Technogenic Fallout of Uranium and Thorium in Novosibirsk vicinity (Russia, West Siberia)
The article is devoted to the problem of technogenic pollution of environment: the results of the mineralogical and geochemical investigation of suspension content of melted snow and soils samples of Novosibirsk vicinity are considered. Content of U, Th and heavy metals were determined by means of X-ray fluorescence elemental analysis with synchrotron radiation (SR-XRF) method. For the 235U and 238U isotope analysis is used mass-spectrometry with inductively coupled plasma (ICP-MS) method. Mineral formations of aerosol particles were studied with scanning electron microscopy.
Previously shown that the V, Mn, I, Ga are the main geochemical indicators of emission of Novosibirsk heat and electric power plants (HEPP -2, -3, -5) [Artamonova, 2011]. But the Th and U is revealed to be the geochemical indicators of HEPP emission too. Brown coal of Kuzbas and Kansk-Achinsk coal basin are used as firewood of Novosibirsk TETs. Coal of these deposit basin is known to be enriched by heavy metals and natural radionuclides during their geological origin time. So, Th and U are significant in technogenic fallout of vicinity. This fact is confirmed by studies results: U and Th content in aerosols and soil of HEPP vicinity are a few times greater than in pure background cite.
The second source of U fallout are the emissions of the No¬vosibirsk Chemical Concentrates Plant (NCCP) of Rosatom State Nuclear Energy Corporation. Namely the isotope 238U/235U ratio is used as the main indicator of NCCP aerosol pollution. The maximal distance of NCCP emission plume is revealed to arrive by 70 km, where 238U/235U ratio of aerosol is 132.1 3.3. The 238U/235U increases up to about natural ratio 138.4 at 110 km far from NCCP emission northern east plume only. In the NCCP vicinity the particles of uranium oxides in technogenic aerosol were established by means of scanning electron microscopy. Thus the U, Th technogenic pollution of Novosibirsk vicinity is revealed. The ecological situation may be developed by heat and electric power plant modernization, by gaseous will stand the dominating firewood of Novosibirsk HEPP. The elemental SR-XRF analysis of snow precipitation and soil can be used to carry out a timely and reliable environmental assessment of an urban territory. The work was supported by the Russian Foundation for Basic Research under project No. 14-05-00289.