The
Chernobyl disaster (also referred to as
Chernobyl or
the Chernobyl accident) was a
catastrophic nuclear accident that occurred on 26 April 1986 at the
Chernobyl Nuclear Power Plant in the town of
Pripyat, in Ukraine (then officially the
Ukrainian SSR), which was under the direct jurisdiction of the central authorities of the
Soviet Union. An explosion and fire released large quantities of radioactive particles into the atmosphere, which spread over much of the western USSR and
Europe.