Probabilistic structural integrity assessment of reactor coolant pressure boundary piping, 1; The Scatter of welding conditions and welding residual stress

Tobita, Toru; Katsuyama, Jinya  ; Ito, Hiroto; Onizawa, Kunio 

Residual stress by welding would be one of the most significant factors in evaluating failure probabilities of PLR piping since the SCC growth behavior is strongly affected by residual stress distribution. The residual stress distribution is well known to change caused by varying of welding conditions. Therefore, to evaluate the scatter of welding condition and their influence on residual stress is important to assess the structural integrity of PLR piping. In present work, the scatters of welding conditions were evaluated by producing some series of butt-welding pipe specimens made of stainless steel. Residual stress distributions due to welding were measured by applying X-ray diffraction method and stress relief method. Measured welding conditions and residual stress distributions are provided to determine the conditions of welding residual stress simulations and to confirm an accuracy of the simulation described in the following paper.