反应堆冷却剂流量质量位异常分析与处理

Analysis and Treatment of Quality Bit Anomaly of Reactor Coolant Flow Rate

针对海南昌江核电1、2号机组调试期间发生的单泵运行时环路上3个流量计全部超量程触发质量位异常现象,从反应堆冷却剂流量信号测量原理、停堆保护逻辑和质量位设置原则入手,对环路流量测量方法及冷停堆状态下流量信号实测数据进行了分析研究,指出现设计流量信号物理量程无法包络多种运行工况下的相对流量值。根据分析,需对流量计测量范围进行调整,使其输出的4~20 mA电流换算后对应的工艺流量量程从0~120%FP(FP为满功率)调整为0~129%FP(环路流量信号显示为X%FP,表示当前流量为相对满功率运行时流量的X%),并在调试期间将正常满功率运行时的流量计输出电流标定至13.615 mA。

Aiming at the phenomenon of over-range triggered quality bit anomaly of all three loop flowmeters during single pump operation in the commissioning of Hainan 1&2 units,the measurement method of loop flow rate and the measured data of flow signal in cold shutdown state are analyzed and studied based on the measurement principle of reactor coolant flow signal,shutdown protection logic and quality bit setting principle.This paper points out that the physical range of flow signal currently designed cannot envelope the relative flow rate value under various conditions.According to the analysis,it is necessary to adjust the measurement range of the flow meter so that the corresponding process flow range after converting the output 4~20 mA current is adjusted from 0~120%FP(FP is full power)to 0~129%FP(the loop flow signal shows X%FP,indicating that the current flow is X%of the relative flow rate during full power operation),and the current output of the flowmeters during the normal full power operation should be calibrated to 13.615 mA.