Uranium-bearing phases in Hanford nuclear waste

Reynolds, Jacob G.; Cooke, Gary A.; Page, Jason S.; Warrant, R.W.

doi:10.1007/s10967-018-5724-5

Cited by 20 publications

(3 citation statements)

References 65 publications

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“…Similarities within structural topology can also be used to understand trends in uranyl vibrational frequencies. Uranyl phosphates, which are a well-studied group of compounds due to their relative abundance as a secondary mineral phase in geologic systems and waste products [103,104], contain the two major 2-D structural topologies autunite or phosphoruranylite sheets [12]. The autunite sheet contains uranyl square bipyramids that share vertices to phosphate tetrahedral and account for 17+ different compounds.…”

Section: Chemical and Structural Elucidation Of Uranium Solid-state Cmentioning

confidence: 99%

Detection and identification of solids, surfaces, and solutions of uranium using vibrational spectroscopy

Haes

Forbes

2018

Coordination Chemistry Reviews

129

128

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The purpose of this review is to provide an overview of uranium speciation using vibrational spectroscopy methods including Raman and IR. Uranium is a naturally occurring, radioactive element that is utilized in the nuclear energy and national security sectors. Fundamental uranium chemistry is also an active area of investigation due to ongoing questions regarding the participation of 5f orbitals in bonding, variation in oxidation states and coordination environments, and unique chemical and physical properties. Importantly, uranium speciation affects fate and transportation in the environment, influences bioavailability and toxicity to human health, controls separation processes for nuclear waste, and impacts isotopic partitioning and geochronological dating. This review article provides a thorough discussion of the vibrational modes for U(IV), U(V), and U(VI) and applications of infrared absorption and Raman scattering spectroscopies in the identification and detection of both naturally occurring and synthetic uranium species in solid and solution states. The vibrational frequencies of the uranyl moiety, including both symmetric and asymmetric stretches are sensitive to the coordinating ligands and used to identify individual species in water, organic solvents, and ionic liquids or on the surface of materials. Additionally, vibrational spectroscopy allows for the in situ detection and real-time monitoring of chemical reactions involving uranium. Finally, techniques to enhance uranium species signals with vibrational modes are discussed to expand the application of vibrational spectroscopy to biological, environmental, inorganic, and materials scientists and engineers.

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Section: Chemical and Structural Elucidation Of Uranium Solid-state Cmentioning

confidence: 99%

Detection and identification of solids, surfaces, and solutions of uranium using vibrational spectroscopy

Haes

Forbes

2018

Coordination Chemistry Reviews

129

128

View full text Add to dashboard Cite

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“…Uranium (U) is released to the environment from a series of naturally occurring U rich minerals and bedrocks such as alum shale 1 and granite. Uranium is also associated with the release from anthropogenic sources, particularly those stemming from the nuclear weapon and fuel cycles, 2 such as U mining and milling industries, 3 nuclear reactor accidents, 4,5 nuclear weapon detonations, 6 nuclear waste storage, 7,8 nuclear fuel reprocessing, 9 civilian and military use of depleted U, 10 and, potentially, from the catalyst industry. 11 In the environment, U can be present in different physicochemical forms varying in size and charge properties.…”

Section: ■ Introductionmentioning

confidence: 99%

Synchrotron XRF and Histological Analyses Identify Damage to Digestive Tract of Uranium NP-Exposed Daphnia magna

Byrnes

Rossbach

Jaroszewicz

et al. 2023

Environ. Sci. Technol.

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Micro- and nanoscopic X-ray techniques were used to investigate the relationship between uranium (U) tissue distributions and adverse effects to the digestive tract of aquatic model organism Daphnia magna following uranium nanoparticle (UNP) exposure. X-ray absorption computed tomography measurements of intact daphnids exposed to sublethal concentrations of UNPs or a U reference solution (URef) showed adverse morphological changes to the midgut and the hepatic ceca. Histological analyses of exposed organisms revealed a high proportion of abnormal and irregularly shaped intestinal epithelial cells. Disruption of the hepatic ceca and midgut epithelial tissues implied digestive functions and intestinal barriers were compromised. Synchrotron-based micro X-ray fluorescence (XRF) elemental mapping identified U co-localized with morphological changes, with substantial accumulation of U in the lumen as well as in the epithelial tissues. Utilizing high-resolution nano-XRF, 400–1000 nm sized U particulates could be identified throughout the midgut and within hepatic ceca cells, coinciding with tissue damages. The results highlight disruption of intestinal function as an important mode of action of acute U toxicity in D. magna and that midgut epithelial cells as well as the hepatic ceca are key target organs.

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“…Natural occurring uranium oxide contains uranium atoms in a variety of oxidation states. − UO 2 and UO 3 are known, although many ores with these oxidation states yield U 3 O 8 upon exposure to atmospheric conditions. , When uranium is mined, used in weapons, or stored for long periods, such as in the radioactive sludge found at the Hanford Nuclear Site, environmental contamination can result in the formation of dissolved coordination complexes or small uranium oxide particles. − The structure, solvation, and chemistry of these species are therefore of wide interest. Mass spectrometry studies have focused on the reactivity of atomic uranium and its small oxides, including the many coordination complexes formed with small ligand or solvent molecules. − The electronic spectroscopy of several small uranium oxide molecules has been reported using photoionization techniques. − More recently, results from infrared laser spectroscopy have been described for mass-selected uranium- and uranyl-ion complexes. − Theoretical studies on actinide systems have been limited by computational expense in the past, but recent advances in methods and basis sets have facilitated higher quality calculations. − Although there has been considerable research on small gas phase ions and their complexes, little is known about larger uranium oxide clusters. , In the present study, we use laser vaporization to produce larger uranium oxide clusters and multiphoton photodissociation to investigate their dissociation products and stabilities.…”

Section: Introductionmentioning

confidence: 99%

Photodissociation and Theory to Investigate Uranium Oxide Cluster Cations

et al. 2020

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Uranium oxide cluster cations of the form U n O m + are produced by laser vaporization of a depleted uranium rod in a pulsed supersonic expansion. Ions are mass-analyzed and mass-selected with a time-of-flight spectrometer and studied with UV laser multiphoton dissociation. Cations of the stoichiometry UO 2 (UO 3 ) n + were observed as photofragments from all photodissociated cluster cations. (UO 3 ) n + clusters were also observed to result from dissociation of larger (UO 3 ) n + clusters, with UO 3 neutral as a common leaving group. Electronic structure calculations were used to investigate the stability of the prominent uranium oxide cluster cations using density functional theory (DFT) with the hybrid B3LYP exchange-correlation functional and at the CCSD(T) level with cc-pVnZ-PP basis sets (n = D,T), including diffuse orbitals as computational expense and availability permitted. Clustering energies, relative energies and dissociation energies of the cations are reported. The lowest energy neutral (UO 3 ) n clusters up to n = 3 are rings, n = 4 and 5 are chains with very low energy rings, and n = 6 is 3D. The lowest energy structures for UO 2 (UO 3 ) n + are composed of uranyl-like UO 2 + units bound by bridging oxygens to other UO 2 2+ units for n = 2 and 3, and for n = 4 a more complex 3D structure is predicted.

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Uranium-bearing phases in Hanford nuclear waste

Cited by 20 publications

References 65 publications

Detection and identification of solids, surfaces, and solutions of uranium using vibrational spectroscopy

Detection and identification of solids, surfaces, and solutions of uranium using vibrational spectroscopy

Synchrotron XRF and Histological Analyses Identify Damage to Digestive Tract of Uranium NP-Exposed Daphnia magna

Photodissociation and Theory to Investigate Uranium Oxide Cluster Cations

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