END PLUG FOR FUEL ROD IN BOILING WATER REACTOR AND METHOD FOR ATTACHING/REMOVING FUEL ROD TO/FROM TIE PLATE OF FUEL ASSEMBLY IN BOILING WATER REACTOR

摘要

An end stop for a fuel rod in a boiling water reactor. The end stop is made up of three regions. The first region attaches to the fuel rod itself and thus has the same diameter as the fuel rod. The second region has a smaller diameter than the first, which is slightly smaller than that of the opening in the fuel element grid plate. The final region is of diameter between the first two regions, but greater than that of the opening in the grid plate. The second and third regions have a dividing split within them and are sprung so that the end-stop deforms as it is pushed into the grid plate opening. The process for insertion of the fuel rod comprises assertion of sufficient axial force to force the sprung end stop through the grid opening and once this has been achieved removal of the force.