Dissolution kinetics of CeO2 powders with different morphologies and analogy to PuO2 dissolution

Several CeO2 powders with different morphologies were synthetized thanks to four different processes (two at the laboratory by sol-gel and oxalic routes and two commercial powders). These powders were divided into five batches each and calcined at several temperatures. Thus, twenty different powders were made, each possessing different structural or morphological properties. After a thorough characterization of the 20 powders, this work is dedicated to the study of their dissolution in nitric acid using the same experimental conditions to exhibit the morphology effect on dissolution kinetics. Significant differences in dissolution kinetics were observed meaning that the morphology of the powders was found to be a key parameter that has to be considered in studies of dissolution kinetics. The effect of the morphological parameters on dissolution kinetics was quantified and a kinetics law was established and then, applied with success to PuO2 dissolution.