Research on Detectable Rate Optimization of Nuclear Grade Pipe Welds

The problem of undetectable welds in nuclear grade pipelines not only makes the weld detectable rate fail to meet the requirements of current standards, but also affects the state monitoring of welds during their life cycle, which is not conducive to the safe operation of reactor coolant system. Taking the pre-service inspection of nuclear grade pipeline welds in floating nuclear power plants as an example, the reasons for the undetectable welds are analyzed in detail by using descriptive statistics. The analysis results show that the imaging obstacle of weld detection is the main factor causing the weld to be undetectable, followed by the inaccessible factor of weld detection. The reasons are related to design, installation, structural functionality and equipment structural characteristics. The proposed optimization measures can improve the weld detectable rate from 65.5% to not less than 74%, which effectively improves the weld detectable rate and ensures the safety of the system operation.