1. INTRODUCTION
1.1 REGULATORY FRAMEWORK FOR A SUITABILITY EVALUATION
1.2 BACKGROUND INFORMATION
1.3 APPROACH TO A SITE SUITABILITY EVALUATION
  1.3.1 Technical Approach for the Suitability Evaluation
  1.3.2 Documentary Bases for the Preclosure Suitability Evaluation
  1.3.3 Documentary Bases for the Postclosure Suitability Evaluation

2. PRECLOSURE SUITABILITY EVALUATION
2.1 KNOWN TECHNOLOGY AND OPERATING SYSTEMS
2.2 BASIC SAFETY ASSESSMENT METHOD
  2.2.1 Event Identification Process
  2.2.2 Event Sequence Categorization Process
  2.2.3 Event Sequence Consequence Analysis Process
  2.2.4 Use of Features and Controls Important to Radiological Safety
  2.2.5 Safety Assessment and Quality Assurance Classification Process
2.3 CONSIDERATION OF THE PRECLOSURE SUITABILITY CRITERIA
  2.3.1 Preliminary Description of Site Characteristics, Surface Facilities, and Subsurface Facilities
  2.3.2 Preliminary Description of Design Bases for Facilities and Limits on Operations
  2.3.3 Preliminary Description of Potential Hazards, Event Sequences, and Consequences
   2.3.3.1 Preliminary Description of External Events
   2.3.3.2 Preliminary Description of Internal Event Sequences
   2.3.3.3 Category 1 Event Sequence Consequences
   2.3.3.4 Category 2 Event Sequence Consequences
  2.3.4 Preliminary Description of the Structures, Systems, Components, Equipment, and Operator Actions Intended to Prevent or Mitigate Accidents
2.4 EVALUATION OF THE PRECLOSURE SUITABILITY CRITERIA
  2.4.1 Ability to Contain Radioactive Material and to Limit Releases of Radioactive Materials
   2.4.1.1 Evaluation
   2.4.1.2 Conclusion
  2.4.2 Ability to Implement Control and Emergency Systems to Limit Exposure to Radiation
   2.4.2.1 Evaluation
   2.4.2.2 Conclusion
  2.4.3 Ability to Maintain a System and Components that Perform Their Intended Safety Functions
   2.4.3.1 Evaluation
   2.4.3.2 Conclusion
  2.4.4 Ability to Preserve the Option to Retrieve Wastes During the Preclosure Period
   2.4.4.1 Evaluation
   2.4.4.2 Conclusion
2.5 SUMMARY OF THE PRECLOSURE SUITABILITY EVALUATION

4. SUMMARY OF RESULTS
4.1 PRECLOSURE SUITABILITY EVALUATION
4.2 POSTCLOSURE SUITABILITY EVALUATION
4.3 SITE SUITABILITY EVALUATION

5. REFERENCES
5.1 DOCUMENTS CITED
5.2 CODES, STANDARDS, REGULATIONS, AND PROCEDURES

GLOSSARY

EXECUTIVE SUMMARY FIGURES

Figure 1. Arial View of Yucca Mountain, Looking South, Showing the Desert Environment and the Remote Location
Figure 2. Conceptual Illustration of Natural and Engineered Barriers and Their Functions Contributing to the Isolation of Waste
Figure 3. Conceptual Illustration of Physical Processes Modeled in the Total System Performance Assessment of a Potential Yucca Mountain Disposal System
Figure 4. Total System Performance Assessment Method
Figure 5. TSPA-SR Model and Supplemental TSPA Model Results of Annual Dose to a Receptor for the Nominal Scenario
Figure 6. Revised Supplemental TSPA Model Results of Annual Dose to a Receptor for Disruptive (Igneous Activity) Scenario, Higher-Temperature Operating Mode
Figure 7. Modified Horsetail Diagram with Individual Realizations Removed and Statistical Measures�Mean and 5^th and 95^th Percentiles�Displayed Separately
Figure 8. Revised Supplemental TSPA Model Results for Activity Concentrations of Gross Alpha Activity (Excluding Rn and U) in the Groundwater, Lower-Temperature Operating Mode
Figure 9. Revised Supplemental TSPA Model Results for Activity Concentrations of Total Radium (²²⁶Ra and ²²⁸Ra) in the Groundwater, Lower-Temperature Operating Mode
Figure 10. Revised Supplemental TSPA Model Results for Annual Dose to Critical Organs from Iodine-129

FIGURES

1-1. Evaluation Process for Preclosure Suitability
1-2. Evaluation Process for Postclosure Suitability
2-1. Sample Event Tree
2-2. Repository Layout for the 70,000 MTHM Case
3-1. The Total System Performance Assessment Process, Component Models, and Site Suitability Performance Measures
3-2. Total System Performance Assessments Called for by Site Suitability Guidelines and Relationships to Proposed and Final Radiological Protection Standards
3-3. TSPA-SR Model and Supplemental TSPA Model Results of Annual Dose to a Receptor for the Nominal Scenario
3-4. TSPA Model Results: Million-Year Annual Dose Histories for Nominal Performance
3-5. Projected Annual Doses for the Igneous Activity Disruptive Scenario
3-6. Revised Supplemental TSPA Model Results of Annual Dose to a Receptor for Disruptive (Igneous Activity) Scenario, Higher-Temperature Operating Mode
3-7. Mean Activity Concentrations of Gross Alpha Activity and Total Radium in the Groundwater, Higher-Temperature Operating Mode
3-8. Mean Activity Concentrations of Gross Alpha Activity and Total Radium in the Groundwater, Lower-Temperature Operating Mode
3-9. Revised Supplemental TSPA Model Results for Activity Concentrations of Gross Alpha Activity (Excluding Rn and U) in the Groundwater, Lower-Temperature Operating Mode
3-10. Revised Supplemental TSPA Model Results for Activity Concentrations of Total Radium (²²⁶Ra and ²²⁸Ra) in the Groundwater, Lower-Temperature Operating Mode
3-11. Revised Supplemental TSPA Model Results for Annual Dose to Critical Organs from Iodine-129
3-12. Modified Horsetail Diagram with Individual Realizations Removed and Statistical Measures—Mean and 5th and 95th Percentiles—Displayed Separately
3-13. Cumulative Fraction of Realizations Reaching Particular Annual Dose Rates at the Peak of the Mean within 10,000 Years Calculated by the Revised Supplemental TSPA Model
3-14. 100,000-Year Annual Dose Histories: TSPA-SR Model and Revised Supplemental TSPA Model (Nominal Scenarios) and Revised Supplemental TSPA Model (Igneous Activity)
3-15. Flow of Yucca Mountain Site Data and Design Information in the Total System Performance Assessment
3-16. Total System Performance Assessment Component Models: Relationships between the GoldSim System Model and External Process-Level Computer Models
3-17. Major Components of the Total System Performance Assessment Supporting the Site Suitability Evaluation
3-18. Relationship among Total System Performance Assessment Component Models, 10 CFR 963.17 Criteria, and Process Model Reports
3-19. Location Map of Southern Nevada Showing County Boundaries, Major Roads, Locations of Cities, Boundary of the Nevada Test Site, and the Yucca Mountain Site
3-20. View of Yucca Mountain Looking Southwest Showing Canyons that Provide Drainage for the Eastern Slope of the Mountain
3-21. Generalized Site Stratigraphic Column Showing Principal Rock Units, Formation Names, and Degree of Welding, and Highlighting the Potential Repository Horizon
3-22. Generalized Geologic Map of the Yucca Mountain Area Showing Locations of Major Faults, Relative Movements, and the Locations of the Exploratory Studies Facility and Enhanced Characterization of the Repository Block Cross-Drift
3-23. Diagrammatic Orthogonal Section of Yucca Mountain Illustrating Hydrologic Features and Processes of the Unsaturated Zone
3-24. Variations in Porosity and Saturation with Depth in Borehole SD-9
3-25. Conceptual Model of Yucca Mountain Showing Major Processes and Important Issues for Performance
3-26. Summary of Issues, Modeling Methodology, Data, and Results for the Analysis of Climate and Infiltration
3-27. Yucca Mountain Site-Scale Geology
3-28. Mean Infiltration Rates for the Three Climate States for the Unsaturated Zone Flow Model
3-29. Simulated Percolation Flux at the Repository Horizon with Present-Day, Mean Infiltration using the Extended Model Grid
3-30. Simulated Percolation Flux at the Water Table with Present-Day, Mean Infiltration using the Extended Model Grid
3-31. Spatial Distribution of Infiltration in the Domain of the Extended Model
3-32. Simulated Percolation Flux at the Repository Horizon for the Flow-Through Perched Water Conceptual Model
3-33. Simulated Percolation Flux at the Water Table for the Flow-Through Perched Water Conceptual Model
3-34. Plan View of Unsaturated Zone Model Domains and Potential Repository Emplacement Area
3-35. Groundwater Elevation Contours, with Their Relationship to a Conceptual Repository Layout
3-36. Summary of Results from Seepage Testing and Modeling
3-37. Example of Permeability Saturation for a Simulated Liquid Release Test in Niche 4
3-38. Water Supply, Measured Seepage Rates, and Predicted Seepage Rates of Seepage
3-39. Distribution of Flux Magnitude within the Two-Dimensional Model Domain, Indicating the Formation of Several High-Flux Flow Paths
3-40. Distribution of Vertical Fluxes within the Two-Dimensional Model Domain (a) at a Depth of 25 m and (b) at the Bottom of the Model Domain
3-41. Comparison of Frequency Distribution of Simulated Fluxes at Different Elevations within the Two-Dimensional Model Domain
3-42. Frequency Distribution of Simulated Fluxes at Different Infiltration Rates within the Two-Dimensional Model Domain
3-43. Changes in pH for Water Samples Collected from the Drift Scale Test, Compared to Modeled Fracture-Water pH at Nearby Model Grid Nodes
3-44. Comparison of Mean Seep Flow Rate in Three Cases for Commercial Spent Nuclear Fuel with 20- to 60-mm/yr Infiltration
3-45. Schematic Presentation of a Cross Section of an Emplacement Drift Showing Major Components of the Engineered Barrier System
3-46. Average Drip Shield Evaporation Rates for Typical Waste Packages Containing (a) Commercial Spent Nuclear Fuel and (b) DOE High-Level Radioactive Waste
3-47. Fluid Flux through a Single Waste Package Calculated with TSPA-SR Models and with Supplemental TSPA Models
3-48. Schematic Representation of the Interrelationship of the Component Models for the Waste Package and Drip Shield
3-49. Conceptual Model for Degradation of Commercial Spent Nuclear Fuel Cladding
3-50. Analysis Model Reports and Calculations for Developing the Clad Degradation–Summary and Abstraction Analysis Model Report
3-51. Simulated Temperature Histories for Center Rod
3-52. Issues Related to Potential Radionuclide Transport in the Unsaturated Zone
3-53. Normalized Tracer Cumulative Flux at the Water Table as a Function of Time
3-54. Schematic Diagram of Diffusion Barriers in Invert and Drift Shadow Zone
3-55. Technetium (a) and Neptunium (b) Transport with a Total Percolation Rate of 10 mm/yr
3-56. Locations of Particle Breakthrough at the Water Table for the Mean Infiltration Glacial-Transition Climate Using Two Perched Water Models
3-57. Schematic Diagram of Thermal-Hydrologic-Chemical Processes around a Heated Drift
3-58. Simulated Changes in Fracture Porosity and Mineralogy after 5,000 Years of Heating
3-59. Change in Vertical Permeability at 1,000 Years
3-60. Horizontal Permeability Change at 1,000 Years Due to Thermal-Hydrologic-Mechanical Effects
3-61. Fracture Liquid Flux Profiles at Center of the Potential Repository for the Higher-Temperature Repository, No Lithophysal Cavities
3-62. Fracture Liquid Flux Profiles at the Center of the Potential Lower-Temperature Repository, No Lithophysal Cavities
3-63. Schematic Illustration of Different Transport Processes Operating in the Volcanic Tuffs and the Alluvium
3-64. Schematic Illustration of Colloid-Facilitated Transport
3-65. Conceptual Illustration of the Setting of the Biosphere in the Context of the Overall Repository System
3-66. Block Diagram of the Biosphere Transport Pathways for the Nominal Scenario
3-67. Illustration of the Two Volcanism Scenarios Analyzed for the Total System Performance Assessment

EXECUTIVE SUMMARY TABLES

Table 1. Summary Preclosure Dose Performance Criteria and Evaluation Results
Table 2. Summary Postclosure Dose and Activity Concentration Limits and Evaluation Results

TABLES

Table 1-1 Preclosure Suitability Evaluation Methods and Suitability Criteria Set Out in 10 CFR Part 963 and Where They are Discussed in this Site Suitability Evaluation
Table 1-2 Postclosure Suitability Evaluation Methods and Suitability Criteria Set Out in 10 CFR Part 963 and Where They are Discussed in this Site Suitability Evaluation
Table 2-1 Generic Internal Events
Table 2-2 Generic External Events
Table 2-3 QL-1 Structures, Systems, and Components
Table 2-4 QL-2 Structures, Systems, and Components
Table 2-5 External Initiating Events and Natural Phenomena
Table 2-6 Category 1 Internal Event Sequences
Table 2-7 Category 2 Internal Event Sequences
Table 2-8 Summary of Preclosure Category 1 Event Sequence Radiation Doses for the Public and Repository Workers
Table 3-1 Suite of TSPA Documentation
Table 3-2 Summary of Applicable Radiation Protection Standards
Table 3-3 Tabulated Peak Mean Annual Dose and Peak 95th Percentile Dose for the Nominal Case and the Disruptive (Igneous Activity) Case
Table 3-4 Nuclear Energy Agency�s FEP Database for Postclosure Repository Performance
Table 3-5 Additional FEPs Identified through TSPA Workshops
Table 3-6 Total System Performance Assessment Component Models
Table 3-7 Identification of Natural and Engineered Barriers at Yucca Mountain
Table 3-8 TSPA Sensitivity Studies for the Nominal Scenario
Table 3-9 TSPA Sensitivity Studies for the Disruptive Scenario
Table 3-10 Lower-Bound, Mean, and Upper-Bound Annual Precipitation for the Three Climate Scenarios
Table 3-11 Lower-Bound, Mean, and Upper-Bound Annual Temperature for the Three Climate Scenarios
Table 3-12 Average Net Infiltration Rates over the Unsaturated Zone Model Domain
Table 3-13 Average Percolation Flux Simulated within the Potential Repository Footprint for the Future Mean Infiltration Scenarios
Table 3-14 Cases Considered in Sensitivity Studies
Table 3-15 Critical Crevice Temperatures for Alloy 22
Table 3-16 Stress Corrosion Cracking Model Development Since TSPA-SR
Table 3-17 Dissolved Concentration Limits for TSPA-SR
Table 3-18 Changes in Permeability for the Various Hydrostratigraphic Layers
Table 4-1 Summary Preclosure Dose Performance Criteria and Evaluation Results
Table 4-2 Summary Postclosure Dose and Activity Concentration Limits and Evaluation Results