MANUFACTURING METHOD FOR FUEL ASSEMBLY

摘要

PROBLEM TO BE SOLVED: To provide a method capable of setting the enrichment degree of plutonium to satisfy designated reactivity even if the composition ratio of uranium and plutonium in fuel material changes between the upper part and the lower part in the axial direction of the fuel assembly. SOLUTION: In this manufacturing method for the fuel assembly, according to the uranium and plutonium isotope composition ratio of fuel material, the plutonium enrichment degree of a fuel rod is determined by the plutonium enrichment degree and equivalent fissile coefficient to the preset standard uranium and plutonium isotope composition ratio. As an equivalent fissile coefficient used in deciding the enrichment degree of plutonium, one of two kinds of equivalent fissile coefficients preset according to the uranium and plutonium isotope composition ratio of the fuel material is selected and used. COPYRIGHT: (C)2003,JPO