High pressure laser welding of nuclear fuel rods

A laser welding apparatus for welding articles together, the apparatus comprising:

• an article positioning assembly that supports and positions the articles to be welded together;
• a sealable weld box cooperating with said article positioning assembly;
• a pressurized gas source communicating with said weld box;
• a laser assembly that generates a welding laser directed into said weld box;
• and
• a controller operatively coupled with said article positioning assembly, said pressurized gas source and said laser assembly, said controller controlling a position of the articles to be welded together, a pressure in the weld box including during application of the laser, and operation of the laser in accordance with predetermined parameters.

A method of welding an end plug to a fuel rod for a nuclear reactor fuel bundle, the method comprising:

• (a) supporting the fuel rod and the end plug in a weld box;
• (b) pressurizing the weld box and the interior of the fuel rod to a first pressure;
• (c) directing a laser toward the fuel rod and the end plug for welding along a laser axis;
• (d) flowing gas along the laser axis at a predetermined axial flow rate;
• and
• (e) varying the pressure in the weld box during application of the laser.