Patent Number: 048184730
Section: abstract

A fuel bundle in which the fuel rods are supported by top and bottom plates and held together by axially spaced straps. Several of the fuel rods are formed as tie rods. Each tie rod has a flat key at the bottom which is passed through a slot in the bottom plate. By turning the tie rod, the key is rotated to a locking position in which its axial movement is prevented. At the top, each tie rod has a flattened plug which is threaded on its rounded sides to receive a nut that has a crimping lip. The plug extends through a slot in the top plate and is threaded to the nut and the crimping lip is crimped to the plug. The tip of the plug is flat. During reconstitution of the fuel bundle, the crimp on each tie rod is broken and the nut is unscrewed while the tip of the plug is held. The top plate is then removed and each tie rod is then turned so that the key can be passed through the slot in the bottom plate. The tie rods may thus be removed and the bundle disassembled without access to the bottom plate. Each tie rod is provided with tabs to prevent axial displacement of the grids.