Aomori Prefecture accommodates nuclear power plants (NPP), their related nuclear facilities, and those under construction. It is necessary for them to satisfy the national safety standards and to be operational. After the Fukushima NPP accident, however, the general inhabitants became anxious and questioned their safety. Not only the general inhabitants but also the firefighting staff had doubts and/or concerns against nuclear power disasters and nuclear accidents. From the regional circumstances, the present study focused on understanding of radiation and its risk among the firefighting staff in Aomori Prefecture. In order to know how well they understand radiation, “a questionnaire survey about radiation” was carried out for the staff of five firefighting headquarters. Results of the questionnaire survey were compared between the staff of two firefighting headquarters where the nuclear facilities are located in their jurisdiction and the staff of three firefighting headquarters. Consequently, it was found that there was many firefighting staff with the incorrect understanding of radiation exposure. When analyzing some difference on recognition of radiation risks, there will be no significance no matter whether firefighters are working around nuclear facilities or not. In addition, most of them recognized that radiation effects would be evident even when the exposure was relatively low, and the main effect was assigned to “cancer” though the other effects were not well recognized. Basic knowledge on radiation and its risk have not yet been sufficiently understood among many participants.
The present study investigated the thoughts of elderly evacuees after the Fukushima Daiichi Nuclear Power Station Accident about for the returning to their hometowns, and discussed the support needed for them. The subjects were 86 elderly people (mean age: 74.2 ± 7.2 years) whose hometown was one city in Fukushima. They completed a questionnaire regarding anxiety about radiation, requirements on return to their hometown, frequency of use of personal dosimetry, and so on. Thirty-nine people answered that they intend to return to their hometown if the evacuation order is lifted. They were mainly worried about the level of radiation and the post-decontamination state. Twenty-one people always use a personal dosimetry, while 34 people use it only on return to their home town temporarily. The rebuilding for evacuees to return to their hometowns needs a construction of a safe living environment such as satisfactory decontamination work and comfortable infrastructure.
Strategic research will be needed to unveil the uncertainty regarding the health effect of radiation at low dose and low dose rate. Recently, the National Council on Radiation Protection and Measurements (NCRP) published Commentary No. 24 dealing with the perspective of integrating radiation biology and epidemiology to address this issue. Results of radiation biology have not been effectively used for radiation risk assessment because 1) available epidemiological studies based on direct observation of human population have been considered to be the most relevant despite their uncertainties and 2) biological studies have not been conducted with their use in risk assessment in mind. The present paper summarizes the Commentary to present perspectives on integrating biology and epidemiology for radiation risk assessment.
In April 2011, the International Commission on Radiological Protection recommended reducing the occupational equivalent dose limit for the lens of the eye. Since then, discussions toward implementation of such a revised dose limit into national law have been made in various countries. In the United States of America (US), the National Council on Radiation Protection and Measurements (NCRP) established Scientific Committee 1-23 (SC 1-23) in January 2014 to provide guidance on whether existing dose limits for the ocular lens should be changed in the US, to which the author of this paper served as Consultant. In January 2017, NCRP published Commentary No. 26 “Guidance on radiation dose limits for the lens of the eye” which was prepared by SC 1-23. With this Commentary, NCRP now recommends reducing the occupational dose limit for the lens from equivalent dose of 150 mSv/year to absorbed dose of 50 mGy/year along with the use of relative biological effectiveness value for high linear energy transfer radiation. This review provides an outline of this Commentary.
In March 2011, the accident occurred at the Fukushima Daiichi Nuclear Power Plant of Tokyo Electric Power Company. During recovery from critical situations, the radiation dose for some emergency workers exceeded the effective dose limit recommended for an emergency situation. A month after the accident, the International Commission on Radiological Protection issued a statement on tissue reactions recommending significant reduction of the equivalent dose limit to the lens of the eye. Many radiation workers will need to be involved in treatment of water contaminated with radionuclides, fuel debris retrieval, and decommissioning of reactors for a long period of time. Thus, the optimized radiation control in the fields, exposure reduction, prevention of tissue reactions, and reduction of stochastic risks for workers becomes necessary. This paper discusses issues in relation to radiation protection of the ocular lens in such recovery workers, from the viewpoint of radiation exposure of workers, its management, manifestations and mechanisms of the lens effects.
The overview of the subcommittee 2 under the technical committee 85 in the International Organization for Standardization (ISO/TC85/SC2) is introduced. Among 28 active projects including 13 of new item proposals the current status of some projects and contributions of domestic committee of ISO/TC85/SC2 are also reported in the present paper.
The progress and results of the Technical Cooperation Programme on nuclear science and technology education for the secondary schools in the Asia-Pacific region by the IAEA over five years from 2012 were introduced. Assembling laboratory instruments accompanying the observation of trajectories of radiation in the classroom, the history of the discovery of radiation and radioactivity timely described in the process, the mechanism and the concept of radiation measurement etc., which were explained and introduced by Team Japan, were all really effective. It is concluded that further development of these activities will become one of the cores of STEM education in Asian countries and play an important role in the expansion and deepening of NST education.
Indoor radon and thoron concentration measurements have been intensively carried out since the 1980s for assessment of radiation doses to workers and the general public. For example, the European Union countries established reference levels for indoor radon concentration in relation to national action plans to address long-term risk from radon exposures. Measurements done using a reliable method are the only way to investigate radon concentration levels. In order to ensure the quality of measurements, intercomparisons among laboratories are performed, as one verification method. The primary purpose of this paper is to provide a concise review of intercomparisons of radon and thoron monitors carried out by four institutions: NIRS (Japan), PHE (UK), BfS (Germany) and SURO (Czech Republic). The different measurement set-ups, evaluation methods and statistical treatments utilized by those institutions are described.
By using information of beryllium-7 (7Be) and its transport, we can obtain important information of the atmospheric transport process which cannot be obtained by atmospheric physical quantities alone. However, in proceeding with the 7Be transport study, one difficulty comes from an integrated research between health physics and meteorology. This review is an attempt to overcome this difficulty, describing meteorological aspects in the 7Be transport process toward health physicists. We stress that (a) 7Be particles do not come from straight above but from far away, and (b) the way of thinking is different depending on timescale. In (a), backward trajectories are calculated, showing that trajectories strongly depend on season. In winter, spring, and autumn, particles generally come from high altitudes in high latitudes, which can be understood by using the notion of potential temperature. In (b), 7Be concentrations are largely influenced by daily disturbances in short timescales, showing large daily variations. In long timescales, they take almost equilibrium values with seasonal variations. We discuss extremely high and low concentrations as examples of short timescales, and seasonality as examples of long timescales. In all the examples, it is important to consider where 7Be particles come from and what happens along the trajectories.