Natural Radionuclides in the Building Materials From the Region of The Small Carpathians (original) (raw)
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Minerals
Stara Planina (also known as the Balkan mountain range) is known for numerous occurrences and deposits of uranium and associated radionuclides. It is also famous for its geodiversity. The geologic framework is highly complex. The mountain is situated between the latitudes of 43 • and 44 • N and the longitudes from 22 • 16 to 23 • 00 E. Uranium exploration and radioactivity testing on Stara Planina began back in 1948. Uranium has also been mined in the zone of Kalna, within the Janja granite intrusive. The naturally radioactive geologic units of Stara Planina are presented in detail in this paper. The main sources of radioactivity on Stara Planina can be classified as: 1. Granitic endogenous-syngenetic-epigenetic deposits and occurrences; 2. Metamorphogenic-syngenetic; and 3. Sedimentary, including occurrences of uranium deposition and fluctuation caused by water in different types of sedimentary rocks formed in a continental setting, which could be classified under epigenetic types. The area of Stara Planina with increased radioactivity (higher than 200 cps), measured by airborne gamma spectrometry, is about 380 square kilometers. The highest values of measured radioactivity and uranium grade were obtained from a sample taken from the Mezdreja uranium mine tailing dump, where 226 Ra measures 2600 ± 100 Bq/kg and the uranium grade is from 76.54 to 77.65 ppm U. The highest uranium (and lead) concentration, among all samples, is measured in graphitic schist with high concentrations of organic (graphitic) material from the Inovska Series-99.47 ppm U and 107.69 ppm Pb. Thorium related radioactivity is the highest in granite samples from the Janja granite in the vicinity of the Mezdreja granite mine and the Gabrovnica granite mine tailing dump, and it is the same-250 ± 10 Bq/kg for 232 Th, while the thorium grade varies from 30.82 to 60.27 ppm Th. In gray siltstones with a small amount of organic material, the highest radioactivity is related to potassium-2080 ± 90 Bq/kg for 40 K.
Natural radioactivity of rocks from the historic Jeroným Mine in the Czech Republic
Environmental Earth Sciences
This study reports the natural radioactivity of characteristic rocks found in the historic Jeroným Mine of the Czech Republic as measured under the laboratory conditions. The rocks analyzed included granites and schists weathered to varying degrees and collected from different levels of the underground workings of the Jeroným Mine. The mine itself has been subject to metal extraction (mainly tin and tungsten) since the sixteenth century and has recently been developed as a cultural and scientific attraction open to the public. Activity concentrations of 40K, 232Th and 238U were measured from nine rock samples using gamma-ray spectrometry. The activity concentrations of 40K varied from 595 Bq kg−1 to 1244 Bq kg−1, while 232Th varied from 25 Bq kg−1 to 55 Bq kg−1. The activities associated with 238U ranged from 46 Bq kg−1 to 386 Bq kg−1. The measured activities were used to estimate two radiation hazard indices typically applied to building materials, the activity concentration index ...
Journal of Radioanalytical and Nuclear Chemistry
The natural radioactivities of five characteristic igneous rocks of the eastern foreland of the Opava Mountains (Eastern Sudetes, Poland), obtained in the laboratory and under in situ conditions, are presented. The activity concentrations of 232 Th, 238 U, and 40 K were measured using an HPGe gamma-ray spectrometry system. The ranges of the activity concentrations of 232 Th were 7-71 Bq kg-1 in the laboratory and 6-68 Bq kg-1 for the in situ measurements. For 238 U, the ranges of the activity concentrations were 5-52 Bq kg-1 in the laboratory and 9-48 Bq kg-1 for the in situ measurements, and for 40 K, the ranges were 520-1560 Bq kg-1 in the laboratory and 537-1700 Bq kg-1 for the in situ measurements. These determined activity concentrations were compared with the average activity concentrations of the radionuclides in similar types of rocks and with data from the Sudetes available in the literature. No significant differences were found between the in situ and laboratory measurements.
Journal of Environmental Radioactivity, 2004
The natural radioactivity of 40 K, 208 Ti, 212 Pb, 212 Bi, 214 Pb, 214 Bi, 228 Ac and the fallout of 137 Cs in typical rocks and soils of Ś wieradó w Zdró j area (Sudetes Mountains, Poland) were measured in situ using a portable gamma-ray spectrometry workstation. The measurement points were chosen for different regional lithology: within hornfelses of the Szklarska Poręba schist-belt, quartz rocks, gneisses of the Ś wieradó w Zdró j unit, leucogranites, leptinites, mica schists of the Stara Kamienica belt, and finally the zones of the southern and northern contacts of the Stara Kamienica schist-belt with leucogranites and gneisses of the Lesna unit, respectively. 40 K activity varied in the range from about 320 Bq kg À1 (quartz) to 1200 Bq kg À1 (gneisses). The activity concentrations associated with 228 Ac ( 232 Th series) varied in the range from 25 Bq kg À1 (quartz) to 62 Bq kg À1 (leucogranites), whereas activity concentration of 226 Ra varied in the range from about 31 Bq kg À1 (hornfelses) to 122 Bq kg À1 (leucogranites). Relatively low deposits of 137 Cs were noted in the investigated area, where the activity concentrations ranged from 4001 (hornfelses) Bq m À2 to less than 154 Bq m À2 (leucogranites). #
2018
The study involved investigation of the relationship between the radon concentrations in the ground air – and thus in the indoor air – and the geological structure of the Lubelskie Voivodeship (eastern Poland). Both passive and active methods were used for measuring the radon concentrations in coal, phosphate and chalk mines, caves, wells as well as indoor environments. The study also included elemental, uranium and lead isotope analyses of rocks. The performed research showed that Paleogene and Mesozoic sedimentary rocks rich in radionuclides are the sources of radon in the Lubelskie Voivodeship. In the case of the buildings located in proximity to such rocks, characterized by relatively high radon exhalations, radon remediation methods are recommended. Already at the designing stage of buildings, the measures which protect against the hazardous radon gas should be applied.
Applied Sciences
The specific activity and spatial distribution of 238U, 232Th and 40K were determined in the surface soil from the Lișava uranium mining sector. This sector belongs to the Banat district, an historically important uranium mining area in Romania (an area with closed uranium mines and a radioactive waste dump). Gamma-ray spectrometry using a high-purity germanium (HPGe) detector was used to measure the activity of naturally occurring radionuclides in the soil. The average specific activities of 238U, 232Th and 40K in the soil were 197.21 Bq/kg for 238U, 16.21 Bq/kg for 232Th and 543.21 Bq/kg for 40K. The mineral contents of selected waste rock samples (sandstones) were examined using a scanning electron microscope (SEM), which revealed that brannerite, pitchblende and coffinite were the most important uranium-bearing minerals. The means of the radiological hazard parameters were calculated to be 262.22 Bq/kg radium equivalent activity (Raeq), 123.72 nGy/h absorbed gamma dose rates (DR...
2019
To determine at which extent the remained radioactive rocks pose a treat to workers, high-resolution gamma spectrometry was used to estimate the contribution of the natural radionuclides K and Th and U radioactive series to the annual effective dose within the National Radioactive Waste Repository Baita, Bihor County, Romania. By using the activity to dose conversion coefficients as recommended by United Nations Scientific Committee on the Effects of Atomic Radiation Report (2012), the final results obtained for the annual dose due to natural radionuclides showed values between 0.29 ± 0.09 and 1.98 ± 0.14 mSv/y with an average value of 0.46 ± 0.45 mSv/y, values which are significantly lower than the thermoluminescence dosimeter (TLD) results previously reported of 1.55 ± 0.11 mSv/y. The relatively steadiness of the total annual effective dose distribution within repository as previously determined by TLD as well as its average value higher than those due to natural radioactivity of ...
226Ra activity distribution of rocks in the Sopron Mts. (West-Hungary)
Journal of Radioanalytical and Nuclear Chemistry, 2015
Radon gas is the largest natural source of human exposure to ionizing radiation and most of that exposure occurs in indoor air. Bedrock geology is an important factor in radon hazard evaluation of an area. The presence of rock types usually rich in uranium can be considered an indication of a potential radon hazard. In this study the average 226 Ra activity concentration of the main rock types (orthogneiss, micaschist, leucophyllite) in the Sopron Mountains was measured by gamma-spectroscopy, to reveal the uranium rich areas. This work is focusing on the distribution of 226 Ra among the different rock types of the Sopron Mountains with similar geological origin. The effect of different retrograde processes such as mylonitisation, fluid migration and argillitic-limonitic alteration on 226 Ra activity concentration was investigated. A few anomalies occurred in these metamorphic rocks. One explanation of the high uranium concentration is the high radioactive level of the rocks before the metamorphosis, but we demonstrated the significance of the above mentioned secondary processes as well. At Nándormagaslat quarry the presence of radium anomaly we found in the limonitic alteration of weathered gneiss (range: 131-726 Bq kg-1) in fractures explains the high air concentration nearby in houses (96-2,051 Bq m-3) and in a corresponding tunnel (maximum 600 kBq m-3).
Concentration of 226Ra in rocks of the southern part of Lower Silesia (SW Poland)
Journal of Environmental Radioactivity, 2004
The aim of the article is to present a preliminary description of rocks in the southern part of Lower Silesia and the Sudety Mountains in particular, with regard to 226 Ra content. The research demonstrates that the average content of this isotope was 40.4 Bq/kg in the rocks of the southern part of Lower Silesia, and 41.7 Bq/kg in the rocks of the Sudetes. These values are slightly higher than the mean 226 Ra content in the upper part of the Earth's crust, while the measured maximum content of this isotope (244 Bq/kg) is more than twice as high as the upper range of the values most frequently recorded in the upper part of the Earth's crust. The minimum values were lower than the detection limit, which was about 1 Bq/kg. These results reflect the mosaic-like geological structure of Lower Silesia, and particularly the Sudety Mountains, the occurrence of SiO 2 -rich igneous rocks and the products of their metamorphism, as well as numerous manifestations of uranium mineralisation or even deposital concentrations of this element. The rocks with the highest 226 Ra contents include (in decreasing order): aplites, granites, gneisses and leucogranites, granite-gneisses, granodiorites and rhyolites, and, finally, mudstones. The lowest values of 226 Ra content, on the other hand, were measured in sandstones, marls and conglomerates, and extremely low-in marbles and quartzites. The results show that background values of 226 Ra content in the rocks of the southern part of Lower Silesia fall within a range from several to about 100 Bq/kg, which is the same as the range most frequently recorded in the upper part of the Earth's crust. Distribution of these values has log-normal character.
In the article are included some parts of the results of the modelling of the behavior of the natural radionuclides and the risk for the environment for the technogenic soils formed after underground and open uranium ore extraction and zonal soil types in the area of 30 sites in the forests of Bulgaria (Stara Planina massif, Rila-Rhodope massif and Transko Kraishte). The modelling performed is based on the established strong negative linear correlations between the studied radionuclides and the pH. With reducing the acidity with one pH unit-the prognosis is for increasing the content of radionuclides (232 Th-section "V shaft" mine, 238 U-"Ribaritsa" mine, 40 K, 232 Th-"Yavorovets" mine, 40 K, 232 Th, 226 Ra, 238 U-"Selishte" mine, 226 Ra, α-activity-"Zdravetz" mine). The environmental risk is significant due to the stimulation of the processes of weathering and release of pollutants. In conclusion, some good practice examples have been proposed as possibilities for reducing the environmental risk, following the re-cultivation of the "Kurilo" mine-"Iskra" section and the "V shaft" section. The technologies used in the re-cultivation are developed on the basis of the specific activity of 226 Ra in the soil. These technologies can be used in sites with a similar activity of 226 Ra in the soil.