1
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Periáñez R, Abascal-Ruíz U, López-Gutiérrez JM, Villa-Alfageme M. Sediments as sinks and sources of marine radionuclides: Implications for their use as ocean tracers. MARINE POLLUTION BULLETIN 2023; 194:115316. [PMID: 37517248 DOI: 10.1016/j.marpolbul.2023.115316] [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: 03/29/2023] [Revised: 07/10/2023] [Accepted: 07/17/2023] [Indexed: 08/01/2023]
Abstract
A Lagrangian transport model for the North Atlantic has been applied to simulate the historical releases of 137Cs, 129I and 236U from the European nuclear fuel reprocessing plants. Advection by currents, mixing and decay are included, as radionuclide interactions between water, sediments and suspended matter. The model was validated comparing predictions with measured radionuclide concentrations in water and sediments in several areas. 129I and 236U signals entering the Arctic Ocean have been compared with the input terms: the 236U signal is distorted, but the 129I signal preserves its shape. In the first moments after the releases, the sediments act as sinks for 236U, but not significantly for 129I and ultimately they become sources of 236U to the open sea. This results in a weaker correlation between input and output signals for 236U than for 129I. The same effects as for 236U have been found for 137Cs signal into the Arctic.
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Affiliation(s)
- Raúl Periáñez
- Dpt Física Aplicada I, ETSIA, Universidad de Sevilla, Ctra Utrera km 1, Sevilla, Spain.
| | - Unai Abascal-Ruíz
- Dpt Física Aplicada II, ETSIE, Universidad de Sevilla, Avda Reina Mercedes s/n, Sevilla, Spain
| | | | - María Villa-Alfageme
- Dpt Física Aplicada II, ETSIE, Universidad de Sevilla, Avda Reina Mercedes s/n, Sevilla, Spain
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2
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Abril-Hernández JM. Kinetic reactive transport explains distinct subsurface deposition patterns of pollutants in sediments. The case of the Sellafield-derived 236U, 137Cs and 239,240Pu in the Esk Estuary, UK. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2023; 323:121244. [PMID: 36775133 DOI: 10.1016/j.envpol.2023.121244] [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: 11/27/2022] [Revised: 01/16/2023] [Accepted: 02/07/2023] [Indexed: 06/18/2023]
Abstract
The kinetics of the uptake of pollutants by solids in sediments interacts with transitional eddy diffusivity in the pore fluid, leading to different depth-distribution patterns. This work aims to gain insights into the still poorly understood behaviour in the marine environment of the anthropogenic 236U, a recently postulated tracer of water masses. It is hypothesized that the transition from mobile U(VI) to highly particle-reactive U(IV) in the anoxic zone of the sediment produces a subsurface deposition pattern. A novel numerical model for kinetic reactive transport in sediments, which merges diagenetic processes for transport and box models for the uptake, is used for concept demonstration. It is applied to synthetic environments with high eddy diffusivity to obtain the singular depth-distribution patterns of pulsed inputs of tracers that mimic the anthropogenic 239,240Pu, 137Cs, and 236U. While the first is retained in the upper cm, the second shows an exponential penetration pattern over few cm, and 236U is deposited with a Gaussian-like pattern centred below the transition to the anoxic zone. These patterns are then merged into a diagenetic model to compute the depth distribution at decadal or centennial scales of dissolved and particle-bound inputs of these radiotracers. It is successfully applied to a real case using literature data for a sediment core from the Esk Estuary, UK, affected by radioactive releases from the Sellafield nuclear reprocessing plant. This work provides insight into until now poorly understood field data and provides a novel view of broad implications in the study of the behaviour of pollutants in surficial aquatic sediments.
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3
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Luo H, Yao H, Li M, Meng F, Zhao H, Yu C, Liang X, Liu H. Fabrication of novel pectin-based adsorbents for extraction of uranium from simulated seawater: synthesis, performance and mechanistic insight. Sep Purif Technol 2023. [DOI: 10.1016/j.seppur.2023.123283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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4
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Casacuberta N, Smith JN. Nuclear Reprocessing Tracers Illuminate Flow Features and Connectivity Between the Arctic and Subpolar North Atlantic Oceans. ANNUAL REVIEW OF MARINE SCIENCE 2023; 15:203-221. [PMID: 36055974 DOI: 10.1146/annurev-marine-032122-112413] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Releases of anthropogenic radionuclides from European nuclear fuel reprocessing plants enter the surface circulation of the high-latitude North Atlantic and are transported northward into the Arctic Ocean and southward from the Nordic Seas into the deep North Atlantic, thereby providing tracers of water circulation, mixing, ventilation, and deep-water formation. Early tracer studies focused on 137Cs, which revealed some of the first significant insights into the Arctic Ocean circulation, while more recent work has benefited from advances in accelerator mass spectrometry to enable the measurement of the conservative, long-lived radionuclide tracers 129I and 236U. The latest studies of these tracers, supported by simulations using the North Atlantic-Arctic Ocean-Sea Ice Model (NAOSIM) and enhanced by the use of transit time distributions to more precisely accommodate mixing, have provided a rich inventory of transport data for circulation in the Arctic and North Atlantic Oceans that are of great importance to global thermohaline circulation and climate.
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Affiliation(s)
- Núria Casacuberta
- Institute of Biogeochemistry and Pollutant Dynamics, Department of Environmental Systems Science, and Laboratory of Ion Beam Physics, ETH Zürich, Zürich, Switzerland;
| | - John N Smith
- Bedford Institute of Oceanography, Fisheries and Oceans Canada, Dartmouth, Nova Scotia, Canada;
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5
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Lin G, Qiao J, Steier P, Danielsen M, Guðnason K, Joensen HP, Stedmon CA. Tracing Atlantic water transit time in the subarctic and Arctic Atlantic using 99Tc- 233U- 236U. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 851:158276. [PMID: 36029821 DOI: 10.1016/j.scitotenv.2022.158276] [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: 05/20/2022] [Revised: 08/18/2022] [Accepted: 08/21/2022] [Indexed: 06/15/2023]
Abstract
The pathway and transport time of Atlantic water passing northern Europe can be traced via anthropogenic radioisotopes released from reprocessing of spent nuclear fuels at Sellafield (SF) and La Hague (LH). These reprocessing derived radioisotopes, with extremely low natural background, are source specific and unique fingerprints for Atlantic water. This study explores a new approach using 99Tc-233U-236U tracer to estimate the transit time of Atlantic water in the coast of Greenland. We isolate the reprocessing plants (RP) signal of 236U (236URP) by incorporating 233U measurements and combine this with 99Tc which solely originates from RP, to estimate the transit time of Atlantic water circulating from Sellafield to the coast of Greenland-Iceland-Faroe Islands. Both being conservative radioisotopes, the temporal variation of 99Tc/236URP ratio in Atlantic water is only influenced by their historic discharges from RP, thus 99Tc/236URP can potentially be a robust tracer to track the transport of Atlantic water in the North Atlantic-Arctic region. Based on our observation data of 99Tc-233U-236U in seawater and the proposed 99Tc/236URP tracer approach, Atlantic water transit times were estimated to be 16-22, 25 and 25 years in the coast of Greenland, Iceland and Faroe Island, respectively. Our estimates from northeast Greenland coastal waters agree with earlier results (17-22 years). Therefore, this work provides an independent approach to estimate Atlantic water transit time with which to compare estimates from ocean modelling and other radiotracer approaches.
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Affiliation(s)
- Gang Lin
- Department of Environmental and Resource Engineering, Technical University of Denmark, DK-4000 Roskilde, Denmark
| | - Jixin Qiao
- Department of Environmental and Resource Engineering, Technical University of Denmark, DK-4000 Roskilde, Denmark.
| | - Peter Steier
- VERA Laboratory, Faculty of Physics, Isotope Physics, University of Vienna, Währinger Straße 17, A-1090 Vienna, Austria
| | | | | | | | - Colin A Stedmon
- National Institute of Aquatic Resources, Technical University of Denmark, Kemitorvet, 2800 Kgs. Lyngby, Denmark
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6
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Shao Y, Zhang J, Luo M, Xu D, Ma L. A review of anthropogenic radionuclide 236U: Environmental application and analytical advances. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2022; 251-252:106944. [PMID: 35696882 DOI: 10.1016/j.jenvrad.2022.106944] [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: 05/30/2022] [Accepted: 06/05/2022] [Indexed: 06/15/2023]
Abstract
236U is an anthropogenic radionuclide that is produced from nuclear reactions of 235U(n, γ) and 238U(n, 3n). It has gained extensive attention in the field of environment, geology, nuclear emergency, and nuclear forensics. Due to the unique physical and chemical character and the distinct fingerprint character from different sources, 236U has been successfully applied in the environmental tracer, nuclear material source appointment, and environmental assessment. Until now, few reviews were published about the database, application, and the latest analytical technology development of 236U. In this review, the 236U concentration and 236U/238U isotope ratio were summarized, and the data were classified into four categories, including soil and seawater samples affected by global fallout and nuclear incidents. Furthermore, the development of environmental application and pretreatment methods were also summarized. The advanced pretreatment technology using alkali fusion and flow injection was especially discussed to introduce the development of a rapid analytical method. Finally, the research challenge and direction of 236U were proposed for further research, such as the tracer application combining 236U with other radionuclides in the terrestrial environment and the precise analysis of minor isotopes in ultra-trace uranium samples. We hope this review will help scholars to have a deep research on the analysis and application of 236U.
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Affiliation(s)
- Yang Shao
- Beijing Engineering Research Center of Radiographic Techniques and Equipment, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049, China
| | - Jilong Zhang
- State Nuclear Security Technology Center, Beijing, 102401, China
| | - Min Luo
- Beijing Engineering Research Center of Radiographic Techniques and Equipment, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049, China
| | - Diandou Xu
- Beijing Engineering Research Center of Radiographic Techniques and Equipment, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049, China
| | - Lingling Ma
- Beijing Engineering Research Center of Radiographic Techniques and Equipment, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049, China.
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Lin M, Qiao J, Hou X, Steier P, Golser R, Schmidt M, Dellwig O, Hansson M, Bäck Ö, Vartti VP, Stedmon C, She J, Murawski J, Aldahan A, Schmied SAK. Anthropogenic 236U and 233U in the Baltic Sea: Distributions, source terms, and budgets. WATER RESEARCH 2022; 210:117987. [PMID: 34954368 DOI: 10.1016/j.watres.2021.117987] [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: 08/17/2021] [Revised: 12/16/2021] [Accepted: 12/17/2021] [Indexed: 06/14/2023]
Abstract
The Baltic Sea receives substantial amounts of hazardous substances and nutrients, which accumulate for decades and persistently impair the Baltic ecosystems. With long half-lives and high solubility, anthropogenic uranium isotopes (236U and 233U) are ideal tracers to depict the ocean dynamics in the Baltic Sea and the associated impacts on the fates of contaminants. However, their applications in the Baltic Sea are hampered by the inadequate source-term information. This study reports the first three-dimensional distributions of 236U and 233U in the Baltic Sea (2018-2019) and the first long-term hindcast simulation for reprocessing-derived 236U dispersion in the North-Baltic Sea (1971-2018). Using 233U/236U fingerprints, we distinguish 236U from the nuclear weapon testing and civil nuclear industries, which have comparable contributions (142 ± 13 and 174 ± 40 g) to the 236U inventory in modern Baltic seawater. Budget calculations for 236U inputs since the 1950s indicate that, the major 236U sources in the Baltic Sea are the atmospheric fallouts (∼1.35 kg) and discharges from nuclear reprocessing plants (> 211 g), and there is a continuous sink of 236U to the anoxic sediments (589 ± 43 g). Our findings also indicate that the limited water renewal endows the Baltic Sea a strong "memory effect" retaining aged 236U signals, and the previously unknown 236U in the Baltic Sea is likely attributed to the retention of the mid-1990s' discharges from the nuclear reprocessing plants. Our preliminary results demonstrate the power of 236U-129I dual-tracer in investigating water-mass mixing and estimating water age in the Baltic Sea, and this work provides fundamental knowledge for future 236U tracer studies in the Baltic Sea.
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Affiliation(s)
- Mu Lin
- Department of Environmental Engineering, DTU Risø Campus, Technical University of Denmark, Roskilde DK-4000, Denmark
| | - Jixin Qiao
- Department of Environmental Engineering, DTU Risø Campus, Technical University of Denmark, Roskilde DK-4000, Denmark.
| | - Xiaolin Hou
- Department of Environmental Engineering, DTU Risø Campus, Technical University of Denmark, Roskilde DK-4000, Denmark
| | - Peter Steier
- VERA Laboratory, Faculty of Physics, Isotope Physics, University of Vienna, Währinger Straße 17, Vienna A-1090, Austria
| | - Robin Golser
- VERA Laboratory, Faculty of Physics, Isotope Physics, University of Vienna, Währinger Straße 17, Vienna A-1090, Austria
| | - Martin Schmidt
- Leibniz Institute for Baltic Sea Research Warnemünde (IOW), Rostock 18119, Germany
| | - Olaf Dellwig
- Leibniz Institute for Baltic Sea Research Warnemünde (IOW), Rostock 18119, Germany
| | - Martin Hansson
- Swedish Meteorological and Hydrological Institute (SMHI), Göteborg SE-426 71, Sweden
| | - Örjan Bäck
- Swedish Meteorological and Hydrological Institute (SMHI), Göteborg SE-426 71, Sweden
| | - Vesa-Pekka Vartti
- Radiation and Nuclear Safety Authority (STUK), Helsinki 00880, Finland
| | - Colin Stedmon
- National Institute of Aquatic Resources, DTU Lyngby Campus, Technical University of Denmark, Lyngby DK-2800, Denmark
| | - Jun She
- Department of Research and Development, Danish Meteorological Institute, København DK-2100, Denmark
| | - Jens Murawski
- Department of Research and Development, Danish Meteorological Institute, København DK-2100, Denmark
| | - Ala Aldahan
- Department of Geosciences, United Arab Emirates University, Al Ain 17551, United Arab Emirates
| | - Stefanie A K Schmied
- Federal Maritime and Hydrographic Agency of Germany (BSH), Hamburg 22589, Germany
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8
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First study on 236U in environmental samples from Bangladesh by ICP-MS/MS prior to the operation of its first nuclear power plant. J Radioanal Nucl Chem 2021. [DOI: 10.1007/s10967-021-07931-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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9
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Lin M, Qiao J, Hou X, Dellwig O, Steier P, Hain K, Golser R, Zhu L. 70-Year Anthropogenic Uranium Imprints of Nuclear Activities in Baltic Sea Sediments. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:8918-8927. [PMID: 34105953 DOI: 10.1021/acs.est.1c02136] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
A strongly stratified water structure and a densely populated catchment make the Baltic Sea one of the most polluted seas. Understanding its circulation pattern and time scale is essential to predict the dynamics of hypoxia, eutrophication, and pollutants. Anthropogenic 236U and 233U have been demonstrated as excellent transient tracers in oceanic studies, but unclear input history and inadequate long-term monitoring records limit their application in the Baltic Sea. From two dated Baltic sediment cores, we obtained high-resolution records of anthropogenic uranium imprints originating from three major human nuclear activities throughout the Atomic Era. Using the novel 233U/236U signature, we distinguished and quantified 236U inputs from global fallout (45.4-52.1%), Chernobyl accident (0.3-1.8%), and discharges from civil nuclear industries (46.1-54.3%) to the Baltic Sea. We estimated the total release of 233U (7-15 kg) from the atmospheric nuclear weapon testing and pinpointed the 233U peak signal in the mid-to-late 1950s as a potential time marker for the onset of the Anthropocene Epoch. This work also provides fundamental 236U data on Chernobyl accident and early discharges from civil nuclear facilities, prompting worldwide 233U-236U tracer studies. We anticipate our data to be used in a broader application in model-observation interdisciplinary research on water circulation and pollutant dynamics in the Baltic Sea.
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Affiliation(s)
- Mu Lin
- Department of Environmental Engineering, Technical University of Denmark, DTU Risø Campus, DK-4000 Roskilde, Denmark
| | - Jixin Qiao
- Department of Environmental Engineering, Technical University of Denmark, DTU Risø Campus, DK-4000 Roskilde, Denmark
| | - Xiaolin Hou
- Department of Environmental Engineering, Technical University of Denmark, DTU Risø Campus, DK-4000 Roskilde, Denmark
| | - Olaf Dellwig
- Department of Marine Geology, Leibniz Institute for Baltic Sea Research Warnemünde, IOW, 18119 Rostock, Germany
| | - Peter Steier
- VERA Laboratory, Faculty of Physics, Isotope Physics, University of Vienna, Währinger Straße 17, A-1090 Vienna, Austria
| | - Karin Hain
- VERA Laboratory, Faculty of Physics, Isotope Physics, University of Vienna, Währinger Straße 17, A-1090 Vienna, Austria
| | - Robin Golser
- VERA Laboratory, Faculty of Physics, Isotope Physics, University of Vienna, Währinger Straße 17, A-1090 Vienna, Austria
| | - Liuchao Zhu
- Department of Environmental Engineering, Technical University of Denmark, DTU Risø Campus, DK-4000 Roskilde, Denmark
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Pittet PA, Josset M, Boilley D, Bernollin A, Rougier G, Froidevaux P. Origin and age of an ongoing radioactive contamination of soils near La hague reprocessing plant based on 239+240Pu/ 238Pu and 241Am/ 241Pu current ratios and 90Sr and Ln(III) soil contents. CHEMOSPHERE 2021; 270:129332. [PMID: 33422999 DOI: 10.1016/j.chemosphere.2020.129332] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 12/10/2020] [Accepted: 12/13/2020] [Indexed: 06/12/2023]
Abstract
Nuclear reprocessing plants are sources of environmental contamination by gaseous or liquid discharges. Numerous radionuclides are of concern, with actinides and 90Sr being the most radiotoxic. Environmental radioactivity survey programs mostly use γ-spectrometry to track contaminations because γ-spectrometry is very cost effective and can be carried out on raw samples. On the other hand, the determination of β- or α-emitting radionuclides in environmental samples requires rather sophisticated analytical methods, and are thus dedicated to specific goals. However, measuring radionuclides such as Pu, Am, and Sr often provides more information about the presence of a current or prior contamination and on its origin, based on the isotopic composition of the samples. We found that the analysis of 241Pu, 239+240Pu, 241Am, and 90Sr of a few selected soil samples taken near the nuclear reprocessing plant of La Hague, France, revealed the presence of a previous environmental contamination originating from several incidents in La Hague site involving atmospheric transfer and leaks in flooded waste pits. The 241Am-241Pu dating method indicated a contamination period prior to 1983. The presence of elevated levels of light non-radioactive lanthanides and yttrium in the soil samples confirmed the involvement of cold fuel. Our results demonstrate how long-lived actinides are likely to reveal a long-term contamination of the environment by spent fuel. Our study indicates that there is a requirement to use more sophisticated tools than γ-spectrometry when surveying the environments surrounding industrial plants for nuclear power and nuclear reprocessing with a potential for the accidental release of radioactivity into the environment.
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Affiliation(s)
- Pierre-André Pittet
- Institute of Radiation Physics, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Mylène Josset
- ACRO, Association pour le Contrôle de La Radioactivité Dans L'Ouest, 138, Rue de L'Eglise, 14200, Hérouville St Clair, France
| | - David Boilley
- ACRO, Association pour le Contrôle de La Radioactivité Dans L'Ouest, 138, Rue de L'Eglise, 14200, Hérouville St Clair, France
| | - Antoine Bernollin
- ACRO, Association pour le Contrôle de La Radioactivité Dans L'Ouest, 138, Rue de L'Eglise, 14200, Hérouville St Clair, France
| | - Guillaume Rougier
- ACRO, Association pour le Contrôle de La Radioactivité Dans L'Ouest, 138, Rue de L'Eglise, 14200, Hérouville St Clair, France
| | - Pascal Froidevaux
- Institute of Radiation Physics, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland.
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11
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López-Lora M, Chamizo E, Levy I, Christl M, Casacuberta N, Kenna TC. 236U, 237Np and 239,240Pu as complementary fingerprints of radioactiveeffluents in the western Mediterranean Sea and in the Canada Basin (Arctic Ocean). THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 765:142741. [PMID: 33071133 DOI: 10.1016/j.scitotenv.2020.142741] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 09/22/2020] [Accepted: 09/27/2020] [Indexed: 06/11/2023]
Abstract
The aim of this study was to assess the potential of combining the conservatively behaving anthropogenic radionuclides 236U and 237Np to gain information on the origin of water masses tagged with liquid effluents from Nuclear Reprocessing Plants. This work includes samples collected from three full-depth water columns in two areas: i) the Arctic Ocean, where Atlantic waters carry the signal of Sellafield (United Kingdom) and La Hague (France) nuclear reprocessing facilities; and ii) the western Mediterranean Sea, directly impacted by Marcoule reprocessing plant (France). This work is complemented by the study of the particle-reactive Pu isotopes as an additional fingerprint of the source region. In the Canada Basin, Atlantic waters showed the highest concentrations and 237Np/236U ratios in agreement with the estimated values for North Atlantic waters entering the Arctic Ocean and tagged with the signal of European Nuclear Reprocessing Plants. These results may reflect the impact of the documented releases for the 1990s. In the Mediterranean Sea, an excess of 236U presumably caused by Marcoule is reflected in the lower 237Np/236U ratios compared to the Global Fallout signal in all the studied samples. On the contrary, the 239,240Pu profiles were mainly governed by the Global Fallout. The impact of Marcoule as a local source is further corroborated when comparing the temporal evolution of these ratios between 2001 and 2013. The lowest 237Np/236U ratios observed in 2001 at the surface reflect a previous local input that is no longer observed in 2013 as it had been homogenized through the whole water column. This work presents the use of 237Np as a new ocean tracer. A more accurate characterization of the main sources is still needed to optimize the use of 236U-237Np as a new tool to understand transient oceanographic processes.
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Affiliation(s)
- Mercedes López-Lora
- Centro Nacional de Aceleradores (CNA), Universidad de Sevilla, Junta de Andalucía, Consejo Superior de Investigaciones Científicas, Parque científico y tecnológico Cartuja, Thomas Alva Edison 7, 41092, Sevilla, Spain; Dpto. de Física Aplicada I, Escuela Politécnica Superior, Universidad de Sevilla, Virgen de África 7, 41011 Sevilla, Spain; Department of Health, Medicine and Caring Sciences (HMV), Linköping University, 58183 Linköping, Sweden.
| | - Elena Chamizo
- Centro Nacional de Aceleradores (CNA), Universidad de Sevilla, Junta de Andalucía, Consejo Superior de Investigaciones Científicas, Parque científico y tecnológico Cartuja, Thomas Alva Edison 7, 41092, Sevilla, Spain
| | - Isabelle Levy
- International Atomic Energy Agency, Environment Laboratories 4a Quai Antoine 1er, MC 98000, Monaco
| | - Marcus Christl
- Laboratory of Ion Beam Physics, ETH Zürich, Otto-Stern-Wen 5, CH-8093 Zürich, Switzerland
| | - Núria Casacuberta
- Laboratory of Ion Beam Physics, ETH Zürich, Otto-Stern-Wen 5, CH-8093 Zürich, Switzerland
| | - Timothy C Kenna
- Lamont-Doherty Earth Observatory, Columbia University, NY, USA
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12
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Lin M, Qiao J, Hou X, Golser R, Hain K, Steier P. On the Quality Control for the Determination of Ultratrace-Level 236U and 233U in Environmental Samples by Accelerator Mass Spectrometry. Anal Chem 2021; 93:3362-3369. [DOI: 10.1021/acs.analchem.0c03623] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Mu Lin
- Department of Environmental Engineering, Technical University of Denmark, DTU Risø Campus, DK-4000 Roskilde, Denmark
| | - Jixin Qiao
- Department of Environmental Engineering, Technical University of Denmark, DTU Risø Campus, DK-4000 Roskilde, Denmark
| | - Xiaolin Hou
- Department of Environmental Engineering, Technical University of Denmark, DTU Risø Campus, DK-4000 Roskilde, Denmark
| | - Robin Golser
- VERA Laboratory, Faculty of Physics, Isotope Physics, University of Vienna, Währinger Straße 17, A-1090 Vienna, Austria
| | - Karin Hain
- VERA Laboratory, Faculty of Physics, Isotope Physics, University of Vienna, Währinger Straße 17, A-1090 Vienna, Austria
| | - Peter Steier
- VERA Laboratory, Faculty of Physics, Isotope Physics, University of Vienna, Währinger Straße 17, A-1090 Vienna, Austria
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An unknown source of reactor radionuclides in the Baltic Sea revealed by multi-isotope fingerprints. Nat Commun 2021; 12:823. [PMID: 33547296 PMCID: PMC7865023 DOI: 10.1038/s41467-021-21059-w] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2020] [Accepted: 01/11/2021] [Indexed: 11/25/2022] Open
Abstract
We present an application of multi-isotopic fingerprints (i.e., 236U/238U, 233U/236U, 236U/129I and 129I/127I) for the discovery of previously unrecognized sources of anthropogenic radioactivity. Our data indicate a source of reactor 236U in the Baltic Sea in addition to inputs from the two European reprocessing plants and global fallout. This additional reactor 236U may come from unreported discharges from Swedish nuclear research facilities as supported by high 236U levels in sediment nearby Studsvik, or from accidental leakages of spent nuclear fuel disposed on the Baltic seafloor, either reported or unreported. Such leakages would indicate problems with the radiological safety of seafloor disposal, and may be accompanied by releases of other radionuclides. The results demonstrate the high sensitivity of multi-isotopic tracer systems, especially the 233U/236U signature, to distinguish environmental emissions of unrevealed radioactive releases for nuclear safeguards, emergency preparedness and environmental tracer studies. Anthropogenic activities lead to the accumulation of radioactive substances in the environment. Here the authors use multi-isotopic fingerprints of uranium and iodine to discover a previously unknown source of reactor uranium in the Baltic Sea, likely sourced from a Swedish nuclear facility.
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14
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Shao Y, Yang G, Zhang J, Luo M, Ma L, Xu D. Progress and Application on the Analysis of Anthropogenic Radionuclide 236U. ACTA CHIMICA SINICA 2021. [DOI: 10.6023/a21020074] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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15
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Wang Y, Hou X, Zhang W, Zhang L, Fan Y. Determination of ultra-low 236U in environment samples using ICP-MS/MS measurement and chemical separation. Talanta 2020; 224:121882. [PMID: 33379091 DOI: 10.1016/j.talanta.2020.121882] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2020] [Revised: 11/04/2020] [Accepted: 11/07/2020] [Indexed: 11/19/2022]
Abstract
236U in the environment mainly originates from human nuclear activities. Based on the unique properties of uranium, 236U can be used as a powerful tracer for investigation of oceanographic and environmental processes. This requires sensitive measuement of 236U in various environmental samples. Due to the ultra-low radioactive level of 236U in the environment, its measurement is only possible by mass spectrometry. Because of the low atomic ratio of 236U/235U down to 10-7-10-5 in the environment, the interferences of 235U1H+ and peak tailings of 235U and 238U are critical challenges in the measurement of 236U by ICP-MS. This work developed a sensitive ICP-MS/MS method for measurement of ultra-low 236U by employing reaction cell technique and sequential quadrupole mass separators. By using 0.6 mL min-1 CO2 - 7 mL min-1 helium as collision/reaction gas to convert U+ and UH+ to UO+, the interferences of UH+ (UOH+/UO+ ratio) were significantly reduced to less than 2.4 × 10-7. A minimum detectable 236U/238U ratio of 3.0 × 10-10 was achieved, which is one order of magnitude better than reported values. By using collision focusing with helium in the reaction cell and APEX sample introduction system, the measurement sensitivity for 236U (236UO+) was improved to 7.5 × 106 cps ppb-1. In combination with an effective chemical separation of uranium from sample matrix and interferences using total borate fusion following extraction chromatography with UTEVA resin, a detection limit of 7.2 × 10-16 g g-1 for 236U was achieved. The developed method was verified by analysis of certified reference materials and by comparison with AMS measurement method. Soil samples collected from Northwest China were successfully analyzed. 236U/238U ratios down to 9 × 10-10 were measured in these samples, and the sources of 236U in different sits were discussed.
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Affiliation(s)
- Yanyun Wang
- Xi'an AMS Center, State Key Laboratory of Loess and Quaternary Geology, Shaanxi Key Laboratory of AMS Technology and Application, Institute of Earth Environment, CAS, Xi'an, 710061, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Xiaolin Hou
- Xi'an AMS Center, State Key Laboratory of Loess and Quaternary Geology, Shaanxi Key Laboratory of AMS Technology and Application, Institute of Earth Environment, CAS, Xi'an, 710061, China; Technical University of Denmark, Department of Environment Engineering, Risø Campus, Building 204, Frederiksborgvej 399, Roskilde, 4000, Denmark; CAS Center of Excellence in Quaternary Science and Global Change, Xi'an, 710061, China; Open Studio for Oceanic-Continental Climate and Environment Changes, Pilot National Laboratory for Marine Science and Technology (Qingdao), Qingdao, 266061, China.
| | - Weichao Zhang
- Xi'an AMS Center, State Key Laboratory of Loess and Quaternary Geology, Shaanxi Key Laboratory of AMS Technology and Application, Institute of Earth Environment, CAS, Xi'an, 710061, China
| | - Luyuan Zhang
- Xi'an AMS Center, State Key Laboratory of Loess and Quaternary Geology, Shaanxi Key Laboratory of AMS Technology and Application, Institute of Earth Environment, CAS, Xi'an, 710061, China; CAS Center of Excellence in Quaternary Science and Global Change, Xi'an, 710061, China; Open Studio for Oceanic-Continental Climate and Environment Changes, Pilot National Laboratory for Marine Science and Technology (Qingdao), Qingdao, 266061, China
| | - Yukun Fan
- Xi'an AMS Center, State Key Laboratory of Loess and Quaternary Geology, Shaanxi Key Laboratory of AMS Technology and Application, Institute of Earth Environment, CAS, Xi'an, 710061, China
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Dissolved Radiotracers and Numerical Modeling in North European Continental Shelf Dispersion Studies (1982–2016): Databases, Methods and Applications. WATER 2020. [DOI: 10.3390/w12061667] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Significant amounts of anthropogenic radionuclides were introduced in ocean waters following nuclear atmospheric tests and development of the nuclear industry. Dispersion of artificial dissolved radionuclides has been extensively measured for decades over the North-European continental shelf. In this area, the radionuclide measurement and release fluxes databases provided here between 1982 and 2016 represent an exceptional opportunity to validate dispersion hydrodynamic models. This work gives accessibility to these data in a comprehensive database. The MARS hydrodynamic model has been applied at different scales to reproduce the measured dispersion in realistic conditions. Specific methods have been developed to obtain qualitative and quantitative results and perform model/measurement comparisons. Model validation concerns short to large scales with dedicated surveys following the dispersion: it was performed within a two- and three-dimensional framework and from minutes and hours following a release up to several years. Results are presented concerning the dispersion of radionuclides in marine systems deduced from standalone measurements, or according to model comparisons. It allows characterizing dispersion over the continental shelf, pathways, transit times, budgets and source terms. This review presents the main approaches developed and types of information derived from studies of artificial radiotracers using observations, hydrodynamic models or a combination of the two, based primarily on the new featured datasets.
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Castrillejo M, Witbaard R, Casacuberta N, Richardson CA, Dekker R, Synal HA, Christl M. Unravelling 5 decades of anthropogenic 236U discharge from nuclear reprocessing plants. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 717:137094. [PMID: 32062259 DOI: 10.1016/j.scitotenv.2020.137094] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Revised: 01/30/2020] [Accepted: 02/01/2020] [Indexed: 06/10/2023]
Abstract
Marine biogenic materials such as corals, shells, or seaweed have long been recognized as recorders of environmental conditions. Here, the bivalve Cerastoderma edule is used for the first time as a recorder of past seawater contamination with anthropogenic uranium, specifically 236U. Several studies have employed the authorized radioactive releases, including 236U, from nuclear reprocessing plants in La Hague, France, into the English Channel, and Sellafield, England, into the Irish Sea, to trace Atlantic waters and to understand recent climate induced circulation changes in the Arctic Ocean. Anthropogenic 236U has emerged over recent years as a new transient tracer to track these changes, but its application has been challenged owing to paucity of fundamental data on the input (timing and amount) of 236U from Sellafield. Here, we present 236U/238U data from bivalve shells collected close to La Hague and Sellafield from two unique shell collections that allow the reconstruction of the historical 236U contamination of seawater since the 1960s, mostly with bi-annual resolution. The novel archive is first validated by comparison with well-documented 236U discharges from La Hague. Then, shells from the Irish Sea are used to reconstruct the regional 236U contamination. Apart from defining new, observationally based 236U input functions that will allow more precise tracer studies in the Arctic Ocean, we find an unexpected peak of 236U releases to the Irish Sea in the 1970s. Using this peak, we provide evidence for a small, but significant recirculation of Irish Sea water into the English Channel. Tracing the 1970s peak should allow extending 236U tracer studies into the South Atlantic Ocean.
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Affiliation(s)
- Maxi Castrillejo
- Laboratory of Ion Beam Physics, ETH - Zurich, Otto Stern Weg 5, 8093 Zurich, Switzerland.
| | - Rob Witbaard
- NIOZ Royal Netherlands Institute for Sea Research and Utrecht University, PO Box 59, 1790 Ab Den Burg, the Netherlands
| | - Núria Casacuberta
- Laboratory of Ion Beam Physics, ETH - Zurich, Otto Stern Weg 5, 8093 Zurich, Switzerland; Institute of Biogeochemistry and Pollutant Dynamics, Environmental Physics, ETH Zurich, Universitätstrasse 16, Zurich 8092, Switzerland
| | | | - Rob Dekker
- NIOZ Royal Netherlands Institute for Sea Research and Utrecht University, PO Box 59, 1790 Ab Den Burg, the Netherlands
| | - Hans-Arno Synal
- Laboratory of Ion Beam Physics, ETH - Zurich, Otto Stern Weg 5, 8093 Zurich, Switzerland
| | - Marcus Christl
- Laboratory of Ion Beam Physics, ETH - Zurich, Otto Stern Weg 5, 8093 Zurich, Switzerland
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18
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233U/ 236U signature allows to distinguish environmental emissions of civil nuclear industry from weapons fallout. Nat Commun 2020; 11:1275. [PMID: 32152279 PMCID: PMC7062840 DOI: 10.1038/s41467-020-15008-2] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Accepted: 02/13/2020] [Indexed: 11/09/2022] Open
Abstract
Isotopic ratios of radioactive releases into the environment are useful signatures for contamination source assessment. Uranium is known to behave conservatively in sea water so that a ratio of uranium trace isotopes may serve as a superior oceanographic tracer. Here we present data on the atomic [Formula: see text]U/[Formula: see text]U ratio analyzed in representative environmental samples finding ratios of (0.1-3.7)[Formula: see text]10[Formula: see text]. The ratios detected in compartments of the environment affected by releases of nuclear power production or by weapons fallout differ by one order of magnitude. Significant amounts of [Formula: see text]U were only released in nuclear weapons fallout, either produced by fast neutron reactions or directly by [Formula: see text]U-fueled devices. This makes the [Formula: see text]U/[Formula: see text]U ratio a promising new fingerprint for radioactive emissions. Our findings indicate a higher release of [Formula: see text]U by nuclear weapons tests before the maximum of global fallout in 1963, setting constraints on the design of the nuclear weapons employed.
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Yang G, Rahman MS, Tazoe H, Hu J, Shao Y, Yamada M. 236U and radiocesium in river bank soil and river sediment in Fukushima Prefecture, after the Fukushima Daiichi Nuclear Power Plant accident. CHEMOSPHERE 2019; 225:388-394. [PMID: 30884300 DOI: 10.1016/j.chemosphere.2019.03.061] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Revised: 02/25/2019] [Accepted: 03/10/2019] [Indexed: 06/09/2023]
Abstract
Almost 8 years after the Japanese Fukushima Daiichi Nuclear Power Plant (FDNPP) accident, data for 236U and 236U/238U have mainly remained limited to only a few heavily contaminated samples. In the present study, activities of 236U, 134Cs, and 137Cs, along with 234U, 235U, 238U, in 15 river bank soil and 10 river sediment samples, were measured by ICP-MS/MS and γ spectrometry. The 134Cs activities and 134Cs/137Cs activity ratios (decay-corrected to March 11, 2011) in these 15 river bank soil samples were from 74.8 to 3.88 × 105 Bq kg-1 and from 0.944 to 1.02, respectively; and in these 10 river sediment samples were from 87.1 to 1.86 × 105 Bq kg-1 and from 0.904 to 0.990, respectively. The 236U activities and 236U/238U atom ratios in these soil samples were in the respective ranges of (0.139-17.6) × 10-5 Bq kg-1 and (0.259-3.83) × 10-8; and in these sediment samples were in the respective ranges of (0.884-27.0) × 10-5 Bq kg-1 and (1.12-5.04) × 10-8. For one river sediment core sample, 134Cs and 236U activities decreased with the depth indicating 134Cs and 236U accumulated in the river sediment with time. Unlike 134Cs, no clear evidence of FDNPP accident-derived 236U has been found in this study, although further monitoring is encouraged to establish the background database on 236U/238U for its potential application as a tracer in environmental studies.
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Affiliation(s)
- Guosheng Yang
- Institute of Radiation Emergency Medicine, Hirosaki University, 66-1 Hon-cho, Hirosaki, Aomori, 036-8564, Japan
| | - M Safiur Rahman
- Institute of Radiation Emergency Medicine, Hirosaki University, 66-1 Hon-cho, Hirosaki, Aomori, 036-8564, Japan; Atmospheric & Environmental Chemistry Lab, Chemistry Division, Atomic Energy Centre, Dhaka, 1000, Bangladesh
| | - Hirofumi Tazoe
- Institute of Radiation Emergency Medicine, Hirosaki University, 66-1 Hon-cho, Hirosaki, Aomori, 036-8564, Japan
| | - Jun Hu
- Institute of Radiation Emergency Medicine, Hirosaki University, 66-1 Hon-cho, Hirosaki, Aomori, 036-8564, Japan
| | - Yang Shao
- Institute of Radiation Emergency Medicine, Hirosaki University, 66-1 Hon-cho, Hirosaki, Aomori, 036-8564, Japan; Beijing Engineering Research Center of Radiographic Techniques and Equipment, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049, China; School of Nuclear Science and Technology, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Masatoshi Yamada
- Institute of Radiation Emergency Medicine, Hirosaki University, 66-1 Hon-cho, Hirosaki, Aomori, 036-8564, Japan.
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Shao Y, Yang G, Xu D, Yamada M, Tazoe H, Luo M, Cheng H, Yang K, Ma L. First report on global fallout 236U and uranium atom ratios in soils from Hunan Province, China. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2019; 197:1-8. [PMID: 30463028 DOI: 10.1016/j.jenvrad.2018.11.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Revised: 11/13/2018] [Accepted: 11/13/2018] [Indexed: 06/09/2023]
Abstract
More nuclear power plants continue to be built in China. Due to its long half-life, radiotoxicity and potential application as an environmental tracer, 236U is one of the most important artificial radionuclides deserving more study since activity data are important for risk assessment. However, the ultra-trace activity of 236U and its dilution by natural uranium isotopes make it difficult to distinguish its sources and there are only limited global fallout 236U data for present in Chinese environmental samples. In order to understand the background levels for uranium isotopes, especially 236U, and clarify their sources, inductively coupled plasma tandem mass spectrometry (ICP-MS/MS) was applied to analyze uranium isotopes in 48 soil samples from Hunan Province, China. The 234U, 235U, 238U and 236U concentrations were measured as 9.91-33.7, 0.312-1.43, 6.63-28.7 Bq kg-1 and (1.61-21.3) × 107 atoms g-1, while, the 236U/238U, 234U/238U and 235U/238U atom ratios were (0.470-4.91) × 10-8, (5.10-9.31) × 10-5, and (7.11-7.82) × 10-3, respectively. The uranium isotopic fractionation may be due to irrigation of the agricultural lands where the samples were collected. Considering the facts that neither previous nuclear tests nor nuclear accidents had occurred in Hunan Province and the present 236U/238U atom ratios were included in the range of global fallout values in other areas, it may be concluded that 236U in soils from Hunan Province is mainly from global fallout. To the best of the authors' knowledge, the presence of global fallout 236U in soil samples from China has been confirmed for the first time, and these values may be useful as background data for risk assessment in the future.
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Affiliation(s)
- Yang Shao
- Beijing Engineering Research Center of Radiographic Techniques and Equipment, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049, China; Department of Radiation Chemistry, Institute of Radiation Emergency Medicine, Hirosaki University, 66-1 Hon-cho, Hirosaki, Aomori, 036-8564, Japan; School of Nuclear Science and Technology, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Guosheng Yang
- Department of Radiation Chemistry, Institute of Radiation Emergency Medicine, Hirosaki University, 66-1 Hon-cho, Hirosaki, Aomori, 036-8564, Japan
| | - Diandou Xu
- Beijing Engineering Research Center of Radiographic Techniques and Equipment, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049, China
| | - Masatoshi Yamada
- Department of Radiation Chemistry, Institute of Radiation Emergency Medicine, Hirosaki University, 66-1 Hon-cho, Hirosaki, Aomori, 036-8564, Japan.
| | - Hirofumi Tazoe
- Department of Radiation Chemistry, Institute of Radiation Emergency Medicine, Hirosaki University, 66-1 Hon-cho, Hirosaki, Aomori, 036-8564, Japan
| | - Min Luo
- Beijing Engineering Research Center of Radiographic Techniques and Equipment, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049, China
| | - Hangxin Cheng
- Key Laboratory of Geochemical Cycling of Carbon and Mercury in the Earth's Critical Zone, Institute of Geophysical and Geochemical Exploration, Chinese Academy of Geological Science, Langfang, 065000, China
| | - Ke Yang
- Key Laboratory of Geochemical Cycling of Carbon and Mercury in the Earth's Critical Zone, Institute of Geophysical and Geochemical Exploration, Chinese Academy of Geological Science, Langfang, 065000, China
| | - Lingling Ma
- Beijing Engineering Research Center of Radiographic Techniques and Equipment, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049, China.
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