Study on laser welding of fuel clad tubes and end plugs made of modified 9Cr-1Mo steel for metallic fuel of Fast Breeder Reactors

► Pulsed laser welding of modified 9Cr-1Mo steel nuclear fuel pin was studied. ► 6.6 mm OD clad tube was welded to end plug with different average powers. ► Average power for laser welding of the fuel pin was optimized at 142 W. ► Welding parameters like frequency, pulse duration, peak power were standardized. ► Acceptable weld microstructure and microhardness could be obtained.