Radioecology studies in the vicinity of a closed uranium mine

Abstract

Although the influential area of the former uranium mine ať Zirovski vrh, Slovenia has been under continuous radiological monitoring, more detailed radioecology studies, focused on assessing mobility and bioavailability of deposited radionuclides, were initiated about five years ago. The mobility of 238 U, 234 U, 230 Th and 226 Ra was studied applying two sequential extraction protocols. The results revealed that both sequential extraction protocols are not comparable as the data obtained are protocol-and radionuclide-dependent. It was found that the most mobile ones were uranium isotopes, followed by 226 Ra and 230 Th. In addition, uptake of particular radionuclides by the wetland plants (Molinia arundinacea, Juncus effusus and Caltha palustris) grown in soils contaminated with seepage waters from the tailings was studied. The plants contained higher levels of 238 U, 226 Ra and 230 Th compared to the plants from the control site. Activity concentration of 226 Ra was the highest for all three plant species. Activity concentration of natural radionuclides in milk collected from the area ofŽirovski vrh was comparable to the reference location, except for uranium where the content was higher. The combined annual effective dose for adults consuming milk from theŽirovski vrh area is 13 ± 2 μSv yr −1 . *

Uranium decay daughters from isolated mines: Accumulation and sources

“…Sequential extractions were also performed on selected samples according to the revised standardized 3-step procedure of Rauret et al (1999). In this study, F1 is the acidosoluble fraction, F2 and F3 are the reducible and the oxidizable one respectively, and finally F4 is the residue.…”

“…A technique widely used to understand the distribution of trace elements in the different solid phases is sequential selective chemical extraction. With that in mind, the revised standardized 3-step procedure of Rauret et al (1999), developed within the framework of the Standards, Measurements and Testing Program (SMTP), offers many benefits, since it is easy to use, rapid, and frequently applied in the case of environmental contamination due to uranium mining and/ or processing (Dhoum and Evans, 1998;Martin et al 1998;Howe et al 2002;Meca et al 2012;Smodi s et al 2012; Strok and Smodi s, 2013).…”