Nuclear reactor fuel or control element - has releasable locking between casing and element end piece

摘要

A nuclear reactor fuel element or control element has a casing of polygonal cross-section with an opening surrounded by a casing edge at one of the casing ends and with a grooved profile formed in the inner casing wall at a predetermined distance from the casing edge, a rod bundle or an elongate absorber body located in the casing interior. An end portion of the element has side faces, which extend parallel to the longitudinal axis of the casing and which conform to the polygonal casing cross-section so that, in one relative position, the end portion can be axially displaced for fitting or removal. In this relative position, the side faces face the casing side walls, the corners between the side faces rounded and axially shaped to form noses which when the end portion is turned about the longitudinal axis into a second relative position for reactor operation, fit into the grooved profile for interlocking with the casing side walls. ADVANTAGE - The design provides a releasable bayonet closure for the end piece to allow simple removal of fuel rods or absorber bodies.