Evaluation of the charactristics of metal nitrate aqueous solutions by microwave heating and the morphologies of synthesized metal oxide powders

Segawa, Tomoomi ; Kawaguchi, Koichi  ; Ishii, Katsunori ; Suzuki, Masahiro ; Fukasawa, Tomonori*; Fukui, Kunihiro*

In the reprocessing process of spent fuels, a mixed solution of uranyl nitrate and plutonium nitrate is converted into mixed oxide powders by the microwave heating. To evaluate the applicability to the macro-scale based on the knowledge obtained in the laboratory-scale experiments, the microwave heating characteristics and metal oxide powder morphologies using a cerium nitrate, copper nitrate and cobalt nitrate aqueous solution were investigated. It was revealed that the denitration rates and the average particle sizes of the products increased in the order of the cerium nitrate aqueous solution, cobalt nitrate aqueous solution, and copper nitrate aqueous solution, and the denitration rate tends to increase at the periphery position and the average particle size at the center position.