Long-Term Performance Monitoring of Metals and Radionuclides in the Subsurface at the Hanford Site. Thomas W. Fogwell, Ph.D., P.E.

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1 Long-Term Performance Monitoring of Metals and Radionuclides in the Subsurface at the Hanford Site Thomas W. Fogwell, Ph.D., P.E. 21 April 2004

2 The Hanford Site

3 Overview of the Hanford Site

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5 Facility Locations

6 Facilities Overview Facilities Overview 100 Areas located along the south and west shores of the Columbia River. These are the sites of nine retired plutonium production reactors. The 100 Areas occupy a total of ~11 square kilometers (~4 square miles). 200-West and 200-East Areas centrally located on a plateau. These areas are ~8 and 11 kilometers (~5 and 7 miles), respectively, south and west of the Columbia River. These areas house facilities that received and dissolved irradiated fuel and then separated out the plutonium. These facilities were called separations plants. The 200 Areas cover a total of ~16 square kilometers (~6 square miles). 300 Area located just north of Richland, Washington. From the early 1940s until the advent of the cleanup mission, most research and development at the Hanford Site were carried out in the 300 Area. The 300 Area was also the location of nuclear fuel fabrication. This area covers ~1.5 square kilometers (~0.6 square mile).

7 Facilities Overview (cont.) 400 Area located northwest of the 300 Area. The 400 Area is the location of the Fast Flux Test Facility, which is scheduled for deactivation during This nuclear reactor was designed to test various types of nuclear fuel. The 400 Area covers ~0.61 square kilometer (~0.23 square mile). 600 Area includes all of the Hanford Site not occupied by the 100, 200, 300, and 400 Areas. Former 1100 Area located generally between the 300 Area and the city of Richland covering an area of 311 hectares (768 acres). On October 1, 1998, this area was transferred to the Port of Benton as a part of DOE s Richland Operations Office economic diversification efforts and is no longer part of the Hanford Site. However, DOE contractors continue to lease facilities in this area.

8 Central Plateau

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11 Preliminary Regional Closure Zone Priorities Number of CLOSURE ZONE Locations See Figures 1-1 through 1-3) Requiring Closure 1 Zone does not support Hanford cleanup operations U Plant Zone 103 Non Radioactive Disposal Waste Landfill and BC Cribs 37 Future Groundwater Contamination Concerns Intrusion Concerns (TRU Waste Residuals) Radiological Cleanup Operations Concerns 99 Tc, U, 129 I U - 99 Tc, 129 I - - (NRDWL/BC) Control Zone PUREX Zone I, H 3 Pu Pu, Cs, Sr Plutonium Finishing Plant (PFP) Zone 133 Pu, CCl 4 Pu Pu C Farm Zone Tc Pu Pu, Cs, Sr B Farm Zone Tc, U, 129 I Pu Pu, Cs, Sr T Farm Zone H, 99 Tc, 129 I Pu Pu, Cs, Sr & 11 Zone 4 3 H - Pu, Cs, Sr Fast Flux Test Facility Zone Semi-Works Zone 48 - Pu Pu, Cs, Sr 200 West Ponds Zone 37 U Pu - Zone supports Hanford cleanup operations & opportunities exist to alter plans and allow earlier cleanup B Plant Zone Sr, 137 Cs, Pu - Cs, Sr East Ponds Zone Tc, 90 Sr, 129 I - - Zone supports Hanford cleanup operations Reduction Oxidation (REDOX) Zone I, 3 H Pu Pu, Cs, Sr T Plant Zone H, CCl 4 Pu Pu, Cs, Sr Waste Management Zone Tc, U Pu Pu S/U Farms Zone Tc, U Pu Pu, Cs, Sr Environmental Restoration Disposal Facility (ERDF) Waste Treatment Plant and A Farm (WTP/A Farm) Zone H, 99 Tc Pu Pu, Cs, Sr Solid Waste Zone Pu Pu Immobilized Low Activity Waste (ILAW) Zone 3 99 Tc, U, 129 I East Administrative Zone Area Effluent Treatment Facility (ETF) Zone Canister Storage Building (CSB) Zone

12 Past Tc-99 Release (Ci), through 2003 Potential Tc-99 Release (Ci), , with and without covers NRDWL-BC_Control WM SU_Farm T_Farm U_Plant WTP_ETF_A_C_Farm B_Farm Semi-Works REDOX ERDF PUREX T_Plant B_Plant 200W-Ponds 200E-Ponds PFP Past Release to Groundwater Release with Early Covers Additional Release without Covers

13 Past Uranium Release (Ci), through 2003 Potential Uranium Release (Ci), , with and without covers B_Farm T_Farm SU_Farm WTP_ETF_A_C_Farm 200E-Ponds 200W-Ponds PUREX U_Plant REDOX Semi-Works B_Plant WM T_Plant PFP ERDF NRDWL-BC_Control Past Release to Groundwater Release with Early Covers Additional Release without Covers

14 Tc-99 at Zone Boundary with no Covers NRDWL-BC_Control 200E-Ponds 200W-Ponds pci/l WTP_ETF_A_C_Farm Drinking Water Standard U Plant WM T Farm Calendar Year B_Farm B_Plant ERDF NRDWL-BC_Control PFP PUREX REDOX Semi-Works SU_Farm T_Farm T_Plant U_Plant WM WTP_ETF_A_C_Farm

15 Calendar Year Tc-99 at Zone Boundary with Covers NRDWL-BC_Control 200E-Ponds 200W-Ponds B_Farm 2500 B_Plant WTP_ETF_A_C_Farm ERDF pci/l T Farm SU Farm Drinking Water Standard NRDWL-BC_Control PFP PUREX REDOX Semi-Works 1000 SU_Farm U Plant T_Farm 500 T_Plant U_Plant WM WTP_ETF_A_C_Farm

16 Tc-99 Reduction due to Covers pci/l NRDWL-BC_Control Semi-Works WTP_ETF_A_C_Farm SU_Farm U Plant WM Calendar Year 200E-Ponds 200W-Ponds B_Farm B_Plant ERDF NRDWL-BC_Control PFP PUREX REDOX Semi-Works SU_Farm T_Farm T_Plant U_Plant WM WTP_ETF_A_C_Farm

17 Uranium at Zone Boundary, no Covers pci/l 30 Drinking Water Standard E-Ponds 15 B Plant 10 5 PUREX Calendar Year 200E-Ponds 200W-Ponds B_Farm B_Plant ERDF NRDWL-BC_Control PFP PUREX REDOX Semi-Works SU_Farm T_Farm T_Plant U_Plant WM WTP_ETF_A_C_Farm

18 Uranium at Zone Boundary with Covers pci/l 30 Drinking Water Standard B Plant E-Ponds 5 PUREX Calendar Year 200E-Ponds 200W-Ponds B_Farm B_Plant ERDF NRDWL-BC_Control PFP PUREX REDOX Semi-Works SU_Farm T_Farm T_Plant U_Plant WM WTP_ETF_A_C_Farm

19 Uranium Reduction Due to Covers E-Ponds B Farm 200E-Ponds 200W-Ponds B_Farm B_Plant pci/l ERDF NRDWL-BC_Control PFP PUREX REDOX Semi-Works SU_Farm T_Farm 1 S/U Farm T_Plant U_Plant WM WTP_ETF_A_C_Farm Calendar Year

20 Max Reduction in Tc-99 Due to Covers NRDWL-BC_Control WM WTP_ETF_A_C_Farm SU_Farm Semi-Works U_Plant T_Farm REDOX PUREX ERDF T_Plant B_Plant 200E-Ponds 200W-Ponds PFP B_Farm 3730 (2340) 2950 (2170) 2010 (2200) 1860 (2150) 1550 (2240) 1250 (2220) 260 (2280) 48 (2200) 38 (3000) 12 (2260) 1.3 (2050) 1.1 (2035) (2130) (2260) (2800) (2005) (2110) Concentration (pci/l)

21 Max Reduction in Uranium Due to Covers 200E-Ponds B_Farm SU_Farm WTP_ETF_A_C_Farm T_Farm B_Plant 200W-Ponds PUREX Semi-Works U_Plant REDOX T_Plant WM PFP ERDF NRDWL-BC_Control 1.6 (3000) 0.62 (3000) 0.39 (3000) 0.28 (2060) 0.18 (2900) (2900) (2700) (3000) (2900) 2.9E-06 (3000) 2.8E-06 (3000) 1.7E-09 (3000) Concentration (pci/l) 9.6 (2130) 7.8 (2800)

22 Types of Conditions Needing VZ Monitoring Waste Sites (Cribs and Trenches) Tank Farm Sites Canyon Buildings (Reactor buildings) Disposal Facilities (ERDF and IDF) Liquid Effluent Retention Facilities Low-Level Burial Grounds

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24 Background Over 1600 liquid and solid waste sites, including 12 tank farms Some 200 Burial Sites covering over 800 Acres are required for waste site closure Uncertainties in field-scale performance require long-term data to demonstrate performance robust, long-lived monitoring technologies resolution of S&T issues (e.g., models, storage capacity, stability, side-slopes) Uncertainties in performance and stewardship

25 Surface Barrier Research Activities at the Hanford Site at the Hanford Site Engineered Barrier Test Facility Hanford Defense Waste EIS On-Site Experience Recharge Studies (e.g. BWTF) Barrier Development Team and Program Field Lysimeter Test Facility (FLTF) Peer and Value Engineering Reviews Prototype Surface Barrier (PSB) 1994-Present Focused Feasibility Study FLTF (more than 16 years of data) PSB (more than 9 years of data)

26 Recharge Studies of Deep Soils Buried Waste Test Facility (BWTF) in the 300 Area Screened Hanford sands 5.9 m 2 lysimeter, 7.6 m deep No plants Average Drainage = 55 mm/yr (8 yr period)

27 Hanford Site Water Balance Estimated Range of Annual Recharge

28 Functional Performance Requirements Function in an arid to sub-humid climate Isolate waste for a minimum of 1000 years Be maintenance free Limit deep drainage of water through the waste to 0.5 mm/yr (1.6E-9 cm/s) Minimize the likelihood of plant, animal, and human intrusion Minimize erosion-related problems Meet or exceed RCRA cover performance requirements Limit exhalation of noxious gases and upward diffusion of soluble contaminants

29 Field Lysimeter Test Facility (FLTF; ca. 1988)

30 Field Lysimeter Test Facility (October 2003) Hanford Barrier Eroded Hanford Barrier New Test Matrix Gravel Mulch Pitrun Gravel Ambient precipitation Basalt Sideslope Sandy Gravel Sideslope Hanford Barrier w/dune Sand Sand Dune Migration Modified RCRA Subtitle C Cover Glass WasteForm Tests D1 D2 D3 D4 D5 D6 D7 W1 W2 C1 C2 C3 C4 C5 C6 D8 D9 D10 D11 D12 D13 D14 W3 W4 Enhanced precipitation

31 raised surface with adequate slope to promote runoff protective side slopes minimum footprint

32 Prototype Surface Barrier (vertical cross-section) section)

33 Rip-rap Side Slope

34 Pit-run Gravel Side Slope

35 Treatability Tests

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37 Current Monitoring Scope Long Term Performance Monitoring Water balance monitoring Vegetation and animal use surveys Stability surveys settlement surface topography riprap side slope stability

38 Example Designs for ET Covers ET- Monofill ET- Capillary Break ET- Imperm ET- Capillary Break- Imperm Soil Roots Roots Roots Roots Sand/Gravel Filter Gravel Imperm (asphalt/hdpe) Capillary Break - discontinuity in hydraulic conductivity when the soil is unsaturated e.g., Silt loam/ sand; Sand/gravel; Gravel/silt loam

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52 VZ Monitoring Technologies Quantities to Measure Moisture change Neutron Probes Time Domain Reflectometry [TDR] Thermocouple Psychrometer Electromagnetic Induction [EMI] Electrical Resistivity Tomography [ERT] Fiber optic cable

53 Moisture Sampling Methods Suction Lysimeter Absorbent Pads Sodium Iodide Gamma Detector Basin Lysimeter Associated Chemical Analyses

54 Instrumentation Deployment Today Lysimeters (suction and basin) Access tubes various materials easy change of technologies inside landfills barrier monitoring

55 Trends in developing technologies More volume integrating Better sensitivity Better remote sensing [less intrusive]

56 Environmental Restoration Disposal Facility (ERDF)

57 ERDF Cells 1 and 2

58 ERDF Floor Liner Detail

59 Basin Lysimeter Under Secondary Sump

60 Other Facilities and Locations on the Central Plateau Future characterization (COS program) Studies on transport properties of radionuclides Better delineation of extent of contamination and inventories Groundwater monitoring Main constituents (Tc-99, Uranium, I-129, CCl 4 ) Optimizing to achieve better efficiency

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62 Future Vadose Zone Monitoring Beneath TSDs (lysimeters, tubes, etc.) (during operations) Liquid retention ponds (mass balance approaches) Caps and barriers (integrity, survey methods, etc.) (after closure) Protection and monitoring for rapidly decaying constituents Continued characterization

63 Future Development Efforts Continue developing instrumentation and monitoring technology Reduce price of instrumentation and deployment of monitoring technology Increase reliability of instrumentation and monitoring technology Allow current designs to incorporate future technology Better barrier design tools Directions in future technologies deployment (redundancy, developing standards, less intrusive)

64 U.S. Locations of Sites