The Finnish Radiation and Nuclear Safety Authority (STUK) played the role of ‘Accident State’ during the exercise on 9 December. Over 70 other countries and international organizations played along to test their own emergency response procedures. STUK developed a scenario involving the Olkiluoto Nuclear Power Plant and their staff played in the exercise to test internal procedures.
For Petteri Tiippana, Head of STUK, the exercise was a success. “The expression ‘respond as you train, train as you respond’ underlines well the importance of training. Having had the exercise with Olkiluoto nuclear power plant just one day before the real event left us even better prepared to respond to it.” The next morning, they were to repeat many of the same initial response steps, only this time for real.
During the morning of 10 December, a malfunction in the purification system for the reactor cooling water at Unit 2 of the plant caused a temporary rise of radiation levels in the steam lines. Both STUK and the plant operator, Teollisuuden Voima Oyj (TVO), went into emergency response mode and the plant’s Unit 2 had automatically been shut down.
“When the event occurred in real life, we reacted immediately and decisively to respond in line with the severity of the first indications from the plant. High dose levels in the steam lines may indicate significant fuel damage in the reactor. Therefore, we immediately alerted our emergency organisation in its full capacity, notified relevant ministries, authorities, the public and the media”, said Tiippana.
At IAEA headquarters in Vienna, the IEC activated into Basic Response Mode and directed On-Call Officers to report to the operational area.
“What we learned in the exercise helped us swiftly respond the very next day,” said Kilian Smith, Emergency Response Manager during the exercise. “Over the last few months, the IAEA has amended some procedures to ensure we work effectively within restrictions related to COVID-19. These procedures were tested during the exercise and they worked perfectly on the day of the real event,” added Smith.
Once STUK acquired a full picture of the event’s cause, it went on to rate the event at “below scale/level 0” on the International Nuclear and Radiological Event Scale (INES), which is a tool to communicate the safety significance of nuclear and radiological events to the public. Events without a safety significance are rated “below scale/level 0”.
Exercises are not isolated activities but are an integral part of emergency preparedness. They enable responders to identify issues in emergency response arrangements and for them to be amended before a real event.
The IAEA will continue its series of exercises in 2021. From 26 to 27 October 2021, a full scope nuclear emergency exercise, called “ConvEx-3”, will be conducted.
