反应堆中子倍增特性分析及标定技术研究

针对反应堆用核测量仪表的反应堆周期测量标定问题,从理论推导和实堆数据验证两方面研究了反应堆中子倍增特性,并确定了使用指数变化规律的信号可以表征反应堆中子注量率随时间的变化特性。为全面标定核测量仪表的反应堆周期测量性能,结合中子探测器输出信号微弱的特点,提出了基于数字技术实现反应堆周期信号模拟的方案。方案包括硬件和软件两方面,识别了关键问题,并设计解决了高精度定时和微弱信号输出问题。同时,研究了仪表的标定方法并按方法对反应堆周期信号输出的性能进行测试。在反应堆周期值为2 s~999 s的范围内,选取7个反应堆周期值进行测试,测试偏差绝对值的最大值为0.45%。

Analysis of Neutron Multiplication Characteristics of Reactors and Study on Calibration Technique

Aiming at calibration of reactor period measurement for reactor nuclear measuring instrumentation, the neutron multiplication characteristics of reactors were studied from the aspcet of theoretical derivation and verification of real stack data, and it was determined that signals with exponential variation laws can characterize the change characteristics of reactor neutron fluence rate over time. In order to fully calibrate the reactor period measurement performance of nuclear measurement instruments, considering the neutron detectors output signal weakly, it proposed a reactor period signal simulation scheme based on digital technology. The scheme includes both hardware and software aspects, identifying key issues, and designing solutions to high-precision timing and weak signal output issues. At the same time, the calibration method was studied, by which the reactor period signal output performance was tested. Within the range of reactor period values from 2 s to 999 s, seven values were selected for testing, and the maximum absolute value of the test deviation was 0.45%.