High pressure laser welding of nuclear fuel rods

摘要

A high pressure laser welding method and apparatus enables seam welding of a nuclear fuel rod at hyperbaric pressure. In an automatic process, a loaded fuel rod and an upper end plug are mated within a sealable weld box. A pressure within the weld box is controlled relative to a pressure within the fuel rod, and a laser assembly welds the seam at hyperbaric pressure. Helium flowing through a laser window nozzle during welding prevents soot contamination of the laser window glass and prevents formation of ionic plasma. The upper end plug fuel rod welding operation is thus reduced to a single step and eliminates inspection related tasks with respect to a sealed hole.