Was Three Mile Island a ‘Normal Accident’?

Abstract

Perrow’s normal accident theory suggests that some major accidents are inevitable for technological reasons. An alternative approach explains major accidents as resulting from management failures, particularly in relation to the communication of information. This latter theory has been shown to be applicable to a wide variety of disasters. By contrast, Perrow’s theory seems to be applicable to relatively few accidents, the exemplar case being the Three Mile Island nuclear power station accident in the U.S. in 1979. This article re‐examines Three Mile Island. It shows that this was not a normal accident in Perrow’s sense and is readily explicable in terms of management failures. The article also notes that Perrow’s theory is motivated by a desire to shift blame away from front line operators and that the alternative approach does this equally well.