Radioactive contamination of permafrost-affected soils with 137Cs and 90Sr, the products of an accidental underground nuclear explosion

The specificity of contamination of permafrost-affected soils with radionuclides derived from an accidental underground nuclear explosion at the Kraton-3 polygon located in the northern taiga subzone has been studied in northwestern Yakutia. It is shown that the high density of the radioactive contamination is preserved in the soils 23 years after the nuclear accident. The concentrations of ¹³⁷Cs and ⁹⁰Sr vary from 34 to 1025 and from 57 to 781 kBq/m², respectively, which is 30–1000 times higher than the global fallout of these radionuclides.     

Content,Distribution, and Migration of 238U in Soils of Natural and Technogenic Landscapes of Southern Yakutia

Eurasian Soil Science - The contents, distribution in the profile, and migration capacity of 238U in automorphic podburs (Entic Podzols) and hydromorphic alluvial (Fluvisols) soils of natural and...     

Radioactive Contamination of Alluvial Soils in the Taiga Landscapes of Yakutia with <Superscript>137</Superscript>Cs, <Superscript>226</Superscript>Ra,and <Superscript>238</Superscript>U

The concentrations and distribution of ¹³⁷Cs in alluvial soils (Fluvisols) of the upper and middle reaches of the Markha River in the northwest of Yakutia and ²²⁶Ra and ²³⁸U in alluvial soils within the El’kon uranium ore deposit in the south of Yakutia have been studied. It is shown that the migration of radiocesium in the permafrost-affected soils of Yakutia owing to alluviation processes extends to more than 600 km from the source of the radioactive contamination. The migration of ¹³⁷Cs with water flows is accompanied by its deposition in the buried horizons of alluvial soils during extremely high floods caused by ice jams. In the technogenic landscapes of southern Yakutia, active water migration of ²³⁸U and ²²⁶Ra from radioactive dump rocks. The leaching of ²³⁸U with surface waters from the rocks is more intense than the leaching of ²²⁶Ra. The vertical distribution patterns of ²³⁸U and ²²⁶Ra in the profiles of alluvial soils are complex. Uranium tends to accumulate in the surface humus horizon and in the buried soil horizons, whereas radium does not display any definite regularities of its distribution in the soil profiles. At present, the migration of ²³⁸U and ²²⁶Ra with river water and their accumulation in the alluvial soils extend to about 30 km from the source.