核测信号的主动降噪方法研究

Research on Active Noise Reduction Method for Nuclear Measurement Signals

由于核测系统输出信号微弱,在核电厂工程建设和运行阶段长期受到电磁干扰问题困扰。在传统电磁场降噪方案无法满足现场需求的情况下,提出了一种通过电磁波降噪的方案。通过对某压水堆(PWR)核电中子测量探头噪声异常问题进行实地排查,确定了噪声源和传输路径。对噪声产生的原理进行了理论分析,并构建降噪理论模型。结合压水堆核电站堆外核仪表系统供电特点,提出了利用电磁波的叠加原理进行降噪的方法。通过对比试验的方法验证,噪声幅值的最大值由110 mV降至31 mV,降噪有效率达78.1%,有效解决了该核电厂中子测量探头噪声异常的问题。该方法可以作为传统屏蔽降噪和距离降噪方案的有效补充,被广泛应用于同类问题的分析和处理。

Due to the weak output signal of nuclear measurement system,it has been plagued by long-term electromagnetic interference problems in the construction and operation of nuclear power plants.In the case that the traditional electromagnetic field noise reduction scheme cannot meet the needs of the site,a scheme of noise reduction by electromagnetic wave is proposed.The noise source and transmission path are determined through the on-site investigation of the abnormal noise of the nuclear neutron measurement probe of a pressurized water reactor(PWR).Theoretical analysis of the principle of noise generation is conducted,and a theoretical model of noise reduction is constructed.Combined with the power supply characteristics of the external nuclear instrument system of PWR nuclear power plant,a noise reduction method based on the superposition principle of electromagnetic wave is provided.The comparative test proves that the maximum noise amplitude is reduced from 110 mV to 31 mV,and the noise reduction efficiency is 78.1%.The problem of abnormal noise of the neutron probe in the nuclear power plant is effectively solved.This method can be used as an effective supplement to the traditional noise reduction schemes such as shielding noise reduction and distance noise reduction,and is widely used in the analysis and processing of similar problems.