International Atomic Energy Agency (IAEA) experts observed an emergency exercise conducted at Ukraine's Zaporizhzhya Nuclear Power Plant (ZNPP) this week, the latest such drill in the country's nuclear facilities during the military conflict, Director General Rafael Mariano Grossi said today.
Thursday's exercise focused on actions that should be taken in response to a hypothetical break of a pipe containing radioactive wastewater and the disconnection of power from one reactor unit.
The IAEA experts followed the two-hour exercise from the ZNPP's temporary emergency centre, observing the coordination of emergency response actions. They also observed field activities during the exercise, including radiation and contamination monitoring as well as preparations for the evacuation of some plant staff. After the exercise was completed, the IAEA team observed the standard debriefing. Overall, the IAEA experts said the exercise scenario was carried out as planned.
Last week, the IAEA team based at Ukraine's Rivne Nuclear Power Plant (NPP) observed an emergency exercise at that site. Also this week, the IAEA team at the Chornobyl site observed an emergency drill at the radioactive liquid waste treatment plant.
"Having effective emergency preparedness and response arrangements is one of the seven indispensable pillars for ensuring nuclear safety and security in an armed conflict. It is vital that the Zaporizhzhya Nuclear Power Plant tests its emergency response arrangements. We encourage the plants in Ukraine to conduct more exercises in future to further test their emergency preparedness," Director General Grossi said.
The ZNPP has throughout the conflict been at the centre of the IAEA's concerns about nuclear safety and security in Ukraine. It is located on the frontline and has lost all off-site power as many as seven times. Director General Grossi told the IAEA Board of Governors on Wednesday that the situation at the plant remained challenging, with six out of the seven pillars of nuclear safety and security during an armed conflict "compromised either fully or partially".
Earlier this week, the ZNPP's unit 5 reached cold shutdown, leaving one of the plant's six reactors in hot shutdown to produce steam and heating. The plant decided to move the unit from hot shutdown after boron was detected in a secondary cooling circuit, albeit at levels below the limits set by its technical specifications. No radioactivity has been detected in the secondary cooling circuit. Borated water is used in the primary coolant to help maintain nuclear safety functions.
After the cold shutdown state was reached at unit 5, the ZNPP informed the IAEA team that it will not immediately investigate the cause of the presence of boron in the secondary cooling circuit of one of the unit's steam generators. The IAEA experts will continue to monitor this issue during its discussions with ZNPP and walkdowns of the plant.
The IAEA experts are also continuing to gather information to fully understand why unit 6 temporarily lost power on 14 November and relied on a diesel generator for 90 minutes. They held multiple discussions on this issue with the ZNPP's electrical department this week.
Unit 4 remains in hot shutdown to provide steam for nuclear safety related activities at the ZNPP and also for heating at the site and the nearby town of Enerhodar, where most plant staff live. Additional heating is provided by mobile diesel boilers installed at the ZNPP together with boilers located in the nearby industrial zone. Reactor units 1, 2, 3, 5 and 6 are now in cold shutdown.
Elsewhere in Ukraine, the IAEA experts at the Chornobyl site have successfully conducted a planned rotation today, with a new team arriving from headquarters in Vienna.
The IAEA teams at the Khmelnitsky, Rivne and South Ukraine NPPs and the Chornobyl site report safe and secure operations of these nuclear facilities despite the continuation of the conflict.
