Removal of liquid and solid impurities from uranyl nitrate hexahydrate crystalline particles in crystal purification process

Nakahara, Masaumi; Nomura, Kazunori  ; Washiya, Tadahiro ; Chikazawa, Takahiro*; Hirasawa, Izumi*

The purification behavior of uranyl nitrate hexahydrate was investigated to evaluate the decontamination performance of liquid and solid impurities using a dissolver solution of mixed oxide fuel in batch experiments by the sweating and the melt filtration processes. Liquid impurities such as Eu were effectively removed by the sweating method, but solid impurities such as Pu, Cs and Ba were affected a little in the batch experiments. On the other hand, the decontamination factor of Ba increased with 0.45 and 5.0 m filters in the melt filtration process. Although the decontamination factors of Pu and Cs did not change with 5.0 m filter, it increased approximately two-fold with 0.45 m filter. The particle size of CsPu(NO) is a little small and might pass through the 5.0 m filter in the melt filtration process.