chernobyl

A nuclear accident is defined by the International Atomic Energy Agency (IAEA) as an incident in which people died or property damage topped $50,000. In 1990, IAEA introduced the International Nuclear and Radiological Event Scale (INES) to rate and rank nuclear accidents. INES is a logarithmic scale that consists of seven levels: 0 (Deviation, no safety significance), 1 (Anomaly), 2 (Incident), 3 (Serious incident), 4 (Accident with local consequences), 5 (Accident with wider consequences), 6 (Serious accident) and 7 (Major accident).

April 26, 1986

A rusting Ferris wheel dominates the skyline of Prypiat, Ukraine’s ghost town. A few kilometers away, within a massive concrete structure called the Sarcophagus, are the remnants of the worst nuclear disaster in history: the ruins of the Chernobyl Nuclear Power Plant’s reactor number four — and about 200 tons of highly radioactive material.