions such as the transportation of foreign research reactor spent nuclear fuel. The DOE also reevaluated the conclusions of previous literature reviews such as those conducted by the NWTRB and the State of Nevada, among others. The DOE has concluded that: (1) while in some instances risk perceptions could result in adverse impacts on portions of a local economy, there are no reliable quantitative methods whereby such impacts could be predicted with any degree of certainty; (2) much of the uncertainty is irreducible, and (3) based on a qualitative analysis, adverse impacts from perceptions of risk would be unlikely or relatively small.

While stigmatization of southern Nevada or along transportation corridors can be envisioned under some scenarios, it is neither inevitable nor quantifiable. Any such stigmatization would likely be an after effect of unpredictable future events, such as serious accidents; based on analysis of potential accident scenarios, the DOE would not expect such accidents to occur.

4.9.3 Demographic Projections

4.9.3 (76)

Commenters have raised an issue that population projections in DOE documents were inadequate because of reliance on 1990 Census data. The rapid growth of towns and counties in Southern Nevada (e.g., Nye County, including Amargosa Valley and Pahrump) made 1990 Census population information obsolete with regard to both the repository and potential transportation corridors.

Commenters have raised an issue that DOE analyses resulted in inappropriate or inaccurate conclusions because of reliance on 1990 Census data. Specifically, it was pointed out that the rapid growth of towns and counties in southern Nevada, specifically, near the repository site, made 1990 Census population information out-of-date. Members of the public raised the issue that the DOE's population estimates should also include visitors to Clark County.

The DOE has determined the population projection estimates are reasonable based on the use of the latest available input data. The DOE has updated its socioeconomic baseline projections and estimated impacts to reflect recent data available from the State of Nevada and local communities and has included visitors to Las Vegas in its population estimates.

When the DOE prepared the DEIS, it based the Nevada population estimates on the then-most-recent available information (1996-1997) from the U.S. Bureau of the Census. The DOE used these data in its economic and demographic forecasting model (Regional Economic Models, Inc., Economic and Demographic Forecasting System) to project population growth in the regions of influence and to evaluate socioeconomic impacts from construction, operation and monitoring, and eventual closure of a repository at Yucca Mountain (both repository and Nevada-related transportation). For its transportation health and safety analyses however, the DOE relied on 1990 population data, which were escalated appropriately for subsequent years and which were the then-most-recent data incorporated in the standard models used for such analyses.

In general, the Bureau of the Census is the preferred source of information for use in the DOE socioeconomic analyses because it provides a greater level of consistency across geopolitical boundaries than most other data sources. Bureau information is based on the direct collection of information, while other information sources often rely either on some form of the Bureau information or on proxies such as telephone and electrical connections to households and businesses. The information for a particular variable provided by local and state agencies or private vendors can differ, sometimes significantly, because of the use of different methods, source data, level of detail and terminology. In addition, Bureau of the Census information is readily available and updated population estimates are available annually.

In response to comments, the DOE has updated its population estimates in the regions of influence to reflect recent state and local economic and demographic information. For the repository- and transportation-related regions of influence, the DOE performed simulations using the Regional Economic Models, Inc., Economic and Demographic Forecasting System model to establish an updated population baseline by incorporating population estimates and projections provided by county governments. In the absence of county information, the DOE used population estimates and projections from the Nevada State Demographer's Office. The updated population baselines were then used to estimate populations for Clark, Nye, and Lincoln counties and the Rest of Nevada through 2035. In this way, model population projections reflected the most recent available information.

To update the health and safety analyses associated with transportation in Nevada, the DOE used the baseline population for each county in the region of influence and forecast to 2035 to scale impacts from results based on the 1990 Census. For example, if a county's population was estimated to double from 1990 to 2035, the DOE assumed that the population along the associated rail corridor also would double and scaled the radiological impacts accordingly. In certain locales, however, such as around the planned Las Vegas beltway, the DOE used local sources of population information to better reflect population growth trends (in this instance, information from a report prepared for the City of North Las Vegas).

On a national basis, the DOE scaled the 1990 population-based impacts upward to reflect the relative state-by-state population growth to 2035. The projections are based on 2000 Census data.

In general, public health impacts to populations residing along candidate transportation routes or rail lines would increase directly with an increase in population (from 1990 to 2035 population estimates), if all other factors relevant to estimating such impacts remained constant. However, some factors, such as the number of anticipated rail shipments and the computer model used to estimate the dose to the public during traffic stops, have changed because of new information or in response to comments. For this reason, the health impacts in the FEIS are similar to, and in some instances less than, those reported in the DEIS, despite generally increased population estimates.

The DEIS, Section 3.1.7.1, identified the annual number of visitors to Las Vegas. The DOE has updated this number in the FEIS, Section 3.1.7.1, and included it in the analysis of transportation accident health effects.

4.9.4 Transportation Related Economic Impacts

4.9.4 (54)

Members of the general public raised issues suggesting that the Yucca Mountain Project would benefit the citizens of the State of Nevada by diversifying the economy and creating jobs. Other commenters wanted to know how the economy would be impacted in terms of job opportunities.

Socioeconomic changes were projected in communities that would be affected by a repository at Yucca Mountain and associated Nevada transportation alternatives. These evaluations included changes to employment, population, economic measures, housing, and some public services. The results reflected new job opportunities with associated increases in real disposable income and Gross Regional Product, primarily affecting the region of influence (Clark, Nye, and Lincoln counties).

The FEIS, Section 3.1.7, presents a baseline of economic parameters (including employment), chosen as representative of the economy during the construction, operation and monitoring and closure activities of a repository. The socioeconomic environment was evaluated in communities near the repository site. These evaluations included changes to employment, economic measures, population, housing and some public services. The evaluation projected economic parameters the use of the Regional Economic Models, Inc., Economic and Demographic Forecasting System 53-sector model. Impacts are measured by comparing the economic parameters in the baseline case with those for the repository or each transportation alternative.

In terms of regional employment, the FEIS, Section 4.1.6.2, discusses the impacts (or enhancements) to regional employment as the result of construction, operation, monitoring, and closure of a repository. In 2006, the peak year of employment during the initial construction phase, about 1,900 direct employment workers (over and above current employment levels at the Yucca Mountain site) would be added by the Yucca Mountain Repository Project. Indirect employment, (i.e., jobs created as a result of expenditures by directly employed project workers), would increase by about 1,500 additional workers during the peak repository construction year of 2006. Therefore, incremental employment increases during the construction phase would add a total of about 3,400 jobs to the region of influence, excluding those associated with transportation that are discussed below. The region of influence is defined as Clark, Nye, and Lincoln counties (see FEIS, Section 3.1.7). The DOE anticipates approximately 80 percent of the workers would live in Clark County and approximately 20 percent in Nye County. Only about five indirect jobs are expected in Lincoln County.

During the repository operational phase beginning in 2010, the direct work force would peak in 2012 at about 1,940 workers. This workforce would support about 720 indirect jobs for a total of about 2,660 workers within the region of influence. In the period following 2012 up through 2033, the average work force would stabilize at about 1,900 direct employees above the current (2001) workforce level. Monitoring and maintenance would begin with the first waste package emplacement and would continue through repository closure. The DOE estimates that about 120 workers would be needed to the monitor and maintain the repository.

Depending upon the transportation alternative selected, the estimated number of construction jobs would vary between about 250 and 3,000. All workers would reside within the region of influence (Clark, Nye, and Lincoln counties), however, 75 to 95 percent of the workforce would reside in Clark County.

Following transition to operations, construction jobs would end, and operational jobs would be generated. The number of jobs depends again on the transportation alternative selected. The DOE's analysis shows that there would be approximately 35 to 275 direct jobs created during the 24-year operational period.

4.9.5 Mitigation of Socioeconomic Impacts

4.9.5 (77)

Commenters stated that, because the project serves a national purpose, it is important that Nevada, which has not been the direct beneficiary of nuclear power, not bear the undue burden attributed to this project. Commenters further stated that it is important and entirely appropriate that state and local impacts of the project be offset through mitigating measures, financial and otherwise. Commenters expressed the belief that a large compensatory package should be developed for residents of the repository area. Commenters raised an issue regarding how property owners would be compensated for land needed by the DOE for possible transportation routes or property value losses due to the proximity to potential transportation routes.
Commenters requested an analysis of the potential economic impacts resulting from a transportation accident and a clarification of how compensation for any resulting impacts would be handled.

An issue has been raised regarding the need for the DOE to mitigate socioeconomic impacts or compensate the citizens of Nevada for accepting the material perceived as the entire Country's problem.

Appropriate mechanisms are in place to ensure that the DOE would provide compensation to local governments to address the impact of a repository at Yucca Mountain. For any land that would be required for transportation routes, the DOE would follow applicable laws and regulations (Uniform Relocation Assistance and Real Property Acquisition Policies Act of 1970, as amended [42 U.S.C. 4601 et seq.]) and would compensate landowners accordingly.

If a decision were made to proceed with a geologic repository at Yucca Mountain, Section 116(c) of the NWPA provides the mechanism for providing financial assistance to the State of Nevada and affected units of local government. At present, the DOE does not have definitive information on the specific tracts of land or specific community elements that could be adversely impacted, so it is premature to identify specific mitigation measures.

Any decision to provide assistance under NWPA Section 116 would be based on an evaluation of any reports submitted to the Secretary of Energy by an affected unit of local government or the State of Nevada pursuant to NWPA Section 116 to document likely economic, social, public health and safety, and environmental impacts.

Another provision of NWPA Section 116 is the DOE Payments-Equal-To-Taxes Program. NWPA Section 116(c)(3)(A), as amended (42 U.S.C. 10136(c)(3)(a)), requires the Secretary of Energy to "...grant to the State of Nevada and any affected unit of local government an amount each fiscal year equal to the amount such State or affected unit of local government, respectively, would receive if authorized to tax site characterization activities at such site, and the development and operation of such repository ...." The NWPA only authorizes the DOE to make payments to the State of Nevada and affected units of local government, which include Nye County and those counties contiguous to Nye County. The purchases (sales and use tax), employees (business tax), and property (taxes) of the Yucca Mountain Site Characterization Project organizations that exercise a federal exemption are subject to the Payments-Equal-To-Taxes Program.

The DOE is considering a range of mitigation measures aimed at reducing adverse effects that would result from the construction of a geologic repository at Yucca Mountain. The mitigation analyses in the FEIS, Chapter 9, discuss impact reduction measures for the repository and for waste transport, as well as other mitigation measures the DOE continues to evaluate.

The FEIS, Section 9.2, discusses mitigation measures the DOE has determined it would implement, or has identified for consideration, to reduce potential impacts from the construction, operation and monitoring, and eventual closure of the repository.

The FEIS, Section 9.3, discusses mitigation measures the DOE has determined it would implement, or has identified for consideration, to reduce potential impacts from the transportation of spent nuclear fuel and high-level radioactive waste. These measures address impacts from the possible construction of a branch rail line or an intermodal transfer station in Nevada; construction of other transportation routes; upgrading of existing Nevada highways to accommodate heavy-haul vehicles; transportation of spent nuclear fuel and high-level radioactive waste from existing storage sites to Yucca Mountain; and fabrication of casks and canisters.

Regarding compensation for takings of business or property interests, the DOE is required to follow applicable laws and regulations (Uniform Relocation Assistance and Real Property Acquisition Policies Act of 1970, as amended (42 U.S.C. 4601 et seq.)).

Issue

Commenters requested an analysis of the potential economic impacts resulting from a transportation accident and a clarification of how compensation for any resulting impacts would be handled.

Response

An analysis of the potential economic impacts to a specific local economy resulting from a transportation accident would be highly speculative and, as a result, no specific analyses were conducted. The Price–Anderson Act (Section 170 of the Atomic Energy Act, as amended (42 U.S.C. 2011 et seq.)) has provisions to compensate the public and governmental units in case of an accident involving the transport of nuclear materials.

The DOE analyzed a range of accident scenarios related to proposed transportation activities in the FEIS, Appendix J. Accident scenarios are based on probabilities with no definitive knowledge of when or where an accident could occur. Consequently, to attempt to assess the potential impacts of an accident to a specific local economy would be highly speculative. The FEIS does, however, address the potential socioeconomic impacts that could occur, directly or indirectly, as a result of the siting, construction, operation and monitoring, and eventual closure of a geologic repository at Yucca Mountain, including transportation activities. The socioeconomic parameters considered in the FEIS include quantitative estimates of changes to populations, employment, and income that could result from repository-related activities.

With regard to cleanup after a transportation accident, the Price–Anderson Act (Section 170 of the Atomic Energy Act, as amended (42 U.S.C. 2011 et seq.)) establishes a system of financial protection for the public in the event of a nuclear incident (compensation for damages, loss, or injury suffered), regardless of who causes the damage. The FEIS, Appendix M, discusses the Price–Anderson Act.

The DOE maintains eight regional coordinating offices, which are also prepared to provide immediate assistance should such events occur. Information concerning these resources can also be found in the FEIS, Appendix M. Also, in the event of an accident involving radioactive materials, states, tribes, and local governments can request assistance from 17 federal agencies under the Federal Radiological Emergency Response Plan (61 FR 20944).

As required by NWPA Section 180(c), the DOE would provide technical assistance funds to states for training for public safety officials of appropriate units of local government and Native American tribes through whose jurisdiction the DOE would transport spent-nuclear fuel and high-level radioactive waste. Training would cover procedures required for safe, routine transportation of these materials, as well as procedures for dealing with emergency response situations. In addition, NWPA Section 116(c)(2)(a) sets forth assistance guidelines covering a number of issues including emergency preparedness and response. A discussion of NWPA Section 180(c) can be found in Appendix M of the FEIS.

Any transportation services contractors would be required to provide drivers and crews with specific written procedures that clearly define actions to be taken in the event of an emergency or incident. Carrier and shipper responsibilities regarding emergency situations also are discussed in the FEIS, Appendix M. Qualifications and training requirements of operators are discussed in the FEIS, Appendix M.2.6. Specifically, U.S. Department of Transportation regulations (49 CFR Part 391) require anyone involved in the preparation or transport of radioactive materials, including loading and unloading, packaging, documentation, or general transport safety, to have proper training. In accordance with 49 Part CFR 172, Subpart H, operators of vehicles transporting Highway Route-Controlled Quantities of Radioactive Materials receive special training that covers the properties and hazards of the radioactive materials being transported, regulations associated with hazardous material transport, and applicable emergency procedures.

4.9.6 Quality of Life Impacts Including Aesthetics, Noise, and Air Quality

4.9.6 (59)

Issues were raised by members of the public regarding possible impacts of a repository and the transportation of spent nuclear fuel and radioactive wastes to the repository on the "quality of life" (i.e., peace and tranquility) within rural southern Nevada. Specifically, these quality-of-life issues are based on potential construction and operation of an intermodal transfer station and rail lines and operation of heavy-haul trucks that could impact visual resources (aesthetics), cause excessive noise and vibration, and impact air quality (dust, carbon monoxide, nitrogen dioxide, sulfur dioxide, ozone, etc.). There are similar concerns related to the construction and operation of the repository.

An issue has been raised regarding potential impacts of a repository and the associated transportation activities on the quality of life, including noise and aesthetic impacts, on residents living in the vicinity of the Yucca Mountain site and transportation routes.

No comments received or comments addressed elsewhere.

The results of analyses in the FEIS, Chapter 6, demonstrate that transportation noise could be a temporary annoyance; however, this noise is below levels that would be unsafe or could cause hearing damage. Similar analyses, presented in the FEIS, Chapter 6, show that ground level vibration resulting from heavy haul trucks and trains would be well below that which could adversely affect historic structures.

A new branch rail line could be constructed or roads could be upgraded or an intermodal transfer station could be built in Nevada. The transportation analysis addressed the impacts on land use, ownership, air quality, hydrology, biological resources (including wild game habitat), soils, public health and safety, socioeconomics, noise, cultural resources, aesthetics, utilities, energy, materials, waste management, and environmental justice (FEIS, Sections 6.3.2 and 6.3.3). In general, the impacts were assessed for regions that extend beyond the area that would be within a rail corridor, highway right-of-way, or site of an intermodal transfer station (see FEIS, Section 6.3 and Appendix J.1).

The State of Nevada does not have noise regulations. Forty-five decibels was used by the DOE for the analyses to conservatively establish a region of influence that would include most receptors. For comparison, residential noise standards in many other states generally use a level of 60 decibels for residential zones and 65 decibels for commercial zones. Residences located near highways along heavy-haul routes would be exposed to instantaneous levels of noise exceeding 60 dBa, which might elicit complaints that the noise is annoying. Annoyance levels are below levels that would be unsafe or could cause hearing damage. The FEIS, Section 3.1.9.2, includes a discussion of noise levels that are potentially unsafe or could cause hearing damage compared to levels that merely result in annoyance.

The FEIS does assess potential land use and noise impacts associated with each transportation scenario. If specific transportation routes are selected, environmental studies would assess transportation scenarios in more detail to support decisions on preferred transportation alignments and any necessary mitigative actions.

The Carlin rail corridor, part of which passes through Crescent Valley, is one of five alternative rail corridors the DOE considered in the FEIS, Section 6.3. Similarly, the Carlin heavy-haul truck route is one of five alternative heavy-haul truck routes the DOE considered in the same section of the FEIS (see FEIS, Sections 6.3.2.1 and 6.3.3.1, for discussion of the impacts from noise and to aesthetics in rail and heavy-haul truck corridors, respectively).

The DOE recognizes that additional, route-specific information would be needed before it constructed either a rail line or upgraded roads to support heavy-haul truck shipping. The DOE believes, however, that sufficient information on impacts to visual resources is provided in the FEIS, Chapter 6, to enable a decision to be made regarding the transport mode (rail or truck) and the specific corridor or heavy-haul route (see FEIS, Section 1.1). More detailed field surveys, government consultation, and National Environmental Policy Act reviews would be conducted if the DOE made a decision to select either a specific rail alignment within a corridor or an intermodal transfer station and associated heavy-haul route. These additional reviews could include more detailed analyses of impacts to visual resources, as well as the identification of possible mitigation measures to minimize any impacts identified.

The FEIS, Section 4.1.10, describes the aesthetic impacts of a repository. There are no Wilderness Study Areas near Yucca Mountain. Therefore, construction and operation of a repository at Yucca Mountain would not affect existing Wilderness Study Areas.

The Caliente rail corridor passes near two Wilderness Study Areas in the Kawich and Reveille Mountains, and the Valley Modified rail corridor passes near two Wilderness Study Areas near the Sheep Range Mountains: the Desert National Wildlife Refuge and the Nellis Air Force Range. The FEIS, Section 6.3.2.1, includes additional discussion of the potential visual impacts on these Wilderness Study Areas from construction and operation of a rail line and impacts associated with the alternative sites for an intermodal transfer station.

Issue

Members of the public have raised a concern that the DOE should address air quality impacts from fugitive dust releases and diesel engine emissions during construction and operations.

Response

The effects on regional air quality of construction of heavy-haul infrastructure improvements or a rail line to Yucca Mountain are addressed in the FEIS. Except for the Las Vegas Valley, all areas of Nevada potentially affected by transportation activities are within limits (in attainment) established by the National Ambient Air Quality Standards.

The FEIS, Chapter 6, and Appendix J, discuss potential impacts of the various transportation alternatives. Specifically, the FEIS, Section 6.3.2, discusses the rail alternatives and Section 6.3.3 discusses the heavy-haul truck alternatives including those specific alternatives that would affect Clark County. The FEIS, Section 6.3.2.2.5, (discussion of the Valley Modified Corridor alternative) notes that the Las Vegas basin air shed is in nonattainment for particulate matter (PM-10) and carbon monoxide. In addition, the FEIS, Chapter 6, discusses the potential air quality impacts from construction and operation if the decision were made to implement both rail and heavy-haul truck transportation scenarios.

Emissions during construction would be temporary and would move as construction progresses along the length of the corridor. Based on federal standards for locomotives, train emissions would not have a significant impact on air quality.

The FEIS, Sections 8.2 and 8.4, address the cumulative short-term impacts during construction, transportation, operation, monitoring, and closure of the repository. Cumulative impacts on air quality are also addressed in these sections.

The FEIS, Sections 6.3.1, 6.3.2, and 6.3.3 includes an in-depth discussion of the potential impacts of increased truck and rail traffic on air quality in the Las Vegas Valley. Additional traffic in the Las Vegas air basin would result in emissions of carbon monoxide during the construction and operating and monitoring phases. The Las Vegas air basin is in nonattainment status for carbon monoxide, which is largely a result of vehicle emissions. As part of the conformity review the DOE conducted using the guidance in the "Clean Air Act General Conformity Requirements and the National Environmental Policy Act Process" [DOE (U.S. Department of Energy) 2000. "Clean Air Act General Conformity Requirements and the National Environmental Policy Act Process." Washington, D.C.: U.S. Department of Energy, Environment, Safety and Health Office of NEPA Policy and Assistance. ACC: MOL.20010802.0219.], it was determined that the air quality effects of the transportation of personnel, materials, and supplies through the Las Vegas air basin would not exceed the General Conformity threshold level (100 tons of emissions per year; 40 CFR 93.153). The highest total emissions for personnel, materials, and supplies would be 50 tons per year during the construction phase and 67 tons per year during the operations and monitoring phases. Emissions would contribute a maximum of an additional 0.07 percent to the estimated year 2000 daily carbon monoxide levels in the non attainment area [Clark County Board of Commissioners 2000. "Carbon Monoxide State Implementation Plan Las Vegas Valley Nonattainment Area, Clark County, Nevada." Las Vegas, Nevada: Clark County Board of Commissioners, Department of Comprehensive Planning.].

4.9.7 Environmental Justice

4.9.7 (15985)

An issue has been raised that the Yucca Mountain program offers the opportunity to develop the best nuclear research facility in the world, including the opportunity for involvement of state university and college systems.

NWPA Section 170 establishes policy limiting the extent of any benefits agreements between the Secretary of Energy and the State of Nevada ensuing from establishment of a permanent repository at Yucca Mountain. NWPA Section 171 presents the schedule of payments according to any agreements established under NWPA Section 170. Any benefits to the State of Nevada, beyond those specified in the NWPA, would require Congressional action.

4.9.8 Other Socioeconomic Concerns

No comments received or comments addressed elsewhere.

4.10 NATIVE AMERICANS

4.10.1 Native American Affected Tribe Status and Determination

No comments received or comments addressed elsewhere.

4.10.2 DOE Communication with Native American Tribes

4.10.2 (108)

Individuals and organizations representing Native American interests have raised issues about the ways in which the DOE communicates with them. They contend that the DOE has not lived up to its obligations for government-to- government consultation with the tribes and that the DOE has not shown respect to tribal officials and tribal representatives commensurate with their positions. They assert that the DOE has failed to live up to previous commitments.
Beyond the process used by the DOE for interactions with the tribes, commenters question the ways in which the DOE has responded to the concerns and views expressed by the Native Americans—that responses were inadequate and, in some instances, condescending. Commenters have questioned whether the DOE has seriously considered Native American concerns and opposing views. They contend that the interactions have been "pro forma" rather than a serious attempt to understand and respond to the concerns and views expressed.

An issue has been raised regarding the perceived failure of the DOE to communicate appropriately with Native American tribes that may be impacted by a repository at Yucca Mountain.

The federal government recognizes tribal governments as sovereign entities, and the DOE interacts with tribal governments on issues of mutual concern. The DOE has interacted mainly with the Consolidated Group of Tribes and Organizations, which comprises representatives of fifteen federally recognized tribes—including the three tribes that would be most directly affected by a Yucca Mountain repository: Southern Paiute, Western Shoshone, and Owens Valley Paiute and Shoshone—one nonrecognized tribe, and one organization. The representatives of this group were officially appointed by their respective tribal governments to present their tribal concerns and perspectives to the DOE.

The DOE understands and takes seriously the federal trust responsibility and fiduciary relationship toward Native Americans. The DOE has engaged local Native Americans in project-related activities since the initiation of its Native American Interaction Program in 1987. It also has met regularly with tribal representatives on a range of cultural and technical concerns and has collaborated with them on specific site characterization tasks in various areas, including ethnobotany, review of artifact collections, field archaeological studies, and the environmental impact statement process. The DOE has encouraged the elaboration of Native American perspectives on a Yucca Mountain repository and has incorporated into the FEIS the potential impacts to historic and other cultural resources identified by Native Americans as important to sustaining and preserving their cultures.

Section C.2.5 of the FEIS explains the DOE interactions with Native American tribal governments. This approach is consistent with DOE policy and guidance [DOE 2000. "A Guide to DOE Employees Working with Indian Tribal Nations." DOE/EM-0571. Washington, D.C.: U.S. Department of Energy. TIC: 251404.]. It is also consistent with a variety of laws and regulations including, as applicable, the American Indian Religious Freedom Act; the NNative American Graves Protection and Repatriation Act; Executive Order 13007, Sacred Sites; and the National Historic Preservation Act (see FEIS, Chapter 11). The DOE has interacted, and would continue to interact, with tribal governments. A major objective of these interactions is to ensure that the DOE addresses the full range of Native American cultural and technical concerns related to a Yucca Mountain repository.

Issue

An issue has been raised concerning the adequacy of the DOE's response to Native American concerns and opposing views related to a repository at Yucca Mountain.

Response

The DOE has considered Native American viewpoints and has incorporated into the FEIS the Native Americans' own identification of potential impacts to historic and other cultural resources important to sustaining and preserving their cultures.

The DOE has maintained long-term and ongoing interactions with Native American tribes regarding Yucca Mountain. The DOE initiated its Native American Interaction Program in 1987 to consult and interact with tribes and organizations on the characterization of the Yucca Mountain site, and the possible construction and operation of a repository. The DOE also interacts cooperatively with the Consolidated Group of Tribes and Organizations, which consists of officially appointed tribal representatives responsible for presenting their tribal concerns and perspectives to the DOE.

During the preparation of the FEIS, the DOE interacted with Native American tribes on a range of topics of interest to assess their viewpoints and perspectives. In addition, the DOE supported the American Indian Writers Subgroup of the Consolidated Group of Tribes and Organizations in its preparation of "American Indian Perspectives on the Yucca Mountain Site Characterization Project and the Repository Environmental Impact Statement" [AIWS (American Indian Writers Subgroup) 1998. "American Indian Perspectives on the Yucca Mountain Site Characterization Project and the Repository Environmental Impact Statement." Las Vegas, Nevada: Consolidated Group of Tribes and Organizations. ACC: MOL.19980420.0041.]. The results of this report are included in the FEIS, Sections 3.1.1.4, 3.1.6.2, 3.1.6.2.2, and 4.1.13.4.

Based on the results of the report and these interactions, the DOE acknowledges in the FEIS that people from many Native American tribes have used the Yucca Mountain area as well as nearby lands; that the lands around the site contain cultural, animal, and plant resources important to those tribes; and that the implementation of a Yucca Mountain repository would continue restrictions on free access to the area around the repository site. Furthermore, the presence of a repository would represent an intrusion into what Native Americans consider an important cultural and spiritual area. Restrictions on public access to the area, however, have also been generally beneficial and protective of cultural resources, sacred sites, and traditional cultural properties.

4.10.3 Native American Tribal Concerns Regarding Land Ownership

4.10.3 (51)

The land encompassing Yucca Mountain is of concern to Native Americans. Commenters contend that there still remains an unsettled land dispute that the DOE has ignored, and thus the Ruby Valley Treaty of 1863 remains in full force and effect. Other commenters stated that the Ruby Valley Treaty of 1863 granted specific rights to the United States and that all other rights, authority, title, and interest within the boundaries of Western Shoshone Territory are reserved by the Western Shoshone Nation for the use and benefit of Western Shoshone citizens. Commenters from the Western Shoshone tribe contended that their ancestors would never have signed such a treaty if they had known that such a substance as nuclear waste would be buried on their land. Commenters stated that if the repository were to be constructed at the Yucca Mountain site, the DOE would be trespassing on Shoshone land.
Other commenters noted that the Western Shoshone do not consider that the funds held in trust for them by the Department of the Interior to constitute payment. Several commenters cited the history of the relations between the United States and the Native American tribes regarding broken treaties and land contamination. Finally, some commenters questioned the validity of the U.S. Supreme Court decision stating that claims to the land under the treaty were gradually extinguished and that the Western Shoshone people were compensated for the land.

A 1985 U.S. Supreme Court decision (United States v. Dann, 470 U.S. 39 (1985)) held that the Western Shoshone claim to land associated with the Ruby Valley Treaty of 1863 has been extinguished, and that fair compensation has been made. The DOE understands that the Western Shoshone people maintain that the Ruby Valley Treaty of 1863 gives them rights to 97,000-square kilometers (37,000-square miles) in Nevada, including the Yucca Mountain region. However, in 1977, the Indian Claims Commission granted a final award to the Western Shoshone people, who dispute the Commission's findings and have not accepted the monetary award for the lands in question. In United States v. Dann, the Supreme Court ruled that even though the money has not been distributed, the United States has met its obligations with the Indian Claims Commission's final award and, as a consequence, the aboriginal title to the land has been extinguished.

4.10.3 (56)

Summary Comment

The effect on the land of a repository at Yucca Mountain is of concern to Native Americans. Commenters noted the cultural beliefs of indigenous peoples and the very special status and sacredness of Yucca Mountain to the Western Shoshone and to other Native American tribes of the southwest.

Response

The DOE appreciates that Native Americans hold a unique knowledge and view of the land. The DOE has the utmost respect for Native American viewpoints and belief systems. The DOE is also aware of the special significance that Yucca Mountain and the surrounding area hold for Native American tribes and bands. The DOE will continue to consider the importance of this relationship via an active partnership with Native American tribes and organizations through the established Yucca Mountain Project Native American Interaction Program.

During the preparation of the FEIS, the DOE interacted with Native American tribes on a range of topics of interest to assess their viewpoints and perspectives. In addition, the DOE supported the American Indian Writers Subgroup of the Consolidated Group of Tribes and Organizations in its preparation of "American Indian Perspectives on the Yucca Mountain Site Characterization Project and the Repository Environmental Impact Statement" [AIWS (American Indian Writers Subgroup) 1998. "American Indian Perspectives on the Yucca Mountain Site Characterization Project and the Repository Environmental Impact Statement." Las Vegas, Nevada: Consolidated Group of Tribes and Organizations. ACC: MOL.19980420.0041.]. The results of this report are included in the FEIS (see Sections 3.1.1.4, 3.1.6.2, 3.1.6.2.2, and 4.1.13.4).

Based on the results of the report and these interactions, the DOE acknowledges in the FEIS that people from many Native American tribes have used the area proposed for the repository as well as nearby lands; that the lands around the site contain cultural, animal, and plant resources important to those tribes; and that the implementation of a Yucca Mountain repository would continue restrictions on free access to the area around the repository site. Furthermore, the presence of a repository would represent an intrusion into what Native Americans consider an important cultural and spiritual area. Restrictions on public access to the area, however, have also been generally beneficial and protective of cultural resources, sacred sites, and traditional cultural properties.

The DOE's analyses of potential groundwater-related exposures have been performed by modeling a RMEI consistent with the EPA's standards in 40 CFR Part 197 and NRC's licensing regulations in 10 CFR Part 63. The EPA and the NRC state that the RMEI prescribed in their standards and regulations, respectively, is expected to provide conservative dose estimates (66 FR 32089 and 66 FR 55750). In other words, the doses to the RMEI used to determine if health standards are satisfied would be higher than those received by the rest of the population. If the selected RMEI is protected, the population would be also.

The EPA has specifically considered the Paiute and Shoshone Tribes' traditional and customary uses of the area around Yucca Mountain to determine whether the RMEI used in the EPA's standard (40 CFR Part 197) prescribes a higher exposure than these Native Americans are likely to receive. The EPA states "...we conclude, after considering their description of tribal uses of the area, that the rural-residential RMEI is fully protective of tribal resources" (66 FR 32090).

The EPA discusses the basis for this conclusion. First, tribal use of natural springs involves water that would have lower contamination levels as a result of repository releases than would wells at the location specified in 40 CFR Part 197, which tap aquifers close and more directly affected. Second, "...tribal use of wildlife and non-irrigated vegetation should not contribute significantly to total individual dose estimates. Gaseous releases from the repository are not a significant contributor to individual doses...through inhalation or rainfall, and should contribute less to contamination of wildlife and non-irrigated vegetation than the use [by the RMEI] of contaminated well water for raising crops and animals for food consumption (66 FR 32090).

The EPA provides another reason to conclude the RMEI prescribed in 40 CFR Part 197 is more conservative than, and thus protective of, Native Americans. The EPA states that their RMEI "...is assumed to be a full-time resident continually exposed to radiation coming from the disposal system. It appears that the tribal uses are intermittent and involve resources which are less likely to be contaminated, resulting in lower doses." (66 FR 32091).

Section 5.4 of the FEIS indicates that forecasted long-term levels of radioactive material concentration in groundwater and the resulting dose levels at the discharge area in Amargosa Valley would be low. More specifically, in Section 3.1.2 of the SSE, Figure 3-3 shows a very small dose (1.7 x 10E-5 millirem per year. for the higher-temperature operating mode and 1.1 x 10E-5 millirem per year for the lower-temperature operating mode) to the model's RMEI during the 10,000-year postclosure period for the nominal scenario. The DOE concludes that the dose rates to plants and animals in the Amargosa Valley would be unlikely to cause detrimental effects in populations of any species. This result is based on dose response information developed by the International Atomic Energy Agency for terrestrial ecosystems including the most radiosensitive species [IAEA (International Atomic Energy Agency) 1992. "Effects of Ionizing Radiation on Plants and Animals at Levels Implied by Current Radiation Protection Standards." Technical Reports Series No. 332. Vienna, Austria: International Atomic Energy Agency. TIC: 243768. Page 53.].

4.10.4 Native American Environmental Justice

4.10.4 (3)