Multi-Hazard Risk Assessment of South Korean Nuclear Power Plants

Abstract

Multi-hazard risk assessments of potential earthquake-triggered tsunamis with the positive contribution of climate change-related sea level rise (SLR) are performed for Hanul and Shin-Hanul (originally the Uljin), Kori and Shin-Kori, and Wolsong and Shin-Wolsong Nuclear Power Plants (NPPs) throughout the 21st century. Logic tree approach is used to construct probabilistic tsunami hazard model for evaluating the inundation levels at the coast of each NPP. Hypothetical earthquake sources are generated throughout the East Sea (Sea of Japan) using Monte Carlo Simulations. Epistemic uncertainty of the sea level rises and aleatory variability of the tsunami hazards is considered for stochastic multi-hazard assessment. Tsunami simulations are performed using revised bathymetric levels based on SLR projections of different Shared Socioeconomic Pathways (SSP) revealed by the Intergovernmental Panel on Climate Change (IPCC). Tsunami hazard curves are presented to determine the level of the adverse effects of SLR on tsunami inundations for the projected years. Environmental risk assessment is conducted by evaluating multi-hazard curves. The results show that the effect of SLR will be extremely significant on tsunami inundation levels, especially for the worst-case scenario estimated by IPCC. Depending on the multi-hazard risk assessments, Hanul NPP is the only site to survive against the worst-case scenario. Wolsong and Shin Wolsong NPP is under moderate multi-hazard risk. Whereas, Kori and Shin-Kori NPP may encounter a destructive multi-hazard environmental risk according to the analysis conducted in this study.