Search

Natural elements like uranium and its by-products can cause health problems if they are present in groundwater at excessive concentrations. Some industrial activities are known to elevate uranium concentrations, such as uranium mining, phosphate fertilizer production, nuclear power plants, metal processing, and coal combustion. This study gives information about the uranium concentration in groundwater samples collected from distinct water sources like hand pumps and tube wells from a variety of depths and numerous locations in Yamuna Nagar, Near Shivalik Hills, and the Origin of Saraswati River, India. Uranium concentration was measured using the LED fluorimetry technique. The average value of uranium (13.09 µg L−1) and annual effective dose (2.18 µSv y−1) is found to be within the as reported by WHO (Guidelines for drinking-water quality, World Health Organization, Geneva, 2011) and as reported by AERB (Drinking water specifications in India, Department of Atomic Energy, Mumbai, 2004) recommended safe limits of 30 µg L−1 and 60 µg L−1 respectively. For the evaluation of health risks associated with groundwater, the chemical toxicity risk and radiological risk of uranium in water are also assessed in this study. The activity of natural radionuclides in some locations is found to be high, which might be due to the local geology, hydrology, and type of industries in that region. The current study will benefit both residents and government agencies regarding uranium exposure to drinking water. [ABSTRACT FROM AUTHOR]

The presence of underlying uranium deposits may contaminate the upper soil of a region. We have carried out a detailed investigation of radionuclides (Ra, Th, and K) present in the soil around the reported uranium deposit site in the Sikar district of Rajasthan, India. Measurements are carried out using the state-of-the-art gamma-ray spectroscopy (HPGe detector) technique. The specific activity of 226Ra, 232Th, and 40K are found in the range of 9.5 ± 0.5–50.6 ± 1.0 Bq kg−1, 11.0 ± 0.4–83.2 ± 1.5 Bq kg−1, and 177 ± 13–753 ± 47 Bq kg−1 with the mean values of 17.8 ± 7.5 Bq kg−1, 22.6 ± 13.4 Bq kg−1, and 393 ± 76 Bq kg−1 respectively. The average value of Ra Eq. activity is 80.4 Bq kg−1, below the recommended limit of 370 Bq kg−1. For radiological implications in the study area, the indoor and outdoor absorbed dose rates and age-dependent annual effective dose are estimated, which are also found below their prescribed safe limit values. The mean value of other hazard indices (Hin and Hex) and level indices (Iα and Iγ) are less than unity. Our study shows that the underlying uranium deposits do not contaminate the soil of the studied area and the soil is safe to use for various purposes. [ABSTRACT FROM AUTHOR]

The effects of uranium and its decay product radon in water are the most important concern in human health. In this paper, efforts have been made to measure and correlate the uranium (Using an LED Fluorimeter) and radon concentrations (Using SMART RnDuo) in the water samples from the Budhakedar region of the Garhwal Himalaya to assess the risk. The concentrations of uranium and radon in the water samples were found to vary between Below Detection Level (BDL) to 1.70 Bq L−1 (with an arithmetic mean of 0.15 Bq L−1) and 0.43 to 1.29 Bq L−1 (with an arithmetic mean of 0.75 Bq L−1) respectively. The annual effective dose to the inhabitants of the study region was also calculated for the different age groups. [ABSTRACT FROM AUTHOR]

Evaluating groundwater uranium concentration is crucial for assessing the radiological impact on human health due to radionuclide ingestion. This study quantifies uranium concentration in groundwater samples collected from various sources in the Patiala district, Punjab. LED Fluorimeter is employed for direct determination of uranium. Results reveal that 78% of locations have uranium concentration below the WHO limit of 30 µg/L, while 22% exceed the safe limit. However, all samples are below the AERB-recommended 60 µg/L limit. The uranium concentration in the groundwater ranges from 5.59 to 57.53 µg/L, with an average concentration of 24.57 µg/L. The variation in uranium concentration is influenced by factors such as pH and the water source. Radiation dose, cancer risk, and daily intake are calculated, suggesting most samples are safe for drinking, but prolonged consumption in high-uranium areas poses health risks. [ABSTRACT FROM AUTHOR]

The measurements of radon concentrations in drinking water sources in and around the Main Central Thrust (MCT) region in Garhwal Himalaya, India, were carried out using the scintillation detector-based SMART RnDuo technique for radiation protection purposes. Radon values in the analyzed samples were observed between 1.1 and 183.9 Bq L−1 (AM = 19.7 Bq L−1). Radon values in 94% of the samples were found well below the World Health Organization (WHO) reference limit. The estimated radiation doses for different age groups were found higher than the WHO safe limit of 100 µSv y−1 (from all sources including radon) except for the age groups of 0–12 months infants and 1–3 years children. The results of this study may be useful for future studies on epidemiology, examining hidden faults, uranium exploration etc. [ABSTRACT FROM AUTHOR]

Civilian and military nuclear programs of several nations over more than 70 years have led to significant quantities of heterogenous solid, organic, and aqueous radioactive wastes bearing actinides, fission products, and activation products. While many physicochemical treatments have been developed to remediate, decontaminate and reduce waste volumes, they can involve high costs (energy input, expensive sorbants, ion exchange resins, chemical reducing/precipitation agents) or can lead to further secondary waste forms. Microorganisms can directly influence radionuclide solubility, via sorption, accumulation, precipitation, redox, and volatilization pathways, thus offering a more sustainable approach to remediation or effluent treatments. Much work to date has focused on fundamentals or laboratory-scale remediation trials, but there is a paucity of information toward field-scale bioremediation and, to a lesser extent, toward biological liquid effluent treatments. From the few biostimulation studies that have been conducted at legacy weapon production/test sites and uranium mining and milling sites, some marked success via bioreduction and biomineralisation has been observed. However, rebounding of radionuclide mobility from (a)biotic scale-up factors are often encountered. Radionuclide, heavy metal, co-contaminant, and/or matrix effects provide more challenging conditions than traditional industrial wastewater systems, thus innovative solutions via indirect interactions with stable element biogeochemical cycles, natural or engineered cultures or communities of metal and irradiation tolerant strains and reactor design inspirations from existing metal wastewater technologies, are required. This review encompasses the current state of the art in radionuclide biogeochemistry fundamentals and bioremediation and establishes links toward transitioning these concepts toward future radioactive effluent treatments. [ABSTRACT FROM AUTHOR]

In this study, we successfully applied a transition-edge sensor (TES) spectrometer as a detector for microbeam X-ray measurements from a synchrotron X-ray light source in the hard X-ray region to determine uranium (U) distribution at the micro-scale and its chemical species in biotite obtained from a U mine. It is difficult to separate the fluorescent X-ray of the U Lα1 line at 13.615 keV from that of the Rb Kα line at 13.395 keV in the X-ray fluorescence spectrum with an energy resolution of approximately 220 eV using a conventional silicon drift detector (SDD). Meanwhile, the fluorescent X-rays of U Lα1 and Rb Kα were fully separated by a TES with 50 eV energy resolution at an energy of around 13 keV. The successful peak separation by the TES led to an accurate mapping analysis of trace U in micro-X-ray fluorescence measurements and a decrease in the signal-to-background ratio in micro-X-ray absorption near edge structure spectroscopy. Thus, it could be a powerful tool for studying the U distribution and speciation in various environmental samples. [ABSTRACT FROM AUTHOR]

In this study, we successfully applied a transition-edge sensor (TES) spectrometer as a detector for microbeam X-ray measurements from a synchrotron X-ray light source in the hard X-ray region to determine uranium (U) distribution at the micro-scale and its chemical species in biotite obtained from a U mine. It is difficult to separate the fluorescent X-ray of the U Lα1 line at 13.615 keV from that of the Rb Kα line at 13.395 keV in the X-ray fluorescence spectrum with an energy resolution of approximately 220 eV using a conventional silicon drift detector (SDD). Meanwhile, the fluorescent X-rays of U Lα1 and Rb Kα were fully separated by a TES with 50 eV energy resolution at an energy of around 13 keV. The successful peak separation by the TES led to an accurate mapping analysis of trace U in micro-X-ray fluorescence measurements and a decrease in the signal-to-background ratio in micro-X-ray absorption near edge structure spectroscopy. Thus, it could be a powerful tool for studying the U distribution and speciation in various environmental samples. [ABSTRACT FROM AUTHOR]

Radiological hazard assessment is an important task. The natural radionuclides in 88 surface soil samples in/surrounding high-level natural radiation areas were measured using a high-purity germanium gamma-ray detector. The 226Ra, 238U, 232Th, and 40K activities varied from 60.4 to 655, 59.3 to 643, 71.2 to 886, and 252 to 745 Bq/kg respectively. The highest radionuclides concentration was found in rare earth element mines, followed by uranium and metallic mines. There was an equilibrium between 238U and 226Ra with 238U/226Ra ratios equal to 1.01. The radiation hazard indices in the study soil samples were far higher than the world average values. [ABSTRACT FROM AUTHOR]

Quantification of uranium levels was done in the water samples collected from different groundwater sources in the Shivalik hills of outer Himalaya using inductively coupled plasma mass spectrometry (ICPMS). The uranium concentration in analyzed samples varying from BDL to 16.137 µg L−1 is observed below 30 µg L−1 advocated by World Health Organization. The estimation of human health risks in terms of hazard quotients and dose quantities is presented in the paper. An effort has also been made to evaluate the retention of uranium levels in human body organs using ICRP's biokinetic model. No significant health hazards were observed due to uranium consumption through potable water. [ABSTRACT FROM AUTHOR]

222Rn is among the most important issues for radiation exposure in/near high background radiation areas such as near rare-earth-element (REE) and uranium mines in North Vietnam. Seasonal 222Rn activity concentration in spring water was determined by RAD-7, with average ranges of 1270 ± 60–66,400 ± 2630 Bq m−3, therein the highest value was a REE, and the lowest a uranium mine. The 222Rn activity concentration was higher in the dry season, which could be attributed to 222Rn leaching to spring waters from nearby mines, and lower in the rainy season due to dilution by rain water. The 222Rn annual effective doses were within permissible limits. [ABSTRACT FROM AUTHOR]

Rare earth elements (REE) can be found in expressive contents in different secondary sources, such as acid mine drainage (AMD). This work evaluated separation of light and heavy rare earth elements (REE) from an acid mine drainage (AMD) generated in a former uranium mine in Brazil by using ion exchange. This AMD presents pH 3.50, total REE content of 97 mg L−1 and 1.3 g L−1 of sulfate and was used in the REE loading experiments. Loading experiments were carried out in columns using a commercial strong acid cation (SAC) exchange resin. Elution was performed with 0.01 mol L−1 NH4EDTA in systems with one, two and three columns. Regarding the loading step, the resin presented a total loading capacity of 0.58 mmol g−1. The resin proved to be more selective for light REE with adsorption efficiency of 78% and 48% for heavy REE. Regarding elution, high efficiencies between 90 and 100% were achieved for REE. The final REE solution is approximately 10 times more concentrated in the liquor related to the acid mine water. Better fractionation results were achieved for the system with three columns. Although the complete separation of the REE into pure elements was not possible, two distinct fractions of heavy and light REE could be obtained, and La was completely separated from the other REE. In order to improve fractionation and separate the REE into individual ones, the concentrated fractions can proceed to subsequent ion exchange systems. [ABSTRACT FROM AUTHOR]

The spatiotemporal coupling relationship between deep hydrocarbon fluid and sandstone uranium mineralization within the shallow buried red‐variegated clastic rocks in the Qianjiadian area of the Songliao Basin remains a topic of controversy. This paper aims to provide a comprehensive understanding of the source, nature and exudative age of deep exotic hydrocarbon, as well as the interaction mechanism and alteration process between hydrocarbon fluid and clastic rock. To achieve this, various methods were employed, including acidolysis hydrocarbon test (AHT), clay x‐ray diffraction (XRF), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), carbon isotope analysis (CIA) and LA‐ICP‐MS U–Pb isotopic dating. The results indicate that some tight sandstones from the Qingshankou Formation in Dalin uranium deposit exhibit high acidolysis hydrocarbon content (AHC), reaching n × 104 μL/kg, and predominantly consisting of low mature oil‐type gas. Local microscopic observations reveal pore fluorescence and hydrocarbon‐bearing inclusions with nattier blue tone. Furthermore, the kaolinites present in the ore area's sand‐bodies show a significantly higher content anomaly, commonly exceeding >50%, compared to the same layer in peripheral regions. Extensive dissolutions of lithic grains and feldspars are observed, along with the widespread occurrence of ferro‐dolomites and colloidal pyrites. Additionally, exotic asphaltenes are sporadically developed in localized areas. These findings provide evidence that the sand‐bodies experienced a significant exfiltration event of external gaseous fluids. The light carbon isotopes (δ13CV‐PDB ranging from −33.26‰ to −30.06‰) of group components and n‐Alkane suggest that the hydrocarbon originates from the source rock of the Lower Cretaceous Jiufotang Formation. A detailed two‐stage alteration sequence caused by acidic and reducing hydrocarbon is clarified, encompassing acidic corrosion, kaolinization, pyritization, silification and asphaltization during the exudation stage, followed by ferro‐dolomitization in the later cessation stage. Notably, vermicular secondary kaolinites, formed through the interaction between acidic hydrocarbon fluid and low‐temperature meteoric groundwater, serve as significant markers for the exfiltration of deep hydrocarbon fluid. In‐situ U–Pb dating of hydrocarbon‐bearing ferro‐dolomite yielded absolute exfiltration ages of 63.54 ± 4.13 and 65.93 ± 3.35 Ma. By integrating the tectonic–sedimentary–fluid evolution history and uranium mineralization characteristics in the study area, a three‐stage superimposed metallogenic model is proposed for the Upper Cretaceous red‐variegated layers: (1) the sedimentary and diagenetic stage of the target layer during the Late Cretaceous, (2) the predominant hydrocarbon exudation stage at the end of the Late Cretaceous, and (3) the main uranium mineralization stage since the Paleogene. This study enhances our understanding of coupled‐genetic sandstone‐type uranium deposit in a sedimentary basin and provides valuable guidance for prospecting similar red‐variegated beds in the Songliao Basin and other sedimentary basins worldwide. [ABSTRACT FROM AUTHOR]

Magmatic rocks host different types of uranium deposits that can range from magmatic/high-temperature hydrothermal systems to post-magmatic, low-temperature hydrothermal deposits. The uranium mineralization in the syn- or late-magmatic systems could be divided into three types. (1) Magmatic deposits related to differentiated peralkaline complexes that are typically rich in SiO2 (>72 wt%) and poor in (B: Fe+Mg+Ti)<100 (in cation values). The Na/K ratio in these rocks is > 1 and they have high contents of incompatible lithophile elements such as Nb, Ta, Zr, REE, Th and U. (2) Magmatic deposits related to strongly peraluminous magmas, derived from partial melting of crust. They are the result of a low degree partial melting of crustal arkosic (quartz-feldspathic) rocks with high SiO2 (>74 wt%), low B < 40 and positive values for (A: Al-[Na+K + 2Ca]) (in cation values)), and are mostly accompanied by Li and F minerals. (3) Magmatic deposits related to the evolved hot peralkaline or metaluminous (A [A2] - to I- types) magma that assimilated fertile materials of the crust and endured a high rate of crystal fractionation. They mostly form high-temperature (vein-type and hybrid system) deposits. The rate of fluid in magma is important for the formation of this type of deposit. Therefore, the fertile magmas for this type of deposits typically have SiO2 >72 wt%, positive values of A, B < 50 and K/Rb < 150. They are possibly rich in Mo and F. Dry-hot alkaline felsic volcanic rocks are more suitable for post-magmatic low-temperature hydrothermal deposits. The altered intrusive rocks with about 200 Ma age and higher contents of refractory minerals, are suitable candidates for supporting the post-magmatic, low-temperature hydrothermal uranium mineralization. [ABSTRACT FROM AUTHOR]

Manufacturing high-performance and reusable materials from radioactive uranium-containing wastewater remains a significant challenge. Herein, a supramolecular self-assembly strategy was proposed, using melamine and cyanuric acid as precursors and using intermolecular hydrogen bond force to form carbon nitride (CN–D) in different solvents through a single thermal polymerization strategy. Supramolecular self-assembly method is a promising strategy to synthesize a novel carbon nitride with molecular regulatory properties. In addition, 98% of U(VI) in wastewater can be removed by using CN–D for 60 min under visible light. After five cycles of recycling, more than 95% of U(VI) can still be reduced, indicating that it has good recyclability and reusability. This study not only provides an efficient photocatalytic method of uranium reduction, but also provides a new method for self-assembly synthesis. [ABSTRACT FROM AUTHOR]

Energy has long been seen as an important factor in meeting needs of people, in order to sustain and support the economic growth and livelihood. To understand the various technological processes in the nuclear power life cycle, it is first necessary to know the types of fuels used today. There are two types of gasoline in use today, "open" and "partially closed," respectively, referred to as "single cycle" (OTC) and "double cycle" (TTC). A distinction must be made between "partial" closed fuel cycles, as they apply to current critical (thermal neutron spectrum) reactor technology, which is limited to two passes, and "full" closed cycles, which allow for greater circulation of spent oil but must be used. Fast reactors (FR) are included in the reactor fleet. Many recoveries of FR—already proven but not yet widely used in industry—will lead to reduced demand for uranium mining. In this section, references to "closed" fuel cycles include "partially" closed cycles, i.e., TTCs. What type, if any, is the correct content or information in question? Analysis of the world's energy consumption in recent years shows that the world's energy consumption has increased by 50% in less than a decade. [ABSTRACT FROM AUTHOR]

The large-sized Tarangaole uranium deposit and its neighboring Daying and Nalinggou deposits, located in the northeastern margin of the Ordos Basin, constitutes a major uranium resource base in northern China. In order to further clarify the sedimentary material source, uranium source and regional sediment–tectonic setting of the uranium-fed clastic rocks (i.e., Zhiluo Formation(J2z)) in the district, this paper carried out whole-rock geochemistry, heavy minerals composition and in situ U-Pb dating of detrital zircons for sandstones from the lower section of the Zhiluo Formation. The results have shown that the average chemical differentiation index (CIA) for the host rocks is 73.16 and the chemical weathering degree is moderate. Heavy minerals are mainly composed of ilmenite, garnet, chlorpyrite, zircon, pyrite, apatite, hematite, etc. The U-Pb dating of detrital zircon generally indicates three age peaks, i.e., 260~Ma, 1850~Ma and 2450~Ma, respectively. In conclusion, the source rocks may have been formed at active continental margins, e.g., in a continental margin arc environment. The sedimentary materials mainly come from khondalite series, TTGs, granulite, and mafic–ultramafic intrusive rocks distributed among the Daqing–Ula Mountains and adjacent areas, etc. The Late Paleozoic U-rich intermediate and acidic magmatic rocks spreading over the eastern part of the Ula–Daqing and Wolf mountains have provided the main uranium sources for the formation of major U deposits in the northern Ordos Basin. [ABSTRACT FROM AUTHOR]

The features of uranium mining on Kazakhstan's enterprises have been examined, and uranium deposits located in the Syrdarya and Shu-Sarysu depressions have been described. Actual and projected data on the development of technological blocks in areas with complex geological structures have been analyzed and compared. Core samples were collected and, using X-ray diffraction analysis, quantitative and qualitative characteristics as well as mineral compositions of ores from various productive horizons of uranium deposits in the Syrdarya and Shu-Sarysu depressions were comparatively analyzed. It was determined that the ores in the Syrdarya depression are relatively homogeneous compared to those in the Shu-Sarysu depression, although in some places, clay minerals and gypsum are present, which hinder the uranium leaching processes. In the ores of the Shu-Sarysu depression, clay minerals that impede the uranium leaching processes are present in certain areas. Microscopic analysis of core material samples using a LEICA DM 2500 P microscope revealed particle sizes and shapes, as well as their distribution within the structure of host rocks in the productive horizon. Using X-ray diffraction analysis, mineral compositions of sediment-forming components during uranium well mining in the considered productive horizons were determined and comparatively analyzed. It was established that in the geotechnological wells of the Syrdarya depression, sediments of predominantly chemical origin, such as gypsum, are formed. However, in the geotechnological wells of the Shu-Sarysu depression, sediments of mechanical origin, consisting predominantly of quartz particles and clay minerals, are formed. Based on the obtained data, a method for intensifying underground uranium leaching in complex geological conditions has been developed, which involves dissolving sediment formations and increasing the oxidative–reductive potential of the leaching solution. The proposed and experimentally substantiated universal methodology for enhancing uranium well production involves the dissolution and prevention of precipitation using hydrofluoric acid solutions, as well as the oxidation of uranium dioxide with hydrogen peroxide. [ABSTRACT FROM AUTHOR]

Metal–organic frameworks (MOF) are a subclass of porous framework materials that have been used for a wide variety of applications in sensing, catalysis, and remediation. Among these myriad applications is their remarkable ability to capture substances in a variety of environments ranging from benign to extreme. Among the most common and problematic substances found throughout the world's oceans and water supplies is [UO2]2+, a common mobile ion of uranium, which is found both naturally and as a result of anthropogenic activities, leading to problematic environmental contamination. While some MOFs possess high capability for the uptake of [UO2]2+, many more of the thousands of MOFs and their modifications that have been produced over the years have yet to be studied for their ability to uptake [UO2]2+. However, studying the thousands of MOFs and their modifications presents an incredibly difficult task. As such, a way to narrow down the numbers seems imperative. Herein, we evaluate the binding behaviors as well as identify the specific binding sites of [UO2]2+ incorporated into six different Zr MOFs to elucidate specific features that improve [UO2]2+ uptake. In doing so, we also present a method for the determination and verification of these binding sites by Anomalous wide-angle X-ray scattering, X-ray fluorescence, and X-ray absorption spectroscopy. This research not only presents a way for future research into the uptake of [UO2]2+ into MOFs to be conducted but also a means to evaluate MOFs more generally for the uptake of other compounds to be applied for environmental remediation and improvement of ecosystems globally. [ABSTRACT FROM AUTHOR]

In this study, the relationship between PM2.5 and ambient temperature, humidity, air pressure, wind speed and air indices was investigated by combining specific facilities at uranium mine with villages and cities. Humidity, atmospheric pressure and air quality index were positively correlated with PM2.5 concentration, whereas temperature and wind speed were negatively correlated, while altitude had no correlation with PM2.5 concentration. By constructing the corresponding PMF model data analysis, this study obtained six sources of eight metallic elements (U, Th, Al, Cu, Pb, Cd, Ti, Zn) in PM2.5 around a decommissioned uranium mine. [ABSTRACT FROM AUTHOR]

The generation of nuclear energy produces a large amount of uranium containing wastewater, which must be treated. In this study, amino functionalized bentonite (Bent-NH2) was prepared by modifing Gaomiaozi bentonite with 3-Aminopropyltriethoxysilane. Various characterization results confirmed the successful grafting. The batch adsorption experiments indicated Bent-NH2 reached its maximum adsorption capacity rapidly (20 min), 49.168 mg/g. Notably, Bent-NH2 had better adsorption performance than unmodified bentonite in really groundwater with different pH. This work demonstrates that Bent-NH2 has excellent adsorption performance and can be used for low uranium wastewater treatment and geological disposal. [ABSTRACT FROM AUTHOR]

The Jurassic Zhiluo Formation in the western Ordos Basin is known for hosting economically significant sandstone-type uranium deposits. However, the understanding of sediment sources for this formation, crucial for guiding uranium exploration, has been a subject of controversy. This study aims to address this issue by presenting a systematic dataset derived from detrital zircons found in the uranium-bearing sandstones of the Zhiluo Formation. The dataset includes U‒Pb dating, trace element analyses, and in-situ Hf isotope compositions. The detrital zircons analysed are predominantly of magmatic origin, as indicated by a Th/U ratio greater than 0.4. Their U‒Pb ages can be broadly categorized into a predominant population ranging from 170 to 500 Ma, with a peak ca. 300 Ma. Additionally, there are two minor age populations: 1600–2050 Ma (peaking at ca. 1850 Ma) and 2300–2650 Ma (peaking at ca. 2500 Ma). The εHf(t) values of these zircons exhibit a range from −27 to 7, concentrating mostly from −16 to 5. Importantly, none of them aligns above the deficit mantle evolutionary line in an εHf(t) vs. age covariant diagram. A comprehensive comparison of the analytical U‒Pb ages and Hf isotopic results with previously reported data from adjacent geological units surrounding the western Ordos Basin suggests that the primary provenance supply area for the sandstones is the Alxa Block, particularly the uranium-rich felsic rocks within it. Minor contributions are inferred from the Yinshan Block and the Qilian Orogenic Belt. The northwestern region of the study appears to be the primary prospect area for uranium exploration, and we have proposed effective measures to refine the exploration target area and enhance exploration efficiency. Overall, the study provided crucial insights into deducing provenance supply areas and transport paths, with implications for uranium exploration in sedimentary basins worldwide. [ABSTRACT FROM AUTHOR]

The Huayangchuan U-polymetallic deposit in the Qinling Orogen is a newly verified carbonatite-hosted deposit on the southern margin of the North China Craton (NCC) in Central China. Granitic magmatism is extensively developed in the Huayangchuan deposit area and is lacking analysis on the reasons for these situations; however, its ages, petrogenesis, and relationship with uranium mineralization are not well constrained. Zircon U–Pb ages for the hornblende-bearing granite porphyry and medium-fine-grained biotite granites in close proximity to carbonatite rocks are 229.8 ± 1.1 and 135.3 ± 0.6 Ma, respectively. High-K calc-alkaline series and weakly peraluminous Triassic hornblende-bearing granite porphyry are slightly enriched in light rare earth elements (LREE) with flat heavy rare earth element (HREE) patterns, enriched in Ba and Sr, and depleted in Nb, Ta, P, and Ti, i.e., geochemical characteristics similar to those of adakite-like rocks. The Early Cretaceous medium-fine-grained biotite granites are characterized by LREE enrichment and flat HREE patterns, which belong to high-K calc-alkaline series, and metaluminous belong to weakly peraluminous I-type granite, with U and large ion lithophile element (LILE) enrichment and high field strength element depletion. The high initial 87Sr/86Sr ratios and enriched Nd (εNd(t) = −10.7 to −9.5 and −19.9 to −18.9, respectively) and Hf (εHf(t) = −21.8 to −13.0 and −30.5 to −19.0, respectively) isotopes revealed that both granitic rocks from the Huayangchuan deposit mainly originated from lower crustal materials, generated by partial melting of the ancient basement materials of the Taihua Group. Triassic hornblende-bearing granite porphyry is significantly different from the mantle origin of the contemporaneous U-mineralization carbonatite. In combination with tectonic evolution, we argue that the Qinling Orogenic Belt was affected by the subduction of the North Mianlian Ocean during the Late Triassic. The ongoing northward subduction of the Yangtze Craton resulted in crustal thickening, forming large-scale Indosinian carbonatites, U-polymetallic mineralization, and contemporaneous intermediate-acid magmatism. Additionally, due to the tectonic system transformation caused by Paleo-Pacific Plate subduction, intracontinental lithosphere extension and lithospheric thinning occurred along the southern NCC margin in the Early Cretaceous. Intense magma underplating of the post-orogeny created a large number of magmatic rocks. The tremendous heat could have provided a thermal source and dynamic mechanism for the Yanshanian large-scale U-polymetallic mineralization events. [ABSTRACT FROM AUTHOR]

Considering the significant issue of radon contamination in deep uranium mining settings, an investigation was conducted on the mechanical-environmental coupling effects of various joint roughness coefficients (JRC), temperature (T), pressure differential (ΔP), water saturation degree (Kw), and ventilation intensity (λv) on the surface radon exhalation of quasi-uranium ore samples. This was accomplished through the utilization of a self-constructed rock radon coupling exhalation experimental device and quasi-uranium ore sample. The findings indicate that the radon concentration in the sample increases in a linear fashion with the duration of radon collection, irrespective of the sample's temperature. Furthermore, the radon exhalation capacity of the sample exhibits an initial rise followed by a decline as the degree of water saturation increases. As the sample pressure differential increases, the radon exhalation capacity of the sample exhibits a monotonically decreasing pattern. The concentration of accumulated radon is inversely associated with the intensity of ventilation. The relationship between the radon exhalation ability of the sample and the JRC is generally manifested in the form of "first decreasing and then increasing", and the maximum and minimum values of the radon exhalation ability occur in the cases of JRC = 16–18 and JRC = 6–8, respectively. The results of this study can provide scientific basis for the design of ventilation and radon control in future deep uranium mines. [ABSTRACT FROM AUTHOR]

Photo‐assisted uranium reduction from uranium mine wastewater is expected to overcome the competition between impurity ions and U(VI) in the traditional process. Here, B‐TiO2@Co2P‐X S‐scheme heterojunction with metal‐oxygen‐hydrogen (M‐O‐H) is developed insitu modification for photo‐assisted U(VI) (hexavalent uranium) reduction. Relying on the DFT calculation and Hard‐Soft‐Acid‐Base (HSAB) theory, the introduction of metal‐oxygen‐hydrogen (M‐O‐H, hard base) metallic bonds in the B‐TiO2@Co2P‐X is found to enhance the hydrophilicity and the capture capability for uranyl ion (hard acid). Accordingly, B‐TiO2@Co2P‐500 hybrid nanosheets exhibit excellent U(VI) reduction ability (>98%) in the presence of competing ions. By self‐consistent energy band calculations and in‐situ KPFM spectral analysis, the formation of the internal electric field between B‐TiO2 and Co2P at the heterojunction is proven, offering a strong driving force and atomic transportation highway for accelerating the S‐scheme charge carriers directed migration and promoting the photocatalytic reduction of uranium. This work provides a valuable route to explore the functionally modified photocatalyst with high‐efficiency photoelectron separation for U(VI) reduction. [ABSTRACT FROM AUTHOR]

Proponents see a reduction in the need for uranium mining and more efficient, cheaper reactors. Opponents see a risk of proliferation. [ABSTRACT FROM AUTHOR]

The DL deposit is a typical tabular-shaped U deposit hosted in sandstones of the Upper Cretaceous Yaojia Formation in the southwestern Songliao Basin, northeast China. Owing to its recent discovery, the origin of the deposit remains unclear. In this study, mineralogical and geochemical data were used to constrain the genesis of the DL deposit. Two sources of U were recognized: (1) pre-ore U enrichment in the Yaojia Formation during diagenesis; and (2) the provenance of the Yaojia Formation, which comprises late Permian–Early Cretaceous granitic rocks from the southern Great Xing'an Range and northern margin of the North China Craton, rather than the oils and diabase dikes in the study area. Mineralogical and geochemical characteristics indicate that organic matter (OM) in the Yaojia Formation was derived mainly from plant debris and hydrocarbons. In situ S isotope data for pyrite from the ore-bearing sandstones show that most of the pyrite has similar δ34S values (−43.8‰ to −20.6‰) to those of pyrite associated with bacterial sulfate reduction (BSR). The pyrite is often typically replaced and/or overgrown by pitchblende, which has a high P2O5 content (0.07–1.64 wt.%), indicative of a genetic relationship between BSR and U mineralization. The geological, mineralogical, and geochemical features suggest that the U mineralization in the DL deposit was mainly associated with BSR. [ABSTRACT FROM AUTHOR]

Sandstone-hosted uranium deposits are indeed significant sources of uranium resources globally. They are typically found in sedimentary basins and have been extensively explored and exploited in various countries. They play a significant role in meeting global uranium demand and are considered important resources for nuclear energy production. Erlian Basin, as one of the sedimentary basins in northern China, is known for its uranium mineralization hosted within sandstone formations. In this research, machine learning (ML) methodology was applied to mineral prospectivity mapping (MPM) of the metallogenic zone in the Manite depression of the Erlian Basin. An ML model of 92% accuracy was implemented with the random forest algorithm. Additionally, the confusion matrix and receiver operating characteristic curve were used as model evaluation indicators. Furthermore, the model explainability research with post hoc interpretability algorithms bridged the gap between complex opaque (black-box) models and geological cognition, enabling the effective and responsible use of AI technologies. The MPM results shown in QGIS provided vivid geological insights for ML-based metallogenic prediction. With the favorable prospective targets delineated, geologists can make decisions for further uranium exploration. [ABSTRACT FROM AUTHOR]

During the extraction of nuclear raw materials, rare earths and other elements from ores containing uranium and thorium, various types of radioactive waste and some recovery tailings are generated. Mining and ore processing residues, i.e. waste and tailings, present a variety of problems related to waste management. Their bulky structure prevents their disposal underground, and their long radioactive half-life causes various problems with regard to their long-term storage. As a matter of fact, the secondary presence of nuclear raw materials together with other minerals requires compliance with hazardous waste procedures in the storage of waste containing nuclear raw materials after the recovery of these main minerals. It may be possible in the future to recover these nuclear raw materials from stockpiles of stored mine waste. The prospect of imbalances in the global uranium supply and demand increases the importance of secondary sources contributing to the global uranium supply. The increasing importance of secondary sources of nuclear raw materials suggests that more attention should be paid to the recovery of these resources together with primary minerals than in the past. In world literature, there is no review article that describes and discusses the waste management of nuclear raw materials in mining and mineral processing together with the opportunities and obstacles for their recovery. Considering this deficiency in the literature, in this study, the properties of waste and tailings resulting from mining and ore preparation activities of nuclear raw materials are explained, the difficulties encountered are mentioned, and solution suggestions are presented by making use of the literature on the recovery of tailings and waste management. [ABSTRACT FROM AUTHOR]

Rhenium is an extremely rare critical metal element in Earth's continental crust. Owing to its extremely high melting point and heat-stable crystalline structure, rhenium is an essential component of alloy materials used in high-performance aircraft engines. Demand for rhenium resources is therefore growing. Currently, most rhenium is produced as a byproduct of molybdenum mining in porphyry copper–molybdenum deposits. Research has therefore focused on the enrichment characteristics of rhenium in this type of deposit, with little attention paid to rhenium in other types of deposits. This study reports the occurrence state and enrichment mechanism of rhenium in the Qianjiadian sandstone-type uranium deposit in the Songliao Basin, Northeast China. Sequential extraction revealed that the average proportions of different forms of rhenium are as follows: water-soluble (57.86%) > organic-sulfide-bound (13.11%) > residual (12.26%) > Fe/Mn oxide-bound (10.67%) > carbonate-bound (6.10%). Combining mineralogical analysis techniques such as SEM-EDS, EMPA, and XRD, it has been established that rhenium does not occur as a substitute in sulfides (e.g., molybdenite) or uranium minerals in various types of deposits. Instead, it is mainly adsorbed onto clay minerals and Fe-Ti oxides, and in a small number of other minerals (pyrite, organic matter, and pitchblende). Rhenium is similar to redox-sensitive elements such as uranium and vanadium, and it is transported in a water-soluble form by oxidizing groundwater to the redox transition zone for enrichment. However, unlike uranium, which generally forms as uranium minerals, rhenium is mainly adsorbed and enriched onto clay minerals (kaolinite and interlayered illite–smectite). Most of the rhenium in sandstone-type uranium deposits occurs in an ion-adsorption state, and is easily leached and extracted during in-situ leaching mining of uranium ores. This type of deposit demonstrates excellent production potential and will become a crucial recoverable resource for future rhenium supply. [ABSTRACT FROM AUTHOR]

In order to achieve a breakthrough in the exploration of uranium orebodies in the Changjiang area of Guangdong province in China, the geo-electrochemical exploration method is used for mineral resource prediction. The logarithmically and isometric log-ratio (ilr) transformations are applied to the geo-electrochemical data in this study area to extract geochemical anomalies. The relationship between element associations and mineralization is revealed through descriptive statistical analysis and further biplot analysis. Then, the energy spectrum density–area fractal model (S-A model) is used to identify geochemical backgrounds and anomalies. The results show that: (i) the logarithmically and ilr-transformed data are more uniform, and they more or less obey the rules of normal distribution; (ii) the biplot shows that the ilr-transformed data eliminates the closure effect, and the robust principal component analysis (RPCA) has a better indicative significance for element associations—PC1 reveals the mineralization element association dominated by U and the multiple periods of hydrothermal activity; (iii) the S-A method could extract the local anomalies from different geochemical backgrounds, which indicates mineralization is more reliable. Finally, four favorable prospecting targets are delineated based on the geological and geochemical indicators. [ABSTRACT FROM AUTHOR]

Natural radiation is an integral component and obligatory factor in the self-development of the biosphere. There are two sources of natural radiation on Earth: radioactive elements in minerals of the Earth's crust and inner geospheres and radiation belts, the existence of which was established in the late 1950s. The coevolution of living objects with natural factors, including ionizing radiation, occurs according to the mechanism of homeostatic self-regulation with the participation of negative feedback. Outside the zone of homeostasis, any living species falls into supercritical zones with positive feedbacks, where deviations from a stable state can become irreversible. The effect of ionizing radiation on biological objects has not been sufficiently studied, which is why existing radiation safety standards still do not take into account positive feedback. The author believes that it is necessary to develop a modern unified concept of radiation gene-natural coevolution, in which the radioecogeochemical law of nature, implemented through the periodic-rhythmic evolution of the biosphere, is substantiated from the position of system analysis. In other words, it is proposed to introduce the radiation factor into the prevailing Lamarck–Darwin theory of anthropogenesis as the main driving force. Spatiotemporal coincidence was established between the powerful geodynamic activity of the East African Rift, the operation of a natural nuclear reactor in the area of the Oklo uranium deposit (Gabon), and discharge from our humanoid ancestor—Australopithecus africanus, or afarensis. The article discusses some specific features of human genealogy under conditions of prolonged natural radiation. The dominant role of implicit memory in the awareness of ego stress in the formation of radiophobia is shown. The new direction, undoubtedly, should contribute to solving topical applied issues related to increasing safety in the construction of nuclear industry structures, overcoming radiophobia, increasing the radioresistance of ethnic groups, and optimizing of the regulatory framework of ROSATOM and the IAEA in the field of nuclear energy use. [ABSTRACT FROM AUTHOR]

The new coronavirus pandemic (2019-nCoV) arrived in Brazil in February 2020, where the worsening led to social isolation. The population started to remain entirely in their homes, mainly the elderly, children, and adolescents. The study aimed to determine the impact of radioecological dosimetry within the residences located in the municipality from Espinharas, Paraíba, Brazil, where one of the main uranium deposits in Brazil occurs. A scintillator-type gamma spectrometer with a combined NaI (Tl) and BGO probe, at 1.0 m from the soil surface, was used. A total occupation factor for the pandemic period was considered. The dose-response for the three months ranged from 0.55 to 1.70 mSv, with an average of 0.68 mSv, which characterises an increase of 25% when compared to the same period of the retrospective study in 2014. In the period of one year, the dosimetric response can vary between 2.22 and 6.80 mSv/y, with an average of 2.73 mSv/y. The work portrays the importance of a database for future affirmative actions and the determination of different radiometric conditions in an environment already considered to have a high level of natural radioactivity. The study also provides definitions of extreme exposure conditions and correlations with public health parameters. [ABSTRACT FROM AUTHOR]

In this paper, a multi-point geostatistical (MPS) method based on variational function partition simulation is proposed to solve the key problem of MPS 3D modeling using 2D training images. The new method uses the FILTERSIM algorithm framework, and the variational function is used to construct simulation partitions and training image sequences, and only a small number of training images close to the unknown nodes are used in the partition simulation to participate in the MPS simulation. To enhance the reliability, a new covariance filter is also designed to capture the diverse features of the training patterns and allow the filter to downsize the training patterns from any direction; in addition, an information entropy method is used to reconstruct the whole 3D space by selecting the global optimal solution from several locally similar training patterns. The stability and applicability of the new method in complex geological modeling are demonstrated by analyzing the parameter sensitivity and algorithm performance. A geological model of a uranium deposit is simulated to test the pumping of five reserved drill holes, and the results show that the accuracy of the simulation results of the new method is improved by 11.36% compared with the traditional MPS method. [ABSTRACT FROM AUTHOR]

This work deals with the methodology and results of forecasting sandstone-type uranium deposits in the territory of the Republic of Niger, based on the use of a set of regional geological and geophysical materials and a new technology for spatial analysis of data by the method of group accounting of arguments. The necessary information on the genesis and localization of the sandstone-type uranium deposits in the study area is briefly presented. Examples of identified formal geological, tectonic, and geophysical features that characterize the location of known large objects of uranium mineralization are given. Using the example of reference ore and inherently ore-free objects, an identification analysis of the features focused on determining their total information content has been carried out. The results of the identification analysis made it possible to assess the weights of the features and to perform a comprehensive regional forecasting of sandstone-type uranium deposits in the territory of the Republic of Niger. Based on the results of the forecast, the three most promising sites where detailed work on the detection of industrial uranium mineralization is recommended have been defined. [ABSTRACT FROM AUTHOR]

Groundwater supplied by Beberibe aquifer, the main source for the metropolitan region north of Recife, Brazil, exhibits radioactivity because of the presence of uranium resulting from the alteration of phosphate rocks that occur at the base of the Gramame formation, which is superimposed on the aquifer. Using geochemical modelling as a tool to characterise hydrodynamic systems, studies were performed assessing uranyl ions and their interaction with other chemical and mineralogical species found in the aquifer. The results of the geochemical modelling made it possible to perform studies of uranium mobility in the aquifer, analysing the alteration of phosphate minerals and revealing the occurrence of different chemical species. This model suggests that the species present in the aquifer were available for the trophic chain and capable of affecting human health in a differentiated way. [ABSTRACT FROM AUTHOR]

Mamuju is an area of high natural radiation in Indonesia with high natural radiation levels (average 613 nSv h−1). Mamuju is anomalous due to its high average 238U and 232Th concentrations of 22,882 and 33,549 Bq kg−1, respectively, in laterite and rock. High natural radionuclide concentrations of 238U, 232Th, and 40K have also been reported in soil samples from several locations in Mamuju, including Botteng, Northern Botteng, Takandeang, Ahu, and Taan. High radiation levels are related to radioactive mineral occurrences in the Adang volcanic complex, comprised of phonolitoid and foiditoid lithologies. According to the International Atomic Energy Agency (IAEA), uranium deposits can be classified into several types, among them a volcanic-related deposits, which include three sub-types: stratabound, structure-bound, and volcano-sedimentary deposits. This study aims to characterize volcanic rock deposit sub-types in the Mamuju area based on uranium radioisotope measurements. The uranium isotopes were measured using a tandem quadrupole inductively coupled plasma mass spectrometer combined with chemical separation by extraction chromatography using UTEVA resin. The analytical results for the 234U/238U ratios are used to determine the formation characteristics of minerals in each deposit sub-type based on mineral formation age, post-formation processes, and disturbances that affected the formation processes. Based on geochronological calculations using 234U/238U mineralization age, the deposits in the Mamuju area are 0.914–1.11 million years old and are classified as recent mineralization. These data have important implications for tracing uranium source rocks in the Mamuju area and may explain the anomalously high radiation levels in the Mamuju area. [ABSTRACT FROM AUTHOR]

How to effectively and economically estimate the occurrence of sandstone-type uranium deposits in deep metallogenic environments considering the high costs of drilling methods has troubled the uranium geologists for a long time. To address this, we developed a novel workflow using a combination of clustering and neural networks in seismic attributes (SA) analysis to characterize uranium-bearing environments in directly predicting uranium zones. In the workflow, PCA and a clustering method for SA analysis in the target layer were first used to predict favorable zones for uranium; second, supervised neural networks were utilized for quantitative estimation of gamma volume, with subsequent delineation of the zones with high gamma anomalies; finally, results from the two processes were examined for mutual intersection, and intersection results with ordinal ranking of A and B were then extracted. In practical application, several A-level and B-level regions were predicted, which represent very high U-mineralization potential and significant potential, respectively. The prediction results were then essentially verified by logging data of the study area. We consider our developed approach to be a reasonably cost-effective technique for uranium-bearing environment prediction as it can yield useful suggestions for drilling programs with significantly reduced cost and prospecting risk. [ABSTRACT FROM AUTHOR]

Finding effective methods and materials for treating radioactive waste water is urgent to combat environmental issues. A new polyethyleneimine-functionalized β-cyclodextrin porous polymer (PEI-PCDP), which was used for fast and efficient elimination of uranium (U(VI)) from nuclear wastewater, was successfully synthesized in this work. It was found that there were a lot of amine/imide groups on the PEI-PCDP surface through X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and specific surface areas (BET), and it displayed an irregular porous network construction with a BET of 82.816 m2 g−1. Static adsorption results revealed that PEI-PCDP has a large adsorption quantity on U(VI), and the maximum theoretical adsorption quantity was 757.40 mg g−1. Meanwhile, kinetic results exhibited rapid adsorption, and the adsorption quantity can reach 80 ± 1% of the equilibrium adsorption quantity in 10 min. Moreover, PEI-PCDP exhibited good regeneration ability. After 5 sorption–desorption cycles, the adsorption quantity decreased by 10.6%. Mechanism analysis via XPS illustrated that the adsorption process was principally attributed to the active site co-constructed by rich oxygen-containing functional groups and multi-amine groups (–NH2, –NH–) in PEI. Hence, PEI-PCDP has striking U(VI) removal performance and has potential application prospects in radioactive wastewater treatment. [ABSTRACT FROM AUTHOR]

Approximately 50% of the world's uranium is mined in a closed way using underground well leaching. In the process of uranium mining at formation-infiltration deposits, an important role is played by the correct identification of the formation of reservoir oxidation zones (ROZs), within which the uranium content is extremely low and which affect the determination of ore reserves and subsequent mining processes. The currently used methodology for identifying ROZs requires the use of highly skilled labor and resource-intensive studies using neutron fission logging; therefore, it is not always performed. At the same time, the available electrical logging measurements data collected in the process of geophysical well surveys and exploration well data can be effectively used to identify ROZs using machine learning models. This study presents a solution to the problem of detecting ROZs in uranium deposits using ensemble machine learning methods. This method provides an index of weighted harmonic measure (f1_weighted) in the range from 0.72 to 0.93 (XGB classifier), and sufficient stability at different ratios of objects in the input dataset. The obtained results demonstrate the potential for practical use of this method for detecting ROZs in formation-infiltration uranium deposits using ensemble machine learning. [ABSTRACT FROM AUTHOR]

Taking the Baiyanghe uranium deposit in Xinjiang as an example, the authors used the 3D geologic modeling and analysis software SKUA-GOCAD to establish a 3D geologic model of its topography, structure, stratum, granite, and ore body based on the study and knowledge of the geologic background, characteristics, and metallogenic rules of the deposit. Meanwhile, the authors summarized the 3D prediction model, conducted a quantitative extraction and analysis of favorable metallogenic information, and carried out the 3D prediction and study on the Baiyanghe uranium deposit by combining the 3D weights of the evidence method and the 3D informational method. Based on the analysis and prediction results, the deep prospecting target area was delineated. The 3D metallogenic prediction of the uranium deposit was achieved, which has provided technical support for the exploration of the Baiyanghe uranium deposit and a beneficial reference for the 3D metallogenic prediction of other minerals. Such a practice can provide a certain practical application value and a reference value for the research in this field. [ABSTRACT FROM AUTHOR]

Regional paleoregolith is found to exist immediately below unconformities separating basin fills from basement rocks in sedimentary basins. However, the controlling role of paleoregolith on unconformity-type uranium mineralization has not been quantitatively addressed before. Coupled hydrothermal fluid flow and reactive mass transport modeling are therefore performed in this study by using the software TOUGHREACT. The modeling results reveal that preferential flow occurs in the regolith due to its relatively high permeability in comparison with that of the host rocks. The thicker the regolith is, the more concentrated the fluids in the footwall of a fault zone are, leading to more compact and higher-grade deposits therein, and vice versa. Also, displacement of the regolith caused by fault offset plays an important role, as it appears to control the shape of uranium deposits. When the displacement is less than 30 m, the deposits are characterized by a more compact shape. When the displacement is over 60 m, the deposits extend more laterally and even exhibit a 'discrete' shape due to the expelling effect of downslope flow that occurs at the fault offset site. [ABSTRACT FROM AUTHOR]

This paper explores the production of vernacular geological knowledge about uranium during the Cold War. In particular, it investigates uranium gathering practices in Siberia as a form of geopower exercised where Soviet citizens were encouraged to participate in geological exploration of the 'bowels of the Earth' for national benefits. This paper further discusses a novel theorization of the early Soviet understanding of the Anthropocene concept in its relation to the notion of nuclearity as formulated by Soviet scholar Vladimir Vernadsky (1863–1945). Finally, the Soviet nuclear project's legacies are analyzed through indigenous experiences of living near the uranium mine in Siberia. The material used for this research comprised a selected set of youth magazine articles and guidelines issued in the 1930s–1950s by Soviet geological agencies with the aim of promoting vernacular geological practices among Soviet citizens, as well as archival materials and field data collected from geologists and indigenous people in Transbaikalia, eastern Siberia, in 2021. This paper shows that Soviet citizens were a crucial part of the nuclear ideology and, at the same time, were treated as the means of nuclear production because of their ability to search for and extract uranium. It further shows how nuclear discourse in the Soviet Union and modern Russia has been shaped by Vernadsky's ideas about the role of nuclear power in the transformation of society. • Novel theorization of the early Soviet understanding of the Anthropocene concept as formulated by Vernadsky. • Nuclearity as a geospatial concept includes social and geographical aspects of the use and extraction of uranium. • The inclusion of all social strata into uranium-gathering practices in the Soviet Union. • The Soviet version of geopower as the idea of mineral resources as a substantial component of the national geo-body. [ABSTRACT FROM AUTHOR]

Analysis of the distribution of uranium concentrations in the water of conjugated components of the Baikal ecosystem (the water of Lake Baikal and its tributaries, headwaters of the Angara River, and groundwater from the wells drilled on Olkhon Island, and in the southwestern coastal part of Lake Baikal) has been carried out. The essential differences of the maximum uranium concentrations in groundwater of Lake Baikal and its inflows and the close average and median values of uranium in the water of Lake Baikal and the Angara River source were determined. The data obtained on the uranium distribution fix the influence of geological and geochemical peculiarities of the structure of the Baikal ecosystem and its surroundings and the climatic and catastrophic (earthquakes, seismic geodynamic activation, etc.) events that take place in the region. The changes in the uranium concentration in the water of Lake Baikal in relation to the seismic process were analyzed on the example of strong earthquakes (M ≥ 5) in the Lake Baikal area. [ABSTRACT FROM AUTHOR]

With the exploitation of uranium–beryllium ore, the waste and wastewater produced have received extensive attention. There are a lot of toxic and harmful substances in uranium–beryllium ore, among which beryllium has not been widely concerned. This paper used hydrochloric acid (HCl) pretreatment activated carbon (H-AC) to study the removal of beryllium from uranium beryllium ore wastewater. This experiment explored the influence of reaction time, reaction temperature, and other conditions on the adsorption effect. It concluded that the adsorption efficiency was 99% when pH = 5, the amount of adsorbent was 2 g/L, and the temperature was 25 °C. The effects of Be–U, Be–Mn, Be–Zn, Be–Fe and, Be–Al binary systems on the adsorption of beryllium by H-AC were analyzed. The results show that the adsorption capacity of H-AC to beryllium is not affected by the coexisting ions. According to thermodynamics, the adsorption process is a spontaneous endothermic single-layer adsorption, and the maximum adsorption capacity fitted by thermodynamics is 30.63 mg/g. Kinetic fitting showed that chemical adsorption was the primary process, and the reaction was intense in the early stage. This study provides a new idea for removing beryllium from uranium beryllium ore wastewater, and H-AC can be considered a potential adsorbent for removing beryllium from industrial wastewater. [ABSTRACT FROM AUTHOR]

Coal-uranium synergistic development has become an emerging research area in recent years. Radon gas emitted by uranium decay in the stratum may be used as an indicator to study the uranium-bearing area. Investigating the relationship between radon exhalation law and the depth, lithology, and mineral composition of coal measures is very important. This paper analyses the influencing factors and mechanism of radon release in coal measure strata in the Ordos Basin which is rich in coal and uranium co-occurrence deposits, by drilling a core at a depth of 18.3–84 m in the mining area, and using low-field nuclear magnetic resonance (NMR), polarizing microscope and environmental radon meter tests. The results show that the proportion of micropores decreases with an increase in particle size, and the proportion of macropores and porosity increases. High porosity has a greater effect on the release of radon gas, resulting in a higher exhalation rate in samples with coarse particle sizes. The radon exhalation rate of sandstone is higher than that of coal, and the radon concentration increases with the improved sealing property of deep rock and soil masses. The radon exhalation rate of sandstone is strongly influenced by feldspar and is positively correlated with each other. The radon exhalation was aided by the submicron structure created by feldspar alteration. The research results may be used as a reference for rock radiation risk assessment in mining areas. [ABSTRACT FROM AUTHOR]