Scientific and Evidence-Based Support in Emergency Preparedness and Resilience Strengthening, Under Volatility and Uncertainty

In the context of the crisis generated by the Russian-Ukrainian conflict, the situation of the five (four operational nuclear power plants) on Ukrainian territory has become a point of major public interest and a prominent sensitive issue for national decision-makers and response personnel. Since the beginning of the conflict, two research-oriented teams from the Horia Hulubei National Institute for R&D in Physics and Nuclear Engineering (IFIN-HH) in Bucharest, Romania and the National Commission for Nuclear Activities Control (CNCAN) have carried out a series of comprehensive situation radiological forecasting activities. The aim was to provide a plausible, well-founded, objective and scientifically defendable assessment of Romania’s territorial vulnerability to a hypothetical radiological accident at any of the nuclear power plants in Ukraine. Evaluations were performed using two distinct platforms of dose projection and radiological assessment to ensure consistency of results. The scenarios were built on the assumption of loss of coolant event followed by a release of radioactive material in the atmosphere resulting from damage to the reactor core and spent fuel pool. The paper provides an overview of the work, addressing key topics such as situational awareness, expert judgment, underlying assumptions, scenario development, and methods for effectively producing and communicating meaningful results. It also highlights some particularly significant and interesting findings and concludes with a few thoughts and observations.