Chlorination-Volatilization Processing of Irradiated Uranium Dioxide, (I)

Abstract

A study was made on the decontamination of F.P. from irradiatcd UO2 fuel by means of a sorption-desorption process using BaC12 bed. A very high degree of decontamination was obtained. Irradiated UO2 pellets were pulverized through a repeated oxidation-reduction process, and then chlorinated with CCl4 vapor at 580°C. The gas containing the vapor of the chlorides formed thereupon was passed through the BaCl2 bed whose temperature varied along its length from 500° to 100°C. The vapor of the chlorides was sorbed on the bed. From this bed, zirconium and niobiutn chlorides were selectively desorbed by maintaining the bed at batween 460° and 480°C in a mixed gas stream of Ar and CCl4 vapor. The uranium chlorides, remaining on the bed, were then desorbed by maintaining the bed at 500°C in a mixed gas stream of Ar, Cl2 and CCl4 vapor. Cesium chloride accomparlied the uranium chlorides in this process. Cerium and ruthenium chlorides remained undesorbed on the bed after both desorption processes. The vapor of uraniu...