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Kavasi N, Arae H, Aono T, Sahoo SK. Distribution of strontium-90 in soils affected by Fukushima dai-ichi nuclear power station accident in the context of cesium-137 contamination. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2023; 326:121487. [PMID: 36958665 DOI: 10.1016/j.envpol.2023.121487] [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: 01/14/2023] [Revised: 03/04/2023] [Accepted: 03/21/2023] [Indexed: 06/18/2023]
Abstract
90Sr and 137Cs activity concentrations were determined by radiometric methods in 76 soil samples (soil, litter, rain gutter deposit, and roadside sediment samples) affected by the Fukushima Dai-ichi Nuclear Power Station (FDNPS) accident and collected from the Fukushima exclusion zone. The 90Sr and 137Cs activity concentrations were in the range of 3 to 1050 Bq kg-1 (median 82 Bq·kg-1) and 0.7 to 6770 kBq·kg-1 (median 890 kBq·kg-1), respectively (decay correction date: March 15, 2011). A strong positive correlation was found between 90Sr and 137Cs activity concentration and higher mobility of 90Sr was confirmed in Japanese soil samples. The activity ratio of 90Sr/137Cs in 85% of all samples was in the range of 5.0 × 10-5 to 5.0 × 10-4 with a median of 1.2 × 10-4. From the activity ratio values it was concluded that the 90Sr released to the atmosphere was only around 0.0003-0.02 PBq which is negligible compared to the Chernobyl accident (∼10 PBq) or other nuclear accident contaminations. From the standpoints of radioecology and radiation safety, 137Cs remains the primary pollutant of the FDNPS accident.
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Affiliation(s)
- Norbert Kavasi
- Department of Radioecology and Fukushima Project, National Institute of Radiological Sciences, National Institutes for Quantum Sciences and Technology, 4-9-1 Anagawa, Inage-ku, Chiba, 263-8555, Japan; Laboratory for Radiochemistry, Department of Environmental Sciences, Jožef Stefan Institute, 39 Jamova, Ljubljana, 1000, Slovenia
| | - Hideki Arae
- Department of Radioecology and Fukushima Project, National Institute of Radiological Sciences, National Institutes for Quantum Sciences and Technology, 4-9-1 Anagawa, Inage-ku, Chiba, 263-8555, Japan
| | - Tatsuo Aono
- Department of Radioecology and Fukushima Project, National Institute of Radiological Sciences, National Institutes for Quantum Sciences and Technology, 4-9-1 Anagawa, Inage-ku, Chiba, 263-8555, Japan
| | - Sarata Kumar Sahoo
- Department of Radioecology and Fukushima Project, National Institute of Radiological Sciences, National Institutes for Quantum Sciences and Technology, 4-9-1 Anagawa, Inage-ku, Chiba, 263-8555, Japan.
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Anderson J, Caron F, Beckett P, Spiers G, Lévesque N, Charbonneau G, Halvorson B, Dufour H, Lock A. Distribution of metals and radionuclides in the lichens Cladonia rangiferina and C. mitis from the past uranium mining region of Elliot Lake, Ontario, Canada. Heliyon 2022; 8:e11863. [PMID: 36544830 PMCID: PMC9761608 DOI: 10.1016/j.heliyon.2022.e11863] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2022] [Revised: 11/07/2022] [Accepted: 11/17/2022] [Indexed: 12/12/2022] Open
Abstract
The present study was performed in the Elliot Lake area (Ontario, Canada), a site of uranium mining and milling for nearly 40 years between 1950's and 1990's. Although mining activities ceased in the mid-1990's, the site hosts several tailings management areas (TMAs) which are under ongoing rehabilitation and monitoring. Several surveys using lichens as a biomonitoring tool were completed in the 1980s and the 1990s to assess the levels of contaminants. The present survey aimed to re-visit the historical surveys, and to determine the current status of environmental recovery of the area. Our survey consisted of sampling two lichen species, Cladonia rangiferina and C. mitis, in an area covering up to 50 km from the former mining operation and the TMAs. The results reported in this work indicated that the levels of metals and radionuclides, diagnostic of mining operations, have decreased over time: particularly, the U, Th and Pb levels in both lichen species dropped by about two orders of magnitude by the 2020's compared to the 1980's. Likewise, the Cs-137 levels in both lichen species reflect present day global background. The study provides a new set of present-day regional baseline elemental concentrations for other metals that are associated with mining (Cd, As, Ti, Cs). Finally, there were weak but statistically significant differences in the levels of some elements (U, Th, Cd) between the two lichens, suggesting these two species might have different capture mechanisms or retention abilities.
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Affiliation(s)
- J. Anderson
- Testmark Laboratories Ltd, 7 Margaret St. Garson, ON P3L 1E1 Canada,Harquail School of Earth Sciences, Laurentian University, 935 Ramsey Lake Rd., Sudbury, ON, P3E 2C6 Canada
| | - F. Caron
- Department of Chemistry and Chemical Engineering, Royal Military College of Canada, 13 General Crerar Cr Kingston, ON, K7K 7B4 Canada,Corresponding author.
| | - P. Beckett
- Vale Living with Lakes Centre, Laurentian University, Sudbury, ON, P3E 2C6 Canada
| | - G.A. Spiers
- Vale Living with Lakes Centre, Laurentian University, Sudbury, ON, P3E 2C6 Canada
| | - N. Lévesque
- School of Natural Sciences, Laurentian University, 935 Ramsey Lake Rd. Sudbury, ON, P3E 2C6 Canada
| | - G.M. Charbonneau
- Testmark Laboratories Ltd, 7 Margaret St. Garson, ON P3L 1E1 Canada
| | - B. Halvorson
- Testmark Laboratories Ltd, 7 Margaret St. Garson, ON P3L 1E1 Canada
| | - H. Dufour
- Harquail School of Earth Sciences, Laurentian University, 935 Ramsey Lake Rd., Sudbury, ON, P3E 2C6 Canada
| | - A. Lock
- School of Natural Sciences, Laurentian University, 935 Ramsey Lake Rd. Sudbury, ON, P3E 2C6 Canada
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Tan S, Ni R. Universality and Intermittency of Pair Dispersion in Turbulence. PHYSICAL REVIEW LETTERS 2022; 128:114502. [PMID: 35363001 DOI: 10.1103/physrevlett.128.114502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Revised: 12/22/2021] [Accepted: 01/28/2022] [Indexed: 06/14/2023]
Abstract
Turbulence can disperse a concentrated parcel of pollutants at a rate over nine orders of magnitude higher than its purely diffusive counterpart. One intriguing signature of turbulent dispersion is its superdiffusive scaling. However, the universality of this scaling law is still in question. By leveraging a new laboratory facility, particle pairs with small initial separations can be tracked over four decades of separation in time and five decades of separation in squared displacement, thereby observing the full range of dispersion scaling laws. The results show that the classical Richardson cubic scaling will be reached not for an initial separation asymptotically close to zero but at a critical value, and this value does not appear to depend on the Reynolds number, providing an effective way to study universal dispersion dynamics. Additionally, the results agree well with the prediction based on the multifractal model and may help reconcile different reported scaling laws from laboratory experiments and field studies.
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Affiliation(s)
- Shiyong Tan
- Department of Mechanical Engineering, The Johns Hopkins University, Baltimore, Maryland 21218, USA
| | - Rui Ni
- Department of Mechanical Engineering, The Johns Hopkins University, Baltimore, Maryland 21218, USA
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Kadowaki M, Furuno A, Nagai H, Kawamura H, Terada H, Tsuduki K, El-Assad H. Validity of the source term for the Fukushima Dai-ichi Nuclear Power Station accident estimated using local-scale atmospheric dispersion simulations to reproduce the large-scale atmospheric dispersion of 137Cs. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2021; 237:106704. [PMID: 34325219 DOI: 10.1016/j.jenvrad.2021.106704] [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: 03/15/2021] [Revised: 07/13/2021] [Accepted: 07/14/2021] [Indexed: 06/13/2023]
Abstract
The source term of 137Cs from the Fukushima Dai-ichi Nuclear Power Station (FDNPS) accident was estimated from the results of local-scale atmospheric dispersion simulations and measurements. To confirm the source term's validity for reproducing the large-scale atmospheric dispersion of 137Cs, this study conducted hemispheric-scale atmospheric and oceanic dispersion simulations. In the dispersion simulations, the atmospheric-dispersion database system Worldwide version of System for Prediction of Environmental Emergency Dose Information (WSPEEDI)-DB and oceanic dispersion model SEA-GEARN-FDM that were developed by the Japan Atomic Energy Agency were used. Compared with the air concentrations of 137Cs measured by the Comprehensive Nuclear-Test-Ban Treaty Organization, overall, the WSPEEDI-DB simulations well reproduced the measurements, whereas the simulation results partly overestimated some measurements. Furthermore, the validity of the deposition of 137Cs by WSPEEDI-DB was investigated using SEA-GEARN-FDM and concentrations of 137Cs in seawater sampled from the North Pacific. Seawater concentrations of 137Cs by the oceanic dispersion simulation, in which the deposition flux of 137Cs by WSPEEDI-DB was used as input from the atmosphere to oceans, were statistically consistent to the measurement. However, the simulated seawater concentrations of 137Cs were underestimated regionally in the North Pacific. Both the overestimation of air concentrations and underestimation of seawater concentrations could be attributed to the less amounts of 137Cs deposition by less precipitation over the North Pacific. The overestimation and underestimation could be improved without contradiction between the air and seawater concentrations of 137Cs using more realistic precipitation in atmospheric dispersion simulations. This shows that the source term validated in this study could reproduce the spatiotemporal distribution of 137Cs from the FDNPS accident in both local and large-scale atmospheric dispersion simulations.
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Affiliation(s)
- Masanao Kadowaki
- Japan Atomic Energy Agency, 2-4 Shirakata, Tokai, Naka-gun, Ibaraki, 319-1195, Japan.
| | - Akiko Furuno
- Japan Atomic Energy Agency, 2-4 Shirakata, Tokai, Naka-gun, Ibaraki, 319-1195, Japan
| | - Haruyasu Nagai
- Japan Atomic Energy Agency, 2-4 Shirakata, Tokai, Naka-gun, Ibaraki, 319-1195, Japan
| | - Hideyuki Kawamura
- Japan Atomic Energy Agency, 2-4 Shirakata, Tokai, Naka-gun, Ibaraki, 319-1195, Japan
| | - Hiroaki Terada
- Japan Atomic Energy Agency, 2-4 Shirakata, Tokai, Naka-gun, Ibaraki, 319-1195, Japan
| | - Katsunori Tsuduki
- Japan Atomic Energy Agency, 2-4 Shirakata, Tokai, Naka-gun, Ibaraki, 319-1195, Japan
| | - Hamza El-Assad
- Japan Atomic Energy Agency, 2-4 Shirakata, Tokai, Naka-gun, Ibaraki, 319-1195, Japan
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Murugan R, Kavasi N, Sahoo SK, Omori Y, Sorimachi A, Takahashi H, Aono T. Measurement of uranium isotope ratios in Fukushima-accident contaminated soil samples using multi collector inductively coupled plasma mass spectrometry. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2021; 232:106568. [PMID: 33740532 DOI: 10.1016/j.jenvrad.2021.106568] [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: 12/15/2020] [Revised: 02/19/2021] [Accepted: 02/21/2021] [Indexed: 06/12/2023]
Abstract
In the present study, 137Cs and 238U activity concentrations, 234U/238U activity ratio, and 235U/238U isotope ratio were measured in fifteen soil samples collected from the exclusion zone around the Fukushima Daiichi Nuclear Power Station (FDNPS). The 137Cs activity concentrations of Fukushima-accident contaminated soil samples ranged from 29.9 to 4780 kBq kg-1 with a mean of 2007 kBq kg-1. On the other hand, the 238U activity concentrations of these soil samples ranged from 5.2 to 22.4 Bq kg-1 with a mean of 13.2 Bq kg-1. The activity ratios of 234U/238U ranged from 0.973 to 1.023. The 235U/238U isotope ratios of these exclusion zone soil samples varied from 0.007246 to 0.007260, and they were similar to the natural terrestrial ratio confirming the natural origin. Using isotope dilution technique, the 235U/137Cs activity ratio was theoretically estimated for highly 137Cs contaminated soil samples from Fukushima exclusion zone ranged from 5.01 × 10-8 - 6.16 × 10-7 with a mean value of 2.51 × 10-7.
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Affiliation(s)
- R Murugan
- National Institutes for Quantum and Radiological Sciences and Technology (QST), 4-9-1 Anagawa, Inage-ku, Chiba, 263-8555, Japan
| | - N Kavasi
- National Institutes for Quantum and Radiological Sciences and Technology (QST), 4-9-1 Anagawa, Inage-ku, Chiba, 263-8555, Japan
| | - S K Sahoo
- National Institutes for Quantum and Radiological Sciences and Technology (QST), 4-9-1 Anagawa, Inage-ku, Chiba, 263-8555, Japan.
| | - Y Omori
- Fukushima Medical University, Hikarigaoka, Fukushima, 960-1295, Japan
| | - A Sorimachi
- Fukushima Medical University, Hikarigaoka, Fukushima, 960-1295, Japan
| | - H Takahashi
- National Institutes for Quantum and Radiological Sciences and Technology (QST), 4-9-1 Anagawa, Inage-ku, Chiba, 263-8555, Japan
| | - T Aono
- National Institutes for Quantum and Radiological Sciences and Technology (QST), 4-9-1 Anagawa, Inage-ku, Chiba, 263-8555, Japan
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Kavasi N, Sahoo SK, Aono T. Analytical procedure using DGA-normal resin developed for separation of 90Sr from radiocaesium and other elements. J Radioanal Nucl Chem 2021. [DOI: 10.1007/s10967-021-07662-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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7
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The Occurrence of Skeletons of Silicoflagellata and Other Siliceous Bioparticles in Floral Honeys. Foods 2021; 10:foods10020421. [PMID: 33672957 PMCID: PMC7918607 DOI: 10.3390/foods10020421] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 02/05/2021] [Accepted: 02/09/2021] [Indexed: 11/17/2022] Open
Abstract
Siliceous marine microfossils were unexpectedly discovered during the analysis of flower honey samples from Poland and Tunisia. The microfossils were represented by protist with siliceous skeletons: silicoflagellates, diatoms, and endoskeletal dinoflagellates. This is the first record of such microfossils in honeys. Based on the high percent of anemophilous pollen grains and spores in the sample, it was hypothesized that silicoflagellates were deposited from the air onto the nectariferous flowers, then bees harvested them with the nectar. Based on the comparison of pollen content of honeys and flowering calendar of Tunisia, the harvest time of honey was identified as a period between 1 April and 31 May 2011. Trajectory analysis of air masses in this period confirmed that siliceous microfossils could be aerosolized by wind from the rocks of the so-called Tripoli Formation of Messinian age (6–7 Ma). Similar to the Tunisian case, the Polish trajectory simulation also supports the hypothesis of atmospheric transport of silicoflagellates from outcrops of Oligocene age in the Polish Outer Carpathians. In the case of diatom content of honey, however, the source can be both natural (wind) and artificial (diatomaceous earth filters). For a correct determination, natural sources of siliceous bioparticles, such as wind transport from nearby outcrops should be also considered. Silicoflagellates could be used as complementary indicators of the geographical origin of honeys collected in areas characterized by diatomite outcrops, supporting the results obtained with other methods; thus, such indicators merit further studies within the area of honey authenticity.
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8
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Higher-order statistics based multifractal predictability measures for anisotropic turbulence and the theoretical limits of aviation weather forecasting. Sci Rep 2019; 9:19829. [PMID: 31882685 PMCID: PMC6934490 DOI: 10.1038/s41598-019-56304-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Accepted: 12/04/2019] [Indexed: 11/08/2022] Open
Abstract
Theoretical predictability measures of turbulent atmospheric flows are essential in estimating how realistic the current storm-scale strategic forecast skill expectations are. Atmospheric predictability studies in the past have usually neglected intermittency and anisotropy, which are typical features of atmospheric flows, rendering their application to the storm-scale weather regime ineffective. Furthermore, these studies are frequently limited to second-order statistical measures, which do not contain information about the rarer, more severe, and, therefore, more important (from a forecasting and mitigation perspective) weather events. Here we overcome these rather severe limitations by proposing an analytical expression for the theoretical predictability limits of anisotropic multifractal fields based on higher-order autocorrelation functions. The predictability limits are dependent on the order of statistical moment (q) and are smaller for larger q. Since higher-order statistical measures take into account rarer events, such more extreme phenomena are less predictable. While spatial anisotropy of the fields seems to increase their predictability limits (making them larger than the commonly expected eddy turnover times), the ratio of anisotropic to isotropic predictability limits is independent of q. Our results indicate that reliable storm-scale weather forecasting with around 3 to 5 hours lead time is theoretically possible.
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9
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Long term corrosion estimation of carbon steel, titanium and its alloy in backfill material of compacted bentonite for nuclear waste repository. Sci Rep 2019; 9:3195. [PMID: 30824747 PMCID: PMC6397154 DOI: 10.1038/s41598-019-39751-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Accepted: 12/10/2018] [Indexed: 11/08/2022] Open
Abstract
The container of high-level radioactive waste (HLRW) being in deep geological disposal, the backfill material is needed to serve as the second defense for HLRW and the highly compacted bentonite is generally selected. As the time goes, the underground water will infiltrate the backfill, causing the corrosion of materials for the building of containers in the formed electrolyte. Carbon steel, titanium and its alloy are the potential candidate materials for the fabrication of HLRW containers. The current investigation aims at assessing the safety of HLRW container in deep geological disposal for hundreds of thousands of years and facilitating the material selection for future container fabrication by estimating their corrosion behavior in compacted bentonite with a series of moisture content at different temperatures through electrochemical methods including open circuit potential (OCP), electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization curve (PC) measurements. The corrosion rates were estimated for a carbon steel, a pure titanium and a titanium alloy in compacted Gaomiaozi Bentonite infiltrated with simulated underground water in Beishan area of China over an expected disposal period up to 106 years respectively, showing that titanium and its alloy are more reliable materials for building HLRW containers than carbon steel.
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10
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Long PK, Hien PD, Quang NH. Atmospheric transport of 131I and 137Cs from Fukushima by the East Asian northeast monsoon. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2019; 197:74-80. [PMID: 30544021 DOI: 10.1016/j.jenvrad.2018.12.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2018] [Revised: 12/01/2018] [Accepted: 12/02/2018] [Indexed: 06/09/2023]
Abstract
The Lagrangian particle dispersion model FLEXPART was used to simulate atmospheric dispersion of radionuclides from the Fukushima nuclear power plant (FNPP) towards the Tropical Western Pacific (TWP) and Southeast Asia (SEA). The simulation model distinguished between hemispherical transport via the jet stream and regional transport within the marine boundary layer by the East Asian northeast monsoon. This regional transport was driven by anticyclonic circulation over southern Japan and the western Pacific resulting from a recurrent eastward extension of the Siberian High to the Pacific Ocean. Activity concentrations of 131I and 137Cs measured at ten monitoring stations in TWP and SEA were used to validate the particle dispersion model. Good agreement between the FLEXPART model and observations yields confidence regarding its application to assess radiation impacts and support emergency planning in response to a possible future nuclear accident in the region.
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Affiliation(s)
- P K Long
- Nuclear Training Center, 140 Nguyen Tuan, Hanoi, Viet Nam
| | - P D Hien
- Vietnam Atomic Energy Institute, 59 Ly Thuong Kiet, Hanoi, Viet Nam.
| | - N H Quang
- Vietnam Atomic Energy Institute, 59 Ly Thuong Kiet, Hanoi, Viet Nam
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11
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Zirconium decontamination factor test on DGA and Sr resin for 90Sr analysis using inorganic mass spectrometry. J Radioanal Nucl Chem 2018. [DOI: 10.1007/s10967-018-6312-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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12
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Leelőssy Á, Lagzi I, Kovács A, Mészáros R. A review of numerical models to predict the atmospheric dispersion of radionuclides. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2018; 182:20-33. [PMID: 29179047 DOI: 10.1016/j.jenvrad.2017.11.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2017] [Revised: 11/03/2017] [Accepted: 11/06/2017] [Indexed: 06/07/2023]
Abstract
The field of atmospheric dispersion modeling has evolved together with nuclear risk assessment and emergency response systems. Atmospheric concentration and deposition of radionuclides originating from an unintended release provide the basis of dose estimations and countermeasure strategies. To predict the atmospheric dispersion and deposition of radionuclides several numerical models are available coupled with numerical weather prediction (NWP) systems. This work provides a review of the main concepts and different approaches of atmospheric dispersion modeling. Key processes of the atmospheric transport of radionuclides are emission, advection, turbulent diffusion, dry and wet deposition, radioactive decay and other physical and chemical transformations. A wide range of modeling software are available to simulate these processes with different physical assumptions, numerical approaches and implementation. The most appropriate modeling tool for a specific purpose can be selected based on the spatial scale, the complexity of meteorology, land surface and physical and chemical transformations, also considering the available data and computational resource. For most regulatory and operational applications, offline coupled NWP-dispersion systems are used, either with a local scale Gaussian, or a regional to global scale Eulerian or Lagrangian approach. The dispersion model results show large sensitivity on the accuracy of the coupled NWP model, especially through the description of planetary boundary layer turbulence, deep convection and wet deposition. Improvement of dispersion predictions can be achieved by online coupling of mesoscale meteorology and atmospheric transport models. The 2011 Fukushima event was the first large-scale nuclear accident where real-time prognostic dispersion modeling provided decision support. Dozens of dispersion models with different approaches were used for prognostic and retrospective simulations of the Fukushima release. An unknown release rate proved to be the largest factor of uncertainty, underlining the importance of inverse modeling and data assimilation in future developments.
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Affiliation(s)
- Ádám Leelőssy
- Department of Meteorology, Eötvös Loránd University, P.O. Box 32, H-1518, Budapest, Hungary.
| | - István Lagzi
- Department of Physics, Budapest University of Technology and Economics, Budafoki út 8, H-1111, Budapest, Hungary; MTA-BME Condensed Matter Research Group, Budafoki út 8, H-1111, Budapest, Hungary
| | - Attila Kovács
- Department of Meteorology, Eötvös Loránd University, P.O. Box 32, H-1518, Budapest, Hungary
| | - Róbert Mészáros
- Department of Meteorology, Eötvös Loránd University, P.O. Box 32, H-1518, Budapest, Hungary
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Kaltofen M, Gundersen A. Radioactively-hot particles detected in dusts and soils from Northern Japan by combination of gamma spectrometry, autoradiography, and SEM/EDS analysis and implications in radiation risk assessment. THE SCIENCE OF THE TOTAL ENVIRONMENT 2017; 607-608:1065-1072. [PMID: 28724245 DOI: 10.1016/j.scitotenv.2017.07.091] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2017] [Revised: 07/07/2017] [Accepted: 07/11/2017] [Indexed: 06/07/2023]
Abstract
After the March 11, 2011, nuclear reactor meltdowns at Fukushima Dai-ichi, 180 samples of Japanese particulate matter (dusts and surface soils) and 235 similar U.S. and Canadian samples were collected and analyzed sequentially by gamma spectrometry, autoradiography, and scanning electron microscopy with energy dispersive X-ray analysis. Samples were collected and analyzed over a five-year period, from 2011 to 2016. Detectable levels of 134Cs and 137Cs were found in 142 of 180 (80%) Japanese particulate matter samples. The median radio-cesium specific activity of Japanese particulate samples was 3.2kBqkg-1±1.8kBqkg-1, and the mean was 25.7kBqkg-1 (σ=72kBqkg-1). The U.S. and Canadian mean and median radio‑cesium activity levels were <0.03kBqkg-1. U.S. and Canadian samples had detectable 134Cs and 137Cs in one dust sample out of 32 collected, and four soils out of 74. The maximum US/Canada radio-cesium particulate matter activity was 0.30±0.10kBqkg-1. The mean in Japan was skewed upward due to nine of the 180 (5%) samples with activities >250kBqkg-1. This skewness was present in both the 2011 and 2016 sample sets. >300 individual radioactively-hot particles were identified in samples from Japan; composed of 1% or more of the elements cesium, americium, radium, polonium, thorium, tellurium, or strontium. Some particles reached specific activities in the MBqμg-1 level and higher. No cesium-containing hot particles were found in the U.S. sample set. Only naturally-occurring radionuclides were found in particles from the U.S. background samples. Some of the hot particles detected in this study could cause significant radiation exposures to individuals if inhaled. Exposure models ignoring these isolated hot particles would potentially understate human radiation dose.
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Affiliation(s)
- Marco Kaltofen
- Nuclear Science and Engineering Program, Department of Physics, Worcester Polytechnic Institute, United States.
| | - Arnie Gundersen
- Fairewinds Energy Education Corp, 70 South Winooski Ave. #289, Burlington, VT 05401, United States
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Jónás J, Somlai J, Tóth-Bodrogi E, Hegedűs M, Kovács T. Study of a remediated coal ash depository from a radiological perspective. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2017; 173:75-84. [PMID: 28041855 DOI: 10.1016/j.jenvrad.2016.11.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2016] [Revised: 11/07/2016] [Accepted: 11/10/2016] [Indexed: 06/06/2023]
Abstract
Coal-fired power plants play a significant role in the production of electricity. The Ra-226 concentration of coals mined in the Ajka region can reach up to 3000 Bq/kg. This study focuses on the effects of a Hungarian (Ajka) remediated coal ash depository on the environment and the effectiveness of the cover layer. During the remediation, a method patented in Hungary was used, in which the upper layer of the depository, which had settled like concrete, was ploughed and mixed with woodchips before being planted with vegetation. The gamma dose rate H*(10) of the depository and its vicinity was measured using Automess 6150AD-b at 32 points, surface Rn-222 exhalation at 19 points and air radon concentration at 34 points; at 32 points, soil gas radon content was measured with AlphaGUARD and soil permeability with RADON-JOK. The nuclide content of nine samples was determined using an HPGe gamma spectrometer and their Rn-222 exhalation rates were measured using the AlphaGUARD. H*(10) was 290 (130-525) nSv/h at the covered depository; CRa-226 was 1997 Bq/kg, 960 Bq/kg and 104 Bq/kg for the ash, cover layer and background soil respectively. CRn-222 in the soil was 25-161 kBq/m3, and soil gas permeability K was between 6.4E-13 and 1.80E-11 m2. The radon exhalation of the uncovered and covered depository was 259-1100 mBq/m2s. The exhalation and emanation coefficients of the samples were 0.05-0.32 mBq/kgs and 8-22%. The effects of vegetation on the migration of radon were also examined. The results show that the Ajka coal ash depository involves higher radiological risk than that reported by previously published studies on depositories. The applied cover layer halved the field radon exhalation; in addition, the vegetation reduced the convective airflow and, with this, the migration of Rn.
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Affiliation(s)
- Jácint Jónás
- University of Pannonia, Institute of Radiochemistry and Radioecology, Veszprém, Hungary; Social Organization for Radioecological Cleanliness, Veszprém, Hungary
| | - János Somlai
- University of Pannonia, Institute of Radiochemistry and Radioecology, Veszprém, Hungary
| | - Edit Tóth-Bodrogi
- University of Pannonia, Institute of Radiochemistry and Radioecology, Veszprém, Hungary
| | - Miklós Hegedűs
- University of Pannonia, Institute of Radiochemistry and Radioecology, Veszprém, Hungary
| | - Tibor Kovács
- University of Pannonia, Institute of Radiochemistry and Radioecology, Veszprém, Hungary; Social Organization for Radioecological Cleanliness, Veszprém, Hungary.
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15
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Oliveri Conti G, Heibati B, Kloog I, Fiore M, Ferrante M. A review of AirQ Models and their applications for forecasting the air pollution health outcomes. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2017; 24:6426-6445. [PMID: 28054264 DOI: 10.1007/s11356-016-8180-1] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Accepted: 11/28/2016] [Indexed: 05/22/2023]
Abstract
Even though clean air is considered as a basic requirement for the maintenance of human health, air pollution continues to pose a significant health threat in developed and developing countries alike. Monitoring and modeling of classic and emerging pollutants is vital to our knowledge of health outcomes in exposed subjects and to our ability to predict them. The ability to anticipate and manage changes in atmospheric pollutant concentrations relies on an accurate representation of the chemical state of the atmosphere. The task of providing the best possible analysis of air pollution thus requires efficient computational tools enabling efficient integration of observational data into models. A number of air quality models have been developed and play an important role in air quality management. Even though a large number of air quality models have been discussed or applied, their heterogeneity makes it difficult to select one approach above the others. This paper provides a brief review on air quality models with respect to several aspects such as prediction of health effects.
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Affiliation(s)
- Gea Oliveri Conti
- Environmental and Food Hygiene Laboratories (LIAA), Department of Medical, Surgical Sciences and Advanced Technologies "G.F. Ingrassia", University of Catania, via Santa Sofia 87, 95123, Catania, Italy.
| | - Behzad Heibati
- Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Itai Kloog
- Department of Environmental Health, Harvard University, Landmark Center, 401 Park Drive, Boston, 02215, Massachusetts, USA
| | - Maria Fiore
- Environmental and Food Hygiene Laboratories (LIAA), Department of Medical, Surgical Sciences and Advanced Technologies "G.F. Ingrassia", University of Catania, via Santa Sofia 87, 95123, Catania, Italy
| | - Margherita Ferrante
- Environmental and Food Hygiene Laboratories (LIAA), Department of Medical, Surgical Sciences and Advanced Technologies "G.F. Ingrassia", University of Catania, via Santa Sofia 87, 95123, Catania, Italy
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16
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Numerical simulations of atmospheric dispersion of iodine-131 by different models. PLoS One 2017; 12:e0172312. [PMID: 28207853 PMCID: PMC5313156 DOI: 10.1371/journal.pone.0172312] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2016] [Accepted: 02/02/2017] [Indexed: 12/03/2022] Open
Abstract
Nowadays, several dispersion models are available to simulate the transport processes of air pollutants and toxic substances including radionuclides in the atmosphere. Reliability of atmospheric transport models has been demonstrated in several recent cases from local to global scale; however, very few actual emission data are available to evaluate model results in real-life cases. In this study, the atmospheric dispersion of 131I emitted to the atmosphere during an industrial process was simulated with different models, namely the WRF-Chem Eulerian online coupled model and the HYSPLIT and the RAPTOR Lagrangian models. Although only limited data of 131I detections has been available, the accuracy of modeled plume direction could be evaluated in complex late autumn weather situations. For the studied cases, the general reliability of models has been demonstrated. However, serious uncertainties arise related to low level inversions, above all in case of an emission event on 4 November 2011, when an important wind shear caused a significant difference between simulated and real transport directions. Results underline the importance of prudent interpretation of dispersion model results and the identification of weather conditions with a potential to cause large model errors.
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17
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Yoshikane T, Yoshimura K, Chang EC, Saya A, Oki T. Long-distance transport of radioactive plume by nocturnal local winds. Sci Rep 2016; 6:36584. [PMID: 27848988 PMCID: PMC5111080 DOI: 10.1038/srep36584] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Accepted: 10/17/2016] [Indexed: 11/17/2022] Open
Abstract
Radioactive plumes can spread far and wide depending on wind conditions. The plumes often frequently reached the Tokyo metropolitan area, which is approximately 200 km away from the Fukushima Daiichi nuclear power plant, under spatially heterogeneous wind fields in March 2011. To reduce exposure to radioactive plumes, the behaviour of the plumes must be known. However, the transport mechanism of radioactive plumes is not fully understood. Using a regional climate model, we show that multiple diurnal cycle processes play a key role in the frequent transport of radioactive plumes to the Tokyo metropolitan area. The observed data and hindcast results indicate that the radioactive plume moves along the local winds, which comprise the northeasterly local wind (NELW) associated with the meso-scale low-pressure system (meso-low) and the northerly sea wind (NSW) during the night. The long-term analysis and sensitivity simulations also show the nocturnal processes that the NELW caused by the meso-low and the NSW are formed east of the Tokyo metropolitan area and from Fukushima offshore east of the Tokyo metropolitan area, respectively, when neither winter monsoons nor extra-tropical cyclones are predominant. These findings indicate that the radioactive plumes could reach faraway places frequently via nocturnal local processes.
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Affiliation(s)
- Takao Yoshikane
- Institute of Industrial Science, The University of Tokyo, 4-6-1, Komaba, Meguro-ku, Tokyo, 153-8505, Japan
| | - Kei Yoshimura
- Institute of Industrial Science, The University of Tokyo, 4-6-1, Komaba, Meguro-ku, Tokyo, 153-8505, Japan.,Atmosphere and Ocean Research Institute, The University of Tokyo, 5-1-5, Kashiwanoha, Kashiwa-shi, Chiba, 277-8564, Japan
| | - Eun-Chul Chang
- Department of Atmospheric Science, Kongju National University, 56 Gongjudaehak-ro, Gongju-si, Chungcheongnam-do, 32588, Korea
| | - Akane Saya
- Institute of Industrial Science, The University of Tokyo, 4-6-1, Komaba, Meguro-ku, Tokyo, 153-8505, Japan
| | - Taikan Oki
- Institute of Industrial Science, The University of Tokyo, 4-6-1, Komaba, Meguro-ku, Tokyo, 153-8505, Japan
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