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Energy consumption in Japan has grown at a faster rate than in any other major industrial country. To maintain continued prosperity, the government has embarked on a crash program for nuclear power. Current progress and issues/reactions to the plan are discussed. (JN)

AbstractPurposeConclusionsSince 2014, an educational activity on radiation and health in northern Japan has been carried out by young scientists, the so-called ‘Educational Symposium on Radiation and Health (ESRAH)’. Close cooperation has been continued in preparing for any possible emergency response to radiation accidents because several facilities, e.g., the Tomari Nuclear Power Plant in Hokkaido and the Low-Level Radioactive Waste Disposal Facility in Aomori prefecture. The ESRAH meeting has provided informational exchange and discussion forum on a broad range of subjects in various. In 2023, the 10th Memorial ESRAH meeting took place to boost scientific understanding and multidisciplinary collaborations for young scientists. Herein, we report on the ESRAH2023 symposium and analyze the research categories of young scientists from the past 10-year presentations.To date, the ESRAH meeting has successfully provided a chance for multi-disciplinary research, which accounted for 27% of the total despite the COVID-19 pandemic. We found that the fraction of multi-disciplinary research in 2023 was the highest during 10-year ESRAH meetings. Meanwhile, amongst the research categories, physics, chemistry, and pharmacological studies were indicated to be less for young scientists. It is desired that further collaboration between physics, chemistry, and pharmacology in addition to the current fields would not only clarify radiation effects on the human body but also promote emergency medical care for radiation exposure in the future. [ABSTRACT FROM AUTHOR]

Background: The Great East Japan Earthquake and the subsequent Fukushima nuclear power plant accident in 2011 posed significant challenges to the educational sector, particularly affecting nursing students in the disaster area. However, to the best of our knowledge, there are no reports on the effects of the natural disaster coupled with the nuclear accident on the nursing students. Therefore, this study aimed to determine the impact of the Fukushima disasters on rate of academic failure events in nursing education. Methods: A retrospective cohort approach was conducted, focusing on 677 students from Soma Nursing School admitted between 2001 and 2017. Four failure events—failure to pass the national examination, student retention, suspension, and withdrawal from school—were compared between three time periods: pre-disaster, early peri-disaster, and later peri-disaster. This analysis was followed by a questionnaire survey among the students and an interview with faculty members to gain further insights. Results: Of the student cohort, 17% had at least one failure event. Students in the later peri-disaster phase faced an elevated failure rate at 29%. Variables such as being male, admission during later peri-disaster period, and local pre-admission residence played a significant role in these failure events in multivariate logistic regression analysis (adjusted odds ratio [95% confidence interval, p value]; 2.63 [1.49–4.64, < 0.001], 3.207 [2.00–5.15, < 0.001], and 1.84 [1.12–3.02, 0.02], respectively). Conclusions: This study highlights the impact of the Great East Japan Earthquake and the following nuclear accident on nursing education. The elevated failure rates in the later peri-disaster period emphasize the challenges posed by continuing disaster phases. Thus, there is a need for intensified and tailored strategies in nursing education in disaster-affected regions. [ABSTRACT FROM AUTHOR]

The article presents the discussion on impact of the Fukushima Daiichi nuclear disaster on problem drinking among plant workers over a three-year period. Topics include highlighting the sustained increase in problem alcohol use due to disaster-related stressors; and longitudinal study design, the limitations of lacking predisaster alcohol use data; and the importance of integrating pre- and postdisaster information for understanding behavioral outcomes.

Objective: Field trips to disaster-affected areas (FTDAs) without a specific purpose, such as medical cooperation, are widely used in medical education. However, what medical students gain from FTDAs remains unclear. The present study aimed to clarify what medical students gain from FTDAs. Five medical students who had visited the Fukushima nuclear power plant in Japan participated in a semi-structured group interview to ask what they gained from such a visit. The narratives were analysed using open coding. Results: The following four themes emerged: "Spirit of scientific inquiry", "Foundation for lifelong education and personal growth", "Broadened understanding of the medical profession", and "Importance of practicing medicine in the community setting". The ambiguity of medical students' specific roles in the field trip compared to the fieldwork may have encouraged them to make sense of the experience from their perspective. As a result, students may have gained a broader perspective of their future work and career through the FTDA. If medical educators can gain consensus from the residents of a disaster site, different disaster-affected areas can be potential sites for medical education using FTDAs. [ABSTRACT FROM AUTHOR]

Atomic energy has played an important role in international relations as a means of state power. From 1945 to 1959, Japan was significantly influenced by developments in atomic energy as a result of the Anglo-American "special relationship." During World War II, Britain and the United States cooperated to develop atomic weapons to use against Japan. In the ensuing Cold War era, the two countries advanced peaceful uses of atomic energy for Japan to counter the influence of the Soviet Union through psychological warfare. The U.S. Atomic Energy Peace Mission visited Japan in May 1955. However, the Japanese government altered its nuclear policy to solicit support from Britain because the United States was falling behind in atomic energy development. A British nuclear reactor was used as the first commercial nuclear power station, in 1959, whereby Britain earned parity with the United States in the context of nuclear power. [ABSTRACT FROM AUTHOR]

Background: In the Fukushima nuclear power plant disaster of March 11, 2011, plant workers were exposed to various traumatic events and reported a subsequent increase in alcohol use. To determine the relationship between disaster‐related experiences and problem drinking, we conducted a three‐year follow‐up study. Methods: Problem drinking among the nuclear plant workers was assessed annually from 2012–2014 using a modified version of the CAGE questionnaire that asked about current, rather than lifetime, drinking. A total of 1378 workers provided at least one CAGE response, and 2875 observations were used in the present analysis. Mixed‐effects logistic regression models were used to analyze the relationship between disaster‐related experiences and problem drinking over time. Results: The prevalence of problem drinking (CAGE score ≥2) increased over time. At the baseline assessment in 2012, a year after the disaster, plant workers who had experienced life‐threatening danger and discrimination had significantly more symptoms of problem drinking, which persisted over the following 2 years. Although at baseline, plant workers who had experienced major property loss or the death of a colleague showed no significant differences in problem drinking symptoms from those without such experiences, over the next 2 years their problem drinking increased significantly. Conclusions: Individuals who experienced life‐threatening danger and discrimination during the Fukushima nuclear power plant disaster reported an increase in problem drinking. Although major property loss and the death of a colleague did not elevate problem drinking prevalence at baseline, it did so over the next 2 years. Different adverse effects of a natural disaster appear to differentially increase drinking behavior over time. [ABSTRACT FROM AUTHOR]

In a nuclear emergency, one of the actions taken for the sake of public is to monitor thyroid exposure to radioiodines. Japan's Nuclear Regulation Authority recently published a report on such monitoring and proposed direct thyroid measurements with conventional NaI(Tl) survey meters (e.g. Hitachi model TCS-172) as a primary screening method. A previous study proposed screening levels (SLs) used in these simplified measurements as the net reading values of the TCS-172 device. Age-specific SLs were derived from a thyroid equivalent dose of 100 mSv due to the inhalation intake of 131I. This study addressed the possible influence of short-lived iodine isotopes other than 131I on the simplified measurements. In preparation for such measurements, the responses of the device for 132I as an ingrowth component from 132Te, 133I, 134I and 135I in the thyroid were evaluated by numerical simulations using age-specific stylized phantoms in addition to those obtained for 131I in the previous study. The radioactivity ratios of the relevant isotopes were taken from the inventory data of the Fukushima Daiichi Nuclear Power Plant. The results were used to predict the net readings of the device when 132Te-132I and 133I as well as 131I were inhaled at 24 or 72 h after the shutdown of a nuclear power plant. In these cases, the signals from 132Te-132I and 133I become undetectable a couple of days after intake, which could lead to underestimations of the thyroid dose. To estimate the thyroid dose accurately from the simplified measurements, it is necessary to identify the exact time of intake after the shutdown and the actual physiochemical property of 132Te that affects the thyroid uptake of 132I. [ABSTRACT FROM AUTHOR]

This study explored public attitudes towards the "local agreement" process as it relates to the restart of nuclear power plants (NPPs) in Japan. Conflicts have arisen over not only whether NPPs should be restarted, but also how and by whom the local agreements on their restart should be made. Using exploratory factor analysis on the data from an online monitor questionnaire survey conducted in four prefectures with NPPs in Japan, this study identified three latent factors behind public attitudes: "the conventional decision makers," "those negatively affected," and "those benefitting from the restart." A multi-regression analysis of factor scores showed that opinions on restarting NPPs, prefectural referendums, and the geographical range of local agreements were related to attitudes towards local agreements. There were also differences in attitudes towards local agreements according to prefectures, gender, and age, while where respondents live in relation to the nearby NPP had little influence. To design a more socially acceptable local agreement process, it is necessary to reconcile such differences. By providing a better understanding of the local politics regarding restarting NPPs in Japan, this study paved the way for resolving conflicts over local agreements. [ABSTRACT FROM AUTHOR]

The 11 March 2011 Tohoku earthquake and tsunami, also known as the Great Sendai severe disaster and as the "Heisei" tsunami, occurred off the northeastern coast of Japan's main Island of Honshu, resulting in extensive destruction and the death of 22,000 people. Also, tsunami waves struck the Fukushima nuclear power plant on the coast, thus setting in motion a major accident and spreading long-lasting radioactive material in the ocean, with farreaching impact on marine life in the North-West Pacific Ocean. Besides the large magnitude of the destructive earthquake, the main factors responsible for the great loss of life was due to the fact that existing tsunami protective countermeasures, such as seawalls, were inadequate in providing protection given the extreme height of the 2011 tsunami waves. The seawall was overtopped by these waves and large sections were destroyed by the accompanying debris flow, thus reaching further into the harbor. Subsequently, waves traveling up the river, transformed into a river-type of tsunami, overtopping river embankments, flooding the surrounding areas, and causing great loss of life and destruction, as in the past 115 years caused by great magnitude earthquakes and destructive tsunami events. These were: 1) The magnitude Mw=8.5 tsunami generating Meiji Sanriku earthquake of 15 June 1896 in Japan; 2) The magnitude Mw=8.4 tsunami generating Showa Sanriku earthquake of 3 March 1933 in Japan; 3) The magnitude Mw= Mw=7.7 Hokkaido Nansei-Oki tsunami generating earthquake of 12 July 1993; and 4) The magnitude Mw=9.4-9 Valdivia-Chile earthquake and tsunami of 22 May1960. The present study examines Japan's government countermeasures in providing effective tsunami predictive and protection measures from such extreme and catastrophic tsunami recurrences in the future, and particularly against the threat of river tsunamis. [ABSTRACT FROM AUTHOR]

Background: In 2011, a nuclear accident severely affected many hospitals in Fukushima. Many nurses faced a dilemma of whether to evacuate voluntarily or keep working. This study examined the voluntary evacuation and returning of nurses and then suggested how nurse administrators can prepare for such situations. Methods: The study was conducted from July through September 2018. Eight hundred nurses who had been working prior to the incident in three hospitals in Koriyama and Aizuwakamatsu participated. Although both cities had higher-than-normal terrestrial radiation levels, Koriyama's level was three times higher. An anonymous questionnaire was administered, and individual interviews were conducted with participants. For statistical analyses, SPSS Statistics for Windows, version 25.0, was used. Results: Ultimately, 723 questionnaires were collected. The proportions of those who considered evacuating (33.1%) and who evacuated (8.1%) were significantly higher in Koriyama. The characteristics of the group who considered evacuation were being pregnant, living with an adult cohabitant, and/or living with small child (ren). The evacuated nurses were all female and had similar characteristics as the group that considered evacuating; however, the age of their children was not related. Four out of six interviewees contacted nurse administrators and/or colleagues and overcame their feelings of guilt when their superiors and colleagues welcomed them back to work. Conclusion: Nurse administrators should understand that, when a radioactive disaster occurs, individuals who are more likely to consider evacuation have conflicts between their personal life and professional responsibilities. Nursing departments should inform nurses of their policies in advance and respect individuals' decision to leave, supporting them when they return to work. Departments should also have a plan in place for managing with a temporarily reduced workforce. [ABSTRACT FROM AUTHOR]

Probabilistic risk assessment (PRA) is an effective methodology that could be used to improve the safety of nuclear power plants in a reasonable manner. Dynamic PRA, as an advanced PRA, allows for more realistic and detailed analyses by handling time-dependent information. However, the applications of this method to practical problems are limited because it remains in the research and development stage. This study aimed to investigate the possibility of utilizing dynamic PRA in risk-informeddecision-making. Specifically, the author performed an accident sequence precursor (ASP) analysis on the failure of emergency diesel generators that occurred at Unit 1 of the Tomari Nuclear Power Plant in Japan using dynamic PRA. The results were evaluated by comparison with the results of simplified classical PRA. The findings indicated that dynamic PRA may estimate lower risks compared with those obtained from classical PRA by reasonable modeling of alternating current power recovery. The author also showed that dynamic PRA can provide detailed information that cannot be obtained with classical PRA, such as uncertainty distribution of core damage timing and importance measure considering the system failure timing. [ABSTRACT FROM AUTHOR]

Twenty-two thousand people died when the 11 March 2011 Tohoku earthquake and tsunami struck Japan with little or no warning from Civil Defense authorities. Both the earthquake and the tsunami also resulted in the failure and destruction of the Fukushima Daiichi Nuclear Power Plant and in large-scale distribution of radioactive elements. The seawalls along the affected coasts were easily destroyed by the tsunami, which also stirred up sludge and sediments from the seabed on land, thus making evacuation extremely difficult. Therefore, it becomes obvious that when a destructive tsunami hits again Japan, all coastal plains will continue to be dangerous zones. People living in such areas do not have enough warning time - particularly from local earthquakes and tsunamis - to evacuate to safer areas inland. Therefore, and in order to protect the people in such vulnerable coastal areas, tsunami shelters must be used or constructed to provide for their short-term protection until the tsunami danger subsides. Rapid escape of the people in danger areas to air-sealed type of existing or constructed enclosures serving as temporary shelters, can save their lives. Specifically, air-tight shelters, even in tsunami flooded coastal areas, can provide temporary protection until there is no threat. Such temporary shelters can be cheaply constructed and reliably save lives. Building codes can be amended for building air-filled tsunami shelters in oceanfront buildings, and thus provide safety from normal-level tsunamis at relatively low cost. Tsunami shelters can be constructed even in subway facilities or underground shopping malls, and thus minimize or reduce to zero losses of human lives, not only from tsunamis, but also from large fires, If coastal towns were equipped with tsunami shelters, the number of deaths from tsunamis as well as from large fires could be minimized and even be reduced to zero. [ABSTRACT FROM AUTHOR]

We studied the spatiotemporal variations in 134Cs, 137Cs, and 228Ra concentrations at the sea surface off southeastern Hokkaido, Japan (off-Doto region) from 2018 to 2022 using low-background γ-spectrometry. The 134Cs concentrations in the off-Doto region, decay-corrected to the date of the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident, exhibited wide lateral variation each year (e.g., 0.7–1.1 mBq/L in 2020). By studying the 228Ra concentrations and salinity, this variation was explained based on the current mixing patterns. Furthermore, the 134Cs concentrations in the waters highly affected by the Oyashio Current (OYC) gradually increased from 2018 to 2020, and subsequently decreased in 2022. This implies that the water mass maximally contaminated with 134Cs was transported back to the side of the Japanese islands 10 years after the FDNPP accident along with counter-clockwise currents (e.g., the OYC) in the northern North Pacific Ocean. The 134Cs concentrations in the OYC-affected waters in the off-Doto region in 2020 were ~ 1/6 times those in the 134Cs-enriched core of waters off the western American Coast in 2015, which can be ascribed to dilution via spatial dispersion during subarctic current circulation. Overall, we elucidated the ocean-scale subarctic current systems in the northwestern North Pacific Ocean, including water circulation timespans. [ABSTRACT FROM AUTHOR]

Two low‐voltage cables, insulated with flame‐retardant ethylene‐propylene‐diene rubber (FR‐EPDM), were removed after being laid in nuclear power plants for many years. We measured the leakage currents flowing through their insulators and found that the resistivity of cable insulation is higher in the two harvested cables than in a similar but new and unused FR‐EPDM one. The reason for this result is discussed in this paper based on a comparison of the leakage currents between new and gamma‐ray irradiated FR‐EPDM sheets. The discussion is continued by referring to our previous papers on mechanical properties and infrared absorption spectra of similar new and gamma‐ray irradiated FR‐EPDM sheets. As a result, it has been clarified that additives such as pigments contained in the cable insulators are likely to act as a source of charge carriers. In addition, the cable insulators became hardened by the long‐term aging in an environment of about 60 °C, which made the ionic conduction difficult and the insulation resistivity higher. © 2023 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

BACKGROUND: Radiological technologists serve as risk communicators who aim to lessen patients' anxiety about radiation exposure, in addition to performing radiological examinations. OBJECTIVE: We conducted a fact-finding survey on knowledge and awareness of radiation disasters among the radiological technologists to reveal their literacy and competencies regarding radiation disasters. METHODS: A paper questionnaire was distributed to 1,835 radiological technologists at 166 National Hospital Organization facilities in Japan. The 28-item questionnaire covered knowledge and awareness of radiation protection and radiation disasters. Radiological technologists were divided into 2 groups by regionality: areas where a nuclear power station was present/nearby (NPS areas) and non-NPS areas. RESULTS: Completed questionnaires were returned from 148 facilities with a facility response rate of 89.2% and from 1,391 radiological technologists with a response rate of 75.8%. There were 1,290 valid responses with a valid response rate of 70.3%. The correct answer rate for knowledge of radiation protection and radiation disasters was high in the 24 NPS areas. There were no differences in awareness of radiation disasters between NPS and non-NPS areas. CONCLUSIONS: Establishing a nationwide, region-independent training system can be expected to improve literacy regarding radiation disasters among radiological technologists. Willingness to assist during disasters was high among radiological technologists irrespective of area, indicating that the competencies of radiological technologists represent a competency model for radiation disaster assistance. [ABSTRACT FROM AUTHOR]

In China, conventional island shield buildings (CISBs), which are situated close to the nuclear islands of nuclear power plants, are class III seismic items. This is the most important level in the seismic fortification standard. Calculations to check resistance overturning under extremely safe seismic action should be carried out. Although strict seismic design has been carried out, many beyond-design-basis events, such as the 3/11 earthquake in Japan, have occurred in recent years. Under the action of such accidental loads, there is still the possibility that the important vertical bearing components of a CISB will be damaged or destroyed, which will lead to the progressive vertical collapse of the CISB structure, and ultimately threaten the safe operation of the nuclear power plant. Therefore, it is necessary to study the progressive collapse resistance mechanism of the CISB in order to further optimize and improve its design. In this paper, we take the CISB as a research object and consider the failure mechanism of its vertical progressive collapse synthetically, using SAP2000 finite element software to study the causation and strength of resistance force and internal force redistribution characteristics due to progressive collapse under different column removal conditions (long-side middle, short-side middle, internal, and corner columns) using the instantaneous unloading method. The results show that the residual structure is at risk of collapse under the corner and long-edge middle column removal conditions, and there is no risk of collapse under the short-edge middle and internal column conditions. The failure and collapse resistance of the corner column only has a beam mechanism, and the long-side middle column forms a catenary mechanism in the Y direction. The short-side middle column can resist collapse by the beam mechanism, while the internal column forms a bidirectional catenary mechanism in the X and Y directions. The axial force of the column in the residual structure is mainly redistributed to column members with adjacent spans to the failure column, and column members with separated spans are less affected. [ABSTRACT FROM AUTHOR]

Consecutive sexual maturation (CSM), an abnormal reproductive phenomenon of a marine snail, Reishia clavigera, has occurred since 2017 in the vicinity of the Fukushima Daiichi Nuclear Power Plant after the nuclear disaster there. We hypothesized that alterations in animal physiology mediated through genetic/epigenetic changes could sensitively reflect environmental pollution. Understanding the mechanism of this rapid biological response should enable us to quantitatively evaluate long-lasting effects of the nuclear disaster. To determine the molecular basis for CSM, we conducted transcriptome profiling in the ganglia of normal and CSM snails. We assembled the short-read cDNA sequences obtained by Illumina sequencing, and succeeded in characterizing more than 60,000 gene models that include 88 kinds of neuropeptide precursors by BLAST search and experimental curation. GO-enrichment analysis of the differentially expressed genes demonstrated that severe downregulation of neuropeptide-related genes occurred concomitantly with CSM. In particular, significant decreases of the transcripts of 37 genes among 88 neuropeptide precursor genes, including those for myomodulin, PentaFVamide, maturation-associated peptide-5A and conopressin, were commonly observed in female and male CSM snails. By contrast, microseminoprotein precursor was the only exceptional case where the expression was increased in CSM snails. These results indicate that down-regulation of neuropeptide precursors is a remarkable feature of CSM. We also found that factors involved in epigenetic modification rather than transcription factors showed altered patterns of expression upon CSM. Comprehensive expression panels of snail neuropeptide precursors made in this study will be useful tools for environmental assessment as well as for studying marine reproductive biology. [ABSTRACT FROM AUTHOR]

With the growing elderly population who are susceptible to poor health, improvement of their quality of life is essential. In the post-disaster setting of the 2011 Fukushima Dai-ichi nuclear power plant (FDNPP) accident, affected municipalities such as Okuma town commenced their recovery processes and lifted evacuation orders in 2019. This study examines the differences in self-reported mental and physical health status, social functioning, risk perception, and intention to return between elderly (age ≥65 years) and non-elderly (age 20–64 years) residents. Questionnaires were distributed to current residents and evacuees of Okuma. Results revealed that the elderly had a 1.4 times higher odds ratio (95%CI 1.0–1.8, p = 0.034) for having anxiety regarding radiation-related health effects on future generations and a 1.3 times higher odds ratio (95%CI 1.1–1.5, p = 0.001) for wanting to know about the release of FDNPP-treated water into the environment than the younger group. Elderly residents also demonstrated a 2.2 times higher odds ratio for reporting poor physical health than younger residents. Clearing misconceptions and disseminating coherent information will reduce risk perception among this group. Further in-depth research regarding the disposal of FDNPP-treated water and its perceived risks is required. Health promotion through the encouragement of social participation, improvement of surroundings to facilitate healthy behaviors, and enhanced access to health services will improve the quality of life of elderly Okuma residents. [ABSTRACT FROM AUTHOR]

After the Fukushima nuclear accident in Japan, whether the structural safety of the nuclear power plant (NPP) can be guaranteed under an earthquake has been of wide concern. Automatic seismic trip systems (ASTS) have been deployed in NPPs. There are generally two units or more double units on the one NPP site, and the vibration energy of the structure can certainly affect its adjacent structures through the soil, and there is energy transfer and conversion between adjacent structures. At present, the distance between two reactors of NPPs of different reactor types is generally 100–200 m (this distance is referring to the distance between the centers of two reactors, which is slightly different for different reactor types). In the past, seismic instruments were used in the ASTS and the setting of shutdown threshold, so the impact of only one unit was considered in the structural analysis of NPPs, and the interaction of two reactors through site conditions was not considered. In addition, as the site conditions of NPPs become more and more complex, it is necessary to consider the impact of one reactor structure on another reactor structure through the soil on the same site under an earthquake. In order to analyze the influence of structure–soil–structure interaction (SSSI), a three-dimensional refined finite element model of NPPs is established in this paper. The soil–structure interaction (SSI) is considered by using viscoelastic boundary. The seismic responses of different positions of the raft foundation and NPP structure, under the conditions of considering SSI effect (one reactor) and SSSI effect (two reactors), are compared. The influence of SSSI effect on the seismic responses of the raft foundation and NPP structure is revealed. It is proposed that SSSI effect should be reasonably considered according to the site conditions for the structural analysis of NPPs for the NPP ASTS. [ABSTRACT FROM AUTHOR]

Background: After the Great East Japan Earthquake and subsequent Fukushima Daiichi Nuclear Power Plant accident in 2011, the Fukushima Prefectural Government launched a long‐term health management survey for the population of Fukushima. Results of the Comprehensive Health Check (CHC) showed that some children aged 6–15 years, who resided in the evacuation area at the time of the disaster, had obesity, hyperlipidemia, liver dysfunction, and/or renal dysfunction from as early as 2011. The aim of the present study was to determine the long‐term trend of obesity and hepatic enzyme abnormalities in Fukushima children. Methods: We evaluated the changes in body mass index standard deviation score (BMI‐SDS), aspartate aminotransferase, alanine aminotransferase, and gamma‐glutamyl transpeptidase from 2011 to 2018. Results: Obesity (BMI‐SDS ≥ 2) was significantly associated with hepatobiliary enzyme abnormalities. The mean BMI‐SDS was significantly higher in 2011 after the disaster, but then soon showed a gradual decrease. The frequency of obesity did not increase significantly after the disaster. There were no significant differences in the prevalence of hepatobiliary enzyme abnormalities in the children aged 6–15 years of either sex from 2011 to 2018. Conclusions: In the present study, we found that the increase in the mean BMI‐SDS after the disaster was temporary, suggesting that the frequency of obesity and liver dysfunction might not have been significantly influenced by the disaster. [ABSTRACT FROM AUTHOR]

After the accident at the Fukushima nuclear power plant in Japan, a large amount of radioactive contaminated soil was generated, which brought great challenges for treating and disposing of the soil. The recycling of slightly polluted soil can reduce the amount of contaminated soil. This paper analyzes the main exposed scenes of 137Cs polluted soil used in the construction of highway subgrade, soil bag handling and paving. The Monte Carlo algorithm (MCNP) and RESRAD-ONSITE program are used to simulate the two scenes respectively, and the concentration of 137Cs is derived in the soil at the effective dose of 1 mSv per year. It is concluded that: the annual effective doses of porter and paver are 0.41 mSv per year and 0.23 mSv per year respectively caused by 1 Bqg-1 137Cs contaminated soil; the activity of 137Cs are 2.44 Bqg and 4.26 Bqg-1 respectively in the soil at 1 mSv per year for porter and paver; the calculated results are consistent with those reported by the Japan Atomic Research Agency. Also, they are lower than the activity concentration corresponding to the effective dose con- trol level of 1 mSv per year under low-probability events in IAEA No. RS-G-1.7 slightly. [ABSTRACT FROM AUTHOR]

Radionuclide contamination in foods has been a public concern in Japan after the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident. To estimate time and regional trends of daily intake and annual committed effective dose of strontium-90 (90Sr) after the accident, we analysed Market basket samples using a low background 2π gas-flow counter. Samples were collected from six regions, once a year from 2013 to 2018. There appeared to be little variation in estimated daily intake and annual committed effective dose of 90Sr across the time periods and regions. The estimated maximum annual committed effective dose of 90Sr was 0.00076 mSv/year, a value sufficiently lower than the intervention exemption level, 1 mSv/year, in foods in Japan. There was no noticeable difference between the range of estimated daily intake of 90Sr in this study compared with daily intake measured before the FDNPP accident. These results suggested that no obvious increase in dietary intake of 90Sr was observed after the FDNPP accident, and that the effects on commercial foods from 90Sr due to the FDNPP accident were negligible. [ABSTRACT FROM AUTHOR]

After the 2011 Fukushima accident, seismic regulations for nuclear power plants (NPPs) in Japan have been strengthened to include countermeasures beyond design‐basis events. Therefore, the importance of seismic probabilistic risk assessments is a topic that deserves attention. Generally, uncertainty quantification has been a crucial undertaking to assess the fragility of NPP buildings. This study aims to quantify realistic uncertainties using a three‐dimensional (3D) finite element (FE) model to reflect the obtained results to the conventional simple sway‐rocking (SR) model, and to develop a seismic fragility assessment method that considers 3D effects. As a first step, a 3D FE model was developed, and a seismic response analysis was performed to evaluate the seismic response of the buildings. For comparison, a seismic response analysis using the conventional SR model was performed. For input ground motions, 200 types of simulated seismic ground motions, generated using fault‐rupture models were adopted. As a second step, two types of uncertainties are evaluated for uncertainty quantification: uncertainty for input seismic ground motion and that due to different locations of equipment installed on a floor. As a third step, to reflect the 3D effect on the uncertainty of the conventional SR model, were investigated the median and logarithm standard deviation of the response ratio (3D FE/SR) of the maximum acceleration of the two models. The results of epistemic uncertainty tended to increase with the increasing elevation level and the epistemic uncertainty result in the basement floor, where important equipment was installed, was relatively small. By reflecting this epistemic uncertainty into the conventional SR model, a more realistic fragility assessment that considers the 3D effect is expected by applying this result as epistemic uncertainty of the SR model of the fragility assessment. [ABSTRACT FROM AUTHOR]

After the 2011 Fukushima nuclear power plant accident, the prevalence of metabolic syndrome sharply increased in municipalities near the nuclear power plant, where a massive evacuation of community residents occurred (the evacuation area). However, after the initial increase, the rate of increase in metabolic syndrome in the evacuation area was slower than that in the surrounding area (non-evacuation area). In this study, we compared the incidence of and recovery from metabolic syndrome as well as its prevalence between evacuation and non-evacuation areas during the 10 years after the accident to explore whether the slower increase in metabolic syndrome after the initial increase in the evacuation area stemmed from suppressed incidence or from fast recovery. We analyzed specific health check-up data of community residents aged 40–74 in Fukushima Prefecture from fiscal year (FY) 2012 to FY 2021 (N = 710,201). To explore the prevalence of metabolic syndrome, we examined the associations of time, residential area, and their interaction with metabolic syndrome using mixed-model repeated measures. We used data from those without metabolic syndrome in FY 2012 to investigate the incidence. We similarly examined the associations of time, residential area, and their interaction with metabolic syndrome using FY 2013 to FY 2021 data. To explore recovery, we used the data of those with metabolic syndrome in FY 2012 and repeated the same procedure. The rate of increase in the prevalence and incidence of metabolic syndrome was slower in the evacuation area than in the non-evacuation area. On the other hand, as for the recovery, the time trend of metabolic syndrome did not differ between the two areas. The slower increase in metabolic syndrome in the evacuation area was partly explained by the slower incidence in the evacuation area but not by recovery. • Metabolic syndrome continuously increased after the nuclear power plant accident. • Prevalence of metabolic syndrome was continuously higher in the evacuation area. • Increasing rate of metabolic syndrome was slower in the evacuation area. • Incidence rate of metabolic syndrome was slower in the evacuation area. • Recovery of metabolic syndrome was not observed. [ABSTRACT FROM AUTHOR]

Since the 2011 Fukushima nuclear power plant accident, multiple social network disruptions have been reported among the community in Fukushima, while posttraumatic stress symptoms among the residents have persisted. In this study, we aimed to explore the influence of time and social networks on the recovery of posttraumatic stress symptoms based on longitudinal data from community residents in Fukushima, following up five to ten years after the nuclear power plant accident. We conducted five questionnaire surveys quasi-annually, the targets of which were randomly sampled 4900 non-evacuee community residents. In this study, the data of 1809 respondents who participated in at least one survey were used (36.9% of the initial target). Setting posttraumatic stress symptoms as the outcome, we examined the interaction between time and social network size using a mixed model, adjusting for sociodemographic characteristics and disaster-related events. Their interaction was statistically significant, and the posttraumatic stress symptoms of those with small social networks persisted, while those with larger social networks recovered. Maintaining and promoting social networks may contribute to mental health recovery after a nuclear disaster. • Posttraumatic stress symptoms remained 10 years after the Fukushima nuclear disaster. • Posttraumatic stress symptoms persisted among those with small social networks. • Posttraumatic stress symptoms decreased among those with not-small social networks. [ABSTRACT FROM AUTHOR]

On March 11, 2011, a serious radionuclide leakage accident occurred at Fukushima Daiichi nuclear power plant, and a large number of radionuclides were released, causing serious pollution to the ocean environment. On August 25, 2021, Japan announced the overall plan for the discharge of radioactive sewage from the Fukushima Daiichi nuclear power plant into the ocean, and the discharge will begin around the spring of 2023. All operational and under-construction nuclear power plants in China are distributed in coastal areas presently. In case of a nuclear leakage accident, radionuclides will diffuse through the ocean and pollute the ecological environment. The study of radionuclide diffusion mechanism in the ocean and emergency response plays an important role in accident mitigation under oceanic radioactive events. A radionuclide diffusion model in the ocean was established and the radionuclide diffusion mechanism in the ocean was analyzed. And then a prediction and monitoring system of radionuclide diffusion in the ocean was proposed. The results show that the short-term radionuclide diffusion is mainly influenced by the source term, flow field and decay of 131I, and the degree of influence decreases in turn. On the whole, influences of the flow field and 131I decay are weakened during the long-term diffusion. At the same time, the influence of 137Cs decay begins to be obvious and the influence of suspended matter is increasing. The influence of ocean organisms is always small. Problems of scientific prediction and protection were analyzed, and the emergency response scheme was given. It is of great significance to improve the capacity of emergency response for oceanic radioactive events. [ABSTRACT FROM AUTHOR]

The unexpected accident at the Fukushima Daiichi Nuclear Power Station in Japan, which occurred on March 11th, 2011, after the Great East Japan Earthquake and tsunami struck the north-eastern coast of Japan, released radionuclides into the environment. Today, because of the amounts of radionuclides released and their relatively long half-life, the levels of radiocesium contaminating foodstuffs remain a significant food safety concern. Foodstuffs in Japan have been sampled and monitored for 134,137Cs since the accident. More than 2.5 million samples of foodstuffs have been examined with the results reported monthly during each Japanese fiscal year (FY, from April 1st to March 31st) from 2012 to 2021. A total of 5,695 samples of foodstuffs within the "general foodstuffs" category collected during this whole period and 13 foodstuffs within the "drinking water including soft drinks containing tea as a raw material" category sampled in FY 2012 were found to exceed the Japanese maximum permitted level (JML) set at 100 and 10 Bq/kg, respectively. No samples from the "milk and infant foodstuffs" category exceeded the JML (50 Bq/kg). The annual proportions of foodstuffs exceeding the JML in the "general foodstuffs" category varied between 0.37% and 2.57%, and were highest in FY 2012. The 134,137Cs concentration for more than 99% of the foodstuffs monitored and reported has been low and not exceeding the JML in recent years, except for those foodstuffs that are difficult to cultivate, feed or manage, such as wild mushrooms, plants, animals and fish. The monitoring data for foodstuffs show the current status of food safety risks from 134,137Cs contamination, particularly for cultured and aquaculture foodstuffs on the market in Japan. [ABSTRACT FROM AUTHOR]

This study aimed to identify concerns related to returning to the Nagadoro district of Iitate Village, Fukushima Prefecture, Japan, in 2023 among its residents as it is designated as a difficult-to-return zone after the Fukushima Daiichi nuclear power plant accident. The following four concerns were extracted from the interviews and qualitative analysis: "Difficulties in restarting/continuing farming," which represent the difficulties in making a living from agriculture due to the absence of family members and neighbors, and the insufficient radiation decontamination; "Discriminatory treatment of products and residents from villagers," which suggests the presence of discriminations that residents of Nagadoro district are eccentrics and its agricultural products should not be treated together with those of other districts in the Village due to the recognition that the district is severely polluted by radiation; "Shift of the responsibility of returning home from the country to residents by scapegoating," which is characterized by the shift of responsibility from the government to the residents, including harsh social criticism of the residents of Nagadoro district for not returning even though the evacuation order has been lifted, when it should have been the government's responsibility to recover the district to a habitable state; "Loss of options for continued evacuation," which is the loss or weakening of the position of residents of the Nagadoro district who continue to evacuate, and of administrative compensation, resulting from the legal change that they are no longer "evacuees" after the evacuation order is lifted. The findings of this study will provide a foundation for the support of residents of the Nagadoro district after lifting the evacuation order scheduled for the spring of 2023. The findings may be transferable to the residents of other difficult-to-return zones expected to be lifted after the Nagadoro district and to also a radiation disaster-affected place in the future. [ABSTRACT FROM AUTHOR]

Background: The increasing prevalence of thyroid cancer among the survivors of atomic bomb attacks in Japan, nuclear fallout in the Marshall Islands, and Chernobyl nuclear power plant accident indicate a strong relationship between nuclear radiation and the occurrence of thyroid cancer. Materials and Methods: Systematic researches were conducted in the medical database of the American National Library of Congress, PubMed, using keywords of thyroid cancer, radiation, papillary thyroid cancer. After screening the titles and abstracts of 1791 citations, a total of 77 citations were identified to include in the current study. Results: The latency period for developing nuclear radiation-induced thyroid cancers was 5 to 10 years to decades after exposure. The most important risk factor for developing radiation-induced thyroid cancer was the received radiation dose. A strong dose-response relationship between radiation dose and the incidence of thyroid cancer has been reported (P value<0.001). Also, a strong relationship between the age of exposure to nuclear radiation and the incidence of thyroid cancer has been reported among the survivors of atomic accidents. Although the incidence rate of thyroid cancer in girls was 2-3 times more than boys in some studies, in other studies from the Chernobyl accident, no gender effect was observed. The risk of radiation-induced thyroid cancer was estimated to be higher in areas with iodine deficiency. The most common route of internal radiation was through absorption of radioactive iodine isotopes via consumption of the contaminated milk. The main mechanism in the pathogenesis of radiation-induced thyroid cancer was activation of the MAPK pathway through genetic alterations (e.g., gene rearrangements in RET family and NTRK1) or point mutations (e.g., in BRAF). Among these genetic alteration, RET/PTC3 and RET/PTC1 rearrangements were more common in radiation--induced thyroid cancer. The clinical behavior of radiation-induced thyroid cancer was a non-invasive type similar to the sporadic one at the same age Conclusion: Nuclear radiation, especially at a young age (under 20 years old), directly or indirectly in a dose-dependent manner via reactive oxygen species production induces gene alterations that underlie the increasing incidence of thyroid cancer after radiation exposure. Preparedness to deal with nuclear radiation including prescription of stable iodine prophylaxis, evacuation of the contaminated regions and restriction of access to contaminated foods are recommended in power plant accidents or atomic bomb explosions. [ABSTRACT FROM AUTHOR]

Purpose: There is a large quantity of contaminated soil with radionuclides due to the accident of Fukushima Daiichi Nuclear Power Plant in Japan. Some previous studies reported that Cs+ could be desorbed from soil with high efficiency; however, these methods required huge input energy for operating. Therefore, we focused on oxalic acid, which has shown relatively high desorption efficiency in previous thermal treatment, and evaluated the potential of oxalic acid as a leaching reagent to reduce the volume of contaminated soil without heating. Methods: Stable isotope Cs+ contaminated biotite was retained in a plastic bag for 3 months for aging. Oxalic acid was added to the contaminated biotite, and the mixture was maintained around 20 °C. After each leaching time, the mixture was separated using filter paper, and the concentration of Cs+ in filtrate was measured. Structural changes in biotite before and after leaching were also analyzed. LiNO3 was also used for comparison studies. Results: The desorption efficiency of Cs+ from biotite by leaching with oxalic acid was 94.9% after 2 weeks, and the intensity of the specific reflection for biotite in the X-ray diffractograms decreased with leaching time. These results indicate that oxalic acid can remove Cs+ from biotite through the decomposition of the biotite structure. Since LiNO3 desorbed only 32.2% of Cs+ as ion-exchangeable form after 2 weeks, oxalic acid can desorb Cs+, which has a strong interaction with biotite such as the inner-sphere complex, without heating. Conclusion: Although the desorption of Cs+ from biotite by leaching with oxalic acid leaching takes a long time, it is a great advantage that this leaching method does not require external energy such as heating. Therefore, oxalic acid leaching has high potential to reduce the volume of contaminated soil with radionuclides. [ABSTRACT FROM AUTHOR]

The Tohoku earthquake off the Pacific coast of Japan on 11 March 2011 and the resulting tsunami led to severe damage to the Fukushima Daiichi Nuclear Power Plant (FDNPP) in Japan. Therefore, a shipboard survey was conducted to elucidate spread processes of radioactive cesium over the coastal ocean in the Kuroshio–Oyashio transition zone (south of the FDNPP) from 07 to 12 September 2011, that is, within 8 d of a river flood event associated with Typhoon Talas (T1112). In the survey, broad distributions of radiocesium and low‐salinity water extending nearly 100 km off the coast were successfully observed at the sea surface. Moreover, a significant negative correlation was detected between radiocesium and salinity in the coastal ocean. Just before the shipboard survey, the typhoon brought extremely heavy rainfall over the catchment areas of the Tone and Naka Rivers flowing into the survey region, resulting in discharges from the Tone and Naka Rivers reaching approximately 2800 and 700 m3 s−1, respectively, at their peaks (04 September). These discharges were the highest recorded since 2007. Satellite images corresponding to the high‐radioactivity and low‐salinity areas revealed that chlorophyll blooms also spread over a broad area during the survey. These results indicate that the broad distributions of radiocesium and low‐salinity water over the coastal ocean were brought about by the high levels of river discharge associated with the typhoon. [ABSTRACT FROM AUTHOR]

Nuclear power is still an important energy source, as well as a renewable energy at a time when promoting clean energy to realize a zero-carbon emission economy is becoming crucial. But the most important question is how to ensure the safety of nuclear power stations. One quantitative analysis method called Probabilistic Risk Assessment (PRA) is highlighted here, as it could help to achieve it. This can be regarded as another example of Evidence-Based Policy Making (EBPM). Japan SPOTLIGHT held the following interview with Dr. George Apostolakis, a distinguished nuclear engineering expert and director of the Nuclear Risk Research Center (NRRC) of the Central Research Institute of Electric Power Industry (CRIEPI) in Japan. [ABSTRACT FROM AUTHOR]

We discuss possible causal factors for the decline in intertidal invertebrate populations around Fukushima Daiichi Nuclear Power Plant (FDNPP) after the 2011 Great East Japan Earthquake and subsequent tsunami and nuclear disaster on the basis of existing knowledge about the effects of radionuclides and ionizing radiation on aquatic organisms. We found a gap between effects observed in the laboratory and those observed in natural aquatic environments, and discuss possible reasons why. Considering the complexity of the environment, we conclude that it is critical to evaluate the effects of ionizing radiation combined with other biotic and abiotic environmental factors, together with the life-history traits of the species examined, for realistic assessment of population-level effects. Finally, we present possible causal factors for strange or abnormal phenomena observed in intertidal biota near FDNPP, namely declines in population densities and number of species of invertebrates, delayed recovery from these declines, and continuous sexual maturation in the rock shell population. [ABSTRACT FROM AUTHOR]

We sought to clarify the relationship between social support, experiences related to voluntary evacuation, stress-related growth (SRG), and the sense of coherence (SOC) in male workers following the voluntary evacuation of their wives and children following a nuclear accident. In workers whose wives and children had voluntarily evacuated and not yet returned, SRG and SOC tended to be lower. Furthermore, larger social support networks were associated with less SRG and lower SOC. Those who hid from others the fact that their family had voluntarily evacuated tended to have less SRG and a lower SOC. [ABSTRACT FROM AUTHOR]

Carbon footprint reduction issues have been drawing more and more attention these days. Reducing the energy consumption is among the basic directions along this line. In the paper, a low-energy approach to tsunami danger evaluation is concerned. After several disaster tsunamis of the XXIst century, the question arises whether is it possible to evaluate in a couple of minutes the tsunami wave parameters, expected at the particular geo location. The point is that it takes around 20 min for the wave to approach the nearest coast after a seismic event offshore of Japan. Currently, the main tool for studying tsunamis is computer modeling. In particular, the expected tsunami height near the coastline, when a major underwater earthquake is detected, can be estimated by a series of numerical experiments of various scenarios of generation and the following wave propagation. Reducing the calculation time of such scenarios and the necessary energy consumption for this is the scope of this study. Moreover, in case of the major earthquake, the electric power shutdown is possible (e.g., the accident at the Fukushima nuclear power station in Japan on 11 May 2011), so the solution should be of low energy-consuming, preferably based at regular personal computers (PCs) or laptops. The way to achieve the requested performance of numerical modeling at the PC platform is a combination of efficient algorithms and their hardware acceleration. Following this strategy, a solution for the fast numerical simulation of tsunami wave propagation has been proposed. Most of tsunami researchers use the shallow-water approximation to simulate tsunami wave propagation at deep water areas. For software implementation, the MacCormack finite-difference scheme has been chosen, as it is suitable for pipelining. For hardware code acceleration, a special processor, that is, the calculator, has been designed at a field-programmable gate array (FPGA) platform. This combination was tested in terms of precision by comparison with the reference code and with the exact solutions (known for some special cases of the bottom profile). The achieved performance made it possible to calculate the wave propagation over a 1000 × 500 km water area in 1 min (the mesh size was compared to 250 m). It was nearly 300 times faster compared to that of a regular PC and 10 times faster compared to the use of a central processing unit (CPU). This result, being implemented into tsunami warning systems, will make it possible to reduce human casualties and economy losses for the so-called near-field tsunamis. The presented paper discussed the new aspect of such implementation, namely low energy consumption. The corresponding measurements for three platforms (PC and two types of FPGA) have been performed, and a comparison of the obtained results of energy consumption was given. As the numerical simulation of numerous tsunami propagation scenarios from different sources are needed for the purpose of coastal tsunami zoning, the integrated amount of the saving energy is expected to be really valuable. For the time being, tsunami researchers have not used the FPGA-based acceleration of computer code execution. Perhaps, the energy-saving aspect is able to promote the use of FPGAs in tsunami researches. The approach to designing special FPGA-based processors for the fast solution of various engineering problems using a PC could be extended to other areas, such as bioinformatics (motif search in DNA sequences and other algorithms of genome analysis and molecular dynamics) and seismic data processing (three-dimensional (3D) wave package decomposition, data compression, noise suppression, etc.). [ABSTRACT FROM AUTHOR]

The radioactive contamination caused by the accident at TEPCO's Fukushima Daiichi Nuclear Power Plant in March 2011 not only led to large-scale evacuations in Japan, but also triggered emigration. But why did people choose to leave Japan, even though they could have found less contaminated places in Japan? This study uses Ernst Bloch's concept of hope as an analytical framework to explain migration from Japan to Australia following the disaster. According to Bloch, the real world does not operate on solid facts, but on processes that are in progress. Thus people's perception of the real world is based not only on what has already happened, but also on the possibilities of what is to come. The most important of Bloch's ideas is the notion of hope as something "not yet" existing. Hope exists only insofar as we hope for, or believe in the possibility of, the realisation of what is not yet. This study, then, examines what people consider to be "present" or "not yet" about the post-disaster world, and how they experience hope or despair, drawing on an analysis of the narratives of 12 emigrants to Australia. The analysis shows that, based on the detected radiation levels and physical symptoms, it was recognised that radioactive material in the environment was definitely "present", and this was the starting point for despair. Therefore, people began to look outside Japan, where radioactive materials were not yet present. At the same time, because of the extremely long-term nature of radioactive materials, people began to look at the future post-disaster world from a long-time perspective. The more convinced they became of the existence of radioactive materials and their long-term effects, the more they inevitably began to think outside the country and into the future about the many possibilities that "do not yet exist". Faced with the invisibility of radioactive materials and the uncertainty of the effects of exposure on future generations, migration is a choice that can be realised through the act of travelling abroad, and a way of finding something definite in the chaos. In this sense, emigration is nothing less than a way of realising hope. [ABSTRACT FROM AUTHOR]

Objective: This study continues former studies on perinatal mortality in Japan after the Fukushima Daiichi nuclear power plant (FDNPP) accident in March 2011. An increased study region is chosen, and the study period is extended to 2019. Methods: Japanese monthly perinatal mortality data are provided on a prefecture level by the Japanese government. The study region consists of 12 prefectures around the FDNPP; the rest of Japan is used as the control region. A combined non-linear regression of perinatal mortality rates in the study- and control regions is conducted. The regression model allows for a common asymptotic lower limit of perinatal mortality, seasonal variations, and periodic peaks in 2012–2019 in the study region. To determine the dependency of the effect on distance from the FDNPP, the study region is divided into four core prefectures and eight prefectures surrounding the core prefectures. Results: Perinatal mortality rates in the study region show a significant 6.4% (95% CI: 1.8%, 13.4%) overall increase in 2012–2019 relative to the trend in preceding years with no attenuation during 2012–19. The increase translates to 590 (165, 1226) excess perinatal deaths (p = 0.016). It is characterized by annual peaks with maxima in April. A 13.6% increase is determined in the four core prefectures and a 4.3% increase in eight prefectures surrounding the core prefectures. Before 2012, there is a peak around April 2011 and a decline in October 2011; another significant peak is detected in November 2012. In the 4 core prefectures, large increases are found in the first quarter of 2018 (+70%) and in May 2019 (+130%). Conclusion: This study finds periodic peaks in perinatal mortality in spring 2012–2019 in 12 prefectures of Japan surrounding the FDNPP. In light of massive increases in 2018 and 2019 in the four core prefectures, continued investigation of perinatal mortality in contaminated regions of Japan is recommended. [ABSTRACT FROM AUTHOR]

The article explores how affect is circulated and managed in comment discussions on networked online platforms, such as Facebook. A mixed-methods analysis is conducted of comments on news about the triple disaster of an earthquake, a tsunami and a meltdown of three reactors at Japan's Fukushima Daiichi nuclear power plant in March 2011 on public Facebook pages of seven Finnish mainstream news media. The article examines how affect sticks and circulates in these discussions, and how the commenters direct and sustain the mode and mood of Facebook discussions. The main findings of the article concern how online discussions are structured by what the author calls affective discipline, in which participants the discussion manage the mood of the discussion through various means. The results open up an important way to study the internal, affective dynamics of contemporary online discussions. In particular, the study helps us understand how flows of affect are shaped and steered in online discussions, and how the same discussions may simultaneously sustain multiple affective dynamics. These dynamics may, in turn contribute to how publics respond to news and official information in crises. [ABSTRACT FROM AUTHOR]

Radiocesium-bearing microparticles (CsMPs) from Fukushima Daiichi Nuclear Power Plant (FDNPP) are observed in Eastern Japan. To examine their source and formation, multiple particles were isolated from soils from three sites around the FDNPP and their radioactivity, morphology, and elemental composition were analyzed. Cesium-137 radioactivity ranged from 0.23 to 8.57 Bq and particles were primarily composed of Si, Fe, Zn, C, and Cs at each site. Uranium-rich parts in certain CsMPs show their origin in the vicinity of the nuclear reactor. Our results will help characterize CsMPs and evaluate the internal dose exposure of personnel employed at the FDNPP. [ABSTRACT FROM AUTHOR]

The resumption of Japan's NPPs has become a controversial issue since the Fukushima Daiichi nuclear disaster in 2011. Although local agreement is a significant process of the resumption, the attitude of the general public toward the local agreement process has received little attention. This study uses a postal questionnaire survey with stratified random sampling to investigate the case of the Hamaoka NPP. Results show that the conventional way of seeking local agreement is not generally supported by the public. This may be explained by apparent widespread support for the participation of broader geographical areas, including those affected by reputational damage and urban areas consuming electricity, and by a general distrust of local governments/assemblies and the 'experts'. It was also found that respondent attitudes regarding local agreement differ depending on the respondent's position on the restart as well as the area in which the respondent resides. [ABSTRACT FROM AUTHOR]

Do the policy preferences expressed through political participation represent the citizens as a whole? Previous studies argue that there is no ideological bias in voting participation in Japan. However, previous studies have only analyzed Japan up to 2010, and it is unclear whether ideological bias was consistently absent in voting participation in the 2010s. In the 2010s, ideological issues, such as the maintenance of nuclear power plants or the acceptance of collective self-defense, emerged in Japan, and the two major political parties, the Liberal Democratic Party and Democratic Party of Japan, became increasingly polarized. Considering these changes, the influence of ideology on political participation may be growing. Therefore, this paper examines the relationship between people's ideological positions and political participation using voter surveys conducted between 2001 and 2017. I find that since 2012, the more ideologically extreme Japanese voters are, the more they participate in voting. Furthermore, the same is true for other forms of participation. In general, the voices of ideologically moderate Japanese are becoming less represented by political parties and politicians. [ABSTRACT FROM AUTHOR]

Using a hedonic regression approach, this research aims to identify what factors affected land price fluctuations in Fukushima Prefecture following the Great East Japan Earthquake and the Fukushima Daiichi Nuclear Power Station accident in 2011. In this paper, taking a long-term perspective, the analysis focuses on Iwaki City in Fukushima, where the real estate market behaved unexpectedly following the two catastrophic events, and land price fluctuation rates were rising abnormally. Results based on analysis of data for eight-year indicate the following: The impact of radiation air dose rate and distance from the nuclear power plant on land price fluctuation rate changed significantly from the fourth year after the disaster. Being located in a reconstruction base area had a negative impact on land price fluctuation rate, while access to sewers and city gas had a positive impact. It appears that the stigma associated with the accident had a little disappeared after approximately four years. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study was to clarify the characteristics and awareness of the need for protection against ionizing radiation, such as sheltering, evacuation, and implementing stable iodine prophylaxis, of guardians parenting young children living in an urgent protective action planning zone (UPZ) of an operating nuclear power plant in Japan.Methods: Self-administered questionnaires were distributed to approximately 3000 guardians through 26 kindergartens located within a UPZ. Responses were obtained from 1172 who lived in the UPZ and were included in the analysis.Results: Of the 1172 guardians, 460 (39.2%) responded that sheltering is not useful to reduce the dose of radiation exposure. On the other hand, 395 (33.7%) guardians responded that implementing stable iodine (SI) prophylaxis could prevent exposure from all radionuclides, and 876 (74.7%) responded that pregnant women should also implement SI prophylaxis in a nuclear emergency. Furthermore, 83.0% (973) responded that they wanted to receive pre-distribution of stable iodine (PDSI) for their children. On the other hand, 38.9% (456) of guardians had not known about SI before the study, and 71.8% (841) of guardians felt anxious about implementing SI prophylaxis for their children.Conclusion: Most guardians had expectations regarding SI and received PDSI, but they felt anxious about implementing SI prophylaxis for their children. It is essential that guardians living in the UPZ of restarted nuclear power plants be educated, and that risk communication about protection against ionizing radiation, including the side effects of implementing SI prophylaxis and radiation health effects, be conducted. [ABSTRACT FROM AUTHOR]

Flame‐retardant cross‐linked polyolefin (FR‐XLPO), is widely used as insulators for electric cables. Several cables installed in nuclear power plants must be functional even when they suffer a severe accident. Therefore, sheets of FR‐XLPO were exposed to heat, gamma rays, and high‐temperature steam. Before and after such aging treatments, samples' mechanical and thermal properties and infrared and THz absorption spectra were measured. As a result, it has become clear that FR‐XLPO is fairly resistant to superheated steam with no oxygen, although it is easily degraded thermally if oxygen is present. It is also resistant to gamma rays to a certain extent. © 2021 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

On 16 March 2021, the Teach311 + COVID-19 Collective () hosted a virtual roundtable discussion entitled "Sources of Disaster: New Epistemic Perspectives in Post-3.11 Japan." The event brought together scholars and students researching the history and anthropology of Japan to explore how the earthquake, tsunami, and nuclear power plant disaster of 11 March 2011 (3.11) changed our ways of knowing the world. The roundtable focused on the idea of the "source" to get at these epistemic shifts in lived experience and practical knowledge as well as historiography, and to investigate ideas that range from what we can know about acceptable risk and safety to notions of home and belonging. "Source" is a way to think about origins, but also the materials—texts, media, or testimony—that we collect and analyze to give rise to new or better knowledge. Building upon previous Teach311 activities that explored the roots of 3.11 and genba, participants in this roundtable expanded upon the significance and meanings of the notion of a "source" relative to the politics of epistemology in their research and studies in order to examine what reconstruction means in history when it is conducted alongside recovery. [ABSTRACT FROM AUTHOR]

The Fukushima Daiichi Nuclear Power Plant accident released considerable radionuclides into the environment. Radioactive particles, composed mainly of SiO 2 , emerged as distinctive features, revealing insights into the accident's dynamics. While studies extensively focused on high-volatile radionuclides like Cs, investigations into low-volatile nuclides such as 90 Sr and Pu remain limited. Understanding their abundance in radioactive particles is crucial for deciphering the accident's details, including reactor temperatures and injection processes. Here, we aimed to determine 90 Sr and Pu amounts in radioactive particles and provide essential data for understanding the formation processes and conditions within the reactor during the accident. We employed radiochemical analysis on nine radioactive particles and determined the amounts of 90 Sr and Pu in these particles. 90 Sr and Pu quantification in radioactive particles showed that the 90 Sr/ 137 Cs radioactivity ratio (corrected to March 11, 2011) aligned with core temperature expectations. However, the 239+240 Pu/ 137 Cs activity ratio indicated nonvolatile Pu introduction, possibly through fuel fragments. Analyzing 90 Sr and Pu enhances our understanding of the Fukushima Daiichi accident. Deviations in 239+240 Pu/ 137 Cs activity ratios underscore nonvolatile processes, emphasizing the accident's complexity. Future research should expand this data set for a more comprehensive understanding of the accident's nuances.

The accident at Fukushima Daiichi Nuclear Power Plant (FDNPP) in 2011 resulted in the dispersion of radioactive materials throughout the surrounding area and an increase in the air dose rate was even confirmed in Fukushima City, which is located approximately 60 km northeast of FDNPP. A Tokyo Electric Power Company (TEPCO) Holdings employee, who has lived and worked in Fukushima City since the FDNPP accident, measured individual external doses, GPS data, and his activities in Fukushima Prefecture over a 9 year period beginning in 2014. This data provides valuable information about the area. The data show the following results. (i) Comparison of the air dose rate at the home location to the individual external dose per hour at the home shows that the average conversion factor has increased over the 9 years and exceeded 0.3 since 2019, indicating an overall relatively good correlation. (ii) Individual external doses measured in the office on the fourth floor of a concrete structure in Fukushima City have not changed significantly from 2014 to 2022, when air dose rates showed a decrease. (iii) Outdoor individual external doses, such as those measured when commuting on foot, have a relatively strong correlation with air dose rates from airborne monitoring with the conversion factor of about 0.6. The conversion factor do not differ significantly from 2014 to 2022.In this study, the individual external dose data is applicable to the TEPCO measurer and is not necessarily representative of all residents of Fukushima City. However individual external dose data for 9 consecutive years will be useful for estimating individual external doses from air dose rates, and estimating annual additional exposure doses, if even some of them are applicable to similar life patterns and lifestyles., (Creative Commons Attribution license.)