Development of asymmetry N-alkyl- N'-alkylamide extractants for nuclear fuel reprocessing

Suzuki, Shinichi; Kobayashi, Toru ; Shiwaku, Hideaki   ; Yaita, Tsuyoshi

It is necessary for the development of the substitute extractant of tri-butyl phosphate (TBP) to improve selectivity and extraction ability for U(VI) and Pu(IV). Furthermore, it is necessary to improve the solubility to the organic solvent of U(VI) and/or Pu(IV)- amide complex. Amine, amide and ether extractants which introduced the alkyl long chain into were developed by such a point of view, and a large amount of research about the extraction of U(VI) and Pu(IV) were performed energetically. In addition, radiolysis and hydrolysis stability of each extractants has been studied. As a result wide research work, N,N-substituted amide compound became the candidate of the substitute compound of TBP1). It is an advantage that N,N-dialkylamide compounds are able to completely burn up by abolished solvent processing(CHON principle)2,3). In this study, we evaluated extractability of uranium and plutonium using the asymmetry N-alkyl-N-alkyl amide compounds which introduced two different alkyl substituents into nitrogen of amide.