REACTOR CORE OF LIGHT WATER REACTOR AND FUEL ASSEMBLY

摘要

PROBLEM TO BE SOLVED: To provide a reactor core of a light water reactor capable of further increasing safety allowance without damaging the economical efficiency of the light water reactor.SOLUTION: The reactor core of the light water reactor loads a plurality of fuel assemblies 41. The fuel assemblies 41 have a plurality of fuel rods 44, the lower end of which is supported by a lower tie plate 15, and the upper end of which is supported by an upper tie plate 14. The fuel rod 44 forms a plenum 2 on a nuclear material filling area 16 and has a neutron absorber filling area 4 under the nuclear material filling area 16. A neutron absorption member 3 attached to the upper tie plate 14 is arranged mutually between plenums 2 of adjacent fuel rods 44 over the nuclear material filling area 16. The neutron absorption member 3 is 500 mm in length and is separate from the nuclear material filling area 16 by 300 mm. If the entire reactor core is assumed to be in a state of 100% void, positive reactivity is not submitted to the reactor core.