Development of advanced reprocessing system using high selective and controllable precipitants, 4; Examination of Pu precipitation by new precitpitants

Kim, S.-Y.; Kawata, Yoshihisa; Morita, Yasuji  ; Ikeda, Yasuhisa*; Nishimura, Kenji*

Precipitation behavior of Pu with pyrrolidone derivatives of N-n-butyl-2-pyrrolidone (NBP), N-propyl-2-pyrrolidone (NProP) and N-iso-butyl-2-pyrrolidone (NiBP) in the solutions of only Pu and U-Pu mixture has been examined in order to evaluate their applicability to the selective U precipitation process in the reprocessing based only on precipitation method. We have previously developed a process with N-cyclohexyl-2-pyrrolidone (NCP). It was found that the precipitation ability of NBP, NProP and NiBP is lower than that of NCP and the lower co-precipitation and faster re-dissolution of Pu(IV) in the mixed solution of U(VI) and Pu(IV) was obtained in the precipitation with NBP, NProP and NiBP than with NCP. From these results, it is expected that those new precipitants would make the selective U precipitation process more selective and effective.