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Author Ammar, F.H.; Deschamps, P.; Chkir, N.; Zouari, K.; Agoune, A.; Hamelin, B. url  openurl
  Title Uranium isotopes as tracers of groundwater evolution in the Complexe Terminal aquifer of southern Tunisia Type Journal Article
  Year 2020 Publication Quaternary International Abbreviated Journal  
  Volume 547 Issue Pages 33-49  
  Keywords CT southern Tunisia, Holocene, Mixing, Radicarbon, Uranium isotopes, Water-rock interaction  
  Abstract The Complexe Terminal (CT) multi-layer aquifer is formed by Neogene/Paleogene sand deposits, Upper Senonian (Campanian-Maastrichtian limestones) and Turonian carbonates. The chemical composition and isotopes of carbon and uranium were investigated in groundwater sampled from the main hydrogeological units of the (CT) aquifer in southern Tunisia. We paid special attention to the variability of uranium contents and isotopes ratio (234U/238U) to provide a better understanding of the evolution of the groundwater system. Uranium concentrations range from 1.5 to 19.5 ppb, typical of oxic or mildly reducing conditions in groundwaters. The lowest concentrations are found southeast of the study area, where active recharge is supposed to take place. When looking at the isotope composition, it appears that all the samples, including those from carbonate levels, are in radioactive disequilibrium with significant 234U excess. A clear-cut distinction is observed between Turonian and Senonian carbonate aquifers on the one hand, with 234U/238U activity ratios between 1.1 and 1.8, and the sandy aquifer on the other hand, showing higher ratios from 1.8 to 3.2. The distribution of uranium in this complex aquifer system seems to be in agreement with the lithological variability and are ultimately a function of a number of physical and chemical factors including the uranium content of the hosting geological formation, water-rock interaction and mixing between waters having different isotopic signatures. Significant relationships also appear when comparing the uranium distribution with the major ions composition. It is noticeable that uranium is better correlated with sulfate, calcium and magnesium than with other major ions as chloride or bicarbonate. The 14C activities and δ13C values of DIC cover a wide range of values, from 1.1 pmc to 30.2 pmc and from −3.6‰ to −10.7‰, respectively. 14C model ages estimated by the Fontes and Garnier model are all younger than 22 Ka and indicate that the recharge of CT groundwater occurred mainly during the end of the last Glacial and throughout the Holocene.  
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  ISSN 1040-6182 ISBN Medium  
  Area Expedition Conference (up)  
  Notes Approved no  
  Call Number THL @ christoph.kuells @ ammar_uranium_2020 Serial 119  
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Author Su, X.; Liu, Z.; Yao, Y.; Du, Z. url  openurl
  Title Petrology, mineralogy, and ore leaching of sandstone-hosted uranium deposits in the Ordos Basin, North China Type Journal Article
  Year 2020 Publication Ore Geology Reviews Abbreviated Journal  
  Volume 127 Issue Pages 103768  
  Keywords Geochemical composition, leach mining, Mineralogy, Ordos Basin, Sandstone-hosted uranium deposit  
  Abstract The Nalinggou–Daying uranium metallogenic belt is situated at the northern Ordos Basin, China. Petrographical, mineralogical and geochemical techniques were used to study the ore-bearing sandstones and host rocks in the Nalinggou–Daying uranium metallogenic belt. The present study shows that uranium minerals, i.e., coffinite, pitchblende, and brannerite, are mostly disseminated around pyrite and detrital particles. The ore-bearing sandstones are enriched in organic matter, with which this reductive environment influenced uranium leaching. The carbonate concentration of the uranium ores is markedly higher than that of the host rocks, and intense carbonatization occurs in the ore-bearing sandstones. In this case, the usage of the classical in-situ leach uranium mining technique by injecting H2SO4 + H2O2 solution produces calcium sulfate precipitate, which can lead to blocking of the ore-bearing strata. For this reason, laboratory and field uranium mining tests were conducted using CO2 + O2 in-situ leaching technology and were demonstrated to be successful, illustrating that this approach is technically feasible. Inhibiting ore bed blockage and increasing the amount of injected O2 are important for uranium leaching in this setting.  
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  Series Volume Series Issue Edition  
  ISSN 0169-1368 ISBN Medium  
  Area Expedition Conference (up)  
  Notes Approved no  
  Call Number THL @ christoph.kuells @ su_petrology_2020 Serial 120  
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Author Khoury, H.N.; salameh, E.M.; Clark, I.D. url  openurl
  Title Mineralogy and origin of surficial uranium deposits hosted in travertine and calcrete from central Jordan Type Journal Article
  Year 2014 Publication Applied Geochemistry Abbreviated Journal  
  Volume 43 Issue Pages 49-65  
  Keywords  
  Abstract Secondary uranium encrustations are hosted in thick travertine and calcrete deposits of Pleistocene–Recent age in central Jordan. The central Jordan varicolored marble and travertine are equivalent to the active metamorphic area in Maqarin, north Jordan. More than 100 samples were collected from the outcrops of the varicolored marble, travertine, calcrete, and the yellow uranium encrustations. The secondary yellow encrustations are mainly composed of uranyl vanadate complexes. Tyuyamunite Ca(UO2)2V25+O8·3(H2O)–strelkinite Na2(UO2)2V2O8·6(H2O) solid solution series are the major components and their composition reflects changes in the Ca/Na ratio in solution. Potentially, new vanadium free calcium uranate phases (restricted to the varicolored marble) were identified with CaO:UO3 ratios different from the known mineral vorlanite (CaU6+)O4. Carbon and oxygen isotope data from calcite in the varicolored marble are characterized by Rayleigh-type enrichment in light isotopes associated with release of 13C and 18O enriched CO2 by high temperature decarbonation during combustion of the bituminous marl. Stable isotope results from uranium hosted travertine and calcrete varieties exhibit a wide range in isotopic values, between decarbonated and normal sedimentary carbonate rocks. The depleted δ13C and δ18O values in the travertine are related to the kinetic reaction of atmospheric CO2 with hyperalkaline Ca(OH)2 water. The gradual enrichment of δ13C and δ18O values in the calcrete towards equilibrium with the surrounding environment is related to continuous evaporation during seasonal dry periods. Uranium mineralization in central Jordan resulted from the interplay of tectonic, climatic, hydrologic, and depositional events. The large distribution of surficial uranium occurrences hosted in travertine and calcrete deposits is related to the artesian ascending groundwater that formed extensive lakes along NNW–SSE trending depressions. Fresh groundwater moved upward through the highly fractured phosphate, bituminous marl and varicolored marble to form unusual highly alkaline water (hydroxide–sulfate type) enriched with sensitive redox elements among which were U and V.  
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  ISSN 0883-2927 ISBN Medium  
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  Notes Approved no  
  Call Number THL @ christoph.kuells @ khoury_mineralogy_2014 Serial 121  
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Author Love, A.J.; Shand, P.; Karlstrom, K.; Crossey, L.; Rousseau-Gueutin, P.; Priestley, S.; Wholing, D.; Fulton, S.; Keppel, M. url  openurl
  Title Geochemistry and Travertine Dating Provide New Insights into the Hydrogeology of the Great Artesian Basin, South Australia Type Journal Article
  Year 2013 Publication Procedia Earth and Planetary Science Abbreviated Journal  
  Volume 7 Issue Pages 521-524  
  Keywords GAB springs, Great Artesian Basin, Helium isotope data, Uranium series dating  
  Abstract While of great national and societal significance, and importance in its own right, the Great Artesian Basin of Australia is an iconic example of a continental scale artesian groundwater system. New geochemical, hydrological, and neo-tectonic data suggests that existing models that involve recharge in eastern Australia, relatively simple flowpaths and discharge in springs in the western margin require modification. New geochemical data indicate a small volume flux of deeply derived (endogenic) fluids mixing into the aquifer system at a continental scale. Neo- tectonic data indicates active tectonism today that provides a fluid pathway through faults for the deeply sourced endogenic fluids to discharge in GAB travertine depositing springs.  
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  ISSN 1878-5220 ISBN Medium  
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  Notes Approved no  
  Call Number THL @ christoph.kuells @ love_geochemistry_2013 Serial 122  
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Author Alvarado, J.A.C.; Balsiger, B.; Röllin, S.; Jakob, A.; Burger, M. url  openurl
  Title Radioactive and chemical contamination of the water resources in the former uranium mining and milling sites of Mailuu Suu (Kyrgyzstan) Type Journal Article
  Year 2014 Publication Journal of Environmental Radioactivity Abbreviated Journal  
  Volume 138 Issue Pages 1-10  
  Keywords Former uranium mines, Kyrgyzstan, Mailuu Suu, Uranium contamination, Water resources  
  Abstract An assessment of the radioactive and chemical contamination of the water resources at the former uranium mines and processing sites of Mailuu-Suu, in Kyrgyzstan, was carried out. A large number of water samples were collected from the drinking water distribution system (DWDS), rivers, shallow aquifers and drainage water from the mine tailings. Radionuclides and trace metal contents in water from the DWDS were low in general, but were extremely high for Fe, Al and Mn. These elements were associated with the particle fractions in the water and strongly correlated with high turbidity levels. Overall, these results suggest that water from the DWDS does not represent a serious radiological hazard to the Mailuu Suu population. However, due to the high turbidities and contents of some elements, this water is not good quality drinking water. Water from artesian and dug wells were characterized by elevated levels of U (up to 10 μg/L) and some trace elements (e.g. As, Se, Cr, V and F) and anions (e.g. Cl−, NO3−, SO42−). In two artesian wells, the WHO guideline value of 10 μg/L for As in water was exceeded. As the artesian wells are used as a source of drinking water by a large number of households, special care should be taken in order to stay within the WHO recommended guidelines. Drainage water from the mine tailings was as expected highly contaminated with many chemicals (e.g. As) and radioactive contaminants (e.g. U). The concentrations of U were more than 200 times the WHO guideline value of 30 μg/L for U in drinking water. A large variation in 234U/238U isotopic ratios in water was observed, with values near equilibrium at the mine tailings and far from equilibrium outside this area (reaching ratios of 2.3 in the artesian well). This result highlights the potential use of this ratio as an indicator of the origin of U contamination in Mailuu Suu.  
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  ISSN 0265-931x ISBN Medium  
  Area Expedition Conference (up)  
  Notes Approved no  
  Call Number THL @ christoph.kuells @ alvarado_radioactive_2014 Serial 123  
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Author Hall, S.M.; Gosen, B.S.V.; Paces, J.B.; Zielinski, R.A.; Breit, G.N. url  openurl
  Title Calcrete uranium deposits in the Southern High Plains, USA Type Journal Article
  Year 2019 Publication Ore Geology Reviews Abbreviated Journal  
  Volume 109 Issue Pages 50-78  
  Keywords Calcrete, Carnotite, Finchite, Geochemistry, Uranium, Vanadium  
  Abstract The Southern High Plains (SHP) is a new and emerging U.S. uranium province. Here, uranyl vanadates form deposits in Pliocene to Pleistocene sandstone, dolomite, and limestone. Fifteen calcrete uranium occurrences are identified; two of these, the Buzzard Draw and Sulfur Springs Draw deposits, have combined in-place resources estimated at about 4 million pounds of U3O8. Ore minerals carnotite and finchite are hosted in dolomite at the Sulfur Springs Draw deposit, with accessory fluorite, celestine, smectite/illite, autunite, and strontium carbonate. Host carbonate at the Sulfur Springs Draw deposit is ∼190 ka and mineralization mobilized as recently as 3.8 ka. Ash collected near the deposit is 631 ka and erupted from the Yellowstone caldera complex. The Triassic Dockum Group that contains sandstone-hosted uranium deposits throughout the region and underlies the SHP is a potential source for uranium and vanadium. Regional uplift and dissection reintroduced oxygenated groundwater into the Dockum Group, mobilizing uranium. Additional uranium may have been contributed to groundwater by weathering of volcanic ash in Pliocene and Pleistocene host rocks. The locations of the uranium occurrences are mostly in modern drainage systems in the southeast portion of the SHP. Modelling of modern groundwater in the SHP carried out in a parallel study shows that a single fluid could form carnotite through evaporation, and that fluids of the requisite composition are more prevalent in the southern portion of the SHP. The southeastern portion of the SHP hosts more uranium occurrences due to a variety of factors including (1) upward transport of groundwater and connectivity between source and host rock, (2) higher uranium and vanadium content of groundwater, (3) higher rates of groundwater recharge in this region to drive the mineralizing system, and (4) shallower groundwater facilitating surface evaporation. Ongoing erosion of host rocks challenges preservation of deposits and may limit their size.  
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  Series Volume Series Issue Edition  
  ISSN 0169-1368 ISBN Medium  
  Area Expedition Conference (up)  
  Notes Approved no  
  Call Number THL @ christoph.kuells @ hall_calcrete_2019 Serial 124  
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Author Salbu, B. url  openurl
  Title Preface: uranium mining legacy issue in Central Asia Type Journal Article
  Year 2013 Publication Journal of Environmental Radioactivity Abbreviated Journal  
  Volume 123 Issue Pages 1-2  
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  ISSN 0265-931x ISBN Medium  
  Area Expedition Conference (up)  
  Notes Approved no  
  Call Number THL @ christoph.kuells @ salbu_preface_2013 Serial 125  
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Author Vogel, J.C.; Talma, A.S.; Heaton, T.H.E.; Kronfeld, J. url  openurl
  Title Evaluating the rate of migration of an uranium deposition front within the Uitenhage Aquifer Type Journal Article
  Year 1999 Publication Journal of Geochemical Exploration Abbreviated Journal  
  Volume 66 Issue 1 Pages 269-276  
  Keywords redox changes in aquifer, sandstone-type uranium deposit, South Africa, uranium series  
  Abstract The solubility of uranium in groundwater is very sensitive to changes in redox conditions. Many secondary (sandstone-type) uranium deposits have been formed when soluble U has precipitated after encountering reducing conditions in the subsurface. In the groundwater of the Uitenhage Aquifer (Cape Province, South Africa), 238U-series isotopes were used to assist in studying the history of the reducing barrier. Uranium isotopes were used to determine the present position of the barrier. Radium and radon were used to evaluate the path of migration that the front of the oxygen depletion zone has taken over the past 105 years. During this time the reducing barrier has moved, leaving in its wake a trail of U in various stages of secular equilibrium with its daughter 230Th. The 226Ra daughter of 230Th is not very mobile. Its growth upon the aquifer wall is reflected in the Rn content of the water. This in turn, due to the relatively great age of the water, indicates the extent of the 230Th ingrowth (from precipitated U) that took place before the barrier migrated.  
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  ISSN 0375-6742 ISBN Medium  
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  Notes Approved no  
  Call Number THL @ christoph.kuells @ vogel_evaluating_1999 Serial 126  
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Author Sahoo, S.K.; Jha, V.N.; Patra, A.C.; Jha, S.K.; Kulkarni, M.S. url  openurl
  Title Scientific background and methodology adopted on derivation of regulatory limit for uranium in drinking water – A global perspective Type Journal Article
  Year 2020 Publication Environmental Advances Abbreviated Journal  
  Volume 2 Issue Pages 100020  
  Keywords Drinking water, Global policy, Regulatory limits, Toxicity, Uranium  
  Abstract Guideline values are prescribed for drinking water to ensure long term protection of the public against anticipated potential adverse effects. There is a great public and regulatory agencies interest in the guideline values of uranium due to its complex behavior in natural aquatic system and divergent guideline values across the countries. Wide variability in guideline values of uranium in drinking water may be attributed to toxicity reference point, variation in threshold values, uncertainty within intraspecies and interspecies, resource availability, socio-economic condition, variation in ingestion rate, etc. Although guideline values vary to a great extent, reasonable scientific basis and technical judgments are essential before it could be implemented. Globally guideline values are derived considering its radiological or chemical toxicity. Minimal or no adverse effect criterions are normally chosen as the basis for deriving the guideline values of uranium. In India, the drinking water limit of 60 µg/L has been estimated on the premise of its radiological concern. A guideline concentration of 2 µg/L is recommended in Japan while 1700 µg/L in Russia. The relative merit of different experimental assumption, scientific approach and its methodology adopted for derivation of guideline value of uranium in drinking water in India and other countries is discussed in the paper.  
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  ISSN 2666-7657 ISBN Medium  
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  Notes Approved no  
  Call Number THL @ christoph.kuells @ sahoo_scientific_2020 Serial 127  
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Author Chen, Y.; Hong, Y.; Huang, D.; Dai, X.; Zhang, M.; Liu, Y.; Xu, Z. url  openurl
  Title Risk assessment management and emergency plan for uranium tailings pond Type Journal Article
  Year 2022 Publication Journal of Radiation Research and Applied Sciences Abbreviated Journal  
  Volume 15 Issue 3 Pages 83-90  
  Keywords Emergency management, Interpreted structural model (ISM), Resilience, Risk coupling, Uranium tailings pond  
  Abstract The safety of uranium tailings pond is closely related to social stability and economic development, so it is necessary to improve the emergency management of uranium tailings pond to ensure its safety by adjusting the emergency plan. The Interpretive Structural Model (ISM) is used to analyze the structural relationship between the main risk factors leading to the occurrence of emergencies. The results show that attention should be paid to the risk factors originating from humans and infrastructures, and effective management measures should be adopted in the process of emergency management, for example, people build tighter employee access system, clarify the responsibilities of employees at all levels, and improve monitoring and organizational means. According to the results of ISM analysis, a structural risk control system can be constructed, and a defensive barrier that can effectively block the risk coupling transmission can be designed to prevent the risk from being transformed into an event. For other risks, system resilience management should be strengthened to respond to risks. The process is set as emergency response and accident response. Different management objects use different management methods to make emergency management work efficiently.  
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  ISSN 1687-8507 ISBN Medium  
  Area Expedition Conference (up)  
  Notes Approved no  
  Call Number THL @ christoph.kuells @ chen_risk_2022 Serial 128  
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