Ukraine's Zaporizhzhya Nuclear Power Plant (ZNPP) lost all off-site power for several hours today, once again underlining the extremely fragile nuclear safety situation at the site, IAEA Director General Rafael Mariano Grossi said today.
The plant's connection to its last remaining 750 kilovolt (kV) power line was cut at 17:37 local time today and restored around 21:11, forcing it to rely on emergency diesel generators for more than three and a half hours. While the cause was not immediately known, it coincided with air raid alarms in the region, Director General Grossi said, citing information from the Ukrainian nuclear regulator.
It was the ninth time the ZNPP suffered a complete loss of off-site power since the conflict began in February 2022, and the first since 2 December 2023.
The IAEA team based at the site, Europe's largest nuclear power plant (NPP), reported that 18 emergency diesel generators immediately started operating to generate the electricity the plant needs to be able to cool the reactors and the spent fuel pools. The plant has diesel fuel for at least 10 days on-site, and arrangements in place to secure further supplies. Once off-site power was restored, the diesel generators were switched off.
"What was once virtually unimaginable - that a major nuclear power plant would repeatedly lose all of its external power connections - has unfortunately become a common occurrence at the Zaporizhzhya Nuclear Power Plant. Almost three and a half years into this devastating war, nuclear safety in Ukraine remains very much in danger," Director General Grossi said.
"Our team on the ground will continue to follow the situation very closely and report on further developments there," he said.
The ZNPP's six reactors have been in cold shutdown since 2024 but still require cooling water for their reactor cores and spent fuel pools. The ZNPP lost the connection to its last remaining 330 kV back-up power line on 7 May, leaving the plant dependent on its sole 750 kV line. Before the conflict, it had ten off-site power lines available, highlighting the extent to which nuclear safety has deteriorated since February 2022.
