Molecular design of N,N-dialkyl monoamide for selective separation of U(VI)

6価ウラン選択分離のためのN,Nージアルキルアミドの分子設計

鈴木 伸一; 小林 徹 ; 塩飽 秀啓   ; 矢板 毅

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

The developments of more effective process for uranium and plutonium were investigated from 1980's. These attempts based on Purex process that focused on re-tuning condition of process running, development of new extractors and reductant of Pu valence control were carried out by lots of researchers. These developments for Purex process did not work on a fundamental solution to problems caused by TBP properties. We started ligand design to be elimination of disadvantages of TBP from process developments. In our group, an innovative chemical separation process is proposed for the recovery of all actinide from spent nuclear fuel. One of the main purposes of this process is selective isolation of uranium with branched alkyl type N,N-dialkyl monoamide(BAMA) and the other is all actinide recovery with hetero donor ligand, phenanthroline amide(PTA), which composed oxygen and nitrogen atoms.Since BAMA has the steric hindrance on the complexation with metal cations, BAMA can be used to separate An(VI) from An(IV). The most bulky BAMA, N,N-di-(2-ethyl)hexyl-(2,2-dimethyl)propanamide (DMPA), can recover U(VI) selectively with high decontamination factor (DF). However DMPA can separate uranium(VI) from plutonium(IV), DMPA is poor U(VI) loading for organic phase, contrary to our expectation. In this presentation, we will report the extraction behavior of An(VI) by branched N,N-di-alkyl monoamides(BAMA) for the transmutation of minor actinides.