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Igarashi J, Ninomiya K, Zheng J, Zhang Z, Fukuda M, Aono T, Minowa H, Yoshikawa H, Sueki K, Satou Y, Shinohara A. Fukushima Daiichi Nuclear Power Plant Accident: Understanding Formation Mechanism of Radioactive Particles through Sr and Pu Quantities. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:14823-14830. [PMID: 39129255 DOI: 10.1021/acs.est.4c03428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/13/2024]
Abstract
The Fukushima Daiichi Nuclear Power Plant accident released considerable radionuclides into the environment. Radioactive particles, composed mainly of SiO2, emerged as distinctive features, revealing insights into the accident's dynamics. While studies extensively focused on high-volatile radionuclides like Cs, investigations into low-volatile nuclides such as 90Sr and Pu remain limited. Understanding their abundance in radioactive particles is crucial for deciphering the accident's details, including reactor temperatures and injection processes. Here, we aimed to determine 90Sr and Pu amounts in radioactive particles and provide essential data for understanding the formation processes and conditions within the reactor during the accident. We employed radiochemical analysis on nine radioactive particles and determined the amounts of 90Sr and Pu in these particles. 90Sr and Pu quantification in radioactive particles showed that the 90Sr/137Cs radioactivity ratio (corrected to March 11, 2011) aligned with core temperature expectations. However, the 239+240Pu/137Cs activity ratio indicated nonvolatile Pu introduction, possibly through fuel fragments. Analyzing 90Sr and Pu enhances our understanding of the Fukushima Daiichi accident. Deviations in 239+240Pu/137Cs activity ratios underscore nonvolatile processes, emphasizing the accident's complexity. Future research should expand this data set for a more comprehensive understanding of the accident's nuances.
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Affiliation(s)
- Junya Igarashi
- Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan
| | - Kazuhiko Ninomiya
- Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan
| | - Jian Zheng
- Institute for Radiological Science, National Institute for Quantum Science and Technology (QST), 491 Anagawa, Inage, Chiba 263-8555, Japan
| | - Zijian Zhang
- Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan
| | - Miho Fukuda
- Institute for Radiological Science, National Institute for Quantum Science and Technology (QST), 491 Anagawa, Inage, Chiba 263-8555, Japan
- Research Department, Fukushima Prefectural Centre for Environmental Creation, 10-2 Fukasaku, Miharu Town, Fukushima 963-7700, Japan
| | - Tatsuo Aono
- Institute for Radiological Science, National Institute for Quantum Science and Technology (QST), 491 Anagawa, Inage, Chiba 263-8555, Japan
| | - Haruka Minowa
- The Jikei University School of Medicine, 3-25 Nishishinbashi, Minato Ward, Tokyo 105-0003, Japan
| | - Hideki Yoshikawa
- The Jikei University School of Medicine, 3-25 Nishishinbashi, Minato Ward, Tokyo 105-0003, Japan
| | - Keisuke Sueki
- Graduate School of Pure and Material, Tsukuba University, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8577, Japan
| | - Yukihiko Satou
- Collaborative Laboratories for Advanced Decommissioning Science, Japan Atomic Energy Agency, 790-1 Otsuka, Motooka, Tomioka, Futaba, Fukushima 979-1151, Japan
| | - Atsushi Shinohara
- Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan
- Faculty of Health Science, Osaka Aoyama University, 2-11-1 Niina, Minoh, Osaka 562-8580, Japan
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Yomogida T, Ouchi K, Morii S, Oka T, Kitatsuji Y, Koma Y, Konno K. Analysis of particles containing alpha emitters in stagnant water in Fukushima Daiichi Nuclear Power Station's Unit 3 reactor building. Sci Rep 2024; 14:14945. [PMID: 38942918 PMCID: PMC11213940 DOI: 10.1038/s41598-024-65522-2] [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: 02/28/2024] [Accepted: 06/20/2024] [Indexed: 06/30/2024] Open
Abstract
Particles containing alpha (α) nuclides were identified from sediment in stagnant water in the Unit 3 reactor building of the Fukushima Daiichi Nuclear Power Station (FDiNPS). We analyzed different concentrations of α-nuclide samples collected at two sampling sites, the torus room and the main steam isolation valve (MSIV) room. The solids in the stagnant water samples were classified, and the uranium (U) and total alpha concentrations of each fraction were measured by dissolution followed by inductively coupled plasma mass spectrometry and α-spectrometry. Most of the α-nuclides in the stagnant water samples from the torus and MSIV rooms were in particle fractions larger than 10 μm. We detected uranium-bearing particles ranging from sub-µm to 10 µm in size by scanning electron microscopy-energy-dispersive X-ray (SEM-EDX) observations. The chemical forms of U particles were determined in U-Zr oxides, oxidized UO2, and U3O8 with micro-Raman spectroscopy. Other short-lived α-nuclides (plutonium [Pu], americium [Am], and curium [Cm]) were detected by alpha track detection, and the particles with α-nuclides was characterized by SEM-EDX analysis. α-nuclide-containing particles with several tens to several 100 µm in size mainly comprised iron (Fe) oxyhydroxides. In addition, we detected adsorbed U onto Fe oxyhydroxide particles in the MSIV room sample, which indicated nuclear fuel dissolution and secondary U accumulation. This study clarifies the major characteristics of U and other α-nuclides in sediment in stagnant water in the FDiNPS Unit 3 reactor building, which significantly contribute to the consideration of removal methods for particles containing α-nuclides in the stagnant water.
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Affiliation(s)
- Takumi Yomogida
- Nuclear Science and Engineering Center, Japan Atomic Energy Agency, Ibaraki, 319-1195, Japan.
| | - Kazuki Ouchi
- Nuclear Science and Engineering Center, Japan Atomic Energy Agency, Ibaraki, 319-1195, Japan
| | - Shiori Morii
- Nuclear Science and Engineering Center, Japan Atomic Energy Agency, Ibaraki, 319-1195, Japan
| | - Toshitaka Oka
- Nuclear Science and Engineering Center, Japan Atomic Energy Agency, Ibaraki, 319-1195, Japan
| | - Yoshihiro Kitatsuji
- Nuclear Science and Engineering Center, Japan Atomic Energy Agency, Ibaraki, 319-1195, Japan
| | - Yoshikazu Koma
- Collaborative Laboratories for Advanced Decommissioning Science (CLADS), Japan Atomic Energy Agency, Fukushima, 979-1151, Japan
| | - Katsuhiro Konno
- Fukushima Daiichi Decontamination and Decommissioning Engineering Company, Tokyo Electric Power Company Holdings Inc., Fukushima, 979-1301, Japan
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Zhao G, Shao Y, Luo M, Xu D, Li D, Liu Z, Ma L. Research progress on the analysis and application of radioactive hot particle. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2023; 270:107313. [PMID: 37857023 DOI: 10.1016/j.jenvrad.2023.107313] [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: 09/25/2023] [Revised: 10/10/2023] [Accepted: 10/11/2023] [Indexed: 10/21/2023]
Abstract
Radioactive hot particle is the particulate form of nuclear material that exists in the environment. The U, Pu, Am, Cs, and other radionuclides isotope in the hot particle contain abundant and accurate fingerprint information, such as the origin and age of the nuclear material. The acquisition and analysis of the key information in the hot particle can be equivalent to the analysis of bulk nuclear material, which could directly reflect the real situation of nuclear activities. Therefore, the single particle analysis of hot particles has become an irreplaceable key technology in nuclear safeguards inspection. The rapid identification, screening, locating, and accurate isotope analysis of hot particles from a large number of particles dispersed in environmental media or on the surface of other materials are one of the most important research field in nuclear emergency. In this review, the research process of the analytical methods for hot particles in the last decade was summarized, including the physical character of hot particles, and the techniques of localization, screening, and extraction of hot particles. Furthermore, we also focused on the mass spectrometry technology for the analysis of hot particle. The advantages and disadvantages of the most used mass spectrometry were summarized. Finally, the research trend for hot particle analysis methods was proposed.
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Affiliation(s)
- Guifang Zhao
- Beijing Engineering Research Center of Radiographic Techniques and Equipment, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049, China; State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing, 100029, China
| | - Yang Shao
- Beijing Engineering Research Center of Radiographic Techniques and Equipment, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049, China
| | - Min Luo
- Beijing Engineering Research Center of Radiographic Techniques and Equipment, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049, China
| | - Diandou Xu
- Beijing Engineering Research Center of Radiographic Techniques and Equipment, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049, China
| | - Duohong Li
- State Nuclear Security Technology Center, Beijing, 102401, China
| | - Zhiming Liu
- State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing, 100029, China
| | - Lingling Ma
- Beijing Engineering Research Center of Radiographic Techniques and Equipment, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049, China.
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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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Diacre A, Chalaux Clergue T, Burban S, Gauthier C, Hubert A, Humbert AC, Lefevre I, Fauré AL, Pointurier F, Evrard O. Temporal evolution of plutonium concentrations and isotopic ratios in the Ukedo - Takase Rivers draining the Difficult-To-Return zone in Fukushima, Japan (2013-2020). ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2023; 319:120963. [PMID: 36587785 DOI: 10.1016/j.envpol.2022.120963] [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: 10/21/2022] [Revised: 12/14/2022] [Accepted: 12/26/2022] [Indexed: 06/17/2023]
Abstract
In 2011, the Fukushima Dai-Ichi Nuclear Power Plant (FDNPP) accident released significant quantities of radionuclides into the environment. Japanese authorities decided to progressively reopen the Difficult-To-Return Zone after the decontamination of priority reconstruction zones. These areas include parts of the initially highly contaminated municipalities located to the north of the FDNPP, including Namie Town, an area drained by the Ukedo and Takase Rivers. Eleven years after the accident, research focused on the spatial distribution of plutonium (Pu) and radiocesium (Cs) isotopes at contrasted individual locations. To complement previous results, the current research was conducted on flood sediment deposits collected at the same locations after major flooding events during eleven fieldwork campaigns organised between 2013 and 2020 at the outlet of the Ukedo and Takase Rivers (n = 22). The results highlighted a global decrease of the Pu and 137Cs contents in sediment with time during the abandonment phase in the region, from 2013 (238.20 fg g-1) to 2020 (4.28 fg g-1). Furthermore, based on the analysis of the 240Pu/239Pu isotopic ratios, the plutonium transiting these rivers (range: 0.166 - 0.220) essentially originated from the global fallout (0.180 ± 0.014 (Kelley et al., 1999)). Sediment showed contrasted properties in the two investigated rivers, which is likely mainly the result of the occurrence of Ogaki Dam on upper sections of the Ukedo River as it strongly impacts the material supply from this river to the Pacific Ocean. A statistical analysis highlighted the strong correlation between Pu activity concentrations and 137Cs activities in both rivers, confirming that both radionuclides are transported with a similar pathway. Despite it was detected early after the accident (2011-2013), the current research demonstrates that plutonium originating from FDNPP is no longer detected in these rivers draining the Difficult-To-Return Zone at the onset of the reopening of the area to its former inhabitants.
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Affiliation(s)
- Aurélie Diacre
- Commissariat à L'Energie Atomique et Aux énergies Alternatives (CEA, DAM, DIF), F-91297, Arpajon, France; Laboratoire des Sciences Du Climat et de L'Environnement (LSCE/IPSL), Unité Mixte de Recherche 8212 (CEA/CNRS/UVSQ), Université Paris-Saclay, Gif-sur-Yvette, France.
| | - Thomas Chalaux Clergue
- Laboratoire des Sciences Du Climat et de L'Environnement (LSCE/IPSL), Unité Mixte de Recherche 8212 (CEA/CNRS/UVSQ), Université Paris-Saclay, Gif-sur-Yvette, France
| | - Soazig Burban
- Commissariat à L'Energie Atomique et Aux énergies Alternatives (CEA, DAM, DIF), F-91297, Arpajon, France
| | - Caroline Gauthier
- Laboratoire des Sciences Du Climat et de L'Environnement (LSCE/IPSL), Unité Mixte de Recherche 8212 (CEA/CNRS/UVSQ), Université Paris-Saclay, Gif-sur-Yvette, France
| | - Amélie Hubert
- Commissariat à L'Energie Atomique et Aux énergies Alternatives (CEA, DAM, DIF), F-91297, Arpajon, France
| | - Anne-Claire Humbert
- Commissariat à L'Energie Atomique et Aux énergies Alternatives (CEA, DAM, DIF), F-91297, Arpajon, France
| | - Irène Lefevre
- Laboratoire des Sciences Du Climat et de L'Environnement (LSCE/IPSL), Unité Mixte de Recherche 8212 (CEA/CNRS/UVSQ), Université Paris-Saclay, Gif-sur-Yvette, France
| | - Anne-Laure Fauré
- Commissariat à L'Energie Atomique et Aux énergies Alternatives (CEA, DAM, DIF), F-91297, Arpajon, France
| | - Fabien Pointurier
- Commissariat à L'Energie Atomique et Aux énergies Alternatives (CEA, DAM, DIF), F-91297, Arpajon, France
| | - Olivier Evrard
- Laboratoire des Sciences Du Climat et de L'Environnement (LSCE/IPSL), Unité Mixte de Recherche 8212 (CEA/CNRS/UVSQ), Université Paris-Saclay, Gif-sur-Yvette, France
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6
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Integrating the theory of sampling into a nuclear forensic investigation. Appl Radiat Isot 2022; 190:110513. [DOI: 10.1016/j.apradiso.2022.110513] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Revised: 08/12/2022] [Accepted: 10/11/2022] [Indexed: 11/17/2022]
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Johansen MP, Child DP, Collins R, Cook M, Davis J, Hotchkis MAC, Howard DL, Howell N, Ikeda-Ohno A, Young E. Radioactive particles from a range of past nuclear events: Challenges posed by highly varied structure and composition. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 842:156755. [PMID: 35718169 DOI: 10.1016/j.scitotenv.2022.156755] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Revised: 06/10/2022] [Accepted: 06/13/2022] [Indexed: 06/15/2023]
Affiliation(s)
- Mathew P Johansen
- Australian Nuclear Science and Technology Organisation (ANSTO), Locked Bag 2001, Kirrawee DC, NSW 2232, Australia.
| | - David P Child
- Australian Nuclear Science and Technology Organisation (ANSTO), Locked Bag 2001, Kirrawee DC, NSW 2232, Australia
| | | | - Megan Cook
- International Atomic Energy Agency (IAEA), Environmental Laboratories, Monaco
| | - Joel Davis
- Australian Nuclear Science and Technology Organisation (ANSTO), Locked Bag 2001, Kirrawee DC, NSW 2232, Australia
| | - Michael A C Hotchkis
- Australian Nuclear Science and Technology Organisation (ANSTO), Locked Bag 2001, Kirrawee DC, NSW 2232, Australia
| | - Daryl L Howard
- Australian Synchrotron, 800 Blackburn Road, Clayton, Victoria 3168, Australia
| | - Nicholas Howell
- Australian Nuclear Science and Technology Organisation (ANSTO), Locked Bag 2001, Kirrawee DC, NSW 2232, Australia
| | - Atsushi Ikeda-Ohno
- Japan Atomic Energy Agency (JAEA), 2-4 Shirakata, Tokai-mura, Naka-gun, Ibaraki-ken 319-1195, Japan
| | - Emma Young
- Australian Nuclear Science and Technology Organisation (ANSTO), Locked Bag 2001, Kirrawee DC, NSW 2232, Australia
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Wu J, Zheng X, Chen J, Yang G, Zheng J, Aono T. Distributions and impacts of plutonium in the environment originating from the Fukushima Daiichi Nuclear Power Plant accident: An overview of a decade of studies. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2022; 248:106884. [PMID: 35398758 DOI: 10.1016/j.jenvrad.2022.106884] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Revised: 03/27/2022] [Accepted: 03/28/2022] [Indexed: 06/14/2023]
Abstract
This paper reviews the current knowledge on plutonium (Pu) isotopic composition (the atom or activity ratios) and activity concentrations of 238Pu, 239Pu, 240Pu, and 241Pu resulting from the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident in 2011. In this critical review, we document the characteristic values of Pu atom or activity ratios (fingerprints) and present their spatial distributions around the FDNPP site. Based on multiple Pu fingerprints (238Pu/239+240Pu activity ratio, 240Pu/239Pu atom ratio, and 241Pu/239Pu atom ratio), we clarify that Pu contamination from the FDNPP accident occurred in a restricted terrestrial area, while Pu in the Northwest Pacific Ocean is still predominately sourced from the Pacific Proving Grounds (PPG) and global fallout. Using a simple two end-member mixing model, we calculate average contributions of Pu from the FDNPP accident of 13 ± 20% (n = 180) in soil samples, 55 ± 32% (n = 38) in leaf litter samples, and 67 ± 26% (n = 129) in air dust/black substances. In the marine environment, the PPG source average contributions are 45 ± 15% (n = 76) in seawater and 42 ± 12% (n = 48) in sediments. The spatial distributions of Pu atom or activity ratios based on existing studies suggest that: 1) in the terrestrial region investigated 80 km northwest of the FDNPP site, the Pu contamination is mainly observed in an area within a 50 km distance, and 2) in the terrestrial region investigated 60 km southwest of the FDNPP site, the Pu contamination is mainly observed in an area within a 30 km distance. Studies of Cs-bearing radioactive particles indicate that Pu occurs as Pu oxide, and the fuel fragments containing Pu that were released from the reactors to the surrounding environment are associated with micron-scale Cs-bearing radioactive particles. We note that the fractionation between Pu and other radionuclides occurred after release. These new findings about the Pu fingerprints around the FDNPP site will help researchers to establish a reference background database for future environmental risk assessment and geochemical study there.
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Affiliation(s)
- Junwen Wu
- Guangdong Provincial Key Laboratory of Marine Disaster Prediction and Prevention & Institute of Marine Sciences, Shantou University, Shantou, 515063, China; Southern Marine Science and Engineering Guangdong Laboratory, Guangzhou, 511458, China
| | - Xuemin Zheng
- Guangdong Provincial Key Laboratory of Marine Disaster Prediction and Prevention & Institute of Marine Sciences, Shantou University, Shantou, 515063, China
| | - Jisheng Chen
- Guangdong Provincial Key Laboratory of Marine Disaster Prediction and Prevention & Institute of Marine Sciences, Shantou University, Shantou, 515063, China
| | - Guosheng Yang
- National Institutes for Quantum Science and Technology, 4-9-1 Anagawa, Inage, Chiba, 263-8555, Japan
| | - Jian Zheng
- National Institutes for Quantum Science and Technology, 4-9-1 Anagawa, Inage, Chiba, 263-8555, Japan.
| | - Tatsuo Aono
- National Institutes for Quantum Science and Technology, 4-9-1 Anagawa, Inage, Chiba, 263-8555, Japan
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Yomogida T, Ouchi K, Oka T, Kitatsuji Y, Koma Y, Konno K. Analysis of particles containing alpha-emitters in stagnant water at torus room of Fukushima Dai-ichi Nuclear Power Station’s Unit 2 reactor. Sci Rep 2022; 12:7191. [PMID: 35577810 PMCID: PMC9110416 DOI: 10.1038/s41598-022-11334-1] [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: 01/13/2022] [Accepted: 04/20/2022] [Indexed: 11/09/2022] Open
Abstract
AbstractParticles containing alpha (α) nuclides were identified from sediment in stagnant water in the torus room of the Fukushima Dai-ichi Nuclear Power Station(FDiNPS)’s Unit 2 reactor. We analyzed uranium (U), which is the main component of nuclear fuel, using scanning electron microscopy (SEM). Other α-nuclides (plutonium [Pu], americium [Am], and curium [Cm]) were detected by alpha track detection and the morphology of particles with α-nuclides were analyzed by SEM-energy dispersive X-Ray (EDX) analysis. Several uranium-bearing particles ranging from sub-µm to several µm in size were identified by SEM observation. These particles contained zirconium (Zr) and other elements which constituted fuel cladding and structural materials. The 235U/238U isotope ratio in the solid fractions that included U particles was consistent with what was found for the nuclear fuel in the Unit 2 reactor. This indicated that the U of similar fuel composition had made finer. The α-nuclide-containing particles identified by alpha track analysis were several tens to several hundred µm in size. The EDX spectra showed that these particles mainly comprised iron (Fe). Since the amount of α-nuclide material was very small, Pu, Am, and Cm were adsorbed on the Fe particles. This study clarifies that the major morphologies of U and other α-nuclides in the sediment of stagnant water in the torus room of FDiNPS’s Unit 2 reactor differed.
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Yamamoto T. Activity and weight ratios of cesium, uranium, plutonium, and curium isotopes based on elaborate inventory calculations of Fukushima Dai-ichi NPP units 1 to 3. J NUCL SCI TECHNOL 2022. [DOI: 10.1080/00223131.2022.2051764] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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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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Zhong N, Li L, Yang X, Zhao Y. Analytical Methods for the Determination of 90Sr and 239,240Pu in Environmental Samples. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27061912. [PMID: 35335276 PMCID: PMC8952015 DOI: 10.3390/molecules27061912] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 02/15/2022] [Accepted: 02/22/2022] [Indexed: 11/16/2022]
Abstract
Artificial long-lived radionuclides such as 90Sr and 239,240Pu have been long released into the environment by human nuclear activities, which have a profound impact on the ecological environment. It is of great significance to monitor the concentration of these radionuclides for environmental safety. This paper summarizes and critically discusses the separation and measurement methods for ultra-trace determination of 90Sr, 239Pu, and 240Pu in the environment. After selecting the measurement method, it is necessary to consider the decontamination of the interference from matrix elements and the key elements, and this involves the choice of the separation method. Measurement methods include both radiometric methods and non-radiometric methods. Radiometric methods, including alpha spectroscopy, liquid scintillation spectrometry, etc., are commonly used methods for measuring 239+240Pu and 90Sr. Mass spectrometry, as the representative of non-radiometric measurement methods, has been regarded as the most promising analytical method due to its high absolute sensitivity, low detection limit, and relatively short sample-analysis time. Through the comparison of various measurement methods, the future development trend of radionuclide measurement is prospected in this review. The fully automatic and rapid analysis method is a highlight. The new mass spectrometer with ultra-high sensitivity shows strong analytical capabilities for extremely low concentrations of 90Sr, 239Pu, and 240Pu, and it is expected to develop determination methods with higher sensitivity and lower detection limit.
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Grambow B, Nitta A, Shibata A, Koma Y, Utsunomiya S, Takami R, Fueda K, Ohnuki T, Jegou C, Laffolley H, Journeau C. Ten years after the NPP accident at Fukushima : review on fuel debris behavior in contact with water. J NUCL SCI TECHNOL 2021. [DOI: 10.1080/00223131.2021.1966347] [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)
- Bernd Grambow
- SUBATECH (IMT Atlantique, CNRS-IN2P3, University De Nantes), Nantes, France
- Advanced Science Research Center, Japan Atomic Energy Agency, Ibaraki, Japan
| | - Ayako Nitta
- Collaborative Laboratories for Advanced Decommissioning Science, Japan Atomic Energy Agency(JAEA), Ibaraki, Japan
| | - Atsuhiro Shibata
- Collaborative Laboratories for Advanced Decommissioning Science, Japan Atomic Energy Agency(JAEA), Ibaraki, Japan
| | - Yoshikazu Koma
- Nuclear Fuel Cycle Engineering Laboratories, Japan Atomic Energy Agency, Ibaraki, Japan
| | | | - Ryu Takami
- Department of Chemistry, Kyushu University, Fukuoka, Japan
| | - Kazuki Fueda
- Department of Chemistry, Kyushu University, Fukuoka, Japan
| | - Toshihiko Ohnuki
- NPO Environmental Sustainable Research Laboratory, Tokyo Institute of Technology, Meguro-ku, Japan
| | - Christophe Jegou
- CEA, DES, ISEC, DE2D, University of Montpellier, Marcoule, France
| | - Hugo Laffolley
- SUBATECH (IMT Atlantique, CNRS-IN2P3, University De Nantes), Nantes, France
- CEA, DES, IRESNE, DTN, Severe Accident Experimental Laboratory, Saint-Paul-Lez-Durance, France
| | - Christophe Journeau
- CEA, DES, IRESNE, DTN, Severe Accident Experimental Laboratory, Saint-Paul-Lez-Durance, France
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Ohnishi S, Thornton B, Koike T, Odano N, Asami M, Kamada S, Nagano K, Ura T. Analysis of radioactive cesium-enriched particles and measurement of their distribution in marine sediment near Fukushima Daiichi nuclear power plant. J NUCL SCI TECHNOL 2021. [DOI: 10.1080/00223131.2021.1879688] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Affiliation(s)
- Seiki Ohnishi
- Department of Marine Risk Assessment, National Maritime Research Institute, Mitaka, Tokyo, Japan
| | - Blair Thornton
- Department of Mechanical and Biofunctional Systems, Institute of Industrial Science, the University of Tokyo, Meguro-ku, Tokyo, Japan
| | - Toshikazu Koike
- Ship & Ocean Project Headquarters, Mitsui Engineering & Shipbuilding Co. Ltd, Akishima, Tokyo, Japan
| | - Naoteru Odano
- Department of Marine Risk Assessment, National Maritime Research Institute, Mitaka, Tokyo, Japan
| | - Mitsufumi Asami
- Department of Marine Risk Assessment, National Maritime Research Institute, Mitaka, Tokyo, Japan
| | - So Kamada
- Department of Marine Risk Assessment, National Maritime Research Institute, Mitaka, Tokyo, Japan
| | - Kazunori Nagano
- Department of Mechanical and Biofunctional Systems, Institute of Industrial Science, the University of Tokyo, Meguro-ku, Tokyo, Japan
| | - Tamaki Ura
- Department of Mechanical and Biofunctional Systems, Institute of Industrial Science, the University of Tokyo, Meguro-ku, Tokyo, Japan
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15
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Tighe C, Castrillejo M, Christl M, Degueldre C, Andrew J, Semple KT, Joyce MJ. Local and global trace plutonium contributions in fast breeder legacy soils. Nat Commun 2021; 12:1381. [PMID: 33741911 PMCID: PMC7979690 DOI: 10.1038/s41467-021-21575-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Accepted: 01/22/2021] [Indexed: 01/31/2023] Open
Abstract
Trace-level plutonium in the environment often comprises local and global contributions, and is usually anthropogenic in origin. Here, we report estimates of local and global contributions to trace-level plutonium in soil from a former, fast-breeder reactor site. The measured 240Pu/239Pu ratio is anomalously low, as per the reduced 240Pu yield expected in plutonium bred with fast neutrons. Anomalies in plutonium concentration and isotopic ratio suggest forensic insight into specific activities on site, such as clean-up or structural change. Local and global 239Pu contributions on-site are estimated at (34 ± 1)% and (66 ± 3)%, respectively, with mass concentrations of (183 ± 6) fg g-1 and (362 ± 13) fg g-1. The latter is consistent with levels at undisturbed and distant sites, (384 ± 44) fg g-1, where no local contribution is expected. The 240Pu/239Pu ratio for site-derived material is estimated at 0.05 ± 0.04. Our study demonstrates the multi-faceted potential of trace plutonium assay to inform clean-up strategies of fast breeder legacies.
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Affiliation(s)
- Chris Tighe
- grid.9835.70000 0000 8190 6402Department of Engineering, Lancaster University, Lancaster, UK
| | - Maxi Castrillejo
- grid.5801.c0000 0001 2156 2780Laboratory of Ion Beam Physics, ETH - Zürich, Zürich, Switzerland
| | - Marcus Christl
- grid.5801.c0000 0001 2156 2780Laboratory of Ion Beam Physics, ETH - Zürich, Zürich, Switzerland
| | - Claude Degueldre
- grid.9835.70000 0000 8190 6402Department of Engineering, Lancaster University, Lancaster, UK
| | - Jeremy Andrew
- Dounreay Site Restoration Ltd., Dounreay, Thurso, Scotland
| | - Kirk T. Semple
- grid.9835.70000 0000 8190 6402Lancaster Environment Centre, Lancaster University, Lancaster, UK
| | - Malcolm J. Joyce
- grid.9835.70000 0000 8190 6402Department of Engineering, Lancaster University, Lancaster, UK
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16
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Johansen MP, Anderson D, Child D, Hotchkis MAC, Tsukada H, Okuda K, Hinton TG. Differentiating Fukushima and Nagasaki plutonium from global fallout using 241Pu/ 239Pu atom ratios: Pu vs. Cs uptake and dose to biota. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 754:141890. [PMID: 32916482 DOI: 10.1016/j.scitotenv.2020.141890] [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: 07/08/2020] [Revised: 08/19/2020] [Accepted: 08/20/2020] [Indexed: 06/11/2023]
Abstract
Plutonium (Pu) has been released in Japan by two very different types of nuclear events - the 2011 Fukushima accident and the 1945 detonation of a Pu-core weapon at Nagasaki. Here we report on the use of Accelerator Mass Spectrometry (AMS) methods to distinguish the FDNPP-accident and Nagasaki-detonation Pu from worldwide fallout in soils and biota. The FDNPP-Pu was distinct in local environmental samples through the use of highly sensitive 241Pu/239Pu atom ratios. In contrast, other typically-used Pu measures (240Pu/239Pu atom ratios, activity concentrations) did not distinguish the FDNPP Pu from background in most 2016 environmental samples. Results indicate the accident contributed new Pu of ~0.4%-2% in the 0-5 cm soils, ~0.3%-3% in earthworms, and ~1%-10% in wild boar near the FDNPP. The uptake of Pu in the boar appears to be relatively uninfluenced by the glassy particle forms of fallout near the FDNPP, whereas the 134,137Cs uptake appears to be highly influenced. Near Nagasaki, the lasting legacy of Pu is greater with high percentages of Pu sourced from the 1945 detonation (~93% soils, ~88% earthworm, ~96% boar). The Pu at Nagasaki contrasts with that from the FDNPP in having proportionately higher 239Pu and was distinguished by both 240Pu/239Pu and 241Pu/239Pu atom ratios. However, compared with the contamination near the Chernobyl accident site, the Pu amounts at all study sites in Japan are orders of magnitude lower. The dose rates from Pu to organisms in the FDNPP and Nagasaki areas, as well as to human consumers of wild boar meat, have been only slightly elevated above background. Our data demonstrate the greater sensitivity of 241Pu/239Pu atom ratios in tracing Pu from nuclear releases and suggest that the Nagasaki-detonation Pu will be distinguishable in the environment for much longer than the FDNPP-accident Pu.
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Affiliation(s)
- Mathew P Johansen
- Australian Nuclear Science and Technology Organisation, Sydney, Australia.
| | - Donovan Anderson
- Institute of Environmental Radioactivity, Fukushima University, 960-1248, Fukushima Prefecture, Fukushima, Kanayagawa, Japan; Symbiotic Systems Science and Technology, Fukushima University, 960-1248, Fukushima Prefecture, Fukushima, Kanayagawa, Japan
| | - David Child
- Australian Nuclear Science and Technology Organisation, Sydney, Australia
| | | | - Hirofumi Tsukada
- Institute of Environmental Radioactivity, Fukushima University, 960-1248, Fukushima Prefecture, Fukushima, Kanayagawa, Japan
| | - Kei Okuda
- Faculty of Human Environmental Studies, Hiroshima Shudo University, 731-3195, Hiroshima Prefecture, Asaminami-ku, Ozuka-higashi, Japan
| | - Thomas G Hinton
- Institute of Environmental Radioactivity, Fukushima University, 960-1248, Fukushima Prefecture, Fukushima, Kanayagawa, Japan; CERAD CoE, Norwegian University of Life sciences, Faculty for Environmental Sciences and Nature Research Management, Aas, Norway
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17
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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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18
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Kurihara E, Takehara M, Suetake M, Ikehara R, Komiya T, Morooka K, Takami R, Yamasaki S, Ohnuki T, Horie K, Takehara M, Law GTW, Bower W, W Mosselmans JF, Warnicke P, Grambow B, Ewing RC, Utsunomiya S. Particulate plutonium released from the Fukushima Daiichi meltdowns. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 743:140539. [PMID: 32663681 DOI: 10.1016/j.scitotenv.2020.140539] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 06/20/2020] [Accepted: 06/24/2020] [Indexed: 06/11/2023]
Abstract
Traces of Pu have been detected in material released from the Fukushima Daiichi Nuclear Power Plant (FDNPP) in March of 2011; however, to date the physical and chemical form of the Pu have remained unknown. Here we report the discovery of particulate Pu associated with cesium-rich microparticles (CsMPs) that formed in and were released from the reactors during the FDNPP meltdowns. The Cs-pollucite-based CsMP contained discrete U(IV)O2 nanoparticles, <~10 nm, one of which is enriched in Pu adjacent to fragments of Zr-cladding. The isotope ratios, 235U/238U, 240Pu/239Pu, and 242Pu/239Pu, of the CsMPs were determined to be ~0.0193, ~0.347, and ~0.065, respectively, which are consistent with the calculated isotopic ratios of irradiated-fuel fragments. Thus, considering the regional distribution of CsMPs, the long-distance dispersion of Pu from FNDPP is attributed to the transport by CsMPs that have incorporated nanoscale fuel fragments prior to their dispersion up to 230 km away from the Fukushima Daiichi reactor site.
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Affiliation(s)
- Eitaro Kurihara
- Department of Chemistry, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Masato Takehara
- Department of Chemistry, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Mizuki Suetake
- Department of Chemistry, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Ryohei Ikehara
- Department of Chemistry, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Tatsuki Komiya
- Department of Chemistry, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Kazuya Morooka
- Department of Chemistry, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Ryu Takami
- Department of Chemistry, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Shinya Yamasaki
- Faculty of Pure and Applied Sciences and Center for Research in Isotopes and Environmental Dynamics, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8577, Japan
| | - Toshihiko Ohnuki
- Laboratory for Advanced Nuclear Energy, Institute of Innovative Research, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8550, Japan
| | - Kenji Horie
- National Institute of Polar Research, 10-3, Midori-cho, Tachikawa-shi, Tokyo 190-8518, Japan; Department of Polar Science, The Graduate University for Advanced Studies (SOKENDAI), Shonan Village, Hayama, Kanagawa 240-0193, Japan
| | - Mami Takehara
- National Institute of Polar Research, 10-3, Midori-cho, Tachikawa-shi, Tokyo 190-8518, Japan
| | - Gareth T W Law
- Radiochemistry Unit, Department of Chemistry, The University of Helsinki, Helsinki 00014, Finland
| | - William Bower
- Radiochemistry Unit, Department of Chemistry, The University of Helsinki, Helsinki 00014, Finland
| | | | - Peter Warnicke
- Swiss Light Source, Paul Scherrer Institute, 5232 Villigen, Switzerland
| | - Bernd Grambow
- SUBATECH, IMT Atlantique, CNRS-IN2P3, The University of Nantes, Nantes 44307, France
| | - Rodney C Ewing
- Department of Geological Sciences and Center for International Security and Cooperation, Stanford University, Stanford, CA 94305-2115, USA
| | - Satoshi Utsunomiya
- Department of Chemistry, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan.
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