Design and Evaluation of Steam Generator Welding Plug

The heat exchange tube of steam generator is the weakest point of primary loop pressure boundary. When the heat exchange tube degrades severely, the plugging is generally performed to prevent the secondary fluid from radiation. To avoid the high level stress and plastic deformation problem of current plug method, or high radiation dose caused by close plugging operation, one type of steam generator self-melted welding plug was designed. The welding residual stress and structural integrity evaluation were also carried out with numerical simulation method. The result assures the safety and reliability of the welding plug design.