Uranium on the Moon: Global distribution and U/Th ratio
[1] The Kaguya Gamma-Ray Spectrometer uniquely identified uranium gamma-ray lines from the Moon with a superior energy resolution of ∼1%. A global lunar map of uranium distribution is derived for the first time. It was found that uranium abundances vary up to 2 ppm with an average of ∼0.3 ppm, while the average thorium …
Estimation of activity concentrations of radionuclides …
The device is calibrated to measure Potassium (K) in percent (%), Thorium (Th) in ppm and Uranium (U) in ppm which is displayed as the assay reading after the …
Natural radioactivity and its radiological implications from …
The calculated uranium and thorium concentration in ppm and potassium in weight % is shown in (Table (Table2). 2). Uranium concentration varied from (1.7 to 5.3) ppm and (1.1 to 4.1) ppm and Thorium concentration was in the range of (6.06 to 22.6) ppm and (4.8 to 14) ppm for soil and rock samples respectively, 40 K concentration was …
Thorium's Long-Term Potential in Nuclear Energy: …
Thorium can generate more fissile material (uranium-233) than it consumes while fuelling a water-cooled or molten-salt reactor. According to estimates, the Earth's …
RELEASE STANDARD FOR URANIUM AND THORIUM …
natural uranium and thorium from place to place (including use as backfill) and still be exempt from the requirements of 10 CFR Part 40. As a result, this exemption could result in exposures above the unrestricted use criterion in 10 CFR 20.1402 for any high concentrations of uranium and thorium that may sometimes be found in nature. 3.2.4 10 …
Lithological characterization of Ijebu-Ife, Southwest, Nigeria …
The content of uranium and thorium in rocks varies from near zero to several hundreds of parts per million (ppm) (Killeen et al. 1975). The content of 40 K, 238 U and 232 Th depends on rock type and the geological environment.
[Uranium, thorium and potassium contents and radioactive
Uranium, thorium and potassium contents and radioactive equilibrium states of the uranium and thorium series nuclides have been studied for 2 phosphate rocks and 7 phosphate fertilizers. Uranium contents were found to be rather high (39-117 ppm) except for phosphate rock from Kola. The uranium serie …
KGS--Geological Log Analysis--The Gamma Ray Log
Shales are the most common radioactive lithology that is seen on a gamma-ray log. However, other lithogies can generate high gamma-ray readings and their expected API values can be computed by applying the 4-8-16 multipliers to analyses of thorium (ppm), uranium (ppm), and potassium (%), where these are available. A Black Shale-Gray …
Abundances of Uranium and Thorium Elements …
The geoneutrinos produced by the radioactive decays of uranium and thorium have been observed with the Kamioka Liquid-Scintillator Antineutrino Detector (KamLAND). Those measurements …
Thorium's Long-Term Potential in Nuclear Energy
It is estimated that the Earth's upper crust contains an average of 10.5 parts per million (ppm) of thorium, compared with about 3 ppm of uranium. "Because of its abundance …
Uranium Supplies: Supply of Uranium
ppm = parts per million * Where uranium is at low levels in rock or sands (certainly less than 1000 ppm) it needs to be in a form which is easily separated for those concentrations to be called 'ore' – that is, …
Determination of uranium and thorium contents in various …
For plant samples the values of uranium (Table 4) vary from 4.4 ppm to 4.8 ppm, whereas the thorium values vary between 11.1 ppm and 21.2 ppm. It is important to make clear that the values registered in present investigation are in good agreement with the results calculated by the SSNTD detection efficiency method ( Misdaq et al, 2000 ).
Relative Contributions of Uranium, Thorium, and …
duction as chondrites, the following. concentrations are required: potassium. = 2.255 X 10-4 g/g, uranium = 2.255 X 10-8 g/g, and thorium = 8.344 X 10-8 g/g. If the earth as a whole has the heat production of chondrites and. if the radioactive elements are elimi-. nated from the core and put into the.
A comparison of analytical methods for determining uranium and thorium
Extraction of uranium from these samples with aqua regia gave 110 ppm whereas addition of HF slightly improved the extraction to 116 ppm. As with the Sokli samples, separation of thorium as a nitrate complex was found to …
Radioactive Rarity on Mars
Thorium and uranium are always found with Rare Earth Element (REE) ores. If REE are mined on Mars for their magnetic and electronic industrial uses, enough U/Th would be produced to allow for nuclear power. ... Conway granite has 56 +/- 6 ppm thorium. New Hampshire is estimated to have 3,000,000 tonnes of this at shallow depth.
Geoscience Wisconsin URANIUM AND THORIUM IN …
The article summarizes the results of uranium and thorium investiga tions, by gamma-ray spectrometry, of several Precambrian rock units in Wisconsin. The highest values were encountered in the Wolf River batholith where uranium values range from less than 1 ppm to more than 30 ppm; thorium values range from less than 5 ppm to more than 50 ppm.
Mass Spectrometric Determination of Uranium and Thorium …
A rapid new method for determining the U and Th mass concentrations in high radiopurity plastics is described, consisting of (1) dry ashing the plastic sample and tracers in low mass crucibles made of ultra low background electroformed copper (ULB EF-Cu) foil cut and folded into boats, (2) dissolving both the ash and the boat in acid, (3) performing …
Uranium and thorium isotopic and concentration
Here, we outline a technique for measuring uranium and thorium isotopic composition and concentrations using a sector-field ICP-MS equipped with a single electron multiplier, which can be operated in ion-counting or analogue mode (a Finnigan Element). ... The 232 Th 1 H + / 232 Th + ratio was less than 4 ppm in the ICP-MS system.
(PDF) Gold, uranium and thorium mineralization in Paleoproterozoic
Uranium and thorium values vary from 1.27 ppm to 25.55 ppm and 9 ppm to 29 ppm respectively. Two samples reveal higher value of uranium (16.07 ppm & 25.55 ppm) which is about 10 times more than ...
Radioactive Elements in Coal and Fly Ash:
Thorium concentrations in coal fall within a similar 1–4 ppm range, compared to an average crustal abundance of approximately 10 ppm. Coals with more than 20 ppm thorium are extremely rare. During coal combustion most of the uranium, thorium, and their decay products are released from the original coal matrix and are distributed …
Evaluation of elemental concentrations of uranium, thorium …
The elemental concentrations of uranium (in ppm), thorium (in ppm) and potassium (in %) can be calculated from measured radioactivity concentrations of 238 U, 232 Th and 40 K (in Bq/kg) using conversion factors …
Evidence and uncertainty for uranium and thorium …
Analysis of igneous rock, common granite and Cornwall granite (hydrothermal mineralisations) shows for uranium concentrations of 3.7, 4.0 and up to 4.8 ppm, and for thorium 12, 16 and 17 ppm, respectively ( Goldschmidt, 1958) with Th/U ratio of 3.59 ± …
GEOLOGICAL STUDIES ON URANIUM, THORIUM, …
The analysis of radiometric data revealed concentrations distribution pattern of primary radioelements: potassium (K), thorium (Th) and uranium (U). The count rate range of K (0.11 - 2.75%), Th (6.79 - 27.71 ppm) and U (1.69 - 6.21 ppm) were observed within the study area. From the analysis of the maps, the relative lower values of Uranium ...
Nature, Sources, Resources, and Production of Thorium
Thorium is a naturally occurring, slightly radioactive element. It is widely distributed in nature with an average concentration of 10.5 ppm Th in the upper earth's crust. In general, thorium occurs in relatively small number in Th-enriched minerals: thorite, thorianite, monazite, bastnaesite, and thorogummite. However, the main world resources …
Naturally-Occurring Radioactive Materials (NORM)
Long-lived radioactive elements such as uranium, thorium and potassium and any of their decay products, such as radium and radon are examples of NORM. These elements have always been present in the Earth's crust …
Uranium and Thorium | Australia's Energy Commodity …
Uranium and thorium are naturally occurring elements that are widespread in the Earth's crust. Mining occurs in locations where such elements are naturally concentrated. ... Uranium is a mildly radioactive element that is widespread at levels of 1–4 parts per million (ppm) in the Earth's crust. Concentrations of uranium-rich minerals, such ...
Natural radioactivity and its radiological implications …
Radio-elemental ratios suggest that an oxic depositional environment with low uranium and high thorium content. Regarding radiological hazard indices, radium …
Radioactive Elements in Coal and Fly Ash: Abundance, …
(ppm). Similar uranium concentrations are found in a vari-ety of common rocks and soils, as indicated in figure 2. Coals with more than 20 ppm uranium are rare in the United States. Thorium concentrations in coal fall within a similar 1–4 ppm range, compared to an average crustal abundance of approximately 10 ppm. Coals with more than 20 ppm
Thorium
Soil contains an average of around 6 parts per million (ppm) of thorium. Thorium is very insoluble, which is why it is plentiful in sands but not in seawater, in contrast to uranium. Thorium exists in nature in a single isotopic form – Th-232 – which decays very slowly (its half-life is about three times the age of the Earth).
In-situ assessment of natural terrestrial-radioactivity …
In-situ assessment of natural terrestrial-radioactivity from Uranium-238 ( 238 U), Thorium-232 ( 232 Th) and Potassium-40 ( 40 K) in coastal urban-environment and …
