Patent Number: 
Section: claims

1. A core of a light water reactor, comprising:a plurality of first fuel assemblies including a plurality of isotopes of transuranic nuclides, said plurality of first fuel assemblies being all fuel assemblies disposed in said core,wherein said transuranic nuclides included in said plurality of first fuel assemblies are different in number of a recycle frequency,wherein a plurality of second fuel assemblies being a part of said plurality of first fuel assemblies and including said transuranic nuclides having a smallest number of recycle frequency are disposed at a central part of said core,wherein a plurality of third fuel assemblies being said plurality of first fuel assemblies except said plurality of second fuel assemblies and including said transuranic nuclides having larger number of recycle frequency than said number of recycle frequency of said transuranic nuclides included in said plurality of second fuel assemblies, are disposed between said central part and an outermost layer zone of said core,wherein between said central part and said outermost layer zone, said plurality of third fuel assemblies including said transuranic nuclides having larger number of recycle frequency among said plurality of third fuel assemblies are disposed on a side of said outermost layer zone, andwherein said plurality of second fuel assemblies disposed at said central part include a nuclear fuel material including the highest rate of Pu-239 in said transuranic nuclides, and between said central part and said outermost layer zone, the third fuel assemblies having a nuclear fuel material including a lower rate of Pu-239 in said transuranic nuclides than said rate of Pu-239 of said plurality of second fuel assembly. 2. The core of a light water reactor according to claim 1,as said number of recycle frequency of said transuranic nuclides included in said plurality of third fuel assemblies become large, said plurality of third fuel assemblies including this transuranic nuclides are disposed on said side of said outermost layer zone. 3. A core of a light water reactor, comprising:a plurality of first fuel assemblies having nuclear fuel material including a plurality of isotopes of transuranic nuclides, said plurality of first fuel assemblies being all fuel assemblies disposed in said core,wherein said transuranic nuclides included in said plurality of first fuel assemblies are different in number of a recycle frequency,wherein a plurality of second fuel assemblies being a part of said plurality of first fuel assemblies and including said transuranic nuclides having a smallest number of recycle frequency are disposed at a central part of said core,wherein a plurality of third fuel assemblies being said plurality of first fuel assemblies except said plurality of second fuel assemblies and including said transuranic nuclides having larger number of recycle frequency than said number of recycle frequency of said transuranic nuclides included in said plurality of second fuel assemblies, are disposed between said central part and an outermost layer zone of said core, andwherein said plurality of second fuel assemblies disposed at said central part having include a nuclear fuel material including the highest rate of Pu-239 in said transuranic nuclides, and said plurality of third fuel assemblies disposed between said central part and said outermost layer zone include a nuclear fuel material including a lower rate of Pu-239 in said transuranic nuclides than said rate of Pu-239 of said plurality of second fuel assemblies. 4. The core of a light water reactor according to claim 3,as said number of recycle frequency of said transuranic nuclides included in said third fuel assemblies become large, said third fuel assemblies including this transuranic nuclides are disposed on said side of said outermost layer zone.