Nevada Test Site Low-Level Radioactive Waste Disposal Operations

1. Nevada Test Site Low-Level Radioactive Waste Disposal Operations Stephen Mellington, Assistant Manager for Environmental Management June 7, 2006 National Governor’s Association

2. The Nevada Test Site (NTS) • Approximately 1,375 square miles of federally owned and controlled land – surrounded by approximately 4,500 square miles of federally owned and controlled land • Located approximately 65 miles northwest of Las Vegas, Nevada

3. U.S. Department of Energy Site Comparisons

4. Environmental Conditions Arid desert climate Average 4-6 inches annual precipitation Evaporation exceeds rainfall by 12 times No significant surface water No permanent streams or lakes Many closed basins Thick alluvial basins Negligible recharge Groundwater from past cooler/wetter climate No “fast” pathways Depth to groundwater for disposal areas Area 3 – 1,600 feet (488 meters) Area 5 – 770 feet (235 meters)

5. Historic Activities at the NTS • First NTS atmospheric nuclear test detonated on January 27, 1951 • 928 atmospheric and underground nuclear tests conducted between 1951 and 1992 • Nuclear weapons development and testing generated radioactive waste

6. Early Disposal Activities • Low-level radioactive waste (LLW) first collected for disposal at an Area 5 site in 1953 • LLW first disposed in Area 5 Sugar Bunker trench in 1961 • LLW first disposed in Area 3 subsidence crater in 1968 • Began accepting LLW generated by other U.S. Department of Energy sites in 1976 • Formal LLW disposal project established in 1978

7. Area 5Radioactive Waste Management Site • Developed around the original Sugar Bunker trench • 732 acres available for disposal – 140 acres currently used • Disposal cells are excavated pits and trenches • Eight (8) active disposal cells (21 closed and two constructed/available)

8. Area 5Radioactive Waste Management Site(continued) • Diverse radioactive waste streams and package types handled • Asbestos • Contact-handled LLW monoliths (in excess of 90,000 pounds each) • High-concentration thorium • Remote-handled LLW monoliths • Roll-off intermodals • Thorium nitrate • Mixed LLW

9. Area 3Radioactive Waste Management Site • Encompasses 120 acres • Subsidence craters from historic underground nuclear testing are used as disposal cells • Five (5) disposal cells (comprised of 7 subsidence craters) • Radioactive waste managed includes LLW and Mixed LLW (cell closed)

10. Mixed LLW at the Nevada Test Site • 1987: Mixed LLW disposal begins • 1990: State of Nevada requires the U.S. Department of Energy to provide a Waste Analysis/Verification Plan • Disposal of off-site generated Mixed LLW is halted

11. Mixed LLW at the Nevada Test Site (continued) • 2000: DOE issues Waste Management Programmatic Environmental Impact Statement Record of Decision declaring the Nevada Test Site as a regional disposal site for LLW and Mixed LLW • 2000-2005: DOE works with State to resolve technical issues affecting the acceptance of off-site Mixed LLW • December 2005: State issues Nevada Test Site Resource Conservation and Recovery Act (RCRA) Part B Permit – lifting the off-site Mixed LLW disposal prohibition

12. Mixed LLW at the Nevada Test Site (continued) • April 11, 2006: Received first off-site MLLW shipment since 1990 Graphic Number:    /454/PICT0089.JPG Photo Date:    4/11/2006

13. Disposal Practices

14. NTS Requirements / Capabilities • U.S. Department of Energy Order 435.1 • NTS Waste Acceptance Criteria (NTSWAC) • Category 2 non-reactor nuclear facility • Documented safety analyses • Technical safety requirements • All disposed waste containers are retrievable • Grid coordinate tracking system for performance modeling and retrievability

15. Tailored Disposal Cells and Waste Forms • Unique waste streams of LLW require specialized disposal cells • High-dose LLW • Non-standard waste packaging • Radon flux requirements • Classified materials • Cells are designed and constructed prior to acceptance/receipt of waste on an as-needed basis • Crane placement and heavy equipment requirements considered • Approximately 200,000 cubic yards of soil moved each year to create custom disposal cells

16. Area 5 Disposal Cells –Waste Container Configuration Boxes containing LLW are placed in a stair-stacked configuration within a engineered grid

17. Area 5 Disposal Cells –Waste Container Configuration (continued) LLW drums are positioned in a single layer with boxes of LLW arranged as “book ends”

18. Area 5 Disposal Cells –Waste Container Configuration(continued) Remote-Handled Monoliths – 10 Rem/hour dose rates and higher Monoliths were “nested” in between LLW cargo containers arranged in an H-pattern 97 high-dose LLW monoliths (~20 R/hr) were received with a cumulative dose of 0.38178 man-Rem for 900 man-hours

19. Site Differences • Area 3 Radioactive Waste Management Site located 15 miles northwest of Area 5 • Area 3 historically used for larger, bulk radioactive waste packages • Layer-cake geometry used to dispose radioactive waste in Area 3

20. Area 3 Disposal Cells –Waste Container Configuration (continued) Cargo containers of LLW

21. Area 3 Disposal Cells –Waste Container Configuration(continued) Bulk equipment such as nozzles, compressors, converters, centrifuges, etc.

22. NTS Approved LLW Generators General Atomics 30 generators are currently approved to ship LLW to the NTS

23. Mixed LLW Generators WVDP INL BNL Mound LLNL Lexington Portsmouth SNL Paducah Oak Ridge(2) Current Perma-Fix Potential SRS

24. NTS LLW Disposal History 2,434 2,422 Volume (1,000 ft3) 1,674 1,440 shipments 930 705 520 Fiscal Year FY 2003 (total) – 3,239,726 ft3 FY 2004 (total) – 3,743,572 ft3 FY 2005 (total) – 2,091,771 ft3 FY 2006 (total received as of 5/21/2006) – 790,933 ft3 *Indicates average per year for that decade

25. NSO Commitment • NSO is committed to supporting accelerated cleanup by providing disposal services to all U.S. Department of Energy sites • NSO is committed to reducing risk to NTS workers, the public, and the environment with timely, cost-effective disposal services • NSO is committed to working cooperatively with regulators and keeping the public informed of its Environmental Management activities through the Community Advisory Board

26. Groundwater

27. Background Information • 1951 to 1992: United States Government conducted 828 underground nuclear tests at the Nevada Test Site (NTS) at depths ranging from approximately 90 to 4,800 feet below the ground surface • About one-third of these tests occurred near or below the water table, which resulted in some contamination of the area’s groundwater

28. Addressing Groundwater Contamination • U.S. Department of Energy began preliminary hydrologic research in the 1970s • A more intensive groundwater studies program was launched in 1989 with the formation of the Groundwater Characterization Project at the Department of Energy Nevada Site Office

29. Addressing Groundwater Contamination (continued) • The Underground Test Area (UGTA) sub-project evaluates the historic testing impacts on groundwater resources and study the extent of contaminant migration • The scope includes collection of multiple sources of field data in order to create a 3-D computer model • This model includes groundwater, flow and transport parameters • The models will be used to help create a monitoring network to ensure that the public/workers are not exposed to groundwater exceeding Safe Drink Water Act standards

30. UGTA Strategy • Drill wells, analyze existing wells, and conduct geophysical studies to collect data • Evaluated the NTS on a regional scale – separated areas hydrologically and geographically into five (5) manageable Corrective Action Units • Develop phased approach – Phase I and Phase II each representing stages of data collection and analysis • Identify contaminant movement and develop contaminant boundaries • Implement recommendations provided by an independent peer review of the strategy