Russia burns occupied Zaporizhzhia nuclear plant’s last-resort generators as everyday power, Ukraine says

The Russian-occupied Zaporizhzhia Nuclear Power Plant lost the 330-kV Ferosplavna-1 line—which the International Atomic Energy Agency (IAEA) called the plant's only remaining off-site power line—on 20 August and has since run on emergency diesel generators, Ukraine's state nuclear operator Energoatom said on 6 September. A day earlier, the IAEA said the plant's diesel reserves were under increasing strain and warned it could lose all power within days unless external power was restored or fuel deliveries continued.

The Zaporizhzhia plant has been under Russian control since March 2022, when Russian forces seized the facility during the invasion. The plant stopped generating electricity in September 2022, and all six reactors have been in cold shutdown since April 2024, leaving the plant dependent on external or backup power for cooling and other essential safety systems. Repeated damage to the plant's external power connections has forced it onto emergency diesel generators multiple times, including during a month-long loss of off-site power in 2025.

How much diesel the Zaporizhzhia plant has left

The plant's most recent delivery to its off-site fuel farm took place in March, and the next one, set for May, is still held up by military activity, the IAEA reported on 20 August. At that point, the plant reported having more than 10 days of diesel available for its emergency generators.

By 29 August, the plant was down to about 10 days of diesel—its minimum regulatory reserve—and IAEA Director General Rafael Grossi said that was roughly how long it had left without restored power or more deliveries. Several dozen tons reached the plant on 27 and 28 August, but a week later the agency shortened the warning to within days, with the plant down to two generators and running its cooling pumps on and off to save fuel. No nuclear plant should have to throttle its essential cooling systems to conserve diesel, Grossi said.

How the plant lost its last external power line

Ferosplavna-1 is a backup line from the thermal plant next door, one of 10 the IAEA counted before the war. The main 750-kV Dniprovska line failed on 24 March. Technicians repaired it under a June ceasefire, but it has never been switched back on, because a substation more than 100 kilometers away was badly damaged. Ferosplavna-1 has carried the plant alone since. It went down on 26 April for the 15th time since 2022, by both counts, and cut out repeatedly around a June attack on the thermal plant. It went dead on 20 August—the 27th loss by Energoatom's count, the 26th by the IAEA's.

Ukrainian technicians began repairs on 5 September under a local ceasefire the IAEA brokered, with a few days' work expected. The line was still dead on 7 September, its 19th day without off-site power, the plant's Russian-installed management claimed to Russian media. Fixing it may not bring the power back anyway, Rosatom chief Aleksei Likhachev claimed the same day, blaming Ukrainian inaction for the other line still sitting repaired and unconnected—which the IAEA puts down to the wrecked substation.

Energoatom's assessment of the generator risk and Russian claims

Russian forces run the plant's emergency generators as everyday power, outside the conditions they were built for, Energoatom said on 6 September. Weeks of continuous running raise the risk of several backups failing together, and constant starts under load make the systems that start them likelier to fail. Even in cold shutdown, a blackout would threaten control of the safety systems and the spent fuel pools, and the plant is already in gross violation of its safe-operation limits, it said. Only a Russian pullout, military and civilian, and a handover back to Energoatom would guarantee safe operation, the company said, which also wants both grid lines back.

The plant has enough fuel for its generators but cannot restock while the access roads are shelled, the plant's Russian-installed management claimed to Russia's state news agency TASS on 31 August. TASS blamed Ukrainian forces for the shelling, though the quoted remarks named no one.