【摘要】 在压水堆组件核材料二氧化铀芯块无损分析中，铀含量和²³⁵U丰度是两个重要的分析参数，它能够反映核材料的状态，而无损分析首先需要相应的标准物质，因此准确分析铀含量和²³⁵U丰度非常重要。为了准确测定二氧化铀芯块中铀含量和²³⁵U丰度，核工业北京地质研究院组织多家实验室采用电位滴定法测定铀含量，采用热电离质谱法（TIMS）或多接收电感耦合等离子体质谱法（MC-ICP-MS）测定²³⁵U丰度。将获得的数据采用正态检验方法进行评价，通过统计产品与服务解决方案软件（SPSS）在线计算，铀含量和²³⁵U丰度的小样本数据统计结果p>0.05，没有呈现出显著性，说明该参数符合正态分布特征。评价了比对结果的不确定度，其中二氧化铀芯块中铀质量分数平均值为88.00%（n=6），相对不确定度为0.057%,²³⁵U丰度平均值为3.232 6%（n=6），相对不确定度为0.062%。通过比对分析得到了由二氧化铀芯块制造的标准压水堆组件中的铀含量及²³⁵U丰度，为后续压水堆无损分析方法研究提供了基础数据。更多还原

【Abstract】 Non-destructive analysis（NDA） techniques can be used to ensure that no sensitive nuclear materials（SNM） are being lost or diverted from their defined flows and containments.Rapid measurements of SNM in feed materials,process lines,finished products,scrap and waste,and holdup in the plant are all possible with NDA techniques.With the development of nuclear industry,it has also brought huge challenges to the supervision of nuclear security and nuclear material control.The NDA of pressurized water reactor fuel assemblies is one of the important technologies for nuclear security.The establishment of the NDA for pressurized water reactor requires the possession of corresponding nuclear material standard materials.Therefore,it is necessary to analyze the uranium content and ²³⁵U abundance accurately in the uranium dioxide pellets of standard pressurized water reactor components.China North Nuclear Fuel Corpotation prepared comparison samples and conducted a uniformity test on the samples.Through F test analysis,it was deemed that the samples had good homogeneity.Beijing Research Institute of Uranium Geology（BRIUG） organizes several laboratories to determine the content of uranium in uranium dioxide by potentiometric titration,and the abundance of ²³⁵U by TIMS or MC-ICP-MS methods.The samples are sent to different laboratories.Six laboratories conducted comparative analysis of uranium content and ²³⁵U abundance.After summarizing and comparing the results,through online SPSS calculations,the small sample data of uranium content and ²³⁵U abundance shows a p-value greater than 0.05,indicating no significant difference.This indicates that the parameter conforms to the normal distribution characteristics.The uncertainty of the comparison data results was evaluated,the uncertainty of sample measurement results refers to ISO guide 35 2017 reference materials:guidance for characterization and assessment of homogeneity and stability,which is mainly composed of three parts:stability uncertainty,homogeneity uncertainty and characterization uncertainty.The uranium content and abundance of ²³⁵U in the sample have good homogeneity,and its properties will not change with time.Moreover,the uncertainty caused by the inhomogeneity of the sample has been reflected in the comparison analysis,so in this calculation,the uncertainty components arising from sample inhomogeneities and instabilities are not considered.The average value of uranium mass fraction is 88.00%（n=6）,the relative uncertainty is 0.057%,and the measured average value of ²³⁵U abundance is 3.232 6%（n=6）,the relative uncertainty is 0.062%.The uranium content and ²³⁵U abundance in standard pres.surized water reactor components made of uranium dioxide pellets were obtained through comparative analysis,providing base data for subsequent research on non-destructive analysis methods for pressurized water reactors.更多还原