国产应力波检漏设备应用于某核电厂的验证分析

Verification and Analysis of the Application of the Domestic Stress Wave Leak Detection Equipment in a Nuclear Power Plant

采用国产和进口应力波设备对国内某核电厂2号机组10台GCT阀门进行内漏诊断和对比分析,结果显示:两台设备测试的结果基本保持一致,对阀门泄漏均有较好的敏感性;大修期间对GCT阀门解体检修,检修结果显示应力波能量值较高的GCT阀门的主阀瓣、主阀座、先导阀瓣、先导阀座均存在明显的不同程度的蒸汽冲刷痕迹,与诊断结果一致,说明国产应力波设备可以准确判断阀门是否存在内漏;GCT-05的内漏诊断结果与解体检修结果之间存在偏差,测温结果也显示在开展应力波测试时阀后的温度也处于偏低的水平,说明阀门的内漏状态并不是恒定的,会受阀门的整体状态影响。

The internal leakage diagnosis and comparative analysis of 10 GCT valves of Unit 2 of a nuclear power plant in China were carried out by using domestic and imported stress wave equipment.The results show that the test results of the two equipment are basically consistent,and they have good sensitivity to valve leakage;During the overhaul,the GCT valve was disassembled for maintenance.The maintenance results showed that the main disc,main valve seat,pilot valve disc and pilot valve seat of the GCT valve with high stress wave energy value had obvious steam scouring traces of varying degrees,which was consistent with the diagnosis results,indicating that the domestic stress wave equipment could accurately judge whether the valve had internal leakage;There is a deviation between the internal leakage diagnosis result of GCT-02 and the result of disassembly and maintenance.The temperature measurement result also shows that the temperature behind the valve is also at a low level during the stress wave test,indicating that the internal leakage state of the valve is not constant and will be affected by the overall state of the valve.