Evaluation of probabilistic distribution of SCC growth rates obtained under the same test conditions in cold worked stainless steel

Probabilistic fracture mechanics (PFM) is a structural integrity assessment methodology that quantifies failure probability of components in nuclear power plants. In PFM analysis, probabilistic distributions expressed as probabilistic density functions are given to input parameters. This paper discusses the probabilistic distribution of SCC crack growth rates (CGRs) for cold worked Type 316L stainless steel in tests simulating a BWR environment. To assess the probabilistic distribution of these SCC CGRs, the associated data for 40 data of SCC CGRs were obtained from the single heat material under the same test conditions. Both normal and lognormal distributions were in agreement, and the standard deviation was much smaller than previously reported. The PFM results were strongly influenced by the standard deviation of the SCC CGR, suggesting that it is important to consider the SCC CGR probabilistic distribution for a reliable assessment of PFM.