Burnable absorber arrangement for fuel bundle

Patent · Tue Dec 16 04:00:00 EST 1986

OSTI ID:7144468

Crowther, R L; Townsend, D B

This patent describes a boiling water reactor core whose operation is characterized by a substantial proportion of steam voids with concomitantly reduced moderation toward the top of the core when the reactor is in its hot operating condition. The reduced moderation leads to slower burnup and greater conversion ratio in an upper core region so that when the reactor is in its cold shut down condition the resulting relatively increased moderation in the upper core region is accompanied by a reactivity profile that peaks in the upper core region. A fuel assembly is described comprising; a component of fissile material distributed over a substantial axial extent of the fuel assembly; and a component of neutron absorbing material having an axial distribution characterized by an enhancement in an axial zone of the fuel assembly, designated the cold shutdown control zone, corresponding to at least a portion of the axial region of the core when the cold shutdown reactivity peaks. The aggregate amount of neutron absorbing material in the cold shutdown zone of the fuel assembly is greater than the aggregate amount of neutron absorbing material in the axial zones of the fuel assembly immediately above and immediately below the cold shutdown control zone whereby the cold shutdown reactivity peak is reduced relative to the cold shutdown reactivity in the zones immediately above and immediately below the cold shutdown control zone. The cold shutdown zone has an axial extent measured from the bottom of the fuel assembly in the range between 68-88 percent of the height of the fissile material in the fuel assembly.

• Assignee: General Electric Co., San Jose, CA
• Patent Number(s): US 4629599
• OSTI ID: 7144468
• 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
22 GENERAL STUDIES OF NUCLEAR REACTORS
220400* -- Nuclear Reactor Technology-- Control Systems
BURNUP
BWR TYPE REACTORS
FISSILE MATERIALS
FISSIONABLE MATERIALS
FUEL ASSEMBLIES
FUEL ELEMENT CLUSTERS
MATERIALS
NEUTRON ABSORBERS
OPERATION
REACTIVITY
REACTOR COMPONENTS
REACTOR CORES
REACTOR MATERIALS
REACTOR OPERATION
REACTOR SHUTDOWN
REACTORS
SHUTDOWNS
WATER COOLED REACTORS
WATER MODERATED REACTORS