A petri net methodology for modeling the resilience of nuclear power plants

In the paper, a novel Petri Net (PN) method for assessing the resilience of nuclear reactors is presented. The PN model constructed aims to simulate the failure of the subsystems in a reactor caused by either natural degradation or external disruptive events such as tsunamis and earthquakes, the resultant accidents due to the failure of different reactor subsystems, the responses of the reactor to different accidents, and the recovery and maintenance of the reactor after the accident. The simulation results are analyzed to identify the key characteristics of the resilience of the nuclear reactor. To demonstrate the feasibility and the capability of the proposed approach, the failure of four heat transport pumps in the primary cooling system of an experimental reactor is chosen as a case study. The research shows that PN modeling is an effective tool for evaluating the resilience of nuclear power plants.