In nuclear energy, we refer to nuclear accident to those incidents that emit a certain level of radiation, which could harm public health.
Nuclear accidents are classified as nuclear accidents and incidents depending on the severity´s level. In this classification nuclear accidents and radioactive accidents are included. To understand the difference between these two types of accidents, a nuclear accident could be the failure of a reactor of a nuclear power plant and a radiation accident could be when pouring a radiation source to a river.
Despite the known nuclear accidents have occurred at nuclear power plants, they can also happen in other places where nuclear energy is used to work; for example hospitals or research laboratories.
To determine the severity of an accident, an International Nuclear Event Scale (better known by its acronym INES) has been established.
Due to the secrecy of governments and the companies that own nuclear plants, in some cases it is difficult to determine the severity or extension if a nuclear accident as well as its impact.
Civilian nuclear accidents during the history of nuclear energy
1952 and 1958 - Nuclear accident in the nuclear power plant Chalk River, Canada
On December 12, 1952, in Canada, the first serious nuclear accident occurs in the nuclear reactor of Chalk River NRX.
1957 - Nuclear Accident in Mayak, Russia
Mayak is the name given to a known center nuclear facilities located between the cities of Kaslo and Kyshtym, in the province of Chelyabinsk, Russia.
It is one of the points of the planet with pollution by radioactive materials, although it is not that known because the Soviet authorities have been trying to hide during 30 years that nuclear leaks have been occurring.
1957 - Nuclear accident at Windscale Pile, United Kingdom
In October 1957, a nuclear accident occurs at the Windscale reactor number one, in Cumberland (now Sellafield, Cumbria). This incident became the worst nuclear accident in history of the United Kingdom classified at Level 5 of the INES scale.
The fire at the nuclear reactor led to the release of radioactive material into the surrounding area. The radiation could have caused about 240 cases of cancer. Nobody was evacuated from the affected area, but there was concern about the possible contamination of the milk.
The air ducts of the reactor outlet were sealed and the fuel cartridges were removed. The second nuclear reactor at the site was also closed, although it was undamaged by fire.
1979 - Nuclear accident in the Three Mile Island nuclear power plant, USA
In March 1979, the nuclear power plant at Three Mile Island had a serious nuclear accident after the first year of operating. Misinterpretation of data caused serious errors in certain decisions of plant personnel. Although the core of the nuclear reactor was badly damaged, it had limited radioactive products escape outwards. The accident was classified as Level 5 on the International Nuclear Event Scale (INES).
1980 - Nuclear accident in the Saint Laurent des Eaux nuclear power plant, France
The worst nuclear accident in France occurred in the nuclear power plant Saint Laurent des Eaux next to the river Loire. It happened in March 1980. A failure in the cooling system caused the melting of a fuel channel in the Saint Laurent A2 reactor.
This nuclear accident was classified as Level 4 on the INES scale. No radioactive material was released outside the plant.
1986 - Nuclear Accident in the Chernobyl nuclear power plant, Ukraine
In April 1986, there was the largest nuclear accident in the history of nuclear power in Chernobyl by a several human errors in the course of a previously planned test. It was classified as level 7 ("major nuclear accident") on the INES scale.
1987 - Nuclear accident in Goiânia, Brazil
In September 1987 the city of Goiânia in Brazil had a radioactive contamination accident. Two men robbed a teletherapy device and they manipulated it. They extracted a cesium capsule from his protective housing what made it a radioactive cesium-137 source. The International Atomic Energy Agency (IAEA) highlighted that nuclear accident as one of the worst radiological incidents worldwide.
The nuclear accident in Goiânia was considered Level 5 on the INES scale. Residences and public places are severely polluted. Four people died and 28 suffered radiation burns. As part of decontamination process, several buildings were demolished and farmland was removed.
In September 1999, there was a nuclear accident at the Tokaimura uranium fuel treatment plant, owned by the company JCO in Tokaimura. All signs pointed out that it was due to human error. The accident was classified as level 4 according to INES scale ("accident without significant off-site risk"), since the amounts of radiation released to the outside were very small, and within the limits and within the site. The damage produced in the equipment and biological barriers was significant, addition to worker exposure fatal.
2011 - Nuclear accident in the Fukushima nuclear power plant, Japan
Last review: November 29, 2014