核电厂小支管裂纹泄漏原因分析和改造

Cause Analysis and Improvement of Crack Leakage of Small Bore Pipe in Nuclear Power Plants

采取试验与理论分析相结合的方法,分析诊断了核电厂安全壳喷淋系统小支管裂纹泄漏的根本原因,确定根本原因是主管道上的节流孔板设计不合理导致了小支管振动疲劳失效。设计多级节流孔板代替单级节流孔板,改造方案实施后,小支管振动大幅度降低,消除了影响核电机组安全运行的缺陷。

Based on the combination of experiment and theoretical analysis,the root cause for the crack leakage of the small bore pipe in the containment spray system of nuclear power plants was analyzed and diagnosed.It is determined that the root cause is that the unreasonable design of orifice plates in main pipes leads to the vibration fatigue failure of small bore pipes.The multi-stage orifice plate is designed to replace the single-stage orifice plate.After modification,the vibration of the small bore pipe is greatly reduced,and the defects affecting the safe operation of nuclear power units were eliminated.