Improvements in or relating to fuel rod end plugs.

摘要

A nuclear reactor fuel rod end plug (100) is adapted to be welded within each end of a nuclear reactor fuel rod cladding tube, especially by means of laser beam welding techniques, although TIG welding techniques may also be employed. An annular groove (126) is defined about the external periphery of the end plug (100) so as to extend radially inwardly of the; long-land region (118) of the plug (100) within the vicinity of the juncture of the land surface (118) and the shoulder portion (120) at which location the girth weld between the end plug (100) and the cladding tubing will be defined. When employing laser beam welding techniques to accomplish the butt-type girth weld between the plug (100) and the cladding tube, the groove (126) serves to eliminate porosity defects within the weldment. When employing TIG welding techniques to accomplish the butt-type girth weld between the plug (100) and the cladding tube, the groove (126) serves to eliminate porosity defects within the weldment without requiring the plug land (118) and shoulder (120) surfaces to be accurately machined in accordance with precisely critical dimensional tolerances as well as the mating surfaces of the cladding tube.