WEEKLY PUZZLES · APRIL 26

Chernobyl Reactor No. 4 Explodes During Safety Test

A late-night test at one reactor changed nuclear safety far beyond the Soviet Union. The first signs of its reach soon appeared outside Ukraine.

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Chernobyl Nuclear Power Plant near Pripyat after the 26 April 1986 explosion at Reactor No. 4 in the Ukrainian SSR.
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Chernobyl Nuclear Power Plant near Pripyat after the 26 April 1986 explosion at Reactor No. 4 in the Ukrainian SSR.

Chernobyl Reactor No. 4 Explodes During Safety Test

A late-night test at one reactor changed nuclear safety far beyond the Soviet Union. The first signs of its reach soon…