Nuclear Disasters
1. Chernobyl Nuclear Disaster:
The Chernobyl disaster was a nuclear accident that occurred on Saturday 26 April 1986, at the No. 4 nuclear reactor in the Chernobyl Nuclear Power Plant, near the city of Pripyat in the north of the Ukrainian SSR. It is considered the worst nuclear disaster in history and is one of only two nuclear energy disasters rated at seven—the maximum severity—on the International Nuclear Event Scale, the other being the 2011 Fukushima Daiichi nuclear disaster in Japan. The accident started during a safety test on an RBMK-type nuclear reactor, which was commonly used throughout the Soviet Union. More details
2. Fukushima Nuclear Disaster:
The Fukushima Daiichi nuclear disaster was a nuclear accident at the Fukushima Daiichi Nuclear Power Plant in Ōkuma, Fukushima Prefecture. The disaster was the most severe nuclear accident since the 26 April 1986 Chernobyl disaster and the only other disaster to be given the Level 7 event classification of the International Nuclear Event Scale. The accident was started by the Tōhoku earthquake and tsunami on Friday, 11 March 2011. On detecting the earthquake, the active reactors automatically shut down their fission reactions. Because of the reactor trips and other grid problems, the electricity supply failed, and the reactors' emergency diesel generators automatically started. More details
3. Three Mile Island Accident:
The Three Mile Island accident was a partial meltdown of reactor number 2 of Three Mile Island Nuclear Generating Station (TMI-2) in Dauphin County, Pennsylvania, near Harrisburg, and subsequent radiation leak that occurred on March 28, 1979. It was the most significant accident in U.S. commercial nuclear power plant history. On the seven-point International Nuclear Event Scale, the incident was rated a five as an "accident with wider consequences". The accident began with failures in the non-nuclear secondary system, followed by a stuck-open pilot-operated relief valve in the primary system, which allowed large amounts of nuclear reactor coolant to escape. More details
4. SL-1 Nuclear Accident:
The SL-1, or Stationary Low-Power Reactor Number One, was a United States Army experimental nuclear power reactor in the United States that 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 the only reactor accident in the U.S. that resulted in immediate fatalities. The accident released about 80 curies (3.0 TBq) of iodine-131, which was not considered significant due to its location in the remote high desert of eastern Idaho. About 1,100 curies (41 TBq) of fission products were released into the atmosphere. More details
5. Castle Bravo Nuclear Disaster:
Castle Bravo was the first in a series of high-yield thermonuclear weapon design tests conducted by the United States at Bikini Atoll, Marshall Islands, as part of Operation Castle. Detonated on March 1, 1954, the device was the most powerful nuclear device detonated by the United States and its first lithium deuteride fueled thermonuclear weapon. Castle Bravo's yield was 15 megatons of TNT, 2.5 times the predicted 6.0 megatons, due to unforeseen additional reactions involving 7Li, which led to the unexpected radioactive contamination of areas to the east of Bikini Atoll. At the time, it was the most powerful artificial explosion in history. More details
6. Windscale Nuclear Disaster:
The Windscale fire of 10 October 1957 was the worst nuclear accident in Great Britain's history, ranked in severity at level 5 out of a possible 7 on the International Nuclear Event Scale. The fire took place in Unit 1 of the two-pile Windscale facility on the northwest coast of England in Cumberland (now Sellafield, Cumbria). The two graphite-moderated reactors, referred to at the time as "piles", had been built as part of the British post-war atomic bomb project. Windscale Pile No. 1 was operational in October 1950 followed by Pile No. 2 in June 1951. More details
7. Simi Valley Nuclear Disaster:
The Sodium Reactor Experiment was a pioneering nuclear power plant built by Atomics International at the Santa Susana Field Laboratory near Simi Valley, California. The reactor operated from 1957 to 1964. On July 12, 1957 the Sodium Reactor Experiment became the first nuclear reactor in the United States to produce electrical power for a commercial power grid by powering the nearby city of Moorpark. In July 1959, the reactor experienced a partial meltdown where 13 of the reactor's 43 fuel elements partially melted, and a controlled release of radioactive gas into the atmosphere occurred. The reactor was repaired and restarted in September 1960. More details
8. Goiânia Nuclear Accident:
The Goiânia accident was a radioactive contamination accident that occurred on September 13, 1987, in Goiânia, in the Brazilian state of Goiás, after a forgotten radiotherapy source was taken from an abandoned hospital site in the city. It was subsequently handled by many people, resulting in four deaths. About 112,000 people were examined for radioactive contamination and 249 of them were found to have been contaminated. In the cleanup operation, topsoil had to be removed from several sites, and several hundred houses were demolished. All the objects from within those houses, including personal possessions, were seized and incinerated. More details
9. The Demon Core:
The demon core was a spherical 6.2-kilogram (14 lb) subcritical mass of plutonium 89 millimetres (3.5 in) in diameter that was involved in two criticality accidents, on August 21, 1945 and May 21, 1946. The core was intended for use in a third nuclear weapon, but remained in use for testing after Japan's surrender. It was designed with a small safety margin to ensure a successful explosion of the bomb. The device briefly went supercritical when it was accidentally placed in supercritical configurations during two separate experiments intended to guarantee the core was indeed close to the critical point. More details
10. Kyshtym Nuclear Disaster:
The Kyshtym disaster was a radioactive contamination accident that occurred on 29 September 1957 at Mayak, a plutonium production site in Russia for nuclear weapons and nuclear fuel reprocessing plant of the Soviet Union. The event occurred in Ozyorsk, Chelyabinsk Oblast, a closed city built around the Mayak plant. It measured as a Level 6 disaster on the International Nuclear Event Scale (INES),making it the third-most serious nuclear accident ever recorded, behind the Fukushima Daiichi nuclear disaster and the Chernobyl disaster (both Level 7 on the INES). At least 22 villages were exposed to radiation from the disaster, with a total population of around 10,000 people evacuated. More details
11. Tokaimura Nuclear Accident:
Tōkai is a village located in Ibaraki Prefecture, Japan. The Japan Atomic Energy Agency along with other organizations currently operate a number of nuclear technology research facilities in the town. In particular, Tōkai Nuclear Power Plant is located in Tōkai. There have been two Tokaimura nuclear accidents at the nuclear facility at Tōkai, Ibaraki: on 11 March 1997, an explosion occurred in a Dōnen plant, and on 30 September 1999, a serious criticality accident happened in a JCO plant. The first Tokaimura nuclear accident occurred in a nuclear reprocessing plant of the Dōnen (Power Reactor and Nuclear Fuel Development Corporation) on 11 March 1997. More details 12. Radium Girls Disaster:
The Radium Girls were female factory workers who contracted radiation poisoning from painting watch dials with self-luminous paint. The painting was done by women at three different United States Radium factories, and the term now applies to the women working at the facilities: one in Orange, New Jersey, beginning around 1917; one in Ottawa, Illinois, beginning in the early 1920s; and a third facility in Waterbury, Connecticut. The women in each facility had been told the paint was harmless, and subsequently ingested deadly amounts of radium after being instructed to "point" their brushes on their lips in order to give them a fine tip. More details
