Uranium and thorium series radionuclides in …
Uranium and thorium series radionuclides in rainwater over several tropical storms - ScienceDirect. Journal of Environmental Radioactivity. Volume 65, Issue 1, …
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Water–rock interactions in the Bruchsal geothermal
Uranium and thorium decay series disequilibria in deep geothermal brines are a result of water–rock interaction processes. The migratory behavior of radionuclides provides valuable site-specific information and can therefore be an important tool for reservoir characterization and sustainable management of geothermal sites. In this …
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Chapter 29 Uranium, Thorium and Anthropogenic …
29 Uranium, Thorium and Anthropogenic Radionuclides as Atmospheric Tracers 593. Monthly total (wet + dry) deposition samples (rain- water between 10 and 100 L) are evaporated to dry- ness in an evaporation dish, or in a glass flask in a rotary vacuum evaporator. Residue samples in the monthly deposition are weighed after being dried in …
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Radioactive Decay | US EPA
For example, the decay chain that begins with Uranium-238 culminates in Lead-206, after forming intermediates such as Uranium-234, Thorium-230, Radium-226, and Radon-222. Also called the "decay series.". ... Some radionuclides have half-lives of mere seconds, ...
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Natural Radionuclides
Included are radionuclides of lead, polonium, bismuth, radium, potassium, carbon, hydrogen, uranium, and thorium. Potassium-40 is the most prominent radionuclide in normal foods and human tissues. The dose to the total body from these internally deposited radionuclides has been estimated to be approximately 40 mrem year −1 for the United ...
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Influence of the soil bioavailability of radionuclides on the …
It can be seen that the transfer of uranium and thorium based on the available fraction was similar to that of radiocaesium and higher than that of other artificial radionuclides. The thorium ATF values were at the same level as 40 K and, for some species of mushroom, also as 137 Cs, and higher than 226 Ra. In the uranium case, the …
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The distribution of uranium and thorium decay-series radionuclides …
@article{osti_263097, title = {The distribution of uranium and thorium decay-series radionuclides in the environment - a review}, author = {Cowart, J B and Burnett, W C}, abstractNote = {Natural radioactivity has played an indispensable role in the development of the earth to the form and shape that we now observe. Energy from …
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Occurrence and behavior of uranium and thorium series radionuclides …
The alpha sources for uranium, thorium, and polonium were covered with a thin film to prevent daughter recoil contamination of detectors (Inn et al. 2008). An alpha spectroscopy system (Mirion Technologies, Inc.), equipped with 72 Passivated Implanted Planar Silicon (PIPS) detectors, connected to an Apex-Alpha software system, was used …
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Production and Supply of α-Particle–Emitting Radionuclides …
Keywords: targeted α-therapy, production and supply of radionuclides, 227 Th/ 223 Ra, 225 Ac/ 213 Bi, 211 At, 212 Pb/ 212 Bi. ... Ac. Radiochemical processing is required for the protactinium, uranium, and thorium, as is already well known and can be achieved by a combination of ion-exchange and solid-phase extraction chromatography.
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Plant and soil relationships of uranium and thorium decay …
The behavior of radionuclides of the uranium (U) and thorium (Th) decay series in terrestrial systems is of interest because of environmental effects of mining and disposal activities related to nuclear power plant fuels. The soil-plant relationships of U, Th, and polonium (Pb), and some other daughter radionuclides, notably radium ({sup …
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Influence of the soil bioavailability of radionuclides on the …
Data on the soil–mushroom transfer of these radionuclides are practically inexistent. Uranium and thorium transfer to another biological compartment—plants—has been more studied, however. The data available correspond to soil–plant transfer factors in the range 10 −5 –10 −2 for thorium and 10 −3 –10 −2 for uranium (IAEA ...
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(PDF) Distribution of uranium and thorium chains radionuclides …
Partitioning of main ²³⁸U series radionuclides between phosphogypsum (PG) and phosphoric acid (PA) phase for PGA phosphogypsum sample; calculations performed assuming 70% retention of uranium ...
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Distribution of uranium and thorium chains radionuclides …
The possible isotopic pairs for possible determination by gamma-ray spectrometry and with relatively long half-lives are 226 Ra and 238 U as well as 210 Pb and 226 Ra in uranium chain, and 228 Th and 228 Ra radionuclides within the thorium series.
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Distribution of uranium and thorium chains radionuclides …
The input of thorium series radionuclides is of marginal significance, exhibiting only negligible fraction of the total activity related to 226 Ra and its progenies. It should be expected that during chemical operations with phosphorite ore, isotopes are preferentially separated according to their chemical properties.
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Primordial Radionuclides | nuclear-power
Bismuth, thorium, uranium, and plutonium are primordial radionuclides because they have half-lives long enough to be still found on the Earth. Potassium-40 also belongs to primordial nuclides. When the Earth was formed, many radioactive elements were formed. After four billion years, all the shorter-lived isotopes have decayed.
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Removal of radionuclides from acidic solution by activated …
Among the relatively limited body of work on the removal of thorium from contaminated environments, confirmed thorium immobilization on acid-modified GAC surfaces, performed better at pH 2.8 when ...
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Radionuclide Basics: Thorium | US EPA
Radionuclide Basics: Thorium. Thorium (chemical symbol Th) is a naturally occurring radioactive metal found at trace levels in soil, rocks, water, plants and animals. Thorium is solid under normal conditions. There are natural and man-made forms of thorium, all of which are radioactive. In general, naturally occurring thorium exists as Th …
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Radionuclide Uptake from Soil to Plants: Influence of Soil
The latter are known as primordial radionuclides and include 40 K (1.3 × 109 years) and the isotopes of uranium and thorium that give rise to various daughter nuclides including 226 Ra (1,600 years), 222 Rn (3.8 days), and 210 Pb (22.3 years) (Strebl et al. 2007). Artificial radionuclides have entered the human environment as a consequence …
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Radionuclide Basics: Uranium | US EPA
Uranium (chemical symbol U) is a naturally occurring radioactive element. When refined, uranium is a silvery-white metal. Uranium has three primary naturally occurring isotopes isotopesA form of an element that has the same number of protons but a different number of neutrons in the nucleus, giving it a different atomic mass. For …
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The state of natural radionuclides of uranium, radium, and thorium …
Abstract. A review of publications is presented on the state of uranium, radium, and thorium in soils. It is shown that the properties of radionuclides in soils provide the diversity of the forms ...
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7 Environmental Protection Agency Guidances and …
The primary purpose of this chapter is to review existing and proposed Environmental Protection Agency (EPA) guidances and regulations that apply to control of routine exposures of the public to naturally occurring radionuclides. As discussed in chapter 2, the naturally occurring radionuclides of primary concern in radiation protection of the public …
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Naturally Occurring Radionuclides
Naturally occurring radionuclides are also produced by cosmic radiation which permeates space, arising primarily from outside of our solar system and occurring in many forms, from high-speed heavy particles to high-energy photons and muons. ... Natural thorium and uranium decay chains. Half-lives and decay, d, days; h, hours; m, minutes; …
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Radionuclides (radioactive materials) | Chemical …
Radionuclides (or radioactive materials) are a class of chemicals where the nucleus of the atom is unstable. They achieve stability through changes in the nucleus (spontaneous fission, emission of alpha particles, or conversion of neutrons to protons or the reverse). This process is called radioactive decay or transformation, and often is ...
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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 …
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Food and drinking water | IAEA
When consumed, this may expose people to radiation. For this reason, it is important to know the amounts of radionuclides in food and drinking water and, if necessary, control their distribution. Naturally occurring radioactive material, such as potassium-40, polonium-210, thorium-232 and uranium-238 can be found in food and drinking water.
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Uranium) Radionuclides (including Radon, Radium and
Natural uranium is a silver-colored radioactive metal that contains three forms (isotopes) of uranium: uranium-234, uranium-235, and uranium-238. The amount of uranium-238 in natural uranium is more than 99 percent, but the uranium-234, present at 0.005 percent in natural uranium, accounts for half of the radioactivity. (2)
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Plant and Soil Relationships of Uranium and Thorium …
The behavior of radionuclides of the uranium (U) and thorium (Th) decay series in terrestrial systems is of interest because of environmental effects of mining and disposal activities related to nuclear power plant fuels. The soft-plant relationships of U, Th, and polonium ...
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Thorium series radionuclides in the environment: Measurement…
The reasons are several and meaningful, e.g. the discovery of radioactivity—and subsequent research efforts—concerned the uranium series; nuclear energy production involved uranium much more than thorium exploitation; 238 U activity concentration in environmental matrices is generally higher than that of 232 Th; and 222 …
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Radionuclide Basics: Thorium | Radiation Protection | US EPA
Radionuclide Basics: Thorium. Thorium (chemical symbol Th) is a naturally occurring radioactive metal found at trace levels in soil, rocks, water, plants and animals. Thorium is solid under normal conditions. There are natural and man-made forms of thorium, all of which are radioactive. In general, naturally occurring thorium exists as Th …
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Applications of PERALS-Alpha Spectrometry for the …
Since 2017, natural radionuclides have been regulated in the Swiss Ordinance on drinking water and water for public baths and shower facilities (TBDV) . ... Uranium and thorium are separated with ALPHAEX/H 2 SO 4 extraction. Pu, Am and Cm are extracted with ALPHAEX/HNO 3. U and Th are separated by sequential extraction …
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