Ukraine's Zaporizhzhya Nuclear Power Plant (ZNPP) lost the connection to its main off-site power line today, forcing it to rely on back-up electricity for reactor cooling in the latest incident underlining the precarious nuclear safety and security situation at the site during the ongoing military conflict, Director General Rafael Mariano Grossi said.
Separately today, the IAEA experts present at the ZNPP heard several rockets that appeared to have been fired from close to the plant. The IAEA team did not see the projectiles because of clouds but the distinctive sound indicated they were fired from a Multiple Launch Rocket System (MLRS) nearby.
"Today's events once again clearly demonstrate the extremely fragile nuclear safety and security situation at the Zaporizhzhya Nuclear Power Plant. Europe's largest nuclear power plant - located on the frontline - continues to face many potential threats as a result of this tragic war," Director General Grossi said.
"I remain deeply concerned about nuclear safety and security at the plant, both when it comes to its vulnerable off-site power supplies - which can be affected by attacks far away from the site - and the more direct military risks it is facing, potentially undermining the principles that I set out at the United Nations Security Council in May. In this context, the apparent firing of rockets from near the plant is a special source of concern," he said.
The ZNPP said a short circuit that occurred around 100 kilometres north of the plant caused the cut in the connection to its sole remaining 750 kilovolt (kV) power line - out of the four that existed before the conflict - at around 10:30am local time.
The plant continues to receive external power from its only available 330 kV back-up power line. However, one emergency diesel generator also started operating to supply reactor unit 4 after the power loss, indicating a possible issue with its electrical configuration. The diesel generator was manually shut down after ten minutes.
The plant said the 750 kV line is being repaired but it was not clear when it will be reconnected.
The ZNPP has lost external power supplies repeatedly during the conflict, including seven complete loss of off-site power events. On each of those occasions, the operation of emergency diesel generators at the site was required to provide the electricity needed by the plant for vital nuclear safety and security functions, including reactor cooling. The connection to the 750 kV line was last lost on 10 August, when the line disconnected and was reconnected twice on the same day.
