Study of girth weld selection principles and solution of inaccessible girth weld for high wear factor pipe in pre-service inspection

摘要

During pre-service inspection (PSI) of the CPR1000 units, there are two inspection problems of girth weld for high wear factor pipes. They are absence of girth weld selection principles and inaccessibility of inspection for girth weld. On the one hand, Summarize selection principles of girth welds for high wear factor pipe welds, by taking consideration of pipeline fracture analysis, system security importance and mechanical calculations; on the other hand, through visit of Nuclear island plant, survey inaccessible situation for PSI, and analyze its reason, finally propose two solutions which are Piping Layout Modification solution and substitute for original girth weld.