Failure mechanism of a prestressed concrete containment vessel in nuclear power plant subjected to accident internal pressure

The leakage of the internal gas could cause structural expansion and cracking of the containment structures in nuclear power plant (NPP). Predicting the ultimate internal pressure resistant capacity and investigating the failure mechanism for the containment structures above the design-basis accident pressure is of great importance. The structural model of a prestressed concrete containment vessel (PCCV) was established accurately by FE software ABAQUS. The tensioning process of prestressed tendons is simulated by the cooling method to establish initial stress of prestressed tendons. The mechanical behavior of the PCCV subjected to the internal pressure above the design-basis accident pressure is investigated in detail. The cracking internal pressure and ultimate internal pressure resistant capacity of the structure are obtained and the failure mechanism of the PCCV is revealed. The influence of prestressing of tendons, the steel liner and the reinforcements on the failure mechanism of the PCCV is revealed systematically.