Fukushima Nuclear Power Plant Research Articles

Non-returning factors from an interview survey of 16 residents of Katsurao village 12years after the Fukushima nuclear power plant accident.

People generally wish to return home after being evacuated due to disaster situations. Evacuation orders have now been lifted in the Fukushima region following the nuclear accident in 2011, and the Japanese government is promoting a return policy. However, many residents who wish to return home remain unable to and continue living in evacuation sites or other areas. Sixteen residents of Katsurao village were interviewed after evacuation orders were lifted in 2016 who have not yet returned. Concerns were cited regarding radiation, prolonged evacuation, health problems, buying a house in the evacuation area and schooling. The problems identified were primarily due to the rapid ageing and decline of the regional population, reflecting similar issues throughout Japan. In particular, health problems and intention to return were thought to be closely related. Over 10 y have passed since the evacuation, and many residents have experienced familial separation and divided living situations.

Assessment of Pollution of the Waters in the South Kuril Fishing Zone of Russia by Radioactive Waters from the Fukushima-1 NPP Based on Lagrangian Modeling

The study investigates the potential hazard arising from the actions taken by the Japanese government regarding the discharge of technical radioactive water from the Fukushima-1 nuclear power plant storage facilities. The contamination of the South Kuril Fishing Zone (SKFZ), which is one of the most promising fishing areas for the Russian Federation, with radioactive particles, is considered. Based on the modeling of passive markers simulating radioactive contamination, the study analyzes the pathways and mechanisms of pollution transfer into the SKFZ. The research is conducted using altimetric data on geostrophic currents for the period from August 24, 2022, to August 24, 2023. The pollution transfer into the SKFZ is determined by a set of conditions related to the current development regime of the First Kuril Meander and the local vortex system with varying characteristics, both near the discharge site and at the SKFZ border. A seasonal dependence of the speed and quantity of polluted water infiltration toward the Russian Federation’s shores is established. The possibility of rapid pollution advection into the SKFZ within 13 days has been discovered. This speed is due to the entrainment of contamination by the Kuril Meander and its further transport by the mesoscale vortex system to the SKFZ border. The study reveals periodicity in the influx of pollution into the SKFZ. Graphs depicting the distribution of the quantity of “dirty” markers over their release times and the arrival of polluted water at the SKFZ border have been created.

Surface Transport of Technical Waters from Fukushima NPP to the South Kuril Fishing Zone

This study explores the potential for the penetration of technical waters from the Fukushima nuclear power plant (Fukushima NPP) into the fishing areas of Russia. Using a Lagrangian approach, which examines the advection of a large number of passive markers simulating waters released from the Fukushima NPP, the typical transport pathways to the South Kuril Islands are investigated, and an estimate of the time of such transport is provided. Calculations are conducted using satellite-derived and modelled velocity fields for the test year from August 24, 2022, to August 24, 2023. This study focuses on the advection of Lagrangian markers and highlights the potential for the rapid arrival of them from the Fukushima NPP into the southern Kuril region. This article emphasizes the importance of considering the seasonal variability in Kuroshio meandering and the impact of local mesoscale vortex advection related to the propagation of Lagrangian markers from the Fukushima NPP.

Prevalence, incidence, and recovery of metabolic syndrome after the fukushima nuclear power plant disaster: A 10-year longitudinal study

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.

Detection of deposits adhered on the back surface of plate-like structures using a scanning laser source technique

An imaging technique using a scanning laser source (SLS) was applied to detect deposits inside pipes, which are necessary for the safe decommissioning of the Fukushima Nuclear Power Plant. Experimental results showed that the more firmly adhered the deposit on the back surface of a flat plate, the clearer it is to obtain an image of the deposit. This result is as expected because the imaging by an SLS technique is dependent on the bending stiffness of the thin plate structure. Furthermore, even epoxy putty as large as 50 mm in diameter adhered to the inner surface of the pipe could be imaged, and even when the receiver device was changed from a piezoelectric device to a non-contact laser doppler vibrometer, the image of the deposit could be obtained properly with some degradation of the image due to the effect of a lower signal-to-noise ratio.

Attitudes towards the release of ALPS water from Fukushima NPP

PurposeThe Japanese government plans to release ALPS treated water from the Fukushima nuclear power plant starting in the summer of 2023. This has appeared to be a controversial topic in Japan and amongst its neighbors in the regions. This paper focuses on the attitudes of Japanese people towards the government policy, placing it within the context of wider issues.Design/methodology/approachAn online survey of 2,000 participants completed an online survey comprising of Likert type and multi-choice type questions. The results were analyzed using logit regression analysis.FindingsWe found that issues other than the ALPS discharge were seen as equally important, but that there was concern about the policy, the impact the discharge would have, and about produce from the area. We also found that the farther away the participants lived, the less concern they showed. Consultations with both local communities and neighboring countries were seen as important by many participants.Originality/valueThis research places the issue of ALPS treated water into a wider context of other global issues and examines the role distance from Fukushima plays in the public’s engagement with the issue. It serves to highlight the mixed results of government efforts to win support for its ALPS discharge policy.

Radiation-Induced Childhood Thyroid Cancer after the Fukushima Daiichi Nuclear Power Plant Accident.

After the Fukushima Nuclear Power Plant accident in March 2011, a large-scale ultrasound examination of childhood thyroid cancer for all Fukushima residents aged 18 years old or younger was initiated. Fukushima was divided into four areas according to the external radioactivity released by the accident: the highest (A), high-intermediate (B), low-intermediate (C), and the lowest (D). Five rounds of surveys were carried out from October 2011 to March 2023. The annual incidence rates of the "Common Case" not affected by the accident were able to be estimated. The difference between the incidence rate of whole patients and the "Common Case" is that of the "Radiation-induced Case". The annual incidence rate of the "Radiation-induced Case" began to increase immediately after the accident, where the highest level was seen in A area, and the order was A > B > C > D. It showed that the development of childhood thyroid cancer was affected by the radiation released by the accident. The effect of the radiation consisted of two phases: the first phase may have been due to the damage to the immune system, and the second phase may have been due to the genetic mutation in the children who were youngest at the time of the accident.

Impact of the Great East Japan Earthquake followed by the nuclear power plant accident on the nursing students’ academic progress in Soma, Fukushima, Japan: a retrospective cohort study with questionnaire survey

BackgroundThe 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.MethodsA 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.ResultsOf 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).ConclusionsThis 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.

Social networks and posttraumatic stress symptoms five to ten years after the Fukushima nuclear power plant disaster

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.

Exothermic characteristics evaluation of the Pt coated α-Al2O3 catalyst in bed for passive airborne radioactive material reduction system under forced flow conditions

After the severe accident at the Fukushima nuclear power plant, there has been heightened interest in the development of severe accident countermeasures. As part of these efforts, a passive filtration system capable of passive operation during power loss is under development.This paper focuses on evaluating the performance of a catalyst-filled bed designed to create a temperature gradient through exothermic reactions between combustible gases generated during accidents and a catalyst. The temperature gradient facilitates the formation of natural convection within the system, enabling passive operation. The catalytic bed is designed in a bed-type configuration filled with exothermic catalysts. To ensure physical and chemical stability under severe accident conditions, heat resistance tests were conducted using inorganic materials as a base to select an optimized exothermic catalyst. A test apparatus was designed for unit evaluation testing of the catalyst-filled bed equipped with the catalytic bed. Exothermic characteristics evaluation tests were conducted by varying the hydrogen volume fraction and face velocity, measuring heat generation in the catalytic bed under each condition. The correlation between these variables and the heat generation performance of the catalytic bed was determined. These findings will be utilized to inform the design parameters of the passive airborne radioactive material reduction system.

Japan's nuclear water disaster on international law

With the development of human science and technology, the ecological environment is also destroyed. One particularly big source of contamination recently is the release of contaminated water from Japan's nuclear reactors. The nuclear waste generated in the operation of nuclear facilities and reactors is radioactive and inevitably causes environmental pollution. If there are mistakes in the operation process and operation procedures, it will lead to nuclear accidents, cause huge environmental disasters, damage human health and cause difficult to estimate property losses. After the cabinet meeting, the Japanese government announced that it will start to discharge contaminated water from the reactors of the Fukushima nuclear power plant from the 24th. According to this idea, the Fukushima nuclear power plant will continue to discharge contaminated water for at least the next 30 years. According to this incident, many media and experts are judging the consequences of this incident and what to do in the future. So, how should we deal with and view this incident? So the first thing to look at is how this is regulated or violated in international law. In the future, more international solutions and actions will be needed to maintain world peace and health.

A model to predict indoor concentrations and internal radiation doses of radioactive aerosols from nuclear accidents

Spread of radiation contaminations can be affected by several factors. Some of these factors were considered in previous articles. Those studies were based on some Computational Fluid Dynamic (CFD) schemes and gave good results for describing deposition and penetration of aerosol particles. In this paper, those CFD schemes are applied to set a model that can be used to calculate the indoor concentrations of the radioactive aerosols that release from nuclear accidents. The one of the Fukushima nuclear power plant (NPP) that took place in 2011 is taken as an example. Furthermore, the internal radiation doses caused by the intake of the radioactive aerosols are estimated. Considering in particular the radionuclide C137s, due to its very long half-life, the internal doses are calculated for the lungs and some of the surrounding vital organs. The radiation transport throughout the body is simulated by codes of the Monte-Carlo N-Particle simulation software, version 5 (MCNP5), with exploiting the human body representation by the phantom of the Oak Ridge National Laboratory-Medical Internal Radiation Dose (ORNL-MIRD). The results show a large spread of the radiation contaminations from outdoors to indoors, and that the whole-body annual dose from C137s is more than tenfold higher than the annual dose limit set by the International Commission on Radiological Protection (ICRP).

Quantifying the impact of earthquakes on urban energy consumption and carbon emissions in Tokyo from a nexus perspective

Unexpected events can have profound impacts on urban resource supply and consumption. The Great East Japan Earthquake (3.11 hereafter) triggered not only the planned blackout in the Tokyo Metropolitan Region soon after the disaster but also the energy shift to fossil fuels to recover from the disfunction of Fukushima nuclear power plants. Previous research has mainly focused on the direct energy consumption and carbon emissions of different sectors while the intensity and extensity of the impact on industries and the environment have never been empirically addressed. This study explores energy-use efficiency and carbon emissions in Tokyo from 2011 to 2015 through a lens of nexus using environmentally extended input-output analysis and community-wide carbon analytic approaches. Results show that the energy consumption is the largest exporter and importer of carbon emissions, whereas energy losses and carbon emissions caused by energy conversion and transmission are almost twice as much as those caused by the direct parts. Strong nexus effects among building and material, transportation, and energy consumption were observed. The 3.11 greatly impacted the energy structure and carbon emission patterns because of the increased consumption of coal for electricity. The share of energy consumption and carbon emissions by raw materials for construction also increased because of the increased demand for the reparation and reconstruction of buildings and transport systems. This structural change provided new scientific evidence for governments to implement decarbonization policies while preparing for unprecedented events.

Развитие ядерной энергетики в Северо-Восточной Азии: история, тенденции, перспективы

The article provides an overview of the formation and development of the nuclear industry in the countries of Northeast Asia: China, Japan, the Republic of Korea, and Taiwan. The impact of the accident at the Fukushima-1 nuclear power plant in 2011 on the prospects for the development of nuclear energy in Northeast Asia is analyzed. A description of the policies of the countries of the region in the field of development of the "peaceful atom" is also given and their export potential in this area is studied. It is concluded that the "Fukushima syndrome" did not have a fatal impact on the development of nuclear energy in the countries of the region.

Radioactivity concentration levels and potential radiotoxicity risk assessment of aquatic superfoods case study of algae supplements

It has been found that algae have a variety of health benefits, although investigations showed that they contain radiotoxic elements, including 226Ra, 232Th, 40K, and 137Cs, which may affect human health. This study is connected to activity concentration measurements of the above radionuclides in the algae supplements available in the Middle East markets. The annual effective radiation doses of measured radionuclides in analyzed algal supplements have been calculated. The highest values of annual effective doses have been estimated for 226Ra in Ecklonia (13.39 μSv/y) and for 232Th in Red Marine Algae (11.80 μSv/y), both from South Korea. In algal “superfoods”, the effective dose of 137Cs is not significantly affected by the Fukushima Nuclear Power Plant. Based on these results, it can be concluded that the activity levels of radionuclides are low, the naturally occurring radionuclides provide the most effective doses, and algae supplements can be considered safe.

Basic Performance Evaluation of a Radiation Survey Meter That Uses a Plastic-Scintillation Sensor.

After the Fukushima nuclear power plant accident in 2011, many types of survey meters were used, including Geiger-Müller (GM) survey meters, which have long been used to measure β-rays. Recently, however, a novel radiation survey meter that uses a plastic-scintillation sensor has been developed. Although manufacturers' catalog data are available for these survey meters, there have been no user reports on performance. In addition, the performance of commercial plastic-scintillation survey meters has not been evaluated. In this study, we experimentally compared the performance of a plastic-scintillation survey meter with that of a GM survey meter. The results show that the two instruments performed very similarly in most respects. The GM survey meter exhibited count losses when the radiation count rate was high, whereas the plastic-scintillation survey meter remained accurate under such circumstances, with almost no count loss at high radiation rates. For measurements at background rates (i.e., low counting rates), the counting rates of the plastic-scintillation and GM survey meters were similar. Therefore, an advantage of plastic-scintillation survey meters is that they are less affected by count loss than GM survey meters. We conclude that the plastic-scintillation survey meter is a useful β-ray measuring/monitoring instrument.

ОБОСНОВАНИЕ НОВОЙ ПРИЧИННО-СЛЕДСТВЕННОЙ ТРАКТОВКИ РАЗВИТИЯ И ТРАНСФОРМАЦИИ ЧРЕЗВЫЧАЙНЫХ СИТУАЦИЙ НА ПРИМЕРЕ АВАРИИ НА АТОМНОЙ ЭЛЕКТРОСТАНЦИИ «ФУКУСИМА-1»

Using the example of the radiation accident at the Fukushima-1 nuclear power plant and subsequent measures to discharge tritium-containing aqueous coolant into the ocean, the adequacy of a new causal interpretation – the «triangle of emergencies», justifying and explaining scenarios of mutual transition of one type of emergency into another, as well as its graphical interpretation is considered. The issues of existing and possible consequences related both directly to the accident and to the discharge of the coolant are investigated. The results of calculating the change in the radioactivity of tritium in the volume of water planned for discharge for a period equal to ten of its half-life are presented. The prospects of applying the concept of an «emergency triangle» are considered, which are seen in the construction of an «emergency space», which is an array of emergency data collected for the purpose of analyzing, interpreting information, establishing cause-effect relationships and forecasting, as well as the principles of its formation.

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

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

Safety evaluation of Multiple Steam Generator Tube rupture accident using the best estimate plus uncertainty approach

Following the disaster in Fukushima Nuclear Power Plant (NPP) in 2011, the awareness of securing the safety of NPP under extreme events has been raised. For this purpose, the concept of Design Extension Conditions (DECs) was introduced, to enhance the plant’s capability to withstand events that are more severe than Design Basis Accidents (DBA), such as Multiple Steam Generator Tube Rupture (MSGTR) accident, given its rapid progression and significant potential for large release of radioactive materials to the environment. It is worth noting that MSGTR has never occurred during the commercial operation of nuclear power plant, therefore the knowledge of consequences of the event and potential mitigation strategy is limited. In this study, a postulated MSGTR (simultaneous rupture of 5 U-tubes in a single SG) accident is analysed using the best-estimate thermal hydraulics code RELAP5/SCDAPSIM/MOD3.4. The main focus of this work is evaluation of appropriate operator mitigation actions under various inherent uncertainties. To this end, the best estimate plus uncertainty (BEPU) approach is adopted, whereby RELAP5/SCDAPSIM/MOD3.4 was coupled to the statistical analysis software, DAKOTA, to conduct the uncertainty quantification (UQ). Using BEPU analysis, an ensemble of system responses under various epistemic and aleatory uncertainties is obtained and used to validate the efficacy of operator actions in bringing the plant to a safe shutdown condition.

International Wrongfulness of Japan's NCW Sea Discharge

International Wrongfulness of Japan's NCW Sea Discharge