Assumed Process of Piping Failure in Nuclear Power Plants Under Destructive Earthquake Conditions

This paper deals with an assumed process of piping failure in nuclear power plants which may cause a catastrophic accident during a destructive earthquake condition. The type of failure discussed is the so-called double-ended guillotine break, DEGB. As a safety problem, we are going to eliminate this type of failure by LBB, and we have assumed that this would then not occur by an earthquake. The author tries to clarify the possibility of failure during earthquakes. He reviews his related papers since 1973, and discusses zipping failure of snubbers and supporting devices. He shows a procedure to simulate the zipping failure of a piping system supported by snubbers.