Introduction of JSME Rules on Fitness for Service for CASS Piping and Proposal for Improvements

Abstract

The Japan Society of Mechanical Engineers (JSME) Code Rules on Fitness for Service (FFS) for Nuclear Power Plants describe a flaw evaluation procedure for stainless steel piping including cast austenitic stainless steel (CASS) piping. It consists of three methods; limit load, elastic plastic fracture mechanics (EPFM) and two-parameter (covering failure modes from brittle fracture to limit load) methods. This paper describes a brief introduction of the flaw evaluation procedure for CASS piping in the JSME rules. Some improvements for the current rules are also proposed.