CEA, DAM, DIF, F-91297, Arpajon, Cedex, France.
CEA, DAM, DIF, F-91297, Arpajon, Cedex, France.
J Environ Radioact. 2022 Oct;251-252:106980. doi: 10.1016/j.jenvrad.2022.106980. Epub 2022 Aug 12.
A global-scale simulation of the Xe atmospheric background is automated at the French National Data Center (NDC) for the purpose of categorizing the radionuclide measurements of the Comprehensive Nuclear-Test-Ban Treaty (CTBT) International Monitoring System (IMS). These simulations take into account Xe releases from all known major industrial emitters in the world, compiled from the literature and described as constant values. Emission data measured directly at the stack of the Institute for Radio Elements (IRE), a medical isotope production facility located in Fleurus (Belgium), were implemented in the simulations with a time resolution of 15 minutes. This work discusses the contribution of real (measured) emissions to the prediction of the Xe atmospheric background at IMS noble gas stations and at a location near Paris, for which IMS-like Xe measurements were available. For the purpose of this study, simulations initiated with the IRE measured emissions were run in parallel to those with the a priori emissions used to date. The benefits of including actual emissions in the simulations were found as a function of the distance between the station and the source of the release. At the closest stations, i.e., near Paris (France) and at Schauinsland, Freiburg (Germany), respectively 250 and 400 km from Fleurus, the simulated activity concentrations differed by a factor greater than 2 more than one third of the time, and by a factor of more than 5 about 10% of the time. No significant or detectable differences were found beyond 1500-2000 km. Furthermore, at the Paris station, the timing of the measured peaks was better reproduced with the actual emission data. However, not all peak amplitudes were correctly reproduced even though the real emissions were used, highlighting the remaining uncertainties, primarily in the meteorological data and transport modeling.
法国国家数据中心（NDC）对 Xe 大气背景的全球规模模拟实现了自动化，目的是对《全面禁止核试验条约》（CTBT）国际监测系统（IMS）的放射性核素测量进行分类。这些模拟考虑了来自世界上所有已知主要工业排放源的 Xe 释放，这些排放源是从文献中编译的，并被描述为恒定值。IRE 烟囱直接测量的排放数据（IRE 是位于比利时弗勒吕斯的一个医用同位素生产设施），被纳入了 15 分钟时间分辨率的模拟中。这项工作讨论了真实（测量）排放对 IMS 惰性气体站和巴黎附近 Xe 大气背景预测的贡献，因为在这些位置有 IMS 类似的 Xe 测量数据。为了进行这项研究，用 IRE 测量的排放启动的模拟与迄今为止使用的先验排放的模拟并行进行。将实际排放纳入模拟的好处是作为排放源与站之间距离的函数。在最近的站，即距离 Fleurus 分别为 250 和 400 公里的巴黎（法国）和 Schauinsland，弗赖堡（德国），模拟的活动浓度在三分之一以上的时间内差异超过 2 倍，在 10%左右的时间内差异超过 5 倍。在 1500-2000 公里以外，没有发现显著或可检测到的差异。此外，在巴黎站，测量峰值的时间更好地用实际排放数据再现。然而，即使使用了实际排放数据，也没有正确再现所有峰值幅度，这突出了仍然存在的不确定性，主要是在气象数据和传输建模方面。
