Chernobyl murdered during the Nazi occupation of 1941–44. Twenty years later, the area was chosen as the site of the first nuclear power station to be built on Ukrainian soil. 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, Reactor No. 4 at the Chernobyl Nuclear Power Plant exploded after tests were done on the reactor improperly and the operators lost control.
Tihange Nuclear Power Station power plants these were already built in after the nuclear disaster in Chernobyl in 1986. Other countries followed this example, latest after the Fukushima nuclear disaster. This kind of system allows for the containment pressure to be relieved in the event of a severe accident. The non-condensible gases that cause pressure within containment to rise are released through a stack (or chimney) via a filtration system that removes large quantities of fission products from the effluent. As part of the stress tests following the Fukushima incident, this issue had already been identified to be included in the stress-test action plan