A review of multihazard risk assessment: Progress, potential, and challenges in the application to nuclear power plants

The risk of natural hazards is continuously increasing because of climate change and the ever-increasing population density. Therefore, understanding and mitigating the risks of natural hazards have become an essential task for critical infrastructure systems (CISs). Particularly, nuclear power plants (NPPs) exposed to multihazards, which are combinations of more than two natural hazards, can lead to severe outcomes. For example, the Fukushima NPP was damaged because of the Great East Japan earthquake and tsunami (2011) and is still at its recovery stage. Therefore, considering the significant consequences of these multihazards, it is essential to understand the phenomena and their effects on structure systems in a quantitative and probabilistic manner. However, compared with single hazard phenomena, concurrent and successive multihazards have not been relatively extensively studied because of their inherent complexity and limited availability of data. In this paper, we review multihazards in terms of the types of disaster combinations based on analysis level such as hazard, fragility, and risk assessment. Furthermore, state-of-the-art models have been reviewed and the progress, potential, and challenges in the application of multihazard risk research to NPPs are discussed.