Failure Estimation Method for Cracked Pipe Repaired with Weld Overlay Method

Flaw may be initiated in the piping systems in long-term operation nuclear power plants due to the age-related degradations such as fatigue or stress corrosion cracking. For cracked pipes, a weld overlay repair method has been provided in ASME BPV Code Section XI. However, the failure evaluation of the repaired pipe is the same as that of the original pipe with cracks, which is a failure evaluation method for cracked pipe made of a kind of material. Addressing this issue, in this paper, the brief description of this repair method is provided. The failure evaluation method of double-layer structure pipeline repaired by WOL repair method is derived, and the failure evaluation method is verified by using the existing experimental data of austenitic stainless steel pipe. The results show that the method is effective and can be applied to engineering.