title: Radioactive contamination of the Balchug (Upper Yenisey) floodplain, Russia in relation to sedimentation processes and geomorphology.
abstract: The radioactive contamination of a riverine floodplain, heavily influenced by discharges from Krasnoyarsk-26, has been studied with respect to sedimentation processes and the geomorphology of the Upper Yenisey floodplain. The study was effected by implementation of a regime of in situ observations and measurements, sampling, and the interpretation of satellite images. The results of the study indicate that on the Balchug Bypass Floodplain, radionuclide contamination is primarily influenced by the thickness of the deposited sediments, and the area can be considered as two depositional environments. The Balchug floodplain area was contaminated due to sedimentation of radionuclide-contaminated alluvium, whose depositional regime significantly changed after the construction of a hydroelectric power station in 1967. Contamination levels are lower on the upstream part of the floodplain where sediment depth is less than 0.2-0.3 m, and this contamination started to accumulate in 1967, while the downstream part of the floodplain, exhibiting deeper deposits, displays higher levels of radionuclide contamination because radionuclides began to deposit here in 1958 when the Krasnoyarsk-26 Mining and Chemical Combine (KMCC) commenced operation. Radionuclide contamination of the floodplain is also related to the elevation of the floodplain, higher regions of the floodplain typically having lower contamination than low-lying areas, which tend to be frequently inundated with sediments being deposited during such inundations. Local relief, its orientation, and vegetation cover have also combined to form sediment traps with significantly higher radionuclide contamination. Lithological analysis combined with radiometric assay indicates a total 137Cs floodplain inventory of 33.7 GBq.
authors.affiliation: Vernadsky Institute of Geochemistry and Analytical Chemistry, Kosygin Street 19, 117975, Moscow, Russia.
authors.forename: V G
authors.initials: VG
authors.lastname: Linnik
authors.forename: J E
authors.initials: JE
authors.lastname: Brown
authors.forename: M
authors.initials: M
authors.lastname: Dowdall
authors.forename: V N
authors.initials: VN
authors.lastname: Potapov
authors.forename: V V
authors.initials: VV
authors.lastname: Surkov
authors.forename: E M
authors.initials: EM
authors.lastname: Korobova
authors.forename: A G
authors.initials: AG
authors.lastname: Volosov
authors.forename: S M
authors.initials: SM
authors.lastname: Vakulovsky
authors.forename: E G
authors.initials: EG
authors.lastname: Tertyshnik
mesh_terms: D002588:Cesium Radioisotopes / Q000032:analysis*; D004784:Environmental Monitoring; D005843:Geography; D019015:Geologic Sediments / Q000032:analysis*; D010316:Particle Size; D011829:Radiation Dosage; D011874:Radiometry; D045483:Rivers / Q000737:chemistry*; D012426:Russia; D012990:Soil Pollutants, Radioactive / Q000032:analysis*; D014872:Water Movements; D014875:Water Pollutants, Radioactive / Q000032:analysis*; D014881:Water Supply
chemical_list: D002588:Cesium Radioisotopes; D012990:Soil Pollutants, Radioactive; D014875:Water Pollutants, Radioactive