Ukraine‘s Chernobyl nuclear power plant, the site of the world’s worst civil nuclear disaster, experienced a complete loss of off-site power on Tuesday morning following extensive military activity, the UN atomic watchdog has confirmed.
The International Atomic Energy Agency (IAEA) reported that several Ukrainian electrical substations, vital for maintaining nuclear safety, were impacted by the ongoing hostilities.
Power lines supplying other nuclear facilities across the country were also affected.
“The IAEA is actively following developments in order to assess impact on nuclear safety,” Rafael Grossi, the director of the International Atomic Energy Agency (IAEA) added.
This incident occurred as Russia launched a significant drone and missile assault on Ukraine early on Tuesday.
Ukrainian officials stated that the attacks knocked out power and heating supplies to thousands of homes in Kyiv, leaving residents in freezing temperatures.
The power loss comes after the UN’s nuclear watchdog previously warned the protective shield at the Chernobyl power plant can no longer contain radioactive material due to damage caused by a drone strike in Feburary 2025.
The plant was damaged by a drone armed with a warhead, which pierced the outer shell, helping prevent radiation leaks from Chernobyl’s reactor Number Four.
Ukraine said Russia was behind the attack, but the Kremlin denied responsibility.
Mr Grossi said an inspection in December 2025 found that the structure had “lost its primary safety functions, including the confinement capability”.
No permanent damage has been done to the load-bearing structures or monitoring systems.
Although repairs have been carried out, the site requires a “comprehensive restoration” in order to “prevent further degradation and ensure long-term nuclear safety”, Mr Grossi said.
The shield was built in 2016 to prevent the release of radioactive material into the atmosphere due to the Chernobyl disaster. The plant’s last working reactor was closed in 2000.
Chernobyl was destroyed in 1986 when the plant exploded and sent radiation across Europe. It remains the world’s worst nuclear accident, killing 31 people.