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Aupiais J, Beccia MR, Monfort M, Den Auwer C. When radiochemistry meets radioecology (the marine environment). THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 935:173247. [PMID: 38754516 DOI: 10.1016/j.scitotenv.2024.173247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2024] [Revised: 04/30/2024] [Accepted: 05/12/2024] [Indexed: 05/18/2024]
Abstract
After the first atomic bomb test in Alamogordo in July 1945, followed by the Hiroshima and Nagasaki bombs in August 1945, radioecology became recognized as a branch of ecology in response to the radioactive fallout associated with the subsequent proliferation of atmospheric nuclear weapons testing which continued throughout the Cold War. In parallel, environmental radiochemistry emerged in the 70s to understand the chemical behavior of possible nuclear contaminants of the environment. In this discussion we stress the need to crosslink radioecology and chemical speciation, where radiochemistry and radioecology should meet to go beyond the present state of the art. Accordingly, we are seeking a methodology that calls for several angles of investigation: speciation (chemistry), toxicology (physiology and biology), accumulation data (environmental studies), distribution (geochemistry).
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2
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Baumer T, Zavarin M, Pearce CI, Emerson HP, Kersting AB. Subsurface Transport of Plutonium in Organic and Aqueous Acidic Processing Wastes at the Hanford Site, USA. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:8909-8918. [PMID: 38728532 PMCID: PMC11112729 DOI: 10.1021/acs.est.3c10082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Revised: 04/19/2024] [Accepted: 04/22/2024] [Indexed: 05/12/2024]
Abstract
Over 4 million liters of mixed acidic (∼pH 2.5), high ionic strength (∼5 M nitrate) plutonium (Pu) processing waste were released into the 216-Z-9 (Z-9) trench at the Hanford Site, USA, and trace Pu has migrated 37 m below the trench. In this study, we used flowthrough columns to investigate Pu transport in simplified processing waste through uncontaminated Hanford sediments to determine the conditions that led to Pu migration. In low pH aqueous fluids, some Pu breakthrough is observed at pH < 4, and increased Pu transport (14% total Pu breakthrough) is observed at pH < 2. However, Pu migrates in organic processing solvents through low pH sediments virtually uninhibited with approximately 94 and 86% total Pu breakthrough observed at pH 1 and pH 3, respectively. This study demonstrates that Pu migration can occur both with and without organic solvents at pH < 4, but significantly more Pu can be transported when partitioned into organic processing solvents. Our data suggest that under acidic conditions (pH < 4) in the vadose zone beneath the Z-9 trench, Pu present in organic processing solvents moved relatively unhindered and may explain the historical downward migration of Pu tens of meters below the Z-9 trench.
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Affiliation(s)
- Teresa Baumer
- Glenn
T. Seaborg Institute, Physical & Life Sciences Directorate, Lawrence Livermore National Laboratory, L-231, P.O. Box 808, Livermore, California 94550, United States
| | - Mavrik Zavarin
- Glenn
T. Seaborg Institute, Physical & Life Sciences Directorate, Lawrence Livermore National Laboratory, L-231, P.O. Box 808, Livermore, California 94550, United States
| | - Carolyn I. Pearce
- Energy
and Environment Directorate, Pacific Northwest
National Laboratory, P.O. Box 999, Richland, Washington 99352, United States
| | - Hilary P. Emerson
- Energy
and Environment Directorate, Pacific Northwest
National Laboratory, P.O. Box 999, Richland, Washington 99352, United States
| | - Annie B. Kersting
- Glenn
T. Seaborg Institute, Physical & Life Sciences Directorate, Lawrence Livermore National Laboratory, L-231, P.O. Box 808, Livermore, California 94550, United States
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3
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Etschmann B, Missen OP, Conradson SD, Mills S, Liu Y, Brugger J. Environmental stability of a uranium-plutonium-carbide phase. Sci Rep 2024; 14:6413. [PMID: 38494506 PMCID: PMC10944826 DOI: 10.1038/s41598-024-56885-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Accepted: 03/12/2024] [Indexed: 03/19/2024] Open
Abstract
A plutonium-rich carbide, (U,Pu)(Al,Fe)3C3, was discovered in a hot particle from the Maralinga nuclear testing site in South Australia. The particle was produced between 1960 and 1963 and has been exposed to ambient conditions since then. The new phase belongs to a group of ternary carbides known as 'derivative-MAX phases'. It formed at high temperature within an explosion cloud via rapid eutectic crystallisation from a complex Al-Fe-U-Pu-C-O melt, and is the major Pu host in this particle. Despite signs of volume expansion due to radiation damage, (U,Pu)(Al,Fe)3C3 remains highly X-ray crystalline 60 years after its formation, with no evidence of Pu leaching from the crystals. Our results highlight that the high-energy conditions of (sub-)critical explosions can create unexpected species. Even micro-particles of a derivative-MAX phase can effectively retain low-valence (metallic-like character) Pu under environmental conditions; the slow physical and chemical weathering of these particles may contribute to the slow release of radionuclides over decades, explaining constant low-levels of radionuclides observed in fauna. This study further suggests that rapidly quenched eutectic melts may be engineered to stabilise actinides in nuclear waste products, removing the need for hydrometallurgical processing.
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Affiliation(s)
- Barbara Etschmann
- School of Earth, Atmosphere & Environment, Monash University, Melbourne, Australia
| | - Owen P Missen
- School of Earth, Atmosphere & Environment, Monash University, Melbourne, Australia
- Geosciences, Museums Victoria, Melbourne, VIC, Australia
- Centre for Ore Deposit and Earth Sciences (CODES), University of Tasmania, Hobart, Australia
| | - Steven D Conradson
- Department of Chemistry, Washington State University, Pullman, WA, USA
- Department of Complex Matter, Josef Stefan Institute, Ljubljana, Slovenia
| | - Stuart Mills
- Geosciences, Museums Victoria, Melbourne, VIC, Australia
| | - Yang Liu
- Monash Centre for Electron Microscopy, Monash University, Melbourne, Australia
| | - Joël Brugger
- School of Earth, Atmosphere & Environment, Monash University, Melbourne, Australia.
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4
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Merino N, Wasserman NL, Coutelot F, Kaplan DI, Powell BA, Jiao Y, Kersting AB, Zavarin M. Microbial community dynamics and cycling of plutonium and iron in a seasonally stratified and radiologically contaminated pond. Sci Rep 2023; 13:19697. [PMID: 37952079 PMCID: PMC10640648 DOI: 10.1038/s41598-023-45182-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2023] [Accepted: 10/17/2023] [Indexed: 11/14/2023] Open
Abstract
Plutonium (Pu) cycling and mobility in the environment can be impacted by the iron cycle and microbial community dynamics. We investigated the spatial and temporal changes of the microbiome in an iron (Fe)-rich, plutonium-contaminated, monomictic reservoir (Pond B, Savannah River Site, South Carolina, USA). The microbial community composition varied with depth during seasonal thermal stratification and was strongly correlated with redox. During stratification, Fe(II) oxidizers (e.g., Ferrovum, Rhodoferax, Chlorobium) were most abundant in the hypoxic/anoxic zones, while Fe(III) reducers (e.g., Geothrix, Geobacter) dominated the deep, anoxic zone. Sulfate reducers and methanogens were present in the anoxic layer, likely contributing to iron and plutonium cycling. Multinomial regression of predicted functions/pathways identified metabolisms highly associated with stratification (within the top 5%), including iron reduction, methanogenesis, C1 compound utilization, fermentation, and aromatic compound degradation. Two sediment cores collected at the Inlet and Outlet of the pond were dominated by putative fermenters and organic matter (OM) degraders. Overall, microbiome analyses revealed the potential for three microbial impacts on the plutonium and iron biogeochemical cycles: (1) plutonium bioaccumulation throughout the water column, (2) Pu-Fe-OM-aggregate formation by Fe(II) oxidizers under microaerophilic/aerobic conditions, and (3) Pu-Fe-OM-aggregate or sediment reductive dissolution and organic matter degradation in the deep, anoxic waters.
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Affiliation(s)
- Nancy Merino
- Glenn T. Seaborg Institute, Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, 7000 East Ave, Livermore, CA, 94550, USA.
| | - Naomi L Wasserman
- Glenn T. Seaborg Institute, Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, 7000 East Ave, Livermore, CA, 94550, USA
| | - Fanny Coutelot
- Department of Environmental Engineering and Earth Sciences, Clemson University, Anderson, SC, 29625, USA
- Center for Nuclear Environmental Engineering Sciences and Radioactive Waste Management, Clemson University, Anderson, SC, 29625, USA
| | - Daniel I Kaplan
- Savannah River Ecology Lab, University of Georgia, Aiken, SC, 29802, USA
| | - Brian A Powell
- Department of Environmental Engineering and Earth Sciences, Clemson University, Anderson, SC, 29625, USA
- Center for Nuclear Environmental Engineering Sciences and Radioactive Waste Management, Clemson University, Anderson, SC, 29625, USA
- Savannah River National Laboratory, Aiken, SC, 29625, USA
| | - Yongqin Jiao
- Glenn T. Seaborg Institute, Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, 7000 East Ave, Livermore, CA, 94550, USA
| | - Annie B Kersting
- Glenn T. Seaborg Institute, Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, 7000 East Ave, Livermore, CA, 94550, USA
| | - Mavrik Zavarin
- Glenn T. Seaborg Institute, Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, 7000 East Ave, Livermore, CA, 94550, USA.
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5
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Uranium oxides structural transformation in human body liquids. Sci Rep 2023; 13:4088. [PMID: 36906622 PMCID: PMC10008576 DOI: 10.1038/s41598-023-31059-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Accepted: 03/06/2023] [Indexed: 03/13/2023] Open
Abstract
Uranium oxide microparticles ingestion is one of the potential sources of internal radiation doses to the humans at accidental or undesirable releases of radioactive materials. It is important to predict the obtained dose and possible biological effect of these microparticles by studying uranium oxides transformations in case of their ingestion or inhalation. Using a combination of methods, a complex examination of structural changes of uranium oxides in the range from UO2 to U4O9, U3O8 and UO3 as well as before and after exposure of uranium oxides in simulated biological fluids: gastro-intestinal and lung-was carried out. Oxides were thoroughly characterized by Raman and XAFS spectroscopy. It was determined that the duration of expose has more influence on all oxides transformations. The greatest changes occurred in U4O9, that transformed into U4O9-y. UO2.05 and U3O8 structures became more ordered and UO3 did not undergo significant transformation.
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Perdrial N, Vázquez-Ortega A, Reinoso-Maset E, O'Day PA, Chorover J. Effects of flow on uranium speciation in soils impacted by acidic waste fluids. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2022; 251-252:106955. [PMID: 35772319 DOI: 10.1016/j.jenvrad.2022.106955] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Revised: 06/07/2022] [Accepted: 06/21/2022] [Indexed: 06/15/2023]
Abstract
Radioactive acidic liquid waste is a common byproduct of uranium (U) and plutonium (Pu) enrichment and recycling processes whose accidental and planned release has led to a significant input of U into soils and sediments across the world, including at the U.S. DOE's Hanford site (WA, USA). Because of the particularly hazardous nature of U, it is important to predict its speciation when introduced into soils and sediments by acidic waste fluids. Of fundamental importance are the coupled effects of acid-driven mineral transformation and reactive transport on U speciation. To evaluate the effect of waste-fluid residence time and co-associated dissolved phosphate concentrations on U speciation in impacted soils and sediments, uncontaminated surface materials (from the Hanford Site) were reacted with U-containing synthetic acidic waste fluids (pH 2) amended with dissolved phosphate concentrations in both batch (no flow) and flow-through column systems for 7-365 days. By comparing dissolved U behavior and solid phase speciation as a function of flow regimen, we found that the availability of proton-promoted dissolution products (such as Si) to sequester U into uranyl silicates was dependent on waste fluid-sediment contact time as uranyl silicates were not detected in short contact time flow-through systems but were detected in no-flow, long contact time, reactors. Moreover, the dominance of uranyl phosphate as neoprecipitate U scavenger (principally in the form of meta-ankoleite) in phosphate amended systems confirmed the importance of phosphate amendments for an efficient sequestration of U in the soils and sediments. Overall, our experiments suggest that the formation of uranyl silicates in soils impacted by acidic waste fluids is likely to be limited unless reaction products are allowed to accumulate in soil pores, highlighting the importance of investigating soil U speciation in flow-through, transport-driven systems as opposed to no-flow, batch systems. This study provides insights into uranium speciation and its potential changes under acidic conditions for better prediction of risks and subsequent development of efficient remediation strategies.
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Affiliation(s)
- Nicolas Perdrial
- Department of Environmental Science, University of Arizona, 1177 East Fourth Street, Tucson, AZ, 85721, USA; Department of Geography & Geosciences, University of Vermont, 180 Colchester Avenue, Burlington, Vermont 05405, USA.
| | - Angélica Vázquez-Ortega
- Department of Environmental Science, University of Arizona, 1177 East Fourth Street, Tucson, AZ, 85721, USA
| | - Estela Reinoso-Maset
- Sierra Nevada Research Institute, University of California Merced, 5200 North Lake Road, Merced, CA, 95343, USA; Centre for Environmental Radioactivity CoE, Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, 1432 Aas, Norway
| | - Peggy A O'Day
- Sierra Nevada Research Institute, University of California Merced, 5200 North Lake Road, Merced, CA, 95343, USA; Life and Environmental Sciences Department, School of Natural Sciences, University of California - Merced, 5200 North Lake Road, Merced, CA, 95343, USA
| | - Jon Chorover
- Department of Environmental Science, University of Arizona, 1177 East Fourth Street, Tucson, AZ, 85721, USA
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7
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Edwards NP, Bargar JR, van Campen D, van Veelen A, Sokaras D, Bergmann U, Webb SM. A new μ-high energy resolution fluorescence detection microprobe imaging spectrometer at the Stanford Synchrotron Radiation Lightsource beamline 6-2. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2022; 93:083101. [PMID: 36050052 PMCID: PMC9392580 DOI: 10.1063/5.0095229] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2022] [Accepted: 07/14/2022] [Indexed: 06/15/2023]
Abstract
Here, we describe a new synchrotron X-ray Fluorescence (XRF) imaging instrument with an integrated High Energy Fluorescence Detection X-ray Absorption Spectroscopy (HERFD-XAS) spectrometer at the Stanford Synchrotron Radiation Lightsource at beamline 6-2. The X-ray beam size on the sample can be defined via a range of pinhole apertures or focusing optics. XRF imaging is performed using a continuous rapid scan system with sample stages covering a travel range of 250 × 200 mm2, allowing for multiple samples and/or large samples to be mounted. The HERFD spectrometer is a Johann-type with seven spherically bent 100 mm diameter crystals arranged on intersecting Rowland circles of 1 m diameter with a total solid angle of about 0.44% of 4π sr. A wide range of emission lines can be studied with the available Bragg angle range of ∼64.5°-82.6°. With this instrument, elements in a sample can be rapidly mapped via XRF and then selected features targeted for HERFD-XAS analysis. Furthermore, utilizing the higher spectral resolution of HERFD for XRF imaging provides better separation of interfering emission lines, and it can be used to select a much narrower emission bandwidth, resulting in increased image contrast for imaging specific element species, i.e., sparse excitation energy XAS imaging. This combination of features and characteristics provides a highly adaptable and valuable tool in the study of a wide range of materials.
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Affiliation(s)
- Nicholas P. Edwards
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA
| | - John R. Bargar
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA
| | - Douglas van Campen
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA
| | - Arjen van Veelen
- Material Science and Technology Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - Dimosthenis Sokaras
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA
| | - Uwe Bergmann
- Physics Department, University of Wisonsin-Madison, 1150 University Avenue, Madison, Wisconsin 53706-1390, USA
| | - Samuel M. Webb
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA
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8
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Beccia MR, Creff G, Den Auwer C, Di Giorgio C, Jeanson A, Michel H. Environmental Chemistry of Radionuclides : Open Questions and Perspectives. Chempluschem 2022; 87:e202200108. [PMID: 35778807 DOI: 10.1002/cplu.202200108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Revised: 06/13/2022] [Indexed: 11/10/2022]
Abstract
Since the discovery of nuclear fission, atomic energy has become for mankind a source of energy, but it has also become a source of consternation. This Perspective presents and discusses the methodological evolution of the work performed in the radiochemistry laboratory that is part of the Institut de Chimie de Nice (France). Most studies in radioecology and environmental radiochemistry have intended to assess the impact and inventory of very low levels of radionuclides in specific environmental compartments. But chemical mechanisms at the molecular level remain a mystery because it is technically impossible (due to large dilution factors) to assess speciation in those systems. Ultra-trace levels of contamination and heterogeneity often preclude the use of spectroscopic techniques and the determination of direct speciation data, thus forming the bottleneck of speciation studies. The work performed in the Nice radiochemistry laboratory underlines this effort to input speciation data (using spectroscopic techniques like X ray Absorption Spectroscopy) in environmental and radioecological metrics.
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Affiliation(s)
| | - Gaëlle Creff
- Université Côte d'Azur, CNRS, ICN, 06108, Nice, France
| | | | | | | | - Hervé Michel
- Université Côte d'Azur, CNRS, ICN, 06108, Nice, France
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9
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van Veelen A, Hickam SM, Edwards NP, Webb SM, Clark DL, Wilkerson MP, Pugmire AL, Bargar JR. Trace Impurities Identified as Forensic Signatures in CMX-5 Fuel Pellets Using X-ray Spectroscopic Techniques. Anal Chem 2022; 94:7084-7091. [PMID: 35512178 DOI: 10.1021/acs.analchem.2c00629] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Small-particle analysis is a highly promising emerging forensic tool for analysis of interdicted special nuclear materials. Integration of microstructural, morphological, compositional, and molecular impurity signatures could provide significant advancements in forensic capabilities. We have applied rapid, high-sensitivity, hard X-ray synchrotron chemical imaging to analyze impurity signatures in two differently fabricated fuel pellets from the 5th Collaborative Materials Exercise (CMX5) of the IAEA Nuclear Forensics International Working Group. The spatial distributions, chemical compositions, and morphological and molecular characteristics of impurities were evaluated using X-ray absorption near-edge structure (XANES) and X-ray fluorescence chemical imaging to discover principal impurities, their granularity, particle sizes, modes of occurrence (distinct grains vs incorporation in the UO2 lattice), and sources and mechanisms of incorporation. Differences in UO2+x stoichiometry were detected at the microscale in nominally identical UO2 ceramics (CMX5-A and CMX5-B), implying the presence of multiple UO2 host phases with characteristic microstructures and feedstock compositions. Al, Fe, Ni, W, and Zr impurities and integrated impurity signature analysis identified distinctly different pellet synthesis and processing methods. For example, two different Al, W, and Zr populations in the CMX5-B sample indicated a more complex processing history than the CMX5-A sample. K-edge XANES measurements reveal both metallic and oxide forms of Fe and Ni but with different proportions between each sample. Altogether, these observations suggest multiple sources of impurities, including fabrication (e.g., force-sieving) and feedstock (mineral oxides). This study demonstrates the potential of synchrotron techniques to integrate different signatures across length scales (angstrom to micrometer) to detect and differentiate between contrasting UO2 fuel fabrication techniques.
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Affiliation(s)
- Arjen van Veelen
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Sarah M Hickam
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Nicholas P Edwards
- SLAC National Accelerator Laboratory, Stanford Synchrotron Radiation Lightsource, Menlo Park, California 94025, United States
| | - Samuel M Webb
- SLAC National Accelerator Laboratory, Stanford Synchrotron Radiation Lightsource, Menlo Park, California 94025, United States
| | - David L Clark
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | | | - Alison L Pugmire
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - John R Bargar
- SLAC National Accelerator Laboratory, Stanford Synchrotron Radiation Lightsource, Menlo Park, California 94025, United States
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10
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Kvashnina KO, Butorin SM. High-energy resolution X-ray spectroscopy at actinide M 4,5 and ligand K edges: what we know, what we want to know, and what we can know. Chem Commun (Camb) 2022; 58:327-342. [PMID: 34874022 PMCID: PMC8725612 DOI: 10.1039/d1cc04851a] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Accepted: 11/15/2021] [Indexed: 12/20/2022]
Abstract
In recent years, scientists have progressively recognized the role of electronic structures in the characterization of chemical properties for actinide containing materials. High-energy resolution X-ray spectroscopy at the actinide M4,5 edges emerged as a promising direction because this method can probe actinide properties at the atomic level through the possibility of reducing the experimental spectral width below the natural core-hole lifetime broadening. Parallel to the technical developments of the X-ray method and experimental discoveries, theoretical models, describing the observed electronic structure phenomena, have also advanced. In this feature article, we describe the latest progress in the field of high-energy resolution X-ray spectroscopy at the actinide M4,5 and ligand K edges and we show that the methods are able to (a) provide fingerprint information on the actinide oxidation state and ground state characters (b) probe 5f occupancy, non-stoichiometry, defects, and ligand/metal ratio and (c) investigate the local symmetry and effects of the crystal field. We discuss the chemical aspects of the electronic structure in terms familiar to chemists and materials scientists and conclude with a brief description of new opportunities and approaches to improve the experimental methodology and theoretical analysis for f-electron systems.
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Affiliation(s)
- Kristina O Kvashnina
- The Rossendorf Beamline at ESRF, The European Synchrotron, CS40220, 38043 Grenoble Cedex 9, France.
- Institute of Resource Ecology, Helmholtz Zentrum Dresden-Rossendorf (HZDR), PO Box 510119, 01314 Dresden, Germany
- Department of Chemistry, Lomonosov Moscow State University, Moscow 119991, Russia
| | - Sergei M Butorin
- Condensed Matter Physics of Energy Materials, X-ray Photon Science, Department of Physics and Astronomy, Uppsala University, P.O. Box 516, SE-751 20 Uppsala, Sweden.
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11
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Cook M, Etschmann B, Ram R, Ignatyev K, Gervinskas G, Conradson SD, Cumberland S, Wong VNL, Brugger J. The nature of Pu-bearing particles from the Maralinga nuclear testing site, Australia. Sci Rep 2021; 11:10698. [PMID: 34021195 PMCID: PMC8139974 DOI: 10.1038/s41598-021-89757-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2020] [Accepted: 04/20/2021] [Indexed: 11/15/2022] Open
Abstract
The high-energy release of plutonium (Pu) and uranium (U) during the Maralinga nuclear trials (1955–1963) in Australia, designed to simulate high temperature, non-critical nuclear accidents, resulted in wide dispersion µm-sized, radioactive, Pu–U-bearing ‘hot’ particles that persist in soils. By combining non-destructive, multi-technique synchrotron-based micro-characterization with the first nano-scale imagining of the composition and textures of six Maralinga particles, we find that all particles display intricate physical and chemical make-ups consistent with formation via condensation and cooling of polymetallic melts (immiscible Fe–Al–Pu–U; and Pb ± Pu–U) within the detonation plumes. Plutonium and U are present predominantly in micro- to nano-particulate forms, and most hot particles contain low valence Pu–U–C compounds; these chemically reactive phases are protected by their inclusion in metallic alloys. Plutonium reworking was observed within an oxidised rim in a Pb-rich particle; however overall Pu remained immobile in the studied particles, while small-scale oxidation and mobility of U is widespread. It is notoriously difficult to predict the long-term environmental behaviour of hot particles. Nano-scale characterization of the hot particles suggests that long-term, slow release of Pu from the hot particles may take place via a range of chemical and physical processes, likely contributing to on-going Pu uptake by wildlife at Maralinga.
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Affiliation(s)
- Megan Cook
- School of Earth, Atmosphere and Environment, Monash University, Clayton, Australia
| | - Barbara Etschmann
- School of Earth, Atmosphere and Environment, Monash University, Clayton, Australia.
| | - Rahul Ram
- School of Earth, Atmosphere and Environment, Monash University, Clayton, Australia
| | - Konstantin Ignatyev
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxon, OX11 0QX, United Kingdom
| | - Gediminas Gervinskas
- Ramaciotti Centre for Cryo-Electron Microscopy, Monash University, Clayton, Australia
| | - Steven D Conradson
- Department of Chemistry, Washington State University, Pullman, WA, USA.,Department of Complex Matter, Josef Stefan Institute, Ljubljana, Slovenia
| | | | - Vanessa N L Wong
- School of Earth, Atmosphere and Environment, Monash University, Clayton, Australia
| | - Joёl Brugger
- School of Earth, Atmosphere and Environment, Monash University, Clayton, Australia.
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12
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Rzhevskaia AV, Romanchuk AY, Vlasova IE, Semenkova AS, Trigub AL, Svetogorov RD, Yapaskurt VO, Paretskov EN, Kalmykov SN. Partitioning of uranium in contaminated bottom sediments: The meaning of fractionation. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2021; 229-230:106539. [PMID: 33493873 DOI: 10.1016/j.jenvrad.2021.106539] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 12/01/2020] [Accepted: 01/12/2021] [Indexed: 06/12/2023]
Abstract
Sequential extraction tests were used to study partitioning of U in the bottom sediments of two reservoirs that have been used for the temporary storage of nuclear waste at the "Mining and Chemical Combine" (Zheleznogorsk, Krasnoyarsk region, Russia). Various sequential extraction protocols were applied to the bottom sediment samples and the results compared with those obtained for laboratory-prepared simulated samples with different speciation and partitioning, e.g., U(VI) sorbed onto various inorganic minerals and organic matter, as well as uranium oxides. The distributions of uranium in fractions extracted from simulated and actual contaminated samples were compared to shed light on the speciation of U in the bottom sediments. X-ray absorption spectroscopy, X-ray diffraction, and scanning electron microscopy were also used to analyze the partitioning of U in contaminated sediments. We also compared the results obtained using the spectroscopic and microscopic techniques, as well as sequential extraction.
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Affiliation(s)
| | - Anna Yu Romanchuk
- Lomonosov Moscow State University, Leninskie Gory, Moscow, 119991, Russia.
| | - Irina E Vlasova
- Lomonosov Moscow State University, Leninskie Gory, Moscow, 119991, Russia
| | - Anna S Semenkova
- Lomonosov Moscow State University, Leninskie Gory, Moscow, 119991, Russia
| | | | | | | | - Evgeny N Paretskov
- FSUE "Mining and Chemical Combine", Zheleznogorsk, Krasnoyarsk Region, Russia
| | - Stepan N Kalmykov
- Lomonosov Moscow State University, Leninskie Gory, Moscow, 119991, Russia; National Research Centre "Kurchatov Institute", Moscow, Russia
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13
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Zheltonozhskaya MV, Zheltonozhsky VA, Vlasova IE, Kuzmenkova NV, Kalmykov SN. The plutonium isotopes and strontium-90 determination in hot particles by characteristic X-rays. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2020; 225:106448. [PMID: 33075716 DOI: 10.1016/j.jenvrad.2020.106448] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Revised: 09/16/2020] [Accepted: 10/12/2020] [Indexed: 06/11/2023]
Abstract
This paper reports the developed non-destructive methods for the plutonium isotopes and strontium-90 content determination in hot particles and other samples. The proposed methods are based on the measurement of the characteristic X-rays accompanying the decay of these radionuclides. For hot particles of NPP accident origin, the proposed method's error limits are 10-15% for hot particles (samples) with activity above 100 Bq and 15-20% for hot particles (samples) with activity less than 100 Bq. For explosive particles, the determination accuracy is 10-15% for activity more than 5 Bq and 20-30% for 0.1-5 Bq activity. The accuracy of the proposed method for determining 90Sr in samples with its specific content of more than 104 Bq/sample is 5%, with ~102 Bq/sample its content is 15-20%. The cost of one sample measurement and the processing time of these methods are significantly reduced compared to traditional studies. The proposed methods are reasonably simple measurement methods and can be carried out even in the field condition. They open up new possibilities for the quick search and study of hot particles and environmental samples.
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Affiliation(s)
| | | | - I E Vlasova
- Lomonosov Moscow State University, Russian Federation
| | | | - S N Kalmykov
- Lomonosov Moscow State University, Russian Federation
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14
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Kurihara E, Takehara M, Suetake M, Ikehara R, Komiya T, Morooka K, Takami R, Yamasaki S, Ohnuki T, Horie K, Takehara M, Law GTW, Bower W, W Mosselmans JF, Warnicke P, Grambow B, Ewing RC, Utsunomiya S. Particulate plutonium released from the Fukushima Daiichi meltdowns. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 743:140539. [PMID: 32663681 DOI: 10.1016/j.scitotenv.2020.140539] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 06/20/2020] [Accepted: 06/24/2020] [Indexed: 06/11/2023]
Abstract
Traces of Pu have been detected in material released from the Fukushima Daiichi Nuclear Power Plant (FDNPP) in March of 2011; however, to date the physical and chemical form of the Pu have remained unknown. Here we report the discovery of particulate Pu associated with cesium-rich microparticles (CsMPs) that formed in and were released from the reactors during the FDNPP meltdowns. The Cs-pollucite-based CsMP contained discrete U(IV)O2 nanoparticles, <~10 nm, one of which is enriched in Pu adjacent to fragments of Zr-cladding. The isotope ratios, 235U/238U, 240Pu/239Pu, and 242Pu/239Pu, of the CsMPs were determined to be ~0.0193, ~0.347, and ~0.065, respectively, which are consistent with the calculated isotopic ratios of irradiated-fuel fragments. Thus, considering the regional distribution of CsMPs, the long-distance dispersion of Pu from FNDPP is attributed to the transport by CsMPs that have incorporated nanoscale fuel fragments prior to their dispersion up to 230 km away from the Fukushima Daiichi reactor site.
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Affiliation(s)
- Eitaro Kurihara
- Department of Chemistry, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Masato Takehara
- Department of Chemistry, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Mizuki Suetake
- Department of Chemistry, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Ryohei Ikehara
- Department of Chemistry, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Tatsuki Komiya
- Department of Chemistry, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Kazuya Morooka
- Department of Chemistry, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Ryu Takami
- Department of Chemistry, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Shinya Yamasaki
- Faculty of Pure and Applied Sciences and Center for Research in Isotopes and Environmental Dynamics, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8577, Japan
| | - Toshihiko Ohnuki
- Laboratory for Advanced Nuclear Energy, Institute of Innovative Research, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8550, Japan
| | - Kenji Horie
- National Institute of Polar Research, 10-3, Midori-cho, Tachikawa-shi, Tokyo 190-8518, Japan; Department of Polar Science, The Graduate University for Advanced Studies (SOKENDAI), Shonan Village, Hayama, Kanagawa 240-0193, Japan
| | - Mami Takehara
- National Institute of Polar Research, 10-3, Midori-cho, Tachikawa-shi, Tokyo 190-8518, Japan
| | - Gareth T W Law
- Radiochemistry Unit, Department of Chemistry, The University of Helsinki, Helsinki 00014, Finland
| | - William Bower
- Radiochemistry Unit, Department of Chemistry, The University of Helsinki, Helsinki 00014, Finland
| | | | - Peter Warnicke
- Swiss Light Source, Paul Scherrer Institute, 5232 Villigen, Switzerland
| | - Bernd Grambow
- SUBATECH, IMT Atlantique, CNRS-IN2P3, The University of Nantes, Nantes 44307, France
| | - Rodney C Ewing
- Department of Geological Sciences and Center for International Security and Cooperation, Stanford University, Stanford, CA 94305-2115, USA
| | - Satoshi Utsunomiya
- Department of Chemistry, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan.
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15
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Straub MD, Arnold J, Fessenden J, Kiplinger JL. Recent Advances in Nuclear Forensic Chemistry. Anal Chem 2020; 93:3-22. [DOI: 10.1021/acs.analchem.0c03571] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Mark D. Straub
- Department of Chemistry, University of California, Berkeley, California 94720, United States
- Los Alamos National Laboratory, Chemistry Division, Mailstop J-514, Los Alamos, New Mexico 87545, United States
| | - John Arnold
- Department of Chemistry, University of California, Berkeley, California 94720, United States
| | - Julianna Fessenden
- Los Alamos National Laboratory, XTD Division, Los Alamos, New Mexico 87545, United States
| | - Jaqueline L. Kiplinger
- Los Alamos National Laboratory, Chemistry Division, Mailstop J-514, Los Alamos, New Mexico 87545, United States
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16
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Romanchuk AY, Vlasova IE, Kalmykov SN. Speciation of Uranium and Plutonium From Nuclear Legacy Sites to the Environment: A Mini Review. Front Chem 2020; 8:630. [PMID: 32903456 PMCID: PMC7434977 DOI: 10.3389/fchem.2020.00630] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2020] [Accepted: 06/17/2020] [Indexed: 12/02/2022] Open
Abstract
The row of 15 chemical elements from Ac to Lr with atomic numbers from 89 to 103 are known as the actinides, which are all radioactive. Among them, uranium and plutonium are the most important as they are used in the nuclear fuel cycle and nuclear weapon production. Since the beginning of national nuclear programs and nuclear tests, many radioactively contaminated nuclear legacy sites, have been formed. This mini review covers the latest experimental, modeling, and case studies of plutonium and uranium migration in the environment, including the speciation of these elements and the chemical reactions that control their migration pathways.
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Affiliation(s)
| | | | - Stepan N. Kalmykov
- Department of Chemistry, Lomonosov Moscow State University, Moscow, Russia
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17
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Yudintsev SV, Mal’kovskii VI, Aleksandrova EV. Primary Colloids at Hydrothermally Modifed Aluminophosphate Glass with Imitators of Radionuclides. RADIOCHEMISTRY 2020. [DOI: 10.1134/s1066362220030157] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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18
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Maloubier M, Emerson H, Peruski K, Kersting AB, Zavarin M, Almond PM, Kaplan DI, Powell BA. Impact of Natural Organic Matter on Plutonium Vadose Zone Migration from an NH 4Pu(V)O 2CO 3(s) Source. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:2688-2697. [PMID: 31942795 DOI: 10.1021/acs.est.9b05651] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
We investigated the influence of natural organic matter (NOM) on the behavior of Pu(V) in the vadose zone through a combination of the field lysimeter and laboratory studies. Well-defined solid sources of NH4Pu(V)O2CO3(s) were placed in two 5-L lysimeters containing NOM-amended soil collected from the Savannah River Site (SRS) or unamended vadose zone soil and exposed to 3 years of natural South Carolina, USA, meteorological conditions. Lysimeter soil cores were removed from the field, used in desorption experiments, and characterized using wet chemistry methods and X-ray absorption spectroscopy. For both lysimeters, Pu migrated slowly with the majority (>95%) remaining within 2 cm of the source. However, without the NOM amendment, Pu was transported significantly farther than in the presence of NOM. Downward Pu migration appears to be influenced by the initial source oxidation state and composition. These Pu(V) sources exhibited significantly greater migration than previous studies using Pu(IV) or Pu(III) sources. However, batch laboratory experiments demonstrated that Pu(V) is reduced by the lysimeter soil in the order of hours, indicating that downward migration of Pu may be due to cycling between Pu(V) and Pu(IV). Under the conditions of these experiments, NOM appeared to both enhance reduction of the Pu(V) source as well as Pu sorption to soils. This indicates that NOM will tend to have a stabilizing effect on Pu migration under SRS vadose zone field conditions.
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Affiliation(s)
- Melody Maloubier
- Department of Environmental Engineering & Earth Sciences, Clemson University, Clemson, South Carolina 29634, United States
| | - Hilary Emerson
- Subsurface Science and Technology, Energy & Environment, Pacific Northwest National Laboratory, Richland, Washington 99354, United States
| | - Kathryn Peruski
- Department of Environmental Engineering & Earth Sciences, Clemson University, Clemson, South Carolina 29634, United States
| | - Annie B Kersting
- Glenn T. Seaborg Institute, Physical & Life Sciences, Lawrence Livermore National Laboratory, Livermore, California 94550, United States
| | - Mavrik Zavarin
- Glenn T. Seaborg Institute, Physical & Life Sciences, Lawrence Livermore National Laboratory, Livermore, California 94550, United States
| | - Philip M Almond
- Savannah River National Laboratory, Aiken, South Carolina 29808, United States
| | - Daniel I Kaplan
- Savannah River National Laboratory, Aiken, South Carolina 29808, United States
| | - Brian A Powell
- Department of Environmental Engineering & Earth Sciences, Clemson University, Clemson, South Carolina 29634, United States
- Savannah River National Laboratory, Aiken, South Carolina 29808, United States
- Department of Chemistry, Clemson University, Clemson, South Carolina 29634, United States
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19
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Ulibarri N, Tracy CL, McCarty RJ. Cleanup and Complexity: Nuclear and Industrial Contamination at The Santa Susana Field Laboratory, California. ENVIRONMENTAL MANAGEMENT 2020; 65:257-271. [PMID: 31828410 DOI: 10.1007/s00267-019-01239-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Accepted: 11/26/2019] [Indexed: 06/10/2023]
Abstract
Environmental contamination, a legacy of industrial activity borne by numerous sites around the world, poses health risks for surrounding communities and presents serious cleanup challenges. One such site, the Santa Susana Field Laboratory (SSFL), served as an aerospace and nuclear energy research facility for over 50 years, during which time radioactive and other hazardous materials were unintentionally and intentionally released into the surrounding environment. These releases, including the partial meltdown of a sodium reactor, were hidden from the public for three decades. The site is now located in suburban Los Angeles, with 730,000 people living within a 10-mile radius. This paper evaluates the technical and social challenges underlying site cleanup at SSFL, including a complex geological setting, uncertain contaminant information, and a convoluted, evolving regulatory framework. These challenges, paired with historical secrecy on the part of responsible organizations and unclear layers of responsibility, have led to uncertainty and distrust within the surrounding community. Lessons learned from other remediated sites are assessed and recommendations for the SSFL cleanup are provided.
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Affiliation(s)
- Nicola Ulibarri
- Department of Urban Planning and Public Policy, University of California, Irvine, 300 Social Ecology I, Irvine, CA, 92697, USA.
| | - Cameron L Tracy
- Belfer Center for Science and International Affairs, Kennedy School of Government, Harvard University, 79 John F. Kennedy St, Cambridge, MA, 02138, USA
| | - Ryan J McCarty
- Department of Chemistry, University of California, Irvine, Natural Sciences II, Irvine, CA, 92697, USA
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20
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Salbu B, Lind OC. Analytical techniques for charactering radioactive particles deposited in the environment. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2020; 211:106078. [PMID: 31677430 DOI: 10.1016/j.jenvrad.2019.106078] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Revised: 10/13/2019] [Accepted: 10/13/2019] [Indexed: 06/10/2023]
Abstract
Since 1945, a series of nuclear and radiological sources have contributed to the release of radioactive particles containing refractory elements into the environment. Several years of research have demonstrated that the particle composition will depend on the source, while the release scenarios will influence particle properties of relevance for environmental transfer. Radioactive particles can also carry sufficient amount of radioactivity (MBq) and represent point sources of radiological concern. Most radiological assessment models, however, are based on bulk concentrations, assuming that radionuclides in the environment are evenly distributed. In contrast, radioactive particles and thereby doses are unevenly distributed, while leaching of radionuclides from particles prior to measurements can be partial, potentially leading to underestimation of inventories. For areas affected by particle contamination, information on particle characteristics controlling the particle weathering rates and remobilization of particle associated radionuclides will therefore be essential to reduce the overall uncertainties of the impact assessments. The present paper will focus on analytical strategies, from screening techniques applicable for identifying hot spots in the field, fractionation techniques and single particle extraction techniques as a preparatory mean to apply non-destructive solid state speciation techniques, till leaching techniques applied sequentially to obtain information on binding mechanisms, mobility and potential bioavailability. Thus, a combination of techniques should be utilized to characterize radioactive particles in order to improve environmental assessments for areas affected by radioactive particle fallout.
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Affiliation(s)
- Brit Salbu
- CERAD CoE, Faculty of Environmental Sciences and nature Resource Management, Norwegian University of Life Sciences, 1432, Aas, Norway
| | - Ole Christian Lind
- CERAD CoE, Faculty of Environmental Sciences and nature Resource Management, Norwegian University of Life Sciences, 1432, Aas, Norway.
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21
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Corbey JF, Reilly DD, Sweet LE, Lach TG. Extraction of plutonium-containing microcrystals from Hanford soil using a focused ion beam for single-crystal X-ray diffraction analysis. J Appl Crystallogr 2019. [DOI: 10.1107/s1600576719012299] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Herein, the successful use of a focused ion beam/scanning electron microscope to prepare microsamples of radioactive single crystals for X-ray diffraction analysis is reported. This technique was used to extract and analyze crystalline Pu-containing particles as small as 28 µm3 from Hanford soil taken from the 216-Z-9 waste crib, which were then crystallographically characterized using single-crystal X-ray diffraction to confirm the cubic structure of PuO2. As a systematic proof of concept, the technique was first tested using UO2 crystals milled into cubic shapes with approximate volumes of 4620, 1331, 125, 8 and 1 µm3, in order to empirically determine the crystal size limits for characterization by a laboratory-based diffractometer with a sealed tube Mo or Ag anode X-ray source and a charge-coupled device detector.
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22
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Salbu B, Teien HC, Lind OC, Tollefsen KE. Why is the multiple stressor concept of relevance to radioecology? Int J Radiat Biol 2019; 95:1015-1024. [DOI: 10.1080/09553002.2019.1605463] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- B. Salbu
- Faculty of Environmental Sciences and Natural Resource Management (MINA), Norwegian University of Life Sciences (NMBU), Ås, Norway
- CERAD Centre for Environmental Radioactivity, Norwegian University of Life Sciences (NMBU), Ås, Norway
| | - H. C. Teien
- Faculty of Environmental Sciences and Natural Resource Management (MINA), Norwegian University of Life Sciences (NMBU), Ås, Norway
- CERAD Centre for Environmental Radioactivity, Norwegian University of Life Sciences (NMBU), Ås, Norway
| | - O. C. Lind
- Faculty of Environmental Sciences and Natural Resource Management (MINA), Norwegian University of Life Sciences (NMBU), Ås, Norway
- CERAD Centre for Environmental Radioactivity, Norwegian University of Life Sciences (NMBU), Ås, Norway
| | - K. E. Tollefsen
- Faculty of Environmental Sciences and Natural Resource Management (MINA), Norwegian University of Life Sciences (NMBU), Ås, Norway
- CERAD Centre for Environmental Radioactivity, Norwegian University of Life Sciences (NMBU), Ås, Norway
- Section of Ecotoxicology and Risk Assessment, Norwegian Institute of Water Research (NIVA), Oslo, Norway
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23
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Tayal A, Conradson SD, Kanzari A, Lahrouch F, Descostes M, Gerard M. Uranium speciation in weathered granitic waste rock piles: an XAFS investigation. RSC Adv 2019; 9:11762-11773. [PMID: 35517003 PMCID: PMC9063418 DOI: 10.1039/c9ra00961b] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Accepted: 04/03/2019] [Indexed: 12/02/2022] Open
Abstract
Investigation of uranium migration in the waste piles of granite rock in the Limousin region of France is vital for developing strategies which address related environmental issues. Despite the fact that the concentration of uranium is far below the lower end of the cut off level in these piles, the large volume of rocks – which measure in the hundreds of metric tons – and their conditions of repository make this type of waste a source of concern for the international community. In this work, X-ray absorption spectroscopy techniques (XAFS) were employed in order to identify the speciation of uranium in the different categories of samples collected from various regions of the rock piles which had undergone 50 years of weathering. The samples, such as weathered granite, arena and technosoils, were studied in order to probe the transformation of the U bearing complex. XANES indicates U(vi) valence with uranyl species in all samples. Using a linear combination analysis and shell fitting approach, distinct speciation of uranium was observed in the different categories of samples. In the weathered rock and arena samples with relics of magmatic U minerals, uranyl phosphates comparable to autunite are shown to be dominantly linked with monodentate PO43−. However, the samples collected from technosoils are found to have a mixture of U-phosphate and U-clay minerals (phyllosilicates and silicates). Irrespective of the collection location, all the samples were found to contain U(vi)-oxo species The equatorial O ligands occur as two shells with an average separation of 0.14–0.21 Å. Moreover, all the samples have an Al/Si/P shell around 3.1 Å. A detailed EXAFS curve fit analysis shows that disorder afflicts the entire range of samples which can be attributed to either inhomogeneous binding sites on the disordered clay minerals or to the presence of a mixture of uranium-bearing minerals. XAFS investigations highlight the uranyl overriding forms of U (as U sorbed on clay minerals and secondary uranyl phosphates or silicates) contribute to the retention of U, even in oxidizing conditions known to enhance the mobility of U. Uranium speciation determined by XAFS reveals its retention in weathered waste rock piles by the formation of stable secondary uranium complexes.![]()
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Affiliation(s)
- Akhil Tayal
- Institut de Minéralogie
- de Physique des Matériaux
- et de Cosmochimie (IMPMC)
- Sorbonne Université
- UMR CNRS 7590
| | | | - Aisha Kanzari
- Institut de Minéralogie
- de Physique des Matériaux
- et de Cosmochimie (IMPMC)
- Sorbonne Université
- UMR CNRS 7590
| | - Florian Lahrouch
- Institut de Minéralogie
- de Physique des Matériaux
- et de Cosmochimie (IMPMC)
- Sorbonne Université
- UMR CNRS 7590
| | | | - Martine Gerard
- Institut de Minéralogie
- de Physique des Matériaux
- et de Cosmochimie (IMPMC)
- Sorbonne Université
- UMR CNRS 7590
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24
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Novikov AP, Vlasova IE, Safonov AV, Ermolaev VM, Zakharova EV, Kalmykov SN. Speciation of actinides in groundwater samples collected near deep nuclear waste repositories. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2018; 192:334-341. [PMID: 30031315 DOI: 10.1016/j.jenvrad.2018.07.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Revised: 06/27/2018] [Accepted: 07/07/2018] [Indexed: 06/08/2023]
Abstract
Actinide binding to colloidal particles of different nature was studied under oxic and anoxic conditions of an underground nuclear waste disposal site using successive micro- and ultrafiltration techniques. According to the actinide redox speciation, under oxic conditions they were present in high oxidation states except for plutonium, for which a significant part was found in the tetravalent state. In case of the anoxic conditions, the share of An (IV) was proportional to the total U(IV) concentration. This indicated formation of intrinsic U(IV) hydroxocolloids, which bound other actinides. Formation of the intrinsic actinide colloids was proven by the secondary ion mass spectrometry (SIMS) with the submicron resolution. In contrast, under the oxic conditions uranium and plutonium were sorbed by natural colloids (amorphous hydrous ferric oxide and Mn oxides).
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Affiliation(s)
- A P Novikov
- Vernadsky Institute of Geochemistry and Analytical Chemistry, Russian Academy of Sciences, 119991, Kosygina str. 19, Moscow, Russia
| | - I E Vlasova
- Radiochemistry Div, Chemical Dept, Lomonosov Moscow State University, 119991, Leninskie Gory 3, Moscow, Russia
| | - A V Safonov
- A.N. Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, 199071, 31, Leninsky Prospect, Moscow, Russia.
| | - V M Ermolaev
- A.N. Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, 199071, 31, Leninsky Prospect, Moscow, Russia
| | - E V Zakharova
- A.N. Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, 199071, 31, Leninsky Prospect, Moscow, Russia
| | - St N Kalmykov
- Vernadsky Institute of Geochemistry and Analytical Chemistry, Russian Academy of Sciences, 119991, Kosygina str. 19, Moscow, Russia; Radiochemistry Div, Chemical Dept, Lomonosov Moscow State University, 119991, Leninskie Gory 3, Moscow, Russia
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25
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Pöml P, Burakov B. Study of the redistribution of U, Zr, Nb, Tc, Mo, Ru, Fe, Cr, and Ni between oxide and metallic phases in the matrix of a multiphase Chernobyl hot-particle extracted from a soil sample of the Western Plume. RADIOCHIM ACTA 2018. [DOI: 10.1515/ract-2018-2957] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
A “hot particle” found 6 km west of the Chernobyl nuclear power plant 4 years after the Chernobyl severe nuclear accident was analysed by scanning electron microscopy and electron probe micro-analysis. The matrix of the particle consists of relics of partly molten UO2 nuclear fuel and two different phases of solidified U–Zr–O melt (U0.77Zr0.23O2 and U0.67Zr0.33O2). The particle also contains a unique metallic inclusion of a size of 30×22 μm. The inclusion is non-homogeneous and in some parts shows a dendrite-like structure. It consists of about 38 wt.% Fe, about 10 wt.% U, Mo, and Nb, about 5 wt.% Ru, Zr, Ni, and Cr, and small amounts of Tc (2 wt.%) and Si (0.4 wt.%). The presence of partly molten nuclear fuel suggests a local temperature exceeding 2850 °C. The metallic inclusion most likely formed when steel, fuel, and cladding reacted together and molten steel incorporated U, Zr, Nb, Tc, Mo, and Ru from molten fuel and cladding during a very fast high-temperature process. Fast quenching of the metallic and the oxide melt left no time for Tc and Mo to evaporate. Molten Zr was partly oxidised and acted as a buffer for O which caused the reduction of a fraction of the U. The data of this study support the previously reported supercritical nature of the Chernobyl explosion.
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Affiliation(s)
- Philipp Pöml
- European Commission, Joint Research Centre, Directorate G – Nuclear Safety and Security , P.O. Box 2340 , 76125 Karlsruhe , Germany
| | - Boris Burakov
- V.G. Khlopin Radium Institute , 28, 2-nd Murinskiy Ave. , St. Petersburg 194021 , Russia
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26
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Peruski KM, Maloubier M, Kaplan DI, Almond PM, Powell BA. Mobility of Aqueous and Colloidal Neptunium Species in Field Lysimeter Experiments. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:1963-1970. [PMID: 29363312 DOI: 10.1021/acs.est.7b05765] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Due to its radiotoxicity, long half-life, and potentially high environmental mobility, neptunium transport is of paramount importance for risk assessment and safety. Environmental transport of neptunium through field lysimeters at the Savannah River Site was observed from both oxidized (Np(V)) and reduced (Np(IV)) source materials. While transport from oxidized neptunium sources was expected, the unexpected transport from reduced neptunium sources spurred further investigation into transport mechanisms. Partial oxidation of the reduced neptunium source resulted in significant release and transport into the mobile aqueous phase, though a reduced colloidal neptunium species appears to have also been present, enhancing neptunium mobility over shorter distances. These field and laboratory experiments demonstrate the multiple controls on neptunium vadose zone transport and chemical behavior, as well as the need for thorough understanding of radionuclide source terms for long-term risk prediction.
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Affiliation(s)
- Kathryn M Peruski
- Environmental Engineering and Earth Sciences, Clemson University , Anderson, South Carolina 29625, United States
| | - Melody Maloubier
- Environmental Engineering and Earth Sciences, Clemson University , Anderson, South Carolina 29625, United States
| | - Daniel I Kaplan
- Savannah River National Laboratory , Aiken, South Carolina 29808, United States
| | - Philip M Almond
- Savannah River National Laboratory , Aiken, South Carolina 29808, United States
| | - Brian A Powell
- Environmental Engineering and Earth Sciences, Clemson University , Anderson, South Carolina 29625, United States
- Department of Chemistry, Clemson University , Clemson, South Carolina 29634, United States
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Beccia MR, Solari PL, Monfort M, Moulin C, Den Auwer C. Focus on speciation assessment in marine radiochemistry using X-ray absorption spectroscopy. NEW J CHEM 2018. [DOI: 10.1039/c7nj04862a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We review the state-of-the-art and recent advances in the determination of radionuclide speciation in seawater.
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Affiliation(s)
| | - Pier Lorenzo Solari
- Synchrotron SOLEIL L’Orme des Merisiers
- Saint-Aubin
- F-91192 Gif-sur-Yvette Cedex
- France
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28
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Wolfsberg A, Dai Z, Zhu L, Reimus P, Xiao T, Ware D. Colloid-Facilitated Plutonium Transport in Fractured Tuffaceous Rock. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:5582-5590. [PMID: 28418667 DOI: 10.1021/acs.est.7b00968] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Colloids have the potential to enhance the mobility of strongly sorbing radionuclide contaminants in groundwater at underground nuclear test sites. This study presents an experimental and numerical investigation of colloid-facilitated plutonium transport in fractured porous media to identify plutonium reactive transport processes. The transport parameters for dispersion, diffusion, sorption, and filtration are estimated with inverse modeling by minimizing the least-squares objective function of multicomponent concentration data from multiple transport experiments with the shuffled complex evolution metropolis algorithm. Capitalizing on an unplanned experimental artifact that led to colloid formation, we adopt a stepwise strategy to first interpret the data from each experiment separately and then to incorporate multiple experiments simultaneously to identify a suite of plutonium-colloid transport processes. Nonequilibrium or kinetic attachment and detachment of plutonium-colloid in fractures were clearly demonstrated and captured in the inverted modeling parameters along with estimates of the source plutonium fraction that formed plutonium-colloids. The results from this study provide valuable insights for understanding the transport mechanisms and environmental impacts of plutonium in groundwater aquifers.
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Affiliation(s)
- Andrew Wolfsberg
- Earth and Environmental Sciences Division, Los Alamos National Laboratory , Los Alamos, New Mexico 87545, United States
| | - Zhenxue Dai
- Earth and Environmental Sciences Division, Los Alamos National Laboratory , Los Alamos, New Mexico 87545, United States
- College of Construction Engineering, Jilin University , Changchun 130026, China
- Key Laboratory of Groundwater Resources and Environment, Ministry of Education Jilin University , Changchun 130026, China
| | - Lin Zhu
- Earth and Environmental Sciences Division, Los Alamos National Laboratory , Los Alamos, New Mexico 87545, United States
- College of Resources Environments and Tourism, Capital Normal University , Beijing 100048, China
| | - Paul Reimus
- Earth and Environmental Sciences Division, Los Alamos National Laboratory , Los Alamos, New Mexico 87545, United States
| | - Ting Xiao
- Earth and Environmental Sciences Division, Los Alamos National Laboratory , Los Alamos, New Mexico 87545, United States
- Energy and Geoscience Institute, University of Utah , Salt Lake City, Utah 84108, United States
| | - Doug Ware
- Earth and Environmental Sciences Division, Los Alamos National Laboratory , Los Alamos, New Mexico 87545, United States
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29
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Pidchenko I, Kvashnina KO, Yokosawa T, Finck N, Bahl S, Schild D, Polly R, Bohnert E, Rossberg A, Göttlicher J, Dardenne K, Rothe J, Schäfer T, Geckeis H, Vitova T. Uranium Redox Transformations after U(VI) Coprecipitation with Magnetite Nanoparticles. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:2217-2225. [PMID: 28094921 DOI: 10.1021/acs.est.6b04035] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Uranium redox states and speciation in magnetite nanoparticles coprecipitated with U(VI) for uranium loadings varying from 1000 to 10 000 ppm are investigated by X-ray absorption spectroscopy (XAS). It is demonstrated that the U M4 high energy resolution X-ray absorption near edge structure (HR-XANES) method is capable to clearly characterize U(IV), U(V), and U(VI) existing simultaneously in the same sample. The contributions of the three different uranium redox states are quantified with the iterative transformation factor analysis (ITFA) method. U L3 XAS and transmission electron microscopy (TEM) reveal that initially sorbed U(VI) species recrystallize to nonstoichiometric UO2+x nanoparticles within 147 days when stored under anoxic conditions. These U(IV) species oxidize again when exposed to air. U M4 HR-XANES data demonstrate strong contribution of U(V) at day 10 and that U(V) remains stable over 142 days under ambient conditions as shown for magnetite nanoparticles containing 1000 ppm U. U L3 XAS indicates that this U(V) species is protected from oxidation likely incorporated into octahedral magnetite sites. XAS results are supported by density functional theory (DFT) calculations. Further characterization of the samples include powder X-ray diffraction (pXRD), scanning electron microscopy (SEM) and Fe 2p X-ray photoelectron spectroscopy (XPS).
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Affiliation(s)
- Ivan Pidchenko
- Karlsruhe Institute of Technology, Institute for Nuclear Waste Disposal (INE) , P.O. Box 3640, D-76021 Karlsruhe, Germany
| | - Kristina O Kvashnina
- European Synchrotron Radiation Facility (ESRF) , CS40220, 38043 Grenoble Cedex 9, France
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Resource Ecology , P.O. Box 510119, D-01314 Dresden, Germany
| | - Tadahiro Yokosawa
- Karlsruhe Institute of Technology, Institute for Nuclear Waste Disposal (INE) , P.O. Box 3640, D-76021 Karlsruhe, Germany
| | - Nicolas Finck
- Karlsruhe Institute of Technology, Institute for Nuclear Waste Disposal (INE) , P.O. Box 3640, D-76021 Karlsruhe, Germany
| | - Sebastian Bahl
- Karlsruhe Institute of Technology, Institute for Nuclear Waste Disposal (INE) , P.O. Box 3640, D-76021 Karlsruhe, Germany
| | - Dieter Schild
- Karlsruhe Institute of Technology, Institute for Nuclear Waste Disposal (INE) , P.O. Box 3640, D-76021 Karlsruhe, Germany
| | - Robert Polly
- Karlsruhe Institute of Technology, Institute for Nuclear Waste Disposal (INE) , P.O. Box 3640, D-76021 Karlsruhe, Germany
| | - Elke Bohnert
- Karlsruhe Institute of Technology, Institute for Nuclear Waste Disposal (INE) , P.O. Box 3640, D-76021 Karlsruhe, Germany
| | - André Rossberg
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Resource Ecology , P.O. Box 510119, D-01314 Dresden, Germany
| | - Jörg Göttlicher
- Karlsruhe Institute of Technology, Institute for Photon Science and Synchrotron Radiation (IPS) , P.O. Box 3640, D-76021 Karlsruhe, Germany
| | - Kathy Dardenne
- Karlsruhe Institute of Technology, Institute for Nuclear Waste Disposal (INE) , P.O. Box 3640, D-76021 Karlsruhe, Germany
| | - Jörg Rothe
- Karlsruhe Institute of Technology, Institute for Nuclear Waste Disposal (INE) , P.O. Box 3640, D-76021 Karlsruhe, Germany
| | - Thorsten Schäfer
- Karlsruhe Institute of Technology, Institute for Nuclear Waste Disposal (INE) , P.O. Box 3640, D-76021 Karlsruhe, Germany
| | - Horst Geckeis
- Karlsruhe Institute of Technology, Institute for Nuclear Waste Disposal (INE) , P.O. Box 3640, D-76021 Karlsruhe, Germany
| | - Tonya Vitova
- Karlsruhe Institute of Technology, Institute for Nuclear Waste Disposal (INE) , P.O. Box 3640, D-76021 Karlsruhe, Germany
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30
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Ikeda-Ohno A, Shahin LM, Howard DL, Collins RN, Payne TE, Johansen MP. Fate of Plutonium at a Former Nuclear Testing Site in Australia. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2016; 50:9098-9104. [PMID: 27548999 DOI: 10.1021/acs.est.6b01864] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
A series of the British nuclear tests conducted on mainland Australia between 1953 and 1963 dispersed long-lived radioactivity and nuclear weapons debris including plutonium (Pu), the legacy of which is a long-lasting source of radioactive contamination to the surrounding biosphere. A reliable assessment of the environmental impact of Pu contaminants and their implications for human health requires an understanding of their physical/chemical characteristics at the molecular scale. In this study, we identify the chemical form of the Pu remaining in the local soils at the Taranaki site, one of the former nuclear testing sites at Maralinga, South Australia. We herein reveal direct spectroscopic evidence that the Pu legacy remaining at the site exists as particulates of Pu(IV) oxyhydroxide compounds, a very concentrated and low-soluble form of Pu, which will serve as ongoing radioactive sources far into the future. Gamma-ray spectrometry and X-ray fluorescence analysis on a collected Pu particle indicate that the Pu in the particle originated in the so-called "Minor trials" that involved the dispersal of weapon components by highly explosive chemicals, not in the nuclear explosion tests called "Major trials". A comprehensive analysis of the data acquired from X-ray fluorescence mapping (XFM), X-ray absorption near-edge structure (XANES), and extended X-ray absorption fine structure (EXAFS) suggests that the collected Pu particle forms a "core-shell" structure with the Pu(IV) oxyhydroxide core surrounded by an external layer containing Ca, Fe, and U, which further helps us to deduce a possible scenario of the physical/chemical transformation of the original Pu materials dispersed in the semiarid environment at Maralinga more than 50 years ago. These findings also highlight the importance of the comprehensive physical/chemical characterization of Pu contaminants for reliable environmental- and radiotoxicological assessment.
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Affiliation(s)
- Atsushi Ikeda-Ohno
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Resource Ecology , Bautzner Landstrasse 400, 01328 Dresden, Germany
- Institute for Environmental Research, Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC, New South Wales 2232, Australia
- School of Civil and Environmental Engineering, The University of New South Wales , Sydney, New South Wales 2052, Australia
| | - Lida Mokhber Shahin
- Institute for Environmental Research, Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC, New South Wales 2232, Australia
| | - Daryl L Howard
- Australian Synchrotron, 800 Blackburn Road, Clayton, Victoria 3168, Australia
| | - Richard N Collins
- School of Civil and Environmental Engineering, The University of New South Wales , Sydney, New South Wales 2052, Australia
| | - Timothy E Payne
- Institute for Environmental Research, Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC, New South Wales 2232, Australia
| | - Mathew P Johansen
- Institute for Environmental Research, Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC, New South Wales 2232, Australia
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