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Home My WebLink AboutDRC-2025-001889Department of Energy Washington,DC 20585 Via email: thomas.lancaster@nrc.gov Mr. Thomas Lancaster U.S. Nuclear Regulatory Commission Attn: Document Control Desk Mail Stop T8-F5 Washington, DC 20555-0001 Subject: U.S. Department of Energy Office of Legacy Management Status of the Green River, Utah, Disposal Site Groundwater Compliance Action Plan Dear Mr. Lancaster: In a letter dated September 30, 2022, the U.S. Department of Energy Office of Legacy Management (LM) responded to the U.S. Nuclear Regulatory Commission’s (NRC’s) requests for additional information (RAIs) about the Green River, Utah, Disposal Site Groundwater Compliance Action Plan (GCAP). That letter indicated LM was working to develop the information necessary to address the RAIs and complete a revised GCAP for the Green River site in accordance with the standards in NUREG-1724. LM recognizes NRC’s concerns regarding the claim of limited use due to low yield in the Browns Wash alluvium and the protectiveness of institutional controls (ICs) for the Cedar Mountain Formation wells. LM is currently in the planning phase of the Green River site GCAP. A work plan is being developed that will identify data gaps, outline necessary field characterization, and define the steps required to finalize a GCAP. While LM has prioritized several sites that require a GCAP or GCAP revision, LM anticipates submitting a work plan for the Green River site in fiscal year 2026, pending prioritization and funding. A comprehensive plan for the development of the final Green River site GCAP will be shared with NRC once an integrated programmatic GCAP schedule is completed. As a best management practice, LM samples 19 groundwater wells and nine surface water locations at the Green River site annually. See Table 1, for groundwater and surface water locations. The detailed analyte suite can be found in the enclosed table, Constituent Sampling Breakdown. The groundwater monitoring section of the annual inspection chapter addresses only those wells designated in the Long-Term Surveillance Plan (LTSP) for postclosure groundwater monitoring, which include point of compliance (POC) wells 0171, 0173, 0181, and 0813. The LTSP included monitoring well 0172, but its construction integrity was suspect, and the well was replaced with monitoring well 0181 in June 2002. Monitoring well 0181 has been monitored as the replacement POC well since July 2002. Table 2 lists the concentration limits in milligrams per liter (mg/L) for POC wells as established in the LTSP. May 27, 2025 2 Table 1. Sampling Locations at the Green River, Utah, Disposal Site Monitoring Well Locations Surface Water Locations 0171 0526 0173 0710 0176 0711 0179 0712 0180 0718 0181 0720 0182 0801 0183 0846 0184 0847 0185 0188 0189 0192 0194 0582 0588 0707 0813 0817 3 Table 2. LTSP Concentration Limits for POC Wells at the Green River, Utah, Disposal Site Monitoring Well Nitratea (mg/L)Sulfate (mg/L) Uranium (mg/L) 0171 10b 3334 0.044b 0173 10b 4000 0.044b 0181c 102 4985 0.067 0813 10b 4440 0.069 Notes: a Nitrate = nitrate plus nitrite as N. b Maximum concentration limit (Title 40 Code of Federal Regulations Section192, Table 1, Subpart A). c Concentration limits for monitoring well 0181 correspond to those derived initially for monitoring well 0172. Currently, non-POC well data is not reported to NRC. All data is publicly available once it is uploaded to LM’s Geospatial Environmental Mapping System (GEMS); however, if NRC would like to be sent all monitoring data directly, LM would be happy to accommodate that request. Please contact me at (970) 640-4644 or Hallie.Katz@lm.doe.gov, if you have any questions. Sincerely, Hallie Katz Green River Site Manager Enclosure cc w/enclosure via email: George Alexander, NRC Linda Gersey, NRC Bill Frazier, DOE-LM Paul Kerl, DOE-LM William Burns, DOE-LM Meghann Hurt, DOE-LM David Atkinson, RSI David Miller, RSI Jordan Cario, RSI FOLD/20/649 Site Analyte Groundwater Surface Water Required Detection Limit (mg/L) Analytical Method Line Item Code Approx. No. Samples/yr 19 9 Field Measurements Total Alkalinity X X Dissolved Oxygen X X Fe 2+X Redox Potential X X pH X X Specific Conductance X X Static Water Level X Turbidity X X Temperature X X Laboratory Measurements Aluminum Ammonia as N (NH3-N) X X 0.1 EPA 350.1 WCH-A-005 Arsenic X X 0.0001 SW-846 6020 LMM-02 Calcium X 5 SW-846 6010 LMM-01 Chloride X 0.5 SM2320 B WCH-A-045 Chromium Iron X 0.1 SW-846 6010 LMM-01 Lithium X X 0.002 SW-846 6020 LMM-02 Lead Magnesium X 5 SW-846 6010 LMM-01 Manganese X 0.005 SW-846 6010 LMM-01 Molybdenum Nitrate + Nitrite as N (NO3+NO2)-N X X 0.05 EPA 353.1 WCH-A-022 Oxygen Isotopes 0171, 0181, 0183, 0184, 0192, 0194, 0582, 0707, 0817 NA Mass Spectrometry LMW-10 Total Phosphate as P 0526, 0710, 0711, 0712, 0718, 0720, 0847 0.1 EPA 365.1 WCH-A-029 Potassium X 1 SW-846 6010 LMM-01 Selenium X X 0.1 SW-846 6010 LMM-01 Silica Sodium X 1 SW-846 6010 LMM-01 Strontium Sulfate X X 0.5 SW-846 9056 MIS-A-045 Sulfur Isotopes 0171, 0181, 0183, 0184, 0192, 0194, 0582, 0707, 0817 NA Mass Spectrometry LMW-10 Sulfide Total Organic Carbon Uranium X X 0.0001 SW-846 6020 LMM-02 Uranium Isotopes 0171, 0181, 0183, 0184, 0192, 0194, 0582, 0707, 0817 0.1 pCi/L Alpha Spectrometry LMR-02 Zinc Total No. of Analytes 17 8 Green River Note: All analyte samples are considered unfiltered unless stated otherwise. All private well samples are to be unfiltered. The total number of analytes does not include field parameters. Constituent Sampling BreakdownConstituent Sampling Breakdown GRN-FY 2025