Spectral shift reactor control method

Patent · Tue Dec 29 04:00:00 EST 1987

OSTI ID:5318177

Impink, Jr, A J

This patent describes the method of operating a pressurized-water fissile-material-fueled spectral-shift nuclear reactor in such manner that short-term reactivity requirement variations can be satisfied without making control rod or chemical shim changes. The reactor includes a pressure vessel enclosing a reactor core and having an inlet and an outlet for circulating a water coolant moderator in heat transfer relationship with the core. The core comprises fuel assemblies disposed therein for generating heat by nuclear fission. The reactor provided with neutron-absorbing control rods which are vertically movable into and out of the core so that movement of the control rods into the core will substantially decrease reactivity and withdrawal of the control rods from the core will substantially increase reactivity. The control rods when inserted into the core displace an equivalent volume of the water coolant moderator. The reactor also provides neutron-spectral-shift rods which have a lower absorptivity for neutrons than the control rods, the neutron-spectral shift rods when inserted into the core displacing an equaivalent volume of the water coolant moderator. The neutron-spectral-shift rods comprises two different types of rods, a first of the different types of the neutron-spectral-shift rods comprising displacer rods which have a low absorptivity for neutrons, the remainder of the neutron-spectral-shift rods comprising gray rods which have an absorption for neutrons which is intermediate the neutron absorption of the control rods and the low neutron absorption of the displacer rods. Each neutron-spectral-shift displacer rod comprises a hollow thin-walled Zircaloy member containing a filling of solid or annular zirconium- or aluminum-containing material for providing internal support and mass for the thin-walled tubular member.

• Assignee: Westinghouse Electric Corp., Pittsburgh, PA
• Patent Number(s): US 4716006
• OSTI ID: 5318177
• Country of Publication: United States
• Language: English

Related Subjects

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
210200* -- Power Reactors
Nonbreeding
Light-Water Moderated
Nonboiling Water Cooled
ALLOYS
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
CHALCOGENIDES
CONFIGURATION CONTROL
CONTROL
CONTROL ELEMENTS
COOLING SYSTEMS
ENERGY SOURCES
ENERGY SYSTEMS
FISSILE MATERIALS
FISSIONABLE MATERIALS
FUEL ASSEMBLIES
FUEL ELEMENT CLUSTERS
FUELS
MATERIALS
NUCLEAR FUELS
OPERATION
OXIDES
OXYGEN COMPOUNDS
PWR TYPE REACTORS
REACTIVITY
REACTOR COMPONENTS
REACTOR COOLING SYSTEMS
REACTOR MATERIALS
REACTOR OPERATION
REACTORS
SPECTRAL SHIFT CONTROL
TIN ALLOYS
TRANSITION ELEMENT COMPOUNDS
WATER COOLED REACTORS
WATER MODERATED REACTORS
ZIRCALOY
ZIRCONIUM ALLOYS
ZIRCONIUM BASE ALLOYS
ZIRCONIUM COMPOUNDS
ZIRCONIUM OXIDES