摘要 |
A method of welding a fuel rod includes the following steps. An end plug and a cladding tube of the fuel rod are brought together to abut each other, and welded by applying a laser beam directed to a welding zone to melt material of the end plug and the cladding tube. The welding is sensed by sensing radiation within a first wavelength range, which includes the wavelength of the laser beam coming from reflections from the welding zone, sensing radiation within a second wavelength range different from the first wavelength range, which includes infrared radiation from melted material, and sensing radiation within a third wavelength range different from the first and second wavelength ranges, which includes radiation from plasma. The welding and melting of material is monitored by monitoring the sensed radiations. |