Report for Westinghouse Hanford Company: Makeup procedures and characterization data for modified DSSF and modified remaining inventory simulated tank waste

The majority of defense wastes generated from reprocessing spent reactor fuel at Hanford are stored in underground Double-Shell Tanks (DST) and in older Single-Shell Tanks (SST). The Tank Waste Remediation System (TWRS) Program has the responsibility of safely managing and immobilizing these tank wastes for disposal. A reference process flowsheet is being developed that includes waste retrieval, pretreatment, and vitrification. Melter technologies for vitrifying low-level tank wastes are being evaluated by Westinghouse Hanford Company. Chemical simulants are being used in the technology testing. For the first phase of low-level waste (LLW) vitrification simulant development, two waste stream compositions were investigated. The first waste simulant was based on the analyses of six tanks of double-shell slurry feed (DSSF) waste and on the projected composition of the wastes exiting the pretreatment operations. A simulant normalized to 6 M sodium was based on the anticipated chemical concentrations after ion exchange and initial separations. The same simulant concentrated to 10 M sodium would represent a waste that had been concentrated by evaporation to reduce the overall volume. The second LLW simulant, referred to as the remaining inventory (RI), included wastes not included in the DSSF tanks and the projected LLW fraction of single-shell tank wastes