分层γ扫描方法测量球形容器核材料滞留量  

Segmented Gamma Scanning Method for Measuring Holdup in the Spherical Container

作　　者：邓景珊 李泽[2] 甘霖[2] 卢文广[2] 董明理[2] 

机构地区：[1]核工业第五研究设计院,郑州450052 [2]中国原子能科学研究院,北京102423

出　　处：《核电子学与探测技术》2007年第5期895-900,904,共7页Nuclear Electronics & Detection Technology

摘　　要：核材料生产线上很多设备(如混合器、反应器设备)是球形结构,在生产过程中,内部会有核材料滞留。知道内部核材料的滞留的数量,对于核材料管理与衡算和核材料临界安全至关重要。本文研究对象为球形反应器内部核燃料滞留量的测量,该反应器左面、右面和后面都有其他设备,测量仪器只能放在其前面的有限空间内进行测量。为此,本文提出探测器分层扫描方法,首先认为球形容器内部的核材料近似球形分布,自上而下分成若干层,在每一层上近似认为滞留的核材料是均匀分布,探测器自上而下逐层进行扫描测量,获取数据;利用蒙特卡罗随机过程模拟方法,计算探测器对每一层的探测效率,应用最小二乘法或最大似然法,对核材料分布进行重建计算,这样不仅可以给出比较准确的反应器内部核材料的总量,而且还可以给出核材料在内部的分布的大致情况。本文采用蒙特卡罗模拟计算和实验两个方面,对该方法进行了验证,证明该方法是正确的。Some special nuclear material（SNM） is inevitably deposited in the facilities（mixer,reactor） of nuclear material process line.Exactly knowing the quantity of nuclear material holdup is very important for nuclear material accountability and critical safety.This paper presents segmented gamma scanning method for SNM holdup measurement of spherical container,at the left,right and back of which other equipments exsit so that the detectors can be put at the only front of container for measurement.The nuclear material deposited in the spherical container can be looked as spherical shell source,which is divided into many layers.The detectors scanning spherical shell source are moved layer by layer from the top to the bottom to obtain projection data,with which deposited material distribution can be reconstructed by using Least Square（LS） method or Maximum Likelihood（ML）method.With these methods accurate total holdup can be obtained by summing up all the segmental values reconstructed.In this paper this measurement method for holdup in the spherical container was verified with Monte-Carlo simulation calculation and experiment.

关 键 词：球形反应器 滞留量 最大似然法 分层γ扫描 蒙特卡罗 

分 类 号：TL7[核科学技术—辐射防护及环境保护]