Electromagnetic field analysis for the development of the microwave heating equipment capable of uniform heating of a metal nitrate aqueous solution and the metal oxide powder with circular polarization control

Segawa, Tomoomi ; Tanigawa, Masafumi ; Kato, Yoshiyuki ; Kawaguchi, Koichi  ; Ishii, Katsunori ; Suzuki, Masahiro ; Kitazawa, Toshihide*; Kashiwa, Tatsuya*

To improve the handling and sinterability of raw powder of a uranium and plutonium mixed oxide produced in the reprocessing process of spent fuels, the microwave heating equipment has been developed considering the microwave property of linear polarization and circularly polarization that contribute to the uniformization of the microwave heating denitration by JAEA. The electromagnetic field simulation analysis was carried out by the Finite-Difference Time-Domain method, and the experimental results were evaluated. An analysis model was developed based on the obtained physical property data which were measured by the cylindrical cavity resonator method. The liquid phase state, microwave was concentrated on the upper surface and bottom surface due to the high loss of the cobalt nitrate aqueous solution, while in the solid phase state, microwave energy was absorbed inside. The absorption electric power distribution became uniform in the circumferential direction.