γ能谱法测量分析废包壳中铀和钚含量技术研究  

Analysis of Uranium and Plutonium Contentsin Leached Hulls by γ-ray Spectroscopy

作　　者：邵婕文[1] 柏磊[1] 王晶 SHAO Jiewen;BAI Lei;WANG Jing(Department of Radiochemistry,China Institute of Atomic Energy,Beijing 102413,China)

机构地区：[1]中国原子能科学研究院放射化学研究所,北京102413

出　　处：《原子能科学技术》2023年第5期1032-1039,共8页Atomic Energy Science and Technology

摘　　要：核电站运行产生的乏燃料,在进行水法后处理时,通过剪切、溶解、共去污、分离、纯化等工序提取其中的铀、钚及其他核素。乏燃料组件经剪切溶解后,溶解液进入后续化工工艺进行处理,燃料元件棒的包壳则保留在溶解器中,称为废包壳,其是水法后处理工艺高放废物的主要来源之一,因设施运行中核材料生产过程的衡算与控制要求,以及废物处理处置的技术需要,需分析其中的铀和钚的含量。本文建立了γ能谱法间接分析废包壳中铀钚含量的方法,采用分段扫描的方式对包壳桶进行分层测量,分析了每层废包壳中137Cs的含量,再利用经燃耗模型计算所得的137Cs与核材料含量的比值,间接获得了铀和钚含量。该方法充分利用了核材料裂变的物理规律,建立了典型裂变产物与铀和钚含量之间的关系,并通过分段测量分析获得基础数据后间接获得铀和钚的含量,在废包壳测量分析、乏燃料组件燃耗测量分析中均可应用,可为设施运行、核材料衡算、废物管理等提供技术支撑。For the spent fuel generated by the operationof nuclear power plant,uranium,plutonium and other nuclides are extracted through the processes of shearing,dissolution,co-decontamination,separation and purification during wet reprocessing.After the spent fuel assembly is sheared and dissolved,the solution enters the subsequent chemical process for treatment,and the cladding of fuel element rod is retained in the dissolver,which is called leached hulls.It is one of the main sources of high-level radioactive waste in wet reprocessing process.Due to the accounting and control requirements of nuclear material production process during facility operation,as well as the needs of waste treatment and disposal,it is necessary to analyze the contents of uranium and plutonium in the cladding.In this paper,a method for indirect analysis of uranium and plutonium contents in leached hulls byγspectroscopy was established.The leached hulls were measured by segment scanning,and the mass of 137 Cs in each layer of the leached hulls was analyzed.The ratio of 137 Cs and nuclear material can be used to calculate the uranium and plutonium mass.The physical law of nuclear material fission was utilized in this method,and the relationship between fission products and the mass of uranium and plutonium was established,and the mass of uranium and plutonium was indirectly obtained after obtaining the basic data through measurement and analysis.This method can be applied in leached hulls and spent fuel assembly burnup measurement and analysis,and provide technical support for facility operation,nuclear material accounting and waste management,etc.In the analysis of 137 Cs,the method of passive efficiency calibration was used to reconstruct the model of leached hulls and calculate the detection efficiency.In order to solve the limit of the number of sampled particles in the simulation calculation,the discrete division technique was used.In the experiment,137 Cs point source was used to verify the method.The results show that the activity deviati

关 键 词：乏燃料 废包壳 Γ能谱法 无源效率刻度 

分 类 号：TL364.5[核科学技术—核技术及应用]