Core-control assembly with a fixed fuel support
AssigneeGeneral Electric Company
InventorRoy C. Challberg
Life of this patent
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Abstract
In a boiling-water nuclear reactor, a core-control assembly comprises a control rod, a fuel support, a control-rod guide tube, a control-rod drive, and a control-rod-drive housing. The fuel support is welded to the control-rod guide tube. To remove the control-rod drive, the reactor vessel can be opened and the adjacent fuel bundles removed from the fuel support. Then the control-rod can be rotated after clearing the fuel support. The control rod is then rotated to decouple its bayonet connection to the control-rod drive. The control rod can then be lifted out of the reactor. This arrangement allows a control rod to be replaced without handling of the fuel support. In addition, the fuel support can be more securely installed since it does not need to be removed.
Claims6
A method of removing a control rod from a boiling-water nuclear reactor, said control rod having plural blades, said method comprising:
- removing a top head of said reactor;
- removing all fuel bundles from a fuel support having an aperture conforming to the cross section of said control rod through its blades;
- positioning a control rod so that its blades clear said aperture sufficiently to permit decoupling of said control rod;
- rotating said control rod so as to decouple it from a control-rod drive;
- and
- lifting said control rod out of said reactor.
A core-control assembly comprising:
- a control rod having a plurality of blades;
- a control-rod guide tube for guiding vertical motion of said control rod;
- a fuel support for supporting fuel bundles separated by said blades, said fuel support having an aperture conforming to a cross section of said control rod through said blades for preventing rotational movement of said control rod to a decoupling orientation when said control rod is between a maximum power position and a minimum power position, said minimum power position being above said maximum power position, said fuel support being supported by said control-rod guide tube;
- control-rod drive means for controlling vertical motion of said control rod, said control-rod drive means providing for vertical motion between said maximum power position and said minimum power position, said control-rod drive means providing for vertical movement to a decoupling position, said decoupling position being no lower than said minimum power position, said decoupling position being at a level sufficient to permit said control rod to rotate to a decoupling orientation relative to said fuel support;
- and
- coupling means for coupling said control rod to said control-rod drive means, said coupling means being releasable by rotational movement of said control rod to said decoupling orientation relative to said control-rod drive means.
Dependencies are inferred from the claim text.