PROBABILISTIC ASSESSMENT OF AIRCRAFT RISK FOR NUCLEAR-POWER PLANTS

The risk to the public from an aircraft striking a nuclear power plant has been evaluated in a quantified manner. Aircraft accident data have been analyzed to estimate the probability of an aircraft striking a typical nuclear power plant at sites adjacent to and remote from an airport. In the event that an aircraft strikes a building, the region of impact is generally restricted to a local component. Two modes of significant damage are delineated: (1) perforation and (2) local collapse. Methods have been developed to estimate the conditional probabilities of such structural damage given an aircraft strike and probability values calculated for a representative structure. Actual risk to the public (probability vs. radioactive-release magnitude) may be estimated from a classification of critical safety components by their structural protection and the likely release magnitude in the event of their damage. Comparison of these risks to socially acceptable risk levels shows that reactor sites beyond 5 miles from an airport or away from a busy air corridor should be acceptable. Other potential sites need individual examination, and in some cases, hardening of the structure may be necessary.