Study on the Application of Probabilistic Tsunami Hazard Analysis for the Nuclear Power Plant Site in Korean Peninsula

Abstract:

The necessity of study on the tsunami hazard assessment for Nuclear Power Plant (NPP) site was suggested since the event of Fukushima in 2011 had been occurred. It has being emphasized because all of the NPPs in Korean Peninsula are located in coastal region. The tsunami hazard is regarded as the annual exceedance probability for the wave heights. The methodology for analysis of tsunami hazard is based on the seismic hazard analysis. The seismic hazard analysis had been performed by using both deterministic and probabilistic method. Recently, the probabilistic method had been received more attention than the deterministic method because the uncertainties of hazard analysis could be considered by using the logic tree approach.

In this study, the probabilistic tsunami hazard analysis for Uljin NPP site was performed by using the information of fault sources which was published by Atomic Energy Society of Japan (AESJ). The wave parameter is the most different parameter with seismic hazard. It could be estimated from the results of tsunami propagation analysis. The TSUNAMI_ver1.0 which was developed by Japan nuclear energy safety organization (JNES), was used for the tsunami simulation. The 80 cases tsunami simulations were performed and then the wave parameters were estimated. For reducing the sensitivity which was encouraged by location of sampling point, the wave parameters were estimated from group of sampling points.

The probability density function on the tsunami height was computed by using the recurrence intervals and the wave parameters. And then the exceedance probability distribution was calculated from the probability density function. The tsunami hazards for the sampling groups were calculated. The fractile curves which were shown the uncertainties of input parameters were estimated from the hazards by using the round-robin algorithm. In general, tsunami hazard analysis is focused on the maximum wave heights. But the minimum wave height should be considered for the tsunami hazard analysis on the NPP site since it is connected with water intake system. The results of tsunami hazard analysis for the NPP site was suggested by the annual exceedance probability with the wave heights. This study shows that the PTHA method could be applied for the estimation of tsunami wave height in NPP sites