Preparation of Feedstock for Uranium and Plutonium Mixed Oxide Fuels Containing Minor Actinides by Microwave Heating

To prepare a feedstock of U and Pu mixed oxide (MOX) fuel powder containing minor actinides (MA), MA was recovered from high-level liquid waste derived from irradiated fast reactor fuel using extraction chromatography.The recovered MA nitrate solution was then mixed with U and Pu nitrate solution, and MOX fuel powders containing MA were prepared using microwave heating.In addition to these powders, another MOX fuel powder was prepared without adding the MA nitrate solution.Both samples were characterized using X-ray diffraction (XRD) analysis.The XRD results revealed differences in the MOX fuel powders prepared with and without adding MA nitrate solution.These differences are attributed to the presence of U hydroxides in both types of MOX fuel powders.Overall, this study provides basic experimental data on the denitration behavior and characteristics of MA-bearing MOX fuel powders.Further investigation is needed to better understand these processes, and denitration conditions need to be optimized for the efficient preparation of MA-bearing MOX fuel powders.