Analysis of Curium in MOX Fuel Irradiated in Fast Reactor

Osaka, Masahiko  ; Osaka, Masahiko  ; Koyama, Shinichi  ; Mitsugashira, Toshiaki

Cm isotopes formed in irradiated MOX fuel in the experimental fast reactor JOYO were analyzed by applying a sophisticated radiochemical technique. Cm was isolated from the irradiated fuel by anion ion-exchange chromatography using a mixed medium of nitric acid and methanol. The isotopic ratio of Cm and its content were determined by thermal ionization mass spectroscopy and alpha-spectrometry, respectively. U, Pu, Am and Nd were also isolated and analyzed for the determination of the Cm content and burnup. The Cm content was less than 0.004 at.%, which is much smaller than that of PWR-MOX at 60 GWd/t. On the basis of the present analytical results, the transmutation behavior of Cm isotopes in a fast reactor was discussed from various viewpoints. Transmutation speeds of Cm isotopes were estimated; the speed for 246Cm, which is known to be a key nuclide in the transmutation of Cm, was smaller than the previously reported value. Transmutation behavior of each Cm isotope was also eval