The exercise scenario was based on a nuclear accident at Forsmark, according to officials. It consisted of three phases designed to test comprehensive emergency coordination. In the first phase, participants tested the alarm chain to ensure information from Forsmark reached relevant actors and they initiated initial collaboration.
The second phase was a command exercise reflecting hours 4–13 after the accident, including a seminar exercise on evacuating the inner preparedness zone near Forsmark, which according to the scenario occurred the day after the start. In the final phase, participants practiced mapping radioactive waste. According to SVT Uppland, the mapping helps determine where it is relevant to evacuate areas.
Operational details included the rescue service using cars and radiation measurement equipment to report results to the field site in Gimo. In the scenario, a few days have passed since the accident, a field site is established in Gimo, and radiation measurement occurs around Forsmark to locate radiological fallout after the release. Many different actors participated in the exercise, including rescue services, the Radiation Safety Authority, the Armed Forces, and the County Administrative Board.
The exact number of participants and specific protective equipment used against radiation were not disclosed. It remains unclear whether the exercise caused any real-world disruptions or public alerts, and results from the radiation mapping have not been detailed. Comparisons to previous Havsörn exercises in scale or effectiveness were not provided.