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Issues for the Tank Waste Committee Hanford Advisorary Board October 10, 2006

Issues for the Tank Waste Committee Hanford Advisorary Board October 10, 2006. Inadequate Characterization/ Groundwater Issues. Ongoing degradation of groundwater due to past tank leaks, absence of RCRA Corrective Action

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Issues for the Tank Waste Committee Hanford Advisorary Board October 10, 2006

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  1. Issues for the Tank Waste CommitteeHanford Advisorary BoardOctober 10, 2006

  2. Inadequate Characterization/Groundwater Issues • Ongoing degradation of groundwater due to past tank leaks, absence of RCRA Corrective Action • Groundwater contamination has yet to be officially attributed to an Individual tank leak • None of the larger tank leaks have been adequately characterized • Soil samples have not been acquired in any of the areas with ongoing migration of radionuclides • Questionable estimates of past tank leaks (RPP-23405)

  3. Tank Farms located in 200 East(Figure from DOE/ORP-2005-1)

  4. Ongoing degradation of groundwater due to past tank leaks

  5. Handbook of Groundwater Protection and Cleanup Policies for RCRA Corrective ActionEPA530-R-04-030

  6. PNNL Annual Groundwater MonitoringB-BX-BY WMA and Surrounding Waste Sites1995 through 2000 • Five year gap in the mapping of the uranium groundwater plume. • ~10 metric tons of U lost to soil at tank BX-102 in 1951 • ~1.5 metric tons of U discharged to Cribs and Trenches

  7. Development of the Uranium Groundwater Plume in the B-BX-BY Area

  8. Characterization Results for the B-BX-BY WMA and Surrounding Waste Sites Fails to Explain the Presence of Uranium in Groundwater • Anthropogenic uranium in the vadose zone was not detected within 190 feet of groundwater at the liquid waste sites • BY Cribs (DOE/RL-92-70, DOE/RL-2002-42, DOE/GJO-2003-458-TAC) • 216-B-7A & 7B Cribs (DOE/GJO-2002-343-TAR and DOE/RL-2002-42) • 216-B-8 Crib (DOE/GJO-2002-343-TAR) • Modeling results for the waste sites suggest that uranium will not reach groundwater for hundreds of years (DOE/RL-2002-42) • Characterization of the B-BX-BY WMA (RPP-10098) suggested that the source of uranium in groundwater was from the nearby liquid waste sites

  9. Visualization of 238U Vadose ZoneData in the B-BX-BY WMA Area(Figure from DOE/GJO-2003-545-TAC, which has never been issued)

  10. Borehole 299-E33-41 Comparisonof Geophysical Logging Runs(Figure from CTUIR-DOSE) • Logged in 1991, 1997, 2002 and 2006 • Significant influx of uranium contamination between log depths of 120 and 247 ft • Influx occurred between 1991 and 1997 • 2006 results have not been released • Reference: DOE/GJO-2002-343-TAR)

  11. Uranium concentrations tripled between 1997 and 2006 at 299-E33-18(Figure from Rick McCain, The S.M. Stoller Corp.) • Logged in 1992, 1997, 2002 and 2006 • Uranium not detected in 1992 • Influx of uranium occurred between 1992 and 1997 • Uranium detected in 1997 and 2006 at log depths between 232 and 264 ft

  12. Uranium Vadose Zone Plume Map for the BX-102 Tank Leak (from CTUIR-DOSE)

  13. Uranium Vadose Zone Plume Map for the BX Tank Farm (modified from RPP-10098)

  14. Visualization of Uranium Vadose Zone Plume for the BX-102 Tank Leak(Figure from DOE/GJO-2002-343-TAC)

  15. B-BX-BY FIR underestimates extent of uranium contamination

  16. Uranium Concentrations in Groundwater Samples From Wells in Vicinity of B-BX-BY Waste Management Area (PNNL 11826)

  17. Uranium Vadose Zone and Groundwater Contamination from the BX-102 Tank Leak(Figure from DOE/GJO-2003-545-TAC, which has never been issued)

  18. BX-102 Tank Leak • The 1951 uranium spill at tank BX-102 is the only identified source of uranium in groundwater based on geophysical logging results of 287 boreholes ( ~70,000 individual measurements) • Based on log data, uranium concentrations in the deep vadose zone increased in boreholes 299-E33-41 and 299-E33-18 between 1991 and 2006 • A southeastnorthwest-trending uranium plume has developed in the groundwater since 1993 • DOE’s failure to identify the source of uranium in groundwater casts doubt upon the characterization/remediation efforts at Hanford and the validity of risk modeling • No short terms goals for RCRA Corrective Action

  19. C Tank FarmSpecific Conductance

  20. Cobalt-60 in deep vadose zone at C tank Farm

  21. Ongoing Migration of Co-60 Since 1978 at 30-08-02 (near Tank C-108)(Figure fromDOE/GJO–2003–400–TAC)

  22. C Tank Farm • C Tank Farm is the source of the recent Tc-99 groundwater plume • Groundwater monitoring network lacks upgradient well • Co-60 detected in vadose zone outside of the fence line • Ongoing migration of radionuclides in the vadose zone • Insufficient characterization for closure

  23. IssuesTank Leak Volume Estimates(RPP-23405, Rev. 1) • Inconsistent tank leak criteria • Reduction of documented leaks without a technical basis • Multiple leaks from a tank • Highest gamma activity results not considered • Minimum leak detection volume • Tank leaks attributed to surface spills • Misuse of krigging estimates • Dismissal of the Historical Leak Model (HNF-3233)

  24. Inconsistent tank leak criteria • Evidence of a tank leak (RPP-23405) • Cs-137 activities greater than 10,000 pCi/g • Below base of tank • Inconsistent with field results • Maximum Cs-137detected with SGLS near bases of SX-115 and SX-113 are less than 10 pCi/g • 50,000 gallons lost at SX-115 • More than 15,000 gallons lost at SX-113

  25. Evidence of tank leaks not always considered in RPP-23405 • Radionuclides other than Cs-137 • Co-60, Eu-152, Eu-154, Nb-94, Sb-125, Sn-126, U-235, and U-238 • Lower levels of Cs-137 (i.e. TY-102) • Logging anomalies on gross gamma data

  26. Reduction of documented leak volumes without a technical basis • RPP-23405 estimates 1,000 gallon leak SX-112 • ARH-R-43 is not discussed or referenced in the section on SX-112 in RPP-23405 • ARH-R-43 is listed as reference in RPP-23405 • ARH-R-43 reported a leak of 30,000 gallons from SX-112 based on: • Liquid level measurements • Soil radiation readings

  27. Multiple leaks from a tank • Represented as single event • Volume from one leak event represented in RPP-23405 • Examples • A-105 • Reported as a 1,000 gallon leak in RPP-23405 • Unstable liner resulted in 26 “suck back occurrences” (ARH-78) not discussed in RPP-23405 • Gross gamma logging results for the laterals (RPP-26705) • Maximum estimated Cs-137 encountered was 34 million pCi/g • SX-113 • Volume “well documented” according to RPP-23405 • 1958 leak event (HW-56972) • 1962 leak test • Only the 15,000 gallon leak from the leak test is reported in RPP-23405

  28. Highest Gamma ActivityResults Not Considered • Activities greater than 10,000 pCi/g below base of tank criteria for a tank leak according to RPP-23405 • Examples where RPP-23405 should have developed leak estimates • B-105 (20-05-06 and 20-06-06) • TX-114 (51-14-04) • BX-110 (21-10-05)

  29. Cs-137 Described as “Isolated Narrow Band” in RPP-23405, Rev. 1

  30. Tank BX-110Description of 21-10-05

  31. Minimum Leak Detection Volume • Assumed as 1,000 gallons in RPP-23405 • De-Minimus leak volume estimate (Appendix A, RPP-23405) • 5,000 gallons • Issues • Differences in stratigraphy underneath the tanks • Number of drywells • Depth of drywells • Location of tank leak • Based on moisture measurements instead of gamma activity which was actually measured • In-tank levels reported to nearest inch for many years • Waste transfers reported to nearest 1,000 gallons (HW-83906) • One inch change in a 75 ft diameter tank is ~2750 gallons (HW-83906) • Maximum permissible leak was 50,000 gallons (HW-68661)

  32. Misuse of Krigging Estimates • BY Tank Farm • SX Tank Farm • IPEP’s review of krigging estimate (HNF-5782) is ignored • Gross gamma logging results for the laterals (RPP-26705) • Maximum estimated Cs-137 encountered was greater than 200 million pCi/g • Upper limit for Cs-137 detected by HRLS in drywells had appeared to be 100 million pCi/g • Krigging based on data from HNF-5782 underestimates leak volumes in SX tank farm • Upper limit for Cs-137 appeared to be ~50 million pCi/g (under SX-107)

  33. Tank Leaks Attributed to Surface Spills • BY Tank Farm • RPP-23405 claims Co-60 detected below base of tanks is from the surface • This claim is not supported by SGLS data (i.e. 22-12-03) • Co-60 detected between 3 and 15 ft bgs is unrelated to Co-60 detected below 83 ft bgs

  34. Historical Leak Model (HNF-3233) • Premature dismissal by HNF-4756 • Recent logging results (RPP-26705) may validate estimates in HNF-3233 • Maximum Cs-137 in laterals under SX-108 was estimated (HNF-5782) at between 5 and 50 million pCi/g versus 200 million pCi/g (RPP-26705) • RPP-6285 estimates based on krigging may be an order of magnitude low for SX-108 • Field data tend to support HNF-3233 tank leak estimates

  35. Conclusions • Tank Farms are the source of recent groundwater plumes in 200 East, absence of RCRA Corrective Action • DOE’s failure to identify the source of uranium in 200 East groundwater casts doubt upon the characterization/remediation efforts at Hanford and the validity of risk modeling • Soil samples have not been acquired in any of the areas with ongoing migration of radionuclides • RPP-23405 provides questionable estimates of past tank leaks. Unsupported estimates from RPP-23405 should not be used in any risk modeling • Historical Leak Model (HNF-3233) estimates should be used as an upper limit for SX tank leaks

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