Trial-Piping Design by ASME CC N-900

Abstract In recent years, elastic-plastic analysis has been increasingly used in the seismic design of nuclear piping. Therefore, ASME BPVC published a code case that provides strain-based acceptance criteria for seismic evaluation of piping system for Level D service level in 2019. However, it is still not widely used in actual seismic design due to its conservatism on applicability limitations and strain-based criteria. The modification of the CC N-900[1] has been started and under the review/ballot by the ASME BPVC committees. This paper provides a trial piping design sample to demonstrate the validity of the piping seismic design work by ASME CC N-900 draft revision. Also, the piping targeted for trial piping design is the large bore crossover piping against seismic isolation boundaries (including support attachment). In conclusion, we have confirmed that the application of the ASME CC N-900 draft revision proposal makes it possible to conduct more rational piping design than with the conventional ASME piping design method by ASME NCD-3650.