Ukraine. Province of Kiev. Chernobyl atomic power station. Three workers are leaving Chernobyl atomic power station and are checked passing through a machine if they are clean from any radioactivity contamination. Nuclear power plant. 20 years after the catastrophe which took place on April 1986 at 1.23 am with the explosion of reactor No 4. It was the world's worst nuclear power accident. © 2006 Didier Ruef