Zelensky warns of 'critical' risk at Zaporizhzhia Nuclear Plant after power loss

Ukraine’s president Volodymyr Zelensky and the UN nuclear watchdog chief have raised alarms over the safety of the Zaporizhzhia Nuclear Power Plant, which has been without external power for more than a week as fighting continues nearby.

The facility, Europe’s largest nuclear plant and one of the 10 biggest in the world, is relying on emergency diesel generators to run cooling systems for its six shutdown reactors and spent fuel.

International Atomic Energy Agency (IAEA) Director-General Rafael Mariano Grossi said there is no immediate danger, but warned, “it is clearly not a sustainable situation in terms of nuclear safety.”

Zelensky said the backup systems were never meant to operate this long. “The generators and the plant were not designed for this,” he stated on Tuesday night, describing the situation as “critical.”

The IAEA confirmed that eight diesel generators are currently running, while nine are on standby and three under maintenance. Fuel reserves allow them to operate for more than 10 days, with supplies being regularly replenished. The plant has been alternating generators in use and servicing idle ones to keep them reliable. Grossi stressed the urgency of restoring external power, saying, “Nevertheless, it is extremely important that off-site power is restored.”

This is the 10th time since the war began that Zaporizhzhia has lost grid connection. The latest outage happened on September 23, when its last functioning power line was damaged by military activity about 1.5 kilometres from the plant, according to the IAEA.

Control of the facility has been a source of tension since Russian forces seized it in the early days of their full-scale invasion of Ukraine on February 24, 2022. The site has repeatedly been caught in the crossfire. Zelensky has blamed Russian artillery for the latest damage, while Kremlin spokesman Dmitry Peskov insisted it was caused by Ukrainian shelling. “It is stupid to accuse the Russian side of shelling the plant it controls,” Peskov told reporters Wednesday.

The IAEA has been balancing its role carefully, aiming to preserve access to nuclear facilities while avoiding angering either Moscow or Kyiv. Ukraine operates four nuclear plants, but Zaporizhzhia is the only one under Russian occupation.

The growing concern over Zaporizhzhia’s safety comes amid wider regional security worries. European leaders, rattled by recent airspace violations by drones and Russian aircraft, gathered Wednesday in Denmark for two summits focused on defence and the war in Ukraine.

Grossi noted that for now, “The current status of the reactor units and spent fuel is stable as long as the emergency diesel generators are able to provide sufficient power to maintain essential safety-related functions and cooling.” He said he remains in contact with both Russian and Ukrainian officials to push for a swift reconnection to the power grid.