乏燃料后处理设施近实时衡算系统设计与初步评价

Design and Preliminary Evaluation of the Near Real-time Accounting System for a Reprocessing Facility

为对乏燃料后处理设施的核材料近实时衡算系统进行设计并开展初步评价,本研究基于传统的例行周期衡算,采用缩短衡算周期的方法,结合核材料存量数据,初步建立了核材料近实时衡算分析模型。采用国际原子能机构STR-193文件的参考200 MTHM/a设施及其运行数据,利用逐批误差计算与合成的模式,进行了不同周期的近实时衡算分析,并与例行闭合衡算的半年度分析数据进行了对比。基于上述衡算模型,采用时间关联的动态数据模拟,初步开展了动态分析和佩琦测试评价。结果表明,近实时衡算的方法可行,在该衡算模型下,以月度为衡算周期即可满足要求。累计和评价和佩琦测试对于核材料的大量突然流失均有效;佩琦测试在探测核材料累积流失方面,尤其是对于衡算周期较长的、接近探测限度的工况,其异常识别能力优于累计和评价,且误报警率能够得到控制。近实时衡算系统具有更加有效的异常探测能力,未来可用于核材料管理的动态趋势分析,提高核材料衡算管理的应用价值。

The near real-time nuclear material accounting system for a spent fuel reprocessing facility was designed and preliminarily evaluated.Based on routine cycle accounting and the method of shortening the traditional accounting cycle,combined with the inventory data of nuclear materials in process equipment or containers,a preliminary real-time accounting analysis model for nuclear materials has been established.This study employed the reference 200 MTHM/a facility and its operating data from the International Atomic Energy Agency's STR-193,the real-time balance calculation analysis across different time intervals was conducted by using a batch-wise error calculation and synthesized model.Comparative analysis was performed against semi-annual analysis data from routine closed balance calculations.The results indicate that near real-time accounting is feasible and a monthly calculation period is deemed sufficient under this specified balance model.A preliminary investigation of dynamic analysis and Page's test was conducted using time-correlated dynamic data simulation upon this balance calculation model.The results indicate that both cumulative and Page's test are effective in detecting significant sudden losses of nuclear materials.Page's test,particularly in detecting cumulative losses of nuclear materials,especially under conditions with longer accounting periods and approaching detection limits,demonstrates superior anomaly detection capabilities compared to cumulative evaluation,with the ability to control false alarm rate.The near real-time accounting system makes the entire system more effective in anomaly detection and can be used for dynamic trend analysis of nuclear material management in the future,thereby improving the application value of nuclear material accounting management.