Control rods and method of producing same

Patent · Tue May 29 04:00:00 EDT 1984

OSTI ID:6291457

Nishimura, E; Hayashi, T; Ibe, E; Kitamura, M; Saito, K; Uchida, S

A control rod for a boiling-water reactor having blades arranged in the form of a cross in transverse cross section includes a plurality of poison tubes disposed therein. Boron carbide powder which is a neutron absorbing material causing an (n,a) reaction to take place is charged in the poison tubes. The control rod has plates of Hf-Zr alloy arranged in the blades in a position nearer to a forward end of the control rod at which the control rod is inserted in a reactor core than the poison tubes. The plates of Hf-Zr alloy are formed of an alloy of Hf having a large neutron absorption cross section and Zr having a small neutron absorption cross section. The concentration of Hf in the plates of Hf-Zr alloy is successively reduced in going from an end thereof adjacent the poison tubes toward and end thereof at the inserting end of the control rod. The plates of Hf-Zr alloy and the poison tubes have the same neutron absorbing capacity at the boundary therebetween at which they are in contact with each other.

• Assignee: Hitachi Ltd. (Japan)
• Patent Number(s): US 4451428
• OSTI ID: 6291457
• 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
ALLOYS
BORON CARBIDES
BORON COMPOUNDS
BWR TYPE REACTORS
CARBIDES
CARBON COMPOUNDS
CONTROL ELEMENTS
CROSS SECTIONS
FABRICATION
HAFNIUM ALLOYS
NEUTRON ABSORBERS
POWDERS
QUANTITY RATIO
REACTOR COMPONENTS
REACTORS
WATER COOLED REACTORS
WATER MODERATED REACTORS
ZIRCONIUM ALLOYS