The worst nuclear disaster in history, rated maximum severity on the INES scale, released radioactive contamination across Europe and displaced over 100,000 people.
Key Facts
- Direct ARS deaths (within 3 months)
- 28
- Workers hospitalized
- 237
- Response personnel
- 500,000+
- Estimated total cost
- 700 billion USD
- Childhood thyroid cancer cases (to 2005)
- 6,000
- People evacuated
- ~117,000
By the Numbers
Location
Cause → Event → Consequence
Plant operators conducted a safety test to simulate reactor cooling during a power blackout. Following an accidental drop in reactor power, operators proceeded with the test in conditions outside safe parameters. Design flaws in the reactor made it unstable at low power, and when operators attempted to shut it down, the flaws triggered an uncontrolled power surge.
On 26 April 1986, reactor 4 at the Chernobyl Nuclear Power Plant exploded after the power surge ruptured reactor components and caused a loss of coolant. The resulting steam explosions and nuclear meltdown destroyed the reactor building, followed by a core fire that scattered radioactive material across the Soviet Union and Europe.
The Soviet government evacuated roughly 117,000 people and established a 30 km exclusion zone. Pripyat was permanently abandoned. Twenty-eight emergency workers died of acute radiation syndrome within three months. Long-term death estimates range from 4,000 to 16,000. A concrete sarcophagus was erected in 1986, later enclosed by the New Safe Confinement structure completed in 2018, with full clean-up projected for 2065.
Human Cost
Each dot represents approximately 10,000 deaths. Total estimated: 4,000 (other)
Range: 4,000 – 16,000