METHOD FOR CONTROLLING CRITICALITY OF NUCLEAR FUEL CYCLE FACILITY, METHOD FOR MANUFACTURING URANIUM DIOXIDE POWDER, NUCLEAR REACTOR'S FUEL RODS, AND FUEL ASSEMBLY

摘要

PPROBLEM TO BE SOLVED: To reduce an influence on criticality control measures in nuclear fuel cycle facility, by uniformly adding trace amounts of gadolinia to nuclear reactor's fuel having an uranium enrichment of over 5 wt.%, and to attain an improvement of economic efficiency, by effectively utilizing a fuel cycle cost reduction effect through increase of enrichment in the fuel of the nuclear reactor. PSOLUTION: By uniformly adding minute amounts, for example, less than 0.1 wt.% gadolinia to UOSB2/SBpowder, having an uranium enrichment of over 5 wt.% which is to be handled in a fuel production plant, criticality control of nuclear fuel cycle facility is performed, such that the effective neutron multiplication factor becomes equal to or smaller than the maximum value of effective neutron multiplication factor at the limiting value of mass control or geometric control, which serves as constraint on criticality safety for UOSB2/SBpowder having an uranium enrichment of 5 wt.%. PCOPYRIGHT: (C)2009,JPO&INPIT