Effect of Elevated Temperature and Internal Pressure due to Severe Accidents on the Internal Pressure Capacity of Prestressed Concrete Containment Vessel

The integrity of containment buildings in nuclear power plants is crucial for preventing the release of radioactive materials during severe accidents. This study investigates the effect of the uncertainty in temperature-dependent strength of concrete on the internal pressure capacity of prestressed concrete containment vessel (PCCV). To this end, a high-fidelity finite element model is developed and the uncertainty in concrete material properties due to temperature variations is taken into account for a finite element analysis with internal pressure and temperature histories. In addition, two limit states of PCCV, such as onset of leakage and functional failure, are defined to investigate internal pressure capacity depending on the different damages to PCCV. The results provide insights into the behavior of PCCV under severe accident conditions and the impact of the uncertainty in the concrete material due to temperature on their performance, in terms of the leakage of PCCV. This research enhances the understanding of PCCV's response to internal pressure and temperature and contributes to the safety assessment of nuclear power plants.