Uranium waste, which is one of the wastes containing radioactive substances of natural origin, is generated in association with the use of nuclear power generation. While there have been long discussions about handling and disposal of the uranium wastes for last 50 years in Japan, its clear vision including a specific disposal site has not yet been received. For improving this situation, the authors perceived that it is necessary to refocus this issue from the view of humanities and social sciences, rather than that of natural science and engineering and have had in-depth discussions in a specialized study group established in the Japan Health Physics Society. This commentary provides an overview of the two-year discussions in that group.

Measurements of radioactivity concentrations of airborne dust are important because they are used to protect workers from intakes and to assess internal exposure doses. Therefore, we developed a portable β-ray dust monitor by using an ultra-thin plastic scintillator, which is designed for continuous monitoring of highly-concentrated airborne contaminants (> 10^–2 Bq/cm³, equivalent to 30 times larger than the derived air concentration of ⁹⁰Sr) such as a decommissioning work in the Fukushima Daiichi Nuclear Power Plant. From the performance test results, it is evaluated that the developed portable β-ray dust monitor is functional in continuous monitoring with an airborne concentration of 1 Bq/cm³.

Subcommittee 1 of the JHPS Working Group on Accidental X-ray Exposures has discussed issues based on field-specific perspectives from cases of X-ray accidents and troubles and their backgrounds, mainly positioned as proposals and recommendations to the Expert Group for solving the problems. As a result, it was agreed that it is extremely important to improve education and training, including the development of a safety culture, whether in the field of industry, research or medicine. Stakeholders closely related to X-ray generators are encouraged to refer this report to promote the safety level of environments for the use of the equipment. Experts should continue to develop the mechanisms of academic societies and strengthen their cooperation activities with other organizations and institutions to ensure that the stable, appropriate and effective use of X-rays can continue on the basis of an enhanced safety environment.

The JHPS Working Group for Discussion on X-ray Exposure Accidents summarized the background of the X-ray exposure accident happened in Himeji, Hyogo in May 2021. The working group paid attention to the viewpoint of fostering a further awareness of the need to the radiation safety culture and discussed issues identified to contribute to the prevention of possible future X-ray accidents as one of the goals. The article introduces an example to apply the dose estimation method using a Monte Carlo simulation discussed in the working group. The authors summarized other methods of dose estimation, the technical limitations and the challenges of each method. The authors believe that these summary for dose estimation method will be informative and helpful to overcome the future issues in this area. The authors also considered that information on the energy distribution of low-energy X-rays in the body of an exposed patient is important for radiation emergency medicine and radiation protection purposes and that individual and environmental monitoring of low-energy X-rays is still challenging.

The third subcommittee mainly discussed how to disseminate information on X-Ray accidents and how to roll out accident prevention initiatives to stakeholders. There have been various discussions on the role of academic societies in accident response, which is still in the trial-and-error stage. As a representative example of accident response, the medical accident investigation system based on laws and regulations aimed at preventing recurrence was noted. In the study of issues related to this accident, the Japan Society of Health Physics and the Japan Radiation Safety Management Society attempted to collaborate, and it is hoped that such attempts will be expanded with the understanding and cooperation of more related societies. As support for industry by academic societies, the WG collaborated with the nondestructive testing industry to organize issues and propose countermeasures. Involvement of external organizations to support facilities is also effective, and one suggestion is to consider providing external evaluation services for safety activities in the future. Based on these studies, the WG has made interim reports on its activities at the Hobutsu Seminar 2021 and the Japan Society of Health Physics 2022 Symposium. It is important to actively exchange opinions among the parties concerned at these opportunities. It is also necessary to consider what the society can do and contribute to the effective utilization and wide deployment of information and findings on accidents collected from users by the Ministry of Health, Labor and Welfare and other organizations.