4.6　Tsunami or Lake Surge Set-up

4.6.1　For coastal（lakeside）plant sites，the possibility that they are endangered by potential tsunami or lake surge in the region shall be evaluated.

4.6.2　The effects of tsunami or lake surge shall be analyzed by cross validating the tidal（water）level process line measured at the tide station（lake water level station）at or near the plant site with tsunami or lake surge data in modern time.

4.6.3　For plant sites subject to severe threat of tsunami or lake surge，the design basis flood level shall be determined by taking the maximum possible tsunami or lake surge as the major combination of events.

4.6.4　The study area with potential earthquake and tsunami shall be determined with earthquake and geological professionals.Multiple seismic and tsunami origins which may cause the severest effects on the plant site shall be forecasted.Besides，the parameters related to potential seismic and tsunami origins such as earthquake magnitude，the maximum vertical displacement of the stratum，the length and width of the epicenter（the area of tsunami origin），the depth，orientation and shape of seismic origin，and principal axis azimuth of the tsunami origin shall be determined.

4.6.5　Earthquake and tsunami can be simulated with a numerical model based on potential near-surface seismic origins，providing the maximum possible sea level rise and fall caused by earthquake and tsunami.The water level rise，tidal level record，tsunami observation report and other historical data as well as the consequent damage shall be analyzed to determine and verify if the simulated calculation of tsunami is correct.The computation results of maximum possible tsunami shall be analyzed for reasonableness，and verified for conservativeness in any case.

4.6.6　For tsunami caused by landslides，ice crumble，benthic sink and volcano eruption，mass shift，boundary conditions and other data may be used as input in the numerical model to simulate the formation and transmission of tsunami.