GLOBALLY-ASYNCHRONOUS, LOCALLY-SYNCHRONOUS WRAPPER CONFIGURATIONS FOR POINT-TO-POINT AND MULTI-POINT DATA COMMUNICATION

To remove the bottom nozzle of a nuclear fuel assembly, the nozzle plate must be disconnected from the control-rod thimbles. For nozzles whose control-rod thimbles are connected to the nozzle plate by screw fasteners having lock pins welded to the nozzle plate, a cutter for severing the welds is provided. The cutter is rotated by a motor at the work position through a long floating shaft. A long feed shaft operated by a thumb nut at the work position feeds the floating shaft and cutter downwardly through the weld. The bushings extend from a bushing plate, each encircling a screw fastener. Each bushing has a yieldable sleeve for sealing the region around a screw fastener to trap the chips from the severed weld. The cutter is indexed from weld to weld by indexing plates. To remove chips adhering to the cutter, the suction tube of a suction-pump-operated eductor is inserted in the auxiliary hole and the cutter is inserted in the bushing and chips are removed by suction. By inserting the suction tube into the bushings which seal the regions around the screw fasteners and enabling the eductor, the captured chips may be removed. Once the welds are severed the screw-fasteners may be unscrewed and removed by the eductor. The bottom nozzle may then be removed.

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