A Reliability-Based Approach for Low-Cycle Fatigue Design of Class 2 and 3 Nuclear Piping

Abstract

This paper presents a reliability-based low-cycle fatigue design approach for class 2 and 3 nuclear pipes. Initially, the methodology and background for the design of the pipes according to the ASME Boiler and Pressure Vessel (B&PV) Code is presented. Then a probabilistic design methodology based on the ASME B&PV Code and focused on straight pipes with butt-welds is presented. The method ensures an acceptable reliability level for piping by keeping the failure probability within some upper threshold and accounting for the uncertainties of the design variables. In opposition, the current design may result in diverse and often unknown probabilities of failure for piping. A computational example illustrates the developed method.