Abstract
We report a process for stoichiometric reduction of U3O8 and (U3O8,PuO2) mixed oxide powders using an indigenously developed 2.4 GHz microwave processing system. The process parameters were optimized by interpreting reduction kinetic curves at a temperature which is 150 °C lower than the conventional reduction. The process improved the sinterability of the powder which was evaluated in terms of average particle size, BET specific surface area and bulk density. A quick method for controlled oxidation of the reduced powder to incorporate a controlled amount of hyper-stoichiometry was demonstrated by modifying the same reduction process. The percent reduction was measured experimentally using O:(U + Pu) ratio. The X-ray diffraction analysis confirmed the various phases present. The process is novel considering shorter processing cycle, lower temperature processing, improved powder properties, energy efficiency and cost effectiveness.
•A process for stoichiometric reduction of (U3O8,PuO2) was demonstrated using 2.4 GHz microwave.•A simple and quick method for obtaining controlled hyper-stoichiometry in the reduced powder was successfully demonstrated.•The process is novel relative to conventional methods in terms of time and energy economy and sinter-activity.