In December 2021, the International Commission on Radiological Protection (ICRP) called for transparent engagement of stakeholders in the review and revision of the ICRP 2007 General Recommendations by publishing the paper “Keeping the ICRP Recommendations Fit for Purpose” to present the main points at issue. Subsequently, the Expert Group on International Recommendations (EGIR) of the OECD Nuclear Energy Agency (NEA), one of the ICRP’s Special Liaison Organizations (SLOs), issued the report entitled “Initial Views on the Review and Revision of the System of Radiological Protection” in April 2023. The EGIR’s report summarizes the views of radiation protection experts on five priority themes: (1) The system of radiological protection, (2) optimization, (3) environmental protection, (4) radiation detriment and risk, and (5) exposure situations. This review paper provides an overview of the five priority themes extracted by the EGIR and presents a summary of recent international developments towards the next ICRP General Recommendations scheduled for the 2030s.

The International Commission on Radiological Protection (ICRP) started to prepare the new general recommendations. The Fukushima Daiichi Nuclear Power Plant accident in March 2011 which followed the Great East Japan Earthquake and a gigantic Tsunami was the first large nuclear accident since ICRP 2007 Recommendations became effective. The experiences and notions of the accidents, countermeasures, and restorations are expected to contribute to the production of the new general recommendations. The author served as a member of the main commission (MC) of ICRP from July 2001 to June 2009 and participated in nearly the whole process of producing ICRP 2007 Recommendations. This article reminisces about the works in which the MC had engaged during that period. The author expects the story which includes personal impressions may serve as useful information for those who are involved in preparation of the new recommendations, from Japan in particular. This article is based on an invited lecture which was presented at the 56th Congress of the Japan Health Physics Society held jointly with the 7th International Symposium on the System of Radiological Protection (ICRP 2023) in Tokyo.

In recent years, there has been significant progress in the development of targeted radionuclide therapy and the global market is expected to further expand in the future. Positron emission tomography (PET) images and single photon emission computed tomography (SPECT) images have been established quantitatively to some extent. Dosimetry has been proposed to calculate absorbed doses for targets and risk organs in targeted radionuclide therapy based on quantitative nuclear medicine images. It is important to note that there are some factors that can cause fluctuations in absorbed doses within the steps for dosimetry. Radionuclides for therapy emit a wide variety of energies and the effects of bremsstrahlung are particularly problematic for high-energy β-rays. Medical staff must take more appropriate radiation protection measures at the time of work compared to radionuclides used for diagnostics. Patients undergoing targeted radionuclide therapy must be admitted to a dedicated treatment room or special care unit until discharge criteria are met. Medical staff must take appropriate precautions regarding the contamination of rooms and patient excretions to reduce public exposure. The proper management of radiation protection and radiation control in targeted radionuclide therapy facilities is an extremely important issue for medical use and should be addressed in accordance with the actual conditions of each facility, while paying attention to laws and regulations.

In recent years, public interest in ICRP publications has increased. The ICRP publications are widely disseminated not only to regulators and operators but also to the concerned members of the public. Translations of ICRP Publications are essential for understanding the ICRP Recommendations and sharing them widely with stakeholders. In the fiscal year 2017, the Nuclear Regulation Authority of Japan (NRA) launched an outsourced project “Survey of International Commission on Radiological Protection publications for domestic regulations.” A Japanese translation has been published after a multi-stage check by several experts under a Translation Committee. This report provides an overview of the activities of Japanese Translation Committee and the translation process of ICRP Publication 138. This publication is a unique ICRP report that deals with ethical foundations of the system of radiological protection.

We have developed a tritium screening method focused on seafood. Time saving and simplicity of tritium analysis were achieved by performing analysis as total tritium that simultaneously obtains the recovered water of TFWT and OBT. We carried out the experiment using HTO and L-leucine[4, 5 – ³H], and confirmed that total tritium was sufficiently recovered. The developed method has a low detection limit, and it gives us a tool to judge smoothly the annual radiation dose caused by consumption of seafood is below the guidelines authorized by international organizations, the safety level for public. The detectable radiation dose by tritium is 9.2 × 10^–6 mSv/y for average consumption of seafood in Japan. This method can evaluate 2–3 orders lower dose level authorized by international organizations for public.