Study on radiation resistance of polyvinylpolypyrrolidone for adsorption of U and Pu

Nogami, Masanobu*; Sugiyama, Yuichi*; Kawasaki, Takeshi*; Harada, Masayuki*; Ikeda, Yasuhisa*; Kikuchi, Toshiaki*; Kawata, Yoshihisa; Morita, Yasuji  

In the novel reprocessing system under development for spent FBR fuels based on the precipitation method, U and Pu of very low concentrations remain in the supernatant after almost all U and Pu in the dissolvent solution are separated by precipitation. The remaining U and Pu are supposed to be removed by an adsorption method using polyvinylpolypyrrolidone (PVPP) which is insoluble in water. In this study, stability of PVPP in HNO solutions under -ray irradiation was investigated. As the result, remarkable decreases in the capacity were not found in all samples. Or rather, the capacity was found to be increased for the sample irradiated in 6M HNO for 0.90 MGy. These facts revealed that PVPP maintains the adsorptivity to U(VI) under various concentrations of HNO for 10 days of operation under -ray irradiation.