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Yucca Mountain Science and Engineering Report Rev 1
DOE/RW-0539-1
Front Matter
COVER
INSIDE COVER
EXECUTIVE SUMMARY
ACRONYMS AND ABBREVIATIONS
TABLE OF CONTENTS
1. INTRODUCTION
1.1 PURPOSE AND SCOPE
1.2 BACKGROUND INFORMATION
1.2.1 Sources of Materials Considered for Disposal
1.2.1.1 Commercial Spent Nuclear Fuel
1.2.1.2 U.S. Department of Energy Spent Nuclear Fuel
1.2.1.3 High-Level Radioactive Waste
1.2.1.4 Surplus Plutonium
1.2.1.5 Present Location of Spent Nuclear Fuel and High-Level Radioactive Waste
1.2.2 U.S. Policy: The Rationale for Geologic Disposal
1.3 DESCRIPTION OF THE SITE CHARACTERIZATION PROGRAM AND THE YUCCA MOUNTAIN SITE
1.3.1 Site Characterization Investigations
1.3.2 Description of the Yucca Mountain Site
1.3.2.1 Geography, Land Use, and Population
1.3.2.2 Geology
1.4 POSTCLOSURE PERFORMANCE
1.4.1 Performance Assessment
1.4.2 Importance of Repository System Components to Long-Term Performance
1.4.3 Addressing Uncertainty in Total System Performance Assessment
1.4.4 Time Frame for Performance Analyses
2. DESCRIPTION OF THE POTENTIAL REPOSITORY
2.1 ENGINEERING AND DESIGN ANALYSIS
2.1.1 Design Process
2.1.1.1 Allocation of Yucca Mountain Site Characterization Project Requirements
2.1.1.2 Safety Classification of Structures, Systems, and Components
2.1.1.3 System Description Documents
2.1.2 Design and Operational Mode Evolution
2.1.2.1 Summary of Evolution of Design Features
2.1.2.2 Summary of Evolution of Operational Parameters
2.1.2.3 Design and Operating Mode Evolution
2.1.3 Design Flexibility
2.1.4 Operating Flexibility to Achieve a Range of Thermal Operating Modes
2.1.5 Assessing The Performance of a Lower-Temperature Operating Mode
2.1.5.1 Lower-Temperature Operating Mode—Coupled Operational Parameters
2.1.5.2 Example Lower-Temperature Operating Scenarios
2.1.5.3 Comparative Analysis of Alternative Lower-Temperature Operating Scenarios
2.1.5.4 Other Considerations of Lower-Temperature and Lower-Humidity Operating Modes
2.2 REPOSITORY SURFACE FACILITIES
2.2.1 Fuel Blending Inventory Strategy
2.2.2 Operations in the North Portal Repository Operations Area
2.2.2.1 Waste Receiving Operations
2.2.2.2 Waste Handling Operations
2.2.2.3 Treatment of Low-Level Radioactive Waste from Repository Operations
2.2.3 North Portal Repository Operations Area Layout
2.2.4 Surface Systems and Structures
2.2.4.1 Carrier Preparation Building
2.2.4.2 Waste Handling Building
2.2.4.3 Waste Treatment Building
2.2.5 Surface Facilities Radiological Control and Management Systems
2.2.5.1 Dose Assessment and Designing for ALARA Goals
2.2.5.2 Radiological and Emergency Response Systems
2.2.6 Site-Wide Support Systems
2.2.6.1 Emergency Response System
2.2.6.2 Site Fire Protection
2.2.6.3 Surface Environmental Monitoring System
2.2.6.4 Safeguards and Security System
2.2.6.5 Maintenance and Supply System
2.2.6.6 Site Electrical Power
2.2.6.7 Site Solar Power System
2.2.7 Operational Maintenance
2.2.8 Decontamination and Decommissioning of Surface Facilities
2.3 REPOSITORY SUBSURFACE FACILITIES
2.3.1 Repository Design Capacity
2.3.1.1 The Base Case Repository Layout
2.3.1.2 The Full Inventory Repository Layout
2.3.1.3 Additional Repository Capacities
2.3.2 Functional Requirements
2.3.2.1 Subsurface Systems Functions
2.3.2.2 Containment and Isolation
2.3.2.3 Thermal Management
2.3.3 Concept of Operations and Maintenance
2.3.3.1 Subsurface Facilities Construction
2.3.3.2 Operations Support Facilities
2.3.3.3 Operational Phase
2.3.3.4 Maintenance
2.3.4 Design Descriptions and Systems Operations
2.3.4.1 Developing and Maintaining Stable Excavations
2.3.4.2 Maintaining a Safe Working Environment
2.3.4.3 Thermal Load Requirements
2.3.4.4 Waste Transfer and Transport
2.3.4.5 Waste Package Emplacement
2.3.4.6 Retrieval
2.3.4.7 Decommissioning
2.3.4.8 Closure and Sealing Structures
2.3.5 Phased Construction—Development and Emplacement Sequence
2.3.5.1 Initial Construction
2.3.5.2 Development and Emplacement Phase I
2.3.5.3 Development and Emplacement Phase II
2.3.5.4 Development and Emplacement Phase III
2.3.5.5 Development and Emplacement Phase IV
2.4 ENGINEERED BARRIERS
2.4.1 Drift Invert
2.4.1.1 Steel Invert Structure
2.4.1.2 Invert Ballast
2.4.2 Ground Support
2.4.3 Support Assembly for the Waste Package
2.4.3.1 Pallet Design
2.4.3.2 Pallet Interface with Invert
2.4.4 Drip Shield
2.4.4.1 Drip Shield Design
2.4.4.2 Drip Shield Interface with Invert
2.4.4.3 Drip Shield Emplacement
2.5 PERFORMANCE CONFIRMATION FACILITIES DESIGN
2.5.1 Facilities Functions and Types
2.5.2 Proposed Performance Confirmation Facilities
2.5.2.1 Postclosure Simulation Test Area
2.5.2.2 Observation Drifts
2.5.2.3 Other Performance Confirmation Facilities
2.5.3 Subsurface Performance Confirmation Support Facilities
2.5.3.1 Data Acquisition Support Facilities
2.5.3.2 Mobile Vehicle Control Systems
3. DESCRIPTION OF THE WASTE FORM AND PACKAGING
3.1 GENERAL DESIGN BASIS FOR THE WASTE PACKAGE
3.1.1 Waste Package Functions
3.1.2 Preclosure Design Performance Specifications
3.1.3 Postclosure Performance Specification
3.1.4 Design Descriptions
3.2 COMMERCIAL SPENT NUCLEAR FUEL
3.2.1 Commercial Spent Nuclear Fuel: Assigning the Right Waste Package
3.2.1.1 Physical Characteristics of Commercial Spent Nuclear Fuel
3.2.1.2 Thermal Output
3.2.1.3 Criticality Control
3.2.2 Commercial Spent Nuclear Fuel Waste Package Designs
3.2.2.1 Internal Basket Design
3.2.2.2 Control Rods
3.2.3 Preliminary Engineering Specifications for the Commercial Spent Nuclear Fuel Waste Package Designs
3.3 U.S. DEPARTMENT OF ENERGY SPENT NUCLEAR FUEL, HIGH-LEVEL RADIOACTIVE WASTE, AND IMMOBILIZED PLUTONIUM
3.3.1 U.S. Department of Energy Spent Nuclear Fuel
3.3.1.1 Physical Characteristics
3.3.1.2 Thermal Output
3.3.1.3 Criticality Control
3.3.2 High-Level Radioactive Waste and Immobilized Plutonium
3.3.2.1 Physical Characteristics
3.3.2.2 Thermal Output
3.3.2.3 Criticality Control
3.3.3 U.S. Department of Energy Waste Package Designs
3.3.4 Preliminary Engineering Specifications
3.4 SELECTING MATERIALS AND FABRICATING WASTE PACKAGES
3.4.1 Material Selection
3.4.1.1 Waste Package Materials: Contributing to Containment
3.4.1.2 Waste Package Materials: Internal Components
3.4.1.3 Fill Gas
3.4.2 Waste Package Fabrication Process
3.4.2.1 Outer Cylinder Fabrication
3.4.2.2 Inner Cylinder Fabrication
3.4.2.3 Lid Fabrication
3.4.2.4 Assembly of Support Ring
3.4.2.5 Assembly of Lid to Cylinder
3.4.2.6 Annealing of Outer Cylinder
3.4.2.7 Assembly of Commercial Spent Nuclear Fuel Waste Package
3.4.2.8 Basket and Internal Components
3.5 WASTE PACKAGE DESIGN EVALUATIONS
3.5.1 Thermal Evaluations Performed on the Waste Package Design
3.5.1.1 Spent Nuclear Fuel Cladding Temperature
3.5.1.2 High-Level Radioactive Waste Canister Temperatures
3.5.2 Criticality Evaluations Performed on Waste Package Designs
3.5.2.1 Preclosure Evaluations—Commercial Spent Nuclear Fuel
3.5.2.2 Postclosure Criticality Evaluation: Commercial Spent Nuclear Fuel
3.5.2.3 Evaluations of Criticality Potential of U.S. Department of Energy Spent Nuclear Fuel
3.5.2.4 Evaluation of Criticality Potential of the Immobilized Plutonium Waste Package
3.5.3 Structural Evaluations Performed on Waste Package Designs
3.5.3.1 Internal Pressurization
3.5.3.2 Retrieval
3.5.3.3 Rockfall
3.5.3.4 Vertical Drop
3.5.3.5 Tipover
3.5.3.6 Missile Impact
3.5.4 Shielding Evaluations Performed on the Waste Package Design
3.5.4.1 Source Term
3.5.4.2 Results
4. DISCUSSION OF DATA RELATING TO THE POSTCLOSURE SAFETY OF THE SITE
4.1 THE POSTCLOSURE SAFETY ASSESSMENT METHOD
4.1.1 Total System Performance Assessment
4.1.1.1 Total System Performance Assessment Methods and Objectives
4.1.1.2 Treatment of Uncertainty in the Performance Assessment
4.1.1.3 Explicit Consideration of Disruptive Processes and Events that Could Affect Repository Performance
4.1.2 Observations from Natural and Man-Made Analogues
4.1.3 Use of Defense in Depth and Safety Margin to Increase Confidence in System Performance
4.1.4 Mitigation of Uncertainties by Selection of a Thermal Operating Mode
4.1.5 Performance Confirmation, Postclosure Monitoring, and Site Stewardship
4.2 DESCRIPTION OF SITE CHARACTERIZATION DATA AND ANALYSES RELATED TO POSTCLOSURE SAFETY
4.2.1 Unsaturated Zone Flow
4.2.1.1 Conceptual Basis
4.2.1.2 Summary State of Knowledge
4.2.1.3 Process Model Development and Integration
4.2.1.4 Total System Performance Assessment Abstraction
4.2.2 Effects of Decay Heat on Water Movement
4.2.2.1 Conceptual Basis
4.2.2.2 Summary State of Knowledge
4.2.2.3 Process Model Development and Integration
4.2.2.4 Total System Performance Assessment Abstraction
4.2.3 Physical and Chemical Environment
4.2.3.1 Conceptual Basis
4.2.3.2 Summary State of Knowledge
4.2.3.3 Process Model Development and Integration
4.2.3.4 Total System Performance Assessment Abstraction
4.2.4 Waste Package and Drip Shield Degradation
4.2.4.1 Conceptual Basis
4.2.4.2 Summary State of Knowledge
4.2.4.3 Process Model Development and Integration
4.2.4.4 Total System Performance Assessment Abstraction
4.2.5 Water Diversion Performance of the Engineered Barriers
4.2.5.1 Conceptual Basis
4.2.5.2 Summary State of Knowledge
4.2.5.3 Process Model Development and Integration
4.2.5.4 Total System Performance Assessment Abstraction
4.2.6 Waste Form Degradation and Radionuclide Release
4.2.6.1 Conceptual Basis
4.2.6.2 Summary State of Knowledge
4.2.6.3 Process Models
4.2.6.4 Total System Performance Assessment Abstraction
4.2.7 Engineered Barrier System Transport
4.2.7.1 Conceptual Basis
4.2.7.2 Summary State of Knowledge
4.2.7.3 Engineered Barrier System Process Model Development
4.2.7.4 Engineered Barrier System Flow and Transport Abstraction
4.2.8 Unsaturated Zone Transport
4.2.8.1 Conceptual Basis of Unsaturated Zone Transport
4.2.8.2 Summary State of Knowledge
4.2.8.3 Unsaturated Zone Flow and Transport Process Models
4.2.8.4 Total System Performance Assessment Abstraction
4.2.9 Saturated Zone Flow and Transport
4.2.9.1 Conceptual Basis of Flow and Transport
4.2.9.2 Summary State of Knowledge
4.2.9.3 Saturated Zone Flow and Transport Process Model Development and Integration
4.2.9.4 Total System Performance Assessment Abstraction
4.2.10 Biosphere
4.2.10.1 Conceptual Basis
4.2.10.2 Summary State of Knowledge
4.2.10.3 Process Model Development and Integration
4.2.10.4 Total System Performance Assessment Abstraction
4.3 SCENARIOS OF FUTURE CONDITIONS THAT COULD AFFECT REPOSITORY PERFORMANCE
4.3.1 Methodology for Developing Scenarios
4.3.2 Scenarios Considered in Total System Performance Assessment
4.3.2.1 Volcanic/Igneous Activity
4.3.2.2 Seismic Activity
4.3.2.3 Human Intrusion Scenario
4.3.3 Scenarios Addressed and Screened Out of Total System Performance Assessment
4.3.3.1 Long-Term Stability of the Water Table
4.3.3.2 Nuclear Criticality
4.4 ASSESSMENT OF PERFORMANCE
4.4.1 Total System Model
4.4.1.1 Components and Integration of the Total System Performance Assessment Model
4.4.1.2 Treatment of Uncertainty in Total System Performance Assessment Analyses
4.4.1.3 Treatment of Potentially Disruptive Scenarios
4.4.1.4 Summary of Radionuclides of Concern Considered in Dose Assessment
4.4.2 Total System Performance for the Nominal Scenario
4.4.2.1 Definition of the Nominal Scenario
4.4.2.2 Nominal Performance Results for Individual Protection Performance Measure
4.4.2.3 Nominal Performance Results for Groundwater Protection
4.4.2.4 Nominal Performance Results for Peak Dose
4.4.2.5 Summary of Nominal Scenario Performance Assessment Results
4.4.3 Total System Performance for the Disruptive Scenario
4.4.3.1 Total System Performance Assessment Model for Volcanic Eruption
4.4.3.2 Total System Performance Assessment Model for Groundwater Transport of Radionuclides Following Igneous Intrusion
4.4.3.3 Results and Interpretation
4.4.3.4 Combined Releases from the Nominal and Disruptive Scenarios
4.4.4 Assessment of Human Intrusion Scenario
4.4.4.1 Background
4.4.4.2 Results
4.4.5 Sensitivity Analysis and Evaluation of Robustness of Repository Performance
4.4.5.1 TSPA-SR Model Nominal Scenario Sensitivity Analysis
4.4.5.2 TSPA-SR Model Sensitivity Analyses for Disruptive Scenarios
4.4.5.3 TSPA-SR Model Sensitivity Analyses of the Human Intrusion Scenario
4.4.5.4 Summary of TSPA-SR Sensitivity Analyses
4.4.5.5 Supplemental TSPA Sensitivity Analyses For Nominal Performance
4.4.5.6 Evaluation of Disruptive Events
4.5 MULTIPLE BARRIER ANALYSES
4.5.1 Identification and Description of Barriers
4.5.2 Approaches to Evaluation of Multiple Barriers
4.5.3 Evaluation of Natural Barrier Components
4.5.4 Evaluation of Engineered Barrier Components
4.5.5 Summary of Barrier-Importance Analyses
4.6 PERFORMANCE CONFIRMATION, POSTCLOSURE MONITORING, AND SITE STEWARDSHIP
4.6.1 Performance Monitoring
4.6.1.1 Performance Confirmation Program
4.6.2 Safeguards and Security
5. DESCRIPTION OF THE PRECLOSURE SAFETY ASSESSMENT
5.1 KNOWN TECHNOLOGY AND OPERATING SYSTEMS
5.2 BASIC SAFETY ASSESSMENT METHOD
5.2.1 Event Identification Process
5.2.2 Event Sequence Categorization Process
5.2.3 Event Sequence Consequence Analysis Process
5.2.4 Use of Features and Controls Important to Radiological Safety
5.2.5 Quality Assurance Classification Process
5.3 PRELIMINARY DESCRIPTION OF potential hazards, EVENT Sequences, AND CONSEQUENCES
5.3.1 Preliminary Description of External Events
5.3.2 Preliminary Description of Internal Event Sequences
5.3.2.1 Internal Event Sequences with Potential Releases
5.3.2.2 Internal Event Sequence with No Radioactive Material Release
5.3.2.3 Beyond Category 1 and Category 2 Event Sequences
5.3.3 Consequence Evaluations
5.3.3.1 Category 1 Event Sequence Consequences
5.3.3.2 Category 2 Event Sequence Consequences
5.4 PRECLOSURE SAFETY: TEST AND EVALUATION PROGRAM
5.4.1 Development Testing
5.4.2 Prototype Testing
5.4.3 Component Testing
5.4.4 Construction and Preoperational Testing
5.4.5 Hot Startup Testing
5.4.6 Periodic Performance Testing and Surveillance
6. REFERENCES
6.1 DOCUMENTS CITED
6.2 CODES, STANDARDS, REGULATIONS, AND PROCEDURES
GLOSSARY
EXECUTIVE SUMMARY FIGURES
Figure 1. Map Showing Current Locations of Waste Destined for Geologic Disposal
Figure 2. Proposed Repository Facilities
Figure 3. Schematic Illustration of the Emplacement Drift, with Cutaway Views of Different Waste Packages
Figure 4. Schematic Illustration of the Processes Modeled for Total System Performance Assessment
Figure 5. Regional Map of the Saturated Zone Flow System
FIGURES
1-1. Aerial View of Yucca Mountain, Looking South, Showing the Desert Environment and the Remote Location
1-2. Map Showing Locations of Spent Nuclear Fuel and High-Level Radioactive Waste Destined for Geologic Disposal
1-3. Site Investigation Area Showing Location of the Surface-Based and Underground Test Facilities at Yucca Mountain, Including Boreholes and Underground Excavations
1-4. Photograph Showing the Tunnel Boring Machine Operating at Yucca Mountain
1-5. Map Showing the Location of Yucca Mountain in Relation to Major Highways; Surrounding Counties, Cities, and Towns in Nevada and California; the Nevada Test Site; and Death Valley National Park
1-6. Map Showing the Location of Yucca Mountain and Land Status in the Region
1-7. Map Showing the Location of Yucca Mountain and Major Physiographic Provinces of the Southwest
1-8. Simplified Geologic Map Showing the Location of Yucca Mountain in Relation to the Southwestern Nevada Volcanic Field
1-9. Simplified Geologic Map of Yucca Mountain Near the Potential Repository
1-10. Simplified Cross Section of Yucca Mountain Near the Potential Repository
1-11. Layout and Boundaries of the Potential Repository
1-12. View Looking Down Exploratory Studies Facility
1-13. Groundwater Elevation Contours, with Their Relationship to a Conceptual Repository Layout
1-14. Mapped Faults at Yucca Mountain and in the Yucca Mountain Vicinity
2-1. Proposed Monitored Geologic Repository Facilities at Yucca Mountain
2-2. Allocation of Functions, Criteria, and Requirements
2-3. Preclosure Safety Analysis Process
2-4. Design Documents Development
2-5. Potential Repository Areas and Emplacement Area for the Higher-Temperature Operating Modes
2-6. Potential Repository Areas and Emplacement Area for the Lower-Temperature Operating Modes
2-7. Repository Layouts for the Draft Environmental Impact Statement for High, Intermediate, and Low Thermal Load Scenarios and the Design for the Higher-Temperature Operating Mode
2-8. Variables Affecting the Thermal Performance of the Repository
2-9. Window of Potentially Increased Susceptibility of Localized Corrosion for Alloy 22
2-10. Layout of Potential Repository Development Areas, Showing Areas Utilized in Example Operating Mode Scenarios for a Repository Capacity of 70,000 MTHM
2-11. Below-Boiling Repository Operating Curves
2-12. Waste Package Surface and Drift Wall Temperatures for an Operational Scenario in Which Drifts Loaded at 1 kW/m in the Last Year of Emplacement Operations are Actively Ventilated for 50 Years and Naturally Ventilated for Another 250 Years
2-13. Waste Package Surface and Drift Wall Temperatures for an Operational Scenario in Which Drifts Loaded at 0.7 kW/m in the Last Year of Emplacement Operations are Actively Ventilated for 100 Years
2-14. Waste Package Surface and Drift Wall Temperatures for an Operational Scenario in which Drifts Loaded at 0.5 kW/m in the Last Year of Emplacement Operations are Actively Ventilated for 75 Years
2-15. Waste Package Surface Temperature, Drift Wall Temperature, and In-Drift Relative Humidity for an Operational Scenario in Which Drifts Loaded at the End of Emplacement Operations at 1.45 kW/m are Actively Ventilated for 50 Years and then Naturally Ventilated Indefinitely
2-16. Repository Overall Site Plan
2-17. Casks, Containers, and Waste Forms Handled at the Surface Facility
2-18. Waste Receiving Operations
2-19. Waste Handling Operations
2-20. North Portal Repository Operations Area Site Plan
2-21. Carrier Preparation Building Materials Handling System
2-22. Waste Handling Building Systems Layout
2-23. Waste Handling Building Sections
2-24. Waste Handling Building Radiation Levels
2-25. Carrier/Cask Handling System
2-26. Canister Transfer System
2-27. Assembly Transfer System (1 of 3)
2-28. Assembly Transfer System (2 of 3)
2-29. Assembly Transfer System (3 of 3)
2-30. Disposal Container Handling System
2-31. Waste Package Remediation System
2-32. Waste Handling Building Heating, Ventilation, and Air Conditioning Confinement Flow Diagram
2-33. Waste Handling Building Confinement Zone Configuration
2-34. Recyclable Liquid Low-Level Radioactive Waste Collection System Diagram
2-35. Nonrecyclable Liquid Low-Level Radioactive Waste Treatment System Diagram
2-36. Dry Solid Low-Level Radioactive Waste Processing System
2-37. Monitored Geologic Repository Site Electrical Power Distribution Diagram
2-38. Repository Layout for the 70,000-MTHM Case
2-39. Repository Layout for the 97,000-MTHM Case
2-40. Emplacement Drift Ground Support
2-41. Typical Final Ground Support System for Nonemplacement Excavations
2-42. Ventilation and Radiation Monitoring Conceptual Diagram, Part 1
2-43. Ventilation and Radiation Monitoring Conceptual Diagram, Part 2
2-44. Repository Emplacement Area General Airflow Pattern
2-45. Flow Process Diagram for the Repository Emplacement Ventilation
2-46. Repository Exhaust Shaft Conceptual Dual Fan Installation
2-47. Waste Package Emplacement Route—Key Locations
2-48. Locomotives and Waste Package Transporter Approaching the North Portal
2-49. Locomotive Operations at Emplacement Drift Turnout
2-50. Docked Transporter with Pallet and Waste Package on Transporter's Open Deck and Emplacement Gantry Approaching the Docking Area for Pickup
2-51. Emplacement Pallet Isometric View
2-52. Emplacement Pallet Loaded with Waste Package
2-53. Waste Package Transportation Equipment Traveling Along Main Drift
2-54. Waste Package Transporter and Its Components
2-55. Bottom/Side Lift Emplacement Gantry—Perspective View
2-56. Bottom/Side Lift Emplacement Gantry—End View within Emplacement Drift
2-57. Equipment and Sequence of Operations for Normal Retrieval
2-58. Emplacement Drift Gantry Carrier and Multipurpose Hauler
2-59. Multipurpose Hauler Used with Multipurpose Vehicle for Pallet and Waste Package Retrieval
2-60. Gantry Recovery with Emplacement Drift Gantry Carrier
2-61. Conceptual Arrangement for Placement of Backfill in Ramps and Main Drifts
2-62. Conceptual Arrangement for Placement of Backfill in Shafts
2-63. Conceptual Arrangement of Shaft Plug
2-64. Dual Concrete Seal Plug Design Concept
2-65. Repository Subsurface Layout—Initial Construction
2-66. Examples of Global and Local Ventilation
2-67. Repository Subsurface Layout—Development and Emplacement for Phase I
2-68. Repository Subsurface Layout—Development and Emplacement for Phase II
2-69. Repository Subsurface Layout—Development and Emplacement for Phase III
2-70. Repository Subsurface Layout—Development and Emplacement for Phase IV
2-71. Emplacement Drift Cross Section with Invert Structure in Place
2-72. Emplacement Drift Perspective View with Steel Invert Structures in Place
2-73. Drip Shield Isometric View
2-74. Drip Shield Interlocking Connection
2-75. Drip Shield Structural Components
2-76. Drip Shield Emplacement Gantry and Lift Pin Mechanism
2-77. Typical Section of Emplacement Drift with Waste Packages and Drip Shields in Place
2-78. Subsurface Performance Confirmation Facilities Layout
2-79. Conceptual Configuration for Postclosure Simulation Test Sections
2-80. Observation Drift Airflow Concept
2-81. Remote Inspection Gantry Used for In-Drift Performance Confirmation Activities
3-1. Cross-Sectional Illustration of an Alloy 22 and Stainless Steel Emplaced Dual-Metal Waste Package
3-2. 21-PWR Absorber Plate Waste Package Design
3-3. Schematic Illustration of the Emplacement Drift with Cutaway Views of Different Waste Packages
3-4. Waste Form Inventory
3-5. Waste Package Designs with Waste Forms
3-6. Cross-Sectional Illustration of a Typical Pressurized Water Reactor Fuel Assembly
3-7. Waste Package Fabrication Process
3-8. Waste Package Final Closure Welds
3-9. Administrative Limit for Calculated keff and Typical Loading Curve
4-1. Total System Performance Assessment Pyramid Illustrating the Progressive and Iterative Process of Synthesizing Design Information, Site Data, Process Models, and Total System Performance Assessment Expertise
4-2. Schematic Illustration of the Ten General Processes Considered and Modeled for Total System Performance Assessment
4-3. Main Models Included in the Unsaturated Zone Process Model Report, Their Interrelations, and Their Connections to Total System Performance Assessment
4-4. Schematic Block Diagram Showing Major Unsaturated Zone Flow Processes Above, Within, and Below Repository Emplacement Drifts
4-5. Lithostratigraphic Transitions at the Upper and Lower Margins of the PTn Hydrogeologic Unit
4-6. Lithophysal Transitions within the TSw Unit
4-7. Lithostratigraphic Transitions and Flow Patterns at the TSw–CHn Interface
4-8. Schematic of Phenomena and Processes Affecting Drift Seepage
4-9. Yucca Mountain Site-Scale Geology
4-10. Geological and Geophysical Studies on the Surface and along the Exploratory Studies Facility
4-11. Fracture–Matrix Interaction Test at Alcove 6
4-12. Paintbrush Fault and Porous Matrix Test at Alcove 4
4-13. Distribution of Zeolites in Certain Layers below the Potential Repository Horizon
4-14. Geochemical Studies of Tuff Samples
4-15. Isotopic Studies of Tuff Samples
4-16. Lower Lithophysal Seepage Test at Cross-Drift Niche 5
4-17. Drift Seepage Test at Niche 2
4-18. Damp Feature Observed during Dry Excavation of Niche 1 and Bomb-Pulse Chlorine-36 Isotopic Signals along the Exploratory Studies Facility
4-19. Analogue Studies for Unsaturated Zone Flow, Transport, and Seepage
4-20. Schematic of the Major Input Data to the Unsaturated Zone Flow Model and Models that Use Its Output
4-21. Flow Diagram Showing Key Input Data Used in Numerical Grid Development, the Types of Grids Generated, and the End Users
4-22. Perspective View of the Unsaturated Zone Model Domain of Yucca Mountain, Showing Hydrogeologic Units, Layers, and Major Faults
4-23. Percolation Flux Map for Three-Dimensional Calibration Grid
4-24. Comparison between Simulated Percolation Flux (mm/yr) Contours at the Potential Repository Horizon and at the Water Table Under the Present-Day Mean Infiltration Rate
4-25. Simulated Percolation Fluxes at the Potential Repository Horizon Under the Mean Infiltration Scenarios
4-26. Infiltration Distribution over the Flow Model Domain for the Mean Infiltration Scenarios
4-27. Simulated Percolation Flux in the Matrix and in Fractures at the Potential Repository Horizon, Using Present-Day Mean Infiltration Rate
4-28. Summary of the Unsaturated Zone Flow Model Results
4-29. Conceptual Model of Unsaturated Zone Flow and Transport at Yucca Mountain Showing Results from Analysis of Geochemical Data
4-30. Schematic Showing Data Flow and Series of Models Supporting Evaluation of Drift Seepage
4-31. Schematic Showing General Approach for the Development of the Seepage Calibration Model
4-32. Calibrated One-Dimensional Simulation Match to Saturation, Water Potential, and Pneumatic Data
4-33. Calibrated Two-Dimensional Simulation Match to Saturation, Water Potential, and Pneumatic Data
4-34. Comparison of Simulated and Observed Matrix Liquid Saturations, Showing Perched Water Elevations
4-35. Comparison of Predictions from the Three-Dimensional Model with In Situ Water Potential Data and Pneumatic Pressure Data
4-36. Comparison between the Measured Seepage Mass and Seepage Mass Calculated with Two-Dimensional and Three-Dimensional Homogeneous and Heterogeneous Models
4-37. Summary of Qualitative and Quantitative Results from Seepage Testing and Modeling
4-38. Drift-Scale Schematic Illustration Showing Decay-Heat-Driven Thermal-Hydrologic Flow and Transport Processes
4-39. Mountain-Scale Schematic Illustration Showing Decay-Heat-Driven Thermal-Hydrologic Flow and Transport Processes that Influence Moisture Redistribution and the Moisture Balance in the Unsaturated Zone
4-40. Schematic Diagram Showing Relation between Thermal-Hydrologic Processes and Geochemical Processes
4-41. Permeability of a Single Fracture in a Core Sample of Topopah Spring Welded Tuff as a Function of Time and Exposure to Flowing Water
4-42. Difference X-Ray Radiography Images of 7.2 Hours (left) and 0.67 Hours (right) after Flow was Initiated
4-43. Pentane and Temperature Distribution Showing Heat Pipe
4-44 Photograph of the Large Block Test Site
4-45. Schematic of the Large Block Test Instrument Boreholes
4-46 Temperatures Measured at (a) TT1-14 and (b) TT2-14 of the Large Block Test as a Function of Elapsed Time
4-47. Vertical Temperature Profiles through the Large Block for June 4 and June 25, 1997, Showing Development of a Heat Pipe Zone
4-48. Temperatures at Several Resistance Temperature Detectors in TT1, Showing the Fluctuations Due to a Thermal-Hydrologic Event on September 2, 1997
4-49. Electrical Resistance Tomographs of an East-West Vertical Cross Section of the Large Block Test, Showing the Variation of the Moisture Distribution within the Imaging Plane
4-50. Difference Fraction Volume Water in Large Block Test Borehole TN3 as a Function of Depth, from 103 to 565 Days of Heating
4-51. Schematic Illustration of the Single Heater Test in the Exploratory Studies Facility
4-52. Schematic Illustration of the Drift Scale Test in the Exploratory Studies Facility
4-53. Temperature Measured at 2 m (6.6 ft) from the Collar of Boreholes 158 to 162 in the Drift Scale Test as a Function of Time, Showing the Spatial Variation of the Boiling of the Pore Water
4-54. Comparison of Distributions of Drift Scale Test Water Saturation Measured by Electrical Resistivity Tomography and Simulated by NUFT at 547 Days
4-55. Difference Fraction Volume Water in Borehole 67 of the Drift Scale Test as a Function of Depth from Collar
4-56. Tomogram Showing Saturation Change from Preheat Ambient Values after Approximately 13 Months of Heating
4-57. Measured Drift Scale Test Temperatures as a Function of Distance of Sensor Locations from Borehole Collars after 18 Months of Heating
4-58. Analogue Studies for the Effects of Decay Heat and Thermal-Hydrologic-Chemical Coupled Processes
4-59. Plan View of the Three-Dimensional Grid Used for the Unsaturated Zone Flow Model and the Mountain-Scale Thermal-Hydrologic Model
4-60. Lateral and Vertical Discretization at the NS#2 Cross Section Based on the Refined Numerical Grid
4-61. Schematic Showing Input Data and the Unsaturated Zone Models that Support the Development of the Thermal-Hydrologic Model
4-62. Temperature Distribution at 1,000 Years along NS#2 Cross Section from the Mountain-Scale Thermal-Hydrologic Model
4-63. Matrix Liquid Saturation at 1,000 Years along NS#2 Cross Section from the Mountain-Scale Thermal-Hydrologic Model
4-64. Fracture Liquid Flux along NS#2 Cross Section from the Mountain-Scale Thermal-Hydrologic Model
4-65. Layout of the Potential Repository Used in the Multiscale Thermal-Hydrologic Model
4-66. Thermal-Hydrologic-Chemical Seepage Model Mesh Showing Hydrogeologic Units in Proximity of the Drift, and Blowup Showing Discretization of In-Drift Design Components
4-67. Contour Plot of Modeled Liquid Saturations and Temperatures in the Matrix at 600 Years (Near Maximum Dryout) for Three Infiltration Rate Scenarios
4-68. Contour Plot of Calculated Total Fracture Porosity Change at 10,000 Years for Three Infiltration Rate Scenarios
4-69. Comparison of Simulated and Measured Temperature Profiles along Large Block Test Borehole TT1, at Five Times from 30 to 400 Days
4-70. Comparison of Simulated and Measured Liquid-Phase Saturation Profiles along Large Block Test Borehole TN3, at Three Times from 100 to 500 Days
4-71. Comparison of Simulated and Measured Temperatures along Single Heater Test Borehole ESF-HD-137 at 365 and 547 Days
4-72. Drift-Wall Temperature Predicted by the Multiscale Thermal-Hydrologic Model Compared to the Temperature Predicted by an East–West Cross-Sectional Mountain-Scale Thermal-Hydrologic Model
4-73. Simulated CO2 Volume Fractions in Fractures and Matrix after 6 Months and 20 Months of Heating During the Drift Scale Test
4-74. Emplacement Drift Cross Section Showing the Processes Considered in the Evolution of the Physical and Chemical Environment, and in the Transport of Radionuclides, within the Emplacement Drifts
4-75. Deliquescence Points (Expressed as Relative Humidity [RH]) and Boiling Points for Several Pure Salts
4-76. Model Diagram Relating Inputs and Outputs for the Thermal-Hydrologic-Chemical Seepage Model, with the Thermal-Hydrologic Drift Scale Test Model, Thermal-Hydrologic-Chemical Drift Scale Test Model, Calibrated Properties Model, Unsaturated Flow and Transport Model, Other Data Input, and Design Information
4-77. Comparison of Modeled Carbon Dioxide Concentrations in Fractures and Matrix to Measured Concentrations in Boreholes for the First 21 Months of the Drift Scale Test
4-78. Time Profiles of Modeled Carbon Dioxide Concentrations in the Gas Phase in Fractures at Three Drift Wall Locations for Different Climate Change Scenarios
4-79. Alloy C Test Coupon after Almost 60 Years of Exposure to a Marine Environment
4-80. Schematic Illustration of the Arrangement of Waste Packages and Drip Shield
4-81. Schematic Illustration of a Typical Waste Package Designed for 21 Pressurized Water Reactor Fuel Assemblies, and the Materials Used for the Various Components
4-82. Arrangement of the Test Specimens in the Racks
4-83. Typical Appearance of an Alloy 22 Specimen after 12 Months of Exposure to an Aqueous Environment in the Long-Term Corrosion Test Facility
4-84. Schematic Representation of the Elements of Process Models and the Interrelationships among the Process Models
4-85. Foundation for Model Confidence, including Inputs and Outputs for the Various Degradation Process Models
4-86. Effects of Aging on Precipitation at Alloy 22 Grain Boundaries
4-87. Isothermal Time-Temperature Transformation Diagram for Alloy 22 Base Metal
4-88. Temperature of the Waste Package Outer Barrier Surface as a Function of Time for the Hottest Waste Package
4-89. Schematic Illustration of the Dual Alloy 22 Lid Waste Package Design
4-90. Conceptual Design of Remote Welding, Annealing, and Laser Peening for the Closure Welding of the Waste Package
4-91. Graphical Extrapolation of the Curves to Repository-Relevant Temperatures
4-92. TSPA-SR Performance Assessment Results for Waste Package Degradation (Nominal Scenario)
4-93. Schematic of Drip Shield Test
4-94. Schematic of Drip Shield Test Measurements
4-95. Water Balance for the Pilot-Scale Drip Shield Test without Backfill
4-96. Relative Humidity in the Pilot-Scale Drip Shield Test without Backfill
4-97. Components of the Waste Form Degradation Model
4-98. Conceptual Model of In-Package Chemistry
4-99. Conceptual Model of the Formation of Reversibly and Irreversibly Attached Radionuclides on Colloids
4-100. pH History for Commercial Spent Nuclear Fuel Process Model Calculations
4-101. pH History for Codisposal Process Model Calculations
4-102. Conceptual Model of Commercial Spent Nuclear Fuel Cladding Degradation
4-103. Abstracted Degradation Rates for Commercial Spent Nuclear Fuel
4-104. Abstracted Degradation Rates for High-Level Radioactive Waste Glass
4-105. Neptunium Solubility Abstraction and Neptunium Solubility Data
4-106. Linkage of Subcomponents of the Waste Form Degradation Process Model Colloidal Radionuclide Component
4-107. Plot of Long-Term Estimated Glass Dissolution Rates vs. Stage III Measured Product Consistency Test Rates
4-108. The Waste Form Inventory, Detailing Waste Types, Allocation, and Waste Packages
4-109. Conceptualization of an Emplacement Drift with the Major Components of the Engineered Barrier System, and Seepage Diverted by the Drip Shield
4-110. Conceptualization of an Emplacement Drift after the Drip Shield and Waste Package are Breached
4-111. Schematic Representation of Inputs and Outputs of Engineered Barrier System Flow and Transport Model for Total System Performance Assessment
4-112. Construction Water Distribution below the Exploratory Facilities Drift
4-113. El Niño Infiltration and Seepage Test at Alcove 1
4-114. Alcove 8–Niche 3 Cross-Drift Tests
4-115. Unsaturated Zone Transport Test at Busted Butte
4-116. Schematic Diagram of Diffusion Barriers in Invert and Drift Shadow Zone
4-117. Saturation Profiles around a Drift from a Seepage Model for Performance Assessment
4-118. Condensate Shedding during the Thermal Period
4-119. Perched Water at the Base of the Topopah Spring Welded Hydrogeologic Unit
4-120. Locations of Particle Breakthrough at the Water Table for the Mean Infiltration, Glacial-Transition Climate Using Two Perched Water Models
4-121. Relationships of Other Models and Data Inputs to the Unsaturated Zone Transport Model
4-122. Flow and Transport in Two Representative Unsaturated Zone Hydrogeologic Profiles
4-123. Comparison of Transport Characteristics in USW UZ-14 and USW SD-6
4-124. Normalized Release Rate and Dependence of Technetium-99 Transport on Infiltration Rates
4-125. Normalized Mass Fraction Distribution of Technetium-99 in Fractures at the Bottom of the Topopah Spring Welded Hydrogeologic Unit and at the Water Table
4-126. Key Issues of Unsaturated Zone Transport
4-127. Regional Map of the Saturated Zone Flow System Showing Direction of Flow and Outline of the Three Dimensional Saturated Zone Flow Model Domain
4-128. Conceptualization of Features and Processes Important to Saturated Zone Transport
4-129. Flow Paths Predicted by the Site-Scale Saturated Zone Flow and Transport Model for the TSPA-SR
4-130. Concepts of Advection and Dispersion in Porous Medium and the Resulting Breakthrough Curves Defined by the Time History of Solute Concentration Measured in a Well
4-131. Nye County Early Warning Drilling Program Boreholes, the C-Wells Complex, and 19D (the Location of the Alluvial Testing Complex)
4-132. Fracture Properties of Aperture (Width), Length, and Frequency (Number of Fractures per Volume)
4-133. Groundwater Flow Paths near Yucca Mountain as Inferred from Chloride Concentrations at Sites near Yucca Mountain
4-134. Conceptualization of Solute and Colloid Transport in a Fracture with Sorption in the Rock Matrix
4-135. Estimated Dispersivity as a Function of Length Scale
4-136. Colloid-Facilitated Transport
4-137. Natural Analogue Sites Used for Comparison with Yucca Mountain
4-138. Domain of Site-Scale Saturated Zone Flow and Transport Model for the TSPA-SR
4-139. Computational Grid Developed for the Site-Scale Saturated Zone Flow and Transport Model
4-140. Complex Spatial Pattern of Hydrogeologic Units Depicted as a Fence Diagram
4-141. Site-Scale Saturated Zone Model Area, Showing Potentiometric Surface Contours, Water Level Altitudes, and Tertiary Faults
4-142. Lateral and Top Boundary Conditions for the Three-Dimensional Saturated Zone Flow Model for the Present-Day Climate
4-143. Three-Dimensional Saturated Zone Model Domain Showing the Different Permeability Fields
4-144. Structural and Tectonic Features within the Site-Scale Saturated Zone Model
4-145. The Use of Anisotropy to Simulate an Alternate Conceptual Flow and Transport Model
4-146. Simulated Potentiometric Surface with Three-Dimensional Flow Model Calibration Residuals
4-147. Simulated Particle Paths after a Hypothetical Radionuclide Release from the Potential Repository
4-148. Estimated and Observed Permeabilities for Nine Stratigraphic Units at Yucca Mountain
4-149. Estimated and Observed Permeabilities for Four Aquifers at Yucca Mountain
4-150. Physical System, Conceptual Model, and Normalized Tracer Responses from the Prow Pass Multiple Tracer Test
4-151. Map of Yucca Mountain Area with the Site-Scale Model Boundary
4-152. Representative Breakthrough Curve and Histogram
4-153. Convolution Integral Method Used in Saturated Zone Flow and Transport Calculations for Total System Performance Assessment–Site Recommendation
4-154. Illustration of the Biosphere Transport Pathways and Processes Contributing Dose to the Biosphere Receptor(s)
4-155. Satellite Image Showing the Yucca Mountain Area, Including the Amargosa Valley, with Details of the Area
4-156. Major Steps in Scenario Selection Methodology
4-157. Schematic Illustration of the Screening Process
4-158. Location of Miocene (Circles) and Post-Miocene (Triangles) Basaltic Vents of the Yucca Mountain Region
4-159. Location and Age of Quaternary (<2 Million Years) and Pliocene (2 to 5 Million Years) Volcanoes (or Clusters where Multiple Volcanoes have Indistinguishable Ages) and Probable Buried Basalt in the Yucca Mountain Region
4-160. Schematic Illustration of Hypothetical Igneous Activity at Yucca Mountain
4-161. Schematic Representation of the Two Volcanism Scenarios Analyzed for TSPA-SR
4-162. Historical Seismicity (1868 to 1996) Showing Events of Mw 3.5 or Modified Mercalli Intensity III and Larger within 300 km (186 mi) of Yucca Mountain
4-163. Recordings of Frenchman Flat Earthquake at the Ground Surface and the Thermal Test Alcove 245 m (804 ft) Underground
4-164. Known or Suspected Quaternary Faults and Potentially Significant Local Faults within 100 km of Yucca Mountain
4-165. Locations of Specified Design Basis Earthquake Ground Motion Input
4-166. Preliminary Ground Motion Calculated by the TSPA-SR Model at Points B and C with 1 Chance in 10,000 of being Exceeded Each Year
4-167. Human Intrusion Scenario
4-168. Veins in Trench 14 Pinching Out with Depth
4-169. Photograph of Travertine Deposit and Feeder Vein at Travertine Point, along Furnace Creek, Death Valley, California
4-170. Representation of the Postclosure Criticality Methodology
4-171. Different Stages of Internal Degradation for a Typical 21-PWR Absorber Plate Waste Package After 10,000 Years
4-172. Relationship of Data, Models, and Information Flow in the Total System Performance Assessment Model
4-173. Schematic of the Principal Process Models Included in the Nominal and Disruptive Event Scenarios
4-174. Monte Carlo Simulation
4-175. Information Feeds to Igneous Consequence Modeling in the Total System Performance Assessment
4-176. All Radionuclides Considered in the TSPA model, Showing Decay-Chain Relationships (with Half-Lives in Years)
4-177. Component Models and Information Flow in the Total System Performance Assessment Model
4-178. Component Models in the Total System Performance Assessment Nominal Scenario Model
4-179. TSPA-SR Model and Revised Supplemental TSPA Model Results of Annual Dose to a Receptor for the Nominal Scenario
4-180. TSPA Model Results: Million-Year Annual Dose Histories for Nominal Performance
4-181. Mean Annual Dose Rate for Key Radionuclides for the Nominal Scenario Projected by the TSPA-SR Model
4-182. Fraction of Mean Total Annual Dose Attributed to Different Radionuclides for the Nominal Scenario Projected by the TSPA-SR Model
4-183. Mean Groundwater Concentrations for Gross Alpha and Total Radium Activity Projected by the TSPA-SR model
4-184. Mean Critical Organ Dose Rates Combined Beta- and Photon-Emitting Radionuclides Projected by the TSPA-SR model
4-185. Mean Activity Concentrations of Gross Alpha Activity and Total Radium in the Groundwater, Higher-Temperature Operating Mode
4-186. Mean Activity Concentrations of Gross Alpha Activity and Total Radium in the Groundwater, Lower-Temperature Operating Mode
4-187. TSPA-SR Model Results for the Million-Year Annual Dose to a Receptor for the Nominal Scenario Using Nominal TSPA Models
4-188. TSPA-SR Model Results for the Million-Year Annual Dose to a Receptor for the Nominal Scenario Using Nominal TSPA-SR Models and Revised Solubility Model
4-189. TSPA-SR Model Results for Million-Year Annual Dose to a Receptor for the Nominal Scenario Using Nominal TSPA-SR Models and Revised Solubility and Climate Models
4-190. 100,000-Year Annual Dose Histories: TSPA-SR Model and Revised Supplemental TSPA Model (Nominal Scenarios) and Revised Supplemental TSPA Model (Igneous Activity)
4-191. Schematic Representation of a Volcanic Eruption at Yucca Mountain, Showing Transport of Radioactive Waste in an Ash Plume
4-192. Schematic Diagram Showing an Igneous Intrusion at Yucca Mountain and Subsequent Transport of Radionuclides in Groundwater
4-193. TSPA-SR Model and Revised Supplemental TSPA Models Results of Annual Dose to a Receptor for Igneous Activity Scenario
4-194. Igneous Dose Histories for Major Contributing Radionuclides Projected by the TSPA-SR Model
4-195. Projected Annual Doses for the Igneous Activity Disruptive Scenario
4-196. Conceptualization of Human Intrusion Scenario in the TSPA-SR Model
4-197. TSPA-SR Model and Revised Supplemental TSPA Results of Annual Dose to a Receptor for the Human Intrusion Scenario
4-198. Summary of TSPA-SR Model Stochastic Sensitivity Analyses for Nominal Scenario—Parameters Affecting Dose Rate Uncertainty at Various Times
4-199. Summary of Stochastic TSPA-SR Model Sensitivity Analyses for Nominal Scenario—Parameters Affecting Uncertainty in Time of Dose Rate for Various Dose Rates
4-200. Sensitivity of the Mean Annual Dose Calculated by the TSPA-SR Model to Uncertainty in the Stress State at Closure Welds
4-201. Sensitivity of the Mean Annual Dose Calculated by the TSPA-SR Model to Uncertainty in the Median General Corrosion Rate of Alloy 22
4-202. Sensitivity of the Mean Annual Dose Calculated by the TSPA-SR Model to Uncertainty in Infiltration Rate
4-203. Sensitivity of the Mean Annual Dose Calculated by the TSPA-SR Model to Uncertainty in the Seepage Rate
4-204. Sensitivity of the Mean Annual Dose Calculated by the TSPA-SR Model to Adding Backfill to the Repository Design
4-205. Comparison of Doses Projected by the TSPA-SR Model and Revised Supplemental TSPA Model for the Higher- and Lower-Temperature Operating Modes for the Nominal Scenario
4-206. Sensitivity of the Mean Annual Dose Calculated by the TSPA-SR Model for the Volcanic Scenario to Uncertainty in Probability of Volcanic Intrusion and Eruption
4-207. Sensitivity of the Mean Annual Dose for the Volcanic Scenario Calculated by the TSPA-SR Model to Uncertainty in the Number and Extent of Waste Packages Damaged by the Volcanic Intrusion
4-208. Sensitivity of the Mean Dose Rate Projected by the TSPA-SR Base-Case Model Assuming a Degraded and an Enhanced Infiltration Barrier
4-209. Sensitivity of the Mean Dose Rate Projected by the TSPA-SR Base-Case Model Assuming a Degraded and an Enhanced Seepage Barrier
4-210. Sensitivity of the Mean Dose Rate Projected by the TSPA-SR Base-Case Model Assuming a Degraded and an Enhanced Unsaturated Zone Transport Barrier
4-211. Sensitivity of the Mean Dose Rate Projected by the TSPA-SR Base-Case Model Assuming a Degraded and an Enhanced Unsaturated Zone Flow, Unsaturated Zone Transport, and Seepage Barrier
4-212. Sensitivity of the Mean Dose Rate Projected by the TSPA-SR Base-Case Model Assuming a Degraded and an Enhanced Saturated Zone Flow and Transport Barrier
4-213. Sensitivity of the Mean Dose Rate Projected by the TSPA-SR Base-Case Model Assuming a Degraded and an Enhanced Drip Shield Barrier
4-214. Sensitivity of the Mean Dose Rate Projected by the TSPA-SR Base-Case Model Assuming a Degraded and an Enhanced Waste Package Barrier
4-215. Sensitivity of the Mean Dose Rate Projected by the TSPA-SR Base-Case Model Assuming a Degraded and an Enhanced Cladding Barrier
4-216. Sensitivity of the Mean Dose Rate Projected by the TSPA-SR Base-Case Model Assuming a Degraded and an Enhanced Concentration Limits Barrier
4-217. Sensitivity of the Mean Dose Rate Projected by the TSPA-SR Base-Case Model Assuming a Degraded and an Enhanced Engineered Barrier System Transport Barrier
4-218. Sensitivity of the Mean Dose Rate Projected by the TSPA-SR Base-Case Model Assuming a Juvenile Waste Package Failure with a Degraded Cladding Barrier
4-219. Performance Confirmation Process, From Testing to Data Evaluation
4-220. Conceptual Illustration of a Performance Confirmation Inspection Gantry
5-1. Sample Event Tree
TABLES
2-1. Event Sequence Frequency Categories
2-2. Comparison of Estimates of Operational Parameters for Example Lower-Temperature Operating Modes
2-3. Preliminary Crane and Lifting Machine Performance Specifications
2-4. Preliminary Waste Handling Building Performance Specifications
2-5. Preliminary Facility Space Specifications for the Waste Handling Building
2-6. Preliminary Canister Transfer System Performance Specifications
2-7. Preliminary Assembly Transfer System Performance Specifications
2-8. Preliminary Facility Space Specifications for the Waste Treatment Building
2-9. Preliminary Subsurface Excavation Dimensions for the Base Case Repository Layout
2-10. Safety Classifications for Repository Subsurface Systems
2-11. Lithostratigraphic Units and Relationship to Thermal-Mechanical Units of the Topopah Spring Tuff Within the Repository Emplacement Horizon
2-12. Subsurface Ground Control Components
2-13. Design Basis of Ventilation System for Base Case Repository Layout
2-14. Allowable Subsurface Working Temperatures
2-15. Summary of Waste Emplacement Track Specifications
2-16. Summary Description of Waste Package Transporter Components
2-17. Summary of Waste Emplacement Locomotive Specifications
2-18. Summary of Bounding Weights of Waste Package Transporter Components
2-19. Design Basis Summary of Waste Package Transporter Performance
2-20. Summary of Design Basis of Closure and Sealing Components
2-21. Summary of Closure and Sealing Component Materials
2-22. Drip Shield Design Detail
3-1. Bounding Event Sequences for Waste Packages
3-2. Waste Package Design
3-3. Breakdown of Waste Packages for 70,000 MTHM
3-4. Design Basis Dimensions of Assemblies for Boiling Water Reactors
3-5. Design Basis Dimensions of Assemblies for Pressurized Water Reactors
3-6. Fuel Assembly Characteristics at Arrival
3-7. Physical Dimensions of Commercial Waste Package Designs
3-8. Commercial Spent Nuclear Fuel Characteristics by Waste Package Design
3-9. Waste Package Design Component Materials
3-10. U.S. Department of Energy Waste Forms for Disposal, According to Waste Package Design
3-11. Physical Dimensions of Waste Packages Designed for U.S. Department of Energy Waste Forms
3-12. Chemical Composition of Alloy 22
3-13. Chemical Composition of Stainless Steel Type 316NG
3-14. Summary of Results for Rockfall Calculation
3-15. Summary of Results of Tipover Calculation for 21-PWR Absorber Plate Waste Package
4-1. Process Models and Natural Analogues
4-2. Identification of Natural and Engineered Barriers at Yucca Mountain
4-3. Correlation of Key Attributes of Yucca Mountain, Barriers to Radionuclide Release, and Processes Important to Performance, with Reference to Where Descriptions of the Processes can be Found in this Report and Process Model Reports
4-4. Major Hydrogeologic Unit, Lithostratigraphic Unit, Detailed Hydrogeologic Unit, and Unsaturated Zone Model Layer Nomenclatures
4-5. Natural Analogues for Climate and Infiltration Process Evaluation
4-6. Natural Analogues for Unsaturated Flow and Seepage Process Evaluation
4-7. Comparison of the Water Flux through Matrix and Fractures as a Percentage of the Total Flux at the Middle PTn and at the Potential Repository Horizon
4-8. Comparison of Water Flux through Faults as a Percentage of the Total Flux at Four Different Horizons for the Three Mean Infiltration Scenarios
4-9. Average Percolation Fluxes Simulated within the Potential Repository Footprint for the Three Mean Infiltration Scenarios
4-10. Comparison of Water Flux through Fractures as a Percentage of the Total Flux at the Potential Repository and at the Water Table, Using the Nine Infiltration Scenarios
4-11. Average Precipitation and Average Infiltration Rates over the Unsaturated Zone Flow Model and Transport Model Domain
4-12. Summary of Current Understanding Used to Develop Conceptual and Numerical Models for Unsaturated Zone Flow and Seepage into Drifts
4-13. Parameter Ranges for Which Seepage is Evaluated Using the Seepage Model for Performance Assessment
4-14. Uncertainty in Seepage Parameters as a Function of Percolation
4-15. Geothermal Analogues for Process Evaluation
4-16. Thermal-Hydrologic Variables Predicted with the Multiscale Thermal-Hydrologic Model at 610 Locations in the Potential Repository
4-17. Thermal-Hydrologic-Chemical Abstraction for the Mean Infiltration Rate Case with Climate Change
4-18. Range of In-Package Fluid Compositions
4-19. Isotope Selection
4-20. Canister Designs
4-21. Waste Package Designs
4-22. Waste Configurations Used in the Inventory Abstraction
4-23. Average Radionuclide Inventory in Grams in Commercial Spent Nuclear Fuel and Codisposal Waste Packages for TSPA-SR
4-24. Dissolved Concentration Limits for TSPA-SR
4-25. Distribution Parameters for Matrix Diffusion Coefficients
4-26. Sorption Coefficient Distributions for Unsaturated Zone Hydrogeologic Units from Batch Experiments
4-27. Summary of Radionuclide Sorption Results from Busted Butte Tests
4-28. Transport Parameters Deduced from Bullfrog Tuff and the Prow Pass Tuff Tracer Tests
4-29. Sorption-Coefficient Distributions for Saturated Zone Units From Laboratory Batch Tests
4-30. Biosphere Dose Conversion Factor and Soil Buildup Factors for Radionuclides Introduced into the Biosphere through Irrigation with Contaminated Groundwater
4-31. Statistical Output for Direct Volcanic Release Scenario Biosphere Dose Conversion Factors for the TSPA-SR
4-32. Potentially Significant Faults and Fault Parameters within 10 km (6.2 mi) of the Potential Repository
4-33. Summary Postclosure Dose and Activity Concentration Limits and Evaluation Results
4-34. Total System Performance Assessment Model Components
4-35. Igneous Intrusion Groundwater Event Scenario Input Parameters
4-36. Radionuclides Selected for Consideration in Total System Performance Assessment-Site Recommendation Based on Contribution to Dose
4-37. Tabulated Peak Mean Annual Dose and Peak 95th Percentile Dose for the Nominal Case and the Disruptive (Igneous Activity) Case
4-38. Key Aspects and Technical Assumptions in the Human Intrusion Scenario in the TSPA-SR Model
4-39. Correlation of Barrier and Barrier Functions to Key Attributes of Yucca Mountain Repository System and Process Models
4-40. Partially Degraded Barrier Importance Analyses Figures
4-41. Performance Confirmation Factors Based on Processes Important to Safety
4-42. Performance Confirmation Factors Consistent with Potential Licensing Requirement
4-43. Performance Confirmation Factors Based on Potential Data Needs
4-44. Identified Performance Confirmation Testing and Monitoring Activities
5-1. Generic Internal Events
5-2. Generic External Events
5-3. QL-1 Structures, Systems, and Components
5-4. QL-2 Structures, Systems, and Components
5-5. External Initiating Events and Natural Phenomena
5-6. Category 1 Internal Event Sequences
5-7. Category 2 Internal Event Sequences
5-8. Summary of Preclosure Category 1 Event Sequence Radiation Doses for the Public and Workers