Nuclear Disaster Medical Response and Preparedness: Perceived Radiation Risk in Ongoing Decommissioning Work and Future Strategies

Abstract This study aimed to assess the situations involving potential risks of over-exposure to radiation faced by workers during the decommissioning of the Fukushima Daiichi Nuclear Power Plant (FDNPP), and to prepare effective medical countermeasures. While deaths have occurred at regular intervals at the FDNPP site, they cannot be attributed to direct effects of radiation. Radiation exposure among decommissioning workers is strictly maintained within regulatory limits, and no deterministic or stochastic radiation effects have been observed. High-risk areas include the reactor buildings of Units 1-4 and the filtration systems for cooling water contaminated by decay heat from melted nuclear fuel. The reactor buildings contain a mix of α, β, and γ radionuclides, which may increase the need for medical responses specifically targeting α radionuclides in cases of internal contamination. With nuclear fuel removal in September 2024, there are growing concerns regarding the potential increase in radiation risks at the decommissioning site.