A VENTED UPPER RETAINER FOR FACILITATING REPLACEMENT OF A TOP NOZZLE SUBASSEMBLY ON A RECONSTITUTED NUCLEAR FUEL ASSEMBLY

摘要

The invention relates to means for facilitating the reattachment of a top nozzle subassembly to tubular guide-thimble extensions of a nuclear fuel assembly under reconstitution while submerged in water. The top noble subassembly is attached to the tubular guide-thimble extensions by means of collar-like retainers (44) each of which has a groove (46) formed circumferentially in the inner periphery thereof and is affixed to the associated guide-thimble extension by having an annular bulge on the latter expanded into locking engagement with the groove. Each retainer (44) has at least one radial opening (50) and/or at least one axial internal slot which defines a liquid flow path enabling water to escape from the groove (46) as the bulge on the associated guide-thimble extension is being expanded into the groove.