Development of advanced reprocessing system using high selective and controllable precipitants, 5; Examination of stability of the precipitate against -ray irradiation

Morita, Yasuji  ; Kim, S.-Y.; Ikeda, Yasuhisa*; Nogami, Masanobu*; Nishimura, Kenji*

We have been developing an advanced reprocessing system for spent FBR fuels based on precipitation method using pyrrolidone derivatives. In previous investigation, N-cyclohexyl-2-pyrrolidone (NCP) is used as a precipitant, which is able to precipitate selectively U(IV) in nitirc acid solution, and a process consisting of two separation steps; selective U precipitation step and U-Pu co-precipitation step, was developed. In order to make the process more effective and more economical, we are now studying precipitation of U and Pu with other pyrrolidone derivatives. In the present study, stability of the precipitate against -ray was examined with the U(VI)-NCP precipitate and U-Pu-NCP precipitate. We could not find any specific difference in U dissolution rate between -irradiation and -irradiation.