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J C Lozano - One of the best experts on this subject based on the ideXlab platform.
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fractionation of Natural Radionuclides in soils from a uranium mineralized area in the south west of spain
Journal of Environmental Radioactivity, 2005Co-Authors: P Blanco, Vera F Tome, J C LozanoAbstract:A new version of a classical method was applied to study the distribution of Natural Radionuclides (238U, 230Th, and 226Ra) in the soil fractions obtained by a sequential extraction procedure. The potential significance of the fractions obtained with this method was tested on two very similar soils but with very different contents of the three Radionuclides, collected in the proximity of a disused uranium mine located in the Extremadura region in the south-west of Spain. The results confirmed that, if only non-residual fractions are considered, the sequential method applied shows a characteristic speciation pattern of these Natural Radionuclides in this soil matrix, i.e., the distribution of each of the three Radionuclides was very similar for the two soil samples.
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soil to plant transfer factors for Natural Radionuclides and stable elements in a mediterranean area
Journal of Environmental Radioactivity, 2003Co-Authors: Vera F Tome, M Blanco P Rodriguez, J C LozanoAbstract:The transfer factors (TF) for Natural uranium isotopes (238U and 234U), thorium isotopes (232Th, 230Th and 228Th), and 226Ra were obtained in plant samples (grass-pasture) growing in granitic and alluvial soils around a disused uranium mine located in the Extremadura region in the south-west of Spain. Affected and non-affected areas of the mine presented large differences in the activity concentrations of Radionuclides of the uranium series. We also determined transfer factors for several stable elements (essential and non-essential). A set of statistical tests were applied to validate the data. The results showed that the transfer factors for both the Natural Radionuclides and the stable elements are independent of the two substrate types involved and also of the two areas considered in the study.
R.j. Meijer - One of the best experts on this subject based on the ideXlab platform.
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mcnp modelling of scintillation detector γ ray spectra from Natural Radionuclides
Applied Radiation and Isotopes, 2002Co-Authors: P H G M Hendriks, Marko Maucec, R.j. MeijerAbstract:gamma-ray spectra of Natural Radionuclides are simulated for a BGO detector in a borehole geometry using the Monte Carlo code MCNP. All gamma-ray emissions of the decay of K-40 and the series of Th-232 and U-238 are used to describe the source. A procedure is proposed which excludes the time-consuming electron tracking in less relevant areas of the geometry. The simulated gamma-ray spectra are benchmarked against laboratory data. (C) 2002 Elsevier Science Ltd. All rights reserved.
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Natural Radionuclides as tracers of the dispersal of dredge spoil dumped at sea
Journal of Environmental Radioactivity, 2001Co-Authors: L B Venema, R.j. MeijerAbstract:Monitoring large (underwater) surfaces, with rapidly varying composition, requires a sampling density which exceeds the capabilities of standard techniques. These techniques involve sample collection and a number of treatments and measurements in the laboratory; both steps are laborious, tedious and costly. This paper presents an in situ method in which a detector system is trailed over the surface and measures continuously the gamma rays emitted by the Natural Radionuclides in the sediment. Since each sediment component has its own characteristic set of activity-concentration values (radiometric fingerprint), the composition of the sediment can be deduced quantitatively. This paper shows the application of this technique for monitoring the dispersal of dredge spoil from Rotterdam harbour, dumped in the North Sea. In addition to a qualitative picture of dredge spoil dispersal, a mass balance equation has been used to quantitatively assess the dredge spoil transport with time.
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Natural Radionuclides as tracers of the dispersal of dredge spoil dumped at sea
Journal of Geochemical Exploration, 2001Co-Authors: L B Venema, R.j. MeijerAbstract:Monitoring large (underwater) surfaces, with rapidly varying composition, requires a sampling density which exceeds the capabilities of standard techniques. These techniques involve sample collection and a number of treatments and measurements in the laboratory; both steps are laborious, tedious and costly. This paper presents an in situ method in which a detector system is trailed over the surface and measures continuously the gamma rays emitted by the Natural Radionuclides in the sediment. Since each sediment component has its own characteristic set of activity-concentration values (radiometric fingerprint), the composition of the sediment can be deduced quantitatively. This paper shows the application of this technique for monitoring the dispersal of dredge spoil from Rotterdam harbour, dumped in the North Sea. In addition to a qualitative picture of dredge spoil dispersal, a mass-balance equation has been used to quantitatively assess the dredge spoil transport with time. (C) 2001 Elsevier Science Ltd. All rights reserved.
Vera F Tome - One of the best experts on this subject based on the ideXlab platform.
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fractionation of Natural Radionuclides in soils from a uranium mineralized area in the south west of spain
Journal of Environmental Radioactivity, 2005Co-Authors: P Blanco, Vera F Tome, J C LozanoAbstract:A new version of a classical method was applied to study the distribution of Natural Radionuclides (238U, 230Th, and 226Ra) in the soil fractions obtained by a sequential extraction procedure. The potential significance of the fractions obtained with this method was tested on two very similar soils but with very different contents of the three Radionuclides, collected in the proximity of a disused uranium mine located in the Extremadura region in the south-west of Spain. The results confirmed that, if only non-residual fractions are considered, the sequential method applied shows a characteristic speciation pattern of these Natural Radionuclides in this soil matrix, i.e., the distribution of each of the three Radionuclides was very similar for the two soil samples.
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soil to plant transfer factors for Natural Radionuclides and stable elements in a mediterranean area
Journal of Environmental Radioactivity, 2003Co-Authors: Vera F Tome, M Blanco P Rodriguez, J C LozanoAbstract:The transfer factors (TF) for Natural uranium isotopes (238U and 234U), thorium isotopes (232Th, 230Th and 228Th), and 226Ra were obtained in plant samples (grass-pasture) growing in granitic and alluvial soils around a disused uranium mine located in the Extremadura region in the south-west of Spain. Affected and non-affected areas of the mine presented large differences in the activity concentrations of Radionuclides of the uranium series. We also determined transfer factors for several stable elements (essential and non-essential). A set of statistical tests were applied to validate the data. The results showed that the transfer factors for both the Natural Radionuclides and the stable elements are independent of the two substrate types involved and also of the two areas considered in the study.
Borut Smodiš - One of the best experts on this subject based on the ideXlab platform.
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Partitioning of Natural Radionuclides in sediments around a former uranium mine and mill
Journal of radioanalytical and nuclear chemistry, 2013Co-Authors: Borut Smodiš, Marko ŠtrokAbstract:Partitioning of Natural Radionuclides in sediments from streams affected by the waste piles of the former uranium mine and mill located atZ irovski vrh, Slovenia, was performed by applying a sequential extraction procedure. The sediments were collected at three sites located upstream and three sites located downstream of the waste piles. Then the four-step Community Bureau of Reference (BCR) sequential extraction protocol was applied to the samples and the Natural Radionuclides 238U, 230Th, 226Ra, 210Pb and 210Po were analysed in each extraction fraction. It was expected that the fractionation of Natural Radionuclides originating from the waste piles would differ from that upstream of the influence of waste piles because their chemical environment had been altered during the processes of uranium extraction. This difference could allow tracing of the Radionuclides coming from the waste piles downstream of the affected watercourses. The results definitely showed that the total activity concentrations at sites downstream of the influence of the waste piles were higher than at sites upstream of the piles. However, this difference was geographically very limited and could no longer be detected already at a distance of about 5 km downstream. Unexpectedly, the fractionation of Radionuclides upstream and downstream of the area of influence of the waste piles did not appear to be significantly altered. The sole differences found were for 238U and 226Ra in the second fraction (the Fe/Mn oxides fraction) and for 210Po in the fourth fraction (the residue fraction) of the BCR sequential extraction protocol.
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Transfer of Natural Radionuclides from hay and silage to cow's milk in the vicinity of a former uranium mine.
Journal of environmental radioactivity, 2012Co-Authors: Marko Štrok, Borut SmodišAbstract:Abstract After the closure of the former Žirovski Vrh uranium mine in Slovenia, mining and milling wastes were deposited on two waste piles, which are located close to the mine. These wastes contain elevated levels of Natural Radionuclides from the uranium decay chain. Due to different migration processes (erosion, aerial deposition, through groundwater), these Radionuclides can be transported via fodder into cow’s milk, which is an important foodstuff for Slovenian people. Therefore, Natural Radionuclides were analysed in the transfer food chain from soil to cow’s fodder and cow’s milk. After sampling, 238 U, 234 U, 230 Th, 226 Ra, 210 Pb and 210 Po were determined using radiochemical separation methods and alpha spectrometry or proportional counting. Hay and silage to milk concentration ratios (kg dry weight L −1 ) were calculated and were 0.260 for 238 U, 0.255 for 230 Th, 0.070 for 226 Ra, 0.021 for 210 Pb and 0.019 for 210 Po. The calculated annual ingestion dose due to milk consumption for the Natural Radionuclides analysed was 9 μSv/year for adults and 389 μSv/year for infants with the highest contribution of 210 Po (51% for adults and 63% for infants) and 210 Pb (36% for adults and 24% for infants). This study provides new data quantifying the transfer of Natural Radionuclides to milk, which is a parameter for which there have been very few previously reported values.
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Natural Radionuclides in sediments and rocks from Adriatic Sea
Journal of Radioanalytical and Nuclear Chemistry, 2010Co-Authors: Marko Štrok, Borut Smodiš, Branko PetrinecAbstract:During the International Scientific Cruise to Adriatic and Ionian Seas organised by the International Atomic Energy Agency, sediment and rock samples were collected. Sediments were sampled with grab corer at six locations in the Southeast Adriatic Sea. Rocks were collected on three islets in the Adriatic Sea. In the samples, Natural Radionuclides ^238U, ^234U, ^232Th, ^230Th, ^226Ra and ^210Pb were determined. After sampling and sample preparation, radiochemical separation procedures were applied. Then the samples were measured by alpha spectrometry system equipped with passivated implanted planar silicon detectors or by low background gas-flow proportional counter. Activity concentrations of Natural Radionuclides in samples were from 6.2 to 27.0 Bq/kg for ^238U, from 7.9 to 28.1 Bq/kg for ^234U, from 1.6 to 31.9 Bq/kg for ^232Th, from 9.7 to 42.0 Bq/kg for ^230Th, from 8.3 to 45.7 Bq/kg for ^226Ra and from 3.0 to 113.4 for ^210Pb. The obtained values are discussed in detail and compared with results of similar investigations carried out elsewhere.
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Natural Radionuclides in sediments and rocks from Adriatic Sea
Journal of Radioanalytical and Nuclear Chemistry, 2010Co-Authors: Marko Štrok, Borut Smodiš, Branko PetrinecAbstract:During the International Scientific Cruise to Adriatic and Ionian Seas organised by the International Atomic Energy Agency, sediment and rock samples were collected. Sediments were sampled with grab corer at six locations in the Southeast Adriatic Sea. Rocks were col- lected on three islets in the Adriatic Sea. In the samples, Natural Radionuclides 238 U, 234 U, 232 Th, 230 Th, 226 Ra and 210 Pb were determined. After sampling and sample prep- aration, radiochemical separation procedures were applied. Then the samples were measured by alpha spectrometry system equipped with passivated implanted planar silicon detectors or by low background gas-flow proportional counter. Activity concentrations of Natural Radionuclides in samples were from 6.2 to 27.0 Bq/kg for 238 U, from 7.9 to 28.1 Bq/kg for 234 U, from 1.6 to 31.9 Bq/kg for 232 Th, from 9.7 to 42.0 Bq/kg for 230 Th, from 8.3 to 45.7 Bq/kg for 226 Ra and from 3.0 to 113.4 for 210 Pb. The obtained
L B Venema - One of the best experts on this subject based on the ideXlab platform.
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Natural Radionuclides as tracers of the dispersal of dredge spoil dumped at sea
Journal of Environmental Radioactivity, 2001Co-Authors: L B Venema, R.j. MeijerAbstract:Monitoring large (underwater) surfaces, with rapidly varying composition, requires a sampling density which exceeds the capabilities of standard techniques. These techniques involve sample collection and a number of treatments and measurements in the laboratory; both steps are laborious, tedious and costly. This paper presents an in situ method in which a detector system is trailed over the surface and measures continuously the gamma rays emitted by the Natural Radionuclides in the sediment. Since each sediment component has its own characteristic set of activity-concentration values (radiometric fingerprint), the composition of the sediment can be deduced quantitatively. This paper shows the application of this technique for monitoring the dispersal of dredge spoil from Rotterdam harbour, dumped in the North Sea. In addition to a qualitative picture of dredge spoil dispersal, a mass balance equation has been used to quantitatively assess the dredge spoil transport with time.
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Natural Radionuclides as tracers of the dispersal of dredge spoil dumped at sea
Journal of Geochemical Exploration, 2001Co-Authors: L B Venema, R.j. MeijerAbstract:Monitoring large (underwater) surfaces, with rapidly varying composition, requires a sampling density which exceeds the capabilities of standard techniques. These techniques involve sample collection and a number of treatments and measurements in the laboratory; both steps are laborious, tedious and costly. This paper presents an in situ method in which a detector system is trailed over the surface and measures continuously the gamma rays emitted by the Natural Radionuclides in the sediment. Since each sediment component has its own characteristic set of activity-concentration values (radiometric fingerprint), the composition of the sediment can be deduced quantitatively. This paper shows the application of this technique for monitoring the dispersal of dredge spoil from Rotterdam harbour, dumped in the North Sea. In addition to a qualitative picture of dredge spoil dispersal, a mass-balance equation has been used to quantitatively assess the dredge spoil transport with time. (C) 2001 Elsevier Science Ltd. All rights reserved.
