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Background: The Health Physics Society of Japan established a working group to obtain insights and findings from articles related to the Fukushima Daiichi Nuclear Power Station (1F) accident, published in the Japanese Journal of Health Physics. Materials and Methods: This study describes the review results of 47 articles on opinion and others related to the 1F accident in the field other than risk communication, environmental measurement and monitoring, radiation dose measurement and assessment, radiation medicine, and radioactive waste. Results and Discussion: The reviewed articles contain various insights and issues depending on the authors’ standpoints and relevant social interests. As a result, the 1F accident-relevant articles offer various discussion points depending on the authors’ awareness of the issues and their positions, which give an opportunity to make reconsiderations on what kind of academic system health physics or radiation protection should be on the basis of the experiences from the 1F accident. Conclusion: It is crucial for the future development of the Health Physics Society of Japan and relevant academic societies and researchers to address these matters and continue to ask what health physics (or radiation protection) is.

The Japanese Journal of Health Physics has published a large number of articles related to the accident at Tokyo Electric Power Company (TEPCO)’s Fukushima Daiichi Nuclear Power Plant in March 2011. Of these, 13 articles on risk communication had been published as of March 2022. The various issues related to risk communication are not limited to radiation and there is no absolute right answer for each case. The articles presented in this journal, which are based on the experiences of experts in the field of radiation protection, may also be seen as a record of the practical issues at the time. Please refer to the original articles.

Radiation is widely used in medicine but has both benefits and risks. Three important points must be taken into account in the medical use of radiation: justification, optimization, and dose limits. However, dose limits are not established for patients when the potential benefit is greater than the exposure risk. The International Commission on Radiological Protection (ICRP) introduced the concept of diagnostic reference levels (DRLs) to optimize the protection of patients from medical radiation exposure for diagnostic and interventional procedures. The ICRP also recommended that these levels be reviewed periodically. This paper reviews the current status of DRLs in computed tomography (CT) in Japan and provides a foundation for future revisions. A literature review of the origins of DRLs in the field of CT imaging in Japan was conducted, along with a detailed discussion of the establishment of the 2020 DRLs by a project team of which the author was a member. Japan’s first medical exposure guidelines were presented by the Japan Association of Radiological Technologists in 2000. The Japan Network for Research and Information on Medical Exposures was set up in response to the so-called ‘Lancet paper incident’ in 2004, in which it was suggested that diagnostic X-rays could increase cancer incidence, as well as ICRP Publications 103 and 105, and the 2020 DRLs were established in response to ICRP Publication 135 and corresponding revisions of laws and regulations. The DRLs for CT of the brain are higher in Japan than in Western countries but are otherwise comparable. This report summarizes the historical background of setting DRLs in Japan based on a literature review and discusses the details of the 2020 DRLs in the field of CT. DRLs must be updated periodically to keep pace with changes in social conditions and advances in medical technology and equipment.

Background: This study represents a thorough exploration of the radioactivity levels in soil and rock samples collected from Stubla Village, Kosovo. The main aim is to evaluate the potential hazards and risks associated with using these materials in construction, and this is a common practice among residents when building homes. Materials and Methods: Gamma spectrometry was employed to analyze 19 soil samples and seven rock samples, followed by the calculation of the primary radiological parameters. Results and Discussion: The activity concentration of 226Ra, 232Th, 40K, and 137Cs was determined in soil samples (95.84±67.5, 75.51±35.5, 12.87±23.5, and 738.87±186.7 Bq/kg, respectively) and natural rock samples (199.8±190.2, 147.0±14.3, 967.1±47.4 Bq/kg, and not detected, respectively). Almost all the calculated health radiological hazard factors exceeded the recommended limits by international professional organizations. Conclusion: The rocks from this specific region are unsuitable for construction work due to their high radioactivity levels. This emphasizes potential environmental and health risks. The findings underscore the importance of implementing alternative materials for construction. Additionally, further investigations into radioactivity risks in the area under study should be conducted, such as assessing radioactivity concentrations in drinking water, food, and indoor radon exposures, to ensure the safety and well-being of the community and the environment.

Background: Medical imaging radiation dose records are important for the process of optimising patient imaging in radiography. Understanding and monitoring the ionizing radiation doses delivered to patients while carrying out an imaging protocol is essential if that imaging protocol is to be adjusted with the goal of achieving a clinically acceptable result while reducing the radiation dose delivered to patients. Dose management software (DMS) systems are now available for use in conjunction with picture archiving and communication systems (PACS). They facilitate the collection and analysis of Digital Imaging and COmmunications in Medicine (DICOM) standard radiation dose structured reports (RDSRs). Implementation of DMS systems allows for the routine establishment of local diagnostic reference levels (LDRLs) for defined clinical imaging protocols in medical imaging including for computed tomography (CT), fluoroscopic, and general radiographic modalities. Materials and Methods: Implementation of a DMS was recently completed in a Local Health District in New South Wales in conjunction with a PACS upgrade across the district. LDRLs obtained using this DMS have been assessed and compared to the manual methods used for compiling contributions to nationwide surveys carried out by the Australian Radiation Protection and Nuclear Safety Agency (ARPANSA) to establish national LDRLs for a range of CT imaging protocols. Results and Discussion: The mean difference between the dose metrics determined for LDRLs using manually generated and comprehensive DMS samples was 6.9% when using volumetric computed tomography dose index as dose metric, and 6% when using dose length product as the dose metric. Conclusion: Results of the comparison show that a DMS can readily replace manual surveys conducted previously, and RDSRs allow greater opportunity to better understand the factors impacting the doses delivered during CT procedures.

Background: In order to gain approval of decommissioning of nuclear power plants (NPPs), the operator has to submit a final decommissioning plan (FDP) to the regulatory body. The safety assessment is an essential part to be described in the FDP. In safety assessment, dose of the general public near the plant site due to decommissioning activities should be evaluated and described. As gaseous radioactive effluents are expected to be released in the process of decommissioning, it is necessary to assess the public dose. In this study, we assessed the public dose due to gaseous radioactive effluents released in NPP decommissioning activities. Materials and Methods: The source term of gaseous radioactive effluent was set based on the decommissioning scenarios suggested in the NUREG-0130. The critical group assumed the maximum individual for adults on the exclusion area boundary. Public exposure pathway was set in accordance with the guideline 2.2 of the Korea Institute of Nuclear Safety (KINS). In addition, the public dose was assessed through the GASPAR computer code with the factors suggested by the KINS. Results and Discussion: In the decommissioning scenario, the source term for gaseous radioactive effluent was set by using the nuclide fraction according to the contamination type of structures, systems, components in the reference reactor. As a result of the public dose assessment, total annual public dose in the overall decommissioning scenario was 1.95×10–2 μSv/yr. Segmentation on non-activated stainless steel task was the highest at 1.43×10–2 μSv/yr. In the overall scenario, the nuclide with the highest contribution to the public dose was Co-60. As a result of the assessment, it was found that the public dose due to the gaseous radioactive effluent during the decommissioning of the NPP was insignificant compared to the legal dose limit. Conclusion: The results of this study can be used as a basis for radiological safety assessment and the management of radioactive effluents in the decommissioning of NPP.