Fukushima Nuclear Plant Accident Research Articles

Development of a dose estimation system for external exposure assessment at the late phase for individuals living in areas affected by the Fukushima nuclear accident.

Although the elevated ambient dose equivalent (ADE) rates in areas radiologically affected by the 2011 Fukushima nuclear plant accident decreased as time passed, the assessment of Fukushima residents' external dose is still important. A dose estimation system for external exposure assessment at the late phase for individuals living in Fukushima Prefecture was developed for this purpose. The developed system enables the estimations of external doses over the future based on an individual behavioral pattern and ADE-rate distributions from aerial monitoring data and its predicted ADE rate. To validate the system, the estimated results were compared with the measured readings of personal dosemeters. The results indicate that the developed system properly reproduced the individual external doses of subjects living in areas where the outdoor ADE rates exceeded 0.2μSvh-1.

Diamond Princess Cruise Ship. COVID-19 Medical Operation by the National EMT, Japan DMAT.

Introduction:The Diamond Princess cruise ship (DP) arrived in Yokohama, Japan, on February 3, 2019, with a confirmation of the Polymerase Chain Reaction test (PCR) positive for the Coronavirus disease 2019 (COVID-19) in a passenger who disembarked at Hong Kong. Japan National Emergency Medical Team (N-EMT), and Japan Disaster Medical Assistance Team (DMAT), were dispatched and measures to prevent the spread of viruses were taken for 3,711 (2,666 passengers and 1,045 crew members) on board.Method:Japan DMAT was dispatched and managed the medical operation for DP passengers and crew members. The records of communication logs for the DMAT were evaluated. In this study, evaluation of DMAT medical operations in the DP was conducted to find any positive effectsResults:472 (157 doctors, 123 nurses, 161 medical logisticians, 31 pharmacists) members responded. Among them, 283 (97 doctors, 66 nurses, 91 medical logisticians, 29 pharmacists) worked inside the DP, and 189 (60 doctors, 57 nurses, 70 medical logisticians, two pharmacists) operated outside mainly for patient transport. DMAT conducted a strategic operation and developed categorization for medical care and patient transport. Eventually, DMAT constructed flow to provide rapid medical care and prescription distributions for passengers and crew members.Conclusion:DMAT has been required to respond to unforeseen disasters in the framework since the Fukushima Nuclear Plant accident in 2011. All the past several types of disaster response were contributed to managing medical operations at the DP. These operations are thought to reduce preventable deaths from COVID-19.

Japan DMAT operations in the Diamond Princess cruise ship: COVID-19 medical operation.

The aim of this study was to identify positive effects from the Japan Disaster Medical Assistant Team (DMAT) medical operation in the Diamond Princess cruise ship (DP). Japan DMAT dispatched and managed the medical operation for DP passengers and crew members. The records of communication logs for the DMAT were evaluated. 472 DMAT members were responded. DMAT took 3 to 4 days to manage patients due to a lack of medical supplies at the early phase of operation. The prescription was delayed for prescription required passengers that include passengers who will be in critical health conditions without prescriptions. DMAT conducted a strategic operation and developed categorization for medical care and patient transport. Eventually, DMAT constructed flow to provide rapid medical care and prescription distributions for passengers and crew members. DMAT has been required to respond to unforeseen disasters in the framework since the Fukushima Nuclear Plant accident in 2011. All the past several types of disaster response were contributed to managing medical operations at the DP. These operations are thought to reduce preventable deaths from Coronavirus disease 2019 (COVID-19).

Sacrificing the Fukushima 50 again?

In the aftermath of the 2011 Fukushima nuclear plant accident, many workers helped restore the contaminated site, exposing themselves to a highly radioactive environment. They were referred to as the 'Fukushima 50' and applauded as heroes who saved Japan. A cohort study targeting those emergency workers is, currently, underway. We object to the study on ethical grounds. Ethical and content analyses. First, the low participation rate raises ethical questions about why potential participants declined. Content analyses of nuclear power plant workers' narratives from a television broadcast extracted eight recurrent themes: disposable, treated like a sacrificial pawn, taboo, fear of contamination, readiness to risk one's life, distrust and dissatisfaction with the nation's response, regret over participating and uncertainty about the future. Second, the unscientific nature of the cohort design undermines the ethical basis for conducting it. Third, public resources were allocated in a way that compromises justice. We urge re-considering the current Fukushima 50 research study. We also urge applying the public funds now invested in this research project to activities that would directly benefit the Fukushima 50, such as offering free lifetime healthcare and direct financial compensation.

Evaluation of abundance of artificial radionuclides in food products in South Korea and sources

Food samples are collected nationwide from January 2016 to February 2017 and their contents of artificial radionuclides are measured to address the growing concerns regarding the radioactive contamination of food products in Korea. Specifically, 900 food samples are collected for this study and their contents of representative artificial radionuclides 134Cs, 137Cs, 239,240Pu, and 90Sr are analyzed. The analysis shows that the activity concentrations of 137Cs in fish range from minimum detectable activity (MDA) to 340 mBq/kg of fresh weight. The concentration factor (CF) determined for 137Cs as a measure of its bioavailability is calculated to be ca. 74 and found to be very similar to that (100) recommended by the International Atomic Energy Agency. With an MDA of <0.221 mBq/kg, the results reveal that 239,240Pu values in fish are below the MDA. The activity concentrations of 137Cs and 90Sr are lower than the MDA in both shellfish and seaweed, while the activity concentrations of 239,240Pu in shellfish range from 0.26 to 2.18 mBq/kg, and for seaweed samples range from 2.07 to 3.38 mBq/kg. The atom ratios of 240Pu/239Pu in shellfish caught at the Korean coast vary from 0.209 to 0.237, with a mean of 0.227. The higher 240Pu/239Pu atom ratio determined in shellfish is thought to be caused by the plutonium transported from the Pacific Proving Grounds rather than other sources such as the Fukushima nuclear power plant accident. The activity concentrations of 137Cs in mushrooms are found to vary from 1.0 to 21.4 Bq/kg, with the highest concentrations observed in the Oak (shiitake) and Sarcodon asparatus. 134Cs is detected in three mushroom specimens collected from Jeju Island and about 3–3.6% of 137Cs present in the wild mushrooms native to the Jeju Island are introduced as a result of the Fukushima nuclear plant accident. The annual effective doses of 137Cs received through consumption of mushrooms and fish are 2.0 × 10−4 mSv yr−1 and 3.9 × 10−5 mSv yr−1, and those values are negligible compared to the annual effective doses limit of 1 mSv yr−1.

The New Radiation Emergency Medical System in Japan: Lessons from the Fukushima Nuclear Plant Accident

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原発事故の精神的影響と放射線の健康影響

原発事故の精神的影響と放射線の健康影響

131I age-dependent inhalation dose in Southern Poland from Fukushima accident

A general method for calculating doses absorbed from isotopes released in nuclear accidents is presented. As an example, this method was used to calculate doses for inhabitants of Southern Poland due to inhalation of 131I released due to the Fukushima nuclear plant accident. 131I activity measurements in the air of that region provided the basis for the study. The proposed model is based on a complex biokinetic model for iodine merging the Leggett model developed in 2010 with the human respiratory tract and gastrointestinal tract models recommended by the International Commission on Radiological Protection (ICRP). This model is described here, and it is demonstrated that resulting dose estimates are consistent with those obtained using the ICRP methodology. Using the developed model, total doses were calculated for six age groups of both genders, for gaseous and aerosol fractions alike. The committed effective dose, H50, for an adult man reached 16 nSv, which is lower than 0.001% of the background dose. The dose for the thyroid of an adult reached 0.33 μSv, which corresponds to circa 0.0007% of the dose to the population of Southern Poland after the Chernobyl nuclear plant accident.

Consumers' willingness to pay for renewable and nuclear energy: A comparative analysis between the US and Japan

This paper examines consumers' willingness to pay for nuclear and renewable electricity as two alternatives to fossil fuels for the reduction of greenhouse gas emissions. We conduct a choice experiment of consumer-stated preferences on the basis of an online survey in four US states and Japan after the Fukushima nuclear plant accident. First, the results suggest that US consumers' willingness to pay for a 1% decrease in greenhouse gas emissions is $0.31 per month, which is similar to the results for the US a decade ago. Japanese consumers show a slightly lower willingness to pay of $0.26 per month. Second, the average consumer in both countries expresses a negative preference for increases in nuclear power in the fuel mix (to a greater extent in Japan). Third, renewable energy sources were endorsed by both US and Japanese consumers, who show a willingness to pay $0.71 and $0.31 per month for a 1% increase in the use of renewable source energy. This study also examines the differences in respondents' characteristics. Approximately 60% of the US respondents who did not change their perception concerning the use of nuclear energy subsequent to the Fukushima nuclear crisis have almost no preference for variation in nuclear power, which is in stark contrast to the Japanese respondents' opposition to nuclear energy.

Speciation of radioactive soil particles in the Fukushima contaminated area by IP autoradiography and microanalyses.

Radioactive soil particles several tens of micrometers in size were collected from litter soil in the radiation contaminated area by the Fukushima nuclear plant accident and characterized using electron and X-ray microanalyses. The radioactive particles were discriminated by autoradiography using imaging plates (IP) on which microgrids were formed by laser ablation in order to find the particles under microscopy. Fifty radioactive particles were identified and classified into three types from their morphology and chemical composition, namely: (1) aggregates of clay minerals, (2) organic matter containing clay mineral particulates, and (3) weathered biotite originating from local granite. With respect to the second type, dissolution of the organic matter did not reduce the radiation, suggesting that the radionuclides were also fixed by the clay minerals. The weathered biotite grains have a plate-like shape with well-developed cleavages inside the grains, and kaolin group minerals and goethite filling the cleavage spaces. The reduction of the radiation intensity was measured before and after the trimming of the plate edges using a focused ion beam (FIB), to examine whether radioactive cesium primarily sorbed at frayed edges. The radiation was attenuated in proportion to the volume decrease by the edge trimming, implying that radioactive cesium was sorbed uniformly in the porous weathered biotite.

Distribution and retention of Cs radioisotopes in soil affected by Fukushima nuclear plant accident

There was a large release of radio-cesium (134Cs and 137Cs) to the atmosphere during the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident, and contaminated the soil, over a vast area, due to fallout activity. Therefore, studies on the behaviour of radio-cesium especially migration in soil and its retention on soil particles is very important for external dose assessment and root uptake. We have determined the sorption coefficient (K d) for Cs using the laboratory batch method in soil samples collected from a contaminated area affected by the FDNPP accident, and the effect of various soil parameters on the K d value has been studied. We have noticed that Cs sorption is mostly influenced by cation exchange process and Cs is sorbed on the surface of clay particles. From vertical depth profile of Cs in soil, it is found that most of it is retained on the top layer within a 5-cm thickness. Sequential extraction of soil using various reagents may be helpful to understand better the mechanism of Cs retention.

Current state and future perspectives for the psychological problems caused by the Fukushima nuclear plant accident

Current state and future perspectives for the psychological problems caused by the Fukushima nuclear plant accident

Risk perception for the Fukushima Nuclear Plant Accident: An Analysis from the Behavioral Immune System Hypothesis

Risk perception for the Fukushima Nuclear Plant Accident: An Analysis from the Behavioral Immune System Hypothesis

Parenting in Fukushima City in the post-disaster period: short-term strategies and long-term perspectives.

Growing evidence indicates the adverse psychological and welfare consequences of nuclear power accidents particularly among parents of small children. However, little has been published about the public health experiences of and practical countermeasures to deal with such consequences for parents of small children in the aftermath of disasters. Based on our past research efforts to develop parenting support programmes in Fukushima City, we describe here the discussions and resulting strategies that developed from collaborative efforts between university researchers and public health nurses after the Fukushima nuclear plant accident caused by the Great East Japan Earthquake. The processes presented here may be useful to improve national and international preparedness to protect the health of parents and children in future nuclear disasters.

Effect of Ionizing Radiation on the Living Body

Since the Fukushima nuclear plant accident following the great East Japan earthquake on March 11, 2011, we have been warned to be careful about possible radiation exposure almost every day in newspapers and on TV. Radioactive iodine ((131)I) and cesium ((134)Cs, (137)Cs) produced by nuclear reactions were released into the air during and after the accident, and have been scattered by the winds in Tohoku and in the Kanto district. Even today, 2 years after the accident, there is great public concern about possible pollution of foodstuffs and fishery products with radioactive cesium, not only in Japan, but also in other countries. On the other hand, decontamination work has been proceeding, including removal of contaminated soil near the accident site. Since the accident, many media reports have continued to tell us only that current dose levels of radiation are not dangerous to human health. But, many people are not satisfied with such vague statements, and want to understand the situation in more detail. So, it is important to provide basic education about the effects of radiation to the general public. I am a professor of the Department of Radiation Biosciences at Tokyo University of Science, and so I am very familiar with radiation and its dangers. So, in my lecture today, we would like to explain the effects of radiation and put the present situation into perspective, so that people will better understand the risks, and not be unnecessarily afraid.

What Should the Radiation Education in Japan in the Future Be Like?

In respect to policy and involvement in social cognition of Advanced Science and Technology, people desire to recognize the scientific understanding and social understanding hierarchically and simultaneously. However, the understandings of some sciences and technologies are dependent on the amount of information given and how easy it is to understand it. Nuclear power and radiation are a typical example of such sciences and technologies because their advantages and disadvantages are clear. On the other hand, the Fukushima Nuclear Plant Accident that occurred in March 2011 caused the myth about the safety and security of nuclear power to collapse. Concerns about nuclear power and radiation increased abruptly after the accident. Also the scientific understanding of 'nuclear power' and radiation increased. The content and level of radiation education was highly significant than before the accident. However, it is essential to propose a more detailed explanation for people that are concerned about radioactive contamination of food and also for people living in areas that still have relatively high dose of radioactive material. Although some technical problems such as the influences on the human body by low-dose exposure remain unresolved, not only specialists on nuclear power and radiation, but also the persons that have studied the radiation are desired to explain radiation for familiar people. As a result, in Japan, the learning of individuals spread to society because the Japanese are highly interested in nuclear power and radiation and the understanding of historical background.

Progress for the Revival after the Fukushima Nuclear Plant Accident to Date

Progress for the Revival after the Fukushima Nuclear Plant Accident to Date

原発事故避難者の日常の法的支援と「司法ソーシャルワーク」

原発事故避難者の日常の法的支援と「司法ソーシャルワーク」

避難元，避難先自治体の協働による「連携復興まちづくり」

避難元，避難先自治体の協働による「連携復興まちづくり」

30 MeV X-band Electron Linac Neutron Source for Nuclear Data Study for Fukushima Accident Analysis

X-band (11.424GHz) electron linac as a neutron source for nuclear data study for the Fukushima nuclear plant accident is under development. Originally we developed the linac for Compton scattering X-ray source. Quantitative material analysis and forensics for nuclear security will start several years later after the safe settlement of the accident is established. For the purpose, we should now accumulate more precise nuclear data of U, Pu, TRU and MA (Cm, Am, etc.) especially in epithermal (0.1-10eV) neutrons. Therefore, we have decided to suspend the Compton scattering X-ray experiment and move the linac in the core space of the experimental nuclear reactor “Yayoi” which is now under the decommission procedure. Due to the compactness of the X-band linac, the electron gun and accelerating tube and other components can be installed in a small space in the core. First we plan to perform the TOF (Time Of Flight) transmission measurement for study of the total cross sections of the nuclei for 0.1-10eV neutrons. Therefore, if we adopt a TOF line of less than 10 m, the macro-pulse length of generated neutrons should be shorter than 100ns. Electron energy, macro-pulse length, power and neutron yield are ∼30 MeV, 100ns - 1μs, ∼0.4kW and ∼1012 n/s, ∼103 n/cm2/s at samples, respectively. Optimization of the design of a neutron target (Ta, W, 238U), TOF line and neutron detector (Ce:LiCAF) of high sensitivity and fast response is underway. For the purpose, we are upgrading the electron gun and buncher to realize higher current and beam power with a reasonable beam size in order to avoid damage of the neutron target. Although the neutron flux is limited in case of X-band electron linac based source, we take advantage of its short pulse aspect and availability for nuclear data measurement with a short TOF system. We plan to perform the two phased development and measurement. First, we form a tentative configuration in the current experimental room for Compton scattering in 2014. Then, after the decommissioning has been finished, we move it the “Yayoi” room and perform the operation and measurement.