次临界反应性测量的空间修正及其应用综述

The Spatial Effect in Subcritical Reactivity Measurement and Its Applications

次临界下的反应性测量技术有着自身的特点,次临界下控制棒的动作、堆芯的次临界度以及外中子源的存在都会对堆芯中子通量的分布产生影响,因此通常情况下堆芯的次临界度只能"监视",无法准确测量。在堆芯模拟软件发展的基础上,国外科研人员提出了次临界下点堆模型的空间修正方法,将这种方法用于动态棒价值测量(DRWM),并在此基础上进一步发展了次临界控制棒价值测量(SRWM),这些技术有的已经被国内核电站使用,但是国内对空间修正的原理及方法鲜有介绍。本文针对这种需求,总结概括了国外商用堆次临界反应性测量的基本原理与方法,并结合反应性测量仪表技术,给出了次临界反应性仪的数据处理流程,这对于推进国内商用堆次临界反应性测量的研究和实际应用具有较为重要的意义。

The technology of reactivity measurement in subcritical core has special feature since the distribution of core flux will be affected by the movement of the control rod, the core subcritical reactivity and the extraneous neutron sources. Therefore, in general, the subcritical core reactivity can only be ＂monitored＂ but never accurately ＂measured＂. With the development of core simulation codes, the foreign scientists have researched the spatially corrected methods applied to the point core in subcritical reactivity measurements. Based on these methods, the dynamic rod worth measurement （DRWM） and sub-critical rod worth measurement （SRWM） were applied in plant control rod worth measurements and some nuclear plants in China have used these methods but few people in China introduced the theory of spatially corrected methods.Based on this condition, this article summarized the theory and methods in subcritical core reactivity measurements and provided the data treating process using the reactivity measurement instruments. This will be useful to the research and application of suhcritical reactivity measurement in commercial nuclear power plants in China.