Boiling water reactor fuel bundle

Patent · Tue May 27 04:00:00 EDT 1986

OSTI ID:5539491

Weitzberg, A

A method is described of compensating, without the use of control rods or burnable poisons for power shaping, for reduced moderation of neutrons in an uppermost section of the active core of a boiling water nuclear reactor containing a plurality of elongated fuel rods vertically oriented therein, the fuel rods having nuclear fuel therein, the fuel rods being cooled by water pressurized such that boiling thereof occurs. The method consists of: replacing all of the nuclear fuel in a portion of only the upper half of first predetermined ones of the fuel rods with a solid moderator material of zirconium hydride so that the fuel and the moderator material are axially distributed in the predetermined ones of the fuel rods in an asymmetrical manner relative to a plane through the axial midpoint of each rod and perpendicular to the axis of the rod; placing the moderator material in the first predetermined ones of the fuel rods in respective sealed internal cladding tubes, which are separate from respective external cladding tubes of the first predetermined ones of the fuel rods, to prevent interaction between the moderator material and the external cladding tube of each of the first predetermined ones of the fuel rods; and wherein the number of the first predetermined ones of the fuel rods is at least thirty, and further comprising the steps of: replacing with the moderator material all of the fuel in the upper quarter of each of the at least thirty rods; and also replacing with the moderator material all of the fuel in the adjacent lower quarter of at least sixteen of the at least thirty rods.

• Assignee: NUS Corp., Gaithersburg, MD
• Patent Number(s): US 4591479
• OSTI ID: 5539491
• Country of Publication: United States
• Language: English

Related Subjects

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
210100* -- Power Reactors
Nonbreeding
Light-Water Moderated
Boiling Water Cooled
BARYONS
BOILING
BWR TYPE REACTORS
ELEMENTARY PARTICLES
ENERGY SOURCES
FEEDWATER
FERMIONS
FUEL ASSEMBLIES
FUEL CANS
FUEL ELEMENT CLUSTERS
FUEL ELEMENTS
FUEL RODS
FUELS
HADRONS
HYDRIDE MODERATORS
HYDRIDES
HYDROGEN COMPOUNDS
MATERIALS
MODERATORS
NEUTRONS
NUCLEAR FUELS
NUCLEONS
OXYGEN COMPOUNDS
PHASE TRANSFORMATIONS
PRESSURIZING
REACTOR COMPONENTS
REACTOR MATERIALS
REACTORS
TRANSITION ELEMENT COMPOUNDS
WATER
WATER COOLED REACTORS
WATER MODERATED REACTORS
ZIRCONIUM COMPOUNDS
ZIRCONIUM HYDRIDES