Two Methods for Measuring Total Uranium Content in Co-Extruded AlU

2009 ◽  
pp. 366-366-7
Author(s):  
G. E. Bradley ◽  
E. G. Leverenz ◽  
W. J. McGonnagle
Keyword(s):  
Uranium Content

scholarly journals The Study of Uranium Accumulation in Marine Bottom Sediments: Effect of Redox Conditions at the Time of Sedimentation

Geosciences ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 332
Author(s):  
Nadezhda Khaustova ◽  
Yulia Tikhomirova ◽  
Svetlana Korost ◽  
Elena Poludetkina ◽  
Andrey Voropaev ◽  
...  
Keyword(s):  
Bottom Sediments ◽  
White Sea ◽  
Uranium Content ◽  
Black Shales ◽  
Redox Conditions ◽  
Source Rocks ◽  
Shelf Zone ◽  
The Black Sea ◽  
The White Sea ◽  
Run Off

To evaluate the effect of redox conditions at the sedimentation stage on uranium content and U/TOC ratio in marine source rocks, we analyzed the accumulation of uranium in modern marine bottom sediments formed in different redox conditions. The behavior of uranium from bottom sediments formed in oxidizing and sub-oxidizing settings has been studied on the sediments of the Upper Pleistocene–Holocene age accumulated in the coastal area of the White Sea (Kandalaksha Gulf). We studied the content of uranium, Eh, pH, TOC, C, H, N, and S element and isotope compositions and other parameters in two sampled columns of bottom sediments at a depth of 0–2.5 m. The composition of sediments was typical for the shelf zone where marine genesis mixes with the continental run-off. The upper layer of sediments (0–50 cm) were characterized by oxidizing conditions (Eh ~ 400 mV); with the increase in depth, redox conditions changed from oxidizing to reducing (0 ÷ 200 mV). The uranium concentration in the upper layer was 1–1.5 ppm, U/TOC ratio varied in the range of 0.8–1.1 ppmU/%TOC. The uranium content and U/TOC ratio increased up to the values of 2.6 ppm and 1.4 ppmU/%TOC at a depth of 0.5−2.5 m, respectively, but the general content of uranium in the studied environment was close to the values characterizing continental run-off. The results obtained for the White Sea sediments were compared with the sediment of the Black Sea, formed in the anoxic conditions of hydrogen sulfide contamination. In these conditions, the uranium content varied from 10 to 20 ppm. The obtained data were interpreted using thermodynamic modeling of the uranium forms in the seawater at different pH and Eh. This study demonstrated that the change of redox conditions from oxidizing to reducing leads to increased uranium content due to a decrease in uranium’s solubility in water. These results show that oxidation–reduction potential could be one of the most important factors controlling uranium content in black shales formed in the marine environment.

scholarly journals Construction of new houses on a uranium vein outcrop: a case study from the Czech Republic

Nukleonika ◽  
2016 ◽  
Vol 61 (3) ◽  
pp. 343-349 ◽  
Author(s):  
Viktor Goliáš ◽  
Gereltsetseg Tumurkhuu ◽  
Pavel Kohn ◽  
Ondřej Šálek ◽  
Jakub Plášil ◽  
...  
Keyword(s):  
Planning Process ◽  
Uranium Content ◽  
Uranium Mineralization ◽  
Construction Site ◽  
The Czech Republic ◽  
Uranium Ore ◽  
Safety Requirements ◽  
New Construction ◽  
Radon Risk

Abstract Significant uranium mineralization represented by a typical assemblage of uranyl supergene minerals in a quartz-uraninite vein hosted in the exocontact zone of the Variscan-Tanvald granite was found at a new construction site in the municipality of Jablonec n. Nisou. Activities of 222Rn in soil gas reached 1 MBq/m3 around two houses, with a maximum of 3.33 MBq/m3 between them on a uranium ore lens outcrop. The uranium content reaches up to 291 ppm eU (3595 Bq/kg 226Ra), and it is possible to find many ‘hot’ pieces of uranium ore fragments with a high percentage of uranium in the Quaternary cover in this place. This unfavourable situation is a result of an improper spatial planning process. The constructor was given the permission to construct the building even though the construction site did not meet safety requirements and the geological survey had failed. Not only geological prospecting was underestimated, but also the radon risk assessment was undervalued.

scholarly journals Change of the cadmium, lead and uranium content in the soil pore water depending on the temperature in conditions of low soil moisture

2019 ◽  
Vol 55 (2) ◽  
pp. 212-222
Author(s):  
G. A. Sokolik ◽  
S. V. Ovsiannikova ◽  
M. V. Papenia
Keyword(s):  
Heavy Metal ◽  
Moisture Content ◽  
Pore Water ◽  
Chemical Nature ◽  
Pore Solution ◽  
Uranium Content ◽  
Iron Hydroxides ◽  
Water Capacity ◽  
Cadmium Lead ◽  
Definite Temperature

Effect of the soil temperature on concentration and total reserve of cadmium, lead and uranium in the interstitial (pore) water of (0–20)-cm samples of sod-podzolic soil with moisture content of 60 % of the water capacity (WC) after their keeping at the definite temperature (in the range of 14–40 °С) was established. It was found that character and extent to which temperature effects on concentration and total reserve of every heavy metal (Cd, Pb, U) in the soil pore solution depended on the chemical nature of heavy metal and peculiarities of soil. In the temperature range of 14–40 °С and moisture content in the soil samples 60 % of the WC, portions of the cadmium, lead and uranium in the soil pore solution decreased in the following way: aCd (0.2–0.4 %) > aPb (0.06–0.07 %) > aU (0.03–0.04 %). The concentrations and total reserves of cadmium, lead and uranium in the soil pore solution increased with lowering the temperature and it was especially true in regard to cadmium. The 5 °С temperature decrease in the range of 14–40 °С caused the content of cadmium in the soil pore solution to increase an average of 25 %, lead – 5.2 and U – 4.6 %. The iron content in the soil solution also increased with decreasing temperature, which indicated a decrease in the sorption capacity of iron hydroxides present in the soil, which probably played a prominent role in fixing cadmium, lead and uranium in the soil studied.

scholarly journals A study of radioactive veins containing rare-earth minerals in the area surrounding the Ilímaussaq alkaline intrusion in South Greenland

1968 ◽  
Vol 76 ◽  
pp. 1-51
Author(s):  
J Hansen
Keyword(s):  
Rare Earth ◽  
Uranium Content ◽  
Radioactive Material ◽  
X Ray ◽  
Quartz Veins ◽  
Alkaline Intrusion ◽  
Rare Earth Minerals ◽  
Small Cracks ◽  
Thorium Content ◽  
Iron Manganese

Radioactive veins containing the rare-earth minerals monazite and bastnaesite are found in tension joints in Precambrian sandstone, granite, lavas and dykes on the eastern side of the alkaline Ilímaussaq intrusion in South Greenland. The veins were formed in several phases. First, small cracks were mineralized with hematite, fluorite, quartz and radioactive material. This was followed by emplacement of brown albititic veins in which albite and opaque material predominate, green veins with a high content of ægirine, white albititic veins, carbonate veins and finally quartz veins. All the vein minerals may be coated by a late iron-manganese oxide. Most often the veins are separate, but they may also occur composite. The veins are from a few millimetres to about three metres wide; most commonly they are one to ten centimetres wide. The radioactivity is mostly due to thorium, but a few veins have a uranium content higher than that of thorium. The thorium content ranges from 60 to 4500 ppm, the uranium from 17 to 1500 ppm. The ratio thorium/uranium ranges from 0.1 to 57.2. The radioactivity is predominantly connected with pigmentary material, thorite, thorianite, monazite and bastnäsite. Other minerals identified in the vein are ægirine, acmite, albite, arfvedsonite, apatite, biotite, calcite, chlorite, eudialyte, fluorite, hematite, lithium mica, mesodialyte, microcline, neptunite, pyrite, quartz and sphalerite. The following constants were calculated from X-ray powder diagrams made with a Guinier-Hagg camera.Bastnäsite: a0 = 7.120 ± 7 x 10-3 Å; C0 = 9.77 ± 2 x 10-2 Å; c0/a0 = 1.372; V0 = 428.96 Å3. Monazite: a0 = 6.780 ± 5 x 10-3 Å; b0 = 7.025 ± 4 x 10-3 Å; C

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