Study on Probability Safety Assessment Method of Small Aircraft Crash Event in a Nuclear Power Plant

Abstract

In nuclear power plants, one of the external human-caused events is aircraft crash. The method used to evaluate the risk of aircraft crash must comply with the requirements of national nuclear safety guidelines. When estimating the distance of aircraft from facility, the events for which the aircraft distance satisfying the screening guidelines may be left out of account firstly. While for those unmet, it is necessary to apply probability safety assessment to further study whether the risk of aircraft crash into nuclear power plants is within the probabilistic screening level. If the aircraft impact can not be eliminated through distance or probability screening, the next step is to identify the corresponding aircraft type, and determine the design basis of aircraft crash event as an input. For the purpose, this paper analyzes the impacts of small military airports near nuclear power plants, and researches into the probability safety assessment method for military aircraft impacting nuclear power plants, i.e., airport and non-airport operation risks. According to the study, the risk of airport operation can be ignored as the conditional probability f (x, y) representing the military aircraft falling to the site shows very low. Conservatively considering the military aircraft impact “four-factor formula parameters”, the aircraft crash impact frequency of non-airport operation is 6.23E−08/year, also the total impact frequency of military aircraft crash event, which is less than the screening level in terms of probability and meets the requirements of nuclear safety guidelines. This study aims at providing certain reference value for the establishment of design basis to protect nuclear power plants from aircraft crash.