 The Three Mile Island accident inspired Perrow's book "Normal Accidents", where a nuclear accident occurs, resulting from an unanticipated interaction of multiple failures in a complex system.TMI was an example of a normal accident because it was "unexpected, incomprehensible, uncontrollable and unavoidable".The World Nuclear Association has stated that cleanup of the damaged nuclear reactor system at TMI-2 took nearly 12 years and cost approximately US$973 million.