Abstract. Thorium as a potential source fuel for energy generation has gained new attention in the United States, including consideration in the U.S. Congress (Branan, 2008). Thus, it benefits the ...Web

Uranium and thorium are common elements in the Earth's crust. They can be found in low concentrations almost everywhere in rock, soil, rivers, and oceans. The Australian continent, through its geological heritage, is endowed with well-above-average concentrations of the uranium and thorium.Web

composition. The mean thorium content, 20.3 ppn, and mean Th/D, 3.19, are normal. The most uraniferous and fertile rocks are the peraluminous two- mica granitic suite, although not all two-mica plutons are enriched in uranium. The muscovite-bearing suite has mean uranium content of 22.3 ppm, mean thorium content of 22.8 ppm, and mean Th/U of 2.82.Web

Discussion" OF RESULTS The data in Table 1 are particularly noteworthy for the rather uniform and low thorium and uranium concentrations found in the ordinary orthoquartzites studied. Excluding the three placer-sand samples, the average thorium is 1-7 0-1 p.p.m., the average uranium is 0-45 0-05 p.p.m., and the average Th/U ratio is 3-8 0-8.Web

The average of the activity concentrations of uranium, thorium, potassium, while radio in soil samples were 11,7 BqKg −1, 33,0 BqKg −1, 424,5 BqKg −1, and 15,59 BqKg −1, respectively, and the activity concentrations of radon in the water were 139.3 and 750.4 Bqm −3, which are within the values allowed by the World Health Organization. TheWeb

The highest values of uranium and thorium concentrations (4053 ± 428 ppm and 33578 ± 873 ppm, respectively) were observed in xenotime and monazite; whereas the lowest value was 5.48 ± 0.86 ppm of uranium recorded in waste (sand) and 9 ± 0.32 ppm of thorium for waste (sand) and pyrite.Web

The mean concentrations of 226 Ra and 40 K in this study are far lower than the international reference standards, while the average value of 232 Th is higher than the international recommended ...Web

The average concentration was 13.6 ± 7.6 mg kg −1, which is consistent with the estimated average concentration in the earth crust and is then proposed as average basal concentration for this region. A slight disequilibrium has been found between the natural isotopes of thorium due to the semi-arid nature of the areas and climatic factors.Web

The average thorium concentration in the Earth's crust is about 5.6 ppm (or 5.6 mg/kg). The concentra-tion of thorium is higher in the upper part of the Earth's crust, reaching 10.5 ppm, while its average concentration in the lower layers is 1.2 ppm [1–3]. There are 31 known radioactive thorium isotopes;Web

average thorium, uranium, and potassium contents (using Birch's heat-generation values), the total radiogenic production of the calc-alkalic Boulder batholith (weighted according to rock ... for concentrations from 0.5 to 1 ppm, the analytical uncertainty may be as great as ± 50 percent. A comparison of thorium and uranium values ob­ tained ...Web

Geochemistry of thorium and thorium minerals. Thorium is widely distributed in nature with an average concentration of 10.5 ppm Th in the upper earth's crust, while the middle crust has an average of 6.5 …Web

The atmospheric mass concentration of thorium ranged from 0.2 to 1.0 ng/m 3, with a mean value of ... The average population-weighted concentrations of 232 Th 230and Th in United States community water supplies derived both from surface and groundwater were <0.01 and <0.04 pCi/L, respectively (Cothern 1987; Cothern et al. 1986). ...Web

Thorium concentrations ar e analyzed in less than 100 drill cores, where the average varies between less than 1 and 17 ppm. As there are very few measurements of Th concentrations in westernWeb

Sudden changes in concentration were observed, although no correlation with atmospheric pressure was found. The concentrations of radium (226 Ra) and thorium (228 Th) measured in samples collected from surrounding rock body were at average levels for the Earth's crust—about 12 Bq·kg −1 of 226 Ra and 13 Bq·kg −1 of 228 Th.Web

Natural radioactivity concentrations in recent alluvial soils from swampy areas and Tertiary rocks from Jaintiapur were measured using gamma-ray spectrometer equipped with HPGe detector. The average radioactivity concentration of 226Ra, 232Th and 40K were 47 ± 6, 64 ± 5 and 762 ± 40 Bqkg−1 in soils, whereas, 25 ± 2, 37 ± 4 and …Web

1. Introduction. Radiological hazards in industries involving naturally occurring radioactive materials (NORMs) have become a widespread radiological concern and attracted increased attention from society. 1, 2, 3 Thorium is a radioactive element extensively present in the earth's crust with an average concentration of 7.4 μg/g. 4 As …Web

The granitic rocks which occur in most of the study area contain uranium in the range of 10.2-116 ppm with an average of 35 ppm and thorium between 25.5 and 60.7 ppm with an average of 50 ppm [13Web

Thorium concentrations in the lithosphere range from 8 to 12 μg g −1. It is a weakly radioactive ... bottom and fly ashes from five coal-fired power plants were found to be enriched in REEs and yttrium, with average concentrations of 658 ± 296 mg kg −1 and some elements reaching levels as high as 1257 mg kg −1 (Li C et al., 2019 ...Web

Analyses of fluorapatite grains reveal that they contain an average of 0.233 per cent thorium (Hussey, 2003), making the Nolans Bore deposit a world-class thorium resource. Concentrations of thorium may also be found in iron oxide Cu-Au, skarn and phosphate deposits, and in coal and peat accumulations. ReferencesWeb

On average K 2 O values are less than K air activity concentration, ... showed the highest equivalent thorium concentration (16.22 mg kg −1) and thoron exhalation rate (2138 Bq m −2 h −1), respectively. The summary of soil geochemistry for grouped soil associations is expressed in Table 5. ...Web

Thorium is a chemical element with the atomic number 90 in the periodic table. The average concentration of this substance in the upper crust of Earth amounts to 10.5 ppm, while thorium concentration in the middle layer (the mantle) is around 6.5 ppm. The core (lowest layer) of the Earth's crust contains 1.2 ppm on average.Web

The correlations between exhalation rates of these gases and their parent nuclide exhalation (radium/thorium) concentrations were examined. Finally, indoor radon and thoron and the annual effective dose were calculated from radon/thoron concentrations in the closed chamber. ... (Bq m −3) is the average concentration of thoron in the …Web

The elemental concentrations of uranium, thorium and potassium obtained from the three areas where soil samples were collected are summarized in Table 2. The measured arithmetic mean and stand deviation of elemental concentrations for U 238, T 232 h and K 40 in all the samples studied are 2.29 ± 0.95 ppm, 7.77 ± 3.98 ppm and …Web

Thorium Isotopic Concentration in Three Occupational Cases and the General Population of Grand Junction, Colorado (pCi/kg) ..... 99 7-1. Regulations and Guidelines Applicable to Thorium..... 113 . THORIUM 1 . CHAPTER 1. RELEVANCE TO PUBLIC HEALTH ...Web

the average. For Ra-226, about 30 % of the total amount is extracted with ammonium lactate and acetic acid. ... uranium- and thorium concentrations and the contents of clay and organic matter in the soil. The concentration of Th-232 in the soil was strongly correlated to the clay content. ForWeb

Thorium concentrations in coal fall within a similar 1–4 ppm range, compared to an average crustal abun-dance of approximately 10 ppm. Coals with more than 20 ppm thorium are extremely rare. During coal combustion most of the uranium, tho-rium, and their decay products are released from theWeb

The average thorium concentration in the Earth's crust is about 5.6 ppm (or 5.6 mg/kg). The concentra- tion of thorium is higher in the upper part of the Earth's crust, reaching …Web

The average concentration was 13.6 ± 7.6 mg kg −1, which is consistent with the estimated average concentration in the earth crust and is then proposed as average basal concentration for this region. A slight disequilibrium has been found between the natural isotopes of thorium due to the semi-arid nature of the areas and climatic factors.Web

Thorium occurs naturally in the earth's crust at an average lithospheric concentration of 8–12 μg/g (ppm). The typical concentration range of naturally-occurring thorium in soil …Web

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 are extremely rare. During coal combustion most of the uranium, tho-rium, and their decay products are released from the original coal matrix and are distributed ...Web

thorium processing, preparation of the ore for use in various products. Thorium (Th) is a dense (11.7 grams per cubic centimetre) silvery metal that is softer …Web

Thorium occurs naturally in the earth's crust at an average lithospheric concentration of 8–12 μg/g (ppm). Of the naturally produced thorium isotopes, only 232Th, 230Th, and …Web

Geoaccumulation indexes and enrichment factors did not reveal significant alterations in topsoil thorium concentration. The average concentration was 13.6 ± …Web

Establishment of thorium baseline concentration in topsoil from Zacatecas state, Mexico. Although the accepted estimation of the average crustal thorium concentration is around 10.5 mg kg −1, the debate about the thorium distribution in the crust is currently open (McLennan, 2001; Rudnick and Gao, 2014; Williams et al., 2018).Web