Probabilistic Demand Model, Fragility Analysis, and Probabilistic Safety Assessment for PCCVs under Internal Pressure Considering Temperature Effects

A methodology for analyzing the pressure-bearing fragility and probabilistic safety assessment (PSA) of prestressed concrete containment vessels (PCCVs) was introduced, incorporating the influence of temperature effects. This approach utilized a continuous damage state framework to capture the intricate damage evolution of containment components under thermal–pressure interactions. The Bayesian estimation theory was incorporated to quantify the pressure-bearing fragility and its confidence intervals, elucidating the impact of material and statistical uncertainties. By integrating the fragility with the occurrence of the pressure load, the PSA was realized to provide a comprehensive safety evaluation. The results demonstrate that the proposed damage metrics effectively capture the effects of material uncertainties on the damage evolution of various containment components. The Bayesian estimation theory provides a more strict, flexible, and adaptive approach to constructing the pressure-bearing fragility and its confidence intervals for the studied containment. The obtained results also suggest that overlooking temperature effects can lead to an underestimation of the failure probability of the containment.