UN agency says sarcophagus covering ruined Chernobyl reactor lost key functions after drone strike

The protective sarcophagus built over the highly radioactive remains of Reactor 4 at the Chernobyl Nuclear Power Plant north of Kyiv can no longer perform its key safety functions due to damage caused by a drone strike, the International Atomic Energy Agency (IAEA) announced on Friday.

The damage stems from a February 2025 drone strike that Ukraine says was carried out by Russia, with Ukrainian President Volodymyr Zelensky saying at the time, “The only state in the world that could attack such facilities, occupy the territory of nuclear power plants and wage war without taking its consequences into account at all, is today’s Russia.”

Radiation levels at the plant remained normal and there were no reports of radiation leaks following the strike, the UN said in February. However, after completing a “comprehensive safety assessment” of the protective shield, IAEA experts found that the protective shield had lost “confinement capability”.

“Limited temporary repairs have been carried out on the roof, but timely and comprehensive restoration remains essential to prevent further degradation and ensure long-term nuclear safety,” IAEA Director General Rafael Grossi said.

Completed with assistance from the US and Europe in 2019 and intended to seal the remains of Reactor 4 for 100 years, the New Safe Confinement (NSC) is a massive steel and concrete structure that was commissioned to replace the original sarcophagus built immediately after the Chernobyl disaster in 1986.

Chernobyl’s Reactor 4 exploded on 26 April 1986, causing one the worst nuclear accidents the world has ever seen. Russian troops briefly occupied the plant in the early days of the war before Ukrainian forces regained control of the mothballed complex in March 2022.