Ukraine ousted Khrushchev and became the Soviet leader from 1964 to 1982. Many prominent Soviet sports players, scientists, and artists came from Ukraine. On 26 April 1986, a reactor in the Chernobyl Nuclear Power Plant exploded, resulting in the Chernobyl disaster, the worst nuclear reactor accident in history. This was the only accident to receive the highest possible rating of 7 by the International Nuclear Event Scale, indicating a "major accident", until the Fukushima Daiichi nuclear disaster in March 2011. At the time of the accident, 7 million people lived in the contaminated territories, including 2.2 million in Ukraine. After the
Nuclear safety in the United States that slow the pace and raise the cost of cleanup. The Hanford site represents two-thirds of the nation's high-level radioactive waste by volume. Today, Hanford is the most contaminated nuclear site in the United States and is the focus of the nation's largest environmental cleanup. The SL-1, or Stationary Low-Power Reactor Number One, was a United States Army experimental nuclear power reactor which underwent a steam explosion and meltdown on January 3, 1961, killing its three operators. The direct cause was the improper withdrawal of the central control rod, responsible for absorbing neutrons in the reactor core. The event is