Improvement of DUPIC Pellet Fabrication Processes by Using Simulated Fuel

Abstract

A study to improve the DUPIC pellet fabrication process was carried out using simulated spent fuel. At present, 3 cycles of the OREOX treatment are conducted to convert a spent PWR fuel pellet into sinterable powder. But it takes a long time to treat spent PWR fuel material for 3 cycles of the OREOX treatment. Thus, 1 cycle of OREOX treatment was introduced for improving the powder process. The sinterability of 1 cycle-OREOX treated powder prepared by a simulated spent fuel pellet was investigated in terms of sintering temperature and compacting pressure. And, the effect of TiO₂ addition on the densification and grain growth was investigated. Good pellets with a sintered density of higher than 95% T.D. and average grain size of 8 . were obtained by using 1 cycle-OREOX treated powder. The density and grain size of the sintered pellet increased significantly with the addition of TiO₂.