Model behavior regarding in- and below-cloud 137Cs wet scavenging following the Fukushima accident using 1-km-resolution meteorological field data

Zhuang, Shuhan; Goto, Daisuke; Dong, Xinwen; Xu, Yuhan; Li, Sheng

doi:10.1016/j.scitotenv.2023.162165

Cited by 9 publications

(4 citation statements)

References 23 publications

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“…Pairing analysis of rainfall series and cumulative profiles of total deposition at observation sites. (a) Observed deposition map until April 1, 2011; (b) modeled rainfall series using the WRF-Chem, which has been validated against the radar/rain gauge-analyzed precipitation data; , (c) modeled surface depositions by the WRF-Chem model using constant emissions with a rate of 8.47 GBq/h, constructed by averaging a previous objectively estimated source term; (d) derived depositions at sites D-B and D-C corresponding to four assumed critical emissions that ensure the deposition at site D-A matches the observations at four possible times. The red part in Figure a is the high-deposition area, with observed values exceeding 3000 kBq/m 2 .…”

Section: Methodsmentioning

confidence: 99%

Inversion of Critical Atmospheric ¹³⁷Cs Emissions Following the Fukushima Accident by Resolving Temporal Formation from Total Deposition Data

Dong,

Fang,

Zhuang

et al. 2024

Environ. Sci. Technol.

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Understanding the transport of 137 Cs emitted during the Fukushima accident is challenging because the critical emissions that produced the high-deposition area are not adequately resolved in existing source terms. This paper presents an objective inverse reconstruction of these emissions by fusing atmospheric concentrations with a-priori emissions extracted from total depositions. This extraction, previously considered impossible for complex real-world accidents, is achieved by identifying the critical temporal formation process of depositions in the high-deposition area and estimating the corresponding emissions by using an atmospheric transport model. The reconstructed source term reveals two emission peaks from 10:00−11:00 and 14:00−15:00 on March 15, which agree with the in situ pressure measurements and accident analysis, suggesting that they came from pressure drops in the primary containment vessels of Units 3 and 2, respectively. This finding explains the environmental observations of spherical 137 Cs particles. The source term also objectively and independently confirms the widely used reverse estimate. The corresponding 137 Cs transport simulations better match the various observations than those produced by other source terms, proving that the twopeak emission creates a high-deposition area. The proposed method outperforms the direct fusion of deposition and atmospheric concentration observations, providing a robust tool for multiobservation fusion.

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Section: Methodsmentioning

confidence: 99%

Inversion of Critical Atmospheric ¹³⁷Cs Emissions Following the Fukushima Accident by Resolving Temporal Formation from Total Deposition Data

Dong,

Fang,

Zhuang

et al. 2024

Environ. Sci. Technol.

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“…In this study, we mainly utilized observation data from four stations with relatively high concentrations, namely Tokyo, Chiba, Maebashi, and Naraha. The radionuclide emission source uses the same radionuclide 137 Cs emission data obtained during the high emission period of the Fukushima nuclear accident (11 to 17 March 2011) used by Fang et al [37] and Zhuang et al [38]. Wind field data, including temperature, humidity, wind speed, and wind direction, were obtained from ground-based observatory site data released by the Japan Meteorological Agency (JMA), with a time resolution of 3 h (https://www.data.jma.go.jp/obd/stats/etrn/index.php, accessed on 11 May 2023).…”

Section: Datamentioning

confidence: 99%

“…Fang et al [37] optimized the atmospheric transport modeling of 137 Cs based on the WRF-Chem model by coupling 25 different 137 Cs in-cloud and under-cloud online wet scavenging scenarios with meteorological fields. Zhuang et al [38] studied in-depth the detailed processes of 25 in-cloud and under-cloud wet scavenging modes using high-resolution (1 km × 1 km) meteorological inputs, based on the methods of Fang et al [37], which showed that high-resolution meteorological inputs can more accurately reproduce localscale 137 Cs concentrations.…”

Section: Introductionmentioning

confidence: 99%

The Design of a Parameterization Scheme for 137Cs Based on the WRF-Chem Model and Its Application in Simulating the Fukushima Nuclear Accident

Long,

Zang,

et al. 2024

Atmosphere

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Based on the Weather Research and Forecasting Model Coupled with Chemistry (WRF-Chem) atmospheric chemistry model, a parameterization scheme for the radioactive isotope caesium (137Cs), considering processes such as advection, turbulent diffusion, dry deposition, and wet deposition, was constructed, enabling the spatial distribution simulation of the concentration and deposition of 137Cs. The experimental simulation studies were carried out during the high emission period of the Fukushima nuclear accident (from 11 to 17 March 2011). Two sets of comparison experiments, with or without deposition, were designed, the effects of wind field and precipitation on the spatial transport and ground deposition of 137Cs were analyzed, and the influence of wind field and precipitation on 137Cs vertical transport was analyzed in detail. The results indicate that the model can accurately simulate the meteorological and 137Cs variables. On 15 March, 137Cs dispersed towards the Kanto Plain in Japan under the influence of northeastern winds. In comparison to the experiment without deposition, the concentration of 137Cs in the Fukushima area decreased by approximately 286 Bq·m−3 in the deposition experiment. Under the influence of updrafts in the non-deposition experiment, a 137Cs cloud spread upward to a maximum height of 6 km, whereas in the deposition experiment, the highest dispersion of the 137Cs cloud only reach a height of 4 km. Affected by the wind field, dry deposition is mainly distributed in Fukushima, the Kanto Plain, and their eastern ocean areas, with a maximum dry deposition of 5004.5 kBq·m−2. Wet deposition is mainly influenced by the wind field and precipitation, distributed in the surrounding areas of Fukushima, with a maximum wet deposition of 725.3 kBq·m−2. The single-station test results from the deposition experiment were better than those for the non-deposition experiment: the percentage deviations of the Tokyo, Chiba, Maebashi, and Naraha stations decreased by 61%, 69%, 46%, and 51%, respectively, and the percentage root mean square error decreased by 46%, 25%, 38%, and 48%, respectively.

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“…The temporal variation of the release rate may change the TGDR (Li et al, 2019), as well as several authors (e.g. (Povinec et al, 2013), (Masson et al, 2018), (Guttikunda and Gurjar, 2012), (Jayamurugan et al, 2013), (Gogikar and Tyagi, 2016), (Gogikar et al, 2018), Kristiansen et al, 2016;Sato et al, 2020;Zhuang et al, 2023) have demonstrated the influence of meteorological conditions on the shape of a plume carrying contaminants and on the atmospheric lifetime of radionuclides emitted from a point source on a local and regional scale. In essence, radioactive plumes can spread far and wide depending on the temporal and spatial variation of meteorological parameters, such as rainfall or wind direction and speed, which, in addition, vary throughout the year.…”

Section: Introductionmentioning

confidence: 99%

Analysing the Performance of Radiological Monitoring Network During Nuclear Accidents

Sangiorgi¹,

Ceballos²,

Bolı́var

2023

Preprint

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Model behavior regarding in- and below-cloud 137Cs wet scavenging following the Fukushima accident using 1-km-resolution meteorological field data

Cited by 9 publications

References 23 publications

Inversion of Critical Atmospheric ¹³⁷Cs Emissions Following the Fukushima Accident by Resolving Temporal Formation from Total Deposition Data

Inversion of Critical Atmospheric ¹³⁷Cs Emissions Following the Fukushima Accident by Resolving Temporal Formation from Total Deposition Data

The Design of a Parameterization Scheme for 137Cs Based on the WRF-Chem Model and Its Application in Simulating the Fukushima Nuclear Accident

Analysing the Performance of Radiological Monitoring Network During Nuclear Accidents

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Model behavior regarding in- and below-cloud 137Cs wet scavenging following the Fukushima accident using 1-km-resolution meteorological field data

Cited by 9 publications

References 23 publications

Inversion of Critical Atmospheric 137Cs Emissions Following the Fukushima Accident by Resolving Temporal Formation from Total Deposition Data

Inversion of Critical Atmospheric 137Cs Emissions Following the Fukushima Accident by Resolving Temporal Formation from Total Deposition Data

The Design of a Parameterization Scheme for 137Cs Based on the WRF-Chem Model and Its Application in Simulating the Fukushima Nuclear Accident

Analysing the Performance of Radiological Monitoring Network During Nuclear Accidents

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Inversion of Critical Atmospheric ¹³⁷Cs Emissions Following the Fukushima Accident by Resolving Temporal Formation from Total Deposition Data

Inversion of Critical Atmospheric ¹³⁷Cs Emissions Following the Fukushima Accident by Resolving Temporal Formation from Total Deposition Data