NDT Status of PF1 Coil Welds

Stock Company “NIIEFA,” Russia, within the framework of the international project ITER produces and supplies the PF1 poloidal field coil. The choice of design solutions, materials, and technologies is under high electromagnetic and thermal loads. The PF1 coil uses liquid helium as a cooling system, which is fed into joints through helium inlets. Joints are bimetallic structural components obtained by explosion welding technologies and tungsten inert gas (TIG)-welding with a complex structural profile. Materials used: austenitic stainless steel, bimetallic copper-steel; bonded technology: TIG-welding, explosion welding. The quality of materials, explosion border and welds are subject to the highest requirements of European standards. Technologies of industrial manufacture of the PF1 coil require the use of nondestructive testing (NDT) procedures, caused by complex weld profile, small testing zone, and heterogeneity of welds. This paper shows the technology and NDT equipment for testing material and welds of the PF1 coil.