September 29, 1957: A massive explosion at a warehouse containing nuclear waste at Chelyabinsk 65, a clandestine nuclear plant in the Ural Mountains of the Soviet Union, forces the Soviet authorities to evacuate 11,000 people.
October 7, 1957: A fire at a nuclear reactor in Windescale on the northeast coast of England contaminates the entire country with radioactive material and kills at least 39 people with cancer.
January 3, 1961: A nuclear reactor explodes in a laboratory in Iowa, killing three workers on the spot.
Summer 1967: Lake Karacha in the former Soviet Union, where Chelyabinsk 65 had been used to store nuclear waste, dries up and the winds blow so many radioactive particles around that the authorities have to evacuate 9,000 people.
November 9, 1971: An overstocking of the wastewater storage facility at a nuclear reactor at Northern States Power Company in Minnesota, USA, results in 5,000 gallons of radioactive wastewater flowing into the Mississippi River, some of which even makes its way into the municipal drinking water system in St. Paul.
March 28, 1979: Cooling water and radioactive particles escape from the Three Mile Island nuclear reactor in the U.S. due to mechanical failure and human error, but no injuries are reported.
August 7, 1979: A leak of enriched uranium in the US state of Tennessee results in 1,000 injuries.
January 6, 1986: An explosion caused by faulty heating at a nuclear power plant in Oklahoma, U.S., kills one worker and hospitalizes 100 people.
April 26, 1986: A massive explosion at the Chernobyl nuclear power plant in the former Soviet Union sends a cloud of radioactivity straight to Western Europe, killing about eight thousand people with radiation-induced illnesses. The explosion ultimately resulted in the contamination of more than 200,000 square kilometers of land, with today's Ukraine, Russia, and Belarus suffering the worst nuclear contamination. The radioactive contamination caused by the accident spread over 150,000 square kilometers of the former Soviet Union, where 694.5 million people lived. As a result of the accident, a 30-kilometer area around the nuclear power plant was designated as a quarantine zone, nearby residents were evacuated, crops were completely buried, and trees within 7,000 meters of the plant gradually died. For the next half-century, farming and grazing will not be allowed within 10 kilometers; milk production will be banned within 100 kilometers for 10 years. Chernobyl's radiation was spread by wind, rain and other means, contaminating some of the world's most productive soils in Ukraine, Belarus and Russia. Seventy percent of the radioactive dust leaked from the Chernobyl nuclear accident drifted down to Belarusian territory. In the early days of the accident, most of the citizens of Belarus were exposed to varying degrees of nuclear radiation, 6,000 square kilometers of land were rendered unusable, more than 400 settlements became no-man's land, and the government had to close more than 600 schools, 300 businesses, and 54 large agricultural complexes.
March 12, 2011: A hydrogen explosion occurs at Unit 3 of Japan's Tokyo Electric Power Co.'s Fukushima Daiichi nuclear power plant just after 11 a.m. local time. The Fukushima Prefectural Government said in a release on March 13 that 19 people evacuated from a 3-kilometer radius of the Fukushima Daiichi nuclear power plant were newly confirmed to have been exposed to nuclear radiation, and the number of people confirmed to have been exposed to nuclear radiation thus rose to 22 people. Nuclear material leaking from the Fukushima Daiichi plant has traveled to Tokyo, where the amount of radiation has exceeded 20 times the usual level and continues to rise.
March 15, 2011: An explosion occurs at TEPCO's Kamifukushima Daiichi nuclear power plant, with units 1-4 shutting down automatically after the earthquake, and unit 3 going into "cold shutdown" immediately. As of the 15th, 1, 2 and 4 units all realize "cold temperature stop" stable state, out of the emergency.