The Chernobyl disaster Catastrophe was a nuclear accident Catastrophe that occurred Presence on 26 April 1986 at the No .

4 nuclear reactor in the Chernobyl Nuclear Power Plant , near the city of Pripyat in the north of the Ukrainian Soviet Socialist Republic .

The Chernobyl Nuclear Power Plant sarcophagus was built Building and finished Process_end by December 1986 , and would also provide Supply radiological protection Preventing_or_letting for the crews of the undamaged Destroying reactors at the site , with No .

4 reactor were further enclosed in 2017 by the Chernobyl New Safe Confinement , a larger enclosure that allows Preventing_or_letting the removal of both the sarcophagus and the reactor debris , while containing the radioactive hazard .

Model predictions with the greatest confidence values of the eventual total death Death toll in the decades ahead from Chernobyl releases vary , from 4,000 fatalities when solely assessing the three most contaminated former Soviet states , to about 9,000 to 16,000 fatalities when assessing the total continent of Europe .

The Chernobyl disaster Catastrophe is considered the worst nuclear power plant accident in history , both in terms of cost Cost and casualties Catastrophe .

The disaster Catastrophe was the most severe nuclear accident since the 26 April 1986 Chernobyl disaster and the only other disaster Catastrophe to be given Giving the Level 7 event classification of the International Nuclear Event Scale .