scholarly journals Reassessment of early 131I inhalation doses by the Fukushima nuclear accident based on atmospheric 137Cs and 131I/137Cs observation data and multi-ensemble of atmospheric transport and deposition models

2020 ◽  
Vol 218 ◽  
pp. 106233 ◽  
Author(s):  
Mai Takagi ◽  
Toshimasa Ohara ◽  
Daisuke Goto ◽  
Yu Morino ◽  
Junya Uchida ◽  
...  
Keyword(s):  
Atmospheric Transport ◽  
Nuclear Accident ◽  
Fukushima Nuclear Accident ◽  
Observation Data ◽  
Deposition Models

Assessing Sensitivity of Observations in Source Term Estimation for Nuclear Accidents

2012 ◽  
Author(s):  
Yuanwei Ma ◽  
Dezhong Wang ◽  
Wenji Tan ◽  
Zhilong Ji ◽  
Kuo Zhang
Keyword(s):  
Data Assimilation ◽  
Source Term ◽  
Dynamic Models ◽  
Source Parameters ◽  
Nuclear Accident ◽  
Fukushima Nuclear Accident ◽  
Observation Data ◽  
Source Terms ◽  
Highly Nonlinear ◽  
Assimilation System

In the Fukushima nuclear accident, due to the lack of field observations and the complexity of source terms, researchers failed to estimate the source term accurately immediately. Data assimilation methods to estimate source terms have many good features: they works well with highly nonlinear dynamic models, no linearization in the evolution of error statistics, etc. This study built a data assimilation system using the ensemble Kalman Filter for real-time estimates of source parameters. The assimilation system uses a Gaussian puff model as the atmospheric dispersion model, assimilating forward with the observation data. Considering measurement error, numerical experiments were carried on to verify the stability and accuracy of the scheme. Then the sensitivity of observation configration is tested by the twin experiments. First, the single parameter release rate of the source term is estimated by different sensor grid configurations. In a sparse sensors grid, the error of estimation is about 10%, and in a 11*11 grid configuration, the error is less than 1%. Under the analysis of the Fukushima nuclear accident, ahead for the actual situation, four parameters are estimated at the same time, by 2*2 to 11*11 grid configurations. The studies showed that the radionuclides plume should cover as many sensors as possible, which will lead a to successful estimation.

scholarly journals Simulation of atmospheric radiocesium (137Cs) from Fukushima nuclear accident using FLEXPART-WRF driven by ERA5 reanalysis data

2021 ◽  
Vol 10 (3) ◽  
pp. 01-12
Author(s):  
Kieu Ngoc Dung ◽  
Nguyen Hao Quang ◽  
Hoang Huu Duc ◽  
Nguyen Thi Hang ◽  
Nguyen Thi Thoa ◽  
...  
Keyword(s):  
Atmospheric Transport ◽  
Wrf Model ◽  
Reanalysis Data ◽  
Horizontal Resolution ◽  
Particle Dispersion ◽  
Nuclear Accident ◽  
Fukushima Nuclear Accident ◽  
Reanalysis Dataset ◽  
Statistical Verification ◽  
Simulation Results

This study investigates short-range atmospheric transport of radiocesium (137Cs) after Fukushima nuclear accident using the Weather Research and Forecasting (WRF) model and the Lagrangian particle dispersion FLEXPART-WRF model. The most up-to-date ERA5 reanalysis dataset is used as initial and boundary condition for the WRF model for every hour. Four experiments were carried out to examine the sensitivity of simulation results to micro-physics parameterizations in the WRF model with two configured domains of 5 km and 1 km horizontal resolution. Compared with observation at Futaba and Naraha station, all experiments reproduce reasonably the variation of 137Cs concentration from 11/03 to 26/03/2011. Statistical verification as shown in Taylor diagrams highlights noticeable sensitivity of simulation results to different micro-physics choices. Three configurations of the WRF model are also recommended for further study based on their better performance among all.

scholarly journals Forecasting Radiation Effects on Wildlife in Japan After the Fukushima Nuclear Accident, Based on Limited Information of Post-Accident Early Stage in 2011

2014 ◽  
Vol XL-2 ◽  
pp. 13-20 ◽  
Author(s):  
M. U. Saito ◽  
T. Doko ◽  
F. Koike
Keyword(s):  
Radiation Effects ◽  
Early Stage ◽  
Regional Distribution ◽  
Nuclear Accident ◽  
Radioactive Isotopes ◽  
Fukushima Nuclear Accident ◽  
Observation Data ◽  
Limited Information ◽  
Radioactive Materials ◽  
Chronic Radiation

Due to the 11 March 2011 Tohoku earthquake, massive radioactive materials were released from the Fukushima Daiichi Nuclear Power Plant (Fukushima NPP). It is crucial to predict the regional distribution and magnitude of the effects on wildlife by radioactive materials. However, during the post-accident early stage in 2011, limited information on large-scale pollution and prediction maps was open to public. Hence, this paper aimed to provide (1) the pollution map covering areas within 300 km from the Fukushima NPP where the radiation intensity exceeded 0.5 μSv/h, (2) pollution maps which predicted air dose for the next 30 years after the accident, and (3) maps of areas where wildlife might be affected by radioactive isotopes by the Fukushima nuclear accident. First, the relative contributions of <sup>131</sup>I, <sup>134</sup>Cs, and <sup>137</sup>Cs were estimated from time series observation data. Second, a 30-year prediction of the pollution was calculated based on the isotope half-lives. Third, the chronic radiation effects on vertebrates were estimated using the threshold dose rate proposed by Sazykina et al. (2009). We examined the chronic radiation effects on morbidity, reproduction, and longevity. The results indicated that radioactive materials could have affected vertebrate morbidity within a 350 km<sup>2</sup> area in early April 2011; the threshold level was the median result of Sazykina et al. (2009) with bootstrapping. Based on the prediction, a 15.5 km<sup>2</sup> region will remain affected after 30 years. These areas should be monitored to confirm the effects of radioactivity on wildlife.

scholarly journals Belief in group interdependence: Facilitating evacuee–host interactions after the Fukushima nuclear accident

2021 ◽  
Author(s):  
Tomoyuki Kobayashi ◽  
Kazuki Yoshida ◽  
Yoshitake Takebayashi ◽  
Aya Goto ◽  
Atsushi Kumagai ◽  
...  
Keyword(s):  
Nuclear Accident ◽  
Fukushima Nuclear Accident ◽  
Host Interactions

scholarly journals Deposition and Dispersion of Radio-Cesium Released Due to the Fukushima Nuclear Accident: Sensitivity to Meteorological Models and Physical Modules

2019 ◽  
Vol 124 (3) ◽  
pp. 1823-1845 ◽  
Author(s):  
Mizuo Kajino ◽  
Tsuyoshi Thomas Sekiyama ◽  
Yasuhito Igarashi ◽  
Genki Katata ◽  
Morihiro Sawada ◽  
...  
Keyword(s):  
Nuclear Accident ◽  
Fukushima Nuclear Accident ◽  
Meteorological Models

scholarly journals Communicating With Residents About Risks Following the Fukushima Nuclear Accident

2017 ◽  
Vol 29 (2_suppl) ◽  
pp. 74S-89S ◽  
Author(s):  
Michio Murakami ◽  
Akiko Sato ◽  
Shiro Matsui ◽  
Aya Goto ◽  
Atsushi Kumagai ◽  
...  
Keyword(s):  
Public Health ◽  
Risk Communication ◽  
Health Management ◽  
Well Being ◽  
Lessons Learned ◽  
Nuclear Accident ◽  
Fukushima Nuclear Accident ◽  
Whole Body ◽  
Systematic Evaluation ◽  
Medical Professionals

The Fukushima nuclear accident in March 2011 posed major threats to public health. In response, medical professionals have tried to communicate the risks to residents. To investigate forms of risk communication and to share lessons learned, we reviewed medical professionals’ activities in Fukushima Prefecture from the prefectural level to the individual level: public communication through Fukushima Health Management Surveys, a Yorozu (“general”) health consultation project, communications of radiological conditions and health promotion in Iitate and Kawauchi villages, dialogues based on whole-body counter, and science communications through online media. The activities generally started with radiation risks, mainly through group-based discussions, but gradually shifted to face-to-face communications to address comprehensive health risks to individuals and well-being. The activities were intended to support residents’ decisions and to promote public health in a participatory manner. This article highlights the need for a systematic evaluation of ongoing risk communication practices, and a wider application of successful approaches for Fukushima recovery and for better preparedness for future disasters.

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