SECOND – CYCLE AIROX REPROCESSING AND PELLET REFABRICATING OF HIGHLY IRRADIATED URANIUM DIOXIDE

摘要

Uranium dioxide (UO2) irradiated to burnups from 5,700 to 21,000 Mwd/MTU, and AIROX reprocessed and refabricated into pellets, was reirradiated for an additional 10,000 Mwd/MTU. Postirradiation examination has shown that the second-cycle irradiated UO2 behaved similarly to production grade UO2, Some reduction in thermal conductivity may have occurred however. The second-cycle irradiated UO 2 was AIROX reprocessed and refabricated into pellets. Pellet densities, calculated from gas displacement and geometrical measurements, varied from 92 to 97 and from 92 to 95% of theoretical. Water dis placement densities were 96 to 97% of theoretical. Radio chemical analyses indicated that, except for cesium and noble gases, little or no decontamination occurred.