Naturally-Occurring Radioactive Materials (NORM)
Concentrations of actual radionuclides may or may not have been increased; if they have, the term technologically-enhanced NORM (TENORM) may be used. Long-lived radioactive elements such as uranium, thorium and potassium and any of their decay products, such as radium and radon are … See more
Determination of uranium and thorium in complex samples …
Model samples contained the known concentrations of uranium and thorium. After preconcentration and separation, thorium and uranium were determined by spectrophotometry. Sample volume was 1.33 L for UTEVA resin and 1.04 L for TRU resin, while concentration of uranium and thorium was about 10 μg L −1. At the beginning …
Uranium and thorium isotopic and concentration
We have developed techniques by sector-field inductively coupled plasma mass spectrometry (ICP-MS) for measuring the isotopic composition and concentration of uranium and thorium, focusing on the rare isotopes, 230 Th and 234 U. These isotopes have been widely used as tracers in earth sciences, e.g., chronology, paleoclimatology, …
Thorium Concentrations in Plants: A Review of World Data
The thorium concentrations in plants show high variability and vary from 0.5 × 10 –5 to 2.8 Bq/kg for soils with normal background and from 0.058 to 80 Bq/kg (dry matter) for areas with high thorium concentrations in soil (thorium provinces) and anthropogenically disturbed areas. Anthropogenically disturbed areas include areas …
Evaluation of elemental concentrations of uranium, thorium …
The highest radioactivity concentrations from both uranium and thorium were recorded in the S2 (Calcigypsids) soil, with a value of 1.71 (mg/kg) and 4.45 (mg/kg), respectively. Minimum and maximum values of 40 K are 1.1(%) and 1.27(%) and is prevalent in Aquisalids (S1) and Petrocalcids (S3) soil types, respectively.
2 Natural Radioactivity and Radiation
Where uranium and thorium concentrations are high enough, rocks constitute ores to industrial societies. In the western United States, uranium ores have been extensively mined and milled to produce nuclear fuels. ... In the common rock types, the uranium concentrations range from 0.5 to 4.7 ppm, corresponding to activity concentrations for …
Thorium and uranium isotopes in seawater and sediments
Thorium concentrations in three open Pacific Ocean water samples had values ofn × 10 −10 grams/liter, concentrations similar to those previously measured in the Atlantic.Radioactive disequilibrium exists between the dissolved forms of 228 Th and 232 Th and the dissolved, excess unsupported 228 Th apparently is introduced by the input of …
A critical review on the occurrence and distribution of the uranium
Naturally occurring radionuclides in groundwater resources can pose risks to human health due to both toxicity and radiation. For example, high concentrations of uranium in drinking water have been associated with nephrotoxic and other health effects (Zamora et al., 1998; Kurttio et al., 2002; WHO, 2017; Ma et al., 2020, Ma et al., …
Thorium Concentrations in Terrestrial and Freshwater …
The study area is a part of the tropical zone of Australia with an increased natural radioactive background, a uranium mining area. Data on uranium and thorium isotope concentrations were given for traditional aboriginal foods (fish, buffalo, pig, goose, field snake, goanna, Footnote 2 turtle, and freshwater crocodile) living in this area.
Determination of uranium and thorium concentrations in …
@article{osti_5466319, title = {Determination of uranium and thorium concentrations in unprocessed soil samples}, author = {Lazo, E N and Roessler, G S and Berven, B A}, abstractNote = {An assay technique that directly determines the amount of 238U and 232Th in unprocessed, bulk soil samples has been developed. In this …
Evidence and uncertainty for uranium and thorium …
Thorium abundance is reported in the range 35 ppb–60 ppm, the uranium abundance from 14.9 ppb to 95 ppm and the Th/U concentration ratio from 0.1 to 10. Table 1. Variability of thorium and uranium abundances and ratios. (literature: from recent to early publications). [Th] (ppm) [U] (ppm) [Th/U] (−) Sample ( a number of samples).
A critical review on the occurrence and distribution …
This critical review presents the key factors that control the occurrence of natural elements from the uranium- and thorium-decay series, also known as naturally …
Radiometric maps (a) Potassium concentration; …
Hence, the distribution of radioactive elements such as Potassium (K), Thorium (Th) and Uranium (U) concentration in soil and rocks relate to the differences in lithology of common rocks ...
Value of potassium, uranium and thorium concentration
Download scientific diagram | Value of potassium, uranium and thorium concentration with Th/U ratio, Th/K ratio and the gamma ray in API obtained from the for- mations sample from publication ...
Determination of uranium and thorium concentration and …
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 …
Abundances of Uranium and Thorium Elements in Earth …
The geoneutrinos produced by the radioactive decays of uranium and thorium have been observed with the Kamioka Liquid-Scintillator Antineutrino Detector (KamLAND). ... The crustal composition model used in Enomoto et al. has been updated by changing the U and Th concentrations in the upper continental crust by − 3.6% and …
ICP-MS Determination of Uranium and Thorium …
177 ICP-MS Determination of Uranium and Thorium Concentrations and 235U/238U Isotope Ratios at Trace and Ultratrace Levels in Urine *J.S. Beckera, M. Burowb, S.F. Boulygaa, C. Pickhardta, R ...
Determination of uranium, thorium and potassium activity concentrations
Kim in 1995 reported the presence of radionuclide of thorium's and uranium series in limestone and also same traces concentration of thorium, uranium and potassium in black shale in some regions [4].
Uranium, thorium, potassium and argon in marine phillipsites
The thorium and uranium concentrations decrease while the mineral concentrations increase with depth in the deposit. This observation can be explained by a continuous growth of the phillipsite within the deposits. The varying concentrations of uranium and thorium in phillipsite, fish teeth and clay minerals from given levels of the …
THORIUM, URANIUM AND ZIRCONIUM CONCENTRATIONS …
The uranium concentrations ranged from 2.7 to 26.7 ppm and averaged 11.4 ppm. The thoriumto-uranium ratios ranged from 1.5 to 20.9, with an average value of 5.1. Zirconium determinations on some of the bauxites gave values ranging from 0.02 to 0.65% zirconium, and averaging 0.09% zirconium. The thorium, uranium, and zirconium contents of the ...
Determination of uranium, thorium and potassium activity concentrations …
The concentrations of potassium, thorium, and uranium in the basalts were similar to those in the Apollo 12 basalts, but the potassium: uranium ratios were somewhat higher.
Tantalum, niobium, thorium and uranium concentrations …
Download Table | Tantalum, niobium, thorium and uranium concentrations (in mg/kg DW) in selected reference materials used in this work from publication: Simultaneous determination of tantalum ...
Heat production versus potassium, uranium, and thorium concentrations
The graphs in Figure 6 demonstrate the strong correlation between uranium concentration and heat production, compared with the weaker correlations with thorium and potassium concentration. During ...
Thorium Concentrations in the Environment: A …
Thorium concentrations are usually rather low in surface waters, with the highest values being observed in regions with an elevated thorium content in the parent …
Geoscience Wisconsin URANIUM AND THORIUM IN …
Uranium and thorium are present in trace amounts in almost all geolo gical materials as minor constituents in the lithosphere. Taylor (1964) cal culates that the average concentration of uranium in the earth crust amounts to 1.8 ppm (parts per million) and that of thorium 7.2 ppm. Uranium and thorium
HPS 2018
The average concentration of uranium in the groundwater of the United States is about 0.07 Bq L-1. The US Environmental Protection Agency's (EPA) drinking-water standard …
High resolution analysis of uranium and thorium concentration …
We have mapped U (238 U) and Th (232 Th) elemental concentrations as well as U-series isotope distributions in a Neanderthal tooth from the Middle Palaeolithic site of Payre using laser ablation ICP-MS.The U-concentrations in an enamel section varied between 1 and 1500. ppb.. The U-concentration maps show that U-migration through …
Occurrence of uranium, thorium and rare earth elements in …
Uranium, thorium, and rare earth elements (REEs) are important strategic elements in today's world with a range of applications in high and green technology and power generation. ... Thorium concentrations in the lithosphere range from 8 to 12 μg g −1. It is a weakly radioactive metal, similar to uranium, and occurs naturally in various ...
Naturally-Occurring Radioactive Materials (NORM)
The concentration of uranium and thorium in bottom and flyash can be up to ten times greater than for the burnt coal, while other radionuclides such as Pb-210 and K-40 can concentrate to an even greater degree in the flyash. Some 99% of flyash is typically retained in a modern power station (90% in some older ones).
Determination of uranium, thorium and potassium activity concentrations …
The samples have been analysed by using gamma-ray spectrometry. From the measured gamma-ray spectra, activity concentrations are determined for (238)U, (232)Th and (40)K. The mean acti … Determination of uranium, thorium and potassium activity concentrations in soil cores in Araba valley, Jordan Radiat Prot Dosimetry. …
