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To retrieve the diffusion trajectory of the 131I dispersed in the environment by the nuclear power plant accident in Fukushima in 2011, airborne particulate matter (APM) samples collected in the Tokyo metropolitan area were analyzed for their 129I contents by means of accelerator mass spectrometry. In evaluating blank levels of chemicals and filters used for collecting APM, we established the analytical procedure for determining the 129I activity of as low as 10−8 Bq for a small piece of filter samples (about 0.1 cm2). Coupled with 131I data determined just after the accident, activity ratios of 129I/131I were obtained with a mean value of 2.29 × 10−8 (±28% of a standard deviation). This value is systematically smaller than a mean value of soil samples by 16–24% and the inventory data by 27%, suggesting that 129I was partly lost from APM. As 129I can be a proxy of 131I for APM, it is possible to trace how 131I in the particulate phase spread in eastern Japan and, furthermore, evaluate the internal radiation exposure due to 131I by inhalation of 131I-containing airborne particulates. • 10−8 Bq of 129I can be quantified for aerogel on 0.1 cm2 filter paper. • 129I/131I activity ratios for aerosol from the Fukushima nuclear accident determined. • 129I can be a proxy of 131I for reproducing the diffusion trajectory of 131I. [ABSTRACT FROM AUTHOR]

Given the need to rein in the rise in the global average temperature, decarbonizing the electricity sector, which accounts for nearly 50% of global greenhouse gas (GHG) emissions, is crucial. The suitability of nuclear power as a base-load technology and its relatively negligible GHG emissions raised expectations of a nuclear renaissance, until the Fukushima disaster brought discussions about nuclear power’s potential to a standstill. However, completely ruling out nuclear may not be sustainable owing to the realities of rising energy demand, climate change considerations, and the need for reliable base-load supply technology, especially in the case of fast growing economies in the Association of South East Asian Nations (ASEAN). The Fukushima disaster was a wake-up call for both governments and the nuclear industry. Led by the International Atomic Energy Agency, the more advanced economies conducted stringent reviews of safety standards and emergency response procedures in the event of a catastrophe. Meanwhile the industry responded with strong commitments towards “Fukushima proof” designs, alongside other advancements towards “safer” fission power. In the ASEAN context, we argue in this paper that in addition to the economic advantage, nuclear power can help address the twin objectives of energy security and mitigating climate change effects. In ASEAN, there is still a strong momentum towards nuclear power development due to strategic considerations. In this paper, we reviewed in a holistic approach the various factors influencing decision making on nuclear power. Using ASEAN as a case study, we argue that nuclear power remains an important option and should be taken up rapidly if decarbonizing electricity generation is a grave concern. We also provide some recommendations towards the “safer nuclear” for ASEAN at the end of this paper. [ABSTRACT FROM AUTHOR]

Abstract: The threat of a major accidental or deliberate event that would lead to hazardous materials emission in the atmosphere is a great cause of concern to societies. This is due to the potential large scale of casualties and damages that could result from the release of explosive, flammable or toxic gases from industrial plants or transport accidents, radioactive material from nuclear power plants (NPPs), and chemical, biological, radiological or nuclear (CBRN) terrorist attacks. In order to respond efficiently to such events, emergency services and authorities resort to appropriate planning and organizational patterns. This paper focuses on the use of atmospheric dispersion modeling (ADM) as a support tool for emergency planning and response, to assess the propagation of the hazardous cloud and thereby, take adequate counter measures. This paper intends to illustrate the noticeable evolution in the operational use of ADM tools over 25 y and especially in emergency situations. This study is based on data available in scientific publications and exemplified using the two most severe nuclear accidents: Chernobyl (1986) and Fukushima (2011). It appears that during the Chernobyl accident, ADM were used few days after the beginning of the accident mainly in a diagnosis approach trying to reconstruct what happened, whereas 25 y later, ADM was also used during the first days and weeks of the Fukushima accident to anticipate the potentially threatened areas. We argue that the recent developments in ADM tools play an increasing role in emergencies and crises management, by supporting stakeholders in anticipating, monitoring and assessing post-event damages. However, despite technological evolutions, its prognostic and diagnostic use in emergency situations still arise many issues. [Copyright &y& Elsevier]

Abstract: Only three days after the beginning of the nuclear catastrophe in Fukushima, Japan, on 11 March 2011, the German government ordered 8 of the country''s 17 existing nuclear power plants (NPPs) to stop operating within a few days. In summer 2011 the government put forward a law – passed in parliament by a large majority – that calls for a complete nuclear phase-out by the end of 2022. These government actions were in contrast to its initial plans, laid out in fall 2010, to expand the lifetimes of the country''s NPPs. The immediate closure of 8 NPPs and the plans for a complete nuclear phase-out within little more than a decade, raised concerns about Germany''s ability to secure a stable supply of electricity. Some observers feared power supply shortages, increasing CO2-emissions and a need for Germany to become a net importer of electricity. Now – a little more than a year after the phase-out law entered into force – this paper examines these concerns using (a) recent statistical data on electricity production and demand in the first 15 months after the German government''s immediate reaction to the Fukushima accident and (b) reviews the most recent projections and scenarios by different stakeholders on how the German electricity system may develop until 2025, when NPPs will no longer be in operation. The paper finds that Germany has a realistic chance of fully replacing nuclear power with additional renewable electricity generation on an annual basis by 2025 or earlier, provided that several related challenges, e.g. expansion of the grids and provision of balancing power, can be solved successfully. Already in 2012 additional electricity generation from renewable energy sources in combination with a reduced domestic demand for electricity will likely fully compensate for the reduced power generation from the NPPs shut down in March 2011. If current political targets will be realised, Germany neither has to become a net electricity importer, nor will be unable to gradually reduce fossil fuel generated electricity. Whether the reduction in fossil fuel use will be sufficient to adequately contribute to national greenhouse gas mitigation targets significantly depends on an active policy to promote electricity savings, continuous efforts to increase the use of renewables and a higher share of natural gas (preferably used in combined heat and power plants) in fossil fuel power generation. [Copyright &y& Elsevier]

The Great Tohoku–Kanto earthquake and the resulting tsunami have brought considerable attention to the issue of building new nuclear power plants. In this paper we argue that nuclear power is not a sustainable solution to energy problems. First, we explore the stock of uranium-235 and the different methods, fast breeder and MOX fuel reactors, developed by the nuclear power industry to exploit this resource. Second, we show that these fuel reactors are not feasible. Third, we show that the claim that nuclear energy can be used to reduce CO2 emissions is false: the emissions from the increased water evaporation from nuclear power generation must be accounted for. In the case of Japan, water from nuclear power plants is drained into the surrounding sea, raising the water temperature which has an adverse effect on the immediate ecosystem, as well as increasing CO2 emissions from increased water evaporation from the sea. Next, a short exercise is used to show that nuclear power is not needed to meet electricity demand in Japan. Such an exercise should be performed for any country considering the construction of additional nuclear power plants. Lastly, the paper is concluded with a discussion of the implications of our paper. [Copyright &y& Elsevier]

Dose prediction tools making use of existing knowledge on the environmental behaviour of radiocontaminants are essential for justification and optimisation of recovery countermeasure strategies for contaminated inhabited areas. In this context, one necessary requirement is to estimate the relative initial contaminant distribution on different types of surfaces in the environment and the resultant initial dose rates to humans staying in the environment. This paper reports on the latest parametric refinements in this context for use in the ERMIN inhabited area dose model, which is an integral part of the European emergency management decision support systems ARGOS and RODOS. • Deposition relations on urban surfaces of a wide range of contaminants are estimated. • Deposition parameters are given for different types of weather conditions (wet/dry). • The deposition data contains uncertainty estimates for use in decision making. • Dose rate conversion factors used in European decision support were recalculated. [ABSTRACT FROM AUTHOR]

Abstract Citizen science data from the Safecast project were shown to provide a reliable estimation of the spatial distribution of concentrations of elevated radiation levels around Fukushima when compared to government data. A comparison is presented between the HYSPLIT Lagrangian atmospheric transport and dispersion (T&D) model and a reflected Gaussian model to both government and Safecast contributed measurements. The advantage of contributed data with respect to the government data is that they are collected over a long period of time and have a larger spatial coverage. First, the Safecast contributed measurements are compared to aerial surveys completed by the Department of Energy (DOE) and the National Nuclear Security Administration (NNSA). Then the HYSPLIT T&D model is run to simulate the nuclear release using high resolution terrain and meteorological data. A Gaussian dispersion model is also run for comparison using meteorological data observed at the time of the accident. The results of both models and observed data are decay corrected to December 2016 in order to use a larger quantity of contributed measurements in the comparison. The comparison of areas of elevated radiation shows that the citizen science observations align with the prediction of models representing dynamic behavior of radionuclides dispersed in the environment. This paper shows that citizen science data can be used to validate and potentially better calibrate atmospheric T&D models. Highlights • Comparison of observations and models reveals new insights on spatial patterns. • Unique aspects support the need to use multiple sources and not ignore limitations. • Citizen science is particularly ideal for monitoring in populated areas of interest. • Citizen science can act as an early warning system and be integrated with models. [ABSTRACT FROM AUTHOR]

The JRODOS ( J ava-based R eal-time O nline D ecisi O n S upport) is a decision support system for off-site emergency management for releases of radioactive material into the environment. This paper documents the application of JRODOS by the Hong Kong Observatory in accident consequence assessment and emergency preparedness studies. For operational considerations, the most computational efficient dispersion model in JRODOS, ATSTEP, is adopted. Verification studies for JRODOS's ATSTEP model have been conducted. Comparison with tracer experiment results showed that under neutral atmospheric conditions and distances up to 50 km, the JRODOS simulation outputs were in general of the same order of magnitude with the tracer data. To further evaluate the capability of JRODOS in short-range simulation, a case study on the Fukushima nuclear power plant accident was also carried out. JRODOS was able to produce realistic simulation results which were comparable to the actual airborne monitoring data of the Cs-137 ground deposition from the Fukushima accident. Furthermore, the results of a comprehensive study to assess the potential consequences of accidents at a nearby nuclear power station are presented. Simulation using the French S3 source term for the Guangdong Nuclear Power Station at Daya Bay showed that the projected effective doses within Hong Kong remain far below the IAEA generic criteria of projected dose for urgent protective actions in sheltering/evacuation, while the projected equivalent dose in thyroid may meet the IAEA generic criteria for use of thyroid blocking agent at some areas in the northeastern part of Hong Kong, at distances of up to about 40 km from Daya Bay depending on the prevailing weather conditions in different seasons. [ABSTRACT FROM AUTHOR]

Exposure to radiation is a potential hazard to humans and the environment. The Fukushima accident reminded the world of the importance of a reliable risk management system that incorporates the dose received from radiation exposures. The dose to humans from exposure to radiation can be quantified using a well-defined system; its environmental equivalent, however, is still in a developmental state. Additionally, the results of several papers published over the last decade have been criticized because of poor dosimetry. Therefore, a workshop on environmental dosimetry was organized by the STAR (Strategy for Allied Radioecology) Network of Excellence to review the state of the art in environmental dosimetry and prioritize areas of methodological and guidance development. Herein, we report the key findings from that international workshop, summarise parameters that affect the dose animals and plants receive when exposed to radiation, and identify further research needs. Current dosimetry practices for determining environmental protection are based on simple screening dose assessments using knowledge of fundamental radiation physics, source-target geometry relationships, the influence of organism shape and size, and knowledge of how radionuclide distributions in the body and in the soil profile alter dose. In screening model calculations that estimate whole-body dose to biota the shapes of organisms are simply represented as ellipsoids, while recently developed complex voxel phantom models allow organ-specific dose estimates. We identified several research and guidance development priorities for dosimetry. For external exposures, the uncertainty in dose estimates due to spatially heterogeneous distributions of radionuclide contamination is currently being evaluated. Guidance is needed on the level of dosimetry that is required when screening benchmarks are exceeded and how to report exposure in dose-effect studies, including quantification of uncertainties. Further research is needed to establish whether and how dosimetry should account for differences in tissue physiology, organism life stages, seasonal variability (in ecology, physiology and radiation field), species life span, and the proportion of a population that is actually exposed. We contend that, although major advances have recently been made in environmental radiation protection, substantive improvements are required to reduce uncertainties and increase the reliability of environmental dosimetry. [ABSTRACT FROM AUTHOR]

This paper evaluates how geographical theories of scale can give a more robust understanding of the governance of complex environmental risks. We assess the case of fisheries in Iwaki City, Fukushima Prefecture in Japan following the 2011 nuclear disaster. Fisheries in Iwaki and Fukushima more widely are operating on a trial basis as understanding of the marine radiation situation becomes clearer, however questions remain over whether consumers will buy produce and to what extent full-scale fisheries will resume. Based on empirical fieldwork undertaken in Fukushima plus supporting documentary analysis, we construct a scalar account of post-disaster Iwaki fisheries. We use this to argue that framing post-disaster fisheries governance at the municipal scale rather than the prefectural scale has opened up opportunities for enacting the more two-way forms of risk governance that contemporary environmental issues may require. We also argue locally-situated ‘experts’ (e.g. fisheries extension officers and citizen science groups) play a key role in negotiating citizens’ and fishers’ relationships with larger-scale scientific discourses due to their ability to work across scales, despite having less techno-scientific expertise than their national-level counterparts. In turn, we suggest that in governance of complex environmental issues, policymakers ought to (a) consider how community-level expectations may differ from risk governance processes developed at larger scales; (b) identify key institutions or figures who can work across scales and support them accordingly; and (c) show cognisance to the social effects that may arise from spatial demarcation of environmental problems. [ABSTRACT FROM AUTHOR]

• Socio-economic aspects and living conditions contribute to well-being. • Local facilitator-expert-population networks are fruitful structures of dialogue. • Self-help protective actions and counselling are key levers to help the resilience of affected populations. • Strong need of education & training programmes on radiological protection culture. This paper explores how health concerns of populations living in contaminated areas following radiological accidents can be considered in developing health surveillance. The research was performed in the framework of the SHAMISEN project, and aimed at identifying the impacts on, and challenges associated with, living and social conditions of affected populations. These objectives were achieved through the analysis of specific Case Studies in different situations observed after the Chernobyl accident (Belarus and Norway) and the activities carried out after the Fukushima accident. It incorporates an analysis of testimonies of medical experts and local stakeholders from contaminated territories in Japan within two Case Studies as well as through a dedicated workshop jointly organised with Fukushima Medical University in Japan in March 2016. The analysis addresses the following topics: • Expectations and worries of the people regarding their health and welfare; • Role of the different stakeholders (health professionals, radiological protection professionals, local population, authorities, etc.) in improving living and social conditions in contaminated areas; • Contribution of the implemented protective actions to well-being and their direct benefits for populations; • Sustainability and continuity of the projects/actions; • Ethical considerations; • Stakeholder participation, dialogue, information and communication issues; • Education and training provision and need. Thus, this paper outlines key lessons learned from each of these topics, by providing tangibles examples from the analysis of the various Case Studies. [ABSTRACT FROM AUTHOR]

The town of Marumori in southern Miyagi Prefecture borders on Fukushima Prefecture, and following the accident at the Fukushima Daiichi nuclear power plant, there were concerns about cesium deposition in forested areas. One of the authors of this paper has continually surveyed leaf litter from the forested areas. As leaf litter may be a source of cesium contamination from the forest to downstream areas, we considered a simplified version of wet oxidation, a method previously presented by one of the authors of this study, as a technology to reduce leaf litter weight and cesium concentration, separating radioactive nuclides from non-radioactive ones, in leaf litter. We tested our method in three experiments. Experiment 1 used new leaf litter (232 Bq/kg) from the surface of a small stream at the forest edge nearby an area with air dose level higher than the national standard threshold of 0.23 μSv/h for the implementation of governmental decontamination works. Experiment 2 applied wet oxidation to older leaf litter (705 Bq/kg) harvested from a pasture nearby the stream mentioned above. We also used the same leaf litter in experiment 3 for a cesium release tests using pure water. In experiment 1 and 2 we treated leaf litter with a sodium hypochlorite solution, optimizing sodium hypochlorite concentration and reaction temperature. We measured a 50–60% decrease in the leaf litter weight and a 60% decrease in the cesium concentration. Moreover, we also measured the amount of cesium washout. The cesium budget of experiment 1 showed no cesium gasification (wet oxidation avoids airborne cesium as this element is prone to be volatile at 600 °C), and that high sodium hypochlorite concentration and high temperature had a strong positive effect on leaf litter volume reduction and cesium decontamination. Experiment 2 confirmed the reproducibility of these results in leaves with different cesium concentration and harvested in different conditions. We could also explain the mechanism behind leaf litter weight and cesium concentration reduction. Experiment 3 helped us to investigate the effects of the matter present on the surface of the water and the contribution of water soluble cesium. Concurrent experiments on changes in leaf litter chemical composition confirmed that our modified wet oxidation method had an effect on the removal of acid-insoluble lignin. Removal of lignin, a refractory component, might allow for a better utilization of the residue left after implementation of the proposed simplified wet oxidation. Thus, real wastes could be smaller than the residues. Together with the observed smaller cesium concentration in the residue, the proposed method in this study is expected to contribute to mitigate the risk due to the fallen leaves containing cesium. [ABSTRACT FROM AUTHOR]

This paper presents a multiscale data integration method to estimate the spatial distribution of air dose rates in the regional scale around the Fukushima Daiichi Nuclear Power Plant. We integrate various types of datasets, such as ground-based walk and car surveys, and airborne surveys, all of which have different scales, resolutions, spatial coverage, and accuracy. This method is based on geostatistics to represent spatial heterogeneous structures, and also on Bayesian hierarchical models to integrate multiscale, multi-type datasets in a consistent manner. The Bayesian method allows us to quantify the uncertainty in the estimates, and to provide the confidence intervals that are critical for robust decision-making. Although this approach is primarily data-driven, it has great flexibility to include mechanistic models for representing radiation transport or other complex correlations. We demonstrate our approach using three types of datasets collected at the same time over Fukushima City in Japan: (1) coarse-resolution airborne surveys covering the entire area, (2) car surveys along major roads, and (3) walk surveys in multiple neighborhoods. Results show that the method can successfully integrate three types of datasets and create an integrated map (including the confidence intervals) of air dose rates over the domain in high resolution. Moreover, this study provides us with various insights into the characteristics of each dataset, as well as radiocaesium distribution. In particular, the urban areas show high heterogeneity in the contaminant distribution due to human activities as well as large discrepancy among different surveys due to such heterogeneity. [ABSTRACT FROM AUTHOR]

This paper addresses the New Alamein City and its proximity to El Dabaa nuclear power plant. It is mainly concerned with the 32 km radius of low population zone around the plant. It questions the erection of the new city and its future extension and their proximity to El Dabaa plant because nuclear safety regulations require the presence of a low population zone (100–194 inhabitants/square kilometer) around nuclear power plants. International and national regulatory standards have been revised for this purpose. Egyptian regulations for population are derived from the IAEA guides, the USNRC regulation and the Russian regulations regarding population protection zones around nuclear power plants. The research is status defining and data based, and the methodology used is the analysis of maps and documents, measurements and calculations. Data about the New Alamein City are reviewed and distances between El Dabaa nuclear power plant and the new city are measured in Google maps. Population numbers are collected, estimated, and areas and densities are calculated. Wind directions from the plant in the direction of the city are outlined. The distance between the Dabaa site and the west border of New Alamein City is 27.4kms, 4.6 km inside the recommended 32kms radius of low population zone around the plant. The intersection between that part of the city and the low population zone covers an area of 16.4 sq km. The population density of that part is 9900 inhabitants/sq km, which means that around 162,630 inhabitants may inhabit that area. The downwind from the plant reaches the lower half of the city. Recommendations are made to reduce the population density in that part of the new city lying in the downwind of the nuclear power plant and omission of future plans of extending it to the west direction. No new areas should be populated, as the density recommended for low population zone has already been exceeded. The only extension to New Alamein City can be in the east direction away from the plant. When a site is brilliant but is near highly populated areas, feasible emergency plan is key. Yet, the process of evacuation is not an easy job as the Fukushima accident has proved, even though Japan is a highly developed country, as many elderly people have died from the evacuation and fear of it, rather than from the radiation by the accident. [ABSTRACT FROM AUTHOR]

Temporal absences in observation records lead to release losses during the source term inversions of atmospheric radionuclide emissions. Consequently, objectively-estimated source terms for the Fukushima accident contain fewer release details and present large discrepancies when compared with the expert-judged one. This paper describes an objective method that can adaptively recover the missing releases caused by the temporal absences of observations. The proposed method assumes that the accident releases of radionuclides are piecewise-constant and comprise both peaks and constant releases. The missing releases are adaptively recovered as either peaks or constant releases by minimizing the total variation of the estimated source term. The proposed method is applied to the Fukushima accident and evaluated against regional airborne and deposited 137Cs observations. The results demonstrate that this method effectively recovers the missing releases, producing a source term that matches the timing of both on-site gamma dose rate peaks and accident events. The retrieved source term improves the simulation of air concentrations and reproduces most of the deposition patterns. This is the first time that an objective method has independently reproduced the details in the expert-judged one for the Fukushima accident. [Display omitted] • Recovery of missing releases caused by temporal absences of observations. • Preservation of both sharp peaks and constant releases. • First independent objective source term matching the expert-judged one. • Agreement with on-site gamma dose rate peak timing and accident events. • Improved spatiotemporal simulation of airborne 137Cs for the Fukushima accident. [ABSTRACT FROM AUTHOR]

Most of the countries have increased the production of renewable energy to reduce pollution and their dependency on oil and natural gas. In case of Japan, solar power is increased rapidly, especially after the Fukushima Nuclear Accident. The load leveling and fluctuation absorption are the main bottlenecks to the integration of solar PV power into the future electricity system. Hydrogen is considered as an energy carrier in a future energy system based on renewable resources. Totalized Hydrogen Energy Utilization System (THEUS) consists of a unitized reversible fuel cell and a hydrogen storage tank. The main objective of this paper is to evaluate the THEUS operation and performance at different variations in solar photovoltaic (PV) power during a sunny day and a partly cloudy day and to characterize its dynamic response. Energy efficiency of the THEUS was evaluated in water electrolyzer and fuel cell mode operation. [ABSTRACT FROM AUTHOR]

In March 2011, severe nuclear accident happened at the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) after the gigantic earthquake and following huge tsunami wave. A lot of investigations to assess environmental and radiological impacts of released radionuclides have been conducted by domestic and international organizations. Environmental radioactivity research related to the FDNPP accident has spread widely over different scientific fields due to specific features of the accident, and specifically its impact on the marine environment. The present paper summarizes major lessons learned from the environmental investigations of the FDNPP accident. Environmental radioactivity studies have typical interdisciplinary character; especially physics and chemistry are fundamental as a base of process studies in the environment. In this sight, we review chemical aspects regarding FDNPP-derived radiocesium transfer within and between compartments (atmosphere, ocean and land). We also discuss future trends in investigations of behavior of anthropogenic radionuclides in the environment, important not only for a better understanding of impacts of the FDNPP accident on the environment, but also for improving our general knowledge of the total environment in the Anthropocene era and its protection for the future. • 10 years after the FDNPP accident, the environment has been contaminated mainly by Cs-137. • Understanding of Cs-transfer within and between compartments has considerably improved. • Chemical processes are a key factor of Cs-transfer between aquatic and solid phases. • Migration of Cs-137 in terrestrial and marine ecosystems will dominate in future studies. [ABSTRACT FROM AUTHOR]

7-Methyl-2H-1,5-benzodioxepin-3(4H)-one (Calone®) is used in fragrances to impart a marine note. It is produced industrially at volumes requiring repeated dose and developmental/reproductive toxicology data (OECD TG 422) under European chemicals legislation (i.e., REACH). Additionally, Japanese chemicals legislation requires evaluation of Calone® biodegradability and identification of metabolites in an environmental biodegradation test. 7-Methyl-2H-1,5-benzodioxepin-3-ol (Calol) was the sole metabolite identified following biodegradation and a 28-day repeated dose toxicity study (OECD TG 407) would normally be required to support registration in Japan. The current paper presents results showing no adverse effects in the parental, reproductive, or developmental phases of an OECD TG 422 study following dietary administration of Calone® to rats at targeted doses of up to 1000 mg/kg/day. The No Observed Adverse Effect Level (NOAEL) was the highest administered dose of 791 and 922 mg/kg/day for males and females, respectively. An i n vitro metabolism study conducted with rat and human liver microsomes demonstrated that greater than 90% of Calone® was metabolically reduced into Calol, the same metabolite observed in the environmental biodegradation test. Accordingly, the results from the OECD TG 422 study with Calone® are directly applicable to Calol and it would be expected to have the same NOAEL. [ABSTRACT FROM AUTHOR]

The Fukushima Daiichi Nuclear Plant (FDNPP) accident resulted in huge environmental and socioeconomic impacts to Japan. To document the actual environmental and socioeconomic effects of the FDNPP accident, we describe here atmospheric and marine contamination due to radionuclides released from the FDNPP accident using papers published during past five years, in which temporal and spatial variations of FDNPP-derived radionuclides in air, deposition and seawater and their mapping are recorded by local, regional and global monitoring activities. High radioactivity-contaminated area in land were formed by the dispersion of the radioactive cloud and precipitation, depending on land topography and local meteorological conditions, whereas extremely high concentrations of 131 I and radiocesium in seawater occurred due to direct release of radioactivity-contaminated stagnant water in addition to atmospheric deposition. For both of atmosphere and ocean, numerical model simulations, including local, regional and global-scale modeling, were extensively employed to evaluate source terms of the FDNPP-derived radionuclides from the monitoring data. These models also provided predictions of the dispersion and high deposition areas of the FDNPP-derived radionuclides. However, there are significant differences between the observed and simulated values. Then, the monitoring data would give a good opportunity to improve numerical modeling. [ABSTRACT FROM AUTHOR]

The air dose rate in an environment contaminated with 134 Cs and 137 Cs depends on the amount, depth profile and horizontal distribution of these contaminants within the ground. This paper introduces and verifies a tool that models these variables and calculates ambient dose equivalent rates at 1 m above the ground. Good correlation is found between predicted dose rates and dose rates measured with survey meters in Fukushima Prefecture in areas contaminated with radiocesium from the Fukushima Dai-ichi Nuclear Power Plant accident. This finding is insensitive to the choice for modeling the activity depth distribution in the ground using activity measurements of collected soil layers, or by using exponential and hyperbolic secant fits to the measurement data. Better predictions are obtained by modeling the horizontal distribution of radioactive cesium across an area if multiple soil samples are available, as opposed to assuming a spatially homogeneous contamination distribution. Reductions seen in air dose rates above flat, undisturbed fields in Fukushima Prefecture are consistent with decrement by radioactive decay and downward migration of cesium into soil. Analysis of remediation strategies for farmland soils confirmed that topsoil removal and interchanging a topsoil layer with a subsoil layer result in similar reductions in the air dose rate. These two strategies are more effective than reverse tillage to invert and mix the topsoil. [ABSTRACT FROM AUTHOR]

Since 2011, the scientific community has worked to identify the exact transport and deposition patterns of radionuclides released from the accident at the Fukushima Daiichi Nuclear Power Plant (FDNPP) in Japan. Nevertheless, there still remain many unknowns concerning the health and environmental impacts of these radionuclides. The present paper reviews the current understanding of the FDNPP accident with respect to interactions of the released radionuclides with the environment and impacts on human and non-human biota. Here, we scrutinize existing literature and combine and interpret observations and modeling assessments derived after Fukushima. Finally, we discuss the behavior and applications of radionuclides that might be used as tracers of environmental processes. This review focuses on 137 Cs and 131 I releases derived from Fukushima. Published estimates suggest total release amounts of 12–36.7 PBq of 137 Cs and 150–160 PBq of 131 I. Maximum estimated human mortality due to the Fukushima nuclear accident is 10,000 (due to all causes) and the maximum estimates for lifetime cancer mortality and morbidity are 1500 and 1800, respectively. Studies of plants and animals in the forests of Fukushima have recorded a range of physiological, developmental, morphological, and behavioral consequences of exposure to radioactivity. Some of the effects observed in the exposed populations include the following: hematological aberrations in Fukushima monkeys; genetic, developmental and morphological aberrations in a butterfly; declines in abundances of birds, butterflies and cicadas; aberrant growth forms in trees; and morphological abnormalities in aphids. These findings are discussed from the perspective of conservation biology. [ABSTRACT FROM AUTHOR]

Tritium emissions are one of the main concerns with regard to CANDU reactors and Canadian nuclear facilities. After the Fukushima accident, the Canadian Nuclear Regulatory Commission suggested that models used in risk assessment of Canadian nuclear facilities be firmly based on measured data. Procedures for measurement of tritium as HTO (tritiated water) are well established, but there are no standard methods and certified reference materials for measurement of organically bound tritium (OBT) in environmental samples. This paper describes and discusses an inter-laboratory comparison study in which OBT in three different dried environmental samples (fish, Swiss chard and potato) was measured to evaluate OBT analysis methods currently used by CANDU Owners Group (COG) members. The variations in the measured OBT activity concentrations between all laboratories were less than approximately 20%, with a total uncertainty between 11 and 17%. Based on the results using the dried samples, the current OBT analysis methods for combustion, distillation and counting are generally acceptable. However, a complete consensus OBT analysis methodology with respect to freeze-drying, rinsing, combustion, distillation and counting is required. Also, an exercise using low-level tritium samples (less than 100 Bq/L or 20 Bq/kg-fresh) would be useful in the near future to more fully evaluate the current OBT analysis methods. [ABSTRACT FROM AUTHOR]

A transfer coefficient matrix (TCM) was created in a previous study using a Lagrangian dispersion model to provide plume predictions under different emission scenarios. The TCM estimates the contribution of each emission period to all sampling locations and can be used to estimate source terms by adjusting emission rates to match the model prediction with the measurements. In this paper, the TCM is used to formulate a cost functional that measures the differences between the model predictions and the actual air concentration measurements. The cost functional also includes a background term which adds the differences between a first guess and the updated emission estimates. Uncertainties of the measurements, as well as those for the first guess of source terms are both considered in the cost functional. In addition, a penalty term is added to create a smooth temporal change in the release rate. The method is first tested with pseudo observations generated using the Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model at the same location and time as the actual observations. The inverse estimation system is able to accurately recover the release rates and performs better than a direct solution using singular value decomposition (SVD). It is found that computing ln ( c ) differences between model and observations is better than using the original concentration c differences in the cost functional. The inverse estimation results are not sensitive to artificially introduced observational errors or different first guesses. To further test the method, daily average cesium-137 air concentration measurements around the globe from the Fukushima nuclear accident are used to estimate the release of the radionuclide. Compared with the latest estimates by Katata et al. (2014), the recovered release rates successfully capture the main temporal variations. When using subsets of the measured data, the inverse estimation method still manages to identify most of the major events in the temporal profile of the release. [ABSTRACT FROM AUTHOR]

In this paper we analyse the properties of an eighteen-member ensemble generated by the combination of five atmospheric dispersion modelling systems and six meteorological data sets. The models have been applied to the total deposition of 137 Cs, following the nuclear accident of the Fukushima power plant in March 2011. Analysis is carried out with the scope of determining whether the ensemble is reliable, sufficiently diverse and if its accuracy and precision can be improved. Although ensemble practice is becoming more and more popular in many geophysical applications, good practice guidelines are missing as to how models should be combined for the ensembles to offer an improvement over single model realisations. We show that the ensemble of models share large portions of bias and variance and make use of several techniques to further show that subsets of models can explain the same amount of variance as the full ensemble mean with the advantage of being poorly correlated, allowing to save computational resources and reduce noise (and thus improving accuracy). We further propose and discuss two methods for selecting subsets of skilful and diverse members, and prove that, in the contingency of the present analysis, their mean outscores the full ensemble mean in terms of both accuracy (error) and precision (variance). [ABSTRACT FROM AUTHOR]

In the present paper the role of precipitation as FLEXPART model input is investigated for one possible release scenario of the Fukushima Daiichi accident. Precipitation data from the European Center for Medium-Range Weather Forecast (ECMWF), the NOAA's National Center for Environmental Prediction (NCEP), the Japan Meteorological Agency's (JMA) mesoscale analysis and a JMA radar-rain gauge precipitation analysis product were utilized. The accident of Fukushima in March 2011 and the following observations enable us to assess the impact of these precipitation products at least for this single case. As expected the differences in the statistical scores are visible but not large. Increasing the ECMWF resolution of all the fields from 0.5° to 0.2° rises the correlation from 0.71 to 0.80 and an overall rank from 3.38 to 3.44. Substituting ECMWF precipitation, while the rest of the variables remains unmodified, by the JMA mesoscale precipitation analysis and the JMA radar gauge precipitation data yield the best results on a regional scale, specially when a new and more robust wet deposition scheme is introduced. The best results are obtained with a combination of ECMWF 0.2° data with precipitation from JMA mesoscale analyses and the modified wet deposition with a correlation of 0.83 and an overall rank of 3.58. NCEP-based results with the same source term are generally poorer, giving correlations around 0.66, and comparatively large negative biases and an overall rank of 3.05 that worsens when regional precipitation data is introduced. [ABSTRACT FROM AUTHOR]

This paper describes an investigation into the impact of different meteorological data sets and different wet scavenging coefficients on the model predictions of radionuclide deposits following the accident at the Fukushima Dai-ichi nuclear power plant in March 2011. Three separate operational meteorological data sets, the UK Met Office global meteorology, the ECMWF global meteorology and the Japan Meteorological Agency (JMA) mesoscale meteorology as well as radar rainfall analyses from JMA were all used as inputs to the UK Met Office's dispersion model NAME (the Numerical Atmospheric-dispersion Modelling Environment). The model predictions of Caesium-137 deposits based on these meteorological models all showed good agreement with observations of deposits made in eastern Japan with correlation coefficients ranging from 0.44 to 0.80. Unexpectedly the NAME run using radar rainfall data had a lower correlation coefficient ( R = 0.66), when compared to observations, than the run using the JMA mesoscale model rainfall ( R = 0.76) or the run using ECMWF met data ( R = 0.80). Additionally the impact of modifying the wet scavenging coefficients used in the parameterisation of wet deposition was investigated. The results showed that modifying the scavenging parameters had a similar impact to modifying the driving meteorology on the rank calculated from comparing the modelled and observed deposition. [ABSTRACT FROM AUTHOR]

After the Fukushima Dai-ichi nuclear accident, a need for assuring safety of fusion energy has grown in the Japanese (JA) fusion research community. DEMO safety research has been launched as a part of Broader Approach DEMO Design Activities (BA-DDA). This paper reports progress in the fusion DEMO safety research conducted under BA-DDA. Safety requirements and evaluation guidelines have been, first of all, established based on those established in the Japanese ITER site invitation activities. The radioactive source terms and energies that can mobilize such source terms have been assessed for a reference DEMO concept. This concept employs in-vessel components that are cooled by pressurized water and built of a low activation ferritic steel (F82H), contains solid pebble beds made of lithium-titanate (Li 2 TiO 3 ) and beryllium–titanium (Be 12 Ti) for tritium breeding and neutron multiplication, respectively. It is shown that unlike the energies expected in ITER, the enthalpy in the first wall/blanket cooling loops is large compared to the other energies expected in the reference DEMO concept. Reference accident event sequences in the reference DEMO in this study have been analyzed based on the Master Logic Diagram and Functional Failure Mode and Effect Analysis techniques. Accident events of particular concern in the DEMO have been selected based on the event sequence analysis and the hazard assessment. [ABSTRACT FROM AUTHOR]

Abstract: Radionuclide aerosol sampling is a vital component in the detection of nuclear explosions, nuclear accidents, and other radiation releases. This was proven by the detection and tracking of emissions from the Fukushima Daiichi incident across the globe by IMS stations. Two separate aerosol samplers were operated in Richland, WA following the event and debris from the accident were measured at levels well above detection limits. While the atmospheric activity concentration of radionuclides generally compared well between the two stations, they did not agree within uncertainties. This paper includes a detailed study of the aerosol sample homogeneity of 134Cs and 137Cs, then relates it to the overall uncertainty of the original measurement. Our results show that sample inhomogeneity adds an additional 5−10% uncertainty to each aerosol measurement and that this uncertainty is in the same range as the discrepancies between the two aerosol sample measurements from Richland, WA. [Copyright &y& Elsevier]

• Coolability of nuclear reactor debris beds is studied experimentally. • Distributed temperature sensing is used to depict local dryout heat flux. • Influence of seawater impurities on the dryout flux is examined. During the Fukushima nuclear reactor accident, seawater was injected into the reactor core to cool the decay heat from the heat generating porous debris bed. However, the impact of dissolved salts in water on the coolability of a debris bed is not well understood. This paper is one of the first works to investigate the cooling mechanisms for debris bed using seawater. An experimental system was built where the packed bed test section was volumetrically heated via a high frequency induction heater. The temperature along the axis of the test section was measured using a high resolution temperature sensor based on Optical Frequency Domain Reflectometry. Experimental results show that the dryout heat flux increases with an increase in concentration, with pure water having a dryout volumetric heat flux of 1.8 MW/m 3 and salt water of concentration 7% having a dryout volumetric heat flux of 2.8 MW/m 3. However, this enhanced coolability using salt water is short term, as the crystallization fouling mechanism becomes significant over time and leads to gradual temperature excursion in the bed. The fouling mechanism eventually leads to a cross section of the debris bed to plug with the deposited salts, and this leads to a pressure build up in the lower regions of the debris bed. [ABSTRACT FROM AUTHOR]

A serious accident at Fukushima Dai-Ichi NPP triggered radioactive emission to the atmosphere on 12 March 2011. The results of gamma spectrometric measurements of both gaseous and aerosol fraction of the air, collected in Krakow over the period from March 21 till the end of May 2011, as well as wet and dry deposition recorded from March till the end of October 2011, are presented in this paper. Krakow happened to be the first Polish location where radioactive isotopes characteristic for reactor releases, such as 131I, 132I, 129mTe, 132Te, 134Cs, 136Cs, and 137Cs, were detected. The maximum activity for aerosols equal to (5.73 ± 0.35) mBq/m3, (0.461 ± 0.041) mBq/m3 and (0.436 ± 0.038) mBq/m3 for 131I, 134Cs and 137Cs, respectively, was recorded for March 29, 2011. The data on the fallout are also given. The results of the radiochemical analysis of aerosol samples showed no traces of plutonium or americium isotopes associated with the disaster to be detected. The results of air activity concentration from Fukushima accident observed in Central Europe, Poland, in comparison to those of Chernobyl accident observed in Japan are presented and discussed. The comparison has revealed a discrepancy in the recognized relative scale of both accidents, and important difference in long distance transport of contamination, to exist. An attempt to explain the variation in the activity ratios between the aerosol fraction for 131I and 137Cs as resulting from exchange between the gaseous and aerosol fractions of 131I while the contamination had been propagating, is made. [ABSTRACT FROM AUTHOR]

Abstract: A new TRS document on Transfer of radionuclides to Wildlife has compiled equilibrium CRwo-media values for a variety of radionuclides and ecosystems. Assessment tools such as the ERICA Tool use equilibrium whole organism concentration ratios (CRwo-media) to predict radionuclide activity concentrations in wildlife from those in media (e.g. water). The aim of this paper is to compare and contrast model predictions of doses from 137Cs to marine organisms using three different approaches: (i) the ERICA Tool utilising the new TRS values to estimate internal and external doses to reference organisms for the Black sea and the Aegean Sea and for the sea close to the Fukushima Dai-ichi plant. (ii) a hydrodynamic site specific model for seawater for parts of the Aegean Sea, Greece which estimates radionuclide concentrations using site specific data and (iii) a biokinetic model for fish applied to the Fukushima releases to the Pacific. The advantages and limitations of these approaches are discussed with respect to determining doses to pelagic fish. The applicability of the three approaches will vary with the objective of an assessment. The site specific model can predict variation in 137Cs with depth and uses site specific CR values. The application of the biokinetic model to predicted 137Cs activity concentrations in seawater and fish due to near coastal inputs from Fukushima Dai-ichi showed that the maximum internal dose-rates in fish attributable to 137Cs would be substantially lower than those determined using equilibrium assumptions in ERICA but the accumulative doses over 100 days were similar. [Copyright &y& Elsevier]

Abstract: An in-situ fixed point radioactivity surveillance network has been developed at the Radiation Protection Bureau, Health Canada. The network consists of a number of spectrometric NaI(Tl) detectors measuring, in real-time, ambient gamma dose-rate. The present paper describes the gamma dose-rate monitoring by one detector installed at the Canadian embassy in Tokyo during the Fukushima nuclear accident. Soil samples were collected for the measurement of fallout fission products inventories at each location where the NaI(Tl) detector was installed. The gamma-ray attenuation by the soil matrix was estimated by the information on the depth distribution of 137Cs activities. The study demonstrated that the gamma dose-rates measured by the field NaI(Tl) spectrometric method agreed well with the laboratory results estimated by the inventories of fallout fission products deposited in the soil and the vertical distribution of 137Cs in the soil. [Copyright &y& Elsevier]

Highlights: [•] Chernobyl accident had limited influence on basic research in nuclear energy. [•] Budget allocation to R&D and number of published papers have recently decreased. [•] Citation network analysis revealed reactor safety and fusion as current research trend. [•] Nuclear energy research policy will change after Fukushima disaster. [Copyright &y& Elsevier]

Abstract: This paper attempts to investigate the mass media coverage of Fukushima No. 1 (Dai-ichi) Nuclear Power Plant (NPP) accident in 2011. The purpose of this study is to explore how NHK and BBC World covered the Fukushima accident, what became the focus of their coverage, and what similarities and differences NHK and BBC World had in reporting this case. The data is collected from the Japanese public television station NHK and BBC English by recording the entire programs on NHK and BBC from March 11-18, 2011. The investigation of NHK and BBC coverage on the nuclear crisis in Fukushima will be focused on the news sources, news format and news themes. The discussion is focused on the news framing of the three main themes, i.e., the first explosion occurring at the Fukushima nuclear power plant, the operation of watering down the reactor by helicopter, and the delivery of video messages from the Japanese emperor. The analysis shows that NHK seemed to be in favour of the Japanese government and the Tokyo Electric Power Company in the selection of information sources that were dominated by the goverment''s official statements. In addition to the bias of its information sources, NHK also supported government policy through their news framing of the accident. [Copyright &y& Elsevier]

Abstract: Social and political fallout following the March 2011 Fukushima-Daiichi nuclear disaster permanently altered the zeitgeist of global public attitude towards nuclear power and towards energy technology in general. This area of public policy, which in Japan is particularly opaque and stagnant, was forced into a period of energy sector review amid domestic and worldwide debate. This study explores novel methodologies for measuring these developments, covering the 1) framing effects of traditional media and the 2) user-sourced content of social media. This quantitative approach yielded the following hypothesis verifications; 1) in an AHP-style online survey, exposure to real and simulated nuclear-related disaster headlines reduced collective partiality towards nuclear power by 3% and 4% respectively, and 2) retrospective opinion mining of Twitter procured an relative increase in negative nuclear-related posts of 38% and 134% in Japanese and English respectively, from the pre to post-Fukushima world. Using nuclear power and Fukushima as a case study, this paper attempts to elucidate both the influence of media on the public sphere, and the influence of the public sphere on policy and policymakers. From the results it is possible to make the conjecture that a lack of scientific education with regard to energy issues increases the former influence, and similarly reduces the latter. [Copyright &y& Elsevier]

Abstract: This paper presents measurements of the effect of the atmospheric radioactive release from the Fukushima Dai-ichi nuclear power station at three sites belonging to the Spanish environmental monitoring system. Measured values varied depending on the locations of the sites in Spain and their respective climatic characteristics. 134Cs, 136Cs, 137Cs, 131I, and 132Te activity concentrations in filter samples were studied and associated levels of 131I fallout were estimated from wet and dry deposition. Particulate aerosol activity concentrations ranges, in μBq/m3, were 1.63–3080 (131I), 2.8–690 (137Cs), 1.3–620 (134Cs) and 3.6–330 (132Te), while the associated 131I fallout was roughly estimated to be less than 20 Bq/m2, Gaseous 131I was also detected and the 131I-gaseous/131I-total ratio increased at the three stations from approximately 0.75 at the end of March to 0.85–0.9 during the first few days of April. Finally, the presence of 131I in some crucial parts of the food chain was also studied. 131I was detected in samples from goat''s and cow''s milk (maximum levels of 1.11 Bq/L) and in broadleaf plants (maximum level 1.42 Bq/kg). [Copyright &y& Elsevier]

Abstract: The radioactivity levels in the air of the radionuclides released by the Fukushima accident were measured at the Laboratoire Souterrain de Modane, in the South-East of France, during the period 25 March–18 April 2011. Air-filters from the ventilation system exposed for one or two days were measured using low-background gamma-ray spectrometry. In this paper we present the activity concentrations obtained for the radionuclides 131I, 132Te, 134Cs, 137Cs, 95Nb, 95Zr, 106Ru, 140Ba/La and 103Ru. The activity concentration of 131I was of the order of 100 μBq/m3, more than 100 times higher than the activities of other fission products. The highest activities of 131I were measured as a first peak on 30 March and a second peak on 3–4 April. The activity concentrations of 134Cs and 137Cs varied from 5 to 30 μBq/m3. The highest activity concentration recorded for Cs corresponded to the same period as for 131I, with a peak on 2–3 April. The results of the radioactivity concentration levels in grass and mushrooms exposed to the air in the Modane region were also measured. Activity concentrations of 131I of about 100 mBq/m2 were found in grass. [Copyright &y& Elsevier]

Abstract: On 11 March 2011, the magnitude-9.0 earthquake and a substantial tsunami struck off the northeast coast of Japan. The Fukushima nuclear power plants were inundated and stricken, followed by radionuclide releases outside the crippled reactors. Provisional regulation values for radioactivity in food and drink were set on 17 March and were adopted from the preset index values, except that for radioiodines in water and milk ingested by infants. For radiocesiums, uranium, plutonium and transuranic α emitters, index values were defined in all food and drink not to exceed a committed effective dose of 5 mSv/year. Index values for radioiodines were defined not to exceed a committed equivalent dose to the thyroid of 50 mSv/year, and set in water, milk and some vegetables, but not in other foodstuffs. Index values were calculated as radioactive concentrations of indicator radionuclides (131I for radioiodines, 134Cs and 137Cs for radiocesiums) by postulating the relative radioactive concentration of coexisting radionuclides (e.g., 132I, 133I, 134I, 135I and 132Te for 131I). Surveys were thence conducted to monitor levels of 131I, 134Cs and 137Cs. Provisional regulation values were exceeded in tap water, raw milk and some vegetables, and restrictions on distribution and consumption began on 21 March. Fish contaminated with radioiodines at levels of concern were then detected, so that the provisional regulation value for radioiodines in seafood adopted from that in vegetables were additionally set on 5 April. Overall, restrictions started within 25 days after the first excess in each food or drink item, and maximum levels were detected in leafy vegetables (54,100 Bq/kg for 131I, and a total of 82,000 Bq/kg for 134Cs and 137Cs). This paper focuses on the logic behind such food safety regulations, and discusses its underlying issues. The outlines of the food monitoring results for 24,685 samples and the enforced restrictions will also be described. [Copyright &y& Elsevier]

Abstract: This paper uses cross-country data compiled immediately after the Fukushima nuclear accident to investigate how the experience of such disasters affects the perception of the risk of nuclear accidents. Estimation results show that the perceived risk of a nuclear accident is positively associated with experiencing technological disasters but not with that of natural disasters. [Copyright &y& Elsevier]

Abstract: The impact of the Fukushima accident on the nuclear fuel cycle back-end is obvious. In the present paper the various back-end options and their impact on the environment will be presented in view of this new perspective. The partitioning and transmutation (P&T) concept and the direct disposal of nuclear fuel including a very long intermediate storage will certainly be revisited with respect to safety considerations; here the instant release fraction (IRF) and the long-term stability of the fuel matrix under real repository conditions are highly relevant. Furthermore the impact of released radionuclides to the environment will have a higher attention. [Copyright &y& Elsevier]

Abstract: Despite bringing many external benefits, economic growth has not solved all problems. In Japan today two problems seem to stand out: an aging population and the need to protect the population from natural disasters. The first problem has long been noted but the population is aging so fast that society seems incapable of adjusting properly to the new situation. Japan experienced a huge earthquake and tsunami on 11 March 2011 that took more than 21,000 lives and destroyed tens of thousands of homes. The disaster also damaged the nuclear power plant in Fukushima. As a result, tens of thousands more people have been forced from their homes to live in refugee camps outside the contaminated areas. These events have caused a reassessment of the issue of disaster safety. The two problems mentioned above appear to be separate issues, but are in fact closely related. For example, the majority of the victims of the recent natural disaster were elderly and we have not built a system to improve their situation. This paper discusses transport policies for future generations in Japan in connection with the problems above. [ABSTRACT FROM AUTHOR]

• Evacuation plans need to be tailored to the type of resident with specific considerations for vulnerable people. • Information and instructions should be provided in the event of a nuclear accident. • Necessary resources for the sheltering option need to be secured with the support from the governments. • Coordinated approaches for the case of a long-term relocation. • Plans for lifting evacuation need to be carefully determined with the involvement of stakeholders. Standards and guidelines for preparedness and response in the case of a nuclear accident cover radiation protection, health management and communication with affected populations. Decision makers use these recommendations to decide on measures that protect people residing around a nuclear power plant that suffers an accident from radiation exposure; for example, sheltering, evacuation and relocation. While technological and radiological criteria exist for these protective measures, studies on past radiological and nuclear emergencies have shown that evacuation and relocation result in serious health effects; this needs to be considered in accident preparedness and responses in the future. Within the framework of the Nuclear Emergency Situations Improvement of Medical and Health Surveillance (SHAMISEN) (Ohba et al., 2020), a critical review of recommendations and experiences of previous major nuclear accidents was conducted, and the current paper focuses on the lessons learned about evacuation and relocation. We reviewed the contents of official documents and literature relating to the evacuation and relocation of residents, and to the evacuation of medical and other facilities in the three largest nuclear accidents to date: the Three Mile Island accident, Chernobyl accident, and Fukushima accident. We developed recommendations classified into the preparedness phase, early and intermediate phases, and recovery phase after an accident. In the cases of Three Mile Island and Fukushima, the evacuation area was set at 8–10 km from the nuclear power plant in the disaster prevention plan, and emergency responses, such as information provision and evacuation, had been developed only in this area. When the Fukushima accident occurred, evacuation beyond this area was urgently planned or instructed, resulting in marked confusion, such as forced multiple evacuations and relocations for long periods. Furthermore, information was lacking, and personal protective measures such as respiratory protection and iodine prophylaxis were not applied to evacuees. In hospital and facility evacuation, it became more difficult to implement evacuation owing to a lack of advance planning and support in the event of the accident. In Fukushima, more than 60 people in hospitals and nursing care facilities died during or soon after evacuation. In long-term relocation, in addition to continuing adverse mental effects, there were health effects relating to relocation, such as lifestyle-related disease. The return of residents to the evacuation area required many issues, such as a delayed recovery of the living environment, to be overcome in addition to measures to reduce the effects of radiation. Recommendations for evacuation in the SHAMISEN framework were developed (SHAMISEN Consortium, 2017; Liutsko et al., 2020) from these lessons of previous accidents. [ABSTRACT FROM AUTHOR]

Radiocesium was dispersed from the Fukushima Dai-ichi disaster in March 2011, causing comparatively high radioactive contamination in nearby environments. Radionuclide concentrations in wild rodents (Apodemus argenteus , and Apodemus speciosus) within these areas were monitored from 2012 to 2016. However, whole-organism to soil transfer parameters (i.e., concentration ratio, CR wo-soil) for wild rodents at Fukushima were not determined and hence were lacking from the international transfer databases. We augmented the 2012–2016 data by collecting soil activity concentrations (Bq kg−1, dry mass) from five rodent sampling sites in Fukushima Prefecture, and developed corresponding CR wo-soil values for radiocesium (134Cs and 137Cs) based on rodent radioactivity concentrations (Bq kg−1, fresh mass). The CR wo-soil were added to the Wildlife Transfer Database (WTD; http://www.wildlifetransferdatabase.org/), supporting the development of the International Commission on Radiological Protection's (ICRP) environmental protection framework, and increasing the WTD from 84 to 477 entries for cesium and Muridae ('Reference Rat'). Significant variation occurred in CR wo-soil values between study sites within Fukushima Prefecture. The geometric mean CR wo-soil , in this paper, was higher than that reported for Muridae species for Chernobyl. Radiocaesium absorbed dose rates were also estimated for wild rodents inhabiting the five Fukushima study sites and ranged from 1.3 to 33 μGy h−1. Absorbed dose rates decreased by a factor of two from 2012 to 2016. Dose rates in highly contaminated areas were within the ICRP derived consideration reference level for Reference Rat (0.1–1 mGy d−1), suggesting the possible occurrence of deleterious effects and need for radiological effect studies in the Fukushima area. • First published CR wo-soil values for wild rodents in the Fukushima area. • CR wo-soil values comprise 80% of the data available for ICRP Reference Rat-Cs. • GM CR wo-soil , in this study, was higher than CR wo-soil reported for Chernobyl. • Absorbed dose rates ranged from 1.3 to 33 μGy h−1 for wild rodents in Fukushima. • Estimated absorbed dose rates for wild rodents decreased 50% from 2012 to 2016. [ABSTRACT FROM AUTHOR]

• Thyroid cancer (TC) risk is one of the major concerns after a nuclear accident. • Mass thyroid screening is aimed at complete ascertainment of TC cases, but can lead to over-diagnosis. • Mass thyroid screening may cause adverse side-effects (anxiety, overtreatment). • A mass thyroid screening is not recommended after a nuclear accident. • Thyroid monitoring should be available, with appropriate information and counselling. Exposure of the thyroid gland to ionizing radiation at a young age is the main recognized risk factor for differentiated thyroid cancer. After the Chernobyl and Fukushima nuclear accidents, thyroid cancer screening was implemented mainly for children, leading to case over-diagnosis as seen in South Korea after the implementation of opportunistic screening (where subjects are recruited at healthcare sites). The aim of cancer screening is to reduce morbidity and mortality, but screening can also cause negative effects on health (with unnecessary treatment if over-diagnosis) and on quality of life. This paper from the SHAMISEN special issue (Nuclear Emergency Situations - Improvement of Medical And Health Surveillance) presents the principles of cancer screening, the lessons learned from thyroid cancer screening, as well as the knowledge on thyroid cancer incidence after exposure to iodine-131. The SHAMISEN Consortium recommends to envisage systematic health screening after a nuclear accident, only when appropriately justified, i.e. ensuring that screening will do more good than harm. Based on the experience of the Fukushima screening, the consortium does not recommend mass or population-based thyroid cancer screening, as the negative psychological and physical effects are likely to outweigh any possible benefit in affected populations; thyroid health monitoring should however be made available to persons who request it (regardless of whether they are at increased risk or not), accompanied with appropriate information and support. [ABSTRACT FROM AUTHOR]

The Fukushima Daiichi Nuclear Power Plant (FDNPP) accident, which occurred in March 2011, has released large amounts of radionuclides (such as radioiodine and radiocesium) into the atmosphere, resulting in the contamination of terrestrial and marine environments. To assess radiological and environmental effects of the FDNPP-derived radionuclides, huge amounts of radioactive monitoring activities have been conducted to environmental samples. In this paper, we review results of atmospheric radioactivity monitoring for the FDNPP accident. Learning from atmospheric radioactivity monitoring of the FDNPP accident is as follows; 1. At the initial stage of accident, large spatiotemporal variability of emitted radionuclides near the FDNPP site occurred at short (less than 1 h) time scale and small (less than 10 km) space scale due to complicated emissions of radionuclides and variable flow of Fukushima radioactive plume, 2. Chemical form of FDNPP-derived radionuclides, in which a typical example is coexistence of 137Cs-bearing submicron particles and 137Cs-bearing large hot particles in the plume, is important to have better understanding of their atmospheric behaviors as do released mechanisms and their fate in environment, 3. Atmospheric effects of the FDNPP accident continue over 8 years, in which high activity levels of the FDNPP-derived 137Cs in surface air and deposition have continued at least until the end of 2018 owing to the post-accident release and resuspension because most of the FDNPP-derived 137Cs deposited on the ground surface still remains in the soil surface as a potential source of atmospheric 137Cs. • The atmospheric effects of radiocesium derived from the Fukushima Daiichi Nuclear Power Plant accident was reviewed. • The maximum activity of 137Cs in surface air near the FDNPP was 13.6 kBq m−3 just after vent operation of Reactor Unit 1. • High radioactive particles with enriched radiocesium were released in the environment. • The late atmospheric effects of the FDNPP-derived radiocesium continued in the end of 2018. • The annual 137Cs deposition showed a small peak in 2017. [ABSTRACT FROM AUTHOR]

The utilization of numerical atmospheric dispersion prediction (NDP) models for assisting the emergency response to emission of radionuclides has been recommended by a working group of the Meteorological Society of Japan. This paper verifies the feasibility of the recommendation through NDP model intercomparison with limited emission source information for the case of the Fukushima Dai-ichi Nuclear Power Plant accident caused by the Great East Japan Earthquake in 2011. According to the recommendation of the working group, the NDP models are run under the assumption of a constant rate of emission during the whole forecast period. This is the worst-case scenario when limited source information is available. Generally, no information is provided on the temporal variability and strength of the emissions, while the source location is known. Surface air radionuclide forecasts are utilized for providing warnings of the risk of inhaling radioactive substances suspended in the low-level atmosphere, whereas column-integrated radionuclide forecasts are utilized for estimating the potential maximum wet deposition of radioactive materials on the ground due to precipitation. The NDP model short-range forecasts were validated with observational data for three locations, at the times when the most serious contamination events occurred at each of the three monitoring stations. The NDP models successfully predicted the risk of surface air contamination and/or ground surface contamination caused by wet deposition in these cases. Particularly, the NDP model forecasts allow us to disseminate warnings at effective lead times before exposure to radiation. The different NDP models gradually deviate their forecasts as the lead time progresses. The deviations may indicate the magnitude of forecast errors. Thus, the use of multi-model forecasts is of greater benefit than the single model forecasts, because forecast error information is suggested. Image 1 • We propose the use of prediction models for environmental emergencies. • We performed model prediction experiments for atmospheric radionuclide dispersion. • The prediction models were validated with the Fukushima nuclear accident data. • Model prediction allows us to disseminate warnings at effective lead times. [ABSTRACT FROM AUTHOR]