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Title: Positioning means for circumferentially locating inspection apparatus in a nuclear reactor vessel

Patent ·
OSTI ID:5379458

Positioning means for locating inspection apparatus used to volumetrically examine a nuclear reactor vessel is disclosed. The positioning means is provided with a support ring having an annular key positioned longitudinally about its periphery. Three support legs are attached to the support ring by brackets adapted to fit the annular key. The support ring also carries three guide stud bushings which are movably mounted by clamps adapted to engage the support ring key. Prior to lowering the inspection apparatus into the vessel, the guide stud bushings are each moved to a point of alignment with one of three guide studs extending upwardly from the vessel. After alignment has been verified, the guide stud bushings are clamped in position. The inspection apparatus is lowered towards its fully seated position within the vessel and is coarsely circumferentially positioned with by the engagement of the guide studs within the guide stud bushings. A fine degree of circumferential positioning is achieved by providing a specially configured shoe for one of the support legs. With the core barrel internals in, the special shoe is adapted to key onto a core barrel pin the exact location of which is known. With the core barrel internals removed, the special shoe is adapted to place a locating key into a notch in a vessel flange, the location of which is known. As the inspection apparatus is lowered into its fully seated position, exact circumferential positioning with respect to the vessel is achieved. The other support legs rest on an inner circumferential flange so that no portion of the inspection apparatus touches or threatens the vessel's top flange. 19 claims.

Assignee:
Westinghouse Electric Corp.
Patent Number(s):
US 4174999
Application Number:
TRN: 80-008506
OSTI ID:
5379458
Resource Relation:
Patent File Date: Filed date 25 Mar 1977
Country of Publication:
United States
Language:
English