NUCLEAR REACTOR CORE AND METHOD OF OPERATING NUCLEAR REACTOR

摘要

PROBLEM TO BE SOLVED: To provide a nuclear reactor core capable of operating a nuclear plant continuously over for 15 years or more without requiring fuel replacement, capable of shortening maintenance manhours and a term of a periodical inspection in the plant, capable of contributing to remarkable enhancement in plant operation rate and an economical aspect, and effective for prevention of nuclear proliferation. SOLUTION: Plural fuel assemblies 103 constituted to be arranged with fuel rods 100 and water rods 107 square-grating likely are arranged square-grating- likely with a fixed pitch. Respective blades 102a of a cross-shaped control rod 102 are insertion-arranged respectively between clearances faced with four adjacent fuel assemblies 100. A ratio B/S of each blade width B of the control rod 102 to a fuel grating area S which is an area of a square having one pitch of the fuel assemblies 103 as its one side is set to be 0.06 or more.