摘要 |
PROBLEM TO BE SOLVED: To obtain a core that enables 14-month or longer safe operation and where uranium/MOX fuel assemblies with the pattern of control rods simplified are intermingled. SOLUTION: In the core of a boiling water reactor which is loaded with uranium fuel assemblies containing only uranium as a fuel material and MOX fuel assemblies containing uranium-plutonium mixed oxide as a nuclear fuel material at the same time and which is designed so that the average discharged burnup of the MOX fuel assemblies can be lower than that of the uranium fuel assemblies, the MOX fuel assemblies are located in 80% or more of the outermost region and three or more are uranium fuel assemblies in a CC (control cell) comprising four or more fuel assemblies. COPYRIGHT: (C)2011,JPO&INPIT |