Results 1 - 10 of 3207
Results 1 - 10 of 3207. Search took: 0.03 seconds
|Sort by: date | relevance|
[en] A massive release of artificial radionuclides from the Fukushima Dai-ichi Nuclear Power Plant caused radioactive contamination of farms as well as of aquatic products. Carp in small ponds in the highly radiocontaminated area of Iitate Village, Fukushima Prefecture, have been confined to the ponds since the accident, and it is thought that the carp may have suffered health issues as a result. Therefore, I investigated the health condition of the carp in order to elucidate the effects of radiation. Blood neutrophil, monocyte and lymphocyte counts in the carp from three ponds in Fukushima were lower than those in carp from a non-polluted pond in Tochigi Prefecture. Histological observations indicated abnormal hyperplasia of macrophages in the spleen, kidney, liver and pancreas of carp in Fukushima. Although there are likely to have been deleterious effects on carp health due to the radiation in Fukushima, this has not yet been confirmed because only one control pond was available for comparison, and I was not able to find any symptoms in the carp that correlated with internal cesium concentration. Further research is now being conducted to investigate the effects of radiation on carp
[en] Highlights: •We identify unreliable instrumentation and provide alternative signals. •Proposed the Empirical Parameter Network based on statistically related parameters. •Connectivity determines which parameters are most important from an I&C perspective. •Proposed method was demonstrated through various SBLOCA scenarios. -- Abstract: During the Fukushima Daiichi nuclear accident, the plant operators' ability to observe the status of the power plant using the instrumentation and control (I&C) system was severely hampered by breakdowns in the plant's network, caused by the earthquake and tsunami. Thus it was difficult to obtain essential information for monitoring the internal situation of the power plant. Also, missing and incorrect information on status caused confusion, which then led to an accident. Clearly, it is crucial that I&C systems maintain the ability to monitor the internal state of reactors, even in such an inferior working environment. Herein we propose a method to identify unreliable instrumentation and to provide alternative signals. Our method, called the Empirical Parameter Network (EPN), provides estimates to replace faulty information based on statistically related parameters, and includes visualizations and other tools to enable recognition of various scenarios. The EPN included essential parameters that were selected on the basis of a literature survey, and was based on statistical analysis of an array of simulated post-accident data. The behavior of each parameter was identified and a data visualization technique was developed to intuitively display parameter correlation information. Connectivity analysis to reveal associations was performed based on the data visualization results. By incorporating the concept of connectivity, we were able to determine which parameters were most important from an I&C perspective, allowing further construction of the EPN. This newly constructed EPN will propose an alternative signal when an incorrect input signal is generated, or even when a specific parameter is missing altogether. The proposed method was demonstrated through various scenarios originating from an initial SBLOCA event, which is considered to be one of the greatest contributors to overall severe accident risk. In this research, the relationships between parameters were confirmed based on analysis of connectivity during an accident. Overall, in the damaged network condition, the reliability of the monitoring system can be improved by using the relationships between the parameters. This research can be helpful in managing accidents.
[en] Risk comparison is essential for effective societal and individual decision-making. After the Fukushima disaster, studies compared radiation and other disaster-related risks to determine the effective prioritizing of measures for response. Evaluating the value of risk comparison information can enable effective risk communication. In this review, the value of risk comparison after the Fukushima disaster for societal and individual decision-making is discussed while clarifying the concept of radiation risk assessment at low doses. The objectives of radiation risk assessment are explained within a regulatory science framework, including the historical adoption of the linear non-threshold theory. An example of risk comparison (i.e. radiation risk versus evacuation-related risk in nursing homes) is used to discuss the prioritization of pre-disaster measures. The effective communication of risk information by authorities is discussed with respect to group-based and face-to-face approaches. Furthermore, future perspectives regarding radiation risk comparisons are discussed.
[en] Work-related mental health impairment is recognized as a real problem in the context of helping responders, including health professionals, due to adverse health outcomes after a severe disaster. The Great East-Japan Earthquake, which occurred on 11 March 2011, was an unprecedented complex disaster that caused a nuclear accident at the Fukushima Daiichi Nuclear Power Plant (NPP). In addition to disaster stress and daily work, medical and health-care professionals, particularly nurses, provided counseling services to residents concerned about radiation health risks or mental health issues. This review focuses on the psychological aspects of the complex nuclear disaster, which was a combined artificial nuclear accident and natural disaster, and we investigated the psychological effects on hospital nurses associated with their experiences during the disaster. We looked at several investigations into the mental health of nurses after a nuclear disaster and in other situations. It was shown that mental health of nurses is impacted, not only after nuclear disasters but also in other circumstances. Furthermore, we noted the effects of extended periods of a heavy workload and daily life. Regarding anxiety about radiation exposure, nurses who had more knowledge of radiation tended to have better mental health, suggesting that education about the health risks of radiation exposure is important for health-care professionals. In summary, it is essential that nurses are provided with education about radiation exposure and its associated health risks, and also that there is a comprehensive approach to mental health care for nurses during the chronic phase of a disaster.
[en] Following the severe accidents at the Japanese Fukushima Daiichi Nuclear Power Station in 2011, the US Department of Energy initiated research and development on the enhancement of the accident tolerance of light water reactors by the development of fuels/cladding that, in comparison with the standard UO2/Zircaloy (Zr) system, can tolerate loss of active cooling in the core for a considerably longer time period while maintaining or improving the fuel performance during normal operations. Analyses are presented that illustrate the impact of these new candidate fuel/cladding materials on the fuel performance at normal operating conditions and on the reactor system under DB and BDB accident conditions
[en] On 11 March 2011 a massive earthquake and tsunami caused a major accident at the Fukushima Daiichi nuclear power plant in Japan, the world’s worst nuclear accident since Chernobyl in 1986. Fuel removal and postaccident stabilization and cleanup activities are ongoing at the plant, with the aim that active dismantling can proceed in due course. In the five years since the accident, at the request of the Government of Japan, the IAEA sent more than ten expert missions to advise the country in various areas, including three on the safety and technological aspects of decommissioning and remediation. The objective of the decommissioning peer review missions was to provide an independent assessment of the activities associated with the planning and implementation of decommissioning the plant.
[en] Highlights: • For inspiration to others the special Nordic cooperation pathways in nuclear emergency preparedness are outlined. • Recent Nordic research work under NKS has produced international state-of-the art results on nuclear emergency preparedness. • Cooperation on nuclear emergency preparedness of smallish countries with similar cultural background can be cost-effective. • Internet links are provided from NKS activity discussions to all relevant NKS project reports for cost-free download. - Abstract: Contrary to most areas of Europe, the Nordic countries (Denmark, Finland, Iceland, Norway, Sweden, and the Faroe Islands) have for many years shared a regional research and development program on nuclear reactor safety and emergency preparedness - NKS. In spite of its project results having received great recognition and having been integrated in state-of-the-art emergency preparedness tools over the world, NKS as an organization does not seem well known outside the Nordic countries. Although the Fukushima accident had no health impact at all in Nordic areas, it taught a number of lessons of generic nature with respect to new R&D tasks that could further strengthen and secure future maintenance of the Nordic region's capability to effectively respond to such events. For broader inspiration, this paper briefly introduces the Nordic nuclear emergency preparedness cooperation channels and outlines the related NKS R&D project initiatives launched after the Fukushima accident, many of which should be of general interest also far outside the region. The paper is intended as an introduction to NKS with an invitation to explore its results. All project results are available cost-free on the NKS website.