Retention strap in a grid assembly fixture

摘要

An improved retention strap for maintaining a fuel assembly grid in an assembled condition during manufacture in a grid assembly fixture includes four members extendible along the respective outer grid straps, between the corners and about the periphery of the grid. Each member has a pair of end posts and a cross member extending between and connected with the end posts. The end posts of the members are disposed adjacent the respective corners of the grid when the grid is in the assembled condition. Pairs of brackets interconnect respective ones of the end posts of the members, whereas pairs of releasable connectors fasten respective others of the end posts of the members so as to form diagonally opposite pairs of substantially rigidly squared first fixed and second openable corners. Also, the retention strap includes a pair of clamps disposed at each of the fixed and openable corners formed by the end posts. The clamps are engagable with a selected one of the end portions of the outer grid straps forming the respective grid corner disposed adjacent one of the squared corners of the retention strap. The outer grid strap end portion selected is the one having a terminal edge defining the inner part of the lap joint at the grid corner. The clamps have inner hook-shaped elements which engage on the selected end portion to pull outwardly thereon and thereby pull outwardly on the other end portion of the pair thereof forming the grid corner which secures the end portions against the respective one of the squared corners of the retention strap and thereby prevents distortion of the grid corner during welding of each respective lap joint at a corner of the grid. Each clamp also has a second adjustable element adapted to bear against the retention strap member and exert an outwardly-directed pulling force on the outer grid strap end portion via the first element thereon.