Radionuclides in underground water in an area contaminated with uranium mill waste (original) (raw)
Related papers
Journal of Environmental Radioactivity, 2010
As a result of former uranium mining and milling activities at Žirovski vrh, Slovenia, 0.6 million tons of uranium mill tailings (UMT) were deposited onto a nearby waste pile Boršt. Resulting enhanced levels of natural radionuclides in UMT could pose threat for the surrounding environment. Therefore, sequential extraction protocol was performed to assess mobility and bioavailability of 238 U, 234 U, 230 Th and 226 Ra in soils from the waste pile and its surrounding. The radionuclides associated with exchangeable, organic, carbonate, Fe/Mn oxides and residual fraction, respectively, were determined. Results showed that the highest activity concentrations for the studied radionuclides were on the bottom of the waste pile. In non-contaminated locations, about 80% of all radionuclides were in the residual fraction. Considering activity concentrations in the UMT, 238 U and 234 U are the most mobile. Mobility of 226 Ra is suppressed by high sulphate concentrations and is similar to mobility of 230 Th.
Uranium and its decay products in samples contaminated with uranium mine and mill waste
Journal de Physique IV (Proceedings), 2003
The routine determination of the activity concentrations of uranium isotopes (mU, mU and 234U), thorium isotopes (212Th, 230TI, and 228Th), 23'Pa, 22'Ra, 210Pb and 210pro in the environment is one of the most important tasks in uranium mining areas. Natural radionuclides contribute negligibly to the extemal radiation dose, but in the case of ingestion or inhalation can represent a very serious hazard. The objective of this study was to determine the activities of uranium and its decay products 230Th, 231Pa, 226Ra, 210Pb alld 210po in sediments and water below sources of contamination (uranium mine, disposal sites and individual inflows) using gamma and alpha spectrometry, beta counting, me liquid scintillation technique and radiochemical neutron activation analysis.
Radioecology studies in the vicinity of a closed uranium mine
EPJ Web of Conferences, 2012
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 .
Radioprotection, 2011
Uranium mine Žirovski vrh in Slovenia was closed in the year 1993. In the past years a lot of work was done for restoration of the area around the mine. There are two tailing sites, Jazbec and Boršt, filled with material with high specific activity of 226 Ra. Tailings are covered by different layers of clay and soil in depth of 2 m for reducing radon exhalation rate. Gras, growing on the surface of tailing sites has been used as fodder for domestic animals. We were interesting about the amount of the specific activity of natural radionuclides 238 U, 226 Ra or 210 Pb, transferred from the covering soil on the tailing to the grass on the surface area. The transfer factors of naturally occurring radionuclides have not been studied to the same extent as their artificial counterparts, but some comprehensive investigations have been done by various institutions around the world. In case of 226 Ra calculated values are two times or four times bigger than measured. For 210 Pb measured values are up to hundred times bigger than calculated. The reason for that is radon in the air, decays to the 210 Pb, deposited on the grass and not 210 Pb coming from the soil.
Radiation Measurements, 2008
The alpha radioactivity of surface and ground water samples has been determined by liquid scintillation counting (LSC) after chemical preparation of the samples by cation exchange using the Chelex 100 resin. The method applied to certain natural waters is selective for uranium and the alpha radioactivity measured corresponds primarily to the uranium radioactivity in those systems. Method calibration using uranium standard solutions results in a detector efficiency of (97 ± 2)% and in a cation exchange separation efficiency of (85 ± 6)%. Application of the method to laboratory solutions of constant uranium concentration and variable composition (0.1, 0.5 and 1 M NaCl; 0.1 and 0.5 M Ca(NO 3) 2 ; 0.1 and 1 mM FeCl 3 ; 10 and 100 ppm SiO 2 ; 10 and 100 ppm humic acid) shows generally that the cation exchange efficiency is not significantly affected by the presence of major components, except for increased Fe(III) concentrations in a solution (> 0.1 mM). Radiometric analysis of local (Cypriot) natural waters showed that uranium concentration in ground waters varies strongly (1600-90 mBq l −1) depending on the hosting geological matrix, whereas surface waters contain relatively low uranium (40-110 mBq l −1) resulting in values for alpha radioactivity close to the detection limits of the method (30 mBq l −1).
2007
Blomqvist, Runar, Juhani Suksi, Timo Ruskeeniemi, Lasse Ahonen, Heikki Niini, Ulla Vuorinen, and Kai Jakobsson. The Palmottu Natural Analogue Project, Summary Report 1992-1994. The behaviour of natural radionuclides in and around uranium deposits, Nr 8. Geological Survey of Finland, Nuclear Waste Disposal Research, Report YST-88, 82 pages. ISBN 951-690-580-3. ISSN 07833555; also Finnish Centre for Radiation and Nuclear Safety, STUK-YTO-TR 84, Helsinki 1995. ISBN 951-712-033-8. ISSN 0785-9325. The Palmottu U-Th mineralization at Nummi-Pusula, southwestern Finland, has been studied as a natural analogue to deep disposal of radioactive wastes since 1988. This report gives a summary of the results of investigations carried out during the years 1992-1994. The Palmottu Analogue Project aims at a more profound understanding of radionuclide transport processes in fractured crystalline bedrock. The essential factors controlling transport are groundwater flow and interaction between water and...
Procedia Earth and Planetary Science, 2013
This paper presents results of detailed sampling of groundwater and surface water near the storage sites of radioactive waste from the Electrochemical Plant ECP (Zelenogorsk, Krasnoyarsk region, Russia) and the Angarsk Electrolysis Chemical Complex AEC (Angarsk, Irkutsk region, Russia), both of which have produced enriched uranium since 1960s. The liquid (LRW) and solid (SRW) radioactive wastes belong to the category of low-level activity waste. The main result is that the uranium is below the recommended MPC for drinking waters in all types of groundwater around the sludge of ECP and AEC. But alkaline nitrate solutions have been penetrating and spreading into the aquifers under the LRW sludge pits. According to our calculations, redox conditions in the groundwater influenced by discharge are controlled by the couple NO 3-/NO 2 that facilitates U(VI) migration. The groundwater under SRW repositories is distinguished by its low mineralization and neutral pH. Co-contaminants, such as Mo, V, and Zr may serve as markers of technogenous contamination in storage sites of the LRW sludge.
Dissolved radionuclide in the industrial effluent of uranium facilities, Jaduguda, India
International Journal of Low Radiation, 2014
Dissolved radionuclides in the effluent of uranium mining industry were studied. Activity concentrations of uranium and radium were estimated in effluent water from different uranium mines and mill tailings ponds. The concentrations of U and 226 Ra in untreated effluent water were found to be elevated. The concentrations of dissolved radionuclides in the adjacent aquatic streams and river were found to be of low range. The waste management technology used for removal process of dissolved radionuclides in the Effluent Treatment Plant (ETP) is found to be effective.
The article summarizes the activity concentrations data of 226 Ra and the sum of uranium isotopes (∑U) in samples of drinking underground water for different regions of Ukraine studied during 1998-2023 in the radiation monitoring laboratory of the State Institution "O.M. Marzieiev Institute of Public Health National Academy of Medical Sciences of Ukraine. Arithmetic mean and standard deviations, minimum and maximum values for 226 Ra and ∑U activity concentrations are presented for the entire 1240 sample set and for each region separately. Collected data show that the established state permissible level for drinking water of 1.0 Bq/l is exceeded for 226 Ra in 1.1% of the studied samples, and for ∑U-in 3.9% correspondingly. The detected high levels of 226 Ra and ∑U activity concentrations correspond to certain regions belonging to the Ukrainian crystalline shield territory. A comparison of the current data with the data of previous studies held during of 1989-1991 indicates a significant difference: for the previous studies the average and standard deviations are much higher. We attribute this to the fact that the centralized sampling of previous studies was random, and it was related exclusively to communal water supply systems. At the same time, the current sample set covers a much larger number of regions, different water consumers; the data set includes the results of repeated studies for a large number of sources, in particular, sources with purified water. Hypothetical exposure doses caused by consumption of 226 Ra and ∑U in water for the current sample set were estimated for different age groups for each sample studied, as is, without taking into account the pattern of water consumption. The corresponding dose exceeds the WHO recommended value of 0.1 mSv per year for children under the age of one year for 220 cases (17.7%). This dose limit excess for other age groups corresponds-for children: aged 12-17 years-13.1%, aged 1-2 years-7.4%, 7-12 years old-5.6%, 2-7 years old-3.9% and for adults-4.1%. Protection of underground water is commonly much higher than for surface water with regard to chemical and microbiological pollutants, which sets the priority of its use as drinking water source 1. At the same time, underground water contains natural radionuclides of the U and Th series. The radioactivity concentration in water is formed by the radioactive composition of the rocks, the level of fissuring of the rocks, the chemical properties of the water and the contact time of the water with the rocks 2. Author shoved scatted plot of uranium versus 226 Ra in random Australian ground water illustrating the lack of correlation between parent and decay product. The introduction of natural radionuclides into water occurs due to diffusion of gas (222 Rn) or leaching (U, Ra) from the surface of rocks. The chemical composition of water defines the intensity and priority of certain radionuclides leaching. High levels of natural radionuclides in drinking water are observed primarily for artesian wells with a depth of several tens to hundreds of meters, although in some places favorable conditions for the entry of natural radionuclides into water present even for aquifers with a depth of only a few meters or even for surface streams 3. In addition, high levels of natural radionuclides in surface water can form discharges from mining and processing industrial enterprises, mines.