SINGLE FAILURE EFFECTS OF REACTOR COOLANT SYSTEM LARGE BORE HYDRAULIC SNUBBERS FOR KOREAN STANDARD NUCLEAR POWER PLANT

摘要

A potential snubber single failure is one of the safety significances identified in General Safety Issue 113 for Large Bore Hydraulic Snubber (LBHS) dynamic qualification. This paper investigates dynamic structural effects of single failures of the steam generator and reactor coolant pump snubbers in Korean Standard Nuclear Power Plant by performing the time history dynamic analyses for the reactor coolant system under seismic and postulated pipe break events. The seismic input motions considered are the synthesized ground time histories conforming to SRP 3.7.1, and the postulated pipe break input loadings result from steam generator main steam line and feedwater line pipe breaks which govern pipe breaks remaining after applying LBB to the main coolant line and primary side branch lines equal to and greater than 12 inch nominal pipe size.