Treatment options and flow sheets for ORNL low-level liquid waste supernate

Low-level liquid waste (LLLW) is currently contained in ten 50,000-gal storage and process tanks at Oak Ridge National Laboratory (ORNL) and as residual heels in an number of older tanks that are no longer in active use. Plans are being formulated to treat these wastes, along with similar LLLW that will be generated in the future, to yield decontaminated effluents that can be disposed of and stable solid waste forms that can be permanently stored. The primary purpose of this report is to summarize the performance of the most promising separations processes that are appropriate for treatment of the LLLW supernate solution to remove the two dominant radionuclides, 137Cs and 90Sr; to indicate how they can be integrated into an effective flowsheet; and to estimate the expected performance of such flowsheets in comparison to waste treatment requirements