Radionuclide speciation in sediments of the Yenisei River

Bolsunovsky, A. Ya.

doi:10.1051/radiopro/20116457s

Cited by 3 publications

(2 citation statements)

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“…Detailed radioecological studies of the Yenisey focusing on the contamination of water and sediments started only in the 1990s and were most frequent in the last decade (Sukhorukov et al 2000;Bondareva and Bolsunovskii 2008;Bondareva and Artamonova 2011;Sukhorukov et al 2004Sukhorukov et al , 2006Linnik et al 2005Linnik et al , 2006Vakulovsky et al 2006Vakulovsky et al , 2014Bolsunovsky 2011;Kropatcheva et al 2012;Korobova et al 2014). The main practical goal of these studies was to evaluate the level and extent of contamination and its radioecological significance.…”

Section: Introductionmentioning

confidence: 97%

Distribution of artificial radioisotopes in granulometric and organic fractions of alluvial soils downstream from the Krasnoyarsk Mining and Chemical Combine (KMCC), Russia

2015

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Purpose The purpose of this study was to compare the distribution of the most significant medium and long-lived radioisotopes, i.e., 60 Co, 137 Cs, and 152 Eu, in granulometric and organic fractions of alluvial soils downstream from the Krasnoyarsk Mining and Chemical Combine (KMCC), Russia, to reveal natural patterns of their behavior and accumulation. Materials and methods Soil samples collected at different elevations and depths in a floodplain of the Yenisey River downstream from the KMCC (20-250 km) were subjected to granulometric analysis by dry screening and a modified Petelin method. Fractions <0.05 mm were collected by a pipette method. Radionuclide activity in the different soil layers and in their fractions was determined using a spectrometer equipped with an HPGe detector. Concentration of total C (Ctot) and C of carbonates (Ccarb) was determined using a CHN analyzer before and after elimination of carbonates, organic C (Corg) being calculated as the difference between the obtained values. Organic fractions were separated by saturation of the air-dry sample with 0.1 M NaOH and further precipitation of humic acid from filtrate by 1 M HCl at pH 1. The separation resulted in three fractions of the fulvic acids, humic acids, and the residue containing the denuded mineral phase and the refractory organic residue. The selected bulk samples and fractions were analyzed for radionuclide activity. Results and discussion Based on earlier results, the distribution of the pelite (<0.01 mm) and aleurite (0.01-0.1 mm) fractions in alluvium and soil samples have been analyzed to evaluate the grain-size contribution to radionuclide fixation. A positive correlation between radionuclide activity and the portion of pelite fraction was established for 60 Co and 152 Eu, while 137 Cs accumulation was not related with this fraction. In organic matter (OM) extracts, more than 90 % of 137 Cs, at proportions similar to those attributable to 238 Th and 40 K, were associated with the residue fraction, while 72 % of 152 Eu and 46 % of 60 Co were found in the mobile fraction of the low molecular fulvic acids. In successive layers of the soil vertical profile, approximately 94 % of the 152 Eu variation may be explained by a linear model with Corg and Ccarb values as independent variables. Conclusions Different associations of 137 Cs, 60 Co, and 152 Eu with particulate and organic fractions in river sediments and floodplain soils could be explained by the dominating discharge form (water soluble or particulate), affinity to organic substances of different mobility, sorption by minerals and their aggregates, and chemisorption.

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Section: Introductionmentioning

confidence: 97%

Distribution of artificial radioisotopes in granulometric and organic fractions of alluvial soils downstream from the Krasnoyarsk Mining and Chemical Combine (KMCC), Russia

2015

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“…The radiochemical plant and other MCC facilities are still operating. Several scientific expeditions revealed that the Yenisei River floodplain is contaminated with artificial radionuclides, including plutonium isotopes, within 2000 km downstream of the MCC Klemt et al, 2002;Bolsunovsky & Bondareva, 2007;Bolsunovsky, 2010Bolsunovsky, , 2011Bolsunovsky & Dementyev, 2010;Semizhon et al, 2010). Since 1995, researchers of the Institute of Biophysics (Krasnoyarsk) and the Institute of Geology and Mineralogy (Novosibirsk) have found radioactive particles in floodplain soils and sediments during their sampling campaigns at the Yenisei (Bolsunovsky & Tcherkezian, 2001;Bolsunovsky, 2009;Chuguevskii et al, 2010).…”

Section: Introductionmentioning

confidence: 99%

A Study of Sediments and Radioactive Particles of the Yenisei River Using a Variety of Analytical Methods

Bolsunovsky¹,

Melgunov²

2014

GEP

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The Yenisei River, one of the largest rivers in the world, is contaminated with artificial radionuclides released by a Russian nuclear facility producing weapon-grade plutonium, which has been in operation for many years. Examination of Yenisei River sediment samples revealed the presence of artificial radionuclides typical of radioactive discharge from the Mining-and-ChemicalCombine (MCC) nuclear facility: isotopes of europium ( 152 Eu, 154 Eu, and 155 Eu), cesium ( 137 Cs and 134 Cs), 60 Co, 90 Sr, and transuranium elements. The MCC is also a source of radioactive particles in the Yenisei. New data on radionuclide concentrations in sediments and radioactive particles in the Yenisei River were obtained using a wide range of analytical methods. Sequential extraction performed on samples of sediment cores showed different degrees of potential environmental availability of artificial radionuclides and uranium. In a few samples, 241 Am was present in the unextractable form, which may be accounted for by the presence of microparticles of the reactor fuel. These microparticles were investigated using scanning electron microscopy, and their reactor origin was confirmed.

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