Risk assessment for nuclear power plants against natural disasters

With the increasing tendency of natural hazards, the typhoon/hurricane/tropical cyclone induced surge, wave, precipitation and river flood as extreme external loads not only menace Nuclear Power Plants (NPP) in coastal areas, but also some inland territorial NPP. For all of planned, designed and constructed NPP the National Nuclear Safety Administration of China and International Atomic Energy Agency (IAEA) recommended safety regulations for NPP site evaluation installation and coastal defense infrastructures. These standards include Probable Maximum Hurricane /Typhoon (PMH/T), Probable Maximum Storm Surge (PMSS), Probable Maximum Flood (PMF) as well as Design Basis Flood (DBF). This paper discusses the joint probability analysis of meteorological, oceanographic and hydrological hazards based on our proposed Compound Extreme Value Distribution (CEVD), Multivariate Compound Extreme Value Distribution (MCEVD), Double Layer Nested Multi-Objective Probability Model (DLNMOPM) and compares with IAEA 2006-2011 recommended safety regulation design criteria for NPP coastal defense infrastructures in China. During the past 34 years since our CEVD firstly used to predict typhoon/hurricane extreme sea hazards in China, US Atlantic and Gulf of Mexico areas, 2005 hurricane Katrina, Rita and 2012 hurricane Sandy induced disasters proved 1982 CEVD and 2006 MCEVD predicted extreme hazards in New Orleans, Gulf of Mexico and Philadelphian areas, similarly, 2013 typhoon Fitow induced disaster in Shanghai area proved MCEVD and DLNMOPM 2004-2006 predicted results. Safety regulation for some NPP constructed coastal defense infrastructures located along East and South China Sea which recommended by China and IAEA are much lower than 500 years return period typhoon induced sea hazards predicted by our proposed models. Some inland NPP are not only menaced by extreme precipitation and flood, but also landslides and debris flows triggered by rainfall for NPP around territories. Key-Words: Risk assessment; Nuclear Power Plant; Compound Extreme Value Distribution