in uranium minerals and standards

Berkovits, D.; Feldstein, H.; Ghelberg, S.; Hershkowitz, A.; Navon, E.; Paul, M.

doi:10.1016/s0168-583x(00)00152-x

Cited by 90 publications

(52 citation statements)

References 12 publications

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“…This is discussed further in Section 6.3. Natural U-236 is produced in extremely small amounts through neutron capture by U-235, mainly in uranium ore where the neutron flux is elevated (Berkovits et al 2000;Davis and Mewherter 1962;Zhao et al 1994). Neutron capture is discussed in Section 6.2.…”

Section: Uranium Decay Series and Natural Isotopic Ratiosmentioning

confidence: 99%

A Site Wide Perspective on Uranium Geochemistry at the Hanford Site

Zachara¹,

Brown²,

Christensen³

et al. 2007

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Executive SummaryUranium (U) is an important risk-driving contaminant at the Hanford Site. Over 200,000 kg have been released to the vadose zone over the course of site operations, and a number of vadose zone and groundwater plumes containing the uranyl cation [UO 2 2+ , U(VI)] have been identified. U is recognized to be of moderate-to-high mobility, conditions dependent. The site is currently making decisions on several of these plumes with long-lasting implications, and others are soon to come.Uranium is one of nature's most intriguing and chemically complex elements. The fate and transport of U(VI) has been studied over the long lifetime of the Hanford Site by various contractors, along with the Pacific Northwest National Laboratory (PNNL) and its collaborators. Significant research has more recently been contributed by the national scientific community with support from the U.S. Department of Energy's (DOE) Office of Science through its Environmental Remediation Sciences Division (ERSD). This report represents a first attempt to integrate these findings into a cohesive view of the subsurface geochemistry of U at the Hanford Site. The objective is to inform all interested Hanford parties about the in-ground inventory of U and its geochemical behavior. This report also comments on the prospects for the development of a robust generic model to more accurately forecast future U(VI) migration at different Hanford waste sites, along with further research necessary to reach this goal.To accomplish the report objectives, the environmental geochemistry of U at the Hanford Site is discussed in terms of both the vadose and saturated zone, to the extent that it is known. Hexavalent uranium [U(VI)] is the dominant valence form of U under the predominantly oxidizing subsurface conditions at the Hanford Site, and the researchers' analyses consequently emphasize this species. The nature and concentration of background U in Hanford subsurface sediments is identified to place contaminant U(VI) concentrations and behavior in perspective to the natural system. In-ground U-waste inventories are quantified and characterized with regard to source term, to the extent possible, and the most important sites from an inventory perspective are identified. The U-isotopic content of various waste streams are discussed from the perspective of waste-source tracking. The geochemical attenuation processes responsible for slowing the rate of subsurface U migration, relative to the transporting water front, are illustrated through careful consideration of both field characterization studies of existing U vadose-zone and groundwater plumes, and laboratory studies of derived contaminated and uncontaminated sediments. Both empirical and more mechanistic models of these attenuation processes are considered as well as the parameters that define attenuation magnitude. Attention is given to the behavior of contaminant U(VI) that has been in contact with Hanford sediments for extended periods (circa 10-50 years), as long contact imparts unique characte...

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Section: Uranium Decay Series and Natural Isotopic Ratiosmentioning

confidence: 99%

A Site Wide Perspective on Uranium Geochemistry at the Hanford Site

Zachara¹,

Brown²,

Christensen³

et al. 2007

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“…The presence of 236 U at the very low level of about 10 −11 relative isotopic abundance in uranium ore has been confirmed by accelerator mass spectrometry (AMS) [1][2][3]. Additionally the non-naturally occurring isotope 233 U plays an important role as analytical tool, because it is an ideal spike material for isotope dilution analyses.…”

Section: Introductionmentioning

confidence: 97%

Evaluating the status of uranium isotope ratio measurements using an inter-laboratory comparison campaign

Stephan

Alonso

Jan

et al. 2007

International Journal of Mass Spectrometry

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“…in the Ural region (Russia) and Chernobyl (Ukraine) [31,32] Pu is a beta emitter with a half-life of ~14.4 years. In spent nuclear fuel the 236 U/ 238 U isotope ratio are higher by several orders of magnitude than in non-contaminated natural uranium ores [33][34][35][36][37][38]. Thus, knowledge of the isotopic composition of artificial actinides is important for evaluating their origin in the environment and the isotopic composition of U and Pu helps in the determination of burn-up of spent nuclear fuel.…”

Section: Applications In Nuclear Industrymentioning

confidence: 99%

Mass Spectrometry: A Boon to Nuclear Industry

Ramkumar¹

2014

J Anal Bioanal Tech

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What is Mass Spectrometry?Mass spectrometry is analytical instrument which has been used for more than a century with its initial work on mass charge ratio being carried out by W. Wien, J.J. Thomson, and other physicists [1]. Mass Spectroscopy is an analytical laboratory technique to separate the components of a sample by their mass. The sample is vaporized into a gas and then ionized. The ions are then accelerated through a potential difference and focused into a beam. The ion beam passes through a magnetic field which bends the charged stream. Lighter components or components with more ionic charge will deflect in the field more than heavier or less charged components. A detector counts the number of ions at different deflections and the data can be plotted as a 'spectrum' of different masses. Therefore it is clear that mass spectrometer performs a simple measurement that of mass. The earlier work in the measurement of mass had led to the discovery of isotopes and it was in the 1930s that these measurements were correlated to the chemical structures and therefore were used extensively for biological applications for the characterization of natural products. Further progress in the field of mass spectrometry including isotopic labeling methods, hyphenated techniques and softer ionization methods made it an ideal tool for the analysis of macromolecules [2]. With the various fields that employ mass spectrometry growing in number, nuclear industry is also an important area wherein applications of mass spectrometry exist. Chronological Development in Mass spectrometryThe earliest mass spectrometry was in 1897 with the discovery of electrons made by J.J.Thomson. Around 1919, the observation studies of isotopes using mass spectrometry were carried out by F.W. Aston created a mass spectrometer in which ions were dispersed by mass and focused by velocity. This design improved the mass spectrometer resolving power by an order of magnitude compared to that achieved by AbstractMass spectrometry is a versatile technique that is used for the determination of elements at the trace and ultratrace level along with the isotope ratios. The accuracy in the quantification of isotope ratios of radionuclides is essential for environmental monitoring, migration studies, dating, determination of burn-up of fuel, nuclear material accounting and radioactive waste control. Inductively coupled plasma mass spectrometry (ICP-MS) is advantageous due to its outstanding sensitivity, precision and good accuracy for isotope ratio measurements and enhanced figures of merit for the determination of isotope ratio measurements. These advantages can be enhanced by various other variations of ICP-MS like the use of a multiple ion collector device (MC-ICP-MS). The review gives an idea of the various applications in the nuclear field and touches upon some of the important elements used in nuclear industry.

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in uranium minerals and standards

Cited by 90 publications

References 12 publications

A Site Wide Perspective on Uranium Geochemistry at the Hanford Site

A Site Wide Perspective on Uranium Geochemistry at the Hanford Site

Evaluating the status of uranium isotope ratio measurements using an inter-laboratory comparison campaign

Mass Spectrometry: A Boon to Nuclear Industry

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