Thorium Concentrations Research Articles

Assignment of complex species by affinity capillary electrophoresis: The case of Th(IV)-desferrioxamine B.

The electrophoretic mobility change of desferrioxamine B (DFO) was monitored by UV absorption spectrophotometry upon increasing the thorium(IV) concentration in the background electrolyte at two acidities ([HClO4 ]Tot = 0.0316 and 0.0100 M). These data enabled to assess the speciation model and to determine the equilibrium constant of [Th(DFO)H2 ]3+ at fixed ionic strength (I = 0.1 M (H,Na)ClO4 ). Affinity capillary electrophoresis (ACE) turned out to be most helpful in identifying the complexed species by ascertaining its charge and protonation state. The assignment of the correct stoichiometry relied on the reliable estimation of the electrophoretic mobility by assuming similar hydrodynamic radii for (DFO)H4+ and the chelate. The value of the apparent equilibrium constant (log β112 = 38.7±0.4) obtained by ACE compares favorably well with those reported in the literature for thorium and a range of other metal ions, according to a linear free-energy relationship. This method is useful for studying metal-ligand binding equilibria and provides valuable information for further modelling the behavior of tetravalent actinides under environmental conditions. Structural information about the prevalent solution species in acidic conditions was gained by DFT calculations, confirming the bishydroxamato coordination mode of Th4+ by the diprotonated ligand.

Integrated reservoir characterization of the Paleozoic and Mesozoic sandstones of the El Ouar field, Algeria

This study presents the interpretation of depositional environment and petrophysical properties of Mesozoic and Paleozoic reservoirs from the south-eastern Berkine Basin, Algeria by integrating core analyses and geophysical logs. Sedimentary structures and ichnofossils identified from 100 m of recovered cores have been interpreted to characterize the depositional settings of the studied reservoirs. During the mid-late Triassic, fluvial to marginal marine processes deposited the TAGS and TAGI reservoirs, while the Palaeozoic megasequences are characterized by shallow marine reservoirs (tidal bars and foreshore deposits) interbedded with thin marine shales. Porosity and water saturation have been estimated from geophysical logs and calibrated with core-based laboratory measurements. An empirical relationship between core porosity and permeability has been established for the El Ouar area and the same has been employed to generate a continuous and confident permeability profile against the target reservoir formations. Petrophysical characterization indicates a higher porosity and permeability in Triassic and Carboniferous sandstones than the Devonian F6 members. Triassic TAGS and TAGI sandstones possess the highest reservoir qualities in the El Ouar field. The Thorium and Potassium content available from spectral gamma-ray data have been utilized to identify the clay types associated with various sandstone reservoirs (Illite in Triassic sandstone, Kaolinite in Carboniferous units, mixed clay and Th bearing heavy mineral dominance in Devonian units). The study will be helpful for understanding of hydrocarbon resource potential and subsequent production planning in the study area.

Radioactivity and Risk Assessment with Uncertainty Treatment for Analysis of Black Sand Minerals

Precise radiological analysis of environmental, ores, nuclear materials and minerals samples is of great value for monitoring and surveillance objectives. The information deduced from the analysis can be used to identify the origin and nature of the accompanied activities. This work focuses on analysis of some black sand ore samples to identify and quantify their radioisotopes and potential risk. The analysis can provide useful information about the environmental transport mechanism and about the sources of radionuclides in the studied area; Rashid city coast, Egypt. To achieve this target, a Non‐destructive gamma spectrometer (NDGS) was used to trace and amount the radioisotopes types and activities. The efficiency was calculated with uncertainty treatment. The specific activity with uncertainty assessment of 238U, 232Th decay series and 40K of these samples were varied from 72.2 to 252.4 with average value 111 ± 25 Bq·kg–1, 94.2 to 579.8 with average value 140 ± 22 Bq·kg–1 and 427.9 to 527.5 with average value 475 ± 36 Bq·kg–1 respectively. The mineralogical signature of the analyzed samples (XRD) indicates that the samples are mainly composed of ilmenite, zircon, rutile, sphene and monazite. The potential risk assay shows that the hazard parameters of these samples; the Absorbed Gamma Dose Rate (AGDR), Gamma Activity Index (Iγ), Annual Effective Dose Rate Equivalent (AEDRE), Radium equivalent, External and Internal Hazard Index (Hex and Hin) are of specific characteristics. The total absorbed gamma dose rate and the annual effective dose due these samples were found to be with average values 158 ± 24 (nGy/h) and 195 ± 29 (μSv/y) which are higher than the world average value of 59 nGy/h and 70 μSv/y respectively. The results obtained are important to establish baseline levels to detect any upcoming changes due to any activities. It can be observed that the studied area has elevated thorium and uranium content. The relatively high dose rate will be considered as a spa for the physical therapy such as treatment of some skin diseases and rheumatoid.

Early Cretaceous Terrestrial Milankovitch Cycles in the Luanping Basin, North China and Time Constraints on Early Stage Jehol Biota Evolution

This research analyzes the cyclostratigraphy of the lacustrine Dabeigou Formation (DBG) of early Jehol Biota age (~130-135 Ma) in the Luanping Basin, northern China. A high-resolution (2 cm interval), 117.82-meter-long magnetic susceptibility (MS) stratigraphic series was measured along the Yushuxia section. MS is positively correlated with thorium, potassium and uranium concentrations associated with gamma ray intensity, and represents a proxy for detrital influx to the Luanping Basin. Power spectral analysis identifies a hierarchy of sedimentary cycles with wavelengths of 16.38 m, 5.85-3.28 m, 1.88-1.33 m and 0.98-0.7 m, which are interpreted to represent Earth’s orbital eccentricity, obliquity and precession index cycles. Objective testing of the MS series supports the interpretation of Milankovitch cycles, indicating an average sedimentation rate of 4.642 cm/kyr to 4.723 cm/kyr. A floating astronomical time scale with a duration of 2478 kyr is established from interpreted 405 kyr long orbital eccentricity cycles along the MS series. The 405-kyr tuned DBG MS time series closely matches the predicted orbital eccentricity of the La2004 astronomical solution from 130.787 Ma to 133.265 Ma, providing independent temporal constraints on early stage Jehol Biota evolution. Finally, this estimated time interval for the DBG MS time series indicates that it occurred entirely within the Weissert Event.

Conceptual Process to Produce ThO2 from Monazite

This study level process design represents an economically viable method for extracting thorium dioxide and other rare earth elements from monazite ore. This paper incorporates results from the 2019 capstone project from the honors Design Internship in Green Engineering in Chemical and Biomolecular Engineering. In this activity, senior students in Chemical Engineering at the University of Tennessee (UT) focused on the development and study of a process for the recovery of thorium dioxide and P2O5 from monazite. While not mandated, the process offers rare earth oxides as attractive byproducts. The project focused on recovery of byproducts rather than the creation or addition to waste streams. Additionally, (1) the process economics relied heavily on recovery of rare earth byproducts, (2) thorium handling portions of the process could be effectively segregated from rare earth and phosphate handling portions of the process, and (3) thorium and uranium content of waste streams should be carefully managed and eliminated where possible.

PENENTUAN UMUR ABSOLUT BATUAN KUBAH LAVA ANDESIT DAERAH PANAS BUMI LEJJA-KABUPATEN SOPPENG, PROVINSI SULAWESI SELATAN MENGGUNAKAN METODE THERMOLUMINESCENCE (TL)

Saat ini metode Thermoluminescence (TL) sudah diaplikasikan sebagai salah satu metode pentarikhan (dating) umur batuan. Dalam eksplorasi panas bumi informasi tentang umur batuan/material vulkanik sangat penting untuk merekonstruksi sejarah geologi yang berkaitan dengan aktivitas termal. Penentuan umur batuan yang diperkirakan sebagai sumber panas di prospek Panas Bumi Lejja Kabupaten Soppeng, Provinsi Sulawesi Selatan dilakukan menggunakan metode TL. Prosedur pengukuran dilakukan dengan dosis aditif pada butiran kristal kuarsa, Pengukuran dosis dengan irradiasi dilakukan dua kali yaitu pada dosis 10 Gray (Gy) dan 30 Gy sedangkan untuk annual dose ditentukan dengan menganalisis konsentrasi uranium, thorium, dan kalium menggunakan metode X-ray Fluorescence (XRF). Garis trendline dibuat untuk menentukan persamaan linear hubungan antara intensitas TL alami dengan dosis yang diberikan pada prosses irradiasi, dan menunjukkan bahwa bahwa intensitas TL alami setara dengan 304,05-315,96 Gy, sedangkan hasil perhitungan annual dose menunjukkan 0,5408 Gy/ka. Dengan kalkulasi menggunakan formula dalam metode ini diketahui bahwa usia absolut tubuh batuan yang diperkirakan sebagai sumber panas di prospek panas bumi Lejja, Kabupaten Soppeng adalah 573 ± 11 kilo tahun.

Application of SPS in the fabrication of UN and (U,Th)N pellets from microspheres

In this study, the process involved in the fabrication of a potential accident tolerant fuel is described. Homogeneous uranium nitride microspheres doped with different thorium content were successfully manufactured using an internal gelation process followed by carbothermic reduction, and nitridation. Elemental analysis of the materials showed low carbon and oxygen content, the two major impurities found in the products of carbothermic reduction. Uranium nitride microspheres were pressed and sintered using spark plasma sintering (SPS) to produce pellets with variable density. Final density can be tailored by choosing the sintering temperature, pressure and time. Density values of 77–98% of theoretical density (%TD) were found. As expected, higher temperatures and pressures resulted in a denser material. Furthermore, a direct correlation between the onset sintering temperature and thorium content in the materials was observed. The change of onset temperature has been related to an increment in the activation energy for self-diffusion due to the substitution of uranium atoms by thorium in the crystal structure.

ВЛИЯНИЕ ГЕОЛОГИЧЕСКИХ ФАКТОРОВ НА РАСПРЕДЕЛЕНИЕ УРАНА И ТОРИЯ В СОЛЕВЫХ ОТЛОЖЕНИЯХ ПИТЬЕВЫХ ВОД (РЕСПУБЛИКА БАШКОРТОСТАН)

Актуальность исследования обусловлена необходимостью выявления источников поступления естественных радиоактивных элементов в питьевую воду,а также возможностью использования солевых отложений питьевых вод (накипи) в геохимических и экологических исследованиях. Наличие на территории Башкортостана различных геологических структур (горная область, предгорный прогиб, платформа), а также большое разнообразие горных пород различного возраста и состава (вулканогенные, интрузивные, осадочные, метаморфические) благоприятствует данным исследованиям и обуславливает большое разнообразие микроэлементного профиля местности. Цель:оценка содержания и пространственного распределения радиоактивных элементов в солевых отложениях питьевых вод (накипи) на территории Республики Башкортостан. Объекты. Проанализированы данные по содержанию U и Th в 467 пробах солевых отложений питьевых вод (накипи) из 267 населенных пунктов Республики Башкортостан. Пробы отобраны из различной посуды (эмалированные и электрические чайники, кастрюли, котлы, самовары), которая используется для кипячения воды из централизованных и индивидуальных (скважины, колодцы, ручьи) источников водоснабжения. Методы. Для анализа содержания Uи Thиспользовался метод инструментального нейтронно-активационного анализана базе исследовательского ядерного реактора ИРТ-Т ТПУ. Обработка данных проводилась с использованием программных пакетов Statistica 8.0 и MicrosoftExcel 2013. Построение карт пространственного распределения естественных радиоактивных элементов в солевых отложениях питьевых вод проведено с помощью программы ArcGIS 10.2 в модуле GeostatisticalAnalyst методом обратных расстояний. Результаты. Полученные данные позволяют говорить о неравномерном распределении естественных радиоактивных элементов (U, Th) в солевых отложениях на территории Республики Башкортостан. Региональный фон концентрацииU и Th отличается пониженными значениями. Вариации их содержания определяются воздействием как природных, так и антропогенных факторов. Закономерности распределения U в пробах накипи хорошо согласуются с особенностями геологического строения территории. В пределах платформенной части распределение Uявляется более равномерным по площади, чем в горной части республики, что отражает сравнительную однородность геологических и тектонических условий. По результатам картирования выделено четыре зоны повышенного содержания Uв образцах солевых отложений: зауральская, уральская, западная и южная.В пространственном распределении Th не выявлено четкой корреляционной связи с особенностями геологического строения и металлогении территории. Выделены три зоны: северная, центральная и юго-восточная. Отмечены отрицательные аномалии содержания Th, территориально совпадающие с крупными горнодобывающими центрами.Показатель Th/U отношения характеризуется низким значением для всей территории Башкортостана – 0,002. При этом положительные аномалии данного показателя зафиксированы в северной и юго-восточной частях республики, где они обусловлены, преимущественно, геологической составляющей.

Removal of thorium and uranium from leach solutions of ion-adsorption rare earth ores by solvent extraction with Cextrant 230

The removal of radioactive elements thorium and uranium from the leach solution of ion-adsorption rare earth ores by aluminum sulfate was studied using di(2-ethylhexyl) [N-(2-ethylhexyl)aminomethyl] phosphonate (Cextrant 230, L).The extraction of thorium, uranium, rare earths, aluminum and other elements was investigated in detail, especially for uranium. The extracted complex was inferred to be UO2SO4·2L, in which phosphoryl oxygen atom of Cextrant 230 was involved in the coordination of UO22+. The thermodynamic parameters, such as ΔH, ΔG, ΔS were calculated. The negative value of ΔH suggests that the extraction of U(VI) by Cextrant 230 is an exothermic process. The extraction capacities of 5% (v/v) Cextrant 230 for Th(IV) and U(VI) were determined to be 4.08 g/L and 6.16 g/L, respectively. The loaded U(VI) and Th(IV) can be stripped using common inorganic acids. By just one stage extraction, the concentrations of thorium and uranium in the simulated leaching solution decreased obviously from 2.73 mg/L and 0.82 mg/L to <0.1 mg/L.

Geophysical-geological model of the Pedra Branca massif in the Goiás Tin Province, Brazil

The Pedra Branca massif is located in central Brazil, northeast Goiás, near the city of Nova Roma, occupying an area of approximately 80 km2. It is part of the Goiás Tin Province (GTP), located within the oldest tin subprovince, Rio Paranã, which, together with the Rio Tocantins Subprovince, are the most economically important provinces of the GTP. The massif is part of the Pedra Branca suite and is defined as an A-type granite from the Paleoproterozoic (1.6–1.77 Ga), rich in several ores such as tin, fluorine and rare-earth elements (REE) with anomalous concentration of indium, niobium, uranium, and thorium. Its magmatic evolution is closely related to the continental evolution and bimodal volcanism of the Araí rift. The mineralization zones are pre-tectonic, hosted in greisens with the presence of cassiterite; the main mineralization zones are named Zona da Bacia and Faixa Placha. This area is characterized by metallogenic importance. However, only a few geophysical studies have focused on the granite area. The lack of geophysical information makes it difficult to establish the signature of the Pedra Branca massif. The main goal of this study is to increase geophysical information by determining the magnetic and gamma-ray spectrometric signatures of the granite massif, and to generate a geophysical-geological model representative of the surface and subsurface geological features. These signatures are investigated and related to the geological structures and tin mineralized zones (cassiterite) present in the massif. Based on the analysis of airborne and ground gamma-ray spectrometry data and geochemical data, it was possible to characterize the anomalous zones of uranium (U) and thorium (Th) of the granitic massif. From the magnetometric Total Gradient Amplitude (TGA) and Tilt Derivative (TDR) products, it was possible to define important magnetic signatures, as well as to delimit the intrusion and its contact with enclosing and surrounding rocks. These products, in conjunction with products generated by Matched Filtering and Euler Solutions, provide subsurface magnetic signature information and their depth estimates. The forward modeling and the inversion of the magnetic data generated from the Induced Magnetization Vector (MVI), were correlated in order to generate a 2D geophysical-geological model that presents main sources of shallow magnetic susceptibility (ca. 800 m) corresponding to the Faixa Placha (0.029SI) and sources of high susceptibility (0.012SI - MVI), located in greater depth (ca. 2 km) inside and outside the massif. Within the massif, the source of high susceptibility was interpreted as mafic pluton due to the bimodal magmatism of the Araí rift. On the surface, this mafic magmatism emerges as diabase dikes. The other magnetic source in the southeast edge is interpreted like a mafic magmatism body from the bimodal volcanism of Araí Group or Quartz Diorite Nova Roma. The interpretation of geophysical data is consistent with the underplating process, commonly accepted as responsible for the generation of type A magmas, based on the partial melting of the continental crust, caused by the rise of mafic magma.

Use of response surface methodology for optimization of thorium(IV) removal from aqueous solutions by electrodeionization (EDI)

In this research, the thorium(IV) removal from the aqueous solution was conducted by electrodeionization (EDI). Thorium(IV) removal experiments with EDI are designed using RSM based on CCD, and three independent variables were scrutinized, including applied voltage (X1), flow rate (X2), and thorium(IV) concentration (X3). A quadratic model with R2 equal to 0.9825 was the best model for the analysis of variance, which was in a good agreement with experimental results. The X1X2 did have a significant effect, and other interactions had an insignificant effect. The optimal values of voltage, flow rate, and thorium(IV) concentration were obtained 9.8 V, 3.4 mL min−1, and 63.1 mg L−1, respectively. In these conditions, the thorium(IV) removal was 99.06%, which was 0.31% different from the software prediction. The EDI efficiency was evaluated by calculating the current efficiency, mass flux and mass transfer coefficient. The results showed that the flow rate increment has a more significant effect on the increase of the mass flux and mass transfer coefficient than the impact of the voltage increases. Thorium(IV) removal with different resin configuration was as follow: layered < mixed < only cationic resin. EDI and electrodialysis comparisons showed that with EDI, thorium(IV) removal increased by more than 35%. Through this study, the desirable removal of thorium(IV) was achieved by EDI.

Radiogenic helium concentration and isotope variations in crustal gas pools from Sichuan Basin, China

Helium is an exhaustible natural resource and the main commercial helium was separated from helium-rich natural gas. The helium in the sedimentary basin is mainly the radiogenic origin of crustal rocks with high level of uranium and thorium. Data from 242 natural gas samples were used to investigate the distribution and formation mechanism of helium-rich gases in the Sichuan Basin of China. All gas samples show remarkably low 3He/4He ratios with ranging from 0.002 to 0.05 Ra, which represent typical crustal helium. The Weiyuan gas pool in the southern Sichuan Basin possesses high levels of helium (1500–18770 ppm, average 2785.7 ppm) in Precambrian and Cambrian strata. A positive relationship were observed in the helium and nitrogen contents increased with reservoir layer age for all Weiyuan gas samples. Presinian granite was considered as the main helium source for the Weiyuan gas pool. Gaoshiti–Moxi and Weiyuan gas pools belonged to the same ancient gas pool before the Late Cretaceous, but the helium abundance of Gaoshiti–Moxi gas pool is relatively low (200–891 ppm). The change of pressure and fracture system caused by the uplift of Weiyuan structure in the Himalayan orogenesis led to the helium accumulation and enrichment of Weiyuan gas pool. The shale of the Silurian Longmaxi Formation has high contents of uranium and thorium and generated a large amount of helium while forming large quantities of hydrocarbon gases. Generally, the helium abundance of shale gases and conventional gases generated from the Longmaxi Formation ranges from 63 to 1500 ppm and some of the gas pool are sufficient for commercial helium resource exploitation. Therefore, the relative quantities of helium and hydrocarbon gases are act as a key factor influencing the formation of helium-rich natural gas reservoirs.

Study of thorium and uranium isotopes activity concentration after percolation or agitation leaching, in mining lixiviation liquor samples

This work refers to determination of thorium and uranium isotopes in the mining lixiviation liquor samples. The analytical procedure involves sample preparation steps for rare earth elements, thorium and uranium separation, besides alpha spectrometry analysis of the isolated radionuclides. An isotopic tracer is used to determine the overall chemical yield and to ensure traceability to a standard sample from NIST. The paper presents and discusses that the chemical yield of thorium and uranium depends on the leaching method used, that is, column leaching or agitated leaching. We improved the method looking for reproducibility and isotopes isolation as required by alpha spectrometry and the method showing effective in analysis of mining liquor

Preparation and optimization of thorium selective ion imprinted nonwoven fabric grafted with poly(2-dimethylaminoethyl methacrylate) by electron beam irradiation technique

2-dimethylaminoethyl methacrylate (DMAEMA) was grafted onto PP/PE non-woven fabrics (NWF) using pre-radiation graft polymerization technique and subsequent mutual radiation crosslinking with divinylbenzene (DVB). The ion-imprinted polymer (IIP) was synthesized by DVB crosslinking with DMAEMA and thorium complex through radiation. Non-imprinted polymer (NIP) was prepared with the same conditions but utilizing pure DMAEMA instead of DMAEMA-Thorium complex. The NWF, DMAEMA-grafted-NWF, IIP and NIP were characterized with Field Emission Scanning Electron Microscopy (FESEM), Fourier Transformed Infrared Spectroscopy (ATR-FTIR), Thermogravimetric Analyzer (TGA), X-ray photoelectron spectroscopy (XPS), and X-ray Diffraction (XRD). The grafting process parameters were optimized prior to radiation crosslinking with DVB. The effects of DMAEMA concentration and reaction temperature as a function of different irradiation doses were investigated in order to attain optimal grafting conditions. The effects of DVB concentration, process temperature and radiation dosage on the degree of crosslinking were examined. In addition, the effects of crosslinking percentage, initial thorium concentration and concentration of imprinted thorium to the selectivity of IIP and NIP were also determined. The thorium selectivity of both IIP and NIP was measured using batch mixed ions system by inductively coupled plasma mass spectrometry (ICP-MS) analysis. Instead of simultaneous grafting and crosslinking process in bulk along with imprint template, this current study conciliates all grafting, imprint template and crosslinking process independently. Thus, the originality of the research is attributed to individuality grafting and crosslinking technique using ion beam irradiation to obtain IIP of high thorium selectivity without compromising the chemical and physical properties of the adsorbent.

Geochemical characteristics and uranium mineralization exploration potential of late Miocene molasse sediments of NW Himalayan foreland basin Pakistan

This study has defined the provenance, tectonic settings, paleo-weathering, sediment-recycling, and sandstone-type uranium mineralization potential of late Miocene mid-Siwalik Dhok Pathan Formation from Surghar-Shingar Range of NW-Himalayan foreland Fold-and-Thrust-belt. Twenty-six sandstone samples were analyzed on XRF and ICP-MS to determine concentrations of different geochemical species. These Himalayan molasse sediments are moderately rich in quartz. The other framework gains include igno-metamorphic and sedimentary lithic fragments (second in abundance after quartz), feldspars, and dominance of ferroan phlogopite (biotite) over white mica. Garnet, epidot, amphibole, magnetite, tourmaline, rutile, zircon, monazite, and uranothorite are present as common accessory minerals. These sandstones are generally classified as lithic arenite, greywacke, and arkose on the basis of geochemistry. These molasse sediments have recorded the signatures of first-cycle detritus mainly contributed by felsic-igneous rocks in collision-arc tectonic settings. Chemical index of weathering and alteration (CIW and CIA) revealed slight/low weathering of source areas. The REE patterns and Eu/Eu* values are also supporting felsic-igneous provenance for the studied samples. The median high concentrations (ppm) of vanadium (V 79.57), thorium (Th 10.08) and uranium (U 33.05) in sandstone, positive correlation of U with Al2O3 (r = 0.22), deposition in strong anoxic environments are the characteristic features of uranium enrichment/accumulation processes in sandstone-type environments thus signifying good potential for uranium exploration.

Determination of Water Quality in Springs of Ekaterinburg and Sverdlovsk Oblast

This article reported a study of water quality in 31 springs of the city of Ekaterinburg and the Sverdlovsk Oblast. We determined that water in only 7 springs (22%) fully met the requirements of sanitary norms from the point of view of content of chemical and radioactive pollutants. In 17 cases, water did not meet the requirements of the norms for the chemical factor, in 4 cases – for the radiation factor, and in 3 cases – for both the chemical and radiation factors. Among the natural radionuclides, only 222Rn showed levels higher than intervention level (60 Bq/L); the maximum activity concentration of radon was found to be 161 Bq / l (Pavlovsky spring). At the same time, activity concentrations of uranium and thorium did not exceed the level of intervention. A detailed analysis of the content of natural radionuclides showed the absence of correlations between the activity concentrations of radon, uranium and thorium in spring waters. Inconsistency of spring waters with sanitary standards for chemical factors in the vast majority of cases was associated with excess MPC for iron. Also, in a number of samples, an excess of the MPC for manganese and barium was found, while in the spring Europe-Asia (Yekaterinburg) an almost 9-fold excess of the MPC for barium was found.

Characterisation for &amp;lt;i&amp;gt;Radioelements&amp;lt;/i&amp;gt; over an Escarpment Feature(S): A Case Study of the Duku-Tarasa Gwandu Ridge Area of Birnin Kebbi NW Nigeria

The paper presents results of radiometric investigations of an area (Duku-Tarasa) near the capital city of the State of Birnin Kebbi, NW Nigeria. The area of study is about 440 m × 420 m and encloses an Escarpment Feature/Structure on a sedimentary rock generally referred to as the Gwandu Formation. The Gwandu Formation (though not described in the paper) consists of continental lacustrine sediments and is the youngest Palaeogene Formation present in the Sokoto sector of the larger Iullemmeden Basin. The study measured, along some selected profiles across this escarpment feature, radiometric signatures using a Sim-Max G411 portable field gamma-ray spectrometer (giving counts for U, Th and K relative to the background values over the area), the ground total-field magnetic data (using the proton precession magnetometer) along those profiles and collected some (5) rock samples for flame photometry and AAS analyses towards the target proposition. Activity concentration levels due to potassium (K), uranium (U) and thorium (Th) were measured in the area along the five established profiles spaced at 50 metres. The results from these measurements and analyses were displayed (in Tables/histograms and gray level maps/images of concentrations of Uranium, Thorium and Potassium prospects) and interpreted (dismissing the magnetic data as seemingly passive as no filter was applied to the mapped data).

Using Gamma Spectroscopy to Calculate Radioactive Contaminants in Foreign and Local Tobacco Samples

The normal radioactivity levels of Uranium-238, Thorium-232, and Potassium-40 were calculated for ten types of foreign and local cigarettes available on the Iraqi market using a gamma-ray spectroscopy technique employing the germanium detector system. The results of this study showed that the average specific activity for each of Uranium-238, Thorium-232 and Potassium-40 were 21.689± 4.596, 18.906 ± 4.148, and 430.094 ± 19.449 (Bq/Kg) respectively. The annual effective dose, radium equivalent activity and excess lifetime cancer risk for the studied samples were also calculated, and their rates were 11.582 μsv/y, 81.841 Bq/Kg, and 40.538 people per million per year respectively. The outcomes indicate that the rate of concentration of uranium and thorium is lower than the permissible values, whereas the average concentration of potassium was slightly higher than the permissible values. This research is important because it warns against several types of cigarettes that contain high concentrations of radionuclides, which can lead to infection cancer and then lead to the death of the person who has used it profusely. Therefore, the aim of the current research is to evaluate the radiological risks of radionuclides in tobacco cigarette smoke by evaluating their natural radionuclide concentrations.

Natural radioactivity measurement of gold mine tailings in Vatukoula, Fiji Islands

Gold mining is one of the primary industry in Fiji, and it could expose the naturally occurring radioactive materials (NORMs) that may produce health risk to the people working in mining. The present study focuses on the assessment of soil samples in the vicinity of gold mining to assess the concentration of these nuclides. The average activity concentrations of Uranium (238U), Thorium (232Th) and Potassium (40K) in the soil samples from the gold mining area in Vatukoula, Fiji were computed using NaI(Tl) detector. The activity concentrations varied from 30.7 Bq kg−⁡1 and 175.73 Bq kg−⁡1 for 238U and 40K with the absence of 232Th in the decommissioned site. 19.49 Bq kg−⁡1, 123.06 Bq kg−⁡1 and 86.86 Bq kg−⁡1 was determined for 238U, 232Th and 40K of the commissioned sites respectively which is less than the world averages according to the United Nations Scientific Committee on the Effects of Atomic Radiation report [1], except for 232Th which is expected to be higher due to the mineral composition of monazite derivatives. Our preliminary results on the activity of these radioactive nuclides demonstrate that the mining activities at Vatukoula poses no significant radionuclide hazard to the miners and the general public.

Calculation of Radiogenic Heat Productions from Marble and Glazed Tiles Used as Covering Building Materials in Turkey

Covering or decorative building materials derived from rock and soil include primordial radionuclides such as 238 U and 232 Th series, and potassium radioisotope ( 40 K) varying from one country to another and from one location to another in the same country. The kinetic energy of radiation emitted from these radionuclides in the covering building materials like other building materials are sources of radiogenic heat. Marble tiles are commonly used as wall and floor covering, facing materials for buildings, kitchen counter- top, vanity tops and inner and outer decorative materials because of their appearance, attractive colours, polished surface and durability against external conditions and high resistance to wear. In this study, radiogenic heat productions of marble and glazed tiles samples are calculated based on the elemental concentrations of uranium (in terms of mg/kg), thorium (in terms of mg/kg) and potassium (in terms of %) in the samples collected from various provinces in Turkey. The radiogenic heat productions from the marble tile samples varied from 0.05 to 2.17 µW/m 3 with an average of 0.26 µW/m 3 . The average the radiogenic heat production of the marble tile samples is approximately four times lower than the average continental crust of 0.9 µW/m 3 .