Featured moment · World history

Chernobyl nuclear disaster

26 April 1986

An explosion at the Chernobyl nuclear power plant released radioactive material across large areas.

Later photograph of the damaged Chernobyl Reactor 4 building and its protective shelter — Photograph: Dana Sacchetti / IAEA Imagebank, photographed in 2010 / Wikimedia Commons (not a photograph from 1986). View image, creator and licence on Wikimedia Commons.

What happened?

During a late-night safety test on 26 April 1986, Reactor 4 at the Chernobyl nuclear power plant, in what is now Ukraine, suffered a catastrophic power surge and explosions. Fire and damage to the reactor released radioactive material, and nearby communities including Pripyat were evacuated.

Why it mattered

The disaster caused long-term human, environmental and economic harm. It exposed shortcomings in reactor design, operational practices and emergency information-sharing, prompting international attention to nuclear safety and emergency preparedness.