scholarly journals Measurement of natural radioactivity in rock samples using gamma ray spectrometry

2015 ◽  
Vol 38 (1) ◽  
pp. 11 ◽  
Author(s):  
Mohd Zubair
Author(s):  
Jiří Zimák

The objective of this study was to assess the amount of natural radionuclides in fresh parent rocks and their effect on natural radioactivity of soils developed from them. Forty-five fresh rocks consisting mainly of granitoids, syenitoids, acid to basic metavolcanites, mica schists, gneisses, quartzites, serpentinites, sandstones, graywackes, and limestones and their corresponding overlying soils were sampled for laboratory gamma-ray spectrometric analysis. Contents of potassium, uranium and thorium were converted to mass activity of 226Ra equivalent (am) and terrestrial gamma radiation dose rate (D). Data are tabled and discussed. The highest am values occured in syenitoids (386–441 Bq·kg-1) followed by granitoids, mica schists, greywackes and gneisses, whereas the lowest am values were found in quartzose sandstones (15–36 Bq·kg-1) followed by limestones (less than 15 Bq·kg-1) and serpentinites (less than 6 Bq·kg-1). The natural radioactivity of soils is usually slightly lower than that of parent rocks due to the lower content of potassium, uranium and thorium in soils. This is typical for granitoids, syenitoids and rocks of similar mineralogical composition. In soils developed on granitoids and syenitoids were found increased concentrations of all three elements in the grain size fraction below 0.063 mm. Soils developed on rocks with low natural radioactivity (such as limestones and serpentinites) tend to have significantly higher natural radioactivity than their parent rocks. This may complicate the interpretation of data obtained by airborne gamma-ray spectrometry.


2020 ◽  
Author(s):  
Jan Kisiel ◽  
Kinga Polaczek-Grelik ◽  
Katarzyna Szkliniarz ◽  
Agata Walencik-Łata ◽  
Jari Joutsenvaara ◽  
...  

<p>The BSUIN (Baltic Sea Underground Innovation Network) aims to enhance the accessibility of the underground laboratories in the Baltic Sea region for innovation, business and science. One of the BSUIN project activities is characterization of natural background radiation (NBR) in underground facilities. In this talk results from NBR measurements performed in Callio Lab, Pyhäsalmi, Finland, at the depth of 4100 m w.e. will be presented. The in-situ gamma spectra were collected with the use of  HPGe semiconductor spectrometer, whereas the  concentration of radon were measured with RAD7 electronic detector. In addition, the water and rock samples were taken for laboratory analysis in Institute of Physics, University of Silesia, Poland. The concentration radioisotopes in water samples were performed by using a liquid scintillation α/β counter (LSC) and α-particle spectrometry, while the concentration of radioisotopes in rock samples were performed by using laboratory gamma ray spectrometry and also α-particle spectrometry.</p>


2017 ◽  
Vol 24 (1-2) ◽  
Author(s):  
Jiří Zimák

The paper deals with natural radioactivity of metamorphic and igneous rocks and Palaeozoic sediments within the map sheet 14-33 Polička. Studied rocks belong to three geological units: the Hlinsko Zone (phyllites and quartzites of the Mrákotín Fm., flysch sediments of the Hlinsko-Rychmburk Fm.), the Svratka Crystalline Complex (mainly mica schists, paragneisses, orthogneisses and migmatites, also amphibolites, skarns, erlans and quartzites) and the Polička Crystalline Complex (mica schists, paragneisses to migmatites and the Variscan granitoids are dominant). Concentrations of potassium, uranium and thorium were measured using a laboratory gamma-ray spectrometer in 805 rock samples. Data are tabled and discussed. Natural radioactivity of rocks is evaluated on the basis of the calculated values of mass activity of 226Ra equivalent (am). Slightly increased am values were found in migmatites and orthogneisses of the Svratka Crystalline Complex (187 Bq.kg-1 on average), granites and granodiorites of the Budislav Pluton (216 Bq.kg-1), granodiorites and rocks of a tonalite suite of the Miřetín Pluton (199 and 194 Bq.kg-1). Increased concentrations of uranium and thorium were found in some samples of pegmatite and aplite. Radioactivity of rocks of the Hlinsko-Rychmburk and Mrákotín Fms. can be assessed as relatively low.


2019 ◽  
Vol 184 (3-4) ◽  
pp. 359-362
Author(s):  
Mudassir H Yarima ◽  
M U Khandaker ◽  
A Nadhiya ◽  
M A Olatunji

Abstract Uranium, thorium and potassium are the most abundant naturally occurring radioactive materials (NORMs) found in soils and other environmental media including foodstuffs. Since the human exposures to NORMs is an unavoidable phenomenon, in such a way that they can easily find their way to human being via food chain, detailed knowledge on their presence in foodstuffs is necessary to assess the radiation dose to the population. Thus, the present study concerns the assessment of natural radioactivity in maize, a staple foodstuff for Nigerian, via HPGe gamma-ray spectrometry. Activity concentrations (Bq/kg) in the maize samples were found to be in the range of 6.1 ± 0.6–8.2 ± 1.3, 2.2 ± 0.4–5.1 ± 0.7 and 288 ± 16–401 ± 24 for 226Ra, 232Th and 40K, respectively. Measured data for 226Ra and 232Th show below the world average values of 67 Bq/kg and 82 Bq/kg, respectively, while the activity of 40K exceeds the global average of 310 Bq/kg. The annual effective dose via the maize consumption was found to be far below the UNSCEAR recommended ingestion dose limit of 290 μSv/y, and the estimated lifetime cancer risk show lower than the ICRP (1991) cancer risk factor of 2.5 × 10−3 based on the additional annual dose limit of 1 mSv for general public, thus pose no adverse health risk to the Nigerian populace.


2021 ◽  
Vol 11 (14) ◽  
pp. 6471
Author(s):  
Nasser M. Moghazy ◽  
Amira M. El-Tohamy ◽  
Mona M. Fawzy ◽  
Hamdy A. Awad ◽  
Hesham M. H. Zakaly ◽  
...  

The present study was carried out on commercial types of Aswan granite used as building and decorative materials. Nearly 29 granitic rocks samples from 11 classes (black Aswan, red Aswan, dark Rosa, light Rosa, yellow Verdi, grey Shirka, Gandolla, Forsan, red Nefertiti, Royal, and white Halayeb) were collected from three stations near Aswan city for petrographical description and assessment of natural radioactivity. The petrographical study of granites was conducted by polarized-light microscope in order to determine their mineralogical composition and investigate their texture; the activity of the natural radionuclides 238U, Ra226, 232Th, and 40K was measured by gamma-ray spectrometry with a NaI(Tl) detector. The average values of the activities, 52.2 Bq kg−1, 57.8 Bq kg−1, 31.2 Bq kg−1, and 1055.7 Bq kg−1 of U-238, Th-232, Ra-226, and K-40, respectively, were higher than that the world average values of 35 Bq kg−1, 30 Bq kg−1 and 400 Bq kg−1 for 226Ra, 232Th, and 40K, respectively, according to the recommended levels from UNSCEAR reports. The minimum and maximum values obtained were compared with the value ranges from other locations in the Eastern Desert, highlighting the fact that that the maximum values obtained in this work are higher than those in other areas. According to the radiological hazards indices results, most samples lie in the permissible level ranges, suggesting their favorability for use as building materials. In contrast to that, some samples have some environmental parameters higher than the international levels, indicating their unsuitability as building materials.


2019 ◽  
Vol 26 (1-2) ◽  
Author(s):  
Jiří Zimák ◽  
Marek Slobodník ◽  
Přemysl Pořádek

This paper deals with the natural radioactivity of Palaeozoic rocks on the map sheets 15- 31 Bruntál and 15-33 Moravský Beroun in the NE part of the Bohemian Massif. Studied rocks belong to the Vrbno Group (greenschists and phyllites) and mainly to the MoravoSilesian Palaeozoic, particulary to the Andělská Hora, Horní Benešov and Moravice Fms. Potassium, uranium and thorium contents were measured in 1 596 rock samples using a laboratory gamma–ray spectrometer, values of mass activity of 226Ra equivalent (am) were calculated. The average am of analysed rock samples is 138 Bq.kg-1. This value is very close to the am value calculated for the average continental crust. Natural radioactivity of flysch sedimentary rocks of the Andělská Hora, Horní Benešov and Moravice Fms. (1 350 analysed samples, avg. am = 150 Bq.kg-1) grows from psefi tes (conglomerates) to psammites (dominating greywackes) up to the group of aleurites and pelites (siltstones, silty shales, clay shales). The highest uranium and thorium contents, along with other metals (Cs, Ga, Rb, Sn, Zr, La, Ce, Pb, Zn, As) were found in flysch rocks of the Horní Benešov Fm. in the area near Valšov: greywacke shows content up to 13 ppm U and 25 ppm Th (am = 364 Bq.kg-1) and siltstone up to 21 ppm U and 43 ppm Th (am = 624 Bq.kg-1). Low-grade metamorphic mobilization of elements is documented by hydrothermal minerals in syntectonic quartz veins which are e.g. fluorite, sulphides, REE-bearing phases, U-bearing phases.


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