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AssigneeWestinghouse Electric Corp.
InventorsDavid A. Altman, James R. Chrise, Bruce W. Bevilacqua, Gregory L. Calhoun
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The guide pin aligning a top nozzle of a nuclear fuel assembly to an upper core plate of a nuclear reactor, is replaced working exclusively from below the upper core plate. The replacement guide pin has a shaft portion engaged with the upper core plate and the clamping nut which held the original guide pin, by threadable connection and/or by an expansion fitting. A shoulder on the pin bears against a lower surface of the upper core plate, and a nose of the pin is received in the top nozzle of the fuel assembly. A preferred expansion fitting has a bushing with ridges on its outer surface and a conical inside surface, and is inserted into the bored out original guide pin shaft. A threaded conical plug is pulled axially with rotation of the replacement pin shaft to expand the bushing. The ridges rigidly lock the replacement pin between the shoulder and the clamping nut. By attaching the replacement pin to the stub of the original pin, the invention utilizes existing attachments of the original pin to the upper core plate.
A guide structure for aligning a top nozzle of a nuclear fuel assembly to an upper core plate of a nuclear reactor, the guide structure including a replacement for an original guide pin structure having an original guide pin rigidly mounted at a through bore in the upper core plate via a clamping nut rigidly attached to an upper surface of the upper core plate, said guide structure comprising:
A replacement guide pin for aligning a top nozzle of a nuclear fuel assembly to an upper core plate of a nuclear reactor, the replacement guide pin apparatus being arranged as a replacement for an original guide pin structure including an original guide pin rigidly mounted at a through bore in the upper core plate via a clamping nut rigidly attached to an upper surface of the upper core plate, said replacement guide pin comprising:
Dependencies are inferred from the claim text.