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The article presents a summary of the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) White paper which shows developments on the radiation levels and exposure due to the nuclear accident at Fukushima Daiichi Nuclear Power Station (FDNPS) in Japan since 2013. Topics discussed include the radionuclide releases to atmosphere and water, assessment of radiation doses to the public from external exposure, and radiation doses to FDNPS workers.

Radiocesium released by the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident still exists in the environment in two forms: adsorbed species on mineral particles in the soil and microparticles containing radiocesium mainly composed of silicate glass (CsMPs). CsMPs are dispersed not only around the FDNPP but also over a wide area of the Kanto region. The behavior and characteristics of CsMPs must be investigated to evaluate the impact of the FDNPP accident. Deposited particles including radiocesium were wiped from metal handrails on balconies and car hoods using tissue papers at six locations in the Kanto region (Tokai village, Ushiku City, Abiko City, Chiba City, Kawaguchi City, and Arakawa Ward) between March 15 and 21, 2011. CsMPs were isolated from the samples, and their characteristics were investigated. In total, 106 CsMPs derived from Unit 2 were successfully separated from 13 tissue paper samples. The radiation images of the two types of CsMPs discovered in Ushiku City demonstrate that CsMPs can easily become susceptible to fragmentation over time, even in the absence of weathering effects. [ABSTRACT FROM AUTHOR]

The aim of this paper is to examine the lessons learned till mid-2023 from the war in Ukraine to find out how attacking or seizing nuclear power plants (NPPs) can be utilised to advance military and political objectives during an armed conflict. The qualitative research approach has been applied to the study, focusing on an analysis of academic research and relevant acts of international law. In order to examine Russia’s approach to the attacks against the Chernobyl and Zaporizhzhia NPPs, numerous reports, official statements by the authorities, press releases, and Internet sources have been analysed. For evaluation of nuclear security and safety standards in Ukraine, the “seven pillars” model proposed by the International Atomic Energy Agency has been adopted. The study indicates that strategically located NPPs can be used as “nuclear shields” for the occupying forces deployed at the plant or nearby. They may also become useful tools of “lawfare” waged with the use of flawed interpretations of international humanitarian law. Finally, nuclear security-related narrations analysed in the paper clearly prove that seized NPPs can be effectively used in information warfare. The research leads to the conclusion that civil NPPs in war zones can be weaponised and exploited by the hostile forces not only for impeding energy supplies (and thus shattering the public morale of the adversary) but also for blackmailing and coercing the decisionmakers of the attacked state and their international allies with a vision of man-made nuclear disaster. [ABSTRACT FROM AUTHOR]

The events of the 2011 Fukushima nuclear accident in Japan have garnered global concern. Despite nuclear power plants addressing numerous energy challenges, they poses substantial risks to environmental safety. The global legal basis to fulfill due regard obligations toward nuclear wastewater discharge involves international nuclear energy and marine environmental protection laws. There is substantive scope of due regard obligations toward nuclear wastewater discharge, including fulfilling international duties, prohibiting marine environmental pollution, preventing transboundary harm, and ensuring procedural obligations. The procedural obligations encompass timely notification of nuclear pollution, scientific assessment, and active consultation and cooperation with the international community. As there are still numerous obstacles to the application of due regard in the discharge of nuclear wastewater, the international marine environment frequently suffers from nuclear pollution. Considering the potential for transboundary environmental harm owing to the discharge of nuclear wastewater, this paper proposes effective solutions to this issue from the perspective of sustainable development of the marine environment. These solutions include formulating specific normative guidelines, clarifying liability for paying transboundary harm compensation, developing unified international assessment standards, and establishing an international platform for mandatory cooperation. Such solutions reinforce the national responsibility of all countries to actively fulfill their due regard obligations and effectively resolve the issue of potential irreversible damage to the marine environment. Additionally, the paper provides suggestions regarding how the international community can address the issue of Japan's nuclear wastewater discharge and other similar issues that may arise. [ABSTRACT FROM AUTHOR]

Background: The need to call out and expose authors for their persistence in improperly using epidemiology has been previously noted. Tsuda et al. have done well to expose Schüz et al.'s arguments/assertions in their recent publication in Environmental Heath. In this Comment, I point out that, also warranting being called out, are the arguments/assertions of Cléro et al. who, in their recent response to an article by Tsuda et al., reiterated the conclusions and recommendations derived from their European project, which were published in Environment International in 2021. Tsuda et al. had critiqued the Cléro et al. 2021 publication in their 2022 review article. However, in their response to it, Cléro et al. deflected by not addressing any of the key points that Tsuda et al. had made in their review regarding the aftermath of the Chernobyl and Fukushima nuclear accidents. In this Comment, I critique Cléro et al.'s inadequate response. Publication of this Comment will help in routing out the improper use of epidemiology in the formulation of public health policy and thereby reduce the influence of misinformation on both science and public policy. My critique of Cléro et al. is not dissimilar from Tsuda et al.'s critique of Schüz et al.: in as much as Schüz et al. should withdraw their work, so should Cléro et al.'s article be retracted. Main body: The response by Cléro et al. consists of four paragraphs. First was their assertion that the purpose of the SHAMISEN project was to make recommendations based on scientific evidence and that it was not a systematic review of all related articles. I point out that the Cléro et al. recommendations were not based on objective scientific evidence, but on biased studies. In the second paragraph, Cléro et al. reaffirmed the SHAMISEN Consortium report, which claimed that the overdiagnosis observed in non-exposed adults was applicable to children because children are mirrors of adults. However, the authors of that report withheld statements about secondary examinations in Fukushima that provided evidence against overdiagnosis. In the third paragraph, Cléro et al. provided an explanation regarding their disclosure of conflicting interests, which was contrary to professional norms for transparency and thus was unacceptable. Finally, their insistence that the Tsuda et al. study was an ecological study susceptible to "the ecological fallacy" indicated their lack of epidemiological knowledge about ecological studies. Ironically, many of the papers cited by Cléro et al. regarding overdiagnosis were, in fact, ecological studies. Conclusion: Cléro et al. and the SHAMISEN Consortium should withdraw their recommendation "not to launch a mass thyroid cancer screening after a nuclear accident, but rather to make it available (with appropriate information counselling) to those who request it." Their recommendation is based on biased evidence and would cause confusion regarding public health measures following a nuclear accident. Those authors should, in my assessment, acquaint themselves with modern epidemiology and evidence-based public health. Like Tsuda et al. recommended of Schüz et al., Cléro et al. ought also to retract their article. [ABSTRACT FROM AUTHOR]

With combined use of the ocean-atmosphere simulation models and field observation data, we evaluate the parameters associated with the total caesium-137 amounts of the direct release into the ocean and atmospheric deposition over the Western North Pacific caused by the accident of Fukushima Daiichi nuclear power plant (FNPP) that occurred in March 2011. The Green's function approach is adopted for the estimation of two parameters determining the total emission amounts for the period from 12 March to 6 May 2011. It is confirmed that the validity of the estimation depends on the simulation skill near FNPP. The total amount of the direct release is estimated as 5.5-5.9x1015 Bq, while that of the atmospheric deposition is estimated as 5.5-9.7x1015 Bq, which indicates broader range of the estimate than that of the direct release owing to uncertainty of the dispersion widely spread over the Western North Pacific. [ABSTRACT FROM AUTHOR]

The Anthropocene denotes an era of accelerated human impact on the environment. Although discourses of the Anthropocene are often criticized for representing colonial and specifically capitalist interests of economic growth, this paper examines, in the case of Ukraine, how these discourses can be applied to uncover and address social (post)colonial impacts of non-capitalist regimes (those also not classified as "Global North"). In particular, the analysis focuses on the aftermath of the 1986 Chernobyl nuclear plant accident on local communities in Ukraine. As academics of Ukrainian background, authors share their first-hand experiences of such impact on their lives and wellbeing of their families, communities, and land. The narrative research framework is used to engage with the modern Ukrainian community and discuss the implications of geopolitical and cultural proximity of the coloniser, with a particular focus on displacement and forced migration. This is especially relevant as it is reflected in the current refugee crisis and tactics of nuclear terrorism used by the Russian government in the war against Ukraine. This paper is a valuable resource for promoting and giving a voice to the Ukrainian people and potentially other peoples in post-Soviet space to unveil their colonial legacy and utilise the discourses of the Anthropocene to aid more effective decolonisation processes in the future of the region. [ABSTRACT FROM AUTHOR]

People's perceptions concerning radiation inform decision making in relation to nuclear power production. There have been extensive studies of people's perceptions of radiation including in relation to the Fukushima and Chernobyl nuclear events. This paper reports on a social science literature review study and is concerned with public responses to low dose radiation (LDR) and nuclear facilities, particularly in the marine environment. This review confirms that people with little knowledge about radiation have the highest risk perceptions in relation to nuclear power; conversely people with a broader knowledge have lower risk perceptions and are more favourable to nuclear power. Education can increase positive perceptions, but the influence of underlying experience of feeling, emotion, attachment, or mood may dampen this effect. This paper reports studies which document anxiety within the Japanese community in relation to the Fukushima nuclear accident. Literature concerning specific radionuclides released is described. While there are uncertainties about the presence of health impacts following LDR exposures, public attitudes are not in line. There is a need for better dialogue between nuclear professionals and scientists to achieve better nuclear education and public communication outcomes; more specific communication surrounding multi-isotopes, and multi-elements of nuclear power plant disaster releases is warranted. Trusted communicators should include nuclear and social scientists as well as regulators. Given the importance of decarbonization in the context of climate change, this is increasingly important. [ABSTRACT FROM AUTHOR]

This paper investigates the relationship between political constraint and investor perception of policy risk using an analysis of the reaction of Australian and Canadian uranium company stocks to the Fukushima nuclear disaster in 2011. Our dataset traces 933 projects of 322 uranium firms located across 36 countries and posits a U-shaped relationship between political constraint and investor perceptions of policy risk. Using an event study methodology as applied to the natural quasi-experiment arising from the event, we link heterogeneous changes in stock returns to the policy risk in the uranium project locations of the firms. The results corroborate the expected relationship and hold even after we control for home-country bias. [ABSTRACT FROM AUTHOR]

Spatiotemporal distributions of anthropogenic radionuclides in surface sediments off Miyagi, Fukushima, and Ibaraki Prefectures were analyzed on the basis of data collected during the monitoring program launched by the Japanese Ministry of Education, Sports, Science and Technology in 2011 right after the Fukushima Nuclear Power Plant accident. Concentrations of 137Cs in the surface sediments varied spatially by two orders of magnitude from 1.7 to 580 Bq kg-dry-1, and there was no obvious correlation between 137Cs concentration and the proximity of the sampling location to the site of the accident. The total inventory of 137Cs accumulated in the upper 3 cm of surface sediment in the monitoring area was estimated to be 3.78x1013 Bq, that is 0.1-2% of the total 137Cs flux from the plant to the ocean as a result of the accident (the percentage depends on the model used to estimate the total flux). The spatial variations of 137Cs concentration and inventory depended on two main factors: the 137Cs concentration in the overlying water during the first several months after the accident and the physical characteristics of the sediment (water content and bulk density). The tem-poral variations of the concentrations of other anthropogenic radionuclides (90Sr, 95Nb, 110mAg, 125Sb, 129Te, and 129mTe) in the sediments were also investigated. The temporal variations of the activity ratios of these nuclides to 137Cs suggest that before the Fukushima-derived nuclides became homogeneous in seawater, they were removed from the water to the sediment. [ABSTRACT FROM AUTHOR]

Effects of a heavy rain event on radiocesium export were studied at stations on the Natsui River and the Same River in Fukushima Prefecture, Japan after Typhoon Roke during 21-22 September 2011, six months after the Fukushima Daiichi Nuclear Power Plant accident. Radioactivity of 134Cs and 137Cs in river waters was 0.011- 0.098 Bq L-1 at normal flow conditions during July-September in 2011, but it increased to 0.85 Bq L-1 in high flow conditions by heavy rains occurring with the typhoon. The particulate fractions of 134Cs and 137Cs were 21-56% in the normal flow condition, but were close to 100% after the typhoon. These results indicate that the pulse input of radiocesium associated with suspended particles from land to coastal ocean occurred by the heavy rain event. Export flux of 134Cs and 137Cs by the heavy rain accounts for 30-50% of annual radiocesium flux in 2011. Results show that rain events are one factor controlling the transport and dispersion of radiocesium in river watersheds and coastal marine environments. [ABSTRACT FROM AUTHOR]

Following the failure of the nuclear power plant in Fukushima Prefecture in March 2011, peer-reviewed publications describing radioactivity levels in organisms inhabiting coastal environments are scarce. This paper reports on elevated levels of 134Cs and 137Cs in macroalgae and mussels (up to ~800 Bq kg-1 drywt.) in June 2011. Cs concentrations in biota sampled in early June 2011 were higher in areas south of Fukushima than sampled in the last third of the month north of Fukushima. Radioactivity from 134+137Cs in organisms south of Fukushima were comparable to or lower than that from the naturally occuring 40K in the same samples. While 210Pb and Po concentrations were generally lower than these other radionuclides, 210Po as an α-emitter is more significant from a radiological viewpoint than γ-emitters as it can inflict greater biological damage. By applying known bioconcentration factors of Cs in biota, measured biota concentrations of Cs were also used to estimate Cs concentraitons in coastal seawater to be in the range of 10²-10³ Bqm-3. These estimates show that 3 months after the accident and maximal release of radioactive Cs, levels of Cs persisted in coastal waters, although at levels that were two orders of magnitude lower than at the time of release. These June coastal seawater Cs levels were four orders of magnitude above Cs concentrations off Japan prior to the Fukushima disaster. [ABSTRACT FROM AUTHOR]

The impact of the earthquake and tsunami in the east coast of Japan in 11 March 2011 caused a loss of power at the Fukushima Dai-ichi Nuclear Power Plant (NPP) that resulted in one of the most important releases of artificial radioactivity to the environment. Although several works were devoted to evaluate the atmospheric dispersion of radionuclides, the impact of the discharges to the ocean has been less investigated. Here we evaluate the distribution of Fukushima-derived 90Sr and 89Sr throughout waters 30-600 km offshore in June 2011. Concentrations of 90Sr and 89Sr in both surface waters and shallow profiles ranged from 0.8 ± 0.2 to 85 ± 3 Bq m-3 and from 19 ± 6 to 265 ± 74 Bq m-3, respectively. Because of its short half-life, all measured 89Sr was due to the accident, while the 90Sr concentrations can be compared to the background levels in the Pacific Ocean of about 1.2 Bq m-3. Fukushima-derived radiostrontium was mainly detected north of Kuroshio Current, as this was acting as a southern boundary for transport. The highest activities were associated with near-shore eddies, and larger inventories were found in the closest stations to Fukushima NPP. The data evidences a major influence of direct liquid discharges of radiostrontium compared to the atmospheric deposition. Existing 137Cs data reported from the same samples allowed us establishing a 90Sr/137Cs ratio of 0.0256 ± 0.0006 in seawater off Fukushima, being significantly different than that of the global atmospheric fallout (i.e. 0.63) and may be used in future studies to track waters coming from the east coast of Japan. Liquid discharges of 90Sr to the ocean were estimated, resulting in an inventory of 53 ± 1 TBq of 90Sr in the inshore study area in June 2011 and total releases of 90Sr ranging from 90 to 900 TBq, depending upon the reported estimates of 137Cs releases that are considered. [ABSTRACT FROM AUTHOR]

The United States Nuclear Regulatory Commission issued requests for licensees to re-evaluate the seismic hazards at their sites after the accident at the Fukushima Daiichi Nuclear Power Plant in Japan on March 11 in 2011 and to identify and address any site-specific vulnerabilities associated with seismic hazards. The primary guidance for performing those evaluations is provided in the Electric Power Research Institute EPRI-1025287 report, which also provides guidance for evaluating spent fuel pool (SFP) integrity. In addition, the EPRI-3002009564 report also provides evaluation approaches regarding the effects of seismic ground motions on SFPs that supplement the guidance provided in EPRI-1025287. SFP integrity has become increasingly important for active and decommissioned nuclear power plants. According to EPRI-1025287, the SFP integrity evaluation emphasizes failure modes of the SFP that could result in "rapid drain-down." The definition of "rapid drain-down" is a failure that could lead to the uncovering of irradiated fuel stored in the SFP within 72 h of an earthquake. Possible failures can be classified into two categories: failures relevant to the SFP structure and failures relevant to non-structural elements. This paper aims to study the approaches of implementing seismic evaluation of an SFP structure. EPRI-3002009564 provides separate seismic evaluation approaches for plants with a ground motion response spectrum (GMRS) peak Sa ≤ 0. 8 g and for plants with a GMRS peak Sa > 0. 8 g. Structural dynamic analysis is also a common approach for implementing seismic evaluation if a detailed finite element model is available. In this paper, a sample SFP structure was evaluated using the two approaches, structural dynamic analysis and structural analysis criteria. The results indicate that shear failure controlled the failure mode of the SFP structure for both approaches. This shows that the two approaches drew the same conclusion regarding the failure mode. Furthermore, a smaller seismic margin was obtained using the structural analysis criteria, which means this evaluative approach is more conservative. [ABSTRACT FROM AUTHOR]

One of the impacts of the Fukushima disaster was the shutdown of all nuclear power plants in Japan, reaching zero production in 2015. In response, the country started importing more fossil energy including coal, oil, and natural gas to fill the energy gap. However, this led to a significant increase in carbon emissions, hindering the efforts to reduce its carbon footprint. In the current situation, Japan is actively working to balance its energy requirements with environmental considerations, including the utilization of hydrogen fuel. Therefore, this paper aims to explore the feasibility and implications of using hydrogen power plants as a means to reduce emissions, and this analysis will be conducted using the energy modeling of the MARKAL-TIMES Japan framework. The hydrogen scenario (HS) is assumed with the extensive integration of hydrogen into the power generation sector, supported by a hydrogen import scheme. Additionally, this scenario will be compared with the Business as Usual (BAU) scenario. The results showed that the generation capacities of the BAU and HS scenarios have significantly different primary energy supplies. The BAU scenario is highly dependent on fossil fuels, while the HS scenario integrates hydrogen contribution along with an increase in renewable energy, reaching a peak contribution of 2,160 PJ in 2050. In the HS scenario, the target of reducing CO2 emissions by 80% is achieved through significant hydrogen penetration. By 2050, the total CO2 emissions are estimated to be 939 million tons for the BAU scenario and 261 million tons for the Hydrogen scenario. In addition, the contribution of hydrogen to electricity generation is expected to be 153 TWh, smaller than PV and wind power. [ABSTRACT FROM AUTHOR]

This paper presents a comprehensive analysis of the suitability of nuclear power as an option to combat the escalating climate emergency. Summarizing and evaluating key arguments, we elucidate why nuclear power is unsuitable for addressing climate change. The primary argument centers around the unresolved technical and human risks of accidents and proliferation, which are unlikely to be effectively mitigated in the future. Furthermore, we highlight the significant cost disparities between nuclear power and other non-fossil energy sources, such as solar photovoltaics and wind power, considering levelized costs of electricity. We also address the incompatibility of nuclear power with renewable energy systems, emphasizing the need for flexibility in the face of variable solar and wind resources. Alternative reactor technologies will not be available in time to make a major contribution. Nuclear power also poses challenges in power plant operation amid climate change and war. Ultimately, we argue that other motivations should be explored to explain the continued interest in nuclear power in some countries, as energy supply arguments alone are insufficient to justify new investments. [ABSTRACT FROM AUTHOR]

In 1985, British psychoanalyst Hanna Segal delivered the paper 'Silence is the Real Crime' to the first meeting of the group International Psychoanalysts Against Nuclear Weapons in Hamburg, appealing to her fellow analysts to counteract the denial of the geopolitical realities that characterized the late Cold War by intervening in public debates regarding the threat of nuclear war. A year later she gave a paper in London discussing clinical cases of patients who brought their nuclear anxieties to the couch. This article considers Segal's political and clinical writings on the psychological consequences of the atomic age, situating them in the context in which she was living, writing and practising as an analyst: 1980s Britain in a moment of 'nuclear anxiety'. I argue that Segal's anti-nuclear writings shed light on what she called the 'very very tricky' relationship between psychoanalysis and politics. Segal confronted the tension between maintaining clinical neutrality in the consulting room while publicly expressing her political commitments, wrestling with the complex relationships between individuals and the societies in which they live. [ABSTRACT FROM AUTHOR]

Radionuclide impact of the Fukushima Dai-ichi nuclear power plant accident on the distribution of radionuclides in seawater of the NW Pacific Ocean is compared with global fallout from atmospheric tests of nuclear weapons. Surface and water column seawater samples collected during the international expedition in June 2011 were analyzed for 134Cs, 137Cs, 129I and ³H. The 137Cs, 129I and 3H levels in surface seawater offshore Fukushima varied between 0.002--3.5 Bq L-1, 0.01--0.8 µ Bq L-1, and 0.05--0.15 Bq L-1, respectively. At the sampling site about 40 km from the coast, where all three radionuclides were analyzed, the Fukushima impact on the levels of these three radionuclides represent an increase above the global fallout background by factors of about 1000, 30 and 3, respectively. The water column data indicate that the transport of Fukushimaderived radionuclides downward to the depth of 300 m has already occurred. The observed 137Cs levels in surface waters and in the water column are in reasonable agreement with predictions obtained from the Ocean General Circulation Model, which indicates that the radionuclides have been transported from the Fukushima coast eastward. The 137Cs inventory in the water column (the area from 34 to 37° N, and from 142 to 147° E) due to the Fukushima accident is estimated to be about 2.2 PBq. The amount of 129I and ³H released and deposited on the NW Pacific Ocean after the Fukushima accident was estimated to be about 7 GBq and 0.1 PBq, respectively. Due to a suitable residence time in the ocean, Fukushima-derived radionuclides will provide useful tracers for isotope oceanography studies on the transport of water masses in the NW Pacific Ocean. [ABSTRACT FROM AUTHOR]

Rate of cesium-137 (137Cs) release to the sea from the Fukushima Dai-ichi Nuclear Power Plant was estimated until September 2012. Based on publicly released data of 137Cs in seawater near the power plant by Tokyo Electric Power Company, a continuing release of radionuclides to the sea is strongly suggested. The plant has an artificial harbour facility, and the exchange rate of harbour water with surrounding seawater was estimated by decrease of radioactivity immediately after an intense event of radioactive water release. The estimated exchange rate of water in the harbour is 0.44 day-1 during the period from 6 to 19 April 2011. 137Cs radioactivity of the harbour water is substantially higher than seawater outside and remained relatively stable after June 2011. A quasi-steady state was assumed with continuous water exchange, and an average release rate of 137Cs was estimated to be 93 GBq day-1 in summer 2011 and 8.1 GBq day-1 in summer 2012. [ABSTRACT FROM AUTHOR]

At two stations in the western North Pacific, K2 in the subarctic gyre and S1 in the subtropical gyre, time-series sediment traps were collecting sinking particles when the Fukushima Daiichi Nuclear Power Plant (FNPP1) accident occurred on 11 March 2011. Radiocesium (134Cs and 137Cs) derived from FNPP1 accident was detected in sinking particles collected at 500m by late March 2011 and at 4810m by early April 2011 at both stations. The sinking velocity of 134Cs and 137Cs was estimated to be 8 to 36m day-1 between the surface and 500m and > 180m day-1 between 500m and 4810m. 137Cs specific activity varied from 0.14 to 0.25 Bq g-1 dry weight. These values are higher than those of surface seawater, suspended particles, and zooplankton collected in April 2011. Although the radiocesium may have been adsorbed onto or in- corporated into clay minerals, correlations between 134Cs and lithogenic material were not always significant; therefore, the form of the cesium associated with the sinking particles is still an open question. The total 137Cs flux by late June at K2 and by late July at S1 was 0.5 to 1.7 Bq m-2 at both depths. Compared with 137Cs input to both stations by April 2011, estimated from the surface 137Cs activity and mixed layer depth and by assuming that the observed 137Cs flux was constant throughout the year, the estimated removal rate of 137Cs from the upper layer (residence time in the upper layer) was 0.3 to 1.5% (68 to 312 yr). The estimated removal rates and residence times are comparable to previously reported values. [ABSTRACT FROM AUTHOR]

Radium has four naturally occurring isotopes that have proven useful in constraining water mass source, age, and mixing rates in the coastal and open ocean. In this study, we used radium isotopes to determine the fate and flux of runoff-derived cesium from the Fukushima Nuclear Power Plant (NPP). During a June 2011 cruise, the highest Cs concentrations were found along the eastern shelf of northern Japan, from Fukushima south, to the edge of the Kuroshio current, and in an eddy ~130 km from the NPP site. Locations with the highest cesium also had some of the highest radium activities, suggesting much of the direct ocean discharges of Cs remained in the coastal zone 2-3 months after the accident. We used a short-lived Ra isotope ( 223Ra, t1/2 = 11.4 d) to derive an average water mass age (Tr) in the coastal zone of 32 days. To ground-truth the Ra age model, we conducted a direct, station-by-station comparison of water mass ages with a numerical oceanographic model and found them to be in excellent agreement (model avg. Tr = 27days). From these independent Tr values and the inventory of Cs within the water column at the time of our cruise, we were able to calculate an offshore 134 Cs flux of 3.9-4.6x1013 Bq d-1. Radium-228 (t1/2 = 5.75 yr) was used to derive a vertical eddy diffusivity (Kz) of 0.7m² d-1 (0.1 cm² s-1); from this Kz and 134Cs inventory, we estimated a 134 Cs flux across the pycnocline of 1.8x104 Bq d-1 for the same time period. On average, our results show that horizontal mixing loss of Cs from the coastal zone was ~109 greater than vertical exchange below the surface mixed layer. Finally, a mixing/dilution model that utilized our Ra-based and oceanographic model water mass ages produced a direct ocean discharge of 134Cs from the FNPP of 11-16 PBq at the time of the peak release in early April 2011. Our results can be used to calculate discharge of other water-soluble radionuclides that were released to the ocean directly from the Fukushima NPP. [ABSTRACT FROM AUTHOR]

Huge amounts of radionuclides, especially 137Cs, were released into the western North Pacific Ocean after the Fukushima nuclear power plant (FNPP) accident that occurred on 11 March 2011, resulting in contamination of the marine biota. In this study we developed a radioecological model to estimate 137Cs concentrations in phytoplankton and zooplankton populations representing the lower levels of the pelagic trophic chain. We coupled this model to a lower trophic level ecosystem model and an ocean circulation model to take into account the site-specific environmental conditions in the area. The different radioecological parameters of the model were estimated by calibration, and a sensitivity analysis to parameter uncertainties was carried out, showing a high sensitivity of the model results, especially to the 137Cs concentration in seawater, to the rates of uptake from water and to the radionuclide assimilation efficiency for zooplankton. The results of the 137Cs concentrations in planktonic populations simulated in this study were then validated through comparison with the some data available in the region after the accident. The model results have shown that the maximum concentrations in plankton after the accident were about two to four orders of magnitude higher than those observed before the accident depending on the distance from FNPP. Finally, the maximum 137Cs absorbed dose rate for phyto- and zooplankton populations was estimated to be about 10−2 μGy h−1, and was, therefore, lower than the 10 μGy h−1 benchmark value defined in the ERICA assessment approach from which a measurable effect on the marine biota can be observed. [ABSTRACT FROM AUTHOR]

After the Fukushima nuclear accident, the development of new accident-tolerant fuel cladding materials has become a research hotspot around the world. Due to its outstanding corrosion resistance, radiation resistance, and creep properties at elevated temperatures, the oxide dispersion strengthened (ODS) FeCrAl alloy, as one of the most promising candidate materials for accident-tolerant fuel cladding, has been extensively studied during the past decade. Recent research on chemical composition design as well as its effects on the microstructure and mechanical properties has been reviewed in this paper. In particular, the reasonable/optimized content of Cr is explained from the aspects of oxidation resistance, radiation resistance, and thermal stability. The essential role of the Al element in oxidation resistance, high-temperature stability, and workability was reviewed in detail. The roles of oxide-forming elements, i.e., Y (Y2O3), Ti, and Zr, and the solid solution strengthening element, i.e., W, were discussed. Additionally, their reasonable contents were summarized. Typical types of oxide, i.e., Y–Ti–O, Y–Al–O, and Y–Zr–O, and their formation mechanisms were also discussed in this paper. All aspects mentioned above provide an important reference for understanding the effects of composition design parameters on the properties of nuclear-level ODS FeCrAl alloy. [ABSTRACT FROM AUTHOR]

This paper focuses on the issues of international law involved in discharging of nuclear contaminated water from a nuclear accident into the sea, taking Japan as an example, and proposes a pathway for marine environmental cooperation as a reference for regional States and the international community. Specifically, this paper first examines the current situation of the discharge of contaminated water from the nuclear accident in Japan. Secondly, we explore the negative effect of discharging contaminated water from the nuclear accident into the sea, particularly its impact on the marine environment and marine industries. Thirdly, we analyze the dilemma faced by the current system of international law in regulating the discharge of contaminated water from the nuclear accident into the sea. Fourthly, we illustrate the potential responsibilities of the NACW discharging States. Finally, the article takes international cooperation as the principal means and proposes several detailed ways to establish and develop the regulation regarding the discharge of contaminated water from the nuclear accident into the sea. [ABSTRACT FROM AUTHOR]

Anthropogenic radionuclides were released into the environment in large quantities by the Fukushima Daiichi Nuclear Power Plant (1FNPP) accident. To evaluate accident- derived 129I, the 129I concentrations in seawater before and after the accident were compared.-2010), the 129I concentrations in the western margin of the North Pacific between 36° N and 44° N showed a latitudinal gradient that was expressed as a linear function of latitude. The highest and average 129I concentrations after the accident were 73 times and approximately 8 times, respectively, higher than those before the accident in this study area. Considering the distribution of 129I in surface seawater, the accident-derived 129I in the southern and northern stations of the 1FNPP was predominantly supplied by seawater advection and atmospheric deposition, respectively. As of October 2011, depth profiles of 129I revealed that 129I originating from the 1FNPP existed mainly in the upper 100m depth. From the depth profiles, the cumulative inventories of accident-derived 129I were estimated to be (1.8-9.9) x 1012 atoms m-2 in this study area. On the basis of the 129I data in the seawater near Fukushima, the effective dose of 129I from seafood ingestion was much smaller than the annual dose limit. [ABSTRACT FROM AUTHOR]

Summary: The Extensive Damage Mitigation Guideline (EDMG), which was developed by the U.S. Nuclear Energy Institute (NEI) owing to the motivation of 911 terrorist attacks and not allowed to spread before the Fukushima nuclear accident, was publicly available after Fukushima nuclear accident and paid attention to worldwide. Many countries have adopted the U.S. EDMG methodology and developed their strategies (some are not called EDMG but have similar functions), planning to introduce it into the emergency plans of their domestic nuclear power plants (NPPs). Based on the defense‐in‐depth (DID) concept of nuclear safety, the experience of the Fukushima nuclear accident, and the state‐of‐the‐art of EDMGs research, this paper will give a comprehensive review of EDMG. To illustrate the reason for the introduction of EDMG into the traditional NPP procedures/guidelines, the review work started from the perspective of DID in nuclear safety and the reason for the Fukushima nuclear accident from the viewpoint of DID, which showed the weaknesses of DID implementation strategy ‐ underestimation of the damage during a beyond‐design‐basis external event (BDBEE). EDMG is crucial complementary for the old framework of procedures/guidelines to enhance the concept of DID. The research progress of EDMG in different countries has been reviewed and a rough comparison has been made among them according to the present state‐of‐the‐art from literature. The methodology of EDMG is summarized as follows: (a) Loss of Large Area (LOLA) ‐ the originally designed scenario for EDMG; (b) elements of EDMG ‐ the summarized contents for EDMG implementation; (c) classification of EDMG ‐ initial response EDMGs and Technical Support Center (TSC) response EDMGs; (d) implementation of EDMG‐introduction of three phases of EDMG implementation step by step. Furthermore, three typical methods to integrate EDMG into the traditional procedures/guidelines are reviewed. Finally, this paper gives some concluding remarks for EDMG‐related critical issues and recommended future work, which may be challenges for the development and application of EDMG and useful for the related researchers. Novelty Statement: The studies of the extensive damage mitigation guideline (EDMG), its methodology, and the progress in different countries have been reviewed.Three typical methods to integrate EDMG into the traditional procedures/guidelines are summarized and reviewed.Concluding remarks for EDMG‐related critical issues and recommended future work are summarized. [ABSTRACT FROM AUTHOR]

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This paper's theme "Creative Robot Contest for Decommissioning (hereinafter, this Creative Robot Contest)" may be called a contest that would never have been planned in the absence of the Great East Japan Earthquake on March 11, 2011 and the core meltdown accident at Fukushima Daiichi Nuclear Power Plant of Tokyo Electric Power Company. When it was decided to decommission the nuclear reactors, their decommissioning was immediately put in hand, which, however, met with a high barrier of high radiation doses unconquerable even by the modern science and technologies. In order to advance the stagnating decommissioning work and in hopes of some creative breakthrough ideas from KOSEN students, this Robot Contest, first held in 2016, has been held by KOSEN teams who have shown their willingness to participate in it as a venue useful to address any difficulties they will face in the real world or as teaching material for them to consider social problems. This Robot Contest, sponsored by the Japan Atomic Energy Agency and the Council of Technical Colleges for Human Resource Development for Decommissioning, is planned and managed by the Executive Committee of Creative Robot Contest for Decommissioning (hereinafter, the Executive Committee) with its secretariat at National Institute of Technology, Fukushima College (hereinafter, Fukushima KOSEN) in Fukushima Prefecture where Fukushima Daiichi Nuclear Power Plant is located. In this paper, teachers at Osaka Metropolitan University College of Technology (hereinafter, Osaka Metropolitan University KOSEN) and at Nara National College of Technology, Nara College (hereinafter, Nara KOSEN), whose respective teams have participated in this Robot Contest every year from the first one, and teachers at Fukushima KOSEN who organize and manage the executive committee describe their own views on this Robot Contest based on their viewpoints as KOSEN educators. In the first half, this paper reviews this Robot Contest and outlines the robots of Osaka Metropolitan University KOSEN which participated in it in FY2016 and FY2017 and of Nara KOSEN which did in FY2016. In the latter half, this paper describes the views of the KOSEN teachers who educate engineers in the framework of robot contests from the viewpoints of the teachers who have instructed the teams of Osaka Metropolitan University KOSEN and Nara KOSEN who have participated in this Robot Contest up to the sixth one and who have held this Robot Contest. [ABSTRACT FROM AUTHOR]

Fillet samples of marine fish collected from the East/West Greenland current (GC) and from the Baltic Sea (BS), have been investigated by gamma-ray spectrometry within the regular German monitoring program. In samples of the second half of 2011 134Cs traces have been detected, suggested to originate from the Fukushima fallout being deposited in March/April 2011 over the northern North Atlantic and accumulated by fish. The radionuclide 134Cs (half-live 2 yr) was indeed detected with quite small activities at about 0.0036 Bqkg-1 w.w. Existing box-models describing the transport of Cs within seawater boxes of the NE Atlantic allowed estimating that 134Cs contributions from other sources, i.e. from the Chernobyl fallout and from discharges by the two major European nuclear reprocessing plants, both were negligible around Greenland, while for the Chernobyl fallout a small 134Cs background contribution to BS fish was estimated. Model results confirmed the level of 134Cs measured in BS fish and showed its maximum to have occurred in winter 2011/2012 followed by a continuous decrease. It was also determined that 134Cs activity, but not that of 137Cs, showed a significant negative correlation with sampling depth (150-400 m) of GC fish; this strengthens our Fukushima fallout assumption. As a result, the Fukushima fallout in these sea areas only marginally enhanced (GC: 4 %; BS: 0.1 %) pre-Fukushima levels of individual dose rates received by human fish consumers; the addition was around 0.001 µSv following the consumption of 10 kg fish per year, which is not expected to cause concern according to present guidelines for radiation protection. [ABSTRACT FROM AUTHOR]

The horizontal distribution of radioactive cesium (Cs) derived from the Fukushima Dai-ichi Nuclear Power Plant (FNPP) in the North Pacific is still unclear due to the limitation of direct measurement of the seawater in the open ocean. We present the result of direct observation of radioactive Cs in surface seawater collected from broad area in the western and central North Pacific in July, October 2011 and July 2012. We also conducted a simple particle tracking experiment to estimate the qualitative spatial distribution of radioactive Cs in the North Pacific. 134Cs were detected at 94 stations out of 123 stations and 137Cs was detected at all stations. The high 134Cs and 137Cs concentrations more than 10mBq kg-1 were observed in the area where the northern part of Kuroshio extension at 144° E and 155° E in July 2011, in the area 147° E-175° E around 40° N in October 2011, and the northern part of Kuroshio extension at 155° E and 175° 30' E in July 2012. Combining the result of direct observations and particle tracking experiment, the radioactive Cs derived from FNPP had been dispersed eastward to the central North Pacific during 2011. It was considered from the horizontal distribution that radioactive Cs was dispersed not only eastward but also north- and southward in the central North Pacific. Pronounced dilution process of radioactive Cs from FNPP during study period is suggested from temporal change in the activity ratio of 134Cs/137Cs which was decay corrected at 6 April 2011, and relationships between radioactive Cs and temperature. [ABSTRACT FROM AUTHOR]

The Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident led to the release of large amounts of radionuclides into the atmosphere as well as direct discharges into the sea. In contrast to the intensive studies on the distribution of the released high volatility fission products, such as 131I, 134Cs and 137Cs, similar studies of the actinides, especially the Pu isotopes, are limited. To obtain the vertical distribution of Pu isotopes in marine sediments and to better assess the possible contamination of Pu from the FDNPP accident in the marine environment, we determined the activities of 239+240Pu and 241Pu as well as the atom ratios of 240Pu/239Pu and 241Pu/239Pu in sediment core samples collected in the western North Pacific off Fukushima from July 2011 to July 2012. We also measured surface sediment samples collected from seven Japanese estuaries before the FNDPP accident to establish the comprehensive background baseline data. The observed results of both the Pu activities and the Pu atom ratios for the sediments in the western North Pacific were comparable to the baseline data, suggesting that the FDNPP accident did not cause detectable Pu contamination to the studied regions prior to the sampling time. The Pu isotopes in the western North Pacific 30 km off Fukushima coast originated from global fallout and Pacific Proving Ground close-in fallout. [ABSTRACT FROM AUTHOR]

Following the Fukushima Daiichi Nuclear Power Plant accident, a survey for estimating individual external doses for the first 4 months after the accident was started, and it remains ongoing. Since the authors' previous paper, 44 605 new dose estimates have been made. The new dose estimates increase the number of dose estimates to 465 999 and are reported in this note. Since the previous paper, most of the recently collected responses have been gotten through public relations activities to encourage responses across the prefecture. Thus, recent respondents might be biased ('selection bias'). Also, the dose estimates were based on self-administered responses about personal behaviour, which relied on memories of residents. In this respect, incorrect behaviour records possibly resulted as memories have faded over time ('recall bias'). However, the effects of these biases on dose distribution on a whole-prefecture basis seemed to be small. [ABSTRACT FROM AUTHOR]

Robots usually carry out rescue tasks after nuclear accidents due to harsh environmental conditions such as radiation, high temperatures, and pressure. The assignment of rescue robots is a crucial aspect of this study, serving as a preliminary step in multi-robot task allocation. Its primary objective is to allocate robots to different groups based on the distribution of tasks. This paper models robot assignment as a multi-objective optimization problem by considering total execution time, regional load balance degree, and total transfer time. An improved hypervolume estimated multi-objective evolutionary algorithm (IHypE) is proposed. An encoding method is devised to represent the assignment of the robots. A corner-point-based hypervolume approximation method is proposed to efficiently measure the quality of each solution. An environmental selection that is more applicable to this problem is developed. In the experimental section, we conduct a comparative analysis between the proposed method and four state-of-the-art algorithms, namely MMODE-ICD, MOEA/D-2TH, NSGA-II, and SPEA2SDE. This comparison is performed on nine instances with varying scales. By evaluating the algorithm's performance using five evaluation indicators, including hypervolume, inverse generational distance, C-Metric, Spacing, and Spread, we demonstrate the competitiveness of the proposed algorithm in terms of convergence and diversity. [ABSTRACT FROM AUTHOR]

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Following Russia's invasion of Ukraine in February 2022 there has been renewed attention on the security and protection of civilian nuclear infrastructure. This has been a longstanding issue in Pakistan, where the security of the country's nuclear estate has attracted considerable international attention for decades. However, rather than looking at Pakistan's civilian estate, assessments have instead prioritised the security of the country's nuclear arsenal. They have also been widely divergent: Western analysts have raised serious concerns over Pakistan's ability to secure sensitive nuclear materials, the country's domestic instability and its poor non-proliferation history. In contrast Pakistani officials downplay these risks, and point to various programmes of reform. Against this backdrop, this article reviews the available literature on Pakistan's civilian nuclear security regime and provides new insights by benchmarking developments against key elements of IAEA guidance. It concludes that Pakistan's civilian nuclear security regime is largely consistent with accepted international principles and approaches, although there are still areas where improvements in transparency would help the completeness of available information and the external evaluation of the country's regime. The paper also identifies several areas where improvements could be made, most notably in the promotion of cyber security and nuclear security culture. [ABSTRACT FROM AUTHOR]

In the frame of the France-Japan agreement on nuclear collaboration, a bilateral collaboration agreement on nuclear energy was signed on March 21st, 2017, including a topic dedicated to Sodium-cooled Fast Reactor (SFR). This agreement has set the framework to start a bilateral discussion on a joint view of an SFR concept. France (CEA and FRAMATOME) and Japan (JAEA, MHI and MFBR) have carried out these studies from 2017 to 2019. Based on the beginning of the basic design phase of ASTRID project − ASTRID − 600 MWe (ASTRID for Advanced Sodium Technological Reactor for Industrial Demonstration), the two countries performed a common work to examine ways to develop a feasible common design concept, which could be realized both in France and in Japan. The subject was then extended and extrapolated with the ASTRID − 150 MWe data (reduced power reactor and enhanced experimental capabilities) in a second phase of this study. France and Japan first focused on design requirements. Common requirements were identified, as well as differences in the safety approach and the structural design requirements, according to national standards and respective site conditions, in particular considering seismic hazards. The teams developed common Top-Level design Requirements (TLRs) to allow common specification data, then joint design. This collaborative work was carried out through the implementation of twelve France-Japan Working Groups, working jointly. This paper is providing a review of this joint synthesis on Sodium Fast Reactor design concept. It is summarizing the context and objectives, then the definition and approaches of the Top Level Requirements. This paper is then dealing with the major design features: the core design and their related safety aspects, and the nuclear island design. Thus, this paper is providing a comprehensive review of this joint work gathering French and Japan nuclear design teams during two full years. [ABSTRACT FROM AUTHOR]

With Japan's thrust towards a more balanced energy mix, it has been undergoing what can be termed as an energy transition. While the Fukushima Disaster has played a crucial role in this transition, the Paris Agreement has further acted as an impetus for the same. However, since 2012 Japan was under the political leadership of Shinzo Abe, who today is the longest-serving Prime Minister of Japan until Yoshihide Suga took over the prime ministership recently. Under Abe's guidance, Japan's energy policy has been a mixed bag with a few hits and some major misses. Now, as Japan welcomes its new Prime Minister Suga, it falls upon him to lead Japan on a path of just transition. One which balances its energy and economic goals and pays heed to the necessity of building a climate-friendly sustainable model. This paper maps and evaluates the Abe administration's broad energy policy measures and attempts to foresee the changes Suga administration can introduce to the ongoing energy transition of Japan. It also highlights the areas within the energy sector, which might require the focus of PM Suga to enable Japan to take advantage of the opportunity of making Japan a part of global green leadership. [ABSTRACT FROM AUTHOR]

Surface seawater 134Cs and 137Cs samples were collected in the central and western North Pacific Ocean during the 1.5 yr after the Fukushima Dai-ichi nuclear power plant accident to monitor dispersion patterns of these radioisotopes towards the Hawaiian Islands. In the absence of other recent sources and due to its short half-life only those parts of the Pacific Ocean would have detectable 134Cs that were impacted by Fukushima releases. Between March and May 2011, 134Cs was not detected around the Hawaiian Islands and Guam. Here, most 137Cs activities (1.2-1.5 Bqm-3) were in the range of expected preexisting levels. Some samples north of the Hawaiian Islands (1.6-1.8 Bqm-3) were elevated above the 18-month baseline established in surface seawater in Hawaii indicating that those might carry atmospheric fallout. The 18-month time-series analysis of surface seawater from Hawaii did not reveal any seasonal variability or trends, with an average activity of 1.46±0.06 Bqm-3 (Station Aloha, 17 values). In contrast, samples collected between Japan and Hawaii contained 134Cs activities in the range of 1-4 Bqm-3 and 137Cs levels were about 2-3 times above the pre-existing activities. We found that the southern boundary of the Kuroshio and Kuroshio extension currents represented a boundary for radiation dispersion with higher activities detected within and north of the major currents. The radiation plume has not been detected over the past 1.5 yr at the main Hawaiian Islands due to the transport patterns across the Kuroshio and Kuroshio extension currents. [ABSTRACT FROM AUTHOR]

The Fukushima-Daiichi accidents in 2011 underlined the importance of severe accident management (SAM), including external events, in nuclear power plants (NPP) and the need of implementing efficient mitigation strategies. To this end, the Euratom work programmes for 2012 and 2013 was focused on nuclear safety, in particular on the management of a possible severe accident at the European level. Relying upon the outcomes of the successful Euratom SARNET and SARNET2 projects, new projects were launched addressing the highest priority issues, aimed at reducing the uncertainties still affecting the main phenomena. Among them, PASSAM and IVMR project led by IRSN, ALISA and SAFEST projects led by KIT, CESAM led by GRS and sCO2-HeRO lead by the University of Duisburg-Essen. The aim of the present paper is to give an overview on the main outcomes of these projects. [ABSTRACT FROM AUTHOR]

This paper presents a radiation-tolerant design of a wireless system which allows commercial off-the-shelf electronic components to be used in high-level radiation fields, such as those found in a nuclear power plant (NPP) after a severe accident. This paper starts with the analysis of the characteristics of the radiation environment after a severe accident, with the focus on radiation effects on electronics. Based on such analysis, two approaches have been taken to mitigate the impact of radiation and to prolong the life of the electronics system: radiation shielding and radiation-tolerant design. To assess the effectiveness of this design approach, an evaluation method for radiation protection and system reliability evaluation has been developed. Even though such an assessment technique cannot replace physical radiation tests, it provides an effective way to select suitable components and estimate the radiation-tolerance at the system design stage. The results of the assessment for the current design have concluded that under the radiation conditions similar to those in an NPP under a severe accident, the designed system can be comparable to those made of radiation-hardened components. The developed redundant wireless system can be deployed in environments with a radiation up to $1 ~\text {M}\cdot \text {Rad}$ (Si). [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]

Radioactive iodine is a hazardous fission product and a major concern for public health. Special attention is paid to iodine out of 80 fission products because of its short half-life of 8.02 days, high activity, and potential health hazards like its irreversible accumulation in thyroid gland and ability to cause thyroid cancer locally. Radioactive iodine can get released in the form of aerosols (cesium iodide), elemental iodine, and organic iodide after a nuclear accident and can cause off-site and on-site contamination. Filtered containment venting system (FCVS) is a safety system whose main objective is mitigation of severe accidents via controlled venting and removal of different forms of iodine to ensure safety of people and environment. After nuclear accidents like Fukushima, extensive research has been done on the removal of iodine by using dry scrubbers. This review paper presents research status of iodine removal by dry adsorbents especially after 10 years of Fukushima to assess the progress, research gap, and challenges that require more attention. A good adsorbent should be cost-effective; it should have high selective adsorption towards iodine, high thermal and chemical stability, and good loading capacity; and its adsorption should remain unaffected by aging and the presence of inhibitors like CO, NO2, CH3Cl, H2O, and Cl2 and radiation. Research on different dry adsorbents was discussed, and their capability as a potential filter for FCVS was reviewed on the basis of all the above-mentioned features. Metal fiber filters have been widely used for removal of aerosols especially micro- and nanoscale aerosols. For designing a metal fiber filter, optimal size or combination of sizes of fibers, number of layers, and loading capacity of filter should be decided according to feasibility and requirement. Balance between flow resistance and removal efficiency is also very important. Sand bed filters were successful in retention of aerosols, but they showed low trapping of iodine and no trapping of methyl iodide at all. For iodine and methyl iodide removal, many adsorbents like activated carbon, zeolites, metal organic frameworks (MOFs), porous organic frameworks (POPs), silica, aerogels, titanosilicates, etc. have been used. Impregnated activated carbon showed good results but low auto-ignition temperature and decline in adsorption due to aging and inhibitors like NOx made them less suitable. Silver zeolites have been very successful in methyl iodide and iodine removal, but they are expensive and affected by presence of CO. Titanosilicates, macroreticular resins, and chalcogels were also studied and they showed good adsorption capacities, but their thermal stability was low. Other adsorbents like silica, MOFs, aerogels, and POPs also showed promising results for iodine adsorption and good thermal stability, but very limited or no research is available on their performance in severe accident conditions. This review will be very helpful for researchers to understand the merits and demerits of different types of dry adsorbents, the important operating parameters that need optimization for designing an efficient scrubber, margin of research, and foreseeable challenges in removal of different forms of iodine. [ABSTRACT FROM AUTHOR]

There has been considerable debate about the formation mechanisms of Cs-bearing silicate glass microparticles (CsMPs) (Types A–E) released uniquely during the Fukushima Daiichi nuclear power station accident. The author proposed that these CsMPs were formed because the high-efficiency particulate air (HEPA) filters or the insulation materials in the reactor building melted and atomized during the hydrogen explosion. However, this hypothesis is complex because it includes the interdisciplinary issues between the thermohydraulics in the reactor and atmospheric dispersion. This paper describes the basis of the hypothesis, verification, future issues, and recommendations from the viewpoint of improving nuclear safety. [ABSTRACT FROM AUTHOR]

In this paper, two decision support systems have been used to re-analyze the Fukushima accident emissions: the European Realtime Online Decision Support System for Nuclear Emergency Management (RODOS, version JRodos 2019)—providing a set of modules for the dispersion of nuclides following atmospheric and aquatic releases, dosimetry modules for dose estimation to individuals and communities for all exposure pathways with application of countermeasures, and modules for time estimation of the radiological situation in inhabited and agricultural areas—and CBRNE Platform, developed by IFIN-HH within a research project on anticipative and prognostic evaluation of chemical, biological, radiological, nuclear and explosive events (CBRNE), which is a tool for effect diagnosis functions, response measures and consecutive recommendation for a large variety of scenarios. We have reproduced the event on both systems, using accident time weather data and updated source terms. Current and initial results were cross-compared and evaluated. [ABSTRACT FROM AUTHOR]

Copyright of Asian Journals of Ecotoxicology is the property of Gai Kan Bian Wei Hui and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

How do some large-scale adverse events receive major media coverage and become crises for public actors while others are treated as routine events? This article reinvestigates this question based on a case study of the media treatment in France of the Chernobyl and Fukushima nuclear accidents. Drawing on an original set of media data and an ethnographic study, the article shows how both accidents were subject to forms of opacity that limit their effects on nuclear institutions: Chernobyl has been treated through secrecy that leads to contestation of nuclear institutions, whereas Fukushima has been characterized by "public containment," relying on extensive publication but low-priority and uncontroversial narratives that do not reflect the stakes of a given policy field. This paper explains the role of Fukushima in France through institutional transformations that public actors engaged in following Chernobyl to reestablish the credibility of public information sources and to monitor public debates over nuclear accidents by developing "hybrid" spaces, located at the interface of organizational frontstages and backstages. This case shows how responding to transparency demands may sometimes create new forms of opacity by reducing the epistemic quality of public debates while containing political crises. [ABSTRACT FROM AUTHOR]