Removal investigation of N,N-dialkylamide degradation products by ion-exchange resin

Suzuki, Shinichi; Kobayashi, Toru ; Yaita, Tsuyoshi

The amide compounds like N,N-dialkylamide showed good performance to recover actinide from spent nuclear fuels. The extraction properties of actinide elements with these amide compounds were investigated by lots of researchers. One of the most important properties of above organic compounds for adapting nuclear fuels cycle is stability for radiation of actinide and fission products. The items to examine in a radiolysis study are evaluation of (1) stability of organic compounds themselves, (2) influence of degradation products to decontamination factor, and (3) removal degradation products from organic phase. In this study removal investigation of carboxylic acid and secondary amine as N,N-dialkylamide degradation products are carried out. As a result of above treatment, the carboxylic acid was removed easily by scrubbing with alkaline solution like NaOH solution. However secondary amine could not remove by alkaline scrubbing, these compounds remained in organic phase. Furthermore, secondary amine extracted some fission products which stand for decrease of decontamination factor. So we studied secondary amine recovering with inorganic ion-exchange resin. An investigated resin were commercial resin having sulfo group like SO. We obtained more than 99% recovery efficiency of secondary amine with sulfo group resin treatment.