Expanding the radiation monitoring network as an effective approach to reducing uncertainties in emergency response preparedness during armed conflict

The current Russian aggression against Ukraine leads to complex needs for and challenges to the expansion of the Ukrainian radiation monitoring network. The issue of preparedness and response in times of war, in particular during the seizure of the Zaporizhzhia Nuclear Power plant site, has greatly exacerbated the issue of developing a response strategy based not only on expert opinion on possible scenarios but also on actual measurements in the first hours of a potential release. In this context, the shortage of radiation monitoring stations has become a significant issue for operators, the public, and various organisations, including State Nuclear Regulatory Inspectorate of Ukraine (SNRIU) and State Scientific and Technical Center for Nuclear and Radiation Safety. To address this, proposals have been made to identify suitable locations for additional automatic radiation monitoring systems to complement the existing ones. The main environment for solving this problem became the RESTORATION project, conducted in 2023-2024 in collaboration with Norwegian Radiation and Nuclear Safety Authority SNRIU, and State Scientific and Technical Center for Nuclear and Radiation Safety. The main objective of activities is to identify the data needed to select appropriate locations for radiation monitoring stations using the European decision support system JRODOS. For this study, the reference severe accident scenario at Ukrainian nuclear facilities was selected in accordance with the IAEA Emergency Preparedness Category I. Such an event may cause significant impacts beyond the boundary of the monitoring zone and enables the assessment of how actual meteorological conditions influence the atmospheric dispersion of radionuclides. Meteorological data from a five year period were used for statistical calculations. Preliminary monitoring quantities were based on the data requirements of the JRODOS decision support system, which provided the necessary statistical outputs. The paper highlights the role of the radiation monitoring network during an emergency as well as the problem of its potential development in view of the challenges with regard to civil protection, analysis of radiological situations, dispersion modelling, and dose projection. An overview of the existing networks and hierarchy of monitoring data providers among the Ukrainian organisations is presented. Based on the Ukrainian experience, in particular the results of the RESTORATION project, a methodological approach and recommendations for expansion of the radiation monitoring network are presented.