QA: QA (text) DOC.20060829.0002 TDR-NBS-HS-000017 REV00 August 2006 Chlorine-36 Validation Study at Yucca Mountain, Nevada Prepared for: U.S. Department of Energy Office of Civilian Radioactive Waste Management Office of Repository Development P.O. Box 364629 North Las Vegas, Nevada 89036 Prepared by: U.S. Geological Survey Yucca Mountain Project Branch P.O. Box 25046, MS 963 Denver Federal Center Denver, Colorado 80225 Under Interagency Agreement DE-AI28-02RW12167 INTENTIONALLY LEFT BLANK INTENTIONALLY LEFT BLANK EXECUTIVE SUMMARY Chlorine-36 (36Cl) data were collected by Los Alamos National Laboratory (LANL) during the late 1990s using leachates of rock samples collected from the walls of the Exploratory Studies Facility (ESF) in the unsaturated zone (UZ) at Yucca Mountain, Nevada, to test whether the Paintbrush Tuff nonwelded hydrogeologic unit (PTn) represents an effective barrier to vertical flow, whether water in the matrix of the Topopah Spring welded hydrogeologic unit (TSw) is essentially stagnant, and whether fast pathways transporting water to the proposed repository horizon occur at discrete locations associated with fault structures. Thirteen percent of the 36Cl measurements (37 of 288 samples) showed elevated values for ratios of 36Cl to total chloride (36Cl/Cl) at the level of the proposed repository, indicating that small amounts of water carrying bomb-pulse 36Cl (i.e., 36Cl/Cl ratios greater than 1250 × 10-15 resulting from 36Cl produced by atmospheric testing of nuclear devices during the 1950s and early 1960s) had percolated through welded and nonwelded tuffs to depths of 200 to 300 meters (m) beneath the land surface over the past 50 years. Because of the implications of short travel times to the performance of the proposed repository, the U.S. Department of Energy (DOE), Office of Civilian Radioactive Waste Management (OCRWM), Office of Repository Development (ORD) decided to verify the 36Cl/Cl data with an independent validation study. DOE asked the U.S. Geological Survey (USGS) to design and implement a validation study that would include 36Cl and tritium (3H) analyses. Study participants included the USGS, Lawrence Livermore National Laboratory (LLNL), Atomic Energy of Canada Limited (AECL), and LANL. Core samples were taken from 50 new boreholes drilled across two zones in the ESF where a substantial number of samples with elevated 36Cl/Cl ratios had been identified previously. Also, core intervals from the Sample Management Facility (SMF) were acquired for water extraction and 3H analyses. The 36Cl validation study was conducted in three phases. Results from Phase I of the work conducted at LLNL indicated that active leaching pulverized the rock samples and extracted too much rock chloride relative to meteoric chloride (36Cl/Cl ratios range from 47 × 10-15 to 248 × 10-15; all values but one are less than 156 × 10-15). Results from Phase I of the work conducted at LANL on validation core samples from the Sundance fault zone yielded 36Cl/Cl values consistent with analyses from previous LANL studies. Following a detailed series of leaching experiments in Phase II of the validation study, a 1-hour passive leaching protocol was established for processing samples in Phase III of the study. The passive leaching process extracted less rock chloride relative to meteoric chloride. USGS-LLNL 36Cl/Cl values for leachates of 34 samples of core from validation study boreholes across an area that includes the Sundance fault zone range from 137 × 10-15 to 615 × 10-15, with a mean value of 326 × 10-15 . These are lower than bomb-pulse values previously reported for feature-based tunnel-wall samples in the same area. 36Cl/Cl ratios for passive leachates of validation study core samples prepared at the USGS and processed separately at LLNL and LANL agree within analytical error. The reproducibility of results also was tested at USGS-LLNL and LANL using available core from Niche #1, a short drift that was driven from the ESF to access the Sundance fault by drilling. LLNL analyses of six Niche #1 core samples prepared at the USGS are statistically indistinguishable from validation study borehole data. (36Cl/Cl ratios range from 226 × 10-15 to 717 × 10-15). LANL 36Cl/Cl validation results for seven Niche #1 core samples yielded bomb-pulse values that are comparable to previous LANL 36Cl data (1,016 × 10-15 to 8,558 × 10-15). One LANL validation study analysis and several previous analyses of samples from the Enhanced Characterization of the Repository Block (ECRB) Cross Drift also show large 36Cl/Cl values. Tritium concentrations in pore water extracted from validation study core samples across the Drill Hole Wash fault zone and the Sundance fault zone range from less than 0.1 to 2.6 tritium units (TU). Tritium concentrations in pore water extracted from samples from areas of known faulting in the ESF indicate the presence of modern water (i.e., water that entered the Yucca Mountain UZ after 1952, thus indicating fast pathways). Tritium concentrations in pore water extracted from core samples from the ECRB Cross Drift range from less than 0.1 to 10.3 TU. The USGS and LANL established different thresholds for interpreting 3H values as indicators of modern water (2.0 TU and 1.4 TU, respectively). The lower LANL threshold allows for the presence of modern water in a larger number of locations in the ESF and ECRB Cross Drift. The validation study work conducted by USGS-LLNL did not confirm previously reported bomb-pulse 36Cl/Cl ratios in the Sundance fault zone, but new analyses at LANL of Niche #1 core samples and ECRB Cross Drift tunnel-wall samples were consistent with results from previous studies. Consequently, a number of issues were identified that need to be addressed. Recommendations include a detailed evaluation of potential field contamination and sample handling and processing, including a rigorous evaluation of crushing blanks; additional 36Cl/Cl analyses of validation study core samples; confirmation of young water in high-3H samples by analyzing the same core samples for 36Cl; and an independent validation study using new samples. CONTENTS EXECUTIVE SUMMARY ............................................................................................................ v ACRONYMS, ABBREVIATIONS, AND SYMBOLS ............................................................. xvii STRATIGRAPHIC AND HYDROGEOLOGIC NAMES.......................................................... xix CONVERSION FACTORS ......................................................................................................... xx REPORTING OF UNCERTAINTIES AND PARAMETER VARIABILITIES ........................ xx NOTATION OF CHLORINE-36/CHLORIDE RATIOS IN TEXT, TABLES, AND FIGURES ............................................................................................................................... xx ACKNOWLEDGMENTS ........................................................................................................... xxi 1. INTRODUCTION .................................................................................................................... 1 1.1 PURPOSE.....................................................................................................................1 1.2 QUALITY ASSURANCE............................................................................................ 2 1.3 ORGANIZATION OF THE REPORT......................................................................... 2 2. BACKGROUND ...................................................................................................................... 3 2.1 STUDIES OF CHLORINE-36 AND FRACTURE MINERALS IN THE EXPLORATORY STUDIES FACILITY..................................................................... 4 2.1.1 Results from Previous Chlorine-36 Studies...................................................... 4 2.1.2 Fracture Mineral Studies................................................................................... 7 2.2 PREVIOUS STUDIES OF OTHER BOMB-PULSE ISOTOPES ............................... 7 2.3 PEER REVIEW OF CHLORINE-36 STUDIES .......................................................... 8 3. DESIGN AND IMPLEMENTATION OF THE VALIDATION STUDY ............................ 11 3.1 DESIGN OF SAMPLING PROTOCOL .................................................................... 11 3.2 DESCRIPTION AND ALLOCATION OF VALIDATION STUDY CORE ............ 13 4. CHLORINE-36 MEASUREMENTS ..................................................................................... 17 4.1 PHASE I: MEASUREMENTS MADE AT LLNL .................................................... 17 4.1.1 Methods........................................................................................................... 17 4.1.2 Results............................................................................................................. 17 4.2 PHASE I: MEASUREMENTS MADE AT LANL.................................................... 18 4.2.1 Methods........................................................................................................... 18 4.2.2 Results............................................................................................................. 18 4.3 PHASE II: LEACHING EXPERIMENTS ................................................................. 19 4.3.1 Preparation of the Reference Sample.............................................................. 19 4.3.2 Leaching Experiments Conducted at LANL................................................... 20 4.3.2.1 Methods ............................................................................................. 20 4.3.2.2 Results ............................................................................................... 21 4.3.2.3 Discussion of Results ........................................................................ 22 4.3.3 Leaching Experiments Conducted at AECL................................................... 23 4.3.3.1 Methods ............................................................................................. 23 4.3.3.2 Results ............................................................................................... 24 4.3.3.3 Discussion of Results ........................................................................ 26 4.3.4 Conclusions from the Phase II Leaching Experiments................................... 27 4.4 PHASE III: MEASUREMENTS MADE AT USGS-LLNL ...................................... 27 4.4.1 Methods........................................................................................................... 28 4.4.1.1 Sample Processing............................................................................. 28 4.4.1.2 Crushing Experiments ....................................................................... 29 4.4.1.3 Procedural Blanks.............................................................................. 30 4.4.2 Results............................................................................................................. 31 4.4.2.1 Anions in Leachates of Validation Study Core ................................. 31 4.4.2.2 Chlorine-36 in Leachates of Validation Study Core ......................... 32 4.4.2.3 Re-Analysis of Niche #1 Core for Chlorine-36................................. 33 4.5 PHASE III: MEASUREMENTS MADE AT LANL ................................................. 34 4.5.1 Methods........................................................................................................... 34 4.5.1.1 Sample Processing............................................................................. 34 4.5.1.2 Procedural Blanks.............................................................................. 35 4.5.2 Results............................................................................................................. 35 4.5.2.1 Chlorine-36 in Leachates of Validation Study Core ......................... 35 4.5.2.2 Chlorine-36 in ECRB Cross Drift Tunnel-Wall Samples ................. 36 4.5.2.3 Re-Analysis of Niche #1 Core for Chlorine-36................................. 36 4.6 DISCUSSION OF THE CHLORINE-36 MEASUREMENTS.................................. 37 4.6.1 Active Leaching.............................................................................................. 37 4.6.2 Chloride Sources and Leaching Experiments................................................. 37 4.6.3 Procedural Blanks and Detection Limits for the Total Chloride and Chlorine-36 Analyses...................................................................................... 38 4.6.4 Analysis of Duplicate Samples ....................................................................... 39 4.6.5 LANL Data from the ECRB Cross Drift ........................................................ 40 4.6.6 Comparison of Validation Study Data with Previous Chlorine-36 Data........ 40 4.6.6.1 Sundance Fault Zone......................................................................... 40 4.6.6.2 Southern Exploratory Studies Facility .............................................. 41 4.6.7 Comparison of USGS-LLNL Niche #1 Data and LANL-LLNL Niche #1 Data ................................................................................................. 41 5. TRITIUM MEASUREMENTS .............................................................................................. 43 5.1 POTENTIAL SOURCES OF TRITIUM IN CORE SAMPLES FROM THE YUCCA MOUNTAIN UNSATURATED ZONE...................................................... 43 5.2 METHODS ................................................................................................................. 44 5.3 RESULTS ................................................................................................................... 45 5.3.1 Tritium in Validation Study Core Samples..................................................... 45 5.3.2 Tritium in Other Core Samples from the Exploratory Studies Facility.......... 45 5.3.3 Tritium in Core Samples from the ECRB Cross Drift.................................... 46 5.4 THRESHOLD VALUES FOR DETECTING MODERN WATER .......................... 47 5.4.1 USGS Establishment of a Threshold for Identifying Modern Water ............. 47 5.4.2 LANL Establishment of a Threshold for Identifying Modern Water............. 48 5.5 INTERPRETATION OF THE TRITIUM MEASUREMENTS ................................ 51 5.5.1 USGS Interpretation of the Tritium Measurements........................................ 51 5.5.2 LANL Interpretation of the Tritium Measurements ....................................... 51 6. SUMMARY OF RESULTS, CONCLUSIONS, REMAINING ISSUES, AND RECOMMENDATIONS........................................................................................................ 53 6.1 SUMMARY OF RESULTS ....................................................................................... 53 6.2 CONCLUSIONS......................................................................................................... 54 6.3 REMAINING ISSUES ............................................................................................... 54 6.3.1 Absence of Elevated Chlorine-36/Chloride Ratios in USGS-LLNL Measurements ................................................................................................. 54 6.3.2 Results for Niche #1 Core............................................................................... 55 6.3.3 Spatial Distribution of Elevated Chlorine-36 Values and Tritium Values ............................................................................................................. 55 6.3.3.1 USGS Interpretation of the Spatial Distribution of Elevated Values................................................................................................ 56 6.3.3.2 LANL Interpretation of the Spatial Distribution of Elevated Values................................................................................................ 56 6.3.4 Potential Contamination from Field and Laboratory Environments............... 57 6.3.4.1 USGS Interpretation of the Potential for Contamination from Field and Laboratory Environments.................................................. 57 6.3.4.2 LANL Interpretation of the Potential for Contamination from Field and Laboratory Environments.................................................. 58 6.4 RECOMMENDATIONS............................................................................................ 59 6.4.1 Evaluation of Field Contamination................................................................. 60 6.4.2 Evaluation of Laboratory Blanks.................................................................... 60 6.4.3 Additional 36Cl/Cl Analyses of Validation Study Core and ECRB Cross Drift Core.............................................................................................. 60 6.4.4 Independent Validation Study Using New Samples....................................... 60 7. REFERENCES CITED........................................................................................................... 61 7.1 DOCUMENTS CITED............................................................................................... 61 7.2 CODES, STANDARDS, REGULATIONS, AND PROCEDURES.......................... 68 7.3 SOURCE DATA, LISTED BY DATA TRACKING NUMBER .............................. 68 APPENDIX A –CHLORIDE CONCENTRATIONS AND CHLORINE-36/CHLORIDE RATIOS IN SALTS LEACHED FROM ESF ROCK SAMPLES AT LOS ALAMOS NATIONAL LABORATORY AS OF SEPTEMBER 8, 1998 ............................................. A1 APPENDIX B –VIDEO-LOG OBSERVATIONS FROM VALIDATION STUDY BOREHOLES........................................................................................................................B1 APPENDIX C –ACCELERATOR MASS SPECTROMETRY METHODS ..............................C1 INTENTIONALLY LEFT BLANK FIGURES 1-1. Generalized Map of Central Yucca Mountain (A) and Schematic Geologic Section along the ESF Showing the Sundance Fault Zone Validation Study Area (B) 2-1. Distribution of Chloride Concentrations (A) and 36Cl/Cl Ratios (B) in the ESF, as Reported by LANL in 1996, 1997, and 1998 2-2. Relations between Fault/Shear Intensity as Mapped in the ESF and 36Cl/Cl Ratios for Samples Described as Localities Associated with Faults or Shears 3-1. Distribution of 36Cl along the Drill Hole Wash Fault Zone in the ESF, between 1,500 and 2.500 meters (A) and between 1,880 and 1,980 meters (B), as Reported by LANL in 1996 3-2. Distribution of 36Cl in and adjacent to the Sundance Fault in the ESF, as Reported by LANL in 1996 and 1998 3-3. Distribution of Fracture Densities in the ESF 3-4. Histograms Showing the Linear Spacing (A) and Log Spacing (B) between Fractures and Cooling Joints Longer than 1 Meter, Measured from Detailed Line Surveys between ESF Stations 16+00 and 21+00 3-5. Histograms Showing the Linear Spacing (A) and Log Spacing (B) between Fractures and Cooling Joints Longer than 1 Meter, Measured from Detailed Line Surveys between ESF Stations 34+00 and 36+00 3-6. Schematic Map Showing General Relations of Niche #1 to the ESF Main Drift and Sundance Fault, and the Orientations of Boreholes Used for the Validation Study 3-7. Distribution of Niche #1 Core Intervals Used for the Validation Study 4-1. Chloride Concentrations and 36Cl/Cl Ratios in Active Leachates of Validation Study Samples Processed and Analyzed at LLNL during Phase I 4-2. Distribution of Chloride Concentrations (A) and 36Cl/Cl Ratios (B) in Active Leachates of Validation Study Samples Processed and Analyzed at LLNL during Phase I 4-3. Relations between Reciprocal Chloride Concentrations and 36Cl/Cl Ratios in Active Leachates of Validation Study Samples Processed and Analyzed at LLNL during Phase I (A), and for Passive Leachates of ESF Samples Reported Previously by LANL (B) 4-4. Relations between Chloride Concentrations (A) and Cumulative Chloride Concentrations (B) Plotted against Leach Duration for Sequential Leachates of Reference Sample EVAL001 Leached at LANL by Passive and Active Methods during Phase II 4-5. Relations between 36Cl/Cl Ratios (A) and Cumulative 36Cl/Cl Ratios (B) Plotted against Leach Duration for Sequential Leachates of Reference Sample EVAL001 Leached at LANL by Passive and Active Methods during Phase II 4-6. Relations between Chloride Concentrations (A, showing all data) and Cumulative Chloride Concentrations (B, showing a subset of the data at a larger scale) Plotted against Leach Duration for Sequential Passive Leachates of the 6.3- to 12.5-mm Fraction of Six Samples from the ECRB Cross Drift Analyzed at LANL during Phase II 4-7. Relations between 36Cl/Cl Ratios (A) and Cumulative 36Cl/Cl Ratios (B) Plotted against Leach Duration for Sequential Passive Leachates of the 6.3- to 12.5-mm Fraction of Six Samples from the ECRB Cross Drift Analyzed at LANL during Phase II 4-8. Relations between Chloride Concentrations (A) and Cumulative Chloride Concentrations (B) Plotted against Leach Duration for Passive Leachates of Different Size Fractions of ECRB Cross Drift Sample EXD-069 Analyzed at LANL during Phase II 4-9. Relations between 36Cl/Cl Ratios (A) and Cumulative 36Cl/Cl Ratios (B) Plotted against Leach Duration for Passive Leachates of Different Size Fractions of ECRB Cross Drift Sample EXD-069 Analyzed at LANL during Phase II 4-10. Relations between 36Cl/Cl Ratios and Reciprocal Chloride Concentrations in Sequential Leachates of Reference Sample EVAL001 and ECRB Cross Drift Samples Analyzed at LANL during Phase II 4-11. Effect of Particle Size on Leach Duration and Chloride Concentration for Two Size Fractions of Tuff from Unfractured (CT and FT series, #2) and Relatively Unfractured (2CT series, #14) Core Samples Analyzed at AECL during Phase II 4-12. Detail from Figure 4-11 Showing the Changes in Chloride Concentrations in the First Few Hours of Two Leaching Tests on the Coarse Tuff 4-13. Effect of Particle Size on Chloride Concentrations in Phase II Leachates of Intact Core from Borehole ESF-SD-ClV#2 (GS series in Table 4-6) and Broken Core from Borehole ESF-SD-ClV#14 (2A2 series in Table 4-6) 4-14. Effect of Particle Size and Leach Duration on Rubblized Core Fragments from Borehole ESF-SD-ClV#9 (BT series in Table 4-6) 4-15. Comparison of Chloride Concentrations in Phase II Leachates of Core Samples from ESF-SD-ClV and Niche #1 Boreholes in the Sundance Fault Zone 4-16. Relations between Chloride Concentrations and 36Cl/Cl Ratios in Phase III Leachates of Core Samples from Borehole ESF-SAD-GTB#1 4-17. Relations between 36Cl/Cl Ratios and Chloride Concentrations (A) and Reciprocal Chloride Concentrations (B) in Phase III Leachates of Validation Study Samples Leached at the USGS and Analyzed at LLNL 4-18. Box Plots of Chloride Concentration Data Comparing Phase III Leachates of Core Samples from the Drill Hole Wash and Sundance Fault Zones (A), and from Different Samples within the Sundance Fault Zone (B) 4-19. Concentrations of Chloride Determined by Ion Chromatography in Phase III Leachates of Validation Study Core Samples and Niche #1 Core Samples from the Sundance Fault Zone (A) and Drill Hole Wash Fault Zone (B) 4-20. Comparison of Chloride Concentrations in Phase III Leachates of Validation Study Core Leached at the USGS, with NO3 Concentrations (A) and SO4 Concentrations (B) 4-21. Comparison of Chloride Concentrations in Phase III Leachates of Validation Study Samples Analyzed by Ion Chromatography at the USGS and by Isotope Dilution at LLNL 4-22. Histograms Showing Chloride Concentrations (A) and 36Cl/Cl Ratios (B) in Phase III Leachates of Validation Study Samples Leached at the USGS and Analyzed at LLNL 4-23. Relations between Sample Locations in the ESF and Chloride Concentrations (A) and 36Cl/Cl Ratios (B) in Phase III Leachates of Validation Study Samples Leached at the USGS and Analyzed at LLNL 4-24. Relations between Borehole Completion Dates and 36Cl/Cl Ratios in Phase III Leachates of Validation Study Samples Leached at the USGS and Analyzed at LLNL 4-25. Histogram Showing 36Cl/Cl Ratios in Phase III Leachates of ESF-SD-ClV and Niche #1 Core Samples Prepared at the USGS and Analyzed at LLNL 4-26. Relations between Reciprocal Chloride Concentrations and 36Cl/Cl Ratios in Phase III Leachates of Niche #1 Core Samples as Linear (A) and Semi-Log (B) Plots 4-27. Comparison of Reciprocal Chloride Concentrations and 36Cl/Cl Ratios in Phase III Leachates of Samples from ESF Tunnel Walls (Sundance Fault Zone between Stations 34+28 and 37+00) and Niche #1 Core 4-28. Relations between Reciprocal Chloride Concentrations and 36Cl/Cl Ratios in Phase III Leachates of Validation Study Samples from the Sundance Fault Zone within the ESF 4-29. Conceptual Model of the Isotopic Evolution of 36Cl/Cl Ratios in Passively Leached Solutions with Time 4-30. Comparison of Chloride Concentrations (A) and 36Cl/Cl Ratios (B) in Aliquots of Validation Study Samples Passively Leached for 1 Hour at the USGS and Sent to LLNL and LANL for AgCl Target Preparation 4-31. Frequency Distribution (A) and Box Plot (B) of 36Cl/Cl Ratios in Leachates of Validation Study Core Leached at the USGS and Sent to LLNL and LANL for AgCl Precipitation and Analysis 4-32. Relations between 36Cl/Cl Ratios Determined at LANL and Distance in the ECRB Cross Drift 4-33. Distribution of Chloride Concentrations (A) and 36Cl/Cl Ratios (B) in Leachates of Samples from the Sundance Fault Zone within the ESF 4-34. Relations between Reciprocal Chloride Concentrations and 36Cl/Cl Ratios in Leachates of Samples from the Sundance Fault Zone 4-35. Distribution of Chloride Concentrations (A) and 36Cl/Cl Ratios (B) in Leachates of USGS–LLNL Samples from the Sundance Fault Zone and LANL Samples from the Southern ESF 5-1. Distribution of Tritium Concentrations in Samples of Pore Water Extracted from Validation Study Core along the Drill Hole Wash Fault Zone (A) and Sundance Fault Zone (B) 5-2. Frequency Distribution of Tritium Concentrations in Pore Water from Validation Study Core Samples 5-3. Distribution of Tritium Concentrations Plotted at Full Scale (A) and at a Reduced Scale (B) in Samples of Pore Water Extracted from Drill Core throughout the ESF 5-4. Frequency Distribution of Tritium Concentrations in Pore Water from Boreholes along the ESF South Ramp 5-5. Geologic Section of the ESF South Ramp Showing Locations of Samples Analyzed for Tritium 5-6. Distribution of Tritium Concentrations in Samples of Pore Water Extracted from Drill Core along the ECRB Cross Drift 5-7. Frequency Distribution of Tritium Concentrations in Pore Water from ECRB Cross Drift Drill Core 5-8. Application of Chauvenet’s Criterion to Establish a Cutoff Tritium Concentration for Identifying the Presence of Bomb-Pulse Tritium in Samples from the ESF and ECRB Cross Drift (USGS) 5-9. Application of Chauvenet’s Criterion to Establish a Cutoff Tritium Concentration for Identifying the Presence of Bomb-Pulse Tritium in Validation Study Boreholes and ECRB Cross Drift Samples (LANL) 6-1. Relations between 36Cl/Cl Ratios in Validation Study Samples from the Sundance Fault Zone and 36Cl/Cl Ratios in Samples from the Same Area Reported by LANL in 1996, 1997, and 1998 TABLES 3-1. Chronology of Locations and Personnel Directly Involved in the Preparation and Analysis of LANL 36Cl Samples 3-2. Validation Study Boreholes 3-3. Core Samples from Niche #1 Boreholes 4-1. Chloride Concentrations and 36Cl/Cl Ratios in Active Leachates Prepared and Analyzed at LLNL during Phase I 4-2. Chloride, Bromide, and Sulfate Concentrations, and 36Cl/Cl Ratios in Leachates of Validation Study Core Samples Analyzed at LANL during Phase I 4-3. Chloride Concentrations and 36Cl/Cl Ratios in Sequential Leachates of Reference Sample EVAL001 and Six Samples from the ECRB Cross Drift Analyzed at LANL during Phase II 4-4. Possible Sources for 36Cl/Cl Ratios in Tuff Samples from Yucca Mountain 4-5. Dry-Drilled Core Samples Used in Chloride Leaching Experiments Conducted at AECL during Phase II 4-6. Summary of Data for Core Samples Analyzed at AECL during Phase II 4-7. Processing History of Validation Study Core Samples Leached at the USGS during Phase III 4-8. Validation Study Core Intervals Chosen for Passive Leaching at the USGS during Phase III 4-9. Chloride Concentrations and 36Cl/Cl Ratios in Core Samples Leached and Analyzed at USGS–LLNL during Phase III 4-10. Concentrations and Chloride Isotopic Compositions of Procedural Blanks Obtained for Passive Leaching at the USGS and Chloride Precipitation and Analysis at LLNL during Phase III USGS-LLNL in Silicon Crushing Blanks, System Process Blanks, and a 4-11. Chloride Concentrations and 36Cl/Cl Ratios Measured during Phase III at Composite Sample of Niche #1 Core Crushed and Sieved at LANL 4-12. Chloride Concentrations and 36Cl/Cl Ratios in Leachates of Validation Study Samples Analyzed at LANL during Phase III 4-13. Concentrations of Anions in Leachates of Validation Study Samples Analyzed by Ion Chromatography at the USGS during Phase III 4-14. Summary of Anion Concentrations in Leachates of Validation Study Samples Analyzed by Ion Chromatography at the USGS during Phase III 4-15. Summary of Chloride Concentrations and 36Cl/Cl Ratios in Core Samples Leached and Analyzed at USGS–LLNL during Phase III 4-16. Mass of Total Chloride, 36Cl/Cl Ratios, and Mass of 36Cl Present in Validation Study Blanks Processed at LANL during Phase III 4-17. Chloride, Bromide, and Sulfate Concentrations, and 36Cl/Cl Ratios in Leachates of ECRB Cross Drift Samples Analyzed at LANL during Phase III 4-18. Chloride Concentrations and 36Cl/Cl Ratios in Duplicate Analyses Used to Calculate External Error in 36Cl/Cl Ratios during Phase III 5-1. Tritium Concentrations in Water Standards with Known Values 5-2. Tritium Concentrations in Pore Water Extracted from Validation Study Core Samples 5-3. Tritium Concentrations in Pore Water Extracted from ESF Core Samples 5-4. Tritium Concentrations in Pore Water Extracted from ECRB Cross Drift Core Samples ACRONYMS, ABBREVIATIONS, AND SYMBOLS 40Ca calcium-40 137Cs cesium-137 35Cl chlorine-35 36Cl chlorine-36 37Cl chlorine-37 2H deuterium 3H tritium 6Li lithium-6 18O oxygen-1887Sr/86Sr strontium-87/strontium-86 99Tc technetium-99 s sigma 1s 1 standard deviation 2s 2 standard deviations A ampere AECL Atomic Energy of Canada Limited AgCl silver chloride AMS accelerator mass spectrometry Br bromine BSC Bechtel SAIC Company CAMS Center for Accelerator Mass Spectrometry, Lawrence Livermore National Laboratory CHn Calico Hills nonwelded hydrogeologic unit Ci curie Cl chlorine cm centimeter CRWMS Civilian Radioactive Waste Management System DIRS Document Input Reference System DOE U.S. Department of Energy ECRB Enhanced Characterization of the Repository Block ESF Exploratory Studies Facility F fluorine g gram IBM International Business Machines Corporation ka thousand years ago kg kilogram km kilometer L liter LANL Los Alamos National Laboratory LLNL Lawrence Livermore National Laboratory LRL laboratory reporting level LT-MDL long-term method detection limit µm micrometer m meter M&O management and operating (contractor) MDL method detection limit mg milligram mm millimeter ML minimum level of quantitation NO3 nitrate NWQL National Water Quality Laboratory, U.S. Geological Survey NWTRB Nuclear Waste Technical Review Board OCRWM Office of Civilian Radioactive Waste Management ORD Office of Repository Development pCi picocurie PRIME Lab Purdue Rare Isotope Measurement Laboratory psi pounds per square inch PTn Paintbrush Tuff nonwelded hydrogeologic unit SE standard error SMF Sample Management Facility SO4 sulfate TCw Tiva Canyon welded hydrogeologic unit TDMS Technical Data Management System TIMS thermal ionization mass spectrometry TIP technical implementation procedure TSw Topopah Spring welded hydrogeologic unit TU tritium unit USEPA U.S. Environmental Protection Agency USGS U.S. Geological Survey UZ unsaturated zone YMPB Yucca Mountain Project Branch, U.S. Geological Survey STRATIGRAPHIC AND HYDROGEOLOGIC NAMES Yucca Mountain consists of north-trending fault-block ridges composed of gently dipping Miocene ash-flow tuffs (Scott and Bonk 1984). Differences in the hydrologic character of the welded and nonwelded tuffs led Montazer and Wilson (1984) and Ortiz et al. (1985) to develop a hydrogeologic classification of the volcanic rocks. Because these units are based on hydrologic properties, they do not correspond exactly with the stratigraphic units described by Sawyer et al. (1994). For example, as shown below, the Paintbrush Tuff nonwelded hydrogeologic unit (PTn) consists of the nonwelded basal part of the Tiva Canyon Tuff, the entire Yucca Mountain and Pah Canyon Tuffs and associated but unnamed bedded tuffs, and the nonwelded upper part of the Topopah Spring Tuff. Both nomenclatures are used in this report. Stratigraphic Unit Hydrogeologic Unit Alluvium Alluvium Tiva Canyon Tuff Tiva Canyon welded (TCw) Paintbrush Group Paintbrush Tuff nonwelded (PTn) Yucca Mountain Tuff bedded tuff Pah Canyon Tuff bedded tuff Topopah Spring Tuff Topopah Spring welded (TSw) Calico Hills nonwelded (CHn) Calico Hills Formation Crater FlatGroup Prow Pass Tuff Bullfrog Tuff Crater Flat undifferentiated (CFu) Modified from Montazer and Wilson (1984) CONVERSION FACTORS Multiply by To obtain centimeter (cm) 0.3937 inch (in.) millimeter (mm) micrometer (µm) 0.03937 3.937 × 10-5inch (in.) inch (in.) meter (m) 3.281 foot (ft) kilometer 0.6214 mile (mi) liter (L) 33.82 ounce (oz) liter (L) 1.0567 quart (qt) kilogram (kg) milligram (mg) milligram (mg) 2.205 2.205 × 10-6 3.527 × 10-5 pound (lb) pound (lb) ounce (oz) REPORTING OF UNCERTAINTIES AND PARAMETER VARIABILITIES Throughout this report uncertainties are cited for individual measurements and means of multiple measurements. For individual measurements, the uncertainty is expressed as 2 standard deviations (2s), unless otherwise specified. One standard deviation (1s) is used to express natural variability of measured parameters, such as concentrations and isotope ratios, within a group of samples. For averages of multiple measurements, uncertainty is expressed as standard error (SE), which is 1s divided by the square root of the number of measurements. Weighted averages were calculated for multiple measurements with highly variable errors (for example, process blanks), using reciprocals of squared individual 1s uncertainties as weighting factors. NOTATION OF CHLORINE-36/CHLORIDE RATIOS IN TEXT, TABLES, AND FIGURES In the text of this report, 36Cl/Cl ratios are given as a value multiplied by 10-15 . For example, a ratio of 0.000000000000666 is cited as “666 × 10-15.” To simplify the tabulation of the data and the labels for the graphs, these ratios have been multiplied by 1015. Thus, the example 36Cl/Cl ratio will be given as “666” in a table where the column heading indicates “36Cl/Cl × 1015.” ACKNOWLEDGMENTS L.A. Neymark (USGS), Z.E. Peterman (USGS), B.D. Marshall (USGS), G.J. Nimz (LLNL), M. Gascoyne (AECL and Gascoyne GeoProjects, Inc., Pinawa, Manitoba), and G.L. Patterson (USGS) contributed to this report. INTENTIONALLY LEFT BLANK 1. INTRODUCTION The amount, spatial distribution, and velocity of water percolating through the unsaturated zone (UZ) at Yucca Mountain, Nevada, are important issues for assessing the performance of the proposed deep geologic repository for spent nuclear fuel and high-level radioactive waste. To help characterize the nature and history of UZ flow, isotopic studies were initiated in 1995, using rock samples collected from the Miocene ash-flow tuffs in the Exploratory Studies Facility (ESF), an 8-km-long tunnel constructed along the north-south extent of the repository block, and the Enhanced Characterization of the Repository Block (ECRB) Cross Drift, a 2.5-km-long tunnel constructed across the repository block (Figure 1-1, Sources: Modified from DOE 2002 [Figure 1-14] and USBR 1996). Scientists from Los Alamos National Laboratory (LANL) analyzed for chlorine-36 (36Cl) in salts leached from whole-rock samples collected from tunnel walls and subsurface boreholes, and scientists from the U.S. Geological Survey (USGS) analyzed for isotopes of oxygen, carbon, uranium, lead, thorium, and strontium in secondary minerals collected from subsurface fractures and lithophysal cavities. Elevated values for ratios of 36Cl to total chloride (36Cl/Cl) at the level of the proposed repository indicated that small amounts of water carrying bomb-pulse 36Cl (i.e., 36Cl/Cl ratios greater than 1250 × 10-15 resulting from 36Cl produced by atmospheric testing of nuclear devices during the 1950s and early 1960s) had percolated through welded and nonwelded tuffs to depths of 200 to 300 meters (m) beneath the land surface over the past 50 years. Because of the implications of short travel times to the performance of the proposed repository, the U.S. Department of Energy (DOE)/Office of Civilian Radioactive Waste Management (OCRWM), Office of Repository Development (ORD), decided to verify the 36Cl/Cl data with an independent validation study. DOE asked the USGS to design and implement a validation study that would include 36Cl and tritium (3H) analyses. Core samples were taken from 50 new boreholes drilled across two zones in the ESF where a substantial number of samples with elevated 36Cl/Cl ratios had been identified previously. Also, core intervals from the Sample Management Facility (SMF) were acquired for water extraction and 3H analyses. 1.1 PURPOSE This report documents the background and history of the validation study and presents the results of the 36Cl to total chloride (36Cl/Cl) and 3H analyses. The study was funded by the DOE/OCRWM ORD to attempt to validate elevated 36Cl/Cl values reported by LANL, and to apply other isotopic methods to identify evidence of rapid flow in the UZ at Yucca Mountain. This report was prepared as part of activities being conducted under Technical Work Plan for: Performance Assessment Unsaturated Zone (BSC 2002) and Test Plan for: Chlorine-36 Validation (USGS 2002). Study participants included the USGS, Lawrence Livermore National Laboratory (LLNL), Atomic Energy of Canada Limited (AECL), and LANL. LANL was funded to analyze 36Cl in some of the validation study samples. The Purdue Rare Isotope Measurement Laboratory (PRIME Lab) and Rosenstiel School of Marine and Atmospheric Science Laboratory at the University of Miami performed 36Cl and 3H analyses, respectively, and Phillips Enterprises, L.L.C. in Golden, Colorado prepared the reference sample that was used to standardize the leaching procedure. 1.2 QUALITY ASSURANCE The Yucca Mountain Project activities and data summarized in this report were subject to the revision of the Quality Assurance Requirements and Description that was in place at the time the work was completed (current Revision 16: DOE 2004). The quality assurance status (qualified [“Q”] or unqualified [“UQ”]) of the data presented in this report is determined by the activities under which they were generated. Although this is a “Q” document, not all data presented are “Q” data. The qualification status of the data is indicated in Section 7.3 of this report and in the electronic Document Input Reference System (DIRS) database. This report has been prepared in accordance with PA-PRO-0313, Technical Reports. It is a summary report, with no technical outputs that could be used as input to another Yucca Mountain Project technical report. Commercial, off-the-shelf software (i.e., Microsoft Excel 2000 running under the Microsoft Windows XP operating system on an International Business Machines Corporation [IBM]-compatible personal computer) was used for data compilation, reduction, computation, and graphical representation of output in the figures and tables contained in this report. 1.3 ORGANIZATION OF THE REPORT The background for initiating the 36Cl validation study is given in Section 2 of this report, along with a summary of previous 36Cl studies. Section 3 describes the design and implementation of the validation study. Chlorine-36 results from the validation study are presented in Section 4. Section 5 describes 3H measurements, which also may be used to identify rapid percolation. Section 6 summarizes the results of the validation study, presents the main conclusions, and describes the important analytical issues that remain unresolved. Section 6 also gives recommendations for a path forward that will help resolve these issues. Publications and data cited in the report are listed in Section 7. Supporting information is contained in the appendixes, including a compilation of previous 36Cl results (Appendix A), video logs for the validation study boreholes (Appendix B), and a description of accelerator mass spectrometry (AMS) analytical methods (Appendix C). 2. BACKGROUND Chlorine-36 is the only naturally occurring radioactive isotope of chlorine. It is produced by cosmic ray-induced reactions in the atmosphere and in minerals at and near the earth’s surface. Chlorine-36 also is produced in the subsurface by reactions with neutrons from the natural decay of uranium- and thorium-series elements. Large amounts of 36Cl, relative to natural abundances, were produced during atmospheric thermonuclear tests in the western Pacific Ocean during the 1950s and early 1960s (Phillips 2000, p. 318). Chlorine-36 in rocks and water at Yucca Mountain derives from multiple sources. Meteoric 36Cl produced by cosmic radiation in the upper atmosphere is rapidly transferred to the land surface by dry-fall or by incorporation into precipitation. At Yucca Mountain, meteoric 36Cl/Cl ratios have been about 500 × 10-15 throughout the Holocene (CRWMS M&O 2000, Table 25, Section 6.6.3.1), but 36Cl/Cl ratios have varied in the past due to several factors. Production rates of 36Cl vary inversely with the intensity of the geomagnetic field (CRWMS M&O 2000, Figure 31, Section 6.6.3.1). Theoretical reconstructions and measurements of fossil urine from pack-rat middens indicate that meteoric 36Cl/Cl ratios prior to about 10 thousand years ago (ka) were appreciably larger (Fabryka-Martin, Wolfsberg et al. 1996, Figure 2-2; Plummer et al. 1997, Figure 2), with average late Pleistocene 36Cl/Cl ratios of about 900 × 10-15 and peak values as high as about 1,100 × 10-15 (Fabryka-Martin et al. 1997, p. 3-3). High concentrations of atmospheric 36Cl produced during atmospheric thermonuclear tests resulted in 36Cl/Cl ratios of meteoric water and soil water ranging from 10-12 to 10-10 (Fabryka- Martin et al. 1997, p. 3-5). Atmospheric concentrations of 36Cl have since returned to pre-bombpulse values (Phillips 2000, Figure 10.8). Infiltration has carried this bomb-pulse 36Cl into the subsurface. In alluvium in arid regions where infiltration is low, most of the bomb-pulse 36Cl has remained within a few meters of the land surface (Tyler et al. 1996, p. 1489; Norris et al. 1987, p. 377). In situ production of 36Cl from natural neutron fluxes in the tuffs at Yucca Mountain results in low 36Cl/Cl values. An equilibrium 36Cl/Cl value of about 40 × 10-15 was calculated by Fabryka- Martin et al. (1997, Section 3.4.1). Large chloride concentrations of 7.6 to 17.6 milligrams per kilogram (mg/kg) and small 36Cl/Cl values of 43 × 10-15 to 57 × 10-15 were measured in leachates of powdered rock samples after most of the meteoric chloride components had been removed (Fabryka-Martin, Wolfsberg, et al. 1996, Table 5-4). Cosmogenic production of 36Cl also takes place in rocks within the upper few meters of the land surface, dominantly through spallation of 40Ca in calcium-rich soils (Stone et al. 1996, Section 4.1). Spallation-derived 36Cl may contribute elevated 36Cl/Cl values to infiltration under wetter climate conditions when old soil carbonate may dissolve and re-crystallize, releasing the accumulated 36Cl to soil water. Also, radioactive decay will result in lowering the 36Cl values, regardless of original sources. The 301,000-year half-life of 36Cl (Phillips 2000, p. 299) is sufficiently long so that decay will not considerably affect processes less than about 50,000 years old, but must be taken into account when considering older geologic and hydrologic processes. 2.1 STUDIES OF CHLORINE-36 AND FRACTURE MINERALS IN THE EXPLORATORY STUDIES FACILITY The ESF was constructed between September 1994 and April 1997, through Miocene ash-flow tuffs, using a tunnel boring machine (DOE 2001, p. 1-16). A 36Cl study was initiated by LANL in 1995 to test whether the Paintbrush Tuff nonwelded hydrogeologic unit (PTn) is an effective barrier to vertical flow, whether water in the matrix of the Topopah Spring welded hydrogeologic unit (TSw) is essentially stagnant, and whether fast paths transporting water to the proposed repository horizon occur at discrete locations associated primarily with fault structures (Fabryka-Martin, Wolfsberg et al. 1996, p. 1). During this time, the USGS began isotopic and geochronologic studies of low-temperature minerals in fractures and lithophysal cavities to evaluate the history of fracture flow over the past 500,000 years (Paces et al. 2001, p. 3). Early sampling for both 36Cl and fracture mineral studies followed advances of the tunnel boring machine through the ESF. One of the objectives of the early work was to evaluate the effectiveness of lateral diversion of percolating water in the PTn (Montazer and Wilson 1984, p. 14). Several nonwelded and mostly vitric pyroclastic units lie between the lower, densely welded part of the overlying Tiva Canyon welded hydrogeologic unit (TCw) and the top of the underlying, crystal-rich vitrophyre of the TSw (Moyer et al. 1996, p. 1). The moderate-to-high porosity and permeability of the PTn and the relatively sharp upper and lower contacts may influence downward percolation into the TSw (Montazer and Wilson 1984, p. 47; Kwicklis et al. 1994, p. 2341; Moyer et al. 1996, p. 2). 2.1.1 Results from Previous Chlorine-36 Studies Analyses of 36Cl/Cl ratios in salts leached from ESF samples were presented in a series of milestone reports (Fabryka-Martin, Wolfsberg et al. 1996; Fabryka-Martin et al. 1997; CRWMS M&O 1998). Data collected through September 1998 are tabulated in Appendix A. Because sampling followed tunnel advances, analytical results were obtained progressively in time and space (Figure 2-1). 36Cl/Cl ratios obtained for samples from the northern ESF, reported in 1996 (Fabryka-Martin, Wolfsberg et al. 1996, Table 5-3), differ from values for samples from the southern ESF, reported in 1997 (Fabryka-Martin et al. 1997, Appendix B). Most 36Cl/Cl ratios from the northern ESF are greater than 500 × 10-15, the value generally accepted for Holocene meteoric input (Fabryka-Martin et al. 1993, Section IV.A; Fabryka-Martin, Wolfsberg et al. 1996, p. 3; Fabryka-Martin et al. 1997, Section 3.1.1). About one fifth of the data from the northern ESF (up to station 45+001, obtained through the Summer of 1996) are either sporadic or clustered 36Cl/Cl values greater than 1,250 × 10-15 (Fabryka-Martin et al. 1997, p. 4-15, Figure 4-6), the cutoff value established by statistical methods as an upper limit of the normal distribution of background samples. Samples with 36Cl/Cl ratios above this cutoff were interpreted to contain a component of bomb-pulse 36Cl. Samples from the southern ESF (beyond station 45+00) have 36Cl/Cl ratios less than 1,250 × 10-15 and some are less than the 500 × 10-15 Holocene meteoric value. Later efforts focused on samples from near the Sundance fault zone in Niche #1 (equivalent to Niche 3566 in other publications) and the Ghost Dance fault zone in Alcoves #6 and #7. Five ESF station numbers are equivalent to distances, in hundreds of meters from a point outside the north portal of the ESF, defined as station 00+00. Thus, ESF station 45+00 is 4,500 m from the north portal. 1 samples from the walls of Niche #1, including a damp breccia, showed 36Cl/Cl ratios between 540 × 10-15 and 635 × 10-15 (CRWMS M&O 1998, Table 3-2). Core samples from Niche #1 produced 36Cl/Cl values from 997 × 1015 to 2,038 × 1015 (CRWMS M&O 1998, Table 3-4). 36Cl/Cl ratios in eight of 20 samples from the walls of the northern Ghost Dance fault zone (Alcove #6) were greater than 1,000 ×10-15, although most samples directly from the Ghost Dance fault exposed in alcove walls were within analytical uncertainty of the Holocene meteoric input value of 500 × 10-15 (CRWMS M&O 1998, Table 3-2). 36Cl/Cl ratios for samples from the southern Ghost Dance fault zone (Alcove #7) did not exceed 644 × 10-15 . The elevated 36Cl/Cl ratios in samples from the northern ESF were of immediate interest because of the implications of fast pathways in the UZ. Elevated levels of both 36Cl and 3H identified in soils elsewhere in the semi-arid southwestern United States were attributed to global fallout from aboveground testing of thermonuclear devices in the 1950s and early 1960s (Phillips et al. 1988; Scanlon 1992; Tyler et al. 1996, p. 1489; Norris et al. 1987, p. 377). The bomb-pulse 36Cl “bulge” observed during these studies was restricted to the upper 1 to 2 m of the soil profiles. Similar profiles of 36Cl/Cl ratios are present in thick alluvium at Yucca Mountain (CRWMS M&O 2000, Section 6.6.3.2). Where alluvial cover is thin or absent, bomb-pulse 36Cl has entered fractures in the bedrock and rapidly penetrated to depths as great as 24 m in surface- based borehole USW UZ-N11, 56 m in USW UZ-N53, and 77 m in USW UZ-N55 (Fabryka- Martin et al. 1993, Table 2). Identification of bomb-pulse 36Cl in cuttings from these boreholes was complicated by the presence of 36Cl/Cl ratios in cuttings from borehole USW UZ-N55 that were “considerably higher than can be explained by global fallout” (Fabryka-Martin et al. 1993, p. 66) (i.e., 36Cl/Cl values up to 27,040 × 10-15, Fabryka-Martin et al. 1993, Table 2). This observation led the authors to conclude that “the possibility that elevated levels in any of these holes may also be attributable to contamination cannot as yet be ruled out” and that “until the source of these elevated 36Cl signals can be identified, the 36Cl/Cl results in the other N-holes2 are also suspect” (Fabryka-Martin et al. 1993, p. 66). Subsequent interpretation of the data, however, indicated that the high 36Cl/Cl ratios measured in the cuttings were possible (Fabryka-Martin, Turin et al. 1996, Table 4-3, and Sections 4.3.3 and 5.3.1). Further tests of core samples from borehole USW UZ-N55, in the same zones where cuttings gave very high 36Cl/Cl values, yielded much lower 36Cl/Cl values (1,152 × 10-15 to 7,937 × 10-15 , Fabryka-Martin and Liu 1995, Table 3-3), leading the authors to conclude that the “difference supports—but does not prove—the hypothesis that the cuttings may have been contaminated during the drilling or collection process” (Fabryka-Martin and Liu 1995, Section 3.1.3). Soils and equipment contaminated with very high levels of 36Cl from the Rover Nuclear Rocket Program in Test Cell C of the Nevada Test Site were discovered in subsequent work (Fabryka- Martin, Turin et al. 1996, Table 4-3, Sections 4.3.3 and 5.3.1). Ratios of 36Cl/Cl as high as 227,102 × 10-15 were obtained from soil pits within 60 m of the rocket tests (Fabryka-Martin, Turin et al. 1996, Table 4-3), and drilling equipment that was used in these areas was later used to drill borehole USW UZ-N55 (Fabryka-Martin, Turin et al. 1996, Section 5.3.1). However, the authors later concluded “. . . it is likely that this issue will never be resolved but may be a moot point because the same conclusion is reached with either set of data. Regardless of the origin of 2 “N-holes” are holes drilled for neutron logging. the 36Cl in the cuttings, elevated ratios for the drillcore samples clearly indicate bomb-pulse 36Cl at this location” (Fabryka-Martin, Turin et al. 1996, Section 5.3.1). The subset of elevated 36Cl/Cl values in the northern ESF was interpreted to indicate that at least some meteoric water has percolated rapidly through the fractured TCw and the PTn into the TSw to depths of 300 m below the surface in the last 50 years (Fabryka-Martin, Wolfsberg et al. 1996, Section 9; Fabryka-Martin et al. 1997, Section 9; CRWMS M&O 1998, Section 10; Wolfsberg et al. 2000, p. 349; Campbell et al. 2003, p. 43). Alternative explanations for the elevated 36Cl/Cl ratios were discussed, including deep, subsurface production in rocks and cosmogenic production in surface rocks and calcrete (Fabryka-Martin et al. 1997, Section 3.4). Although calcrete samples were shown to have substantial cosmogenically produced 36Cl (36Cl/Cl values of 5,067 × 10-15 and 9,772 × 10-15 for two of three soil calcites analyzed, Fabryka-Martin et al. 1997, Table 3-3), 36Cl from this source was estimated to be at least an order of magnitude less than that from the atmosphere (Fabryka-Martin et al. 1997, p. 3-10). To simulate the differences in 36Cl signatures observed in the ESF, a UZ flow and transport model was developed that incorporated a large number of geological and hydrological elements (Fabryka-Martin et al. 1997, Section 9.2; Wolfsberg et al. 2000, Section 4; Flint et al. 2001, Section 4.5; Campbell et al. 2003, Section 2). The model requires faults cutting through the PTn for rapid transport of bomb-pulse 36Cl to depth within the TSw. Unless a structural discontinuity existed, percolation into the PTn would transition to matrix-dominated flow, where travel times would greatly exceed the approximately 50-year existence of bomb-pulse tracer isotopes (Wolfsberg et al. 2000, Section 4; Campbell et al. 2003, p. 46). A formal statistical approach based on log-linear models produced “a very strong association” between ESF samples with elevated 36Cl and faults that cut the PTn (Campbell et al. 2003, p. 59). This analysis evaluated the relation between sites where elevated 36Cl was identified and the locations of known PTncutting structures. Within the TSw, the relation between elevated 36Cl occurrences and faults and shears is not evident (Figure 2-2). Because structural features were targeted for 36Cl studies, approximately one-third of the LANL samples listed in Appendix A were collected from sites associated with faults and shears (DTN: LAJF831222AQ98.004 [Q]). Differences in the amount of infiltration between the northern ESF and southern ESF also were considered important in explaining the presence or absence of elevated 36Cl (CRWMS M&O 1998, p. 10-1; Campbell et al. 2003, p. 59). As precipitation is not likely to vary greatly across the area overlying the ESF, other factors, such as the slope and orientation of the land surface and soil thickness, were considered important in controlling differences in infiltration. Fabryka- Martin et al. (1997, Figure 6-4) and CRWMS M&O (1998, Figure 4-2c) show differences in simulated soil thicknesses between the northern ESF and southern ESF, with more occurrences of thicker soils over the southern ESF. However, simulated infiltration rates based on the numerical model of Flint et al. (1996) are similar in both areas (Fabryka-Martin et al. 1997, Figure 6-3; CRWMS M&O 1998, Figure 4-2b; Campbell et al. 2003, Figure 1c). To explain this difference between the infiltration and 36Cl models, Fabryka-Martin et al. (CRWMS M&O 1998, p. 10-1) cited elevated chloride concentrations in pore waters from the ESF south ramp to suggest that the numerical infiltration model should be modified to allow for lower infiltration rates above the southern ESF. Bomb-pulse 36Cl/Cl ratios were reported in shallow surface deposits (less than 0.5 m depth) between surface-based boreholes USW UZ-N53 and USW UZ-N55, approximately 800 m east of ESF station 51+00; at the UE-25 NRG #5 drill pad, near ESF station 17+00; and in soil pits near the ESF north portal (Fabryka-Martin et al. 1997, Table 4-6). In addition, elevated 36Cl/Cl ratios were common in shallow surface deposits above the southern ESF between ESF stations 67+00 and 78+00 (CRWMS M&O 1998, Table 3-5). These data confirm that bomb-pulse 36Cl has not been completely removed from soil profiles and that infiltration throughout the site is likely to carry bomb-pulse 36Cl into the bedrock (CRWMS M&O 1998, p. 3-5). Just as there are differences in the distribution of elevated 36Cl in the ESF, there is a distinct spatial trend in the non-bomb-pulse 36Cl data (Campbell et al. 2003, p. 57). Most samples from the northern ESF and main drift (up to about ESF station 60+00, Figure 2-1) have 36Cl/Cl ratios between 500 × 10-15 to 1,250 × 10-15 . These intermediate 36Cl/Cl values may be the result of a more dilute bomb-pulse signal or mixtures of the modern meteoric chloride with late Pleistocene meteoric water having higher baseline 36Cl/Cl values (Plummer et al. 1997, Figure 2). Campbell et al. (2003, Section 7) used statistical tests to conclude that intermediate 36Cl/Cl ratios are not associated with the same structural features as the elevated 36Cl/Cl ratios. Therefore, they deduced that the thicker PTn in the northern ESF provides greater average residence time for percolating water, resulting in a larger component of Pleistocene meteoric 36Cl (Campbell et al. 2003, p. 59). 2.1.2 Fracture Mineral Studies Secondary calcite and silica deposits in the ESF have been interpreted as having formed from fracture flow through the welded tuffs (Paces et al. 1996; Paces et al. 1997; Paces et al. 1998; Whelan et al. 1998; Paces et al. 2001; Whelan et al. 2002; Marshall and Futa 2003; Marshall et al. 2003). Geochemical, isotopic, and geochronological data indicate evolution of fracture flow from a meteoric source that was modified by water-rock interactions in the overlying PTn prior to percolation through a small number of fractures in the welded tuffs. Seepage of water films into cavities permitted evaporation with the resulting slow growth of secondary minerals (millimeters per million years) (Paces et al. 2004; Paces et al. 2001, p. 59; Neymark and Paces 2000, p. 158; Neymark et al. 2000, Section 5.3; Neymark et al. 2002, Section 6.7). The slow growth rates preclude identification of minerals deposited since the generation of bomb-pulse isotopes, and carbon-14 (14C) and 230Th/U ages and 234U/238U ratios of fracture minerals from zones with elevated 36Cl/Cl ratios in the northern ESF are indistinguishable from those of secondary minerals outside these zones (Paces et al. 2001, p. 20, Figures 11, 14, and 16). 2.2 PREVIOUS STUDIES OF OTHER BOMB-PULSE ISOTOPES Following the identification of elevated 36Cl/Cl ratios in the ESF, studies using other isotopes related to thermonuclear weapons testing were initiated to substantiate the bomb-pulse interpretation. Both 14C and 3H were produced during atmospheric testing of nuclear devices and have been analyzed in a variety of gas and water samples at Yucca Mountain (Yang et al. 1996, p. 25; 1998, p. 16). The sporadic distribution of elevated concentrations of 14C and 3H in pore water samples from surface-based boreholes was interpreted as evidence of rapid transport of young waters to deeper parts of the UZ (Yang et al. 1996, p. 31; 1998, p. 16). More recent evaluations of the earlier pore water data have identified sampling and analytical problems with the 14C and 3H data sets. In a paper describing pore water travel times based on UZ gas data, Yang (2002, Section 4.1.2) concluded that 14C concentrations reported in earlier studies “were not representative of the pore water residence time because of contamination by atmospheric14CO2 during drilling, resulting in apparently younger residence times.” Yang (2002, Section 4.1.2) proposed using the depth-dependent variation of radiocarbon in the gas phase, which indicates that the average age of water at the repository level is several thousand years. A re-evaluation of the analytical precision for analyses of 3H in pore water produced in the USGS Yucca Mountain Project Branch (YMPB) laboratory in Denver (DTN: GS030508312272.004 [UQ]) resulted in a 22 to 31 tritium unit (TU) detection limit for reliability of significance above background levels. A similar “cutoff” for bomb-pulse values of 25 TU was obtained by statistical analysis of previous 3H results (CRWMS M&O 2000, p. 60 and Figure 30). This larger value reduces the number of analyses that may be interpreted to indicate the presence of modern water. Bomb-pulse technetium-99 (99Tc) was detected in soil and rock samples from the shallow UZ, including samples of Bow Ridge fault gouge exposed in the ESF and cuttings from borehole USW UZ-N55. High 36Cl/Cl ratios also were detected in cuttings from USW UZ-N55; however, the elevated 36Cl/Cl ratios in USW UZ-N55 cuttings were suspected to have resulted from 36Cl contamination from equipment used elsewhere on the Nevada Test Site (Fabryka-Martin and Liu 1995, Section 3.1.3; Fabryka-Martin, Turin et al. 1996, Sections 4.3.3 and 5.3.1; Fabryka-Martin et al. 1997, Section 6.2.2). In addition, measurable levels of cesium-137 (137Cs) were detected in three soil samples (0-5 centimeters [cm]) from the Midway Valley soil pits, located east of Yucca Mountain, but 137Cs was not detected in a soil sample (0-40 cm) from the USW NRG-5 drill pad, located north of the ESF north ramp. Plutonium was detected in two soil samples (one from Midway Valley and the other from the USW NRG-5 drill pad), but plutonium was not detected in the fault gouge sample and was not analyzed for in the cuttings. These results were interpreted to indicate the immobility of cesium and plutonium in surface sediments at Yucca Mountain, limiting their use as ground-water tracers (Fabryka-Martin et al. 1997, p. 6-13, and Fabryka-Martin, Wolfsberg et al. 1996, Table 6-1). 2.3 PEER REVIEW OF CHLORINE-36 STUDIES In January 1998, DOE convened a formal peer review of the 36Cl and related investigations at Yucca Mountain. The Peer Review Team was tasked with reviewing the existing 36Cl reports in the context of the UZ flow and transport models; evaluating the sampling approach and locations; evaluating the adequacy of the analytical approach, including the precision and accuracy of the data; and evaluating the adequacy of interpretations of 36Cl and other isotope data in the context of conceptual UZ flow models. The Peer Review Team identified five major issues (YMP 1998, Section 3.2): • Whether the bomb-pulse 36Cl/Cl values are real [presumably the Peer Review Team was concerned about the large 36Cl/Cl values], • Whether 36Cl/Cl distributions can be explained by variations in source strength with time or by mixing of waters with different 36Cl/Cl ratios, • Whether 36Cl anomalies are an artifact of sampling and analysis, • Whether there is adequate integration of 36Cl and other environmental tracer programs to achieve a consistent conceptual model of the UZ flow system, and • Whether results of 36Cl and other environmental tracers are effectively integrated with conceptual and numerical flow models. The Peer Review Team concluded that bomb-pulse sources were currently the only plausible explanation for the elevated 36Cl/Cl values observed in the ESF (YMP 1998, Section 4.1). Contributions from other sources, primarily spallation of 40Ca in surficial calcrete, were considered and dismissed. The Team also evaluated the possibility that 36Cl anomalies might be artifacts of sampling and analytical practices (YMP 1998, Section 3.5) and included discussions on sample collection, extraction of chloride, and corrections to chloride and 36Cl measurements. The Team accepted the conclusion that bomb-pulse 36Cl entered the ground-water system through infiltration (YMP 1998, Section 3.3.2). Field and/or laboratory contamination as a source for the elevated 36Cl/Cl values was considered in a general sense and the Team did not see obvious evidence or “red flags” to indicate that contamination was an issue. However, the Team did acknowledge that contamination was not a primary focus of their review and it was not examined in detail (Coleman 2005). The Peer Review Team recognized the limitations of using a single isotopic tracer to identify paths of rapid flow in the UZ and recommended coordination of 36Cl/Cl studies with studies of other isotopes and environmental tracers, including 3H, deuterium (2H), oxygen-18 (18O), 14C, strontium-87/strontium-86 (87Sr/86Sr), and 99Tc (YMP 1998, Section 3.6). The Team emphasized the importance of evaluating 3H data relative to 36Cl/Cl ratios, but also recognized the difficulties in interpreting the 3H results (YMP 1998, Section 3.6.2). In particular, the Team discussed the potential for obtaining false positive values (elevated 3H values not related to fast-path fracture flow) through contamination with air from tunnel or drilling activities. Finally, the Peer Review Team recommended continuation of the 36Cl studies, with suggestions on sampling strategies and integration with other isotopic and environmental tracer methods (YMP 1998, Section 4.2). In response to the recommendations of the Peer Review Team, the USGS conducted 3H analyses of pore water, Sr isotope analyses of pore water and pore-water salts, and uranium isotopic (234U/238U) analyses of bulk rock samples within and outside of fracture zones. Results of 3H study are given elsewhere in this report (Section 5). The strontium and uranium isotopic analyses yielded equivocal results with regard to the identification of potential fast flow pathways, and the analytical data are not included in this report. All of the bulk rock samples exhibited a small depletion of approximately 5 percent in 234U relative to the secular equilibrium value of unity for 234U/238U, with no significant differences between samples collected in areas of elevated 36Cl/Cl and those collected elsewhere in the ESF (Gascoyne et al. 2002, p. 788). Similarly, strontium-isotope ratios of pore water and pore-water salts from different locations were in the same range regardless of associated differences in 36Cl/Cl values (Marshall and Futa 2003, p. 375). INTENTIONALLY LEFT BLANK 3. DESIGN AND IMPLEMENTATION OF THE VALIDATION STUDY Because of the potential impact of 36Cl data on conceptual models of UZ flow and transport, DOE asked the USGS to design and implement an independent validation study. With support from the Yucca Mountain Project Management and Test Coordination Office, scientists from the USGS, LLNL, and AECL drafted a proposal that was submitted to DOE in January 1999. Collection of new data was part of the validation study, and members of the validation study team were granted wide latitude in the design of the field work and laboratory experiments. The Center for Accelerator Mass Spectrometry (CAMS) at LLNL was charged with processing and analyzing the new samples for 36Cl/Cl ratios. Following recommendations of the 36Cl Peer Review Team, the use of other isotopic tracers was viewed as an essential part of the validation study. Finding elevated concentrations of 3H would support the interpretation of fast-paths based on elevated 36Cl/Cl ratios. However, substantial improvements in analytical sensitivity were required in the 3H measurements for this method to be useful. Laboratory capabilities for water extraction by vacuum distillation were well established (Yang et al. 1998, p. 25). Samples of extracted pore water were sent to the University of Miami Rosenstiel School of Marine and Atmospheric Science Tritium Laboratory for 3H analysis following enrichment by electrolysis. Tritium sampling and analysis are described in Section 5 of this report. LANL’s participation in the validation study included measuring 36Cl/Cl ratios in a few of the validation study samples. Leachates of core samples from seven validation study boreholes were analyzed prior to 2000 under the same conditions as the previous LANL 36Cl studies. However, by the Fall of 2000, substantial changes had occurred in the LANL 36Cl program (Table 3-1). Damage caused by the Cerro Grande fire in the Spring of 2000 necessitated lengthy shutdowns and relocation of laboratory facilities. In February 2001, the 36Cl laboratory was moved from its previous location in Technical Area 48 (Radiochemistry Site) to a laboratory in Technical Area 3 (Geochemistry and Geomaterials Research Laboratories, SM494, Room 107). The new laboratory was located in a general geosciences facility designated as a non-radiological facility. Sample processing in the new laboratory began in March 2001, and all subsequent analyses of validation study samples were conducted there. In this report, LANL 36Cl/Cl data collected prior to 2000 are generally considered to be from the previous 36Cl/Cl studies, and data collected during and after 2000 are considered to be part of the 36Cl validation study. Initially, LANL’s participation in the validation study was not fully integrated with other parts of the study. However, from 2000 on, LANL scientists coordinated more closely with the other validation study participants, to include analyses of the same leachates and crushed materials. This coordination was ultimately critical for producing a better understanding of the conflicting results obtained by the different investigators. 3.1 DESIGN OF SAMPLING PROTOCOL Difficulties in replicating elevated 36Cl/Cl ratios in ESF samples led to the hypothesis that the elevated 36Cl is inhomogeneously distributed in fractured rock (CRWMS M&O 1998, p. 3-3). Therefore, for the validation study, attempts to replicate the previous analyses were based on the likelihood of finding elevated values along reaches of the ESF where numerous occurrences were identified by the previous analyses. Thus, the fundamental assumption of the validation study was that a sufficiently detailed re-sampling of the same areas should yield a similar proportion of elevated 36Cl/Cl values. Elevated 36Cl/Cl ratios were reported in multiple samples from two intervals in the northern ESF. These are associated with the Drill Hole Wash fault (Figure 3-1), between ESF stations 18+96 and 19+42, and the Sundance fault (Figure 3-2), between ESF stations 34+28 and 35+93. Both intervals include northwest-trending strike-slip faults exposed in tunnel walls and in surface exposures on the east slope of Yucca Mountain. Of the seven analyses from five samples collected previously from the 100-m interval including the Drill Hole Wash fault, five of the analyses yielded 36Cl/Cl values greater than the bomb-pulse threshold of 1,250 × 10-15, with a sixth analysis very near the bomb-pulse threshold (1,144 × 10-15) (1,880 to 1,980 m; Figure 3-1). From the nine samples collected at and north of the Sundance fault (3,428 to 3,593 m; Figure 32), 11 of 16 analyses had 36Cl/Cl values greater than 1,250 × 10-15 . In addition, eight of 15 analyses of samples associated with Niche #1, which was constructed to access the Sundance fault, had 36Cl/Cl values greater than 1,250 × 10-15 . Five analyses from four samples of the walls of Niche #1 had values between 540 × 10-15 and 659 × 10-15; whereas, eight of 10 samples obtained from boreholes drilled along the axis of the niche prior to excavation, or from the end of Niche #1 toward the Sundance fault, yielded 36Cl/Cl values greater than 1,250 × 10-15 . A ninth sample had a 36Cl/Cl value of 1,235 × 10-15 (CRWMS M&O 1998, p. 3-4, Table 3-4). Because of these elevated values, the Drill Hole Wash fault zone and Sundance fault zone were targeted for validation study sample collection. Most of the previous samples had been collected from tunnel walls shortly after excavation, between 1995 and 1997. Re-sampling of tunnel walls for the validation study was not desirable because chloride may have been lost when tunnel walls were washed and (or) if the tunnel walls were contaminated with 36Cl-enriched dust brought into the ESF by the ventilation system. Instead, core was sampled from 4- and 10-m-long dry-drilled boreholes spaced along the right rib (side) of the ESF at approximately 5-m intervals. Fifty new boreholes were sited across the two zones (10 boreholes from the Drill Hole Wash fault zone and 40 from the Sundance fault zone; Table 3-2 and Figures 3-1 and 3-2). One advantage of using a borehole sampling approach is the probability that the deeper core intervals extend beyond the zone of penetration of construction water and ventilation-induced dry-out. Therefore, the deeper intervals could be used for water extraction and 3H analyses as an independent indicator of a bomb-pulse component. Selection of sampling sites for the validation study differed from that of the previous studies, which had been based on two sampling approaches (Fabryka-Martin et al. 1996, p. 1-3). The first, referred to as “feature-based” sampling, targeted specific features such as faults, fractures, and cooling joints. These samples were collected to maximize the surface area of the targeted feature. Of the 234 feature-based samples, 35 (15 percent) had bomb-pulse 36Cl values. The second sampling approach, referred to as “systematic sampling,” consisted of sampling sites at 200-m intervals between stations 5+00 and 59+00. The spacing was later reduced to 100-m intervals from stations 59+00 to 69+00 and stations 69+50 to 76+50 (Fabryka-Martin et al. 1997, p. 55). According to Fabryka-Martin et al. (1997, p. 55), “The systematic sampling was designed to acquire isotopic data unbiased by any other selection criteria. These samples represent the rock matrix and whatever fracture fabric typifies the collection site.” Of the 54 systematic samples, two (4 percent) had bomb-pulse 36Cl values. The validation study boreholes also were spaced systematically, but the spacing was on 5-m centers over the areas of interest rather than 100 m, and at least 4 m of rock were penetrated. Sampling for previous work typically penetrated only a few tens of centimeters into the tunnel walls. Prior to drilling for the validation study, the original tunnel-wall sample sites were examined and the conclusion was reached that, given the number of boreholes that were to be drilled, the fracture density, and the amount of rock sampled by the boreholes, the validation study would have a high probability of accessing potential zones of fast flow. To evaluate the validation study sampling plan, fracture density data for the ESF were examined (Figure 3-3). These data were obtained by documenting individual fractures and cooling joints with traces on the tunnel wall greater than 1 m. The two validation study target zones are characterized by distinctly different fracture densities. Fracture density data can be converted to fracture spacing along the detailed line surveys by measuring distances between successive fractures intersecting the survey line. Distributions of fracture spacing are given in Figure 3-4A for the tunnel around the Drill Hole Wash fault (ESF stations 16+00 to 21+00) and Figure 3-5A for the Sundance fault (ESF station 34+00 to 36+00). For both zones, fracture spacing is strongly skewed, with the largest frequencies having the shortest spacings. The median values for fracture spacings are 0.78 m for the Drill Hole Wash fault zone and 0.15 m for the Sundance fault zone. Because of the skewed distributions, arithmetic means are inappropriate. However, values for the log10 of the fracture spacings are more normally distributed and give geometric means closer to the medians (Figures 3-4B and 3-5B). These data, along with the variable fracture orientations, indicate that the 4-m-long validation study boreholes should have intersected multiple (between about 5 and 27) fractures with trace lengths greater than 1 m. In addition to these fractures, short-trace-length fractures with trace lengths less than 1 m are locally important geologic and hydrologic features (Sweetkind et al. 1998, p. S231). Because short-trace-length fractures were excluded from detailed line surveys, true fracture densities throughout the ESF are underestimated by the evaluation shown in Figures 3-4 and 3-5, with the greatest disparities observed in lithophysal units (Sweetkind et al. 1998, p. S231). Thus, abundant fractures were expected in the validation study boreholes in the Sundance fault zone. The validation study sampling approach was further supported by earlier results obtained from leachates of core samples collected from the Sundance fault zone. Elevated 36Cl/Cl values between 1,235 × 10-15 and 2,038 × 10-15 were obtained for eight of 10 samples from different intervals from three boreholes associated with Niche #1 (boreholes ESF-MD-NICHE3566#1, #2, #LT in Appendix A). Therefore, although the previously analyzed sites would not be re-sampled for the validation study, it was expected that a statistically significant percentage of the validation study analyses would contain bomb-pulse 36Cl. 3.2 DESCRIPTION AND ALLOCATION OF VALIDATION STUDY CORE Fifty validation study boreholes were drilled between mid-March 1999 and early-October 1999. Drilling activities were conducted by the Yucca Mountain Project Management and Test Coordination Office and core documentation, preservation, and handling were performed by the Sample Management Facility (SMF) in accordance with NWI-DS-001Q, Field Logging, Handling, & Documenting Borehole Samples. Core intervals deeper than 2 m in each borehole were preserved for pore water extraction by packaging in Lexan® sleeves sealed inside ProtecCore™ after video logging each core run. The video logs were examined and the core was classified on the basis of core recovery and fracturing. This classification was intended to identify zones with the greatest amounts of fracturing, which were then selected for further analysis. Assignment of mechanical classes of core was intended as a qualitative measure of the degree of fracturing and included descriptors such as “intact,” “broken,” “rubbly,” and “shattered,” in order of increasing fracture intensity (Paces 2003). Results of video logging are included in Appendix B. Most core is classified as broken to rubbly, indicating core fragments are generally less than about 7 cm (broken) to 2 cm (rubble or rubbly). These observations are consistent with the fracture densities determined from the detailed line surveys and measurements of short-trace-length fractures (Section 3.1). The video logs formed the basis for distribution of core intervals to LLNL, USGS, and AECL. Core intervals were selected from the deeper half of the borehole to avoid both dry-out and contamination with construction water. To provide sufficient chloride for 36Cl analyses, and water for 3H analyses, core intervals of approximately 60 cm were selected. LLNL received the core with the greatest fracture densities, providing the greatest probability of including a flow path containing bomb-pulse 36Cl. Although samples for 3H analyses may have contained fewer fractures, core intervals from the deepest parts of the boreholes were selected to minimize the effects of dry-out. Core intervals from intermediate depths (1.2 to 2.0 m) in boreholes in the Sundance fault zone were selected for 36Cl/Cl analysis at LANL. All core intervals were distributed from the SMF shortly after the boreholes were completed. In addition to the 50 new validation study boreholes (Figures 3-1 and 3-2; Table 3-2), samples of existing core were obtained from the same three Niche #1 boreholes that had been analyzed previously (ESF-MD-NICHE3566#1, ESF-MD-NICHE3566#2, and ESF-MD-NICHE3566LT#1). These intervals were originally requested from the SMF for 36Cl/Cl analyses shortly after the boreholes were completed in 1997. Core selected for validation study analyses had remained unopened in the original SMF packaging. The 41 intervals available for the validation study were distributed between the USGS and LANL. The approximate locations of these three boreholes relative to the ESF main drift and Sundance fault are shown in Figure 3-6 (Source: USGS 1996). Because individual intervals were generally too small to supply sufficient chloride for reliable 36Cl measurements, multiple intervals were combined into six samples leached at the USGS and five samples leached at LANL. Two of the LANL samples were further subdivided into coarser (6.3 to 12.5 millimeters [mm]) and finer (less than 6.3 mm) fractions, resulting in a total of seven leachate analyses. These combined samples were selected to provide at least some overlap of core intervals from each borehole to facilitate a more-or-less direct comparison between USGS and LANL validation study analyses (Table 3-3 and Figure 3-7), as well as comparison between validation study results and results reported previously by LANL (CRWMS M&O 1998, Table 3-4). To determine whether the method of crushing affected the release of chloride during leaching, samples from borehole ESF-SAD-GTB#1 (southern Ghost Dance fault, Alcove #7) were crushed by hand with a hammer and steel plate, and by jaw crusher. Three samples were screened to the same particle size and leached for the same length of time. Core from ESF-SAD-GTB#1 was selected for the crushing experiments because it was similar to the validation study core (i.e., both the validation study boreholes and ESF-SAD-GTB#1 were drilled in the crystal-poor, middle nonlithophysal unit of the Topopah Spring Tuff), and because a large amount was available to the USGS in Denver. Experimental methods and results of the crushing experiments are described in Section 4.4.1.2. INTENTIONALLY LEFT BLANK 4. CHLORINE-36 MEASUREMENTS The validation study proceeded in three phases, beginning in late-1999 and continuing through late-2002. In Phase I, 36Cl experiments were conducted at LLNL, including crushing, leaching, silver chloride (AgCl) target preparation, and isotope analysis. Concurrent with the work at LLNL, several samples of the validation study core were analyzed at LANL in accordance with the standard analytical procedures used previously by LANL. Results from the two sets of experiments differed significantly. The active-leach protocol used by LLNL during this phase of the investigation resulted in anomalously large chloride concentrations and low 36Cl/Cl ratios compared to the LANL results for the validation study core and previous LANL results for tunnel-wall samples. This prompted a halt in 36Cl data-collection activities and initiation of Phase II of the study to evaluate leaching protocols that would maximize the probability of identifying a meteoric chloride component. Leaching experiments were conducted on systematic and feature-based samples collected previously by LANL from the ECRB Cross Drift. Results of these experiments indicated that the release of rock chloride was minimized by passive-leach methods and that most of the meteoric chloride components were liberated after short leaching times. A final 1-hour passive-leach protocol was then adopted by all the study participants for Phase III of the validation study. In Phase III, responsibility for crushing and leaching validation study samples shifted to the USGS and LANL, although LLNL-CAMS and PRIME Lab continued to analyze the new samples. Details of the procedures used and results obtained are given in the following sections. 4.1 PHASE I: MEASUREMENTS MADE AT LLNL 4.1.1 Methods An active-leach approach was used by LLNL during Phase I of the validation study to provide a repeatable process for extracting chloride from Yucca Mountain tuffs. The procedure involved mechanical crushing and sieving of samples to a 1- to 2-cm size fraction. Between 1.4 and 3.0 kg of rock were combined with 1.3 to 1.7 times that weight of de-ionized water. The mixture was placed in a stainless-steel tumbler and allowed to rotate slowly for 7 hours. The resulting slurry was decanted from the tumbler into a stack of 150- to 38-µm stainless steel sieves. This solution was filtered using vacuum flasks fitted with a series of filters of decreasing pore size (25, 8, 0.8, 0.45, and 0.22 µm). Chloride was precipitated from this final, clear solution following the chemical procedures described in Appendix C. The resulting AgCl target was analyzed for 36Cl/Cl ratios by accelerator mass spectrometry (AMS) at the LLNL-CAMS facility. No procedural blanks were reported for this phase of the validation study. 4.1.2 Results The active-leach method was used for 25 validation study core samples from the Sundance fault zone between ESF stations 33+89 and 36+75. Chloride concentrations and 36Cl/Cl ratios are given in Table 4-1 and plotted against borehole locations in the ESF in Figure 4-1. Chloride concentrations varied between 1.25 and 3.54 mg/kg, with a median value of 2.13 mg/kg rock and a mean of 2.07 ±1.24 mg/kg rock (Figure 4-2A). 36Cl/Cl ratios range between 48 × 10-15 and 248 × 10-15, although all values but one are less than 156 × 10-15 . The median value for all 25 samples is 88 × 10-15, and the mean is 97 ±86 × 10-15 (Figure 4-2B). Isotope ratios are commonly plotted against the reciprocal of the concentration values so that binary mixing relations are linear (Faure 1986, p. 142). On such a plot the data form a diffuse cluster with a positive slope (R2 value of 0.2 if sample ESF-SD-ClV#32, with a ratio of 248 × 10-15, is excluded), showing that leachates with higher chloride concentrations tend to have lower 36Cl/Cl ratios (Figure 4-3A). Results of the active-leach experiments performed at LLNL differ from the results of passive-leach experiments conducted previously at LANL (Figure 4-3B). Chloride concentrations in the 25 active leachates reported in Table 4-1 are within the range of values obtained earlier by LANL, although the median of 2.1 mg/kg for active leachates is higher than the median of 1.0 mg/kg rock calculated for the 293 passive leachates reported by LANL (Appendix A). (Note: Ten of the samples listed in Appendix A were not analyzed for chloride concentrations). The 36Cl/Cl values of the two data sets plot in distinct fields, with very little overlap. The median 36Cl/Cl value for the active leachates is 85 × 10-15, whereas the median value for the passive leachates is 569 × 10-15 . The median value for the passive leachates, excluding the 47 samples with 36Cl/Cl at or over the 1,250 × 10-15 bomb-pulse threshold, is only slightly lower (531 × 10-15). Roback et al. (2002, p. 235) demonstrated that active leaching methods released a greater proportion of rock chloride relative to meteoric chloride, thus yielding smaller 36Cl/Cl ratios than obtained by passive leaching methods. Similarly, measurements of chloride concentrations and 36Cl/Cl ratios in leachates of powdered rock samples after most of the meteoric chloride components had been removed resulted in large chloride concentrations (7.6 to 17.6 mg/L) and small 36Cl/Cl values (43 × 10-15 to 57 × 10-15) (Fabryka-Martin, Wolfsberg et al. 1996, Table 5-4). These 36Cl/Cl values were interpreted to reflect 36Cl produced in situ through neutron capture by stable chlorine-35 (35Cl) (Fabryka-Martin, Turin et al. 1996, Section 4.4.3). The relation of measured rock chloride values along a projection of the regression line for the active-leach data (Figure 4-3A) provides a strong indication that the active-leach method is too aggressive and extracts too much rock chloride, which masks the meteoric chloride component. 4.2 PHASE I: MEASUREMENTS MADE AT LANL 4.2.1 Methods Methods used by LANL for the 36Cl validation study involved crushing, leaching, and chemical processing procedures similar to those used in previous LANL 36Cl studies (Fabryka-Martin, Turin, et al. 1996, Section 3; Fabryka-Martin et al. 1997, Section 4; CRWMS M&O 1998, Section 2.3). No procedural blanks were reported for this phase of the validation study. 4.2.2 Results Core samples from the Sundance fault zone were selected by LANL for analysis as oversight to the active-leach experiments performed at LLNL. Chloride concentrations in these leachates are uniform, ranging from 0.23 to 0.35 mg/kg rock (Table 4-2). Measured 36Cl/Cl ratios range from 508 × 10-15 to 942 × 10-15, with no values exceeding the 1,250 × 10-15 bomb-pulse threshold. These values are similar to other northern ESF samples analyzed at LANL prior to 2000 (Appendix A). 4.3 PHASE II: LEACHING EXPERIMENTS Phase I results from active leaching at LLNL and passive leaching at LANL were presented at the May 1, 2000, meeting of the Nuclear Waste Technical Review Board (NWTRB) in Pahrump, Nevada. The large discrepancies in 36Cl/Cl values between the two data sets were debated and led to a letter from the NWTRB to the Director of the DOE OCRWM (Cohon 2000), urging that high priority be given to resolution of the disagreements. In response, the validation study participants agreed that additional work was necessary to identify a standardized leaching procedure for extracting labile meteoric chloride and minimizing releases of rock chloride. To accommodate this work, a large sample of tuff with homogenous chloride was required for a reference sample so that comparable splits could be distributed to LANL and LLNL for leaching experiments. The 36Cl/Cl composition of this reference sample was not critical and could be a mixture of chloride from meteoric, bomb-pulse, or construction-water sources, as long as the mixture was uniformly distributed throughout the material. The reference sample would then be used to test the effects of leaching methods, leaching times, and particle sizes. Due to changes in personnel at LLNL during this period, no leaching experiments were conducted at LLNL. In addition to the leaching experiments conducted at LANL, leaching experiments were also conducted at AECL to determine the distribution of chloride in validation study core samples associated with the Sundance fault zone. The goal of this work was to understand the sources and locations of chloride (and, by extension, 36Cl) in the tuff and to determine whether the difficulties in reproducing 36Cl/Cl ratios could be explained in terms of the sample treatment processes used. These analyses produced chloride concentrations but did not determine 36Cl/Cl ratios in the leachates. 4.3.1 Preparation of the Reference Sample The USGS worked with the Yucca Mountain Project Management and Test Coordination Office to identify and collect a large rock sample that could be used as the reference sample (referred to as “EVAL001” by LANL). The sample (SPC00557088) consisted of two 55-gallon drums of coarse muck collected from the discharge end of the Alpine miner during construction of Niche #5 in the ECRB Cross Drift (Figure 1-1). Niche #5 is located within the lower part of the TSw. The muck was shipped to Phillips Enterprises, LLC, of Golden, Colorado, where it was removed from the shipping containers, spread out on clean plastic tarps, and allowed to air-dry over a 3-day period prior to processing. The muck was then stage-crushed using a jaw crusher and screened to recover the maximum quantity from the 6.3- to 12.5-mm size fraction. Approximately 136.1 kg of crushed and sized rock was produced in this manner, after which it was homogenized by hand mixing. The sized material was then split into ten 13.61-kg sub- samples, and each was given a final blow-down with compressed dry nitrogen to remove dust adhering to rock surfaces. Blow-down was conducted on a vibrating screen to promote maximum dust removal. Each sub-sample was placed in a polyethylene bag, sealed, and stored in a plastic-lined 55-gallon drum. 4.3.2 Leaching Experiments Conducted at LANL During Phase II of the validation study, LANL performed a series of experiments using EVAL001 and several samples from the ECRB Cross Drift to determine the effects of leaching time, leaching method, and particle size on the release of chloride and the resulting differences in36Cl/Cl ratios. The goals of these experiments were to identify the processing method that would be most effective in identifying a bomb-pulse 36Cl/Cl component if one is present, and to provide information to evaluate previous 36Cl/Cl data from the Yucca Mountain UZ. Substantial changes occurred in the LANL 36Cl program between Phases I and II of the validation study. In the Fall of 2000, a new principal investigator assumed the lead role for the Yucca Mountain 36Cl studies. Personnel responsible for sample processing also changed by October 2001, after a 2-month overlap. In February 2001, the LANL 36Cl laboratory was moved from its previous location in Technical Area 48 (Radiochemistry Site) to a laboratory in Technical Area 3 (Geochemistry Analytical Facility, SM494, Room 107). The new laboratory is located in a general geosciences laboratory facility designated as a non-radioactive facility. The laboratory was cleaned prior to relocating the 36Cl laboratory equipment. Sample processing in the new laboratory began in March 2001 and all subsequent analyses for Phases II and III of the validation study were conducted in this laboratory. Although many of the methods used in Phases II and III were the same as those used previously by LANL, some changes were made to accommodate changing objectives of the project. Methods related to establishing a standard leaching protocol during Phase II are described below. Methods related to sample processing during Phases II and III are described in Section 4.5.1. 4.3.2.1 Methods LANL patterned the leaching experiments after work that was done at LANL between July and December 2000. EVAL001 was split into aliquots using a geotechnical sample splitter. Some of these aliquots were crushed further to investigate the effects of particle size on leaching. Crushed aliquots were sized using an Endecotts® EFL2 mk3 Test Sieve Shaker to obtain sub- samples of uniform particle-size range. Portions of some samples were pulverized to a fine powder in a pre-cleaned Bico® shatter box to determine the chloride and bromide content of the rock. Two aliquots of EVAL001 (-7 and -11) were passively leached by leaving the rock and leachate undisturbed during leaching. To determine whether vigorous agitation during leaching liberates additional chloride from the rock, 3 splits from EVAL001 (-8, -9, -11) were actively leached by placing the rock fragments into a 2-L polyethylene bottle with a sub-equal weight of de-ionized water. The bottle was shaken in a horizontal position using a Glas-Col Apparatus Company® Shaker-in-the-Round Model S500 shaker. The shaker rotated the bottle laterally 32º in 0.45 seconds, before returning it to its original position. The shaker was allowed to oscillate in this manner continuously for up to 7 days. Both active- and passive-leach splits were leached for 0.5, 2.0, 7.0 and 76 to 165 hours. One active-leach sample was leached for 0.05-0.12 hours. The mass of rock leached (after combining the actively leached samples) ranged from 2.961 to 5.044 kg. These rock masses yielded a minimum of 0.44 mg of chloride (not including chloride in the tracer or procedural blank) for analysis. Chloride isotopic analyses were performed at PRIME Lab. LANL also performed sequential leaching experiments on six samples that were collected from the ECRB Cross Drift for the pre-2000 LANL 36Cl studies (Table 4-3, samples with the prefix “EXD”). For these experiments, only the passive-leach method was used, with leaching times of 0.5, 2, 7 and 48 hours. After each leaching period, the water was removed and replaced with new de-ionized water. One sample (EXD-069) was separated into three size fractions prior to leaching. The 6.3- to 12.5-mm size fraction was used for all other samples. Rock mass typically varied between 3 and 6 kg. In all cases, this amount of material yielded a minimum of 0.3 mg of rock chloride (not including chloride in the tracer or blank), and in most cases considerably more rock chloride (mean of 1.2 mg, maximum of 6.8 mg chloride). Analyses of 36Cl/Cl ratios were performed at LLNL-CAMS. 4.3.2.2 Results Chloride concentrations for aliquots of the two passive-leach samples (EVAL001-7 and EVAL001-11) range from 0.11 mg/kg rock to 0.25 mg/kg rock, with a mean of 0.16 mg/kg rock for all aliquots (Table 4-3). Chloride concentrations for the active-leach splits (EVAL001-8, -9, -10) are larger, ranging from 0.15 mg/kg rock to 0.31 mg/kg rock, with a mean of 0.21 mg/kg rock. 36Cl/Cl ratios for the two passive-leach splits range from 492 × 10-15 to 889 × 10-15, with analytically indistinguishable means of 619 × 10-15 for EVAL001-7 leachates and 585 × 10-15 for EVAL001-11 leachates. In contrast, the 36Cl/Cl ratios for the active-leach splits are smaller than the passive-leach splits, with a range of 234 × 10-15 to 501 × 10-15 and a mean of 397 × 10-15 . Relations between chloride concentration, 36Cl/Cl ratios, and time are plotted in Figures 4-4 and 4-5. These plots show the evolution of compositions with increasing leach duration and the differences in results obtained from passive and active leaching. Most passive-leach samples have smaller chloride concentrations, and all have larger 36Cl/Cl ratios for equivalent leaching times when compared to the active-leach samples. In all samples, the chloride concentration increases rapidly through the first 7 hours. Chloride concentrations remain constant or decrease in the longer leaches for passive-leach samples, whereas the active-leach sample shows continued increases in the release of chloride with increases in leaching time. Passive-leach samples have larger 36Cl/Cl ratios for equivalent leaching times compared to the active-leach sample. The largest 36Cl/Cl ratios were obtained in the shortest leaching time for both passive- leach samples. Passive leachates from EVAL001-7 show a consistent decrease in the 36Cl/Cl ratios over time, from a value of 889 × 10-15 for the 0.5-hour leach to a value of 493 × 10-15 for the longest leach (Table 4-3). Data from both passive-leach EVAL001 samples converge to identical 36Cl/Cl ratios of approximately 575 × 10-15 for cumulative values. Active leachates from EVAL001-8, -9, and -10 have 36Cl/Cl ratios between 423 × 10-15 and 501 × 10-15 for the first 7 hours and a substantially smaller value of 234 × 10-15 for the longest leaching time. Chloride concentrations in sequential leachates of the 6.3- to 12.5-mm size fraction of ECRB Cross Drift samples varied considerably, with values ranging from 0.07 mg/kg rock to 0.66 mg/kg rock (Table 4-3). Chloride concentrations in leachates remained relatively constant for successive leaches of increasing durations in four of six samples (Figure 4-6A). As a result, chloride extraction rates are much greater for the initial leaches and decrease dramatically as leaching times exceed 7 hours. This is reflected in the flattening of cumulative chloride concentration curves with increased leaching time (Figure 4-6B). Like chloride concentrations, 36Cl/Cl ratios show wide variations among samples, but much smaller variations for different leach durations of the same sample (Figure 4-7). 36Cl/Cl ratios range from 234 × 10-15 to 924 × 10-15 for the 6.3- to 12.5-mm size fraction (Table 4-3). Most samples have relatively constant 36Cl/Cl ratios regardless of leach duration. Leachates of sample EXD-072 show a statistically significant change in 36Cl/Cl ratios as leaching progressed, with values decreasing from 924 × 10-15 for the 0.5-hour leach to more-or-less constant values between 676 × 10-15 and 753 × 10-15 in subsequent leaches. The opposite trend of small 36Cl/Cl ratios progressively increasing to larger values in subsequent samples was observed for EXD-049; however, these samples have large and overlapping analytical uncertainties. The other four samples show remarkably consistent 36Cl/Cl ratios throughout the entire 48-hour leach duration. In an additional leaching experiment, one sample was used to evaluate the effects of different particle sizes on chloride concentrations and 36Cl/Cl ratios (sample EXD-069 in Table 4-3). A consistent pattern of leachable chloride concentrations was not observed for the size fractions used (Figure 4-8A). For the shortest leach duration (0.5 hour), the finest fraction (less than 2 mm) had the smallest chloride concentration (0.40 mg/kg rock), and the intermediate size fractions (2 to 6.3 mm) had the largest chloride concentration (0.99 mg/kg rock). However, the relatively constant chloride extracted from the coarsest fraction (6.3 to 12.5 mm) over time resulted in the largest cumulative chloride concentration after 48 hours (Figure 4-8B). Values of 36Cl/Cl in successive leaches of each size fraction also are nearly constant with leach duration (Figure 4-9). The finest size fraction has both the smallest chloride concentration and the largest 36Cl/Cl ratio in all sequential leachates, ranging from 317 × 10-15 to 432 × 10-15 (all values are within 2s error or very nearly so). The intermediate and coarse size fractions have smaller 36Cl/Cl ratios (261 × 10-15 to 297 × 10-15), which are distinguishable (within 2s error) from values for the fine fraction. Cumulative 36Cl/Cl ratios obtained over time for these samples are constant, indicating that 36Cl and total chloride are extracted in the same proportions throughout the experiments. 4.3.2.3 Discussion of Results Leaching experiments performed at LANL were designed to test the effects of leaching methods, leaching times, and particle size on the measured 36Cl/Cl ratios. Most 36Cl/Cl values for samples leached by the passive-leach method are consistent with derivation from the conceptualized sources listed in Table 4-4, involving salts precipitated from meteoric water less than 10 ka or a mixture of salts less than 10 ka and greater than 10 ka. Three samples show a decrease in 36Cl/Cl ratios over time, with the largest ratios corresponding to the shortest leaching time. This trend is interpreted to indicate that these samples may contain a small component of bomb-pulse or surface contaminant 36Cl, which is mixed with pre-bomb-pulse meteoric salts. Dilution of this elevated 36Cl signal increases throughout the leaching process. Only one sample shows a substantial decrease in the 36Cl/Cl ratio in the final leaching step, indicating increasing input of rock chloride. Different aliquots of the reference sample, EVAL001 (which was homogenized), displayed a large range of 36Cl/Cl values in the first 0.5 hour (Table 4-3). This suggests that splits of EVAL001 have different 36Cl/Cl values in the most labile chloride component. The constancy of the 36Cl/Cl ratios in individual samples with increasing leaching time, and the fact that they remained uniform despite the variability of measured ratios among the samples, indicate that there is only a single source of chloride in the rock or that a uniform mixture of different sources of chloride was leached. On a plot of 36Cl/Cl ratio versus reciprocal of chloride concentration (Figure 4-10), most samples do not show a correlation between 36Cl/Cl ratios and chloride concentrations, with the exception of EVAL001-8, -9, -10, obtained by active leaching. The small 36Cl/Cl ratios and the observed correlation between 36Cl/Cl ratios and chloride concentrations is a result of the active-leach process. Active leaching liberates more rock chloride, which dilutes the meteoric chloride and results in smaller 36Cl/Cl ratios. Leachates of all aliquots of sample EXD-069 have a wide range of chloride concentrations and small 36Cl/Cl ratios (Figure 4-10A), and they show uniform 36Cl/Cl ratios in each fraction for different leach durations. The small 36Cl/Cl ratios in the coarser fractions of this sample are similar to many of the USGS-LLNL leachates (Section 4.4). These results imply that some samples, and perhaps rock masses in the subsurface, may be characterized by uniformly small 36Cl/Cl ratios. However, leachates of the finer fraction (less than 2 mm) have substantially larger 36Cl/Cl ratios than the coarser fractions. A similar negative correlation of 36Cl/Cl ratios with particle size is observed in samples of Niche #1 core analyzed at LANL. These relations contradict the conceptual model of chloride distribution described by Lu et al. (2003), as discussed in Section 4.6.2. 4.3.3 Leaching Experiments Conducted at AECL As indicated in Section 4.3.2, the location and distribution of primary chloride in tuffs at Yucca Mountain is not well understood. Noble et al. (1967, p. 222) have shown that, on average, 80 percent of the chloride originally present in silicic volcanic glass is lost during formation of densely welded tuffs. Chloride liberated during devitrification may have been deposited locally during cooling of the tuffs, forming soluble minerals that would be dissolved readily by percolating water. Twenty rock samples of the crystal-poor part of the devitrified TSw from the ECRB Cross Drift have a mean value and 1s for chloride of 170±40 µg/g (Peterman and Cloke, 2002, p. 695). The chloride concentrations in the volcanic glass contained in the tuff before devitrification were probably much larger. In an attempt to characterize the primary rock chloride, Fabryka-Martin, Wolfsberg et al. (1996, Table 5-4) leached finely ground tuff for chloride concentrations and 36Cl/Cl ratios. The resultant concentrations are more than a factor of 10 less than the mean rock value of 170 µg/g, indicating that a substantial amount of the rock chloride is tightly bound and unavailable to leaching. More recently, work done at AECL has further investigated the chloride content of samples of the TSw from the validation study boreholes. This work is described below. 4.3.3.1 Methods The crush-leach method was used to determine the chloride distribution in validation study samples and the effects of leaching time and grain size on the leachable chloride content. By varying the particle size and leaching time, it was thought possible to gain an understanding of the location of chloride in the rock and, hence, what might happen to infiltrated 36Cl on leaching. Samples used for the leaching experiments (Table 4-5) were from three of the dry-drilled validation study boreholes in the vicinity of the Sundance fault (fault trace at about ESF station 35+93). The proximity of the boreholes to the fault varied: ESF-SD-ClV#2 was the farthest (about 82 m south of the fault trace at ESF station 36+75), ESF-SD-ClV#14 was at an intermediate distance (about 48 m north of the fault trace at ESF station 35+45), and ESF-SD-ClV#9 was within 10 m of the fault trace on the ESF tunnel wall. The intensity of fracturing also varied within the boreholes. Core was largely intact in the 30-cm interval from ESF-SD-ClV#2, broken with two to three fractures in the 55-cm interval from ESF-SD-ClV#14, and largely rubble in the 49-cm interval from ESF-SD-ClV#9. The latter sample was selected to determine the leaching characteristics of very coarse fractions of rubblized rock. Test parameters for the leaching experiments are listed in Table 4-5. The leaching experiments were designed to test differences in the amount of chloride extracted from different particle sizes for rock crushed by both laboratory and natural processes over different leaching times. Samples were crushed in the laboratory using a rock breaker, jaw crusher, and shatter box, if needed. No attempt was made to trim the core sample or wash its surface to remove external contaminants. In addition, experiments designed to evaluate the effects of both leaching time and particle size on naturally broken rock were performed using fragments that were hand-picked and sieved from the rubblized interval of borehole ESF-SD-ClV#9 near the Sundance fault. Six fractions of this sample, including coarse fractions up to 60 mm, were obtained by hand-picking and sieving without laboratory crushing. All size fractions were leached with de-ionized water for durations ranging from 10 minutes to 72 hours, depending on the experiment. De-ionized water used for leaching had blank chloride concentrations below the detection limit of 0.15 mg/L, whereas most rock leachates had concentrations at this level or higher. Also, chloride concentrations varied systematically down to the lowest values, implying that the true detection limit is probably lower than 0.15 mg/L. Leaching bottles containing measured amounts of sample and water were gently shaken occasionally and just prior to sampling to ensure the homogeneity of the leachate. Small volumes of leachate were drawn off by syringe, filtered through a 0.45-µm filter, and analyzed by ion chromatography. The leaching method used by AECL was similar to that used by LANL for chloride extraction in previous 36Cl studies; however, it was different from the leaching experiments conducted at LANL during the this study, where the leachate was completely removed and replaced with new de-ionized water after each leach period was complete. All chloride concentrations in leachates are expressed as milligrams per kilogram rock after correction for the water-rock ratio used in the leaching process and removal of small amounts of leachate for analysis during the leaching experiments. 4.3.3.2 Results Three time-series experiments, lasting a total of 70 to 72 hours (Table 4-6), were conducted on two of the core samples. Leachates of the coarser fraction (4 to 10 mm) of core from ESF-SD-ClV#2 and ESF-SD-ClV#14 attained maximum chloride concentrations of about 1 and 0.68 mg/kg rock (tests CT and 2CT in Table 4-6), and leaching of chloride was essentially complete (constant chloride concentrations) after 24 hours. A similar time-series experiment performed on a finer fraction (less than 0.125 mm) of core from ESF-SD-ClV#2 (FT series in Table 4-6) yielded substantially larger chloride concentrations of approximately 5 mg/kg rock (Figure 4-11). The decrease in chloride concentration in the fine fraction with time (filled diamonds in Figure 4-11) may be accounted for by analytical error (approximately ±5 percent). In addition, the larger chloride concentrations in the fine-fraction leachates were obtained in much less time than those for the coarse-fraction leachates. Maximum chloride concentrations were observed in the first leachate sampled after only 10 minutes. Differences in chloride concentrations of the two coarse-fraction leachates also are apparent. Leachates from the first 10 hours show that chloride concentrations in both the CT and 2CT time-series experiments increase progressively (Figure 4-12). However, leachates from broken core at an intermediate distance from the Sundance fault (ESF-SD-ClV#14, 2CT series) are systematically lower in chloride concentration than the intact core at a greater distance from the Sundance fault (ESF-SD-ClV#2, CT). Concentrations of chloride in the 2CT time-series leachates are typically 50 to 70 percent of those in the CT leachates extrapolated to an equivalent time. The particle size of the material being leached has a large but variable effect on the concentration of chloride in the leachates (Figure 4-13). In these experiments, sized fractions of core from intervals in ESF-SD-ClV#2 (GS series) and ESF-SD-ClV#14 (2A2 series), ranging from less than 0.063 to 12 mm, were each leached for 24 hours. Except for the coarsest GS series fraction, resulting chloride concentrations increased progressively with decreasing particle size. Chloride concentrations continued to increase as particle size became smaller in both experiments with no indications of leveling out, implying that additional chloride would have been leached if the rock was ground to particle sizes less than 0.063 mm. In addition to the differences in size fractions from each core sample, differences in chloride concentrations were observed for leachates of the same size fractions between the two core samples. For the three coarser size fractions with particles between 0.25 and 4 mm, chloride concentrations are 2.1 to 1.2 times larger in leachates of the intact core from ESF-SD-ClV#2 than leachates of the broken core from ESF-SD-ClV#14 (Figure 4-13). The opposite trend is present in finer size fractions, where chloride concentrations become up to 3.8 times larger in leachates of ESF-SD-ClV#14 core relative to leachates of ESF-SD-ClV#2. The differences in chloride concentrations in leachates of these two core intervals change progressively as particle size changes. Causes for the differences in leaching behavior of these two samples are not known. A third set of leaching experiments was conducted on naturally rubblized core from borehole ESF-SD-ClV#9, adjacent to the Sundance fault. Both leach duration and fragment size varied in this series of experiments (BT series in Table 4-6). Small increases in the soluble chloride concentrations corresponding to increasing leach durations are observed for the coarse fractions (Figure 4-14). However, reversals in these trends occur in the finer size fractions. A steady decrease in leachable chloride from the finest to coarsest particle sizes, and a lack of a “step” in the data, indicates that there is no preferential accumulation of chloride on rock surfaces in the fractures, as this would likely be more available to leaching solutions than chloride in the matrix. As a result, these results suggest that leaching of matrix pore fluid salts is the dominant source of chloride in both the finer and coarser size fractions. 4.3.3.3 Discussion of Results Time-series leaching experiments conducted at AECL on the coarser fractions of rock (4 to 10 mm) indicated that extraction of leachable chloride was essentially complete after 24 hours. Crushing the rock to finer fractions shortens this leaching time to as little as 10 minutes. These results indicate that minor differences in leaching times or particle sizes would cause only minor differences in the amounts of chloride leached from rock samples. However, chloride concentrations observed in different leachates of relatively coarse tuff samples are not greatly affected by sample preparation and processing, and probably cannot explain the large differences in 36Cl/Cl ratios obtained by LLNL and LANL during Phase I of the validation study. Experiments designed to determine the effects of particle size (between 6.3 to 12.5 mm and less than 0.063 mm) on the leaching of chloride showed that more chloride was leached from the finer size fractions. Results also suggest that more leachable chloride would have been obtained if the rock had been ground to sizes less than 0.063 mm. In general, particle size appears to have greater influence on chloride concentrations than does leaching time. This effect is likely a function of the increased surface area as particle size decreases. Values for the surface area per mass unit have been calculated assuming that particles in each size fraction have a spherical shape, a mean size between upper and lower sieve openings, and a mean bulk density of 2.25 g/cm3 (Flint 2003, value for the middle nonlithophysal unit of the Topopah Spring Tuff, Table 3). Results for both the BT (natural rubble) and 2A2 (mechanically crushed) leaching series show a relatively smooth trend of increasing chloride concentrations with increasing particle surface area per mass unit (Figure 4-15). Results for the GS series leachates (core ESFSD- ClV#2, sample names GS1-GS7, in Table 4-6) show similar increases, but with a lower slope. The contributions from meteoric and rock chloride sources cannot be determined directly from these data; however, estimates from end-member compositions can be calculated. The concentration of chloride in pore fluids in a kilogram of rock can be calculated from the mean concentration in pore fluids (34.5 mg/L; Peterman and Marshall 2002, p. 308) corrected for the mean porosity (0.110), saturation (0.848), and bulk density (2.25 g/cm3) of the crystal-poor, middle nonlithophysal unit of the Topopah Spring Tuff (mean values from Flint 2003, Table 3). This calculation reveals that a chloride concentration of 1.4 mg/kg rock is potentially available to leaching solutions. Therefore, a meteoric chloride source may provide all the chloride in leachates of rock crushed to sizes greater than about 0.5 mm. However, rock chloride is required to provide a substantial amount of the chloride leached from rock fractions finer than 0.5 mm. A maximum chloride concentration of about 16 mg/kg rock for the finest fraction of the 2A2 series represents only about 10 percent of the total chloride present in the rock mass (mean value of 170 mg/kg rock; Peterman and Cloke 2002, Table 6). Therefore, a substantial fraction of the chloride remains tightly bound in solid phases in the rock and is unavailable for leaching from even the most finely ground samples. A possible trend of decreasing chloride concentrations toward the Sundance fault also was noted during these leaching experiments. Concentrations of chloride in 21- to 24-hour leachates of the 4- to 10-mm size fraction were largest for the intact core at approximately 82 m from the fault trace (1.00 mg/kg for ESF-SD-ClV#2-CT9 in Table 4-6), intermediate for the broken core at approximately 48 m from the fault trace (0.53 mg/kg for ESF-SD-ClV#14-2CT-6 in Table 4-6), and smallest for the naturally rubblized core from within 2 m of the fault trace (0.34 mg/kg for ESF-SD-ClV#9-2BT-4 in Table 4-6). Although these differences may be caused by random variations in the chloride content of pore fluids in the tuff, it is possible they may be caused by differential flow of fracture water and pore water across this zone. Increased percolation fluxes focused in the Sundance fault zone could cause lower chloride concentrations in the rubblized rocks due to previous natural leaching processes. 4.3.4 Conclusions from the Phase II Leaching Experiments Results from the leaching experiments performed at LANL and AECL indicate that variations in particle size and leaching times can affect chloride concentrations and 36Cl/Cl compositions of leachates, but probably not in substantial ways. Experiments conducted at LANL using the reference sample, EVAL001, demonstrated that most passive-leach aliquots have smaller chloride concentrations and all have larger 36Cl/Cl ratios compared to active-leach aliquots taken at equivalent leaching times. These results confirm that active leaching is likely to extract more rock chloride compared to passive leaching, and they explain the differences between initial LLNL active-leach results and those obtained previously by LANL (Figure 4-3). Results also support the intuitive view that passive leaching and shorter leaching times favor extraction of more labile, meteoric chloride components that may contain bomb-pulse 36Cl. Based on these results, the active-leach method was abandoned. Leaching experiments performed at LANL with multiple samples from the ECRB Cross Drift demonstrate the presence of a wide range of chloride concentrations and 36Cl/Cl ratios at different sites. However, results of the sequential leaching experiments show only minor variability in a single set of leachates. These results indicate that 36Cl/Cl ratios for individual samples have a tendency to remain relatively constant (typically within the range of analytical error) regardless of leach durations between 0.5 and 48 hours. Only one sample shows a statistically significant change in 36Cl/Cl ratios between the first leaching time (taken at 0.5 hr) and those for subsequent leaching times (Figure 4-5, EVAL001-7). These experiments imply either that there is only a single source of leachable chloride in the rock or that a uniform mixture of different sources of chloride was maintained in spite of variable leaching times. Although leaching experiments conducted at AECL did not include analyses of 36Cl/Cl ratios, they provide information on the nature of extractable chloride in tuff samples. Rates of extraction of soluble chloride from coarser fractions of rock were greatest in the first several hours of leaching and extraction was largely complete after 24 hours. Crushing the rock to finer fractions shortened this leaching time to as little as 10 minutes. The effects of particle size were larger than the effects of leach duration. However, these experiments demonstrated that for coarser particle sizes (greater than 0.5 mm), much of the chloride in leachates most likely has a meteoric source, and that large amounts of rock chloride are not likely unless the sample is more finely ground. Similar results were obtained from 36Cl leaching experiments conducted at LANL. 4.4 PHASE III: MEASUREMENTS MADE AT USGS-LLNL Results from the Phase II leaching experiments (Section 4.3) led to substantial modifications in the method used to leach additional validation study samples. The active-leach method used by LLNL in Phase I was abandoned in favor of the passive-leach method developed in Phase II to minimize contributions of rock chloride to the leachate. Also, because the leaching experiments indicated that much of the readily leachable chloride was extracted in the first several hours of passive leaching, the study participants agreed that passive leaching for short time periods was the most reliable means of obtaining labile, meteoric chloride. The study participants also agreed that adopting an approach that minimized variables in analytical procedures was an important aspect of Phase III. By minimizing the variables, each step could be evaluated separately. The first step in this process involved crushing at either the SMF or USGS, followed by leaching at the USGS, and distribution of leachates to LANL and LLNL for AgCl precipitation and target preparation. Targets made in each laboratory were analyzed at a single AMS facility (LLNL-CAMS). This strategy was applied to samples sent for analysis as Batch #1. A similar strategy was applied to Batch #2 samples, except that targets prepared at LANL were analyzed at PRIME Lab and targets prepared at LLNL were analyzed at LLNL-CAMS. Targets for Batches #3, #4, and #5 were prepared and analyzed at LLNL. Table 4-7 gives the unique identification numbers assigned to leachates of samples that were crushed at the SMF or USGS, and leached at the USGS. 4.4.1 Methods Processing of validation study core resumed in the Summer of 2001 on new core intervals requested from the SMF (identified as “36Cl (USGS)” in Appendix B). The heavily fractured intervals from the deepest 2 m of the core had been sent previously to LLNL for 36Cl analysis, leaving core intervals that ranged from rubblized to intact intervals. General descriptions of the intervals prepared during core logging indicate that 11 of the 39 core intervals were relatively intact, with only about one to three fractures per foot (Table 4-8). The other 28 core intervals had fracture densities similar to the intervals selected for the original allocations. 4.4.1.1 Sample Processing Samples of validation study core were crushed and sieved at the SMF using a jaw crusher, which was previously used only for crushing samples of TSw, and new 6.3- to 19-mm stainless-steel sieves. Crushed samples were shipped to the USGS YMPB laboratory in Denver, where they were re-sieved and the fines were removed using compressed nitrogen before leaching. For each leachate, between 0.989 and 2.399 kg (median of 1.788 kg) of crushed rock was placed in a stainless-steel wire basket and immersed in a stainless-steel stockpot containing an approximately equal weight of de-ionized water. The basket was initially raised and lowered five times to wet all rock surfaces and then allowed to soak for 1 hour. This process approximated the passive-leach methods used in previous LANL studies, except for a substantial reduction in the 24- to 72-hour leaching times used previously. After the 1-hour leach, the basket was raised and lowered five times to rinse the rock surfaces, then removed from the pot. The leachate was filtered through a pre-rinsed 0.45-µm barrel filter into two 1-L polyethylene bottles, which were sent to LLNL (Batches #1 to #5) and LANL (Batches #3 to #5) for AgCl precipitation and target preparation. An additional 30-mL aliquot of the leachate was filtered through a 0.2-µm filter for anion analysis (Cl-1, NO3-1, SO4-2, F-1, Br-1) at the USGS. 4.4.1.2 Crushing Experiments The USGS modified the sample processing procedures slightly near the end of the validation study in response to concerns about differences in crushing methods and their possible impact on the 36Cl results. Validation study core were being crushed using a jaw crusher, whereas samples analyzed previously at LANL were generally crushed by hand using a hammer and steel plate. To evaluate the differences between mechanical crushing and hand crushing on the release of rock chloride, the USGS conducted a crushing experiment on approximately 8 kg of core from six intervals in borehole ESF-SAD-GTB#1 (southern Ghost Dance fault zone, Alcove #7) that were combined, homogenized, and split into two aliquots. One aliquot was crushed using a hammer and steel plate and the other was passed through a mechanical jaw crusher to replicate the process used on the validation study core. In both cases, coarse fragments were crushed to pass a 19-mm (¾-inch) sieve. In addition to leachates from the 6.3- to 19-mm (¼-inch to ¾-inch) size fraction for both aliquots, a third sample was used to test the effects of increasing the size range to 2 to 19 mm (10 mesh to ¾ inch). The different crushing methods did not result in significant differences in 36Cl/Cl ratios (Table 4-9). For the two leachates of the 6.3- to 19-mm (¼-inch to ¾-inch) size fraction from ESF-SAD-GTB#1, the mechanically crushed sample yielded a slightly larger chloride concentration (0.517 mg/kg rock) and a smaller 36Cl/Cl ratio (344 ±104 × 10-15) compared to the hand-crushed sample (0.474 mg/kg rock and 457 ±107 × 10-15, respectively). However, the differences are within analytical error (Figure 4-16). The leachate from the finer fraction of hand-crushed material (2 to 19 mm, [10 mesh to ¾ inch]) had a larger chloride concentration (0.697 mg/kg rock) than those obtained from the coarser fractions; however, the 36Cl/Cl ratio of 510 ±108 × 10-15 was within analytical error of the other leachates. Although core samples from outside the areas investigated for the 36Cl validation study were used for these experiments, the 36Cl/Cl values are within the range observed for core from the Sundance fault zone (red diamonds [ESF-SD-ClV drill core] on Figure 4-17). Chloride concentrations in leachates of the ESF-SAD-GTB#1 core from the southern part of the ESF are larger than the leachates of validation study samples located to the north. This trend is consistent with results reported previously by LANL. The median chloride concentration for 155 samples from the northern half of the ESF (stations 0+00 to 39+00) is 0.7 mg/kg rock, whereas the value for 138 samples from the southern half of the ESF (stations 39+39 to 78+50) is 1.7 mg/kg rock (Appendix A). In addition, 36Cl/Cl ratios for ESF-SAD-GTB#1 core from Alcove #7 (mean and 1s of 437 ±85 × 10-15) are similar to the LANL values obtained for six samples of Alcove #7 rocks listed in Appendix A (mean and 1s of 551 ±55 × 10-15). Results of the crushing experiments on ESF-SAD-GTB#1 core indicate that differences in crushing and particle size are unlikely the cause of major differences in chloride concentrations and 36Cl/Cl ratios obtained using the validation study protocols and earlier LANL protocols. Therefore, the large differences in 36Cl/Cl ratios between LANL leachates with bomb-pulse values and USGS-LLNL validation study leachates (36Cl/Cl ratios less than 619 × 10-15) must be attributed to other causes. To evaluate the large differences in 36Cl/Cl ratios between LANL leachates with bomb-pulse values and USGS-LLNL leachates without bomb-pulse values, the study participants conducted additional comparative studies using intervals of the same Niche #1 core samples that had been analyzed previously at LANL (Section 4.4.2.3). 4.4.1.3 Procedural Blanks Measured chloride consists of a mixture of natural chloride present in the rock sample plus chloride that is added to the rock sample and leachate during sample collection, crushing, leaching, and AgCl target preparation. To determine the mass of 35Cl, 36Cl, and chlorine-37 (37Cl) in a sample, the mass of chloride added during the analytical processing (process blank) must be subtracted from the measured results. At different times during the 36Cl validation study, the mass of chloride and its isotopic composition were measured in de-ionized water that was processed using the leaching and target preparation procedures and run as unknown samples. In addition, the chloride isotopic composition of a blank was determined for water from the deionization system without further processing. Results of blank analyses for samples leached at the USGS and AgCl precipitated at LLNL are given in Table 4-10. Concentrations of total chloride in the blank samples prepared at the USGS and analyzed at LLNL (USGS-LLNL) varied between 0.004 and 0.017 mg/kg water, with a mean of 0.0104 ±0.0047 (1s). Precise measurements of 36Cl/Cl ratios could not be made on the small chloride concentrations of the blank samples. Individual 36Cl/Cl ratios ranged from 47 ±211 (1s) × 10-15 to 1,839 ±555 (1s) × 10-15. Chloride concentrations and 36Cl/Cl ratios in the process blanks and the water blank were similar. The mean 36Cl/Cl ratio of five blank measurements was 555 ±337 (1 standard error [SE]) × 10-15. These data are more meaningful if they are converted to concentrations of 36Cl added during sample processing. The five USGS-LLNL blanks represent between 0.47 × 10-15 and 7.6 × 10-15 mg 36Cl added per kilogram of water used, with a mean of 3.5 ±3.0 × 10-15 (1s) mg 36Cl/kg water. Thus, although the 36Cl/Cl ratios in the blanks ranged widely, the amounts of 36Cl that would be added during processing of the samples is very small. In addition to chloride added during leaching and target preparation, both crushing and handling operations could add chloride to a sample. This contribution was not measured in previous studies because of the lack of a chloride-free material with physical properties similar to the densely welded tuffs. Methods of investigating this source of contamination were initiated at the USGS. Electronics-grade silicon was chosen because of its extremely high purity (typical metal contamination levels are less than 1 × 10-11 g/g silicon). A 3.8-kg cylindrical (approximately 15-cm diameter by 15-cm height), monocrystalline silicon ingot was obtained from the DOE’s National Renewable Energy Laboratory in Golden, Colorado. The ingot and all crushing equipment were cleaned with de-ionized water to remove surface contamination, then the ingot was broken into fragments using a rock hammer. Approximately half of the material was crushed using a hammer and steel plate, and the other half was crushed using a steel mortar and pestle. Both sets of material were sieved to obtain a 2- to 19-mm size fraction and leached using the same passive-leach process used by USGS for the Niche #1 samples (Section 4.4.2.3). The samples were analyzed by ion chromatography using low-level detection methods (0.01 mg/L detection limit) at the USGS National Water Quality Laboratory (NWQL) and by isotope dilution at LLNL (Table 4-11). Chloride concentrations in the two crushing blanks were only slightly larger (0.019 and 0.014 mg/L) than the value obtained for the system leaching blank processed at the same time (less than 0.010 mg/L). The 36Cl/Cl ratios in the two crushing blanks were 957 ±174 × 10-15 and 1,033 ±249 × 10-15 . These values are within analytical uncertainty of the mean value obtained from the USGS-LLNL leaching blanks analyzed earlier in the validation study and consistent with meteoric values expected for Colorado (Phillips 2000, Figure 10.3). Although small amounts of chloride may be added during crushing and sieving, the added chloride does not have small 36Cl/Cl values that would explain the differences between small 36Cl/Cl ratios obtained for the USGS-LLNL validation study samples and the large 36Cl/Cl ratios measured previously at LANL. These results indicate that crushing at the USGS did not add substantial amounts of chloride and that added chloride has a 36Cl/Cl composition similar to meteoric chloride. A similar evaluation of crushing blanks was not performed at LANL. However, two samples of Niche #1 core that had been crushed and sieved at LANL were sent to the USGS for leaching. The samples, Niche 1-RCR-1A (approximately 1.3 kg) and Niche LT-RCR-1A (approximately 0.7 kg), were remnants of the 6.3- to 12.5-mm size fraction that had been analyzed at LANL (Table 4-12) and had 36Cl/Cl ratios of 1,163 ±94 × 10-15 and 1,016 ±87 × 10-15, respectively. The two samples were combined into a single 2.0-kg sample (NICHE3566#1+NICHE3566#LT1) at the USGS to ensure sufficient chloride for analysis, and the sample was leached without additional handling. The resulting USGS-LLNL chloride concentration of 0.188 mg/kg water and 36Cl/Cl ratio of 1,185 ±121 × 10-15 (Table 4-11), are similar to values obtained by LANL, but distinctly higher than values obtained for other USGS-LLNL leachates. 4.4.2 Results 4.4.2.1 Anions in Leachates of Validation Study Core The USGS used ion chromatography to measure concentrations of the soluble anions Cl-1, Br-1, NO3-1, and SO4-2 in leachates of validation study core, Niche #1 core, and Alcove #7 core, as well as leachates of the EVAL001 reference sample (Table 4-13). These data do not reflect true concentrations of pore water and are generally much more dilute than values obtained directly from water extracted from the core (Peterman and Marshall 2002, p. 308), due in part to the relatively large volumes of water used for leaching. However, all leachates of validation study core were obtained from similar amounts of the same size fractions leached for the same time periods. Therefore, measured differences in concentration should reflect natural variability rather than artifacts of laboratory processing. Concentrations of chloride in leachates of samples from the Sundance fault zone (including Niche #1) vary from 0.050 to 0.31 mg/kg rock, with a median value of 0.120 mg/kg rock and a mean value of 0.145 ±0.074 (1s, 51 analyses) mg/kg rock (Table 4-14). Values for leachates from the Drill Hole Wash fault zone are slightly higher, with a median chloride concentration of 0.205 mg/kg rock and a mean of 0.223 ±0.053 (1s, 10 analyses) mg/kg rock. Differences in mean values between the two groups of data are significant at the 95 percent confidence level (Figure 4-18). In contrast to leachate chloride concentrations, pore water chloride concentrations obtained by ultra-centrifugation of high-silica rhyolite units of the Topopah Spring Tuff are generally much larger (mean and 1s of 34.5 ±16.7 mg/L; Peterman and Marshall 2002, p. 308). A mean chloride concentration of 1.4 mg/kg rock is calculated for the middle nonlithophysal unit of the Topopah Spring Tuff using the mean pore water chloride concentration and the mean pore water content of 0.093 (Flint 2003, Table 3). Chloride concentrations in leachates indicate that less than 10 percent of the total pore water chloride available in the rock is extracted during the 1-hour leaching process. Chloride concentrations in leachates show variations with distance across the Sundance fault zone (Figure 4-19A). Values tend to be smallest in leachates of ESF-SD-ClV core between ESF stations 35+40 and 36+00 adjacent to and north of the trace of the Sundance fault. The mean chloride concentration in leachates from this zone is 0.066 ±0.018 mg/kg rock (1s, 10 analyses). Leachates of ESF-SD-ClV samples from either side of this zone have a combined mean chloride concentration of 0.151 ±0.066 mg/kg rock (1s, 35 analyses), which is significantly different at the 95 percent confidence level. Similar variations across the Drill Hole Wash fault zone are not apparent (Figure 4-19B). Relations between chloride concentration and proximity to the Sundance fault observed from ESF-SD-ClV core are complicated by results for leachates of Niche #1 core. Although the Niche #1 boreholes were not drilled normal to the walls of the ESF main drift, the resulting core lies within the interval between ESF stations 35+40 and 36+00. Leachates of core from all three Niche #1 boreholes have substantially higher chloride concentrations than the ESF-SD-ClV core, with a mean of 0.231 ±0.044 mg/kg rock (1s, 6 analyses) (Figure 4-19A). Concentrations of other anions in leachates of validation study core are poorly to moderately correlated with chloride. Concentrations of NO3-1 in leachates of core from the Sundance fault zone (including Niche #1) range from less than 0.04 to 0.44 mg/kg rock (Table 4-14) and are poorly correlated with chloride concentrations (Figure 4-20A). Large concentrations of NO3-1 are not present in leachates with small chloride concentrations; however, NO3-1 concentrations commonly remain small as chloride concentrations increase. In contrast, SO4-2 concentrations ranging from less than 0.03 to 0.51 mg/kg rock show a positive correlation with chloride concentrations (Table 4-14 and Figure 4-20B). Concentrations of Br-1 are below detection limits (0.02 mg/kg water) for all leachates of dry-drilled validation study core. Because the construction water that was used during excavation of the ESF and ECRB was tagged with LiBr, this result indicates the absence of substantial amounts of construction water in all samples, some of which are from depths as shallow as 0.40 to 0.60 m from the tunnel wall. Concentrations of Br-1 are above detection limits in analyses of two leachates of the reference sample EVAL001 (0.18 and 0.14 mg/kg rock, Table 4-14), which was collected with mining equipment that used construction water for dust suppression. Because there is no detectable Br-1 in any of the leachates of validation study core, corrections for construction water are not necessary. 4.4.2.2 Chlorine-36 in Leachates of Validation Study Core USGS-LLNL used AMS to analyze 34 1-hour passive leachates of core samples from 29 validation study boreholes (ESF-SD-ClV) located across the Sundance fault zone (Table 4-15). Chloride concentrations range from 0.037 to 0.372 mg/kg rock, with an arithmetic mean of 0.130 mg/kg rock and a median value of 0.120 mg/kg rock. Chloride concentrations determined by isotope dilution at LLNL typically agree within error with chloride concentrations determined by ion chromatography at the USGS (Figure 4-21). All but three analyses fall in a narrower range between 0.037 and 0.197 mg/kg rock (Figure 4-22A). The three elevated values are from core locations scattered across the Sundance fault zone (Figure 4-23A). The isotope dilution data confirm the pattern of chloride distribution that was determined on the larger ion chromatography data set (compare Figure 4-23A with Figure 4-19A). Leachates of validation study core have 36Cl/Cl ratios ranging between 137 × 10-15 and 615 × 10-15 (ESF-SD-ClV core, excluding Niche #1, Table 4-15). Values for the median and mean 36Cl/Cl are 316 × 10-15 and 326 × 10-15, respectively. The frequency distribution of these 34 values of 36Cl/Cl does not show any indication of being skewed toward high ratios (Figure 4-22B). Use of the Anderson-Darling normality test (Stephens 1974) results in a probability value of 0.141, which indicates that the sample population cannot be distinguished from a normal distribution at the 95 percent confidence level. Unlike chloride concentrations that appear to be correlated with respect to location of the Sundance fault trace (Figure 4-19A and Figure 4-23A), 36Cl/Cl ratios vary randomly between ESF stations 34+95 and 36+75. However, 36Cl/Cl ratios show a general trend of decreasing values from about 540 × 10-15 to 580 × 10-15 at around ESF station 34+00, to about 140 × 10-15 to 190 × 10-15 around ESF station 34+70 (Figure 4-23B). To evaluate this trend, 36Cl/Cl ratios were plotted against borehole completion dates with analyses discriminated by batch number (Figure 4-24). Although most of the boreholes constituting this trend were completed in sequence during the first round of drilling between March and April, 1999, borehole ESF-SD-ClV#26 at ESF station 34+73, containing the lowest 36Cl/Cl values, was completed at the end of the second round of drilling in June 1999. Most other samples from the second round of drilling have substantially higher 36Cl/Cl ratios. Progressive contamination (or decontamination) from drilling equipment is not suspected because the Yucca Mountain Project Management and Test Coordination Office advised that new drill bits and rods were used for drilling, and because 36Cl/Cl ratios in core samples from the second and third rounds of drilling (September 1999) span most of the range observed in core obtained from the first round. Also, 36Cl/Cl ratios in different batches of leachates analyzed in different AMS runs overlap. Therefore, natural chloride compositional variations are the likely cause for the trend of monotonically decreasing 36Cl/Cl ratios observed between ESF stations 33+98 and 34+73. The 36Cl/Cl ratios in leachates of validation study core do not correlate with chloride concentrations (Figure 4-17). If the relatively small 36Cl/Cl ratios measured in validation study core were the result of mixing chloride from meteoric and rock sources, data would plot on a mixing line between a meteoric end-member with large 36Cl/Cl–high reciprocal chloride concentration values (small chloride concentrations) and a rock end-member with small36Cl/Cl-low reciprocal chloride concentration values (large chloride concentrations). Instead, 36Cl/Cl ratios remain uniform across the range of reciprocal chloride concentration values, indicating that small 36Cl/Cl ratios are as likely in the samples with the smallest concentrations as they are in the samples with the largest concentrations. 4.4.2.3 Re-Analysis of Niche #1 Core for Chlorine-36 As part of the in situ testing for the UZ flow and transport model, 10-m-long boreholes were drilled before and after construction of Niche #1 at ESF station 35+66 (Figure 3-6). Nine of the 10 core samples from three boreholes (ESF-MD-NICHE3566#1, ESF-MD-NICHE3566#2, and ESF-MD-NICHE3566LT#1) analyzed at LANL had 36Cl/Cl values between 1,235 × 10-15 and 2,038 × 10-15 (CRWMS M&O 1998, Table 3-4). Core intervals remaining at LANL (sealed in the original SMF packaging) were inventoried and split between LANL and USGS to span the intervals analyzed previously at LANL and to ensure that comparable samples were analyzed by the separate laboratories. Multiple, overlapping intervals were combined into single samples so that sufficient rock was available for leaching (Figure 3-7). After the outer surfaces of the sealed ProtecCore™ packages were rinsed with de-ionized water, intervals within individual composite samples were crushed, homogenized, sieved (2 to 19 mm at the USGS and either 6.3 to 12.5 mm or 2 to 12.5 mm at LANL), and leached at the USGS and LANL. Composited sample sizes ranged from 1.2 to 1.8 kg. All samples were leached for 1 hour. The AgCl precipitates were prepared at LLNL and analyzed at LLNL-CAMS. Chloride concentrations in leachates of the coarse material prepared at the USGS range from 0.17 to 0.27 mg/kg rock (Table 4-9). The 36Cl/Cl ratios from the six Niche #1 leachates range from 226 × 10-15 to 717 × 10-15 and have median and mean values of 387 × 10-15 and 401 × 10-15 (Table 4-15). These 36Cl/Cl ratios are in the same range as those obtained from leachates of ESF-SD-ClV core (Figure 4-25). The means of the two sample groups (34 samples of ESF-SD-ClV core and six samples of Niche #1 core) are indistinguishable at the 95 percent confidence level. Therefore, all leachate data for samples from the Sundance fault zone prepared at the USGS were pooled to give median and mean values for 36Cl/Cl of 316 × 10-15 and 337 × 10-15 (Table 4-15). 4.5 PHASE III: MEASUREMENTS MADE AT LANL 4.5.1 Methods 4.5.1.1 Sample Processing Most rock samples were composed of a wide range of particle sizes, from pieces as large as 20 cm to dust. Therefore, samples required crushing and sieving to obtain the desired size fractions. Prior to use, all crushing and sieving equipment was thoroughly cleaned. Hammers and steel plates were cleaned by scrubbing with a wire brush, blowing with compressed air, and rinsing with de-ionized water. These steps were repeated so that no visible evidence of the prior samples remained. Sieves were cleaned by manually removing any pieces lodged in openings, scrubbing with a soft brush, blowing off with compressed air, and rinsing in de-ionized water. The table on which crushing and sieving was performed also was wiped clean with de-ionized water. Crushing and sieving were performed inside a new cardboard file box, with one side cut and folded down for access, into which a clean plastic garbage bag was placed. The crushed sample was then poured into a stack of sieves and gently shaken. Fragments of the desired size fraction were placed into a clean zip-lock bag, and the process was repeated until enough material of each size fraction was obtained. If necessary, large pieces were crushed with a hammer and steel plate in the file box. In some instances, as noted below, the dust was blown from the final fraction with dry compressed nitrogen prior to leaching. Leaching was performed in stainless steel buckets with tight-fitting lids. These were washed thoroughly in soapy water, rinsed three times with de-ionized water, and placed upside-down on towels to dry prior to use. Samples were poured into pre-weighed buckets and re-weighed to determine sample mass by difference. A sub-equal mass of de-ionized water was added to the sample. Typically, water and sample mass differed by less than 10 percent. The de-ionized water and sample were left covered and undisturbed for the desired length of time. For this study, the leaching time was intentionally varied for a number of samples to determine the effects of leaching time on chloride concentrations and 36Cl/Cl ratios. 4.5.1.2 Procedural Blanks Twelve procedural blanks were collected by LANL during the course of the investigation. Procedural blanks consisted of de-ionized water that was processed in the same manner as, and along side, the samples. As a result, these procedural blanks capture all the same processing steps as the rock samples, with the exception of crushing. Procedural blanks processed at LANL (Table 4-16) have low total chloride concentrations, with a mean of 0.008 ±0.006 (1s) mg/kg water, similar to the mean value of 0.010 ±0.005 (1s) mg/kg water for the USGS procedural blanks (Table 4-10). One blank consisting of LANL water was processed simultaneously with three blanks that consisted of USGS water that was representative of the water used to leach validation core samples. Results for the USGS water are comparable with those of the LANL water blanks. The 36Cl/Cl ratios have a mean of 1,994 ±400 × 10-15 (1 standard error [SE]) (median value of 1,441 × 10-15, n = 12). Although these values are larger than the values for the USGS blanks, the overall total mass of 36Cl in the LANL blanks is small, with a range from 2.99 × 10-15 to 25.54 × 10-15 mg/kg water used (Table 4-16). These values represent a maximum of 15 percent of the total 36Cl in the samples for the smallest samples analyzed, but in most cases the blank accounts for between 0.2 and 5 percent of the total mass of 36Cl in the samples. The consistently small values for procedural blanks relative to the samples indicate that they do not significantly affect the results. All reported ratios are corrected for the mean of the blank values analyzed with a sample set. The corrections are generally within the uncertainty of the measurement and do not affect the interpretation. Crushing blanks were not measured at LANL for this study; however, crushing blanks are not expected to contribute significantly to the samples because the crushing equipment was thoroughly cleaned by scrubbing with a wire brush, blowing with compressed air, and rinsing with de-ionized water prior to use. This procedure ensured that any contamination from prior samples or dust particles that accumulated during storage of the equipment was removed. Crushing typically exposed the samples to the atmosphere for up to a few hours, limiting the likelihood of 36Cl contamination from this source. In contrast, sample leachates and accompanying blanks are left open to the atmosphere (to allow evaporation of the sample) for up to a week. In all instances the leaching blanks still showed very small levels of 36Cl. Contamination from the steel itself is not expected because the steel is not likely to contain significant 36Cl, distilled water-leachable components of the steel will be insignificant, and the amount of steel contamination in a sample is also very small. Thus, it is expected that the crushing process did not contribute an anomalously large amount of contamination to any of the samples. Additional arguments to support the lack of laboratory contamination in samples processed at LANL are presented in Section 6.3.4.2. 4.5.2 Results 4.5.2.1 Chlorine-36 in Leachates of Validation Study Core During Phase III, samples of validation study core were crushed at the SMF and leached at the USGS. Two sub-equal volumes of leachate were split and sent to LLNL and LANL for AgCl target preparation and analysis. Results for the LANL splits analyzed at PRIME Lab (ESF samples from the Sundance fault zone) are shown in Table 4-12. Chloride concentrations range from 0.07 mg/kg rock to 0.32 mg/kg rock. 36Cl/Cl ratios range from 163 ±30 × 10-15 to 640 ±162 × 10-15 . 4.5.2.2 Chlorine-36 in ECRB Cross Drift Tunnel-Wall Samples Previously unreported 36Cl data for 58 samples from the ECRB Cross Drift are included in this report (Table 4-17). These samples were processed prior to the relocation of the LANL laboratory and changes in LANL personnel in 2000. These data are reported for comparison with other ECRB samples processed as part of the validation study. Leachates for most of these samples were made using the 2- to 20-mm size fraction. However, three samples (EXD-064, EXD-071, and EXD-085) were collected as highly fragmented samples and processed without sieving or additional crushing. All samples were leached for 19 hours and all were greater than 4.4 kg. Chloride concentrations range from 0.20 mg/kg rock to 3.59 mg/kg rock. 36Cl/Cl ratios range from 161 ±22 × 10-15 to 4,890 ±349 × 10-15 . Eight of the 58 samples (14 percent) contain 36Cl/Cl values greater than 1,250 × 10-15 . 4.5.2.3 Re-Analysis of Niche #1 Core for Chlorine-36 Multiple, nearly adjacent intervals of Niche #1 core were combined into single samples so that sufficient rock was available for leaching (Figure 3-7). After the outer surfaces of the sealed ProtecCore™ packages were rinsed with de-ionized water, intervals within individual composite samples were crushed, homogenized, sieved (either 6.3 to 12.5 mm or 2 to 12.5 mm), and leached at LANL. Composited sample sizes ranged from 1.2 to 1.8 kg. All samples were leached for 1 hour. All crushing, leaching, and AgCl precipitation for LANL leachates was performed at LANL. Silver chloride precipitates were analyzed at LLNL-CAMS. In addition, fines (less than 6.3 mm) from two of the samples crushed at LANL (Niche 1-RCR-1B and Niche LT-RCR-1B, Table 4-12) were leached at LANL and analyzed at LLNL. Chloride concentrations for leachates of the coarser material are 0.13 and 0.28 mg/kg rock (Niche LT-RCR-1A and Niche 1-RCR-3, Table 4-12). Leachates of the two finer fractions (Niche 1-RCR-1B and Niche LT-RCR-1B) have substantially larger chloride concentrations (0.69 and 0.67 mg/kg rock). The 36Cl/Cl ratios obtained by LANL for composite samples of Niche #1 core are larger than the USGS-LLNL results for overlapping composite samples of the same core (Table 4-9 and Figure 4-26). The new LANL analyses are similar to previous LANL analyses of Niche #1 core (CRWMS M&O 1998, Table 3-4) in that some of the 36Cl/Cl values exceed the 1,250 × 10-15 bomb-pulse threshold (four of seven analyses). New LANL 36Cl/Cl values range from 1,016 × 10-15 to 8,558 × 10-15 . The new analyses show a positive correlation between 36Cl/Cl ratios and chloride concentration (largest 36Cl/Cl ratios in leachates with the largest chloride concentrations). The observation of the largest 36Cl/Cl ratios in leachates of Niche #1 core, which consist entirely of fine fractions (less than 6.3 mm), is the opposite of the relation observed in leachates of tunnel-wall samples reported previously (Figure 4-27). Larger chloride concentrations in leachates of finer material previously have been attributed to addition of progressively more rock chloride liberated from particle surfaces as the total surface area per unit mass of sample increases (Fabryka Martin, Wolfsberg et al. 1996, p. 24; and this report, Section 4.3). 4.6 DISCUSSION OF THE CHLORINE-36 MEASUREMENTS Analytical protocols evolved during the course of the validation study in response to preliminary results and discussions among the participants. The final passive-leach procedure was designed to maximize contributions from meteoric chloride and minimize contributions from rock chloride unrelated to UZ percolation. 36Cl/Cl ratios in the validation study samples from both USGS-LLNL and USGS-LANL generally agree within analytical error despite the analytical challenges of dealing with the low chloride concentrations in the 1-hour leachates. However, large differences in 36Cl/Cl ratios exist between results for Niche #1 samples processed at the USGS and LANL, and between results obtained from USGS-LLNL leachates and those obtained previously by LANL from samples in the Sundance fault zone. 4.6.1 Active Leaching The analytical procedure used by LLNL during Phase I of the validation study, which involved leaching crushed rock in a slowly rotating tumbler for 7 hours (active-leach process), resulted in leachates with relatively large chloride concentrations and small 36Cl/Cl ratios. Results obtained from active leaching are distinct from those obtained from passive leaching (previous LANL studies and work conducted at LANL and USGS-LLNL during Phase III) for both longer and shorter leaching times (Figures 4-3B and 4-28). The data obtained from active leaching are interpreted to be the result of adding large amounts of rock chloride during the extraction process. Consequently, the 36Cl/Cl ratios in the leachates cannot be used to detect the bomb- pulse meteoric component along the Sundance fault zone. 4.6.2 Chloride Sources and Leaching Experiments Rock samples from the Yucca Mountain UZ contain chloride and 36Cl from multiple sources, including 36Cl potentially added to sample sites during tunnel construction and operation, and to samples during processing (Table 4-4). Lu et al. (2003, p. 3-5) discuss these sources and categorize them into “(1) leach-accessible salts or fluids (present in the inter-granular connected pores and fractures) and (2) leach-limited salts or fluids present in fluid inclusions, disconnected pores, and grain boundaries (called isolated and boundary salts)”. Figure 4-29 presents a conceptual model of the effects of leaching on 36Cl/Cl ratios in rocks. Bomb-pulse and contaminant 36Cl in a sample should be readily leachable from the rock, and chloride from these sources will be mixed during leaching. It is likely that longer leaching times will dilute a bomb- pulse signal. Eventually, any bomb-pulse meteoric salts, if present, will be thoroughly dissolved and the 36Cl/Cl ratio will reflect a mixture of salts precipitated from younger (i.e., less than 10 ka) and older (i.e., greater than 10 ka) meteoric water. Prolonged or aggressive leaching could potentially liberate older meteoric salts or rock chloride, resulting in a decrease in the36Cl/Cl ratio. It is clear from this conceptual model that shorter (and less vigorous) leaching should favor extraction of the most recently deposited meteoric salts, including a bomb-pulse component, if present. However, sufficient chloride must be leached from the rock for a reliable analysis. 4.6.3 Procedural Blanks and Detection Limits for the Total Chloride and Chlorine-36 Analyses Because several results are based on leachates with low chloride concentrations, the contribution of blanks and the limits of detection of chloride and 36Cl become very important in determining the validity of these data. The U.S. Environmental Protection Agency (USEPA) has a procedure for determining the “method detection limit” (MDL), which “. . . is defined as the minimum concentration of a substance that can be measured and reported with 99 percent confidence that the analyte concentration is greater than zero and is determined from analysis of a sample in a given matrix containing the analyte.” (40 CFR 136, 2004, Appendix B, p. 317). The procedure is based on the analysis of detection limits presented by Glaser et al. (1981). The calculation involves determining the standard deviation of seven samples with analyte concentrations that are one to five times the assumed detection limit, and using the Student’s t multiplier (R. Università di Roma 1925, pp. 105-108) for the 99 percent confidence level to calculate the MDL. Analyses of leaching blanks processed at the USGS (Table 4-10) and LANL (Table 4-16) can be used to evaluate the MDL for both laboratories because blank levels define minimum measurable concentrations in real samples. Mean concentrations of total chloride in the USGS and LANL blank samples are 0.0104 ±0.0047 mg/kg water (1s) and 0.0087±0.0067 mg/kg water (1s), respectively. For both laboratories, multiplying obtained standard deviations by the Student’s t factors for the 99 percent confidence level gives values of 0.020 mg chloride/kg water for the MDL of total chloride. Five isotopic analyses of USGS blanks and nine analyses of LANL blanks yielded mean values of 3.5±3.0× 10-15 (1s) and 12.9±8.7×10-15 (1s) mg 36Cl/kg water, respectively (Tables 4-10 and 4-16). Multiplying obtained standard deviations by the Student’s t factors for the 99 percent confidence level gives values of 11× 10-15 mg 36Cl/kg water for the MDL at USGS and 24× 10-15 mg 36Cl/kg water for the MDL at LANL. Although these MDLs are lower than most of the measured total chloride and 36Cl concentrations in the validation study samples, some of the 1-hour passive-leach analyses with low 36Cl concentrations obtained during Phase III of the validation study are very close to these detection limits and should be interpreted with caution. However, three USGS system blanks processed at LANL, where AgCl targets were precipitated, yielded results that are similar to USGS blanks spiked and precipitated at LLNL. These analyses yielded a mean value of 4.7±1.1× 10-15 (1s) mg 36Cl/kg water, which is in good agreement with the mean value of 3.5±3.0× 10-15 (1s) mg 36Cl/kg water for blanks processed by USGS. The close agreement of mean values for blanks analyzed at two independent laboratories indicates that chloride isotopic results are generally reproducible even at the smallest chloride concentrations. LANL analyses with elevated 36Cl/Cl ratios measured during Phase II and Phase III of the validation study contain 36Cl concentrations that are significantly higher than the MDL. Similar assessment of the MDL for earlier LANL results cannot be made because 36Cl concentrations in blanks were not reported. 4.6.4 Analysis of Duplicate Samples Validation study samples were analyzed in several stages as work progressed. The USGS prepared the first batch of samples using the modified 1-hour passive-leach process. Sixteen leachates were each split into aliquots and sent to LANL and LLNL for independent spiking, AgCl precipitation, and target preparation. All AgCl targets were then analyzed at LLNL. All samples had small chloride concentrations, ranging from 0.069 mg/kg rock to 0.372 mg/kg rock (Table 4-18). The duplicates of the 14 analyses that were run successfully had similar chloride concentrations and 36Cl/Cl ratios, with no indications of inter-laboratory biases (Figure 4-30). The duplicate analyses were used to evaluate the analytical reproducibility of 36Cl/Cl measurements. In addition to in-run statistics, analytical uncertainties include estimates of external precision obtained by duplicate analyses of the same material. Therefore, the external error to be added to the total analytical uncertainties is estimated from the 14 duplicate analyses given in Table 4-18. The standard deviation was determined from the duplicate pairs following the equation given by Youden (1951, p. 16): S(RLLNL - RLANL )2 Standard deviation = (Eq. 1) 2n where RLLNL and RLANL are the 36Cl/Cl ratios obtained from the LLNL and LANL preparations, respectively, and n is the number of duplicate pairs (as well as the number of degrees of freedom). The resulting value of 48 × 10-15 is an appropriate estimate for the absolute 1s external error of a typical 36Cl/Cl measurement. This external error was propagated with the error from other sources to obtain the final estimate of 2s analytical uncertainty for each measurement of the USGS-LLNL 36Cl/Cl data (Table 4-9). A similar comparison of results was made on splits of six Batch #2 leachates prepared at the USGS and analyzed at LLNL-CAMS and LANL-PRIME Lab (Tables 4-9 and 4-12). Chloride concentrations and 36Cl/Cl ratios determined for the duplicate splits are in general agreement, although they exhibit larger deviations than the Batch 1 results obtained from a single AMS facility. Chloride concentrations in Batch 2 samples ranged from 0.071 to 0.265 mg/kg rock for the LANL-PRIME Lab analyses (mean 0.140 ±0.078 mg/kg rock, 1s) and 0.087 to 0.333 mg/kg rock for LLNL-CAMS analyses (mean 0.171 ±0.089 mg/kg rock). Measured 36Cl/Cl ratios range from 180 × 10-15 to 640 × 10-15 for LANL-PRIME Lab analyses (mean 361 ±177 × 10-15, 1s) and from 294 × 10-15 to 615 × 10-15 for LLNL analyses (mean 442 ±132 × 10-15, 1s). Standard deviation (1s external error) for 36Cl/Cl ratios in this set of six duplicate pairs obtained by two different laboratories is 125 × 10-15, or about 2.5 times larger than the comparison of duplicate pairs made for analyses conducted at LLNL-CAMS. This estimate for external error was not incorporated into individual analyses because of the smaller number of analyses used for the comparison and because direct comparisons of USGS-LLNL and LANL-PRIME Lab validation study data were made only on leachates from Niche #1, which were all analyzed at the LLNL-CAMS facility. Chloride concentrations and 36Cl/Cl analyses of passive 1-hour leachates prepared at the USGS and sent to LLNL and LANL for AgCl precipitation and analysis commonly agree within analytical uncertainty (squares and circles in Figure 4-28). The two groups of analyses show no systematic differences in 36Cl/Cl ratios ranging from 163 × 10-15 to 721 × 10-15 (Figure 4-31). The difference between the mean 36Cl/Cl ratio for the 20 leachates sent to LANL for processing (307 × 10-15) and the mean ratio for 40 leachates sent to LLNL (360 × 10-15) is not statistically significant at the 95 percent confidence level. The LANL results also include 36Cl/Cl measurements made at both LLNL-CAMS and PRIME Lab. The agreement between36Cl/Cl values obtained by both laboratories on separate aliquots of the same leachates indicates that the process of AgCl target preparation and AMS isotope analysis does not cause significant differences in 36Cl results. 4.6.5 LANL Data from the ECRB Cross Drift A considerable body of 36Cl data has been collected for previous studies of the ECRB Cross Drift (Table 4-17). Leaching time for the previously analyzed samples was typically 48 hours, and particle size was between 2 and 20 mm. Results from these previous studies are compared in Figure 4-32 with results from the validation study. Both data sets agree for samples between stations 0+77 and 20+00 and most values range between 500 × 10-15 and 1,000 × 10-15 . This range includes samples that were processed using different leaching times. Each data set contains at least one sample with a 36Cl/Cl ratio greater than 1,250 × 10-15 (beyond ECRB Cross Drift station 21+00), which is interpreted to represent a bomb-pulse signal. In all cases, for both data sets, samples with bomb-pulse 36Cl/Cl ratios were collected from faults. These data are interpreted by LANL to support previous hypotheses (Fabryka-Martin et al. 1997, Section 9.3; Campbell et al. 2003, Section 9) that faults are conduits for rapid flow (less than 50 years to depths of about 300 m) of meteoric water from the surface to the depths of the ECRB Cross Drift. Sample EXD-059 (Table 4-12) yielded a 36Cl/Cl value of 1,309 ±114 × 10-15 . This value is slightly larger than the lower cutoff value (1,250 × 10-15) used to detect bomb-pulse 36Cl (Fabryka-Martin et al. 1997, Section 4.2.4) and is therefore used to indicate the presence of bomb-pulse 36Cl in this sample. Values between 412 × 10-15 and 671 × 10-15 are interpreted to indicate that the chloride was derived predominantly from meteoric salts deposited in the past 10 ka (but not in the past approximately 60 years). One sample (EXD-066), has an anomalously small 36Cl/Cl value of 161 ±22 × 10-15 and an anomalously large chloride concentration of 3.59 mg/kg; larger than any other leachates analyzed at LANL for this study by more than a factor of two. It is likely that this small 36Cl/Cl ratio is due to dilution of a meteoric signal by rock chloride. 4.6.6 Comparison of Validation Study Data with Previous Chlorine-36 Data 4.6.6.1 Sundance Fault Zone Thirty-four analyses of samples of Niche #1 core and samples from the Sundance fault zone between ESF stations 34+28 and 37+00 were reported as part of the previous studies (Appendix A). Chloride concentrations in these 48-hour leachates are larger, on average (mean of 0.55 mg/kg rock), than those obtained for the 1-hour leachates obtained during the validation study (mean of 0.141 mg/kg rock) (Figure 4-33A). This result is consistent with the general relations between leach duration and chloride concentration. The larger chloride concentrations from earlier LANL results show a wide range of 36Cl/Cl values from 388 × 10-15 to 4,105 × 10-15 (Figure 4-33B). LANL results obtained during Phase I for seven validation study core samples (Table 4-2) are within this range, but show no bomb-pulse values. These 36Cl/Cl ratios have only a limited overlap at their lower end, with the much smaller values obtained from the 36Cl validation study samples analyzed by USGS-LLNL during Phase III (Figure 4-33B). The differences in 36Cl/Cl ratios between these two data sets are inconsistent with an interpretation that smaller ratios are caused by greater contributions from rock chloride. It would have been expected that the longer leaching times used for LANL samples would have diluted a bomb- pulse signal with chloride from older meteoric salts and/or rock chloride with small 36Cl/Cl ratios. This type of mixing relation is shown by the LANL Sundance fault zone data set (Figure 4-34) as a negative correlation between 36Cl/Cl ratios and chloride concentrations (that is, larger 36Cl/Cl ratios are present in leachates with the smallest chloride concentrations, resulting in a positive correlation with reciprocal chloride values). In contrast, USGS-LLNL leachates have a wide range of chloride concentrations, but show no correlation between 36Cl/Cl ratios and reciprocal chloride concentrations, resulting in the horizontal trend in Figure 4-34. Low chloride concentrations in 1-hour leachates should be particularly susceptible to contributions of rock chloride or other sources of potential low 36Cl contamination. However, the 36Cl/Cl ratios in these leachates remain more-or-less uniformly small despite the order-of-magnitude variation in chloride concentrations. 4.6.6.2 Southern Exploratory Studies Facility Additional evidence that contamination from a low-36Cl/Cl source is not the cause for the smaller 36Cl/Cl ratios observed in USGS-LLNL leachates is their similarity with data obtained for samples from the southern ESF. LANL’s analysis of 125 leachates from ESF stations 45+78 to 78+50 (Appendix A) show large chloride concentrations, ranging from 0.3 to 11.5 mg/kg rock (Figure 4-35A). The variability of chloride concentrations increases with distance (Figure 2-1A) along the southern ESF, including the south ramp. These data define a triangular field, with the maximum chloride concentrations increasing toward the south portal (Figure 2-1A). 36Cl/Cl ratios in these samples range from 140 × 10-15 to 1,117 × 10-15 (Figure 4-35B). These data have a median 36Cl/Cl value of 467 × 10-15 and a mean value of 480 × 10-15 . Chloride concentrations in USGS-LLNL leachates are systematically lower than, and only partly overlap, the smallest values for LANL leachates from southern ESF samples (Figure 4-35A). Chlorine isotope data from USGS-LLNL leachates overlap most of the range observed for southern ESF samples (Figure 4-35B). However, the distribution of USGS-LLNL 36Cl/Cl values is shifted toward the lower side of the LANL southern ESF data set. The 40 analyses constituting the USGS-LLNL data set have a mean 36Cl/Cl value of 337 × 10-15, which is statistically different from the LANL mean value of 480 × 10-15 at greater than 99 percent confidence level. 4.6.7 Comparison of USGS-LLNL Niche #1 Data and LANL-LLNL Niche #1 Data 36Cl/Cl ratios are significantly different for samples of Niche #1 core separately prepared and leached at the USGS and LANL. Although samples were not homogenized prior to splitting between the two facilities, alternating intervals were selected to minimize sampling differences (Figure 3-7). Six samples of the 2- to 19-mm size fraction crushed and leached at the USGS and analyzed at LLNL have a mean 36Cl/Cl value of 412 × 10-15 (open circles in Figure 4-28). LANL crushed and leached two size fractions of Niche #1 core which were analyzed at LLNL. Five samples of coarser material (6.3 to 12.5 mm) have a mean value of 1,616 × 10-15 (Niche 1-RCR-1A, Niche 1-RCR-2, Niche 1-RCR-3, Niche 2-RCR-1, Niche LT-RCR-1A in Table 4-12, and red triangles in Figure 4-28). Leachates of the finer fractions (less than 6.3 mm) have significantly larger chloride concentrations and 36Cl/Cl ratios than leachates of the coarser fractions of the same material, including the largest 36Cl/Cl ratio (8,558 × 10-15) yet reported for ESF samples (Niche 1-RCR-1B and Niche LT-RCR-1B in Table 4-12). The large 36Cl/Cl ratios in the new LANL analyses are consistent with previous LANL results (CRWMS M&O 1998, Table 3-4), but the relation between the largest 36Cl/Cl ratios and the largest chloride concentrations differs from previous LANL results for tunnel-wall samples. Finally, one sample crushed and homogenized at LANL and sent to the USGS for leaching yielded comparable36Cl/Cl ratios between the two laboratories (1,016 × 10-15 and 1,163 × 10-15 for the two LANL analyses and 1,181 × 10-15 for the single USGS-LLNL composite sample). This elevated 36Cl/Cl ratio represents the largest value obtained in the USGS-LLNL data set and indicates that the USGS leaching process captured elevated 36Cl/Cl ratios present in the sample. Comparisons of the new Niche #1 results are important because they are independent of other factors that complicate direct comparisons of validation study results with previous results. The Niche #1 data are exclusively from core samples, eliminating the possibility that bomb-pulse measurements are unique to features observed on tunnel walls. Also, the new Niche #1 samples processed by USGS-LLNL and LANL-LLNL are more-or-less evenly distributed among the same three boreholes to achieve the goal of having equivalent material analyzed by both laboratories. Processing and analysis of the new Niche #1 samples was also nearly identical at both laboratories. 5. TRITIUM MEASUREMENTS Tritium (3H) has a half-life of 12.33 years and is produced mainly through the bombardment of nitrogen atoms with neutrons in the upper atmosphere (Solomon and Cook 2000, p. 397). This cosmogenic 3H combines with oxygen to form water that enters the hydrologic system as precipitation. Levels of cosmogenic 3H vary with latitude due to the shielding effects of the geomagnetic field from 3 to 6 TU for Europe and North America to approximately 15 TU for coastal Antarctic snow (Solomon and Cook 2000, p. 398). Beginning in 1952, concentrations of3H in the atmosphere began to increase due to nuclear weapons testing and reached peak values in 1962 and 1963 (Plummer et al., 1993, p. 258). Atmospheric 3H concentrations have declined steadily since above-ground nuclear weapons testing ended in 1963, although small amounts of anthropogenic 3H continue to be produced at nuclear power plants and processing facilities. Present-day 3H values of precipitation at Yucca Mountain are not well constrained. Water from a perched spring near Yucca Mountain contains 6.3±0.4 TU, and this value is assumed to be close to that of present-day precipitation (Striegl et al. 1998, Table 3, p. 12-13). 5.1 POTENTIAL SOURCES OF TRITIUM IN CORE SAMPLES FROM THE YUCCA MOUNTAIN UNSATURATED ZONE Pore water in the UZ at Yucca Mountain could be composed of mixtures of pre-bomb-pulse water and modern water. Modern water is defined by Clark and Fritz (1997, p. 172) as water that was recharged since the inception of nuclear testing (i.e., since 1952). Modern water may include bomb-pulse water and recent recharge. Water that entered the UZ immediately before 1952 (containing about 6 TU, similar to present-day precipitation), and remained isolated from the atmosphere would, at present, contain approximately 0.4 TU. In contrast, water with thousands of TU recharged to the UZ between 1962 and 1963 would presently contain hundreds of TU. A threshold value must be established to distinguish between modern water and pre- bomb-pulse water whose 3H values may have been modified by sampling, extraction, and/or analytical errors. This threshold should not result in false positive values, which were a concern of the 36Cl Peer Review Team in suggesting 3H as a corroborating bomb-pulse isotope (YMP, 1998, Section 3.6.2). Threshold values used in interpreting the 3H data are described in Section 5.4. Low-level concentrations of 3H in small-volume pore water samples are not easy to interpret. As Lehmann et al. (1993, p. 2034) state in their discussion of atmospheric and subsurface sources of radionuclides in ground water, “One of the most vexing problems related to 3H is the apparent evidence of small amounts of young water at great depths in water which should have been isolated from the atmosphere for thousands of years.” They note four possible explanations for the presence of 3H in otherwise old water: (1) sample contamination by younger water during collection; (2) movement of young water to depth along fast pathways; (3) subsurface production; and (4) contamination during analysis, such as from exposure to tritiated exit signs or illuminated watches. In addition, circulation of water-saturated air through the UZ at Yucca Mountain is a possible mechanism for introducing young water to large depths in the mountain. Such vapor-phase transport of 3H in alluvium at relatively shallow depths has been well documented at a low-level waste disposal site near Yucca Mountain (Striegl et al. 1998, p. 1). The possibility of contamination during sample collection is difficult to evaluate but must be considered, at least at a low level. During and following excavation, tunnel walls in the ESF and ECRB Cross Drift were repeatedly washed with construction water that was obtained from well UE-25 J-13. Water from this well has a 3H concentration of less than 0.3 TU (DTN: GS040108312232.001 [Q]). This construction water was tagged with lithium bromide (LiBr) at concentrations typically between 18 and 22 mg/L, but not exceeding 30 mg/L. Evaporation of the construction water on the surface of the tunnel walls and from within the rock next to the walls would leave LiBr as a salt. The absence of measurable Br-1 in leachates of validation study core samples (Table 4-13), some from depths as shallow as 0.4 to 0.6 m, indicates that construction water is not an important contaminant of pore water samples, and therefore not of concern in determining their 3H content. Core from which water for 3H measurements was extracted was obtained by a “dry drilling” technique in which compressed air was used to remove cuttings and to cool the drill bit. No measurements of the moisture content of the “dried air” are available, nor is it known what volume of air was used per meter of drill advance. Contamination of pore water extracted from core with atmospheric 14CO2 has been documented by Yang (2002, Section 4.1.2). Some level of 3H contamination is therefore possible, but this level is not known. The maximum effect of drilling contamination or natural deep atmospheric circulation of saturated air would be the complete replacement of the native pore water with modern water that has a 3H concentration of approximately 6.3 TU. This is not the case for most of the samples. In situ production of 3H within the rock mass occurs primarily through a neutron-induced reaction with 6Li (Andrews and Kay, 1982, p. 361). Calculations using average crustal rock compositions indicate that 3H generated from subsurface production should contribute less than 0.2 TU to ground water (Lehmann et al., 1993, p. 2034). 5.2 METHODS Water for 3H analyses was extracted from the 50 validation study core samples and core samples from other boreholes in the ESF and ECRB Cross Drift (Figure 1-1; Appendix B). Samples from the north ramp included 11 samples of TCw and rocks younger than the TCw from boreholes in Alcove #2 that intersect the Bow Ridge fault, three samples of PTn from the north ramp moisture study boreholes, and 10 samples of TSw from the validation study boreholes in the Drill Hole Wash fault zone. From the ESF main drift, 42 samples from the 40 validation study boreholes associated with the Sundance fault, 10 samples from the northern Ghost Dance fault zone (Alcove #6), and five samples from the southern Ghost Dance fault zone (Alcove #7) were used for water extraction. Twenty-three samples of TCw, PTn, and TSw were collected from the south ramp moisture study boreholes between stations 59+65 and 75+10. In addition, 22 pore water samples from 19 boreholes between stations 6+00 and 25+00 in the TSw in the ECRB were analyzed. All boreholes were dry drilled, using compressed air. Core was video-logged and wrapped in plastic film, inserted into Lexan® tubing with caps taped onto each end, and sealed in ProtecCore™ packages. Where possible, core for 3H analysis was selected from the deepest parts of the borehole to minimize the effects of dry-out and construction water contamination. Core was shipped and stored under refrigerated conditions until samples were ready for processing. Pore water was extracted from the core samples by vacuum distillation (Yang et al. 1998, pp. 25-27). Water volumes ranged from 39 to 169 mL per sample. Samples from Alcove #2 were processed and analyzed at the USGS YMPB laboratory in Denver using a low-energy beta- counting technique with a detection limit of about 25 TU. Other samples were sent to the University of Miami, Rosenstiel School of Marine and Atmospheric Science Tritium Laboratory for low-level analysis. Details of the analytical procedure are given by Ostlund (1987, pp. 8–10). Pore water samples with low-level 3H concentrations were processed using an electrolytic enrichment step in which 3H concentrations are increased about 60-fold through volume reduction. Tritium activities were measured by internal gas proportional counting of hydrogen (H2) gas made from the water samples. Accuracy of the low-level measurement with enrichment for a 1-liter sample is 0.10 TU (0.3 pCi L-1 of H2O), or 3.5 percent, whichever is greater (http://www.rsmas.miami.edu/groups/tritium/). For smaller samples, accuracy is estimated to be 1.0 TU, or 10 percent for 50 mL samples, and 0.4 TU, or 10 percent for 100 mL samples (Happell 2005). The 2s uncertainties given for the 3H values include only counting uncertainties assigned by the laboratory and do not include a 1s external error of 0.36 TU determined from replicate analyses of standards. Multiple aliquots of five water standards with known 3H concentrations ranging between 0 and 2.15 TU were analyzed (Table 5-1). In general, the mean 3H concentrations obtained for each standard are in good agreement with the accepted values. Standard deviations obtained for these replicate measurements are similar to or slightly larger than the reported analytical errors, based on counting statistics alone. 5.3 RESULTS 5.3.1 Tritium in Validation Study Core Samples Pore water extracted from validation study core across the Drill Hole Wash fault zone and Sundance fault zone had 3H concentrations ranging from less than 0.1 to 2.6±1.0 TU (Figure 5-1 and Table 5-2). Most analyses have large uncertainties due to the small sample volumes. Collectively, 3H concentrations define a skewed distribution (Figure 5-2), with a median value of 0.40 TU and a geometric mean of 0.41 TU. One sample from the Sundance fault zone (ESF-SD- ClV#18, 12.3 to 13.3 ft [3.75 to 4.05 m]) had a 3H concentration of 2.6 ±1.0 TU, but a sample from an adjacent interval in the same borehole (10.9 to 11.8 ft [3.32 to 3.6 m]) had a smaller 3H value of 1.4 ±1.6 TU. 5.3.2 Tritium in Other Core Samples from the Exploratory Studies Facility Pore water extracted from core sampled elsewhere in the ESF shows a wider range of 3H concentrations than pore water extracted from the validation study core (Table 5-3). Eight of 11 core samples from Alcove #2 (30 m below the surface), which intersects the highly fractured Bow Ridge fault zone, have 3H concentrations ranging from 28.8 ±8.4 TU to 155 ±11 TU. These 3H concentrations, which are larger than the detection limit of about 25 TU for this data set, are compelling evidence for the presence of bomb-pulse 3H in the shallow subsurface. Elevated 3H concentrations in these samples correlate with elevated 36Cl/Cl ratios observed in samples associated with the Bow Ridge fault zone, exposed nearby in the ESF tunnel walls (Appendix A). Pore water in 7 core samples of PTn from the north ramp moisture study boreholes between stations 7+70 and 10+69 has 3H concentrations ranging from less than 0.1 TU to about 0.8 TU (Table 5-3). Eighteen analyses of pore water from core samples from the northern Ghost Dance fault zone (Alcove #6) have 3H concentrations between 0.3 ±0.8 TU and 2.2 ±1.2 TU (Figure 5-3). Samples with elevated 3H concentrations are common in the southern part of the ESF. Pore water from five core samples of TSw from borehole ESF-SAD-GTB#1 drilled in Alcove #7 has 3H concentrations between 1.1 ±0.6 TU and 3.7 ±1.4 TU (Table 5-3). Samples from the south ramp of the ESF between stations 59+65 and 75+10 typically have elevated 3H. Concentrations of 3H in 28 samples, primarily from several exposures of faulted PTn, have a distribution that is skewed toward large values (Figure 5-4). Elevated 3H concentrations also are present in the welded tuffs above and below the PTn (Figure 5-5, Source: Modified from USBR 1997). Four of the south ramp samples have 3H concentrations (8.2 ±1.0, 12.5 ±1.2, 14.3 ±2.0, and 28.6 ±3.6 TU) that are above the 6 TU value for present-day precipitation (Striegl et al. 1998, Table 3, p. 12-13). 5.3.3 Tritium in Core Samples from the ECRB Cross Drift Tritium concentrations in pore water samples from welded TSw in the ECRB Cross Drift (Table 5-4 and Figure 5-6) are larger than in those from the ESF (Table 5-3 and Figure 5-3). The frequency distribution of 3H values is skewed toward values as large as 10.3 ±1.8 TU, well above the modern atmospheric value of 6.3 TU (Figure 5-7). No samples were obtained from the immediate vicinity of the Sundance fault, located approximately at ECRB Cross Drift station 11+35; however, samples closest to the fault (stations 10+00, 12+00, and 13+00) had low3H values. The samples closest to the Solitario Canyon fault, collected at ECRB Cross Drift station 25+00, also had small 3H concentrations. Samples with elevated 3H concentrations are scattered throughout the ECRB Cross Drift and are not known to be associated with major faults. The USGS made several attempts to replicate elevated 3H concentrations observed in initial pore water extractions from boreholes ECRB-SYS-CS1500 and ECRB-SYS-CS2150. The work yielded mixed results (Table 5-4). The sample containing the largest 3H concentration determined in the first set of analyses from 5.5 to 6.7 ft (1.67 to 2.04 m) in borehole ECRB-SYS-CS2150 had a 3H value of 9.8 ±1.0 TU. A 3H measurement from core between 3.4 and 4.1 ft (1.04 and 1.25 m) in the same borehole yielded a value of less than 0.1 TU. The second largest 3H concentration measured in the first set of analyses was from 14.4 to 17.4 ft (4.39 to 5.30 m) in borehole ECRB-SYS-CS1500, with a 3H concentration of 2.5 ±0.8 TU. Subsequent analyses of pore water from different intervals of core (4.3 to 7.1 ft [1.31 to 2.16 m] and 9.5 to 12.1 ft [2.90 to 3.69 m]) from the same borehole yielded 3H concentrations of 10.3 ±1.8 TU and 1.5 ±0.8 TU, respectively. The difficulty in replicating these large values is not understood. 5.4 THRESHOLD VALUES FOR DETECTING MODERN WATER As noted in Section 5.1, a major challenge in using 3H to detect modern water in the UZ is the establishment of a realistic threshold value that will minimize false positive values. This problem is not unique to the use of 3H in hydrology and applies to a number of geochemical problems where the analyte of interest occurs at low concentrations, close to the method detection limits. In the following paragraphs, two alternative approaches are given for establishing the threshold value for 3H. 5.4.1 USGS Establishment of a Threshold for Identifying Modern Water To establish a realistic threshold value for interpreting measured 3H values as indicators of modern water, the USGS first evaluated the limitations of the analytical method. The USEPA has a procedure for determining the “method detection limit” (MDL). A brief description of the procedure and its application to the 36Cl data was discussed in Section 4.6.3. Assuming the detection limit for low-level analysis of 3H in small (about 100 mL) water samples is about 0.4 TU (Happell 2005), replicate analyses of standards with 3H concentrations of 1.31, 1.75, and 1.81 TU (Table 5-1) are suitable for evaluating the variability of the results at low levels. For this calculation, the USGS pooled the replicate analyses of the standards (Table 5-1) and calculated a standard deviation following Youden (1951, p. 16). The pooled standard deviation for these three sets of analyses (n=16, degrees of freedom=13) is 0.36 and the calculated MDL is 1.0 TU. The F-test (Youden 1951, p. 29-32) shows that the standard deviations for the data from three sets of standards are equal at the 95 percent confidence level. This pooling also is valid because the standard deviation is not a function of the concentration in the range of 0 to 2.0 TU, as is evident from the counting errors reported for real samples with 3H values that are within this range of concentrations (i.e., the errors are not systematically larger for larger values). Values below 1.0 TU should be considered statistically indistinguishable from zero at the 99 percent confidence level and should not be interpreted as real 3H concentrations. The USEPA states that, “It is essential that all sample-processing steps of the analytical method be included in the determination of the method detection limit” (40 CFR 136, 2004, Appendix B, p. 317). Because the effects of drilling and water extraction methods were not evaluated for the validation study, this value of MDL=1.0 TU may be an overly optimistic estimate. The USGS (Childress et al. 1999, p. 6) proposed a long-term method detection level (LT-MDL) that would incorporate additional measurement variability derived from multiple instruments, operators, calibrations, and sample preparation events. A larger number of duplicates, at least 24 per year, is required for calculation of the LT-MDL. Neither the MDL nor the LT-MDL addresses the issue of reporting levels, as pointed out by Childress et al. (1999, p. 7), and both limits lead to a 50 percent probability of false negative values. Childress et al. (1999, p. 7) further discuss various reporting levels that have been used, which are 5 to 10 times the MDL, and they cite USEPA’s use of minimum level of quantitation (ML), which is 3.18 times the MDL for n=7 replicates. Childress et al. (1999, p. 8) devised the laboratory reporting level (LRL) to limit the rate of false negative values to 1 percent or less. The LRL is defined as twice the LT-MDL. Using the USGS-calculated MDL of 1.0 TU as an approximate representation of the USGS LT-MDL, the LRL for the 3H data set is 2.0 TU. Analyses with concentrations between 1.0 and 2.0 TU should be reported as estimates because detection in this region should have a =1 percent probability of being a false positive value. The USGS considers the LRL of 2.0 TU to be a reliable threshold value for the 3H measurements. The statistical approach discussed below further supports the use of this 2.0 TU threshold value. The statistical approach that was used to estimate a threshold for bomb-pulse 36Cl/Cl values (Fabryka-Martin et al. 1997, Section 4.2.4) also was used to establish an independent threshold for 3H in pore water extracted from ESF and ECRB Cross Drift core samples. The USGS applied this approach to the 3H analyses contained in Tables 5-2, 5-3, and 5-4. These analyses were ranked by increasing 3H concentration, and cumulative averages and standard deviations were calculated at each added value. The 11 samples with 3H concentrations reported as less than 0.1 TU were arbitrarily assigned concentrations between 0 and 0.1 in 0.01 increments to avoid standard deviations of zero. This artificial approach could cause the excursion of data above the curve on a plot (Figure 5-8) showing the number of standard deviations for each value from the cumulative mean. However, similar results are obtained if these 11 samples are excluded from the statistical analysis. The plot shows a relatively smooth curve for the first 108 samples in the data set (Figure 5-8). Tritium concentrations for these samples are less than 2.0 TU. After this ranking, the deviation of individual data points increases markedly, such that the probability of these values being that far from the cumulative mean of the ranked data set is less than 0.5 percent. The limit of 0.5 percent probability, known as Chauvenet’s criterion, establishes a boundary for values that are likely to lie outside a sample population that is normally distributed (Taylor 1982, Chapter 6.2). The threshold value of 2.0 TU established using Chauvenet’s criterion agrees with the threshold value using the USEPA MDL and USGS LRL methods. The 2.0 TU threshold minimizes the potential for obtaining false positive or false negative values. 5.4.2 LANL Establishment of a Threshold for Identifying Modern Water As pointed out in Section 5.1, interpretation of low-level 3H concentrations in small-volume pore water samples is not straightforward. Complications may arise due to the fact that most environmental samples will be exposed to the atmosphere at some time(s) during their collection. Thus, it is difficult or impossible to completely rule out some contamination of samples. The statistical analyses of MDL and Chauvenet’s criterion presented in Section 5.4.1 are used to determine a “threshold value” that will minimize false positives. These analyses result in a threshold value of 2 TU, a value that is considerably larger (by a factor of about 10) than would be expected if only in situ-produced 3H were present, and a factor of 2 to 5 greater than the quoted analytical detection limit. The applicability of the statistical methods applied above in determining this threshold value is discussed below. Although methods to determine MDLs may vary, it is agreed that determination of an MDL requires rigorous analyses of many standards of appropriate concentrations. Tritium data reported herein were analyzed by the University of Miami, Rosenstiel School of Marine and Atmospheric Science Tritium Laboratory for low-level analysis, one of two laboratories used for 3H analyses by the NWQL. They report a detection limit of 0.1 TU and a reportable accuracy and precision of 0.1 TU or ±3.5 percent, whichever is larger, for 1-L samples. Most of the samples analyzed for this study are smaller, however, and therefore larger detection limits of 0.4 TU for 100-mL samples and 1.0 TU for 50-mL samples are reported. The method to determine MDL, as applied in Section 5.4.1, has several requirements and assumptions, many of which are not satisfied in the analysis above, as follows. • The data are assumed to have a normal distribution about a mean value. Although the available data do not show a normal distribution, their numbers are likely insufficient to prove or disprove such a distribution. • The USEPA method calls for a minimum of seven analyses of the same standard; the method used by the NWQL requires at least 24 analyses per year. The maximum number of replicates of a single standard is seven (Table 5-1). Values from three standards were pooled to derive the MDL above (Section 5.4.1); however, the total number of analyses pooled is still below the minimum requirements of the NWQL. • Choice of the appropriate standard concentrations to use for determination of MDLs is based on the assumption that at small concentrations, the standard deviation of the sample set will become constant at a small value because small differences in small instrument signals cannot be measured accurately. This is an important assumption for determination of the MDL. Standard deviations of the three sample sets used in Section 5.4.1 are not constant, nor do they show a trend with sample size. As a result, they are overly large and result in an over-estimation of the MDL. • Finally, the USEPA method recommends an iterative process by analyzing standards with increasingly smaller concentrations to ensure robustness of the method. This was not conducted in this study. The analysis to determine MDL, as described in Section 5.4.1, violates most of the basic requirements and assumptions of the method. The MDL of 1.0 TU determined by this analysis is not statistically robust and should be considered a qualitative assessment. Analysis using the NWQL, which is based on the USEPA method, is then used to arrive at a reliable threshold value for the 3H measurement of 2.0 TU. It should be reiterated, however, that values between the MDL and the LRL have a =1 percent probability of being a false positive value. Thus, values between 1.0 and 2.0 should be reported as detections. Chauvenet’s criterion is a simple test that can be used to identify data that may be considered as outliers of a normally distributed data set (Taylor 1982, Chapter 6.2). The use of Chauvenet’s criterion, however, is controversial and “some scientists believe that data should never be rejected without external evidence that the measurement in question is incorrect” (Taylor, 1982, p. 169). The use of Chauvenet’s criterion to evaluate potential outliers in the 3H data set and the implications of the interpretations based on this approach may not be appropriate. Potential problems with this approach fall into two categories: (1) whether or not use of this statistical approach is appropriate for such a data set, and (2) the interpretation of the results of the statistical analysis presented above is not unique. Chauvenet’s criterion for rejection is typically used on data sets for which the range in values is expected to be normally distributed around a single mean value. In this case, the method is applied to a set of unknowns, for which the individual data points are not likely to have a common mean value. Application of the method implicitly assumes that variability in the data due to hydrogeologic heterogeneity is small compared to other sources of spread in the data. This is an invalid assumption for these geologic samples. Infiltration at Yucca Mountain is predicted to be heterogeneous due to the fractured nature of the rocks. Tritium concentrations will reflect these heterogeneities, unless a sampling scheme is carefully designed and the number of samples is sufficient to reflect a true average value. The 3H data clearly reflect these heterogeneities. Many of these samples targeted features such as fault zones (e.g., the Bow Ridge fault zone, Ghost Dance fault zone), stratigraphic and/or hydrogeologic units (e.g., the Topopah Spring Tuff, PTn), or regions (e.g., the ESF south ramp). As expected, the data show a range in values from very small (equivalent to zero) to the largest values reported in this study (155 TU). Of the 3H data collected for this study, the data sets most likely to average natural hydrogeologic heterogeneities are the samples from the ECRB (Table 5-4) and the validation study core (Table 5-2). These data were obtained from cores that were drilled on regularly spaced intervals. Although the validation study boreholes were located near fault zones, it is reasonable to suggest that the random spacing of the boreholes could average geologic heterogeneities, and that this data set approximates a random sampling. On the basis of fracture density data it was expected that the validation study boreholes would intersect multiple fractures in the tuff (Section 3.1). Application of Chauvenet’s criterion to this subset of the data (Figure 5-9) presents a potentially different picture than that presented for the entire data set (Figure 5-8). Figure 5-9 shows two distinct jumps in the data that rise beyond Chauvenet’s criterion for outliers. The first of these jumps lies between 1.1 and 1.4 TU, values that differ from the 1.8 to 2.2 TU cutoff obtained when the entire data set is used (Figure 5-8). This analysis illustrates the point that a different result may be obtained when a different subset of the data is selected for statistical analysis. An alternate interpretation that unifies the 3H data with analytical and geologic information follows. As shown in Figures 5-2 and 5-7, the 3H data do not form a normal distribution. In all cases the data form distributions with maxima skewed to small values and long tails of larger values. However, data should form a normal distribution about a true composite detection limit. Reduced chi-squared tests performed on all of the data, and data from only the ECRB Cross Drift and validation study core samples, show best fits to normal distributions for data below approximately 1.2 TU. The mean for all data below 1.2 TU is 0.5 TU, with a standard deviation of 0.3. The mean and standard deviation for the ECRB Cross Drift and validation study core data are 0.4 and 0.3, respectively. These values also can be deduced by examination of histograms, which show maxima at these median values. These values are interpreted to indicate a “composite 3H background” that represents the sum of all small sources of 3H that may have entered the sample, either through natural processes or through sampling, processing, and analysis. This background value thus includes natural in situ 3H, possibly 3H derived from construction water and the natural circulation of modern water vapor, and all other sources of 3H contamination. These values lead to MDLs of 1.3 to 1.4 TU at the 99 percent confidence level. These values are larger than those assigned by the analytical facility, consistent with the fact that these samples have undergone more extensive processing than have the standards. This value is also in reasonable agreement with the MDL of 1.0 TU discussed above, but suggests a high probability that values above 1.4 TU are true quantifiable detections. As pointed out above, analyses with concentrations between 1.0 and 2.0 TU will have a greater than 99 percent probability of being a true positive value. 5.5 INTERPRETATION OF THE TRITIUM MEASUREMENTS Any discussion of the significance of the 3H results is dependent on the estimation of the threshold value for the unambiguous detection of modern water described in Sections 5.4.1 and 5.4.2. The following paragraphs reflect differences in the two interpretations of the data. 5.5.1 USGS Interpretation of the Tritium Measurements Tritium values in Alcove #2 that are above the 25 TU detection limit (Section 2.2) indicate the presence of modern water associated with the Bow Ridge fault zone. Other locations of modern water include numerous sample sites along the south ramp of the ESF, the southern Ghost Dance fault zone (Alcove #7), and several locations along the ECRB Cross Drift. Slightly elevated 3H values are noted near the Sundance fault in the main ESF drift and near the northern Ghost Dance fault zone (Alcove #6). These values are marginally above the 2.0 TU threshold. Eight pore water samples from the ECRB Cross Drift have 3H values in excess of 2.0 TU. None of these locations is associated with known, through-going faults. This contrasts with observations in the ESF, where modern water occurrences are associated with faults or highly faulted zones, such as the south ramp. The lack of association of elevated 3H values with faults led to a concern by the USGS about the possibility of analytical problems that may have caused the larger 3H values. The attempt to replicate analyses by extracting water from adjacent intervals of core produced ambiguous results. At the present time, the USGS views the 3H values in this area as suggestive but not conclusive proof of the presence of modern water. 5.5.2 LANL Interpretation of the Tritium Measurements Interpretation of 3H data obtained from low-level, small-volume samples is not straightforward. The problem is likely compounded for small-volume pore water samples as are presented here because of the more involved collection and processing schemes (e.g., drilling and water extraction) compared to saturated zone ground-water collection. Ideally, a composite background that incorporates the potential for higher than predicted analytical errors, as well as sample contamination, would have been rigorously determined. This campaign would involve analysis of a statistically sufficient number of standards of the appropriate composition that were subjected to all the same processing steps of the samples in all the same places. Such a campaign, which would be very difficult, time consuming, and costly, was not conducted. The robustness of the data was monitored through analysis of standards. Standards submitted along with the samples were of comparable volume and 3H concentration as a large number of samples. Data from 18 standards agree well with the accepted value, indicating that these small-volume, low-concentration standards can be analyzed accurately. Two samples of dead water (zero 3H) also were analyzed accurately. These data demonstrate that the standards were handled without introducing contamination. They also demonstrate the robustness of the analytical techniques for small volume samples with small 3H concentrations. Although the data from the standards do not indicate analytical or contamination problems, they did not undergo the same sampling and extraction procedures as the samples. The actual samples will likely reflect increased analytical errors and are more susceptible to contamination when compared to the standards. The large number and skewed distribution of analyses below the detection limit of 0.4 for samples less than 100-mL and 1.0 for samples less than 50 mL indicate that many of the samples were processed without substantial contamination. On the basis of arguments presented above, the following guidelines for interpretation of the 3H data are suggested. These guidelines are designed to not over-interpret potential false positives, while at the same time to not eliminate possibly important and accurate 3H detections. Samples with 3H concentrations greater than 1.4 TU should be considered as having a greater than 99 percent probability of being a detection above a composite background value of approximately 0.5 TU, and thus indicate the presence of a component of modern water. The presence of modern water in samples with 3H values between 0.5 and 1.4 TU is equivocal, but should be considered a possibility, especially for samples greater than 1.1 TU, which have a 97.7 percent probability of being a true detection. The presence of bomb-pulse water is indicated by 3H concentrations above 6 TU, the value assumed for modern precipitation (see Sections 5.0 and 5.1). Given these guidelines, it is likely that modern water (Clark and Fritz 1997, p. 172) is present in the validation study core and ECRB tunnel samples in a number of locations. One sample with a value of 2.6±1.0 TU from the validation study core near the Sundance fault zone shows the presence of modern water. The presence of modern water is suggested in four additional samples: two from the Sundance fault zone and two from the Drill Hole Wash fault zone. Most samples from Alcove #2, near the Bow Ridge fault, show the presence of bomb-pulse water. Five samples from the northern Ghost Dance fault zone (Alcove #6), with values between 1.4±0.08 and 2.2±1.2 TU, show the presence of modern water. Two samples from borehole ESF-SAD-GTB#1, drilled in Alcove #7, with values of 1.8±1.4 and 2.3±0.6 TU, indicate the presence of modern water. The presence of modern water is widespread in the south ramp, with 17 of 28 samples containing 3H concentrations greater than 1.5 TU; five of these are greater than 6 TU. Modern water is also widely distributed in the ECRB. Eleven of 22 samples have 3H concentrations greater than 1.5 TU; five of these have concentrations greater than 6 TU, indicating the presence of bomb-pulse water. 6. SUMMARY OF RESULTS, CONCLUSIONS, REMAINING ISSUES, AND RECOMMENDATIONS 6.1 SUMMARY OF RESULTS The 36Cl validation study was conducted in three phases and involved the collection of new samples by drilling into the ESF tunnel walls so that 36Cl/Cl and 3H measurements could be made in areas where previous studies identified elevated 36Cl/Cl ratios. The results of the validation study are summarized as follows: • Results from Phase I work conducted at LLNL indicated that active leaching abraded the rock samples and extracted too much rock chloride relative to meteoric chloride (36Cl/Cl ratios range from 47 × 10-15 to 248 × 10-15; all but one value are less than 156 × 10-15). • Results from Phase I work conducted at LANL on validation core samples from the Sundance fault zone yielded 36Cl/Cl values consistent with analyses from previous LANL studies. • Following a detailed series of leaching experiments in Phase II of the validation study, a 1-hour passive leaching protocol was established for processing samples in Phase III of the study. The passive leaching process extracted less rock chloride relative to meteoric chloride. • USGS-LLNL 36Cl/Cl values for Phase III leachates of 34 samples of core from validation study boreholes across an area that includes the Sundance fault zone range from 137 × 10-15 to 615 × 10-15 . These contrast with values greater than 1250 × 10-15 reported previously for feature-based tunnel-wall samples in the same area (Figure 6-1). • 36Cl/Cl ratios for Phase III leachates of validation study core prepared at the USGS and processed separately at LLNL and LANL agree within analytical error (Figure 6-1). • LLNL analyses of six Niche #1 core samples prepared at the USGS are statistically indistinguishable from validation study borehole data (36Cl/Cl ratios range from 226 × 10-15 to 717 × 10-15). • LLNL analyses of seven Niche #1 core samples prepared at LANL yielded bomb-pulse values that are comparable to previous LANL data (36Cl/Cl ratios range from 1,016 × 10-15 to 8,558 × 10-15). • One LANL validation study analysis and several previous LANL analyses of samples from the ECRB Cross Drift also have 36Cl/Cl ratios above the 1,250× 10-15 bomb-pulse threshold. • Tritium concentrations in pore water extracted from validation study core across the Drill Hole Wash fault zone and the Sundance fault zone range from less than 0.1 to 2.6±1.0 TU. • Tritium concentrations in pore water extracted from samples from areas of known faulting in the north ramp, south ramp, and Alcove #7 indicate the presence of modern water (i.e., water that entered the Yucca Mountain UZ after 1952). • Tritium concentrations in pore water extracted from core samples from the ECRB Cross Drift range from less than 0.1 to 10.3±1.8 TU. • The USGS and LANL established different 3H thresholds for identifying modern water. The USGS value is 2.0 TU and the LANL value is 1.4 TU. 6.2 CONCLUSIONS The main conclusions of the validation study are as follows: • USGS-LLNL did not find 36Cl/Cl ratios greater than 1,250× 10-15 in samples from the Sundance fault zone comparable to values reported previously by LANL. • New analyses by LANL-LLNL on Niche #1 core and ECRB Cross Drift tunnel-wall samples were consistent with results from previous LANL studies showing the presence of bomb-pulse 36Cl in the ESF and ECRB Cross Drift. Analyses of these core samples by USGS-LLNL did not produce comparable results. • With one exception, 3H values in pore water from validation study core samples from the ESF do not exceed the USGS or LANL threshold values beyond the 2s error limits. Tritium values in pore water from two validation study core samples from the Drillhole Wash fault zone exceed the LANL threshold value of 1.4 TU. • Regardless of whether the USGS or LANL threshold value is used, 3H analyses of samples from areas of known faulting in the ESF north ramp, south ramp, and Alcove #7 indicate the presence of modern water. Several locations in the ECRB Cross Drift that are not associated with major faults may also contain modern water; however, several attempts to replicate elevated 3H values yielded ambiguous results. The difficulty in replicating these large values is not understood. 6.3 REMAINING ISSUES 6.3.1 Absence of Elevated Chlorine-36/Chloride Ratios in USGS-LLNL Measurements Small concentrations of chloride in USGS-LLNL leachates resulted in relatively large uncertainties in 36Cl/Cl ratios. Use of the passive-leach protocol with short (1 hour) leaching times resulted in small chloride concentrations. Despite the large uncertainties of 36Cl/Cl ratios in AMS measurements of leachates with small concentrations of chloride, the replicate analyses of leachates from rocks (as well as blanks) are consistent and are considered to be reliable. However, bomb-pulse 36Cl/Cl ratios were not found using this technique. Thirty-four leachates from the validation study boreholes, plus leachates of core from existing Niche #1 boreholes, yielded a mean 36Cl/Cl ratio of 337 ±141 (1s) × 10-15 and a maximum 36Cl ratio of 717 ±139 × 10-15 . This mean value contrasts with 19 of 34 LANL analyses (24 tunnel-wall samples and 10 Niche #1 core samples), which have 36Cl/Cl ratios in excess of 1,250 × 10-15 and one value of 4,108 × 10-15 . The limited range of 36Cl/Cl ratios in the USGS-LLNL data over a wide range of chloride concentrations indicates that these data are not the result of mixing between distinct components with high and low 36Cl/Cl ratios. In addition to a lack of bomb-pulse 36Cl values, the 36Cl/Cl ratios determined by USGS-LLNL for samples from the Sundance fault zone are, on average, smaller than the Holocene value of about 500 × 10-15 . The USGS-LLNL results differ from the background LANL 36Cl/Cl values, which are higher than the Holocene value for northern ESF samples, but are closer to, although still statistically different from, the LANL values for southern ESF samples. Whether the differences between 36Cl/Cl ratios determined for the validation study and those determined for the previous studies can be ascribed to differences in sampling protocol is currently a matter of professional opinion. The justification for using a borehole strategy across a broad 36Cl anomaly was discussed in Section 3.1. As noted previously in this report, feature- based samples obtained from the tunnel walls allow selection of sub-samples with a greater fracture surface area per mass unit of rock than do the core samples. However, the different results obtained by USGS-LLNL and LANL-LLNL for representative core samples from the Niche #1 boreholes demonstrate that other factors, such as laboratory contamination, also should be considered. 6.3.2 Results for Niche #1 Core Leaching experiments showed that leachates of more finely crushed material contain larger chloride concentrations than those from the more coarsely crushed material and that particle size is more important than leach duration. The increase in surface area as particle size decreases allows a greater amount of rock chloride to be extracted, resulting in a negative correlation between chloride concentration and 36Cl/Cl ratio. This negative correlation is observed in data for leachates from the active-leach process. In contrast, validation study leachates of Niche #1 core crushed and processed at LANL show the opposite trend. For the five samples of the coarsest material, 36Cl/Cl ratios are smallest in the two samples with the smallest chloride concentration. Leachates of the fines from both of these samples also were analyzed and yielded not only larger chloride concentrations, as expected, but also much larger 36Cl/Cl ratios, including the largest value reported for an ESF sample (8,558 × 10-15). These results are opposite of the conclusions of Lu et al. (2003), who stated that larger 36Cl/Cl ratios should be observed in leachates with smaller chloride concentrations from larger particle sizes. These contradictions show that the present understanding of chloride sources and mixing during leaching is inadequate. 6.3.3 Spatial Distribution of Elevated Chlorine-36 Values and Tritium Values The USGS and LANL differ in their interpretations of the spatial distribution of elevated 36Cl/Cl ratios and 3H results, as described below. 6.3.3.1 USGS Interpretation of the Spatial Distribution of Elevated Values The 36Cl Peer Review Team recommended that future studies include analyses of other bomb- pulse indicators, in particular 3H. All of the 52 analyses of validation study core from the Drill Hole Wash fault zone and Sundance fault zone yielded 3H concentrations that were either less than the 2.0 TU background cutoff value or were indistinguishable within 2s analytical error. In contrast, the presence of modern water is indicated by elevated 3H concentrations in the south ramp. Some water samples have 3H concentrations that were substantially larger than modern atmospheric levels, indicating a bomb-pulse origin. The distribution of 3H in south ramp samples contrasts with the distribution of previously reported 36Cl/Cl analyses from the same area. A large number of tunnel-wall samples from the ESF south ramp did not contain 36Cl/Cl ratios with bomb-pulse values. In addition, samples from the northern ESF show bomb-pulse 36Cl/Cl ratios, but 3H values below the threshold value of 2.0 TU. Similar differences between the location of elevated 3H and 36Cl/Cl values occur in the ECRB Cross Drift. Samples with elevated 36Cl/Cl ratios were obtained only from areas associated with the Solitario Canyon fault and an unnamed fault near ECRB Cross Drift station 22+37. Samples with elevated 3H concentrations, including two values indicative of a bomb-pulse origin, were scattered throughout the ECRB Cross Drift. In one case, samples within 4 m of each other contained a 3H concentration of 9.8 TU (sampled at ECRB Cross Drift station 21+49; Table 5-4), and a 36Cl/Cl ratio of 4,890 × 10-15 (sampled at ECRB Cross Drift station 21+54.5; Table 4-17). However, attempts to reproduce the 3H measurement from core in the same borehole resulted in a value of 0.1 TU. Analyses of adjacent tunnel-wall samples at stations 21+54 and 21+55 (Table 4-17) had 36Cl/Cl values of 915 × 10-15 and 553 × 10-15, respectively. Additional samples at stations 22+50 and 25+00 (Table 5-4) had 3H concentrations below 1 TU. 3H measurements were not made for samples beyond station 25+00 in the area where multiple bomb-pulse 36Cl/Cl values were observed, because core was not available. 6.3.3.2 LANL Interpretation of the Spatial Distribution of Elevated Values Interpretation of 3H data collected for this study relies heavily on interpretations of a threshold value, below which an analysis is not considered indicative of modern water (Section 5). If, as discussed in Section 5.4.2, a value of 1.4 TU is taken as a lower limit for quantifiable 3H values and some smaller values are accepted as possible indicators of modern water, then the comparison of the spatial differences between 3H and 36Cl changes substantially. Given these lower limits for 3H detections, modern water was detected in at least one (value of 2.6±1.0) and up to four (three 3H values between 1.4 and 1.6) of 52 samples of the validation study core. These core samples were collected at 5-m spaced intervals, a collection scheme similar to that used to collect systematic samples for previous LANL 36Cl studies. In these samples the occurrence of bomb-pulse 36Cl is two of the 54 samples. The occurrences of modern water based on 3H and 36Cl for systematically collected samples are therefore in reasonable agreement. Contrasting distributions of 3H and 36Cl ratios in the south ramp are readily attributable to the elevated chloride concentrations in pore water in this region. Elevated pore water chloride concentrations mask potential bomb-pulse signals through dilution (Lu et al. 2003), but do not affect 3H concentrations. Apparent differences between 3H and 36Cl distribution in the ECRB Cross Drift are difficult to evaluate because none of the samples were precisely collocated. Nonetheless, most 3H and 36Cl data from samples collocated within a few meters agree (i.e., 3H is below detection and 36Cl is less than 1200 × 10-15, both values indicating pre-bomb-pulse water). As stated above, the sample pair most closely collocated (4 m apart) shows the second largest 3H value (9.8 TU) and the largest 36Cl value (4890 × 10-15) measured in the ECRB Cross Drift. Of other samples with either a (but not both) 3H or 36Cl bomb-pulse signature, none is collocated closer than 12 m. Unfortunately, these two studies were conducted independently and thus did not emphasize collocation of samples. As a result, comparison of the spatial distribution of modern water deduced from 3H and 36Cl data is inconclusive. The data, however, are not contradictory, but rather suggest a rough correlation. 6.3.4 Potential Contamination from Field and Laboratory Environments The USGS and LANL differ in their interpretations of the potential for contamination from field and laboratory environments, as described below. 6.3.4.1 USGS Interpretation of the Potential for Contamination from Field and Laboratory Environments Contamination of USGS-LLNL leachates by sources with low 36Cl/Cl ratios or contamination of LANL leachates by sources with high 36Cl/Cl ratios could explain the differences in 36Cl/Cl ratios determined by USGS-LLNL and LANL. Analysis of laboratory blanks testing the amount and composition of chloride added during crushing, leaching, and target preparation by USGS-LLNL has not identified a source with consistently low 36Cl/Cl ratios (Sections 4.4.1 and 4.6). Samples analyzed by USGS-LLNL included rock crushed and sieved at the SMF, the USGS, and Phillips Enterprises LLC of Golden, Colorado, by machine and by hand. Resulting36Cl/Cl ratios are similar regardless of where the sample was crushed. Therefore, contributions from a contaminant introduced during crushing would have to be similar at all three facilities and the same for both hand and machine crushing. Furthermore, the absence of a correlation between chloride concentrations and 36Cl/Cl ratios in the USGS-LLNL data seems to be inconsistent with mixing of multiple components with distinct compositions. Possible contamination of samples with large 36Cl/Cl ratios in field and laboratory environments has been evaluated. The very high 36Cl/Cl ratios measured in cuttings from a surface-based borehole (USW UZ-N55), with eight of 14 leachates having 36Cl/Cl ratios between 10,480 × 10-15 and 27,040 × 10-15 (Fabryka-Martin et al. 1993, Table 2), were likely caused by drilling or sample collection using 36Cl-contaminated equipment (Fabryka-Martin and Liu 1995, Section 3.1.3; Fabryka-Martin, Turin et al. 1996, Sections 4.3.3 and 5.3.1). The presence of laboratory equipment contaminated with 36Cl also was mentioned in later LANL reports that presented results from ESF samples: “Although this nuclide has been found to be present at unacceptably high levels in some laboratory equipment and rooms, these items and work environments are simply avoided for routine processing” (Fabryka-Martin, Wolfsberg et al. 1996, p. 15). “A particular piece of equipment is not used to prepare samples if an excessively high 36Cl level is measured in a blank prepared using it; for example, such was the case for a shatterbox that was being used to characterize the in situ halide and SO4 concentrations of Paintbrush Tuffs” (Fabryka-Martin et al. 1997, p. 4-2). Details of the nature and extent of the 36Cl contamination have not been presented. In each case, the authors indicate that 36Cl/Cl levels were monitored and that contamination was not “at a level to cause concern” (Fabryka-Martin, Wolfsberg et al. 1996, p. 15). Studies of 36Cl performed at other sites hosting nuclear activities have reported high blank 36Cl from laboratory processing. Background values for 36Cl/Cl as high as 1,000,000 × 10-15 were observed at the AECL’s Chalk River Laboratories and were attributed to reactor and waste- management operations (Andrews et al. 1994, Section 3.2). Although special care taken during handling and processing of samples allowed background 36Cl/Cl limits of 10-15 to be achieved for most types of samples, rock samples remained an exception, having about 10 times higher background levels (Andrews et al. 1994, Section 3.2). Determinations of 36Cl/Cl ratios at the Australian Nuclear Science and Technology Organization’s Lucas Heights reactor facility also have identified 36Cl/Cl contamination up to 10,000 × 10-15 that was traced to neutron irradiation of 35Cl in the air circulated around the High Flux Australian Reactor (Bird et al. 1990, Section 2.2). High values of 36Cl/Cl (up to 24,000 × 10-15) also were observed in blanks stored in a desiccator for a 6-month period as well as in chloride extracted from the silica gel desiccant (Bird et al. 1990, Section 2.4). The authors attributed this contamination to vapor phase exchange of chloride. They further cite that “samples with 36Cl/Cl ratios on the order of 10-11 [tens of thousands × 10-15] have also been observed in radiochemistry laboratories” (citation credited to “J. Fabryka-Martin, private communication, 1989” in Bird et al. 1990, Section 2.4 and reference [10]). Potential sources of field contamination of tunnel walls have not been fully evaluated. Contaminated soils in Jackass Flats, within a few kilometers of the north portal, contain 36Cl/Cl ratios two orders of magnitude larger than bomb-pulse values in the ESF (Section 2.1.1). The ESF ventilation system continually intakes unfiltered outside air, which is distributed throughout the tunnel. The amount and source of exogenous dust brought into the tunnel is currently under investigation. Another source of chlorine contamination was recently discovered. The conveyor belt covers (CRWMS M&O 1995) contain approximately 10 percent chlorinated paraffin wax, which is 71.5 percent chlorine by weight (Skeggs 2005). 6.3.4.2 LANL Interpretation of the Potential for Contamination from Field and Laboratory Environments Procedural blanks taken throughout the course of this study indicate that blank levels are small and do not affect the 36Cl/Cl ratios substantially, even for smallest sample sizes. In addition to the analytical data collected during this and previous studies by LANL, there are a number of additional reasons why it is unlikely that blanks are a cause of large 36Cl/Cl ratios in LANL samples including: • Niche #1 core with the largest 36Cl/Cl ratios also has the largest chloride concentrations. Therefore it would take an extremely high 36Cl blank to account for these values. Furthermore, the largest measured 36Cl/Cl blank for samples analyzed at LANL during this study was 4,257 × 10-15, with most being considerably less (Table 4-16). This largest blank ratio is still considerably smaller than the maximum value of 8,558 × 10-15 for Niche #1 core (Table 4-12). Available data preclude blank 36Cl from being the reason for this large value. • The data from Niche #1 follow a consistent pattern with the largest chloride concentrations and 36Cl/Cl ratios in the finest samples, smallest values in the coarsest fractions, and intermediate values for intermediate size fractions. This pattern is consistent for five separate samples, three of which did not undergo the same sieving sequence. It is difficult to imagine a mechanism by which the large blanks required by the sample size might manifest themselves in such a consistent fashion. • Samples from the ESF and ECRB Cross Drift with bomb-pulse values are typically large; generally rock samples between 3 and 5 kg were processed. Leachate chloride concentrations are typically between 0.4 and 1.0 mg/kg (DTN: LA0305RR831222.001 [UQ], LAJF831222AQ98.004 [Q]). A 4-kg sample with 0.5 mg/kg chloride concentration and a 36Cl/Cl ratio of 2000 will contain approximately 4 × 10-12 mg 36Cl. The mean 36Cl mass for 12 blanks reported by LANL is 1.6 × 10-14 mg (Table 4-16). Thus, a typical sample with a bomb-pulse signal contains 250 times more 36Cl than the mean blank. In order for a bomb-pulse measurement in a sample to be due solely to blank contamination, that blank value would have to be enormously high relative to measured values. Blanks in this study vary by a maximum of a factor of seven. • Most samples with bomb-pulse values were found near structures; systematic samples rarely show bomb-pulse values, as discussed above (DTN: LA0305RR831222.001 [UQ], LAJF831222AQ98.004 [Q]). It is highly unlikely that anomalously elevated blanks would correlate with structures. • The data for samples processed from the ECRB Cross Drift as part of this study (Table 4-17) compare well to those from previous studies (Appendix A), with both data sets containing bomb-pulse signals; values between 500 × 10-15 and 1,250 × 10-15 and values less than 500 × 10-15 . These data sets were generated by different personnel, working in different laboratories with different laboratory equipment, and processing samples by slightly different methods. Analyses were also performed by a different analytical facility. Thus, the two studies meet qualifications of an independent validation study. • Bomb-pulse 36Cl values for samples collected at Yucca Mountain, including some from the deep subsurface, have been obtained by facilities other than LANL in investigations that have spanned 20 years. Table 3-1 outlines the sample processing history of Yucca Mountain Project 36Cl samples. The table corroborates arguments above that 36Cl contamination from laboratory processing is not responsible for bomb-pulse values observed in Yucca Mountain samples. 6.4 RECOMMENDATIONS The differences between 36Cl/Cl measurements obtained from previous 36Cl studies and the 36Cl validation study cannot be explained by presently available data. However, these data do point to areas where continued investigations may resolve many of the remaining issues outlined in Section 6.3. The following recommendations for further investigations include additional evaluations of existing work, additional analyses of blank materials and existing samples, and an independent validation study that incorporates the lessons learned, to date. 6.4.1 Evaluation of Field Contamination The USGS and Bechtel SAIC Company (BSC) are collecting dust samples from various environments at Yucca Mountain, including dust in the ESF and ECRB Cross Drift. The 36Cl/Cl ratios in this dust should be determined. Further, the isotopic composition of chlorine in neoprene and other potential chlorine-bearing materials used in construction should be measured. If further samples for 3H measurements are collected by dry-drilling methods, sampling blanks should be designed, implemented, and monitored. For example, the 3H content of moisture in the compressed air should be determined and its effect on sampling evaluated. 6.4.2 Evaluation of Laboratory Blanks All stages of sample processing should be fully controlled by adequate blank measurements. Long-term environmental exposure blanks could capture sporadic 36Cl contamination, if present. Also, crushing blanks remain a potential source of uncertainty in identifying possible contamination problems. Although it is difficult to evaluate crushing blanks, approaches such as those outlined in Section 4.4.1.2 would help document important aspects of sample processing that may have been unconstrained in the past. Better data on crushing blanks need to be collected using protocols that replicate previous handling and processing steps. Additional 3H measurements should be made to evaluate potential contamination during all stages of pore water extraction. One approach would involve imbibing 3H-free water under controlled conditions into the rock sample from which water was previously extracted. Re-extraction of water for 3H analyses would yield a laboratory process blank. 6.4.3 Additional 36Cl/Cl Analyses of Validation Study Core and ECRB Cross Drift Core Validation study core used for pore water distillation and 3H analysis is archived at the USGS. Although the core was dried out during vacuum distillation, the process did not remove chloride. Therefore, this core is suitable for chloride extraction. Validation study core from the Sundance fault zone, Drill Hole Wash fault zone, and ECRB Cross Drift remaining after vacuum distillation should be split and leached using previous methods, with the exception of increasing sample sizes or leaching times to increase the total amount of chloride available for 36Cl/Cl analysis. This test should include handling and crushing processes to detect possible differences in 36Cl/Cl values from USGS-LLNL and LANL. In addition, splits of these samples should be sent to an independent laboratory with no history of 36Cl contamination. Also, 36Cl/Cl ratios should be re-analyzed in the ECRB Cross Drift samples where elevated 3H values were observed. 6.4.4 Independent Validation Study Using New Samples Using existing samples, the experiments outlined above may provide sufficient insight to resolve the issue of whether or not bomb-pulse 36Cl is present at depth in the Yucca Mountain UZ. However, in the event these experiments do not provide conclusive evidence, it is recommended that a third party, without previous ties to either the USGS or LANL, should be assigned the task of designing an independent validation study that includes new sample collection. 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(Q) GS060308312272.002. Tritium Abundance Data from Pore Water in Core Samples from Yucca Mountain ESF ECRB. (Q) GS060383122410.001. Tritium Data from Pore Water from ESF Borehole Cores, 1998 Analyses by University of Miami. (UQ) GS960708314224.008. Provisional Results: Geotechnical Data for Station 30+00 to Station 35+00, Main Drift of the ESF. (Q) GS960708314224.010. Provisional Results: Geotechnical Data for Station 40+00 to Station 45+00, Main Drift of the ESF. (Q) GS960908314224.014. Provisional Results—ESF Main Drift, Station 50+00 to Station 55+00. (Q) 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. (Q) GS970208314224.003. Geotechnical Data for Station 60+00 to Station 65+00, South Ramp of the ESF. (Q) GS970808314224.008. Provisional Results: Geotechnical Data for Station 65+00 to Station 70+00, South Ramp of the ESF. (Q) GS970808314224.010. Provisional Results: Geotechnical Data for Station 70+00 to Station 75+00, South Ramp of the ESF. (Q) GS970808314224.012. Provisional Results: Geotechnical Data for Station 75+00 to Station 78+77, South Ramp of the ESF. (Q) GS971108314224.020. Revision 1 of Detailed Line Survey Data, Station 0+60 to Station 4+00, North Ramp Starter Tunnel, Exploratory Studies Facility. (Q) GS971108314224.021. Revision 1 of Detailed Line Survey Data, Station 4+00 to Station 8+00, North Ramp, Exploratory Studies Facility. (Q) GS971108314224.022. Revision 1 of Detailed Line Survey Data, Station 8+00 to Station 10+00, North Ramp, Exploratory Studies Facility. (Q) GS971108314224.023. Revision 1 of Detailed Line Survey Data, Station 10+00 to Station 18+00, North Ramp, Exploratory Studies Facility. (Q) GS971108314224.024. Revision 1 of Detailed Line Survey Data, Station 18+00 to Station 26+00, North Ramp, Exploratory Studies Facility. (Q) GS971108314224.025. Revision 1 of Detailed Line Survey Data, Station 26+00 to Station 30+00, North Ramp and Main Drift, Exploratory Studies Facility. (Q) GS971108314224.026. Revision 1 of Detailed Line Survey Data, Station 45+00 to Station 50+00, Main Drift, Exploratory Studies Facility. (Q) GS971108314224.028. Revision 1 of Detailed Line Survey Data, Station 55+00 to Station 60+00, Main Drift and South Ramp, Exploratory Studies Facility. (Q) LA0305RR831222.001. Chlorine-36 and Cl in Salts Leached from Rock Samples for the Chlorine-36 Validation Study. (UQ) LA0307RR831222.001. Chloride, Bromide, Sulfate, and Chlorine-36 Analyses of Salts Leached from Cross Drift Rock Samples in FY99 and FY00. (UQ) LA0307RR831222.002. Chloride, Bromide, Sulfate, and Chlorine-36 Analyses of Salts Leached from ESF Chlorine-36 Validation Drillcore Samples in FY99. (UQ) LA0509JF831222.001. Chlorine-36 Analyses of Salts Leached from ESF Niche #3566 (Niche #1) Drillcore. (Q) LAJF831222AQ98.004. Chloride, Bromide, Sulfate, and Chlorine-36 Analyses of Salts Leached from ESF Rock Samples. (Q) LL030408023121.027. Cl Abundance and Cl Ratios of Leachates from ESF Core Samples. (Q) LL031200223121.036. Cl Abundance and Cl Ratio of Leachates from ESF Core Samples. (Q) APPENDIX A CHLORIDE CONCENTRATIONS AND CHLORINE-36/CHLORIDE RATIOS IN SALTS LEACHED FROM EXPLORATORY STUDIES FACILITY ROCK SAMPLES AT LOS ALAMOS NATIONAL LABORATORY AS OF SEPTEMBER 8, 1998 INTENTIONALLY LEFT BLANK Chloride Concentrations and Chlorine-36/Chloride Ratios in Salts Leached From Exploratory Studies Facility Rock Samples at Los Alamos National Laboratory as of September 8, 1998 Sample Number SMF Barcode Number Location (approximate) Sample Type Material Year Reported Leachate Cl Conc. (mg/kg) AgCl Target Identifier Corrected 36Cl/Cl (x1015) E001-1 SPC00507923 01+98 Bow Ridge fault zone Wall rock 1996 2 YM401 518 ±20 E008-2 SPC00509016 01+99.8 Bow Ridge fault zone Breccia 1996 2.6 YM336 2138 ±137 E009-2 SPC00509017 01+99.8 Bow Ridge fault zone Breccia 1996 2 YM337 2444 ±169 E010-2 SPC00509018 01+99.8 Bow Ridge fault zone Rubble 1996 2.3 YM338 720 ±49 E011-2 SPC00509019 01+99.8 Bow Ridge fault zone Rubble 1996 2 YM339 2378 ±153 E012-2 SPC00509020 01+99.8 Bow Ridge fault zone Breccia 1996 2.1 YM340 2398 ±154 E243-1 SPC00509751 01+99.8 Bow Ridge fault zone Breccia 1996 4.4 YM596 381 ±16 E163-3 SPC00512551 04+94 Systematic Representative bulk material 1996 2.4 YM529 485 ±12 E073-1 SPC00504280 05+04 Fracture Breccia 1996 5.6 YM438 468 ±19 E074-1 SPC00503866 05+05.5 Fracture Breccia 1996 11.8 YM424 493 ±17 E164-3 SPC00512550 07+00 Systematic Representative bulk material 1996 0.6 YM530 571 ±35 E165-3 SPC00512549 07+70 Subunit contact Representative bulk material 1996 2.9 YM531 496 ±14 E166-3 SPC00512548 07+70 Subunit contact Representative bulk material 1996 12.2 YM527 484 ±15 E167-3 SPC00512547 07+70 Subunit contact Representative bulk material 1996 24.1 YM528 427 ±13 E168-3 SPC00512546 08+59 Subunit contact Representative bulk material 1996 0.8 YM552 802 ±29 E169-3 SPC00512545 08+59 Subunit contact Representative bulk material 1996 0.6 YM553 1096 ±40 E170-3 SPC00512544 08+59 Subunit contact Representative bulk material 1996 1.1 YM554 635 ±23 E191-2 SPC00515104 08+75 Subunit contact Representative bulk material 1996 0.9 YM572 904 ±28 E192-2 SPC00515105 08+75 Subunit contact Representative bulk material 1996 0.8 YM573 698 ±20 E193-2 SPC00515106 08+75 Subunit contact Representative bulk material 1996 1.5 YM574 748 ±21 E171-1 SPC00512554 08+90 Subunit contact Representative bulk material 1996 0.7 YM555 1335 ±56 E172-3 SPC00512553 08+90 Subunit contact Representative bulk material 1996 0.6 YM557 637 ±26 E174-3 SPC00512543 09+00 Systematic Representative bulk material 1996 0.6 YM559 660 ±29 E194-2 SPC00512586 10+56 Subunit contact Representative bulk material 1996 0.7 YM575 1354 ±45 E195-2 SPC00512587 10+56 Subunit contact Representative bulk material 1996 0.8 YM576 1292 ±37 TDR-NBS-HS-000017 REV00 A3 Chloride Concentrations and Chlorine-36/Chloride Ratios in Salts Leached From Exploratory Studies Facility Rock Samples at Los Alamos National Laboratory as of September 8, 1998 Sample Number SMF Barcode Number Location (approximate) Sample Type Material Year Reported Leachate Cl Conc. (mg/kg) AgCl Target Identifier Corrected 36Cl/Cl (x1015) E195-2 SPC00512587 10+56 Subunit contact Representative bulk material 1996 0.8 YM576 1292 ±37 E197-2 SPC00512585 10+62.5 Subunit contact Representative bulk material 1996 0.1 YM578 1452 ±72 E086-1 SPC00510583 11+43 Bedrock Representative bulk material 1996 0.7 YM439 640 ±29 E213-1 SPC00510792 12+36.5 Fracture Breccia 1996 0.3 YM598 719 ±68 E028-1 SPC00503934 12+44 Cooling joints Representative bulk material 1996 0.2 YM452 2629 ±105 E214-1 SPC00510790 12+44 Cooling joints Representative bulk material 1996 0.5 YM599 751 ±27 E215-1 SPC00510791 12+49 Cooling joints Representative bulk material 1996 0.4 YM600 668 ±54 E029-1 SPC00503932 13+00 Systematic Representative bulk material 1996 0.6 YM426 640 ±28 E030-2 SPC00503931 13+67 Cooling joints Breccia < 0.5 cm 1996 0.5 YM563 1634 ±85 E031-3 SPC00503930 14+00 Shear zone Breccia < 1 cm 1996 0.7 YM564 2399 ±191 E032-2 SPC00503929 14+14 Shear zone Representative bulk material 1996 0.8 YM454 680 ±45 E033-1 SPC00503928 14+41 Fault Gouge 1996 0.3 YM427 876 ±42 E034-1 SPC00503926 15+00 Systematic Representative bulk material 1996 0.3 YM428 954 ±51 E035-1 SPC00503925 15+05 Fracture Breccia 1996 1 YM429 628 ±61 E036-1 SPC00509242 16+12 Cooling joint Representative bulk material 1996 1.4 YM455 382 ±57 E037-2 SPC00509241 16+19 Fracture Representative bulk material 1996 0.5 YM430 982 ±42 E038-1 SPC00503924 17+00 Systematic Representative bulk material 1996 0.4 YM450 714 ±38 E040-1 SPC00503922 18+96 Broken rock Representative bulk material 1996 0.6 YM456 1642 ±59 E041-1 SPC00503921 19+00 Systematic Representative bulk material 1996 0.6 YM431 746 ±27 E042-2 SPC00503920 19+31 Fault zone Breccia > ~0.5 cm 1996 0.6 YM457 3023 ±94 E042-3 SPC00503920 19+31 Fault zone Breccia < ~0.5 cm 1996 0.6 YM458 1838 ±65 E043-2 SPC00503919 19+37 Fault zone Representative bulk material 1996 0.8 YM459 1144 ±36 E044-2 SPC00503918 19+42 Breccia zone Representative bulk material 1996 0.6 YM460 2290 ±74 E045-1 SPC00503917 21+00 Systematic Representative bulk material 1996 0.6 YM432 799 ±29 E046-1 SPC00503916 22+71 Fracture zone Representative bulk material 1996 1 YM461 864 ±44 TDR-NBS-HS-000017 REV00 A4 Chloride Concentrations and Chlorine-36/Chloride Ratios in Salts Leached From Exploratory Studies Facility Rock Samples at Los Alamos National Laboratory as of September 8, 1998 Sample Number SMF Barcode Number Location (approximate) Sample Type Material Year Reported Leachate Cl Conc. (mg/kg) AgCl Target Identifier Corrected 36Cl/Cl (x1015) E047-1 SPC00509247 23+00 Systematic Representative bulk material 1996 0.8 YM451 663 ±37 E050-2 SPC00509240 24+40 Fault zone Breccia 1996 0.4 YM462 2579 ±94 E020-1 SPC00509220 24+68 Fracture Representative bulk material 1996 0.6 YM448 814 ±56 E051-1 SPC00509259 25+00 Systematic Representative bulk material 1996 0.5 YM433 1003 ±49 E217-1 SPC00510716 26+19 Cooling joints Representative bulk material 1996 0.7 YM602 522 ±21 E218-1 SPC00510714 26+36 Fracture Representative bulk material 1996 1.2 YM603 603 ±20 E219-1 SPC00510713 26+46 Fracture Representative bulk material 1996 0.4 YM604 578 ±38 E052-1 SPC00509244 26+79 Shear zone Representative bulk material 1996 0.4 YM463 2036 ±68 E220-1 SPC00510719 26+79 Fracture Representative bulk material 1996 1.3 YM605 564 ±25 E054-1 SPC00509257 27+00 Systematic Representative bulk material 1996 0.4 YM434 973 ±29 E056-1 SPC00509243 27+18 Fault Representative bulk material 1996 0.4 YM565 1709 ±53 E057-2 SPC00509238 27+50 Fracture Breccia 1996 1.3 YM435 779 ±23 E058-2 SPC00509237 27+66 Fault Breccia 1996 1.4 YM436 458 ±19 E059-2 SPC00509236 28+40 Fault Breccia 1996 2.1 YM437 512 ±21 E141-1 SPC00503947 29+00 Systematic Representative bulk material 1996 0.4 YM464 922 ±36 E142-1 SPC00503983 29+21 Fracture Representative bulk material 1996 0.5 YM493 583 ±28 E143-1 SPC00503948 29+65 Fault Representative bulk material 1996 0.4 YM494 1077 ±162 E144-1 SPC00503949 29+73 Cooling joint Representative bulk material 1996 0.2 YM495 815 ±34 E147-1 SPC00503976 30+27 Cooling joints Representative bulk material 1996 1.7 YM496 490 ±15 E149-1 SPC00503973 31+64 Cooling joint Representative bulk material 1996 0.7 YM465 631 ±29 E150-1 SPC00503939 33+00 Systematic Representative bulk material 1996 0.2 YM473 1341 ±56 E152-1 SPC00503993 34+28 Fractures Representative bulk material 1996 0.3 YM478 4105 ±310 E153-3 SPC00503938 34+32 Cooling joints Representative bulk material 1996 0.2 YM479 3261 ±160 E154-1 SPC00503937 34+71 Cooling joints Breccia 1996 0.3 YM474 803 ±41 E154-3 SPC00503937 34+71 Cooling joints Wall rock 1996 0.2 YM480 3794 ±120 TDR-NBS-HS-000017 REV00 A5 Chloride Concentrations and Chlorine-36/Chloride Ratios in Salts Leached From Exploratory Studies Facility Rock Samples at Los Alamos National Laboratory as of September 8, 1998 Sample Number SMF Barcode Number Location (approximate) Sample Type Material Year Reported Leachate Cl Conc. (mg/kg) AgCl Target Identifier Corrected 36Cl/Cl (x1015) E156-1 SPC00503969 35+00 Cooling joints Representative bulk material 1996 1 YM467 626 ±29 E155-1 SPC00503980 35+00 Systematic Representative bulk material 1996 0.5 YM466 1013 ±60 E157-3 SPC00503994 35+03 Cooling joints Representative bulk material 1996 0.5 YM566 1339 ±76 E158-1 SPC00503995 35+08 Cooling joints Breccia < ~0.5 cm 1996 0.7 YM475 1113 ±58 E158-3 SPC00503995 35+08 Cooling joints Breccia > ~0.5 cm 1996 0.5 YM492 2671 ±158 E160-1 SPC00503979 35+45 Cooling joints Representative bulk material 1996 0.3 YM481 3529 ±205 E161-3 SPC00503999 35+58 Cooling joint Breccia > ~0.5 cm 1996 0.5 YM501 2169 ±80 E175-1 SPC00512511 35+93 Fault Breccia > ~0.5 cm 1996 0.3 YM514 2840 ±231 E175-3 SPC00512511 35+93 Fault Breccia < ~0.5 cm 1996 0.3 YM515 1674 ±141 E176-1 SPC00512506 36+55 Fault Breccia > ~0.5 cm 1996 0.9 YM516 888 ±27 E176-3 SPC00512506 36+55 Fault Breccia < ~0.5 cm 1996 1 YM517 604 ±25 E177-1 SPC00512510 37+00 Systematic Representative bulk material 1996 0.9 YM518 484 ±15 E178-1 SPC00512504 37+60 Cooling joint Gouge 1996 1.8 YM503 471 ±26 E179-1 SPC00512509 37+68 Cooling joint Breccia 1996 1.5 YM504 363 ±22 E179-3 SPC00512509 37+68 Cooling joint Wall rock 1996 1.5 YM519 397 ±13 E182-1 SPC00512502 38+79 Fracture Breccia 1996 0.4 YM505 379 ±38 E183-1 SPC00512517 38+95 Cooling joint Breccia 1996 0.4 YM506 745 ±39 E184-1 SPC00512508 39+00 Systematic Representative bulk material 1996 0.2 YM520 536 ±29 E185-1 SPC00503944 39+39 Frac/lith cavity Representative bulk material 1996 0.3 YM521 897 ±46 E186-1 SPC00503943 39+47 Cooling joint Breccia/gouge 1996 0.5 YM507 561 ±34 E187-1 SPC00503946 39+61 Cooling joint Breccia/gouge 1996 0.9 YM508 540 ±33 E221-1 SPC00510710 41+00 Systematic Representative bulk material 1996 0.6 YM606 773 ±24 E198-2 SPC00510700 41+65 Cooling joint Representative bulk material 1996 1.9 YM584 291 ±12 E199-2 SPC00512590 43+00 Systematic Representative bulk material 1996 0.3 YM585 1042 ±53 E200-2 SPC00512589 43+39 Fault Gouge 1996 0.3 YM586 967 ±66 TDR-NBS-HS-000017 REV00 A6 Chloride Concentrations and Chlorine-36/Chloride Ratios in Salts Leached From Exploratory Studies Facility Rock Samples at Los Alamos National Laboratory as of September 8, 1998 Sample Number SMF Barcode Number Location (approximate) Sample Type Material Year Reported Leachate Cl Conc. (mg/kg) AgCl Target Identifier Corrected 36Cl/Cl (x1015) E201-2 SPC00512591 43+63 Cooling joint Representative bulk material 1996 0.4 YM587 1974 ±65 E202-2 SPC00512592 44+20 Cooling joint Representative bulk material 1996 0.6 YM588 3463 ±97 E203-2 SPC00512593 44+21 Cooling joint Representative bulk material 1996 0.4 YM589 849 ±34 E204-2 SPC00512594 44+22 Cooling joint Representative bulk material 1996 0.6 YM590 772 ±31 E205-2 SPC00512595 45+00 Systematic Representative bulk material 1996 0.3 YM591 1514 ±69 E207-2 SPC00512597 45+79 Cooling joint Representative bulk material 1996 1.6 YM592 593 ±15 E211-2 SPC00515107 Alc 4/0+51.58 Subunit contact Representative bulk material 1996 2.1 YM594 810 ±24 E210-2 SPC00515109 Alc 4/0+51.58 Subunit contact Representative bulk material 1996 4.3 YM593 712 ±31 E212-2 SPC00515108 Alc 4/0+51.58 Subunit contact Representative bulk material 1996 2.9 YM597 815 ±18 E007-2 SPC00507924 02+03 Fault zone Wall rock 1997 3.4 YM402 519 ±13 E188-2 SPC00515100 08+26.5 Subunit contact Representative bulk material 1997 2.2 YM569 766 ±24 E189-2 SPC00515101 08+26.5 Subunit contact Representative bulk material 1997 4.3 YM570 625 ±17 E190-2 SPC00515102 08+26.5 Subunit contact Representative bulk material 1997 6.3 YM571 647 ±14 E244-1 SPC00515135 08+38 Fault Representative bulk material 1997 1.5 YM654 488 ±17 E245-1 SPC00515136 08+44 Fracture Representative bulk material 1997 1.7 YM655 530 ±21 E246-1 SPC00515137 08+66 Fault Representative bulk material 1997 0.8 YM656 475 ±17 E247-1 SPC00515138 09+32 Fault Representative bulk material 1997 0.6 YM657 509 ±22 E126-1 SPC00509155 10+34 Fault zone Representative bulk material 1997 0.8 YM671 633 ±41 E128-1 SPC00509147 10+40 Fault zone Representative bulk material 1997 1.5 YM672 662 ±27 E130-1 SPC00509150 10+41 Fault zone Representative bulk material 1997 0.7 YM673 773 ±40 E196-2 SPC00512588 10+56 Subunit contact Representative bulk material 1997 0.4 YM577 1202 ±27 E134-1 SPC00510506 10+66 Fault Representative bulk material 1997 1.8 YM728 747 ±41 E136-1 SPC00510505 10+66.8 Fault Representative bulk material 1997 2.5 YM729 801 ±33 E139-1 SPC00510510 10+74.2 Fault Representative bulk material 1997 1.4 YM730 738 ±52 E248-1 SPC00515139 10+75 Fault Representative bulk material 1997 0.5 YM658 570 ±37 TDR-NBS-HS-000017 REV00 A7 Chloride Concentrations and Chlorine-36/Chloride Ratios in Salts Leached From Exploratory Studies Facility Rock Samples at Los Alamos National Laboratory as of September 8, 1998 Sample Number SMF Barcode Number Location (approximate) Sample Type Material Year Reported Leachate Cl Conc. (mg/kg) AgCl Target Identifier Corrected 36Cl/Cl (x1015) E249-1 SPC00515142 11+00 Systematic Representative bulk material 1997 0.5 YM659 657 ±37 E027-3 SPC00503935 11+00 Systematic Representative bulk material 1997 0.3 YM749 1076 ±52 E249-3 SPC00515142 11+00 Systematic Representative bulk material 1997 0.4 YM733 672 ±46 E249-4 SPC00515142 11+00 Systematic Representative bulk material 1997 1 YM734 912 ±58 E250-1 SPC00515140 11+43 Fault Representative bulk material 1997 0.4 YM660 532 ±35 E251-1 SPC00515141 11+77 Fault Representative bulk material 1997 0.5 YM661 633 ±38 E030-1 SPC00503931 13+67 Cooling joints Breccia < 0.5 cm 1997 1 YM449 698 ±35 E031-1 SPC00503930 14+00 Shear zone Breccia > 1 cm 1997 0.6 YM453 1039 ±35 E216-1 SPC00510788 20+71 Fracture Representative bulk material 1997 1.2 YM601 840 ±38 E046-4 SPC00503916 22+71 Fracture zone Representative bulk material 1997 1.1 PRIME 458 ±24 E146-4 SPC00503987 30+18 Lith cavity Representative bulk material 1997 1.8 PRIME 496 ±24 E151-4 SPC00503990 33+16 Lith cavity Representative bulk material 1997 2.3 PRIME 529 ±24 E160-4 SPC00503979 35+45 Cooling joints Representative bulk material 1997 1.8 PRIME 388 ±17 E161-1 SPC00503999 35+58 Cooling joint Breccia < ~0.5 cm 1997 0.8 YM476 1951 ±103 E222-1 SPC00510724 42+55 Shear sets Gouge 1997 3.8 YM608 605 ±18 E222-2 SPC00510724 42+55 Shear sets Wall rock 1997 2.9 YM609 531 ±16 E206-1 SPC00512596 45+78 Fracture zone Representative bulk material 1997 1.6 YM731 525 ±29 E208-1 SPC00515103 46+18 Fault Breccia 1997 1.9 YM732 497 ±26 E223-1 SPC00510728 47+00 Systematic Representative bulk material 1997 0.3 YM610 734 ±37 E225-1 SPC00510731 48+56 Cooling joints Breccia 1997 1.2 YM612 350 ±14 E224-1 SPC00510734 49+00 Systematic Representative bulk material 1997 1.7 YM611 499 ±16 E226-1 SPC00510737 49+56 Cooling joint Breccia 1997 1.1 YM613 450 ±20 E226-2 SPC00510737 49+56 Cooling joint Wall rock 1997 1 YM614 456 ±20 E227-1 SPC00510705 49+89 Cooling joints Breccia 1997 0.5 YM615 497 ±33 E230-1 SPC00510739 51+00 Systematic Representative bulk material 1997 0.5 YM625 555 ±23 TDR-NBS-HS-000017 REV00 A8 Chloride Concentrations and Chlorine-36/Chloride Ratios in Salts Leached From Exploratory Studies Facility Rock Samples at Los Alamos National Laboratory as of September 8, 1998 Sample Number SMF Barcode Number Location (approximate) Sample Type Material Year Reported Leachate Cl Conc. (mg/kg) AgCl Target Identifier Corrected 36Cl/Cl (x1015) E231-1 SPC00510740 51+07 Cooling joints Wall rock 1997 0.5 YM626 709 ±30 E231-2 SPC00510740 51+07 Cooling joints Breccia 1997 0.5 YM627 530 ±26 E232-1 SPC00510741 51+33 Cooling joints Representative bulk material 1997 0.4 YM628 942 ±42 E233-1 SPC00510742 51+73 Fracture Representative bulk material 1997 0.3 YM629 647 ±30 E234-1 SPC00510743 52+43 Cooling joint Representative bulk material 1997 0.5 YM630 291 ±26 E235-1 SPC00510744 52+46 Cooling joint Representative bulk material 1997 0.3 YM631 596 ±43 E236-1 SPC00510745 53+00 Systematic Representative bulk material 1997 0.7 YM632 417 ±17 E237-1 SPC00510746 53+61 Cooling joint Representative bulk material 1997 0.4 YM633 539 ±27 E238-1 SPC00510747 54+20 Cooling joint Breccia 1997 1.3 YM634 727 ±37 E239-1 SPC00510748 55+00 Systematic Representative bulk material 1997 0.3 YM635 464 ±23 E240-1 SPC00510756 56+63 Cooling joint Breccia 1997 0.3 YM636 673 ±42 E241-1 SPC00510754 56+85 Cooling joint Breccia 1997 0.7 YM637 777 ±38 E242-1 SPC00510750 56+93 Cooling joint Breccia >2 mm 1997 0.7 YM638 664 ±30 E242-2 SPC00510750 56+93 Cooling joint Breccia <2 mm 1997 0.9 YM639 1117 ±49 E252-1 SPC00515143 57+00 Systematic Representative bulk material 1997 0.7 YM641 388 ±23 E253-1 SPC00515144 57+27 Fault Representative bulk material 1997 1.7 YM642 483 ±14 E254-1 SPC00515145 58+66 Fault Breccia 1997 0.5 YM643 588 ±58 E255-1 SPC00515146 58+77 Subunit contact Representative bulk material 1997 3 YM644 140 ±9 E256-1 SPC00515147 59+00 Systematic Breccia 1997 0.5 YM645 347 ±41 E256-3 SPC00515147 59+00 Systematic Wall rock 1997 1.7 YM675 359 ±23 E290-1 SPC00521128 59+98 Systematic Representative bulk material 1997 0.6 YM711 205 ±14 E257-1 SPC00515148 61+00 Systematic Representative bulk material 1997 1.2 YM646 428 ±26 E258-1 SPC00515149 61+92 Fracture Representative bulk material 1997 0.8 YM647 276 ±21 E259-1 SPC00515150 62+00 Systematic Representative bulk material 1997 0.5 YM648 409 ±28 E260-1 SPC00515151 62+05 Fault Representative bulk material 1997 1.2 YM649 261 ±13 TDR-NBS-HS-000017 REV00 A9 Chloride Concentrations and Chlorine-36/Chloride Ratios in Salts Leached From Exploratory Studies Facility Rock Samples at Los Alamos National Laboratory as of September 8, 1998 Sample Number SMF Barcode Number Location (approximate) Sample Type Material Year Reported Leachate Cl Conc. (mg/kg) AgCl Target Identifier Corrected 36Cl/Cl (x1015) E261-1 SPC00515152 62+18 Fault Representative bulk material 1997 0.5 YM650 749 ±39 E262-1 SPC00515153 62+71 Shear Representative bulk material 1997 0.4 YM651 420 ±28 E263-1 SPC00515154 63+00 Systematic Representative bulk material 1997 3 YM662 465 ±14 E264-1 SPC00515155 63+06 Fracture Representative bulk material 1997 1.7 YM663 458 ±13 E265-1 SPC00515156 63+21 Fracture Representative bulk material 1997 3.3 YM664 452 ±12 E266-1 SPC00515157 63+26 Fracture Representative bulk material 1997 3.7 YM676 486 ±16 E267-1 SPC00515158 63+30 Fault Representative bulk material 1997 3.7 YM677 427 ±14 E269-1 SPC00515188 63+73 Fracture Representative bulk material 1997 2.5 YM698 551 ±14 E270-1 SPC00515187 63+81 Fracture Representative bulk material 1997 3.6 YM678 439 ±14 E271-1 SPC00515186 64+00 Systematic Representative bulk material 1997 3.2 YM699 467 ±20 E271-1D SPC00515186 64+00 Systematic Representative bulk material 1997 3.2 YM707 438 ±18 E272-1 SPC00515185 64+34 Broken rock Representative bulk material 1997 1.4 YM679 467 ±22 E273-1 SPC00515184 64+50 Broken rock Representative bulk material 1997 1.4 YM700 610 ±22 E274-1 SPC00515182 64+93 Fracture Representative bulk material 1997 2.9 YM701 491 ±25 E275-1 SPC00515181 65+00 Systematic Representative bulk material 1997 1.8 YM684 443 ±19 E268-1 SPC00515180 65+20 Fracture zone Breccia 1997 1.7 YM683 468 ±18 E276-1 SPC00515179 65+56 Fracture zone Breccia 1997 1.6 YM702 480 ±14 E277-1 SPC00515178 65+80 Fracture zone Representative bulk material 1997 2 YM685 424 ±33 E278-1 SPC00515177 66+00 Systematic Representative bulk material 1997 1.5 YM703 520 ±61 E279-1 SPC00515176 66+15 Fault Breccia 1997 1.3 YM686 402 ±40 E280-1 SPC00515175 66+40 Fault Representative bulk material 1997 0.3 YM687 238 ±30 E281-1 SPC00515174 67+00 Systematic Representative bulk material 1997 2.3 YM688 453 ±18 E283-1 SPC00515172 67+27 Fault Representative bulk material 1997 3 YM689 470 ±21 E284-3 SPC00515173 67+35 Subunit contact Representative bulk material 1997 1.3 YM710 509 ±20 E284-1 SPC00515173 67+35 Subunit contact Representative bulk material 1997 1.8 YM709 502 ±19 TDR-NBS-HS-000017 REV00 A10 Chloride Concentrations and Chlorine-36/Chloride Ratios in Salts Leached From Exploratory Studies Facility Rock Samples at Los Alamos National Laboratory as of September 8, 1998 Sample Number SMF Barcode Number Location (approximate) Sample Type Material Year Reported Leachate Cl Conc. (mg/kg) AgCl Target Identifier Corrected 36Cl/Cl (x1015) E289-1 SPC00515170 67+61 Fault Gouge 1997 4.4 YM692 589 ±23 E285-1 SPC00515171 67+73 Damp zone Representative bulk material 1997 4.8 YM680 468 ±23 E286-4 SPC00515133 67+87 Fault zone Wall rock 1997 0.7 YM704 645 ±29 E286-1 SPC00515133 67+87 Fault zone Clay fracture filling 1997 2.2 YM690 475 ±22 E287-1 SPC00515134 67+87 Fault Breccia 1997 2.3 YM691 517 ±19 E288-1 SPC00515132 67+90 Fault footwall Wall rock 1997 1.1 YM681 557 ±31 E298-1 SPC00521127 68+00 Systematic Representative bulk material 1997 1.4 YM718 606 ±17 E292-1 SPC00521123 69+00 Systematic Representative bulk material 1997 3.1 YM712 414 ±17 E293-1 SPC00521122 69+14.5 Fault zone Breccia 1997 2.7 YM713 454 ±35 E294-1 SPC00521121 69+32.5 Fracture Breccia 1997 1.7 YM714 474 ±22 E295-1 SPC00521120 69+41.7 Fracture zone Representative bulk material 1997 1.9 YM715 476 ±21 E299-1 SPC00522221 69+47 Systematic Representative bulk material 1997 2.1 YM750 441 ±20 E300-1 SPC00522220 69+68 Fault (?) Representative bulk material 1997 2.5 YM763 354 ±13 E300-3 SPC00522220 69+68 Fault (?) Representative bulk material 1997 2.3 YM764 376 ±16 E302-1 SPC00522218 70+19 Fault Representative bulk material 1997 5.8 YM736 327 ±13 E303-1 SPC00522217 70+36 Fault Representative bulk material 1997 2.3 YM751 439 ±17 E304-1 SPC00522216 70+50 Systematic Representative bulk material 1997 5.1 YM765 491 ±21 E305-1 SPC00522215 70+55.5 Fault Breccia 1997 4.4 YM752 386 ±12 E306-1 SPC00522214 70+66 Fault Breccia 1997 3.3 YM766 499 ±19 E307-1 SPC00522212 71+34 Fault Representative bulk material 1997 0.7 YM737 557 ±29 E308-1 SPC00522213 71+39 Fault Representative bulk material 1997 1.1 YM753 492 ±13 E309-1 SPC00522211 71+41 Fault Representative bulk material 1997 1 YM767 445 ±21 E310-1 SPC00522210 71+50 Systematic Representative bulk material 1997 1 YM768 441 ±21 E311-1 SPC00522209 72+50 Systematic Representative bulk material 1997 2.4 YM754 459 ±11 E312-1 SPC00522208 72+69 Fault Representative bulk material 1997 1.6 YM769 463 ±18 TDR-NBS-HS-000017 REV00 A11 Chloride Concentrations and Chlorine-36/Chloride Ratios in Salts Leached From Exploratory Studies Facility Rock Samples at Los Alamos National Laboratory as of September 8, 1998 Sample Number SMF Barcode Number Location (approximate) Sample Type Material Year Reported Leachate Cl Conc. (mg/kg) AgCl Target Identifier Corrected 36Cl/Cl (x1015) E313-1 SPC00522207 73+48 Systematic Representative bulk material 1997 3.8 YM770 367 ±14 E315-1A SPC00522205 74+49 Systematic Representative bulk material 1997 11.5 YM738 435 ±16 E316-1 SPC00522202 74+89 Fault Representative bulk material 1997 5.9 YM755 459 ±11 E317-1 SPC00522201 75+09 Subunit contact Representative bulk material 1997 1.8 YM740 402 ±30 E318-1 SPC00522203 75+09.5 Subunit contact Representative bulk material 1997 2.3 YM756 395 ±16 E319-1 SPC00522204 75+10 Subunit contact Representative bulk material 1997 3.6 YM741 414 ±16 E321-1 SPC00521287 75+34 Fault Breccia 1997 6.1 YM757 476 ±12 E323-1 SPC00521289 75+53.5 Cooling joints Breccia 1997 3.4 YM742 465 ±17 E323-3 SPC00521289 75+53.5 Cooling joints Wall rock 1997 4.4 YM743 413 ±19 E324-1 SPC00521290 75+78 Fault Breccia 1997 5.4 YM744 418 ±31 E324-3 SPC00521290 75+78 Fault Wall rock 1997 4.5 YM745 322 ±13 E325-1 SPC00521291 76+30 Fault Breccia 1997 2.3 YM771 380 ±20 E326-1 SPC00521292 76+31 Fault Wall rock 1997 4.7 YM758 423 ±9 E326-3 SPC00521292 76+31 Fault Wall rock 1997 3.4 YM759 419 ±11 E327-1 SPC00521295 76+50 Systematic Representative bulk material 1997 2.4 YM772 281 ±12 E328-1 SPC00521294 76+76 Fault Breccia < ~1 cm 1997 1.3 YM746 334 ±15 E328-3 SPC00521294 76+76 Fault Breccia > ~1 cm 1997 0.6 YM747 445 ±20 E329-1 SPC00521293 77+10 Fault Representative bulk material 1997 0.5 YM773 394 ±19 E228-1 SPC00510795 Alc 2/0+25 Drill & blast Representative bulk material 1997 0.7 YM674 362 ±41 E229-1 SPC00510702 Alc 3/014 Intact bedrock Representative bulk material 1997 3.4 YM616 558 ±19 E296-1 SPC00521129 Alc 6/0+95 Fault Representative bulk material 1997 1.6 YM716 533 ±52 E297-1 SPC00521130 Alc 6/0+98 Fault Representative bulk material 1997 1.8 YM717 499 ±27 E044-4 SPC00503918 19+42 Breccia zone Representative bulk material 1998 0.7 YM775 4270 ±159 E160-7 SPC00503979 35+45 Cooling joints Representative bulk material 1998 0.2 YM776 1704 ±76 E301-1 SPC00522219 69+95.8 Fault Representative bulk material 1998 0.6 YM777 224 ±11 TDR-NBS-HS-000017 REV00 A12 Chloride Concentrations and Chlorine-36/Chloride Ratios in Salts Leached From Exploratory Studies Facility Rock Samples at Los Alamos National Laboratory as of September 8, 1998 Sample Number SMF Barcode Number Location (approximate) Sample Type Material Year Reported Leachate Cl Conc. (mg/kg) AgCl Target Identifier Corrected 36Cl/Cl (x1015) E306-3 SPC00522214 70+66 Fault Representative bulk material 1998 3.3 YM778 496 ±20 E314-1 SPC00522206 74+43 Fracture Representative bulk material 1998 2.1 YM779 341 ±18 E352-1 SPC00524963 74+55.5 Fault Representative bulk material 1998 3.2 YM883 484 ±21 E320-1 SPC00522200 75+20 Subunit contact Representative bulk material 1998 3.7 YM780 457 ±20 E322-1 SPC00521288 75+47.5 Systematic Representative bulk material 1998 2.9 YM781 318 ±81 E353-1 SPC00524964 76+01 Fracture Representative bulk material 1998 2.9 YM884 515 ±19 E354-1 SPC00524965 76+08 Fracture Breccia 1998 1.9 YM885 616 ±21 E355-1 SPC00524971 76+11.5 Fault Wall rock 1998 3.7 YM886 473 ±18 E356-1 SPC00524966 76+11.5 Fault Gouge 1998 1.8 YM887 570 ±24 E335-1 SPC00524901 77+19 Fracture Representative bulk material 1998 1.9 YM812 186 ±9 E357-1 SPC00524967 77+29.5 Broken rock Representative bulk material 1998 0.6 YM888 621 ±26 E358-1 SPC00524968 77+31 Broken rock Representative bulk material 1998 0.7 YM889 341 ±14 E359-1 SPC00524969 77+49.5 Systematic Representative bulk material 1998 4.2 YM890 511 ±23 E360-1 SPC00524970 78+50 Systematic Representative bulk material 1998 1.6 YM891 973 ±27 E337-1 SPC00525144 Alc 6/0+30 Systematic Representative bulk material 1998 0.9 YM858 666 ±24 E338-1 SPC00525145 Alc 6/0+60 Systematic Representative bulk material 1998 0.8 YM859 689 ±22 E339-1 SPC00525130 Alc 6/0+82 Breccia zone Representative bulk material 1998 0.6 YM860 703 ±36 E340-1 SPC00525131 Alc 6/0+93 Breccia zone Representative bulk material 1998 0.6 YM861 1511 ±48 E341-1 SPC00525132 Alc 6/0+97 Fault Gouge 1998 0.5 YM840 513 ±23 E342-1 SPC00525135 Alc 6/1+00 Breccia zone Representative bulk material 1998 0.7 YM841 927 ±35 E343-1 SPC00525136 Alc 6/1+05 Fracture zone Representative bulk material 1998 0.9 YM842 1080 ±33 E344-1 SPC00525137 Alc 6/1+10 Fault Representative bulk material 1998 1.5 YM843 884 ±32 E345-1 SPC00525138 Alc 6/1+17 Fault Representative bulk material 1998 0.9 YM844 1081 ±37 E346-1 SPC00525139 Alc 6/1+24 Fracture Representative bulk material 1998 1.1 YM845 1130 ±38 E347-1 SPC00525140 Alc 6/1+40 Fault Representative bulk material 1998 1.3 YM862 455 ±23 TDR-NBS-HS-000017 REV00 A13 Chloride Concentrations and Chlorine-36/Chloride Ratios in Salts Leached From Exploratory Studies Facility Rock Samples at Los Alamos National Laboratory as of September 8, 1998 Sample Number SMF Barcode Number Location (approximate) Sample Type Material Year Reported Leachate Cl Conc. (mg/kg) AgCl Target Identifier Corrected 36Cl/Cl (x1015) E348-1 SPC00530000 Alc 6/1+52 Fault Breccia 1998 0.5 YM846 1250 ±65 E349-1 SPC00525141 Alc 6/1+52 Fault Wall rock 1998 0.5 YM847 3357 ±132 E333-1 SPC00524960 Alc 6/1+53 Fault Representative bulk material 1998 0.5 YM809 521 ±32 E333-2 SPC00524960 Alc 6/1+53 Fault Representative bulk material 1998 0.5 YM810 497 ±23 E350-1 SPC00525142 Alc 6/1+60 Cooling joints Representative bulk material 1998 0.5 YM848 1699 ±70 E351-1 SPC00525143 Alc 6/1+68 Broken rock Representative bulk material 1998 0.3 YM849 1792 ±77 E351-2 SPC00525143 Alc 6/1+68 Broken rock Representative bulk material 1998 0.3 YM850 499 ±20 E334-1 SPC00524959 Alc 7/1+30 Fracture Representative bulk material 1998 1.2 YM811 474 ±16 E361-1 SPC00524975 Alc 7/1+54.5 Fault Representative bulk material 1998 0.9 YM911 539 ±24 E362-1 SPC00524973 Alc 7/1+67 Fault Representative bulk material 1998 2.1 YM912 541 ±25 E363-1 SPC00524974 Alc 7/1+67.5 Fault Representative bulk material 1998 1.9 YM913 643 ±29 E364-1 SPC00524976 Alc 7/1+84 Fault Representative bulk material 1998 1.1 YM914 569 ±27 E365-1 SPC00524972 Alc 7/2+00 Fault Representative bulk material 1998 1.9 YM915 538 ±26 DCN0862 SPC01003078 ESF-MDNICHE3566# 1 (22.223.0) NA NA 1998 NA YM903 1372 ±69 DCN0072/ 008-1 SPC01003096 SPC01003097 SPC01003098 ESF-MDNICHE3566# 1 (32.133.1) NA NA 1998 NA YM894 2008 ±90 DCN0241/ 025-2 SPC01003131 SPC01003132 SPC01003133 ESF-MDNICHE3566# 2 (15.717.1) NA NA 1998 NA YM896 2038 ±99 DCN0152 SPC01003111 ESF-MDNICHE3566# 2 (6.77.5) NA NA 1998 NA YM895 1235 ±62 DCN0381/ 039-2 SPC01004399 SPC01004400 SPC01004401 SPC01004402 ESF-MDNICHE3566LT# 1 (1.75.0) NA NA 1998 NA YM897 997 ±49 DCN0481/ 049-2 SPC01004420 SPC01004421 ESF-MDNICHE3566LT# 1 NA NA 1998 NA YM898 1476 ±75 TDR-NBS-HS-000017 REV00 A14 Chloride Concentrations and Chlorine-36/Chloride Ratios in Salts Leached From Exploratory Studies Facility Rock Samples at Los Alamos National Laboratory as of September 8, 1998 Sample Number SMF Barcode Number Location (approximate) Sample Type Material Year Reported Leachate Cl Conc. (mg/kg) AgCl Target Identifier Corrected 36Cl/Cl (x1015) SPC01004422 (14.3-16.3) DCN0501/ 051-2 SPC01004424 SPC01004425 SPC01004426 SPC01004427 ESF-MDNICHE3566LT# 1 (16.6-19.3) NA NA 1998 NA YM899 1252 ±68 DCN0592/ 060-1 SPC01004445 SPC01004446 SPC01004447 ESF-MDNICHE3566LT# 1 (29.0-30.7) NA NA 1998 NA YM900 1627 ±73 DCN0621 SPC01004453 ESF-MDNICHE3566LT# 1 (32.1-33.1) NA NA 1998 NA YM901 1705 ±87 DCN0642 SPC01004457 ESF-MDNICHE3566LT# 1 (34.4-35.5) NA NA 1998 NA YM902 1335 ±67 E331-1 SPC00524998 Niche 1/0+13.5 Breccia zone Representative bulk material 1998 0.2 YM806 540 ±31 E332-1 SPC00524999 Niche 1/0+13.5 Breccia zone Representative bulk material 1998 0.4 YM807 588 ±37 E332-2 SPC00524999 Niche 1/0+13.5 Breccia zone Representative bulk material 1998 0.3 YM808 618 ±45 E330-1 SPC00524900 Niche 1/0+10 Breccia zone Representative bulk material 1998 0.9 YM805 553 ±29 E336-1 SPC00008073 Niche 1/7+05 Fracture Representative bulk material 1998 0.3 YM817 659 ±177 DTNs: LAJF831222AQ98.004 (Q), LA0509JF831222.001 (Q) NOTES: SMF = Sample Management Facility, Alc = Alcove, NA = Not Available. Locations (i.e., ESF stations, borehole intervals) are approximate. The Sundance fault zone is located between ESF stations 33+89 and 36+89 (approx.). Samples E331-1, E332-1, E332-2, E330-1, and E336-1 are tunnel wall samples. Samples from ESF-MD-NICHE3566#1, #2, and LT1 are borehole samples. Errors are 1s. One-sigma analytical errors given for construction-water corrected 36Cl/Cl ratios are based on in-run counting statistics. Leachate chloride concentrations are given as salts leached per kilogram of rock. TDR-NBS-HS-000017 REV00 A15 Chloride Concentrations and Chlorine-36/Chloride Ratios in Salts Leached From Exploratory Studies Facility Rock Samples at Los Alamos National Laboratory as of September 8, 1998 Measured 36Cl/Cl ratios have been corrected for the addition of a 35Cl tracer and for the addition of Cl from construction water using the approach described in Fabryka-Martin et al. (1997, p. B-1, Section 4.2.2). The concentration of salts extracted from each sample is only a qualitative indicator of the pore-water composition: no attempt was made to maximize the yield of the leaching process, which is probably highly variable. The data were originally reported in Fabryka-Martin, Wolfsberg, et al. (1996), Fabryka-Martin et al. (1997), CRWMS M&O (1998). Small differences were noted for some values contained in the cited reports and the final data reported in DTNs LAJF831222AQ98.004 and LA0509JF831222.001. These reflect final adjustments and corrections to analytical data and do not affect any of the conclusions based on these data. TDR-NBS-HS-000017 REV00 A16 REFERENCES CITED A.1 DOCUMENTS CITED CRWMS M&O (Civilian Radioactive Waste Management System Management and Operating Contractor) 1998. Evaluation of Flow and Transport Models of Yucca Mountain, Based on Chlorine-36 and Chloride Studies for FY98. BA0000000-017175700- 00007, Rev. 00. Las Vegas, Nevada: CRWMS M&O. ACC: MOL.19981208.0119. Fabryka-Martin, J.; Wolfsberg, A.V.; Dixon, P.R.; Levy, S.; Musgrave, J.; and Turin, H.J. 1996. Summary Report of Chlorine-36 Studies: Sampling, Analysis and Simulation of Chlorine-36 in the Exploratory Studies Facility. Milestone 3783M. Los Alamos, New Mexico: Los Alamos National Laboratory. ACC: MOL.19970103.0047. Fabryka-Martin, J.T.; Flint, A.L.; Sweetkind, D.S.; Wolfsberg, A.V.; Levy, S.S.; Roemer, G.J.C.; Roach, J.L.; Wolfsberg, L.E.; and Duff, M.C. 1997. Evaluation of Flow and Transport Models of Yucca Mountain, Based on Chlorine-36 Studies for FY97. LA-CSTTIP- 97-010. Los Alamos, New Mexico: Los Alamos National Laboratory. ACC: MOL.19980204.0196. A.2 SOURCE DATA, LISTED BY DATA TRACKING NUMBER LA0509JF831222.001. Chlorine-36 Analyses of Salts Leached from ESF Niche #3566 (Niche #1) Drillcore. (Q) LAJF831222AQ98.004. Chloride, Bromide, Sulfate, and Chlorine-36 Analyses of Salts Leached from ESF Rock Samples. (Q) INTENTIONALLY LEFT BLANK APPENDIX B VIDEO-LOG OBSERVATIONS FROM VALIDATION STUDY BOREHOLES INTENTIONALLY LEFT BLANK Video Log Observations from Validation Study Boreholes SMF Name: 879 Borehole name: ESF-DHW-ClV#1 ESF Station 19+65 Completion date: Total depth (ft) 9/30/1999 13.4 Run # 1 Interval (ft) 0.0 - 2.9 Recovery (ft) Fractures/Comments 1.7 rubble Unrecovered Core Interval (ft) 1.7 - 1.9 2 2.9 - 5.2 2.1 rubble 5.0 - 5.2 3 5.2 - 7.9 1.8 rubble 7.0 - 7.9 4 7.9 - 10.9 2.3 rubble 10.2 - 10.9 2 3.2 - 5.6 1.6 rubble 4.8 - 5.6 3 5.6 - 8.2 2.6 5.6 - 7.2 = rubble; 7.2 - 8.2 = fairly intact w/ 3 fractures none 4 8.2 - 10.7 1.7 rubble 9.9 - 10.7 2 3.1 - 5.0 1.5 rubble 4.6 - 5.0 3 5.0 - 6.9 1.9 rubble none 4 6.9 - 8.1 1.1 rubble 8.0 - 8.1 5 8.1 - 10.1 1.6 rubble 9.7 - 10.1 6 10.1 - 10.6 0.5 10.1 - 10.4 = rubble; 10.4 - 10.6 = intact none 7 10.6 - 12.0 0.6 rubble 11.2 - 12.0 2.0 - 3.7 0.6 rubble 2.6 - 3.7 3.7 - 5.8 0.5 rubble 4.2 - 5.8 5 10.9 - 13.4 2.3 rubble 13.2 - 13.4 SMF Name: 880 Borehole name: ESF-DHW-ClV#2 ESF Station 19+55 Completion date: 9/29/1999 Total depth (ft) 13.5 Run # Interval (ft) Recovery Fractures/Comments Unrecovered (ft) Core Interval (ft) 1 0.0 - 3.2 1.8 rubble 1.8 - 3.2 5 10.7 - 13.5 0.9 rubble 11.6 - 13.5 SMF Name: 881 Borehole name: ESF-DHW-ClV#3 ESF Station 19+50 Completion date: 9/29/1999 Total depth (ft) 13.6 Run # Interval (ft) Recovery Fractures/Comments Unrecovered (ft) Core Interval (ft) 1 0.0 - 3.1 1.5 rubble 1.5 - 3.1 8 12.0 - 13.6 1.3 rubble 13.3 - 13.6 SMF Name: 906 Borehole name: ESF-DHW-ClV#4 ESF Station 19+45 Completion date: 9/28/1999 Total depth (ft) 13.8 Run # Interval (ft) Recovery Fractures/Comments Unrecovered (ft) Core Interval (ft) 0.0 - 2.0 0.9 rubble 0.9 - 2.0 5.8 - 7.6 0.3 rubble 6.1 - 7.6 7.6 - 9.6 2 7.6 - 8.5 = rubble; 8.5 - 8.7 = fractured, rubbly; 9.2 - 9.6 = intact none 9.6 - 10.5 0.9 9.6 - 9.9 = rubble; 9.9 - 10.5 = intact w/ 2 fractures none 10.5 - 13.8 3.2 10.5 - 11.1= fairly intact w/2 fractures; 11.1 - 11.5 = rubble; 11.5 - 13.7 = 13.7 - 13.8 fairly intact w/ 6 fractures Video Log Observations from Validation Study Boreholes SMF Name: 907 Borehole name: ESF-DHW-ClV#5 ESF Station 19+40 Completion date: Total depth (ft) 9/27/1999 33.3 Run # 1 Interval (ft) 0.0 - 3.5 Recovery (ft) Fractures/Comments 0.7 rubble Unrecovered Core Interval (ft) 0.7 - 3.5 2 3.5 - 5.7 1.6 3.5 - 3.9 = rubble; 3.9 - 4.4 = fairly intact w/ 2 fractures; 4.4 - 4.6 = 5.1 - 5.7 rubble; 4.6 - 5.1 = fairly intact w/ 1 fracture 3 5.7 - 9.4 2.5 5.7 - 6.5 = rubble; 6.5 - 6.8 = fairly intact w/ 1 fracture; 6.8 - 7.3 = rubble; 8.2 - 9.4 7.3 - 7.7 = fractured; 7.7 - 8.2 = fairly intact w/ 2 fractures 6 14.3 - 16.3 1.1 rubble 15.4 - 16.3 7 16.3 - 19.1 1.4 16.3 - 16.9 = rubble; 16.9 - 17.4 = fairly intact w/ 1 fracture; 17.4 - 17.7 = 17.7 - 19.1 rubble 8 19.1 - 21.2 1.6 19.1 - 19.7= fairly intact w/2 fractures; 19.7 - 20.1 = rubble; 20.1 - 20.5 = 20.7 - 21.2 fairly intact w/ 1 fracture; 20.5 - 20.7 = rubble 9 21.2 - 23.4 1.8 21.2 - 22.2 = rubble; 22.2 - 22.6 = fairly intact w/ 2 fractures; 22.6 - 23.0 23.0 - 23.4 = rubble 4 9.4 -11.5 1.5 9.4 - 9.8 = rubble; 9.8 - 10.2 = intact; 10.2 - 10.9 = rubbly, fractured 10.9 - 11.5 5 11.5 - 14.3 1.2 11.5 - 11.8 = rubble; 11.8 - 12.3 = intact w/ 1 fracture; 12.3 - 12.7 = 12.7 - 14.3 rubble 10 23.4 - 25.4 2 rubble none 11 25.4 - 29.4 3.3 25.4 - 26.8 = rubble; 26.8 - 27.3 = fairly intact w/ 2 fractures; 27.3 - 27.5 28.7 - 29.4 = rubble; 27.5 - 28.7 = fairly intact w/ 5 fractures 12 29.4 - 33.3 3.3 rubble 32.7 - 33.3 SMF Name: 908 Borehole name: ESF-DHW-ClV#6 ESF Station 19+35 Completion date: 9/30/1999 Total depth (ft) 13.9 Run # Interval (ft) Recovery Fractures/Comments Unrecovered (ft) Core Interval (ft) 1 0.0 - 2.2 1.6 0.0 - 0.5 = rubble; 0.5 - 0.8 = fairly intact w/ 1 fracture; 0.8 - 1.2 = 1.6 - 2.2 rubble; 1.2 - 1.6 = fairly intact 2 2.2 - 4.8 2.1 2.2 - 2.6 = fairly intact w/ 1 fracture; 2.6 - 3.3 = fractured; 3.3 - 3.6 = 4.3 - 4.8 rubble; 3.6 - 4.1 = intact; 4.1 - 4.3 = fractured 3 4.8 - 7.2 2.4 4.8 - 5.0 = rubble; 5.0 - 5.4 = fractured; 5.4 - 5.7 = rubble; 5.7 - 6.6 = none fairly intact w/ 3 fractures; 6.6 - 6.9 = fractured; 6.9 - 7.2 = intact 4 7.2 - 10.7 2.9 7.2 - 8.0 = fractured; 8.0 - 8.7 = intact w/ 1 fracture; 8.7 - 8.9 = rubble; 10.1 - 10.7 8.9 - 9.3 = intact; 9.3 - 9.4 = rubble; 9.4 - 10.1 = intact w/ 1 fracture 5 10.7 - 13.9 3.4 (3.2 + 10.7 - 10.9 = fractured; 10.9 - 12.2 = intact w/ 1 fracture; 12.2 - 13.7 = none 0.2) intact w/ 3 fractures; 13.7 - 13.9 = rubble Video Log Observations from Validation Study Boreholes SMF Name: 909 Borehole name: ESF-DHW-ClV#7 ESF Station 19+30 Completion date: Total depth (ft) 10/5/1999 13.6 Run # 1 Interval (ft) 0.0 - 2.2 Recovery (ft) Fractures/Comments 1.2 rubble Unrecovered Core Interval (ft) 1.2 - 2.2 2 2.2 - 5.4 2.2 2.2 - 2.5 = rubble; 2.5 - 2.7 = intact; 2.7 - 3.9 = rubble; 3.9 - 4.4 = intact 4.4 - 5.4 3 5.4 - 7.3 1.9 rubble none 4 7.3 - 9.6 1.7 7.3 - 7.6 = rubble; 7.6 - 8.0 = intact; 8.0 - 8.8 = rubble; 8.8 - 9.0 9.0 - 9.6 =fractured 5 9.6 - 13.6 3 9.6 - 10.0 = rubble; 10.0 - 12.1 = fairly intact w/ 6 fractures; 12.1 - 12.6 = 12.6 - 13.6 fractured, rubbly SMF Name: 910 Borehole name: ESF-DHW-ClV#8 ESF Station 19+25 Completion date: 10/5/1999 Total depth (ft) 13.4 Run # Interval (ft) Recovery Fractures/Comments Unrecovered (ft) Core Interval (ft) 1 0.0 - 1.4 0.8 fractured, broken 0.8 - 1.4 2 1.4 - 3.8 1.2 1.4 - 1.5 = rubble; 1.5 - 2.2 = fairly intact w/ 2 fractures and crystal-lined 2.6 - 3.8 cavities in this section; 2.2 - 2.6 = rubble 3 3.8 - 7.4 3.2 3.8 - 4.2 = fractured rubbly; 4.2 - 5.0 = fairly intact w/ 3 fractures; 5.0 - 7.0 - 7.4 6.8 = intact w/ 2 frac. & 2 cavities; 6.8 - 7.0 = rubble 4 7.4 - 10.3 1.8 7.4 - 7.5 = rubble; 7.5 - 7.7 = intact; 7.7 - 8.1 = rubble; 8.1 - 8.7 = intact; 9.2 - 10.3 8.7 - 9.2 = fractured, rubbly 5 10.3 - 13.4 2.8 10.3 - 10.7 = rubble; 10.7 - 11.5 = fairly intact w/ 3 fractures; 11.5 - 11.8 13.1 - 13.4 = rubble; 11.8 - 12.5 = fairly intact w/ 1 fracture; 12.5 - 12.9 = fractured, broken; 12.9 - 13.1 = intact SMF Name: 911 Borehole name: ESF-DHW-ClV#9 ESF Station 19+20 Completion date: 10/6/1999 Total depth (ft) 13.3 Run # Interval (ft) Recovery Fractures/Comments Unrecovered (ft) Core Interval (ft) 1 0.0 - 2.4 0.9 rubble 0.9 - 2.4 2 2.4 - 5.2 2.5 2.4 - 2.8 = rubble; 2.8 - 3.3 = fairly intact w/ 1 fracture; 3.3 - 3.8 = rubble; 4.9 - 5.2 3.8 - 4.5 = intact w/ 1 fracture; 4.5 - 4.9 = fractured, rubbly 3 5.2 - 7.3 1.7 5.2 - 5.7 = fractured, broken; 5.7 - 6.1 = fairly intact w/ 2 fractures; 6.1 - 6.9 - 7.3 6.9 = rubble 4 7.3 - 10.3 2.2 7.3 - 8.2 = rubble; 8.2 - 8.7 = intact w/ 1 fracture; 8.7 - 9.5 = fractured, 9.5 - 10.3 rubbly 5 10.3 - 12.3 2.2 10.3 - 10.8 = intact w/1 frac. & lg. cavity; 10.8 - 11.5 = rubble; 11.5 - 12.2 12.5 - 13.3 = fairly intact w/ 4 fractures; 12.2 - 12.5 = rubble Video Log Observations from Validation Study Boreholes SMF Name: 912 Borehole name: ESF-DHW-ClV#10 ESF Station 19+10 Completion date: Total depth (ft) 10/6/1999 13.4 Run # 1 Interval (ft) 0.0 - 2.4 Recovery (ft) Fractures/Comments 0.5 rubble Unrecovered Core Interval (ft) .05 - 2.4 2 2.4 - 5.3 2.3 2.4 - 2.7 = rubble; 2.7 - 3.7 = fractured, broken; 3.7 - 4.7 = rubble 4.7 - 5.3 3 5.3 - 7.6 0.6 rubble 5.9 - 7.6 4 7.6 - 10.4 1.6 7.6 - 8.2 = rubble; 8.2 - 8.6 = fairly intact w/ 2 fractures; 8.6 - 9.0 = 9.2 - 10.4 rubble; 9.0 - 9.2 = intact 2 2.1 - 4.3 2.8 Intact, ~2 Fractures, Broken (3.7 - 3.8) 4.2 - 4.3 3 4.3 - 6.3 2 Broken 6.2 - 6.3 4 6.3 - 8.1 1.8 Intact, 2-3 Fractures 8.0 - 8.1 5 8.1 - 9.1 0.9 Broken 9.0 - 9.1 6 9.1 - 11.0 1.4 ~2 Fractures, Broken 10.5 - 11.0 7 11.0 - 12.8 2.1 Broken - 8 12.8 - 13.5 0.9 Broken - 5 10.4 - 13.4 2 10.4 - 11.2 = fractured, rubbly; 11.2 - 12.0 = fairly intact w/ 2 fractures; 12.4 - 13.4 12.0 - 12.4 = fractured, rubbly SMF Name: 913 Borehole name: ESF-SD-ClV#1 ESF Station 36+90 Completion date: 6/17/1999 Total depth (ft) 13.5 Run # Interval (ft) Recovery Description Unrecovered (ft) Core Interval (ft) 1 0.0 - 2.1 1.4 Broken, ~1 Fracture 1.4 - 2.1 SMF Name: 914 Borehole name: ESF-SD-ClV#2 ESF Station 36+75 Completion date: 6/16/1999 Total depth (ft) 13.6 Run # Interval (ft) Recovery Fractures/Comments Unrecovered (ft) Core Interval (ft) 1 0.0 - 2.0 1.8 Broken(0.0 - 1.8) 1.8 - 2.0 9 12.5 - 13.6 0.9 Intact, 1 Fracture(12.5 - 13.4) 13.4 - 13.6 2 2.0 - 3.9 1.4 Rubbly(2.0 - 2.3); Intact(2.3 - 2.7); Intact with ~4 Fractures(2.7 - 3.9) - 3 3.9 - 4.7 0.9 Broken(3.9 - 4.1); Intact(4.1 - 4.7) - 4 4.7 - 5.9 1.2 Rubbly(4.7 - 4.8); Intact, ~1 Fracture(4.8 - 5.9) - 5 5.9 - 8.0 2.1 Intact(5.9 - 6.4); Broken(6.4 - 7.0); Intact(7.0 - 7.6); Broken(7.6 - 8.0) - 6 8.0 - 9.9 1.9 Intact, ~3 Fractures(8.0 - 9.9) - 7 9.9 - 12.0 1.9 Intact(9.9 - 10.7); Intact(10.7 - 11.5); Broken(11.5 - 11.8) 11.8 - 12.0 8 12.0 - 12.5 0.5 Broken - Video Log Observations from Validation Study Boreholes SMF Name: 915 Borehole name: ESF-SD-ClV#3 ESF Station 36+60 Completion date: Total depth (ft) 6/15/1999 13.6 Run # 1 Interval (ft) 0.0 - 0.6 Recovery (ft) Fractures/Comments 0.6 Rubbly(0.0 - 0.6) Unrecovered Core Interval (ft) - 2 0.6 -2.5 1.7 Broken(0.6 - 2.3) 2.3 - 2.5 3 2.5 - 4.2 1.8 Broken, ~3 Fractures - 4 4.2 - 6.3 2 Broken, ~7 Fractures(4.2 - 6.2) 6.2 - 6.3 5 6.3 - 7.4 1.1 Intact(6.3 - 7.2); Broken(7.2 - 7.4) - 6 7.4 - 9.4 1.9 Broken, ~6 Fractures(7.4 - 9.3) 9.3 - 9.4 7 9.4 - 11.4 2 Broken(9.4 - 10.8); Broken - Rubbly(10.8 - 11.4) - 8 11.4 - 12.8 1.2 Rubbly(11.4 - 11.8); Intact(11.8 - 12.3); Rubbly(12.3 - 12.6); Broken(12.6 - - 12.8) 9 12.8 - 13.6 0.7 Broken(12.8 - 12.5) 13.5 - 13.6 SMF Name: 916 Borehole name: ESF-SD-ClV#4 ESF Station 36+35 Completion date: 6/14/1999 Total depth (ft) 13.4 Run # Interval (ft) Recovery Fractures/Comments Unrecovered (ft) Core Interval (ft) 1 0.0 - 2.1 1.8 Broken, >8 Fractures(0.0 - 1.8) 1.8 - 2.1 2 2.1 - 4.4 1.7 Rubbly(2.1 - 2.8); Broken(2.8 - 3.1); Rubbly - Broken(3.1 - 3.8) 3.8 - 4.4 3 4.4 - 5.7 1.2 Rubbly(4.4 - 4.7); Rubbly - Broken(4.7 - 5.3); Rubbly(5.3 - 5.6) 5.6 - 5.7 4 5.7 - 6.3 0.6 Broken(5.7 - 5.9); Rubbly(5.9 - 6.3) - 5 6.3 - 8.3 2 Intact(6.3 - 6.7); Broken(6.7 - 7.2); Rubbly(7.2 - 7.8); Broken(7.8 - 8.3) - 6 8.3 - 10.3 1.6 Rubbly(8.3 - 9.4); Broken(9.4 - 9.9) 9.9 - 10.3 7 10.3 - 12.3 2 Broken - Rubbly(10.3 - 11.1); Broken, >6 Fractures(11.1 - 12.3) - 8 12.3 - 13.4 1.1 Broken, ~6 Fractures(12.3 - 13.4) - SMF Name: 917 Borehole name: ESF-SD-ClV#5 ESF Station 36+20 Completion date: 6/10/1999 Total depth (ft) 13.5 Run # Interval (ft) Recovery Fractures/Comments Unrecovered (ft) Core Interval (ft) 1 0.0 - 2.1 0.9 Rubbly - Shattered(0.0 - 0.9) 0.9 - 2.1 2 2.1 - 4.1 2.3 Shattered - Rubbly(2.1 - 2.5); Broken(2.5 - 4.1) - 3 4.1 - 5.8 1 Rubbly(4.1 - 5.1) 5.1 - 5.8 4 5.8 - 7.9 0.9 Rubbly(5.8 - 6.7) 6.7 - 7.9 5 7.9 - 10.1 1.8 Rubbly - Shattered(7.9 - 9.7) 9.7 - 10.1 6 10.1 - 12.1 0.7 Block(10.1 - 10.4); Rubbly(10.4 - 10.8) 10.8 - 12.1 7 12.1 - 13.5 0.9 Rubbly(12.1 - 13.0) 13.0 - 13.5 Video Log Observations from Validation Study Boreholes SMF Name: 918 Borehole name: ESF-SD-ClV#6 ESF Station 36+10 Completion date: Total depth (ft) 6/10/1999 13.4 Run # 1 Interval (ft) 0.0 - 2.0 Recovery (ft) Fractures/Comments 0.4 Broken - Rubbly(0.0 - 0.4) Unrecovered Core Interval (ft) 0.4 - 2.0 2 2.0 - 4.0 1.9 Rubbly(2.0 - 3.9) 3.9 - 4.0 3 4.0 - 5.7 1.3 Rubbly(4.0 - 5.0); Intact, few hairline fractures(5.0 - 5.3) 5.3 - 5.7 4 5.7 - 7.8 1.2 Rubbly(5.7 - 6.9) 6.9 - 7.8 5 7.8 - 10.8 2.7 Rubbly - Shattered(7.8 - 9.3); Broken(9.4 - 10.2); Rubbly(10.2 - 10.5) 10.5 - 10.8 6 10.8 - 12.3 1.2 Rubbly(10.8 - 11.4); Broken(11.4 - 12.0) 12.0 - 12.3 7 12.3 - 12.4 0 No Core 12.3 - 12.4 SMF Name: 919 Borehole name: ESF-SD-ClV#7 ESF Station 36+05 Completion date: 6/8/1999 Total depth (ft) 13.5 Run # Interval (ft) Recovery Fractures/Comments Unrecovered (ft) Core Interval (ft) 1 0.0 - 2.0 1.1 Rubbly(0.0 - 1.1) 1.1 - 2.0 2 2.0 - 3.9 0.1 Rubbly(2.0 - 2.1) 2.1 - 3.9 3 3.9 - 6.0 0.5 2 blocks(3.9 - 4.4) 4.4 - 6.0 4 6.0 - 8.1 2 Broken, >12 Fractures(6.0 - 8.0) 8.0 - 8.1 5 8.1 - 10.7 1.6 Broken, ~3 Fractures(8.1 - 8.8); Rubbly(8.8 - 9.4); Broken(9.4 - 9.6); 9.7 - 10.7 Rubbly(9.6 - 9.7) 6 10.7 - 11.7 1 Rubbly - 7 11.7 - 13.5 0.6 Rubbly(11.7 - 12.3) 12.3 - 13.5 SMF Name: 920 Borehole name: ESF-SD-ClV#8 ESF Station 36+00 Completion date: 6/8/1999 Total depth (ft) 13.5 Run # Interval (ft) Recovery Fractures/Comments Unrecovered (ft) Core Interval (ft) 1 0.0 - 2.0 1.7 Rubbly(0.0 - 1.0); Broken(1.0 - 1.7) 1.7 - 2.0 2 2.0 - 4.0 1.4 Broken - Rubbly(2.0 - 2.8); Rubbly(2.8 - 3.4) 3.4 - 4.0 3 4.0 - 6.0 1.5 Rubbly(4.0 - 4.3); Block(4.3 - 4.7); Rubbly(4.7 - 5.5) 5.5 - 6.0 4 6.0 - 7.9 0.2 Block(6.0 - 6.2) 6.2 - 7.9 5 7.9 - 9.9 2 Rubbly(7.9 - 9.9) - 6 9.9 - 11.9 1.9 Rubbly(9.9 - 11.8) 11.8 - 11.9 7 11.9 - 13.5 1.1 Rubbly(11.9 - 12.3); Broken(12.3 - 13.0) 13.0 - 13.5 Video Log Observations from Validation Study Boreholes SMF Name: 921 Borehole name: ESF-SD-ClV#9 ESF Station 35+95 Completion date: Total depth (ft) 6/7/1999 13.6 Run # 1 Interval (ft) 0.0 - 4.5 Recovery (ft) Fractures/Comments 0.3 Rubbly(0.0 - 0.3) Unrecovered Core Interval (ft) 0.3 - 4.5 2 4.5 - 6.5 0.8 Rubbly(4.5 - 5.3) 5.3 - 6.5 3 6.5 - 8.6 1.6 Rubbly(6.5 - 8.1) 8.1 - 8.6 4 8.6 - 10.1 1.5 Rubbly(8.6 - 9.5); Block(9.5 - 9.7); Rubbly(9.7 - 10.1) - 5 10.1 - 11.5 1.4 Broken, ~6 Fractures(10.1 - 11.2); Rubbly(11.2 - 11.5) - 6 11.5 - 12.9 1.2 Block(11.5 - 11.7); Rubbly(11.7 - 12.7) 12.7 - 12.9 7 12.9 - 13.6 0.7 Rubbly(12.9 - 13.6) - SMF Name: 922 Borehole name: ESF-SD-ClV#10 ESF Station 35+90 Completion date: 6/3/1999 Total depth (ft) 13.4 Run # Interval (ft) Recovery Fractures/Comments Unrecovered (ft) Core Interval (ft) 1 0.0 - 2.0 1.9 Rubbly(0.0 - 0.6); Broken, ~ 2-4 Fractures(0.6 - 1.9) 1.9 - 2.0 2 2.0 - 7.0 1.9 Block(2.0 - 2.2); Rubbly - Shattered(2.2 - 3.65); Block(3.7 - 3.9) 3.9 - 7.0 3 7.0 - 9.9 1 Rubbly(7.0 - 8.0) 8.0 - 9.9 4 9.9 - 13.4 3.1 Block(9.9 - 10.2); Rubbly(10.2 - 10.8); Block(10.8 - 11.1); Rubbly(11.05 - 13.0 - 13.4 11.7); Broken, ~4-6 Fractures(11.7 - 12.8); Rubbly(12.8 - 13.0) SMF Name: 923 Borehole name: ESF-SD-ClV#11 ESF Station 35+85 Completion date: 6/3/1999 Total depth (ft) 13.6 Run # Interval (ft) Recovery Fractures/Comments Unrecovered (ft) Core Interval (ft) 1 0.0 - 4.1 3.4 ~2 Fractures(0.0 - 1.7); Broken, ~5 Fractures(1.7 - 3.0); Broken - 3.4 - 4.1 Rubbly(3.0 - 3.4) 2 2.0 - 7.1 5.1 Intact, few hairline fractures(2.0 - 3.3); Broken(3.3 - 3.65); Intact(3.65 - - 4.3); Broken(4.3 - 5.6); Rubbly(5.6 - 7.1) 3 7.1 - 11.5 3.3 Rubbly(7.1 - 7.5); Broken(7.5 - 8.9); Rubbly(8.9 - 9.4); Broken(9.4 - 9.8); 10.4 - 11.5 Rubbly(9.8 - 10.4) 4 11.5 - 13.6 1.9 Rubbly(11.5 - 11.85); Broken(11.85 - 12.2); Intact, few hairline 13.4 - 13.6 fractures(12.2 - 12.9); Rubbly - Broken(12.9 - 13.4) 2 4.1 - 5.7 1.1 Rubbly(4.1 - 5.1) 5.1 - 5.7 3 5.7 - 9.0 2.2 Rubbly(5.7 - 6.7); Broken(6.7 - 7.9) 7.9 - 9.0 4 9.0 - 13.6 3.5 Broken(9.0 - 9.6); Rubbly - Shattered(9.6 -10.6); Broken(10.6 - 12.5) 12.5 - 13.6 SMF Name: 924 Borehole name: ESF-SD-ClV#12 ESF Station 35+80 Completion date: 6/2/1999 Total depth (ft) 13.6 Run # Interval (ft) Recovery Fractures/Comments Unrecovered (ft) Core Interval (ft) 1 0.0 - 2.0 1.7 Broken - Rubbly(0.0 - 1.2); Broken(1.2 - 1.7) 1.7 - 2.0 Video Log Observations from Validation Study Boreholes SMF Name: 925 Borehole name: ESF-SD-ClV#13 ESF Station 35+75 Completion date: 6/2/1999 Total depth (ft) 32.6 Run # Interval (ft) Recovery Fractures/Comments Unrecovered (ft) Core Interval (ft) 1 0.0 - 1.7 1.7 Rubbly - Broken - 2 1.7 - 2.9 1.2 Broken - Rubbly - 3 2.9 - 7.0 3.8 Broken, >12 Fractures(2.9 - 6.3); Rubbly(6.3 - 6.7) 6.7 - 7.0 4 7.0 - 9.7 1.6 Rubbly - Broken(7.0 - 8.6) 8.6 - 9.7 5 9.7 - 13.9 3 Rubbly(9.7 - 11.4); Intact(11.4 - 11.85); Broken(11.85 - 12.7) 12.7 - 13.9 6 13.9 - 17.0 2.2 Broken(13.9 - 14.4); Rubbly(14.4 - 14.7); Broken(14.7 - 15.0); Intact(15.0 16.1 - 17.0 - 15.8); Broken(15.8 - 16.1) 7 17.0 - 18.8 1.3 Intact(17.0 - 17.5); Broken(17.5 - 17.9); Rubbly(17.9 - 18.3) 18.3 - 18.8 8 18.8 - 21.7 2.9 Rubbly(18.8 - 19.6); Broken(19.6 - 20.5); Broken - Rubbly(20.5 - 21.7) - 9 21.7 - 23.2 1.5 Rubbly(21.7 - 23.2) - 10 23.2 - 24.8 1.2 Broken - Rubbly(23.2 - 24.4) 24.4 - 24.8 11 24.8 - 25.3 0.5 Broken(24.8 - 25.3) - 12 25.3 - 30.0 2 Rubbly(25.3 - 27.3) 27.3 - 30.0 13 30.0 - 32.6 2.3 Rubbly(30.0 - 30.6); Broken - Rubbly(30.6 - 32.3) 32.3 - 32.6 SMF Name: 926 Borehole name: ESF-SD-ClV#14 ESF Station 35+45 Completion date: 9/22/1999 Total depth (ft) 13.4 Run # Interval (ft) Recovery Fractures/Comments Unrecovered (ft) Core Interval (ft) 1 0.0 - 2.8 2.1 Mostly Broken, Rubbly 2.1 - 2.8 2 2.8 - 5.4 2.6 Mostly Rubble, Broken - 3 5.4 - 6.9 1.5 Broken - 4 6.9 - 8.0 1 Broken, ~1 Fracture 7.9 - 8.0 5 8.0 - 11.9 3.5 Rubbly (8.2 - 8.9), Broken, 2-3 Fractures 11.5 - 11.9 6 11.9 - 13.4 1.8 Broken, 1 Fracture - SMF Name: 927 Borehole name: ESF-SD-ClV#15 ESF Station 35+40 Completion date: 9/21/1999 Total depth (ft) 13.5 Run # Interval (ft) Recovery Fractures/Comments Unrecovered (ft) Core Interval (ft) 1 0.0 - 1.9 1.7 Broken 1.7 - 1.9 2 1.9 - 4.7 2.7 Mostly intact, Broken (4.3 - 4.6) 4.6 - 4.7 3 4.7 - 7.8 2.4 Broken, ~2 Fractures 7.1 - 7.8 4 7.8 - 12.1 4.1 Broken, ~3 Fractures 11.9 - 12.1 5 12.1 - 13.5 1.6 Broken, ~2 Fractures - Video Log Observations from Validation Study Boreholes SMF Name: 928 Borehole name: ESF-SD-ClV#16 ESF Station 35+35 Completion date: 9/20/1999 Total depth (ft) 13.5 Run # Interval (ft) Recovery Fractures/Comments Unrecovered (ft) Core Interval (ft) 1 0.0 - 0.5 0.2 1 Block 0.2 - 0.5 2 0.5 - 1.7 1.2 1 Fracture, Broken - 3 1.7 - 2.5 0.9 Intact, ~1 Fracture - 4 2.5 - 2.8 0.1 1 Block 2.6 - 2.8 5 2.8 - 5.0 2.2 Broken - 6 5.0 - 6.7 1.7 Broken, ~1 Fracture - 7 6.7 - 7.4 0.6 Broken 7.3 - 7.4 8 7.4 - 9.3 1.8 Broken 9.2 - 9.3 9 9.3 - 13.5 3.9 Broken 13.2 - 13.5 SMF Name: 929 Borehole name: ESF-SD-ClV#17 ESF Station 35+30 Completion date: 9/17/1999 Total depth (ft) 13.3 Run # Interval (ft) Recovery Fractures/Comments Unrecovered (ft) Core Interval (ft) 1 0.0 - 0.5 0.5 Broken - 2 0.5 - 2.6 2.1 Broken, ~3 Fractures - 3 2.6 - 4.7 2.1 Broken - 4 4.7 - 5.5 0.8 Broken, Blocky - 5 5.5 - 6.9 1.4 Broken, Some Fractures? (Video black out) - 6 6.9 - 8.5 1.6 Broken, ~2 Fractures - 7 8.5 - 9.8 0.8 Broken 9.3 - 9.8 8 9.8 - 10.5 0.9 Broken, Blocky - 9 10.5 - 13.3 2.7 Broken, 2-3 Fractures 13.2 - 13.3 SMF Name: 930 Borehole name: ESF-SD-ClV#18 ESF Station 35+25 Completion date: Total depth (ft) 9/16/1999 13.5 Run # 1 Interval (ft) 0.0 - 2.1 Recovery (ft) Fractures/Comments 1.9 Broken, ~2 Fractures Unrecovered Core Interval (ft) 1.9 - 2.1 2 2.1 - 3.6 1.5 Broken, ~3 Fractures - 3 3.6 - 5.7 2.1 Broken 5.6 - 5.7 4 5.7 - 7.5 1.5 Broken 7.2 - 7.5 5 7.5 - 8.8 1.2 Broken, ~2 Fractures? 8.7 - 8.8 6 8.8 - 10.2 1.4 Broken - 7 10.2 - 10.9 0.7 Broken - 8 10.9 - 12.6 0.9 Broken 11.8 - 12.6 9 12.6 - 13.5 1.2 Rubbly - Broken - Video Log Observations from Validation Study Boreholes SMF Name: 931 Borehole name: ESF-SD-ClV#19 ESF Station 35+20 Completion date: 9/15/1999 Total depth (ft) 13.4 Run # Interval (ft) Recovery Fractures/Comments Unrecovered (ft) Core Interval (ft) 1 0.0 - 3.4 2.9 Intact, 2 Fractures, Broken (1.0 - 1.3) 2.9 - 3.4 5 9.4 - 10.2 0.6 Broken, Blocky 10.0 - 10.2 6 10.2 - 11.7 1.5 Broken - 7 11.7 - 13.4 1.4 Broken, 1 Fracture 13.1 - 13.4 2 3.4 - 5.7 2.3 Intact - Broken - 3 5.7 - 8.3 2.4 Broken - Rubbly 8.1 - 8.3 4 8.3 - 9.4 1 1 Fracture, Broken 9.3 - 9.4 SMF Name: 932 Borehole name: ESF-SD-ClV#20 ESF Station 35+15 Completion date: 9/14/1999 Total depth (ft) 13.2 Run # Interval (ft) Recovery Fractures/Comments Unrecovered (ft) Core Interval (ft) 1 0.0 - 1.3 1 Rubbly 1.0 - 1.3 5 8.6 - 9.1 0.5 Broken, Blocky - 6 9.1 - 10.5 1.3 Intact, 1 Fracture, Broken 10.4 - 10.5 7 10.5 - 11.4 0.9 2-3 Fractures, Broken - 8 11.4 - 13.2 1.6 Broken, Blocky 13.0 - 13.2 2 1.3 - 3.5 1.5 Broken - Rubble 2.8 - 3.5 3 3.5 - 6.1 2.6 Broken - Rubble - 4 6.1 - 8.6 2.6 Broken - SMF Name: 933 Borehole name: ESF-SD-ClV#21 ESF Station 35+10 Completion date: 9/13/1999 Total depth (ft) 13.4 Run # Interval (ft) Recovery Fractures/Comments Unrecovered (ft) Core Interval (ft) 1 0.0 - 1.7 1.4 Very Broken 1.4 - 1.7 2 1.7 - 4.7 2.9 Broken - Rubbly 4.6 - 4.7 3 4.7 - 7.1 2.4 Broken - 4 7.1 - 11.3 4 Intact, ~3 Fractures, Broken in some areas 11.1 - 11.3 5 11.3 - 13.4 2.1 Intact, 1 Fracture, Broken (13.0 - 13.4) - Video Log Observations from Validation Study Boreholes SMF Name: 934 Borehole name: ESF-SD-ClV#22 ESF Station 35+05 Completion date: 9/13/1999 Total depth (ft) 14.0 Run # Interval (ft) Recovery Fractures/Comments Unrecovered (ft) Core Interval (ft) 1 0.0 - 2.3 1.9 Broken, Blocky, 1.9 - 2.3 2 2.3 - 3.4 1.1 Broken, Blocky, - 3 3.4 - 6.5 2.9 Very Broken 6.3 - 6.5 4 6.5 - 11.3 4.7 Broken 11.2 - 11.3 5 11.3 - 14.8 2.3 Broken - Rubbly 13.6 - 14.8 SMF Name: 935 Borehole name: ESF-SD-ClV#23 ESF Station 35+00 Completion date: 9/10/1999 Total depth (ft) 13.7 Run # Interval (ft) Recovery Fractures/Comments Unrecovered (ft) Core Interval (ft) 1 0.0 - 0.9 0.9 Broken - 2 0.9 - 1.3 0.3 1 Block 1.2 - 1.3 3 1.3 - 2.0 0.7 Broken, Blocky - 4 2.0 - 2.3 0.3 1 Block - 5 2.3 - 4.9 2.5 Broken, 2-3 Fractures? 4.8 - 4.9 6 4.9 - 6.7 1.9 Broken - 7 6.7 - 11.4 4.7 Intact, 4 Fractures, Broken (9.4 - 10.1) - 8 11.4 - 11.6 0.1 Rubble 11.5 - 11.6 9 11.6 - 13.7 2.1 Broken, ~3 Fractures - SMF Name: 936 Borehole name: ESF-SD-ClV#24 ESF Station 34+95 Completion date: 9/9/1999 Total depth (ft) 13.4 Run # Interval (ft) Recovery Fractures/Comments Unrecovered (ft) Core Interval (ft) 1 0.0 - 2.1 2 Rubble (0.0 - 0.8), Broken (0.8 - 2.0) 2.0 - 2.1 2 2.1 - 7.0 4.9 Large intact pieces, broken in 6 areas - 3 7.0 - 8.8 1.8 Broken - 4 8.8 - 10.1 1.2 Broken, 1 Fracture? 10.0 - 10.1 5 10.1 - 11.3 0.9 Broken 11.0 - 11.3 6 11.3 - 13.4 2.1 Broken - Video Log Observations from Validation Study Boreholes SMF Name: 937 Borehole name: ESF-SD-ClV#25 ESF Station 34+90 Completion date: 9/23/1999 Total depth (ft) 13.2 Run # Interval (ft) Recovery Fractures/Comments Unrecovered (ft) Core Interval (ft) 1 0.0 - 0.4 0.2 1 Block, Rubbly 0.2 - 0.4 2 0.4 - 1.9 1.4 Blocky - Rubbly 1.8 - 1.9 3 1.9 - 3.9 1.3 Rubble (1.9 - 2.2), Intact, 1 Fracture (2.2 - 3.0), Rubble (3.0 - 3.2) 3.2 - 3.9 4 3.9 - 5.3 1.4 Broken - 5 5.3 - 5.6 0.4 Broken - 6 5.6 - 7.8 2.2 Broken, 3 Fractures, Very broken (7.3 - 7.8) - 7 7.8 - 9.9 2.1 Rubble ( 7.8 - 8.7), Broken (8.7 - 9.9) - 8 9.9 - 11.2 1.3 Broken - Rubbly 11.0 - 11.2 9 11.2 - 13.2 1.3 Broken - Rubbly 12.5 - 13.2 SMF Name: 938 Borehole name: ESF-SD-ClV#26 ESF Station 34+73 Completion date: 9/22/1999 Total depth (ft) 13.2 Run # Interval (ft) Recovery Fractures/Comments Unrecovered (ft) Core Interval (ft) 1 0.0 - 2.1 1.8 Intact ~ 2 Fractures 1.8 - 2.1 2 2.1 - 2.6 0.6 Broken fragment, 1 Block 2.4 - 2.6 3 2.6 - 3.2 0.6 Broken 3.1 - 3.2 4 3.2 - 4.0 1 Broken, - 5 4.0 - 4.8 0.8 Intact, 1 Fracture - 6 4.8 - 5.1 0.2 1 Block 5.0 - 5.1 7 5.1 - 6.9 1.8 Intact, ~2 Fractures - 8 6.9 - 9.0 2 Intact, ~3 Fractures 8.9 - 9.0 9 9.0 - 11.0 1.9 Broken, 2-3 Fractures 10.9 - 11.0 10 11.0 - 13.2 2.2 Intact, 2 Fractures - SMF Name: 939 Borehole name: ESF-SD-ClV#27 ESF Station 34+70 Completion date: 4/9/1999 Total depth (ft) 13.4 Run # Interval (ft) Recovery Fractures/Comments Unrecovered (ft) Core Interval (ft) 1 0.0 - 3.6 3.5 0'-0.6' rubbly; 0.6'-3.6' Intact w/ several discrete fracs 2 3.6 - 7.3 3.6 Intact w/ several discrete fracs 3 7.3 - 12 4.7 7.3'-9.2' sparsely broken; 9.2-10.0 intact; 10.0-12.0 intact w/ 2-3 fracs 4 12.0 - 13.4 1.4 Intact w/ ~4 fracs particularly between 13.0' and 13.4' Video Log Observations from Validation Study Boreholes SMF Name: 940 Borehole name: ESF-SD-ClV#28 ESF Station 34+65 Completion date: 4/8/1999 Total depth (ft) 13.3 Run # Interval (ft) Recovery Fractures/Comments Unrecovered (ft) Core Interval (ft) 1 0.0 - 2.2 1.9 Rubbly to broken; Good calcite @ 0.2 2 2.2 - 4.0 1.8 Intact w/ 2-3 discrete fracs 3 4.0 - 5.2 1.1 Increasingly broken towards the bottom of the run 4 5.2 - 6.2 1 Broken between 5.6'-6.2' 5 6.2 - 8.6 2.4 Intact w/ 4-5 fracs to 8.0'; 8.0'-8.6' is broken 6 8.6 - 9.5 0.3 Rubble 7 9.5 - 11.3 1.8 Intact to 10.5'; 10.5'-11.3' is broken 8 11.3 - 12.7 1.4 Broken 9 12.7 - 13.3 0.6 Rubble SMF Name: 941 Borehole name: ESF-SD-ClV#29 ESF Station 34+60 Completion date: 4/6/1999 Total depth (ft) 13.2 Run # Interval (ft) Recovery Fractures/Comments Unrecovered (ft) Core Interval (ft) 1 0.0 - 2.9 2.6 Broken by 6-10 discrete fracs 2 2.9 - 5.8 2.9 Intact w/ 4-5 discrete fracs 3 5.8 - 7.5 1.7 Broken 4 7.5 - 8.9 1.2 Broken to rubble 5 8.9 - 10.7 1.3 Intact to ~10.0' 6 10.7 - 13.2 1.6 Broken SMF Name: 942 Borehole name: ESF-SD-ClV#30 ESF Station 34+55 Completion date: 4/5/1999 Total depth (ft) 13.4 Run # Interval (ft) Recovery Fractures/Comments Unrecovered (ft) Core Interval (ft) 1 0.0 - 0.6 0.3 3 small chunks 2 0.6 - 3.3 2.7 Broken 3 3.5 - 5.9 1.7 Broken to rubble 4 5.9 - 8.5 2.5 Broken 5 8.5 - 10.5 2 Rubble to broken 6 10.5 - 11.8 0.9 Rubble 7 11.8 - 13.4 1.8 Broken Video Log Observations from Validation Study Boreholes SMF Name: 943 Borehole name: ESF-SD-ClV#31 ESF Station 34+50 Completion date: 4/2/1999 Total depth (ft) 13.0 Run # Interval (ft) Recovery Fractures/Comments Unrecovered (ft) Core Interval (ft) 1 0.0 - 0.9 0.7 Broken 2 0.9 - 1.1 0.2 1 chunk 3 1.1 - 2.2 1 Broken w/ 4-5 transverse fracs 4 2.2 - 2.8 0.6 Broken 5 2.8 - 3.8 1 Broken 6 3.8 - 4.7 0.7 Broken 7 4.7 - 7.8 2.6 Rubble - 4.7'-6.2' in Lexan 8 7.8 - 11.0 0.7 Rubble 9 11.0 - 13.0 1.6 Rubble SMF Name: 944 Borehole name: ESF-SD-ClV#32 ESF Station 34+45 Completion date: 4/1/1999 Total depth (ft) 13.2 Run # Interval (ft) Recovery Fractures/Comments Unrecovered (ft) Core Interval (ft) 1 0.0 - 0.7 0.6 Broken 2 0.7 - 3.3 2.6 0.7'-2.5' broken 3 3.3 - 7.6 4.1 Broken w/ longitudinal fracs 4 7.6 - 9.6 2.0 Intact 5 9.6 - 10.4 0.2 1 chunk 6 10.4 - 13.2 3.5 10.8'-11.7' fracture zone SMF Name: 945 Borehole name: ESF-SD-ClV#33 ESF Station 34+40 Completion date: 3/31/1999 Total depth (ft) 13.4 Run # Interval (ft) Recovery Fractures/Comments Unrecovered (ft) Core Interval (ft) 1 0.0 - 0.8 0.6 Broken 2 0.8 - 3.0 2.1 2.0'-3.0' broken 3 3.0 - 6.2 3 4.0'-6.2' broken 4 6.2 - 9.5 2.7 6.8'-7.0' frac zone; 7.5'-9.5' longitudinal frac 5 9.5 - 11.4 2.5 Intact w/ ~ 3 fracs 6 11.4 - 13.9 1.4 Partially broken Video Log Observations from Validation Study Boreholes SMF Name: 946 Borehole name: ESF-SD-ClV#34 ESF Station 34+35 Completion date: 3/30/1999 Total depth (ft) 13.3 Run # Interval (ft) Recovery Fractures/Comments Unrecovered (ft) Core Interval (ft) 1 0.0 - 1.4 0.9 Broken 6 3.0 - 3.8 0.5 Rubbly 7 3.8 - 4.8 1 Intact w/ ~ 3 fracs 8 4.8 - 7.7 2.8 4.8'-6.6' rubbly; 6.6'-7.7' intact w/ ~2-3 fracs 9 7.7 - 8.3 0.5 Rubbly 10 8.3 - 13.3 4.7 8.3'-10.0' rubbly; 10.4'-10.5' frac zone; 11.2'-13.0' longitudinal frac 2 2.2 - 4.0 1.8 Broken to rubbly 3 4.0 - 6.3 1.9 Intact w/ ~ 2 fracs 4 6.3 - 6.4 0.1 1 chunk 5 6.4 - 8.5 2.1 6.3'-8.5' broken 6 8.5 - 9.2 0.5 Several chunks 7 9.2 - 11.4 2.4 10.5'-10.7' broken zone; 11.2'-11.4' broken 8 11.4 - 11.6 0.2 1 chunk 9 11.6 - 12.8 1.2 Intact w/ 2-3 fracs 10 12.8 - 13.3 0.5 2 1.4 - 1.8 0.4 Broken 3 1.8 -2.1 0.3 Broken 4 2.1 - 2.5 0.3 Broken 5 2.5 - 3.0 0.6 Broken SMF Name: 947 Borehole name: ESF-SD-ClV#35 ESF Station 34+30 Completion date: Total depth (ft) 3/26/1999 13.3 Run # 1 Interval (ft) 0.0 - 2.2 Recovery (ft) Fractures/Comments 1.9 Broken Unrecovered Core Interval (ft) SMF Name: 948 Borehole name: ESF-SD-ClV#36 ESF Station 34+25 Completion date: 3/25/1999 Total depth (ft) 13.3 Run # Interval (ft) Recovery Fractures/Comments Unrecovered (ft) Core Interval (ft) 1 0.0 - 1.0 0.7 Rubbly 2 1.0 - 2.7 1.4 1.4'-2.4' broken 3 2.7 - 3.4 0.8 ~4 fracs - broken 4 3.4 - 3.9 0.5 Rubbly 5 3.9 - 6.7 2.8 Broken 6 6.7 -9.1 2.4 6.7'-7.0' rubbly; 7.0'-9.1' intact w/ ~4 fracs 7 9.1 - 9.4 0.3 1 chunk 8 9.4 - 10.6 1.2 Intact w/ ~ 5 fracs 9 10.6 - 10.8 0.2 2 chunks 10 10.8 - 13.3 1.3 10.8'-12.1' rubbly Video Log Observations from Validation Study Boreholes SMF Name: 949 Borehole name: ESF-SD-ClV#37 ESF Station 34+20 Completion date: 3/24/1999 Total depth (ft) 13.3 Run # Interval (ft) Recovery Fractures/Comments Unrecovered (ft) Core Interval (ft) 1 0.0 - 0.3 0.3 2 blocks 2 0.3 - 0.9 0.4 4 blocks 3 0.9 - 1.3 0.6 1 block 4 1.3 - 5.9 4 1.3'-3.0' broken; 3.0'-5.9 intact w/ 2-3 discrete fracs 5 5.9 - 8.9 3.8 Intact w/ ~7 discrete fracs 6 8.9 - 9.7 ? ? 7 9.7 - 13.3 3.3 9.7'-11.2' intact w/ ~3 fracs; 11.4'-13.0' broken SMF Name: 950 Borehole name: ESF-SD-ClV#38 ESF Station 34+10 Completion date: 3/23/1999 Total depth (ft) 13.2 Run # Interval (ft) Recovery Fractures/Comments Unrecovered (ft) Core Interval (ft) 1 0.0 - 0.6 0.4 Broken @ top 2 0.6 - 1.4 0.8 4 fracs over 0.8' ~"broken" 3 1.4 - 6.1 4.4 1.4'-2.6' intact; 2.6'-5.0' broken to rubbly; 5.0'-6.1' intact 4 6.1 - 9.1 2.9 Intact w/ 4-5 discrete fracs 5 9.1 - 11.0 1.7 9.1'-9.8' rubbly; 10.5'-10.8' broken 6 11.0 - 12.7 1.7 11.0'-11.5' imbricate slices; 11.5'-12.7' intact 7 12.7 - 13.2 0.4 ? SMF Name: 951 Borehole name: ESF-SD-ClV#39 ESF Station 33+98 Completion date: Total depth (ft) 3/19/1999 13.4 Run # 1 Interval (ft) 0.0 - 2.1 Recovery (ft) Fractures/Comments 1.9 Intact - 3 total (1@0.2 & 2@2.1) Unrecovered Core Interval (ft) 2 2.1 - 5.7 3.6 Intact to ~5.0'; broken btwn 5.0-5.3'; rubbly btwn 5.4-5.7' 3 5.7 - 7.8 2.1 Rubbly btwn ~6.6'-6.9'; 2-3 fracs @~7.3' 4 7.8 - 8.0 0 Unrecovered 5 8.0 - 9.3 Broken btwn 8.6'-9.3' 6 9.3 - 10.1 0.8 Rubbly 7 10.1 - 11.0 0.7 Broken 8 11.0 - 13.4 2.4 Broken btwn 11.0'-12.1'; broken btwn 12.6'-13.4' Video Log Observations from Validation Study Boreholes SMF Name: 952 Borehole name: ESF-SD-ClV#40 ESF Station 33+89 Completion date: 3/17/1999 Total depth (ft) 13.3 Run # Interval (ft) Recovery Fractures/Comments Unrecovered (ft) Core Interval (ft) 1 0.0 - 1.2 Intact - Complex frac. w/ cc filling 2 1.2 - 5.2 3.8 Intact - 4-5 discrete fracs 3 5.2 - 6.0 0.7 Intact - 2 discrete fracs 4 6.0 - 8.1 2.1 Intact - 2 discrete fracs 5 8.1 - 8.9 0.8 Intact - 2 discrete fracs 6 8.9 - 11.6 2.7 5-6 fracs mostly btwn 10.5'-11.6' 7 11.6 - 12.3 0.6 Rubbly 8 12.3 - 13.3 1 1-2 @ ~12.9' Source: Paces (2003) NOTE: The information contained in this Appendix is not considered to be data, and it has not been collected under any formal QA procedure. INTENTIONALLY LEFT BLANK APPENDIX C ACCELERATOR MASS SPECTROMETRY METHODS INTENTIONALLY LEFT BLANK C1. OVERVIEW OF YUCCA MOUNTAIN PROJECT CHLORINE-36 WORK AT LAWRENCE LIVERMORE NATIONAL LABORATORY Work at Lawrence Livermore National Laboratory (LLNL) supporting the chlorine-36 (36Cl) validation study was carried out in two phases, each involving somewhat different techniques, approaches, and personnel. The first phase occurred primarily in 2000, with the work consisting of active leaching of rock core samples, chlorine extraction from the leachate, chlorine concentration determination of the leachate by ion chromatography, and measurement of the 36Cl/Cl ratio of the chlorine by accelerator mass spectrometry (AMS). The second phase occurred during the latter part of 2001 and continued through 2002, with the work consisting of chlorine extraction from leachates that were prepared by passive leaching at the U.S. Geological Survey (USGS) in Denver, chlorine concentration determination by measurement of the 35Cl/37Cl ratio by AMS in isotopically spiked samples, and measurement of the 36Cl/Cl ratio of the chlorine by AMS. The AMS measurements were made at the Center for Accelerator Mass Spectrometry (CAMS) at LLNL. The primary differences between the work in 2000 and that in 2001 and 2002 were that (1) the leachates were derived from active (about 7 hours) leaching at LLNL in 2000, whereas they were derived from passive leaching (about 1 hour) at the USGS in 20012002, and (2) chlorine concentration determination was by ion chromatography in 2000, but was by isotope dilution AMS in 2001-2002. The difference in method of chlorine concentration measurement had no effect on the outcome of the project, and precisions are regarded as similar between the ion chromatography and the AMS methods. Both methods produced agreement between aliquots measured at the USGS and with independent samples measured at Los Alamos National Laboratory (LANL). The difference in leaching techniques (active versus passive), however, did affect the outcome of the project. Active leaching produced a far higher concentration of chlorine than passive leaching, resulting in more chlorine being available for AMS analysis. This produced lower and more unstable AMS ion beam currents, which ultimately produced lower statistical analytical precision, as well as lower confidence in the replicability of the analysis. The latter concern, however, is lessened by the generally good replication of the two split aliquots prepared by LANL and LLNL, respectively, measured in the November 2001 AMS run. In 2001-2002, silver chloride (AgCl) samples were prepared at LANL and sent to LLNL for measurement of 36Cl/Cl and 35Cl/37Cl by AMS. The samples were treated for AMS analysis in every respect like the AgCl samples prepared at LLNL. Therefore, the discussion below concerning the procedures for AMS analysis of LLNL AgCl samples also applies to the LANL AgCl samples. Active and passive leaching procedures are discussed in the body of this report. This appendix discusses the details of the LLNL procedures for chlorine extraction, chlorine concentration measurement, and 36Cl/Cl and 35Cl/37Cl determination by AMS. C2. PROCEDURES FOR CHLORINE EXTRACTION FROM LEACHATE C2.1 Year 2000 Procedures Leachate solutions produced in 2000 ranged in size from about 2100 to about 3800 g. Of this liquid, one or two small (about 50 mL) aliquots were removed for ion chromatography chlorine concentration analysis. The remainder was then weighed and a pre-weighed amount of chlorine carrier (36Cl-free chloride salt) was added to the solution. The main purpose of this carrier was to increase the mass of chloride in the solution to facilitate chlorine extraction. The carrier chlorine itself was measured for its 36Cl content during every AMS run to ensure that no additional 36Cl was being added to the sample during carrier addition. Because of the very large amount of liquid involved, extraction of chloride relied on pumping the sample through an ion-exchange column containing AG-4X anion resin, using a peristaltic pump. The column was initially conditioned using three applications of 40 mL of high-purity nitric acid (HNO3 in two 1N applications and one 2.5N application). After all the leachate had passed through the column, chloride was eluted by applying three elution rinses of 40 mL 1N high-purity ammonium hydroxide (NH4OH) solution. Chlorine was then extracted from this solution using the chlorine extraction procedure described below, which also was used in 2001-2002. C2.2 Years 2001-2002 Procedures There were three main differences in procedures used between 2000 and 2001-2002. First, in 2001-2002, the leachate solution was created at the USGS and smaller sample sizes than those of 2000 were available (less than 2 L). It was felt that the smaller sample sizes did not require the anion column extraction method, and so this was not used. Second, no leachate aliquot was removed at LLNL for chlorine concentration analysis, although aliquots were removed and analyzed in Denver by the USGS. Third, for 20012002, the chlorine isotope tracer with a known 35Cl/37Cl ratio (TIP-CL-95, Preparation of Samples for Chlorine-36 Analysis) was added to the sample, and this was used in the AMS analysis for isotope dilution chlorine concentration determination. Other than these differences, the chlorine extraction procedures for both project phases were similar, as described in the following paragraphs. C2.3 Chloride Extraction Procedures The leachate solution was placed in an appropriately sized pre-cleaned glass beaker (typically 250 mL in 2000, and 1 L in 2001-2002). In 2001-2002, the sample was weighed prior to being placed in the beaker (in 2000, the sample was weighed prior to being passed through the anion column). In 2001-2002, the tracer solution was then added to the leachate (the carrier was added prior to the columns in 2000). The sample was then acidified by addition of concentrated high-purity nitric acid (HNO3). Silver was added to the solution in the form of a 5 percent solution of silver nitrate (AgNO3). Under acidic conditions, AgNO3 is dissociated while AgCl becomes insoluble, leading to the precipitation of AgCl. The sample was then left to sit overnight, covered with parafilm and enclosed in a Plexiglass® hood for contamination protection, during which time the AgCl flocculated to the bottom of the beaker. The leachate solution (now chlorine-free) was then carefully removed from the beaker, leaving behind the AgCl precipitate. The precipitate was dissolved in less than 40 mL of a 1:1 solution of ultra-clean Milli-Q® deionized water (resistivity greater than 17.5 megaohm-cm) and concentrated high-purity ammonium hydroxide (NH4OH), and this solution was transferred to capped centrifuge tubes for further processing. The sample was then reprecipitated using HNO3 and centrifuged before the supernate was poured off. The precipitate was washed twice with ultra-clean Milli-Q® water, each time vortexing to break up the precipitate in the centrifuge tube and centrifuging to re-assemble the AgCl in the bottom of the tube. After each of the washings, the supernate water was poured off and after the first washing replaced with about 6 mL of clean Milli-Q® water. After the second washing, the sample was redissolved in a less than 10 mL solution of 1:1 NH4OH (as above), filtered through a pre-cleaned 0.45-µm cellulose nitrate membrane syringe filter attached to the tip of a 10-mL capacity medical-grade syringe. HNO3 was added to the sample until AgCl again precipitated. The precipitate was then washed three times in Milli-Q® water, using the vortexing/centrifuging alternation used for the first water washings. After the final washing, the sample was dried overnight in its centrifuge tube in a small laboratory convection oven at about 70ºC. The dried AgCl sample was then ready for mounting into an AMS target for 36Cl analysis. Although chlorine extraction procedures were somewhat different at LANL, the final product—the AgCl sample—was the same, and it was this sample that was sent to LLNL for AMS analysis. Therefore, from this stage onward, the sample handing and analysis was the same for samples originating at LANL and samples processed at LLNL. Typically, between four and seven samples were prepared simultaneously. With each preparation episode, one to three chemical extraction blanks were prepared. These samples were treated exactly like the actual samples, except that ultra-clean Milli-Q® water was used instead of a leachate solution. The same amount of reagents, AgNO3, and carrier or tracer solutions were added to the chemical extraction blanks as were added to the samples. These blanks were then analyzed by AMS during the sample runs to determine the amount of 36Cl being added to the sample by the reagents, AgNO3, and carrier/tracer. The amount of 36Cl added, as determined by this measurement, was subtracted from the measured values of each actual sample during data reduction. The 36Cl/Cl ratios reported by LLNL (DTNs: LL030408023121.027 [Q] and LL031200223121.036 [Q]) reflect this subtraction. In all cases, the amount subtracted was extremely minor, because very little 36Cl was ever detected in the blanks. C3. PROCEDURES FOR DETERMINATION OF LEACHATE CHLORINE CONCENTRATIONS C3.1 Year 2000 Procedures Chlorine concentrations were measured by ion chromatography at LLNL in 2000. Details of the analytical procedure are described in TIP-CL-110, Use of Ion Chromatography to Determine Anion Concentrations, and will not be discussed here. However, a few of the most pertinent points will be mentioned. The instrument used was a commercially available Dionex AI-450 Ion Chromatograph, using the imbedded Dionex PeakNet software for instrument control and data reduction. The eluent used was a solution of NaHCO3 + Na2CO3, in about 1:1 molar amounts. The microbore piston option was used, allowing a liquid flow of 0.3 mL/min at a pressure of about 1,400 psi. This produced an anion column retention time for chlorine of about 3.8 min. Total collection time for the ion chromatography spectrum was 14 min. Sample concentrations were derived by reference to standard solutions with nominal values of 0.3, 0.5, 2.0, and 3.0 µg/g chlorine. The standards were prepared from a commercially available NIST-traceable (confirmation vs. SRM 3182) 1,000 µg/g stock standard solution. Preparation of standard solutions used for the ion chromatography calibration curve was done using a 100-g capacity, 0.1 percent sensitivity (quantities greater than 0.4 g) analytical balance. Because the analyses were done over a short time period, the same calibration curve could be used for all of the analyses. The calibration was by peak area (as opposed to height), with a linear fit curve forced through the origin. The r2 value of the fit of the calibration standards to the curve was 0.9796. Due to time pressures, all samples were analyzed only once, which was allowed by the controlling technical implementation procedure (TIP-CL-110). Analytical precision can be assessed only by replication of standard solutions run as unknowns, including some standards not used to derive the calibration curve. Replication ranges from about 6 percent at the 0.5 µg/g chlorine level, to about 2 percent at the 3.0 µg/g level. Most samples analyzed by ion chromatography in this project had concentrations greater than 1 µg/g, and an analytical error of 5 percent (2s) has been assigned to all of the analyses. This appears to be sufficiently conservative. C3.2 Years 2001-2002 Procedures The procedure used for chlorine concentration determination in 2001-2002 was isotope dilution mass spectrometry using the LLNL AMS. The method employs the variation between the measured 35Cl/37Cl ratio in the sample and the measured 35Cl/37Cl ratio in the tracer that has been added to the sample (as discussed above). The measured deviation from the tracer 35Cl/37Cl value (~0.9 in this project) is due to the addition of the natural chlorine in the leachate (with the terrestrial natural 35Cl/37Cl ratio of 3.127). The magnitude of the deviation is directly related to the concentration of chloride in the leachate sample. Therefore, the leachate sample concentration can be calculated from the magnitude of the deviation. This method is the same as the standard isotope dilution method commonly used in mass spectrometry, and the calculations used to derive the sample chlorine concentration from the measured values also are commonly recognizable. For this project, the tracer 35Cl/37Cl ratio was measured in one or more tracer-only (“blank”) samples during the course of each run. To account for instrumental mass bias, the value was normalized to the 35Cl/37Cl ratio measured in the AMS standards (LLNL111) used during the run. It was this in-run value for the tracer that was used during data reduction. The conditions of the AMS analysis pertinent to the isotope dilution 35Cl/37Cl measurement are discussed in the following section. C4. PROCEDURES FOR DETERMINATION OF CHLORINE-36/CHLORINE AND CHLORINE-35/CHLORINE-37 BY ACCELERATOR MASS SPECTROMETRY Samples were analyzed for chlorine isotopes using the FN tandem accelerator mass spectrometer housed within the CAMS at LLNL. Samples are ionized to negative chlorine ions by bombardment with a cesium ion beam in the instrument source. The negative ions are then extracted, using a positive electrical potential, into the beamline of the instrument where the ion particles are accelerated to 8.3MV within the tandem accelerator. In the center of the tandem, the ion beam is passed through a thin carbon foil, which breaks up molecular species that can be mass/energy interferences and also strips electrons from the chlorine anions, creating positively charged chlorine cations. The cations are then further accelerated by a negative electrical potential to the end of the tandem unit, where they pass into a long instrument beamline with extensive beam focusing, steering, and deflecting capabilities, including two 90º curvature mass- separation magnets that separate the three chlorine isotopes into separate streams. The stream (beam) that finally makes it to the detector is composed almost entirely of 36Cl ions, although an unwanted amount of interfering 36S can still be present. The ions are detected through 5-fold coincident detection of electrons given off during collisional interaction between the ions and gas within the detector (i.e., five coincident detections equals one 36Cl count). This provides the mechanism for discriminating between 36Cl ions and 36S ions within the detector, because the very small difference in mass between the two species produces different energy loss during gas interaction and therefore different coincident detection patterns. Two Faraday cups located between the two 90º magnets measure the currents of 35Cl and 37Cl. The ratio of the currents normalized to those of the standards is the 35Cl/37Cl ratio. Procedures specific to the 36Cl analyses for the two phases of this project are given in the following sections. C4.1 Year 2000 Procedures The AMS procedures used in 2000 are identical to those used in 2001-2002, except that the 35Cl/37Cl ratio was not measured because the isotope dilution technique for chlorine concentration determination was not used. A substantial difference between the two phases of the project exists, however, due to the larger AgCl sample sizes obtained in 2000. The larger AgCl sizes were due both to the higher chlorine concentrations of the leachates and to the larger leachate volumes available for analysis. Larger amounts of AgCl result in larger and more stable AMS beam currents, resulting in greater analytical precision and probably greater replicability of results. This is discussed more fully below with respect to the procedures for 2001-2002. C4.2 Years 2001-2002 Procedures In order to place AgCl samples within the AMS instrument for analysis, the AgCl must be placed in stainless steel holders, commonly called “targets.” The targets are small, hollow cylinders about 1 inch long, with an inner diameter opening of about 0.25 inches. They are closed at one end, giving them the appearance of a small bullet casing (shell). The center of the target is filled with silver bromide (AgBr), which eliminates 36Cl and 36S contamination derived from the stainless steel and acts as a thermal and electrical buffer to the AgCl during analysis. A small hole is drilled into the center of the AgBr into which the AgCl of the sample is packed. It has been standard practice through the years to use at least about 3 mg AgCl for an analysis. This amount was available in 2000, but not in 2001-2002. During this second phase, samples as small as 0.3 mg AgCl were used, for which a smaller diameter hole was drilled in the target AgBr. The purpose of drilling smaller diameter holes is to slow ionization and prolong the analysis as much as possible, so that several determinations of a single sample can be made during the course of the analytical day. This produces better between-determination statistics and more confidence in the individual determinations. However, this method has at least three important negative effects. First, the smaller diameter of the sample hole produces a smaller ion “cloud” in the source, resulting in smaller beam currents for the same extraction potential. A typical 37Cl beam current (measured in the Faraday cup) for a 3 mg AgCl sample is about 20 µA, whereas beam currents for 2001-2002 samples (small holes) were often in the 1 to 5 µA range. Because extraction potential cannot be substantially increased without causing electrical instability within the source, beam currents cannot be “artificially” increased for small samples. For the same duration of analysis, smaller beam currents produce fewer 36Cl detector counts than normal beam currents, and this of course produces poorer within-determination statistical precision (most simplistically, 1/vn). Second, the smaller samples were expended during the course of analysis, so that more 36Cl counts (better statistics) could not be achieved simply by running the sample for a longer period. This also produced fewer individual determinations during the course of the run (the larger samples analyzed in 2000 typically had three to five determinations during the course of the run, while 2001-2002 samples often had only one or two determinations). Third, the cesium beam that causes the initial ionization “rasters” over the small region of the AgCl in the target and this cannot be made smaller to accommodate the smaller diameter holes. Inevitably, the cesium beam “rasters” outside of the AgCl area into the AgBr area. When this happens, chlorine ionization decreases. The fluctuation in ionization causes a fluctuation in beam current. The efficiency of the various mass and energy filters in the AMS beamline depends on the strength of the beam current, such that beam instability translates into greater within-determination variability in the various isotope beam currents. That is, the measured variability in the 36Cl/Cl or the 35Cl/37Cl ratios increases with increased variability in beam current. Due to the intrinsic differences in beam sizes for the chlorine isotopes, this effect is more pronounced for the 36Cl/Cl ratio than for the 35Cl/37Cl ratio. Therefore, the precision of the 35Cl/37Cl ratio is not substantially worsened. These three effects can be summarized by saying that smaller sample sizes lead to increased analytical uncertainty for 36Cl/Cl. This problem is compounded by the fact that the LLNL AMS facility has had little experience with replication of small (less than 1 mg AgCl) samples or standards over time. Replication of samples or standards over the course of months or years produces an understanding of the instrumental variability that can occur, which would take the form of a time integrated assessment of true analytical precision. The facility experience gathered over more than a decade of analyzing 36Cl from samples greater in size than 3 mg AgCl indicates that the true analytical uncertainty is better than ±5 percent for 36Cl/Cl ratios. This is believed to apply to the samples for the 2000 phase of this project, but for samples for 2001-2002, the true analytical uncertainty may not bethat low. However, the reasonably good sample replication achieved during the November 2001 AMS run between the samples chemically processed at LANL and their aliquot splits chemically processed at LLNL demonstrated that the uncertainty is not exceedingly large. In all cases, the analytical precisions reported (DTNs: LL030408023121.027 [Q] and LL031200223121.036 [Q]) are the within-run analytical precisions as derived through the statistical treatment of the data reduction code used for all years of this project (FUDGER3.1), and reflect what are commonly referred to as “counting statistics.” The AMS 36Cl/Cl standard used for the project (“LLNL111”) is a NIST-traceable 36Cl standard, which has been gravimetrically adjusted with 36Cl-free chloride salt to produce a 36Cl/Cl ratio of 111 x10-15 . This was done using a 100-g capacity, 0.1 percent sensitivity (quantities greater than 0.4 g) analytical balance. The final 36Cl/Cl ratio was confirmed against the original standard material as well as several in-house standards that have been in use for many years. Data reduction for both phases of this project was accomplished in two basic steps. The first used the computer program FUDGER3.1, which was developed at LLNL. The program reads the original data file from the AMS instrument and allows the analyst to assess the quality of each individual determination through examination of variables, such as sulfur count rates, total 36Cl counts registered, and individual determination deviations relative to other determinations for that sample on that day. Individual determinations, including LLNL111 determinations, can be deleted from the data set on this basis. The program then normalizes each sample determination relative to determinations for the LLNL111 standard, using a weighted average (based on the precision of the standard determination) of the four LLNL111 determinations made closest in time to that of the sample. The values for each determination are then averaged, weighting them relative to the precision of the determination. These values are then output as a tab-delimited text file. The second step in data reduction involves derivation of final 36Cl/Cl ratios, 35Cl/37Cl ratios, and chlorine concentrations by Excel spreadsheet calculations incorporating the required external data (e.g., leachate sample size, amount of added carrier/tracer, and blank subtraction). All steps in the calculations are included in the spreadsheets submitted to the Yucca Mountain Project Technical Data Management System (TDMS) database (DTNs: LL030408023121.027 [Q] and LL031200223121.036 [Q]). C.5 REFERENCES CITED C.5.1 CODES, STANDARDS, REGULATIONS AND PROCEDURES TIP-CL-95, Rev. 0. Preparation of Samples for Chlorine-36 Analysis. Livermore, California: Lawrence Livermore National Laboratory. ACC: MOL.20000412.0094. TIP-CL-110, Rev. 0. Use of Ion Chromatography to Determine Anion Concentrations. Livermore, California: Lawrence Livermore National Laboratory. ACC: MOL.20000301.0188. C.5.2 SOURCE DATA, LISTED BY DATA TRACKING NUMBER LL030408023121.027. Cl Abundance and Cl Ratios of Leachates from ESF Core Samples. Submittal date: 04/17/2003. (Q) LL031200223121.036. Cl Abundance and Cl Ratio of Leachates from ESF Core Samples. Submittal date: 12/03/2003. (Q) Sources: Modified from DOE (2002, Figure 1-14) and USBR (1996) Figure 1-1. Generalized Map of Central Yucca Mountain (A) and Schematic Geologic Section along the ESF Showing the Sundance Fault Zone Validation Study Area (B) TDR-NBS-HS-000017 REV00 F1 DTNs: LAJF831222AQ98.004 (Q), LA0509JF831222.001 (Q) NOTES: ESF = Exploratory Studies Facility. Error bars are 2s. The 1996 report is Fabryka-Martin, Wolfsberg et al. (1996). The 1997 report is Fabryka-Martin et al. (1997). The 1998 report is CRWMS M&O (1998). Figure 2-1. Distribution of Chloride Concentrations (A) and 36Cl/Cl Ratios (B) in the ESF, as Reported by LANL in 1996, 1997, and 1998 TDR-NBS-HS-000017 REV00 F2 0 5 10 15 20 25 30 Number of faults and shears per33.3 m interval 0 500 1,000 1,500 2,000 2,500 3,000 3,500 4,000 36 Cl/Cl ×10 15 Fault/Shear intensity ³6Cl/Cl sample 0 1,000 2,000 3,000 4,000 5,000 6,000 7,000 8,000 Distance from the ESF north portal (m) DTNs: GS960708314224.008 (Q), GS960708314224.010 (Q), GS000608314224.004 (Q), GS960908314224.014 (Q), GS970208314224.003 (Q), GS970808314224.008 (Q), GS970808314224.010 (Q), GS970808314224.012 (Q), GS971108314224.020 (Q), GS971108314224.021 (Q), GS971108314224.022 (Q), GS971108314224.023 (Q), GS971108314224.024 (Q), GS971108314224.025 (Q), GS971108314224.026 (Q), GS971108314224.028 (Q) See also Appendix A, which contains information regarding sample numbers, locations, and types. NOTE: ESF = Exploratory Studies Facility. Figure 2-2. Relations between Fault/Shear Intensity as Mapped in the ESF and 36Cl/Cl Ratios for Samples Described as Localities Associated with Faults or Shears A. 4,500 1996 LANL report 4,000 ESF-DHW-ClV Borehole 3,500 36Cl/Cl x10 15 3,000 2,500 2,000 1,500 Bomb-pulse threshold for 36Cl 1,000 500 Holocene meteoric value for 36Cl 0 1,500 1,700 1,900 2,100 2,300 2,500 Distance from ESF North Portal (m) Drill Hole Wash fault 1,000 Holocene meteoric value for 36Cl 500 0 1,880 1,890 1,900 1,910 1,920 1,930 1,940 1,950 1,960 1,970 1,980 Distance from ESF North Portal (m) DTN: LAJF831222AQ98.004 (Q) NOTES: ESF = Exploratory Studies Facility, LANL = Los Alamos National Laboratory. The 1996 LANL report is Fabryka-Martin, Wolfsberg, et al. (1996). Figure 3-1. Distribution of 36Cl along the Drill Hole Wash Fault Zone in the ESF, between 1,500 and 2,500 meters (A) and between 1,880 and 1,980 meters (B), as Reported by LANL in 1996 B. 4,500 1996 LANL report 4,000 ESF-DHW-ClV Borehole 3,500 36Cl/Cl x10 15 3,000 2,500 2,000 1,500 Bomb-pulse threshold for 36Cl Bomb-pulse threshold for 36Cl Holocene meteoric value for 36Cl DTNs: LAJF831222AQ98.004 (Q), LA0509JF831222.001 (Q) NOTES: ESF = Exploratory Studies Facility, LANL = Los Alamos National Laboratory. The 1996 LANL report is Fabryka-Martin, Wolfsberg et al. (1996), and the 1998 LANL report is CRWMS M&O (1998). Figure 3-2. Distribution of 36Cl in and adjacent to the Sundance Fault in the ESF, as Reported by LANL in 1996 and 1998 Fracture density (fracures per m averaged to 10 m intervals) 14 12 10 8 6 4 2 0 0 5001,0001,5002,0002,5003,0003,5004,0004,5005,0005,5006,0006,5007,0007,500 Distance from ESF north portal (m) DTNs: GS960708314224.008 (Q), GS960708314224.010 (Q), GS000608314224.004 (Q), GS960908314224.014 (Q), GS970208314224.003 (Q), GS970808314224.008 (Q), GS970808314224.010 (Q), GS970808314224.012 (Q), GS971108314224.020 (Q), GS971108314224.021 (Q), GS971108314224.022 (Q), GS971108314224.023 (Q), GS971108314224.024 (Q), GS971108314224.025 (Q), GS971108314224.026 (Q), GS971108314224.028 (Q) NOTE: ESF = Exploratory Studies Facility. Figure 3-3. Distribution of Fracture Densities in the ESF A.. B.. DTNs: GS971108314224.023 (Q), GS971108314224.024 (Q) NOTE: ESF = Exploratory Studies Facility. Figure 3-4. Histograms Showing Linear Spacing (A) and Log Spacing (B) between Fractures and Cooling Joints Longer than 1 Meter, Measured from Detailed Line Surveys between ESF Stations 16+00 and 21+00 A. B. DTNs: GS000608314224.004 (Q), GS960708314224.008 (Q) NOTE: ESF = Exploratory Studies Facility. Figure 3-5. Histograms Showing the Linear Spacing (A) and Log Spacing (B) between Fractures and Cooling Joints Longer than 1 Meter, Measured from Detailed Line Surveys between ESF Stations 34+00 and 36+00 Source: USGS (1996) NOTES: ESF = Exploratory Studies Facility. Station values represent hundreds of meters from the north portal of the ESF. Projection of the Sundance fault is estimated from tunnel-wall intersections shown on full- periphery map (USGS 1996). Coordinates are Nevada State Plane (NAD27) in meters. Figure 3-6. Schematic Map Showing General Relations of Niche #1 to the ESF Main Drift and Sundance Fault, and the Orientations of Niche Boreholes Used for the Validation Study DTNs: LA0509JF831222.001 (Q); LA0305RR831222.001 (UQ); LL031200223121.036 (Q), Filename: Total_AMS_Summary_2001-02c.xls NOTES: LANL = Los Alamos National Laboratory, LLNL = Lawrence Livermore National Laboratory, USGS = U.S. Geological Survey. Bold alphanumeric symbols to the right of individual core intervals are reference codes identifying multiple core intervals composited into single samples, keyed to sample details given in Table 3-3. Figure 3-7. Distribution of Niche #1 Core Intervals Used for the Validation Study TDR-NBS-HS-000017 REV00 F10 0 50 100 150 200 250 300 350 400 36 Cl / Cl x1015 -1.0 -0.5 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 Leachate Cl concentration (mg/kg rock) ³6 Cl/Cl ratio Cl concentration 3,300 3,400 3,500 3,600 3,700 Distance from the ESF north portal (m) DTN: LL030408023121.027 (Q), Filename: Total_AMS_Summary_2000.xls NOTES: ESF = Exploratory Studies Facility. Error bars represent 2s analytical uncertainties. Borehole locations are listed in Table 3-2. Figure 4-1. Chloride Concentrations and 36Cl/Cl Ratios in Active Leachates of Validation Study Samples Processed and Analyzed at LLNL during Phase I A. 0 1 2 3 4 5 6 7 8 0 - 1.0 1.0 1.4 1.8 2.2 2.6 3.0 3.4 3.8 Frequency N = 25 Maximum = 3.54 mg/kg Minimum = 1.25 mg/kg Median = 2.13 mg/kg Mean = 2.07 mg/kg Std. Deviation = 0.62 mg/kg 1.4 1.8 2.2 2.6 3.0 3.4 3.8 4.2 Leachate Cl concentration (mg/kg rock) 0 1 2 3 4 5 6 7 8 9 10 Frequency N = 25 Maximum = 248 ×10-15 Minimum = 48 ×10-15 Median = 88 ×10-15 Mean = 97 ×10-15 Std. Deviation = 43 ×10-15 B. 0 -25 -50 -75 -100 -125 -150 -175 -200 -225 -250 25 50 75 100 125 150 175 200 225 250 275 36Cl / Cl ×1015 DTN: LL030408023121.027 (Q) Figure 4-2. Distribution of Chloride Concentrations (A) and 36Cl/Cl Ratios (B) in Active Leachates of Validation Study Samples Processed and Analyzed at LLNL during Phase I A. y = 94.3x + 41.1 R2 = 0.2 0 50 100 150 200 250 300 36 Cl/Cl ×10 15 LLNL active-leach results LANL powdered-rock leachate 0.0 0.2 0.4 0.6 0.8 1.0 1 / [leachate Cl concentration] (kg rock / mg Cl) B. 10 100 1,000 10,000 36 Cl/Cl ×10 15 LANL passive-leach results LLNL active-leach results N = 293 Median [Cl] = 1.0 mg/kg Median 36Cl/Cl = 569 ×10-15 N = 25 Median [Cl] = 2.1 mg/kg Median 36Cl/Cl = 85 ×10-15 0.01 0.1 1 10 1 / [leachate Cl concentration] (kg rock / mg Cl) DTNs: LL030408023121.027 (Q), LAJF831222AQ98.004 (Q) NOTES: LANL = Los Alamos National Laboratory, LLNL = Lawrence Livermore National Laboratory. The open diamond in (A) is a statistical outlier that was not included in the regression. LANL data in (A) are from Table 5-4 of Fabryka-Martin, Wolfsberg et al. (1996). LANL data in (B) are listed in Appendix A. LLNL data in (B) are listed in Table 4-1. Error bars are 2s. Figure 4-3. Relations between Reciprocal Chloride Concentrations and 36Cl/Cl Ratios in Active Leachates of Validation Study Samples Processed and Analyzed at LLNL during Phase I (A), and for Passive Leachates of ESF Samples Reported Previously by LANL (B) DTN: LA0305RR831222.001 (UQ) NOTES: The figures plot measured and cumulative chloride concentrations or 36Cl/Cl values against leach duration. Cumulative values are derived by sequentially summing respective values from previous leach increments. Figure 4-4. Relations between Chloride Concentrations (A) and Cumulative Chloride Concentrations (B) Plotted against Leach Duration for Sequential Leachates of Reference Sample EVAL001 Leached at LANL by Passive and Active Methods during Phase II DTN: LA0305RR831222.001 (UQ) NOTES: The figures plot measured and cumulative chloride concentrations or 36Cl/Cl values against leach duration. Cumulative values are derived by sequentially summing respective values from previous leach increments. Figure 4-5. Relations between 36Cl/Cl Ratios (A) and Cumulative 36Cl/Cl Ratios (B) Plotted against Leach Duration for Sequential Leachates of Reference Sample EVAL001 Leached at LANL by Passive and Active Methods during Phase II A. 0.8 EXD-049 EXD-050 EXD-069 EXD-070 EXD-072 EXD-080 0.7 Cl concentration (mg/kg rock) 0.6 0.5 0.4 0.3 0.2 0.1 0.0 0 10 20 30 40 50 Leach duration (hr) EXD-049 EXD-050 EXD-069 B. 3.0 EXD-070 EXD-072 EXD-080 Cumulative Cl (mg/kg rock) 2.0 2.5 1.0 1.5 0.0 0.5 0 10 20 30 Leach duration (hr) DTN: LA0305RR831222.001 (UQ) 40 50 NOTES: The figures plot measured and cumulative chloride concentrations or 36Cl/Cl values against leach duration. Cumulative values are derived by sequentially summing respective values from previous leach increments. Figure 4-6. Relations between Chloride Concentrations (A, showing all data) and Cumulative Chloride Concentrations (B, showing a subset of the data at a larger scale) Plotted against Leach Duration for Sequential Passive Leachates of the 6.3- to 12.5-mm Fraction of Six Samples from the ECRB Cross Drift Analyzed at LANL during Phase II A. 1100 EXD-049 EXD-050 EXD-069 EXD-070 EXD-072 EXD-080 1000 900 36Cl/Cl ×10 15 800 600 700 500 400 300 200 0 10 20 30 Leach duration (hr) 40 50 B. 1000 EXD-049 EXD-050 EXD-069 EXD-070 EXD-072 EXD-080 900 Cumulative 36Cl/Cl ×10 15 800 700 600 500 300 400 200 0 10 DTN: LA0305RR831222.001 (UQ) 20 30 40 50 Leach duration (hr) NOTES: The figures plot measured and cumulative chloride concentrations or 36Cl/Cl values against leach duration. Cumulative values are derived by sequentially summing respective values from previous leach increments. Figure 4-7. Relations between 36Cl/Cl Ratios (A) and Cumulative 36Cl/Cl Ratios (B) Plotted against Leach Duration for Sequential Passive Leachates of the 6.3- to 12.5-mm Fraction of Six Samples from the ECRB Cross Drift Analyzed at LANL during Phase II A. 1.2 <2 mm 2to 6.3 mm 6.3 to 12.5 mm Cl concentration (mg/kg rock) 1.0 0.8 0.6 0.4 0.2 0.0 0 10 20 30 Leach duration (hr) 40 50 3.0 B. <2 mm 2 to 6.3 mm 6.3 to 12.5 mm Cumulative Cl (mg/kg rock) 2.0 2.5 1.0 1.5 0.0 0.5 0 10 20 30 40 50 Leach duration (hr) DTN: LA0305RR831222.001 (UQ) NOTES: The figures plot measured and cumulative chloride concentrations or 36Cl/Cl values against leach duration. Cumulative values are derived by sequentially summing respective values from previous leach increments. Figure 4-8. Relations between Chloride Concentrations (A) and Cumulative Chloride Concentrations (B) Plotted against Leach Duration for Passive Leachates of Different Size Fractions of ECRB Cross Drift Sample EXD-069 Analyzed at LANL during Phase II TDR-NBS-HS-000017 REV00 F18 A. 500 450 36Cl/Cl ×10 15 400 350 300 250 200 0 10 20 30 40 50 Leach duration (hr) <2 m m 2 to 6.3 m m 6.3 to 12.5 m m B. 400 <2 mm 2 to 6.3 mm 6.3 to 12.5 mm 380 Cumulative 36Cl/Cl ×10 15 360 340 320 300 280 260 240 220 200 0 10 20 30 40 50 Leach duration (hr) DTN: LA0305RR831222.001 (UQ) NOTES: The figures plot measured and cumulative chloride concentrations or 36Cl/Cl values against leach duration. Cumulative values are derived by sequentially summing respective values from previous leach increments. Figure 4-9. Relations between 36Cl/Cl Ratios (A) and Cumulative 36Cl/Cl Ratios (B) Plotted against Leach Duration for Passive Leachates of Different Size Fractions of ECRB Cross Drift Sample EXD-069 Analyzed at LANL during Phase II TDR-NBS-HS-000017 REV00 F19 A.1,000 900 800 700 36Cl/Cl ×1015 600 500 400 300 200 100 0 y = 74.95x + 8.28 R2 = 0.93 Other ECRB Cross Drift samples (see below ) EXD-069 (<2mm) EXD-069 (2-6.3 mm) EXD-069 (6.3-12.5 mm) EVAL001-8,9,10 (active leach) 0 2 4 6 8 10 12 14 16 1 / [Cl concentration] (kg rock/mg Cl) B. 1,000 36Cl/Cl ×1015 900 800 700 600 500 400 EVAL001-7 EVAL001-11 EXD-049 EXD-050 EXD-070 EXD-072 EXD-080 0 2 4 6 810 12 14 16 1 / [Cl concentration] (kg rock/mg Cl) DTN: LA0305RR831222.001 (UQ) NOTES: ECRB = Enhanced Characterization of the Repository Block. All samples are shown in (A), and a selected subset of samples is shown in (B). Figure 4-10. Relations between 36Cl/Cl Ratios and Reciprocal Chloride Concentrations in Sequential Leachates of Reference Sample EVAL001 and ECRB Cross Drift Samples Analyzed at LANL during Phase II 0 1 2 3 4 5 6 7 Coarse ESF-SD-ClV#2 (CT leach) Coarse ESF-SD-ClV#14 (2CT leach) Fine ESF-SD-ClV#2 (FT leach) Cl concentration (mg/k rock) 0 20 40 60 80 Leach duration (hr) DTN: GS030508312272.003 (UQ) Figure 4-11. Effect of Particle Size on Leach Duration and Chloride Concentration for Two Size Fractions of Tuff from Unfractured (CT and FT series, #2) and Relatively Unfractured (2CT series, #14) Core Samples Analyzed at AECL during Phase II 0 9 8 7 6 5 4 3 Coarse ESF-SD-ClV#2 (CT leach) 2 Coarse ESF-SD-ClV#14 (2CT leach) 1 0.0 02 46 810 Leach duration (hr) DTN: GS030508312272.003 (UQ) Figure 4-12. Detail from Figure 4-11 Showing the Changes in Chloride Concentrations in the First Few Hours of Two Leaching Tests on the Coarse Tuff Cl concentration (mg/k rock) 0 2 4 6 8 10 12 14 16 18 Cl concentration (mg/kg rock) ESF-SD-ClV#2 (GS series) leachates ESF-SD-ClV#14 (2A2 series) leachates 6-12 2-4 0.5-2 0.25-0.5 0.125-0.063-<0.063 0.25 0.125 Size fraction (mm) DTN: GS030508312272.003 (UQ) Figure 4-13. Effect of Particle Size on Chloride Concentrations in Phase II Leachates of Intact Core from Borehole ESF-SD-ClV#2 (GS series in Table 4-6) and Broken Core from Borehole ESF-SD-ClV#14 (2A2 series in Table 4-6) 0.00 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40 0.45 0.50 Cl concentration (mg/kg rock) 24-hr duration 48-hr duration 70-hr duration 30-60 20-30 10-20 5-10 >4 4-1 Size fraction (mm) DTN: GS030508312272.003 (UQ) Figure 4-14. Effect of Particle Size and Leach Duration on Rubblized Core Fragments from Borehole ESF-SD-ClV#9 (BT series in Table 4-6) 100 10 1 0.1 0.01 y = 0.6738Ln(x) - 0.1242 R2 = 0.9774 y = 0.1319x0.738 R2 = 0.9719 y = 0.1087Ln(x) + 0.1831 R2 = 0.9813 GS series (24 hr) mechanical GS series 6-12 mm fraction 2A2 series (24 hr) mechanical BT series (24 hr) natural SD-ClV core (1 hr) mechanical Niche #1 (1 hr) hand 0.1 1 10 100 1000 Calculated particle surface area per gram rock (cm²/g) DTNs: GS030508312272.003 (UQ); LL031200223121.036 (Q), Filename: Total_AMS_Summary_2001-02c.xls NOTES: Particle surface area per gram rock is calculated assuming spherical particles with radius equal to half the difference between upper and lower sieve opening dimensions and a density of 2.25 g/cm3 to calculate particle mass, number of spheres per gram, and, finally, total surface area per gram. The open diamond is a statistical outlier that was not included in the regression. Figure 4-15. Comparison of Chloride Concentrations in Phase II Leachates of Core Samples from ESF-SD-ClV and Niche #1 Boreholes in the Sundance Fault Zone Cl concentration (mg/kg rock) 200 250 300 350 400 450 500 550 600 650 36 Cl/Cl ×10 15Hand crush (2-19 mm) Hand crush (6-19 mm) Mechanical crush (6-19 mm) Mean 36Cl/Cl (±2SE) = 437 (±98) ×10-15 1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4 1 / [leachate Cl concentration] (kg rock/mg Cl) DTN: LL031200223121.036 (Q), Filename: Total_AMS_Summary_2001-02c.xls NOTES: SE = standard error. Error bars are 2s. Figure 4-16. Relations between Chloride Concentrations and 36Cl/Cl Ratios in Phase III Leachates of Core Samples from Borehole ESF-SAD-GTB#1 EVAL001 A. 1000 ESF-SD-ClV core 900 Niche #1 core ESFSAD-GTB#1 core 800 36Cl/Cl ×1015 700 600 500 400 A 300 200 100 0 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 Leachate Cl concentration (mg/kg rock) EVAL001 ESF-SD-ClV core B. 1000 900 Niche #1 core ESFSAD-GTB#1 core 800 36Cl/Cl ×1015 700 600 500 400 300 200 100 0 0 5 101520 25 1 / [leachate Cl Concentration] (kg rock/mg Cl) DTN: LL031200223121.036 (Q), Filename: Total_AMS_Summary_2001-02c.xls; GS030608312272.005 (Q) NOTE: Error bars are 2s. Figure 4-17. Relations between 36Cl/Cl Ratios and Chloride Concentrations (A) and Reciprocal Chloride Concentrations (B) in Phase III Leachates of Validation Study Samples Leached at the USGS and Analyzed at LLNL TDR-NBS-HS-000017 REV00 F27 DTN: GS030608312272.005 (Q) NOTES: ESF = Exploratory Studies Facility. The median value is given by the dark red line; mean value is given by the red-filled circle. The middle 50% of the data are within the gray-filled boxes and the upper- and lower-most quartiles are represented by the lines on either side of the boxes. Statistical outliers are shown as asterisks. Data from the DTN were converted from mg/L to mg/kg (see Table 4-13). Figure 4-18. Box Plots of Chloride Concentration Data Comparing Phase III Leachates of Core Samples from the Drill Hole Wash and Sundance Fault Zones (A), and from Different Samples within the Sundance Fault Zone (B) A. 0.40 ESF-SD-ClV core Niche #1 core 0.00 0.05 0.10 0.15 0.20 0.25 0.30 0.35 Cl concentration (mg/kg rock) Drill Hole Wash fault 0.40 Cl concentration (mg/kg rock) 0.35 0.30 0.25 0.20 0.15 0.10 0.05 0.00 Sundance fault 3,350 3,400 3,450 3,500 3,550 3,600 3,650 3,700 Distance from ESF north portal (m) B. 1,900 1,910 1,920 1,930 1,940 1,950 1,960 1,970 Distance from ESF north portal (m) DTN: GS030608312272.005 (Q) NOTES: ESF = Exploratory Studies Facility. Error bars are 2s. Data from the DTN were converted from mg/L to mg/kg (see Table 4-13). Borehole locations are listed in Table 3-2. Figure 4-19. Concentrations of Chloride Determined by Ion Chromatography in Phase III Leachates of Validation Study Core Samples and Niche #1 Core Samples from the Sundance Fault Zone (A) and Drill Hole Wash Fault Zone (B) 0.00 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40 0.45 0.50 NO3 concentration (mg/kg rock) A. 0.00 0.05 0.10 0.15 0.20 0.25 0.30 0.35 Cl concentration (mg/kg rock) y = 1.14x -0.003 R2 = 0.67 0.00 0.10 0.20 0.30 0.40 0.50 0.60 SO4 concentration (mg/kg rock) B. 0.00 0.05 0.10 0.15 0.20 0.25 0.30 0.35 Cl concentration (mg/kg rock) DTN: GS030608312272.005 (Q) NOTES: Linear-regression curve is shown in (B) with straight-line equations and R2 values. Data from the DTN were converted from mg/L to mg/kg (see Table 4-13). Figure 4-20. Comparison Chloride Concentrations in Phase III Leachates of Validation Study Core Leached at the USGS, with NO3 Concentrations (A) and SO4 Concentrations (B) DTNs: LL031200223121.036 (Q), Filename: Total_AMS_Summary_2001-02c.xls; GS030608312272.005 (Q) NOTES: Error bars are 2s. Data from the DTN were converted from mg/L to mg/kg (see Table 4-13). Figure 4-21. Comparison of Chloride Concentrations in Phase III Leachates of Validation Study Samples Analyzed by Ion Chromatography at the USGS and by Isotope Dilution at LLNL DTN: LL031200223121.036 (Q), Filename: Total_AMS_Summary_2001-02c.xls NOTE: SE = standard error. Figure 4-22. Histograms Showing Chloride Concentrations (A) and 36Cl/Cl Ratios (B) in Phase III Leachates of Validation Study Samples Leached at the USGS and Analyzed at LLNL A. 0.00 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40 0.45 Leachate Cl concentration (mg/kg rock) Sundance fault 3350 3400 3450 3500 3550 3600 3650 3700 Distance from ESF north portal (m) 0 100 200 300 400 500 600 700 800 900 1000 36 Cl/Cl ×1015 Sundance fault B. 3350 3400 3450 3500 3550 3600 3650 3700 Distance from ESF north portal (m) DTN: LL031200223121.036 (Q), Filename: Total_AMS_Summary_2001-02c.xls NOTES: ESF = Exploratory Studies Facility. Error bars are 2s. Borehole locations are listed in Table 3-2. Figure 4-23. Relations between Sample Locations in the ESF and Chloride Concentrations (A) and 36Cl/Cl Ratios (B) in Phase III Leachates of Validation Study Samples Leached at the USGS and Analyzed at LLNL 0 100 200 300 400 500 600 700 800 900 36 Cl/Cl ×10 15 Batch #1 - 10/26/2001 Batch #2 - 11/29/2001 Batch #3 - 3/8/2002 Batch #3 - 5/24/2002 03/01/99 03/31/99 05/01/99 05/31/99 07/01/99 07/31/99 08/31/99 09/30/99 Date of borehole completion DTN: LL031200223121.036 (Q), Filename: Total_AMS_Summary_2001-02c.xls NOTES: Data are grouped by leaching batch number and analysis date. Borehole completion dates are listed in Table 3-2. Error bars are 2s. Figure 4-24. Relations between Borehole Completion Dates and 36Cl/Cl Ratios in Phase III Leachates of Validation Study Samples Leached at the USGS and Analyzed at LLNL DTN: LL031200223121.036 (Q), Filename: Total_AMS_Summary_2001-02c.xls NOTES: SE = standard error. Error bars are 2s. Data are shown (from left to right) in order presented in Table 4-9. Figure 4-25. Histogram Showing 36Cl/Cl Ratios in Phase III Leachates of ESF-SD-ClV and Niche #1 Core Samples Prepared at the USGS and Analyzed at LLNL A. NICHE3566#1 (USGS-LLNL ) NICHE3566#1 (LANL ) 36Cl/Cl ×1015 10,000 9,000 8,000 7,000 6,000 5,000 4,000 3,000 2,000 1,000 0 Fine fractions - Bomb-pulse threNICHE3566#2 (USGS-LLNL ) NICHE3566LT#1 (USGS-LLNL ) Coarse fractions shold for 36Cl NICHE3566#2 (LANL ) NICHE3566LT#1 (LANL ) 0123456789 1 / [leachate Cl concentration] (kg rock/mg Cl) B. 10,000 36Cl/Cl ×1015 1,000 100 0 1 2 3 4 5 6 7 8 9 1 / [leachate Cl concentration] (kg rock/mg Cl) NICHE3566#1 (USGS-LLNL ) NICHE3566#1 (LANL ) NICHE3566#2 (USGS-LLNL ) NICHE3566#2 (LANL ) NICHE3566LT#1 (USGS-LLNL ) NICHE3566LT#1 (LANL ) -Bomb-pulse threshold for 36Cl DTNs: LL031200223121.036 (Q), Filename: Total_AMS_Summary_2001-02c.xls; LA0305RR831222.001 (UQ) NOTES: LANL = Los Alamos National Laboratory, LLNL = Lawrence Livermore National Laboratory, USGS = U.S. Geological Survey. The dash-dot lines in (A) and (B) are drawn between different size fractions of the same samples. Error bars are 2s. Figure 4-26. Relations between Reciprocal Chloride Concentrations and 36Cl/Cl Ratios in Phase III Leachates of Niche #1 Core Samples as Linear (A) and Semi-Log (B) Plots 100 1,000 10,000 36 Cl/Cl ×1015 LANL Sundance fault zone tunnel-wall samples LANL Niche #1 core samples 0.1 1 10 1 / [leachate Cl concentration] (kg rock/mg Cl) DTNs: LA0305RR831222.001 (UQ), LAJF831222AQ98.004 (Q) NOTE: LANL = Los Alamos National Laboratory. Figure 4-27. Comparison of Reciprocal Chloride Concentrations and 36Cl/Cl Ratios in Phase III Leachates of Samples from ESF Tunnel Walls (Sundance Fault Zone between Stations 34+28 and 37+00) and Niche #1 Core DTNs: LL031200223121.036 (Q), Filename: Total_AMS_Summary_2001-02c.xls); LL030408023121.027 (Q); LA0305RR831222.001(UQ) NOTES: LANL = Los Alamos National Laboratory, LLNL = Lawrence Livermore National Laboratory, SMF = Sample Management Facility, USGS = U.S. Geological Survey. Figure 4-28. Relations between Reciprocal Chloride Concentrations and 36Cl/Cl Ratios in Phase III Leachates of Validation Study Samples from the Sundance Fault Zone within the ESF Source: Conceptualization based on chloride sources described in Fabryka-Martin et al. (1997, Section 9); for illustration purposes only NOTES: YM = Yucca Mountain. The red line shows a possible evolution pathway as leaching progresses; however, results of leaching experiments typically show sub-horizontal trends with only minor changes in 36Cl/Cl ratios (Section 4.3). Figure 4-29. Conceptual Model of the Isotopic Evolution of 36Cl/Cl Ratios in Passively Leached Solutions with Time A. 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40 LANL Cl concentration (mg/kg rock) 1:1 line 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40 LLNL Cl concentration (mg/kg rock) 0 100 200 300 400 500 600 LANL 36 Cl/Cl ratio ×1015 B. 1:1 line 0 100 200 300 400 500 600 LLNL 36Cl/Cl ratio ×1015 DTNs: LA0305RR831222.001 (UQ); LL031200223121.036 (Q), Filename: Total_AMS_Summary_2001-02c.xls NOTES: LANL = Los Alamos National Laboratory, LLNL = Lawrence Livermore National Laboratory. All targets were analyzed at the LLNL Center for Accelerator Mass Spectrometry (CAMS) facility. Sources of error (shown as 2s error bars) include in-run counting statistics, background and spike corrections, and corrections from blank. Figure 4-30. Comparison of Chloride Concentrations (A) and 36Cl/Cl Ratios (B) in Aliquots of Validation Study Samples Passively Leached for 1 Hour at the USGS and Sent to LLNL and LANL for AgCl Target Preparation DTNs: LL031200223121.036 (Q), Filename: Total_AMS_Summary_2001-02c.xls); LA0305RR831222.001 (UQ) NOTES: LANL = Los Alamos National Laboratory, LLNL = Lawrence Livermore National Laboratory, USGS = U.S. Geological Survey. Box plot shows range of data (vertical lines), middle two quartiles (boxes), median values (horizontal lines), and mean values (filled circles). Figure 4-31. Frequency Distribution (A) and Box Plot (B) of 36Cl/Cl Ratios in Leachates of Validation Study Core Leached at the USGS and Sent to LLNL and LANL for AgCl Precipitation and Analysis 0 1,000 2,000 3,000 4,000 5,000 6,000 36 Cl/Cl ×1015 LANL validation study analyses pre-2000 LANL analyses Solitario Canyon fault Samples along minor, through- going faults Sundance faultun-named fault 0 500 1,000 1,500 2,000 2,500 3,000 Distance from Cross-Drift portal (m) DTN: LA0305RR831222.001(UQ) NOTES: LANL = Los Alamos National Laboratory. Results of all sequential leachates processed between 0.5 and 2 hours are included. Figure 4-32. Relations between 36Cl/Cl Ratios Determined at LANL and Distance in the ECRB Cross Drift DTNs: LL031200223121.036 (Q), Filename: Total_AMS_Summary_2001-02c.xls; LAJF831222AQ98.004 (Q); LA0509JF831222.001 (Q) NOTES: ESF = Exploratory Studies Facility, LANL = Los Alamos National Laboratory, LLNL = Lawrence Livermore National Laboratory, USGS = U.S. Geological Survey. Figure 4-33. Distribution of Chloride Concentrations (A) and 36Cl/Cl Ratios (B) in Leachates of Samples from the Sundance Fault Zone within the ESF TDR-NBS-HS-000017 REV00 F43 36Cl/Cl ×1015 5,000 USGS-LLNL Sundance fault zone 4,500 LANL Sundance fault zone (pre-phase III) 4,000 3,500 3,000 2,500 2,000 1,500 1,000 500 0 0 5 10152025 1 / [leachate Cl concentration] (kg rock/mg Cl) DTNs: LL031200223121.036 (Q), Filename: Total_AMS_Summary_2001-02c.xls); LAJF831222AQ98.004 (Q) NOTES: LANL = Los Alamos National Laboratory, LLNL = Lawrence Livermore National Laboratory, USGS = U.S. Geological Survey. Figure 4-34. Relations between Reciprocal Chloride Concentrations and 36Cl/Cl Ratios in Leachates of Samples from the Sundance Fault Zone DTNs: LAJF831222AQ98.004 (Q); LL031200223121.036 (Q), Filename: Total_AMS_Summary_2001-02c.xls NOTES: ESF = Exploratory Studies Facility, LANL = Los Alamos National Laboratory, LLNL = Lawrence Livermore National Laboratory, USGS = U.S. Geological Survey. Figure 4-35. Distribution of Chloride Concentrations (A) and 36Cl/Cl Ratios (B) in Leachates of USGS-LLNL Samples from the Sundance Fault Zone and LANL Samples from the Southern ESF TDR-NBS-HS-000017 REV00 F45 A. 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 3 H concentration (TU) ESF-DHW-ClV core (Drill Hole Wash fault zone) Cutoff based on Chauvenet's criterion approach 1900 1910 1920 1930 1940 1950 1960 1970 Distance from the ESF north portal (m) B. 4.0 3.5 3H concentration (TU) 3.0 2.5 2.0 1.5 1.0 0.5 0.0 ESF-SD-ClV core (Sundance fault zone) Cutoff based on Chauvenet's criterion approach 3360 3400 3440 3480 3520 3560 3600 3640 3680 3720 Distance from the ESF north portal (m) DTN: GS060308312272.001 (Q) NOTES: ESF = Exploratory Studies Facility, TU = tritium unit. Dashed horizontal line represents 1 TU background cutoff proposed initially. Solid horizontal line represents 2 TU background cutoff based on statistical criterion from 135 3H measurements. Error bars are 2s. Borehole locations are listed in Table 3-2. Figure 5-1. Distribution of Tritium Concentrations in Samples of Pore Water Extracted from Validation Study Core along the Drill Hole Wash Fault Zone (A) and Sundance Fault Zone (B) DTN: GS060308312272.001 (Q) NOTE: TU = tritium unit. Figure 5-2. Frequency Distribution of Tritium Concentrations in Pore Water from Validation Study Core Samples DTNs: GS040108312232.001 (Q), GS060308312272.001 (Q), GS060383122410.001 (Q), GS961108312261.006 (Q) NOTES: ECRB = Enhanced Characterization of the Repository Block, ESF = Exploratory Studies Facility, TU = tritium unit. The same data are plotted at both full scale (A) to show large 3H concentrations in samples from the Bow Ridge fault zone and one sample from the South Ramp Moisture Study area, and at a reduced scale (B) to show variations in low-3H concentration samples. Error bars are 2s. Dashed horizontal line represents 1 TU background cutoff proposed initially. Solid horizontal line represents 2 TU background cutoff based on statistical criterion from 135 3H measurements. Borehole locations are listed in Table 3-2. Figure 5-3. Distribution of Tritium Concentrations Plotted at Full Scale (A) and at a Reduced Scale (B) in Samples of Pore Water Extracted from Drill Core throughout the ESF DTNs: GS060308312272.001 (Q), GS060383122410.001 (UQ) NOTE: TU = tritium unit. Figure 5-4. Frequency Distribution of Tritium Concentrations in Pore Water from Boreholes along the ESF South Ramp Source: Modified from USBR (1997) DTNs: GS060308312272.001 (Q), GS060383122410.001 (UQ) NOTES: ESF = Exploratory Studies Facility, TU = tritium unit. Sample locations are from Table 5-3. Figure 5-5. Geologic Section of the ESF South Ramp Showing Locations of Samples Analyzed for Tritium DTN: GS060308312272.002 (Q) NOTES: ECRB = Enhanced Characterization of the Repository Block, TU = tritium unit. Major faults are shown as vertical red lines. Error bars are 2s. Dashed horizontal line represents 1 TU background cutoff proposed initially. Solid horizontal line represents 2 TU background cutoff based on statistical criterion from 135 tritium measurements. Figure 5-6. Distribution of Tritium Concentrations in Samples of Pore Water Extracted from Drill Core along the ECRB Cross Drift DTN: GS060308312272.002 (Q) NOTE: TU = tritium unit. Figure 5-7. Frequency Distribution of Tritium Concentrations in Pore Water from ECRB Cross Drift Drill Core DTNs: GS060308312272.001 (Q), GS060383122410.001 (UQ), GS060308312272.002 (Q); Chauvenet’s criterion plotted as in Fabryka-Martin et al. (1997, Figure 4-6) NOTE: TU = tritium unit. Figure 5-8. Application of Chauvenet’s Criterion to Establish a Cutoff Tritium Concentration for Identifying the Presence of Bomb-Pulse Tritium in Samples from the ESF and ECRB Cross Drift (USGS) 0 1 2 3 4 5 6 0 10 20 30 40 50 60 70 80 Rank Number of standard deviations fromcumulative average 3H concentrationsTritium concentration data Chauvenet's criterion for outliers Cutoff value for indicating presence of bomb-pulse 3H between 1.1 and 1.4 TU DTNs: GS060308312272.001 (Q), GS060308312272.002 (Q); Chauvenet’s criterion plotted as in Fabryka-Martin et al. (1997, Figure 4-6) NOTE: TU = tritium unit. Figure 5-9. Application of Chauvenet’s Criterion to Establish a Cutoff Tritium Concentration for Identifying the Presence of Bomb-Pulse Tritium in Validation Study Boreholes and ECRB Cross Drift Samples (LANL) DTNs: LA0305RR831222.001 (UQ); LA0307RR831222,002 (UQ); LA0509JF831222.001 (Q); LAJF831222AQ98.004 (Q); LL031200223121.036 (Q), Filename: Total_AMS_Summary_2001-02c.xls NOTES: ESF = Exploratory Studies Facility. Error bars are 2s. USGS-LLNL = Samples leached at USGS, processed (i.e., target preparation) at LLNL, and analyzed at LLNL. USGS-LANL = Samples leached at USGS, processed (i.e., target preparation and spiking) at LANL, and analyzed at LLNL. Errors for these data are similar to USGS-LLNL data (error bars are not shown for these data because they overlap with error bars shown for the USGS-LLNL data). Figure 6-1. Relations between 36Cl/Cl Ratios in Validation Study Samples from the Sundance Fault Zone and 36Cl/Cl Ratios in Samples from the Same Area Reported by LANL in 1996, 1997, and 1998. INTENTIONALLY LEFT BLANK Table 3-1. Chronology of Locations and Personnel Directly Involved in the Preparation and Analysis of LANL 36Cl Samples Principal Investigator of 36Cl Activity Location of Sample Preparation Laboratory Supervisor of Sample Preparation Analytical Facility Examples of 36Cl/Cl Results Kurt Wolfsberg (until 1984) Hydro Geo Chem (Tucson) Harold Bentley University of Rochester Background ratios and bomb- pulse in soil profiles; bomb- pulse in UZ-1 cuttings; bomb- pulse in G Tunnel samples; in situ ratios in Yucca Mountain tuff. Ted Norris (1984-1990) Hydro Geo Chem (Tucson) Seth Gifford (1984-1988) Songlin Cheng (1988-1990) Susan Maida (1990-1992) June Fabryka-Martin (1990-2000) Hydro Geo Chem (Tucson, until 1994) Susan Maida (1990-1992) Scott Wightman (1992-1995) University of Rochester (until 1992); LLNL (1992-1994); PRIME Lab (1993-2000) Inter-laboratory comparisons of blanks, standards, samples; background ratio and bomb- pulse in soil profiles; bomb- pulse in neutron hole cuttings. LANL (May 1994 until May 2000, TA-48, Bldg. 45) Scott Wightman Beiling Liu Paul Dixon Jeff Roach Robert Roback PRIME Lab Bomb-pulse in the ESF; bomb- pulse in runoff; and bomb- pulse in the ECRB Cross Drift. PRIME Lab Stephen Vogt PRIME Lab Rock 36Cl/Cl (no bomb-pulse). New Mexico Tech (Socorro) Mitch Plummer PRIME Lab Pack rat samples; background and bomb-pulse ratios. Robert Roback (2000- present) LANL (TA-03, Bldg. 215) Robert Roback Catherine Jones PRIME Lab LLNL ECRB Cross Drift, one sample with bomb-pulse; ESF Niche #1; validation study core; sequential leaching experiments. Compiled by R.C. Roback May 26, 2005 Table 3-2. Validation Study Boreholes Fault Zone Borehole Identifier ESF Station Date Completed Total Depth (m) Sundance ESF-SD-ClV#1 36+89 06/17/99 4 ESF-SD-ClV#2 36+74 06/16/99 4 ESF-SD-ClV#3 36+59 06/15/99 4 ESF-SD-ClV#4 36+35 06/14/99 4 ESF-SD-ClV#5 36+20 06/10/99 4 ESF-SD-ClV#6 36+10 06/10/99 4 ESF-SD-ClV#7 36+05 06/08/99 4 ESF-SD-ClV#8 36+00 06/08/99 4 ESF-SD-ClV#9 35+95 06/07/99 4 ESF-SD-ClV#10 35+90 06/03/99 4 ESF-SD-ClV#11 35+85 06/03/99 4 ESF-SD-ClV#12 35+80 06/02/99 4 ESF-SD-ClV#13 35+75 06/02/99 10 ESF-SD-ClV#14 35+45 09/22/99 4 ESF-SD-ClV#15 35+40 09/21/99 4 ESF-SD-ClV#16 35+35 09/20/99 4 ESF-SD-ClV#17 35+31 09/17/99 4 ESF-SD-ClV#18 35+25 09/16/99 4 ESF-SD-ClV#19 35+20 09/15/99 4 ESF-SD-ClV#20 35+15 09/14/99 4 ESF-SD-ClV#21 35+10 09/13/99 4 ESF-SD-ClV#22 35+05 09/13/99 4 ESF-SD-ClV#23 35+00 09/10/99 4 ESF-SD-ClV#24 34+95 09/09/99 4 ESF-SD-ClV#25 34+90 09/23/99 4 ESF-SD-ClV#26 34+73 09/22/99 4 ESF-SD-ClV#27 34+70 04/09/99 4 ESF-SD-ClV#28 34+65 04/08/99 4 ESF-SD-ClV#29 34+60 04/06/99 4 ESF-SD-ClV#30 34+55 04/05/99 4 ESF-SD-ClV#3 34+50 04/02/99 4 ESF-SD-ClV#3 34+45 04/01/99 4 ESF-SD-ClV# 3 34+40 03/31/99 4 ESF-SD-ClV#3 34+35 03/30/99 4 ESF-SD-ClV#3 34+30 03/26/99 4 ESF-SD-ClV#3 34+25 03/25/99 4 ESF-SD-ClV#3 34+20 03/24/99 4 ESF-SD-ClV#3 34+10 03/23/99 4 ESF-SD-ClV#3 33+99 03/19/99 4 ESF-SD-ClV#40 33+89 03/17/99 4 Table 3-2. Validation Study Boreholes (continued) Fault Zone Borehole Identifier ESF Station Date Completed Total Depth (m) Drill Hole Wash ESF-DHW-ClV#1 19+65 09/30/99 4 ESF-DHW-ClV#2 19+55 09/29/99 4 ESF-DHW-ClV#3 19+50 09/29/99 4 ESF-DHW-ClV#4 19+45 09/28/99 4 ESF-DHW-ClV#5 19+40 09/27/99 10 ESF-DHW-ClV#6 19+35 09/30/99 4 ESF-DHW-ClV#7 19+30 10/05/99 4 ESF-DHW-ClV#8 19+25 10/05/99 4 ESF-DHW-ClV#9 19+20 10/06/99 4 ESF-DHW-ClV#10 19+10 10/06/99 4 Source: Paces (2003); surveyed borehole locations (i.e., ESF station numbers) from DTN: LL031200223121.036 (Q) Note: ESF = Exploratory Studies Facility. Table 3-3. Core Samples from Niche #1 Boreholes Figure 3-7 Reference Number Sample Identifier Borehole Identifier Interval (ft) SMF Barcode Identifier Laboratory Data Source A1 DCN086-2 ESF-MDNICHE3566# 1 22.2–23.0 SPC01003078 LANL LA0509JF831222.001 (Q) A2 DCN007-2/0081 ESF-MDNICHE3566# 1 32.1–33.1 SPC01003096 SPC01003097 SPC01003098 LANL LA0509JF831222.001 (Q) A3 DCN015-2 ESF-MDNICHE3566# 2 6.7–7.5 SPC01003111 LANL LA0509JF831222.001 (Q) A4 DCN024-1/0252 ESF-MDNICHE3566# 2 15.7–17.1 SPC01003131 SPC01003132 SPC01003133 LANL LA0509JF831222.001 (Q) A5 DCN038-1/0392 ESF-MDNICHE3566LT# 1 1.7–5.0 SPC01004399 SPC01004400 SPC01004401 SPC01004402 LANL LA0509JF831222.001 (Q) A6 DCN048-1/0492 ESF-MDNICHE3566LT# 1 14.3–16.3 SPC01004420 SPC01004421 SPC01004422 LANL LA0509JF831222.001 (Q) A7 DCN050-1/0512 ESF-MDNICHE3566LT# 1 16.6–19.3 SPC01004424 SPC01004425 SPC01004426 SPC01004427 LANL LA0509JF831222.001 (Q) A8 DCN059-2/0601 ESF-MDNICHE3566LT# 1 29.0–30.7 SPC01004445 SPC01004446 SPC01004447 LANL LA0509JF831222.001 (Q) A9 DCN062-1 ESF-MDNICHE3566LT# 1 32.1-33.1 SPC01004453 LANL LA0509JF831222.001 (Q) A10 DCN064-2 ESF-MDNICHE3566LT# 1 34.4–35.5 SPC01004457 LANL LA0509JF831222.001 (Q) B1 Niche 1-RCR1A Niche 1-RCR1B ESF-MDNICHE3566# 1 3.2–4.2 4.6–5.7 5.9–6.8 7.4–8.2 8.4–9.0 9.3–10.4 SPC01003045 SPC01003048 SPC01003050 SPC01003053 SPC01003055 SPC01003057 LANL LA0305RR831222.001 (UQ) B2 Niche 1-RCR-2 ESF-MDNICHE3566# 1 17.2–17.9 18.1–18.7 18.9–20.0 SPC01003068 SPC01003070 SPC01003072 LANL LA0305RR831222.001 (UQ) B3 Niche 1- RCR-3 ESF-MDNICHE3566# 1 24.2–25.0 27.1–27.9 29.2–30.1 SPC01003082 SPC01003087 SPC01003091 LANL LA0305RR831222.001 (UQ) B4 Niche 2-RCR-1 ESF-MDNICHE3566# 2 10.6–11.2 12.2–12.9 13.9–14.7 17.4–18.5 SPC01003119 SPC01003123 SPC01003127 SPC01003135 LANL LA0305RR831222.001 (UQ) 12.1–13.2 SPC01004416 B5 Niche LT-RCR1A Niche LT-RCR1B ESF-MDNICHE3566LT# 1 20.5–21.1 21.4–22.2 23.8–24.8 26.8–27.9 36.2–37.0 SPC01004431 SPC01004433 SPC01004437 SPC01004441 SPC01004460 LANL LA0305RR831222.001 (UQ) 38.3–38.9 SPC01004464 Table 3-3. Core Samples from Niche #1 Boreholes (continued) Figure 3-7 Reference Number Sample Identifier Borehole Identifier Interval (ft) SMF Barcode Identifier Laboratory Data Source C1 ESF-MDNICHE3566# 1 (14.7'-20.9') ESF-MDNICHE3566# 1 14.7–15.8 20.3–20.9 SPC01003066 SPC01003074 USGSLLNL LL031200223121.036 (Q) C2 ESF-MDNICHE3566# 1 (25.3'-31.7') ESF-MDNICHE3566# 1 25.3–26.0 28.1–28.9 30.8–31.7 SPC01003084 SPC01003089 SPC01003094 USGSLLNL LL031200223121.036 (Q) C3 ESF-MDNICHE3566# 2 (11.5'-15.4') ESF-MDNICHE3566# 2 11.5–11.9 13.2–13.7 15.0–15.4 SPC01003121 SPC01003125 SPC01003129 USGSLLNL LL031200223121.036 (Q) C4 ESF-MDNICHE3566# 2 (20.2'-32.5') ESF-MDNICHE3566# 2 20.2–20.7 29.8–30.4 32.0–32.5 SPC01003140 SPC01003155 SPC01003156 USGSLLNL LL031200223121.036 (Q) C5 ESF-MDNICHE3566# LT1 (10.9'-23.5') ESF-MDNICHE3566LT# 1 10.9–11.9 13.4–14.1 22.8–23.5 SPC01004414 SPC01004418 SPC01004435 USGSLLNL LL031200223121.036 (Q) C6 ESF-MDNICHE3566# LT1 (25.0'-38.1') ESF-MDNICHE3566LT# 1 25.0–25.9 28.2–28.8 31.5–31.9 37.1–38.1 SPC01004439 SPC01004443 SPC01004451 SPC01004462 USGSLLNL LL031200223121.036 (Q) NOTES: LANL = Los Alamos National Laboratory, LLNL = Lawrence Livermore National Laboratory, SMF = Sample Management Facility, USGS = U.S. Geological Survey. SMF barcode identifiers and intervals are contained in the data record package for the associated DTN. Table 4-1. Chloride Concentrations and 36Cl/Cl Ratios in Active Leachates Prepared and Analyzed at LLNL during Phase I Sample Name SMF Barcode Identifier Interval Leached (ft) CAMS Number Date AMS Analyzed Rock Mass (g) Leachate Mass (g) Leachate [Cl] (mg/kg) Cl Concentration (mg/kg rock) 36Cl/Cl ×1015 2s ×1015 ESF-SD-ClV#27 SPC02016025 7.3–9.2 CL7684 1/14/00 3,000.0 4,002.4 1.04 1.39 151 15 ESF-SD-ClV#32 SPC02016116 3.3–5.6 CL7685 1/14/00 3,000.6 4,001.2 2.12 2.83 248 34 ESF-SD-ClV#33 SPC02016117 3.0-5.4 CL7686 1/14/00 3,000.1 3,999.7 2.36 3.15 72 7 ESF-SD-ClV#34 SPC02015957 8.3–10.5 CL7687 1/14/00 3,000.0 4,001.1 1.14 1.52 130 10 ESF-SD-ClV#28 SPC02016022 SPC02016023 11.3–12.7 12.7–13.3 CL7775 2/17/00 2,000.1 3,001.6 1.83 2.75 112 33 ESF-SD-ClV#29 SPC02015993 SPC02015994 6.5–7.5 7.5–8.7 CL7776 2/17/00 2,506.1 3,500.1 1.59 2.22 103 28 ESF-SD-ClV#37 SPC02016031 11.2–13.0 CL7777 2/17/00 2,000.7 2,996.3 1.71 2.56 83 36 ESF-SD-ClV#30 SPC02015999 8.5–10.5 CL7779 2/17/00 2,504.1 3,511.6 1.85 2.59 48 18 ESF-SD-ClV#35 SPC02016119 2.2–4.0 CL7780 2/17/00 2,302.6 3,306.2 1.22 1.75 57 21 ESF-SD-ClV#40 SPC02015925 SPC02015926 10.5–11.6 11.6–12.2 CL7781 2/17/00 2,064.1 3,039.3 1.47 2.16 71 23 ESF-SD-ClV#2 SPC02016280 6.6–8.0 CL7918 4/21/00 2,000.7 3,002.8 1.28 1.92 139 6 ESF-SD-ClV#3 SPC02016290 SPC02016291 SPC02016292 11.4–12.3 12.3–12.8 12.8–13.5 CL7919 4/21/00 1,999.6 3,002.1 1.69 2.54 125 6 ESF-SD-ClV#4 SPC02016293 SPC02016294 6.3–7.3 7.3–8.3 CL7920 4/21/00 1,999.4 3,001.1 1.50 2.25 101 6 ESF-SD-ClV#5 SPC03017201 SPC03017202 4.1–5.1 5.8–6.7 CL7921 4/21/00 1,500.8 2,506.8 1.48 2.47 93 9 ESF-SD-ClV#6 SPC03017203 SPC02016303 5.7–6.9 7.8–9.3 CL7922 4/21/00 1,999.4 2,999.9 1.42 2.13 75 5 -T6 TDR-NBS-HS-000017 REV00 TDR-NBS-HS-000017 REV00 T7 Table 4-1. Chloride Concentrations and 36Cl/Cl Ratios in Active Leachates Prepared and Analyzed at LLNL during Phase I (continued) Sample Name SMF Barcode Identifier Interval Leached (ft) CAMS Number Date AMS Analyzed Rock Mass (g) Leachate Mass (g) Leachate [Cl] (mg/kg) Cl Concentration (mg/kg rock) 36Cl/Cl ×1015 2s ×1015 ESF-SD-ClV#7 SPC02016267 6.5–8.0 CL7923 4/21/00 1,999.0 3,004.7 1.46 2.19 73 4 ESF-SD-ClV#8 SPC02016273 9.9–11.8 CL7924 4/21/00 1,999.5 3,008.6 0.96 1.44 106 7 ESF-SD-ClV#9 SPC02016276 8.6–10.1 CL7925 4/21/00 1,800.4 2,812.2 0.91 1.42 93 7 ESF-SD-ClV#10 SPC02016255 9.9–11.2 CL7926 4/21/00 1,579.0 2,506.3 1.06 1.68 88 6 ESF-SD-ClV#11 SPC02016259 9.0–10.2 CL7927 4/21/00 1,670.1 2,631.1 0.97 1.53 65 16 ESF-SD-ClV#12 SPC02016264 SPC02016265 8.4–9.4 9.4–10.4 CL7928 4/21/00 2,046.6 3,015.4 1.27 1.87 53 6 ESF-SD-ClV#31 SPC02016115 4.7–6.2 CL7929 4/21/00 1,859.8 2,862.2 0.94 1.45 80 20 ESF-SD-ClV#36 SPC02015947 SPC02015948 10.6–10.8 10.8–12.1 CL7930 4/21/00 1,780.2 2,772.1 0.80 1.25 99 7 ESF-SD-ClV#38 SPC02015940 9.1–10.8 CL7931 4/21/00 2,005.0 3,074.1 2.31 3.54 58 4 ESF-SD-ClV#39 SPC02015930 9.3–10.1 CL7932 4/21/00 1,358.2 2,328.3 1.58 2.71 71 5 DTN: LL030408023121.027 (Q), GS030608312272.005 (Q) NOTES: AMS = accelerator mass spectrometer, CAMS = Center for Accelerator Mass Spectrometry, SMF = Sample Management Facility. Chloride concentrations have a uniform 2s uncertainty of 5% of the stated value. Table 4-2. Chloride, Bromide, and Sulfate Concentrations, and 36Cl/Cl Ratios in Leachates of Validation Study Core Samples Analyzed at LANL during Phase I Sample Identifier SMF Barcode Identifier Borehole Identifier Interval Used (ft) ESF Station AgCl Target Identifier Concentration (mg/kg rock) SO4/ Cl Measured 36Cl/Cl ×1015 (2s)Cl-1 Br-1 SO4 -1 VAL01-1 SPC02016192 ESF-SD-ClV#27 4.2–5.9 34+70 YM1000 0.25 ND 0.32 1.28 717 ±74 VAL02-1 SPC02016193 ESF-SD-ClV#30 3.8–5.0 34+55 YM1001 0.23 ND 0.26 1.13 942 ±104 VAL03-1 SPC02016194 ESF-SD-ClV#34 5.7–6.6 34+35 YM1002 0.30 ND 0.38 1.27 665 ±100 VAL03-2 SPC02016194 ESF-SD-ClV#34 4.8–5.7 34+35 YM1003 0.35 ND 0.34 0.97 508 ±108 VAL04-1 SPC02016195 ESF-SD-ClV#36 3.9–5.4 34+25 YM1004 0.30 ND 0.33 1.10 806 ±78 VAL05-1 SPC02016196 ESF-SD-ClV#38 4.5-5.8 34+10 YM1005 0.25 ND 0.44 1.76 758 ±88 VAL06-1 SPC02016197 ESF-SD-ClV#39 3.5-5.7 33+99 YM1006 0.31 ND 0.52 1.68 538 ±70 DTN: LA0307RR831222.002 (UQ) NOTES: ESF = Exploratory Studies Facility, ND = not detected, SMF = Sample Management Facility. Concentration of salts extracted from each sample is only a qualitative indicator of the sample's salt content. Because the focus of this activity is on determining anion ratios, no attempt has been made to maximize the yield of the leaching process, which is probably highly variable. Measured 36Cl/Cl ratios have been corrected for the addition of 35Cl tracer. Interval used for chloride, bromide, sulfate, and 36Cl/Cl analysis is smaller than the interval traceable to the SMF barcode number; a portion of each core sample was removed in the laboratory and set aside for other analyses. Table 4-3. Chloride Concentrations and 36Cl/Cl Ratios for Sequential Leachates of Reference Sample EVAL001 and Six Samples from the ECRB Cross Drift Analyzed at LANL during Phase II Sample or Aliquot Identifier SMF Barcode Identifier Leach Duration (hr) Leach Type Size Fraction (mm) LANL Identifier AMS Facility AMS Identifier Date Analyzed Cl Concentration (mg/kg rock) Sample + Blank 36Cl/Cl ×1015 Sample36Cl/Cl ×1015 (2s) EVAL001-7 (30) SPC00536900 0.5 Passive 6.3–12.5 YM2000 PRIME T010604,5A 5/21/2001 0.11 838 889 ±141 EVAL001-7 (120) SPC00536900 2 Passive 6.3–12.5 YM2001 PRIME T010605,5A 5/21/2001 0.12 557 570 ±110 EVAL001-7 (420) SPC00536900 7 Passive 6.3–12.5 YM2002 PRIME T010606,5A 5/21/2001 0.19 519 526 ±57 EVAL001-7 (9900) SPC00536900 165 Passive 6.3–12.5 YM2003 PRIME T010607,5A 5/21/2001 0.22 488 493 ±126 EVAL001-11 (30) SPC00536900 0.5 Passive 6.3–12.5 YM2008 PRIME T010612,5A 5/21/2001 0.12 609 633 ±78 EVAL001-11 (120) SPC00536900 2 Passive 6.3–12.5 YM2009 PRIME T010613,5A 5/21/2001 0.12 505 516 ±69 EVAL001-11 (420) SPC00536900 7 Passive 6.3–12.5 YM2010 PRIME T010614,5A 5/21/2001 0.25 488 492 ±40 EVAL001-11 (4560) SPC00536900 76 Passive 6.3–12.5 YM2011 PRIME T010615,5A 5/21/2001 0.17 680 698 ±137 EVAL0018,9,10 (30) SPC00536900 0.5 Active 6.3–12.5 YM2004 PRIME T010608,5A 5/21/2001 0.18 420 423 ±79 EVAL0018,9,10 (120) SPC00536900 2 Active 6.3–12.5 YM2005 PRIME T010609,5A 5/21/2001 0.15 490 501 ±126 EVAL0018,9,10 (420) SPC00536900 7 Active 6.3–12.5 YM2006 PRIME T010610,5A 5/21/2001 0.20 427 430 ±88 EVAL0018,9,10 (3-7) SPC00536900 0.05- 0.12 Active 6.3–12.5 YM2007 PRIME T010611,5A 5/21/2001 0.31 243 234 ±40 EXD-049 (0.5 hr) SPC00521148 0.5 Passive 6.3–12.5 YM2051 CAMS CL9724 11/29/2001 0.08 638 603 ±208 EXD-049 (2 hr) SPC00521148 2 Passive 6.3–12.5 YM2052 CAMS CL9725 11/29/2001 0.07 735 704 ±164 EXD-049 (7 hr) SPC00521148 7 Passive 6.3–12.5 YM2053 CAMS CL9726 11/29/2001 0.09 752 726 ±64 EXD-049 (48 hr) SPC00521148 48 Passive 6.3–12.5 YM2054 CAMS CL9727 11/29/2001 0.07 683 650 ±93 EXD-050 0.25-0.5" (0.5 hr) SPC00521147 0.5 Passive 6.3–12.5 YM2095 CAMS CL10134 5/23/2002 0.11 842 777 ±102 EXD-050 0.25-0.5" (2 hr) SPC00521147 2 Passive 6.3–12.5 YM2096 CAMS CL10135 5/23/2002 0.13 793 742 ±95 EXD-050 0.25-0.5" (7 hr) SPC00521147 7 Passive 6.3–12.5 YM2097 CAMS CL10136 5/23/2002 0.12 758 701 ±87 EXD-050 0.25-0.5" (48 hr) SPC00521147 48 Passive 6.3–12.5 YM2098 CAMS CL10137 5/23/2002 0.11 796 735 ±92 EXD-069 <2 mm (0.5 hr) SPC00541213 0.5 Passive <2.0 YM2084A CAMS CL10123 5/23/2002 0.40 382 351 ±40 EXD-069 <2 mm (2 hr) SPC00541213 2 Passive <2.0 YM2085 CAMS CL10124 5/23/2002 0.29 394 356 ±44 Table 4-3. Chloride Concentrations and 36Cl/Cl Ratios in Sequential Leachates of Reference Sample EVAL001 and Six Samples from the ECRB Cross Drift Analyzed at LANL during Phase II (continued) Sample or Aliquot Identifier SMF Barcode Identifier Leach Duration (hr) Leach Type Size Fraction (mm) LANL Identifier AMS Facility AMS Identifier Date Analyzed Cl Concentration (mg/kg rock) Sample + Blank 36Cl/Cl ×1015 Sample36Cl/Cl ×1015 (2s) EXD-069 <2 mm (7 hr) SPC00541213 7 Passive <2.0 YM2086 CAMS CL10125 5/23/2002 0.17 370 317 ±52 EXD-069 <2 mm (48 hr) SPC00541213 48 Passive <2.0 YM2087 CAMS CL10126 5/23/2002 0.17 477 432 ±55 EXD-069 2 mm-0.25" (0.5/2 hr) SPC00541213 0.5/2 Passive 2.0–6.3 YM2088 CAMS CL10127 5/23/2002 0.99 282 277 ±22 EXD-069 2 mm-0.25" (7 hr) SPC00541213 7 Passive 2.0–6.3 YM2089 CAMS CL10128 5/23/2002 0.41 283 261 ±29 EXD-069 2 mm-0.25" (48 hr) SPC00541213 48 Passive 2.0–6.3 YM2090 CAMS CL10129 5/23/2002 0.21 313 273 ±40 EXD-069 0.25-0.5" (0.5 hr) SPC00541213 0.5 Passive 6.3–12.5 YM2091 CAMS CL10130 5/23/2002 0.57 300 284 ±28 EXD-069 0.25-0.5" (2 hr) SPC00541213 2 Passive 6.3–12.5 YM2092 CAMS CL10131 5/23/2002 0.66 297 282 ±27 EXD-069 0.25-0.5" (7 hr) SPC00541213 7 Passive 6.3–12.5 YM2093 CAMS CL10132 5/23/2002 0.61 305 290 ±27 EXD-069 0.25-0.5" (48 hr) SPC00541213 48 Passive 6.3–12.5 YM2094 CAMS CL10133 5/23/2002 0.62 312 297 ±27 EXD-070 (0.5 hr) SPC00541215 0.5 Passive 6.3–12.5 YM2055 CAMS CL9728 11/29/2001 0.43 543 536 ±39 EXD-070 (2 hr) SPC00541215 2 Passive 6.3–12.5 YM2056 CAMS CL9729 11/29/2001 0.30 544 536 ±40 EXD-070 (7 hr) SPC00541215 7 Passive 6.3–12.5 YM2057 CAMS CL9730 11/29/2001 0.31 553 545 ±40 EXD-070 (48 hr) SPC00541215 48 Passive 6.3–12.5 YM2058 CAMS CL9731 11/29/2001 0.30 526 518 ±40 EXD-072 (0.5 hr) SPC00521171 0.5 Passive 6.3–12.5 YM2059 CAMS CL9732 11/29/2001 0.22 936 924 ±64 EXD-072 (2 hr) SPC00521171 2 Passive 6.3–12.5 YM2060 CAMS CL9733 11/29/2001 0.21 697 685 ±58 EXD-072 (7 hr) SPC00521171 7 Passive 6.3–12.5 YM2061 CAMS CL9734 11/29/2001 0.23 687 676 ±47 EXD-072 (48 hr) SPC00521171 48 Passive 6.3–12.5 YM2062 CAMS CL9735 11/29/2001 0.18 766 753 ±53 EXD-080 (0.5 hr) SPC00533393 0.5 Passive 6.3–12.5 YM2063 CAMS CL9736 11/29/2001 0.17 586 568 ±45 EXD-080 (2 hr) SPC00533393 2 Passive 6.3–12.5 YM2064 CAMS CL9737 11/29/2001 0.16 559 543 ±44 Table 4-3. Chloride Concentrations and 36Cl/Cl Ratios in Sequential Leachates of Reference Sample EVAL001 and Six Samples from the ECRB Cross Drift Analyzed at LANL during Phase II (continued) Sample or Aliquot Identifier SMF Barcode Identifier Leach Duration (hr) Leach Type Size Fraction (mm) LANL Identifier AMS Facility AMS Identifier Date Analyzed Cl Concentration (mg/kg rock) Sample + Blank 36Cl/Cl ×1015 Sample36Cl/Cl ×1015 (2s) EXD-080 (7 hr) SPC00533393 7 Passive 6.3–12.5 YM2065 CAMS CL9738 11/29/2001 0.19 560 546 ±41 EXD-080 (48 hr) SPC00533393 48 Passive 6.3–12.5 YM2066 CAMS CL9739 11/29/2001 0.11 569 546 ±60 DTN: GS030608312272.005 (Q), LA0305RR831222.001 (UQ) NOTES: AMS = accelerator mass spectrometer, CAMS = Center for Accelerator Mass Spectrometry, LANL = Los Alamos National Laboratory, PRIME = Purdue Rare Isotope Measurement Laboratory, SMF = Sample Management Facility. Chloride concentrations have a uniform 2s uncertainty of 5% of the stated value. For LANL Identifier YM2088, the 0.5-hour and 2-hour leachates were combined. The sample or aliquot identifier is from the LANL DTN, which reports the size fraction in inches. The text refers to the size fraction column of the table, which reports the size fraction in millimeters. The numbers in parentheses for the EVAL001 samples are the leach duration, in minutes. Table 4-4. Possible Sources for 36Cl/Cl Ratios in Tuff Samples from Yucca Mountain 36Cl/Cl Source 36Cl/Cl Ratio Likely Location in Rock References Bomb-pulse More than 1,200 ×10-15 Active, throughgoing fractures and connected pores Fabryka-Martin et al. (1997, Section 4.2.4) Meteoric water younger than 10 ka About 500 ×10-15 Active fractures, connected pores, but potentially less so than above Fabryka-Martin et al. (1993, Section IV.A) Meteoric water older than 10 ka About 700 to about 1,100 ×10-15 Less active fractures and pores than above Fabryka-Martin et al. (1997, Section 3.1.2) Rock chloride Less than about 50 ×10-15 As mineral component and fluid inclusions Fabryka-Martin, Wolfsberg et al. (1996, Table 5-4) and Fabryka-Martin et al. (1997, Section 3.4.1) “Old” meteoric salts 0 to 1,100 ×10-15 (depending on age and the 301,000-year half-life of 36Cl) Least accessible pores, clogged pores, insoluble salts Fabryka-Martin et al. (1997, Section 9) Contamination introduced during sampling and processing Wide range, depending on the source of contamination Surfaces of rock fragments Fabryka-Martin et al. (1997, Section 3.3) Table 4-5. Dry-Drilled Core Samples Used in Chloride Leaching Experiments Conducted at AECL during Phase II Core Number SMF Barcode Identifier Location (ESF station) Core Interval (ft) Experiment Designation Parameter Tested Size Fraction (mm) Leach Duration ESF-SD-ClV #2 SPC02016282 36+74 9.9–10.9 CT Duration 4–10 10 min– 72 hr FT Duration <0.125 10 min– 72 hr GS Particle size <0.063–12 24 hr ESF-SD-ClV #14 SPC03017135 35+45 9.7–11.5 2A2 Particle size <0.063–4 24 hr 2CT Duration 4–10 10 min– 70 hr ESF-SD-ClV #9 SPC02016275 35+95 6.5–8.1 2BT Particle size 1–60 24 hr 3BT Particle size 1–60 48 hr 4BT Particle size 1–60 72 hr DTN: GS030508312272.003 (UQ) NOTES: ESF = Exploratory Studies Facility, SMF = Sample Management Facility. Only a portion of the SPC02016282 interval was used in the chloride leaching experiments. Table 4-6. Summary Data for Core Samples Analyzed at AECL during Phase II Core Used Sample Name Leach Duration (hr) Particle Size (mm) Cl-1 Concentration (mg/kg) ESF-SD-ClV#2 CT 1 0.17 4–10 0.14 CT2 0.33 4–10 0.22 CT3 0.5 4–10 0.25 CT4 1.0 4–10 0.4 CT5 2.0 4–10 0.57 CT6 4.0 4–10 0.72 CT7 8.0 4–10 0.88 CT8 12.0 4–10 0.91 CT9 23.5 4–10 1.0 CT10 39.0 4–10 0.96 CT11 60.0 4–10 0.97 CT12 72.0 4–10 0.9 ESF-SD-ClV#14 2CT-1 0.17 4–10 0.1 2CT-2 0.34 4–10 0.2 2CT-3 0.75 4–10 0.19 2CT-4 2.5 4–10 0.39 2CT-5 7.0 4–10 0.46 2CT-6 21.0 4–10 0.53 2CT-7 34.0 4–10 0.68 2CT-8 49.0 4–10 0.58 2CT-9 70.0 4–10 0.6 ESF-SD-ClV#2 FT 0.17 <0.125 6.34 FT 0.33 <0.125 4.56 FT 0.67 <0.125 4.74 FT 1.0 <0.125 5.17 FT 2.25 <0.125 3.79 FT 4.33 <0.125 5.46 FT 8.0 <0.125 5.2 FT 12.0 <0.125 5.08 FT 24.0 <0.125 4.92 FT 38.5 <0.125 4.61 FT 60.0 <0.125 4.72 FT 72.0 <0.125 4.42 Table 4-6. Summary Data for Core Samples Analyzed at AECL during Phase II (continued) Core Used Sample Name Leach Duration (hr) Particle Size (mm) Cl-1 Concentration (mg/kg) ESF-SD-ClV#2 GS1 24.0 6-12 2.2 GS2 24.0 2-4 1.5 GS3 24.0 0.5-2 1.64 GS4 24.0 0.25-0.5 2.93 GS5 24.0 0.125-0.25 3.18 GS6 24.0 0.063-0.125 3.7 GS7 24.0 <0.063 4.39 ESF-SD-ClV#14 2A2-1 24.0 2–4 0.72 2A2-2 24.0 0.5–2 1.15 2A2-3 24.0 0.25–0.5 2.4 2A2-4 24.0 0.125–0.25 5.83 2A2-5 24.0 0.063–0.125 11.56 2A2-6 24.0 <0.063 15.73 ESF-SD-ClV#9 2BT-1 24.0 30–60 0.12 2BT-2 24.0 20–30 0.2 2BT-3 24.0 10–20 0.24 2BT-4 24.0 5–10 0.34 2BT-5 24.0 >4 0.35 2BT-6 24.0 1–4 0.45 ESF-SD-ClV#9 3BT-1 48.0 30–60 0.16 3BT-2 48.0 20–30 0.21 3BT-3 48.0 10–20 0.29 3BT-4 48.0 5–10 0.33 3BT-5 48.0 >4 0.37 3BT-6 48.0 1–4 0.44 ESF-SD-ClV#9 4BT-1 72.0 30–60 0.17 4BT-2 72.0 20–30 0.28 4BT-3 72.0 10–20 0.29 4BT-4 72.0 5–10 0.37 4BT-5 72.0 >4 0.38 4BT-6 72.0 1–4 0.44 DTN: GS030508312272.003 (UQ) NOTE: Sample name includes experiment designation (Table 4-5) and number. Table 4-7. Processing History of Validation Study Core Samples Leached at the USGS during Phase III Batch No. Sample Identifier Interval (ft) SMF Barcode Identifier Rock Mass (g) Water Mass (g) USGS-IC Barcode Identifier Cl Precip. and Target Prep. 36Cl Barcode Identifier AMS Facility 1 LLNL SPC00536901 EVAL001 NA SPC00557088 1,871 2,098 SPC00536900 LLNL LANL SPC00536902 1 ESF-SD-ClV#33 9.9–11.4 SPC02016014 1,787 2,057 SPC00536903 LLNL SPC00536904 LLNL LANL SPC00536905 1 ESF-SD-ClV#28 6.2–8.0 SPC02016017 1,893 2,130 SPC00536906 LLNL SPC00536907 LLNL LANL SPC00536908 1 ESF-SD-ClV#36 5.4–6.7 8.1–9.1 SPC01014834 SPC02015944 2,002 2,038 SPC00536909 LLNL SPC00536910 LLNL 9.1–9.4 SPC02015945 LANL SPC00536911 1 NA NA NA 2,034 SPC00536912 LLNL SPC00536913 LLNL DI blank (8/22/01) LANL SPC00536914 1 ESF-SD-ClV#31 2.8–3.8 SPC01014835 1,786 2,014 SPC00536915 LLNL SPC00536916 LLNL 3.8–4.5 SPC01014829 LANL SPC00536917 1 ESF-SD-ClV#21 11.3–13.0 SPC03017095 1,935 2,115 SPC00536918 LLNL SPC00536919 LLNL LANL SPC00536920 1 ESF-SD-ClV#30 6.4–8.4 SPC02015998 1,965 2,092 SPC00536921 LLNL SPC00536922 LLNL LANL SPC00536923 1 ESF-SD-ClV#32 7.6–9.5 SPC02016007 2,310 2,089 SPC00536924 LLNL SPC00536925 LLNL LANL SPC00536926 1 ESF-SD-ClV#28 4.0–5.1 SPC01014826 2,333 2,134 SPC00536927 LLNL SPC00536928 LLNL 5.2–6.2 SPC01014827 LANL SPC00536929 1 ESF-SD-ClV#34 2.1–2.4 2.4–3.0 3.0–3.5 3.8–4.8 SPC01014830 SPC01014831 SPC01014832 SPC01014833 2,399 2,103 SPC00536930 LLNL SPC00536931 LLNL LANL SPC00536932 TDR-NBS-HS-000017 REV00 T16 Table 4-7. Processing History of Validation Study Core Samples Leached at the USGS during Phase III (continued) Batch No. Sample Identifier Interval (ft) SMF Barcode Identifier Rock Mass (g) Water Mass (g) USGS-IC Barcode Identifier Cl Precip. and Target Prep. 36Cl Barcode Identifier AMS Facility 1 ESF-SD-ClV#22 4.5–6.3 SPC01014821 1,840 2,096 SPC00536933 LLNL SPC00536934 LLNL LANL SPC00536935 1 ESF-SD-ClV#21 2.8–4.6 SPC01014819 1,736 2,049 SPC00536936 LLNL SPC00536937 LLNL LANL SPC00536938 1 NA NA NA 2,061 SPC00536939 LLNL SPC00536940 LLNL DI blank (8/24/01) LANL SPC00536941 1 ESF-SD-ClV#35 6.4–8.5 SPC02015949 2,366 2,135 SPC00536942 LLNL SPC00536943 LLNL LANL SPC00536944 1 ESF-SD-ClV#27 10.0–12.0 SPC02016027 2,211 SPC00536945 LLNL SPC00536946 LLNL LANL SPC00536947 1 ESF-SD-ClV#26 3.0–4.0 4.0–4.8 SPC01014822 SPC01014823 1,688 2,040 SPC00536948 LLNL SPC00536949 LLNL 4.8–5.0 5.1–6.3 SPC01014824 SPC01014825 LANL SPC00536950 1 ESF-SD-ClV#26 3.0–4.0 4.0–4.8 SPC01014822 SPC01014823 1,700 2,044 SPC00536951 LLNL SPC00536952 LLNL 4.8–5.0 5.1–6.3 SPC01014824 SPC01014825 LANL SPC00536953 1 DI system water NA NA NA NA NA LLNL SPC00516600 LLNL sample (8/28/01) LANL SPC00516601 2 ESF-SD-ClV#24 4.0–6.6 SPC01015063 1,863 2,054 SPC00536954 LLNL SPC00536955 LLNL LANL SPC00536956 PRIME 2 ESF-SD-ClV#38 1.4–3.3 SPC01015068 1,959 2,076 SPC00536957 LLNL SPC00536958 LLNL 3.3–3.9 SPC01015069 LANL SPC00536959 PRIME 2 ESF-SD-ClV#37 3.6–5.3 SPC01015066 1,726 2,055 SPC00536960 LLNL SPC00536961 LLNL LANL SPC00536962 PRIME 2 USGS system blank (9/5/01) NA NA NA 2,057 SPC00536963 LLNL SPC00516602 LLNL LANL SPC00516603 PRIME TDR-NBS-HS-000017 REV00 T17 Table 4-7. Processing History of Validation Study Core Samples Leached at the USGS during Phase III (continued) Batch No. Sample Identifier Interval (ft) SMF Barcode Identifier Rock Mass (g) Water Mass (g) USGS-IC Barcode Identifier Cl Precip. and Target Prep. 36Cl Barcode Identifier AMS Facility 2 ESF-SD-ClV#39 2.1–3.5 SPC01015071 1,665 2,045 SPC00516604 LLNL SPC00516605 LLNL LANL SPC00516606 PRIME 2 ESF-SD-ClV#24 2.1–4.0 SPC01015062 1,907 2,050 SPC00516607 LLNL SPC00516608 LLNL LANL SPC00516609 PRIME 2 ESF-SD-ClV#23 4.8–5.9 SPC01015060 1,788 2,048 SPC00516610 LLNL SPC00516611 LLNL 5.9–6.7 SPC01015061 LANL SPC00516612 failed 2 ESF-SD-ClV#20 3.8–5.1 SPC01015057 1,909 2,054 SPC00516613 LLNL SPC00516614 LLNL 5.1–6.1 SPC01015058 LANL SPC00516615 PRIME 2 ESF-SD-ClV#19 4.4–5.7 SPC01015054 2,193 2,072 SPC00516616 LLNL SPC00516617 LLNL 5.7–6.4 SPC01015055 LANL SPC00516618 PRIME 2 ESF-SD-ClV#18 3.6–5.6 SPC01015051 1,799 2,057 SPC00516619 LLNL SPC00516620 LLNL LANL SPC00516621 PRIME 2 ESF-SD-ClV#17 3.9–4.7 4.7–5.5 SPC01015047 SPC01015048 2,276 2,061 SPC00516622 LLNL SPC00516623 LLNL 5.5–6.4 SPC01015049 LANL SPC00516624 PRIME 3 ESF-SD-ClV#2 4.7–5.9 5.9–6.6 SPC01015393 SPC01015394 2,322 2,051 SPC00516640 LLNL SPC00516641 SPC00516642 LLNL 3 ESF-SD-ClV#4 4.4–5.6 5.7–6.3 SPC01015399 SPC01015400 1,562 1,890 SPC00516691 LLNL SPC00516692 SPC00516693 LLNL 3 ESF-SD-ClV#7 3.9–4.4 6.0–6.5 SPC01015406 SPC01015407 989 1,107 SPC00516643 LLNL SPC00516644 SPC00516645 LLNL 3 ESF-SD-ClV#11 2.4–3.4 4.1–5.2 SPC01015475 SPC01015476 1,513 1,955 SPC00516670 LLNL SPC00516671 SPC00516672 LLNL 3 ESF-SD-ClV#8 2.0–3.4 SPC01015408 1,198 1,448 SPC00516625 LLNL SPC00516626 SPC00516627 LLNL 3 ESF-SD-ClV#8 4.0–5.5 6.0–6.2 SPC01015409 SPC01015410 1,360 1,700 SPC01015124 LLNL SPC01015125 SPC01015126 LLNL TDR-NBS-HS-000017 REV00 T18 Table 4-7. Processing History of Validation Study Core Samples Leached at the USGS during Phase III (continued) Batch No. Sample Identifier Interval (ft) SMF Barcode Identifier Rock Mass (g) Water Mass (g) USGS-IC Barcode Identifier Cl Precip. and Target Prep. 36Cl Barcode Identifier AMS Facility 3 ESF-SD-ClV#10 2.0–3.9 SPC01015473 1,046 1,489 SPC00516697 LLNL SPC01015119 SPC01015120 LLNL 3 ESF-SD-ClV#12 2.0–4.4 SPC01015478 2,202 2,039 SPC00516667 LLNL SPC00516668 SPC00516669 LLNL 3 ESF-SD-ClV#13 2.9–4.5 SPC01015483 1,858 2,018 SPC00516682 LLNL SPC00516683 SPC00516684 LLNL 3 ESF-SD-ClV#15 4.7–6.0 6.0–6.6 SPC01015494 SPC01015495 2,073 2,052 SPC00516652 LLNL SPC00516653 SPC00516654 LLNL 4 ESF-SAD-GTB#1 hand crush (10 mesh–3/4") 178.5–179.1 179.3–180.1 180.8–181.8 182.0–183.2 183.9–184.8 185.0–186.3 SPC01002899 SPC01002901 SPC01002903 SPC01002905 SPC01002907 SPC01002909 1,605 1,853 SPC01015160 LLNL SPC01015161 SPC01015162 LLNL 4 ESF-SAD-GTB#1 hand crush (1/4–3/4") 178.5–179.1 179.3–180.1 180.8–181.8 182.0–183.2 183.9–184.8 185.0–186.3 SPC01002899 SPC01002901 SPC01002903 SPC01002905 SPC01002907 SPC01002909 1,477 1,534 SPC01015163 LLNL SPC01015164 SPC01015165 LLNL 4 ESF-SAD-GTB#1 mechanical crush (1/4–3/4") 178.5–179.1 179.3–180.1 180.8–181.8 182.0–183.2 183.9–184.8 185.0–186.3 SPC01002899 SPC01002901 SPC01002903 SPC01002905 SPC01002907 SPC01002909 1,706 1,802 SPC01015169 LLNL SPC01015170 SPC01015171 LLNL 5 ESF-MDNICHE3566# 1 25.3–26.0 28.1–28.9 30.8–31.7 SPC01003084 SPC01003089 SPC01003094 1,358 1,456 SPC01015172 LLNL SPC01015173 SPC01015174 LLNL TDR-NBS-HS-000017 REV00 T19 Table 4-7. Processing History of Validation Study Core Samples Leached at the USGS during Phase III (continued) Batch No. Sample Identifier Interval (ft) SMF Barcode Identifier Rock Mass (g) Water Mass (g) USGS-IC Barcode Identifier Cl Precip. and Target Prep. 36Cl Barcode Identifier AMS Facility 5 ESF-MD- NICHE3566#2 20.2–20.7 29.8–30.4 32.0–32.5 SPC01003140 SPC01003155 SPC01003156 1,312 1,446 SPC01015175 LLNL SPC01015176 SPC01015177 LLNL 5 ESF-MD- NICHE3566#2 11.5–11.9 13.2–13.7 15.0–15.4 SPC01003121 SPC01003125 SPC01003129 1,153 1,419 SPC01015181 LLNL SPC01015182 SPC01015183 LLNL 5 ESF-MD- NICHE3566#1 14.7–15.8 20.3–20.9 SPC01003066 SPC01003074 1,435 1,511 SPC01015184 LLNL SPC01015185 SPC01015186 LLNL 5 ESF-MD- NICHE3566#LT1 10.9–11.9 13.4–14.1 22.8–23.5 SPC01004414 SPC01004418 SPC01004435 1,339 1,454 SPC01015187 LLNL SPC01015188 SPC01015189 LLNL 25.0–25.9 SPC01004439 5 ESF-MD- NICHE3566#LT1 28.2–28.8 31.5–31.9 SPC01004443 SPC01004451 1,665 1,737 SPC01015190 LLNL SPC01015191 SPC01015192 LLNL 37.1–38.1 SPC01004462 5 USGS system blank (6/24/02) NA NA NA 1,615 SPC01015193 LLNL SPC01015194 SPC01015195 LLNL DTNs: LL031200223121.036 (Q), Filename: Total_AMS_Summary_2001-02c.xls; GS030608312272.005 (Q);LA0305RR831222.001 (UQ) NOTES: AMS = accelerator mass spectrometer, DI = deionized water; IC = ion chromatography, LANL = Los Alamos National Laboratory, LLNL = Lawrence Livermore National Laboratory, NA = not applicable, PRIME = Purdue Rare Isotope Measurement Laboratory, SMF = Sample Management Facility, USGS = U.S. Geological Survey. Samples were crushed at either the SMF or USGS, and leached at the USGS. The leachates were distributed to LANL and LLNL for AgCl precipitation and target preparation. For Batch #1 samples, targets prepared at LANL and LLNL were analyzed at LLNL-CAMS. For Batch #2, the targets prepared at LANL were analyzed at PRIME Lab and targets prepared at LLNL were analyzed at LLNL-CAMS. Targets for Batches #3, #4, and #5 were prepared and analyzed at LLNL. The weight of water was not recorded for ESF-SD-ClV#27. The concentration was calculated assuming a 1:1 water to rock mass ratio (MOL.20030626.0093, p. 2). DI blank (8/28/01) was an unfiltered 1-L sample from the DI water system. Due to high 36S, which interferes with 36Cl measurements, LLNL did not report data for ClV#18 (see file YMP_Cl35-36-37C.Nov_29_01.xls in LL031200223121.036). The USGS data for ClV#18 are located in GS030608312272.005. TDR-NBS-HS-000017 REV00 T20 Table 4-8. Validation Study Core Intervals Chosen for Passive Leaching at the USGS during Phase III Sample Identifier Interval (ft) Comments ESF-SD-ClV#2 4.7–5.9 5.9–6.6 Rubbly (4.7–4.8); intact, about 1 fracture (4.8–5.9), intact (5.9– 6.4); broken (6.4–7.0) ESF-SD-ClV#4 4.4–5.6 5.7–6.3 Rubbly (4.4–4.7); rubbly-broken (4.7–5.3); rubbly (5.3–5.6); broken (5.7–5.9); rubbly (5.9–6.3) ESF-SD-ClV#7 3.9–4.4 6.0–6.5 2 blocks (3.9–4.4); broken, more than 12 fractures (6.0–8.0) ESF-SD-ClV#8 2.0–3.4 Broken-rubbly (2.0–2.8); rubbly (2.8–3.4) ESF-SD-ClV#8 4.0–5.5 6.0–6.2 Rubbly (4.0–4.3); block (4.3–4.7); rubbly (4.7–5.5); block (6.0– 6.2) ESF-SD-ClV#10 2.0–3.9 Block (2.0–2.2); rubbly-shattered (2.2–3.65); block (3.7–3.9) ESF-SD-ClV#11 2.4–3.4 4.1–5.2 Broken, about 5 fractures (1.7–3.0); broken-rubbly (3.0–3.4); rubbly (4.1–5.1) ESF-SD-ClV#12 2.0–4.4 Intact, few hairline fractures (2.0–3.3); broken (3.3–3.65); intact (3.65–4.3); broken (4.3–4.4) ESF-SD-ClV#13 2.9–4.5 Broken, more than 12 fractures (2.9–6.3) ESF-SD-ClV#15 4.7–6.0 6.0–6.6 Broken, about 2 fractures ESF-SD-ClV#17 3.9–6.4 Broken, blocky ESF-SD-ClV#18 3.6-5.6 Broken ESF-SD-ClV#19 4.4–6.4 Intact-broken-rubbly ESF-SD-ClV#20 3.8–6.1 Broken-rubble ESF-SD-ClV#21 11.3–13.0 Intact, 1 fracture ESF-SD-ClV#21 2.8–4.6 Broken-rubbly ESF-SD-ClV#22 4.5–6.3 Very broken ESF-SD-ClV#23 4.8–6.7 Broken ESF-SD-ClV#24 2.1–4.0 Large intact pieces, broken in 6 areas ESF-SD-ClV#24 4.0–6.6 Large intact pieces, broken in 6 areas ESF-SD-ClV#26 3.0–6.3 Broken ESF-SD-ClV#27 10.0–12.0 10.0–12.0 intact with 2 to 3 fractures ESF-SD-ClV#28 4.0–6.2 Increasingly broken toward the bottom of the run; broken from 5.6–6.2 ESF-SD-ClV#28 6.2–8.0 Intact with 4 to 5 fractures to 8.0 ESF-SD-ClV#30 6.4–8.4 Broken ESF-SD-ClV#31 2.8–4.5 Broken ESF-SD-ClV#32 7.6–9.5 Intact ESF-SD-ClV#33 9.9–11.4 Intact with about 3 fractures ESF-SD-ClV#34 2.1–4.8 Broken (2.1–3.0); rubbly (3.0–3.8); intact with about 3 fractures (3.8–4.8) ESF-SD-ClV#35 6.4–8.5 Broken ESF-SD-ClV#36 5.4–9.4 Broken (5.4–6.7); rubbly (6.7–7.0); intact with about 4 fractures (7.0–9.1), 9.1-9.4, one chunk ESF-SD-ClV#37 3.6–5.3 3.0–5.9 intact with 2 to 3 discrete fractures ESF-SD-ClV#38 1.4–3.9 1.4–2.6 intact; 2.6–3.9 broken to rubbly ESF-SD-ClV#39 2.1–3.5 Intact DTN: LL031200223121.036 (Q), Filename: Total_AMS_Summary_2001-02c.xls NOTE: “Comments” are from the video log observations described in Appendix B. TDR-NBS-HS-000017 REV00 T21 TDR-NBS-HS-000017 REV00 T22 Table 4-9. Chloride Concentrations and 36Cl/Cl Ratios in Core Samples Leached and Analyzed at USGS-LLNL during Phase III Batch No. Sample Identifier SMF Barcode Identifier for LLNL Sample Water Mass Used for Analysis (kg) Date Submitted to LLNL AMS Results Final Results CAMS ID Sulfur Figure of Merit Leachate Cl Concentration (mg/kg water) 36Cl/Cl ×1015 Leachate Cl Concentration (mg/kg water) Leachate Cl Concentration (mg/kg rock) 36Cl/Cl ×1015 1 EVAL001 SPC00536901 0.900 08/28/01 CL9634 0.99 0.140 ±0.007 462 ±40 0.130 ±0.008 0.146 ±0.009 454 ±145 1 ESF-SD-ClV#21 (2.8-4.6) SPC00536919 0.900 08/28/01 CL9640 0.98 0.145 ±0.007 381 ±21 0.135 ±0.008 0.147±0.009 368 ±122 1 ESF-SD-ClV#21 (11.3-13.0) SPC00536937 0.900 08/28/01 CL9646 0.97 0.325 ±0.016 305 ±25 0.315 ±0.016 0.372 ±0.019 297 ±114 1 ESF-SD-ClV#22 (4.5-6.3) SPC00536934 0.900 08/28/01 CL9645 0.99 0.154 ±0.008 333 ±22 0.144 ±0.009 0.165 ±0.010 317 ±121 1 ESF-SD-ClV#26-1 (3.0-6.3) SPC00536949 0.900 08/28/01 CL9650 0.83 0.097 ±0.005 200 ±23 0.087 ±0.006 0.105 ±0.008 159 ±137 1 ESF-SD-ClV#26-2 (3.0-6.3) SPC00536952 0.900 08/28/01 CL9651 0.87 0.105 ±0.005 177 ±27 0.095 ±0.006 0.114 ±0.008 137 ±136 1 ESF-SD-ClV#27 (10.0-12.0) SPC00536946 0.900 08/28/01 CL9649 0.97 0.149 ±0.007 211 ±21 0.139 ±0.008 0.125 ±0.007 186 ±118 1 ESF-SD-ClV#28 (4.0-6.2) SPC00536928 0.900 08/28/01 CL9643 0.85 0.089 ±0.004 204 ±32 0.079 ±0.006 0.073 ±0.005 160 ±150 1 ESF-SD-ClV#28 (6.2-8.0) SPC00536907 0.900 08/28/01 CL9636 0.92 0.146 ±0.007 189 ±55 0.136 ±0.008 0.153 ±0.009 163 ±161 1 ESF-SD-ClV#30 (6.4-8.4) SPC00536922 0.900 08/28/01 CL9641 0.98 0.138 ±0.007 185 ±19 0.128 ±0.008 0.136 ±0.009 156 ±119 1 ESF-SD-ClV#31 (2.8-4.5) SPC00536916 0.900 08/28/01 CL9639 0.98 0.065 ±0.003 301 ±27 0.055 ±0.005 0.062 ±0.006 255 ±176 1 ESF-SD-ClV#32 (7.6-9.5) SPC00536925 0.900 08/28/01 CL9642 0.98 0.180 ±0.009 222 ±22 0.170 ±0.010 0.154±0.009 203 ±115 1 ESF-SD-ClV#33 (9.9-11.4) SPC00536904 0.900 08/28/01 CL9635 0.99 0.090 ±0.005 363 ±34 0.080 ±0.006 0.092 ±0.007 339 ±156 1 ESF-SD-ClV#34 (2.1-4.8) SPC00536931 0.900 08/28/01 CL9644 0.97 0.100 ±0.005 267 ±26 0.090 ±0.006 0.079 ±0.006 236 ±139 1 ESF-SD-ClV#35 (6.4-8.5) SPC00536943 0.900 08/28/01 CL9648 0.95 0.111 ±0.006 235 ±43 0.101 ±0.007 0.091 ±0.007 203 ±154 1 ESF-SD-ClV#36 (5.4-6.7/8.1-9.4) SPC00536910 0.900 08/28/01 CL9637 0.96 0.078 ±0.004 416 ±31 0.068 ±0.006 0.069±0.006 395 ±164 TDR-NBS-HS-000017 REV00 T23 Table 4-9. Chloride Concentrations and 36Cl/Cl Ratios in Core Samples Leached and Analyzed at USGS-LLNL during Phase III (continued) Batch No. Sample Identifier SMF Barcode Identifier for LLNL Sample Water Mass Used for Analysis (kg) Date Submitted to LLNL AMS Results Final Results CAMS ID Sulfur Figure of Merit Leachate Cl Concentration (mg/kg water) 36Cl/Cl ×1015 Leachate Cl Concentration (mg/kg water) Leachate Cl Concentration (mg/kg rock) 36Cl/Cl ×1015 2 ESF-SD-ClV#17 (3.9-6.4) SPC00516623 0.900 09/10/01 CL9722 0.99 0.186 ±0.009 308 ±15 0.176 ±0.010 0.160 ±0.009 294 ±111 2 ESF-SD-ClV#19 (4.4-6.4) SPC00516617 0.900 09/10/01 CL9720 0.88 0.166 ±0.008 333 ±68 0.156 ±0.009 0.148 ±0.008 319 ±182 2 ESF-SD-ClV#20 (3.8-6.1) SPC00516614 0.900 09/10/01 CL9719 0.96 0.090 ±0.005 444 ±61 0.080 ±0.006 0.087 ±0.007 430 ±194 2 ESF-SD-ClV#23 (4.8-6.7) SPC00516611 0.900 09/10/01 CL9718 0.95 0.158 ±0.008 327 ±33 0.148 ±0.009 0.170 ±0.010 311 ±131 2 ESF-SD-ClV#24 (2.1-4.0) SPC00516608 0.900 09/10/01 CL9717 0.98 0.133 ±0.007 333 ±21 0.123 ±0.008 0.133 ±0.009 315 ±124 2 ESF-SD-ClV#24 (4.6-6.6) SPC00536955 0.900 09/10/01 CL9712 0.98 0.189 ±0.009 611 ±90 0.179 ±0.010 0.197±0.011 615 ±221 2 ESF-SD-ClV#37 (3.6-5.3) SPC00936961 0.900 09/10/01 CL9714 0.95 0.093 ±0.005 428 ±48 0.089 ±0.011 0.099 ±0.008 413 ±173 2 ESF-SD-ClV#38 (1.4-3.9) SPC00536958 0.900 09/10/01 CL9713 0.99 0.324 ±0.016 582 ±31 0.314 ±0.016 0.333 ±0.017 583 ±125 2 ESF-SD-ClV#39 (2.1-3.5) SPC00516605 0.900 09/10/01 CL9716 0.92 0.114 ±0.006 540 ±93 0.104 ±0.007 0.128 ±0.009 538 ±241 3 ESF-SD-ClV#2 (4.7-6.6) SPC00516641 0.900 01/25/02 CL10023 1 0.421 ±0.021 320 ±30 0.411 ±0.021 0.363 ±0.019 314 ±117 3 ESF-SD-ClV#4 (4.4-6.3) SPC00516692 0.877 01/25/02 CL10024 1 0.136 ±0.007 535 ±63 0.126 ±0.008 0.153 ±0.010 533 ±182 3 ESF-SD-ClV#7 (3.9-4.4) SPC00516644 0.900 01/25/02 CL10025 1 0.077 ±0.004 211 ±175 0.067 ±0.006 0.075 ±0.006 159 ±428 3 ESF-SD-ClV#8 (2.0-3.4) SPC00516627 0.411 01/25/02 CL10117 0.8 0.121 ±0.006 341 ±116 0.111 ±0.007 0.134 ±0.009 322 ±279 3 ESF-SD-ClV#8 (4.0-6.2) SPC01015126 0.513 01/25/02 CL10118 0.98 0.055 ±0.003 286 ±71 0.045 ±0.005 0.056 ±0.006 226 ±255 3 ESF-SD-ClV#10 (2.0-3.9) SPC01015120 0.470 01/25/02 CL10119 0.97 0.043 ±0.002 553 ±112 0.033 ±0.004 0.046 ±0.006 552 ±386 3 ESF-SD-ClV#11 (2.4-5.2) SPC00516671 0.900 01/25/02 CL10026 1 0.039 ±0.002 465 ±367 0.029 ±0.004 0.037 ±0.006 434 ±1,026 3 ESF-SD-ClV#12 (2.0-4.4) SPC00516668 SPC00516669 0.936 01/25/02 CL10120 0.95 0.058 ±0.003 362 ±64 0.048 ±0.005 0.044 ±0.005 321 ±238 TDR-NBS-HS-000017 REV00 T24 Table 4-9. Chloride Concentrations and 36Cl/Cl Ratios in Core Samples Leached and Analyzed at USGS-LLNL during Phase III (continued) Batch No. Sample Identifier SMF Barcode Identifier for LLNL Sample Water Mass Used for Analysis (kg) Date Submitted to LLNL AMS Results Final Results CAMS ID Sulfur Figure of Merit Leachate Cl Concentration (mg/kg water) 36Cl/Cl ×1015 Leachate Cl Concentration (mg/kg water) Leachate Cl Concentration (mg/kg rock) 36Cl/Cl ×1015 3 ESF-SD-ClV#13 (2.9-4.5) SPC00516683 SPC00516684 0.938 01/25/02 CL10121 0.95 0.051 ±0.003 433 ±75 0.041 ±0.005 0.044 ±0.005 403 ±278 3 ESF-SD-ClV#15 (4.7-6.6) SPC00516653 SPC00516654 0.977 01/25/02 CL10122 0.97 0.073 ±0.004 437 ±49 0.063 ±0.006 0.062 ±0.006 418 ±193 4 ESF-SAD-GTB#1 hand crush (10 mesh-3/4") SPC01015161 0.900 06/12/02 CL10322 0.99 0.61 ±0.031 511 ±15 0.604 ±0.031 0.697 ±0.036 510 ±108 4 ESF-SAD-GTB#1 hand crush (1/4"-3/4") SPC01015164 0.900 06/12/02 CL10323 0.99 0.47 ±0.023 460 ±14 0.456 ±0.023 0.474 ±0.024 457 ±107 4 ESF-SAD-GTB#1 mech. crush (1/4"-3/4") SPC01015170 0.900 06/12/02 CL10324 0.98 0.50 ±0.025 348 ±13 0.489 ±0.025 0.517 ±0.027 344 ±104 5 ESF-MD- NICHE3566#1 (14.7-20.9) SPC01015185 0.900 06/26/02 CL10329 0.92 0.202 ±0.010 709 ±36 0.192 ±0.011 0.202 ±0.011 717 ±139 5 ESF-MDNICHE3566# 1 (25.3-31.7) SPC01015173 0.900 06/26/02 CL10326 0.98 0.172 ±0.009 450 ±20 0.162 ±0.010 0.173 ±0.011 443 ±119 5 ESF-MDNICHE3566# 2 (11.5-15.4) SPC01015182 0.900 06/26/02 CL10328 0.76 0.181 ±0.009 408 ±26 0.171 ±0.006 0.210 ±0.007 399 ±120 5 ESF-MDNICHE3566# 2 (20.2–32.5) SPC01015176 0.900 06/26/02 CL10327 0.91 0.255 ±0.013 257 ±14 0.245 ±0.014 0.270 ±0.015 245 ±106 Table 4-9. Chloride Concentrations and 36Cl/Cl Ratios in Core Samples Leached and Analyzed at USGS-LLNL during Phase III (continued) TDR-NBS-HS-000017 REV00 T25 Water AMS Results Final Results Leachate Cl Leachate Cl Batch No. Sample Identifier SMF Barcode Identifier for LLNL Sample Mass Used for Analysis (kg) Date Submitted to LLNL CAMS ID Sulfur Figure of Merit Leachate Cl Concentration (mg/kg water) 36Cl/Cl ×1015 Concentration (mg/kg water) Concentration (mg/kg rock) 36Cl/Cl ×1015 5 ESF-MDNICHE3566# LT1 (10.9-23.5) SPC01015188 0.900 06/26/02 CL10330 0.98 0.195 ±0.010 384 ±17 0.185 ±0.011 0.201 ±0.012 374 ±113 5 ESF-MDNICHE3566# LT1 (25.0-38.1) SPC01015191 0.900 06/26/02 CL10331 0.78 0.180 ±0.009 244 ±25 0.170 ±0.010 0.178 ±0.010 226 ±119 DTN: LL031200223121.036 (Q), Filename: Total_AMS_Summary_2001-02c.xls NOTES: AMS = accelerator mass spectrometer, CAMS = Center for Accelerator Mass Spectrometry, ID = identifier, LLNL = Lawrence Livermore National Laboratory, SMF = Sample Management Facility, U.S. Geological Survey. Sample Identifier includes core interval (in parentheses). Measured isotope ratios were normalized to a NIST-traceable standard (LLNL111) with a 36Cl/Cl ratio of 1.11 ×10-13 and a 35Cl/37Cl ratio of 3.127. Measured 36Cl/37Cl ratios were not corrected for spurious counts at mass-36 attributed to 36S present in the sample because of the small amounts of sulfur present (sulfur figure of merit values greater than 0.75 correspond to sulfur corrections less than 25%). AMS isotope ratios were corrected for background values measured in chemical processing blanks included in the same AMS runs and for the addition of spike. Analytical errors for AMS results are 2s for leachate chloride concentrations relative to water and 1s for 36Cl/Cl. Final results given in the last three columns are also corrected for leach-process blanks. Because equal volumes of water were used for blank determinations and for sample leaching, the process blank correction was -1559.0×10 (mg/kg water); S i 1= done by subtracting concentrations of total chloride and 36Cl in blank (the weighted average values for the five blank analyses are given in Table 4-10) from measured AMS concentrations of total Cl and 36Cl in the sample. For example, for EVAL001: Final Cl conc. (mg/kg water) = AMS Cl conc. 0.140 (mg/kg water) – Blank Cl conc. 0.010 (mg/kg water) = 0.130 (mg/kg water); Final 36Cl conc. (mg/kg water) = [AMS Cl conc. 0.140 (mg/kg water) × AMS 36Cl/Cl 462 ×10-15] – [Blank Cl conc. 0.010 (mg/kg water) × 555×10-15] = Final 36Cl/Cl = Final 36Cl conc. 59.0×10-15 (mg/kg water) ÷ Final Cl conc. 0.130 (mg/kg water) = 454×10-15 . Errors for blank-corrected values were propagated assuming statistical independence of errors for blanks and samples using the general equation: f 22 sfxi . s . .... 2 n (x1,..., xn ) = . .... xi . TDR-NBS-HS-000017 REV00 T26 Table 4-9. Chloride Concentrations and 36Cl/Cl Ratios in Core Samples Leached and Analyzed at USGS-LLNL during Phase III (continued) The final uncertainty for isotope ratios (total 2s error) includes an external error derived from duplicate analyses of 14 leachates given in Table 4-10. Analytical errors for final results are 2s for leachate chloride concentrations relative to both water and rock. Samples were crushed at either the SMF or USGS, and leached at the USGS. The leachates were distributed to LANL and LLNL for AgCl precipitation and target preparation. For Batch #1 samples, targets prepared at LANL and LLNL were analyzed at LLNL-CAMS. For Batch #2, the targets prepared at LANL were analyzed at PRIME Lab and targets prepared at LLNL were analyzed at LLNL-CAMS. Targets for Batches #3, #4, and #5 were prepared and analyzed at LLNL. Table 4-10. Concentrations and Chloride Isotopic Compositions of Procedural Blanks Obtained for Passive Leaching at the USGS and Chloride Precipitation and Analysis at LLNL during Phase III Sample Identifier SMF Barcode Identifier for LLNL Sample Water Mass Analyzed (kg) AMS Results (corrected for background and spike) Mass of 36Cl in Blank (mg) ×1015 Conc. of 36Cl in Blank (mg/kg water) ×1015 Cl Conc. in Blank (mg/kg water) 36Cl/Cl ×1015 DI blank SPC00536913 0.900 0.004 1,839 ±555 6.9 7.6 ±2.3 DI blank SPC00536940 0.900 0.010 47 ±211 0.42 0.47 ±2.1 DI system water sample SPC00516600 0.900 0.017 110 ±118 1.7 1.8 ±2.0 USGS system blank SPC00516602 0.900 0.009 626 ±126 5.1 5.7 ±1.2 USGS system blank SPC01015194 0.900 0.01 152 ±148 1.6 1.8 ±1.8 Arithmetic mean 0.010 555 3.1 3.5 Standard deviation 0.005 754 2.7 3.0 Standard error 0.002 337 1.2 1.3 DTN: LL031200223121.036 (Q), Filename: Total_AMS_Summary_2001-02c.xls NOTES: AMS = accelerator mass spectrometer, DI = deionized water, LLNL = Lawrence Livermore National Laboratory, SMF = Sample Management Facility, USGS = U.S. Geological Survey. Analytical errors are 1s for 36Cl/Cl (corrected for background and spike) and concentration of 36Cl in blank. Cl conc. in blank (mg/kg water) = Mass Cl in blank (mg) ÷ Water mass analyzed (kg). Mass of 36Cl in blank (mg) = Water mass analyzed (kg) x Cl conc. in blank (mg/kg water) x 36Cl/Cl x10-15 . Conc. of 36Cl in blank (mg/kg water) = Mass of 36Cl in blank (mg) ÷ Water mass analyzed (kg). Table 4-11. Chloride Concentrations and 36Cl/Cl Ratios Measured during Phase III at USGS-LLNL in Silicon Crushing Blanks, System Process Blanks, and a Composite Sample of Niche #1 Core Crushed and Sieved at LANL Sample Identifier SMF Barcode Identifier Mass of Rock (kg) Mass of Water (kg) Cl Conc. (mg/kg water) by Ion Chromatography Cl Conc. (mg/kg rock) by Ion Chromatography Corrected for Cl and 36Cl Measured in Chemistry Process Blank CL10348 Cl Conc. (mg/kg water) by Isotope Dilution 36Cl/Cl ×1015 (1s) Silicon blank (plate) SPC01015196 SPC01015197 1.571 1.824 0.019 0.022 0.028 957 ±174 Silicon blank (mortar) SPC01015202 SPC01015203 1.792 1.952 0.014 0.015 0.047 1,033 ±249 Leaching blank (9/4/02) SPC01015199 SPC01015200 NA 1.907 <0.010 NA 0.02 1,077 ±252 Mix of NICHE3566#1 and NICHE3566#LT1 SPC01015205 2.000 2.005 0.114 0.114 0.188 1,185 ±121 DTNs: LL031200223121.036 (Q), Filename: Total_AMS_Summary_2001-02c.xls; GS030608312272.006 (UQ) NOTES: LANL = Los Alamos National Laboratory, LLNL = Lawrence Livermore National Laboratory, NA = not applicable, SMF = Sample Management Facility, USGS = U.S. Geological Survey. Cl concentrations and 36Cl/Cl ratios corrected for values measured in the Lawrence Livermore National Laboratory Chemistry Process Blank CL10348 run in the same batch having 0.006 ±0.002 mg Cl/kg water and a 36Cl/Cl ratio of 2,388 ±634 (1s) ×10-15 . Cl conc. (mg/kg rock) = [Cl conc. (mg/kg water)] x [Mass of water (kg) ÷ Mass of rock (kg)]. Table 4-12. Chloride Concentrations and 36Cl/Cl Ratios in Leachates of Validation Study Samples Analyzed at LANL during Phase III Sample or Aliquot Identifier SMF Barcode Identifier Sample Location LANL Identifier AMS Facility AMS Identifier Date Analyzed Cl Concentration (mg/kg rock) Sample + Blank 36Cl/Cl ×1015 Sample 36Cl/Cl ×1015 (2s) EVAL001 SPC00536902 ESF Sundance fault zone YM2033 CAMS CL9659 10/26/2001 0.15 380 361 ±42 ESF-SD-ClV#34 (2.1-4.8) SPC00536932 ESF Sundance fault zone YM2030 CAMS CL9656 10/26/2001 0.08 347 315 ±59 ESF-SD-ClV#22 (4.5-6.3) SPC00536935 ESF Sundance fault zone YM2032 CAMS CL9658 10/26/2001 0.15 426 408 ±43 ESF-SD-ClV#28 (6.2-8.0) SPC00536908 ESF Sundance fault zone YM2034 CAMS CL9660 10/26/2001 0.16 225 203 ±28 ESF-SD-ClV#32 (7.6-9.5) SPC00536926 ESF Sundance fault zone YM2035 CAMS CL9661 10/26/2001 0.16 254 235 ±29 ESF-SD-ClV#21 (2.8-4.6) SPC00536938 ESF Sundance fault zone YM2036 CAMS CL9662 10/26/2001 0.18 362 344 ±38 ESF-SD-ClV#35 (6.4-8.5) SPC00536944 ESF Sundance fault zone YM2037 CAMS CL9663 10/26/2001 0.09 292 264 ±45 ESF-SD-ClV#21 (11.3-13.0) SPC00536920 ESF Sundance fault zone YM2038 CAMS CL9664 10/26/2001 0.32 320 310 ±29 ESF-SD-ClV#30 (6.4-8.4) SPC00536923 ESF Sundance fault zone YM2039 CAMS CL9665 10/26/2001 0.16 186 163 ±30 ESF-SD-ClV#27 (10.0-12.0) SPC00536947 ESF Sundance fault zone YM2040 CAMS CL9666 10/26/2001 0.15 230 208 ±29 ESF-SD-ClV#33 (9.9-11.4) SPC00536905 ESF Sundance fault zone YM2041 CAMS CL9667 10/26/2001 0.11 282 249 ±44 ESF-SD-ClV#26-1 (3.0-6.3) SPC00536950 ESF Sundance fault zone YM2047 CAMS CL9673 10/26/2001 0.10 307 270 ±72 ESF-SD-ClV#26-2 (3.0-6.3) SPC00536953 ESF Sundance fault zone YM2048 CAMS CL9674 10/26/2001 0.11 260 225 ±44 ESF-SD-ClV#36 (5.4-9.4) SPC00536911 ESF Sundance fault zone YM2049 CAMS CL9675 10/26/2001 0.07 360 322 ±66 ESF-SD-ClV#24 (4.6-6.6) SPC00536956 ESF Sundance fault zone YM2071 PRIME R02-0200,5A 8/21/2002 0.20 471 410 ±151 ESF-SD-ClV#38 (1.4-3.9) SPC00536959 ESF Sundance fault zone YM2072 PRIME R02-0201,5A 8/21/2002 0.26 666 640 ±162 ESF-SD-ClV#37 (3.6-5.3) SPC00536962 ESF Sundance fault zone YM2073 PRIME R02-0202,5A 8/21/2002 0.07 409 180 ±204 ESF-SD-ClV#20 (3.8-6.1) SPC00516615 ESF Sundance fault zone YM2078 PRIME R02-0207,5A 8/21/2002 0.08 371 180 ±208 TDR-NBS-HS-000017 REV00 T29 TDR-NBS-HS-000017 REV00 T30 Table 4-12. Chloride Concentrations and 36Cl/Cl Ratios in Leachates of Validation Study Samples Analyzed at LANL during Phase III (continued) Sample or Aliquot Identifier SMF Barcode Identifier Sample Location LANL Identifier AMS Facility AMS Identifier Date Analyzed Cl Concentration (mg/kg rock) Sample + Blank 36Cl/Cl ×1015 Sample 36Cl/Cl ×1015 (2s) ESF-SD-ClV#19 (4.4-6.4) SPC00516618 ESF Sundance fault zone YM2079 PRIME R02-0208,5A 8/21/2002 0.09 432 308 ±194 ESF-SD-ClV#18 (3.6-5.6) SPC00516621 ESF Sundance fault zone YM2080 PRIME R02-0209,5A 8/21/2002 0.10 557 456 ±283 ESF-SD-ClV#17 (3.9-6.4) SPC00516624 ESF Sundance fault zone YM2081 PRIME R02-0210,5A 8/21/2002 0.14 519 450 ±210 Niche 1-RCR-1A SPC01003045, SPC01003048, SPC01003050, SPC01003053, SPC01003055, SPC01003057 ESF Niche #1 YM2103 CAMS CL10291 7/30/2002 0.14 1,194 1,163 ±94 Niche 1-RCR-1B SPC01003045, SPC01003048, SPC01003050, SPC01003053, SPC01003055, SPC01003057 ESF Niche #1 YM2104 CAMS CL10292 7/30/2002 0.67 8,530 8,558 ±485 Niche 1-RCR-2 SPC01003068, SPC01003070, SPC01003072 ESF Niche #1 YM2105 CAMS CL10293 7/30/2002 0.27 1,636 1,624 ±120 Niche 1- RCR-3 SPC01003082, SPC01003087, SPC01003091 ESF Niche #1 YM2106 CAMS CL10294 7/30/2002 0.28 3,164 3,166 ±199 Niche 2-RCR-1 SPC01003119, SPC01003123, SPC01003127, SPC01003135 ESF Niche #1 YM2107 CAMS CL10295 7/30/2002 0.21 1,130 1,109 ±78 Niche LT-RCR-1A SPC01004416, SPC01004431, SPC01004433, SPC01004437, SPC01004441, SPC01004460, SPC01004464 ESF Niche #1 YM2108 CAMS CL10296 7/30/2002 0.13 1,050 1,016 ±87 TDR-NBS-HS-000017 REV00 T31 Table 4-12. Chloride Concentrations and 36Cl/Cl Ratios in Leachates of Validation Study Samples Analyzed at LANL during Phase III (continued) Sample or Aliquot Identifier SMF Barcode Identifier Sample Location LANL Identifier AMS Facility AMS Identifier Date Analyzed Cl Concentration (mg/kg rock) Sample + Blank 36Cl/Cl ×1015 Sample36Cl/Cl ×1015 (2s) Niche LT-RCR-1B SPC01004416, SPC01004431, SPC01004433, SPC01004437, SPC01004441, SPC01004460, SPC01004464 ESF Niche #1 YM2109 CAMS CL10297 7/30/2002 0.69 3,388 3,390 ±196 EXD046-1 SPC00521151 ECRB Cross Drift YM2012 PRIME T01-0852,5A 12/7/2001 0.53 603 607 ±51 EXD052-1 SPC00521144 ECRB Cross Drift YM2013 PRIME T01-0853,5A 12/7/2001 0.38 568 574 ±56 EXD059-1 SPC00521138 ECRB Cross Drift YM2014 PRIME T01-0854,5A 12/7/2001 0.30 1,274 1,309 ±114 EXD066-1 SPC00541211 ECRB Cross Drift YM2015 PRIME T01-0855,5A 12/7/2001 3.59 162 161 ±22 EXD071-1 SPC00541216 ECRB Cross Drift YM2016 PRIME T01-0856,5A 12/7/2001 0.59 472 474 ±46 EXD076-1 SPC00533396 ECRB Cross Drift YM2017 PRIME T01-0857,5A 12/7/2001 0.37 663 671 ±75 EXD084-1 SPC00521175 ECRB Cross Drift YM2018 PRIME T01-0858,5A 12/7/2001 0.74 511 513 ±57 EXD085-1 SPC00521174 ECRB Cross Drift YM2019 PRIME T01-0859,5A 12/7/2001 1.12 412 412 ±35 EXD086-1 SPC00521176 ECRB Cross Drift YM2020 PRIME T01-0860,5A 12/7/2001 0.92 548 550 ±179 T200-1 (EXD085-1 split) SPC00521174 ECRB Cross Drift YM2022 PRIME T01-0874,5A 12/7/2001 1.59 434 434 ±43 DTN: LA0305RR831222.001 (UQ) NOTES: AMS = accelerator mass spectrometer, CAMS = Center for Accelerator Mass Spectrometry, ECRB = Enhanced Characterization of the Repository Block, ESF = Exploratory Studies Facility, LANL = Los Alamos National Laboratory, PRIME = Purdue Rare Isotope Measurement Laboratory, SMF = Sample Management Facility. Chloride concentrations have a uniform 2s uncertainty of 5% of the stated value. TDR-NBS-HS-000017 REV00 T32 Table 4-13. Concentrations of Anions in Leachates of Validation Study Samples Analyzed by Ion Chromatography at the USGS during Phase III Batch No. Sample Identifier SMF Barcode Identifier Mass of Rock (kg) Mass of Water (kg) F-1 (mg/kg) Cl-1 (mg/kg) Br-1 (mg/kg) NO3 -1 (mg/kg) SO4 -2 (mg/kg) 1 EVAL001 (bulk rock material) SPC00536900 1.871 2.098 ND 0.19 0.18 0.15 0.22 1 ESF-SD-ClV#33 (9.9–11.4) SPC00536903 1.787 2.057 ND 0.11 <0.02 0.24 0.10 1 ESF-SD-ClV#28 (6.2–8.0) SPC00536906 1.893 2.130 ND 0.18 <0.02 0.21 0.21 1 ESF-SD-ClV#36 (5.4–6.7/ 8.1–9.4) SPC00536909 2.002 2.038 ND 0.098 <0.02 0.19 0.092 1 SYSTEM BLANK (8/22/01) SPC00536912 2.034 2.034 ND <0.04 <0.02 <0.03 <0.03 1 SYSTEM BLANK (8/22/01) rerun SPC00536912 2.034 2.034 ND <0.04 <0.02 <0.03 <0.03 1 ESF-SD-ClV#31 (2.8–4.5) SPC00536915 1.786 2.014 ND 0.070 <0.02 0.16 0.067 1 ESF-SD-ClV#21 (11.3–13.0) SPC00536918 1.935 2.115 ND 0.31 <0.02 0.26 0.42 1 ESF-SD-ClV#30 (6.4–8.4) SPC00536921 1.965 2.092 ND 0.15 <0.02 0.26 0.13 1 ESF-SD-ClV#30 (6.4–8.4) rerun SPC00536921 1.965 2.092 ND 0.17 <0.02 0.22 0.14 1 ESF-SD-ClV#32 (7.6–9.5) SPC00536924 2.310 2.089 ND 0.16 <0.02 0.29 0.16 1 ESF-SD-ClV#28 (4.0–6.2) SPC00536927 2.333 2.134 ND 0.091 <0.02 0.13 0.065 1 ESF-SD-ClV#34 (2.1–4.8) SPC00536930 2.399 2.103 ND 0.082 <0.02 0.18 0.087 1 ESF-SD-ClV#22 (4.5–6.3) SPC00536933 1.840 2.096 ND 0.15 <0.02 0.21 0.24 1 ESF-SD-ClV#21 (2.8–4.6) SPC00536936 1.736 2.049 ND 0.18 <0.02 0.18 0.27 1 SYSTEM BLANK (8/24/01) SPC00536939 2.061 2.061 ND <0.04 <0.02 <0.03 <0.03 1 ESF-SD-ClV#35 (6.4–8.5) SPC00536942 2.366 2.135 ND 0.090 <0.02 0.20 0.14 1 ESF-SD-ClV#27 (10.0–12.0) SPC00536945 2.211 ND 0.14 <0.02 0.086 0.19 1 ESF-SD-ClV#26-1 (3.0–6.3) SPC00536948 1.688 2.040 ND 0.095 <0.02 0.13 0.10 1 ESF-SD-ClV#26-2 (3.0–6.3) SPC00536951 1.700 2.044 ND 0.11 <0.02 0.11 0.10 2 ESF-SD-ClV#24 (4.6–6.6) SPC00536954 1.863 2.054 ND 0.22 <0.02 0.44 0.44 2 ESF-SD-ClV#38 (1.4–3.9) SPC00536957 1.959 2.076 ND 0.30 <0.02 1.6 0.28 2 ESF-SD-ClV#38 (1.4–3.9) rerun SPC00536957 1.959 2.076 ND 0.30 <0.02 1.6 0.31 2 ESF-SD-ClV#37 (3.6–5.3) SPC00536960 1.726 2.055 ND 0.092 <0.02 0.21 0.063 2 SYSTEM BLANK (9/5/01) SPC00536963 2.057 2.057 ND <0.04 <0.02 0.092 <0.03 2 SYSTEM BLANK (9/5/01) rerun SPC00536963 NA 2.057 ND <0.04 <0.02 0.041 <0.03 2 ESF-SD-ClV#39 (2.1–3.5) SPC00516604 1.665 2.045 ND 0.091 <0.02 0.20 <0.04 TDR-NBS-HS-000017 REV00 T33 Table 4-13. Concentrations of Anions in Leachates of Validation Study Samples Analyzed by Ion Chromatography at the USGS during Phase III (continued) Batch No. Sample Identifier SMF Barcode Identifier Mass of Rock (kg) Mass of Water (kg) F-1 (mg/kg) Cl-1 (mg/kg) Br-1 (mg/kg) NO3 -1 (mg/kg) SO4 -2 (mg/kg) 2 ESF-SD-ClV#24 (2.1–4.0) SPC00516607 1.907 2.050 ND 0.12 <0.02 0.15 0.064 2 ESF-SD-ClV#23 (4.8–6.7) SPC00516610 1.788 2.048 ND 0.15 <0.02 0.33 0.13 2 ESF-SD-ClV#20 (3.8–6.1) SPC00516613 1.909 2.054 ND 0.10 <0.02 0.16 0.075 2 ESF-SD-ClV#19 (4.4–6.4) SPC00516616 2.193 2.072 ND 0.088 <0.02 0.19 0.15 2 ESF-SD-ClV#18 (3.6–5.6) SPC00516619 1.799 2.057 ND 0.13 <0.02 0.23 0.15 2 ESF-SD-ClV#17 (3.9–6.4) SPC00516622 2.276 2.061 ND 0.14 <0.02 0.27 0.14 3 ESF-SD-ClV#8 (2.0–3.4) SPC00516625 1.198 1.448 ND 0.091 <0.02 <0.04 0.16 3 ESF-SD-ClV#6 (2.0–5.2) SPC00516628 2.087 2.013 ND 0.11 <0.02 0.15 0.18 3 ESF-SD-ClV#1 (4.2–6.2) SPC00516631 2.364 2.051 ND 0.18 <0.02 0.095 0.13 3 ESF-SD-ClV#1 (4.2–6.2) rerun SPC00516631 2.364 2.051 ND 0.16 <0.02 0.10 0.12 3 ESF-SD-ClV#1 (1.4–3.7) SPC00516634 2.312 2.093 ND 0.26 <0.02 0.13 0.21 3 SYSTEM BLANK (10/31/01) SPC00516637 2.050 2.050 ND <0.04 <0.02 0.032 <0.03 3 SYSTEM BLANK (10/31/01) rerun SPC00516637 2.050 2.050 ND <0.04 <0.02 0.039 <0.03 3 SYSTEM BLANK (10/31/01) rerun SPC00516637 2.050 2.050 ND 0.049 <0.02 <0.03 <0.03 3 ESF-SD-ClV#2 (4.7–6.6) SPC00516640 2.322 2.051 ND 0.30 <0.02 0.097 0.25 3 ESF-SD-ClV#7 (3.9–6.5) SPC00516643 0.989 1.107 ND 0.11 <0.02 0.11 0.067 3 ESF-SD-ClV#4 (2.1–3.8) SPC00516646 1.530 1.495 ND 0.23 <0.02 0.18 0.21 3 ESF-SD-ClV#14 (4.6–6.4) SPC00516649 1.907 2.057 ND 0.078 <0.02 0.094 0.14 3 ESF-SD-ClV#15 (4.7–6.6) SPC00516652 2.073 2.052 ND 0.099 <0.02 0.13 0.081 3 EVAL001 (bulk rock material) SPC00516655 2.315 2.041 ND 0.17 0.15 0.19 0.20 3 EVAL001 (bulk rock material) rerun SPC00516655 2.315 2.041 ND 0.17 0.12 0.19 0.17 3 ESF-DHW-ClV#5 (3.5–6.5) SPC00516658 1.362 1.966 ND 0.19 <0.03 0.29 0.22 3 SYSTEM BLANK (1/4/02) SPC00516661 2.103 2.103 ND <0.04 <0.02 0.036 <0.03 3 SYSTEM BLANK (1/4/02) rerun SPC00516661 2.103 2.103 ND <0.04 <0.02 <0.03 <0.03 3 ESF-SD-ClV#16 (4.3–5.0) SPC00516664 1.804 1.948 ND 0.093 <0.02 0.14 0.13 3 ESF-SD-ClV#12 (2.0–4.4) SPC00516667 2.202 2.039 ND 0.060 <0.02 0.035 0.041 3 ESF-SD-ClV#11 (2.4–5.2) SPC00516670 1.513 1.955 ND 0.056 <0.03 0.089 <0.04 3 ESF-DHW-ClV#8 (3.8–6.4) SPC00516673 1.758 2.004 ND 0.18 <0.02 0.35 0.25 TDR-NBS-HS-000017 REV00 T34 Table 4-13. Concentrations of Anions in Leachates of Validation Study Samples Analyzed by Ion Chromatography at the USGS during Phase III (continued) Batch No. Sample Identifier SMF Barcode Identifier Mass of Rock (kg) Mass of Water (kg) F-1 (mg/kg) Cl-1 (mg/kg) Br-1 (mg/kg) NO3 -1 (mg/kg) SO4 -2 (mg/kg) 3 ESF-DHW-ClV#8 (3.8–6.4) rerun SPC00516673 1.758 2.004 ND 0.17 <0.02 0.40 0.23 3 ESF-DHW-ClV#9 (2.4–4.9) SPC00516676 1.468 1.903 ND 0.17 <0.03 0.34 0.25 3 ESF-DHW-ClV#3 (3.1–6.9) SPC00516679 1.605 2.037 ND 0.32 <0.03 0.38 0.33 3 ESF-SD-ClV#13 (2.9–4.5) SPC00516682 1.858 2.018 ND 0.058 <0.02 0.038 0.056 3 ESF-DHW-ClV#1 (2.9–5.0) SPC00516685 1.092 1.514 ND 0.29 <0.03 0.44 0.25 3 ESF-DHW-ClV#7 (2.2–6.5) SPC00516688 1.659 2.028 ND 0.22 <0.02 0.43 0.27 3 ESF-SD-ClV#4 (4.4–6.3) SPC00516691 1.562 1.890 ND 0.16 <0.02 0.12 0.15 3 SYSTEM BLANK (1/7/02) SPC00516694 2.045 2.045 ND <0.04 <0.02 <0.03 <0.03 3 SYSTEM BLANK (1/7/02) rerun SPC00516694 2.045 2.045 ND <0.04 <0.02 <0.03 <0.03 3 ESF-SD-ClV#10 (2.0–3.9) SPC00516697 1.046 1.489 ND 0.060 <0.03 0.097 0.63 3 ESF-DHW-ClV#10 (2.4–4.7) SPC01015121 1.156 1.497 ND 0.18 <0.03 0.47 0.27 3 ESF-SD-ClV#8 (4.0–6.2) SPC01015124 1.360 1.700 ND 0.050 <0.03 0.12 0.056 3 ESF-SD-ClV#25 (5.6–6.7) SPC01015127 1.264 1.500 ND 0.11 <0.02 0.12 0.087 3 SYSTEM BLANK (1/8/02) SPC01015130 2.042 2.042 ND <0.04 <0.02 <0.03 <0.03 3 ESF-SD-ClV#15 (2.3–4.2) SPC01015135 2.109 2.446 ND 0.055 <0.02 0.13 0.095 3 ESF-DHW-ClV#2 (3.2–6.5) SPC01015138 1.434 1.962 ND 0.18 <0.03 0.33 0.29 3 ESF-SD-ClV#12 (4.4–6.5) SPC01015141 2.137 2.306 ND 0.051 <0.02 0.076 0.067 3 SYSTEM BLANK (1/9/02) SPC01015144 2.094 2.094 ND <0.04 <0.02 <0.03 <0.03 3 ESF-SD-ClV#5 (1.8–4.1) SPC01015147 1.433 2.039 ND 0.20 <0.03 0.26 0.23 3 ESF-DHW-ClV#6 (2.2–6.6) SPC01015150 2.483 2.552 ND 0.23 <0.02 0.43 0.30 3 ESF-DHW-ClV#6 (2.2–6.6) rerun SPC01015150 2.483 2.552 ND 0.25 <0.02 0.45 0.32 3 SYSTEM BLANK (1/10/02) SPC01015153 2.108 2.108 ND <0.04 <0.02 0.038 0.035 3 SYSTEM BLANK (1/10/02) rerun SPC01015153 2.108 2.108 ND 0.043 <0.02 0.037 <0.03 3 ESF-SD-ClV#3 (4.2–6.2) SPC01015156 2.177 2.389 ND 0.21 <0.02 0.11 0.20 3 ESF-DHW-ClV#4 (2.0–6.1) SPC01015159 0.663 1.144 ND 0.26 <0.03 0.38 0.29 4 ESF-SAD-GTB#1 hand crush (10 mesh–3/4") SPC01015160 1.605 1.853 0.060 0.62 <0.02 0.11 0.50 4 ESF-SAD-GTB#1 hand crush (1/4"–3/4") SPC01015163 1.477 1.534 0.047 0.44 <0.02 <0.03 0.48 TDR-NBS-HS-000017 REV00 T35 Table 4-13. Concentrations of Anions in Leachates of Validation Study Samples Analyzed by Ion Chromatography at the USGS during Phase III (continued) Batch No. Sample Identifier SMF Barcode Identifier Mass of Rock (kg) Mass of Water (kg) F-1 (mg/kg) Cl-1 (mg/kg) Br-1 (mg/kg) NO3 -1 (mg/kg) SO4 -2 (mg/kg) 4 SYSTEM BLANK (6/10/02) SPC01015166 1.571 1.571 0.033 <0.04 <0.02 <0.03 <0.03 4 ESF-SAD-GTB#1 mech. crush (1/4"–3/4") SPC01015169 1.706 1.802 0.055 0.48 <0.02 <0.03 0.41 5 ESF-MD-NICHE3566#1 (25.3–31.7) SPC01015172 1.358 1.456 0.086 0.23 <0.02 <0.03 0.28 5 ESF-MD-NICHE3566#2 (20.2–32.5) SPC01015175 1.312 1.446 0.064 0.29 <0.02 <0.03 0.51 5 SYSTEM BLANK (6/24/02) SPC01015178 1.539 1.539 0.038 <0.04 <0.02 <0.03 <0.03 5 ESF-MD-NICHE3566#2 (11.5–15.4) SPC01015181 1.153 1.419 0.11 0.21 <0.02 0.14 0.16 5 ESF-MD-NICHE3566#1 (14.7–20.9) SPC01015184 1.435 1.511 0.075 0.21 <0.02 0.16 <0.03 5 ESF-MD-NICHE3566#LT1 (10.9–23.5) SPC01015187 1.339 1.454 0.073 0.28 <0.02 0.16 0.22 5 ESF-MD-NICHE3566#LT1 (25.0–38.1) SPC01015190 1.665 1.737 0.095 0.19 <0.02 0.10 0.15 5 SYSTEM BLANK (6/24/02) SPC01015193 1.615 1.615 0.042 0.076 <0.02 <0.03 <0.03 DTN: GS030608312272.005 (Q) NOTES: NA = not applicable, ND = not determined, SMF = Sample Management Facility, USGS = U.S. Geological Survey. Samples were crushed at either the SMF or USGS, and leached at the USGS. The leachates were distributed to LANL and LLNL for AgCl precipitation and target preparation. For Batch #1 samples, targets prepared at LANL and LLNL were analyzed at LLNL-CAMS. For Batch #2, the targets prepared at LANL were analyzed at PRIME Lab and targets prepared at LLNL were analyzed at LLNL-CAMS. Targets for Batches #3, #4, and #5 were prepared and analyzed at LLNL. Data are ordered by leaching sequence. Concentrations are given with respect to the amount of rock used after passive-leaching for 1 hour. Less- than symbols indicate concentrations that are less than the ion-chromatography method detection limits after correction for water/rock ratio. Analytical errors (2s) for Cl are ±0.03 mg/kg for concentrations <0.2 mg/kg and ±0.08 mg/kg for concentrations >0.2 mg/kg. Fluorine analyses were not determined prior to June 2002 because of insufficient peak separations. Data reported in mg/L in the DTN have been converted to mg/kg in this table to normalize the concentration data to mass of rock:ion concentration in mg/kg = (ion concentration in mg/L) * (mass of water in kg) ÷ (mass of rock in kg). Assumes 1 kg water = 1 L of water. For ESF-SD-ClV#27, the mass of water was assumed to be 2000 g. Table 4-14. Summary of Anion Concentrations in Leachates of Validation Study Samples Analyzed by Ion Chromatography at the USGS during Phase III Sample Identifier Sample Grouping F-1 (mg/kg) Cl-1 (mg/kg) Br-1 (mg/kg) NO3 -1 (mg/kg) SO4 -2 (mg/kg) Drill Hole Wash fault zone n = 0 10 10 10 10 (ESF-DHW-ClV series) Maximum = ND 0.32 <0.02 0.47 0.33 Minimum = ND 0.17 <0.02 0.29 0.22 Median = NA 0.205 <0.02 0.380 0.270 Average = NA 0.223 <0.02 0.388 0.272 Standard Deviation = NA 0.053 <0.02 0.057 0.034 Sundance fault zone, n = 6 51 51 50 49 Incl. Niche #1 Maximum = 0.11 0.31 <0.02 0.44 0.51 (ESF-SD-ClV series) Minimum = 0.064 0.050 <0.02 <0.04 <0.03 Median = 0.081 0.120 <0.02 0.145 0.140 Average = 0.084 0.145 <0.02 0.156 0.157 Standard Deviation = 0.017 0.074 <0.02 0.082 0.104 Southern Ghost Dance fault zone (Alcove #7) n = 3 3 3 3 3 (ESF-SAD-GTB#1) Maximum = 0.06 0.62 <0.02 0.11 0.50 Minimum = 0.05 0.44 <0.02 <0.04 0.41 Median = NA NA NA NA NA Average = 0.054 0.513 <0.02 0.050 0.463 Standard Deviation = 0.007 0.95 <0.02 0.052 0.047 EVAL001 n = 0 2 2 2 2 Maximum = ND 0.19 0.18 0.19 0.22 Minimum = ND 0.17 0.14 0.15 0.19 Median = NA NA NA NA NA Average = NA NA NA NA NA Standard Deviation = NA NA NA NA NA DTN: GS030608312272.005 (Q) NOTES: NA = not applicable, ND = not determined, USGS = U.S. Geological Survey. Statistics are compiled from data given in Table 4-13 with samples grouped by area (i.e., Drill Hole Wash fault zone, Sundance fault zone, southern Ghost Dance fault zone, and EVAL001). Re-runs of ion chromatography determinations have been averaged to yield a single value for each sample. Concentrations reported as less than the method detection limit (MDL) have been assigned a value of 0.5 × MDL for statistical analysis. Table 4-15. Summary of Chloride Concentrations and 36Cl/Cl Ratios in Core Samples Leached and Analyzed at USGS-LLNL during Phase III Sample Identifier Sample Grouping Leachate Cl Concentration (mg/kg rock) 36Cl/Cl × 1015 ESF-SD-ClV core n = 34 34 (excludes Niche #1) Minimum = 0.037 137 Maximum = 0.372 615 Anderson-Darling P-Value = (Distribution) = 0.000 (non-normal) 0.108 (normal) Median = 0.120 316 Arithmetic Mean = 0.130 326 Standard Deviation = 0.083 134 2 × Standard Error = 0.029 46 Niche #1 n = 6 6 Minimum = 0.173 226 Maximum = 0.270 717 Anderson-Darling P-Value = (Distribution) = 0.133 (normal) 0.287 (normal) Median = 0.201 387 Arithmetic Mean = 0.206 401 Standard Deviation = 0.035 177 2 × Standard Error = 0.028 145 All Sundance fault zone n = 40 40 (pooled data) Minimum = 0.037 137 Maximum = 0.372 717 Anderson-Darling P-Value = (Distribution) = 0.003 (non-normal) 0.125 (normal) Median = 0.120 316 Arithmetic Mean = 0.141 337 Standard Deviation = 0.082 141 2 × Standard Error = 0.026 45 DTN: Calculated from data in LL031200223121.036 (Q), Filename: Total_AMS_Summary_2001-02c.xls NOTE: Statistics are compiled from data given in Table 4-9, with samples grouped by area (i.e., ESF-SD-ClV, Niche #1, and Sundance fault zone). Table 4-16. Mass of Total Chloride, 36Cl/Cl Ratios, and Mass of 36Cl Present in Validation Study Blanks Processed at LANL during Phase III Sample or Aliquot Identifier SMF Barcode Identifier LANL Identifier AMS Facility AMS Identifier Date Analyzed Water Mass Analyzed (kg) Mass Cl in Blank (mg) Cl Conc. in Blank (mg/kg water) 36Cl/Cl ×1015 Mass 36Cl in Blank (mg) ×1015 Conc. 36Cl in Blank (mg/kg water) ×1015 Procedural blank (USGS water) SPC 00536914 YM2042 CAMS CL9668 10/26/2001 0.899 0.0048 0.0053 1,022 4.91 5.46 Procedural blank (USGS water) SPC 00536941 YM2043 CAMS CL9669 10/26/2001 0.950 0.0048 0.0051 630 3.02 3.18 Procedural blank (USGS water) SPC 00516601 YM2046 CAMS CL9672 10/26/2001 0.923 0.0046 0.0050 1,095 5.04 5.46 Procedural blank (PB 301) NA YM2021 PRIME W01-0861, 5A 12/7/2001 3.934 0.052 0.013 396 20.59 5.23 Procedural blank (PB 303) NA YM2031 CAMS CL9657 10/26/2001 0.930 0.0024 0.0027 1,158 2.78 2.99 Procedural blank (PB 305) NA YM2068 CAMS CL9741 11/29/2001 0.500 0.0034 0.0068 3,756 12.77 25.54 Procedural blank (PB 306) NA YM2082 PRIME R020211,5A 8/21/2002 1.000 0.022 0.022 920 20.24 20.24 Procedural blank (PB 307) NA YM2099 CAMS CL10138 5/23/2002 1.804 0.0254 0.014 1,724 43.79 24.27 Procedural blank (PB 308) NA YM2100 CAMS CL10139 5/23/2002 1.567 0.0097 0.0062 3,722 36.10 23.04 Procedural blank (PB 309) NA YM2110 CAMS CL10298 7/30/2002 0.967 0.0041 0.0042 3,349 13.73 14.2 Table 4-16. Mass of Total Chloride, 36Cl/Cl Ratios, and Mass of 36Cl Present in Validation Study Blanks Processed at LANL during Phase III (continued) Sample or Aliquot Identifier SMF Barcode Identifier LANL Identifier AMS Facility AMS Identifier Date Analyzed Water Mass Analyzed (kg) Mass Cl in Blank (mg) Cl Conc. in Blank (mg/kg water) 36Cl/Cl ×1015 Mass 36Cl in Blank (mg) ×1015 Conc. 36Cl in Blank (mg/kg water) ×1015 Procedural blank (PB 310) NA YM2111 CAMS CL10299 7/30/2002 0.951 0.0035 0.0037 4,257 14.90 15.67 Procedural blank (PB 311) NA YM2112 CAMS CL10300 7/30/2002 0.999 0.0053 0.0053 1,897 10.05 10.05 Arithmetic mean 0.008 1,994 15.7 12.9 Standard deviation 0.006 1,387 13.0 8.7 Standard error 0.002 400 3.7 2.5 DTN: LA0305RR831222.001 (UQ) NOTES: AMS = accelerator mass spectrometer, CAMS = Center for Accelerator Mass Spectrometry, LANL = Los Alamos National Laboratory, NA = not applicable, PRIME = Purdue Rare Isotope Measurement Laboratory, SMF = Sample Management Facility, USGS = U.S. Geological Survey. Analytical errors are 1s for 36Cl/Cl (corrected for background and spike) and concentration of 36Cl in blank. Cl conc. in blank (mg/kg water) = Mass Cl in blank (mg) ÷ Water mass analyzed (kg). Mass of 36Cl in Blank (mg) = Water mass analyzed (kg) x Cl Conc. in blank (mg/kg water) x 36Cl/Cl x10-15 . Conc. 36Cl in blank (mg/kg water) = Mass 36Cl in blank (mg) ÷ Water mass analyzed (kg). Table 4-17. Chloride, Bromide, and Sulfate Concentrations, and 36Cl/Cl Ratios in Leachates of ECRB Cross Drift Samples Analyzed at LANL during Phase III Sample Identifier SMF Barcode Identifier Distance from Start of ECRB Cross Drift (m) Sample Type Description of Sampled Feature AgCl Target ID Concentration (mg/kg rock) Br/ Cl SO4/ Cl Measured 36Cl/Cl ×1015 (2s) Cl-1 Br-1 SO4 -2 EXD001-1 SPC00504392 2,545 Opportunistic Highly fractured bedrock, Solitario Canyon fault zone YM960 0.65 0.362 0.90 0.558 1.4 789 ±66 EXD002-1 SPC00504390 2,550 Opportunistic Fractured rock and gouge, Solitario Canyon fault zone YM961 2.12 0.674 2.51 0.318 1.2 342 ±42 EXD003-1 SPC00524980 1,135.5 Fault transect Breccia from Sundance fault zone YM962 0.72 0.005 0.59 0.006 0.8 347 ±32 EXD004-1 SPC00524981 1,137 Fault transect Fractured wall rock adjacent to Sundance fault zone YM963 0.25 0.089 0.39 0.358 1.6 1,124 ±171 EXD005-1 SPC00524977 1,317 Fault transect Breccia YM964 0.40 0.080 0.97 0.199 2.4 582 ±79 EXD006-1 SPC00524978 1,318 Fault transect Breccia in fault zone YM965 0.57 0.018 0.46 0.031 0.8 343 ±57 EXD007-1 SPC00533390 1,320 Fault transect Fractured wall rock near fault YM1008 0.27 0.102 0.54 0.377 2.0 624 ±62 EXD008-1 SPC00533387 2,154 Fault transect Breccia in fault zone YM968 0.49 0.015 0.70 0.031 1.4 915 ±97 EXD009-1 SPC00538284 2,154.5 Fault transect Breccia in fault zone YM969 0.59 0.011 0.61 0.018 1.0 4,890 ±349 EXD010-1 SPC00533388 2,155 Fault transect Fractured rock in fault hanging wall YM1043 0.41 0.050 0.85 0.123 2.1 553 ±34 EXD011-1 SPC00533389 2,162 Other fault Breccia from minor fault YM1032 0.50 NA 1.16 NA 2.3 550 ±59 EXD012-1 SPC00538283 2,238 Other fault Breccia in fault zone YM970 0.51 0.014 0.45 0.027 0.9 2,349 ±210 EXD012-3 SPC00538283 2,238 Other fault Breccia in fault zone YM1009 0.92 NA 0.97 NA 1.1 3,549 ±500 EXD013-1 SPC00538282 2,348 Other fault Fault with 3 m offset YM971,B 0.71 0.063 0.75 0.088 1.1 1,043 ±74 EXD014-1 SPC00538281 2,445 Other fault Fault with 2.5 m offset YM1044 0.34 0.150 0.56 0.442 1.6 550 ±51 EXD015-1 SPC00538279 2,500 Systematic feature Fault with 0.4 m offset YM1045 0.23 0.117 0.56 0.510 2.4 812 ±72 EXD016-1 SPC00538280 2,530.5 Fault transect Fractured rock between 2 faults YM972 0.65 NA 1.15 NA 1.8 1,122 ±89 EXD017-1 SPC00538275 2,570 Fault transect Solitario Canyon fault zone YM973 0.52 NA 0.87 NA 1.7 2,158 ±175 EXD017-3 SPC00538275 2,570 Fault transect Solitario Canyon fault zone YM1010 0.80 NA 1.12 NA 1.4 3,068 ±258 Table 4-17. Chloride, Bromide, and Sulfate Concentrations, and 36Cl/Cl Ratios in Leachates of ECRB Cross Drift Samples Analyzed at LANL during Phase III (continued) Distance Concentration Sample Identifier SMF Barcode Identifier from Start of ECRB Cross Drift (m) Sample Type Description of Sampled Feature AgCl Target ID (mg/kg rock) Br/ Cl SO4/ Cl Measuredc 36Cl/Cl ×1015 (2s) Cl-1 Br-1 SO4 -2 EXD018-1 SPC00538273 2,580 Fault transect Solitario Canyon fault zone YM974 0.69 0.020 0.95 0.029 1.4 890 ±109 Brecciated EXD019-1 SPC00538270 2,585 Other fault footwall of Solitario YM975 0.87 0.029 0.92 0.034 1.1 2,447 ±205 Canyon fault EXD020-1 SPC00538280 2,530.5 Other fault Solitario Canyon fault plane YM1046 0.79 0.094 2.06 0.119 2.6 720 ±43 EXD020-3 SPC00538271 2,586 Other fault Solitario Canyon fault plane YM1033 0.52 0.055 0.92 0.105 1.8 641 ±67 EXD021-1 SPC00538272 2,586.5 Other fault Brecciated hanging wall of Solitario Canyon fault YM976 1.83 0.134 1.76 0.073 1.0 1,227 ±82 EXD022-1 SPC00538269 2,590 Fault transect Solitario Canyon fault zone YM977 0.83 0.110 1.16 0.133 1.4 1,360 ±113 EXD023-1 SPC00524985 2,600 Fault transect Solitario Canyon fault zone YM1047 0.69 0.084 0.69 0.121 1.0 554 ±34 EXD024-1 SPC00538276 2,610 Fault transect Solitario Canyon fault zone YM1048 0.74 0.205 0.68 0.277 0.9 618 ±41 Solitario EXD025-1 SPC00538277 2,621 Other fault Canyon fault YM978 0.65 0.032 0.82 0.050 1.3 954 ±96 zone Solitario EXD026-1 SPC00538278 2,658 Other fault Canyon fault YM1034 0.45 0.090 0.59 0.200 1.3 680 ±63 zone Junction of EXD028-1 SPC00521169 892.5 Other fault normal and YM1035 1.04 0.089 1.59 0.086 1.5 517 ±46 reverse faults EXD029-1 SPC00521168 901 QA/QC No structures YM1049 1.52 0.060 2.48 0.039 1.6 505 ±40 EXD030-1 SPC00521167 904 Systematic feature Fault YM1050 0.82 0.062 1.51 0.076 1.8 566 ±38 EXD031-1 SPC00521166 1,004 Systematic feature Set of parallel fractures YM1011 0.67 0.178 0.70 0.265 1.0 873 ±128 EXD032-1 SPC00521165 1,102 Systematic feature High-angle fracture YM1051 0.26 0.037 0.47 0.143 1.8 440 ±57 EXD033-1 SPC00521164 1,130.5 Fault transect Cooling joint network YM1036 0.31 NA 0.57 NA 1.8 707 ±50 EXD034-1 SPC00521163 1,133 Fault transect Cooling joint that trends toward Sundance fault zone YM1052 0.50 0.142 1.02 0.284 2.1 643 ±46 Footwall of EXD035-1 SPC00521162 1,135 Other fault Sundance YM1037 0.35 0.034 0.58 0.096 1.7 661 ±68 fault Table 4-17. Chloride, Bromide, and Sulfate Concentrations and 36Cl/Cl Ratios in Leachates of ECRB Cross Drift Samples Analyzed at LANL during Phase III (continued) Sample Identifier SMF Barcode Identifier Distance from Start of ECRB Cross Drift (m) Sample Type Description of Sampled Feature AgCl Target ID Concentration (mg/kg rock) Br/ Cl SO4/ Cl Measured 36Cl/Cl ×1015 (2s) Cl-1 Br-1 SO4 -2 Broken rock EXD037-1 SPC00521160 1,201.5 Systematic feature from hanging wall of Sundance YM1038 0.70 NA 0.81 NA 1.2 490 ±43 fault zone EXD037-3 SPC00521160 1,201.5 Systematic feature Broken rock from hanging wall of Sundance fault zone YM1039 0.53 0.093 0.83 0.176 1.6 497 ±34 EXD038-1 SPC00521159 1,205 Other feature Fracture set YM1040 0.48 NA 0.70 NA 1.5 385 ±33 EXD039-1 SPC00521158 1,301 Systematic feature Fracture set with no offset YM1041 0.20 NA 0.63 NA 3.2 569 ±38 EXD040-1 SPC00521157 1,316 Fault transect Cooling joint and fracture set: fault footwall YM1042 0.59 0.111 0.73 0.188 1.2 658 ±60 EXD046-1 SPC00521151 1,500 YM2012 0.53 607 ±51 EXD047-1 SPC00521150 1,542.5 Systematic feature Fault (shear) with unknown offset YM1012 1.16 0.222 1.61 0.191 1.4 589 ±52 EXD051-1 SPC00521146 2,000 Systematic feature Highly fractured rock next to throughgoing fracture YM1013 0.63 0.106 0.94 0.169 1.5 878 ±74 EXD052-1 SPC00521144 2,100 YM2013 0.38 574 ±56 EXD059-1 SPC00521138 2,387 YM2014 0.30 1,309 ±114 EXD063-1 SPC00521132 2,612 Other fault Shear zone YM1014 0.86 0.037 1.08 0.043 1.3 570 ±44 EXD064-1 SPC00521131 2,630.5 Other fault Hanging wall of Solitario Canyon fault zone YM1015 0.45 0.030 0.72 0.066 1.6 612 ±59 EXD066-1 SPC00541211 2,560 YM2015 3.59 161 ±22 EXD071-1 SPC00541216 2,585 YM2016 0.59 474 ±46 EXD075-1 SPC00533397 206 Systematic feature Fracture YM1016 1.26 0.128 2.12 0.102 1.7 629 ±52 EXD076-1 SPC00533396 300 YM2017 0.37 671 ±75 Possible north end of EXD078-1 SPC00533395 499 Other fault Ghost Dance YM1017 3.12 0.020 3.56 0.006 1.1 481 ±42 fault; gouge zone EXD084-1 SPC00521175 Alcove #8 YM2018 0.74 513 ±57 EXD085-1 SPC00521174 Alcove #8 Other fault YM2019 1.12 412 ±35 Table 4-17. Chloride, Bromide, and Sulfate Concentrations and 36Cl/Cl Ratios in Leachates of ECRB Cross Drift Samples Analyzed at LANL during Phase III (continued) Sample Identifier SMF Barcode Identifier Distance from Start of ECRB Cross Drift (m) Sample Type Description of Sampled Feature AgCl Target ID Concentration (mg/kg rock) Br/ Cl SO4/ Cl Measured 36Cl/Cl ×1015 (2s) Cl-1 Br-1 SO4 -2 T200-1 (EXD085-1 split) SPC00521174 Alcove #8 Other fault YM2022 1.59 434 ±43 EXD086-1 SPC00521176 Alcove #8 Fracture feature YM2020 0.92 550 ±179 DTNs: LA0305RR831222.001 (UQ), LA0307RR831222.001 (UQ) NOTES: ECRB = Enhanced Characterization of the Repository Block, ID = identifier, LANL = Los Alamos National Laboratory, SMF = Sample Management Facility. Concentration of salts extracted from each sample is only a qualitative indicator of the sample's salt content. Because the focus of this activity is on determining anion ratios, no attempt has been made to maximize the yield of the leaching process, which is probably highly variable. Measured 36Cl/Cl ratios have been corrected for the addition of 35Cl tracer. TDR-NBS-HS-000017 REV00 T44 Table 4-18. Chloride Concentrations and 36Cl/Cl Ratios in Duplicate Analyses Used to Calculate External Error in 36Cl/Cl Ratios during Phase III Sample Identifier USGS-LLNL-LLNL USGS-LANL-LLNL Barcode Identifier for LLNL Sample CAMS Identifier Leachate Cl Concentration (mg/kg rock) 36Cl/Cl ×1015 (2s) Barcode Identifier for LANL Sample CAMS Identifier Leachate Cl Concentration (mg/kg rock) 36Cl/Cl ×1015 (2s) EVAL001 SPC00536901 CL9634 0.146 454 ±109 SPC00536902 CL9659 0.15 361 ±42 ESF-SD-ClV#21 (2.8–4.6) SPC00536919 CL9640 0.147 368 ±76 SPC00536938 CL9662 0.18 344 ±38 ESF-SD-ClV#21 (11.3–13.0) SPC00536937 CL9646 0.372 297 ±61 SPC00536920 CL9664 0.32 310 ±29 ESF-SD-ClV#22 (4.5–6.3) SPC00536934 CL9645 0.165 317 ±73 SPC00536935 CL9658 0.15 408 ±43 ESF-SD-ClV#26-1 (3.0–6.3) SPC00536949 CL9650 0.105 159 ±98 SPC00536950 CL9673 0.10 270 ±72 ESF-SD-ClV#26-2 (3.0–6.3) SPC00536952 CL9651 0.114 137 ±96 SPC00536953 CL9674 0.11 225 ±44 ESF-SD-ClV#27 (10.0–12.0) SPC00536946 CL9649 0.125 186 ±69 SPC00536947 CL9666 0.15 208 ±29 ESF-SD-ClV#28 (6.2–8.0) SPC00536907 CL9636 0.153 163 ±129 SPC00536908 CL9660 0.16 203 ±28 ESF-SD-ClV#30 (6.4–8.4) SPC00536922 CL9641 0.136 156 ±70 SPC00536923 CL9665 0.16 163 ±30 ESF-SD-ClV#32 (7.6–9.5) SPC00536925 CL9642 0.154 203 ±64 SPC00536926 CL9661 0.16 235 ±29 ESF-SD-ClV#33 (9.9–11.4) SPC00536904 CL9635 0.092 339 ±123 SPC00536905 CL9667 0.11 249 ±44 ESF-SD-ClV#34 (2.1–4.8) SPC00536931 CL9644 0.079 236 ±101 SPC00536932 CL9656 0.08 315 ±59 TDR-NBS-HS-000017 REV00 T45 Table 4-18. Chloride Concentrations and 36Cl/Cl Ratios in Duplicate Analyses Used to Calculate External Error in 36Cl/Cl Ratios during Phase III (continued) Sample Identifier USGS-LLNL-LLNL USGS-LANL-LLNL Barcode Identifier for LLNL Sample CAMS Identifier Leachate Cl Concentration (mg/kg rock) 36Cl/Cl ×1015 (2s) Barcode Identifier for LLNL Sample CAMS Identifier Leachate Cl Concentration (mg/kg rock) 36Cl/Cl ×1015 (2s) ESF-SD-ClV#36 (5.4-6.7/8.1-9.4) SPC00536910 CL9637 0.069 395±133 SPC00536911 CL9675 0.07 322±66 DTNs: LL031200223121.036 (Q), Filename: Total_AMS_Summary_2001-02c.xls; LA0305RR831222.001 (UQ) NOTES: AMS = accelerator mass spectrometer, CAMS = Center for Accelerator Mass Spectrometry, LANL = Los Alamos National Laboratory, LLNL = Lawrence Livermore National Laboratory, USGS = U.S. Geological Survey. All data were generated for aliquots of leachates obtained at the USGS and analyzed at LLNL-CAMS. Silver chloride (AgCl) targets were prepared either at LLNL (first set of columns) or LANL (second set of columns). Errors listed for the USGS-LLNL-LLNL 36Cl/Cl data do not include external errors (see Section 4.6.4). Table 5-1. Tritium Concentrations in Water Standards with Known Values Standard Name Date Sample Submitted for Analysis Volume Used (mL) Accepted 3H Concentration (TU) Measured 3H Concentration (TU) 1s Analytical Error (TU) D 3/6/2000 100 2.15 1.7 0.4 H 10/29/1999 110 1.81 2.09 0.26 10/29/1999 118 1.81 2.24 0.24 4/26/2000 114 1.81 1.4 0.3 4/26/2000 115 1.81 1.91 0.24 5/10/2002 112 1.81 1.45 0.26 8/2/2002 115 1.81 1.7 0.3 8/2/2002 115 1.81 1.8 0.3 Average 1.80 Standard Deviation 0.31 E 3/30/2000 104 1.75 1.84 0.25 6/28/2000 107 1.75 2.2 0.3 7/19/2000 107 1.75 1.59 0.24 9/7/2000 111 1.75 1.7 0.8 Average 1.83 Standard Deviation 0.27 L 4/17/2001 125 1.31 1.73 0.25 4/10/2002 112 1.31 1.24 0.2 10/29/1999 110 1.31 1.04 0.17 10/29/1999 108 1.31 1.18 0.16 2/7/2000 87 1.31 0.85 0.29 2/7/2000 89 1.31 2.1 0.4 Average 1.36 Standard Deviation 0.47 Dead Water 8/2/2002 110 0 0.2 0.2 8/2/2002 119 0 -0.1 0.3 Average 0.05 DTNs: GS060308312272.001 (Q) (MOL.20020926.0121), GS060308312272.002 (Q) (MOL.20030331.0364) Table 5-2. Tritium Concentrations in Pore Water Extracted from Validation Study Core Samples SMF Barcode Identifier Borehole Name ESF Station Feature Interval Used (ft) 3H Concentration (TU) (2s) SPC03017174 SPC03017175 ESF-DHW-ClV#1 19+65 Drill Hole Wash fault 10.9–13.2a 1.00 ±0.80 SPC03017162 SPC03017163 ESF-DHW-ClV#2 19+55 Drill Hole Wash fault 6.5–8.2a 0.50 ±1.40 SPC03017171 ESF-DHW-ClV#3 19+50 Drill Hole Wash fault 12.0–13.3 1.60 ±0.80 SPC03017159 SPC03017160 ESF-DHW-ClV#4 19+45 Drill Hole Wash fault 12.3–13.7b 0.90 ±0.60 SPC03017150 SPC03017151 ESF-DHW-ClV#5 19+40 Drill Hole Wash fault 26.7–28.7a 0.70 ±0.60 SPC03017180 ESF-DHW-ClV#6 19+35 Drill Hole Wash fault 12.2–13.9 0.48 ±0.56 SPC03017184 ESF-DHW-ClV#7 19+30 Drill Hole Wash fault 9.6–11.0 1.60 ±0.80 SPC03017190 ESF-DHW-ClV#8 19+25 Drill Hole Wash fault 11.7–13.1 0.20 ±1.00 SPC03017198 ESF-DHW-ClV#9 19+20 Drill Hole Wash fault 11.5–12.5 0.60 ±1.20 SPC03017194 ESF-DHW-ClV#10 19+10 Drill Hole Wash fault 11.2–12.4 0.94 ±0.48 SPC02016331 ESF-SD-ClV#1 36+89 Sundance fault 11.5–12.6 0.50 ±0.80 SPC02016281 ESF-SD-ClV#2 36+74 Sundance fault 8.0–9.9 0.10 ±0.60 SPC02016289 ESF-SD-ClV#3 36+59 Sundance Fault 10.7–11.4 0.60 ±0.60 SPC02016297 SPC02016298 ESF-SD-ClV#4 36+35 Sundance fault 11.8–13.4b 0.30 ±0.80 SPC02016299 SPC02016300 ESF-SD-ClV#5 36+20 Sundance fault 7.9–9.7a 0.71 ±0.46 SPC02016304 ESF-SD-ClV#6 36+10 Sundance fault 9.3–10.5 1.10 ±1.00 SPC02016268 ESF-SD-ClV#7 36+05 Sundance fault 8.1–9.7 0.30 ±0.80 SPC02016271 SPC02016272 ESF-SD-ClV#8 36+00 Sundance fault 7.9–9.9a 0.60 ±0.60 SPC02016277 ESF-SD-ClV#9 35+95 Sundance fault 10.1–11.5 0.20 ±0.60 SPC02016257 ESF-SD-ClV#10 35+90 Sundance fault 11.8–13.0 0.37 ±0.58 SPC02016260 SPC02016261 ESF-SD-ClV# 1 35+85 Sundance fault 11.0–12.5 a,b 0.15 ±0.56 SPC02016266 ESF-SD-ClV#1 35+80 Sundance fault 11.8–13.4b 0.20 ±0.54 SPC02016252 SPC02016253 ESF-SD-ClV#1 35+75 Sundance fault 30.5–32.3 a,b 0.60 ±0.80 SPC03017136 ESF-SD-ClV#1 35+45 Sundance fault 11.6–13.4 <0.1 ±0.30 SPC03017132 ESF-SD-ClV#1 35+40 Sundance fault 12.0–13.5 b 0.60 ±1.00 SPC03017124 SPC03017125 ESF-SD-ClV#1 35+35 Sundance fault 12.0–13.2 a,b 0.20 ±0.60 Table 5-2. Tritium Concentrations in Pore Water Extracted from Validation Study Core Samples (continued) SMF Barcode Identifier Borehole Name ESF Station Feature Interval Used (ft) 3H concentration (TU) (2s) SPC03017107 ESF-SD-ClV#17 35+31 Sundance fault 10.5–12.0 0.95 ±0.52 SPC03017108 ESF-SD-ClV#17 35+31 Sundance fault 12.0–13.2 0.70 ±0.80 SPC03017113 ESF-SD-ClV#18 35+25 Sundance fault 10.9–11.8 1.40 ±1.60 SPC03017114 ESF-SD-ClV#18 35+25 Sundance fault 12.3–13.5 2.60 ±1.00 SPC03017119 ESF-SD-ClV#19 35+20 Sundance fault 11.7–13.1 0.60 ±0.80 SPC03017101 SPC03017102 ESF-SD-ClV#20 35+15 Sundance fault 10.5–13.0a <0.1 ±0.48 SPC03017094 ESF-SD-ClV#21 35+10 Sundance fault 9.8–11.1 0.40 ±0.56 SPC03017088 ESF-SD-ClV#22 35+05 Sundance fault 10.4–11.2b 0.15 ±0.54 SPC03017085 ESF-SD-ClV#23 35+00 Sundance fault 12.6–13.7 0.22 ±0.58 SPC03017080 ESF-SD-ClV#24 34+95 Sundance fault 12.1–13.4 0.40 ±0.60 SPC02016342 ESF-SD-ClV#25 34+90 Sundance fault 8.7–9.9 0.20 ±0.80 SPC02016339 ESF-SD-ClV#26 34+73 Sundance fault 12.2–13.2 0.10 ±0.80 SPC02016028 ESF-SD-ClV#27 34+70 Sundance fault 12.0–13.4 0.22 ±0.34 SPC02016018 SPC02016019 SPC02016021 ESF-SD-ClV#28 34+65 Sundance fault 8.0–11.3c 1.14 ±0.52 SPC02015996 ESF-SD-ClV#29 34+60 Sundance fault 10.7–12.2b 0.28 ±0.34 SPC02016001 ESF-SD-ClV#30 34+55 Sundance fault 12.2–13.4b 0.20 ±0.60 SPC02016004 SPC02016005 ESF-SD-ClV#31 34+50 Sundance fault 11.0–12.6a 0.30 ±0.80 SPC02016010 ESF-SD-ClV#32 34+45 Sundance fault 11.6–13.2b 0.31 ±0.46 SPC02016036 ESF-SD-ClV#33 34+40 Sundance fault 7.7–8.9 0.90 ±0.60 SPC02016034 ESF-SD-ClV#34 34+35 Sundance fault 10.5–12.0b 0.46 ±0.42 SPC02015951 ESF-SD-ClV#35 34+30 Sundance fault 10.0–11.4b 0.29 ±0.44 SPC02015943 ESF-SD-ClV#36 34+25 Sundance fault 6.7–8.1 <0.1 ±0.36 SPC02015936 ESF-SD-ClV#37 34+20 Sundance fault 9.7–11.2 0.28 ±0.26 SPC02015941 ESF-SD-ClV#38 34+10 Sundance fault 11.0–12.5b 1.40 ±1.60 Table 5-2. Tritium Concentrations in Pore Water Extracted from Validation Study Core Samples (continued) SMF Barcode Identifier Borehole Name ESF Station Feature Interval Used (ft) 3H concentration (TU) (2s) SPC02015932 ESF-SD-ClV#39 33+99 Sundance fault 11.2–12.7b 0.23 ±0.28 SPC02015927 ESF-SD-ClV#40 33+89 Sundance fault 12.3–13.3 0.30 ±0.32 DTN: GS060308312272.001 (Q) NOTES: ESF = Exploratory Studies Facility, SMF = Sample Management Facility, TU = tritium unit. a Adjacent intervals combined to obtain sufficient sample volume. b Interval used for tritium analysis is smaller than the interval traceable to the SMF barcode identifier; a portion of the core sample was removed in the laboratory and set aside for other analyses. c Non-adjacent intervals combined to obtain sufficient sample volume. Table 5-3. Tritium Concentrations in Pore Water Extracted from ESF Core Samples SMF Barcode Number Borehole Name ESF Station Feature Interval Used (ft) 3H Concentration (TU) (2s) SPC00046007 ESF-AL#2-HPF#1 01+68 Bow Ridge fault 16.4–16.7b <0.1 SPC00046009 ESF-AL#2-HPF#1 01+68 Bow Ridge fault 23.2–23.5b 2.0 ±7.8 SPC00046012 ESF-AL#2-HPF#1 01+68 Bow Ridge fault 27.8–28.0b 5.1 ±7.8 SPC00046014 ESF-AL#2-HPF#1 01+68 Bow Ridge fault 34.3–34.6b 28.8 ±8.4 SPC00046017 ESF-AL#2-HPF#1 01+68 Bow Ridge fault 47.2–47.6b 30.9 ±8.4 SPC00046018 ESF-AL#2-HPF#1 01+68 Bow Ridge fault 50.5–50.7 118 ±19 SPC00046019 ESF-AL#2-HPF#1 01+68 Bow Ridge fault 55.4–55.7 128 ±10 SPC00046022 ESF-AL#2-HPF#1 01+68 Bow Ridge fault 58.9–59.0b 78.6 ±9.4 SPC00046025 ESF-AL#2-HPF#1 01+68 Bow Ridge fault 61.2–61.3b 65.3 ±9.2 SPC00046030 ESF-AL#2-HPF#1 01+68 Bow Ridge fault 68.6–68.9b 155 ±11 SPC00046032 ESF-AL#2-HPF#1 01+68 Bow Ridge fault 83.6–83.8b 32.9 ±8.6 SPC01004381 ESF-LPCAMOISTSTDY# 2 10+28 North Ramp 6.4–7.0 <0.1 SPC01004190 ESF-NRMOISTSTDY# 3 07+68 North Ramp 4.4–5.0 0.20 ±0.80 SPC01004175 SPC01004179 ESF-NRMOISTSTDY# 4 07+73 North Ramp 4.2-6.9c 0.76 ±0.24 SPC01004175 SPC01004179 ESF-NRMOISTSTDY# 4 07+73 North Ramp 4.2-6.9c 0.66 ±0.20 SPC01004240 SPC01004244 ESF-NRMOISTSTDY# 10 08+80 North Ramp 4.0–6.5b,c 0.22 ±0.30 SPC01004301 ESF-NRMOISTSTDY# 13 10+07 North Ramp 4.3–5.1 0.55 ±0.30 SPC01004340 ESF-NRMOISTSTDY# 16 10+70 North Ramp 5.8-6.6 0.44 ±0.30 SPC01001947 ESF/NAD/GTB#1A 37+37 Northern Ghost Dance fault 114.0–115.0 0.50 ±0.60 SPC01001960 SPC01001962 ESF/NAD/GTB#1A 37+37 Northern Ghost Dance fault 120.3– 121.6b,c 1.0 ±0.8 SPC01001975 SPC01001976 ESF/NAD/GTB#1A 37+37 Northern Ghost Dance fault 127.0– 129.0c 1.6 ±1.2 SPC01002037 SPC01002038 ESF/NAD/GTB#1A 37+37 Northern Ghost Dance fault 165.8– 166.7a 0.8 ±1.0 SPC01003300 SPC01003302 ESF-AL6-NDR-MF#1 37+37 Northern Ghost Dance fault 53.9–55.6c 1.3 ±1.0 SPC01003455 SPC01003457 ESF-AL6-NDR-MF#2 37+37 Northern Ghost Dance fault 42.3–43.9c 1.6 ±1.4 Table 5-3. Tritium Concentrations in Pore Water Extracted from ESF Core Samples (continued) SMF Barcode Identifier Borehole Name ESF Station Feature Interval Used (ft) 3H Concentration (TU) (2s) SPC01003458 SPC01003460 ESF-AL6-NDRMF# 02 37+37 Northern Ghost Dance fault 47.3–49.0b,c 1.2 ±0.4 SPC01003462 SPC01003464 ESF-AL6-NDRMF# 02 37+37 Northern Ghost Dance fault 49.3–51.3c 1.1 ±1.0 SPC01003468 SPC01003470 ESF-AL6-NDRMF# 02 37+37 Northern Ghost Dance fault 55.3–57.0c 1.0 ±1.2 SPC01003478 SPC01003480 ESF-AL6-NDRMF# 02 37+37 Northern Ghost Dance fault 61.1–62.9c 0.9 ±1.4 SPC01001916 SPC01001918 SPC01001920 ESF-NADGTB# 1A 37+37 Northern Ghost Dance fault 98.4-101.0c 1.4 ±0.8 SPC01001964 SPC01001966 ESF-NADGTB# 1A 37+37 Northern Ghost Dance fault 122.1-123.8c 1.2 ±0.8 SPC01001968 SPC01001970 SPC01001971 ESF-NADGTB# 1A 37+37 Northern Ghost Dance fault 124.4-126.0c 1.2 ±0.8 SPC01001980 SPC01001982 ESF-NADGTB# 1A 37+37 Northern Ghost Dance fault 130.2-131.9c 0.8 ±1.4 SPC01001991 SPC01001993 SPC01001995 SPC01001998 ESF-NADGTB# 1A 37+37 Northern Ghost Dance fault 137.0-142.0c 0.3 ±0.8 SPC01002042 SPC01002045 ESF-NADGTB# 1A 37+37 Northern Ghost Dance fault 168.0-169.8c 0.8 ±1.0 SPC01003284 SPC01003286 ESF-NDR-MF#1 37+37 Northern Ghost Dance fault 44.2-46.0b,c 1.6 ±1.0 SPC01003292 SPC01003294 SPC01003296 ESF-NDR-MF#1 37+37 Northern Ghost Dance fault 48.9-50.9b,c 2.2 ±1.2 SPC01002776 ESF/SAD/GTB#1 50+64 Southern Ghost Dance fault 103.4–104.1 3.7 ±1.4 SPC01002800 SPC01002802 ESF/SAD/GTB#1 50+64 Southern Ghost Dance fault 124.3– 125.9c 1.1 ±0.6 SPC01002879 SPC01002897 ESF/SAD/GTB#1 50+64 Southern Ghost Dance fault 175.4– 177.0c 1.8 ±1.4 SPC01002956 SPC01002958 ESF/SAD/GTB#1 50+64 Southern Ghost Dance fault 214.5– 216.9c 2.3 ±0.6 SPC01002754 ESF/SAD/GTB#1 50+64 Southern Ghost Dance fault 85.1–86.0 1.2 ±1.0 SPC01004630 SPC01004634 ESF-SRMOISTSTDY# 3 59+65 South Ramp 2.9–5.7c 1.7 ±0.8 Table 5-3. Tritium Concentrations in Pore Water Extracted from ESF Core Samples (continued) SMF Barcode Identifier Borehole Name ESF Station Feature Interval Used (ft) 3H Concentration (TU) (2s) SPC01004661 SPC01004665 ESF-SRMOISTSTDY# 5 63+00 South Ramp 3.6-6.5b,c 0.42 ±0.3 SPC01004672 SPC01004676 ESF-SRMOISTSTDY# 6 63+89 South Ramp 2.6-7.0c 0.81 ±0.28 SPC01004686 SPC01004690 ESF-SRMOISTSTDY# 7 64+80 South Ramp 3.8-7.0c 3.2 ±0.4 SPC01004726 SPC01004728 ESF-SRMOISTSTDY# 10 66+48 South Ramp 2.4–6.4c 28.6 ±3.6 SPC01004759 SPC01004763 ESF-SRMOISTSTDY# 11 66+58 South Ramp 3.2–6.9c 4.8 ±0.8 SPC01004805 ESF-SRMOISTSTDY# 13 66+80 South Ramp 6.0–6.8 3.1 ±0.5 SPC01004786 SPC01004790 ESF-SRMOISTSTDY# 16 67+21 South Ramp 4.6–6.8b,c 8.2 ±1.0 SPC01002407 SPC01002409 ESF-SRMOISTSTDY# 1 67+22 South Ramp 2.1-3.6c 0.3 ±0.3 SPC01002421 SPC01002423 ESF-SRMOISTSTDY# 2 67+20 South Ramp 2.2-3.9c 0.03 ±0.2 SPC01004821 ESF-SRMOISTSTDY# 17 67+30 South Ramp 5.8–6.7 3.8 ±0.6 SPC01004821 ESF-SRMOISTSTDY# 17 67+30 South Ramp 5.8–6.7 3.5 ±1.0 SPC01004831 SPC01004835 ESF-SRMOISTSTDY# 18 67+48 South Ramp 4.6–6.7c 1.1 ±0.8 SPC01004844 SPC01004848 ESF-SRMOISTSTDY# 19 68+26 South Ramp 4.5–6.9c 14.3 ±2.0 SPC01004858 SPC01004862 ESF-SRMOISTSTDY# 20 69+37 South Ramp 4.2–6.8c 7.4 ±0.8 SPC01005233 ESF-SRMOISTSTDY# 23 70+59 South Ramp 16.2–17.0 0.45 ±0.30 SPC01005233 ESF-SRMOISTSTDY# 23 70+59 South Ramp 16.2–17.0 0.25 ±0.32 SPC01004967 SPC01004970 ESF-SRMOISTSTDY# 25 74+35 South Ramp 5.0–6.9 c 4.4 ±0.8 SPC01005175 SPC01005179 ESF-SRMOISTSTDY# 26 74+41 South Ramp 7.4–9.6 c 4.9 ±0.5 SPC01004921 ESF-SRMOISTSTDY# 27 74+44 South Ramp 5.9–6.8 1.5 ±0.8 SPC01004930 SPC01004936 ESF-SRMOISTSTDY# 28 74+47 South Ramp 2.5–6.8c 3.2 ±0.8 SPC01004949 SPC01004953 ESF-SRMOISTSTDY# 29 74+54 South Ramp 4.5–6.8c 0.77 ±0.46 SPC01005033 SPC01005037 ESF-SRMOISTSTDY# 30 74+60 South Ramp 3.8–6.7c 12.5 ±1.2 SPC01004981 SPC01004985 ESF-SRMOISTSTDY# 31 74+66 South Ramp 4.7–7.0c 5.4 ±0.6 SPC01005054 ESF-SRMOISTSTDY# 33 74+77 South Ramp 5.9–6.9 2.7 ±0.6 SPC01005012 ESF-SRMOISTSTDY# 34 74+82 South Ramp 5.9–6.8 1.2 ±0.5 Table 5-3. Tritium Concentrations in Pore Water Extracted from ESF Core Samples (continued) SMF Barcode Identifier Borehole Name ESF Station Feature Interval Used (ft) 3H Concentration (TU) (2s) SPC01005099 ESF-SRMOISTSTDY# 38 75+03 South Ramp 5.9–6.8 1.7 ±0.6 SPC01005113 ESF-SRMOISTSTDY# 40 75+10 South Ramp 5.9–6.9 0.58 ±0.32 DTNs: GS060308312272.001 (Q), GS040108312232.001 (Q), GS961108312261.006 (Q), GS060383122410.001 (UQ) NOTES: ESF = Exploratory Studies Facility, SMF = Sample Management Facility; TU = tritium unit. a Adjacent intervals combined to obtain sufficient sample volume. b Interval used for tritium analysis is smaller than the interval traceable to the SMF barcode identifier; a portion of the core sample was removed in the laboratory and set aside for other analyses. c Non-adjacent intervals combined to obtain sufficient sample volume. Table 5-4. Tritium Concentrations in Pore Water Extracted from ECRB Cross Drift Core Samples SMF Barcode Identifier Borehole Name ECRB Station Interval Used (ft) Volume of Water Extracted (mL) 3H Concentration (TU) (2s) SPC02013439 SPC02013442 ECRB-SYS-CS0600 06+01 3.2–6.0a 120 0.79 ±0.58 SPC02013547 SPC02013543 ECRB-SYS-CS0750 07+50 3.6–6.2a 100.4 6.2 ±1.0 SPC02013530 SPC02013534 ECRB-SYS-CS0800 08+00 2.9–5.8a 80.4 1.7 ±0.6 SPC02013613 SPC02013617 ECRB-SYS-CS0900 09+01 3.5–6.4a 78.8 6.5 ±1.2 SPC02013628 SPC02013624 ECRB-SYS-CS0950 09+50 2.8–5.6a 64.4 6.1 ±0.8 SPC02013695 ECRB-SYS-CS1000 10+00 17.4–18.2 80.8 0.5 ±0.6 SPC02014326 SPC02014330 SPC02014334 ECRB-SYS-CS1200 11+99 2.9–6.9a 109 0.41 ±0.46 SPC02014285 SPC02014289 ECRB-SYS-CS1300 13+01 3.0–5.5a 50 0.7 ±1.4 SPC02014299 SPC02014303 ECRB-SYS-CS1350 13+51 3.6–6.4a 82.6 3.80 ±1.00 SPC02014349 SPC02014353 ECRB-SYS-CS1450 14+50 4.0–6.5a 56 0.3 ±1.0 SPC02014381 SPC02014385 ECRB-SYS-CS1500 14+99 14.4–17.4a 79.4 2.5 ±0.8 SPC02014361 SPC02014365 ECRB-SYS-CS1500 14+99 4.3–7.1a 98 10.3 ±1.8 SPC02014371 SPC02014375 ECRB-SYS-CS1500 14+99 9.5–12.1a 51 1.5 ±0.8 SPC02014406 ECRB-SYS-CS1600 16+00 3.4–4.3 54 1.7 ±1.8 SPC02014436 SPC02014440 ECRB-SYS-CS1750 17+50 3.3–5.9a 78.3 0.6 ±0.8 SPC02014450 SPC02014454 ECRB-SYS-CS1800 18+01 3.6–6.1a 51 0.1 ±1.6 SPC02014486 SPC02014490 ECRB-SYS-CS1950 19+50 4.0–6.5a 104 3.6 ±1.0 SPC02014623 ECRB-SYS-CS2000 19+99 11.0–11.9 63.7 0.1 ±1.0 SPC02014661 ECRB-SYS-CS2150 21+49 3.4–4.1 62 <0.1 SPC02014665 ECRB-SYS-CS2150 21+49 5.5–6.7 67.7 9.8 ±1.0 SPC02014683 ECRB-SYS-CS2250 22+50 2.9–3.9 65 0.8 ±0.8 SPC02014774 SPC02014778 ECRB-SYS-CS2500 25+00 16.7–19.8a 72.4 0.64 ±0.6 DTN: GS060308312272.002 (Q) NOTES: ECRB = Enhanced Characterization of the Repository Block, SMF = Sample Management Facility, TU = tritium unit. a Adjacent intervals combined to obtain sufficient sample volume.