Reliability analysis of nuclear piping system using semi-Markov process model

► A semi-Markov model for evaluating the rupture frequencies and reliability of the piping system in nuclear power plant is proposed. ► The flaw initiation is modelled by Weibull distribution. ► The influence of flaw and leak inspection intervals on the piping rupture probability is investigated. ► The proposed model provides a tool set to optimize the pipe inspection and maintenance program over the life cycle of the plant. ► It was observed that the pipe rupture rate increases with increase in the variability of time to flaw initiation distribution.