Ukraine says Russian drone struck Chernobyl reactor 4 dome

A Russian drone strike caused an explosion and a fire at the dome protecting the remains of the nuclear reactor that exploded in Chernobyl in 1986, according to Ukrainian President Zelenskyy. The damage to the shelter was described as “significant.”

An explosion and subsequent fire were reported at the New Safe Confinement (NSC) structure at the former Chernobyl Nuclear Plant at around 1:50 a.m. on Friday, according to the International Atomic Energy Agency (IAEA). The explosion was reportedly caused by an unmanned aerial vehicle (UAV).

So far, there is no indication of a breach in the NSC’s inner containment, and radiation levels inside and outside remain normal and stable, according to the IAEA. No casualties have been reported.

“Last night, a Russian attack drone with a high-explosive warhead struck the shelter protecting the world from radiation at the destroyed 4th power unit of the Chernobyl Nuclear Power Plant,” said President Zelenskyy. “The only country in the world that attacks such sites, occupies nuclear power plants, and wages war without any regard for the consequences is today’s Russia. This is a terrorist threat to the entire world.”

“The shelter at the Chernobyl NPP was damaged by this drone. The fire has been extinguished. As of now, radiation levels have not increased and are being constantly monitored,” Zelenskyy added. “According to initial assessments, the damage to the shelter is significant.”

Surveillance footage showed the moment of the drone impact on the dome. A sudden explosion can be seen at the shelter protecting the reactor, followed by a fire. A hole in the dome and visible damage can be seen in the aftermath.

In what is considered the worst nuclear disaster in human history, Reactor 4 at the Chernobyl Nuclear Power Plant in Pripyat, Soviet Ukraine, exploded during a late-night safety test on April 26, 1986.

A combination of reactor design flaws and operator errors led to an uncontrolled nuclear reaction, triggering a massive steam explosion and subsequent graphite fire. The explosion released large amounts of radioactive material, contaminating vast areas of Ukraine, Belarus, and Russia, and spreading fallout across Europe.

The Soviet Union initially attempted to conceal the incident, but rising radiation levels forced the evacuation of more than 100,000 people from the surrounding areas. The disaster is classified as a Level 7 event on the International Nuclear Event Scale (INES)—the highest possible rating—and remains the costliest nuclear accident in history, with an estimated financial impact of $700 billion USD.

To contain the radiation, Soviet authorities quickly constructed a concrete and steel “sarcophagus” over Reactor 4. However, the structure was hastily built and began deteriorating over time, raising concerns about potential radiation leaks.

In response, an international effort led to the construction of the New Safe Confinement (NSC), a massive steel arch designed to replace the original sarcophagus. Completed in 2016 and fully operational by 2019, the NSC is the largest movable land-based structure ever built, measuring 108 meters tall, 162 meters long, and 257 meters wide. The structure prevents further radiation leaks and enables the safe decommissioning of the damaged reactor, a process expected to take several decades.