Abstract— Two closely located major sources of radioactive contamination are operating in the Middle Urals: the Beloyarsk Nuclear Power Plant (BNPP) and Institute of Reactor Materials (IRM). The contamination density of automorphic soils with 239,240 Pu is at the global background level, and that with 90 Sr and 137 Cs, at the level of regional background formed by radionuclides of different genesis deposited from the atmosphere. The front of radioactive contamination has shifted to deeper parts of the soil profile during the past 35 years. Based on the results of our research, the area of deposition of the BNPP and IRM emission plume has been delimited for the first time. The contribution of these sources to its contamination with 137 Cs reaches 2.7 kBq/m 2 . Agreggated transfer coefficients for plants in the BNPP zone are higher than in the East Ural Radioactive Trace, where 90 Sr and 137 Cs contamination levels are three to four orders of magnitude higher than the background levels. These coefficients depend on the properties of radionuclides and taxonomic identity of plants and decrease with time. This temporal trend is explained by decrease in atmospheric fallout, vertical migration of radionuclides, and increasingly tight 137 Cs fixation in soils.

中文翻译：

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核企业影响区陆地生态系统土壤和植物中的技术放射性核素

摘要——两个位置接近的主要放射性污染源在中乌拉尔地区运行：别洛亚尔斯克核电站 (BNPP) 和反应堆材料研究所 (IRM)。239,240 Pu自形土的污染密度处于全球背景水平，而90 Sr和137 Cs的污染密度处于由大气沉积的不同成因放射性核素形成的区域背景水平。在过去的 35 年中，放射性污染的前沿已经转移到土壤剖面的更深部分。根据我们的研究结果，首次划定了 BNPP 和 IRM 排放羽流的沉积区域。这些来源对其 137 Cs 污染的贡献达到 2.7 kBq/m 2 。BNPP 区植物的总转移系数高于东乌拉尔放射性痕迹，其中 90 Sr 和 137 Cs 污染水平比背景水平高三到四个数量级。这些系数取决于放射性核素的特性和植物的分类特性，并随着时间的推移而减少。这种时间趋势的原因是大气沉降物的减少、放射性核素的垂直迁移以及土壤中 137 Cs 的固定越来越紧密。