Daiichi Nuclear Power Plant Accident Research Articles

Awareness of disaster preparedness between administrative staff and residents in the vicinity of the Genkai and Ikata nuclear power plants following the Fukushima Daiichi nuclear power plant disaster

Abstract When considering disaster preparedness, one challenge is mitigating the health impacts of evacuations. Nuclear disaster preparedness has evolved based on past experiences from numerous disasters, including the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident. However, there is a lack of comprehensive reporting on the awareness of administrative staff, medical personnel, and residents in the areas surrounding nuclear power plants (NPPs). This study reports on a survey aimed at gaining insights into the understanding and current state of disaster preparedness and elucidating the differences in perceptions of nuclear disaster preparedness among the relevant stakeholders surrounding NPPs. Interview surveys were conducted from 14 to 16 September 2022 in the area surrounding Kyushu Electric Power's Genkai NPP in Saga Prefecture and from 11 to 13 January 2023 in the area around Shikoku Electric Power's Ikata NPP. The surveys targeted administrative, medical, and nursing care facilities and residents. Responses from 57 participants indicated a lack of awareness of natural and nuclear disasters, challenges in evacuation planning, and a gap between nuclear disaster training and residents’ understanding of evacuation protocols. This study highlights inadequacies in nuclear disaster preparedness and the need for a better understanding among residents regarding evacuation procedures. This study identified three key issues: (1) a lack of awareness about disasters, including nuclear disasters; (2) concerns about complex disasters and the difficulties in creating evacuation plans; and (3) a discrepancy between nuclear disaster training and residents’ understanding of evacuation procedures. To bridge this gap, it is important to deepen residents’ understanding of nuclear disasters, continuously convey the lessons learned from the FDNPP accident, and regularly reassess and update nuclear disaster preparedness strategies.

Mass balance and economic analysis of volume reduction treatment for final disposal of radiocesium-contaminated incineration residues

This study evaluates the mass balance and economic feasibility of volume reduction treatment for radiocesium-contaminated incineration residues at the Interim Storage Facility for radioactive waste resulting from the accident at TEPCO’s Fukushima Daiichi Nuclear Power Plant accident in 2011. Operational since March 2020, the Volume Reduction Facility employs thermal melting treatment to concentrate the radiocesium, resulting in the production of 42,000 tons of highly radioactive fly ash. Technologies for further volume reduction of the fly ash have been considered as one possible treatment scenario, but there have been no studies evaluating the optimization of this process. This work focuses on evaluating the feasibility of one promising approach: washing, selective adsorption of radiocesium into an adsorbent, and subsequent adsorbent stabilization. Unit costs were set for each step of the volume reduction process, and mass balance and economic evaluation were conducted. The findings reveal the generation of 390 tons of stabilized waste requring final disposal, along with 10,000 tons of washing residue and 320,000 tons of wastewater. The subtotal cost of fly ash volume reduction was approximately 38 billion yen, with 61% attributed to adsorption treatment. Sensitivity analysis suggested that adsorbents with an adsorption ratio above 5,000 could effectively reduce costs. Notably, the cost of adsorption process significantly influences subtotal costs. These insights enhance understanding of the economic viability and efficiency of volume reduction treatment for radiocesium-contaminated incineration residues, contributing to optimized strategies and technologies for volume reduction prior to final disposal.

Decline in the Conception Rate of Wild Japanese Monkeys after the Fukushima Daiichi Nuclear Power Plant Accident.

We examined the conception rate of wild Japanese monkeys (Macaca fuscata) in Fukushima City that were exposed to radiation as a result of the Fukushima Daiichi Nuclear Power Plant accident in March 2011. The conception rate in the year of delivery from 2009 to 2022 was estimated by dissecting individuals that were euthanized by the government for population control as a countermeasure against crop damage. To evaluate the effects of exposure, the cumulative exposure dose for each individual was calculated using the concentration of radiocesium deposited in the soil at the capture site and the concentration of radiocesium in muscle estimated from the aggregated transfer factor. There were no significant differences in conception rates across all age classes over time. In terms of conception rates by age class, there was a significant decrease post-exposure compared with pre-exposure in the age class ≥ 8years, but no significant differences in the age class 5-7years. The non-ovulation rate did not significantly differ between the pre- and post-exposure periods for any age class. Body fat index, which can affect fertility, was compared between the pre- and post-exposure periods, and no significant differences were found in either age class. In contrast, the median total cumulative exposure (cumulative internal exposure + cumulative external exposure) was significantly higher in the age class ≥ 8years compared with the age class 5-7years. These results suggest that the total cumulative exposure dose may be one of the reasons for the lower conception rate in the post-exposure period among the age class ≥ 8years.

Attitudes toward future child-rearing among male and female adults without children in different prefectures at 11 years after the Fukushima Daiichi Nuclear Power Plant accident

Attitudes toward future child-rearing among male and female adults without children in different prefectures at 11 years after the Fukushima Daiichi Nuclear Power Plant accident

Investigation of sorption behavior of 137Cs in a river–sea system boundary area after the Fukushima Dai-ichi nuclear power plant accident

The radiocesium (137Cs) distribution between dissolved and particulate phases was examined in river water and coastal seawater as a function of the 137Cs sorption behavior on suspended particles. Dissolved 137Cs activity concentrations in the Tomioka River (salinity <0.1), about 10 km south of Fukushima Dai-ichi Nuclear Power Plant, and in coastal seawater at Tomioka fishery port (salinity >30), Fukushima Prefecture, from June 2019 to October 2021 were 3.6–20 Bq/m3 (geometric mean 11 Bq/m3) and 2.4–86 Bq/m3 (13 Bq/m3), respectively. Although the suspended particle concentration was lower in the river than in seawater, the mean 137Cs activity on suspended particles was 11,000 Bq/kg-dry in the river versus 3200 Bq/kg-dry in seawater. Proportions of ion-exchangeable, organically bound, and refractory fractions of 137Cs on suspended particles were determined by sequential extraction. The ion-exchangeable fraction accounted for 0.3–2.0% (average: 1.2%) and 0.4–1.3% (0.8%) at the river and port sites, respectively. The organically bound fraction accounted for 0.3–4.8% (1.8%) and 0.1–5.5% (2.1%) at the river and port sites, respectively. In both areas, the refractory fraction accounted for >90% of 137Cs. Therefore, the small labile 137Cs fraction on suspended particles in coastal seawater indicates that the mobility of 137Cs to marine biota is quite low. SynopsisThis study is the first to examine radiocesium sorption forms on suspended particles in coastal seawater near the Fukushima Dai-ichi Nuclear Power Plant. It suggests immobility of 137Cs in suspended particles being incorporated to marine biota.

Ultrastructural Analysis of Large Japanese Field Mouse (Apodemus speciosus) Testes Exposed to Low-Dose-Rate (LDR) Radiation after the Fukushima Nuclear Power Plant Accident.

Since the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident, great attention has been paid to the impact of chronic low-dose-rate (LDR) radiation exposure on biological systems. The reproductive system is sensitive to radiation, with implications connected to infertility. We investigated the testis ultrastructure of the wild large Japanese field mouse (Apodemus speciosus) from three areas contaminated after the FDNPP accident, with different levels of LDR radiation (0.29 µSv/h, 5.11 µSv/h, and 11.80 µSv/h). Results showed good preservation of the seminiferous tubules, comparable to the unexposed animals (controls), except for some ultrastructural modifications. Increases in the numerical density of lipid droplet clusters in spermatogenic cells were found at high levels of LDR radiation, indicating an antioxidant activity rising due to radiation recovery. In all groups, wide intercellular spaces were found between spermatogenic cells, and cytoplasmic vacuolization increased at intermediate and high levels and vacuolated mitochondria at the high-level. However, these findings were also related to the physiological dynamics of spermatogenesis. In conclusion, the testes of A. speciosus exposed to LDR radiation associated with the FDNPP accident showed a normal spermatogenesis, with some ultrastructural changes. These outcomes may add information on the reproductive potential of mammals chronically exposed to LDR radiation.

Exploring simple ways to avoid collecting highly 137Cs-contaminated Aralia elata buds for the revival of local wild vegetable cultures.

Collection and cooking of wild vegetables have provided seasonal enjoyments for Japanese local people as provisioning and cultural ecosystem services. However, the Fukushima Daiichi Nuclear Power Plant accident in March 2011 caused extensive radiocesium contamination of wild vegetables. Restrictions on commercial shipments of wild vegetables have been in place for the last 10 years. Some species, including buds of Aralia elata, are currently showing radiocesium concentrations both above and below the Japanese reference level for food (100 Bq/kg), implying that there are factors decreasing and increasing the 137Cs concentration. Here, we evaluated easy-to-measure environmental variables (dose rate at the soil surface, organic soil layer thickness, slope steepness, and presence/absence of decontamination practices) and the 137Cs concentrations of 40 A. elata buds at 38 locations in Fukushima Prefecture to provide helpful information on avoiding collecting highly contaminated buds. The 137Cs concentrations in A. elata buds ranged from 1 to 6,280 Bq/kg fresh weight and increased significantly with increases in the dose rate at the soil surface (0.10-6.50 μSv/h). Meanwhile, the 137Cs concentration in A. elata buds were not reduced by decontamination practices. These findings suggest that measuring the latest dose rate at the soil surface at the base of A. elata plants is a helpful way to avoid collecting buds with higher 137Cs concentrations and aid in the management of species in polluted regions.

Southward key pathways of radioactive materials from the Fukushima Daiichi Nuclear Power Plant

This study examines the interannual and seasonal variations in the distribution of radioactive materials released from the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident in the surface layer of the Kuroshio Extension (KE). Focusing on the contrasting flow conditions in 2015 (southward) and 2021 (northward) – significant oscillatory phases of the KE’s mean flow axis – the research analyzes the impact of seasonal variations on particle transport pathways. The findings reveal distinct seasonal patterns: summer releases primarily follow the eastward KE movement, while winter releases exhibit a southward trajectory. The study further quantifies the transport timescales, demonstrating that particles can reach the Luzon Strait within 10 months, subsequently diverging northward along the Kuroshio and northwestward along the Kuroshio Branch Current, potentially entering the South China Sea within 13 months. This research contributes valuable insights into the seasonal dynamics governing the dispersion and transport of Fukushima-derived radioisotopes in the surface ocean, highlighting the crucial role of the KE in influencing their trajectories.

Resilient design in nuclear energy: Critical lessons from a cross-disciplinary analysis of the Fukushima Dai-ichi nuclear accident

This paper presents a multidisciplinary analysis of the Fukushima Dai-ichi Nuclear Power Plant accident. Along with the latest observations and simulation studies, we synthesize the time-series and event progressions during the accident across multiple disciplines, including in-plant physics and engineering systems, operators' actions, emergency responses, meteorology, radionuclide release and transport, land contamination, and health impacts. We identify three key factors that exacerbated the consequences of the accident: (1) the failure of Unit 2 containment venting, (2) the insufficient integration of radiation measurements and meteorology data in the evacuation strategy, and (3) the limited risk assessment and emergency preparedness. We conclude with new research and development directions to improve the resilience of nuclear energy systems and communities, including (1) meteorology-informed proactive venting, (2) machine learning-enabled adaptive evacuation zones, and (3) comprehensive risk-informed emergency planning while leveraging the experience from responses to other disasters.

Surface and subsurface dispersal of radioactive materials from Fukushima by subpolar gyre and intermediate waters in the North Pacific

Radioactive materials were released into the ocean following the Fukushima Daiichi Nuclear Power Plant accident in 2011. Six years after the accident, the radioactive material concentration was markedly increased in the Okhotsk Intermediate Water (OIW) of the Sea of Okhotsk. This material may have been subjected to southward subsurface dispersal by the North Pacific Intermediate Water (NPIW), which originates from the OIW. The spatiotemporal limitations of available methods have made it challenging to track the dispersal paths of radioactive materials in the North Pacific Subpolar region. Here, we performed a tracer experiment using a three-dimensional numerical model to determine the path of 137Cs from Fukushima to the Sea of Okhotsk via surface subpolar gyre currents and subsurface dispersion by OIW and NPIW. The results showed that the 137Cs concentration in the Sea of Okhotsk increased via the surface current and moved progressively southward via OIW six years after the accident and eastward via OIW and NPIW nine years after the accident, indicating that 137Cs transported by NPIW entered the subtropical region. Based on experiments, this temporal change was mainly caused by ocean currents. Thus, subsurface recirculation of radioactive material via the OIW and NPIW should be considered based on the predicted path and travel time of additional materials released from the power plant.

Determination of 90Sr in highly radioactive aqueous samples via conversion to a kinetically stable 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid complex followed by concentration–separation–fractionation based on capillary electrophoresis–liquid scintillation

BackgroundThe Fukushima Daiichi Nuclear Power Plant accident (2011) released large amounts of radioactive substances into the environment and generated highly radioactive debris. Post-accident countermeasures are currently in the phase of fuel debris removal, which requires the analysis of radioactive contaminants in the environment and fuel. The spectra of solely β-emitting nuclides, such as 90Sr, overlap; thus, an effective method for nuclide separation is desired. Since conventional methods for high-dose sample analysis pose substantial exposure risks and generate large amounts of secondary radioactive waste, faster procedures allowing for decreased radiation emission are highly desirable. ResultsIn this study, we developed a 90Sr2+ quantitation technique based on liquid scintillation counting (LSC)–coupled capillary transient isotachophoresis (ctITP), along with two-point detection and relying on the rapid concentration, separation, and fractionation of 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA)-complexed 90Sr2+ in a single run. The applicability of our method for the analysis of real-world samples was verified by conducting addition-recovery experiments using a seawater reference material and radioactive liquid waste obtained from the radioactive waste treatment facility at the Japan Atomic Energy Agency. The recovery determined by LSC was 95–113%, indicating successful quantitative analysis. 90Sr recovery was determined to be 90.1% from a contaminated water sample obtained from the Fukushima Daiichi Nuclear Power Plant, which was analyzed using the standard addition of 90Sr. The sensitivity (detection limit = 0.016 Bq) of the proposed method on a radioactivity basis was equal to or higher than that of the conventional method using ion exchange-LSC (0.012–0.07 Bq). Significance and noveltyOur method allows for the handling of high-dose radioactive samples at the microliter level and is substantially faster than conventional ion exchange protocols, whereas ctITP has not been used for practical applications due to inaccurate collection and lack of a suitable chemical system. The concentration–separation–fractionation protocol in ctITP is successful due to the existence of a rare inert Sr2+ complex and precise fractionation. This study establishes a pathway toward safer and more practical analysis of radionuclides.

Special Issue on Robotic, Mechatronic and Information Systems for Decommissioning

The Fukushima Daiichi Nuclear Power Plant accident, triggered by the Great East Japan Earthquake and the tsunami, has had a major impact on societies across the world. The subsequent focus on decommissioning efforts has attracted worldwide attention. It has been consistently asserted since the aftermath of the accident that the decommissioning of the Fukushima Daiichi Nuclear Power Plant will take approximately 30 to 40 years. The promotion of decommissioning work means that we will continue to face the problems with uncertainties in the work, as sometimes referred to as Unknown Unknowns. Typical elemental technologies required in remotely operated robotic systems for decommissioning include mobile mechanisms and their control, handling mechanisms and their control, information communication, operation interface (information presentation and command input), shielding (radiation resistance) and so on. Although many tasks using remotely operated robotic systems have been carried out with noteworthy results, there are lingering issues yet to be clarified. To ensure the safe and effective execution of various types of decommissioning tasks over a period of several decades, continuous research and development of each elemental technology are imperative, and these technologies must be integrated into a system appropriately to the assumed tasks. In addition, human resource development and the transfer of knowledge and experience are also important issues. From such viewpoint, this special issue is titled “Robotic, Mechatronic and Information Systems for Decommissioning.” It contains papers and development reports on robotics, mechatronics, information processing, and information systems technologies relevant to decommissioning work. It also features recent activities of nuclear emergency response organizations. We hope this special issue will acquaint readers with the latest research and development results and organizational activities related to decommissioning. At the same time, we hope that we were able to provide readers interested in robots, mechatronics, and information technology with an opportunity to become aware of the issues and necessary perspectives related to decommissioning and nuclear disasters. Lastly, we would like to thank the editorial board of the Journal of Robotics and Mechatronics, the editorial team of Fuji Technology Press, and the reviewers for their support in the planning and publication of this special issue. Their dedicated efforts are deeply appreciated.

Transport of radioactive materials from terrestrial to marine environments in Fukushima over the past decade

Abstract While 20 % of radionuclides released from the Fukushima Daiichi Nuclear Power Plant accident had been deposited in the terrestrial environment, rivers remain the long-term source for 137Cs, primarily through particulate transfer, from terrestrial to marine ecosystems. In this study, we estimated the suspended 137Cs flux to the ocean at 11 sites in the coastal area between October 2012 and December 2020 to be 17 TBq, based on our long-term monitoring data of concentrations of suspended 137Cs and suspended solids. The cumulative loss of suspended 137Cs from each site to the ocean ranged from 0.1 % to 1.7 % of initial deposition throughout the observation period, depending on the effect of dam lakes and normalized river discharge. The higher loss is also thought to be the large outflow of runoff during the typhoon. The current level of the suspended 137Cs concentrations was lowered to 1/10–1/100 of those immediately after the accident. The average value of the decreasing trend for each site was approximated using the equation: y = a1 e −k 1 t + a2 e −k 2t. The rate constant k 1 is higher in areas with intensive land use, such as pastures, bare land, and water surfaces, and k 2 is lower in urban areas.

Intra-mediary expertise: Trans-science and expert understanding of the public.

What is the role of experts and their expertise in the context of trans-science, in which issues that are raised in scientific terms cannot be answered by science alone? This article examines the discourses and practices around safety of low-dose exposure to radiation in the ongoing aftermath of the Fukushima Daiichi Nuclear Power Plant accident in Japan in 2011. Following the nuclear fallout, scientific experts and STS scholars in Japan debated what forms of science communication were adequate to address the situation. Ethnographic research and textual analysis of their debates show a shift in emphasis on the role of experts from cultivating 'public understanding of science' for the sake of science and policy to an 'expert understanding of the public' for the sake of the public and its diverse everyday concerns. Two forms of expertise are emerging: 'co-expertise' and 'intra-mediary expertise'. Both are parts of a transition from a paternalistic form of expertise to one that acknowledges the need to engage the public to address issues of scientific uncertainty. However, co-expertise ultimately upholds the existing political structures that shape risk governance, while intra-mediary expertise engages those often excluded from current structures of accountability. Discussion of the potentials and limitations of emerging forms of expertise in Japan show that epistemic justice is not enough. Civic justice that acknowledges diverse publics and their needs must be upheld in the uncertain sphere between science, politics, and everyday life.

Dispersant-enhanced migration of radiocesium among soil size fractions: A novel strategy for volume reduction of radioactively contaminated soil

In the aftermath of the Fukushima Daiichi Nuclear Power Plant accident, a pioneering large-scale decontamination project was initiated, aiming to enable the return of evacuees. This project, the first of its kind in human history, involved the transportation of soils collected during decontamination to interim storage facilities. Before recycling or disposal, these soils undergo processes like volume reduction. However, there's a need for innovative methods to reduce volume effectively and treat secondary wastes more efficiently. The current study explores the impact of a dispersant, sodium hexametaphosphate (SHMP), on the behavior of radiocesium (r-Cs: 137Cs) dynamics in different size fractions of radioactively contaminated soils from Fukushima. The solid-phase speciation analysis of Fukushima soils validated that at least 50% of the 137Cs or other minerals are associated with difficult-to-extract soil phases. Nonetheless, the low 137Cs/133Cs ratio in corresponding soil phases implies a slower r-Cs fixation mechanism. The wet-sieving of r-Cs contaminated soil fraction, < 2 mm, with SHMP, resulted in different soil subfractions (2000–212, 212–53, and < 53 μm). Following SHMP treatment, dispersion of > 92% of 137Cs associated with < 212 μm soil size fractions was observed. The migration of 137Cs towards smaller soil size fractions can be attributed to either SHMP-induced cation exchange or the formation of polyvalent complexes involving SHMP and soil minerals. The condensation of 137Cs in < 212 μm, as induced by SHMP, enabled the subsequent reuse of the larger soil fraction (> 212 μm), which was less contaminated. This study provides a new perspective on the effects of dispersants and contributes to a better understanding of the complex interactions among organic carbon, 137Cs, monovalent and polyvalent cations, and soil functional groups concerning the volume reduction of soils contaminated with r-Cs.

Evaluating thyroid cancer risks for nuclear workers related to the Fukushima Daiichi Nuclear Power Plant accident based on LNT theory is problematic.

Evaluating thyroid cancer risks for nuclear workers related to the Fukushima Daiichi Nuclear Power Plant accident based on LNT theory is problematic.

Categorization of disaster-related deaths in Minamisoma city after the Fukushima nuclear disaster using clustering analysis

The medical situation during disasters often differs from that at usual times. Disasters can lead to significant mortality that can be difficult to monitor. The types of disaster-related deaths are largely unknown. In this study, we conducted a survey to categorize the disaster-related deaths caused by a radiation disaster. A total of 520 people living in Minamisoma City, Fukushima Prefecture, at the time of the Fukushima Daiichi Nuclear Power Plant accident, who were certified to have died due to disaster-related causes were surveyed. We divided the participants into those who were at home at the time of the earthquake and those who were in hospitals or facilities when the disaster struck and conducted a hierarchical cluster analysis of the two groups. Disaster-related deaths could be divided into seven groups for those who were at home at the time of the disaster and five groups for those who were in hospitals or facilities at the time of the disaster. Each group showed different characteristics, such as "the group with disabilities," "the group receiving care," and "the group with depression," and it became evident that not only uniform post-disaster support, but support tailored to the characteristics of each group is necessary.

Post-Disaster Community Transition of Psychiatric Inpatients: Lessons from the Fukushima Nuclear Accident.

This study sought to explore factors related to community transition after the mandatory evacuation of psychiatric inpatients to other hospitals owing to the Fukushima Daiichi Nuclear Power Plant accident. A retrospective cohort design was adopted and 391 psychiatric patients were examined. Univariate and multivariate analyses were conducted to confirm the association between the achievement or non-achievement of discharge to community living and their backgrounds (age, gender, evacuation destination, psychiatric diagnoses, and physical complications). Multivariate analysis indicated that patients with psychiatric diagnoses of schizophrenia, schizotypal, and delusional disorders (International Statistical Classification of Diseases and Related Health Problems 10th revision, F20-29), and those with physical diagnoses of the circulatory (I00-95) and digestive (K00-93) systems showed a significant association with the non-attainment of community transition. From these results, we hypothesized that difficulties in the management of medication during and immediately after the extremely chaotic settings of evacuation could have negative effects on the community transitions. Furthermore, another possible concern was that individuals' persistent psychotic status before the accident had been carried over to the destination hospitals. Therefore, pre-disaster daily cooperation across hospitals and challenges for vulnerable psychiatric patients' future community lives are also essential.

Study on the relationship between the dispersal of wild boar (Sus scrofa) and the associated variability of Cesium-137 concentrations in its muscle Post-Fukushima Daiichi Nuclear Power Plant accident

After the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident in 2011, the wild boar (Sus scrofa) population within the Fukushima Evacuation Zone (FEZ) increased substantially in size and distribution. This growing population and their potential dispersal from the FEZ, where they are exposed to high levels of radionuclides, into the surrounding landscape underscores the need to better understand boar movement patterns in order to establish policies for managing shipping restrictions for boar meat and develop management strategies. In this study, we quantified the genetic population structure of boar in and around Fukushima prefecture using sequence data of the mitochondrial DNA control region and MIG-seq analysis using 348 boar samples to clarify boar dispersal patterns. Among boar samples, seven Asian haplotypes and one European haplotype were detected. The European haplotype originated from hybridization between domestic pigs and native boar in the evacuation zone after the accident and was detected in 15 samples across a broad geographic area. Our MIG-seq analysis revealed genetic structure of boar was significantly different between boar inhabiting the eastern (including FEZ. i.e., East clade) and western (i.e., West clade) regions in Fukushima prefecture. In addition, we investigated the relationships between boar dispersal and Cesium (Cs)-137 activity concentrations in boar muscle using MIG-seq genetic data in Nihonmatsu city, located in the central-northern region of Fukushima. High Cs-137 activity concentrations, exceeding 1000 Bq/kg, in boar muscle had a significantly high probability of belonging to the East clade within localized regions. Thus, our results provide evidence of the spatial scale of dispersal of individuals or offspring of boar from the FEZ. Results of this research also indicate that dispersal of individuals between areas with different Cs-137 contamination levels is one of the biggest factors contributing to variation in Cs-137 activity concentration in boar muscle within localized regions.

Prolonged impact of the Fukushima Nuclear Power Plant Accident on health and society

Prolonged impact of the Fukushima Nuclear Power Plant Accident on health and society Naomi Ito, Research Assistant at the Fukushima Medical University, tells us how the 2011 Fukushima Daiichi Nuclear Power Plant Accident impacted and continues to impact local residents. The health effects on local residents following a nuclear power plant accident are diverse, not only because of radiation exposure but also because of changes in lifestyle and social environment. It has also been indicated that various environmental changes that could emerge during the restoration process may affect residents in various ways over a long time. On March 11, 2011, the Great East Japan Earthquake struck Japan with a magnitude of 9.0. Within an hour, a tsunami hit the shore. Three reactors at the Fukushima Daiichi Nuclear Power Plant (FDNPP, operated by Tokyo Electric Power Company) lost power. The reactors could not be cooled, and core meltdowns occurred, which resulted in an explosion due to hydrogen being generated at high temperatures. As a result, radioactive materials were released and scattered northwest from the power plant.