What nuclear power plant disaster occurred in Ukraine in 1986?

The nuclear power plant disaster that occurred in Ukraine in 1986 was the Chernobyl disaster.

On April 26, 1986, reactor No. 4 at the Chernobyl Nuclear Power Plant exploded during a safety test near the city of Pripyat in the Ukrainian SSR, then part of the Soviet Union. A rapid power surge, reactor design flaws, and operator actions caused explosions and a prolonged graphite fire that released radioactive material across the Soviet Union and parts of Europe.

The accident was rated Level 7, the maximum category on the International Nuclear Event Scale. Pripyat was evacuated, and authorities eventually created a 30-kilometre exclusion zone around the plant. Emergency workers, known as liquidators, fought the fire and contained the damaged reactor under a concrete structure later replaced by the New Safe Confinement.

Chernobyl is often confused with Three Mile Island or Fukushima. Three Mile Island occurred in the United States in 1979, while Fukushima occurred in Japan in 2011. Chernobyl remains especially notable for its reactor explosion, open-air fire, and enormous long-term political and environmental impact.