UZ Flow Models and Submodels Rev 00, ICN 00 MDL-NBS-HS-000006 March 2000 1. PURPOSE The purpose of this Analysis/Model Report (AMR) is to document the unsaturated zone (UZ) fluid flow and solute transport models and submodels as well as the flow fields generated utilizing the UZ Flow and Transport Model of Yucca Mountain, Nevada (UZ Model). This is in accordance with the AMR Development Plan for U0050 UZ Flow Models and Submodels (CRWMS M&O 1999a). The flow fields are used directly by Performance Assessment (PA). The model and submodels evaluate important hydrogeologic processes in the unsaturated zone as well as geochemistry. These provide the necessary framework to test conceptual hypotheses of flow and transport at different scales and predict flow and transport behavior under a variety of climatic conditions. The AMR supports the UZ Flow and Transport Process Model Report (PMR); PA activities including abstractions, particle tracking transport simulations, and conversion of flow fields for use in the RIP model; and the UZ Radionuclide Transport Model. The UZ Model is an important process model for the YMP’s Repository Safety Strategy and for support of the License Application (LA). The Total System Performance Assessment for Site Recommendation (TSPA-SR) will use the unsaturated-zone flow simulation to provide input to other models such as ambient and thermal drift-scale models, and the mountain-scale thermohydrological model. The base case flow fields are generated using the UZ Model, with input parameters based on the calibrated property sets documented in the AMR Calibrated Properties Model (CRWMS M&O 2000b) and in this AMR. The flow fields are developed for spatially varying maps representing the mean, lower, and upper bounds of estimated net infiltration for the current climate and two projected future climates (Monsoon and Glacial Transition). Each net infiltration case is evaluated using two different perched water models, providing a total of 18 flow fields. These flow fields have been submitted to the Technical Data Management System (TDMS) for use by PA and for Total System Performance Assessment (TSPA) activities. The process submodels documented in this AMR include the temperature, geochemistry, and groundwater travel and tracer transport submodels. The temperature submodel characterizes ambient geothermal conditions with temperature data for use in the UZ Model. The geochemical submodel includes two specific constituents (chloride and calcite). The chloride submodel represents the conceptual model for the spatial and temporal variations in chloride chemistry and is compared with pore-water concentrations measured in samples from boreholes and the Exploratory Studies Facility (ESF). The strontium submodel incorporates the effects of ratelimited dissolution and precipitation on the concentration of a solute, in addition to dispersion, radioactive decay, and linear equilibrium adsorption. The caveats for use of the modeling results and flow fields documented in this AMR are that the model development and calibrated properties on which these modeling results and flow fields were based are limited by the available site data, and the flow fields reflect only the conceptual models and quantitative approaches utilized in the models and submodels, as discussed in the AMR Conceptual and Numerical Models for UZ Flow and Transport (CRWMS M&O 2000c). Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 18 March 2000 INTENTIONALLY LEFT BLANK Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 19 March 2000 2. QUALITY ASSURANCE This AMR was developed in accordance with AP-3.10Q, Analyses and Models. Other applicable Department of Energy (DOE) Office of Civilian Radioactive Waste Management (OCRWM) Administrative Procedures (APs) and YMP-LBNL Quality Implementing Procedures (QIPs) are identified in the AMR Development Plan for U0050 UZ Flow Models and Submodels, Rev 00 (CRWMS M&O 1999a). The activities documented in this Analysis/Model Report (AMR) were evaluated with other related activities in accordance with QAP-2-0, Conduct of Activities, and were determined to be subject to the requirements of the U.S. DOE Office of Civilian Radioactive Waste Management (OCRWM) Quality Assurance Requirements and Description (QARD) (DOE 1999). This evaluation is documented in CRWMS M&O (1999b, 1999c) and Wemheuer (1999, Activity Evaluation for Work Package WP 1401213UM1). Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 20 March 2000 INTENTIONALLY LEFT BLANK Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 21 March 2000 3. COMPUTER SOFTWARE AND MODEL USAGE The software and routines used in this study are listed in Table 3-1. These are appropriate for the intended application, were used only within the range of validation. These codes were submitted and obtained from software configuration management in accordance with AP-SI.1Q, Software Management. The codes were obtained after these simulations were completed and an impact review per AP-3.17Q, Impact Reviews, is being conducted, but no impact is expected. The qualification status of this software is given in Attachment I. The codes listed in Table 3-1 were qualified under AP-SI.1Q. The software code TOUGH2 VI.4 was used to generate flow fields (Section 6.6), conduct model calibrations (Sections 6.2 and 6.3). T2R3D VI.4 was used for tracer transport simulations and groundwater travel-time estimates (Section 6.7) and modeling pore-water chemistry (Section 6.4). ITOUGH2 V3.2, TOUGHREACTE9 (TOUGH Code for Multiphase multi-species reactive transport with EOS9 flow module) V1.0 and were TOUGHREACT V2.2 used for modeling of calcite geochemistry (Section 6.5). ITOUGH2 V3.2 was used for Alcove 1 tests. Infil2grid V1.6 was used to apply infiltration maps onto the grids used for simulating flow and transport (Sections 6.1, 6.2, 6.3, 6.4, 6.6 and 6.7). The routines in Table 3-1 were qualified per Section 5.1 of AP-SI.1Q. Standard spreadsheet (Excel 97.SR-1) and plotting programs (Tecplot v 7) were also used but are not subject to software quality assurance requirements. Table 3-1. Computer Software Software Name, Codes Version Software Tracking Number (STN) Computer Type, Operational System TOUGH2 1.4 10007-1.4-01 Win95/98, SUN and DEC w/ Unix OS T2R3D 1.4 10006-1.4-00 Win95/98, SUN and DEC w/ Unix OS ITOUGH2 3.2 10054-3.2-00 SUN and DEC w/ Unix OS TOUGHREACTE9 1.0 10153-1.0-00 SUN w/ Unix OS TOUGHREACT 2.2 10154-2.2-00 SUN and DEC w/ Unix OS Infil2grid 1.6 10077-1.6-00 Win95/98 PC,SUN and DEC w/ Unix OS EARTHVISION 4.0 30035-2 V4.0 UNIX EXT 1.0_MEOS9 10227-1.0MEOS9-00 UNIX Software Routines: Read- TDB 1.0 MOL.19990903.0031 Win95/98 or DOS Frac_Calc 1.1 MOL.19990903.0032 Win95/98 or DOS TBgas3D 1.0 MOL.19991012.0222 SUN and DEC w/ Unix OS ECRB-XYZ .03 30093 V.03 PC Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 22 March 2000 INTENTIONALLY LEFT BLANK Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 23 March 2000 4. INPUTS Inputs to the modeling activities described in this AMR are obtained from TDMS include the following: • Matrix property data from the ESF (Exploratory Studies Facility) and boreholes • Stratigraphy data from borehole logs • Infiltration maps • Calibrated fracture and matrix properties • Hydrologic property data for CHn (Calico Hills non-welded hydrogeologic unit) • Geochemistry data from the ESF and boreholes • UZ Model grids • Temperature data for boreholes • Pneumatic pressure data • Locations and elevations of perched water in boreholes • Uncalibrated fracture and matrix properties • Water-potential data • Matrix liquid-saturation data 4.1PARA METERS The key input data used in the UZ Model and its submodel development include the following: • Fracture properties (frequency, permeability, van Genuchten a and m parameters, aperture, porosity, and interface area per unit volume rock) for each UZ Model layer • Matrix properties (porosity, permeability, and the van Genuchten a and m parameters) for each UZ Model layer • Thermal properties (grain density, wet and dry thermal conductivity, grain specific heat, and tortuosity coefficients) for each UZ Model layer • Fault properties (matrix and fracture parameters) for each major hydrogeologic unit as defined by Table 6-2. Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 24 March 2000 The calibrated parameter sets also include an estimate of the active-fracture parameter, ., (Liu et al. 1998) for each model layer that accounts for the reduction in interaction between matrix and fracture flow resulting from flow fingering and channelization. Specific input data sets, associated Data Tracking Numbers (DTNs) and Accession Numbers (ACC) are tabulated below. Quality assurance status is provided in Attachment 1. Table 4-1. Input Data Source and Data Tracking Numbers Data Description Section Used In DTN or Reference SO4 infiltration flux 6.4.4.3 GS910908315214.003 SO4 infiltration flux 6.4.4.3 GS931008315214.032 NRG-6 and NRG-7a pneumatic pressure and temperature 6.3 6.8.4 GS951108312232.008 GS950208312232.003 NRG#5 pneumatic pressure 6.8.4 GS960208312261.001 SD-12, UZ-7a, NRG-6, and NRG-7a pneumatic pressure and temperature 6.2 6.3 6.6 6.8.4 GS960308312232.001 Perched water elevation UZ-14 6.2 6.6 GS960308312312.005 NRG-6 and NRG-7a pneumatic pressure and temperature 6.4 6.8.4 GS960808312232.004 Matrix hydrologic property data 6.2 6.3 6.6 6.7 6.8.1, 6.8.2 6.8.3 GS960908312231.004 In situ gas pressure - SD-7 6.8.4 GS960908312261.004 Chemical composition of pore water samples 6.4.2.1 GS961108312261.006 In situ borehole instrumentation and monitoring for NRG-7a, NRG-6, UZ#4, UZ#5, UZ-7a and SD-12- temperature, pressure, and water potential 6.3 GS970108312232.002 Perched water elevation - G-2 6.2 6.6 GS970208312312.003 In situ borehole instrumentation and monitoring for NRG-7a, UZ#4, UZ#5, UZ-7a and SD-12 - temperature, pressure, and water potential 6.3 GS970808312232.005 In situ borehole instrumentation and monitoring for NRG-7a, UZ#4, UZ#5, UZ-7a and SD-12- temperature, pressure, and water potential 6.3 GS971108312232.007 Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 25 March 2000 Detailed line survey data from ESF station 0+60m to 0+80m 6.8.1 GS971108314224.020 In situ borehole instrumentation and monitoring for NRG-7a, NRG-6, UZ#4, UZ#5, UZ-7a and SD-12- temperature, pressure, and water potential 6.3 GS980408312232.001 WT-24 perched water observations 6.2 6.6 6.8.3 GS980508312313.001 WT-24 saturation data 6.2 6.6 6.8.3 GS980708312242.010 SD-6 saturation data 6.2 6.6 6.8.3 GS980808312242.014 Water potential data along ECRB tunnel 6.8.2 GS980908312242.036 Perched water elevation G-2 6.2 6.6 GS981008312313.003 Matrix diffusion coefficients for Tc and 237Np 6.7 LAIT831341AQ96.001 Mineral abundance in fractures 6.5 LASL831151AQ98.001 Chemical composition of pore water samples 6.4.2.1 LASL831222AQ98.002 Model input and output files for Mineralogic Model (borehole SD-9 XRD data) 6.5 LA9908JC831321.001 Flow fields and calibrated hydrologic properties 6.2 6.3 6.6 6.7 6.8.1, 6.8.2 6.8.3 LB971212001254.006 Air-injection, tracer test, and fracture porosity data 6.2 6.3 6.6 6.7 6.8 LB980912332245.002 Table 4-1. Input Data Source and Data Tracking Numbers Data Description Section Used In DTN or Reference Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 26 March 2000 Uncalibrated hydrologic property data 6.2 6.3 6.6 6.7 6.8 LB990501233129.001 1-D grid for flow property calibration 6.5 LB990501233129.002 3-D UZ Model calibration grid 6.1 6.2 6.3 6.8.2 6.8.3 LB990501233129.004 3-D UZ Model TSPA grid 6.1 6.6 6.7 6.8.4 LB990701233129.001 3-D UZ Model calibration grid for non waterperching model 6.1 6.2 6.3 6.8.2 6.8.3 LB990701233129.002 Calibrated fault property 6.2 6.3 6.6 6.7 6.8 LB991091233129.003 Calibrated fault property 6.8.4 LB991091233129.004 Kinetic Data 6.5 LB991200DSTTHC.001 Calibrated parameters for the base case infiltration scenario - flow through perched water conceptual model 6.2 6.3 6.4 6.6 6.7 6.8.2 6.8.3 6.8.4 LB991121233129.001 Table 4-1. Input Data Source and Data Tracking Numbers Data Description Section Used In DTN or Reference Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 27 March 2000 Calibrated parameters for the base case infiltration scenario - by-passing perched water conceptual model 6.2 6.3 6.4 6.6 6.7 6.8.4 LB991121233129.002 Calibrated parameters for the upper bound infiltration scenario - flow through perched water conceptual model 6.2 6.6 6.7 LB991121233129.003 Calibrated parameters for the upper bound infiltration scenario - by-passing perched water conceptual model 6.2 6.6 6.7 LB991121233129.004 Calibrated parameters for the lower bound infiltration scenario - flow through perched water conceptual model 6.2 6.6 6.7 LB991121233129.005 Calibrated parameters for the lower bound infiltration scenario - by-passing perched water conceptual model 6.2 6.6 6.7 LB991121233129.006 Calibrated parameters for the base case infiltration scenario - non-perching perched water conceptual model 6.2 6.6 6.7 LB991121233129.007 Calibrated flow and thermal parameters base case 6.2 6.3 6.4 6.6 6.7 6.8.2, 6.8.3 6.8.4 LB997141233129.001 Calibrated flow and thermal parameters upperbound 6.2 6.6 6.7 6.8.4 LB997141233129.002 Calibrated flow and thermal parameters lowerbound 6.2 6.6 6.7 6.8.4 LB997141233129.003 Table 4-1. Input Data Source and Data Tracking Numbers Data Description Section Used In DTN or Reference Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 28 March 2000 Saturation data from cores for boreholes USW SD- 7, USW SD-9, USW SD-12, USW UZ-14, UE-25, UZ#16 & USW UZ-7a 6.1 6.2 6.6 DTN: GS000399991221.004., ACC: MOL.19991027.0149 Mean, lower-bound, and upper-bound infiltration rates for present-day, future monsoon, and future glacial transition climates 6.1 6.2 6.3 6.6 6.7 6.8.2, 6.8.3 DTN: GS000399991221.002., ACCN: MOL.1991014.0102 Alcove 1 infiltration and tracer test data 6.8.1 DTN: GS000399991221.003., ACCN: MOL.20000118.0092 Perched water elevation for well SD-12 6.2 6.6 DTN: GS960908312232.006., ACCN: MOL.19991213.0041 Table 4-1. Input Data Source and Data Tracking Numbers Data Description Section Used In DTN or Reference Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 29 March 2000 This AMR documents the flow models and submodels in the UZ Flow and Transport Model. It utilizes properties from the Calibrated Properties Model. The input and output files for the model runs presented in this AMR are listed in Tables 6-9, 6-16, 6-17, 6-18, 6-26, 6-27, and 6-28, and some of the model input fracture and matrix parameters are given in Attachment II. 4.2 CRITERIA This AMR complies with the DOE interim guidance (Dyer 1999). Subparts of the interim guidance that apply to this analysis or modeling activity are those pertaining to the characterization of the Yucca Mountain site (Subpart B, Section 15). The compilation of information regarding geology of the site is in support of the License Application (Subpart B, Section 21(c)(1)(ii)), and the definition of geologic parameters and conceptual models used in performance assessment, (Subpart E, Section 114(a)). The compilation of information regarding hydrology of the site is in support of the License Application (Subpart B, Section 21(c)(1)(ii)) and the definition of hydrologic parameters and conceptual models used in performance assessment (Subpart E, Section 114(a)). The compilation of information regarding geochemistry and mineral stability of the site is in support of the License Application (Subpart B, Section 21(c)(1)(ii)), and the definition of geochemical parameters and conceptual models used in performance assessment (Subpart E, Section 114(a)). 4.3 CODES AND STANDARDS No specific formally established standards have been identified as applying to this analysis and modeling activity. Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 30 March 2000 INTENTIONALLY LEFT BLANK Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 31 March 2000 5. ASSUMPTIONS The assumptions documented below are required to develop the UZ flow models and submodels. This section presents these assumptions and the rationale which are used throughout the development of the UZ models. 1. The water table is used as the bottom model boundary which is subject to constant water pressure (equal to the atmospherical pressure). Rationale: The water table is a surface where the water pressure is a fixed single value. Within the numerical models, only one single set of model primary variables for solving Richards’ equations is specified for the bottom boundary and this is equivalent to specifying a constant saturation. 2. The bottom model boundary representing the water table is subject to fixed gas pressure. Rationale: Due to limitations in the way boundaries may be specified in the numerical models used, a constant gas pressure must be specified when a constant water pressure (saturation) is specified. The impact of this assumption on all but simulations of barometric pumping is insignificant (see assumption 4 below for an alternate assumption used for simulations of barometric pumping). 3. The bottom model boundary representing the water table is subject to spatially varying but constant temperature conditions. Rationale: This assumption is corroborated by data reported by Sass et al. (1988) and the actual temperature distribution along the water table and further confirmed by matching qualified temperature profiles from a number of boreholes. 4. For simulations of barometric pumping, the bottom model boundary representing the water table is assumed to be a no-flow boundary. Rationale: At the water table, a connected gas phase does not exist, so gas phase flow does not occur across this boundary. Due to the limitations of the code used for simulation, this boundary must also be no-flow for the liquid phase (heat flow is not considered in these simulations). Liquid flow across the boundary over the time span of the simulation (360 days) is not large enough to significantly change the gas flow in the TSw (Topopah Spring welded hydrogeologic unit) and above where data is available. 5. The lateral boundaries of the model domain are subject to no-flow boundary conditions. Rationale: The boundaries of the northern and southern model domain are located so far away from the potential repository area that lateral flow effects along these boundaries on flow at the potential repository should be small. The eastern boundary is for most parts along the Bow Ridge fault, and no lateral flow crossing the fault is reasoned. The western boundary is separated from the potential repository by the Solitario Canyon fault, therefore this boundary condition effects are expected to be insignificant. 6. Perched water occurrence results from permeability barrier effects. Rationale: Consistent with the conceptual model that ambient conditions reflect long-term, steadystate or transient flow through the unsaturated zone, perched water under steady-state flow conditions may only be due to a permeability barrier. Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 32 March 2000 7. Under steady-state flow conditions, moisture flow and tracer transport processes can be decoupled. Rationale: Steady-state flow conditions result in an unchanging flow field, and as long as the concentrations of tracers and/or radionuclides are such that they do not significantly change the properties of the fluid, which is the case for simulations documented in this AMR, then the flow field does not have to be coupled to transport. 8. Water flow through the UZ is assumed to occur under steady-state conditions. Transient, “fast-pathway” flow, such has conveyed 36Cl to the ESF horizon, is assumed not to contribute significantly to the total flow through the UZ. 9. The dual-permeability formulation is assumed to be appropriate for simulating flow and transport through fractured tuffs. 10. The time required for moisture conditions within the UZ to adjust to changes in the spatial and temporal distribution of net infiltration at land surface induced by climatic change is assumed to be short compared to the time over which climatic conditions change so that simulated conditions within the UZ reflect the present-day and estimated future net-infiltration rates imposed on the upper land-surface boundary of the UZ model. 11. Regarding calcite deposition in the unsaturated zone, the following assumptions are made: (a) the gas phase is at a constant (atmospheric) pressure, and air flow is neglected for the purpose of solving water flow; (b) a constant infiltration rate and water chemistry over the entire simulation period is applied to the top boundary; (c) steadystate water flow condition remains during chemical transport and fluid-rock interactions. All the assumptions made are justifiable based on the rationales stated and the scientific principles and practices used in conducting modeling studies of flow and transport in porous media. The methodological premises used for specific modeling studies are more appropriately discussed in the context of the modeling methodologies in Section 6. Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 33 March 2000 6. ANALYSIS/MODEL As outlined in Section 1, this AMR documents the development and results of the unsaturated zone (UZ) flow and the temperature and geochemistry submodels. This section consists of the following: • Model description • 3-D (three-dimensional) UZ flow calibrations • Geothermal model • Geochemical model for chloride • Calcite analysis • 3-D flow fields for performance analyses • Groundwater travel and tracer transport The UZ flow and temperature model and submodels of geochemistry have been developed to simulate past, present, and future hydrologic, geothermal and geochemical conditions in the UZ of Yucca Mountain. Yucca Mountain has been studied extensively, and many types of data have been collected. These data have been used in developing conceptual and numerical models for the hydrological, geothermal and geochemical behavior of the site. These models simulate ambient conditions and perform predictive studies of changes in the mountain caused by climatic, thermal, and geochemical perturbations. The comprehensive model that integrates all pertinent data from the UZ at Yucca Mountain is the 3-D site-scale UZ flow and transport model, developed over the past decade at the Lawrence Berkeley National Laboratory (LBNL) by Bodvarsson et al. (1999) and Wu et al. (1999a), among others. Model development described in this AMR results from the continued modeling investigations on flow and transport behavior in the UZ system of Yucca Mountain. The primary objectives of developing the UZ flow model and its submodels are: • To integrate the available data from the UZ system into a single, comprehensive, and calibrated 3-D model for simulating the ambient hydrological, thermal, and geochemical conditions and predicting system response to future climate conditions • To quantify the flow of moisture, heat, and gas through the UZ, under Present-Day and hypothesized future climate scenarios • To evaluate the effects of potential repository thermal loading on moisture, gas, and heat flow within the mountain • To perform detailed studies of perched water, percolation through the Paintbrush nonwelded (PTn) unit flow, through Calico Hills non-welded (CHn) zeolitic units, and the pore-water chemical and calcite analyses. • To predict the migration of potential radionuclide releases after waste emplacement • To contribute model parameters and boundary conditions for drift seepage studies Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 34 March 2000 • To provide Performance Assessment and Repository Design with a scientifically defensible and credible model of all relevant UZ processes The UZ Model is a process model whose results directly address Principal Factors within the YMP Repository Safety Strategy (CRWMS M&O 2000e) and for support of the License Application (LA). The Total System Performance Assessment for Site Recommendation (TSPASR) will use the unsaturated-zone flow simulation to provide input to other models such as ambient and thermal drift-scale models, the mountain-scale thermohydrological model, and the radionuclide transport model. The UZ Model and its submodels evaluate processes that are important to the performance of the potential repository, all of which contribute to the TSPA-SR and TSPA-LA, such as: • The spatially distributed values of the percolation flux at the potential repository horizon • The components of fracture and matrix flow within and below the potential repository horizon • The perched water zones and associated flow barriers • The probable flow paths from the potential repository to the water table • Groundwater travel/tracer transport times and radionuclide migration paths from the potential repository to the water table, and breakthrough curves and areas at the water table for tracers and radionuclides. In developing the UZ Model, much emphasis has been placed on preparing a defensible and credible UZ Model for Yucca Mountain to evaluate its potential as an underground radioactive waste potential repository. Major activities, as reported in this AMR, include updated model calibration studies of 3-D UZ flow, perched water, geochemistry, geothermal conditions, estimates of groundwater travel time and radionuclide transport, and model validation efforts. The other activities involving generating 28 3-D flow fields (Sections 6.2 and 6.6) to evaluate the uncertainty and sensitivity of the UZ Model relative to fracture-matrix parameters and infiltration rates over the mountain by using three sets of model parameters and nine infiltration scenarios. Eighteen of the 28 flow fields are submitted for use in TSPA calculations of radionuclide transport through the UZ system and other activities such as drift seepage abstraction. Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 35 March 2000 Key scientific notebooks (with relevant page numbers) used for modeling and validation activities described in this AMR are listed in Table 6-1. 6.1MODEL DESCRIPTION The conceptual and numerical models used for the modeling studies documented in this AMR are fully documented in the AMR: Conceptual and Numerical Models for Flow & Transport (CRWMS M&O 2000c). Elements of the conceptual and numerical models are included in this section so that a complete discussion of the model is presented. 6.1.1 Geological Model and Numerical Grids The geological model used in this AMR for developing the UZ Model and its submodels is based on the Geological Framework Model (GFM) 3.1 and Integrated Site Model (ISM) 3.0, and the development and features of the two 3-D model grids with the geological model are documented in the AMR entitled, Development of Numerical Grids for UZ Flow and Transport Modeling (CRWMS M&O 1999d). Table 6-2 lists the geological units/layers for different hydrogeologic units and the associated UZ Model numerical grid-layer information. These geologic formations have been reorganized into layered hydrogeologic units based primarily on the degree of welding (Montazer and Wilson. 1984). These are the Tiva Canyon welded (TCw) hydrogeologic unit, the Paintbrush nonwelded unit (PTn), the Topopah Spring welded (TSw) unit, the Calico Hills nonwelded (CHn), and the Crater Flat undifferentiated (CFu) units. Table 6-1. Model Development Documentation Scientific Notebooks LBNL Scientific Notebook Page #/Related Contents Accession Number (ACC) YMP-LBNL-GSB-YSW-2 p. 132-188/ UZ Model calibrations, TSPA flow fields and groundwater travel times and tracer transport MOL.20000308.129 YMP-LBNL-UZJL-1.0 P.1 - 104 / Chloride modeling studies and analyses MOL.20000308.130 YMP-LBNL-YSW-WZ-1 p. 73-93, 122-127/Post-processing and analyses of results for calibrations, flow fields and transport MOL.20000308.131 YMP-LBNL-GSB-1.6.3 p. 74-104/Geothermal calibrations MOL.20000308.132 YMP-LBNL-GBS-TX-1 p. 17-59/Calcite calibrations MOL.20000308.133 YMP-LBNL-JSW-CFA-6.1 YMP-LBNL-GBS-1.1.2 p. 1-26, 39-48, 72-88/Alcove 1 simulations p. 153-157-D pneumatic & Alcove 1 simulations MOL.20000308.134 MOL.20000308.135 YMP-LBNL-GSB-LHH-2 p. 67-73/Alcove1 modeling MOL.20000308.136 YMP-LBNL-YWT-ELS-1 p. 37-42, p. 49-52 / Reactive surface areas MOL.20000308.137 Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 36 March 2000 Table 6-2. GFM3.1 (CRWMS M&O 1999d) Lithostratigraphy, UZ Model Layer, and Hydrogeologic Unit Correlation Used in the UZ Flow Model and Submodels Major Unit GFM3.1* Lithostratigraphic Nomenclature FY 99 UZ Model Layer Hydrogeologic Unit Tiva Canyon welded (TCw) Tiva_Rainier tcw11 CCR, CUC Tpcp tcw12 CUL, CW TpcLD Tpcpv3 tcw13 CMW Tpcpv2 Paintbrush nonwelded (PTn) Tpcpv1 ptn21 CNW Tpbt4 ptn22 BT4 Tpy (Yucca) ptn23 TPY ptn24 BT3 Tpbt3 Tpp (Pah) ptn25 TPP Tpbt2 ptn26 BT2 Tptrv3 Tptrv2 Topopah Spring welded (TSw) Tptrv1 tsw31 TC Tptrn tsw32 TR Tptrl, Tpt fts w33 TUL Tptpul Tptpmn tsw34 TMN Tptpll tsw35 TLL Tptpln tsw36 TM2 (upper 2/3 of Tptpln) tsw37 TM1 (lower 1/3 of Tptpln) Tptpv3 tsw38 PV3 Tptpv2 tsw39 PV2 Calico Hills nonwelded (CHn) Tptpv1 ch1 (vit, zeo) BT1 or BT1a (altered) Tpbt1 NOTE: * GFM3.1 (CRWMS M&O 1999d) refers to the Geologic Framework Model Version 3.1. Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 37 March 2000 The 3-D model domain and the two 3-D numerical grids for this study are shown in plan view in Figures 6-1 and 6-2 respectively. The first model grid, shown in Figure 6-1, is referred to as the 3-D calibration grid. It includes refined gridding along the Enhanced Characterization of Repository Block (ECRB) and ESF tunnels and is primarily used for the purpose of model calibration. The second grid (Figure 6-2), the TSPA grid, is designed for simulations of 3-D flow fields delivered for use in TSPA calculations. This TSPA grid uses a refined mesh in the vicinity of the potential repository, located near the center of the model domain. Also, shown in Figures 6-1 and 6-2 are the locations of several boreholes used in model calibrations and analyses. The model domain is selected to focus on the study area of the potential repository area and to investigate the effects of different infiltration scenarios and major faults on moisture flow around and below the potential repository. Faults are represented in the model by vertical or inclined 30- meter thick zones. Tac (Calico) ch2 (vit, zeo) CHV (vitric) or CHZ (zeolitic) ch3 (vit, zeo) ch4 (vit, zeo) ch5 (vit, zeo) Tacbt (Calicobt) ch6 BT Tcpuv (Prowuv) pp4 PP4 (zeolitic) Tcpuc (Prowuc) pp3 PP3 (devitrified) Tcpm (Prowmd) pp2 PP2 (devitrified) Tcplc (Prowlc) Tcplv (Prowlv) pp1 PP1 (zeolitic) Tcpbt (Prowbt) Tcbuv (Bullfroguv) Crater Flat undifferentiated (CFu) Tcbuc (Bullfroguc) bf3 BF3 (welded) Tcbm (Bullfrogmd) Tcblc (Bullfroglc) Tcblv (Bullfroglv) bf2 BF2 (nonwelded) Tcbbt (Bullfrogbt) Tctuv (Tramuv) Tctuc (Tramuc) tr3 Not Available Tctm (Trammd) Tctlc (Tramlc) Tctlv (Tramlv) tr2 Not Available Tctbt (Trambt) Table 6-2. GFM3.1 (CRWMS M&O 1999d) Lithostratigraphy, UZ Model Layer, and Hydrogeologic Unit Correlation Used in the UZ Flow Model and Submodels (Cont.) Major Unit GFM3.1* Lithostratigraphic Nomenclature FY 99 UZ Model Layer Hydrogeologic Unit NOTE: * GFM3.1 (CRWMS M&O 1999d) refers to the Geologic Framework Model Version 3.1. Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 38 March 2000 DTN: LB990501233129.004 Figure 6-1. Plan View of the 3-D UZ Calibration Model Grid, Showing the Model Domain, Faults Incorporated, ESF and ECRB, and Several Borehole Locations. 168000 170000 172000 174000 230000 231000 232000 233000 234000 235000 236000 237000 238000 239000 UZ-14 SD-9 WT-24 G-2 SD-12 SD-7 G-3 UZ#16 SD-6 H-5 NRG-7a UZ#4 Solitario West Fault SolitarioCanyonFault ECRB ESF Ghost Dance Fault Dune Wash F ault Imbrica te Fault Drillhole Wash Fault Pagany Wash Fault SeverWashFault East Nevada Coordinates (m) North Nevada Coordinates (m) N Borehole Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 39 March 2000 DTN: LB990701233129.001 Figure 6-2. Plan View of the 3-D UZ TSPA Model Grid, Showing the Model Domain, Faults Incorporated and Several Borehole Locations. 168000 170000 172000 174000 230000 231000 232000 233000 234000 235000 236000 237000 238000 239000 UZ-14 NRG-7a SD-9 WT-24 G-2 SD-12 SD-7 G-3 UZ#16 SD-6 H-5 UZ#4 Solitario West Fault Solitario Canyon Fault Ghost Dance Fault ImbricateFault Dune Wash Fault Drillhole Wash F ault Pagany W ashFault SeverWash Fault East Nevada Coordinates (m) North Nevada Coordinates (m) N Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 40 March 2000 The calibration grid, as shown in Figure 6-1, has 1,434 mesh columns of both fracture and matrix continua and a maximum of 37 computational grid layers in the vertical direction, resulting in 104,156 gridblocks and 421,134 connections in a dual-permeability grid. The TSPA grid (Figure 6-2) has 1,324 mesh columns for the TSPA grid, a maximum of 37 computational grid layers in the vertical direction, with 97,976 gridblocks and 396,770 connections in a dual-permeability grid. 6.1.2 Numerical Codes and Modeling Approach The simulation results presented in this AMR were carried out using TOUGH2 V1.4 (STN: 10007-1.4-0.1, Version 1.4); T2R3D V1.4 (STN: 10006-1.4-00, Version 1-4), TOUGHREACTE9 V1.0 (STN: 10153-1.0-00), and TOUGHREACT V2.2 (STN: 10154-2.2-00, Version 2.2), as summarized in Section 3. The single active liquid phase flow module (EOS9) (Wu et al. 1996) was used to calibrate the UZ Model and several submodels and to generate 3-D TSPA flow fields. For temperature simulation, the TOUGH2 V1.4 EOS3 module (Pruess 1991) was used. Tracer transport and chloride studies were performed using the decoupled module of T2R3D V1.4 and flow fields from the EOS9 module. The TOUGHREACTE9 V1.0 code was used for calcite calibration. To model the flow and transport processes occurring in the UZ at Yucca Mountain, mathematical models or governing equations are needed to describe the physical processes quantitatively to model the flow and transport processes occurring in the unsaturated zone. The physical processes associated with flow and transport in porous media are governed by the fundamental conservation laws, i.e., conservation of mass, momentum, and energy governs the behavior of fluid flow, chemical transport, and heat transfer through fractured porous media. The macroscopic continuum approach has been most commonly used in practical applications. In this approach the physical laws governing flow of several fluids, transport of multicomponents, and heat transfer in porous media are often represented mathematically on the macroscopic level by a set of partial differential or integral equations. Fluid and heat flow and chemical transport processes in fracture and matrix systems in the UZ are described using a macroscopic continuum approach. In addition to the conservation or continuity equations of mass and thermal energy in fracture and matrix systems, specific relationships or mechanisms are needed that describe why and how fluid flow, solute transport, and heat transfer occur in porous and fractured media. The following specific laws act as such mechanisms by governing local fluid flow, component transport, and heat transfer processes in porous and fractured media: 1. Darcy’s law is applied to describe the two-phase flow of gas and water in both fractures and matrix. In particular, Richards’ equation is used in describing isothermal, unsaturated liquid flow through the UZ at Yucca Mountain. Relative permeability and capillary functions of both fractures and matrix follow the van Genuchten model (van Genuchten, 1980). 2. The migration of dissolved mass components or chemical species within a fluid in the two-phase fractured-porous media system is governed by advective, diffusive, and dispersive processes. It is also subject to other processes such as radioactive decay, adsorption, dissolution and precipitation, mass exchange or partition between phases, Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 41 March 2000 and other chemical reactions under local thermodynamic equilibration or kinetic reactions. 3. The generalized Fick’s law, including hydrodynamic dispersion effects in a multiphase system, is used to evaluate diffusive and dispersive flux of chemical transport. The multiphase extension of Darcy’s law, Richards’ equation, and the generalized Fick’s law have been used as fundamental laws that govern flow and transport processes within porous medium rocks in both research and application. These fundamental laws or correlations, mainly based on experimental and field studies, reflect our current understanding of porous-medium physics. A key issue for simulating fluid and heat flow and chemical transport in the fractured-porous rock of Yucca Mountain is how to handle fracture and matrix flow and interactions under multiphase, multicomponent, and isothermal or nonisothermal conditions. The available methods for treating fluid flow in fractures and the rock matrix using a numerical approach include: (1) an explicit discrete-fracture and matrix representation; (2) the dual-continua method, including double- and multi-porosity, dual-permeability, or the more general "multiple interacting continua'' (MINC) method (Pruess and Narasimhan 1985); and (3) the generalized effective continuum method (ECM). For the work documented in this AMR, the dual-permeability conceptual model is applied to evaluate fluid and heat flow and transport in the fracture-matrix system of the UZ system of Yucca Mountain and the active fracture model is adopted to modify fracture-matrix interface areas for flow and transport between fracture and matrix systems. The dual-continua method provides an appropriate representation of flow and transport processes within the UZ at Yucca Mountain (Doughty 1999; CRWMS M&O 2000c) and is computationally much less demanding than the discrete-fracture-modeling approach and therefore has become the main approach used in the modeling studies of the Yucca Mountain Site Characterization Project. The dual-permeability methodology for handling fluid flow, tracer transport, and heat transfer through fractured rocks treats fracture and rock matrix flow and interactions with a multi-continua numerical approach. It considers global flow occurring not only between fractures but also between matrix grid blocks. In this approach, fracture and matrix are each represented by one gridblock, connected to each other. Because of the one-block representation of fracture or matrix, the interflow between fractures and matrix has to be handled using some quasi-steady-state flow assumption, and this may limit its application in estimating effects of gradients of pressures, temperatures, and concentrations within the matrix. Under steady-state flow conditions, however, the gradients near the matrix surfaces become minimal, and the model is expected to produce accurate solutions (Doughty 1999). When applied as documented in this AMR, the traditional dual-permeability concept is further modified using an active fracture model (Liu et al. 1998) to represent fingering effects of flow through fractures and to limit flow into the matrix system. As an alternative, use of the discrete fracture or weeps type model will face extremely high uncertainties in fracture distribution data within the mountain and extensive computational burden that cannot be solved in the near future. On the other hand, the ECM approach, although the most computationally efficient, may not capture important, rapid transient interactions in flow and transport between fractures and matrix. For temperature calibration, the ECM modeling approach is used instead of the dual-permeability formulation because at ambient geothermal conditions, fractures and matrix are in thermal equilibrium and the ECM provides a good approximation. Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 42 March 2000 Ambient variably saturated flow in the UZ underlying Yucca Mountain is approximated as an isothermal, steady-state flow system. This is considered to be a good approximation within the UZ below the PTn unit because the relatively unfractured nonwelded PTn unit is expected to damp and homogenize downward moving transient pulses arising from episodic surface infiltration events. 6.1.3 Model Boundary Conditions The ground surface of the mountain (or the tuff-alluvium contact in areas of significant alluvial cover) is taken as the top model boundary; the water table is treated as the bottom model boundary. Both the top and bottom boundaries of the model are treated as Dirichlet-type conditions with specified constant but spatially distributed temperature, gas pressure, and constant liquid saturation values along these surfaces. For flow simulations using the EOS9 module, only pressure or saturation values are needed along the top and bottom model boundaries. Surface infiltration, as discussed below in Section 6.1.4, is applied using a source term in the gridblocks within the second grid layer from the top. This method was adopted because the first layer is treated as a Dirichlet-type boundary with constant pressure, saturation, and temperature to represent average atmospheric conditions. All lateral boundaries, as shown in Figures 6-1 and 6-2, are treated as no-flow (closed) boundaries, which allow flow only within the faults. This treatment should be reasonable for the eastern boundary, which is along the Bow Ridge fault, because high vertical permeability and lower capillary forces are expected for the faults (see fault properties estimated in the AMR, (CRWMS M&O 1999d). For the southern, western, and northern lateral boundaries, no lateral flow boundaries would have little effect on moisture flow within and near the potential repository areas because these boundaries are far away from the potential repository. The spatially distributed values of temperatures along the top and bottom boundaries are based on field observation. The pressure conditions at the bottom boundary of the model are based on observed gas-pressure values. The water table, which is the bottom boundary of the UZ Model, is assumed to be a flat, stable surface (CRWMS M&O 1999d). The flat water table specification has little effect on the flow simulation results because flow is essentially determined by upstream, not downstream conditions. In the eastern part of the site to the Solitario Canyon fault, the water table elevation is about 730 meters above sea level (masl); however, the water table elevation increases by 46 meters west of the Solitario Canyon fault. The gas pressures are estimated using a pressure value of 0.92 bars at an elevation of 730 m. Surface gas pressures are determined by running the TOUGH2 code, EOS3 module to steady-state under given temperature, bottom pressure, and surface-infiltration conditions. This is necessary to generate a steady-state, equilibrated gaspressure boundary to avoid artificial air flow or circulation, which may occur when nonequilibrated pressures are imposed on the ground surface boundaries. 6.1.4 Infiltration Scenarios Water entering the UZ as net infiltration from precipitation at land surface is the major control on overall hydrologic and thermohydrologic conditions within the UZ at Yucca Mountain. Net infiltration is the ultimate source of percolation through the UZ, and water percolating downward Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 43 March 2000 through the UZ will be the principal means by which radionuclides may be transported from the potential repository to the water table. A total of nine net infiltration maps are implemented with the UZ Model and its submodels. These infiltration maps are documented in the two AMRs (Climate Model; Infiltration Model) for infiltration and climate models. They include present-day, Monsoon, and Glacial Transition – three climatic scenarios, each of which consists of lower-bound, mean and upper-bound rates. The nine infiltration rates are summarized in Table 6-3 for average values over the model domain. As shown in Table 6-3, the average rate for the present-day mean infiltration with the calibration grid is 4.56 mm/yr distributed over the model domain, which is considered as a base-case scenario. The lower- and upper-bound infiltration values are intended to cover the uncertainties in the infiltration models of possible higher or lower rates. The two future climatic scenarios, the Monsoon and Glacial Transition periods, are used to account for possible higher precipitation and infiltration conditions in the future at Yucca Mountain. Note that the Glacial Transition has higher infiltration rates except for the lower-bound use. The average values in Table 6-3 are based on the TSPA grid shown in Figure 6-2. A plan view of the spatial distribution of the three mean infiltration maps, as interpolated onto the TSPA grid, is shown in Figures 6-3, 6-4 and 6-5 respectively, for the present-day, Monsoon, and Glacial Transition mean infiltration scenarios. The figures show similar flux distributions of the three infiltration rates, with higher infiltration rates in the northern part of the model domain and along the mountain ridge east of the Solitario Canyon fault from south to north. Table 6-3. Infiltration Rates (mm/year) Averaged over the Model Domain Scenario Lower Bound Infiltration Mean Infiltration Upper Bound Infiltration Present-Day 1.20 4.56 11.24 Monsoon 4.60 12.36 20.12 Glacial Transition 2.40 17.96 33.52 ACC and DTNs: MOL.19991014.0102:, LB990501233129.004, LB990701233129.001 Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 44 March 2000 DTN: GS000399991221.002 Figure 6-3. Plan View of Net Infiltration Distributed Over the 3-D UZ TSPA Model Grid for the Base-Case, or Present-Day, Mean Infiltration Scenario. 170000 172000 174000 Nevada Coordinate E-W (m) 230000 232000 234000 236000 238000 Nevada Coordinate N-S (m) 15 14.25 13.5 12.75 12 11.25 10.5 9.75 9 8.25 7.5 6.75 6 5.25 4.5 3.75 3 2.25 1.5 0.75 0 (mm/yr) >_ Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 45 March 2000 DTN: GS000399991221.002 Figure 6-4. Plan View of Net Infiltration Distributed Over the 3-D UZ TSPA Model Grid for the Monsoon, Mean Infiltration Scenario. 170000 172000 174000 Nevada Coordinate E-W (m) 230000 232000 234000 236000 238000 Nevada Coordinate N-S (m) 40 38 36 34 32 30 28 26 24 22 20 18 16 14 12 10 8 6 4 2 0 (mm/yr) >_ Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 46 March 2000 DTN: GS000399991221.002 Figure 6-5. Plan View of Net Infiltration Distributed Over the 3-D UZ TSPA Model Grid for the Glacial Transition, Mean Infiltration Scenario. 170000 172000 174000 Nevada Coordinate E-W (m) 230000 232000 234000 236000 238000 Nevada Coordinate N-S (m) 40 (mm/yr) 38 36 34 32 30 28 26 24 22 20 18 16 14 12 10 8 6 4 2 0 >_ Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 47 March 2000 6.1.5 Model Parameters and Rock Properties The key input rock and fluid-flow parameters used in UZ Model development are summarized in Section 4. They include (1) fracture properties (frequency, permeability, van Genuchten a and m parameters, aperture, porosity, interface area, and residual and satiated saturations) for each UZ Model layer; (2) matrix properties (porosity, permeability, the van Genuchten a and m parameters, and residual and satiated saturations) for each UZ Model layer; (3) thermal and transport properties (grain density, wet and dry thermal conductivity, grain specific heat, and tortuosity coefficients) for each UZ Model layer; and (4) fault properties (matrix and fracture parameters) for each of the major hydrogeologic units (Table 6-1). The development and estimation of these parameters are presented in the AMR: Calibrated Properties Model (CRWMS M&O 2000b) and DTN: GS000399991221.004. The rock parameter specification in the 3-D UZ Model and its submodels is, in general, layer by layer, but certain portions of grid layers representing the CHn unit are altered. In these layers, zeolitic tuff properties are specified for altered zones. We treat all of the geological units, including those representing fault zones, as fracture-matrix systems using a dual-permeability approach. The van Genuchten relative permeability and capillary pressure functions (van Genuchten 1980) are used to describe flow in both fractures and matrix. 6.2 3-D UZ FLOW MODEL CALIBRATION A critical step in developing the 3-D UZ flow model was to use field-measured liquid saturation, water potential, and perched water data for calibrations of the 3-D model. This is part of the important iterative processes of model calibration and verification which increases confidence in model predictions for the site conditions. A detailed modeling investigation is reported in the AMR (CRWMS M&O 2000b) using one-dimensional (1-D) models for estimating model parameters with water potential, saturation and other types of data. However, these 1-D models do not predict perched water occurrence in several hydrogeological units below the potential repository level. This section documents a further model calibration effort, focusing on the 3-D perched water calibrations using the 3-D calibration grid (Figure 6-1). The calibration was conducted using the three sets of parameters (CRWMS M&O 2000b), three present-day infiltration rates (See Table 6-3), and the geological model and numerical grid for calibration (CRWMS M&O 1999d). Two water perching models were investigated in which rock properties were locally modified in several gridlayers of the lower basal vitrophyre in the TSw unit and upper zeolites in the CHn unit. The objective of using these different water-perching models was (1) to match occurrences as observed at the site with different conceptual models for perched water and (2) to investigate effects on groundwater travel and radionuclide transport by varying the percentage of “flow-through” and “by-passing” flow of the perched bodies. 6.2.1Cali bration Data Calibration data used in the 3-D UZ flow model calibration are matrix liquid saturations, matrix water potentials and perched water elevations, as observed from boreholes and the ECRB. Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 48 March 2000 Table 6-4 shows the types of data from boreholes and the ECRB used in the calibration, and Figure 6-1 shows the locations of the boreholes and the tunnel at Yucca Mountain. 6.2.2 Perched Water Conceptual Models Conceptual models involving perched water in the unsaturated zone below the potential repository horizon are of particular interest in assessing the system performance of the potential repository. Waste- isolation strategies at the potential repository depend in part on sorption within the zeolitic portions of the CHn and on groundwater travel times between the potential repository horizon and the water table. The genesis of perched water at Yucca Mountain is much debated among Yucca Mountain project scientists, and several conceptual models have been discussed (e.g., Wu et al. 1999b). Perched water may occur where percolation flux exceeds the capacity of the geologic media to transmit vertical flux in the unsaturated zone. Perched water has been encountered in a number of boreholes at Yucca Mountain, including UZ-14, SD-7, SD-9, SD-12, NRG-7a, G-2, and WT-24. These perched water occurrences are found to be associated with low-permeability zeolites in the CHn or the densely welded basal vitrophyre (Tptpv3, Table 6-2) of the TSw unit. Possible mechanisms of water-perching in the unsaturated zone of Yucca Mountain may be permeability or capillary barrier effects at faults, or a combination of both. A permeability-barrier conceptual model (Conceptual Model #1) for perched water occurrence has been used in the UZ flow-modeling studies since 1996, as summarized in Wu et al. (1999b). In this model, perched water bodies in the vicinity of the ESF North Ramp (near boreholes UZ- 14, SD-9, NRG-7a, G-2 and WT-24) are observed to occur above the base of the TSw, underlain by a zone of low-permeability zeolitized rock. The perched bodies in this northern area of the potential repository may be interconnected. However, the perched water zones at boreholes SD-7 and SD-12 are considered here as local, isolated bodies. In this conceptual model, both vertical and lateral water movement in the vicinity of the perched zones is considered to be controlled mainly by the fracture and matrix permeability distribution in these areas. The major aspects of the permeability-barrier conceptual model are: (1) no large-scale vertically connected potentially Table 6-4. Data Used for 3-D Flow Model Calibration Borehole/ECRB Matrix Liquid Saturation (core) Matrix Liquid Water Potential (in situ) Perched Water Elevation (masl) USW NRG-7a . . USW SD-6 . USW SD-7 . . USW SD-9 . . USW SD-12 . . . USW UZ-14 . . UE-25 UZ#16 . USW WT-24 . . USW G-2 . ECRB . Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 49 March 2000 fluid-conducting fractures transect the underlying low-permeability units, (2) both vertical and horizontal permeabilities within and below the perched water zone are small compared with permeabilities outside perching zones, and (3) sufficient percolation flux (>1 mm/yr) exists due to the lower permeability of the matrix rock. Previous modeling studies (Wu et al. 1999b) concluded that this conceptual water-perching model is able to match the observation data of perched water in the unsaturated zone of Yucca Mountain. Another perched water conceptual model (Conceptual Model #2) is the unfractured zeolite model. Similar to the permeability barrier model discussed above, this model presumes that the occurrence of perched water at Yucca Mountain results mainly from the lack of globally connected, fluid conducting fractures within zeolitic units. This model can be considered a special case of the permeability-barrier model, in which a water-perching mechanism is controlled by the low-permeability zeolitic matrix only, i.e., it is assumed that fractures are not present in perching layers. The concept of an unfractured zeolite model is partially supported by the fracture data presented in an AMR for the analysis of hydrologic properties data (DTN: LB990501233129.001), which suggests a very small fracture frequency within zeolitic units. In the present numerical studies, the occurrence of perched water is assumed to follow either of the two conceptual models, i.e., permeability-barrier and unfractured-zeolite models. In other words, perched water bodies are formed as a result of permeability-barrier effects. There are three conceptual flow scenarios investigated in this AMR, as described in Table 6-5. In addition to the two conceptual water-perching models, Table 6-5 also lists a third scenario called the non-waterperching model. This scenario cannot predict perched water in the UZ, and therefore provides an extreme case in which maximum flow through the zeolites occurs. This non-perching model is used for sensitivity analyses and comparative studies with the two water-perching models. Table 6-5. Conceptual Flow Scenarios Conceptual Model Description #1 Flow-through Model Conceptual Model #1 (flow-through model) is the permeability-barrier model, using the calibrated, perched water parameters for fractures and matrix in the northern part of model domain. Properties are modified property layers in the tsw38, tsw39, ch1z, and ch2z, where the lower basal vitrophyre of the TSw is above the perching zeolites of the CHn. For local regions near boreholes SD-7 and SD-12 in the southern part of the model domain, properties are modified only for the gridblocks to which the borehole grid columns are directly connected, as well as the gridblocks along the two boreholes, for blocks representing ch5z, ch6z and pp4z for SD-7 and tsw38 and tsw39 for SD-12, respectively. Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 50 March 2000 The simulations with respect to the three water-perching modeling scenarios are realized and carried out by modifying the two grid files. For Conceptual Model #1 (flow-through model), a dual-permeability mesh for the UZ calibration grid is modified by the following: • Replace property cards of grid layers of tsw38 (tswF8/tswM8), tsw39 (tswF9/tswM9), ch1z (ch1Fz/ch1Mz) and ch2z (ch2Fz/ch2Mz) by (pcF38/pcM38), (pcF39/ pcM39), (pcF1z/pcM1z), and (pcF2z/pcM2z), respectively, where the basal vitrophyre of the TSw is underlain by zeolitic units. • Near Borehole SD-7, properties are modified for the gridblocks in grid columns, i62, k88, l43, l44, and k90, over grid layers of ch5z (ch5Fz/ch5Mz), ch6z (ch6Fz/ch6Mz) and pp4 (pp4Fz/pp4Mz) by (pcF5z/pcM5z), (pcF6z/pcM6z), and (pcF4p/pcM4p), respectively. • Near borehole SD-12, properties are modified for the gridblocks in grid columns, k64, b93, b99, k61, k62 and k67, over grid layers of tsw38 (tswF8/tswM8) and tsw39 (tswF9/ tswM9) by (pcF38/pcM38) and (pcF39/pcM39), respectively. For Conceptual Model #2 (unfractured zeolite or by-passing model), the dual-permeability mesh is modified by reassigning rock properties only at SD-12 over two gridlayers: • Near gridblocks in grid columns, k64, b93, b99, k61, k62 and k67, over grid layers of tsw38 (tswF8/tswM8) and tsw39 (tswF9/tswM9) by (pcF38/pcM38) and (pcF39/ pcM39), were modified respectively. • Assigning the fracture blocks in the zeolitic CHn layers of model to matrix parameters, effectively removing the fractures. The two perched models and the non-perched model are represented using three sets of 3-D, dual-permeability calibration model grids: • “3d2kcalib_pc1.mesh” for perched water Conceptual Model #1 (DTN: LB990501233129.004). • “3d2kcalib_pc2.mesh” for perched water Conceptual Model #2 (DTN: LB990501233129.004). #2 By-passing Model Conceptual Model #2 is the unfractured zeolite model, excluding all fractures in the zeolitic units of the CHn and using the permeability values of 1-D calibration results directly for matrix rocks in the zeolitic and transitional units of the CHn. For a local region near Borehole SD-12, properties are modified of the direct neighboring blocks as well as the borehole gridblocks, for representing tsw38 and tsw39. #3 Non-perching Model Conceptual Model #3 is a non-perched-water model, in which the property sets from the 1-D inversion are directly used. Table 6-5. Conceptual Flow Scenarios Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 51 March 2000 • “MESH_CAL.V1” for non-perched water or Conceptual Model #3 of this AMR (DTN: LB990701233129.002). 6.2.3 Calibrated Parameters for Perched Water Zones As discussed above, to calibrate the 3-D UZ flow model against observed perched water conditions at Yucca Mountain, some local modification of rock properties is necessary. In general, permeability was adjusted only within the model layers associated with the perched water occurrence. At Yucca Mountain, a common example of water-perching caused by a permeability barrier is the case in which the highly fractured basal vitrophyre of the TSw unit overlies bedded units of low permeability. In addition to a permeability barrier, two other conditions are required for perched water to exist: a certain lateral flow resistance and sufficient percolation flux. For perched water Conceptual Model #1, calibrated parameters of fracture and matrix permeabilities within perched zones are results from a series of modeling studies of 3-D simulations. Matrix permeabilities of potential perched layers/zones, as identified in the model grid layers of Section 6.2.2, are based on average values of the measured matrix permeabilities, while fracture permeabilities used for the northern perched zones are 10 times higher than matrix permeabilities under the mean and upper-bound infiltration scenarios. In the lower infiltration case, the same permeability values exist for both fractures and matrix for perched zones near SD- 7 or SD-12 effectively removing fractures and making this into a special case of Conceptual Model #2. Other than intrinsic permeabilities, van Genuchten’s a and m parameters, as well as residual saturations for matrix blocks within perched zones, are identical to parameters estimated from the 1-D inversions (CRWMS M&O 2000b). The active-fracture parameter, ., is set to zero for all the perched zones, causing the fracture-matrix interface area factor to be equivalent to liquid saturation (Liu et al. 1998). Tables 6-6, Table 6-7 and 6-8 present the final three sets of calibrated rock properties at zones with perched water using Conceptual Model #1, with base-case (mean), upper-bound, and lower-bound present-day infiltration scenarios, respectively. Table 6-6. Calibrated Parameters for Perched Water Conceptual Model #1 (Flow-Through Model) for the Base-Case Present-Day Infiltration Scenario Model Layer kM (m2) aM (1/Pa) mM (-) kF (m2) aF (1/Pa) mF (-) . (-) Tsw38/pcM38/ pcF38 3.00E-19 6.94E-6 0.324 3.00E-18 6.94E-6 0.324 0.00 Tsw39/pcM39/ pcF39 6.20E-18 2.29E-5 0.381 6.20E-17 2.29E-5 0.381 0.00 ch1z/pcM1z/pcF1z 9.30E-20 2.68E-7 0.316 9.30E-19 2.68E-7 0.316 0.00 ch2z/pcM2z/pcF2z 2.40E-18 3.47E-6 0.245 2.40E-17 3.47E-6 0.245 0.00 ch5z/pcM5z/pcF5z 2.40E-18 3.47E-6 0.245 2.40E-18 3.47E-6 0.245 0.00 ch6/pcM6z/pcF6z 1.10E-19 3.38E-7 0.510 1.10E-19 3.38E-7 0.510 0.00 pp4/pcM4p/pcF4p 7.70E-19 1.51E-7 0.676 7.70E-19 1.51E-7 0.676 0.00 DTN: LB991121233129.001 Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 52 March 2000 The modified “fracture” properties in the three tables are more close to those of matrix, in other words, fractures in water perching layers are effectively removed. For perched water Conceptual Model #2 of the unfractured zeolite or by-passing model, rock properties of all the fractures within the potential perched layers/zones are replaced by the corresponding matrix properties from the 1-D inversions (CRWMS M&O 2000b). In addition, properties of the blocks adjacent to SD-12 and the borehole column itself were adjusted. The actual perched water parameters are given in Tables 6-6, 6-7, and 6-8 under layer names tsw38/pcM38/pcF38 and tsw38/pcM38/ pcF38. 6.2.4 Numerical Treatment and Solution Convergence Numerical modeling of large-scale 3-D flow and transport in the UZ beneath Yucca Mountain is mathematically challenging. The difficulty mainly stems from the highly nonlinear coupling of Table 6-7. Calibrated Parameters for Perched Water Conceptual Model #1 (Flow-Through Model) for the Upper- Bound Present-Day Infiltration Scenario Model Layer kM (m2) aM (1/Pa) mM (-) kF (m2) aF (1/Pa) mF (-) . (-) tsw38/pcM38/pcF38 3.00E-19 5.56E-7 0.314 3.00E-18 5.56E-7 0.314 0.00 tsw39/ pcM39/ pcF39 6.20E-18 1.82E-5 0.377 6.20E-17 1.82E-5 0.377 0.00 ch1z/pcM1z/pcF1z 9.30E-20 4.23E-7 0.336 9.30E-19 4.23E-7 0.336 0.00 ch2z/pcM2z/pcF2z 2.40E-18 1.13E-6 0.229 2.40E-17 1.13E-6 0.229 0.00 ch5z/pcM5z/pcF5z 2.40E-18 1.13E-6 0.229 2.40E-18 1.13E-6 0.229 0.00 ch6/pcM6z/pcF6z 1.10E-19 3.57E-7 0.502 1.10E-19 3.57E-7 0.502 0.00 pp4/pcM4p/pcF4p 7.70E-19 1.83E-7 0.683 7.70E-19 1.83E-7 0.683 0.00 DTN: LB991121233129.003 Table 6-8. Calibrated Parameters for Perched Water Conceptual Model #1 (Flow-Through Model) for the Lower- Bound Present-Day Infiltration Scenario Model Layer kM (m2) aM (1/Pa) mM (-) kF (m2) aF (1/Pa) mF (-) . (-) tsw38/pcM38/pcF38 3.00E-19 3.72E-6 0.291 3.00E-19 3.72E-6 0.291 0.00 tsw39/ pcM39/ pcF39 6.20E-18 2.37E-5 0.321 6.20E-18 2.37E-5 0.321 0.00 ch1z/pcM1z/pcF1z 9.30E-20 7.26E-7 0.304 9.30E-20 7.26E-7 0.304 0.00 ch2z/pcM2z/pcF2z 2.40E-18 2.44E-6 0.135 2.40E-18 2.44E-6 0.135 0.00 ch5z/pcM5z/pcF5z 2.40E-18 2.44E-6 0.135 2.40E-18 2.44E-6 0.135 0.00 ch6/pcM6z/pcF6z 1.10E-19 5.06E-7 0.445 1.10E-19 5.06E-7 0.445 0.00 pp4/pcM4p/pcF4p 7.70E-19 1.83E-7 0.653 7.70E-19 1.83E-7 0.653 0.00 DTN: LB991121233129.005 Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 53 March 2000 the flow system. First, the hydrogeologic system is distinctly heterogeneous on all model scales, and there are orders-of-magnitude contrasts in permeabilities across geological layers and between fracture and matrix rock. Secondly, the two-phase flow functions of relative permeability and capillary pressure for Yucca Mountain tuffs are extremely nonlinear for both fractures and matrix systems. The mathematical difficulties become even more severe when using the dual-permeability modeling approach for handling fracture-matrix interactions. In this case, flows through fractures and matrix are on very different time scales, with fracture flow being orders of magnitude faster than matrix flow. In addition, fracture elements have a much smaller storage space than matrix elements. In general, it takes simulation times of thousands to millions of years for the system to equilibrate. Rapid flow through fractures, plus the slow response in the matrix, makes it very difficult to obtain steady-state solutions numerically. For all flow simulations (this section and Section 6.6), the EOS9 module of TOUGH2 VI.4 is used to solve Richards’ equation in the unsaturated flow calculations. In this method, air/gas flow dynamics are ignored by using a constant gas-phase pressure in an isothermal system. The reason for using this simplified two-phase flow solution for the 3-D model calibrations and TSPA flow field simulations is that it is the most computationally efficient approach and at the same time provides accurate results for isothermal two-phase flow. We solve two-phase flow problems with one equation per gridblock instead of solving two or three equations as required by the EOS3 module. Secondly, numerical tests conclude that for moisture flow and distributions at steady state, the EOS9 solutions always provide almost identical answers to EOS3, “true two-phase” flow solutions ((LBNL Scientific Notebook: YMP-LBNL-YSW-2, p. 152). Model calibrations and flow-field simulations are based on steady-state solutions using the EOS9 module. In each simulation, fracture, fault, and zeolitic element volumes are increased by a factor of 10,000 to overcome convergence difficulties associated with these nodes while keeping all other mesh geometric information unchanged. This approach does not affect the final solution as long as a “true” steady-state solution is obtained for a given run. The initial condition for a new scenario run is estimated using a default (uniform) initial condition or results of a previous, different run with a similar modeling condition. Each simulation is usually subdivided into stages. For the first-stage runs, a large convergence tolerance on the order of 10,000 or more is used to keep simulation progressing with a large time step size. It has been found that at this stage using large residual tolerance has no effects on final, steady-state solutions as long as no oscillations or unphysical solutions occur. After running the solution to 109 years or more with a large tolerance, the convergence tolerance is reduced to 10-4, and the model is run until a steady-state solution is reached. The final steady-state solutions are confirmed using a global mass-balance check, as discussed in the next section. 6.2.5 Simulation Scenarios, Results and Analyses This section summarizes the seven flow model calibration scenarios performed for this AMR, including simulation results and analyses. The seven model calibrations are performed using (1) the calibration grid (Figure 6-1), and three present-day infiltration maps, as discussed in Section 6.1.4; (2) the seven parameter sets in Attachment II of this AMR; and (3) the three conceptual models and the calibrated perched water parameters of Section 6.2.3. Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 54 March 2000 Simulation Scenarios: Table 6-9 summarizes these seven simulation scenarios, associated conceptual models/grids, parameter sets, and infiltration rates used. Table 6-9. Seven UZ Flow Simulation Scenarios: Data Files, Conceptual Models/Grids, Parameter Sets, Infiltration Maps for the UZ Model Calibrations Designation/ Simulation Conceptual Model/Grid (Table 6-5) Parameter Set/ Calibration Infiltration Map uz99_m #3 Non-perching model/ MESH_CAL.V1 DTN:LB990701233129.002 Parameter set from Table II-7, basecase/ present-day, mean infiltration (AMR: CRWMS M&O 2000b) without 3-D calibration (DTN: LB991121233129.007) Present-day, mean infiltration (Figure 6-3) pch1_L2 #1 Flow-through perched water model/ 3d2kcalib_pc1.mesh DTN:LB990501233129.004 Parameter set from Table II-1, lower-bound/present-day infiltration (DTN: LB991121233129.005) Present-day, lowerbound infiltration pch2_L2 #2 By-passing perched water model/ 3d2kcalib_pc2.mesh DTN:LB990501233129.004 Parameter set from Table II-2, lowerbound/ present-day infiltration (DTN: LB991121233129.006) Present-day, lowerbound infiltration pch1_m2 #1 Flow-through perched water model/ 3d2kcalib_pc1.mesh DTN:LB990501233129.004 Parameter set from Table II-3, base-case/mean/present-day infiltration (DTN: LB991121233129.001) Present-day, mean infiltration (Figure 6-3) pch2_m2 #2 By-passing perched water model/ 3d2kcalib_pc2.mesh DTN:LB990501233129.004 Parameter set from Table II-4, base-case/mean /present-day infiltration (DTN: LB991121233129.002) Present-day, mean infiltration (Figure 6-3) pch1_u2 #1 Flow-through perched water model/ 3d2kcalib_pc1.mesh DTN:LB990501233129.004 Parameter set from Table II-5, upperbound/ present-day infiltration (DTN: LB991121233129.003) Present-day, upperbound infiltration pch2_u2 #2 By-passing perched water model/ 3d2kcalib_pc2.mesh DTN:LB990501233129.004 Parameter set from Table II-6, upperbound/ present-day infiltration (DTN: LB991121233129.004) Present-day, upperbound infiltration Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 55 March 2000 As shown in Table 6-9, only one simulation is conducted for the non-perching model, which uses the present-day mean infiltration map. For perched water Conceptual Models #1 or #2, simulations are carried out for all the three infiltration scenarios. Mass Balance and Solution Convergence: Table 6-10 shows the mass-balance results for the seven simulation scenarios. In Table 6-10, “Inflow” is the total infiltration rate over the entire model top boundary, representing a net water recharge rate into the system for the infiltration scenario simulated. “Outflow” is the cumulative total-flow rate out of the model and into the lower boundary representing the water table. Global mass-balance errors of inflow and outflow out of the system, as shown in Table 6-10, are less than 0.001% for the seven simulations leading to the conclusions that steady-state solutions are obtained. Model Calibrations and Results: As listed in Table 6-9, there are seven scenarios for model calibrations, consisting of one non-perching simulation (uz99_m) and the rest – six water perching simulations with the two perched water conceptual models and three infiltration rates. Six out of the seven simulations, except the non-perching one, have been calibrated against the field-observed data of perched water. The observed matrix liquid saturations and water potentials (when available), are used to examine modeling results. A perched water body is defined as fully liquid saturated gridblocks with zero capillary pressure or possible waterbend for calibration. The data source used in the calibrations are listed in Section 4-1. Only in-situ measurement water potentials are used. In this section, the simulation results are presented and discussed in terms of (1) comparisons with matrix liquid saturation, water potential, and perched water data, (2) examination of simulated perched water bodies, and (3) examination of simulated percolation flux and fracture-matrix flow components. All the seven simulations are checked against observed saturation, water potential and perched water data. However, only a few of these comparisons are shown in the report and boreholes UZ- 14 and SD-12 are selected to show the match between observed and modeled vertical-saturation profiles and perched water locations for six simulations with perched water occurrence. Matches to other borehole data are similar. Table 6-10. Mass Balance Results for Flow Simulations Using the Calibration Grid Simulation Scenarios Inflow from infiltration (kg/s) Outflow to water table (kg/s) Relative error (%) uz99_m 5.6190232 5.6190755 0.00093 pch1_L2 1.4704485 1.4704460 0.00017 pch2_L2 1.4704485 1.4704472 0.00009 pch1_m2 5.6190232 5.6190643 0.00073 pch2_m2 5.6190232 5.6190252 0.00004 pch1_u2 13.842166 13.842181 0.00011 pch2_u2 13.842166 13.842169 0.00002 Model Results - DTNs: LB990801233129.022, LB990801233129.023, LB990801233129.024, LB990801233129.025, LB990801233129.026, LB990801233129.027, LB990801233129.028, respectively. Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 56 March 2000 Comparisons with Liquid Saturation, Water Potential and Perched-Water Data: Measured matrix liquid saturation, water-potential data and perched water elevations are compared against 3-D model results from the seven simulations. Matrix liquid saturation, water potential, and perched water data used for comparisons are taken from nine boreholes (NRG-7a, SD-6, SD-7, SD-9, SD-12, UZ-14, UZ#16, WT-24 and G-2). The locations of these boreholes are shown in Figure 6-1. The comparisons of simulated and observed matrix liquid saturations along the vertical column representing boreholes UZ-14 and SD-12 are shown in Figures 6-6 and 6-7 for the two perched water conceptual models under the present-day, mean infiltration scenario. Figure 6-8 shows comparison with water potentials for SD-12. In general, the modeled results from all the six simulations with perched water Conceptual Models #1 and #2 are in reasonable agreement with the measured saturation and water potential profiles, as shown in Figures 6-6, 6-7 and 6-8. Data - CRWMS M&O (2000a), DTN: 65960308312312.005 Model Results - DTNs: LB990801233129.025, LB990801233129.026 Figure 6-6. Comparison to the Simulated and Observed Matrix Liquid Saturations and Perched-Water Elevations for Borehole UZ-14, Using the Results of pch1_m2 and pch2_m2 with Present-Day, Mean Infiltration Rate. 0.0 0.5 1.0 Saturation 700 800 900 1000 1100 1200 1300 1400 Elevation (m) USGS Data Hydro. Unit pch1-m2 pch2-m2 TSw TCw CHn Perched Water PTn Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 57 March 2000 DTN: GS960908312232.006 Model Results - DTNs: LB990801233129.025, LB990801233129.026 Figure 6-7. Comparison to the Simulated and Observed Matrix Liquid Saturations and Perched-Water Elevations for Borehole SD-12, Using the Results of pch1_m2 and pch2_m2 with Present-Day, Mean Infiltration Rate. DTN: GS960908312232.006 Model Results - DTNs: LB990801233129.025, LB990801233129.026 Figure 6-8. Comparison to the Simulated and Observed Matrix Water Potentials and Perched-Water Elevations for Borehole SD-12, Using the Results of pch1_m2 and pch2_m2 with Present-Day, Mean Infiltration Rate. 0.0 0.5 1.0 Saturation 700 800 900 1000 1100 1200 1300 Elevation (m) USGS Data Hydro. Unit pch1-m2 pch2-m2 TSw TCw CHn Perched Water PTn 0.0 2.0 4.0 6.0 8.0 10.0 Logarithm of Water Potential (Pa) 700 800 900 1000 1100 1200 1300 Elevation (m) USGS In-situ Data Hydro. Unit pch1-m2 pch2-m2 TSw TCw CHn Perched Water PTn Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 58 March 2000 Also shown in Figures 6-6, 6-7 and 6-8 are the perched water elevations at the two boreholes, indicating a good agreement between observed and simulated data. For borehole UZ-14 under Conceptual Model #2, Figure 6-6 shows that the modeled perched water elevation is a little lower than the observed elevation. In addition, each of the six simulations has been compared to perched water data as observed from the seven perched water boreholes of Table 6-4 (See Appendix A of YMP-LBNL-GSB-YSW-2 for detailed comparisons), and the results are as follows: • Under the present-day, mean infiltration scenario (pch1_m2 and pch2_m2, Table 6-9), both perched water conceptual models generally match water perching conditions in the UZ Model domain. • Under the present-day, upper-bound infiltration scenario (pch1_u2 and pch2_u2, Table 6- 9), the two perched water conceptual models generally reproduce water perching conditions in the UZ Model domain. • Under the present-day, lower-bound infiltration scenario (pch1_L2 and pch2_L2, Table 6-9), the perched water conceptual models generally reproduce water-perching conditions at G-2, NRG-7a, SD-12, and WT-24 only. The models do not match the perched water data very well in SD-7, SD-9 and UZ-14 because of the low percolation fluxes at these borehole locations (0.01, 0.01 and 0.005 mm/year, respectively). Examination of Simulated Perched Water Bodies: Figures 6-9 and 6-10 present examples of a simulated perspective view of 3-D perched water bodies and their volumetric extensions. Figure 6-9 shows a perspective view of fracture-water saturation contours along the bottom of the TSw or the low basal vitrophyre layer for perched water Conceptual Model #1. The blue isosurfaces on the figure reflect the regions of 100% liquid saturations, or perched water zones, within fractures along the model layer, while the green isosurface represents a portion of the model layer with fracture liquid saturations less than 100%. Figure 6-9 shows clearly several extensive perched water bodies predicted in the northern part of the model domain, located near the basal vitrophyre of the TSw, and separated by faults. Figure 6-9 also indicates that boreholes G-2, WT-24, UZ-14, NRG-7a, SD-9, as well as SD-12, intersect perched water bodies at this layer. Figure 6-10 shows perched water bodies simulated using perched water Conceptual Model #2, along the top, zeolitic layer of the CHn. The perched water zone (Blue) on Figure 6-10 is similar to that or Figure 6-9 (Conceptual Model #1), but slightly larger. Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 59 March 2000 Based on - DTN: LB990801233129.025 Figure 6-9. Simulated Perspective View of 3-D Perched Bodies Along the Base of the TSw, Using the Results of Simulation pch1_m2 of Conceptual Model #1 (Flow-Through) with Present-Day, Mean Infiltration Rate.(Blue 100% Saturation, Green < 100%) Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 60 March 2000 Based on - DTN: LB990801233129.026 Figure 6-10. Simulated Perspective View of 3-D Perched Bodies Along the Top of the CHn, Using the Results of Simulation pch1_m2 of Conceptual Model #2 (By-Passing) with Present-Day, Mean Infiltration Rate. (Blue 100% Saturation, Green < 100%) Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 61 March 2000 Percolation Fluxes and Fracture-Matrix Flow Components: Percolation flux through the unsaturated zone is one of the most critical factors affecting potential repository performance for TSPA calculations. The quantity and spatial and temporal variations in percolation flux directly affect: (1) the amount of water flowing into potential waste-emplacement drifts; (2) moisture conditions and the corrosion environment of waste packages within the drifts; (3) waste mobilization from the potential repository; and (4) radionuclide migration from the UZ to the saturated zone. However, because percolation fluxes of unsaturated flow cannot be readily measured in the field, indirect data and model results are used to estimate these fluxes. Model studies (Wu et al. 1999a, 1999b) indicate that accuracy of model predictions of percolation fluxes at Yucca Mountain depend on many factors. The most important factors are (1) net infiltration rates over the surface boundary; (2) representative geological and conceptual models; (3) reliable distributed rock-property values of fractures and matrix blocks; and (4) treatment of fracture-matrix flow and interactions. In this section, percolation fluxes at the potential repository horizon are analyzed using the seven simulation results of Table 6-9. The percolation flux is defined as total vertical liquid mass flux through both fractures and matrix, and is converted to mm/yr per unit area using a constant water density. Figures 6-11, 6-12, and 6-13 show percolation fluxes at the potential repository level for the three present-day infiltration scenarios with perched water Conceptual Model #1. Percolation fluxes at the potential repository are nearly the same if the same infiltration map is used, regardless of the perched water conceptual model. This occurs because the perched water models are different in the rock properties only in the bottom layers of the TSw and zeolitic units in the CHn, which have little effect on flow at and above the potential repository level. Figures 6-11, 6-12 and 6-13 display a nonuniform pattern of flux distributions (the darker blue spots on the figure indicate the higher modeled percolation fluxes). The high percolation fluxes are located primarily north of the potential repository, but also along the Solitario Canyon fault in the middle portion of the model domain. A comparison of the present-day surface infiltration maps (e.g., Figure 6-3) and the modeled, corresponding flux maps shown in Figures 6-11, 6-12 and 6-13 indicate similar flux patterns. Especially for the lower-bound and upper-bound infiltration cases, the simulation results show little lateral diversion occurring during flow from surface to potential repository level. For the mean infiltration, the simulated percolation fluxes at the potential repository level show that small lateral movement occurs in the middle of the model domain, and higher fluxes are seen to move down the faults in these areas. Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 62 March 2000 Based on model results from this AMR submitted under DTN: LB990801233129.023 Figure 6-11. Simulated Percolation Fluxes at the Potential Repository Horizon Under Present-Day, Lower-Bound Infiltration Using the Results of Simulation pch1_L2. 170000 172000 174000 Nevada Coordinate E-W (m) 230000 232000 234000 236000 238000 Nevada Coordinate N-S (m) 5 4.75 4.5 4.25 4 3.75 3.5 3.25 3 2.75 2.5 2.25 2 1.75 1.5 1.25 1 0.75 0.5 0.25 0 (mm/yr) >_ Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 63 March 2000 Based on DTN: LB990801233129.025 Figure 6-12. Simulated Percolation Fluxes at the Potential Repository Horizon Under Present-Day, Mean Infiltration Using the Results of Simulation pch1_m2. 170000 172000 174000 Nevada Coordinate E-W (m) 230000 232000 234000 236000 238000 Nevada Coordinate N-S (m) 15 (mm/yr) 14.25 13.5 12.75 12 11.25 10.5 9.75 9 8.25 7.5 6.75 6 5.25 4.5 3.75 3 2.25 1.5 0.75 0 >_ Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 64 March 2000 Based on DTN: LB990801233129.027 Figure 6-13. Simulated Percolation Fluxes at the Potential Repository Horizon Under Present-Day, Upper-Bound Infiltration Using the Results of Simulation pch1_u2. 170000 172000 174000 Nevada Coordinate E-W (m) 230000 232000 234000 236000 238000 Nevada Coordinate N-S (m) 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 (mm/yr) >_ Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 65 March 2000 Table 6-11 lists fracture-matrix flow components at the potential repository horizon and the water table within the model domain, calculated based on vertical flow along each grid column. These statistics indicate that fracture flow is dominant both at the potential repository horizon and at the water table. At the potential repository level, fracture flow consists of more than 80% of the total percolation fluxes. Fracture flow at the water table takes 70-90% of the total flow, whereas the second perched water conceptual model predicts consistently lower fracture-flow components at the water table for all three infiltration scenarios. Flow-Through and By-Passing Perched Water Zones: The percentage of water flowing through or by-passing perched water bodies below the potential repository may have an effect on groundwater flow paths and travel times. This may in turn affect the adsorbtion of radionuclides onto zeolitic and vitric rocks, directly impacting potential repository performance. The percentage of flow-through or by-passing perched bodies can be further analyzed using the 3-D model calibration results. Figures 6-14 and 6-15 show vertical flow at locations near SD-6 and UZ-14 from the seven calibration simulations. The locations of the two boreholes are shown in Figure 6- 1, with SD-6 and UZ-14 located in the southern and northern parts of the potential repository, respectively. Figure 6-14 shows that at SD-6, perched water Conceptual Model #1 permits much larger (almost complete) flow through the CHn unit than Conceptual Model #2. For the location near UZ-14, Conceptual Model #1 also predicts more percentage (50%) of flow through perched water layers with the mean infiltration rate than Conceptual Model #2. In both cases, the non-water-perching, Conceptual Model #3 predicts the highest, most complete flow through for the mean infiltration scenario (Figures 6-14b and 6-15b). Figures 6-14 and 6-15, as well as the analyses of the seven calibration runs, indicate the following: • Perched water zones may only partially block vertical water flow; a certain percentage of water is always flowing through perched bodies. • The higher the infiltration rates, the higher the by-passing percentages predicted by Conceptual Model #2. Table 6-11. Comparison of the Water Flux Through Matrix and Fractures as a Percentage of the Total Flux at Two Different Horizons (1) at the Potential Repository and (2) at the Water Table. Simulation Designation Flux at Potential Repository Horizon (%) Flux at Water Table (%) Fracture Matrix Fracture Matrix uz99_m 80.80 19.20 pch1_L2 86.13 13.87 84.23 15.77 pch2_L2 86.00 14.00 70.04 29.96 pch1_m2 82.44 17.56 87.28 12.72 pch2_m2 82.44 17.56 72.70 27.30 pch1_u2 94.06 5.94 95.46 4.54 pch2_u2 93.97 6.03 82.67 17.33 Model Results - DTNs: LB990801233129.022, LB990801233129.023, LB990801233129.024, LB990801233129.025, LB990801233129.026, LB990801233129.027, LB990801233129.028, respectively. Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 66 March 2000 • Conceptual Model #1 results in consistently higher flow-through rates than Conceptual Model #2. • Non-water-perching model (#3) predicts nearly complete flow through the zeolites in the CHn. As a result, perched water Conceptual Model #1 is defined as the “flow-through” model, even though it is only partially “flow-through,” and Conceptual Model #2 is called the “by-passing” model. These results are consistent with the conceptual models used to develop the modeling scenarios. Model Results - DTNs: LB990801233129.022, LB990801233129.023, LB990801233129.024, LB990801233129.025, LB990801233129.026, LB990801233129.027, LB990801233129.028 Figure 6-14. Comparisons between Simulated Vertical Percolation Fluxes at the Location of SD-6 using Different Perched-Water Conceptual Models. (a) (c) (b) 0.0 0.5 1.0 1.5 2.0 Total Liquid Flux (mm/year) 700 800 900 1000 1100 1200 1300 1400 1500 Elevation (m) pch1-L 2 pch2-L 2 0.0 2.0 4.0 6.0 8.0 10.0 Total Liquid Flux (mm/year) 700 800 900 1000 1100 1200 1300 1400 1500 Elevation (m) pch1-m2 pch2-m2 uz99-m 0.0 5.0 10.0 15.0 20.0 25.0 Total Liquid Flux (mm/year) 700 800 900 1000 1100 1200 1300 1400 1500 Elevation (m) pch1-u2 pch2-u2 TCw PTn TSw CHn TCw PTn TSw CHn TCw PTn TSw CHn (a) Conceptual Model #1 versus #2 for lower-bound infiltration rate. (b) Conceptual Model #1 versus #3 for mean infiltration rate. (c) Conceptual Model #1 versus #2 for upper-bound infiltration rate. Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 67 March 2000 Model Results - DTN: LB990801233129.022, LB990801233129.023, LB990801233129.024, LB990801233129.025, LB990801233129.026, LB990801233129.027, LB990801233129.028 Figure 6-15. Comparisons between Simulated Vertical Percolation Fluxes at the Location of UZ-14 using Different Perched-Water Conceptual Models. 0.000 0.005 0.010 0.015 0.020 Total Liquid Flux (mm/year) 700 800 900 1000 1100 1200 1300 1400 1500 Elevation (m) pch1-L 2 pch2-L2 0.0 1.0 2.0 3.0 4.0 5.0 6.0 Total Liquid Flux (mm/year) 700 800 900 1000 1100 1200 1300 1400 1500 Elevation (m) pch1-m2 pch2-m2 uz99-m 0.0 5.0 10.0 15.0 20.0 Total Liquid Flux (mm/year) 700 800 900 1000 1100 1200 1300 1400 1500 Elevation (m) pch1-u2 pch2-u2 (a) (c) (b) TCw PTn TSw CHn TCw PTn TSw CHn TCw PTn TSw CHn (a) Conceptual Model #1 versus #2 for lower-bound infiltration rate. (b) Conceptual Model #1 versus #2 and #3 for mean infiltration rate. (c) Conceptual Model #1 versus # for upper-bound infiltration rate. Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 68 March 2000 6.3 TEMPERATURE CALIBRATION For thermo-hydrological studies, the steady-state, ambient temperature and saturation distributions are needed to serve as initial conditions for the UZ model to evaluate various thermal-load and infiltration scenarios. Temperature data are required to describe the geothermal conditions of the UZ Model using measured field data. A steady-state, ambient temperature distribution for Yucca Mountain can be obtained using TOUGH2 simulation under fixed top and bottom temperature-boundary conditions. 6.3.1 Top Boundary Temperature To account for differences in temperature in the mountain caused by variations in elevation, measured mean surface temperature and an equation that correlates surface temperature with elevation are used. The surface temperature was measured for mean surface temperature in boreholes NRG-6 and NRG-7a (DTN: GS950208312232.003), with several years of continuous temperature monitoring data. The surface temperature Ts at any elevation Z is computed and fixed according to the following equation (Driscoll, 1986, pp. 49–51; Wu et al. 1999a, p. 196): (Eq. 1) where Tref is mean surface temperature at reference elevation Zref and . is the dry adiabatic atmospheric lapse rate in oC/m. This lapse is 0.01oC/m (Driscoll 1986, p. 50). In this model, the reference temperature used is 18.23oC, the mean value at an elevation of 1231.0 m measured in borehole NRG-6 (DTN: GS950208312232.003). The mean temperature at NRG-7a at an elevation 1282.2 m is 17.78oC. The calculated mean lapse rate, based on these field measurements, is 0.009oC/m. 6.3.2 Bottom Boundary Temperature For the bottom boundary at the water table, temperatures were interpolated from unqualified borehole temperature profile data reported in Sass et al. (1988). Because several of these boreholes do not actually extend to the water table, temperatures at the water table were obtained by linear extrapolation of the measured profiles. The resulting temperature distribution was plotted and interpolated over the entire model domain. This interpolated temperature distribution was calibrated against recently acquired qualified temperature data in boreholes NRG-6, NRG-7a, SD-12 UZ#4, UZ#5 and UZ-7a. To obtain accurate bottom-temperature boundary conditions for use in thermo-hydrological simulations, the initial distribution of boundary temperature was adjusted so that the computed steady-state temperature profiles matched measured temperature profiles in the six boreholes with Q-temperature data. Several non-Q measured temperature profiles (Sass et al. 1988) were used as corroborative data. 6.3.3 Calibration of Ambient Temperature The temperature profiles are controlled by many factors, such as the formation thermal conductivity, the geothermal gradient, and the ambient infiltration. Because of the small range of ) ( ref ref s Z Z T T - - = . Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 69 March 2000 uncertainties associated with measured thermal conductivities, the temperature calibration may be conducted using either ambient infiltration or temperature gradient data or both. In this report, we fixed the ambient infiltration rate and only calibrated the temperature conditions along the bottom and top boundaries because there is insufficient temperature data collected along these boundaries. The ambient temperature condition was calibrated using the 3-D calibration grid (DTN: LB990501233129.002 and CRWMS M&O 1999d), an ECM mesh. The simulations were performed using TOUGH2 V1.4 with the EOS3 module. The rock properties of the ECM formulation were obtained from the 1-D inversion (DTN: LB997141233129.001), thermal properties (DTN: LB991091233129.001), and UZ fracture properties (DTN: LB990501233129.001). We use the definition of parameters in the ECM model to obtain an equivalent set of ECM properties directly from the dual-permeability property set (Table II-7). Thermal conductivities are treated as a linear function of liquid saturation between their dry and wet values. The infiltration was the base-case, present-day, mean infiltration scenario. Table 6-12 shows the boreholes and the corresponding column names used in the 3-D calibration of model ambient temperature. The last three columns give the x- and y-coordinates of grid columns, the absolute distance between the coordinates of the boreholes (in GFM 3.1) and the nearest gridblock center. The corresponding simulated temperature profiles for the boreholes were extracted from the TOUGH2 output. Figure 6-16 shows the calibrated and measured temperature profiles in the Q-temperature boreholes. The figures show a reasonable match between measured and simulated temperature using the specified boundary conditions and the infiltration rate. However, near the ground surface in five of the boreholes, observed temperature show significant seasonal variations. However, these seasonal changes in surface temperature have little impact on steadystate heat flow in the deeper (more than 20 meters) UZ. Table 6-12. Boreholes with Qualified Data Used in Calibration of UZ Ambient Temperature Distribution Borehole Element Column Nevada Coordinates of Element Columns Distance to Boreholes (m) E-W (m) N-S (m) NRG-6 I61 171956.0 233687.0 13.8 NRG-7A k 3 171569.5 234372.4 33.2 SD-12 k61 171169.6 232292.8 49.0 UZ#4 i67 172551.0 234293.0 14.4 UZ#5 i67 172551.0 234293.0 26.9 UZ-7 e37 171379.7 231799.8 59.4 DTN: LB990501233129.004 NOTES: 1. XXXXq = boreholes with Q-temperature data used in model calibration 2. dist (m) is the absolute distance between the nearest grid column coordinates (x_ele, y_ele) and the borehole location (in GFM 3.1). Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 70 March 2000 Data - See Table 4.1 Model Results - DTN: LB991131233129.004, GS970808312232.005 Figure 6-16. Measured and Modeled Ambient Temperature Profiles for the Q-boreholes, with the Present-Day Mean Infiltration. model temperature 0 10 20 30 40 50 -100 0 100 200 300 400 500 UZ#4 3/31/98 UZ#4 12/20/97 UZ#4 6/29/97 Temperature (degC) model temperature model temperature 0 10 20 30 40 50 -100 0 100 200 300 400 500 NRG-6 3/31/98 NRG-6 12/20/97 NRG-6 8/31/96 Temperature (degC) 0 10 20 30 40 50 -100 0 100 200 300 400 500 SD-12 9/30/97 SD-12 6/29/97 SD-12 6/30/96 model temperature Temperature (degC) model temperature 0 10 20 30 40 50 -100 0 100 200 300 400 500 NRG-7a 3/31/98 NRG-7a 12/20/97 NRG-7a 9/30/97 Temperature (degC) model temperature 0 10 20 30 40 50 -100 0 100 200 300 400 500 UZ#5 3/31/98 UZ#5 12/20/97 UZ#5 9/30/97 Temperature (degC) 0 10 20 30 40 50 -100 0 100 200 300 400 500 UZ-7a 3/31/98 UZ-7a 12/20/97 UZ-7a 12/31/96 Temperature (degC) Depth (m) Depth (m) Depth (m) Depth (m) Depth (m) Depth (m) Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 71 March 2000 Based on DTN: LB991131233129.004 Figure 6-17. Model Ambient Temperature Distribution at the Water Table with the Present-Day, Mean Infiltration. Figure 6-17 shows the contour plot of calibrated temperature distribution at the water table. This temperature distribution can be used for simulations in which the model boundary temperature needs to be fixed at the water table. The average temperature at the water table (730 masl) ranges from 28–33oC over the model domain. 1.68E+05 1.70E+05 1.72E+05 1.74E+05 1.76E+05 Nevada Coordinate (m) (E-W) 2.30E+05 2.31E+05 2.32E+05 2.33E+05 2.34E+05 2.35E+05 2.36E+05 2.37E+05 2.38E+05 2.39E+05 Nevada Coordinate (N-S) (m) temp 33.0 32.5 32.0 31.5 31.0 30.5 30.0 29.5 29.0 28.5 28.0 27.5 27.0 26.5 26.0 C o >_ Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 72 March 2000 Based on calibration results, the simulated ambient temperature distribution in the UZ Model can be used to specify steady-state, mountain-scale temperature conditions. The distribution was computed using an ECM formulation of the calibration grid and using present-day, mean infiltration, and base-case properties. Although this temperature distribution is strictly calibrated only under these ECM model conditions, it should be applicable with different model formulations such as the dual-permeability approach. This is because the ambient heat flow is controlled by the steady-state heat conduction process, in which case the ECM model predicts similar results to those from dual-permeability model (Doughty 1999). 6.4 ANALYSIS AND MODELING OF PORE-WATER CHEMICAL DATA This study is part of continuing efforts to analyze and model the geochemical data in the unsaturated zone at Yucca Mountain. The studies use the geochemical model to evaluate the hydrologic system, and assess the magnitude and spatial distribution of surface net infiltration over time (Sonnenthal and Bodvarsson 1999). The UZ system of Yucca Mountain has been the subject of intensive geological, hydrologic, and subsurface engineering studies. One of the main issues is the percolation flux at the potential nuclear waste potential repository. Percolation flux strongly depends on the infiltration rates and their spatial distribution. Much work has been done to estimate the infiltration flux based on various evapotranspiration models (Hevesi et al. 1992; Flint and Flint 1994), and the present mean infiltration rate across the study area has been estimated as low as one millimeter per year to as high as several tens of millimeters per year. The climate change over the past 100,000 years has been used to estimate the possible range in infiltration rates over the next 10,000 years (Sonnenthal and Bodvarsson 1999). Geochemical data provide additional information to analyze the UZ system. Pore-water chemical concentration data have been used to calibrate the UZ model to bound the infiltration flux, flow pathways, and transport time. Distribution of chemical constituents in both liquid and solid phases of the UZ system depends on many factors, such as hydrological and geochemical processes of surface precipitation, evapotranspiration, the fracture-matrix interactions of flow and transport, large-scale mixing via lateral transport, and history of climate changes and recharge. A dualpermeability transient model is necessary to investigate fluid flow and chemical transport phenomena and represent the large spatial and temporal chemical variations. In this study, pore-water chemical concentration data are analyzed and modeled by 3-D chemical transport simulations and analytical methods. Water infiltration-rate calibrations are performed using the pore-water chloride concentrations. Model results of chloride distributions were improved in matching the observed data when the calibrated infiltration rates were used. In addition, an analytical method was applied to analyze transient transport of chemicals. This method was verified by 3-D simulations as able to capture major chloride and chlorine-36 transient behavior and trends. The combined data of chloride and chlorine-36 distributions in the UZ groundwater furnish important information for the UZ Model calibrations. Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 73 March 2000 6.4.1 Available Data 6.4.1.1 Pore-water Chemical Concentration Data Geochemical data available and applied to this study were pore-water concentrations of chloride (Cl), sulfate (SO4), strontium (Sr), and bromine (Br), and the ratio of chloride-36 (36Cl) to chloride (36CI/Cl). Pore-water samples were mainly collected from eight boreholes: NRG-6, NRG-7A, SD-7, SD-9, SD-12, UZ#4, UZ#14, and UZ#16 (Data Sources: DTN: LA9910JF12213U.007), the ECRB tunnel, the ESF tunnel, including South Ramp, North Ramp, and Main Drift (Data Sources: DTN: LASL831222AQ98.002, DTN: LA9910JF12213U.013). The detailed description of these data was given in several reports (e.g. Yang et al. 1998). 6.4.1.2 Infiltration Flux Data The net infiltration flux in the base-case study was from the present-day, mean or modern infiltration map (Table 6-3 and Figure 6-18). Based on studies of Cl chemistry presented in Sonnethal and Bodvarsson (1999, p. 148, Figure 23), the glacial maximum infiltration rate was about 28 mm/year and the modern mean infiltration was approximately 5 mm/year. As an approximation, a glacial infiltration scenario in this section was obtained by multiplying the present-day mean infiltration rate by a factor of 5 with the same distribution pattern. Surface chloride flux includes dissolved material in rain, particulate in snow, and a contribution from windblown dusts (Tyler et al. 1996). Either chloride concentration in infiltrating water or total surface chloride flux can be input into the model. Combining the mean annual precipitation of about 170 mm/year with a present day chloride surface flux of 106 mg/m2 year yields a mean chloride concentration of about 0.62 mg/l (Fabryka-Martin et al., 1997, Sonnenthal and Bodvarsson 1999). Surface chloride flux of this study was obtained applying the mean chloride concentration of precipitated water (which combines infiltrating water in the form of precipitation, run on, and runoff). The same mean chloride concentration was applied to glacial total water precipitation to derive a glacial chloride flux. The 36Cl/Cl ratio in infiltrated water was assumed to be 500 x 10-15 during modern times and 1000 x 10-15 during glacial times (Sonnenthal and Bodvarsson 1999). 6.4.2 Modeling Approaches 6.4.2.1T hree-Dimensional Simulations The system was assumed to be under two-phase isothermal flow conditions of water and air. A three-dimensional dual-permeability model and the T2R3D V1.4 (Section 4) of the TOUGH2 code, which takes into account tracer diffusion, dispersion, radioactive decay, and linear firstorder adsorption (Sonnenthal and Bodvarsson, Section 5.1, 1999), were employed for the simulations. The steady-state liquid-flow fields were obtained using the EOS9 module of T2R3D, as discussed in Section 6.1. Chemical distributions were then computed from transport equations using the decoupled T2R3D module. The flow boundary conditions, simulation grids, basic hydrologic properties of rock matrix and fractures are the same as those used in the 3-D UZ nonperched water model flow simulations described in Section 6.1. Boundary conditions for Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 74 March 2000 chemical components were treated similarly to those for flow simulations, with mass fluxes described at the top boundary, and no-flow and water table conditions at the lateral and bottom boundaries, respectively. The dispersivities for both fracture and matrix continua in the simulation were assumed to be zero (Sonnenthal and Bodvarsson 1999). Diffusion coefficients used were those for chemical ions at 25oC and infinite dilution in water (Lasaga 1998). The tortuosity was set to 0.7 for fracture and 0.2 for matrix (Section 6.8.1), respectively. 6.4.2.2 Analytical Method For transport dominated by vertical flow and porous media of ECM type, the analytical method provides an alternative interpretation of chemical transient transport, which could be difficult by 3-D simulations. It is also efficient in conducting flow parameter sensitivity studies qualitatively. Transient transport modeling in this section was analyzed using an analytical solution for a onedimensional semi-infinite chemical-transport system (Javandel et al. 1984, p.14-18): (Eq. 2) where C0 [mg/l] is the system initial chemical concentration at t=0 [s], C1 [mg/l] the concentration at the surface (z=0 [m]}, v [m/s] the pore velocity, D [m2/s] the dispersion coefficient, and . [1/s] the chemical decay constant. The dispersion coefficient is evaluated by (Eq. 3) with the dispersivity a [m] and the molecular diffusion coefficient Dm [m2/s]. The solution becomes (Eq. 4) in the case of no decay, and (Eq. 5) for steady state. The analytical solution was applied to 1-D columns extracted from 3-D simulation model domain. Average column porosity was calculated by the total pore volume and bulk volume of the column, including both fracture and matrix volumes. . . . . . . . . .. . .. . + . .. . . . . . + + + .. . .. . - . . . . . . . . + - - + = Dt vt z erfc z D D v v Dt vt z erfc z D D v v C C C z t C 2 2 4 exp 2 2 4 exp ) ( 2 1 ) , ( 2 2 0 1 0 . . m D v D + = a .. . .. . .. . .. . + .. . .. . + .. . .. . - - + = Dt vt z erfc D vz Dt vt z erfc C C C z t C 2 exp 2 ) ( 2 1 ) , ( 0 1 0 . . . . . . . . + - - + = z D D v v C C C z C 2 4 exp ) ( ) ( 2 0 1 0 . Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 75 March 2000 6.4.3 Modeling Results and Analyses Pore-water chemical-concentration data were analyzed using 3-D transport simulations and analytical methods. Water infiltration rate calibrations were performed by calculating infiltration rates with measured pore-water Cl concentrations. As a result, modeled results of Cl and 36Cl/Cl distributions were improved with the calibrated infiltration rates. An analytical method was applied to the transient-transport analysis. This method, verified by the 3-D simulations under the same flow and transport conditions, was able to capture major Cl and 36Cl transient transport behavior and trends. 6.4.3.1 Water Infiltra tion Cali bration A base-case simulation was conducted using the present-day (modern), mean infiltration rate (Table 6-3 and Figure 6-18) to compare the uncalibrated model with observed chloride data. Note that Figure 6-18 uses different scales of flux from Figure 6-3 for the same infiltrate map. Input: DTN: GS000399991221.004 Figure 6-18. Present-Day, Mean Infiltration Map Chloride concentrations predicted by the steady-state transport simulation were compared with measured pore-water chloride concentration data. The results of the simulated and measured concentrations along the stations in the ESF, ECRB, and borehole UZ#16 are shown in Figures 6- 19 through 6-21, respectively. Compared to the measurements, the simulated Cl concentrations are higher at the North Ramp (0-2,000 m), South Ramp (6,400 m-8,000 m), the northeast side of 170000 172000 174000 Nevada Coordinate E-W (m) 230000 232000 234000 236000 238000 Nevada Coordinate N-S (m) 10 9 8 7 6 5 4 3 2 1 0 PRESENT DAY (MEAN) INFILTRATION (mm/year) mm/year = Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 76 March 2000 the ECRB (left side of the figure), and borehole UZ#16, and lower at the southwest end of the ECRB (right side of the figure). These differences may result from the infiltration variations, as demonstrated in Figure 6-22, showing a plot of Cl infiltration along the ECRB. At the entrance of the ECRB, higher simulated Cl concentrations correspond to very low infiltration rates, while at the end of the ECRB, extreme higher infiltration leads to lower simulated values of Cl concentrations. The distribution of Cl concentration in infiltrated water shown in Figure 6-23 confirms the significant effect infiltration rates have on Cl distributions and the need to calibrate infiltration. The infiltration rate calibration proceeds from the relationship between water and Cl influxes, and Cl concentration at the surface (Sonnenthal and Bodvarsson 1999, p. 121). (Eq. 6) where JI [kg/s] is the water infiltration (mass) flux, JCl [kg/s] the chloride flux, CCl,I [kg/kg] the mass fraction of Cl in the infiltrated water. Applying Equation 6 with Cl concentration in infiltrated water estimated by the measured porewater Cl concentration data, a modified water infiltration map can be developed, as shown in Figure 6-24. The domain was divided into nine regions based on the observation of the measured Cl data range. The infiltration rate is approximated using an average value of the present-day, mean infiltration scenario (Figure 6-18) in regions where pore-water data is unavailable (Regions I, II and VIII). A comparison of infiltration rates in different regions of the model domain is given in Table 6-13. Simulation results using the calibrated water infiltration map are shown in Figures 6-25 through 6-27. Improvements can be seen when these results are compared with the results in Figures 6-19 through 6-21 using the original calibration rates. 6.4.3.2 Transient Transport The 36Cl/Cl ratios have been used to infer the ages of waters at depth and to locate rapid flow regions. Chloride and 36Cl concentrations at ESF and ECRB stations were calculated using the 1- D analytical solution to each column of the 3-D calibration grid over the model domain. The assumed glacial infiltration rates, corresponding Cl and 36Cl fluxes, and zero initial Cl and 36Cl concentrations were first applied to estimate a glacial steady-state distribution of Cl and 36Cl concentrations. Chloride concentrations and 36Cl/Cl ratios at different modern times were then computed using the calibrated present-day infiltration rates and modern Cl and 36Cl fluxes with the glacial steady-state Cl and 36Cl results as initial concentrations. I Cl Cl I C J J , = Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 77 March 2000 Transport parameters and the radioactive-decay constant were the same as those used in the 3-D simulations. Porosity input was based on the simulation input rock data and converted from dualcontinua type to effective-continuum type. The analytical solutions were first verified by 3-D transport simulations, in which flow fields of both glacial and modern times were assumed at steady state, with all other input parameters the same as those used for the analytical solutions. Figure 6-28 shows good agreement in the comparisons of ESF Cl concentrations at 15,000 years by the two methods. Chloride concentrations at ESF and ECRB stations, and (36Cl/Cl ratio at ESF stations at 10,000, 15,000 and 18,000 years modern times) were computed and plotted in Figures 6-29 through 6-31 against the observed pore-water concentration data. The model solutions are within the range of measured data and able to match major transient-transport behavior and trends. 6.4.3.3 Analysis of Sulfate Data The sulfate analysis provides an alternative interpretation to estimate infiltration rates. The calibration results can be important at places where significant amount of pore-water chemical data are available. The sulfate discussion demonstrates an example of uncertainties in the interpretation of chemical data, and additional information on infiltration, flow mechanism, and climate-change effects is needed in further chemical transport investigations. To study the SO4 distributions, pore-water SO4 concentrations from all available boreholes (NRG-6, NRG-7A, SD- 7, SD-9, SD-12, UZ-14, and UZ#16) and the ESF were averaged by each hydrologic unit, and the results were compared with the same Cl averages in Figure 6-32. The SO4/Cl ratio indicates that SO4 concentrations are higher than Cl concentrations in TCw and PTn, but lower than Cl concentrations in the TSw and CHn units. A preliminary 3-D simulation with SO4 precipitated concentration and SO4 molecular diffusion coefficient was unable to predict these vertical variations. Additional information on infiltration, flow and transport mechanism, and climate-change effects may be needed in further investigations of the geochemistry at Yucca Mountain. Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 78 March 2000 Data - DTN: LAJF831222 DQ99.004, Model Results - DTN: LB991131233129.003 Figure 6-19. ESF Cl Concentrations by 3-D Simulation with the Present-Day, Mean Infiltration. Data - DTN: LAJF831222 DQ99.004, Model Results - DTN: LB991131233129.003 Figure 6-20. ECRB Cl Concentrations by 3-D Simulation with the Present-Day Mean Infiltration. 0 50 100 150 200 250 0 1000 2000 3000 4000 5000 6000 7000 8000 ESF Station [m] Cl [mg/L] Field Data Simulation North Ramp South Ramp Cl[mg/L] Concentration 0 20 40 60 0 500 1000 1500 2000 2500 ECRB Station [m] Cl [mg/L] Field Data Simulation SW NE Cl Concentration [mg/L] Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 79 March 2000 Data - DTN: LA9910JF12213U.0007 Model Results - DTN: LB991131233129.003 Figure 6-21. Borehole UZ#16 Cl Concentrations by 3-D Simulation with the Present-Day, Mean Infiltration. Data - DTN: LAJF831222 DQ99.004, Model Results - DTN: LB991131233129.003 Figure 6-22. Infiltration at ECRB Stations and Cl 3-D Simulation Results Using the Infiltration. 700 800 900 1000 1100 1200 0 100 200 300 400 500 Cl [mg/L] Elevation (m) Field Data Simulation PTn TSw CH PP TCw 0 20 40 60 0 500 1000 1500 2000 2500 ECRB Station [m] Cl Concentration [mg/L] 0 20 40 60 Water Infiltration [mm/yr] Cl Field Data Simulation Infiltration Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 80 March 2000 Data - DTN: LAJF831222 DQ99.004, Model Results - DTN: LB991131233129.003 Figure 6-23. Cross Drift Cl Infiltration Concentration Based on the ECRB Infiltration. 1 10 100 1000 0 500 1000 1500 2000 2500 ECRB Station [m] Field Cl Data Using USGS-99 Infiltration Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 81 March 2000 DTN: LB991131233129.003 Figure 6-24. Calibrated Infiltration Map Table 6-13. Infiltration Data by Region 170000 172000 174000 Nevada Coordinate E-W (m) 230000 232000 234000 236000 238000 Nevada Coordinate N-S (m) 10 9 8 7 6 5 4 3 2 1 0 mm/year Region Present-Day Mean Calibrated I 9.9 25.5 104732 59 104708 58 10.60 10.60 II 5.3 13.8 12353 7 12262 7 2.32 2.30 III 3.7 9.6 26341 15 25910 14 7.12 7.00 IV 3.6 9.4 8844 5 8718 5 2.43 2.40 V 4.6 11.9 12545 7 13835 8 2.72 3.00 VI 2.2 5.6 2486 1 2168 1 1.15 1.00 VII 1.8 4.6 3355 2 2662 1 1.89 1.50 VIII 3.0 7.7 2162 1 2140 1 0.73 0.72 IX 4.7 12.0 5010 3 6993 4 1.07 1.50 Overall 38.7 100.0 177828 100 179396 100 4.6 4.6 Infiltration Rate Infiltration Volume Area Present-Day Mean Calibrated mm/yr km2 % m3/yr % m3/yr % mm/yr Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 82 March 2000 Data - DTN: LAJF831222 DQ99.004, Model Results - DTN: LB991131233129.003 Figure 6-25. ESF Cl Concentrations by 3-D Simulation with Calibrated Infiltration. Data - DTN: LAJF831222 DQ99.004, Model Results - DTN: LB991131233129.003 Figure 6-26. ECRB Cl Concentrations by 3-D Simulation with Calibrated Infiltration. 0 50 100 150 200 250 0 1000 2000 3000 4000 5000 6000 7000 8000 ESF Station [m] Cl [mg/L] Field Data Uncalibrated Infiltration Calibrated Infiltration Cl Concentration [mg/L] 0 20 40 60 0 500 1000 1500 2000 2500 ECRB Station [m] Cl [mg/L] Field Data Uncalibrated Infiltration Calibrated Infiltration Cl Concentration [mg/L] Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 83 March 2000 Data - DTN: LA9910JF12213U.0007 Model Results - DTN: LB991131233129.003 Figure 6-27. Borehole UZ#16 Cl Concentrations by 3-D Simulation with Calibrated Infiltration. Data - DTN: LAJF831222 DQ99.004, Model Results - DTN: LB991131233129.003 Figure 6-28. ESF Cl Concentrations by Analytical Method and 3-D Simulation. 700 800 900 1000 1100 1200 0 100 200 300 400 500 Cl Concentration [mg/L] Elevation (m) Field Data Calibrated Infiltration Uncalibrated Infiltration PTn TSw CH PP TCw 0 20 40 60 80 100 0 1000 2000 3000 4000 5000 6000 7000 8000 ESF Station [m] Cl [mg/L] Field Data Analytical Solution 3D Simulation t=15,000 yrs Cl Concentration [mg/L] Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 84 March 2000 Data - DTN: LAJF831222 DQ99.004, Model Results - DTN: LB991131233129.003 Figure 6-29. Analytical Results of Cl Transient Distributions at ESF Stations. Data - DTN: LAJF831222 DQ99.004, Model Results - DTN: LB991131233129.003 Figure 6-30. Analytical Results of Cl Transient Distributions at ECRB Stations. 0 20 40 60 80 100 0 1000 2000 3000 4000 5000 6000 7000 8000 ESF Station [m] Cl [mg/L] Field Data 10,000 yrs 15,000 yrs 18,000 yrs Analytical Solutions 0 20 40 60 0 500 1000 1500 2000 2500 ECRB St at ion [m Field Dat a 1 0 ,0 0 0 yrs 1 5 ,0 0 0 yrs 1 8 ,0 0 0 yrs Analy t ica l Solut ions Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 85 March 2000 Data - DTN:LASL831222AQ98.002 Model Results - DTN: LB991131233129.003 Figure 6-31. Analytical Results of 36Cl/Cl Transient Analyses at ESF Stations. DTN: LA9910JF122130.007 Figure 6-32. Pore-water Cl, SO4 Concentrations and SO4/Cl Ratios by Hydrogeologic Units. 0 200 400 600 800 1000 1200 0 1000 2000 3000 4000 5000 6000 7000 8000 ESF Station [m] 36Cl/Clx10-15 Field Data 10,000 yrs 18,000 yrs 15,000 yrs Analytical Solutions 0 20 40 60 80 TCw PTn TSw CH PP Cl, SO4 Concentrations [mg/L] 0.0 0.5 1.0 1.5 SO4/Cl Ratio SO4 Cl SO4/Cl ratio I Title: UZ Flow Models and Submodels uooso The CHn unit (below the TSw) was not considered in the geochemical simulations because: (1) lateral flow may occur in the CHn and (2) the CHn has abundant zeolites and volcanic glass for which thermodynamic and kinetic data are more poorly known. The exclusion of the CHn unit doesn’t affect the results on upper units because flow is predominantly gravity-driven, and backward diffusion is not important over the large vertical distance between the potential repository horizon and the CHn. Boundary water and gas chemistry: Two types of chemical compositions were used for the top boundary of the hydrochemical transport simulations. The first water type (Table 6-14) was the average Topopah Spring Tuff water calculated from several observation samples (Scientific Notebook: YMP-LBNL-YWT-NS-1, pp. 78-79). The second water type was a measured TSw pore water extracted from a drill core from Alcove 5 in the Tptpmn (CRWMS M&O 2000d, Table 3), which has a higher Ca concentration. These two waters are slightly oversaturated with respect to calcite. These two water compositions merely provide some possible compositions that span a fairly wide range Ca concentration for the UZ pore waters that have been analyzed above the zeolitic units. Oxidizing conditions were considered for both waters. The boundary water type applied here is considered to be the water after transformation by soil zone processes. Finally, the initial water chemical composition used was uniform throughout the column for both the fracture and matrix blocks, and was adopted from the average TSw water (Type 1). LTable 6-14. Aqueous and Gaseous Chemical Concentrations (mg/L) Used for Initial and Boundary Conditions of Hydrochemical Transport Simulations. Water type I 1 2 . Component Ca2+ Mg2+ Na+ K+ Average TSw water 27 5 91 4 Measured TSw water 101 17 61.3 6 SiWaq) 60 70.5 AIJ’ 9.92x10-’ (5) 9.92x10-‘(1) HCOj (3) 219 200 C l 41 117 SO4 2- 40 116 F- 0.86 0.86 MDL-NBS-HS-000006 REV00 8 9 March 2000 Title: UZ Flow Models and Submodels U0050 Table 6-14. Aqueous and Gaseous Chemical Concentrations (mg/L) Used for Initial and Boundary Conditions of Hydrochemical Transport Simulations. (Cont.) PC02 (bar) (4) 1.322x10-3 DTN: L6991131233129.001 NOTES: 8.565x10-4 (1) Calculated by equilibrating with Ca-smactite at 25 °C (2) Calculated by equilibrating with hematite at 25 °C (3) Total aqueous carbonate as HCO3, calculated from charge balance computed by speciation at 25 °C. (4) Calculated at equilibrium with the solution at 25 °C. (5) Total aqueous Al and Fe are set equal to those of Type 2 water. In addition to aqueous species transport and reaction in water, we considered the diffusive transport of CO, in the gas phase and equilibration with pore water. The CO, gas partial pressures used for initial and top boundary conditions are in equilibrium with the corresponding aqueous chemical composition (the bottom row of Table 6-14). The elevated gas partial pressure (relative to atmospheric value 0.344~10-~ bar) at the upper boundary is uncertain, depending on soil-zone CO, production capability, which varies from location to location. The water chemical composition, especially pH, is controlled primarily by the CO2 partial pressure. Simulations: Two groups of simulations were performed. The first group of simulations were designed to analyze calcite deposition affected by infiltration (percolation) rate and reaction rate. These simulations were based on the NRG-‘IA borehole column with a simple mineralogy. For reporting purposes, this set of simulations is called “NRG-‘IA simulations”. The second group of simulations was based on the borehole WT-24 column where measured calcite deposition data are available for comparison. Both sets of simple and complex mineralogy were used. The second group of simulations is called “WT-24 simulations”. A total simulation time of 10 million years was carried out for all simulations. This simulation time was selected based on mineral growth having remained approximately constant over the past eight million years, as indicated by radiocarbon, 23%I-VU, and U-Pb ages, and on all dated surfaces indicated by ages of outer mineral surfaces being young compared to the 12.7-million year age of the host tuffs (CRWMS M&O 2000a). 6.5.4 NRC-7A Simulations In this section, the sensitivity analysis results of calcite deposition to infiltration (percolation) rate and reaction rate are reported. Simulation setup: First, we used a base-case infiltration rate of 0.2119 mm/yr (DTN GSOOO399991221.002.; ACC: MOL. 19991014.0102), then two additional infiltration rates of 2 and 10 mm/yr. yr. Water Type 1 presented in Table 6-14 were used for the top boundary chemical transport conditions. Estimates of field mineral dissolution and precipitation rates MDL-NBS-HS-OOOOO6 REV00 90 March 2000 Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 91 March 2000 rates of 2 and 10 mm/yr. Water Type 1 presented in Table 6-14 were used for the top boundary chemical transport conditions. Estimates of field mineral dissolution and precipitation rates covered a wide range of values. We first used the reactive areas based on the initial estimated data. For the purpose of this analysis, we then reduced the areas by one order and two orders of magnitude. Scaling all rate constants (surface areas) by the same factor is justified for calcite precipitation in the simple mineralogy system because silica mineral dissolution and precipitation are not directly related to calcite precipitation. However, for the complex mineralogy system, scaling all rate constants (surface areas) by the same factor may not be sufficient. In the complex case, relative scaling of the reactive surface areas may be more appropriate, but there is no information on which to base such an approach at present. Simulations were performed using a different infiltration rate and reactive surface area (indicator of reaction rate). (Details are given in Xu's Scientific Notebook YMP-LBNL-GSB-TX-1, p. 30). Results: We expressed the simulated changes of calcite volume fraction as the average among the matrix and the fractures (calculated by calcite volume in the matrix and fractures divided by the total matrix and fracture solid volume). The calcite precipitation generally increases as infiltration rate increases, especially in the TSw unit (Figure 6-33; more results are given in Xu's Scientific Notebook YMP-LBNL-GSB-TX-1, p. 33). An increase of infiltration results in a slight change in the amount of calcite at the bottom of the PTn unit. DTN: LB991131233129.001 NOTE: (a) Estimated reactive surface areas denoted by Ao, (b) Use of reactive surface areas Ao×10-1 Figure 6-33. Change of Calcite Volume Fraction with Infiltration Rate after 10 Million Years in the NRG-7A Column Using the Type 1 Water for the Top Boundary of Chemical Transport The calcite distribution is also dependent on reaction rate, which was achieved by changing the reactive surface area (Figure 6-34). For the welded TCw unit close to the land surface, the higher the reaction rate, the higher the calcite precipitation. For the deeper welded TSw unit, the highest surface areas (estimated) result in the lowest calcite precipitation. The shift of calcite precipitation 1E+0 1E+1 1E+2 1E+3 1E+4 1E+5 Change o f volume f raction (ppmV) 800 900 1000 1100 1200 1300 Elevation (m) ------------------------------------------- TCw --------------------------------------------- PTn TSw 10 2 0.2119 Infiltration rate (mm/yr) 1E+0 1E+1 1E+2 1E+3 1E+4 1E+5 Change o f volume f raction (ppmV) 800 900 1000 1100 1200 1300 Elevation (m) ------------------------------------------- TCw --------------------------------------------- PTn TSw 10 2 0.2119 Infiltration rate (mm/yr): Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 92 March 2000 from the TCw to the TSw mainly results from the TCw being close to the top boundary, where percolation water and reactants of calcite are applied. Therefore, much more calcite precipitation occurs in the TCw than in the TSw. Increasing the areas by two orders of magnitude showed the same general trend as the initial estimated areas. The surface areas reduced by one order of magnitude from the initial estimated data give the most favorable conditions for calcite formation in the TSw unit. Based on DTN: LB991131233129.001 NOTE: (a) 10 mm/yr infiltration rate, (b) 2 mm/yr infiltration rate Figure 6-34. Change of Calcite Volume Fraction with Reactive Surface Area after 10 Million Years in Borehole NRG-7A Column Obtained Using the Average TSw Water for the Top Boundary of Chemical Transport 6.5.5 WT-24 Simulations In this section, we report the WT-24 simulation results using two different sets of mineralogy (simple and complex) and water chemistry. Simulation setup: We used three infiltration rates, a base-case rate of 5.92 mm/yr (DTN: GS000399991221.002.; ACCN: MOL. 19991014.0102), an additional lower rate of 2 mm/yr, and a higher rate of 20 mm/yr. An upper rate of 10 mm/yr was not chosen as it was for the previous NRG-7A simulations because the base-case rate is greater than that of the previous (5.92 over 0.2119 mm/yr). Two boundary types of water chemical compositions, average TSw water and measured TSw water (Table 6-14), were employed for the top boundary of the model. A total of nine simulations were performed using different infiltration rates, boundary water and gas chemistries, and reactive surface areas, which are summarized in Table 6-15. (a) (b) 1E+0 1E+1 1E+2 1E+3 1E+4 1E+5 Change of volume f raction (ppm V) 800 900 1000 1100 1200 1300 Elevation (m) ------------------------------------------- TCw --------------------------------------------- PTn TSw A0 A0E-1 A0E-2 A0: initial estimated reactive surface areas 1E+0 1E+1 1E+2 1E+3 1E+4 1E+5 Change o f volume f raction (ppmV) 800 900 1000 1100 1200 1300 Elevation (m) ------------------------------------------- TCw --------------------------------------------- PTn TSw A0 A0E-1 A0E-2 A0: initial estimated reactive surface areas Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 93 March 2000 . Results: Simulations 1, 2, and 3 use the same average TSw water (Type 1), simple mineralogy, and reactive surface areas. The reactive surface areas used for the welded TCw and TSw units were reduced by one order of magnitude from the initial estimated data, and those for the nonwelded PTn unit were reduced by two orders of magnitude. The surface-areas were reduced because at the field-scale multimineral system all mineral surfaces may not be in contact with the percolating waters. Reactive surface areas used in the simulations were modified somewhat to match measured calcite data. One order more surface-area reduction in the PTn was according to fewer fractures in this unit. A different infiltration rate was employed for each simulation. The changes of calcite volume fraction are presented in Figure 6-35 for Simulations 1-3, together with measured calcite deposition data in the WT-24 cuttings (the comparison with the measured data will be discussed in a later section). The resulting calcite precipitation in the nonwelded PTn was decreased because of the reduction of the reactive surface areas (compare Figure 6-35 with Figures 6-33 and 6-34). Table 6-15. List of Simulations Performed for Borehole WT-24 Column Using Different Combinations of Infiltration Rate, Boundary Water Chemical Composition, Initial Mineralogy, and Reactive Surface Areas. Simulation Infiltration Rate (mm/yr) Water and Gas Chemistry Mineralogy Surface Area (A0 are referred areas of minerals) 1 2 3 4 5 6 7 8 9 5.92 2 20 5.92 5.92 5.92 2 20 5.92 Type 1 in Table 6-14 “ “ “ “ Type 2 in Table 6-14 “ “ “ Simple Simple Simple Complex Complex Complex Complex Complex Simple A0x10-2 for PTn unit, A0x10-1 for others same as simulation 1 same as simulation 1 A0x10-1 A0x10-1 for calcite, A0x10-3 for others same as simulation 5 same as simulation 5 same as simulation 5 same as simulation 1 Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 94 March 2000 Data - CRWMS M&O (2000a; Figure 53) Model Results - DTN: LB991131233129.001 Figure 6-35. Simulated Changes of Calcite Volume Fraction (Lines) Using Simple Mineralogy with Infiltration Rate after 10 Million Years in Borehole WT-24 Column Together with Measured Calcite Deposition Data (In Diamond Symbols) that are Taken from the Analysis of Geochemical Data for the Unsaturated Zone (CRWMS M&O 2000a, Figure 53). Unlike Simulation 1, Simulation 4 used complex mineralogy. Both simulations employ the same infiltration rate (5.92 mm/yr) and average TSw water-chemical composition (Type 1). The reactive surface areas used in Simulation 4 are reduced by one order of magnitude from the initial estimated data. No calcite precipitation was obtained from Simulation 4 because the other minerals (such as clay) were given very large reactive surface areas. Therefore, Ca was taken up by the Ca-bearing clay and zeolite minerals. (In a field-scale multimineral system, all the clay mineral physical surface areas may not effectively be in contact with the infiltration water). In Simulation 5, we reduced the surface areas by three orders of magnitude for all minerals except for calcite, whose area remained the same (reduced by one order of magnitude) to reflect the lesser water contact by the clays. Results for Simulations 1 and 5 are presented in Figure 6-36. Generally, calcite precipitation obtained with the complex mineralogy was much smaller than that with the simple mineralogy. Only one model layer at the bottom of the PTn unit was exceptional. This layer had a higher matrix water content (or higher water saturation and porosity) than that at the top layer of the TSw unit (Xu, Scientific Notebook, YMP-LBNL-GSB-TX-1, p. 41, Figure 14). Water can reside in the bottom of the PTn for a longer time, potentially precipitating more calcite. 1E+0 1E+1 1E+2 1E+3 1E+4 1E+5 1E+6 Change of volume f raction (ppmV) 900 1000 1100 1200 1300 1400 1500 Elevation (m) TCw PTn TSw 5.92 20 2 Wate r type 1 In filtration rate (mm/yr) -------------------- --------------------- (average TSw water) Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 95 March 2000 Based on DTN: LB991131233129.001 Figure 6-36. Change of Calcite Volume Faction after 10 Million Years in the WT-24 Column under Different Mineralogy Conditions. The values of changes of calcite volume fraction under complex mineralogy in the PTn layers are much smaller than 2, and they are increased to a value of 2 for display purposes. Simulation 6 employs the measured water-chemical composition (Type 4) with a much greater Ca concentration (Table 6-14) than the average TSw water (Type 1) used in Simulation 5. The results for Simulations 5 and 6 are presented in Figure 6-37. More calcite precipitation occurs in the welded TCw and TSw units using the greater Ca concentration water. In both simulations, again no calcite precipitation occurs in the nonwelded PTn unit except at the bottom layer. 1E+0 1E+1 1E+2 1E+3 1E+4 1E+5 1E+6 Change o f vo lume fraction (ppmV) 900 1000 1100 1200 1300 1400 1500 Elevation (m) inf iltration rate: 5.92 mm/yr Average TSw water (Type 1) S imple Mineralogy: Complex Infiltration rate: 5.92 mm/yr Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 96 March 2000 Based on DTN: LB991131233129.001 Figure 6-37. Change of Calcite Volume Fraction with Water Type after 10 Million Years in the WT-24 Column. Simulations 7 and 8 employ, respectively, 2 and 20 mm/yr infiltration rates to analyze the dependence of calcite deposition on infiltration rate under the complex mineralogy conditions (Figure 6-38). Calcite precipitation increases in the welded TCw and TSw units as infiltration rate increases. This is consistent with the result under the simple mineralogy condition (Figure 6-35). 1E+0 1E+1 1E+2 1E+3 1E+4 1E+5 1E+6 Change o f volume fraction (ppmV) 900 1000 1100 1200 1300 1400 1500 Elevation (m) Inf iltration rate: 5.92 mm/yr Water type: Complex mineralogy (measured TSw water) TCw PTn TSw ---------------------------- ------------------------- 1 2 (average TSw water) Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 97 March 2000 Data - CRWMS M&O (2000a; Figure 53) Model Results - DTN: LB991131233129.001 Figure 6-38. Simulated Changes of Calcite Volume Fraction (Lines) Using Complex Mineralogy with Infiltration Rate after 10 Million Years in the WT-24 Column, Together with Measured Calcite Deposition Data (Diamond Symbols) that are Taken from the Analysis of Geochemical Data for the Unsaturated Zone (CRWMS M&O 2000a, Figure 53). Under the complex mineralogy condition, most of the calcite precipitates in the rock matrix (Figure 6-39), especially in the TCw unit, whereas under the simple mineralogy condition (Figure 6-40), almost all calcite precipitation occurs in the fractures for the TCw and PTn units. Some calcite precipitation in the matrix can be observed in the TSw unit, but its density is much lower than that in the fractures. The results indicate that chemical interaction of fracture-matrix is more significant in the complex mineralogy condition than in the simple mineralogy condition for calcite deposition. In the simple mineralogy system, the reactant Ca for calcite precipitation comes only from percolation water. Therefore, calcite precipitation occurs mostly in the preferential water flow path in the fractures. 1E+0 1E+1 1E+2 1E+3 1E+4 1E+5 1E+6 Change of volume fraction (ppmV) 900 1000 1100 1200 1300 1400 1500 Elevation (m) TCw PTn TSw 5.92 20 (measured TSW water) In filtration rate (mm/yr) Water type 2 2 Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 98 March 2000 Based on DTN: LB991131233129.001 Figure 6-39. Change of Calcite Volume Fraction in Fracture (Calculated by Fracture Calcite Volume Divided by Total Fracture and Matrix Solid Volume) and in Total (Same as the Previous Figures, or Calculated by Fracture and Matrix Calcite Volume Divided by Total Fracture and Matrix Solid Volume) under Complex Mineralogy Conditions (Using an Infiltration Rate of 5.92 mm/yr). Based on DTN: LB991131233129.001 Figure 6-40. Change of Calcite Volume Fraction in Fracture and in Total under Simple Mineralogy Conditions (Using an Infiltration Rate of 5.92 mm/yr). 1E+0 1E+1 1E+2 1E+3 1E+4 1E+5 1E+6 Change of volume f raction (ppmV) 900 1000 1100 1200 1300 1400 1500 Elevation (m) TCw PTn TSw Complex minerology Total (f racture + marix) Only f racture 1E+0 1E+1 1E+2 1E+3 1E+4 1E+5 1E+6 Change of volume f raction (ppmV) 900 1000 1100 1200 1300 1400 1500 Elevation (m) TCw PTn TSw Simple minerology Total (fracture + matrix) Only f racture Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 99 March 2000 6.5.6 Discussion and Conclusions Calcite precipitation values for the welded TCw unit obtained by using the simple mineralogy and the average TSw water (Type 1) are closer to the measured data than those obtained by using complex mineralogy and the measured TSw water (compare Figures 6-35 and 6-38). The simple mineralogy simulations also capture the calcite abundances in the nonwelded PTn unit more closely, except for the bottom layer. The improved agreement for the PTn unit is achieved by reducing the reactive surface area, which is consistent with the fact that fewer fractures occur in this unit. The simulated calcite precipitation values at the bottom of PTn unit may be overestimated for the WT-24 column, especially values from the complex-mineralogy simulation. However, according to measurements presented in the Mineralogic Model (DTN: LA9908JC831321.001) the high calcite concentrations at this layer have been observed at several other locations such as (USW G-2 Core). According to Analysis of Geochemical Data for the Unsaturated Zone (CRWMS M&O 2000a, Section 6.10), calcite coatings are frequently found on fractures and lithophysal cavities in the welded TCw and TSw tuffs. This finding is better represented by simple mineralogy simulations such as presented in Figure 6-40, where calcite precipitation occurs primarily in the fractures. This is especially true for the TCw unit close to the land surface, in which reactants of calcite deposition come primarily from percolation water. The calcite precipitation occurs mostly in the preferential water flow paths in the fractures. Thus, the simple mineralogy simulations may be closer to calcite deposition condition. The effects of complex mineralogy on simulations may result from the uncertainty of thermodynamic and kinetic data for clay minerals, which are poorly known at present. Measured calcite deposition varies significantly from location to location and depth to depth. Studies for the WT-24 column can give some general insight into calcite deposition conditions, but may not represent the whole picture at Yucca Mountain. For example, the peak values in the TSw observed in WT-24 cuttings are in contrast with calcite deposition in the Exploratory Studies Facility (ESF). According to the conclusion regarding calcite measurements in the ESF (CRWMS M&O 2000a, Section 6.10), calcite abundance decreases with depth in the TSw unit. The mean calcite abundance in the ESF is 0.034% which is close to the lower bound of calcite observed in WT-24 well cuttings. The mineral abundance in the ESF was determined for 30-m intervals. Thickness, length, and orientation of the mineral deposits were measured. The measured mineral in the ESF is calcite together with opal, with calcite the dominant phase. The simulated results are sensitive to infiltration (percolation). Calcite deposition values obtained from the highest infiltration rate (20 mm/yr) are close to the high bound of the measurements (Figure 6-35). Those from the base-case (5.92 mm/yr) and lower infiltration rate (2 mm/yr) fall in the middle of the TSw measured data range. This may imply that the 20 mm/yr percolation rate is an upper bound for the WT-24 location, whereas the base infiltration (5.92 mm/yr) used in the flow model may be a moderate value. As pointed out in the previous "sensitivity simulation" section, the reactive surface area for calcite reduced by one order of magnitude from the initial estimation provides the most favorable condition for calcite formation in the deeper welded TSw unit. Therefore, the simulated values may be slightly overestimated. Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 100 March 2000 The calcite data obtained from the sensitivity simulations for the NRG-7A column are generally in agreement with the wide range of the WT-24 measured data, except for the simulations with an infiltration equal to or less than 2 mm/yr and the initial estimated surface areas (Figure 6-33a and Figure 6-34b). Calcite deposition data gives some constraints on infiltration-percolation flux, but cannot give a definite value or a narrow range of values. This is because calcite precipitation depends not only upon infiltration-percolation flux, but also water and gas chemistry, reaction rate, and mineralogy. The main reason for calcite precipitation with depth is its inverse solubility with temperature. However, the partial pressure of CO2 and Ca concentration in percolating water controls the abundances of calcite and its stability. The reaction rate, and therefore the reactive surface area, influences its distribution with depth in the preferential fast water flow path in fractures. A number of major uncertainties and approximations are involved in the numerical simulation results. The kinetics of heterogeneous reactions is scale and history-dependent, and cannot be reliably quantified. Reactive surface areas are uncertain and subject to poorly quantifiable phenomena such as armoring of mineral phases. Scaling all rate constants (surface areas) by the same factor is justified for calcite precipitation in the simple mineralogy system, but may not be sufficient in the complex mineralogy system. The effect of changing rate constants (surface areas) in the complex mineralogy system relative to one another may be more appropriate; however, there is no information at present on which to base such an analysis. Variations in water and gas chemistry data could considerably affect rock alteration and deposition patterns. The uncertainties associated with water and gas chemistry also needs to be addressed. In addition, uncertainties could arise from climate and infiltration variations over time, transient water flow condition, and possible lateral water recharge. An alternative conceptual model for calcite deposition would consider its formation as episodic, rather than as steady-state. Because of the kinetics of fracture calcite precipitation, an episodic fluid pulse would tend to change the distribution of calcite with depth. During more typical smaller infiltration events, more precipitation might take place near the surface and less at depth. This does not necessarily change the underlying conceptual model for calcite precipitation (kinetic rate law), but would change the parameters for matching measured abundances. In summary, an analysis of calcite deposition using modeling tools can be used to build some constraints on hydrological parameters such as infiltration-percolation flux. Such an analysis also provides additional evidence for validation of flow and transport model. Over a range of 2-20 mm/yr infiltration rate, the simulated calcite distributions using simple mineralogy capture the measured data from the WT-24 well cuttings. The modeling results can provide useful insight into process mechanisms such as fracture-matrix interaction as well as conditions and parameters controlling calcite deposition. The modeled calcite abundances generally increased as infiltration rate increased. The simulated calcite abundances are also sensitive to water and gas chemistry, and reaction kinetics. However, it should be noted that similar calcite abundances could possibly be obtained by consideration of calcite precipitation under equilibrium conditions with different thermodynamic properties, water compositions, or under transient flow conditions. Hence the kinetic rates and infiltration rates are likely to be nonunique. To refine and improve the present simulations, we need additional studies on the major uncertainties and limitations as discussed above. Furthermore, the model presented here can be used to investigate processes for seepage in Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 101 March 2000 cavities, which has been used as an analog for seepage into the potential repository waste emplacement drifts. 6.6 SIMULATIONS OF TSPA 3-D FLOW FIELDS This section analyzes and summarizes the 21 simulation scenarios, 18 of which are based on perched water Conceptual Models #1 and #2 and are submitted to TSPA for performance analyses. The 21 model simulations are performed using (1) the TSPA grid (Figure 6-2), and nine infiltration maps, as discussed in Section 6.1; (2) the seven parameter sets in Attachment II of this AMR, and the two conceptual perched water models and a non-water perching model. 6.6.1 Simulation Sc enarios Tables 6-16, 6-17 and 6-18 summarize the 21 simulation scenarios, associated conceptual models/ grids, and parameter sets for the nine infiltration maps, respectively. Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 102 March 2000 Table 6-16. Seven TSPA Simulation Scenarios: Data Files, Conceptual Models/Grids, and Parameter Sets for Three Present-Day Infiltration Maps. Designation/ Simulation Conceptual Model/Grid Name and DTN Parameter Set/ Calibration Infiltration Map (DTN: GS000399991221.002) pa99_m #3 Non-perching model/ 3d2kpa.mesh DTN:LB990701233129.001 Parameter set from Table II-7, basecase/ present-day, mean infiltration (AMR: CRWMS M&O 2000b) without 3-D calibration (DTN: LB991121233129.007) Present-day, mean infiltration (Figure 6-3) pa_pchL1 #1 Flow-through perched water model/ 3d2kpa_pc1.mesh DTN:LB990701233129.001 Parameter set from Table II-1, lower-bound/present-day infiltration with 3-D calibration (Table 6-8) (DTN: LB991121233129.005) Present-day, lowerbound infiltration pa_pchL2 #2 By-passing perched water model/ 3d2kpa_pc2.mesh DTN:LB990701233129.001 Parameter set from Table II-2, lower-bound/present-day infiltration with 3-D calibration (Table 6-8) (DTN: LB991121233129.006) Present-day, lowerbound infiltration pa_pchm1 #1 Flow-through perched water model/ 3d2kpa_pc1.mesh DTN:LB990701233129.001 Parameter set from Table II-3, basecase/ mean/present-day infiltration with 3-D calibration (Table 6-6) (DTN: LB991121233129.001) Present-day, mean infiltration (Figure 6-3) pa_pchm2 #2 By-passing perched water model/ 3d2kpa_pc2.mesh DTN:LB990701233129.001 Parameter set from Table II-4, basecase/ mean/present-day infiltration with 3-D calibration (Table 6-6) (DTN: LB991121233129.002) Present-day, mean infiltration (Figure 6-3) pa_pchu1 #1 Flow-through perched water model/ 3d2kpa_pc1.mesh DTN:LB990701233129.001 Parameter set from Table II-5, upper-bound/present-day infiltration with 3-D calibration (Table 6-7) (DTN: LB991121233129.003) Present-day, upperbound infiltration pa_pchu2 #2 By-passing perched water model/ 3d2kpa_pc2.mesh DTN:LB990701233129.001 Parameter set from Table II-6, upper-bound/present-day infiltration with 3-D calibration (Table 6-7) (DTN: LB991121233129.004) Present-day, upperbound infiltration Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 103 March 2000 Table 6-17. Seven TSPA Simulation Scenarios: Data Files, Conceptual Models/Grids, and Parameter Sets for Three Monsoon Climatic Infiltration Maps. Designation/ Simulation Conceptual Model/Grid Name and DTN Parameter Set/ Calibration Infiltration Map (DTN: GS000399991221.002) mon99_m #3 Non-perching model/ 3d2kpa.mesh DTN:LB990701233129.001 Parameter set from Table II-7, base-case/present-day, mean infiltration (AMR: CRWMS M&O 2000b) without 3-D calibration (DTN: LB991121233129.007) Monsoon, mean infiltration (Figure 6-3) pa_monL1 #1 Flow-through perched water model/ 3d2kpa_pc1.mesh DTN:LB990701233129.001 Parameter set from Table II-1, lower-bound/present-day infiltration with 3-D calibration (Table 6-8) (DTN: LB991121233129.005) Monsoon, lower-bound infiltration pa_monL2 #2 By-passing perched water model/ 3d2kpa_pc2.mesh DTN:LB990701233129.001 Parameter set from Table II-2, lower-bound/present-day infiltration with 3-D calibration (Table 6-8) (DTN: LB991121233129.006) Monsoon, lower-bound infiltration pa_monm1 #1 Flow-through perched water model/ 3d2kpa_pc1.mesh DTN:LB990701233129.001 Parameter set from Table II-3, base-case/mean/present-day infiltration with 3-D calibration (Table 6-6) (DTN: LB991121233129.001) Present-day, mean infiltration (Figure 6-3) pa_monm2 #2 By-passing perched water model/ 3d2kpa_pc2.mesh DTN:LB990701233129.001 Parameter set from Table II-4, base-case/mean/present-day infiltration with 3-D calibration (Table 6-6) (DTN: LB991121233129.002) Monsoon, mean infiltration (Figure 6-3) pa_monu1 #1 Flow-through perched water model/ 3d2kpa_pc1.mesh DTN:LB990701233129.001 Parameter set from Table II-5, upper-bound/present-day infiltration with 3-D calibration (Table 6-7) (DTN: LB991121233129.003) Monsoon, upper-bound infiltration pa_monu2 #2 By-passing perched water model/ 3d2kpa_pc2.mesh DTN:LB990701233129.001 Parameter set from Table II-6, upper-bound/present-day infiltration with 3-D calibration (Table 6-7) (DTN: LB991121233129.004) Monsoon, upper-bound infiltration Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 104 March 2000 As shown in Tables 6-16, 6-17 and 6-18, only one simulation is conducted for Conceptual Model #3 (non-perching model) using a mean infiltration map for each climatic scenario. For perched water Conceptual Models #1 and #2, calibrations are carried out for all three climatic scenarios Table 6-18. Seven TSPA Simulation Scenarios: Data Files, Conceptual Models/Grids, Parameter Sets for Three Glacial Transition Infiltration Maps. Designation/ Simulation Conceptual Model/grid Name and DTN Parameter Set/ Calibration Infiltration Map (DTN: GS000399991221.002) gla99_m #3 Non-perching model/ 3d2kpa.mesh DTN:LB990701233129.001 Parameter set from Table II-7, base-case/present-day, mean infiltration (AMR: CRWMS M&O 2000e) without 3-D calibration (DTN: LB991121233129.007) Glacial Transition, mean infiltration (Figure 6.13) pa_glaL1 #1 Flow-through perched water model/ 3d2kpa_pc1.mesh DTN:LB990701233129.001 Parameter set from Table II-1, lower-bound/present-day infiltration with 3-D calibration (Table 6-8) (DTN: LB991121233129.005) Glacial Transition, lower-bound infiltration pa_glaL2 #2 By-passing perched water model/ 3d2kpa_pc2.mesh DTN:LB990701233129.001 Parameter set from Table II-2, lower-bound/present-day infiltration with 3-D calibration (Table 6-8) (DTN: LB991121233129.006) Glacial Transition, lower-bound infiltration pa_glam1 #1 Flow-through perched water model/ 3d2kpa_pc1.mesh DTN:LB990701233129.001 Parameter set from Table II-3, base-case/mean/present-day infiltration with 3-D calibration (Table 6-6) (DTN: LB991121233129.001) Glacial Transition, mean infiltration (Figure 6-3) pa_glam2 #2 By-passing perched water model/ 3d2kpa_pc2.mesh DTN:LB990701233129.001 Parameter set from Table II-4, base-case/mean/present-day infiltration with 3-D calibration (Table 6-6) (DTN: LB991121233129.002) Glacial Transition, mean infiltration (Figure 6-3Figure 6-3) pa_glau1 #1 Flow-through perched water model/ 3d2kpa_pc1.mesh DTN:LB990701233129.001 Parameter set from Table II-5, upper-bound/present-day infiltration with 3-D calibration (Table 6-7) (DTN: LB991121233129.003) Glacial Transition, upper-bound infiltration pa_glau2 #2 By-passing perched water model/ 3d2kpa_pc2.mesh DTN:LB990701233129.001 Parameter set from Table II-6, upper-bound/present-day infiltration with 3-D calibration (Table 6-7) (DTN: LB991121233129.004) Glacial Transition, upper-bound infiltration Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 105 March 2000 (i.e., present-day, Monsoon, and Glacial Transition), and mean, lower-bound and upper-bound infiltration scenarios. 6.6.2 Simulation Results Similar to the calibration simulations, the mass-balance check has been conducted for the 21 simulations using the TSPA grid. Tables 6-19, 6-20 and 6-21 list the global mass balance results. Global mass-balance errors between inflow and outflow of the system for the 18 flow fields (Conceptual Models #1 and #2), as shown in Tables 6-19, 6-20 and 6-21, are about 0.01% or less, indicating that solutions approximate steady state for these cases. Table 6-19. Mass-Balance Results for TSPA simulations using the Present-Day Infiltration Rates. Simulation Scenarios Inflow from infiltration (kg/s) Outflow to water table (kg/s) Relative error (%) pa99_m 5.6404383 5.6350245 0.09598 pa_pchL1 1.4745351 1.4745216 0.00092 pa_pchL2 1.4745351 1.4745337 0.00009 pa_pchm1 5.6404383 5.6404290 0.00016 pa_pchm2 5.6404383 5.6404462 0.00014 pa_pchu1 13.796545 13.796548 0.00002 pa_pchu2 13.796545 13.796567 0.00016 Model Results - DTNs: LB990801233129.001, LB990801233129.002, LB990801233129.003, LB990801233129.004, LB990801233129.005, LB990801233129.006, LB990801233129.019 Table 6-20. Mass-Balance Results for TSPA Simulations using the Monsoon Infiltration Rates. Simulation Scenarios Inflow (kg/s) Outflow (kg/s) Relative Error (%) mon99_m 15.168606 15.198690 0.19833 pa_monL1 5.6404075 5.6409797 0.01014 pa_monL2 5.6404075 5.6397595 0.01149 pa_monm1 15.168606 15.168599 0.00005 pa_monm2 15.168606 15.168625 0.00013 pa_monu1 24.696920 24.697014 0.00038 pa_monu2 24.696920 24.696911 0.00004 Model Results - DTNs: LB990801233129.013, LB990801233129.014, LB990801233129.015, LB990801233129.016, LB990801233129.017, LB990801233129.018, LB990801233129.020 Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 106 March 2000 6.6.3 Result Analyses and Flow Fields Model Examination: 18 out of the 21 3-D flow fields, as delivered for TSPA calculations, have been compared against the field-observed data of perched water. The observed matrix liquid saturations and water potentials (when available) are used for checking model results. The other three flow fields from the non-water perching model were used in sensitivity analyses. The available data used in the calibrations are listed in Table 6-4. One example of the simulation results is given in Figure 6-41, comparing the result for UZ-14 with the results using the three mean infiltration rates of the three climatic scenarios with perched water Conceptual Model #1. The figure shows a good match between simulated and observed saturation and perched water data at this location from the three simulations. Overall, we have the following calibration results: • The simulation results, used for generating the 18 flow fields, matched the available saturation and water potential data from the nine boreholes (Table 6-4) reasonably well. • For calibrations with perched water data, the six simulations with mean, lower-bound and upper-bound present-day infiltration rates and two conceptual perched water models (Models #1 and #2), are similar to the results of the corresponding six calibration simulations of Section 6.2, which match perched water data reasonably well. • The 8 simulations with 4 infiltration scenarios having both mean and upper-bound infiltration rates of two future climates (Monsoon and Glacial Transition) and two perched water conceptual models can reproduce water-perching conditions well in all the observation boreholes. The four lower-bound infiltration simulations could also match perched water data for six of the seven perched water boreholes (at SD-7, the simulations do not match the observed perched water data well). Table 6-21. Mass-Balance Results for TSPA Simulations using the Glacial Transition Infiltration Rates. Scenarios Inflow (kg/s) Outflow (kg/s) Relative Error (%) gla99_m 22.045112 22.045138 0.00012 pa_glaL1 2.9508085 2.9508075 0.00003 pa_glaL2 2.9508085 2.9507693 0.00133 pa_glam1 22.045112 22.045136 0.00011 pa_glam2 22.045112 22.044842 0.00122 pa_glau1 41.139432 41.139387 0.00011 pa_glau2 41.139432 41.139337 0.00023 Model Results - DTNs: LB990801233129.007, LB990801233129.008, LB990801233129.009, LB990801233129.010, LB990801233129.011, LB990801233129.012, LB990801233129.022 Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 107 March 2000 Data - DTN: GS000399991221.004 Model Results - DTNs: LB990801233129.003, LB990801233129.009, LB990801233129.015 Figure 6-41. Comparison to the Simulated and Observed Matrix Liquid Saturations and Perched Water Elevations for Borehole UZ-14, Using the Results of pa_pchm1, pa_monm1 and pa_glam1 Simulations for Three Mean Infiltration Scenarios of Three Climates. Percolation Fluxes and Fracture-Matrix Flow Components: Percolation fluxes at the potential repository horizon, simulated using the three mean infiltration scenarios of the present-day and two future climates, are shown in Figures 6-42, 6-43, and 6-44. The figures show that simulated total (matrix+fracture) percolation fluxes at the potential repository level have very nonuniform distributions, similar to the infiltration maps used for the top boundary conditions. By comparing the three percolation fluxes at the potential repository horizon with the corresponding surfaceinfiltration maps (Figures 6-3, 6-4 and 6-5), we find that little lateral diversion, except near faults, occurs during flow from surface to potential repository level, as predicted in these three simulations with the 3-D calibration grid. 0.0 0.5 1.0 Saturation 700 800 900 1000 1100 1200 1300 1400 Elevation (m) Hydro. Unit pa-pchm1 pa-glam1 pa-monm1 TSw TCw CHn Perched Water PTn Field Data Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 108 March 2000 Based on DTN: LB990801233129.003 Figure 6-42. Simulated Percolation Fluxes at the Potential Repository Horizon Under Present-Day, Mean Infiltration Using the Results of Simulation pa_pchm1. 170000 172000 174000 Nevada Coordinate E-W (m) 230000 232000 234000 236000 238000 Nevada Coordinate N-S (m) 15 14.25 13.5 12.75 12 11.25 10.5 9.75 9 8.25 7.5 6.75 6 5.25 4.5 3.75 3 2.25 1.5 0.75 0 (mm/yr) >_ Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 109 March 2000 Based on DTN: LB990801233129.015 Figure 6-43. Simulated Percolation Fluxes at the Potential Repository Horizon Under Monsoon, Mean Infiltration Using the Results of Simulation pa_monm1. 170000 172000 174000 Nevada Coordinate E-W (m) 230000 232000 234000 236000 238000 Nevada Coordinate N-S (m) 40 38 36 34 32 30 28 26 24 22 20 18 16 14 12 10 8 6 4 2 0 (mm/yr) >_ Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 110 March 2000 Based on DTN: LB990801233129.009 Figure 6-44. Simulated Percolation Fluxes at the Potential Repository Horizon Under Glacial Transition, Mean Infiltration Using the Results of Simulation pa_glam1. 170000 172000 174000 Nevada Coordinate E-W (m) 230000 232000 234000 236000 238000 Nevada Coordinate N-S (m) 40 38 36 34 32 30 28 26 24 22 20 18 16 14 12 10 8 6 4 2 0 (mm/yr) >_ Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 111 March 2000 Figures 6-45 through 6-53 show the simulated percolation fluxes at the water table also using the three mean infiltration scenarios with the three conceptual models. When comparing the percolation fluxes at the potential repository (e.g., Figures 6-42, 6-43, and 6-44) we find the following: • Conceptual Model #3 (non-perching model) predicts a possible maximum, nearly vertical flow through the CHn zeolitic rocks. • Conceptual Model #2 (by-passing model) predicts the least flowing-through or maximum by-passing of perched water zones or zeolites of flow through the CHn. • Conceptual Model #1 (flow-through model) predicts significant vertical flow-through in the southern part of the vitric zones, and large lateral diversion occurring in the northern portion of the potential repository (where thick zeolitic layers are located), but an overall much higher vertical flow rate and much less lateral flow than Conceptual Model #2. Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 112 March 2000 Based on DTN: LB990801233129.003 Figure 6-45. Simulated Percolation Fluxes at the Water Table Under Present-Day, Mean Infiltration Using the Results of Simulation pa_pchm1–Conceptual Model #1. 170000 172000 174000 Nevada Coordinate E-W (m) 230000 232000 234000 236000 238000 Nevada Coordinate N-S (m) 15 14.25 13.5 12.75 12 11.25 10.5 9.75 9 8.25 7.5 6.75 6 5.25 4.5 3.75 3 2.25 1.5 0.75 0 (mm/yr) >_ Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 113 March 2000 Based on DTN: LB990801233129.004 Figure 6-46. Simulated Percolation Fluxes at the Water Table Under Present-Day, Mean Infiltration Using the Results of Simulation pa_pchm2 – Conceptual Model #2. 170000 172000 174000 Nevada Coordinate E-W (m) 230000 232000 234000 236000 238000 Nevada Coordinate N-S (m) 15 14.25 13.5 12.75 12 11.25 10.5 9.75 9 8.25 7.5 6.75 6 5.25 4.5 3.75 3 2.25 1.5 0.75 0 (mm/yr) >_ Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 114 March 2000 Based on DTN: LB990801233129.019 Figure 6-47. Simulated Percolation Fluxes at the Water Table Under Present-Day, Mean Infiltration Using the Results of Simulation pa99_m – Conceptual Model #3. 170000 172000 174000 Nevada Coordinate E-W (m) 230000 232000 234000 236000 238000 Nevada Coordinate N-S (m) 15 14.25 13.5 12.75 12 11.25 10.5 9.75 9 8.25 7.5 6.75 6 5.25 4.5 3.75 3 2.25 1.5 0.75 0 (mm/yr) >_ Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 115 March 2000 Based on DTN: LB990801233129.015 Figure 6-48. Simulated Percolation Fluxes at the Water Table Under Monsoon, Mean Infiltration Using the Results of Simulation pa_monm1 – Conceptual Model #1. 170000 172000 174000 Nevada Coordinate E-W (m) 230000 232000 234000 236000 238000 Nevada Coordinate N-S (m) 40 38 36 34 32 30 28 26 24 22 20 18 16 14 12 10 8 6 4 2 0 (mm/yr) >_ Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 116 March 2000 Based on DTN: LB990801233129.016 Figure 6-49. Simulated Percolation Fluxes at the Water Table Under Monsoon, Mean Infiltration Using the Results of Simulation pa_monm2 – Conceptual Model #2. 170000 172000 174000 Nevada Coordinate E-W (m) 230000 232000 234000 236000 238000 Nevada Coordinate N-S (m) 40 38 36 34 32 30 28 26 24 22 20 18 16 14 12 10 8 6 4 2 0 (mm/yr) >_ Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 117 March 2000 Based on DTN: LB990801233129.020 Figure 6-50. Simulated Percolation Fluxes at the Water Table Under Monsoon, Mean Infiltration Using the Results of Simulation mon99_m – Conceptual Model #3. 170000 172000 174000 Nevada Coordinate E-W (m) 230000 232000 234000 236000 238000 Nevada Coordinate N-S (m) 40 38 36 34 32 30 28 26 24 22 20 18 16 14 12 10 8 6 4 2 0 (mm/yr) >_ Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 118 March 2000 Based on DTN: LB990801233129.009 Figure 6-51. Simulated Percolation Fluxes at the Water Table Under Glacial Transition, Mean Infiltration Using the Results of Simulation pa_glam1 – Conceptual Model #1. 170000 172000 174000 Nevada Coordinate E-W (m) 230000 232000 234000 236000 238000 Nevada Coordinate N-S (m) 40 38 36 34 32 30 28 26 24 22 20 18 16 14 12 10 8 6 4 2 0 (mm/yr) >_ Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 119 March 2000 Based on DTN: LB990801233129.010 Figure 6-52. Simulated Percolation Fluxes at the Water Table Under Glacial Transition, Mean Infiltration Using the Results of Simulation pa_glam2 – Conceptual Model #2. 170000 172000 174000 Nevada Coordinate E-W (m) 230000 232000 234000 236000 238000 Nevada Coordinate N-S (m) 40 38 36 34 32 30 28 26 24 22 20 18 16 14 12 10 8 6 4 2 0 (mm/yr) >_ Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 120 March 2000 Based on DTN: LB990801233129.021 Figure 6-53. Simulated Percolation Fluxes at the Water Table Under Glacial Transition, Mean Infiltration Using the Results of Simulation gla99_m – Conceptual Model #3. 170000 172000 174000 Nevada Coordinate E-W (m) 230000 232000 234000 236000 238000 Nevada Coordinate N-S (m) 40 38 36 34 32 30 28 26 24 22 20 18 16 14 12 10 8 6 4 2 0 (mm/yr) >_ Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 121 March 2000 Tables 6-22, 6-23, and 6-24 list the percentage of fracture-matrix flow components at the potential repository horizon and the water table, respectively, predicted using the 21 simulation results. These statistics show that fracture flow is dominant both at the potential repository horizon and at the water table in all the 21 flow fields. Specific predictions are as follows: • Table 6-22 indicates that for the three present-day infiltration scenarios, simulated fracture-matrix flow components with the TSPA grid are similar to those (Table 6-11) using the calibration grid. At the potential repository level, fracture flow consists of more than 80% of the total flow; at the water table, consists of about 70-90% of the total flow. • Tables 6-23 and 6-24 show, for two future climatic scenarios, a higher percentage of fracture flow at both the potential repository (86-96%) and water table level (71-96%) compared to the results of the present-day infiltration (Table 6-22). The second perched water conceptual model predicts consistently lower fracture-flow components by more than 8% for the two climatic scenarios. Table 6-22. Comparison of the Water Flux through Matrix and Fractures as a Percentage of the Total Flux at two Different Horizons (1) at the Potential Repository and (2) at the Water Table, using the Three Present-Day Infiltration Scenarios. Simulation Designation Flux at Potential Repository (%) Flux at Water Table (%) Fracture Matrix Fracture Matrix pa99_m 83.76 16.24 80.35 19.65 pa_pchL1 86.61 13.39 84.66 15.34 pa_pchL2 86.38 13.62 69.37 30.63 pa_pchm1 83.69 16.31 86.69 13.31 pa_pchm2 83.66 16.34 71.19 28.81 pa_pchu1 94.45 5.55 95.40 4.60 pa_pchu2 94.32 5.68 82.07 17.93 Model Results - DTNs: LB990801233129.001, LB990801233129.002, LB990801233129.003, LB990801233129.004, LB990801233129.005, LB990801233129.006, LB990801233129.019 Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 122 March 2000 6.7 GROUNDWATER TRAVEL TIMES AND TRACER TRANSPORT This section summarizes our studies of groundwater travel times and tracer transport using the 21 TSPA flow fields as well as one flow field with the calibration grid (Figure 6-1) for chloride-36 studies. These studies are conducted to obtain insights into groundwater travel times and radionuclide transport from (a) the potential repository to the water table, and (b) the ground surface to the potential repository level. The results present an evaluation of transport processes of Table 6-23. Comparison of the Water Flux through Matrix and Fractures as a Percentage of the Total Flux at Two Different Horizons (1) at the Potential Repository and (2) at the Water Table, using the Three Monsoon Infiltration Scenarios. Simulation Designation Flux at potential repository (%) Flux at Water Table (%) Fracture Matrix Fracture Matrix mon99_m 89.60 10.40 85.31 14.69 pa_monL1 89.97 10.03 90.10 9.90 pa_monL2 89.90 10.10 76.55 23.45 pa_monm1 89.53 10.47 90.21 9.79 pa_monm2 89.50 10.50 80.87 19.13 pa_monu1 95.61 4.39 96.47 3.53 pa_monu2 95.50 4.50 83.86 16.14 Model Results - DTNs: LB990801233129.013, LB990801233129.014, LB990801233129.015, LB990801233129.016, LB990801233129.017, LB990801233129.018, LB990801233129.020 Table 6-24. Comparison of the Water Flux through Matrix and Fractures as a Percentage of the Total Flux at Two Different Horizons (1) at the Potential Repository and (2) at the Water Table, using the Three Glacial Transition Infiltration Scenarios. Simulation Designation Flux at potential repository (%) Flux at Water Table (%) Fracture Matrix Fracture Matrix gla99_m 91.46 8.54 83.26 16.74 pa_glaL1 86.92 13.08 87.15 12.85 pa_glaL2 86.78 13.22 71.38 28.62 pa_glam1 91.38 8.62 90.47 9.53 pa_glam2 91.37 8.63 83.43 16.57 pa_glau1 96.53 3.47 96.92 3.08 pa_glau2 96.44 3.56 88.97 11.03 Model Results - DTNs: LB990801233129.007, LB990801233129.008, LB990801233129.009, LB990801233129.010, LB990801233129.011, LB990801233129.012, LB990801233129.022 Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 123 March 2000 radionuclides from the potential repository to the water table (saturated zone) and groundwater travels within the mountain, including effects of different perched water conceptual models, infiltration scenarios, and adsorption.Methodology and Transport Parameters. Studies of this section on tracer transport are intended for insight of the transport processes and PA may use other models/codes for radionuclide transport predictions in TSPA. 6.7.1M ethodology a nd Transport Parameters Simulation results and analyses of this section are based on transport studies of conservative and reactive tracers using the T2R3D V1.4 code. The dual-permeability modeling approach, the 3-D TSPA grid (Figure 6-2) and the calibration grid (Figure 6-1) are used in the transport simulations. The 21 steady-state, 3-D flow fields, as discussed in Section 6.6, are directly used as input to the T2R3D code for runs for transport from the potential repository to the water table. Groundwater travel times or 36Cl transport is modeled using the calibration grid with the present-day, mean infiltration rate. Transport from the potential repository to the water table: This study is to assess groundwater travel times from the potential repository to the water table. Tracer or radionuclides are treated as conservative (nonadsorbing) and reactive (adsorbing) components transported through the UZ. For both cases, the hydrodynamic dispersion effect through the fracture-matrix system is ignored because sensitive studies indicate insignificant effect of hydrodynamic dispersion on the cumulative breakthrough curves of tracers at the water table. A constant molecular diffusion coefficient of 3.2 × 10-11 (m2/s) is used for matrix diffusion of the conservative component, and 1.6 × 10-10 (m2/ s) and is used for the reactive component (DTN: LAIT831341AQ96.001). In the case of a reactive or adsorbing tracer, several Kd values are used, as given in Table 6-25, and these values were selected to approximate those for neptunium (237Np) transport (DTN: LAIT831341AQ96.001). For a conservative tracer, Kd is set to zero. These molecular diffusions coefficients and Kd values are selected to represent technitium and neptunium, respectively. All transport simulations were conducted for 1,000,000 years with a constant infiltration and an initial, constant source concentration condition injected into the fracture continuum at the potential repository horizon. A tracer is released at the starting time of a simulation. Transport from the ground surface: This is to investigate groundwater travel times from the ground surface to the potential repository level as well as 36Cl transport phenomena under steady- Table 6-25. Kd Values used for Reactive Tracer Transport in Different Hydrogeologic Units. Hydrogeologic Unit Kd (cc/g) Zeolitic matrix in CHn 4.0 Vitric matrix in CHn 1.0 Matrix in TSw 1.0 Fault matrix in CHn 1.0 Fractures and the matrix in the rest of units 0.0 DTN: LAIT831341AQ96.001 Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 124 March 2000 state UZ flow conditions. A tracer with 36Cl transport properties (Section 6.4.2) is introduced into the second top grid or infiltration layer of the calibration grid with the climate scenario of the present-day, mean infiltration for the modeling studies. There are four simulation scenarios with different surface tracer boundary conditions specified with a small area above the potential repository and the entire model domain, respectively. Use of the small area of the tracer source boundary condition on the land surface is to reduce the possible effects of lateral boundaries and to focus on transport behavior in the immediate vicinity above the potential repository. The small tracer-source area is defined as an area directly above the potential repository, bounded by the Solitario Canyon, Drill Hole Wash and Ghost Dance faults in the western, northern and eastern directions, with the southern boundary in alignment with the south ramp of the ESF. Two types of boundary conditions were specified for the tracer, one being constant initial tracer concentration and the other constant tracer mass injection rate in the fracture gridblocks of the boundary. In the four simulations, the tracer was treated as a conservative, (nonadsorbing) and decaying component. For all cases, the hydrodynamic dispersion effect through the fracture-matrix system was included with longitudinal dispersivities of 20 and 5 m and transverse dispersivities of 4 and 1 m, respectively, for fracture and matrix systems. Also, transport simulations were conducted for 1,000,000 years. 6.7.2 Simulation Scenarios For each TSPA flow simulation, as listed in Tables 6-16, 6-17 and 6-18, there are two transport runs, one for conservative (*_tr1) and one for reactive (*_tr2) tracer transport, respectively. Tables 6-26, 6-27 and 6-28 summarize a total of 21 × 2 simulation scenarios, associated with conceptual models/grids and corresponding TSPA flow fields for the nine infiltration maps of three climates, respectively. Table 6-26 also includes the four simulations using the calibration grid for studies of groundwater travel or 36Cl transport times from the land surface. Among the four scenarios, cam1_CL1 uses a constant initial tracer concentration boundary condition within the small source area; cam1_CL2 uses a constant tracer mass flux boundary condition that is proportional to net infiltration rate for each fracture block, within the small source area; cam1_CL2 uses a constant initial tracer concentration boundary condition over the entire top model area; and cam1_CL4 uses a constant Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 125 March 2000 tracer mass flux boundary condition (Section 6.4.1.2) with each fracture block, over the entire top model area. Table 6-26. Transport Simulation Scenarios: Data Files, Conceptual Models/Grids, Corresponding TSPA Flow Fields with Three Present-Day Infiltration Rates. Designation/ Transport Simulation Designation/ Flow Simulation Perched Water Conceptual Model/Grid Infiltration Map (DTN: GS000399991221.002 pa99_tr1 pa99_tr2 pa99_m #3 Non-perching model/ 3d2kpa.mesh DTN: LB990701233129.001 Present-day, mean infiltration (Figure 6-3) paL1_tr1 paL1_tr2 pa_pchL1 #1 Flow-through perched water model/ 3d2kpa_pc1.mesh DTN: LB990701233129.001 Present-day, lowerbound infiltration paL2_tr1 paL2_tr2 Pa_pchL2 #2 By-passing perched water model/ 3d2kpa_pc2.mesh DTN: LB990701233129.001 Present-day, lowerbound infiltration pam1_tr1 pam1_tr2 pa_pchm1 #1 Flow-through perched water model/ 3d2kpa_pc1.mesh DTN: LB990701233129.001 Present-day, mean infiltration (Figure 6-3) pam2_tr1 pam2_tr2 pa_pchm2 #2 By-passing perched water model/ 3d2kpa_pc2.mesh DTN: LB990701233129.001 Present-day, mean infiltration (Figure 6-3) pau1_tr1 pau1_tr2 pa_pchu1 #1 Flow-through perched water model/ 3d2kpa_pc1.mesh DTN: LB990701233129.001 Present-day, upperbound infiltration pau2_tr1 pau2_tr2 pa_pchu2 #2 By-passing perched water model/ 3d2kpa_pc2.mesh DTN: LB990701233129.001 Present-day, upperbound infiltration cam1_CL1 pch!_m2 #1 Flow through perched water model/ 3d2kcalib_pc1.mesh (DTN: LB997141233129.001) Present-day, mean infiltration (Figure 6.1.3) cam1_CI2 pch1_m2 #1 Flow-through perched water model/ 3d2kcalib_pc1.mesh DTN:LB997141233129.001) Present-day, lowerbound infiltration (Figure 6.1.3) Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 126 March 2000 cam1_CL3 pch1_m2 #1 Flow through perched water model/ 3d2kcalib_pc1.mesh DTN: LB997141233129.001 Present-day, lowerbound infiltration (Figure 6.1.3) cam1_CL4 pch1_m2 #1 Flow-through perched water model/ 3d2kpa_pc1.mesh DTN: LB990701233129.001 Present-day, mean infiltration (Figure 6.1.3) Table 6-26. Transport Simulation Scenarios: Data Files, Conceptual Models/Grids, Corresponding TSPA Flow Fields with Three Present-Day Infiltration Rates. Designation/ Transport Simulation Designation/ Flow Simulation Perched Water Conceptual Model/Grid Infiltration Map (DTN: GS000399991221.002 Table 6-27. Transport Simulation Scenarios: Data Files, Conceptual Models/Grids, Corresponding TSPA Flow Fields with Three Monsoon Infiltration Rates Conceptual Model/Grid Infiltration Map Non-perching mode!f w-through perched water model/ By-passing perched water mode!J monmltR Flow-through perched water model/ 3dZkpqxl.mesh DTN: L8990701233129.001 monm2-trl monm2-tr2 By-passing perched water mod&l 3d2kpampc2.mesh Flow-through perched water mode!J 3d2kpagcl .mesh By-passing perched water mod& 3dZkpagc2.mesh DTN:LS990701233129.001 MDL-NBS-HS-m REV00 127 March 2000 Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 128 March 2000 Table 6-28. Transport Simulation Scenarios: Data Files, Conceptual Models/Grids, Corresponding TSPA Flow Fields with Three Glacial Transition Infiltration Rates. Designation/ Transport Simulation Designation/ Flow Simulation Conceptual Model/Grid Infiltration Map gla99_tr1 gla99_tr2 gla99_m #3 Non-perching model/ 3d2kpa.mesh DTN: LB990701233129.001 Glacial Transition, mean infiltration (Figure 6-5) glaL1_tr1 glaL1_tr2 pa_glaL1 #1 Flow-through perched water model/ 3d2kpa_pc1.mesh DTN: LB990701233129.001 Glacial Transition, lower-bound infiltration glaL2_tr1 glaL2_tr2 pa_glaL2 #2 By-passing perched water model/ 3d2kpa_pc2.mesh DTN: LB990701233129.001 Glacial Transition, lower-bound infiltration glam1_tr1 glam1_tr2 pa_glam1 #1 Flow-through perched water model/ 3d2kpa_pc1.mesh DTN: LB990701233129.001 Glacial Transition, mean infiltration (Figure 6-5) glam2_tr1 glam2_tr2 pa_glam2 #2 By-passing perched water model/ 3d2kpa_pc2.mesh DTN: LB990701233129.001 Glacial Transition, mean infiltration (Figure 6-5) glau1_tr1 glau1_tr2 pa_glau1 #1 Flow-through perched water model/ 3d2kpa_pc1.mesh DTN: LB990701233129.001 Glacial Transition, upper-bound infiltration glau2_tr1 glau2_tr2 pa_glau2 #2 By-passing perched water model/ 3d2kpa_pc2.mesh DTN: LB990701233129.001 Glacial Transition, upper-bound infiltration Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 129 March 2000 6.7.3 Simulation Results and Analyses Groundwater travel and tracer transport times from the potential repository to water table: Groundwater travel times (since release from the potential repository to the water table) may be analyzed using a cumulative or fractional breakthrough curve, as shown in Figures 6-54, 6-55, and 6-56 for 1 million years. The fractional mass breakthrough in these figures is defined as the cumulative mass of a tracer or radionuclide arriving at the water table over the entire bottom model boundary over time, normalized by the total mass of the component initially introduced at the potential repository. In the figures, solid-line curves represent simulation results of conservative/ nonadsorbing tracer transport and dotted-line plots represents reactive, adsorbing tracer transport. The three figures show a wide range of groundwater travel or tracer transport times with different infiltration rates, tracers, and perched water conceptual models from the 42 simulations. The predominant factors in groundwater travel times or tracer transport, as indicated by Figures 6- 54, 6-55 and 6-56, are (1) surface-infiltration rates or net water recharge and (2) adsorption effects, whether the tracer is conservative or reactive. To a certain extent, perched water conceptual models also affect groundwater travel/ transport times. However, the overall impact of the perched water conceptual models on tracer breakthrough at the water table is secondary compared to effects of infiltration and adsorption. Statistics of groundwater travel or tracer transport times of 10% and 50% mass breakthrough at the water table for the 42 simulation scenarios are given in Tables 6-29, 6-30 and 6-31, respectively. Figure 6-57 correlates average infiltration rates and groundwater travel or tracer transport times at 50% mass breakthrough for the 42 simulation scenarios. Figures 6-54 to 6-57 and the statistical data of Tables 6-29, 6-30 and 6-31 show the following: Groundwater travel or tracer transport times are inversely proportional to average surface infiltration (net water recharge) rate over the model domain (Figure 6-57). When an average infiltration rate increases from 5 to 35 (mm/yr), average groundwater travel (50% breakthrough) times decrease by one to two orders of magnitude. As infiltration decreases, the adsorbing species has a lower increasing rate in transport times than that of a nonadsorbing tracer because of retardation effects. Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 130 March 2000 ._ Based on DTN: LB9908T1233129.001 Figure 6-54. Simulated Breakthrough Curves of Cumulative Tracer Mass Arriving at the Water Table, Since Release from the Potential Repository, Using the Three Present-Day Infiltration Scenarios and Three Conceptual Models for Nonadsorbing and Adsorbing Transport Based on DTN: LB9908T1233129.001 Figure 6-55. Simulated Breakthrough Curves of Cumulative Tracer Mass Arriving at the Water Table, Since Release from the Potential Repository, Using the Three Monsoon Infiltration Scenarios and Three Conceptual Models for Nonadsorbing and Adsorbing Transport. 100 101 102 103 104 105 106 TIME (years) 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 Fractional Mass Breakthrough at Water Table pa99-tr1 pa99-tr2 L pal 1-tr2 paL2-tr1 paL2-tr2 pam1-tr1 pam1-tr2 pam2-tr1 pam2-tr2 pau1-tr1 pau1-tr2 pau2-tr1 pau2-tr2 PaL1-tr1 100 101 102 103 104 105 106 TIME (years) 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 Fractional Mass Breakthrough at Water Table mon99-tr1 mon99-tr2 monL1-tr1 monL1-tr2 monL2-tr1 monL2-tr2 monm1-tr1 monm1-tr2 monm2-tr1 monm2-tr2 monu1-tr1 monu1-tr2 monu2-tr1 monu2-tr2 Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 131 March 2000 Based on DTN: LB9908T1233129.001 Figure 6-56. Simulated Breakthrough Curves of Cumulative Tracer Mass Arriving at the Water Table, Since Release from the Potential Repository, Using the Three Glacial Transition Infiltration Scenarios and Three Conceptual Models for Nonadsorbing and Adsorbing Transport. • Nonadsorbing tracers migrate one to two orders of magnitude faster than an adsorbing tracer when traveling from the potential repository to the water table under the same infiltration condition. • The non-perching-water conceptual model (Conceptual Model #3) predicts the shortest arrival times for both nonadsorbing and adsorbing tracers during the first 1,000 years, using the results of the three conceptual models for the three mean infiltration scenarios of the three climates. • In later times (>1,000 years), the results are mixed when comparing travel/transport times from the different conceptual perched water models. For nonadsorbing tracers, Conceptual Model #1 in general has a longer arrival time than Conceptual Model #2. For adsorbing tracers with retardation effects, however, Conceptual Model #1 predicts shorter travel times than Conceptual Model #2 for lower-bound and mean infiltration scenarios. 100 101 102 103 104 105 106 TIME (years) 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 Fractional Mass Breakthrough at Water Table gla99-tr1 gla99-tr2 glaL1-tr1 glaL1-tr2 glaL2-tr1 glaL2-tr2 glam1-tr1 glam1-tr2 glam2-tr1 glam2-tr2 glau1-tr1 glau1-tr2 glau2-tr1 glau2-tr2 Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 132 March 2000 Based on DTN: LB9908T1233129.001 Figure 6-57. Correlations of Average Infiltration Rates and Groundwater Travel or Tracer Transport Times at 50% Mass Breakthrough for the 42 Simulation Scenarios. Table 6-29. Groundwater Travel/Tracer Transport Times at 10% and 50% Mass Breakthrough Times for 14 Transport Simulation Scenarios, Corresponding to TSPA Flow Fields with Three Present-Day Infiltration Rates. Designation/ Transport Simulation Types of Tracer 10% Breakthrough Times (years) 50% Breakthrough Times (years) pa99_tr1 Nonadsorbing 8 3,300 pa99_tr2 Adsorbing 17,000 210,000 paL1_tr1 Nonadsorbing 20,000 320,000 paL1_tr2 Adsorbing 500,000 > 1,000,000 paL2_tr1 Nonadsorbing 24,000 280,000 paL2_tr2 Adsorbing 450,000 > 1,000,000 pam1_tr1 Nonadsorbing 75 3,700 pam1_tr2 Adsorbing 12,000 170,000 pam2_tr1 Nonadsorbing 100 4,300 pam2_tr2 Adsorbing 11,000 140,000 pau1_tr1 Nonadsorbing 5 560 pau1_tr2 Adsorbing 1,600 36,000 pau2_tr1 Nonadsorbing 6 570 pau2_tr2 Adsorbing 1,600 26,000 Model Results - DTN: LB9908T1233129.001 1.0E+01 1.0E+02 1.0E+03 1.0E+04 1.0E+05 1.0E+06 1.0E+07 1 10 100 Average Infiltration Rate Over the Model Domain (mm/year) Travel Times for 50% Mass Breakthrough (years) Model 1, Non-adsorbing Model 2, Non-adsorbing Model 3, Non-adsorbing Model 1, Adsorbing Model 2, Adsorbing Model 3, Adsorbing Non-adsorbing Adsorbing Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 133 March 2000 Table 6-30. Groundwater Travel/Tracer Transport Times at 10% and 50% Mass Breakthrough Times for 14 Transport Simulation Scenarios, Corresponding to TSPA Flow Fields with Three Monsoon Infiltration Rates. _ Designation/ Transport Simulation Types of Tracer 10% Breakthrough Times (years) 50% Breakthrough Times (years) mon99_tr1 Nonadsorbing 3 740 mon99_tr2 Adsorbing 1,100 55,000 monL1_tr1 Nonadsorbing 600 5,300 monL1_tr2 Adsorbing 25,000 120,000 monL2_tr1 Nonadsorbing 820 5,500 monL2_tr2 Adsorbing 26,000 110,000 monm1_tr1 Nonadsorbing 12 630 monm1_tr2 Adsorbing 1,500 35,000 monm2_tr1 Nonadsorbing 6 670 monm2_tr2 Adsorbing 1,200 26,000 monu1_tr1 Nonadsorbing 3 210 monu1_tr2 Adsorbing 570 15,000 monu2_tr1 Nonadsorbing 3 260 monu2_tr2 Adsorbing 600 12,000 Model Results - DTN: LB9908T1233129.001 Table 6-31. Groundwater Travel/Tracer Transport times at 10% and 50% Mass Breakthrough for 14 Transport Simulation Scenarios, Corresponding to TSPA Flow Fields with Three Glacial Transition Infiltration Rates. Designation/ Transport Simulation Types of Tracer 10% Breakthrough Times (years) 50% Breakthrough Times (years) gla99_tr1 Nonadsorbing 2 380 gla99_tr2 Adsorbing 200 28,000 glaL1_tr1 Nonadsorbing 2,400 17,000 glaL1_tr2 Adsorbing 70,000 400,000 glaL2_tr1 Nonadsorbing 2,900 18,000 glaL2_tr2 Adsorbing 66,000 380,000 glam1_tr1 Nonadsorbing 7 310 glam1_tr2 Adsorbing 740 18,000 glam2_tr1 Nonadsorbing 4 330 glam2_tr2 Adsorbing 620 12,000 glau1_tr1 Nonadsorbing 2 90 glau1_tr2 Adsorbing 220 5,400 glau2_tr1 Nonadsorbing 2 120 glau2_tr2 Adsorbing 240 4,300 DTN: LB9908T1233129.001 Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 134 March 2000 Potential locations of tracer breakthrough at the water table: The 42 tracer-transport simulation results can also be used to estimate potential locations or areas where radionuclides are most likely to break through at the water table. This information may be useful for modeling saturated zone transport. Figures 6-58a, 6-58b, 6-59a, and 6-59b show mass fraction contours at the water table at 1,000 years as examples after release from the potential repository for conservative and reactive tracer transport with Conceptual Models #1 and 2, respectively, using the present-day, mean infiltration rate. Figures 6-58a and 6-58b are for comparison between mass fraction contours of a conservative tracer at the water table after 1,000 years, simulated using the present-day, mean infiltration and Conceptual Model #1 (flow-through), and Conceptual Model #2 (by-passing), respectively. The two figures clearly indicate a significant difference in distributions of tracer mass fraction or concentration along the water table with the two conceptual model results. Conceptual Model #1 (Figure 6-58a) predicts a large area of high concentration covering the entire area directly below the potential repository, indicating that transport is predominantly vertical for this case. In contrast Conceptual Model #2 (Figure 6-58b) shows only three high-concentration areas, which are associated mainly with faults. This indicates the significant effects of by-passing flow in the CHn unit on the tracer transport using Conceptual Model #2 (by-passing model). For an adsorbing tracer, Figures 6-59a and 6-59b show similar concentration contours to those on Figures 6-58a and 6-58b for a nonadsorbing tracer, but smaller areas and much lower concentration values for the same flow conditions. Figure 6-59a indicates that after 1,000 years, breakthrough occurs mainly below the southern portion of the potential repository in the vitric zones. In the northern part below the potential repository, breakthrough occurs along only a small portion of the Drillhole Wash fault. A comparison between high-concentration contours in Figures 6-58a and 6-59a shows that adsorption effects are expected to have a significant impact on arriving concentration values and distributions on the water table for the same flow conceptual model (flow-through model). This impact is especially apparent in the northern part below the potential repository, where thick zeolitic layers are located. The tracer has not yet broken through in 1,000 years (with retardation effects included – Figure 6-59a), when compared with Figure 6- 58a without adsorbing effects using the same flow field. Since Conceptual Model #1 predicts a higher percentage of flow-through in the zeolites than Conceptual Model #2, as discussed in Section 6.2, these zeolitic units may effectively retard further transport of the tracer, carried (with this conceptual model) by flow-through waters even under water perching conditions. Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 135 March 2000 Based on DTN: LB9908T1233129.001 Figure 6-58. (a) Simulated Mass Fraction Contours of a Conservative Tracer at the Water Table after 1,000 Years, Indicating Potential Breakthrough Locations at the Time, Using the Present- Day, Mean Infiltration with Conceptual Model #1. 170000 172000 174000 Nevada Coordinate E-W (m) 230000 232000 234000 236000 238000 Nevada Coordinate N-S (m) 1.00E-05 9.50E-06 9.00E-06 8.50E-06 8.00E-06 7.50E-06 7.00E-06 6.50E-06 6.00E-06 5.50E-06 5.00E-06 4.50E-06 4.00E-06 3.50E-06 3.00E-06 2.50E-06 2.00E-06 1.50E-06 1.00E-06 5.00E-07 0.00E+00 (a) Conceptual Model #1 Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 136 March 2000 Based on DTN: LB9908T1233129.001 Figure 6-58 (b) Simulated Mass Fraction Contours of a Conservative Tracer at the Water Table after 1,000 Years, Indicating Potential Breakthrough Locations at the Time, Using the Present- Day, Mean Infiltration with Conceptual Model #2. 170000 172000 174000 Nevada Coordinate E-W (m) 230000 232000 234000 236000 238000 Nevada Coordinate N-S (m) 1.00E-05 9.50E-06 9.00E-06 8.50E-06 8.00E-06 7.50E-06 7.00E-06 6.50E-06 6.00E-06 5.50E-06 5.00E-06 4.50E-06 4.00E-06 3.50E-06 3.00E-06 2.50E-06 2.00E-06 1.50E-06 1.00E-06 5.00E-07 0.00E+00 (b) Conceptual Model #2 (By-Passing) Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 137 March 2000 Based on DTN: LB9908T1233129.001 Figure 6-59. (a) Simulated Mass Fraction Contours of a Reactive Tracer at the Water Table after 1,000 Years, Indicating Potential Breakthrough Locations at the Time, Using the Present- Day, Mean Infiltration with Conceptual Model #1. 170000 172000 174000 Nevada Coordinate E-W (m) 230000 232000 234000 236000 238000 Nevada Coordinate N-S (m) 1.00E-06 9.50E-07 9.00E-07 8.50E-07 8.00E-07 7.50E-07 7.00E-07 6.50E-07 6.00E-07 5.50E-07 5.00E-07 4.50E-07 4.00E-07 3.50E-07 3.00E-07 2.50E-07 2.00E-07 1.50E-07 1.00E-07 5.00E-08 0.00E+00 (mm/yr) Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 138 March 2000 Based on DTN: LB9908T1233129.001 Figure 6-59 (b) Simulated Mass Fraction Contours of a Reactive Tracer at the Water Table after 1,000 Years, Indicating Potential Breakthrough Locations at the Time, Using the Present- Day, Mean Infiltration with Conceptual Model #2. 170000 172000 174000 Nevada Coordinate E-W (m) 230000 232000 234000 236000 238000 Nevada Coordinate N-S (m) 1.00E-06 9.50E-07 9.00E-07 8.50E-07 8.00E-07 7.50E-07 7.00E-07 6.50E-07 6.00E-07 5.50E-07 5.00E-07 4.50E-07 4.00E-07 3.50E-07 3.00E-07 2.50E-07 2.00E-07 1.50E-07 1.00E-07 5.00E-08 0.00E+00 (mm/yr) Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 139 March 2000 Groundwater travel and 36Cl transport times from the land surface: Groundwater travel or 36Cl transport times to the potential repository since release from the ground surface may be estimated using a cumulative or fractional breakthrough curve, as shown in Figures 6-60 for the four simulation scenarios. The figure shows a similar range of groundwater travel or tracer transport times for the four different surface source conditions with the same present-day, mean infiltration rate. Except for the scenario with a constant initial concentration within the small surface source area (cam1_CL1), there is about 1% mass breakthrough during 10 to 100 years after tracer release on the ground. This indicates the existence of possible fast flow pathways with a travel time of 50 years, travelling from the ground surface to the potential repository level, under the steady-state UZ flow condition. However, the cumulative mass breakthrough is small (~1% of the total mass released on the ground) for the early breakthrough at 50 years. The average groundwater travel times from the surface to the potential repository level is estimated between 5,000 to 20,000 year using the 50% mass breakthrough curves of Figure 6-60 from the four simulation results. Figures 6-61 shows spatial profiles of tracer mass fraction or concentrations in the UZ model at 50 years of release from the small source area of the top boundary. In a plan view, Figure 6-61 indicates very localized breakthrough at the potential repository level, with all the high mass fraction/concentration zones associated with faults. Examination of the simulated tracer concentration distributions along vertical cross sections, and the ESF and ECRB tunnels indicates that in the vertical direction, tracer plumes penetrates faster only along high-permeability faults during the earlier travel times of 50 to 1000 years Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 140 March 2000 Based on DTN: LB9908T1233129.001 Figure 6-60. Simulated Breakthrough Curves of Cumulative Tracer (36Cl) Mass Arriving at the Potential Repository Level, Since Release from the Ground Surface, Using the Present-Day, Mean Infiltration and Four Simulation Scenarios 100 101 102 103 104 105 106 TIME (years) 10-3 10-2 10-1 100 Fractional Mass Breakthrough at Repository Level cam1-CL1 cam1-CL2 cam1-CL3 cam1-CL4 Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 141 March 2000 Based on DTN: LB9908T1233129.001 Figure 6-61. Simulated Spatial Distribution of Tracer (36Cl) in the US System at 50 Years since Release from the Ground Surface, Simulated Normalized Mass Fraction Contours at the Potential Repository Level (Note X3 denotes tracer mass fraction normalized to mass fraction values at source). 170000 172000 174000 230000 232000 234000 236000 238000 Nevada Coordinate N-S (m) -3 -3.25 -3.5 -3.75 -4 -4.25 -4.5 -4.75 -5 -5.25 -5.5 -5.75 -6 -6.25 -6.5 -6.75 -7 -7.25 -7.5 -7.75 -8 log(X3 170000 172000 174000 Nevada Coordinate E-W (m) 230000 232000 234000 236000 238000 Nevada Coordinate N-S (m) -3 -3.25 -3.5 -3.75 -4 -4.25 -4.5 -4.75 -5 -5.25 -5.5 -5.75 -6 -6.25 -6.5 -6.75 -7 -7.25 -7.5 -7.75 -8 FRACTURE MASS FRACTION AT REPOSITORY LEVEL log(X3) Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 142 March 2000 6.8 MODEL VALIDATION 6.8.1Alcove 1 Test Results The continuum approach has been used in the UZ Flow and Transport Model. The reasons for using this approach are documented in the AMR describing conceptual and numerical models for UZ flow and transport (CRWMS M&O 2000c). One way to confirm the validity of the continuum approach is to compare simulation results based on these approaches with field observations (Pruess et al. 1999, p. 312). The same continuum concept is used in this modeling study, although grid spacings near the alcove are significantly smaller than those used in the site-scale model. Recently, an infiltration and tracer transport test was performed in the ESF Alcove 1. Alcove 1 is located near the North Portal of the ESF in the upper lithophysal zone of the Tiva Canyon Tuff (Tpcpul) unit, corresponding to hydrogeologic unit CUL (Flint, 1998, p. 3). The Tpcpul unit extends above the alcove to the ground surface, with the crown of the drift approximately 30 m below the ground surface. The infiltration test at Alcove 1 involved applying water at the ground surface directly over the end of Alcove 1. At a late stage of the test, a conservative bromide tracer was introduced into the infiltrating water. The seepage into the alcove and the tracer arrival time were recorded. The experimental observations are directly related to the flow and transport processes in the unsaturated fractured rocks and, therefore, provide a useful data set for evaluating the continuum approaches used in the UZ flow and transport model. The test consisted of two phases. Phase I was performed from March to August in 1998 and corresponds to a relatively large degree of temporal variability in the infiltration-rate data. Phase II was performed from January to June in 1999. This study was documented in Scientific Notebooks (YMP-LBNL-JSWCFA- 6.1 pp. 1-26; 39-48; 72-88, YMP-LBNL-GSB-1.12 p. 153, YMP-LBNL-GSB-1.6.3 pp. 74- 78, and YMP-LBNL-GSB-LHH-2 pp. 67-73). 6.8.1.1 Numerical Model A radially symmetric, two-dimensional (2-D) grid in cylindrical coordinates was constructed for simulation of the infiltration test (Figure 6-62). The grid extended 45 m in the vertical dimension and 30 m in the radial (horizontal) dimension (the diameter is 60 m). The ground surface was approximated as horizontal. A square opening representing the alcove has created in the grid from 30 m to 35.5 m below the ground surface. The grid was regular, with 10-cm grid spacing around the alcove and 1-m grid spacing away from the alcove. The active fracture model (Liu et al. 1998, pp.2633-2646) was employed to describe flow and transport within fractures and between fractures and the matrix. Because of the highly transient nature of the infiltration test, the multiple interacting continua (MINC) approach was used. Three matrix continua were used for developing the numerical grid. The development of the grid is documented in Scientific Notebooks (YMPLBNL- JSW-CFA-6.1 pp. 9; 17-18; 45-46 and YMP-LBNL-GSB-1.1.2 p. 153). Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 143 March 2000 DTN: LB991131233129.002 Figure 6-62. Numerical Grid for the Model of the Infiltration Test Because the test site is located in the same hydrogeological unit, hydraulic properties for fractures and the matrix are assumed to be homogeneously distributed within the model domain. The initial estimate for these properties was taken from different sources for the model calibration (Table 6- 32) because a systematic calibrated property set for the CUL unit, where the test site is located, was not available. Matrix properties were directly taken from those for hydrologic unit CUL in (DTN: GS960908312231.004.) Fracture permeability, residual saturation and van Genuchten a were from DTN: LB971212001254.006 (Table A-2a, tcw11) and fracture van Genuchten m was taken from DTN: LB990501233129.001. The initial estimates of fracture porosity was assumed to be 0.01, based on the porosity data in DTN: LB980912332245.002. The fracture spacing was calculated using fracture-frequency data between ESF stations 0 + 60 m and 0 + 80 m [from the Detailed Line Survey (DTN: GS971108314224.020)]. Software routines Read_TDB (version 1.0) and Frac_Calc (Version 1.1), were used for calculating the fracture frequency. Since the objective of this study is mainly to evaluate the numerical approach, it should be considered as a corroborative study. 0 10 20 30 -40 -30 -20 -10 0 depth (m) seepage face water and tracer 2-D NUMERICAL GRID distance from center (m) Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 144 March 2000 The temporally variable inflow rates are imposed on the top boundary, representing the infiltration condition. The side boundary away from the alcove corresponds to a zero-flow condition in the radial direction, considering that the side boundary is far away from the alcove. The alcove wall boundary is modeled using a zero-capillary-pressure condition, corresponding to 100% humidity within the alcove. The bottom boundary was assigned a constant matrix saturation of 0.61, which is the average matrix saturation of the unit CUL (DTN: GS960908312231.004). Initially, rock mass within the model domain was considered to be in gravity-capillary equilibrium with the low boundary and to be solute-free. 6.8.1.2 Results and Discussion Figure 6-63 shows a comparison between observed seepage rate data for Phase I of the test and the simulation result from model calibration with ITOUGH2 (version 3.2). Table 6-33 gives the rock properties calibrated with Phase I data. Although arrival times of three major peaks in the Phase I seepage rate data are matched, large differences exist between the simulated and observed seepage rate values at these peaks. While it is possible that the homogeneity assumption and the continuum approach underestimates the variability of seepage rates, we believe that the more important reason is the simplicity of the model in representing the site conditions during the Phase I test. Table 6-32. Initial Estimated Hydrologic Properties for Infiltration Test Model Parameter Fracture Matrix Porosity [-] 0.01 0.164 Permeabilitya [m2] 2.29 x10-11 1.2Ex10-15 Van Genuchten a [Pa-1] 2.37 x10-3 7.12x10-6 Van Genuchten m [-] 0.633 0.346 Residual saturation [-] 0.01 0.06 Fracture spacing [m] 0.377 NA DTNs: GS960908312231.004; LB971212001254.006; LB990501233129.001; LB980912332245.002 GSa71108314224.020 NOTES: aIn both the vertical and horizontal directions Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 145 March 2000 Data - CRWMS M&O (1999f) Model Results - DTN: LB991131233129.002 Figure 6-63. Model Calibration Using the Seepage Rate Data of the Phase I of the Test and Prediction for Phase II of the Test. We modeled liquid-water flow with the EOS9 module, which ignores vapor transport. An isothermal condition was also assumed for simplicity. Since the Phase I test was conducted from March to August in 1998, temperatures were relatively high in the late stage of the test, which may have caused considerable vapor transport and evaporation through highly permeable and well-connected fractures. The matrix saturation near the fracture-matrix interface becomes very high with time between the alcove’s ceiling and the ground surface, resulting in very small simulated matrix imbibition between 100 and 200 days. Simulated results consequently show a strong response to the infiltration pulses during this period. In reality, the vapor transport might remove a portion of the liquid water from the fractures and the matrix near the fracture-matrix interface area. This could give rise to a weaker response of the seepage to the infiltration, as indicated by the data (Figure 6-63). Because of the temporally variable infiltration rates in Phase I of the test, a complex wetting and drying process was involved in the matrix. Under these conditions, hysteresis might considerably affect seepage into the alcove. However, not enough data were available for characterizing the matrix hysteresis. Instead, a single matrix water retention curve was used for both the wetting and drying procedure. However, these issues are not specific to the continuum approach used for this study. 100 200 300 400 Time [day] 0 50 100 150 200 250 300 350 400 seepage rate [L/day] Data Calibration Prediction Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 146 March 2000 Figure 6-63 also shows a comparison between the predicted seepage rates and the data for Phase II of the test. Properties calibrated against Phase I test data were used for the prediction. The comparison is fairly reasonable considering that a relatively poor match was obtained for the Phase I test using the inverse modeling. The comparison confirms that ignoring water loss through evapotranspiration for periods of high temperature is a major reason for the poor match of the Phase I data. For the Phase II test, simulated seepage occurs earlier than the observation, and the simulated seepage rates are generally higher in the 350.380 day period (Figure 6-63). As a result of the model’s inability to deal with vapor transport, the fracture-matrix system in the numerical model was wetter than the actual system during the initial stage of the Phase II test. The wetter condition reduces the matrix imbibition and therefore increases the seepage rate. After 380 days, the performance of the model prediction improves, possibly because during this period the actual system is very wet, and actual matrix saturations approximate the modeled results. The Phase II test data, shown in Figure 6-63, were collected from January to May in 1999. In this period, the vapor transport is not considered to be important because the temperature is not very high. More importantly, Figure 6-63 shows that the infiltration and seepage processes can be reasonably represented by the model, considering the complexities of the problem and the simplicity of the model. In other words, a continuum approach is shown to be valid for capturing the complex flow and transport processes in an unsaturated fractured porous medium. Table 6-33. Calibrated Hydrologic Properties for Infiltration Test Model Based on the Phase I Seepage Rate Dataa Parameter Fracture Matrix Porosity [-] 0.028 0.164 Vertical Permeability [m2] 2.90Ex10-11 3.64x10-16 Horizontal Permeability [m2] 3.14Ex10-11 9.35x10-16 Van Genuchten a [Pa-1] 2.07Ex10-3 1.43x10-5 Active fracture parameter . [-] 0.28 NA DTN: LB991131233129.002 NOTE: aParameters that are not shown is this table are the same as those in Table 6-32. They are fixed in the inversion. Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 147 March 2000 Data - DTN: GS000399991221.003 Model Results - DTN: LB991131233129.002 Figure 6-64. Model Calibration Using Seepage Rate Data from Phases I and II Test. To further improve the accuracy of rock property estimates, we conducted the second inversion based on data from both Phase I and Phase II of the test. The initial estimate for rock properties, used in the model calibration, was based on those in Table 6-32. Figure 6-64 shows the comparison between the simulated and observed seepage rates, which is similar to that in Figure 6-63. The calibrated properties are given in Table 6-34. Note that these properties are very comparable to the base case properties of model layer tcw11 (DTN: LB990501233129.001) in terms of order of magnitude. Table 6-34. Calibrated Hydrologic Properties for Infiltration Test Model Based on the Phases I and II Seepage Rate Dataa Parameter Fracture Matrix Porosity [-] 0.03 0.164 Vertical Permeability [m2] 3.23x10-11 3.23x10-16 Horizontal Permeability [m2] 3.53x10-11 8.08x10-16 Van Genuchten a [Pa-1] 2.04x10-3 1.84x10-5 Active fracture parameter . 0.23 NA DTN: LB991131233129.002 NOTE: a Parameters that are not shown is this table are the same as those in Table 6-32. They are fixed in the inversion. 100 200 300 400 Time [day] 0 50 100 150 200 250 300 350 400 seepage rate [L/day] Data Model calibration Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 148 March 2000 Figure 6-65 shows tracer transport simulation results obtained with T2R3D (Version 1.4). The tracer test was carried out over a 51 day period, beginning on May 18, 1999. First detection of the tracer within the seepage occurred after 28 days. To predict the tracer arrival time, we assumed zero dispersivity for the fracture continuum since no data for the dispersivity are available. Note that Figure 6-65 shows the predicted breakthrough curve is not sensitive to the fracture dispersivity value. A molecular diffusion coefficient of 2.0E-9 m2/s was used for bromide (Domenico and Schwartz 1990, p. 368). According to Francis (1997, p. 5), while experimental data for tortuosity are not available for the Yucca Mountain tuff, a representative value of the matrix tortuosity is 0.7. Figure 6-65 shows simulation results for a number of tortuosity values. Since pore velocities in the matrix are generally small, the mechanical dispersion is ignored for the matrix. The calibrated hydrologic properties based on both Phases I and II seepage data (Table 6-34) were used in the simulation. Data - DTN: GS000399991221.003 Model Results - DTN: LB991131233129.002 Figure 6-65. Comparison between Simulation Results of Tracer Transport and Observations. (Note that alpha-l, alpha-t, phi refer to longitudinal dispersivity, transverse dispersivity and fracture porosity, respectively.) As shown in Figure 6-65, the simulated breakthrough curve is closely matched with the tracer concentration data for a tortuosity value of 0.75, which is close to the representative value of 0.7 given by Francis (1997, p. 5). This indicates that our model correctly predicts the tracer transport 10-2 10-1 100 101 102 103 104 Time (days) 0.0 0.2 0.4 0.6 0.8 1.0 1.2 Relative tracer mass fraction (X/X0) threshold tracer test resuslts test results X X alpha-l=30.0m, Dm=2.0e-9, tortuosity=0.75 alpha-l=30.0m,Dm=2.0e-9, tortuosity=0.5 alpha-l=30.0m,Dm=2.0e-9,tortuosity=0.25 alpha-l=0m,Dm=2.0e-9,tortuosity=0.5 alpha-l=0m,Dm=1.0e-10,tortuosity=0.5 X Note : in all cases, phi=0.3 and alpha-t=alpha-l/10 Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 149 March 2000 behavior without calibration of transport parameters. Again, this validates the continuum approach and shows that it can capture important features of the UZ transport processes. An important finding from the tracer simulations is that the breakthrough curve is considerably sensitive to the matrix molecular diffusion coefficient and tortuosity (Figure 6-65), suggesting that matrix diffusion is an important mechanism for UZ transport. This sensitivity also implies that flow and transport between the two continua (fracture-matrix interaction) is correctly simulated with the active fracture model, although complex fingering of flow and transport occurred in the fracture networks during the Alcove 1 test. On the other hand, the simulation result is not sensitive to the fracture dispersivity, possibly because in a dual-continua system, the chemical transport is mainly determined by the largest heterogeneity, the property difference between the matrix and fracture continua. In this case, heterogeneity in each continuum, resulting in the corresponding macroscopic dispersion process, becomes secondary. In summary, the results from this study indicate that the continuum approach is valid for modeling flow and transport in unsaturated fractured rock. The use of an active-fracture model can capture the major features of fingering flow and transport in fractures. The matrix diffusion has a significant effect on the overall transport behavior in unsaturated fractured rocks, while the dispersion in fractures does not. 6.8.2 ECRB Results An east and west cross drift was constructed in 1997 as part of the Enhanced Characterization of the Repository Block (ECRB) program (see Figure 6-1 for the location of the ECRB tunnel). Water-potential data (DTN: GS980908312242.036) were collected from heat dissipation probes installed in the tunnel wall (at a depth of 2 meters) along the ECRB tunnel inside ESF. The probe locations were transferred from station number to Nevada Coordinates system through ECRBXYZ Version 03 (STN: 30093). Water potential data were collected from heat dissipation sensors that have been calibrated for matrix potential. At installation, the borehole was dry drilled, however the sensor was not installed with the wet cement. Thus the sensor was fully saturated and surrounded with contact media to ensure good contact with rock. The sensor then equilibrated with the matrix potential of the rock (took about two to six weeks). Often following the equilibration, the probe would gradually dry out. Since this was the first group of probes installed in the tunnel wall, there were no steps taken to reduce the effects of ventilation drying in the tunnel. Extra steps such as installing double doors were taken during installation and monitoring the first group of probes in the ECRB tunnel. Accuracy of heat dissipation probes calibrated intensively and as a function of temperature is plus or minus 10% of the matrix potential reading. As part of the 3-D flow and transport modeling validation process, modeling results were compared to the field observation data collected from the wall of the tunnel to check the accuracy of the modeling predictions. The 3-D mesh with perched water flow-through model adjustment for the Calibration flow-fields was used (DTN: LB990501233129.004). Infiltration boundary conditions were the same as those documented in Section 6.1.3 and 6.1.4 for the present-day, base-case infiltration scenario Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 150 March 2000 CRWMS M&O 1999e, (DTN: GS000399991221.002). The calibrated properties used for the 3-D prediction are those developed by inversion of saturation, water potential, and pneumatic data using 1-D and 2-D models for the present-day, base-case infiltration scenario. The detail of the model development is documented in Section 6.1 and 6.2. Figure 6-66 shows a comparison of matrix water potential along the wall of the ECRB drift. As shown in the figure, observation data are available only along part of the tunnel. Most of the observed water-potential data are distributed between 0.1 and 1 bar, with a maximum of 3.4 bar. The model predicted approximately 1 bar for the same section of tunnel, which is higher than most of the observed data. The predicted water-potential data from the UZ Model ranged between 0.1 and 3.3 bar. Data - DTN: GS980908312242.036 Model Results - DTN: LB990801233129.003 Figure 6-66. Predicted Water Potential along ECRB Using the Present-Day Mean Infiltration Rate and Perched Water Conceptual Model #1 Since the probe measurements have an error of plus and minus 10%, field heterogeneity will play an important role for a range of data between 0.1 and 1 bar. Even though the data available for comparison at the ECRB drift are limited, results indicated that the UZ Model generally predicted the range of the water-potential data from in situ measurements. Even though the data available for comparison at the ECRB drift are limited, results indicated that the UZ Model results were within the range of the water-potential data from in situ measurements. 170000 170500 171000 171500 Nevada Coordinate E-W (m) 10-2 10-1 100 101 Water Potential (Bar) In-situ Data pch1-m2 Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 151 March 2000 6.8.3 SD-6 and WT-24 Modeling Results Boreholes WT-24 and SD-6 were drilled in 1997 as part of the ECRB program (see Figure 6-1 for borehole locations). Observed saturation data were collected from these two boreholes (see Section 4-1 for DTNs). No perched water was detected in borehole SD-6. However, perched water was detected within the basal vitrophyre of the TSw at an elevation of approximately 985 m for borehole WT-24 (DTN: GS980508312313.001). As part of the modeling validation process, modeling results were compared to the field-observation data to check the accuracy of the modeling predictions. The 3-D mesh with perched water flow-through model adjustment for the calibration flow-fields was used (DTN: LB990501233129.004). Infiltration boundary conditions were the same as those documented in Section 6.1.3 and 6.1.4 for the present-day, base-case infiltration scenario (DTN: GS000399991221.002). The details of the model development are documented in Section 6.1 and 6.2. Figure 6-67 shows a comparison of matrix saturation results with field measurement data at borehole SD-6. As shown on the figure, the modeling prediction is generally consistent with field measurements. The model does not predict perched water occurrence at this borehole, which is consistent with field observation. The modeling result predicts higher saturation in this CHn unit; however, the field measurement indicates a dry condition in the same unit. This is a result of the current geological framework model which specifies this layer as zeolitic layer at the location of SD-6. Data - DTN: GS980808312242.014; Model Results - DTN: LB990801233129.003 Figure 6-67. Predicted Matrix Saturation for Borehole SD-6 using the Present-Day Mean Infiltration Rate and Perched Water Model #1 0.0 0.5 1.0 Saturation 700 800 900 1000 1100 1200 1300 1400 Elevation (m) USGS Data Hydro. Unit pch1-m2 TSw TCw CHn PTn Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 152 March 2000 Figure 6-68 compares matrix saturation results with the field measurement data at borehole WT-24. The observed location of perched water is also shown on the figure. As shown on the figure, the field-measurement data for saturation are limited to the deeper section of the borehole (mostly in the CHn unit). The UZ Model predicts a saturated condition at the location of observed perched water, which matches the field measurement. Even though several low saturation data points appear in the vicinity of perched water elevation, most of the data points collected in the same vicinity have much higher saturations. There is a low saturation layer within the CHn unit (according to the field measurement data) that was not predicted by the UZ Model. Data - DTN: GS980708312242.010 Model Results - DTN: LB990801233129.003 Figure 6-68. Predicted Matrix Saturation for Borehole WT-24 using the Present-Day Mean Infiltration Rate and Perched Water Model #1 The data gaps at the particular units (i.e., CHn) for these two boreholes are due to the inaccuracy of the 3-D geological model GFM3.1 at certain locations. High saturations within the CHn are strongly correlated with the presence of zeolites (portions of the CHn that are vitric tend to show much lower saturations than the zeolitic portions of the CHn). During development of the mountain-scale numerical grids, data on the abundance of zeolites within SD-6 of WT-24 in the CHn were not available. It was assumed that ch1 through ch6 were zeolitic in WT-24 and that ch2 through ch6 were zeolitic in SD-6 (based on geostatistically determined hydraulic conductivity data from the Rock Properties Model (RPM3.0 of ISM3.0). The accuracy of UZ Model depends partly on the accuracy of the Integrated Site Model, which is assumed to represent subsurface geology as well as rock properties. The spatial heterogeneity of low-permeability alteration products such as zeolites has a profound impact on flow and transport calculations, yet the nature 0.0 0.5 1.0 Saturation 700 800 900 1000 1100 1200 1300 1400 Elevation (m) USGS Data Hydro. Unit pch1-m2 TSw TCw CHn Perched Water PTn Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 153 March 2000 of their distribution is not fully understood. The data gaps should be resolved with the updated version of the Integrated Site Model (ISM3.1). In general, the UZ Model accurately predicts the location of perched water at borehole WT-24. Consistent with field data, this model also indicates no perched water at borehole SD-6. The modeling predictions are generally consistent with field measurements for both boreholes. 6.8.4 3-D Pneumatic Prediction As part of the validation effort to build confidence that the calibrated property sets documented in the AMR Calibrated Properties Model (CRWMS M&O 2000b), a fully 3-D pneumatic simulation was performed. The results of this simulation are compared to both the pneumatic data used for the calibration and the pneumatic data for the 30 days immediately following the calibration data. Differences between the 3-D pneumatic prediction and the 1-D and 2-D calibrated pneumatic simulations (CRWMS M&O 2000b, Sections 6.1 and 6.3) were also assessed. Data from 27 instrument stations in six boreholes were then compared to the 3-D prediction. The 3-D mesh for the TSPA flow-fields was used. This mesh is documented in AMR Development of Numerical Grids for UZ Flow and Transport Modeling (CRWMS M&O 1999d, pp. VI-1 to VI-7; DTN: LB990701233129.001). The calibrated properties used for the 3-D pneumatic prediction are those developed by inversion of saturation, water potential, and pneumatic data using 1-D and 2-D models for the present-day, base-case infiltration scenario (CRWMS M&O 2000b, Sections 6.1 and 6.3; DTNs LB997141233129.001 and LB991091233129.004). Infiltration boundary conditions were the same as those documented in Section 6.1.3 for the present-day, base-case infiltration scenario. Pneumatic boundary conditions are developed using the routine TBgas3D (MOL. 19991012.0222) and atmospheric barometric pressure data from boreholes USW NRG-6 and USW NRG-7a, (YMP-LBNL-GSB-1.1.2, pp. 155-156). The 3-D pneumatic predictions were compared to pneumatic data from six boreholes. Table 6-35 shows the start and end dates for the data used to calibrate the property sets and for validation. Data from the first 30 days of each are used for the inversion, as documented in the AMR Calibrated Properties Model (CRWMS M&O 2000b, pp. 41 and 62). Data from the second 30 days are compared to the prediction for validation. Table 6-35. Pneumatic Data Used for Inversion (First Thirty Days) and Validation (Last Thirty Days). Borehole Date/Range UE-25 NRG#5 7/17 – 9/15/95 USW NRG-6 3/27 – 5/26/95 USW NRG-7a 3/27 – 5/26/95 USW SD-7 4/5 – 6/4/96 NOTE: DTNs are provided in Table 4-1. Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 154 March 2000 Comparisons of the 3-D prediction and the data for boreholes USW SD-12 and USW UZ-7a are shown in Figures 6-69 and 6-70, respectively. Both figures show a good match between the prediction and the data. Also shown are the 1-D and 2-D calibrated simulation results documented in the AMR “Calibrated Properties Model” (CRWMS M&O 2000b, Figures 4 and 11). At USW SD-12, the 3-D simulation predicts a larger amplitude signal in the TSw than the calibrated 1-D simulation. This difference can be attributed to the presence of the nearby Ghost Dance fault, which has a higher permeability through the PTn than does the formation (non fault zone) rock at USW SD-12 (CRWMS M&O 2000b, Sections 6.1 and 6.3). At USW UZ-7a, in the Ghost Dance fault, the 3-D simulation predicts a slightly smaller amplitude signal in the TSw than the calibrated 2-D simulation. This difference can be attributed to lateral losses within the fault zone to the north where the PTn is thicker and thus further restricts the propagation of the barometric signal. Observation - GS960308312232.001 Model Results - DTN: DTNs: LB991121233129.007 Figure 6-69. Comparison of 3-D Pneumatic Prediction to Data (Observation) from Borehole USWSD-12 anda 1-D Calibrated Simulation. USW SD-12 12/1/95 – 1/29/96 USW UZ-7a 12/1/95 – 1/29/96 Table 6-35. Pneumatic Data Used for Inversion (First Thirty Days) and Validation (Last Thirty Days). NOTE: DTNs are provided in Table 4-1. 0 10 20 30 40 50 60 Time [days from 12/1/95] 86 87 88 89 90 91 Pressure [kPa] 1-D calibration period observation 1-D calibrated simulation TCw PTn TSw TSw 3-D prediction Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 155 March 2000 Observation - DTN:GS960308312232.001 Model Results - DTN: LB991121233129.007, Figure 6-70. Comparison of 3-D Pneumatic Prediction to Data (Observation) from Borehole USWUZ-7a and 2-D Calibrated Simulation. The good match between the 3-D pneumatic prediction and the pneumatic data builds confidence that the base-case infiltration-scenario calibrated properties are appropriate for gas-flow simulations. The simulations using the upper- and lower-bound infiltration-scenario calibrated properties produced results that were virtually identical to those from simulations using the basecase infiltration-scenario calibrated properties (CRWMS M&O 2000b, Section 6.1). This is not expected to change for the 3-D simulations, and thus the upper- and lower-bound infiltrationscenario calibrated properties are also appropriate for gas-flow simulations. While the comparisons of the 3-D pneumatic predictions with the 1-D and 2-D calibrated pneumatic simulations show that the assumptions of 1-D and 2-D flow (CRWMS M&O 2000b, Section 5), respectively, are not completely correct, they do show that they provide reasonable estimates of fracture permeability for the 3-D UZ Model. 0 10 20 30 40 50 60 Time [days from 12/1/95] 85 86 87 88 89 Pressure [kPa] 2-D calibration period observation 2-D calibrated simulation TCw PTn PTn TSw TSw 3-D prediction Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 156 March 2000 INTENTIONALLY LEFT BLANK Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 157 March 2000 7. CONCLUSIONS This AMR documents the development, results, and analyses of the UZ flow model and submodels, including the: • 3-D UZ flow calibration model • Geothermal calibration model • Chloride submodel • Calcite submodel • 3-D UZ flow model for generating 18 flow fields • Groundwater travel and tracer transport model • Model validation. The UZ flow model and its submodels are developed to simulate past, present, and future hydrogeologic, geothermal, and geochemical conditions within the unsaturated zone of Yucca Mountain to support various TSPA activities. In particular, as part of the output of this AMR, 18 3-D steady-state flow fields of the Yucca Mountain UZ system have been generated for TSPA-SR calculations. This report has documented the UZ flow model and its submodels in terms of modeling approach, hydrogeological conceptual model, data source and incorporation, methodology of model calibrations, perched water parameter estimation, and model results and analysis of the 18 flow fields and associated analyses on groundwater travel times and tracer transport. 7.1UZ FLOW MODEL CALIB RATION As a critical step, field-measured saturation, water potential and perched water data have been used to calibrate the UZ Model. Such calibrations are part of the important iterative processes of model development in order to increase confidence in model predictions of site condition. This AMR continues the model calibration effort using the 1-D inversions reported in CRWMS M&O (2000b) and focuses on 3-D perched water calibrations using a 3-D calibration grid. The calibration was conducted using three sets of parameters CRWMS M&O (1999d), three present-day infiltration rates, and the geological model and numerical grid for calibration (CRWMS M&O 2000b). Two water-perching models were investigated, in which rock properties were locally modified in several gridlayers near the observed perched zones. In addition, one nonperching model was also used for comparative studies. The model calibration efforts conclude that the UZ Model can reproduce moisture conditions in the unsaturated zone of Yucca Mountain in terms of liquid saturations and water potentials, as verified by observations. In general, the modeled results from all the six calibration simulations with perched water Conceptual Models #1 and #2 are in good agreement with the measured water-perching elevations at seven boreholes with perched water occurrence for upper-bound and mean present-day infiltration scenarios. However, under the lower-bound present-day infiltration rate, the models did not match the perched water data very well in boreholes SD-7, SD-9, and UZ- 14 because of the low percolation fluxes at these locations. Conceptual Model #1 is a preferred one because it has a minimum calibration and match perched water data better. Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 158 March 2000 The UZ Flow model provides steady-state results of flow of fluids and heat as well as tracer transport. The steady-state results for model layers above the TSw may be subject to episodic infiltration. These model results may not reflect actual conditions; that are scale-dependent and so the results are not intended to be valid for other scales such as drift-scale studies. In this report, the uncertainties in the results due to input parameter and model gridding uncertainties are evaluated by generating a number of flow fields with various parameter sets, infiltration maps, and conceptual models. Using the dual permeability model, the matrix is represented by one gridblock which is only valid for steady-state flow according to Doughty (1999); and any others that apply to this modeling approach. 7.2 GEOTHERMAL MODEL CALIBRATION Field-measured temperature data was used to calibrate the geothermal conditions of the UZ Model, using the base-case present-day infiltration parameter set with a 3-D ECM model. The calibration results are in good agreement with the observed temperature profiles from boreholes and provide the ambient temperature distributions for determining boundary and initial conditions for thermohydrologic models. 7.3 CHLORIDE SUBMODEL Pore-water chemical-concentration data have been analyzed by 3-D chemical transport numerical simulations. Surface infiltration rate calibrations were performed using the pore-water Cl concentrations. Modeled results of chemical distributions were improved when using the calibrated infiltration map. In addition, an analytical method has been applied to transient transport analysis. The analytic analysis, validated by 3-D simulations under the same flow and transport conditions, was able to capture major Cl and Cl36 transient transport behavior and trends. This work indicates that chemical transport studies provides an alternative interpretation by which to estimate the distribution of net infiltration. The calibration results can be important at places where a significant amount of measured pore-water chemical data are available. Additional information on infiltration, flow mechanism, and climate effects may be helpful to further investigate chemical transport in the UZ system of Yucca Mountain. 7.4 CALCITE SUBMODEL Analysis of calcite deposition using a transport-reaction model not only gives us some constraints on hydrology, but also provides useful insights into the hydrogeochemical processes in the system. The model considers: (1) fracture-matrix interaction, (2) gaseous CO2 diffusive transport and partitioning in liquid and gas phases, (3) ambient geothermal gradient, and (4) kinetics of fluid-rock interaction. Calcite deposition values obtained from simulations can reproduce the measured data. The calcite precipitation generally increases as percolation increases. This interconnection depends on boundary-water types and reaction rates. Calcite deposition is sensitive to boundary-water chemical composition indicated by CO2 partial pressure. The higher the partial pressure, the lower the calcite precipitation. Calcite depth-dependent distribution varies with reaction rate. Simple mineralogy simulations considering most relevant minerals may reproduce the calcite deposition condition better than complex mineralogy simulations. A Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 159 March 2000 thorough understanding of complex mineralogy may be complicated by the uncertainty of thermodynamic and kinetic data for clay minerals that are poorly known at present. 7.5 TSPA FLOW FIELDS Eighteen 3-D UZ flow fields are generated for TSPA_SR calculations. These flow fields are based on (1) the TSPA grid CRWMS M&O (1999d), (2) nine infiltration maps representing three climates; (3) the three parameter sets in CRWMS M&O (2000b); and (4) the two conceptual models of perched water with the calibrated perched water parameters. The purpose of studying a large number of flow fields for various modeling scenarios is to cover all TSPA-SR scenarios and to account for possible current and future site conditions. The main uncertainties currently considered in the UZ Model include fracture-matrix properties, present-day and future infiltration rates over the mountain, and conceptual models for perched water occurrence. The simulation results for 18 flow fields were checked and compared against observed matrix liquid saturation, water potential, and perched water data. In general, model results from the 18 3- D simulations were able to match observed saturation and water potential data. For calibrations with perched water data, the simulations with mean and upper infiltration rates of the three climates with both perched water conceptual models can reproduce water-perching conditions in all the observation boreholes. For lower-bound infiltration runs, the models are also able to match perched water data from most boreholes, except at SD-7 or UZ-14 boreholes (which have zero infiltration rates. A detailed analysis of simulated percolation fluxes at the potential repository level and at the water table was conducted for 18 simulation scenarios of TSPA flow fields. These percolation fluxes and their distributions at the potential repository level indicate that there is relatively small lateral flow or diversion by the PTn unit for all the 18 simulations using both the perched water conceptual models. However, comparing simulated percolation fluxes at the potential repository level with those at the water table, using the two perched water conceptual models, we verified that perched water Conceptual Model #2 (by-passing model) predicts significant lateral flow at perched or zeolitic layers, while Conceptual Model #1 (flow-through model) predicts significantly higher vertical flow crossing perched water or zeolitic zones than Conceptual Model #2 (by-passing model). Fracture-matrix flow components at the potential repository horizon and at the water table were also analyzed for the 18 simulation results. The statistics show that fracture flow is dominant in the welded tuffs, both at the potential repository horizon and at the water table, in all the 18 flow fields. For three present-day infiltration scenarios – fracture-matrix flow components simulated at the potential repository level – fracture flow consists of more than 80% of total flow and at the water table 70–90% of the total flow. For two future climatic scenarios, a higher percentage of fracture flow at both the potential repository (about 86–96%) and water table level (about 70– 96%), compared to the case with the present-day infiltration, was predicted. At the water table, the second perched water conceptual model consistently estimates lower fracture-flow components (by 8% or more under the same infiltration). Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 160 March 2000 7.6 GROUNDWATER TRAVEL TIMES AND TRACER TRANSPORT A total of 42 tracer transport simulations were conducted to obtain insight into the various impacts of infiltration rates, perched water conceptual models, and retardation effects on tracer migration from the potential repository to the water table. All the 18 TSPA flow fields and three additional, non-perching flow simulations were incorporated into these 42 transport runs. For each flow run, there were two tracer transport runs, one for conservative or nonadsorbing and the other for reactive or adsorbing tracer transport, respectively. These tracer-transport studies indicate that there exist a wide range of groundwater travel or tracer transport times associated with different infiltration rates, type of tracers, and perched water conceptual models. The most important factors for groundwater travel/tracer-transport times are (1) surface infiltration rates and (2) adsorption effects in the CHn unit. Compared with effects from infiltration and adsorption, perched water conceptual effects are of secondary importance to the overall impact on groundwater travel/tracer-transport times, but have a primary impact on determining potential breakthrough areas of tracers at the water table. Statistics of groundwater travel or tracer transport times at 10% and 50% mass breakthrough at the water table from the 42 simulations show that groundwater travel or tracer-transport times are inversely proportional to average surface infiltration. When an average infiltration rate increases from 5 to 35 (mm/yr), average groundwater travel (50% breakthrough) times decrease by two to three orders of magnitude. Nonadsorbing tracers migrate two orders of magnitude faster than adsorbing tracer when traveling from the potential repository to the water table under the same infiltration conditions. The non-perching conceptual model predicts the shortest travel times for both nonadsorbing and adsorbing tracers during the first 1,000 years of escape from the potential repository. In addition, four tracer (36Cl) transport simulations were performed to investigate groundwater travel and tracer transport times from the land surface to the potential repository level under steady-state flow conditions. These studies indicate the existence of possible fast flow pathways with travel times of 50 years, for groundwater to travel from the ground surface to the potential repository level. However, the cumulative mass breakthrough carried by the fast flow is relative small (1%) for the early times of 50 years. The 50% mass breakthrough times to the potential repository level since release from the surface is estimated between 5,000 to 20,000 years under the present-day, mean infiltration scenario. The fast flow breakthrough at the earlier time occurs mainly along faults. 7.7 MODEL VALIDATION The current model validation efforts have been documented in this AMR. These activities include simulation studies of the following: (1) Alcove 1 Test; (2) ECRB observation data; (3) SD-6 and WT-24 data; and (4) 3-D gas flow. In all these cases, the results of the UZ Model can reasonably match different types of data, such as water potentials, liquid saturation, seepage rate, breakthrough concentrations, and pneumatic pressures, as observed from the mountain. These efforts have provided validation of the UZ Model and its submodels for their accuracy and reliability in describing and predicting flow and transport processes in the UZ system of Yucca Mountain. Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 161 March 2000 7.8 LIMITATIONS AND UNCERTAINTIES The UZ Model and its submodels are appropriate tools for characterizing flow and transport processes at Yucca Mountain. The accuracy and reliability of the UZ Model predictions are critically dependent on the accuracy of estimated model properties, other types of input data, and conceptual models. These models are limited mainly by the current understanding of the mountain system, including the geological and conceptual models, the volume-average modeling approach, and the available field and laboratory data. Past site investigations have shown that large variabilities exists in the flow and transport parameters over the spatial and temporal scales of the mountain. Even though considerable progress has been made in this area, uncertainty associated with the UZ Model input parameters will continue to be a key issue for future studies. The major uncertainties in model parameters are: (1) accuracy in estimated current, past and future net-infiltration rates over the mountain; (2) quantitative descriptions of heterogeneity of welded and nonwelded tuffs, their flow properties, and detailed spatial distributions within the mountain, especially below the potential repository; (3) fracture properties in zeolitic units and faults from field studies; (4) evidence of lateral diversion caused by zeolites in the CHn units; and (5) transport properties: (e.g., adsorption or Kd coefficients in different rock types, matrix molecular diffusion coefficients in different units for different radionuclides, dispersivities in fracture and matrix systems). These uncertainties have been addressed with the modeling studies in this AMR. This document and its conclusion may be affected by technical product input information that requires confirmation (identified as TBV in Attachment I). Any changes to the document or its conclusion that may occur as a result of completing the confirmation activities will be reflected in subsequent revisions. The status of the input information quality may be confirmed by review of the Document Input Reference System database. However, the results and conclusions of the UZ flow fields will not be affected by the status of temperature and geochemistry data used in the calibration studies, because these flow fields are based on flow simulations under isothermal and different climate conditions. Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 162 March 2000 INTENTIONALLY LEFT BLANK Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 163 March 2000 8. REFERENCES 8.1DOCUM ENTS CI TED Bodvarsson, G.S.; Boyle, W.; Patterson, R.; and Williams, D. 1999. “Overview of Scientific Investigations at Yucca Mountain–the Potential Repository for High-Level Nuclear Waste.” Journal Of Contaminant Hydrology 38 (1–3), 3–24. Amsterdam, The Netherlands: Elsevier Science Publishers. TIC: 244160. CRWMS M&O (Civilian Radioactive Waste Management System, Management & Operating Contractor) 1999a. Analysis & Modeling Development Plan (DP) for U0050, UZ Flow Models and Submodels, Rev. 00. TDP-NBS-HS-000011. Las Vegas, Nevada: CRWMS M&O. ACC: MOL.19991013.0353. CRWMS M&O 1999b. M&O Site Investigations. Activity Evaluation, January 23, 1999. Las Vegas, Nevada: CRWMS M&O. ACC: MOL.19990317.0330. CRWMS M&O 1999c. M&O Site Investigations. Activity Evaluation, September 28, 1999. Las Vegas, Nevada: CRWMS M&O. ACC: MOL.19990928.0224. CRWMS M&O 1999d. Development of Numerical Grids for UZ Flow and Transport Modeling. ANL-NBS-HS-000015. Las Vegas, Nevada: CRWMS M&O. ACC: MOL.19990721.0517. CRWMS M&O 2000a. Analysis of Geochemistry Data for the Unsaturated Zone. ANL-NBSHS- 000017. Las Vegas, Nevada: CRWMS M&O. URN-0048. CRWMS M&O 2000b. Calibrated Properties Model. MDL-NBS-HS-000003. Las Vegas, Nevada: CRWMS M&O. ACC: 19990720.0520. CRWMS M&O 2000c. Conceptual and Numerical Model for the Unsaturated Zone Flow and Transport. MDL-NBS-HS-000005. Las Vegas, Nevada: CRWMS M&O. ACC: MOL.19990721.0526. CRWMS M&O 2000d Drift-Scale Coupled Processes (DST, THC Seepage) Models. MDL-NBSHS- 000001. Las Vegas, Nevada: CRWMS M&O ACC: MOL.19990721.0523. CRWMS M&O 2000e. Repository Safety Strategy: Plan to Prepare the Postclosure Safety Case to Support Yucca Mountain Site recommendation and Licensing Considerations. TDR-WIS-RL- 000001 REV. 3. Las Vegas, Nevada: CRWMS M&O. ACC: MOL.20000119.0189. CRWMS M&O 2000f. Analyses of Hydrologic Properties Data. ANL-NBS-HS-000002. Las Vegas, Nevada: CRWMS M&O URN-0057. Domenico, P.A. and Schwartz, F.W. 1990. Physical and Chemical Hydrogeology. New York, New York: John Wiley and Sons. TIC: 234782. Doughty, C. 1999. "Investigation of Conceptual and Numerical Approaches for Evaluating Moisture, Gas, Chemical, and Heat Transport in Fractured Unsaturated Rock." Journal of Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 164 March 2000 Contaminant Hydrology 38 (1-3), 69-106. Amsterdam, The Netherlands: Elsevier Science Publishers. TIC: 244160. Driscoll, Fletcher G. 1986. Groundwater and Wells, 2nd Edition. St. Paul, Minnesota: Johnson Filtration Systems. TIC: 225919. Dyer, J.R. 1999. “Revised Interim Guidance Pending Issuance of New U.S. Nuclear Regulatory Commission (NRC) Regulations (Revision 01, July 22, 1999), for Yucca Mountain, Nevada.” Letter from J.R. Dyer (DOE) to D.R. Wilkins (CRWMS M&O), September 9, 1999, OL&RC:SB- 1714, with enclosure, “Interim Guidance Pending Issuance of New U.S. Nuclear Regulatory Commission (NRC) Regulations (Revision 01).” ACC: MOL.19990910.0079. Flint, A.L. and Flint, L.E. 1994. “Spatial Distribution of Potential Near Surface Moisture Flux at Yucca Mountain.” Proceedings of the Fifth Annual International Conference on High Level Radioactive Waste Management, 4, Las Vegas, Nevada, May 22–26, 1994, 2352–2358. La Grange Park, Illinois: American Nuclear Society. TIC: 224142. Flint, L.E. 1998. Characterization of Hydrogeologic Units Using Matrix Properties, Yucca Mountain, Nevada. Water-Resources Investigations Report 97-4243. Denver, Colorado: U.S. Geological Survey. ACC: MOL.19980429.0512. Francis, N.D. 1997. "The Base-Case Thermal Properties for TSPA-VA Modeling." Memo from N.D. Francis (SNL) to Distribution, April 16, 1997. Albuquerque, New Mexico: Sandia National Laboratories. ACC: MOL.19980518.0229. Hevesi, J.A.; Flint, A.L.; and Istock, J.D. 1992. “Precipitation Estimation in Mountainous Terrain Using Multivariate Geostatistics, Part II: Isohyetal Maps.” Journal of Applied Meteorology, 31, 677–688. Boston, Massachusetts: American Meteorological Society. TIC: 225248. Javandel, I.; Doughty, C.; and Tsang, C.F. 1984. “Groundwater Transport: Handbook of Mathematical Models.” Water Resources Monograph, 10. Washington, D.C.: American Geophysical Union. TIC: 209908. Lasaga, A.C. 1998. Kinetic Theory in the Earth Sciences. Princeton, New Jersey: Princeton University Press. TIC: 246279. Liu, H.H.; Doughty, C.; and Bodvarsson, G.S. 1998. "An Active Fracture Model for Unsaturated Flow and Transport in Fractured Rocks." Water Resources Research 34 (10), 2633-2646. Washington, D.C.: American Geophysical Union. TIC: 243012. Montazer, P. and Wilson, W.E. 1984. Conceptual Hydrologic Model of Flow in the Unsaturated Zone, Yucca Mountain, Nevada. Water Resources Investigations Report 84-4345. Denver, Colorado: U.S. Geological Survey. TIC: 203223. Pruess, K. and Narasimhan, T.N. 1985. “A Practical Method for Modeling Fluid and Heat Flow in Fractured Porous Media.” Society of Petroleum Engineers Journal, 25 (1), 14–26. Dallas, Texas: Society of Petroleum Engineers. TIC: 221917. Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 165 March 2000 Pruess, K. 1991. "TOUGH2, a General-Purpose Numerical Simulator for Multiphase Fluid and Heat Flow." Report LBL-29400. Berkeley, California: Lawrence Berkeley National Laboratory. ACC: NNA.19940202.0088. Pruess, K.; Faybishenko, B.; and Bodvarsson, G.S. 1999. “Alternative Concepts and Approaches for Modeling Flow and Transport in Thick Unsaturated Zones of Fractured Rocks.” Journal of Contaminant Hydrology (38) 1–3, 281–322. Amsterdam, The Netherlands: Elsevier Science Publishers. TIC: 244160. Sass, J.H.; Lachenbruch, A.H.; Dudly, W.W., Jr.; Priest, S.S.; and Munroe, R.J. 1988. Temperature, Thermal Conductivity and Heat Flow Near Yucca Mountain, Nevada: Some Tectonic and Hydrologic Implications. Open File Rep. 87-649. Denver, Colorado: U.S. Geological Survey. TIC: 203195. Sonnenthal, E. L. and Bodvarsson, G. S. 1999. “Constraints on the Hydrology of the Unsaturated Zone at Yucca Mountain, NV from Three-Dimensional Models of Chloride and Strontium Geochemistry.” Journal of Contaminant Hydrology 38 (1–3), 107–156. Amsterdam, Netherlands: Elsevier Science Publishers. TIC: 244160. Steefel, C.I. and Lichtner, P.C. 1998. “Multicomponent Reactive Transport in Discrete Fractures: II: Infiltration of Hyperalkaline Groundwater at Maqarin, Jordan, a Natural Analogue Site.” Journal of Hydrology, 209, 200–224. Amsterdam, The Netherlands: Elsevier Science Publishers. TIC: applied for. Tyler, S.W.; Chapman, J.B.; Conrad, S.H.; Hammermeister, D.P.; Blout, D.O.; Miller, J.J.; Sully, M.J.; and Ginanni, J.M. 1996. “Soil-Water Flux in the Southern Great Basin, United States: Temporal and Spatial Variations over the Last 120,000 Years.” Water Resources Research 32 (6), 1481–1499. Washington, DC: American Geophysical Union. TIC: 235938. van Genuchten, M. 1980. “A Closed-Form Equation for Predicting the Hydraulic Conductivity of Unsaturated Soils.” Soil Science Society of America Journal, 44 (5), 892–898. Madison, Wisconsin: Soil Science Society of America. TIC: 217327. Wemheuer, R.F. 1999. “First Issue of FY00 NEPO QAP-2-0 Activity Evaluations.” Interoffice correspondence from R.F. Wemheuer (CRWMS M&O) to R.A. Morgan (CRWMS M&O), October 1, 1999, LV.NEPO.RTPS.TAG.10/99-155, with attachments, Activity Evaluation for Work Package #1401213UM1. ACC: MOL.19991028.0162. Wu, Y.S.; Ahlers, C.F.; Fraser, P.; Simmons, A.; and Pruess, K. 1996. Software Qualification of Selected TOUGH2 Modules. Report LBNL-39490, UC-800. Berkeley, California: Lawrence Berkeley National Laboratory. ACC: MOL.19970219.0104. Wu, Y.S.; Haukwa, C. and Bodvarsson, G.S. 1999a. “A Site-Scale Model for Fluid and Heat Flow in the Unsaturated Zone of Yucca Mountain, Nevada.” Journal of Contaminant Hydrology 38 (1–3), 185–215. Amsterdam, The Netherlands: Elsevier Science Publishers. TIC: 244160. Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 166 March 2000 Wu, Y.S.; Ritcey, A.C. and Bodvarsson, G.S. 1999b. “A Modeling Study of Perched Water Phenomena in the Unsaturated Zone at Yucca Mountain.” Journal of Contaminant Hydrology 38 (1–3), 157–184. Amsterdam, The Netherlands: Elsevier Science Publishers. TIC: 244160. Yang, I.C.; Yu, P.; Rattray, G.W.; Ferarese, J.S.; Rayn, J.N. 1998. Hydrochemical Investigations in Characterizing the Unsaturated Zone at Yucca Mountain, Nevada. Water Resources Investigation Report 98-4132. Denver, Colorado: U.S. Geological Survey. TIC: 243710. Software Cited: Software Code: EARTHVISION V4.0. STN: 30035-2 V4.0. Software Code: EXT V1.0_MEOS9. STN: 10227-1.0MEOS9-00. Software Code: infil2grd V1.6. STN: 10077-1.6-00. Software Code: ITOUGH2 V3.2. STN: 10054-3.2-00 Software Code: T2R3D V1.4. STN: 10006-1.4-00. Software Code: TOUGH2 V1.4. STN: 10007-1.4-00. Software Code: TOUGHREACT V2.2. STN: 10154-2.2-00. Software Code: TOUGHREACTE9 V1.0. STN: 10153-1.0-00. Software Routine: ECRB-XYZ V03. STN: 30093-V.03. Software Routine: TBgas3D V.1.1. ACC: MOL.19991012.0222. Software Routine: Read_TDB V1.0. ACC: MOL.19990903.0031. Software Routine: Frac_Calc V1.1. ACC: MOL.19990903.0032. 8.2 CODES, STANDARDS, REGULATIONS, AND PROCEDURES AP-3.10Q, Rev. 1, ICN 1. Analyses and Models. Washington, D.C.: U.S. Department of Energy, Office of Civilian Radioactive Waste Management. ACC: MOL.19991019.0467. AP-SI.1Q, Rev. 1, ICN 0. Software Management. Las Vegas, Nevada: CRWMS M&O. ACC: MOL.19990630.0395. DOE 1999. Quality Assurance Requirements and Description. DOE/RW-0333P, REV 9. Washington D.C.: DOE OCRWM. ACC: MOL.19991028.0012. QAP-2-0, Rev. 5. Conduct of Activities. Las Vegas, Nevada: CRWMS M&O. ACC: MOL.19980826.0209. Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 167 March 2000 8.3 SOURCE DATA, LISTED BY DATA TRACKING NUMBER GS000399991221.002. Rainfall/Runoff/Runon 1999 Simulations. GS000399991221.003. Preliminary Alcove 1 Infiltration Experiment Data. GS000399991221.004. Preliminary Developed Matrix Properties. GS910908315214.003. Meteorological, Stream-Discharge, and Water-Quality Data for 1986 through 1991 from Two Small Basins in Central Nevada. Submittal date: 09/04/1991. Initial use. GS931008315214.032 Meteorological, Stream-Discharge, and Water-Quality Data for Water Year 1992 from Two Small Basins in Central Nevada. Submittal date: 10/08/1993. Initial use. GS950208312232.003. Data, including Water Potential, Pressure and Temperature, Collected from Boreholes USW NRG-6 and USW NRG -7a from Instrumentation through March 31, 1995. Submittal date: 02/13/1995. GS951108312232.008. Data, including Water Potential, Pressure and Temperature, Collected from Boreholes UE-25 UZ#4 & UZ#5 from Instrumentation through September 30, 1995, and from USW NRG-6 & NRG-7a from April 1 through September 30, 1995. Submittal date: 11/21/ 1995. GS960208312261.001. Shut-in Pressure Test Data from April 1995 to December 1995 from Select Wells and Boreholes at Yucca Mountain, NV. Submittal date: 02/07/1996. GS960308312232.001. Deep Unsaturated Zone Surface-Based Borehole Instrumentation Program Data from Boreholes USW NRG-7A, USW NRG-6, UE-25 UZ#4, UE-25 UZ#5, USW UZ-7A, and USW SD-12 for the Time Period 10/01/95 through 3/31/96. Submittal date: 04/04/ 1996. GS960308312312.005. Water-Level, Discharge Rate and Related Data from the Pump Tests Conducted at Well USW UZ-14, August 17 through August 30, 1993. Submittal date: 03/15/ 1996. GS960808312232.004. Deep Unsaturated Zone Surface-Based Borehole Instrumentation Program Data for Boreholes USW NRG-7A, USW NRG-6, UE-25, UZ#4, UE-25 UZ#5, USW UZ-7A and USW SD-12 for the Time Period 4/1/96 through 8/15/96. Submittal date: 08/30/ 1996. GS960908312231.004. Characterization of Hydrogeologic Units Using Matrix Properties at Yucca Mountain, Nevada. Submittal date: 09/12/1996. GS960908312232.006. In-Situ Pneumatic Tests of Boreholes. Submittal Date: 09/18/1996. GS960908312261.004. Shut-In Pressure Test Data from UE-25 NRG#5 And USW SD-7 from November 1995 to July 1996. Submittal date: 09/24/1996. Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 168 March 2000 GS961108312261.006. Gas Chemistry, ESF Alcoves 2 and 3, 11/95 - 4/96; Water Chemistry, Alcove 2 (Tritium), Alcove 3, and ESF Tunnel; and Pneumatic Pressure Response from Boreholes in Exploratory Studies Facility Alcoves 2 and 3, 10/95 - 5/96. Submittal date: 11/12/1996. GS970108312232.002. Deep Unsaturated Zone, Surface-Based Borehole Instrumentation Program - Raw Data Submittal For Boreholes USW NRG-7A, USW NRG-6, UE-25 UZ#4, UE- 25 UZ#5, USW UZ-7A, and USW SD-12, for the Period 8/16/96 through 12/31/96. Submittal date: 01/22/1997. GS970208312312.003. Water-Level and Related Data from Pump Tests Conducted at Well USW G-2, 4/8/96 - 12/17/96. Submittal date: 02/05/1997. GS970808312232.005. Deep Unsaturated Zone Surface-Based Borehole Instrumentation Program Data from Boreholes USW NRG-7A, UE-2 5 UZ#4, UE-25 UZ#5, USW UZ-7A and USW SD-12 for the Time Period 1/1/97 - 6/30/97. Submittal date: 08/28/1997. GS971108312232.007. Deep Unsaturated Zone Surface-Based Borehole Instrumentation Program Data from Boreholes USW NRG-7A, UE-2 5 UZ #4, UE-25 UZ #5, USW UZ-7A and USW SD-12 for the Time Period 7/1/97 - 9/30/97. Submittal date: 11/18/1997. GS971108314224.020. Revision 1 of Detailed Line Survey Data, Station 0+60 to Station 4+00, North Ramp Starter Tunnel, Exploratory Studies Facility. Submittal date: 12/03/1997. GS980408312232.001. Deep Unsaturated Zone Surface-Based Borehole Instrumentation Program Data From Boreholes USW NRG-7A, UE-2 5 UZ #4, USW NRG-6, UE-25 UZ #5, USW UZ-7A and USW SD-12 for the Time Period 10/01/97 - 03/31/98. Submittal date: 04/16/ 1998. GS980508312313.001. Water-Level and Related Data Collected in Support of Perched-Water Testing in Borehole USW WT-24, September 10, 1997 through February 3, 1998. Submittal date: 05/07/1998. GS980708312242.010. Physical Properties of Borehole Core Samples, and Water Potential Measurements Using the Filter Paper Technique, for Borehole Samples from USW WT-24. Submittal date: 07/27/1998. GS980808312242.014. Physical Properties of Borehole Core Samples and Water Potential Measurements Using the Filter Paper Technique for Borehole Samples from USW SD-6. Submittal date: 08/11/1998. GS980908312242.036. Water Potentials Measured With Heat Dissipation Probes in ECRB Holes from 4/23/98 to 7/31/98. Submittal date: 09/22/1998. GS981008312313.003. Manually Measured Water-Level Data from Borehole USW G-2 on 02/ 03/98, Collected in Support of Perched-Water Testing in Borehole USW WT-24. Submittal date: 10/20/1998. Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 169 March 2000 LAIT831341AQ96.001. Radionuclide Retardation. Measurements of Batch Sorption Distribution Coefficients for Barium, Cesium, Selenium, Strontium, Uranium, Plutonium, and Neptunium. Submittal date: 11/12/1996. LASL831151AQ98.001. Mineralogic Characterization of the ESF Single Heater Test Block. Submittal date: 08/31/1998. LASL831222AQ98.002. Mineralogic Data Chlorine-36 Studies. Submittal date: 09/10/1998. LA9908JC831321.001. Mineralogic Model "MM3.0" Version 3.0. Submittal Date: 08/16/1999. LB971212001254.006. Three Files Using DKM Weeps Parameter Sets with Mean Fracture Permeability, Present Day Infiltration, and Estimated Global FMX for Present Day and Long Term Average and Superpluvial Infiltration. Submittal date: 12/12/1997. LB980912332245.002. Gas Tracer Data from Niche 3107 of the ESF. Submittal date: 09/30/ 1998. LB990501233129.001. Fracture Properties for the UZ Model Grids and Uncalibrated Fracture and Matrix Properties for the UZ Model Layers for AMR U0090, "Analysis of Hydrologic Properties Data." Submittal date: 08/25/1999. LB990501233129.002. 1-D Grids For Hydrogeologic Property Set Inversions and Calibrations for AMR U0000, "Development of Numerical Grids For UZ Flow and Transport Modeling." Submittal date: 09/24/1999. LB990501233129.004. 3-D UZ Model Calibration Grids for AMR U0000, "Development of Numerical Grids of UZ Flow and Transport Modeling." Submittal date: 09/24/1999. LB990701233129.001. 3-D UZ Model Grids for Calculation of Flow Fields for PA for AMR U0000, "Development of Numerical Grids for UZ Flow and Transport Modeling." Submittal date: 09/24/1999. LB990701233129.002. 3-D UZ Model Calibration Grid for Calculation of Flow Fields using #3 Perched Water Conceptual Model (Non-Perched Water Model). Submittal date: Will be submitted with AMR. LB991091233129.003. Two-Dimensional Fault Calibration For AMR U0035, "Calibrated Properties Model." Submittal date: 10/22/1999. LB991091233129.004. Calibrated Fault Properties for the UZ Flow and Transport Model for AMR U0035, "Calibrated Properties Model." Submittal date: 10/22/1999. LB991121233129.001. Calibrated parameters for the present-day, mean infiltration scenario, used for simulations with perched water conceptual model #1 (flow through) for the mean infiltration scenarios of the present-day, Monsoon and Glacial transition climates. Submittal date: will be submitted with AMR. Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 170 March 2000 LB991121233129.002. Calibrated parameters for the present-day, mean infiltration scenario, used for simulations with perched water conceptual model #2 (by passing) for the mean infiltration scenarios of the present-day, Monsoon and Glacial transition climates. Submittal date: will be submitted with AMR. LB991121233129.003. Calibrated parameters for the present-day, upper-bound infiltration scenario, used for simulations with perched water conceptual model #1 (flow through) for the upper-bound infiltration scenarios of the present-day, Monsoon and Glacial transition climates. Submittal date: will be submitted with AMR. LB991121233129.004. Calibrated parameters for the present-day, upper-bound infiltration scenario, used for simulations with perched water conceptual model #2 (by passing) for the upperbound infiltration scenarios of the present-day, Monsoon and Glacial transition climates. Submittal date: will be submitted with AMR. LB991121233129.005. Calibrated parameters for the present-day, lower-bound infiltration scenario, used for simulations with perched water conceptual model #1 (flow through) for the lower-bound infiltration scenarios of the present-day, Monsoon and Glacial transition climates. Submittal date: will be submitted with AMR. LB991121233129.006. Calibrated parameters for the present-day, lower-bound infiltration scenario, used for simulations with perched water conceptual model #2 (by passing) for the lowerbound infiltration scenarios of the present-day, Monsoon and Glacial transition climates. Submittal date: will be submitted with AMR. LB991121233129.007. Calibrated parameters for the present-day, mean infiltration scenario, used for simulations with perched water conceptual model #3 (non-perching) for the mean infiltration scenarios of the present-day, Monsoon and Glacial transition climates. Submittal date: will be submitted with AMR. LB991200DSTTHC.001. Pore water composition and CO2 partial pressure input to Thermal- Hydrological-Chemical (THC) simulations: Table 3 of AMR N0120/U0110, "Drift-Scale Coupled Processes (DST and TH Seepage) Models." Submittal date: will be submitted with AMR. LB997141233129.001. Calibrated Basecase Infiltration 1-D Parameter Set for the UZ Flow and Transport Model, FY99. Submittal date: 07/21/1999. LB997141233129.002. Calibrated Upper-Bound Infiltration 1-D Parameter Set for the UZ Flow and Transport Model, FY99. Submittal date: 07/21/1999. LB997141233129.003. Calibrated Lower-Bound Infiltration 1-D Parameter Set for the UZ Flow and Transport Model, FY99. Submittal date: 07/21/1999. 8.4 OUTPUT DATA, LISTED BY DATA TRACKING NUMBER LB9908T1233129.001. Transport Simulations for mean, low, and upper infiltration maps from AMR U0050. Submittal date: will be submitted with AMR. Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 171 March 2000 LB990801233129.001. TSPA Grid Flow Simulations for AMR U0050, "UZ Flow Models and Submodels." Flow Field #1: Present Day Low Infiltration Map for Flow-Through Perched-Water Conceptual Model. Submittal date: will be submitted with AMR. LB990801233129.002. TSPA Grid Flow Simulations for AMR U0050, "UZ Flow Models and Submodels." Flow Field #2: Present Day Low Infiltration Map for Unfractured Zeolite Perched- Water Conceptual Model. Submittal date: will be submitted with AMR. LB990801233129.003. TSPA Grid Flow Simulations for AMR U0050, "UZ Flow Models and Submodels." Flow Field #3: Present Day Mean Infiltration Map for Flow-Through Perched- Water Conceptual Model. Submittal date: will be submitted with AMR. LB990801233129.004. TSPA Grid Flow Simulations for AMR U0050, "UZ Flow Models and Submodels." Flow Field #4: Present Day Mean Infiltration Map for Unfractures Zeolite Perched- Water Conceptual Model. Submittal date: will be submitted with AMR. LB990801233129.005. TSPA Grid Flow Simulations for AMR U0050, "UZ Flow Models and Submodels." Flow Field #5: Present Day Upper Infiltration Map for Flow-Through Perched- Water Conceptual Model. Submittal date: will be submitted with AMR. LB990801233129.006. TSPA Grid Flow Simulations for AMR U0050, "UZ Flow Models and Submodels." Flow Field #6: Present Day Upper Infiltration Map for Unfractured Zeolite Perched-Water Conceptual Model. Submittal date: will be submitted with AMR. LB990801233129.007. TSPA Grid Flow Simulations for AMR U0050, "UZ Flow Models and Submodels." Flow Field #7: Glacial Low Infiltration Map for Flow-Through Perched-Water Conceptual Model. Submittal date: will be submitted with AMR. LB990801233129.008. TSPA Grid Flow Simulations for AMR U0050, "UZ Flow Models and Submodels." Flow Field #8: Glacial Low Infiltration Map for Unfractured Zeolite Perched-Water Conceptual Model. Submittal date: will be submitted with AMR. LB990801233129.009. TSPA Grid Flow Simulations for AMR U0050, "UZ Flow Models and Submodels." Flow Field #9: Glacial Mean Infiltration Map for Flow-Through Perched-Water Conceptual Model. Submittal date: will be submitted with AMR. LB990801233129.010. TSPA Grid Flow Simulations for AMR U0050, "UZ Flow Models and Submodels." Flow Field #10: Glacial Mean Infiltration Map for Unfractured Zeolite Perched- Water Conceptual Model. Submittal date: will be submitted with AMR. LB990801233129.011. TSPA Grid Flow Simulations for AMR U0050, "UZ Flow Models and Submodels." Flow Field #11: Glacial Upper Infiltration Map for Flow-Through Perched-Water Conceptual Model. Submittal date: will be submitted with AMR. LB990801233129.012. TSPA Grid Flow Simulations for AMR U0050, "UZ Flow Models and Submodels." Flow Field #12: Glacial Upper Infiltration Map for Unfractured Zeolite Perched- Water Conceptual Model. Submittal date: will be submitted with AMR. Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 172 March 2000 LB990801233129.013. TSPA Grid Flow Simulations for AMR U0050, "UZ Flow Models and Submodels." Flow Field #13: Monsoon Low Infiltration Map for Flow-Through Perched-Water Conceptual Model. Submittal date: will be submitted with AMR. LB990801233129.014. TSPA Grid Flow Simulations for AMR U0050, "UZ Flow Models and Submodels." Flow Field #14: Monsoon Low Infiltration Map for Unfractured Zeolite Perched- Water Conceptual Model. Submittal date: will be submitted with AMR. LB990801233129.015. TSPA Grid Flow Simulations for AMR U0050, "UZ Flow Models and Submodels." Flow Field #15: Monsoon Mean Infiltration Map for Flow-Through Perched-Water Model. Submittal date: will be submitted with AMR. LB990801233129.016. TSPA Grid Flow Simulations for AMR U0050, "UZ Flow Models and Submodels." Flow Field #16: Monsoon Mean Infiltration Map for Unfractured Zeolite Perched- Water Conceptual Model. Submittal date: will be submitted with AMR. LB990801233129.017. TSPA Grid Flow Simulations for AMR U0050, "UZ Flow Models and Submodels." Flow Field #17: Monsoon Upper Infiltration Map for Flow-Through Perched-Water Conceptual Model. Submittal date: will be submitted with AMR. LB990801233129.018. TSPA Grid Flow Simulations for AMR U0050, "UZ Flow Models and Submodels." Flow Field #18: Monsoon Upper Infiltration Map for Unfractured Zeolite Perched- Water Conceptual Model. Submittal date: will be submitted with AMR. LB990801233129.019. Present day mean infiltration map; #3 or non-perched water model. Submittal date: will be submitted with AMR. LB990801233129.020. Monsoon mean infiltration map; #3 or non-perched water model. Submittal date: will be submitted with AMR. LB990801233129.021. Glacial mean infiltration map; #3 or non-perched water model. Submittal date: will be submitted with AMR. LB990801233129.022. Present day mean infiltration map; #3 non-perched water model. Submittal date: will be submitted with AMR. LB990801233129.023. Present day low infiltration map; #1 perched water conceptual model. Submittal date: will be submitted with AMR. LB990801233129.024. Present day low infiltration map; #2 perched water conceptual model. Submittal date: will be submitted with AMR. LB990801233129.025. Present day mean infiltration map; #1 perched water conceptual model. Submittal date: will be submitted with AMR. LB990801233129.026. Present day mean infiltration map; #2 perched water conceptual model. Submittal date: will be submitted with AMR. Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 173 March 2000 LB990801233129.027. Present day upper infiltration map; #1 perched water conceptual model. Submittal date: will be submitted with AMR. LB990801233129.028. Present day upper infiltration map; #2perched water conceptual model. Submittal date: will be submitted with AMR. LB991131233129.001. Modeling calcite deposition and percolation. Submittal date: will be submitted with AMR. LB991131233129.002. Modeling seepage and tracer tests at Alcove 1. Submittal date: will be submitted with AMR. LB991131233129.003. Analytical and Simulation Results of Cl and Cl36 Analysis. Submittal date: will be submitted with AMR. LB991131233129.004. Modeling of Thermo-Hydrological Data to Simulate Flow, Transport, and Geothermal Conditions of the UZ. Submittal date: will be submitted with AMR. Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 174 March 2000 INTENTIONALLY LEFT BLANK Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 175 March 2000 9. ATTACHMENTS Attachment I - Document Input References Sheet Attachment II - Calibrated parameter sets, combining from one-dimensional inversions and three-dimensional perched water modeling, used in generating the 18 flow fields, groundwater travel and tracer transport times Attachment III - Software Routines Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 176 March 2000 INTENTIONALLY LEFT BLANK Title: UZ Flow Models and Submodels uoosn ATTACHMENT I-DOCUMENT INPUT REFERENCE SHEET DIRS as of the issue date of this AMR. Refer to the DIRS database for the current status of these inputs r I ‘- MDL-NBS-HS-000006 REV00 Attachment I-l March 2000 Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 Attachment II-1 March 2000 ATTACHMENT II Calibrated parameter sets, combining from one-dimensional inversions and three-dimensional perched water modeling, used in generating the 18 flow fields, groundwater travel and tracer transport times. Table II-1. Calibrated parameters for the present-day, mean infiltration scenario, used for simulations with perched water conceptual model #1 (flow-through) for the mean infiltration scenarios of the present-day, Monsoon and Glacial transition climates. Model Layer kM (m2) aM (1/Pa) mM (-) kF (m2) aF (1/Pa) mF (-) . (-) tcw11 3.86E-15 4.00E-5 0.470 2.41E-12 3.15E-3 0.627 0.30 tcw12 2.74E-19 1.81E-5 0.241 1.00E-10 2.13E-3 0.613 0.30 tcw13 9.23E-17 3.44E-6 0.398 5.42E-12 1.26E-3 0.607 0.30 ptn21 9.90E-13 1.01E-5 0.176 1.86E-12 1.68E-3 0.580 0.09 ptn22 2.65E-12 1.60E-4 0.326 2.00E-11 7.68E-4 0.580 0.09 ptn23 1.23E-13 5.58E-6 0.397 2.60E-13 9.23E-4 0.610 0.09 ptn24 7.86E-14 1.53E-4 0.225 4.67E-13 3.37E-3 0.623 0.09 ptn25 7.00E-14 5.27E-5 0.323 7.03E-13 6.33E-4 0.644 0.09 ptn26 2.21E-13 2.49E-4 0.285 4.44E-13 2.79E-4 0.552 0.09 tsw31 6.32E-17 3.61E-5 0.303 3.21E-11 2.49E-4 0.566 0.06 tsw32 5.83E-16 3.61E-5 0.333 3.56E-11 1.27E-3 0.608 0.41 tsw33 3.08E-17 2.13E-5 0.298 3.86E-11 1.46E-3 0.608 0.41 tsw34 4.07E-18 3.86E-6 0.291 1.70E-11 5.16E-4 0.608 0.41 tsw35 3.04E-17 6.44E-6 0.236 4.51E-11 7.39E-4 0.611 0.41 tsw36 5.71E-18 3.55E-6 0.380 7.01E-11 7.84E-4 0.610 0.41 tsw37 4.49E-18 5.33E-6 0.425 7.01E-11 7.84E-4 0.610 0.41 tsw38 4.53E-18 6.94E-6 0.324 5.92E-13 4.87E-4 0.612 0.41 tsw39 5.46E-17 2.29E-5 0.380 4.57E-13 9.63E-4 0.634 0.41 ch1z 1.96E-19 2.68E-7 0.316 3.40E-13 1.43E-3 0.631 0.10 ch1v 9.90E-13 1.43E-5 0.350 1.84E-12 1.09E-3 0.624 0.13 ch2v 9.27E-14 5.13E-5 0.299 2.89E-13 5.18E-4 0.628 0.13 ch3v 9.27E-14 5.13E-5 0.299 2.89E-13 5.18E-4 0.628 0.13 ch4v 9.27E-14 5.13E-5 0.299 2.89E-13 5.18E-4 0.628 0.13 ch5v 9.27E-14 5.13E-5 0.299 2.89E-13 5.18E-4 0.628 0.13 ch2z 6.07E-18 3.47E-6 0.244 3.12E-14 4.88E-4 0.598 0.10 ch3z 6.07E-18 3.47E-6 0.244 3.12E-14 4.88E-4 0.598 0.10 ch4z 6.07E-18 3.47E-6 0.244 3.12E-14 4.88E-4 0.598 0.10 ch5z 6.07E-18 3.47E-6 0.244 3.12E-14 4.88E-4 0.598 0.10 NOTE: These data have been developed as documented in this AMR and submitted under DTN: LB991121233129.001. Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 Attachment II-2 March 2000 ch6 4.23E-19 3.38E-7 0.510 1.67E-14 7.49E-4 0.604 0.10 pp4 4.28E-18 1.51E-7 0.676 3.84E-14 5.72E-4 0.627 0.10 pp3 2.56E-14 2.60E-5 0.363 7.60E-12 8.73E-4 0.655 0.46 pp2 1.57E-16 2.67E-6 0.369 1.38E-13 1.21E-3 0.606 0.46 pp1 6.40E-17 1.14E-6 0.409 1.12E-13 5.33E-4 0.622 0.10 bf3 2.34E-14 4.48E-6 0.481 4.08E-13 9.95E-4 0.624 0.46 bf2 2.51E-17 1.54E-7 0.569 1.30E-14 5.42E-4 0.608 0.10 pcM38/ pcF38 3.00E-19 6.94E-6 0.324 3.00E-18 6.94E-6 0.324 0.00 pcM39/ pcF39 6.20E-18 2.29E-5 0.381 6.20E-17 2.29E-5 0.381 0.00 pcM1z/ pcF1z 9.30E-20 2.68E-7 0.316 9.30E-19 2.68E-7 0.316 0.00 pcM2z/ pcF2z 2.40E-18 3.47E-6 0.245 2.40E-17 3.47E-6 0.245 0.00 pcM5z/ pcF5z 2.40E-18 3.47E-6 0.245 2.40E-18 3.47E-6 0.245 0.00 pcM6z/ pcF6z 1.10E-19 3.38E-7 0.510 1.10E-19 3.38E-7 0.510 0.00 pcM4p/ pcF4p 7.70E-19 1.51E-7 0.676 7.70E-19 1.51E-7 0.676 0.00 Table II-2. Calibrated parameters for the present-day, mean infiltration scenario, used for simulations with perched water conceptual model #2 (by-passing) for the mean infiltration scenarios of the present-day, Monsoon and Glacial transition climates Model Layer kM (m2) aM (1/Pa) mM (-) kF (m2) aF (1/Pa) mF (-) . (-) tcw11 3.86E-15 4.00E-5 0.470 2.41E-12 3.15E-3 0.627 0.30 tcw12 2.74E-19 1.81E-5 0.241 1.00E-10 2.13E-3 0.613 0.30 tcw13 9.23E-17 3.44E-6 0.398 5.42E-12 1.26E-3 0.607 0.30 ptn21 9.90E-13 1.01E-5 0.176 1.86E-12 1.68E-3 0.580 0.09 ptn22 2.65E-12 1.60E-4 0.326 2.00E-11 7.68E-4 0.580 0.09 ptn23 1.23E-13 5.58E-6 0.397 2.60E-13 9.23E-4 0.610 0.09 ptn24 7.86E-14 1.53E-4 0.225 4.67E-13 3.37E-3 0.623 0.09 NOTE: These data have been developed as documented in this AMR and submitted under DTN: LB991121233129.002 Table II-1. Calibrated parameters for the present-day, mean infiltration scenario, used for simulations with perched water conceptual model #1 (flow-through) for the mean infiltration scenarios of the present-day, Monsoon and Glacial transition climates. (Cont.) Model Layer kM (m2) aM (1/Pa) mM (-) kF (m2) aF (1/Pa) mF (-) . (-) NOTE: These data have been developed as documented in this AMR and submitted under DTN: LB991121233129.001. Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 Attachment II-3 March 2000 ptn25 7.00E-14 5.27E-5 0.323 7.03E-13 6.33E-4 0.644 0.09 ptn26 2.21E-13 2.49E-4 0.285 4.44E-13 2.79E-4 0.552 0.09 tsw31 6.32E-17 3.61E-5 0.303 3.21E-11 2.49E-4 0.566 0.06 tsw32 5.83E-16 3.61E-5 0.333 3.56E-11 1.27E-3 0.608 0.41 tsw33 3.08E-17 2.13E-5 0.298 3.86E-11 1.46E-3 0.608 0.41 tsw34 4.07E-18 3.86E-6 0.291 1.70E-11 5.16E-4 0.608 0.41 tsw35 3.04E-17 6.44E-6 0.236 4.51E-11 7.39E-4 0.611 0.41 tsw36 5.71E-18 3.55E-6 0.380 7.01E-11 7.84E-4 0.610 0.41 tsw37 4.49E-18 5.33E-6 0.425 7.01E-11 7.84E-4 0.610 0.41 tsw38 4.53E-18 6.94E-6 0.324 5.92E-13 4.87E-4 0.612 0.41 tsw39 5.46E-17 2.29E-5 0.380 4.57E-13 9.63E-4 0.634 0.41 ch1z 1.96E-19 2.68E-7 0.316 1.96E-19 2.68E-7 0.316 0.00 ch1v 9.90E-13 1.43E-5 0.350 1.84E-12 1.09E-3 0.624 0.13 ch2v 9.27E-14 5.13E-5 0.299 2.89E-13 5.18E-4 0.628 0.13 ch3v 9.27E-14 5.13E-5 0.299 2.89E-13 5.18E-4 0.628 0.13 ch4v 9.27E-14 5.13E-5 0.299 2.89E-13 5.18E-4 0.628 0.13 ch5v 9.27E-14 5.13E-5 0.299 2.89E-13 5.18E-4 0.628 0.13 ch2z 6.07E-18 3.47E-6 0.244 6.07E-18 3.47E-6 0.244 0.00 ch3z 6.07E-18 3.47E-6 0.244 6.07E-18 3.47E-6 0.244 0.00 ch4z 6.07E-18 3.47E-6 0.244 6.07E-18 3.47E-6 0.244 0.00 ch5z 6.07E-18 3.47E-6 0.244 6.07E-18 3.47E-6 0.244 0.00 ch6 4.23E-19 3.38E-7 0.510 4.23E-19 3.38E-7 0.510 0.00 pp4 4.28E-18 1.51E-7 0.676 4.28E-18 1.51E-7 0.676 0.00 pp3 2.56E-14 2.60E-5 0.363 7.60E-12 8.73E-4 0.655 0.46 pp2 1.57E-16 2.67E-6 0.369 1.38E-13 1.21E-3 0.606 0.46 pp1 6.40E-17 1.14E-6 0.409 6.40E-17 1.14E-6 0.409 0.00 bf3 2.34E-14 4.48E-6 0.481 4.08E-13 9.95E-4 0.624 0.46 bf2 2.51E-17 1.54E-7 0.569 2.51E-17 1.54E-7 0.569 0.00 pcM38/ pcF38 3.00E-19 6.94E-6 0.324 3.00E-18 6.94E-6 0.324 0.00 pcM39/ pcF39 6.20E-18 2.29E-5 0.381 6.20E-17 2.29E-5 0.381 0.00 Table II-2. Calibrated parameters for the present-day, mean infiltration scenario, used for simulations with perched water conceptual model #2 (by-passing) for the mean infiltration scenarios of the present-day, Monsoon and Glacial transition climates (Cont.) Model Layer kM (m2) aM (1/Pa) mM (-) kF (m2) aF (1/Pa) mF (-) . (-) NOTE: These data have been developed as documented in this AMR and submitted under DTN: LB991121233129.002 Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 Attachment II-4 March 2000 Table II-3. Calibrated parameters for the present-day, upper-bound infiltration scenario, used for simulations with perched water conceptual model #1 (flow-through) for the upper-bound infiltration scenarios of the present-day, Monsoon and Glacial transition climates Model Layer kM (m2) aM (1/Pa) mM (-) kF (m2) aF (1/Pa) mF (-) . (-) tcw11 3.98E-15 4.27E-5 0.484 2.75E-12 4.67E-3 0.636 0.31 tcw12 3.26E-19 2.18E-5 0.229 1.00E-10 2.18E-3 0.633 0.31 tcw13 1.63E-16 2.17E-6 0.416 2.26E-12 1.71E-3 0.631 0.31 ptn21 1.26E-13 1.84E-4 0.199 1.00E-11 2.38E-3 0.611 0.08 ptn22 5.98E-12 2.42E-5 0.473 1.00E-11 1.26E-3 0.665 0.08 ptn23 3.43E-13 4.06E-6 0.407 1.96E-13 1.25E-3 0.627 0.08 ptn24 3.93E-13 5.27E-5 0.271 4.38E-13 2.25E-3 0.631 0.08 ptn25 1.85E-13 2.95E-5 0.378 6.14E-13 1.00E-3 0.637 0.08 ptn26 6.39E-13 3.54E-4 0.265 3.48E-13 3.98E-4 0.367 0.08 tsw31 9.25E-17 7.79E-5 0.299 2.55E-11 1.78E-4 0.577 0.09 tsw32 5.11E-16 4.90E-5 0.304 2.83E-11 1.32E-3 0.631 0.38 tsw33 1.24E-17 1.97E-5 0.272 3.07E-11 1.50E-3 0.631 0.38 tsw34 7.94E-19 3.32E-6 0.324 1.35E-11 4.05E-4 0.579 0.38 tsw35 1.42E-17 7.64E-6 0.209 3.58E-11 9.43E-4 0.627 0.38 tsw36 1.34E-18 3.37E-6 0.383 5.57E-11 8.21E-4 0.623 0.38 tsw37 7.04E-19 2.70E-6 0.447 5.57E-11 8.21E-4 0.623 0.38 tsw38 4.47E-18 5.56E-7 0.314 4.06E-13 7.69E-4 0.622 0.38 tsw39 3.12E-17 1.82E-5 0.377 5.89E-13 1.30E-3 0.633 0.38 ch1z 8.46E-20 4.23E-7 0.336 5.70E-13 1.29E-3 0.631 0.10 ch1v 4.36E-14 4.23E-5 0.363 7.90E-13 1.66E-3 0.656 0.10 ch2v 3.89E-13 4.86E-5 0.312 4.64E-13 1.45E-3 0.626 0.10 ch3v 3.89E-13 4.86E-5 0.312 4.64E-13 1.45E-3 0.626 0.10 ch4v 3.89E-13 4.86E-5 0.312 4.64E-13 1.45E-3 0.626 0.10 ch5v 3.89E-13 4.86E-5 0.312 4.64E-13 1.45E-3 0.626 0.10 ch2z 1.16E-17 1.13E-6 0.229 2.64E-14 8.45E-4 0.628 0.10 ch3z 1.16E-17 1.13E-6 0.229 2.64E-14 8.45E-4 0.628 0.10 ch4z 1.16E-17 1.13E-6 0.229 2.64E-14 8.45E-4 0.628 0.10 ch5z 1.16E-17 1.13E-6 0.229 2.64E-14 8.45E-4 0.628 0.10 ch6 3.32E-20 3.57E-7 0.502 2.21E-14 1.31E-3 0.631 0.10 pp4 2.00E-18 1.83E-7 0.683 1.07E-13 7.99E-4 0.633 0.10 pp3 1.47E-14 1.02E-5 0.395 7.10E-12 1.29E-3 0.749 0.56 pp2 1.05E-16 2.43E-6 0.367 2.53E-13 1.65E-3 0.629 0.56 pp1 5.49E-17 1.01E-6 0.393 6.25E-13 8.18E-4 0.630 0.10 bf3 2.98E-14 3.83E-6 0.490 1.43E-12 1.50E-3 0.636 0.56 NOTE: These data have been developed as documented in this AMR and submitted under DTN: LB991121233129.003 Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 Attachment II-5 March 2000 bf2 3.86E-17 2.29E-7 0.582 2.26E-14 8.18E-4 0.631 0.10 pcM38/ pcF38 3.00E-19 5.56E-7 0.314 3.00E-18 5.56E-7 0.314 0.00 pcM39/ pcF39 6.20E-18 1.82E-5 0.377 6.20E-17 1.82E-5 0.377 0.00 pcM1z/ pcF1z 9.30E-20 4.23E-7 0.336 9.30E-19 4.23E-7 0.336 0.00 pcM2z/ pcF2z 2.40E-18 1.13E-6 0.229 2.40E-17 1.13E-6 0.229 0.00 pcM5z/ pcF5z 2.40E-18 1.13E-6 0.229 2.40E-18 1.13E-6 0.229 0.00 pcM6z/ pcF6z 1.10E-19 3.57E-7 0.502 1.10E-19 3.57E-7 0.502 0.00 pcM4p/ pcF4p 7.70E-19 1.83E-7 0.683 7.70E-19 1.83E-7 0.683 0.00 Table II-4. Calibrated parameters for the present-day, upper-bound infiltration scenario, used for simulations with perched water conceptual model #2 (by-passing) for the upper-bound infiltration scenarios of the present-day, Monsoon and Glacial transition climates Model Layer kM (m2) aM (1/Pa) mM (-) kF (m2) aF (1/Pa) mF (-) . (-) tcw11 3.98E-15 4.27E-5 0.484 2.75E-12 4.67E-3 0.636 0.31 tcw12 3.26E-19 2.18E-5 0.229 1.00E-10 2.18E-3 0.633 0.31 tcw13 1.63E-16 2.17E-6 0.416 2.26E-12 1.71E-3 0.631 0.31 ptn21 1.26E-13 1.84E-4 0.199 1.00E-11 2.38E-3 0.611 0.08 ptn22 5.98E-12 2.42E-5 0.473 1.00E-11 1.26E-3 0.665 0.08 ptn23 3.43E-13 4.06E-6 0.407 1.96E-13 1.25E-3 0.627 0.08 ptn24 3.93E-13 5.27E-5 0.271 4.38E-13 2.25E-3 0.631 0.08 ptn25 1.85E-13 2.95E-5 0.378 6.14E-13 1.00E-3 0.637 0.08 ptn26 6.39E-13 3.54E-4 0.265 3.48E-13 3.98E-4 0.367 0.08 tsw31 9.25E-17 7.79E-5 0.299 2.55E-11 1.78E-4 0.577 0.09 tsw32 5.11E-16 4.90E-5 0.304 2.83E-11 1.32E-3 0.631 0.38 tsw33 1.24E-17 1.97E-5 0.272 3.07E-11 1.50E-3 0.631 0.38 tsw34 7.94E-19 3.32E-6 0.324 1.35E-11 4.05E-4 0.579 0.38 NOTE: These data have been developed as documented in this AMR and submitted under DTN: LB991121233129.004 Table II-3. Calibrated parameters for the present-day, upper-bound infiltration scenario, used for simulations with perched water conceptual model #1 (flow-through) for the upper-bound infiltration scenarios of the present-day, Monsoon and Glacial transition climates (Cont.) Model Layer kM (m2) aM (1/Pa) mM (-) kF (m2) aF (1/Pa) mF (-) . (-) NOTE: These data have been developed as documented in this AMR and submitted under DTN: LB991121233129.003 Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 Attachment II-6 March 2000 tsw35 1.42E-17 7.64E-6 0.209 3.58E-11 9.43E-4 0.627 0.38 tsw36 1.34E-18 3.37E-6 0.383 5.57E-11 8.21E-4 0.623 0.38 tsw37 7.04E-19 2.70E-6 0.447 5.57E-11 8.21E-4 0.623 0.38 tsw38 4.47E-18 5.56E-7 0.314 4.06E-13 7.69E-4 0.622 0.38 tsw39 3.12E-17 1.82E-5 0.377 5.89E-13 1.30E-3 0.633 0.38 ch1z 8.46E-20 4.23E-7 0.336 8.46E-20 4.23E-7 0.336 0.00 ch1v 4.36E-14 4.23E-5 0.363 7.90E-13 1.66E-3 0.656 0.10 ch2v 3.89E-13 4.86E-5 0.312 4.64E-13 1.45E-3 0.626 0.10 ch3v 3.89E-13 4.86E-5 0.312 4.64E-13 1.45E-3 0.626 0.10 ch4v 3.89E-13 4.86E-5 0.312 4.64E-13 1.45E-3 0.626 0.10 ch5v 3.89E-13 4.86E-5 0.312 4.64E-13 1.45E-3 0.626 0.10 ch2z 1.16E-17 1.13E-6 0.229 1.16E-17 1.13E-6 0.229 0.00 ch3z 1.16E-17 1.13E-6 0.229 1.16E-17 1.13E-6 0.229 0.00 ch4z 1.16E-17 1.13E-6 0.229 1.16E-17 1.13E-6 0.229 0.00 ch5z 1.16E-17 1.13E-6 0.229 1.16E-17 1.13E-6 0.229 0.00 ch6 3.32E-20 3.57E-7 0.502 3.32E-20 3.57E-7 0.502 0.00 pp4 2.00E-18 1.83E-7 0.683 2.00E-18 1.83E-7 0.683 0.00 pp3 1.47E-14 1.02E-5 0.395 7.10E-12 1.29E-3 0.749 0.56 pp2 1.05E-16 2.43E-6 0.367 2.53E-13 1.65E-3 0.629 0.56 pp1 5.49E-17 1.01E-6 0.393 5.49E-17 1.01E-6 0.393 0.00 bf3 2.98E-14 3.83E-6 0.490 1.43E-12 1.50E-3 0.636 0.56 bf2 3.86E-17 2.29E-7 0.582 3.86E-17 2.29E-7 0.582 0.00 pcM38/ pcF38 3.00E-19 5.56E-7 0.314 3.00E-18 5.56E-7 0.314 0.00 pcM39/ pcF39 6.20E-18 1.82E-5 0.377 6.20E-17 1.82E-5 0.377 0.00 Table II-4. Calibrated parameters for the present-day, upper-bound infiltration scenario, used for simulations with perched water conceptual model #2 (by-passing) for the upper-bound infiltration scenarios of the present-day, Monsoon and Glacial transition climates (Cont.) Model Layer kM (m2) aM (1/Pa) mM (-) kF (m2) aF (1/Pa) mF (-) . (-) NOTE: These data have been developed as documented in this AMR and submitted under DTN: LB991121233129.004 Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 Attachment II-7 March 2000 Table II-5. Calibrated parameters for the present-day, lower-bound infiltration scenario, used for simulations with perched water conceptual model #1 (flow-through) for the lower-bound infiltration scenarios of the present-day, Monsoon and Glacial transition climates Model Layer kM (m2) aM (1/Pa) mM (-) kF (m2) aF (1/Pa) mF (-) . (-) tcw11 4.63E-15 1.61E-5 0.460 2.70E-12 2.40E-3 0.598 0.25 tcw12 8.87E-20 2.89E-5 0.241 1.00E-10 2.05E-3 0.608 0.25 tcw13 6.61E-17 1.42E-6 0.368 1.79E-12 9.21E-4 0.600 0.25 ptn21 1.86E-13 6.13E-5 0.165 1.00E-11 1.66E-3 0.503 0.01 ptn22 3.27E-12 1.51E-5 0.390 1.00E-11 9.39E-4 0.651 0.01 ptn23 4.20E-13 2.04E-6 0.387 1.84E-13 1.28E-3 0.518 0.01 ptn24 3.94E-13 2.32E-5 0.210 4.31E-13 2.02E-3 0.594 0.01 ptn25 2.22E-13 2.04E-5 0.296 7.12E-13 7.42E-4 0.555 0.01 ptn26 5.43E-13 1.82E-4 0.264 3.08E-13 2.00E-4 0.401 0.01 tsw31 6.38E-17 2.81E-5 0.317 2.55E-11 4.42E-4 0.545 0.06 tsw32 6.28E-16 6.35E-5 0.279 2.83E-11 1.21E-3 0.603 0.23 tsw33 1.82E-17 2.44E-5 0.248 3.07E-11 1.36E-3 0.600 0.23 tsw34 3.50E-19 3.54E-6 0.309 1.35E-11 2.48E-4 0.515 0.23 tsw35 1.27E-17 7.57E-6 0.187 3.58E-11 6.26E-4 0.612 0.23 tsw36 1.19E-18 3.74E-6 0.328 5.57E-11 4.90E-4 0.540 0.23 tsw37 5.63E-19 3.28E-6 0.423 5.57E-11 4.90E-4 0.540 0.23 tsw38 1.44E-18 3.72E-6 0.291 5.65E-13 4.00E-4 0.603 0.23 tsw39 1.09E-17 2.37E-5 0.321 3.12E-13 6.43E-4 0.605 0.23 ch1z 2.75E-20 7.26E-7 0.304 1.87E-13 1.00E-3 0.611 0.12 ch1v 2.05E-14 9.86E-6 0.402 9.03E-13 1.43E-3 0.658 0.12 ch2v 3.17E-13 1.91E-5 0.326 1.94E-13 6.84E-4 0.544 0.12 ch3v 3.17E-13 1.91E-5 0.326 1.94E-13 6.84E-4 0.544 0.12 ch4v 3.17E-13 1.91E-5 0.326 1.94E-13 6.84E-4 0.544 0.12 ch5v 3.17E-13 1.91E-5 0.326 1.94E-13 6.84E-4 0.544 0.12 ch2z 6.28E-18 2.44E-6 0.135 4.10E-14 2.08E-4 0.613 0.12 ch3z 6.28E-18 2.44E-6 0.135 4.10E-14 2.08E-4 0.613 0.12 ch4z 6.28E-18 2.44E-6 0.135 4.10E-14 2.08E-4 0.613 0.12 ch5z 6.28E-18 2.44E-6 0.135 4.10E-14 2.08E-4 0.613 0.12 ch6 8.20E-20 5.06E-7 0.445 1.12E-14 6.10E-4 0.604 0.12 pp4 2.05E-18 1.83E-7 0.653 3.40E-14 4.86E-4 0.635 0.12 pp3 1.91E-14 1.53E-5 0.355 2.23E-12 5.93E-4 0.699 0.43 pp2 1.08E-16 2.08E-6 0.399 1.42E-13 7.62E-4 0.608 0.43 pp1 6.52E-17 9.40E-7 0.392 7.15E-14 3.90E-4 0.638 0.12 bf3 9.47E-15 3.75E-6 0.509 3.43E-13 7.60E-4 0.611 0.43 NOTE: These data have been developed as documented in this AMR and submitted under DTN: LB991121233129.005 Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 Attachment II-8 March 2000 bf2 1.27E-17 1.38E-7 0.568 9.21E-15 4.18E-4 0.598 0.12 pcM38/ pcF38 3.00E-19 3.72E-6 0.291 3.00E-19 3.72E-6 0.291 0.00 pcM39/ pcF39 6.20E-18 2.37E-5 0.321 6.20E-18 2.37E-5 0.321 0.00 pcM1z/ pcF1z 9.30E-20 7.26E-7 0.304 9.30E-20 7.26E-7 0.304 0.00 pcM2z/ pcF2z 2.40E-18 2.44E-6 0.135 2.40E-18 2.44E-6 0.135 0.00 pcM5z/ pcF5z 2.40E-18 2.44E-6 0.135 2.40E-18 2.44E-6 0.135 0.00 pcM6z/ pcF6z 1.10E-19 5.06E-7 0.445 1.10E-19 5.06E-7 0.445 0.00 pcM4p/ pcF4p 7.70E-19 1.83E-7 0.653 7.70E-19 1.83E-7 0.653 0.00 Table II-6. Calibrated parameters for the present-day, lower-bound infiltration scenario, used for simulations with perched water conceptual model #2 (by-passing) for the lower-bound infiltration scenarios of the present-day, Monsoon and Glacial transition climates Model Layer kM (m2) aM (1/Pa) mM (-) kF (m2) aF (1/Pa) mF (-) . (-) tcw11 4.63E-15 1.61E-5 0.460 2.70E-12 2.40E-3 0.598 0.25 tcw12 8.87E-20 2.89E-5 0.241 1.00E-10 2.05E-3 0.608 0.25 tcw13 6.61E-17 1.42E-6 0.368 1.79E-12 9.21E-4 0.600 0.25 ptn21 1.86E-13 6.13E-5 0.165 1.00E-11 1.66E-3 0.503 0.01 ptn22 3.27E-12 1.51E-5 0.390 1.00E-11 9.39E-4 0.651 0.01 ptn23 4.20E-13 2.04E-6 0.387 1.84E-13 1.28E-3 0.518 0.01 ptn24 3.94E-13 2.32E-5 0.210 4.31E-13 2.02E-3 0.594 0.01 ptn25 2.22E-13 2.04E-5 0.296 7.12E-13 7.42E-4 0.555 0.01 ptn26 5.43E-13 1.82E-4 0.264 3.08E-13 2.00E-4 0.401 0.01 tsw31 6.38E-17 2.81E-5 0.317 2.55E-11 4.42E-4 0.545 0.06 tsw32 6.28E-16 6.35E-5 0.279 2.83E-11 1.21E-3 0.603 0.23 tsw33 1.82E-17 2.44E-5 0.248 3.07E-11 1.36E-3 0.600 0.23 tsw34 3.50E-19 3.54E-6 0.309 1.35E-11 2.48E-4 0.515 0.23 NOTE: These data have been dveloped as documented in this AMR and submitted under DTN: LB991121233129.006 Table II-5. Calibrated parameters for the present-day, lower-bound infiltration scenario, used for simulations with perched water conceptual model #1 (flow-through) for the lower-bound infiltration scenarios of the present-day, Monsoon and Glacial transition climates (Cont.) Model Layer kM (m2) aM (1/Pa) mM (-) kF (m2) aF (1/Pa) mF (-) . (-) NOTE: These data have been developed as documented in this AMR and submitted under DTN: LB991121233129.005 Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 Attachment II-9 March 2000 tsw35 1.27E-17 7.57E-6 0.187 3.58E-11 6.26E-4 0.612 0.23 tsw36 1.19E-18 3.74E-6 0.328 5.57E-11 4.90E-4 0.540 0.23 tsw37 5.63E-19 3.28E-6 0.423 5.57E-11 4.90E-4 0.540 0.23 tsw38 1.44E-18 3.72E-6 0.291 5.65E-13 4.00E-4 0.603 0.23 tsw39 1.09E-17 2.37E-5 0.321 3.12E-13 6.43E-4 0.605 0.23 ch1z 2.75E-20 7.26E-7 0.304 2.75E-20 7.26E-7 0.304 0.00 ch1v 2.05E-14 9.86E-6 0.402 9.03E-13 1.43E-3 0.658 0.12 ch2v 3.17E-13 1.91E-5 0.326 1.94E-13 6.84E-4 0.544 0.12 ch3v 3.17E-13 1.91E-5 0.326 1.94E-13 6.84E-4 0.544 0.12 ch4v 3.17E-13 1.91E-5 0.326 1.94E-13 6.84E-4 0.544 0.12 ch5v 3.17E-13 1.91E-5 0.326 1.94E-13 6.84E-4 0.544 0.12 ch2z 6.28E-18 2.44E-6 0.135 6.28E-18 2.44E-6 0.135 0.00 ch3z 6.28E-18 2.44E-6 0.135 6.28E-18 2.44E-6 0.135 0.00 ch4z 6.28E-18 2.44E-6 0.135 6.28E-18 2.44E-6 0.135 0.00 ch5z 6.28E-18 2.44E-6 0.135 6.28E-18 2.44E-6 0.135 0.00 ch6 8.20E-20 5.06E-7 0.445 8.20E-20 5.06E-7 0.445 0.00 pp4 2.05E-18 1.83E-7 0.653 2.05E-18 1.83E-7 0.653 0.00 pp3 1.91E-14 1.53E-5 0.355 2.23E-12 5.93E-4 0.699 0.43 pp2 1.08E-16 2.08E-6 0.399 1.42E-13 7.62E-4 0.608 0.43 pp1 6.52E-17 9.40E-7 0.392 6.52E-17 9.40E-7 0.392 0.00 bf3 9.47E-15 3.75E-6 0.509 3.43E-13 7.60E-4 0.611 0.43 bf2 1.27E-17 1.38E-7 0.568 1.27E-17 1.38E-7 0.568 0.00 pcM38/ pcF38 3.00E-19 3.72E-6 0.291 3.00E-19 3.72E-6 0.291 0.00 pcM39/ pcF39 6.20E-18 2.37E-5 0.321 6.20E-18 2.37E-5 0.321 0.00 Table II-6. Calibrated parameters for the present-day, lower-bound infiltration scenario, used for simulations with perched water conceptual model #2 (by-passing) for the lower-bound infiltration scenarios of the present-day, Monsoon and Glacial transition climates (Cont.) Model Layer kM (m2) aM (1/Pa) mM (-) kF (m2) aF (1/Pa) mF (-) . (-) NOTE: These data have been dveloped as documented in this AMR and submitted under DTN: LB991121233129.006 Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 Attachment II-10 March 2000 Table II-7. Calibrated parameters for the present-day, mean infiltration scenario, used for simulations with perched water conceptual model #3 (non-perching) for the mean infiltration scenarios of the present-day, Monsoon and Glacial transition climates Model Layer kM (m2) aM (1/Pa) mM (-) kF (m2) aF (1/Pa) mF (-) . (-) tcw11 3.86E-15 4.00E-5 0.470 2.41E-12 3.15E-3 0.627 0.30 tcw12 2.74E-19 1.81E-5 0.241 1.00E-10 2.13E-3 0.613 0.30 tcw13 9.23E-17 3.44E-6 0.398 5.42E-12 1.26E-3 0.607 0.30 ptn21 9.90E-13 1.01E-5 0.176 1.86E-12 1.68E-3 0.580 0.09 ptn22 2.65E-12 1.60E-4 0.326 2.00E-11 7.68E-4 0.580 0.09 ptn23 1.23E-13 5.58E-6 0.397 2.60E-13 9.23E-4 0.610 0.09 ptn24 7.86E-14 1.53E-4 0.225 4.67E-13 3.37E-3 0.623 0.09 ptn25 7.00E-14 5.27E-5 0.323 7.03E-13 6.33E-4 0.644 0.09 ptn26 2.21E-13 2.49E-4 0.285 4.44E-13 2.79E-4 0.552 0.09 tsw31 6.32E-17 3.61E-5 0.303 3.21E-11 2.49E-4 0.566 0.06 tsw32 5.83E-16 3.61E-5 0.333 3.56E-11 1.27E-3 0.608 0.41 tsw33 3.08E-17 2.13E-5 0.298 3.86E-11 1.46E-3 0.608 0.41 tsw34 4.07E-18 3.86E-6 0.291 1.70E-11 5.16E-4 0.608 0.41 tsw35 3.04E-17 6.44E-6 0.236 4.51E-11 7.39E-4 0.611 0.41 tsw36 5.71E-18 3.55E-6 0.380 7.01E-11 7.84E-4 0.610 0.41 tsw37 4.49E-18 5.33E-6 0.425 7.01E-11 7.84E-4 0.610 0.41 tsw38 4.53E-18 6.94E-6 0.324 5.92E-13 4.87E-4 0.612 0.41 tsw39 5.46E-17 2.29E-5 0.380 4.57E-13 9.63E-4 0.634 0.41 ch1z 1.96E-19 2.68E-7 0.316 3.40E-13 1.43E-3 0.631 0.10 ch1v 9.90E-13 1.43E-5 0.350 1.84E-12 1.09E-3 0.624 0.13 ch2v 9.27E-14 5.13E-5 0.299 2.89E-13 5.18E-4 0.628 0.13 ch3v 9.27E-14 5.13E-5 0.299 2.89E-13 5.18E-4 0.628 0.13 ch4v 9.27E-14 5.13E-5 0.299 2.89E-13 5.18E-4 0.628 0.13 ch5v 9.27E-14 5.13E-5 0.299 2.89E-13 5.18E-4 0.628 0.13 ch2z 6.07E-18 3.47E-6 0.244 3.12E-14 4.88E-4 0.598 0.10 ch3z 6.07E-18 3.47E-6 0.244 3.12E-14 4.88E-4 0.598 0.10 ch4z 6.07E-18 3.47E-6 0.244 3.12E-14 4.88E-4 0.598 0.10 ch5z 6.07E-18 3.47E-6 0.244 3.12E-14 4.88E-4 0.598 0.10 ch6 4.23E-19 3.38E-7 0.510 1.67E-14 7.49E-4 0.604 0.10 pp4 4.28E-18 1.51E-7 0.676 3.84E-14 5.72E-4 0.627 0.10 pp3 2.56E-14 2.60E-5 0.363 7.60E-12 8.73E-4 0.655 0.46 pp2 1.57E-16 2.67E-6 0.369 1.38E-13 1.21E-3 0.606 0.46 pp1 6.40E-17 1.14E-6 0.409 1.12E-13 5.33E-4 0.622 0.10 bf3 2.34E-14 4.48E-6 0.481 4.08E-13 9.95E-4 0.624 0.46 NOTE: These data have been developed as documented in this AMR and submitted under DTN: LB991121233129.007 Title: UZ Flow Models and Submodels U0050 MDL-NBS-HS-000006 REV00 Attachment II-11 March 2000 bf2 2.51E-17 1.54E-7 0.569 1.30E-14 5.42E-4 0.608 0.10 Table II-7. Calibrated parameters for the present-day, mean infiltration scenario, used for simulations with perched water conceptual model #3 (non-perching) for the mean infiltration scenarios of the present-day, Monsoon and Glacial transition climates (Cont.) Model Layer kM (m2) aM (1/Pa) mM (-) kF (m2) aF (1/Pa) mF (-) . (-) NOTE: These data have been developed as documented in this AMR and submitted under DTN: LB991121233129.007 ATTACHMENT III SOFTWARE ROUTINES