Preliminary laboratory investigation for the removal of radioactive cesium from Purex aqueous waste solutions

The laboratory work reported in this paper showed that cesium can be removed from current acid waste (CAW) by first removing strontium and rare earth by solvent extraction then passing the resulting 1AW solution through an ion exchange column containing a zeolite. The method for removing strontium and rare earth by solvent extraction is well documented and is not discussed here. Zeolon-900, a synthetic zeolite made by Norton Company, had the highest affinity for cesium of the ion exchangers tested. Maximum cesium absorption occurred between pH 4.0 and pH 8.5. The absorption of cesium from CAW or 1AF was lower than that observed with 1AW. 1AF is B Plant solvent extraction feed made from CAW. 1AW is waste raffinate from solvent extraction. Laboratory ion exchange column runs showed five percent cesium breakthrough occurred at 92 column volumes. Decontamination factors of 1.17 x 104 and 2.92 x 103 were found for aluminum and iron, respectively, during a laboratory column run. Sodium decontamination factors were not measured for these runs; however, Nelson, Alkaire, and Mercer found the decontamination of sodium from cesium during the processing of acid wastes was 1 x 104