ON THE DEPENDENCE OF CHARACTERISTICS OF POWDERS ON THE AUC PROCESS PARAMETERS

The specific surface area and pore distribution of UO2 and U3O8 powders obtained from the calcination of AUC precipitated from uranyl nitrate solutions as a function of calcination temperature and heating rate is studied. It is shown that the specific surface area after calcination is dependent on the heating rate. The decomposition of AUC under identical conditions, but differently precipitated, gives different pore distributions. Also the final densities obtained with this powders in a sintering test are different, suggesting the importance of the contribution of the precipitation conditions on the powder quality. Four samples of different mean particle size separated from an industrial UO2 ex-AUC powder were sintered and showed no relevant differences in their sintering behaviour.