Light water reactor, core of light water reactor and fuel assembly

摘要

The core flow rate of a boiling water reactor (BWR) (19) is adjusted so that it reaches a core flow rate setting that is determined from the characteristic according to the ratio of Pu-239 in transuranic nuclides (TRU) included in a new fuel assembly (1) to be loaded in a core (20). The core flow rate is maintained at the set core flow rate in all operation cycles of the BWR (19). Accordingly, the ratios of a plurality of TRU isotopes included in a fuel assembly (1) when the fuel assembly (1) is taken out of the BWR core (20) as a spent fuel is substantially the same as the ratios of the plurality of TRU isotopes included in a new fuel assembly (1) to be loaded in the BWR core (20). The ratio of Pu-239 in TRU included in the new fuel assembly (1) is 3% or more but 45% or less. As a result, a nuclear proliferation resistance can be increased while restrictive conditions for safety are met, a burnup can be further increased, and TRU multi-recycling becomes feasible.