ON April 25, 1986 engineer Yuri Andreyev left his shift at Nuclear Reactor No. 4 in Chernobyl, Ukraine. Ninety minutes later, a safety experiment went horribly wrong. The fuel rods melted triggering an explosion which blew off the roof, emitting bright raspberry-coloured light into the night sky.

The entrance gate to the Chernobyl reactor zone. (Photo by Flickr user Timm Suess, used under Creative Commons License)
On return, Andreyev faced a scene of utter devastation, stepping over the discarded boots, jackets and helmets of fire fighters, he stood in the ruins of the computer control room and looked up to blue sky.
Twenty-five years later, Andreyev runs Chernobyl Forum, a lobby group for Chernobyl’s 100,000 surviving ‘liquidators’. After weeks of heroic work, these liquidators succeeded in sealing the reactor in a makeshift steel and cement ‘sarcophagus.’