The probabilistic risk assessment (PRA) is a hot topic for highlighting the reliability and safety of infrastructures, especially for nuclear power plants (NPPs). The current internal pressure risk assessment method for prestressed concrete containment vessel (PCCV) generally adopts the internal pressure to characterize its fragility (namely internal-pressure-based fragility), even though the failure of PCCV is factually more tightly associated with PCCV’s realistic responses. This study proposes a novel response-based probabilistic risk assessment method for PCCV under internal pressure. The method adopts the response of the containment to characterize the fragility of components. Additionally, the steel fiber is introduced to form steel fiber reinforced concrete (SFRC) PCCV and the fragility and risk of the SFRC PCCV are quantitatively studied. The results indicate that a real and larger dispersion for the internal pressure risk of the PCCV would be induced by adopting the proposed internal pressure risk assessment method. The strategy of the addition of steel fiber to the conventional PCCV can decrease the internal pressure risk by about 72.1 % on average.
Read full abstract