某压水堆核电厂稳压器排放管疲劳分析方法改进

摘要

稳压器排放管是某压水堆核电厂最重要的核一级管道之一.因稳压器与三组安全阀之间的U形液封管段存在热分层效应,管线承受显著热交变载荷,疲劳累积使用因子过高.根据RCC-M规范,建立管道局部有限元分析模型,采用“混合分析法”对计算分析方法进行改进.分析结果表明,该管线疲劳累积使用因子可显著降低.%Pressurizer relief piping was one of the most important nuclear class 1 piping in PWR nuclear power plant.Thermal stratification exist on the U shaped liquid seal section of piping between the pressurizer and three sets of safety valves,the pipeline was under cyclic thermal loading significantly,fatigue cumulative usage factor was too high.According to RCC-M code,finite element models of the local section on piping were built.Using the "mixed analysis method",fatigue analysis results were improved.The analysis result shows that the fatigue cumulative usage factor of the piping could be significantly reduced.