Innovative separation method for advanced spent fuel reprocessing based on tertiary pyridine resin

Abstract

Radiochemical separation experiments have been performed in order to realize a novel reprocessing method based on chromatography techniques using a novel pyridine resin. The newly synthesized tertiary pyridine resin with two functions of ion exchanger and soft-donor was dedicated to the experiments, where highly irradiated mixed oxide fuel from the experimental fast reactor JOYO was used as a reference spent fuel. With a 3-step separation, pure Am and Cm were individually obtained as minor actinide products, and 106Ru group, lanthanides with 137Cs group and Pu group were fractionated, respectively. The decontamination factor of 137Cs and trivalent lanthanides (155Eu, 144Ce) against the Am product exceeded 3.9 × 104 and 1.0 × 105, respectively. The decontamination factor as the mutual separation of 243Cm was larger than 2.2 × 103 against the Am product. Moreover, the content of 137Cs, trivalent lanthanides and 243Cm in Am product did not exceed 2 ppm. The tertiary pyridine resin method is a candidate separation system for an “advanced ORIENT process”, where enhanced separation, transmutation and utilization of actinides, long-lived fission products and rare metal fission product would be oriented.