重水堆核电厂大气释放阀维修策略和方法优化

Optimization of Maintenance Strategy and Method of Atmospheric Steam Discharge Valve in Heavy Water Reactor Nuclear Power Plants

重水堆核电厂大气释放阀因内漏导致阀后飘汽,分析内漏原因为阀门压紧力不足、行程不到位、定位器零位漂移、密封面夹杂异物或损伤等,通过历史缺陷原因分析、现场检查处理、解体检修等手段确认内漏原因。结合原厂设计文件,制作专用试验装置对阀门在线打压以确保试验合格。通过维修策略和方法优化保障阀门检修可靠性,规避内漏风险。

Steam leakage behind the valve caused by internal leakage of the atmospheric release valve of the heavy water reactor nuclear power plant.The causes of internal leakage were analyzed,such as insufficient compression force of valve,insufficient stroke,zero drift of positioner,foreign matter or damage on sealing surface,etc.The cause of internal leakage was confirmed by means of historical defect cause analysis,on-site inspection and maintenance.Combined with the original design documents,a special test device was made to online pressurize the valve to ensure that the test is qualified.The maintenance strategy and method are optimized to ensure the reliability of valve maintenance and avoid the risk of internal leakage.