Chernobyl was a nuclear power plant and neighbouring city in Ukraine, then part of the Soviet Union.
The plant was notorious for undergoing a meltdown on 26 April 1986 which rendered the entire region uninhabitable. (COMIC: Black Destiny; AUDIO: Power Play) 40,000 people died of cancer as a result of the disaster. (PROSE: Iceberg)
In 2007, agents of the Three Families dropped an abducted Jack Harkness onto the grounds of the plant from a plane, after they had confirmed his ability to heal. (WC: Web of Lies)
Other references
In 2006, Mr Cleaver feared that the Blaidd Drwg project in Cardiff could risk a meltdown a thousand times worse than Chernobyl. (TV: Boom Town)
In 2040, Xin Chun told Roz Forrester about the Chernobyl disaster. (PROSE: The Nuclear Option)