| 摘要 |
<p>The invention concerns an arrangement for releasably attaching the top nozzle of the fuel assembly to a guide thimble thereof, comprising a stepped outer socket which extends through the adapter plate (22) of the top nozzle and has therein a peripheral ledge (32) and a peripheral groove (34) beneath the ledge; an inner socket on the guide thimble inserted into the outer socket and having an upper rim portion including a peripheral bulge (44) which mates with the groove (34); and a locking tube (24) which is slideably insertable into the inner socket to prevent dislodgement of the bulge (44) from the groove (34) and has a flexible wall with means (58,62) thereon for retaining the locking tube against inadvertent displacement thereof from its locking position within the inner socket. The retaining means comprise upper (58) and lower (62) dimples arranged to radially project, respectively, under said ledge (32) and over an inner-socket surface portion above the lowermost edge (52) of the inside concavity (48) of said bulge (44), thereby, in cooperation therewith, to resist both upward displacement and downward displacement, respectively, of the locking tube from its locking position.</p> |
