论文部分内容阅读
近年来,国际社会对核材料保护、控制和衡算日益加强。对不明材料损失量(MUF)的关注逐渐提升。铀材料质量不确定性测量在估算铀材料生产量中扮演重要角色。由于铀材料自发裂变相对较弱,主动中子多重性法被应用于估算铀材料质量。通过拟合对不同系列铀金属壳的数值模拟结果,获得了描述铀材料质量与主动中子多重性特征之间的算法和参数。得到的关系表明,可以通过分析不同重数中子多重性探测结果获得铀部件的质量。对不同探测条件下的模拟结果的定量分析,确定了探测系统设置对铀质量估算的影响,以及认知不确定性和随机不确定在估算过程中传播对质量估算的影响。对不确定度的分析获得了本文模拟采用的探测系统的最佳源强和探测时间窗设置,在此设置下,质量估算的不确定性最小。
In recent years, the international community has steadily increased the control, protection and accounting of nuclear material. Concerns about the loss of unknown material (MUF) are gradually increasing. Measurement of uranium material quality uncertainty plays an important role in estimating uranium material production. Due to the relatively weak spontaneous fission of uranium materials, the active neutron multiplicity method is used to estimate the quality of uranium materials. By fitting numerical simulations of different series of uranium metal shells, algorithms and parameters describing the characteristics of uranium material mass and active neutron multiplicity were obtained. The obtained relationship shows that the quality of uranium parts can be obtained by analyzing the multiplicity detection results of neutrons of different weights. The quantitative analysis of simulation results under different detection conditions determines the impact of the detection system setup on uranium mass estimation, as well as the impact of cognitive uncertainty and random uncertainty on mass estimation in the estimation process. The analysis of uncertainty obtained the optimal source intensity and detection time window settings of the detection system adopted in this paper. Under this setting, the uncertainty of mass estimation is the smallest.