Nuclear reactor control rod with uniformly changeable axial worth

Patent · Tue Nov 17 04:00:00 EST 1987

OSTI ID:5688433

Freeman, T R

In combination with a fuel assembly having at least one hollow guide thimble, means to compensate for a reduction in reactivity occurring generally uniformly in a transverse direction and symmetric in the axial direction is described, comprising: (a) a control rod inserted in the guide thimble including (i) an elongated inner cylindrical member having a lower end, (ii) an elongated outer cylindrical member surrounding the inner member and having a lower end with concentrically-arranged lower inner and outer edge portions defined thereon, (iii) each of the members being composed of alternating poison and nonpoison regions, (iv) the inner member being axially movable relative to the outer member, (v) an outwardly projecting ledge adapted to support in a rest relationship the lower end of the outer member; and (b) means for retaining the outer member in a stationary position in the guide thimble while the inner member is movable axially relative thereto to adjust the degree to which the poison regions of the members overlap with the nonpoison regions and thereby change the overall worth of the rod. (c) The retaining means are in a lower portion of the guide thimble and sized to support the lower end of the outer member at its lower outer edge portion. The retaining means have a central hole sized to allow passage of the lower end and ledge of the inner member therethrough.

• Assignee: Westinghouse Electric Corp., Pittsburgh, PA
• Patent Number(s): US 4707329
• OSTI ID: 5688433
• Country of Publication: United States
• Language: English

Related Subjects

22 GENERAL STUDIES OF NUCLEAR REACTORS
220300* -- Nuclear Reactor Technology-- Fuel Elements
CONFIGURATION
CONTROL ELEMENTS
CYLINDRICAL CONFIGURATION
DESIGN
FUEL ASSEMBLIES
FUEL ELEMENT CLUSTERS
MECHANICAL STRUCTURES
POSITIONING
REACTOR COMPONENTS
SUPPORTS