Question

The explosion of a nuclear electricity-generating plant in 1986 took place at Chernobyl in what location?

Answer 1

I think it was in Ukraine (at the time still part of the Soviet Union).

Explanation:

The term explosion may induce in thinking of a nuclear explosion (as in Hiroshima) but it was rather a fire that consumed the structure of containment of the reactor exposing the core of high radioactive (and very hot) fissionable material.

Answer 2

Chernobyl is North of Kiev the Capital of the Ukraine.

Explanation:

The "explosion" took place during a reactor test that caused the fuel rods to jam in the reactor. The resulting overheating caused the explosion and fire.
There is a small Museum in Kiev dedicated to event an worth the time if you go there.
https://www.tripadvisor.com/LocationPhotoDirectLink-g294474-d858059-i23108037-Chernobyl_National_Museum-Kiev.html