Answer: Romania
Notes: On 24 June 2025, the International Atomic Energy Agency (IAEA) and Romania launched ConvEx-3 (2025), the world’s largest and most complex nuclear emergency exercise. It will simulate a severe accident at Romania’s Cernavodă Nuclear Power Plant, the country’s only nuclear plant located 160 km east of Bucharest. It aims to improve global coordination under the Convention on Early Notification of a Nuclear Accident and the Convention on Assistance in the Case of a Nuclear Accident or Radiological Emergency. ConvEx-3 is the highest level of Convention Exercises, testing full-scale international emergency response capabilities. Romania last hosted ConvEx-3 in 2005.
