Core of light water reactor and fuel assembly

Patent metadata

Field	Value
Publication number	US-10020079-B2
Application number	US-201514695214-A
Country	US
Kind code	B2
Filing date	Apr 24, 2015
Priority date	Dec 28, 2009
Publication date	Jul 10, 2018
Grant date	Jul 10, 2018

Abstract

A core of a light water reactor has a plurality of fuel assemblies. The fuel assemblies include a plurality of fuel rods in which a lower end is supported by a lower tie-plate and an upper end is supported by an upper tie-plate. The fuel rods form plenums above a nuclear fuel material zone and have a neutron absorbing material filling zone under the nuclear fuel material zone. Neutron absorbing members attached to the upper tie-plate are disposed between mutual plenums of the neighboring fuel rods above the nuclear fuel material zone. The neutron absorbing members have a length of 500 mm and are positioned at a distance of 300 mm from the nuclear fuel material zone. Even if the overall core is assumed to become a state of 100% void, no positive reactivity is inserted to the core.

First claim

What is claimed is:

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, and
wherein 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, and
wherein 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.

Assignees

• Hitachi Ge Nuclear Energy Ltd

Inventors

• Takeda Renzo
• Miwa Junichi
• Moriya Kumiaki

Classifications

• G21C3/42

  Selection of substances for use as reactor fuel · CPC title

• G21C5/00

  Moderator or core structure; Selection of materials for use as moderator · CPC title

• G21C19/44

  of irradiated solid fuel · CPC title

• G21C3/328 Primary

  Relative disposition of the elements in the bundle lattice · CPC title

• Y02E30/38

  Cross-Sectional Technologies · mapped topic