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U.S. Department of Energy
Office of Scientific and Technical Information

Sleeve connection for reconstitutable control rod guide tube

Patent ·
OSTI ID:6318878
A reconstitutable nuclear fuel assembly is improved by the placement of a wear sleeve within the control rod guide tube and below the removable guide tube post. The improvement comprises the guide tube having an internal ledge at its upper end from which a flanged, thin-walled metal cylindrical sleeve is suspended. The cylinder is expanded into firm contact with the inner wall of the guide tube over substantially the entire length of the cylinder. The friction fit provided by the firm contact prevents the sleeve from being pushed upward by the flow of coolant through the tube, while the flange and ledge prevent any downward movement of the sleeve in the tube. The flange on the ledge is located in spaced vertical alignment with the lowermost internal portion of the post. Thus, as the sleeve thermally expands it moves upward into the space. The post, however, offers an absolute limit for the upward movement of the sleeve and thereby acts as a redundant vertical stop to prevent the sleeve from becoming dislocated within the post.
Assignee:
Combustion Engineering Inc
Patent Number(s):
US 4333798
OSTI ID:
6318878
Country of Publication:
United States
Language:
English