In this work, we present a method to use the European nuclear emergency response system RODOS for analysis of potential sources of airborne radioactivity of an unknown origin. The method is based on a solution of adjoint equations, without modification of the code of long-range atmospheric dispersion model MATCH used in RODOS. The method has been successfully applied to the Ru-106 accident of 2017. The obtained spatial distribution of the correlation between simulations and measurements which could be achieved with source located in a given place, is in a qualitative agreement with analogous results published in other works. The high correlation is centered on the Ural Mountains; this is explained by a very wide expansion of the plume. However, the location of the maximum correlation obtained in this work is in the northern part of Russia, close to a military test site on Novaya Zemlya. This location is far away from the reprocessing plant Mayak in the South-Eastern Urals mentioned in other investigations as the most probable location of the source. In the results presented here, the correlation at the source location corresponding to the Mayak plant is still quite high (0.49); release inventory from this source of about 300 TBq could explain the observed measurements.

在这项工作中，我们提出了一种使用欧洲核应急系统RODOS来分析来源不明的空中放射性潜在来源的方法。该方法基于伴随方程的解，无需修改RODOS中使用的远程大气弥散模型MATCH的代码。该方法已成功应用于2017年的Ru-106事故。所获得的模拟与测量值之间的相关性的空间分布（在特定位置处存在源可实现），在质量上与其他工作中发表的类似结果相一致。 。高度相关性以乌拉尔山脉为中心；这可以通过羽状流的广泛扩展来解释。但是，这项工作获得的最大相关性位于俄罗斯北部，靠近Novaya Zemlya上的军事测试场。该位置远离东南乌拉尔的玛雅克后处理厂，在其他调查中被称为最可能的源头位置。在此处显示的结果中，与Mayak植物相对应的源位置的相关性仍然很高（0.49）；此来源释放的大约300 TBq的库存可以解释观察到的测量结果。