The International Atomic Energy Agency (IAEA) and Romania will launch tomorrow, 24 June, the world's largest and most complex international nuclear emergency exercise, simulating a severe accident at Romania's Cernavodă Nuclear Power Plant.
Such exercises are held every three to five years and are based on simulated events hosted by IAEA Member States.
Over two days, more than 75 countries and 10 international organizations will take part in the ConvEx-3 (2025)-a full-scale exercise designed to test global readiness for a nuclear or radiological emergency with cross-border consequences. Participation will occur both on-site in Romania and remotely from other countries.
As nuclear use expands globally, its success hinges on strong safety standards and constant vigilance, said IAEA Director General Rafael Mariano Grossi. "This exercise is a clear demonstration of the international community's commitment to protect people and the environment by working together, across borders and systems, when every minute counts."
"Hosting ConvEx-3 is both a responsibility and an opportunity for Romania," said Cantemir Ciurea-Ercău, President, National Commission for Nuclear Activities Control (CNCAN). "Two decades after we hosted the first ConvEx-3, we are proud to again contribute to strengthening global nuclear emergency preparedness. In today's interconnected world, effective preparedness must transcend borders-this exercise reflects our shared commitment to safety, cooperation and transparency."
Romania, bordering five countries, last hosted such an exercise in 2005. Cernavodă is the country's only nuclear power plant, situated roughly 160 kilometres east of Bucharest, close to the Black Sea. During the 36-hour exercise, participants will simulate real-time decisions, emergency communications and international coordination under the Convention on Early Notification of a Nuclear Accident (Early Notification Convention) and the Convention on Assistance in the Case of a Nuclear Accident or Radiological Emergency (Assistance Convention). These will include protective actions such as simulated evacuation and iodine distribution, public outreach and communication, medical response coordination, and the management of food and trade restrictions based on radiological assessments.
The IAEA will activate its Incident and Emergency Centre (IEC) and test critical tools like the Unified System for Information Exchange (USIE), a secure platform for designated contact points from IAEA Member States, and the International Radiation Monitoring System (IRMIS) platform. Member States will also activate their national emergency centres, request or offer assistance, share monitoring data, and coordinate cross-border protective actions and messaging to their populations.
The ConvEx-3 (2025) was developed by SNN Nuclearelectrica and CNCAN, with international coordination by the Inter-Agency Committee on Radiological and Nuclear Emergencies (IACRNE), which includes the World Health Organization, World Meteorological Organization, European Commission, Food and Agriculture Organization of the United Nations, INTERPOL and others.
About Convention Exercises
Convention Exercises, or ConvEx, are held to test the operational arrangements of the Early Notification Convention and the Assistance Convention. The goal is to evaluate and further improve the international framework for emergency preparedness and response. ConvEx are prepared at three levels of complexity:
- ConvEx-1 is designed to test emergency communication links with contact points in Member States that need to be available 24 hours a day, seven days a week, and to test the response times of these contact points.
- ConvEx-2 is designed to test specific parts of the international framework for emergency preparedness and response, for example to rehearse the appropriate use of communication procedures; to practice procedures for international assistance; and to test the arrangements and tools used for assessment and prognosis in a nuclear or radiological emergency.
- ConvEx-3 is a full-scale exercise designed to evaluate international emergency response arrangements and capabilities for a severe nuclear or radiological emergency over several days, regardless of its cause.
Photos from the ConvEx-3 will be made available here.
