摘要
在大多数反应堆中,为了增加堆芯寿命和提高经济效益,考虑在燃料棒中掺入一部分可燃中子毒物来增加其燃耗深度。铒(Er)是一种常见的可燃中子毒物,为了解决这类燃料棒生产过程中Er元素含量的在线监测问题,使用瞬发伽马活化分析技术(Prompt Gamma-ray Neutron Activation Analysis,PGNAA)对大体积样品进行了在线检测研究。利用镅铍(AmBe)同位素中子源和高纯锗搭建试验测量平台,选用氧化铒(Er_(2)O_(3))作为样品,同时结合MCNP进行模拟计算。结果显示,样品的质量和特征峰净面积在经过中子自屏蔽修正后成线性变化关系。该平台对铒元素的质量检测限为24.2 g,相对标准偏差为3.65%,相对误差为3.47%;准确度和精密度受数据统计涨落的影响,后续将对设备进行优化,以增加监测准确度和精密度。研究结果证明了利用该方法进行在线监测的可行性,并为后续使用热中子测量铒元素含量和修正大体积样品中子自屏蔽效应奠定了基础。
In the majority of reactors,a proportion of the combustible neutron poisons is incorporated into the fuel rods with the intention of increasing their burnup depth,thereby extending the operational lifespan of the core and enhancing the economic efficiency of the process.Erbium(Er)is a common combustible neutron poison,and in order to address the issue of on-line monitoring of the Er elemental content during the production of such fuel rods,a solution must be found.A novel approach,namely Prompt Gamma-ray Neutron Activation Analysis(PGNAA),is employed,which is well-suited to large-volume samples and can be detected online.Utilising the americium-beryllium(AmBe)isotope neutron source and high-purity germanium to establish an experimental measurement platform,with erbium oxide(Er_(2)O_(3))selected as the sample.This is also combined with the MCNP to perform simulation calculations.The results demonstrate that the mass and the net area of the characteristic peaks of the sample exhibit a linear variation after correction for neutron self-shielding.The mass detection limit of the platform for erbium was 24.2 g,with a relative standard deviation of 3.65%and a relative error of 3.47%.The accuracy and precision were affected by the statistical fluctuations inherent to the data set.Subsequent optimisation of the equipment will enhance the accuracy and precision.The results demonstrate the feasibility of this method for online monitoring and establish a foundation for the subsequent use of thermal neutrons to measure the elemental content of erbium and to correct the neutron self-shielding effect of large-volume samples.
作者
张镇华
庄皓为
贾文宝
王泽亮
张焱
程璨
ZHANG Zhenhua;ZHUANG Haowei;JIA Wenbao;WANG Zeliang;ZHANG Yan;CHENG Can(Nanjing University of Aeronautics and Astronautics,Nanjing 211106,China;Nanjing Tech University,Nanjing 211816,China;East China University of Technology,Nanchang 330013,China)
出处
《铀矿冶》
CAS
2024年第4期65-71,共7页
Uranium Mining and Metallurgy
基金
国家自然科学基金(12105143,42374226)
国家重点研发计划(2023YFF0717003)
江西省自然科学基金项目(20232BAB201043,20232BCJ23006)
江苏省市场监督管理局科技计划项目(KJ2024009,KJ2024044,KJ2023015)资助。
关键词
瞬发伽马活化分析
同位素中子源
镅铍源(AmBe)
质量检测限
氧化铒
中子自屏蔽校正
Prompt Gamma-ray Neutron Activation Analysis(PGNAA)
isotopic neutron source
americium-beryllium source
mass detection limit
erbium oxide
neutron self-shielding correction
