核电厂松脱部件报警案例分析

Case Analysis of Loose Parts Alarm in Nuclear Power Plants

针对某核电机组在大修热试阶段多次出现松脱部件报警的现象,在关键位置临时安装探头实施了现场试验,通过分析撞击信号阵发波到达传感器的时差对采集试验数据进行定位分析。结果表明,松脱部件报警事件的起源与核电机组热试相关状态改变有关;报警触发源位于主管道冷段上(距离压力容器入口1m处),事件是由于该位置的甩击限制器自发或间接将信号传导至主管道所导致的。此报警事件的成功诊断,不仅解决了工程实际问题,而且对现有松脱部件监测系统探测区间的完善具有重要意义。

In view of the phenomenon that several alarms of loose parts occurred in the thermal test phase of a nuclear power plant during the overhaul,a probe was temporarily installed at a key location for field test,and the event location of the collected test data was conducted by analyzing the time difference of impact signal array waves reaching different sensors.The results show that the origin of the alarm event of the loose part is related to the change of thermal test-related state of the nuclear power unit.The event may be due to the spontaneous or indirect conduction of the swing limiter at that location.The successful diagnosis of this alarm event not only solves the actual engineering problem,but also is with great practical value to improve the detection interval of the existing monitoring system for loose parts.