Ground Zero: The Chernobyl Control Room Moments Before History Changed This image shows the control room of Reactor 4 at the Chernobyl Nuclear Power Plant in Pripyat, Ukraine, just before it became the site of the world's worst nuclear disaster. On April 26, 1986, a scheduled late-night safety test in this very room went catastrophically wrong. Unstable reactor conditions combined with critical design flaws led to an explosion that instantly blew the 1,000-ton reactor lid into the air. This room