AP1000功率量程核测仪表冷却剂密度补偿算法研究

Study of Coolant Density Compensation for AP1000 Power Range Nuclear Instrumentation

AP1000功率量程核测仪表基于堆芯外泄中子测量堆芯功率运行时的堆芯功率,堆外功率量程中子探测器由反应堆压力容器、堆内构件和下降段冷却剂进行屏蔽,在反应堆压力容器内外结构固定的情况下,功率量程探测器中子通量信号与下降段冷却剂密度相关,给测量结果带来偏差。给出一种密度补偿算法,对功率量程探测器中子通量信号因下降段冷却剂密度变化而引起的偏差进行补偿,以减少由其引起的测量误差。

AP1000 power range nuclear instrumentation measures the core power base on the neutrons leaking from the core during power operation. The reactor vessel wall, internals, and downcomer coolant shield the detector from fast neutrons. In the case of fixed structure of reactor vessel, the power range neutron flux detectors signal is therefore sensitive to the density of water in the downcomer, which leads to the errors. To compensate for this effect, an algorithm is provided to compensate the power range neutron flux detectors signal as cold leg density varies.