 The Duga over-the-horizon radar array, several miles outside of Chernobyl, was the origin of the Russian Woodpecker; it was designed as part of an anti-ballistic missile early warning radar network.With the dissolution of the Soviet Union in 1991, Chernobyl remained part of Ukraine.On 26 April 1986, one of the reactors at the Chernobyl Nuclear Power Plant exploded after unsanctioned experiments on the reactor by plant operators were done improperly.