Proposal of fracture estimation for single and double cracked pipes in limit load criteria of JSME code on Fitness-for-Service

JSME Code on Fitness-for-Service for nuclear power generation facilities provides analytical procedures to determine allowable circumferential flaws for pipes subjected to bending moments in the acceptance criteria. The allowable flaws are obtained from limit load criterion or elastic-plastic fracture mechanics. However, analytical procedures for pipes receiving membrane stresses are not provided. In addition, analytical procedure of current Code is only applicable for a single flaw in a pipe. Authors have introduced evaluation method for failure stress of a pipe receiving membrane stress. Furthermore, analytical procedure for circumferential two flaws in a pipe subjected to bending moment has been proposed for the JSME Code. (author)