Abstract

Long-term research has revealed layers with abnormally high concentrations of ¹³⁷Cs in bottom sediments and alluvial soils in the floodplain of the Yenisei River at various distances (as far as 820 km) downstream from the radioactive discharge point of the Mining-and-Chemical Combine (MCC) of Rosatom. The highest activity concentration of ¹³⁷Cs in these layers reached 26 000 Bq/kg, which was higher than the ¹³⁷Cs maximum at the well-known radioactive anomaly in the Yeniseisk riparian zone (330 km downstream from the MCC), which was formed during the 1966 extreme flood event. The radionuclide composition and the ¹³⁷Cs/¹⁵²Eu and ¹³⁷Cs/⁶⁰Co ratios in the anomalous layers studied were the same as those at the Yeniseisk anomalous site, suggesting that they had the same origin by the transport of sediments from the MCC area during the 1966 extreme flood event. The transport of radioactive bottom sediments over long distances from the MCC discharge point downstream along the Yenisei River during the 1966 extreme flood event may continue to pose a possible radiation hazard to the river ecosystem and residents of riverside villages.

中文翻译：

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1966 年极端洪水事件期间人工放射性核素沿叶尼塞河向下游长距离传输

摘要

长期研究表明，叶尼塞河泛滥平原底部沉积物和冲积土中¹³⁷ Cs浓度异常高，距离采矿和化学制品放射性排放点下游不同距离（最远 820 公里）。 Rosatom 的联合 (MCC)。这些层中¹³⁷ Cs的最高活度浓度达到 26 000 Bq/kg，高于叶尼塞斯克河岸带（MCC 下游 330 公里）的著名放射性异常处的¹³⁷ Cs 最大值，该异常形成于1966 年的极端洪水事件。放射性核素成分和¹³⁷ Cs/ ¹⁵² Eu 和¹³⁷ Cs/ ⁶⁰所研究的异常层中的 Co 比率与叶尼塞斯克异常地点的 Co 比率相同，表明它们具有相同的起源，原因是 1966 年极端洪水事件期间来自 MCC 地区的沉积物的运输。1966 年极端洪水事件期间，沿叶尼塞河下游的 MCC 排放点远距离输送放射性底部沉积物，可能继续对河流生态系统和沿河村庄的居民构成可能的辐射危害。