THE RECOVERY AND PURIFICATION OF CESIUM FROM PUREX FORMALDEHYDE-TREATED WASTE BY INORGANIC ION EXCHANGE

摘要

A flow sheet is presented for the removal, purification, and concentration of cesium from Purex formaldehyde-treated waste (FTW). Cesium and a small;part of the sodium and hydrogen ions in the waste are adsorbed on the mineral clinoptilolite, while other cations and radionuclides, except Zr95-Nb95 are only slightly adsorbed. The bulk of the sodium and Zr95-Nb95 is removed with an oxalic acid wash and the cesium is subsequently eluted with ammonium carbonate. The ammonium carbonate is removed by volatilization, leaving a relatively pure cesium carbonate solution. Based on labora¬tory-scale experiments with simulated 1965 FTW, decontamination factors for strontium, cerium and ruthenium are 2.1 x 103, > 9 x 104, and > 1.4 x 105, respectively. Sodium DF's of 103 to > 104 are obtained along with a thirtyfold increase in cesium concentration.