REUSABLE LOCKING TUBE IN A RECONSTITUTABLE FUEL ASSEMBLY

摘要

The invention relates generally to a reconstitutable nuclear fuel assembly having its top nozzle removably affixed to guide-thimble upper end portions (42) forming inner sockets (54) which extend into outer sockets (50) in the top-nozzle adapter plate (40) and there are bulge-fit to the latter. The bulge-fit connection between the inner and outer sockets is maintained by means of locking tubes (48) which are removably inserted into the inner sockets and are held therein against undesirable axial displacement of the locking tubes from their locking positions.
The locking tubes (48) according to the invention are reusable, each consisting of a tubular body (70), and a pair of dimples (72) provided at diametrically opposed locations on the outer surface of the tubular body to form an interference fit between the inner socket and the locking tube when inserted therein, the dimples (72) being preformed on the locking tube prior to initial use thereof, and being configurated such as to resist yielding and dimensional change during insertion and removal of the locking tube.