Remaining Life Prediction of the Core Shroud Due to Stress Corrosion Cracking Failure in BWRs using

• 作 者: Yongkui Li Yoshiyuki Kaji Shanping Lu
• 机 构: Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of
• 出 处: The 4th International Symposium on Materials and Reliability
• 发表日期: 2015年8期

　　Stress corrosion cracking (SCC) of the welded joints in a reactor core shroud is the primary result of the residual stresses caused by welding, corrosion and neutron irradiation in a boiling water reactor (BWR).Therefore, the evaluation of SCC propagation is important for the safe maintenance of the core shroud.This work attempts to predict the remaining life of the core shroud due to SCC failures inBWRconditionsvia SCC propagation time calculations.Firstly, a two-dimensional finite element method model containingH6a girth weld in the core shroud was constructed, and the weld processing was simulated to determinethe welds residual stress distribution.Secondly, using a basic weld residual stress field, the SCC propagationwas simulated using a node release option and the stress redistribution was calculated.Combined withthe J-integral method, the stress intensity factors were calculated at several depths in the crack setting inside and outside core shroud; then, the SCC propagation rates were determinedusing the relation between the SCC propagation rate and the stress intensity factor.The calculations gave the remaining lifes of the core shroud when a 1-mm-deep SCC has beendetected inside and outside of the core shroud.