FREMGANGSMAATE TIL INNSETTING AV BRENSELSTAVER I INDIVIDUELLE CELLER, OG ANORDNING TIL UTOEVELSE AV FREMGANGSMAATEN

摘要

An illustrative embodiment of the invention provides a fuel element assembly technique that facilitates the insertion of a fuel rod into a cell which is formed by a resilient grid structure. Initially, a cam is introduced into the cell. The inserted cam is rotated to deflect the grid surfaces that comprise the cell walls. This deflection prevents a leaf-spring mounted detent formed in the grid surface from extending into the path of the fuel rod. A key with a dimension that generally matches the deflected grid is inserted into the cell in order to engage the temporarily bowed grid surface. The inserted cam is rotated back to the initial orientation relative to the cell configuration and is withdrawn from the grid structure. The deflecting key lodged against the bowed grid surface, however, sustains the deflection in order to enable the fuel rod to be inserted into the cell without being abraded by the detent. After fuel rod insertion, the matching dimension portion of the deflecting key is disengaged from the grid surface and the key is withdrawn from the cell to release the leaf spring and allow the detent to clutch the fuel rod.