防城港核电站堆内中子通量测量系统指套管碰磨分析

防城港核电站1号机组主泵惰走试验期间,在对核电站松脱部件和振动监测系统13路加速度通道进行背景噪声例行检查时发现,通过松脱部件和振动监测系统的声音监听设备监测到,安装于反应堆压力容器底部堆内中子通量测量系统导向管上通道有"哒哒哒"的异常信号。为找出异常信号源,利用松脱部件监测系统声监测功能对压力容器底部监测到的异常信号进行分析,该信号不是由松脱部件产生的信号。通过听音棒的辅助监听,最后综合分析得出该信号是由堆内中子通量测量系统指套管在管道路径上碰磨引起。该事件的分析与解决,不仅解决了工程建设需要,对核安全局批准下一步工作开展提供了支持依据,而且对通过松脱部件监测系统来开展由于流致振动引起的中子通量测量系统指套管异常振动诊断有重大的实用价值。

Impact Analysis of Thimble Tube of Neutron Flux Measurement System In Fang Cheng Gang Power Station

During coastdown test of main coolant pump of Fang Cheng Gang Nuclear Power 1# unit,Background noise of 13 acceleration channels is routine checked by loose parts and vibration monitoring system. Abnormal signal of "dadada"on reactor vessel bottom is monitored by sound monitoring equipment of loose parts and vibration monitoring system. In order to find out the abnormal signal source,the abnormal signal of the reactor vessel bottom is analyzed by the use of loose parts monitoring system of acoustic monitoring function. The acoustic signal is not produced by loose parts,the signal come from thimble tube pipeline path impact of neutron flux measurement system by the auxiliary monitoring of listening rod and the comprehensive analysis of the acoustic signal. By analysis and solution of the event,not only to solve the engineering construction needs,but also to provide support for the approval of the next step work by National Nuclear Safety Administration. It is of great practical value to carry out thimble tube abnormal vibration diagnosis of the neutron flux measurement system due to flow induced vibration by the loose parts monitoring system.