Europe's largest nuclear power plant, Ukraine's Zaporizhzhia facility in the country's southeast, has been without off-site power for more than a week and is operating on emergency diesel generators, the International Atomic Energy Agency (IAEA) warned on Saturday. The plant, which sits on the banks of the Dnipro River and marks the front line in the sector, has been under Russian military occupation since March 2022, weeks after Moscow launched its full-scale invasion of Ukraine in February of that year.

The IAEA said the power loss followed military activity on the northern side of the Dnipro River, severing the plant's regular electricity supply. With only a ten-day diesel reserve on site, the Vienna-based watchdog described fuel availability as being "of paramount importance." The plant had not received a delivery to its off-site storage facility in roughly six months, though emergency diesel supplies were brought in from a separate off-site location on Thursday and Friday. IAEA Director General Rafael Grossi stressed that the crisis "once again shows why reliable external power and secure supply routes are indispensable for nuclear safety and security."

This marks the 27th blackout at the plant since the start of Russia's full-scale invasion, according to Ukraine's deputy head of military law enforcement, Gyunduz Mamedov. Although Zaporizhzhia's six reactors have not generated electricity since September 2022, they must continue to be actively cooled to prevent the nuclear fuel inside from overheating and causing a meltdown. The IAEA, which has maintained a permanent presence at the site since September 2022, is now working to negotiate a localised ceasefire that would allow engineers to repair damaged electrical lines.

Safety concerns at the site have been mounting. The IAEA reported three separate drone incidents at the plant during the past week, wounding two employees. Earlier this month, a drone strike near the facility killed one nuclear specialist and injured 17 others; Moscow blamed Kyiv for the attack. Both sides in the conflict routinely accuse the other of targeting the site. Ukrainian officials have long characterised Russian conduct at and around the plant as nuclear blackmail directed at Ukraine and Europe as a whole.

The recurring blackouts and escalating incidents around Zaporizhzhia underscore the fragility of nuclear safety in an active war zone. With repairs to power lines dependent on a ceasefire that has yet to materialise, and diesel reserves providing only a narrow safety margin, international pressure on both parties to protect the facility is likely to intensify.