堆芯流量变化对压力容器水位测量影响分析

摘要

The CCMS ( Core Cooling and Monitoring System ) calibration test for CPR 1000 nuclear power plants has to be performed during every refueling outage to obtain the core dynamic pressure loss coefficients necessary for calculating the reactor water level (LVSL), which is time-consuming.This paper evaluates the disturbance to core dynamic pressure loss coefficients based on the deviation of the primary coolant flow during the commis -sioning and the refueling outage , and quantificationally analyzes the impacts on LVSL measurement.The results show that in condition that there is no distinct change in loop hydraulic characteristic , the error introduced to LVSL measurement is quite small .It is advised to introduce the impact of changes of core dynamic pressure loss into the estimation of the L VSL measurement uncertainty , and verify whether the impact on core dynamic pressure loss due to flow changes is in allowed range or not during the subsequent refueling outage , which can simplify the CCMS calibration test and enhance the economic behavior of the unit .%CPR1000核电厂在每次换料大修期间需执行CCMS（ Core Cooling and Monitoring System ）校验试验，以获得计算压力容器水位LVSL所需的堆芯动态压头损失系数，完成该试验耗时较长。论文依据调试和换料大修期间一回路冷却剂流量的变化情况评估堆芯动态压头损失系数的变化，并定量评价对LVSL测量的影响。分析结果表明，在回路水力特性未发生明显变化的情形下，对LVSL测量引入的误差很小。建议在LVSL测量不确定度评定时引入堆芯动态压头损失变化的影响，在换料大修时校验流量变化对堆芯动态压头损失的影响是否在允许范围之内，可简化CCMS校验试验，提升机组的经济性。