核电站冷却剂系统测温旁路支吊架失效原因分析及解决措施

An analysis and solution for the failures of the supports and hangers of the NPP coolant's temperature measurement pipline

采用Bentley AutoPIPE软件对在役检查经常出现支吊架失效的核电站冷却剂系统测温旁路管线进行静态分析。结果表明:弹簧吊架热态失载是由于主管道实际热位移偏离设计值,弹簧选型余量不足引起的。通过对弹簧吊架重新选型,其热态位移量在量程范围内,载荷变化率符合设计要求,且更改后的测温旁路一次应力、二次应力均符合规范要求。在随后的机组大修检查中,该条管线未再出现弹簧失效故障。

An static analysis of some NPP coolant’s temperature measurement pipeline, which supports and hangers were often disable in function found in-service inspection, was conducted by Bentley AutoPIPE.The results showed that the cause of spring hangers’ load loss beyond the scale range in thermal state was due to thermal displacement deviate from the design value and short margin of spring selection.After modification,thermal displacement of the spring hanger was in the scope of the scale and the spring load change ratio met the design requirements.And furthermore,the primary stress and secondary stress of the temperature measurement pipeline complied with the code requirements.During the following in-service inspection,no malfunction of spring was found in this pipeline.