深度次临界工况下的控制棒价值测量技术研究  

Study on control rod worth measurement technique under deep subcritical condition

作　　者：司胜义 卑华 陈伦寿 钱仲悠 杜超 高明敏 杨高升 SI Shengyi;BEI Hua;CHEN Lunshou;QIAN Zhongyou;DU Chao;GAO Mingmin;YANG Gaosheng(Nuclear Power Operations Research Institutes,Shanghai 200126,China;Sanmen Nuclear Power Co.,Ltd,Sanmen 317100,China)

机构地区：[1]核电运行研究(上海)有限公司,上海200126 [2]三门核电有限公司,三门317100

出　　处：《核技术》2025年第1期153-161,共9页Nuclear Techniques

摘　　要：与传统控制棒价值测量技术不同,深度次临界工况下的控制棒价值测量(以下简称次临界刻棒),依托达临界试验的提棒过程,在全插棒至全提棒的大跨度临界区间进行控制棒价值测量。作为一种全新的控制棒价值测量方法,其棒价值的计算和分析与传统的方法有较大的差异,需要开展相关研究。深度次临界工况下,堆芯中子源强的空间分布显著不均匀,传统的基于点堆模型的临界外推公式不再适用,须对源量程中子计数率进行相应的空间修正,确保修正后的源量程探测器的计数率倒数比与反应堆次临界度维持良好的线性关系,从而能够精确预测反应堆的次临界度,并通过拟合的方式给出不同棒组的价值。为了对次临界刻棒系统进行验证,在三门核电厂AP1000机型上开展了两次验证试验,各组棒价值均满足验收准则。验证结果表明,开发的次临界刻棒系统具有一定的可靠性,能够满足次临界刻棒试验的要求。[Background]In a series of startup physics tests,measuring the control rod worth is a critical means to determine whether the actual worth of the control rods matches the design values.This test ensures that the reactivity of the reactor can be precisely controlled through the control rods,thereby ensuring the safe operation of the reactor.Traditional methods for this measurement include the boron dilution method and the dynamic rod worth measurement method.Although these methods are now widely used in nuclear power plants(NPP),there is still potential for further improvement in both safety and economic performance.Subcritical control rod worth measurement does not require equipment transformation and on-site operations,which makes it easier to implement whilst control rod worth measurement under deep subcritical conditions is totally a different technique with respect to traditional control rod worth measurements,which changes the reactor condition from the Low Power Physics Test(LPPT)window after reaching criticality to the Criticality Approach Test(CAT)window before reaching criticality.The test conditions vary from near-critical condition to deep subcritical condition,making the core much safer.[Purpose]This study aims to minimize the risk of core re-criticality during control rod withdrawal by measuring control rod worth within existing test windows without occupying the critical path.[Methods]Subcritical control rod worth measurement was implemented within the window of startup physics tests,saving outage time and improving the economic efficiency of the power plant,hence no additional work was required for subcritical control rod worth measurement test,except for collecting relevant data while measuring the worth of control rods during the test.Two functional modules,namely the spatial correction factor calculation module and the data processing and display module were developed for subcritical control rod calibrating system.Under deep subcritical conditions,the traditional point reactor model was no longe

关 键 词：次临界度 控制棒价值测量 源量程探测器 计数率倒数比 空间修正因子 

分 类 号：TL375[核科学技术—核技术及应用]