Batch Tests with IONSIV IE-911 and a Simulant of the Savannah River Site ''Average'' Supernatant: Distribution Ratios vs Time

The Department of Energy (DOE) is required by law to treat and safely dispose of the radioactive wastes from its nuclear weapon production activities. The primary radionuclide in the DOE liquid wastes or supernatants is {sup 137}Cs. At the Savannah River Site (SRS), the In-Tank Precipitation (ITP) process was selected as the baseline technology to remove {sup 137}Cs from the supernatants, which are stored in underground storage tanks. In the ITP process, tetraphenylborate reacts with the water-soluble cesium to form a precipitant. The treated supernatant can then be immobilized in grout or saltstone and stored in vaults at the SRS. However, problems were encountered during the full-scale ITP processing. These difficulties have led to the evaluation of alternative technologies and/or concepts to the currently configured ITP process. The High-Level Waste Salt Disposition Team at the SRS is currently performing this assessment. After an initial screening of all potential alternatives, the Salt Disposition Team selected four primary options to evaluate further before the final down-selection. Crystalline silicotitanate (CST), an inorganic ion exchanger, was chosen as one of the leading alternatives. Since nearly all of the CST tests have been performed on supernatants from Hanford and Oak Ridge, the Salt Disposition Team has requested that personnel at the SRS and Oak Ridge National Laboratory (ORNL) determine the performance of the engineered form of CST, IONSIV{reg_sign} IE-911, with actual and simulated SRS supernatants