The Chernobyl disaster (Ukrainian: Чорнобильська катастрофа, Chornobylska Katastrofa – Chornobyl Catastrophe; also referred to as Chernobyl or the Chornobyl accident) was a catastrophic nuclear accident that occurred on 26 April 1986 at the Chernobyl Nuclear Power Plant in Ukraine (then officially the Ukrainian SSR), which was under the direct jurisdiction of the central authorities of the Soviet Union.