Soviet Documents Reveal Cover-Ups At Chernobyl Nuclear Plant Before 1986 Disaster

After a botched safety test in the fourth reactor of the plant, located in what was then Soviet Ukraine, clouds of radioactive material from Chernobyl spread across much of Europe in what remains the world's worst nuclear disaster.

The Soviet Union knew the Chernobyl nuclear plant was dangerous and covered up emergencies there before the 1986 disaster, the Ukrainian authorities said as they released documents to mark the 35th anniversary of the accident on Monday. After a botched safety test in the fourth reactor of the plant, located in what was then Soviet Ukraine, clouds of radioactive material from Chernobyl spread across much of Europe in what remains the world's worst nuclear disaster. The archives show there was a radiation release at the plant in 1982 that was covered up using what a KGB report at the time called measures "to prevent panic and provocative rumours", Ukraine's security service (SBU) said in a statement on Monday. There were separate "emergencies" at the plant in 1984, it added.