Development of advanced reprocessing system using highly selective and controllable precipitant, 16; Examinations of stability of NBP with low hydrophobicity and decomposition mechanism

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

We have been developing an advanced reprocessing system for spent FBR fuels based on precipitation method using pyrrolidone derivatives. In the present study, the durability of N-n-butyl-2-pyrrolidone (NBP) against -irradiation and heat and the mechanism of degradation were examined in the various conditions. NBP is the most promising candidate as the precipitant for the first step in which U is selectively separated. The results showed that many kinds of multi-functional degradation products were formed by irradiation and heating and therefore that the influence of these degradation products on the following step in the reprocessing system should be investigated in detail.