Determining the Release of Radionuclides from SRS Tank 12H Waste Residual Solids Following Tank Closure
- Savannah River National Laboratory (SRNL), Aiken, SC (United States)
Eight High Level Waste (HLW) tanks used to store radioactive waste slurries have been emptied and closed at the Savannah River Site (SRS). Performance Analyses (PA) modeling of the release of radionuclides from residual waste solids in these tanks into the environment over extended time periods indicated the most likely risk drivers for environmental contamination. Radionuclide leaching studies were desired to provide additional information regarding the residual waste solubility assumptions used in the models. This report serves to provide equilibrium solubility data for several radionuclides identified as risk drivers and adds to the database of solubility values reported in the previous analogous study with Tank 18F solids. Pore water leaching studies were conducted on actual SRS Tank 12H residual waste solids to support Liquid Waste tank closure efforts and closed tank Performance Analyses. Tank 12H was exposed to extensive mechanical cleaning, caustic aluminum dissolution, and oxalic acid chemical cleaning prior to closure. The methodology utilized for leach testing was developed during previous testing. Slurries of tank residual solids and grout-representative solids in simulated grout pore water solutions (based on SRS groundwater compositions) with pH and Eh values expected during the aging of the closed waste tank were produced. The soluble concentrations of selected radionuclides were analyzed versus time to confirm equilibrium conditions were achieved. These are the first leach studies conducted on waste tank residuals exposed to these cleaning conditions.
- Research Organization:
- Savannah River Site (SRS), Aiken, SC (United States)
- Sponsoring Organization:
- USDOE Office of Environmental Management (EM)
- DOE Contract Number:
- AC09-08SR22470
- OSTI ID:
- 1475274
- Report Number(s):
- SRNL-STI-2018-00484
- Country of Publication:
- United States
- Language:
- English
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