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Brown J, Teien HC, Thørring H, Skipperud L, Hosseini A, Lind OC, Oughton D, Salbu B. Transfer of radionuclides through ecological systems: Lessons learned from 10 years of research within CERAD CoE. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 940:173503. [PMID: 38821276 DOI: 10.1016/j.scitotenv.2024.173503] [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: 10/24/2023] [Revised: 04/30/2024] [Accepted: 05/23/2024] [Indexed: 06/02/2024]
Abstract
Norway's Centre of Excellence for Environmental Radioactivity (CERAD) research programme included studies on transfer of radionuclides in various ecosystems within the context of environmental risk assessment. This article provides highlights from 10 years of research within this topic and summarises lessons learnt from the process. The scope has been extensive, involving laboratory-based experiments, field studies and the implementation of transfer models quantifying radionuclide uptake directly from the surrounding environment and via food chains. Field studies have had a global span and have, inter alia, covered sites contaminated with radionuclides associated with particles, ranging from nanoparticles to fragments, due to nuclear accidents (e.g., Chornobyl and Fukushima accidents) along with sites having enhanced levels of naturally occurring radioactive materials (e.g., Fen Complex in Norway and Taboshar in Tajikistan). Focus has been put on speciation and kinetics in determining radionuclide behavior and fate as well as on the influence of environmental factors that are potentially critical for the transfer of radionuclides. In particular, seasonal factors have been shown to greatly affect the dynamics of 137Cs and 90Sr bioaccumulation and loss in freshwater fish. The work has led to the collation of organism-specific (i) parameters important for kinetic models, i.e., uptake and depuration rates, and (ii) steady-state concentration ratios, CRs, where the use of stable analogue CRs as proxies for radionuclides has been brought into question. Dynamic models have been developed and applied for radiocaesium transfer to reindeer, radionuclide transfer in Arctic marine systems, transfer to fish via water and feed and commonly used agricultural food-chain transfer models applied in the context of nuclear emergency preparedness. The CERAD programme should contribute substantially to the scientific community's understanding of radionuclide transfer in environmental systems.
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Affiliation(s)
- Justin Brown
- DSA - Norwegian Radiation and Nuclear Safety Authority, Grini Næringspark 13, 1361 Østerås, Norway; Center for Environmental Radioactivity (CERAD) CoE, Norwegian University of Life Sciences, P.O. Box 5003, N-1432 Ås, Norway.
| | - Hans Christian Teien
- Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, P.O. Box 5003, N-1432 Ås, Norway; Center for Environmental Radioactivity (CERAD) CoE, Norwegian University of Life Sciences, P.O. Box 5003, N-1432 Ås, Norway
| | - Håvard Thørring
- DSA - Norwegian Radiation and Nuclear Safety Authority, Grini Næringspark 13, 1361 Østerås, Norway; Center for Environmental Radioactivity (CERAD) CoE, Norwegian University of Life Sciences, P.O. Box 5003, N-1432 Ås, Norway
| | - Lindis Skipperud
- Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, P.O. Box 5003, N-1432 Ås, Norway; Center for Environmental Radioactivity (CERAD) CoE, Norwegian University of Life Sciences, P.O. Box 5003, N-1432 Ås, Norway
| | - Ali Hosseini
- DSA - Norwegian Radiation and Nuclear Safety Authority, Grini Næringspark 13, 1361 Østerås, Norway; Center for Environmental Radioactivity (CERAD) CoE, Norwegian University of Life Sciences, P.O. Box 5003, N-1432 Ås, Norway
| | - Ole Christian Lind
- Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, P.O. Box 5003, N-1432 Ås, Norway; Center for Environmental Radioactivity (CERAD) CoE, Norwegian University of Life Sciences, P.O. Box 5003, N-1432 Ås, Norway
| | - Deborah Oughton
- Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, P.O. Box 5003, N-1432 Ås, Norway; Center for Environmental Radioactivity (CERAD) CoE, Norwegian University of Life Sciences, P.O. Box 5003, N-1432 Ås, Norway
| | - Brit Salbu
- Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, P.O. Box 5003, N-1432 Ås, Norway; Center for Environmental Radioactivity (CERAD) CoE, Norwegian University of Life Sciences, P.O. Box 5003, N-1432 Ås, Norway
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Hirose K. Review of the sources and behaviors of plutonium isotopes in the atmosphere and ocean. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2024; 277:107466. [PMID: 38838510 DOI: 10.1016/j.jenvrad.2024.107466] [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: 12/19/2023] [Revised: 05/27/2024] [Accepted: 05/28/2024] [Indexed: 06/07/2024]
Abstract
Plutonium, as well as fission products such as 137Cs, had been released into the earth environment in 1945 after the first atmospheric nuclear explosion of plutonium bomb in the desert of New Mexico (USA, July 16) and later over Nagasaki (August 9), followed then by many other explosions. Thus, plutonium cycling in the atmosphere and ocean has become a major public concern as a result of the radiological and chemical toxicity of plutonium. However, plutonium isotopes and 137Cs are important transient tracers of biogeochemical and physical processes in the environment, respectively. In this review, we show that both physical and chemical approaches are needed to comprehensively understand the behaviors of plutonium in the atmosphere and ocean. In the atmosphere, plutonium and 137Cs attach with aerosols; thus, plutonium moves according to physical and chemical processes in connection with aerosols; however, since plutonium is a chemically reactive element, its behavior in an aqueous environment is more complicated, because biogeochemical regulatory factors, in addition to geophysical regulatory factors, must be considered. Meanwhile, 137Cs is chemically inert in aqueous environments. Therefore, the biogeochemical characteristics of plutonium can be elucidated through a comparison with those of 137Cs, which show conservative properties and moves according to physical processes. Finally, we suggest that monitoring of both plutonium and 137Cs can help elucidate geophysical and biogeochemical changes from climate changes.
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Affiliation(s)
- Katsumi Hirose
- Laboratory for Environmental Research at Mount Fuji, Okubo Shinjyuku-ku, Tokyo, Japan.
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Hirose K, Onda Y, Tsukada H, Hiroyama Y, Okada Y, Kikawada Y. Chemical implication of the partition coefficient of 137Cs between the suspended and dissolved phases in natural water. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2024; 278:107486. [PMID: 38936250 DOI: 10.1016/j.jenvrad.2024.107486] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Revised: 06/17/2024] [Accepted: 06/17/2024] [Indexed: 06/29/2024]
Abstract
After the Fukushima Daiichi nuclear power plant accident, the terrestrial environment became severely contaminated with radiocesium. Consequently, the river and lake water in the Fukushima area exhibited high radiocesium levels, which declined subsequently. The partition coefficient of 137Cs between the suspended sediment (SS) and dissolved phases, Kd, was introduced to better understand the dynamic behavior of 137Cs in different systems. However, the Kd values in river water, ranging from 2 × 104 to 7 × 106 L kg-1, showed large spatiotemporal variability. Therefore, the factors controlling the 137Cs partition coefficient in natural water systems should be identified. Herein, we introduce a chemical model to explain the variability in 137Cs Kd in natural water systems. The chemical model includes the complexation of Cs+ with mineral and organic binding sites in SS, metal exchange reactions, and the presence of colloidal species. The application of the chemical model to natural water systems revealed that Cs+ is strongly associated with binding sites in SS, and a major chemical interaction between 137Cs and the binding sites in SS is the isotope exchange reaction between stable Cs and 137Cs, rather than metal exchange reactions with other metal ions such as potassium ions. To explain the effect of the SS concentration on Kd, the presence of colloidal 137Cs passing through a filter is significant as the dominant dissolved species of 137Cs in river water. These results suggest that a better understanding of stable Cs dissolved in natural water is important for discerning the geochemical and ecological behaviors of 137Cs in natural water.
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Affiliation(s)
- Katsumi Hirose
- Laboratory for Environmental Research at Mount Fuji, Shujyuku-ku, Tokyo, 169-0072, Japan.
| | - Yuichi Onda
- Center for Research in Isotopes and Environmental Dynamics, University of Tsukuba, Tsukuba, Ibaraki, 305-0006, Japan
| | - Hirofumi Tsukada
- Institute of Environmental Radioactivity, Fukushima University, Fukushima-City, Fukushima, 960-1296, Japan
| | - Yuko Hiroyama
- Department of Materials and Life Sciences, Faculty of Science and Technology, Sophia University, Kioi-Cho, Chiyoda-ku, Tokyo, 102-8554, Japan
| | - Yukiko Okada
- Atomic Energy Laboratory, Tokyo City University, Ozenji 971, Asao-ku, Kawasaki, 215-0031, Japan
| | - Yoshikazu Kikawada
- Department of Materials and Life Sciences, Faculty of Science and Technology, Sophia University, Kioi-Cho, Chiyoda-ku, Tokyo, 102-8554, Japan
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Mawassy Z, Henner P, Avellan A, Rose J. Comprehensive framework for overcoming scientific challenges related to assessing radioactive ultra-fine (nano/micro) particles transfer at the atmosphere-leaf interface. JOURNAL OF HAZARDOUS MATERIALS 2024; 467:133346. [PMID: 38320349 DOI: 10.1016/j.jhazmat.2023.133346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2023] [Revised: 12/07/2023] [Accepted: 12/20/2023] [Indexed: 02/08/2024]
Abstract
Food products are prone into contamination after a nuclear emission of radionuclides. While the mechanisms of emission and deposition of ultrafine radioactive particles are well documented, the transfer of these species from the atmosphere into plants is poorly assessed. This is evident in the lack of quantification of particles distributed within plants, especially regarding particles physical-chemical criteria to plant of different properties. Such knowledge gaps raise the concern about the representativeness of risk assessment tools designed for the transfer evaluation of ionic/soluble species to be qualified for simulating insoluble species exposure and proposes a possible underestimation. This highlights the possible need for special particle codes development to be implemented in models for future emissions. In addition, the later tools utilize transfer factors aggregating relevant sub-processes, suggesting another weak point in their overall reliability. As researchers specialized in the nuclear safety and protection, we intend in this perspective, to develop a compressive analysis of the interaction of ultrafine particles with plants of different specificities at different level processes starting from particles retention and gradual translocation to sink organs. This analysis is leveraged in providing insights for possible improvements in the current modeling tools for better real-life scenarios representation.
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Affiliation(s)
- Zeinab Mawassy
- Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PSE-ENV/SPDR/LT2S, F-13115 Saint-Paul-lez-Durance, France.
| | - Pascale Henner
- Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PSE-ENV/SPDR/LT2S, F-13115 Saint-Paul-lez-Durance, France.
| | - Astrid Avellan
- Géosciences Environnement Toulouse - CNRS-CNES-IRD-Université Toulouse III Observatoire Midi-Pyrénées, 14 av. Edouard Belin, 31400 Toulouse, France
| | - Jerome Rose
- CNRS, Aix-Marseille Université (AMU), iRD, INRAE, OSU Pytheas, CEREGE UM34, BP 80, 13545 Aix-en-Provence, Cedex 4, France
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Zhuang S, Fang S, Xu Y, Goto D, Dong X. Wet scavenging of multi-mode 137Cs aerosols following the Fukushima accident: Size-resolved microphysics modeling with observed diameters. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 917:170287. [PMID: 38266728 DOI: 10.1016/j.scitotenv.2024.170287] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Revised: 12/27/2023] [Accepted: 01/17/2024] [Indexed: 01/26/2024]
Abstract
Wet scavenging was critical in the atmospheric transport of 137Cs aerosols following the Fukushima accident. The aerosol size diversity and related microphysical processes produce complex behaviors during wet scavenging. Such behaviors are difficult to investigate using traditional simplified size distributions, resulting in inaccurate modeling. This study establishes an improved size-resolved wet scavenging model that considers the activation process. Using this model, five monodisperse simulations with five representative observed diameters with realistic solubility setting are performed to investigate the spatiotemporal wet scavenging behaviors of 137Cs aerosols. One polydisperse simulation with an empirical size distribution is also validated against the observation. The results reveal that 137Cs aerosols with diameters of 0.6 and 2.0 μm are mainly subject to below-cloud scavenging, which makes a significant contribution to low-deposition areas (<300 kBq/m2). For 137Cs aerosols with diameters of 6.4, 15, and 30 μm, in-cloud scavenging dominates, and the resulting depositions make significant contributions in high-deposition areas. The polydisperse results satisfy the criteria for good performance and better agree with the size, and deposition observations than the five monodisperse simulations, whereas for the concentration, the results show a similar RANK2 with the best mono1 and mono2 cases and reach the satisfactory criteria. These findings reveal the complex behavior and wet scavenging process of multi-mode 137Cs aerosols, improving our understanding and modeling.
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Affiliation(s)
- Shuhan Zhuang
- Institute of Nuclear and New Energy Technology, Collaborative Innovation Centre of Advanced Nuclear Energy Technology, Key Laboratory of Advanced Reactor Engineering and Safety of Ministry of Education, Tsinghua University, Beijing 100084, China
| | - Sheng Fang
- Institute of Nuclear and New Energy Technology, Collaborative Innovation Centre of Advanced Nuclear Energy Technology, Key Laboratory of Advanced Reactor Engineering and Safety of Ministry of Education, Tsinghua University, Beijing 100084, China.
| | - Yuhan Xu
- Institute of Nuclear and New Energy Technology, Collaborative Innovation Centre of Advanced Nuclear Energy Technology, Key Laboratory of Advanced Reactor Engineering and Safety of Ministry of Education, Tsinghua University, Beijing 100084, China
| | - Daisuke Goto
- National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506, Japan
| | - Xinwen Dong
- Institute of Nuclear and New Energy Technology, Collaborative Innovation Centre of Advanced Nuclear Energy Technology, Key Laboratory of Advanced Reactor Engineering and Safety of Ministry of Education, Tsinghua University, Beijing 100084, China
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Laffolley H, Journeau C, Grambow B. Simulant molten core-concrete interaction experiments in view of understanding Fukushima Daiichi Nuclear Power Station Cs-bearing particles generation mechanism. Sci Rep 2024; 14:6611. [PMID: 38504092 DOI: 10.1038/s41598-024-56972-9] [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: 12/21/2023] [Accepted: 03/13/2024] [Indexed: 03/21/2024] Open
Abstract
The Fukushima Daiichi accident resulted in the release of a novel form of radioactive Cs contamination into the environment, called Cs-bearing microparticles (CsMP). CsMPs constitute a substantial portion of the radioactive pollution near the nuclear power station and traveled beyond several hundred kilometers. Extensive characterization of the CsMPs revealed an amorphous silica matrix, along with Cs and other minor or trace elements such as Fe and Zn. This study explores the unclear generation mechanism of CsMPs by conducting experimental molten core concrete interactions (MCCI) as a source of Si and analyzing the resultant aerosols. The findings demonstrate that MCCI is in capacity to produce spherical submicronic and micronic particles, primarily composed of amorphous silica and incorporating elements akin to CsMPs. A humid atmosphere is found to favour an even closer chemical composition. Examination of the internal structure of the synthesized particles unveils pores and numerous crystalline nanoinclusions possibly serving as nucleation sites for CsMP formation through the condensation of Si-rich vapors.
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Affiliation(s)
- Hugo Laffolley
- CEA, DES, IRESNE, DTN, Severe Accident Experimental Laboratory, Cadarache, 13108, St-Paul-lez-Durance, France
| | - Christophe Journeau
- CEA, DES, IRESNE, DTN, Severe Accident Experimental Laboratory, Cadarache, 13108, St-Paul-lez-Durance, France.
| | - Bernd Grambow
- SUBATECH (IMT Atlantique, CNRS-IN2P3, University of Nantes), 44307, Nantes, France
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Higaki S, Yoshida-Ohuchi H, Shinohara N. Radiocesium-bearing microparticles discovered on masks worn during indoor cleaning. Sci Rep 2023; 13:10008. [PMID: 37340042 DOI: 10.1038/s41598-023-37191-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Accepted: 06/17/2023] [Indexed: 06/22/2023] Open
Abstract
A decade has passed since the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident on March 11, 2011. However, radioactive particles have recently been detected in the indoor air of some residences near the FDNPP. Following the recommendations of previous research, we determined the presence of radiocesium-bearing microparticles (CsMPs) and measured the radioactivity of radiocesium that adhered on non-woven face masks worn by six persons during the indoor cleaning of 59 residences in Namie, Futaba, Okuma, and Tomioka towns in Fukushima Prefecture. Of the 284 masks worn in this study, significant 137Cs radioactivity was detected in 268, and 44 new CsMPs were discovered in 28. The results of this study also suggest the presence of highly concentrated soluble radiocesium particles or soluble radioactive cesium aerosols adhered to house dust. This implies that the CsMPs constituted a large proportion of radioactivity in the indoor air contamination for particles in the 1.0-2.5 µm size range due to the radioactive radiocesium particles. It is desirable to wear masks during cleaning to prevent inhalation of CsMPs.
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Affiliation(s)
- Shogo Higaki
- Isotope Science Center, The University of Tokyo, 2-11-16 Yayoi, Bunkyo-ku, Tokyo, 113-0032, Japan.
| | | | - Naohide Shinohara
- National Institute of Advanced Industrial Science and Technology, Tsukuba, Japan
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Laffolley H, Journeau C, Thilliez S, Grambow B. Thermodynamics of aerosols during a molten core-concrete interaction at Fukushima Daiichi Unit 2 estimated conditions. ANN NUCL ENERGY 2023. [DOI: 10.1016/j.anucene.2023.109770] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/27/2023]
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9
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Okumura T, Yamaguchi N, Kogure T. Dissolution behavior of radiocesium-bearing microparticles as a function of solution compositions. Sci Rep 2023; 13:4307. [PMID: 36922544 PMCID: PMC10017807 DOI: 10.1038/s41598-023-31519-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Accepted: 03/13/2023] [Indexed: 03/17/2023] Open
Abstract
More than a decade has passed since the Fukushima nuclear accident in 2011 and contamination around the nuclear power plant is primarily caused by 137Cs. One of the materials retaining radiocesium in the environment is radiocesium-bearing silicate glass microparticles (CsMPs), which have not been reported in previous nuclear accidents. Although the prediction of environmental fates of CsMPs is of interest because of their extremely high specific radioactivity, knowledge about their physicochemical properties is still limited. Here we show that the dissolution behavior of CsMPs is comparable to that of silica-rich glass and significantly depends on the surrounding environment. CsMP dissolution experiments were conducted in solutions with various solute components and pH levels at 60 °C. In neutral and basic solutions, the estimated dissolution rate was accelerated by alkali ions such as Na+, which is known to play a catalytic role for the dissolution of silica. In contrast, the dissolution in acid was slow even in the presence of alkali ions. The dissolution under acid conditions was possibly retarded by a thin amorphous silica layer formed on the CsMP surfaces. Such characteristics of the dissolution are consistent with that of silica-rich glass. To infer the dissolution behavior of CsMPs in the human body, the dissolution rate in Ringer's solution at 37 °C was estimated as 1.00 ± 0.37 μm/year.
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Affiliation(s)
- Taiga Okumura
- Department of Earth and Planetary Science, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-Ku, Tokyo, 113-0033, Japan.
| | - Noriko Yamaguchi
- Institute for Agro-Environmental Sciences, NARO, 3-1-3 Kannondai, Tsukuba, Ibaraki, 305-8604, Japan
| | - Toshihiro Kogure
- Department of Earth and Planetary Science, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-Ku, Tokyo, 113-0033, Japan
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Hidaka A. Origin of Cs-bearing silicate glass microparticles observed during Fukushima accident and recommendations on nuclear safety. J Radioanal Nucl Chem 2023. [DOI: 10.1007/s10967-023-08846-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/28/2023]
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Carno LAS, Turner JJ, Martin PG. Modelling 'Type B' ejecta formation reveals reactor Unit 1 conditions during the Fukushima Daiichi Nuclear Disaster. Sci Rep 2023; 13:3686. [PMID: 36878970 PMCID: PMC9988873 DOI: 10.1038/s41598-023-30903-6] [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: 01/13/2022] [Accepted: 03/03/2023] [Indexed: 03/08/2023] Open
Abstract
For the first time, a model was developed to simulate the cooling of the Fukushima Daiichi Nuclear Power Plant reactor Unit 1-derived, 'Type B' radiocaesium bearing microparticles, distributed into the environment during the 2011 nuclear meltdown. By establishing an analogy between 'Type B' CsMP and volcanic pyroclasts, the presented model simulates the rapid cooling of an effervescent silicate melt fragment upon atmospheric release. The model successfully reproduced the bi-modal distribution of internal void diameters observed in 'Type B' CsMP, however, discrepancies resulted primarily due to the neglection of surface tension and internal void coalescence. The model was subsequently utilised to estimate the temperature within reactor Unit 1 in the instant preceding the hydrogen explosion-between 1900 and 1980 K. Such a model demonstrates the accuracy of the volcanic pyroclast-'Type B' CsMP analogue, and confirms radial variations in cooling rate as the cause of the vesicular texture of Unit 1 ejecta. The presented findings provide scope to further explore the comparison between volcanic pyroclasts and 'Type B' CsMP via experimentation, which will provide a deeper understanding of the specific conditions within reactor Unit 1 during the catastrophic meltdown at the Japanese coastal plant.
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Affiliation(s)
- Lior A S Carno
- HH Wills Physics Laboratory, School of Physics, University of Bristol, Tyndall Avenue, Bristol, BS8 1TL, UK
| | - Jack J Turner
- HH Wills Physics Laboratory, School of Physics, University of Bristol, Tyndall Avenue, Bristol, BS8 1TL, UK
| | - Peter G Martin
- HH Wills Physics Laboratory, Interface Analysis Centre, School of Physics, University of Bristol, Tyndall Avenue, Bristol, BS8 1TL, UK.
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Tatsuno T, Waki H, Kakuma M, Nihei N, Takase T, Wada T, Yoshimura K, Nakanishi T, Ohte N. Effect of radioactive cesium-rich microparticles on radioactive cesium concentration and distribution coefficient in rivers flowing through the watersheds with different contaminated condition in Fukushima. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2023; 329:116983. [PMID: 36565500 DOI: 10.1016/j.jenvman.2022.116983] [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: 10/02/2022] [Revised: 12/03/2022] [Accepted: 12/04/2022] [Indexed: 06/17/2023]
Abstract
Radioactive cesium-rich microparticles (CsMPs) derived from the Fukushima Daiichi Nnuclear Power Plant accident were detected from soils and river water around Fukushima Prefecture, Japan. Because CsMPs are insoluble and rich in radioactive cesium (RCs), they may cause the overestimation of solid-water distribution coefficient (Kd) for RCs in the water. Previous studies showed the proportion of RCs derived from CsMPs on RCs concentration in soils collected from areas with different contaminated levels. Because the proportion of RCs concentration derived CsMPs to the RCs concentration of soils in the less contaminated areas is higher than that in the highly contaminated areas, the effect of CsMPs on particulate RCs concentration in river water may be larger in the less contaminated areas. However, the difference in the effects of CsMPs on the particulate RCs concentration and Kd in river water flowing through watersheds with different contaminated levels has not been clarified. In this study, we investigated the effect of CsMPs on the particulate RCs concentration and Kd in two rivers, Takase River and Kami-Oguni River, flowing through the watersheds with different RCs contaminated levels in Fukushima Prefecture. CsMPs might enter rivers due to soil erosion because they were detected only in some samples collected from both rivers during flood events. CsMPs accounted for more than half of particulate RCs concentration in some water samples collected in the flood condition. In particular, the proportion of CsMPs in particulate RCs for the Kami-Oguni River was greater than that for the Takase River. However, when evaluating for the entire water sampling in the flood condition, a proportion of RCs concentration derived from CsMPs in the average RCs concentrations per unit mass of SS in both river waters collected in the flood condition was not large. CsMPs might temporarily increase the particulate RCs concentration and Kd in the flood event, but CsMPs did not significantly affect them when evaluated throughout the event.
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Affiliation(s)
- Takahiro Tatsuno
- Institute of Environment Radioactivity, Fukushima University, 1 Kanayagawa, Fukushima, 960-1296, Japan.
| | - Hiromichi Waki
- Graduate School of Informatics, Kyoto University, Yoshida Hommachi, Sakyo-ku, Kyoto, 606-8501, Japan.
| | - Minato Kakuma
- Graduate School of Informatics, Kyoto University, Yoshida Hommachi, Sakyo-ku, Kyoto, 606-8501, Japan.
| | - Naoto Nihei
- Faculty of Food and Agricultural Science, Fukushima University, 1 Kanayagawa, Fukushima, 960-1296, Japan.
| | - Tsugiko Takase
- Graduate School of Symbiotic Systems Science and Technology, Fukushima University, 1 Kanayagawa, Fukushima, 960-1248, Japan.
| | - Toshihiro Wada
- Institute of Environment Radioactivity, Fukushima University, 1 Kanayagawa, Fukushima, 960-1296, Japan.
| | - Kazuya Yoshimura
- Sector of Fukushima Research and Development, Japan Atomic Energy Agency, 45-169 Sukakeba, Kaibama, Haramachi-ku, Minamisoma City, Fukushima, 975-0036, Japan.
| | - Takahiro Nakanishi
- Sector of Fukushima Research and Development, Japan Atomic Energy Agency, 45-169 Sukakeba, Kaibama, Haramachi-ku, Minamisoma City, Fukushima, 975-0036, Japan; Nuclear Science Research Institute, Japan Atomic Energy Agency, 2-4 Shirakata,Tokai-mura,Naka-gun, Ibaraki, 319-1195, Japan.
| | - Nobuhito Ohte
- Graduate School of Informatics, Kyoto University, Yoshida Hommachi, Sakyo-ku, Kyoto, 606-8501, Japan.
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Identification, isolation, and characterization of a novel type of Fukushima-derived microparticle. J Radioanal Nucl Chem 2022. [DOI: 10.1007/s10967-022-08561-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
AbstractIn the course of the Fukushima nuclear accident, radionuclides were released in various forms, including so-called radiocesium-bearing microparticles (CsMP). So far, four types of CsMP were described: Type A is smaller in size (< 10 μm), Types B, C, and D are larger (> 100 μm). In this work, we present a novel type of CsMP (proclaimed Type E). Three particles of Type E were extracted from a contaminated blade of grass that was sampled 1.5 km from the Fukushima Daiichi nuclear power plant in late 2011. They were located using autoradiography, isolated using an optical microscope and micromanipulator, and characterized using scanning electron microscopy, energy dispersive x-ray spectroscopy, and low-level gamma-ray spectrometry. Type E CsMPs are 10–20 μm in size and exhibit an unusually low and barely detectable 137Cs activity of only ≤ 10 mBq per particle. Their brittle and fragile character may indicate a high surface tension.
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Ikenoue T, Yamada M, Ishii N, Kudo N, Shirotani Y, Ishida Y, Kusakabe M. Cesium-137 and 137Cs/ 133Cs atom ratios in marine zooplankton off the east coast of Japan during 2012-2020 following the Fukushima Dai-ichi nuclear power plant accident. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2022; 311:119962. [PMID: 35981638 DOI: 10.1016/j.envpol.2022.119962] [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: 05/27/2022] [Revised: 07/27/2022] [Accepted: 08/09/2022] [Indexed: 06/15/2023]
Abstract
We measured the concentrations of cesium isotopes (133Cs, 134Cs, and 137Cs) in zooplankton samples collected in waters off the east coast of Japan from May 2015 to June 2020. By combining these data with those obtained previously from May 2012 to February 2015, we evaluated the long-term impacts of the Fukushima Dai-ichi Nuclear Power Plant accident on marine zooplankton. Relatively high 137Cs concentrations in zooplankton, exceeding 10 Bq/kg-dry weight, were sporadically observed until June 2016, regardless of year or station. After May-June 2017, 137Cs concentrations decreased to below 1 Bq/kg-dry at most stations, and by May 2020, concentrations were below 0.5 Bq/kg-dry except those off Fukushima Prefecture. Since the accident, the 137Cs/133Cs atom ratios of zooplankton samples were higher than those of ambient seawater until 2019, but in May-June 2020 the ratios matched those of seawater except off Fukushima Prefecture. Highly radioactive particles were not detected in zooplankton samples by autoradiography using imaging plates after May-June 2017, although they were before. Therefore, the persistence of elevated 137Cs/133Cs ratios in zooplankton relative to seawater for nine years after the accident was probably due to the incorporation of highly radioactive particles (cesium-bearing particles or clay-mineral aggregates with highly adsorbed radiocesium) onto/into zooplankton for several years after the accident. However, since at least May-June 2017, these elevated ratios have likely been caused by small highly radioactive particles (or larger particles disaggregated into small pieces) entering the ocean from land via rivers or directly discharged from the Fukushima Nuclear Power Plant. Microplastics enriched with radiocesium with higher 137Cs/133Cs ratios than seawater may have also contributed 137Cs to the zooplankton.
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Affiliation(s)
- Takahito Ikenoue
- Head Office, Marine Ecology Research Institute, 7F Towa-Edogawabashi Building, 347 Yamabuki-cho, Shinjuku, Tokyo, 162-0801, Japan.
| | - Masatoshi Yamada
- Central Laboratory, Marine Ecology Research Institute, 300 Iwawada, Onjuku-machi, Isumi-gun, Chiba, 299-5105, Japan
| | - Nobuyoshi Ishii
- Biospheric Assessment for Waste Disposal Team & Fukushima Project Headquarters, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Anagawa 4-9-1, Inage, Chiba, 263-8555, Japan
| | - Natsumi Kudo
- Central Laboratory, Marine Ecology Research Institute, 300 Iwawada, Onjuku-machi, Isumi-gun, Chiba, 299-5105, Japan
| | - Yuhei Shirotani
- Central Laboratory, Marine Ecology Research Institute, 300 Iwawada, Onjuku-machi, Isumi-gun, Chiba, 299-5105, Japan
| | - Yasuo Ishida
- Central Laboratory, Marine Ecology Research Institute, 300 Iwawada, Onjuku-machi, Isumi-gun, Chiba, 299-5105, Japan
| | - Masashi Kusakabe
- Central Laboratory, Marine Ecology Research Institute, 300 Iwawada, Onjuku-machi, Isumi-gun, Chiba, 299-5105, Japan
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15
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Hirose K, Povinec PP. Ten years of investigations of Fukushima radionuclides in the environment: A review on process studies in environmental compartments. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2022; 251-252:106929. [PMID: 35717792 DOI: 10.1016/j.jenvrad.2022.106929] [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: 03/16/2022] [Revised: 05/15/2022] [Accepted: 05/27/2022] [Indexed: 06/15/2023]
Abstract
In March 2011, severe nuclear accident happened at the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) after the gigantic earthquake and following huge tsunami wave. A lot of investigations to assess environmental and radiological impacts of released radionuclides have been conducted by domestic and international organizations. Environmental radioactivity research related to the FDNPP accident has spread widely over different scientific fields due to specific features of the accident, and specifically its impact on the marine environment. The present paper summarizes major lessons learned from the environmental investigations of the FDNPP accident. Environmental radioactivity studies have typical interdisciplinary character; especially physics and chemistry are fundamental as a base of process studies in the environment. In this sight, we review chemical aspects regarding FDNPP-derived radiocesium transfer within and between compartments (atmosphere, ocean and land). We also discuss future trends in investigations of behavior of anthropogenic radionuclides in the environment, important not only for a better understanding of impacts of the FDNPP accident on the environment, but also for improving our general knowledge of the total environment in the Anthropocene era and its protection for the future.
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Affiliation(s)
- Katsumi Hirose
- Laboratory for Environmental Research at Mount Fuji, Okubo, Shinjyuku, Tokyo, Japan.
| | - Pavel P Povinec
- Comenius University, Department of Nuclear Physics and Biophysics, Bratislava, Slovakia.
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16
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Laffolley H, Journeau C, Delacroix J, Grambow B, Suteau C. Synthesis of Fukushima Daiichi Cs-bearing microparticles through molten core-concrete interaction in nitrogen atmosphere. NUCLEAR MATERIALS AND ENERGY 2022. [DOI: 10.1016/j.nme.2022.101253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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17
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Konoplev A. Fukushima and Chernobyl: Similarities and Differences of Radiocesium Behavior in the Soil-Water Environment. TOXICS 2022; 10:toxics10100578. [PMID: 36287858 PMCID: PMC9608664 DOI: 10.3390/toxics10100578] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Revised: 08/30/2022] [Accepted: 09/24/2022] [Indexed: 05/29/2023]
Abstract
In the wake of Chernobyl and Fukushima accidents, radiocesium has become a radionuclide of most environmental concern. The ease with which this radionuclide moves through the environment and is taken up by plants and animals is governed by its chemical forms and site-specific environmental characteristics. Distinctions in climate and geomorphology, as well as 137Cs speciation in the fallout, result in differences in the migration rates of 137Cs in the environment and rates of its natural attenuation. In Fukushima areas, 137Cs was strongly bound to soil and sediment particles, with its bioavailability being reduced as a result. Up to 80% of the deposited 137Cs on the soil was reported to be incorporated in hot glassy particles (CsMPs) insoluble in water. Disintegration of these particles in the environment is much slower than that of Chernobyl-derived fuel particles. The higher annual precipitation and steep slopes in Fukushima-contaminated areas are conducive to higher erosion and higher total radiocesium wash-off. Among the common features in the 137Cs behavior in Chernobyl and Fukushima are a slow decrease in the 137Cs activity concentration in small, closed, and semi-closed lakes and its particular seasonal variations: increase in the summer and decrease in the winter.
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Affiliation(s)
- Alexei Konoplev
- Institute of Environmental Radioactivity, Fukushima University, 1 Kanayagawa, Fukushima 960-1296, Japan
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18
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Natural glass alteration under a hyperalkaline condition for about 4000 years. Sci Rep 2022; 12:16012. [PMID: 36163412 PMCID: PMC9512812 DOI: 10.1038/s41598-022-20482-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Accepted: 09/13/2022] [Indexed: 11/30/2022] Open
Abstract
Silicate glasses are durable materials in our daily life, but corrosion rate accelerates under alkaline aqueous environment. Such situation has raised concerns, for example, in nuclear waste disposal where vitrified wastes encounter to alkaline leachate from surrounding concrete materials. Here we report volcanic glass example surviving with a hyperalkaline groundwater (pH > 11) and high flow rate for about 4000 years. The tiny glass fragments were extracted from the volcanic ash layer sandwiched between ultramafic sediments using microanalytical techniques. Sharp elemental distributions at the glass surface, where amorphous-like smectite precursors and crystalline smectites coexist, suggest the corrosion by an interface-coupled dissolution–precipitation mechanism rather than inter-diffusion. The corrosion rate was maintained at, the minimum, 2.5 orders of magnitude less than the rate observed for fresh glass, even in the presence of Fe and Mg that might have consumed Si through the silicate precipitation.
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Tatsuno T, Waki H, Kakuma M, Nihei N, Wada T, Yoshimura K, Nakanishi T, Ohte N. CESIUM-RICH MICROPARTICLES RUNOFF DURING RAINFALL: A CASE STUDY IN THE TAKASE RIVER. RADIATION PROTECTION DOSIMETRY 2022; 198:1052-1057. [PMID: 36083755 DOI: 10.1093/rpd/ncac052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 03/22/2022] [Accepted: 03/23/2022] [Indexed: 06/15/2023]
Abstract
Cesium-rich microparticles (CsMPs) with high cesium-137 (137Cs) concentrations were released and deposited in surface soil after the Fukushima Daiichi Nuclear Power Plant accident. Radioactive materials on the soil surface layer enter rivers owing to soil erosion during rainfall. In this study, we investigated CsMPs runoff through the river via soil erosion during rainfall in the Takase River watershed in Namie Town, Fukushima Prefecture, Japan. CsMPs were rarely detected in suspended solids (SS) in water samples collected during four rainfalls between February and July 2021. Furthermore, the proportion of 137Cs concentration derived from CsMPs to 137Cs concentration in the form of SS (particulate 137Cs) in the water was ~6% on average, which suggests that 137Cs runoff in the form of CsMPs from the forest to the Takase River was not large.
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Affiliation(s)
- Takahiro Tatsuno
- Institute of Environmental Radioactivity, Fukushima University, 1 Kanayagawa, Fukushima, 960-1296, Japan
| | - Hiromichi Waki
- Graduate School of Informatics, Kyoto University, Yoshida Hommachi, Sakyo-ku, Kyoto, 606-8501, Japan
| | - Minato Kakuma
- Graduate School of Informatics, Kyoto University, Yoshida Hommachi, Sakyo-ku, Kyoto, 606-8501, Japan
| | - Naoto Nihei
- Faculty of Food and Agricultural Science, Fukushima University, 1 Kanayagawa, Fukushima, 960-1296, Japan
| | - Toshihiro Wada
- Institute of Environmental Radioactivity, Fukushima University, 1 Kanayagawa, Fukushima, 960-1296, Japan
| | - Kazuya Yoshimura
- Japan Atomic Energy Agency, 45-169 Kaihama-Sukakeba, Haramachi, Minamisoma, Fukushima, 975-0036, Japan
| | - Takahiro Nakanishi
- Japan Atomic Energy Agency, 45-169 Kaihama-Sukakeba, Haramachi, Minamisoma, Fukushima, 975-0036, Japan
| | - Nobuhito Ohte
- Graduate School of Informatics, Kyoto University, Yoshida Hommachi, Sakyo-ku, Kyoto, 606-8501, Japan
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Rizaal M, Nakajima K, Saito T, Osaka M, Okamoto K. High-Temperature Gaseous Reaction of Cesium with Siliceous Thermal Insulation: The Potential Implication to the Provenance of Enigmatic Fukushima Cesium-Bearing Material. ACS OMEGA 2022; 7:29326-29336. [PMID: 36033724 PMCID: PMC9404493 DOI: 10.1021/acsomega.2c03525] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Accepted: 07/22/2022] [Indexed: 06/15/2023]
Abstract
Here, we report an investigation of the gas-solid reaction between cesium hydroxide (CsOH) and siliceous (calcium silicate) thermal insulation at high temperature, which is postulated as the origin for the formation mechanism of cesium-bearing material emitted from the Fukushima Daiichi nuclear power plant. A developed reaction furnace consisting of two heating compartments was used to study the reaction at temperatures of 873, 973, and 1073 K. Under the influence of hydrogen-steam atmospheric conditions (H2/H2O = 0.2), the reaction between cesium hydroxide vapor and solid thermal insulation was confirmed to occur at temperatures of 973 and 1073 K with the formation of dicalcium silicate (Ca2SiO4) and cesium aluminum silicate (CsAlSiO4). Water-dissolution analyses of the reaction products have demonstrated their stability, in particular, CsAlSiO4. Constituent similarity of the field-observed cesium-bearing materials near the Fukushima Daiichi nuclear power plants with CsAlSiO4 suggests for the first time that gaseous reaction between CsOH with calcium silicate thermal insulation could be one of the original formation mechanisms of the cesium-bearing materials.
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Affiliation(s)
- Muhammad Rizaal
- Nuclear
Science and Engineering Center, Japan Atomic
Energy Agency, 2-4 Shirane, Shirakata, Tokai-mura, Naka-gun, Ibaraki 319-1195, Japan
| | - Kunihisa Nakajima
- Nuclear
Science and Engineering Center, Japan Atomic
Energy Agency, 2-4 Shirane, Shirakata, Tokai-mura, Naka-gun, Ibaraki 319-1195, Japan
| | - Takumi Saito
- Nuclear
Professional School, School of Engineering, The University of Tokyo, 2-22 Shirane, Shirakata, Tokai-mura, Naka-gun, Ibaraki 319-1188, Japan
| | - Masahiko Osaka
- Nuclear
Science and Engineering Center, Japan Atomic
Energy Agency, 2-4 Shirane, Shirakata, Tokai-mura, Naka-gun, Ibaraki 319-1195, Japan
| | - Koji Okamoto
- Nuclear
Professional School, School of Engineering, The University of Tokyo, 2-22 Shirane, Shirakata, Tokai-mura, Naka-gun, Ibaraki 319-1188, Japan
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21
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Dohi T, Iijima K, Machida M, Suno H, Ohmura Y, Fujiwara K, Kimura S, Kanno F. Accumulation mechanisms of radiocaesium within lichen thallus tissues determined by means of in situ microscale localisation observation. PLoS One 2022; 17:e0271035. [PMID: 35802691 PMCID: PMC9269901 DOI: 10.1371/journal.pone.0271035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Accepted: 06/22/2022] [Indexed: 11/19/2022] Open
Abstract
Many lichens are well known to accumulate radiocaesium and, thus acting as biomonitors of contamination levels. However, the actual localisation and chemical forms of radiocaesium in contaminated lichens have not yet been elucidated because, despite their high radioactivity, these forms are present in trace amounts as chemical entities. Here, we use autoradiography and demonstrate for the first time in situ microscale localisation of radiocaesium within thallus tissues to investigate the radiocaesium forms and their accumulation mechanism. Radiocaesium distributions showed similar trends in lichen tissues collected two and six years after the Fukushima nuclear accident. The radiocaesium was localised in the brown pigmented parts i.e., melanin-like substances, in the lower cortex of lichen thallus. Quantum chemical calculations showed that functional group of melanin-like substances can chelate Cs+ ion, which indicates that the Cs+ ions form complexes with the substances. Based on these findings, we suggest that radiocaesium ions may be retained stably in melanin-like substances for long periods (two to six years) due to steric factors, such as those seen in porphyrin-like structures and via multimer formation in the lower cortex. In addition, electron microscopy and autoradiography were used to observe radiocaesium-bearing microparticles (CsMPs) on/in the upper cortex and around the medullary layer. Micron-sized particles appeared to adhere to the surface tissue of the thallus, as shown by electron microscopy, suggesting that the particles were trapped by development of an adhesive layer; that is, CsMPs were trapped both physically and physiologically. These findings provide information on in situ localisation of two chemical forms of radiocaesium, cations and particles, in lichen thallus tissues and their accumulation mechanisms.
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Affiliation(s)
- Terumi Dohi
- Sector of Fukushima Research and Development, Japan Atomic Energy Agency, Miharu-town, Fukushima, Japan
- * E-mail:
| | - Kazuki Iijima
- Sector of Fukushima Research and Development, Japan Atomic Energy Agency, Miharu-town, Fukushima, Japan
| | - Masahiko Machida
- Center for Computational Science & e-Systems (CCSE), Japan Atomic Energy Agency, Kashiwa-city, Chiba, Japan
| | - Hiroya Suno
- Center for Computational Science & e-Systems (CCSE), Japan Atomic Energy Agency, Kashiwa-city, Chiba, Japan
| | - Yoshihito Ohmura
- Department of Botany, National Museum of Nature and Science, Tsukuba-city, Ibaraki, Japan
| | - Kenso Fujiwara
- Sector of Fukushima Research and Development, Japan Atomic Energy Agency, Miharu-town, Fukushima, Japan
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22
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Igarashi Y, Tagami K, Takamiya K, Shinohara A. A summary of environmental radioactivity research studies by members of the Japan Society of Nuclear and Radiochemical Sciences. RADIOCHIM ACTA 2022. [DOI: 10.1515/ract-2022-0019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
Many scientists who are members of the Japan Society of Nuclear and Radiochemical Sciences have been involved in academic activities in response to the Fukushima Daiichi Nuclear Power Plant accident. Projects had been implemented that include determining radionuclides in environmental samples, identifying the distribution of radionuclides by large-scale soil monitoring, tracing radionuclide discharge time series, clarifying environmental dynamics of radionuclides, etc. For the last 10 years, these results have been shared and discussed in annual workshops partly sponsored by the society. This review summarizes the studies yielding these results, and they include reconstruction of the 131I distribution on soil by long-lived 129I analysis, reconstruction of the radioactive plume transport, identification of biological resuspension sources, discovery and characterization of cesium particles, and parameterization of the environmental behavior of radiocesium for dose assessment.
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Affiliation(s)
- Yasuhito Igarashi
- Institute for Integrated Radiation and Nuclear Science , Kyoto University , Asashiro-Nishi-2 , Kumatori-cho, Sennan-gun , Osaka , 590-0494 , Japan
| | - Keiko Tagami
- National Institute of Quantum Science and Technology , Anagawa 4-9-1 , Inageku , Chiba 263-8555 , Japan
| | - Koichi Takamiya
- Institute for Integrated Radiation and Nuclear Science , Kyoto University , Asashiro-Nishi-2 , Kumatori-cho, Sennan-gun , Osaka , 590-0494 , Japan
| | - Atsushi Shinohara
- Institute for Radiation Sciences , Osaka University , 2-4 Yamadaoka , Suita , Osaka 565-0871 , Japan
- Faculty of Health Science , Osaka Aoyama University , 2-11-1 Niina , Minoh , Osaka 562-8580 , Japan
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23
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24
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Relationship of 137Cs with Fungal Spore Tracers in the Ambient Aerosols from Fukushima after the 2011 Nuclear Accident, East Japan. ATMOSPHERE 2022. [DOI: 10.3390/atmos13030413] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Even after 7 years of the nuclear accident that occurred in 2011 at the Fukushima Dai-ichi nuclear power plant (F1NPP), high levels of 137Cs have been detected in ambient aerosols from some polluted areas of Fukushima. Higher levels of radionuclides were often observed in the atmosphere during and after rain events. We presume that biological processes such as fungal activity associated with higher relative humidity may be involved with a possible emission of radioactivity to the atmosphere, which was originally emitted from the F1NPP accident and was deposited over the ground, forest, soil, etc. Here, we report, for the first time, relationships of 137Cs and organic tracers of fungal spores (i.e., arabitol, mannitol and trehalose) in the aerosol samples collected from Fukushima, Japan. Although we found twice-higher concentrations of 137Cs at nighttime than at daytime, fungal spore tracers did not show a consistent trend to 137Cs, that is, organic tracers at nighttime were similar with those at daytime or were even higher in daytime. This study has not clearly demonstrated that fungal spores are the important source of high levels of 137Cs at nighttime. The current unclear relationship is probably associated with the sampling strategy (four consecutive days with a sampling on/off program for day/nighttime samples) taken in this campaign, which may have caused a complicated meteorological situation.
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Anderson J, Lévesque N, Caron F, Beckett P, Spiers GA. A review on the use of lichens as a biomonitoring tool for environmental radioactivity. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2022; 243:106797. [PMID: 34968948 DOI: 10.1016/j.jenvrad.2021.106797] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Revised: 12/10/2021] [Accepted: 12/11/2021] [Indexed: 06/14/2023]
Abstract
Lichens have been widely used as a biomonitoring tool to record the distribution and concentration of airborne radioactivity and pollutants such as metals. There are limitations, however: although pollutants can be preserved in lichen tissues for long periods of time, not all radioactive and inert elements behave similarly. The chemical species of elements at the source, once captured, and the mode of storage within lichens play a role in this biomonitoring tool. Lichens are a symbiotic association of an algal or cyanobacterial partner (photobiont) with a fungal host (mycobiont). Lichens grow independently of the host substrates, including rocks, soils, trees and human-made structures. Lacking a root system, lichen nutrient or contaminant uptake is mostly through direct atmospheric inputs, mainly as wet and dry deposition. As lichens grow in a large variety of environments and are resilient in harsh climates, they are adapted to capture and retain nutrients from airborne sources. The context of this review partially relates to future deployment of small modular reactors (SMRs) and mining in remote areas of Canada. SMRs have been identified as a future source of energy (electricity and heat) for remote off-grid mines, potentially replacing diesel fuel generation facilities. For licensing purposes, SMR deployment and mine development requires capabilities to monitor background contaminants (natural radioactivity and metals) before, during and after deployment, including for decommissioning and removal. Key aspects reviewed herein include: (1) how lichens have been used in the past to monitor radioactivity; (2) radiocontaminants capture and storage in lichens; (3) longevity of radiocontaminant storage in lichen tissues; and (4) limitations of lichens use for monitoring radiocontaminants and selected metals.
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Affiliation(s)
- J Anderson
- Mirarco Mining Innovation and Laurentian University, 935 Ramsey Lake Rd., Sudbury, ON, P3E 2C6, Canada; Harquail School of Earth Sciences, Laurentian University, 935 Ramsey Lake Rd., Sudbury, ON, P3E 2C6, Canada
| | - N Lévesque
- Mirarco Mining Innovation and Laurentian University, 935 Ramsey Lake Rd., Sudbury, ON, P3E 2C6, Canada; School of Biological, Chemical & Forensic Sciences, Laurentian University, 935 Ramsey Lake Rd., Sudbury, ON, P3E 2C6, Canada
| | - F Caron
- Mirarco Mining Innovation and Laurentian University, 935 Ramsey Lake Rd., Sudbury, ON, P3E 2C6, Canada.
| | - P Beckett
- Vale Living with Lakes Centre, Laurentian University, 935 Ramsey Lake Rd., Sudbury, ON, P3E 2C6, Canada
| | - G A Spiers
- Harquail School of Earth Sciences, Laurentian University, 935 Ramsey Lake Rd., Sudbury, ON, P3E 2C6, Canada
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Shimada A, Taniguchi Y, Kakiuchi K, Ohira S, Iida Y, Sugiyama T, Amaya M, Maruyama Y. Radiochemical analysis of the drain water sampled at the exhaust stack shared by Units 1 and 2 of the Fukushima Daiichi Nuclear Power Station. Sci Rep 2022; 12:2086. [PMID: 35136098 PMCID: PMC8825831 DOI: 10.1038/s41598-022-05924-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Accepted: 01/14/2022] [Indexed: 11/18/2022] Open
Abstract
Radioactive gas of Unit 1 of the Fukushima Daiichi Nuclear Power Station was released from the exhaust stack shared by Units 1 and 2 through the venting line on March 12th, 2011. In the present study, radiochemical analysis of drain water sampled at the drain pit of the exhaust stack was conducted to study radionuclides released during venting of the Unit 1. Not only volatile 129I, 134Cs and 137Cs but also 60Co, 90Sr, 125Sb and Unit 1-originated stable Mo isotopes were detected. Although Unit 1-originated stable Mo isotopes were clearly detected, their amounts were quite low compared to Cs, suggesting that the formation of Cs2MoO4 was suppressed under the accident condition. Approximately 90% of iodine existed as I− and 10% as IO3− in November 2020. Furthermore, larger amount of 129I than 137Cs was observed, suggesting major chemical form of 131I was molecular iodine rather than CsI at the accident time. The 134Cs/137Cs radioactivity ratio decay-corrected to March 11th, 2011 was 0.86, supported the results that Unit 1 originated radiocesium in environment has smaller 134Cs/137Cs radioactivity ratio than Unit 2 and 3 originated radiocesium.
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Affiliation(s)
- Asako Shimada
- Nuclear Safety Research Center, Japan Atomic Energy Agency, 2-4 Shirakata, Tokai-mura, Naka-gun, Ibaraki, 319-1195, Japan.
| | - Yoshinori Taniguchi
- Nuclear Safety Research Center, Japan Atomic Energy Agency, 2-4 Shirakata, Tokai-mura, Naka-gun, Ibaraki, 319-1195, Japan
| | - Kazuo Kakiuchi
- Nuclear Safety Research Center, Japan Atomic Energy Agency, 2-4 Shirakata, Tokai-mura, Naka-gun, Ibaraki, 319-1195, Japan
| | - Saki Ohira
- Nuclear Safety Research Center, Japan Atomic Energy Agency, 2-4 Shirakata, Tokai-mura, Naka-gun, Ibaraki, 319-1195, Japan
| | - Yoshihisa Iida
- Nuclear Safety Research Center, Japan Atomic Energy Agency, 2-4 Shirakata, Tokai-mura, Naka-gun, Ibaraki, 319-1195, Japan
| | - Tomoyuki Sugiyama
- Nuclear Safety Research Center, Japan Atomic Energy Agency, 2-4 Shirakata, Tokai-mura, Naka-gun, Ibaraki, 319-1195, Japan
| | - Masaki Amaya
- Nuclear Safety Research Center, Japan Atomic Energy Agency, 2-4 Shirakata, Tokai-mura, Naka-gun, Ibaraki, 319-1195, Japan
| | - Yu Maruyama
- Nuclear Safety Research Center, Japan Atomic Energy Agency, 2-4 Shirakata, Tokai-mura, Naka-gun, Ibaraki, 319-1195, Japan
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27
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Hagiwara H, Funaki H, Shiribiki N, Kanno M, Sanada Y. Characterization of radiocesium-bearing microparticles with different morphologies in soil around the Fukushima Daiichi nuclear power plant. J Radioanal Nucl Chem 2022. [DOI: 10.1007/s10967-021-08061-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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28
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Osaka M, Gouëllo M, Nakajima K. Cesium Chemistry in the LWR severe accident and towards the decommissioning of Fukushima Daiichi Nuclear Power Station. J NUCL SCI TECHNOL 2021. [DOI: 10.1080/00223131.2021.1997664] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Masahiko Osaka
- Nuclear Science and Engineering Center, Japan Atomic Energy Agency, Ibaraki, Japan
| | - Mélany Gouëllo
- Severe Accident Analysis, VTT Technical Research Centre of Finland Ltd, Finland
| | - Kunihisa Nakajima
- Nuclear Science and Engineering Center, Japan Atomic Energy Agency, Ibaraki, Japan
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29
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Hidaka A. Identification of Carbon in Glassy Cesium-Bearing Microparticles Using Electron Microscopy and Formation Mechanisms of the Microparticles. NUCL TECHNOL 2021. [DOI: 10.1080/00295450.2021.1929767] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- Akihide Hidaka
- Japan Atomic Energy Agency, 2-4 Shirakata, Tokai-mura, Naka-gun, Ibaraki-ken 319-1195, Japan; and
- Khalifa University, P.O. Box 127788, Abu Dhabi, United Arab Emirates
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Miura H, Ishimaru T, Ito Y, Kurihara Y, Otosaka S, Sakaguchi A, Misumi K, Tsumune D, Kubo A, Higaki S, Kanda J, Takahashi Y. First isolation and analysis of caesium-bearing microparticles from marine samples in the Pacific coastal area near Fukushima Prefecture. Sci Rep 2021; 11:5664. [PMID: 33707572 PMCID: PMC7952385 DOI: 10.1038/s41598-021-85085-w] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Accepted: 02/19/2021] [Indexed: 11/22/2022] Open
Abstract
A part of the radiocaesium from the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident was emitted as glassy, water-resistant caesium-bearing microparticles (CsMPs). Here, we isolated and investigated seven CsMPs from marine particulate matter and sediment. From the elemental composition, the 134Cs/137Cs activity ratio, and the 137Cs activity per unit volume results, we inferred that the five CsMPs collected from particulate matter were emitted from Unit 2 of the FDNPP, whereas the two CsMPs collected from marine sediment were possibly emitted from Unit 3, as suggested by (i) the presence of calcium and absence of zinc and (ii) the direction of the atmospheric plume during the radionuclide emission event from Unit 3. The presence of CsMPs can cause overestimation of the solid-water distribution coefficient of Cs in marine sediments and particulate matter and a high apparent radiocaesium concentration factor for marine biota. CsMPs emitted from Unit 2, which were collected from the estuary of a river that flowed through a highly contaminated area, may have been deposited on land and then transported by the river. By contrast, CsMPs emitted from Unit 3 were possibly transported eastward by the wind and deposited directly onto the ocean surface.
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Affiliation(s)
- Hikaru Miura
- Atmospheric and Marine Environmental Sector, Environmental Science Research Laboratory, Central Research Institute of Electric Power Industry, 1646 Abiko, Abiko, Chiba, 270-1194, Japan.
| | - Takashi Ishimaru
- Department of Ocean Sciences, Graduate Faculty of Marine Science, Tokyo University of Marine Science and Technology, 4-5-7 Konan, Minato-ku, Tokyo, 108-8477, Japan
| | - Yukari Ito
- Department of Ocean Sciences, Graduate Faculty of Marine Science, Tokyo University of Marine Science and Technology, 4-5-7 Konan, Minato-ku, Tokyo, 108-8477, Japan
| | - Yuichi Kurihara
- Ningyo-Toge Environmental Engineering Centre, Japan Atomic Energy Agency, 1550 Kamisaibara, Kagamino-cho, Tomata-gun, Okayama, 708-0698, Japan
| | - Shigeyoshi Otosaka
- Atmosphere and Ocean Research Institute, The University of Tokyo, Kashiwanoha 5-1-5, Kashiwa, Chiba, 277-8564, Japan
| | - Aya Sakaguchi
- Centre for Research in Isotopes and Environmental Dynamics, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, 305-8577, Japan
| | - Kazuhiro Misumi
- Atmospheric and Marine Environmental Sector, Environmental Science Research Laboratory, Central Research Institute of Electric Power Industry, 1646 Abiko, Abiko, Chiba, 270-1194, Japan
| | - Daisuke Tsumune
- Atmospheric and Marine Environmental Sector, Environmental Science Research Laboratory, Central Research Institute of Electric Power Industry, 1646 Abiko, Abiko, Chiba, 270-1194, Japan
| | - Atsushi Kubo
- Department of Geosciences, Faculty of Science College of Science, Academic Institute, Shizuoka University, 836 Ohya, Suruga-ku, Shizuoka, 422-8529, Japan
| | - Shogo Higaki
- Isotope Science Centre, The University of Tokyo, 2-11-16 Yayoi, Bunkyo-ku, Tokyo, 113-0032, Japan
| | - Jota Kanda
- Department of Ocean Sciences, Graduate Faculty of Marine Science, Tokyo University of Marine Science and Technology, 4-5-7 Konan, Minato-ku, Tokyo, 108-8477, Japan
| | - Yoshio Takahashi
- Department of Earth and Planetary Science, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
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31
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Kusumkar VV, Galamboš M, Viglašová E, Daňo M, Šmelková J. Ion-Imprinted Polymers: Synthesis, Characterization, and Adsorption of Radionuclides. MATERIALS (BASEL, SWITZERLAND) 2021; 14:1083. [PMID: 33652580 PMCID: PMC7956459 DOI: 10.3390/ma14051083] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Revised: 02/09/2021] [Accepted: 02/22/2021] [Indexed: 12/21/2022]
Abstract
Growing concern over the hazardous effect of radionuclides on the environment is driving research on mitigation and deposition strategies for radioactive waste management. Currently, there are many techniques used for radionuclides separation from the environment such as ion exchange, solvent extraction, chemical precipitation and adsorption. Adsorbents are the leading area of research and many useful materials are being discovered in this category of radionuclide ion separation. The adsorption technologies lack the ability of selective removal of metal ions from solution. This drawback is eliminated by the use of ion-imprinted polymers, these materials having targeted binding sites for specific ions in the media. In this review article, we present recently published literature about the use of ion-imprinted polymers for the adsorption of 10 important hazardous radionuclides-U, Th, Cs, Sr, Ce, Tc, La, Cr, Ni, Co-found in the nuclear fuel cycle.
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Affiliation(s)
- Vipul Vilas Kusumkar
- Department of Nuclear Chemistry, Faculty of Natural Sciences, Comenius University in Bratislava, Mlynska dolina Ilkovicova 6, 842 15 Bratislava, Slovakia;
| | - Michal Galamboš
- Department of Nuclear Chemistry, Faculty of Natural Sciences, Comenius University in Bratislava, Mlynska dolina Ilkovicova 6, 842 15 Bratislava, Slovakia;
| | - Eva Viglašová
- Department of Nuclear Chemistry, Faculty of Natural Sciences, Comenius University in Bratislava, Mlynska dolina Ilkovicova 6, 842 15 Bratislava, Slovakia;
| | - Martin Daňo
- Department of Nuclear Chemistry, Faculty of Nuclear Sciences and Physical Engineering, Czech Technical University in Prague, Brehová 7, 115 19 Prague, Czech Republic;
| | - Jana Šmelková
- Department of Administrative Law and Environmental Law, Faculty of Law, Comenius University in Bratislava, Safarikovo namestie 6, 810 00 Bratislava, Slovakia;
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Konoplev A, Wakiyama Y, Wada T, Udy C, Kanivets V, Ivanov MM, Komissarov M, Takase T, Goto A, Nanba K. Radiocesium distribution and mid-term dynamics in the ponds of the Fukushima Dai-ichi nuclear power plant exclusion zone in 2015-2019. CHEMOSPHERE 2021; 265:129058. [PMID: 33250230 DOI: 10.1016/j.chemosphere.2020.129058] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 11/16/2020] [Accepted: 11/18/2020] [Indexed: 06/12/2023]
Abstract
This study analyzes the 137Cs behavior in the ponds of Okuma Town from 2015 to 2019 in the Fukushima Dai-ichi nuclear power plant (FDNPP) exclusion zone. A decline in both particulate and dissolved 137Cs activity concentrations was revealed. The decline rate constants for the particulate 137Cs activity concentration were found to be higher than for the dissolved 137Cs activity concentration. In terms of seasonality the dissolved 137Cs concentrations were higher from June to October, depending on the specific pond and year, most likely due to temperature dependence of 137Cs desorption from frayed edge sites of micaceous clay minerals. The apparent Kd(137Cs) in the studied ponds, in absolute value, appeared to be much higher than that for closed and semi-closed lakes of the Chernobyl contaminated area; however, these were comparable to the values characteristic of the rivers and reservoirs of the FDNPP contaminated area. The apparent Kd(137Cs) in the suspended sediment-water system was observed to decrease over time. It was hypothesized that this trend was associated with the decomposition of glassy hot particles. Relying on the theory of selective sorption and fixation, the exchangeable radiocesium interception potential, RIPex(K) was estimated using data on 137Cs speciation in the surface bottom-sediment layer and its distribution in the sediment-water system. For the studied ponds, RIPex(K) was on the average 2050 mEq/kg, which is within the range of values measured in laboratory studies reported in the literature.
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Affiliation(s)
- Alexei Konoplev
- Institute of Environmental Radioactivity, Fukushima University, Kanayagawa 1, Fukushima, 960-1296, Japan.
| | - Yoshifumi Wakiyama
- Institute of Environmental Radioactivity, Fukushima University, Kanayagawa 1, Fukushima, 960-1296, Japan
| | - Toshihiro Wada
- Institute of Environmental Radioactivity, Fukushima University, Kanayagawa 1, Fukushima, 960-1296, Japan
| | - Cameron Udy
- Department of Environmental and Radiological Health Sciences, Colorado State University, Fort Collins, CO, 80521, USA
| | - Volodymyr Kanivets
- Ukrainian Hydrometeorological Institute, Nauki Av., 37, Kiev, 03028, Ukraine
| | - Maxim M Ivanov
- Faculty of Geography, Moscow State University, Moscow, 119991, Russia
| | | | - Tsugiko Takase
- Institute of Environmental Radioactivity, Fukushima University, Kanayagawa 1, Fukushima, 960-1296, Japan
| | - Azusa Goto
- Institute of Environmental Radioactivity, Fukushima University, Kanayagawa 1, Fukushima, 960-1296, Japan
| | - Kenji Nanba
- Institute of Environmental Radioactivity, Fukushima University, Kanayagawa 1, Fukushima, 960-1296, Japan
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Structural and compositional characteristics of Fukushima release particulate material from Units 1 and 3 elucidates release mechanisms, accident chronology and future decommissioning strategy. Sci Rep 2020; 10:22056. [PMID: 33328563 PMCID: PMC7744541 DOI: 10.1038/s41598-020-79169-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Accepted: 12/04/2020] [Indexed: 12/01/2022] Open
Abstract
The structural form and elemental distribution of material originating from different Fukushima Daiichi Nuclear Power Plant reactors (Units 1 and 3) is hereby examined to elucidate their contrasting release dynamics and the current in-reactor conditions to influence future decommissioning challenges. Complimentary computed X-ray absorption tomography and X-ray fluorescence data show that the two suites of Si-based material sourced from the different reactor Units have contrasting internal structure and compositional distribution. The known event and condition chronology correlate with the observed internal and external structures of the particulates examined, which suggest that Unit 1 ejecta material sustained a greater degree of melting than that likely derived from reactor Unit 3. In particular, we attribute the near-spherical shape of Unit 1 ejecta and their internal voids to there being sufficient time for surface tension to round these objects before the hot (and so relatively low viscosity) silicate melt cooled to form glass. In contrast, a more complex internal form associated with the sub-mm particulates invoked to originate from Unit 3 suggest a lower peak temperature, over a longer duration. Using volcanic analogues, we consider the structural form of this material and how it relates to its environmental particulate stability and the bulk removal of residual materials from the damaged reactors. We conclude that the brittle and angular Unit 3 particulate are more susceptible to further fragmentation and particulate generation hazard than the round, higher-strength, more homogenous Unit 1 material.
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Kubo A, Tanabe K, Ito Y, Ishimaru T, Otsuki M, Arakawa H, Watanabe YW, Miura H, Tsumune D, Kanda J. Changes in radioactive cesium concentrations from 2011 to 2017 in Fukushima coastal sediments and relative contributions of radioactive cesium-bearing microparticles. MARINE POLLUTION BULLETIN 2020; 161:111769. [PMID: 33091633 DOI: 10.1016/j.marpolbul.2020.111769] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Revised: 10/10/2020] [Accepted: 10/11/2020] [Indexed: 06/11/2023]
Abstract
Sedimentary cesium-137 concentrations around the Fukushima Daiichi Nuclear Power Plant (FDNPP) were measured from 2011 to 2017 at eight stations. Although high values were observed until 2013, decreasing trends were observed at the surface sediments of seven stations. We isolated 25 radioactive Cs-bearing microparticles (CsMPs; 1.0-5385 Bq per particle). The contribution ratio of CsMPs to each sample ranged from 4.1% to 99.5% (median 58.8%), with the contribution ratio of the CsMPs in the southern part of the FDNPP was low compared to that from the northern part. In the southern part of the FDNPP, small CsMPs that could not be isolated in this study were present in large quantities immediately after the accident, and gradually diffused away and/or were dissolved over time. In contrast, the CsMPs in the northern part of the FDNPP have most likely accumulated over time, as suggested by the silty nature of the sediments there.
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Affiliation(s)
- Atsushi Kubo
- Department of Geosciences, Shizuoka University, Shizuoka, Japan; Department of Ocean Sciences, Tokyo University of Marine Science and Technology, Tokyo, Japan.
| | - Kai Tanabe
- Department of Ocean Sciences, Tokyo University of Marine Science and Technology, Tokyo, Japan
| | - Yukari Ito
- Department of Ocean Sciences, Tokyo University of Marine Science and Technology, Tokyo, Japan
| | - Takashi Ishimaru
- Department of Ocean Sciences, Tokyo University of Marine Science and Technology, Tokyo, Japan
| | - Mayumi Otsuki
- Department of Ocean Sciences, Tokyo University of Marine Science and Technology, Tokyo, Japan
| | - Hisayuki Arakawa
- Department of Ocean Sciences, Tokyo University of Marine Science and Technology, Tokyo, Japan
| | - Yutaka W Watanabe
- Faculty of Environmental Earth Science, Hokkaido University, Sapporo, Japan
| | - Hikaru Miura
- Environmental Science Research Laboratory, Central Research Institute of Electric Power Industry, Chiba, Japan
| | - Daisuke Tsumune
- Environmental Science Research Laboratory, Central Research Institute of Electric Power Industry, Chiba, Japan
| | - Jota Kanda
- Department of Ocean Sciences, Tokyo University of Marine Science and Technology, Tokyo, Japan
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Okumura T, Yamaguchi N, Kogure T. Distinction between Radiocesium (RCs)-bearing Microparticles and RCs-sorbing Minerals Derived from the Fukushima Nuclear Accident Using Acid Treatment. CHEM LETT 2020. [DOI: 10.1246/cl.200374] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Taiga Okumura
- Department of Earth and Planetary Science, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Noriko Yamaguchi
- Institute for Agro-Environmental Sciences, NARO, 3-1-3 Kannondai, Tsukuba, Ibaraki 305-0864, Japan
| | - Toshihiro Kogure
- Department of Earth and Planetary Science, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
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Futagami F, Soliman M, Takamiya K, Sekimoto S, Oki Y, Kubota T, Konno M, Mizuno S, Ohtsuki T. Isolation, characterization and source analysis of radiocaesium micro-particles in soil sample collected from vicinity of Fukushima Dai-ichi nuclear power plant. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2020; 223-224:106388. [PMID: 32868095 DOI: 10.1016/j.jenvrad.2020.106388] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Revised: 07/23/2020] [Accepted: 08/16/2020] [Indexed: 06/11/2023]
Abstract
Radioactive caesium was released during the accident of Fukushima Dai-ichi nuclear power plant (FDNPP) into the surrounding environment. In the current work, radiocaesium micro-particles (CsMPs) and radiocaesium-rich soil particles were selectively separated from soil particles as well as from each other using autoradiography-based procedure. The applied separation scheme is based on water dilution followed by drying of the soil sample prior to imaging plate autoradiography. The SEM/EDS investigation of the individual CsMPs showed that these particles have a silicate glass structure and vary in shape with a diameter less than 10 μm. For the first time, a two-stage formation mechanism was suggested for a CsMP based on shape and structure heterogeneity of its two parts. Perfect spherical core might be formed in the first stage with a remarkable lower content of Al, and relatively higher concentrations of Si and K than an outer angulated structure, which might be attached to the core sphere during a late stage. The radiocaesium-rich soil particles have bigger size than CsMPs and have a plate-like structure with cleavages inside the grains, which suggest that these particles might be a weathered biotite. The average radioactivity ratio of 134Cs/137Cs (dated March 11, 2011) in the investigated particles was found to be 1.05 ± 0.01, which confirmed that the radiocaesium in CsMPs and in the contaminated soil particles has the same source of origin, which could be unite 3 of FDNPP.
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Affiliation(s)
- Fumiya Futagami
- Institute for Integrated Radiation and Nuclear Science, Kyoto University, Osaka, Japan
| | - Mohamed Soliman
- Institute for Integrated Radiation and Nuclear Science, Kyoto University, Osaka, Japan; Egypt Second Research Reactor, Egyptian Atomic Energy Authority, Cairo, Egypt.
| | - Koichi Takamiya
- Institute for Integrated Radiation and Nuclear Science, Kyoto University, Osaka, Japan
| | - Shun Sekimoto
- Institute for Integrated Radiation and Nuclear Science, Kyoto University, Osaka, Japan
| | - Yuichi Oki
- Institute for Integrated Radiation and Nuclear Science, Kyoto University, Osaka, Japan
| | - Takumi Kubota
- Institute for Integrated Radiation and Nuclear Science, Kyoto University, Osaka, Japan
| | - Mitsuyuki Konno
- Citizens and Environmental Affairs Department, Ken-poku Development Bureau, Fukushima Prefecture Government, Japan
| | - Satoshi Mizuno
- Nuclear Power Safety Division, Fukushima Prefecture Government, Japan
| | - Tsutomu Ohtsuki
- Institute for Integrated Radiation and Nuclear Science, Kyoto University, Osaka, Japan
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37
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Yoshida-Ohuchi H, Shinohara N. Estimated internal exposure doses due to indoor radiocaesium contamination in residential houses after the Fukushima nuclear accident. Sci Rep 2020; 10:17212. [PMID: 33057093 PMCID: PMC7560611 DOI: 10.1038/s41598-020-74182-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Accepted: 09/28/2020] [Indexed: 11/30/2022] Open
Abstract
This work first reports the estimation of the internal exposure from ingestion of house dust and inhalation of aerosol, by employing a measured data on 137Cs activities, bioaccessibility (solubility to water and 1 M HCl), and particle size distribution. The house dust and aerosol samples were collected during the actual indoor cleaning by vacuuming and dusting, from 65 houses and buildings in proximity to the Fukushima Daiichi nuclear power plant (FDNPP) (1.6–16.1 km from the FDNPP) during a period from April 2016 to January 2019. Committed effective doses for an adult owing to the ingestion of house dust of 20 mg per day, which adheres to one’s hands through the hand-to-mouth, and those owing to inhalation of aerosol during dusting for 1.5 h while wearing a mask, were calculated using DCAL software for each house or building, as 1.13 µSv and 4.55 µSv as maximum doses, respectively (as of March 2011). Both the committed effective doses, owing to ingestion and inhalation, were inversely correlated with the distance from the FDNPP, and positively correlated with the indoor surface contamination.
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Affiliation(s)
- Hiroko Yoshida-Ohuchi
- Graduate School of Pharmaceutical Sciences, Tohoku University, 6-3 Aramaki-Aoba, Aoba-ku, Sendai, Miyagi, 980-8578, Japan.
| | - Naohide Shinohara
- Research Institute of Science for Safety and Sustainability (RISS), National Institute of Advanced Industrial Science and Technology (AIST), 16-1 Onogawa, Tsukuba, Ibaraki, 305-8569, Japan
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38
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Project IPAD, a database to catalogue the analysis of Fukushima Daiichi accident fragmental release material. Sci Data 2020; 7:282. [PMID: 32859938 PMCID: PMC7455553 DOI: 10.1038/s41597-020-00626-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Accepted: 08/06/2020] [Indexed: 11/15/2022] Open
Abstract
The 2011 accident at Japan’s Fukushima Daiichi Nuclear Power Plant released a considerable inventory of radioactive material into the local and global environments. While the vast majority of this contamination was in the form of gaseous and aerosol species, of which a large component was distributed out over the neighbouring Pacific Ocean (where it was subsequently deposited), a substantial portion of the radioactive release was in particulate form and was deposited across Fukushima Prefecture. To provide an underpinning understanding of the dynamics of this catastrophic accident, alongside assisting in the off-site remediation and eventual reactor decommissioning activities, the ‘International Particle Analysis Database’, or ‘IPAD’, was established to serve as an interactive repository for the continually expanding analysis dataset of the sub-mm ejecta particulate. In addition to a fully interrogatable database of analysis results for registered users (exploiting multiple search methods), the database also comprises an open-access front-end for members of the public to engage with the multi-national analysis activities by exploring a streamlined version of the data. Measurement(s) | activity (of a radionuclide) • composition • isotopic ratio | Technology Type(s) | radioactivity measurement method • gamma-ray spectroscopy • transmission electron microscopy with EDAX • X-ray diffraction • micro-computed tomography • X-ray fluorescence microscopy • X-ray absorption spectroscopy • Raman spectroscopy • proton-induced X-ray emission spectroscopy • alpha-particle spectroscopy • beta-particle spectroscopy • secondary ion mass spectrometry • inductively coupled plasma mass spectrometry • thermal ionisation mass spectrometry • three dimensional-atom probe tomography • resonance ionisation mass spectrometry | Sample Characteristic - Environment | nuclear power plant | Sample Characteristic - Location | Fukushima Prefecture |
Machine-accessible metadata file describing the reported data: 10.6084/m9.figshare.12821081
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Miura H, Kurihara Y, Yamamoto M, Sakaguchi A, Yamaguchi N, Sekizawa O, Nitta K, Higaki S, Tsumune D, Itai T, Takahashi Y. Characterization of two types of cesium-bearing microparticles emitted from the Fukushima accident via multiple synchrotron radiation analyses. Sci Rep 2020; 10:11421. [PMID: 32694627 PMCID: PMC7374699 DOI: 10.1038/s41598-020-68318-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Accepted: 06/22/2020] [Indexed: 12/05/2022] Open
Abstract
A part of radiocesium emitted during the Fukushima nuclear accident was incorporated in glassy water-resistant microparticles, called Type-A particles, which are spherical with ~ 0.1 to 10 µm diameter and ~ 10-2 to 102 Bq cesium-137 (137Cs) radioactivity; they were emitted from Unit 2 or 3 of the Fukushima Daiichi Nuclear Power Plant. Meanwhile, Type-B particles, having various shapes, 50-400 µm diameter, and 101-104 Bq 137Cs radioactivity, were emitted from Unit 1. The chemical properties of these radioactive particles have been reported in detail, but previous studies investigated only a small number of particles, especially Type-B particles. We tried to understand radioactive particles systematically by analyzing a large number of particles. Micro-X-ray computed tomography combined with X-ray fluorescence analysis revealed the presence of many voids and iron-rich part within Type-B particles. The 137Cs concentration (Bq mm-3) of Type-A particles was ~ 10,000 times higher than that of Type-B particles. Among the Type-B particles, the spherical ones had higher concentration of volatile elements than the non-spherical ones. These differences suggested that Type-A particles were formed through gas condensation, whereas Type-B particles were formed through melt solidification. These findings might contribute to the safe decommissioning of reactors and environmental impact assessment.
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Affiliation(s)
- Hikaru Miura
- Atmospheric and Marine Environmental Sector, Environmental Science Research Laboratory, Central Research Institute of Electric Power Industry, 1646 Abiko, Abiko-shi, Chiba, 270-1194, Japan.
| | - Yuichi Kurihara
- Ningyo-Toge Environmental Engineering Center, Japan Atomic Energy Agency, 1550 Kamisaibara, Kagamino-cho, Tomata-gun, Okayama, 708-0698, Japan
| | - Masayoshi Yamamoto
- Low Level Radioactivity Laboratory, Kanazawa University, Kanazawa, Ishikawa, 923-1224, Japan
| | - Aya Sakaguchi
- Center for Research in Isotopes and Environmental Dynamics, University of Tsukuba, 1-1-1, Tennodai, Tsukuba, Ibaraki, 305-8577, Japan
| | - Noriko Yamaguchi
- Institute for Agro-Environmental Sciences, NARO, 3-1-3, Kannondai, Tsukuba, Ibaraki, 305-8604, Japan
| | - Oki Sekizawa
- Japan Synchrotron Radiation Research Institute (JASRI), 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo, 679-5198, Japan
| | - Kiyofumi Nitta
- Japan Synchrotron Radiation Research Institute (JASRI), 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo, 679-5198, Japan
| | - Shogo Higaki
- Isotope Science Center, The University of Tokyo, 2-11-16 Yayoi, Bunkyo-ku, Tokyo, 113-0032, Japan
| | - Daisuke Tsumune
- Atmospheric and Marine Environmental Sector, Environmental Science Research Laboratory, Central Research Institute of Electric Power Industry, 1646 Abiko, Abiko-shi, Chiba, 270-1194, Japan
| | - Takaaki Itai
- Department of Earth and Planetary Science, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Yoshio Takahashi
- Department of Earth and Planetary Science, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
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Zhang Y, Lai JL, Ji XH, Luo XG. Assessment of cyto- and genotoxic effects of Cesium-133 in Vicia faba using single-cell gel electrophoresis and random amplified polymorphic DNA assays. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2020; 197:110620. [PMID: 32311615 DOI: 10.1016/j.ecoenv.2020.110620] [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: 10/11/2019] [Revised: 02/29/2020] [Accepted: 04/09/2020] [Indexed: 06/11/2023]
Abstract
The aim of this study was to evaluate the ecotoxic effect of high concentration cesium (Cs) exposure on plant root growth and its toxicological mechanism. The radicle of broad bean (Vicia faba) was selected as experimental material. The cytotoxic and genotoxic effects of plants exposed to different Cs levels (0.19-1.5 mM) for 48 h were evaluated using scanning electron microscopy (SEM), X-ray fluorescence (XRF) analysis, single-cell gel electrophoresis (SCGE) and random amplified polymorphic DNA (RAPD) assays. The results showed that radicle elongation decreased clearly after 48 h of exposure treatment with different concentrations of Cs solution. The root cell structure was obviously damaged in the Cs treatment groups (0.19-1.5 mM). At a Cs concentration of 1.5 mM, the percentages of viable non-apoptotic cells, viable apoptotic cells, non-viable apoptotic cells, and non-viable cells were 40.09%, 20.67%, 28.73%, and 10.52%, respectively. SCGE showed DNA damage in radicle cells 48 h after Cs exposure. Compared with the control group, the percentage of tail DNA in Cs exposed group (0.38-1.5 mM) increased by 0.56-1.12 times (P < 0.05). RAPD results showed that the genomic stability of V. faba radicles decreased by 4.44%-15.56%. This study confirmed that high concentration Cs exposure had cytotoxicity and genotoxicity effects on plants.
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Affiliation(s)
- Yu Zhang
- School of Life Science and Engineering, Southwest University of Science and Technology, Mianyang, 621010, China
| | - Jin-Long Lai
- School of Life Science and Engineering, Southwest University of Science and Technology, Mianyang, 621010, China; College of Environment and Resources, Southwest University of Science and Technology, Mianyang, 621010, China.
| | - Xiao-Hui Ji
- College of Chemical and Environment Science, Shaanxi University of Technology, Hanzhong, 723000, China
| | - Xue-Gang Luo
- School of Life Science and Engineering, Southwest University of Science and Technology, Mianyang, 621010, China; Engineering Research Center of Biomass Materials, Ministry of Education, Southwest University of Science and Technology, Mianyang, 621010, China.
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Voronina AV, Noskova AY, Semenishchev VS, Gupta DK. Decontamination of seawater from 137Cs and 90Sr radionuclides using inorganic sorbents. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2020; 217:106210. [PMID: 32217243 DOI: 10.1016/j.jenvrad.2020.106210] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Revised: 02/12/2020] [Accepted: 02/15/2020] [Indexed: 06/10/2023]
Abstract
In this work, we have studied sorption of 137Сs and 90Sr radionuclides from seawater under batch conditions by ferrocyanide sorbents based on hydrated titanium and zirconium dioxides (Т-35, NPF-HTD), clinoptilolite and glauconite (NPF-GL, NPF-CL) natural aluminosilicates, zirconium phosphate (T-3A), modified hydrated titanium dioxide (T-3K) as well as by manganese dioxide based on hydrated titanium dioxide (MD-HTD). Isotherms of sorption and dependences of cesium distribution coefficients on salt content and calcium concentration were obtained. Distribution coefficients of cesium and strontium were calculated. Stability of spent sorbents against radionuclides leaching was studied in from the point of view of their further treatment. The NPF-GL and NPF-HTD sorbents are recommended for treatment of seawater-based liquid radioactive waste with various salinity; these sorbents possess high distribution coefficients of cesium 104 and 105 ml/g even at the salinity of waste as high as 100 g L-1. Distribution coefficients of strontium from seawater were (1.0-1.9)·102 ml/g for all sorbents that is conditioned by the presence of colloidal species of strontium (34 ± 7%) in the simulated seawater. Capacities of the sorbents for strontium varied within 200-310 mg/g. The sorbents strongly retain adsorbed radionuclides: the total percentage of leaching for 28 days was 4.4%, 2.2% and 3.1% for 137Cs leaching from the NPF-HTD, T-35 and T-3A sorbents respectively and 10.7% for 90Sr leaching from the NPF-CL sorbent.
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Affiliation(s)
- A V Voronina
- Radiochemistry and Applied Ecology Department, Ural Federal University, Physical Technology Institute, Mira str. 19, Ekaterinburg, Russia.
| | - A Yu Noskova
- Radiochemistry and Applied Ecology Department, Ural Federal University, Physical Technology Institute, Mira str. 19, Ekaterinburg, Russia
| | - V S Semenishchev
- Radiochemistry and Applied Ecology Department, Ural Federal University, Physical Technology Institute, Mira str. 19, Ekaterinburg, Russia
| | - D K Gupta
- Ministry of Environment, Forest and Climate Change, Indira Paryavaran Bhavan, Aliganj, Jorbagh Road, New Delhi, 110003, India
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Dacre HF, Bedwell P, Hertwig D, Leadbetter SJ, Loizou P, Webster HN. Improved representation of particle size and solubility in model simulations of atmospheric dispersion and wet-deposition from Fukushima. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2020; 217:106193. [PMID: 32217253 DOI: 10.1016/j.jenvrad.2020.106193] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Revised: 02/04/2020] [Accepted: 02/05/2020] [Indexed: 06/10/2023]
Abstract
Radionuclides released into the atmosphere following the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident were detected by ground-based monitoring stations worldwide. The inter-continental dispersion of radionuclides provides a unique opportunity to evaluate the ability of atmospheric dispersion models to represent the processes controlling their transport and deposition in the atmosphere. Co-located measurements of radioxenon (133Xe) and caesium (137Cs) concentrations enable individual physical processes (dispersion, dry and wet deposition) to be isolated. In this paper we focus on errors in the prediction of 137Cs attributed to the representation of particle size and solubility, in the process of modelling wet deposition. Simulations of 133Xe and 137Cs concentrations using the UK Met Office NAME (Numerical Atmospheric-dispersion Modelling Environment) model are compared with CTBTO (Comprehensive Nuclear-Test-Ban Treaty Organisation) surface station measurements. NAME predictions of 137Cs using a bulk wet deposition parameterisation (which does not account for particle size dependent scavenging or solubility) significantly underestimate observed 137Cs. When a binned wet deposition parameterisation is implemented (which accounts for particle size dependent scavenging) the correlations between modelled and observed air concentrations improve at all 9 of the Northern Hemisphere sites studied and the respective RMSLE (root-mean-square-log-error) decreases by a factor of 7 due to a decrease in the wet-deposition of Aitken and Accumulation mode particles. Finally, NAME simulations were performed in which insoluble submicron particles are represented. Representing insoluble particles in the NAME simulations improves the RMSLE at all sites further by a factor of 7. Thus NAME is able to predict 137Cs with good accuracy (within a factor of 10 of observed 137Cs values) at distances greater than 10,000 km from FDNPP only if insoluble submicron particles are considered in the description of the source. This result provides further evidence of the presence of insoluble Cs-rich microparticles in the release following the accident at FDNPP and suggests that these small particles travelled across the Pacific Ocean to the US and further across the North Atlantic Ocean towards Europe.
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Affiliation(s)
| | | | | | | | | | - H N Webster
- Met Office, UK; College of Engineering, University of Exeter, UK
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43
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A highly sensitive and selective sensor for trace uranyl (VI) ion based on a graphene-coated carbon paste electrode modified with ion imprinted polymer. Microchem J 2020. [DOI: 10.1016/j.microc.2020.104767] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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44
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Hara T, Takenaka C, Tomioka R. Change in the chemical form of 137Cs with age in needles of Japanese cedar. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2020; 213:106137. [PMID: 31983446 DOI: 10.1016/j.jenvrad.2019.106137] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Revised: 11/21/2019] [Accepted: 12/10/2019] [Indexed: 06/10/2023]
Abstract
Radiocesium (137Cs) derived from the accident of Fukushima Dai-ichi Nuclear Power Plant remains in forests. Although a large proportion of the 137Cs in forests has been transferred to soils, the rates of transfer to soils depend on the chemical form of 137Cs, which determines the mobility of 137Cs in plant tissues and subsequently during decomposition of leaf litter. In order to understand the dynamics of 137Cs in Sugi (Japanese cedar, Cryptomeria japonica) forests, we identified the chemical forms, such as water soluble, ion-exchangeable, and residual of 137Cs, 133Cs, K, and Rb in needle-bearing Sugi branches of different ages across several years. Compared with the results for K and Rb, Cs (133Cs + 137Cs) tended to change from a water-soluble form to an immobilized form with aging of needle-bearing branch segments. In addition, it was observed that a larger proportion of the immobilized Cs were accumulated in the green outer portions of the stems through aging.
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Affiliation(s)
- Tatsuya Hara
- Graduate School of Bioagricultural Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8601, Japan
| | - Chisato Takenaka
- Graduate School of Bioagricultural Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8601, Japan.
| | - Rie Tomioka
- Graduate School of Bioagricultural Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8601, Japan
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45
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Isotopic ratios of uranium and caesium in spherical radioactive caesium-bearing microparticles derived from the Fukushima Dai-ichi Nuclear Power Plant. Sci Rep 2020; 10:3281. [PMID: 32094430 PMCID: PMC7039901 DOI: 10.1038/s41598-020-59933-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Accepted: 02/04/2020] [Indexed: 11/08/2022] Open
Abstract
Spherical radioactive caesium (Cs)-bearing microparticles (CsMPs) were emitted during the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident in March, 2011. The emission source (timing) and formation process of these particles remain unclear. In this study, the isotopic ratios of uranium (235U and 238U) and caesium (133Cs, 134Cs, 135Cs, and 137Cs) isotopes in the five spherical CsMPs (ca. 2 μm in size) sampled at 50 km west of the FDNPP were determined using secondary ion mass spectrometry and laser ablation-ICPMS, respectively. Results showed that the 235U/238U ratios of CsMPs were homogeneous (1.93 ± 0.03, N = 4) and close to those estimated for the fuel cores in units 2 and 3, and that the Cs isotopic ratios of CsMP were identical to those of units 2 and 3. These results indicated that U and Cs in the spherical CsMPs originated exclusively from the fuel melt in the reactors. Based on a thorough review of literatures related to the detailed atmospheric releases of radionuclides, the flow of plumes from the FDNPP reactor units during the accident and the U and Cs isotopic ratio results in this study, we hereby suggest that the spherical CsMPs originate only from the fuel in unit 2 on the night of 14 March to the morning of 15 March. The variation range of the analysed 235U/238U isotopic ratios for the four spherical particles was extremely narrow. Thus, U may have been homogenised in the source through the formation of fuel melt, which ultimately evaporating and taken into CsMPs in the reactor and was released from the unit 2.
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46
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Zuykov M, Fowler SW, Archambault P, Spiers G, Schindler M. Practical advice on monitoring of U and Pu with marine bivalve mollusks near the Fukushima Daiichi Nuclear Power Plant. MARINE POLLUTION BULLETIN 2020; 151:110860. [PMID: 32056642 DOI: 10.1016/j.marpolbul.2019.110860] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Accepted: 12/23/2019] [Indexed: 06/10/2023]
Abstract
Following the Fukushima Daiichi nuclear power plant accident in 2011, some marine radionuclide monitoring studies report a lack of evidence for contamination of Japanese coastal waters by U and Pu, or state that marine contamination by them was negligible. Nevertheless, Fukushima-derived U and Pu were reported as associated with Cs-rich microparticles (CsMPs) found in local soil, vegetation, and river/lake sediments. Over time, CsMPs can be transported to the sea via riverine runoff where actinides, as expected, will leach. We recommend establishing a long-term monitoring of U and Pu in the nearshore area of the Fukushima Prefecture using marine bivalve mollusks; shells, byssal threads and soft tissues should all be analyzed. Here, based on results from Th biosorption experiments, we propose that U and Pu could be present at concentrations several times higher in shells with a completely destroyed external shell layer (periostracum) than in shells with intact periostracum.
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Affiliation(s)
- Michael Zuykov
- School of the Environment, Laurentian University, Sudbury, ON P3E 2C6, Canada.
| | - Scott W Fowler
- School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, NY 11794-5000, USA
| | | | - Graeme Spiers
- School of the Environment, Laurentian University, Sudbury, ON P3E 2C6, Canada
| | - Michael Schindler
- Department of Geological Sciences, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
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Okumura T, Yamaguchi N, Suga H, Takahashi Y, Segawa H, Kogure T. Reactor environment during the Fukushima nuclear accident inferred from radiocaesium-bearing microparticles. Sci Rep 2020; 10:1352. [PMID: 31992831 PMCID: PMC6987194 DOI: 10.1038/s41598-020-58464-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Accepted: 01/15/2020] [Indexed: 11/25/2022] Open
Abstract
Radiocaesium-bearing microparticles (CsMPs), which are substantially silicate glass, were formed inside the damaged reactor and released to the environment by the Fukushima Dai-ichi Nuclear Power Plant accident in March 2011. The present study reports several valuable findings regarding their composition and structure using advanced microanalytical techniques. X-ray absorption near-edge structure of Fe L3-absorption indicated that the oxidation state of the iron dissolved in the glass matrix of the CsMPs was originally nearly divalent, suggesting that the atmosphere in which the CsMPs were formed during the accident was considerably reductive. Another major finding is that sodium, which has not been recognised as a constituent element of CsMPs thus far, is among the major elements in the glass matrix. The atomic percent of Na is higher than that of other alkali elements such as K and Cs. Furthermore, halite (NaCl) was found as an inclusion inside a CsMP. The existence of Na in CsMPs infers that seawater injected for cooling might reach the inside of the reactor before or during the formation of the CsMPs. These results are valuable to infer the environment inside the reactor during the accident and the debris materials to be removed during the decommissioning processes.
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Affiliation(s)
- Taiga Okumura
- The University of Tokyo, Department of Earth and Planetary Science, Graduate School of Science, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan.
| | - Noriko Yamaguchi
- Institute for Agro-Environmental Sciences, NARO, 3-1-3 Kannondai, Tsukuba, Ibaraki, 305-0864, Japan
| | - Hiroki Suga
- The University of Tokyo, Department of Earth and Planetary Science, Graduate School of Science, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Yoshio Takahashi
- The University of Tokyo, Department of Earth and Planetary Science, Graduate School of Science, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Hiroyo Segawa
- National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki, 305-0044, Japan
| | - Toshihiro Kogure
- The University of Tokyo, Department of Earth and Planetary Science, Graduate School of Science, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
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48
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Reinoso-Maset E, Brown J, Pettersen MN, Steenhuisen F, Tetteh A, Wada T, Hinton TG, Salbu B, Lind OC. Linking heterogeneous distribution of radiocaesium in soils and pond sediments in the Fukushima Daiichi exclusion zone to mobility and potential bioavailability. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2020; 211:106080. [PMID: 31677432 DOI: 10.1016/j.jenvrad.2019.106080] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2018] [Revised: 10/15/2019] [Accepted: 10/15/2019] [Indexed: 06/10/2023]
Abstract
During the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident in 2011 significant amounts of radiocaesium were released into the atmosphere from the reactor units 1, 2 and 3. This caused a non-uniform deposition, in composition and direction, of 134Cs and 137Cs in the near field (<30 km) from the reactors. In this work, we elucidate the influence of speciation, including radioactive particles, on mobility and potential bioavailability of radiocaesium in soils and sediments from sites located in different directions and distances from the FDNPP. Samples collected in September 2016 were characterized and subjected to sequential chemical extractions and simulated gastrointestinal fluid leaching, and the 137Cs and 134Cs activities were determined in bulk, grain-size and extracted fractions. The results show that radiocaesium was mainly irreversibly bound and in an inert form. Combined, the two forms contained >90% of the activity present in soils and ~84% in sediments. Digital autoradiography revealed that the inert fraction was predominantly associated with heterogeneities, an indication of radioactive particles. The frequency of heterogeneities was correlated with 137Cs activity concentrations, and both were in agreement with the ambient equivalent air doses measured in situ during sampling. Moreover, in situ gamma spectrometry measurements were used in the InSiCal software tool to derive 134Cs and 137Cs surface contamination. Soil activity concentrations and contamination density estimations, decay-corrected to the day of the FDNPP accident, resulted in 134Cs/137Cs ratios that match the reported release and deposition plumes from the reactor units. Overall, these results demonstrate the persistence of the particle contamination in the Fukushima near field and highlight the importance of including radioactive particles in environmental impact assessments.
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Affiliation(s)
- Estela Reinoso-Maset
- Centre for Environmental Radioactivity CoE, 1432, Ås, Norway; Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, 1432, Ås, Norway.
| | - Justin Brown
- Centre for Environmental Radioactivity CoE, 1432, Ås, Norway; Norwegian Radiation and Nuclear Safety Authority, Grini næringspark 13, 1361, Østerås, Norway
| | - Marit N Pettersen
- Centre for Environmental Radioactivity CoE, 1432, Ås, Norway; Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, 1432, Ås, Norway
| | - Frits Steenhuisen
- Arctic Centre, University of Groningen, Aweg 30, 9718CW, Groningen, the Netherlands
| | - Abednego Tetteh
- Centre for Environmental Radioactivity CoE, 1432, Ås, Norway; Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, 1432, Ås, Norway
| | - Toshihiro Wada
- Institute of Environmental Radioactivity, Fukushima University, 1 Kanayagawa, Fukushima, 960-1296, Japan
| | - Thomas G Hinton
- Institute of Environmental Radioactivity, Fukushima University, 1 Kanayagawa, Fukushima, 960-1296, Japan
| | - Brit Salbu
- Centre for Environmental Radioactivity CoE, 1432, Ås, Norway; Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, 1432, Ås, Norway
| | - Ole Christian Lind
- Centre for Environmental Radioactivity CoE, 1432, Ås, Norway; Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, 1432, Ås, Norway
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Okumura T, Yamaguchi N, Kogure T. Finding Radiocesium-bearing Microparticles More Minute than Previously Reported, Emitted by the Fukushima Nuclear Accident. CHEM LETT 2019. [DOI: 10.1246/cl.190581] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Taiga Okumura
- Department of Earth and Planetary Science, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Noriko Yamaguchi
- Institute for Agro-Environmental Sciences, NARO, 3-1-3 Kannondai, Tsukuba, Ibaraki 305-0864, Japan
| | - Toshihiro Kogure
- Department of Earth and Planetary Science, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
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50
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Kubo A, Tanabe K, Ito Y, Ishimaru T, Arakawa H, Kanda J. Spatial variation in sedimentary radioactive cesium concentrations in Tokyo Bay following the Fukushima Daiichi Nuclear Power Plant accident. CHEMOSPHERE 2019; 235:550-555. [PMID: 31279117 DOI: 10.1016/j.chemosphere.2019.06.215] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Revised: 06/21/2019] [Accepted: 06/27/2019] [Indexed: 06/09/2023]
Abstract
Cesium-137 concentrations in sediment (137Cs) at Tokyo Bay were measured at 26 stations during 2017. Average 137Cs concentrations at the Arakawa river mouth (117 ± 46 Bq kg-1) were approximately six times higher than those of the other stations in the bay (20 ± 16 Bq kg-1). There were radiocesium-bearing microparticles in the bay sediment as well as in suspended matter of Fukushima coastal waters. Radioactivity of radiocesium-bearing microparticles was estimated to be 0.12 Bq. However, the contributions of radiocesium-bearing microparticles to each 137Cs concentration of the bulk sample were low; 3% was the maximum. The 137Cs inventory in sediment at the entire bay was 0.67 TBq, showing that a large amount of 137Cs was supplied to the bay from the river following the Fukushima Daiichi Nuclear Power Plant accident. Approximately 9.2% of the 137Cs which was fallout in the drainage basin has already flowed into the bay from the watershed, which is approximately 3.2 times higher than that of a previous estimate.
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Affiliation(s)
- Atsushi Kubo
- Department of Geosciences, Shizuoka University, Shizuoka, Japan.
| | - Kai Tanabe
- Department of Ocean Sciences, Tokyo University of Marine Science and Technology, Tokyo, Japan
| | - Yukari Ito
- Department of Ocean Sciences, Tokyo University of Marine Science and Technology, Tokyo, Japan
| | - Takashi Ishimaru
- Department of Ocean Sciences, Tokyo University of Marine Science and Technology, Tokyo, Japan
| | - Hisayuki Arakawa
- Department of Ocean Sciences, Tokyo University of Marine Science and Technology, Tokyo, Japan
| | - Jota Kanda
- Department of Ocean Sciences, Tokyo University of Marine Science and Technology, Tokyo, Japan
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