Fukushima Daiichi

To support estimations of early individual internal doses to residents who suffered from the 2011 accident at the Fukushima Daiichi Nuclear Power Plant (FDNPP), we have sought to use whole-body counter (WBC) measurement results of subjects who lived in municipalities neighboring the FDNPP at the time of the accident. These WBC measurements started several months after the accident; the targeted radionuclides were 134Cs and 137Cs. Our previous study had analyzed the relationship between the residual Cs contents of individuals and evacuation behaviors in the period immediately after the accident for residents of Namie-town, one of the most radiologically affected municipalities...

Steady efforts for recovery and reconstruction after the accident at the Fukushima Daiichi Nuclear Power Plant have been underway for 12.5 y. The present study reports on the world's first-ever efforts for a gradual and safe return to areas contaminated with radiation fallout and reconstruction support by providing an overview of the actual situation regarding the strategy for return, especially with the transition after the lifting of the evacuation order by the Japanese government. A stage-by-stage progression of the evacuation order and lifting strategy is summarized chronologically in the following three phases: the Emergency Phase in 2011, the Reconstruction Phase from 2013 to 2020, and the Challenging Phase for Lifting All the Evacuation Zones from 2023...

BACKGROUND: Since the Fukushima Daiichi nuclear power plant (FDNPP) accident in 2011, measures were taken to address occupational health risk, such as heat illness and infectious diseases, and ensuring fitness for duty with the Tokyo Electric Power Company and its contractors. However, with the decommissioning operations to span several decades and an aging workforce, there arose a need for proactive occupational health strategies that not only addressed these risks but also promoted employee health and created a comfortable work environment...

The radiocesium (137 Cs) activity concentration in stemflow, which is an element of the 137 Cs cycle in the forest, is determined by the supply of 137 Cs from the outer bark and leaves. Long-term monitoring data of deciduous broad-leaved trees since the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident have shown the 137 Cs activity concentration in the outer bark decreasing exponentially, while that in the leaves has remained nearly constant. Therefore, it is expected that the contribution of the outer bark to 137 Cs in stemflow eventually becomes smaller than that of leaves over time...

INTRODUCTION: Interest in nuclear power as a cleaner and alternative energy source is increasing in many countries. Despite the relative safety of nuclear power, large-scale disasters such as the Fukushima Daiichi (Japan) and Chernobyl (Ukraine) meltdowns are a reminder that emergency preparedness and safety should be a priority. In an emergency situation, there is a need to balance the tension between a rapid response, preventing harm, protecting communities, and safeguarding workers and responders...

In a nuclear emergency, one of the actions taken for the sake of public is to monitor thyroid exposure to radioiodines. Japan's Nuclear Regulation Authority recently published a report on such monitoring and proposed direct thyroid measurements with conventional NaI(Tl) survey meters (e.g. Hitachi model TCS-172) as a primary screening method. A previous study proposed screening levels (SLs) used in these simplified measurements as the net reading values of the TCS-172 device. Age-specific SLs were derived from a thyroid equivalent dose of 100 mSv due to the inhalation intake of 131I...

Temporal variation and fluctuation in environmental contamination in Futaba town and Okuma town, the location of the Fukushima Daiichi Nuclear Power Plant (FDNPP), were evaluated based on a car-borne survey conducted from October 2021 to November 2022. Although the environmental radioactivity in the interim storage facility area (ISF) was higher than that in open areas (i.e., the evacuation order lifted areas in Futaba town and the Specific Reconstruction and Regeneration Base area [SRRB] in Okuma town), only minor temporal changes were seen in the ambient dose and detection rate of radiocesium (the proportion of radiocesium detected points per all measuring points) in those areas, respectively...

Since the accident at the Fukushima Daiichi nuclear power plant (FDNPP) in March 2011 seawater is still needed to cool the reactor cores. This water, contaminated with radionuclides, has been collected in tanks and treated on the site of the FDNPP. In 2021, the Japanese government decided to gradually discharge treated water into the ocean, which started on the 24th of August 2023 and will continue for the next 30 years. This paper provides a critical analysis of the models that were used in the different radiological impact studies...

The radiocesium contamination caused by the Fukushima Daiichi Nuclear Power Plant accident has made it difficult to use coppice woods as bed logs for mushroom cultivation. Evaluating the variability in the radiocesium activity concentration of logs is necessary in order to predict how many coppice woodlands are available for producing mushroom bed logs. To clarify the variability in radiocesium activity concentrations and to estimate the sample size required to estimate these concentrations with sufficient accuracy, we modeled the log-transformed radiocesium activity concentrations in growing shoots of hardwoods...

BACKGROUND: As a part of the decontamination process after the Fukushima Daiichi Nuclear Power Plant accident of 2011, 1.32 million tonnes of tritium-containing water will be discharged from the power plant into the Pacific Ocean. Although radiobiological impacts of the treated water discharge on the public and the environment were reported to be minimal, Tomioka and Okuma locals expressed unease regarding the long-term recovery of their towns, which are economically dependent on the agricultural, fishery, and tourism sectors...

In nuclear disaster prevention, it is essential not only to make daily efforts to prevent accidents from occurring but also to properly apply lessons learned from actual disasters. Although significant changes have been made to nuclear disaster preparedness in Japan since the Fukushima Daiichi Nuclear Power Plant accident, there is insufficient information on whether these changes have been evaluated as practical and appropriate for the needs of the Japanese public. In this survey, 20 officials of the Cabinet Office and Japan Atomic Energy Agency, in charge of planning nuclear disaster prevention policy, were asked to evaluate the current nuclear disaster prevention plan, compare it with that before the accident, and indicate what elements are lacking in the current plan in the form of a questionnaire...

The microbiome derived from soil associated with plant roots help in plant growth and stress resistance. It exhibits potential benefits for soil remediation and restoration of radioactive-cesium (137 Cs)-contaminated soils. However, there is still limited information about the community and diversity of root-associated microbiome in 137 Cs-contaminated soil after the Fukushima-Daiichi Nuclear Power Plant (FDNPP) disaster. To address this, a comparative analysis of communities and diversity of root-associated microbiomes was conducted in two field types after the FDNPP disaster...

BACKGROUND: After the Great East Japan Earthquake and subsequent Fukushima Daiichi Nuclear Power Plant accident in 2011, the Fukushima Prefectural Government launched a long-term health management survey for the population of Fukushima. Results of the Comprehensive Health Check (CHC) showed that some children aged 6-15 years, who resided in the evacuation area at the time of the disaster, had obesity, hyperlipidemia, liver dysfunction, and/or renal dysfunction from as early as 2011...

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Radioactive substances released during the accident at the Fukushima Daiichi Nuclear Power Station (FDNPS) were deposited on various equipment and building structures. During decommissioning, an investigation of the radioactive substances deposited inside the contaminated equipment and structures can provide information regarding the cause and progression of the accident. This study introduces a quantitative evaluation method for the amount of radioactivity. In this method, a Compton camera, a type of gamma-ray imager, is used to investigate the deposition and contamination level of radioactive substances on contaminated objects...

BACKGROUND: After the Great East Japan Earthquake on March 11, 2011 and the subsequent accident at the Tokyo Electric Power Company-operated Daiichi Nuclear Power Plant, the Fukushima Prefecture government initiated the Fukushima Health Management Survey (FHMS) to assess the long-term health effects of the disaster on Fukushima residents. The blood tests of children aged ≤15 years between 2011 and 2012 did not reveal any changes regarding peripheral blood data; however, long-term monitoring is still necessary...

INTRODUCTION: On March 11, 2011, the Great East Japan Earthquake occurred in Japan, with a nuclear accident subsequently occurring at the Fukushima Daiichi Nuclear Power Plant. The disaster forced many evacuees to change particular aspects of their lifestyles. However, the effect of evacuation on the new-onset of hyperuricemia have not been sufficiently elucidated. This study assessed the association between evacuation and new-onset hyperuricemia after the earthquake based on the Fukushima Health Management Survey from a lifestyle and socio-psychological perspective...

The 2011 nuclear accident at Japan's Fukushima Daiichi Nuclear Power Plant (FDNPP) prompted inquiries about the long-term transfer of Cesium-137 (137 Cs) from soil to agricultural plants. In this context, numerical modeling is particularly useful for the long-term evaluation of the consequences of agroecosystem contamination. Agricultural practices, such as tillage and cover cropping, play key roles in 137 Cs recycling in agroecosystems. In this study, we used 10-year monitoring data to develop a dynamic model to predict 137 Cs redistribution (via uptake, litterfall, translocation, and percolation) under different tillage (no-tillage, NT; rotary cultivation, RC; moldboard plow, MP) and cover crop (rye; hairy vetch; fallow weed) treatments...

In the context of elevated concerns related to nuclear accidents and warfare, the lessons learnt from the Fukushima Daiichi Nuclear Power Plant accident in 2011 are important. In particular, Japanese authorities implemented an ambitious decontamination program to reduce the air dose rate in order to facilitate the return of the local inhabitants to previously evacuated areas. This approach contrasts the strategy adopted in Chernobyl, where the most contaminated areas remain off limits. Nonetheless, the effectiveness of the Japanese decontamination strategy on the dispersion of radioactive contaminant fluxes across mountainous landscapes exposed to typhoons has not been quantified...

Dissolved radiocesium (mainly 134 Cs and 137 Cs) is thought to be leached mainly from suspended sediment in downstream rivers, while organic matter, such as leaf litter, contributes to catchments in forested headwater streams. It is also known that dissolved 137 Cs in headwater streams exhibit seasonal variation with water temperature. Some mechanisms have been proposed as the causes: ionic competition of potassium ion (K+ ) and ammonium ion (NH4 + ), leaching associated with the decomposition of organic matter, and thermodynamic adsorption-desorption processes...