PROCESS FOR SEALING NUCLEAR REACTOR FUEL RODS

摘要

1497486 Fuel elements WESTINGHOUSE ELECTRIC CORP 18 March 1976 [24 March 1975] 10924/76 Heading G6C In a process for welding an end plug in a nuclear reactor fuel rod and then pressurizing the same with the aid of the same welding apparatus, the bottom plug is first welded in one end of a loaded fuel rod and the other end of the rod is then placed in a closed chamber and the top plug welded in place by laser apparatus. To pressurize the fuel rod, the laser apparatus is readjusted and used to melt a hole radially or axially through the end plug and/or wall of the fuel tube to thereby establish communication between the chamber and fuel rod internal areas. A vacuum pump may or may not evacuate the chamber and fuel rod, which in either event, is subsequently pressurized in the range of 15 to 50 kg/cm2 with an inert gas, e.g. argon or helium. The laser apparatus is again readjusted and the previously formed hole is welded shut and the fuel rod withdrawn after the chamber pressure is equalized with the atmosphere.