Core of light water reactor and fuel assembly

摘要

A core (20) of a light water reactor (19) having a plurality of fuel assemblies (1) including a plurality of isotopes of transuranic nuclides,
wherein a ratio of Pu-239 in all of said transuranic nuclides included in said loaded fuel assembly (1) with a burnup of 0, is 3 % or more but less than 40 %.