抄録
Using the difference in vapor pressure between the chlorides of uranium and those of fission products, a chlorination-distillation processing of irradiated uranium dioxide fuel was tried. Cold experiments on a mixture of UO2 and ZrO2, MoO3, CeO2 or ThO2, and on the semi-homogeneous reactor fuel (UO2-C mixture) were carried out with the chlorination agent CCl4 vapor flowing through a quartz reaction tube assembly at various reaction and condensation temperatures. In proper conditions, 98% of Zr, 99% of Mo or 99% of Ce could be separated from U, and 95% of U was recovered from the semi-homogeneous reactor fuel, although the separation of Th and U was not achieved by a single distillation process. Most fission product elements, except Cd and Cs, i.e., Ba, Ce, Eu, I, La, Mo, Nb, Nd, Pr, Sm, Sr, Te, Y and Zr are thought to be separated from U by chlorination-distillation treatment. Hot experiments using irradiated fuel are under way.
