Conceptual study of in-tank cesium removal using an inorganic ion exchange material

摘要

Presently, the Hanford Site contains approximately 230,000 m(sup 3) of mixed waste stored in 177 underground tanks. Approximately 55,000 m(sup 3) of this waste is sludge, 90,000 m(sup 3) is salt cake, and 80,000 m(sup 3) is supernate. Although the pretreatment and final disposal requirements for the waste have not been entirely defined, it is likely that some supernatant pretreatment will be required to remove (sup 137)Cs and possibly (sup 90)Sr and the transuranic components. The objective of this study was to estimate the number of HLW glass canisters resulting from the use of inorganic ion exchanger materials as in-tank pretreatment technology. The variables in the study were: number of contacts between waste and ion exchange material; ion exchange material; and decontamination requirement. This conceptual study investigates a generic in-tank Cs removal flowsheet using crystalline silico-titanates and IE-96 zeolites, and the impact of each ion exchanger on the number of glass canisters produced. In determining glass formulation, data based on current reference technology was used. Sample calculations from the worksheets and summaries of final calculated results are included at the end of this report.