Reliability analysis of stiff versus flexible piping. Status report

Conservative design procedures adopted for nuclear piping systems usually result in stiff piping designs that use excessive support devices such as rigid supports and snubbers. Use of these piping support devices has created safety concerns. This report describes the interim result for a piping research project conducted at Lawrence Livermore National Laboratory (LLNL) for the US Nuclear Regulatory Commission (NRC). The overall objective of this research project is to develop modified design requirements and criteria which will improve piping reliability and minimize the use of pipe supports, snubbers, and pipe whip restraints. The current study was conducted to establish the necessary groundwork for this work based on the piping reliability analysis