List of nuclear power accidents by country
Worldwide, many nuclear accidents and serious incidents have occurred since the Chernobyl disaster in 1986. Two thirds of these mishaps occurred in the US. The French Atomic Energy Commission has concluded that technical innovation cannot eliminate the risk of human errors in nuclear plant operation.
Nuclear safety
The nuclear power industry has improved the safety and performance of reactors, and has proposed new safer reactor designs but there is no guarantee that the reactors will be designed, built and operated correctly. Mistakes do occur and the designers of reactors at Fukushima in Japan did not anticipate that a tsunami generated by a such unexpected large earthquake would disable the backup systems that were supposed to stabilize the reactor after the earthquake. According to UBS AG, the Fukushima I nuclear accidents have cast doubt on whether even an advanced economy like Japan can master nuclear safety. Catastrophic scenarios involving terrorist attacks are also conceivable. An interdisciplinary team from MIT has estimated that given the expected growth of nuclear power from 2005–2055, at least four serious nuclear accidents would be expected in that period.Overview
Globally, there have been at least 99 recorded nuclear power plant accidents from 1952 to 2009, totaling US$20.5 billion in property damages. Property damage costs include destruction of property, emergency response, environmental remediation, evacuation, lost product, fines, and court claims. Because nuclear power plants are large and complex, accidents on site tend to be relatively expensive.The 1979 Three Mile Island accident in Pennsylvania was caused by a series of failures in secondary systems at the reactor, which allowed radioactive steam to escape and resulted in the partial core meltdown of one of two reactors at the site, making it the most significant accident in U.S. history.
The world's worst nuclear accident has been the 1986 Chernobyl disaster in the Soviet Union, one of two accidents that has been rated as a level 7 event on the International Nuclear Event Scale. Note that the Chernobyl disaster may have scored an 8 or 9, if the scale continued. The accident occurred at the Chernobyl Nuclear Power Plant after an unsafe systems test led to a series of steam explosions that destroyed reactor number four. The plume spread in the near distance primarily over Belarus and after that covered extensive portions of Europe with traces of radioactivity, leaving reindeer in Northern Europe and sheep in portions of England unfit for human consumption. A "Zone of alienation" has been formed around the reactor.
At least 57 accidents and severe incidents have occurred since the Chernobyl disaster, and over 56 severe incidents have occurred in the USA. Relatively few accidents have involved fatalities.
Note that not all ratings are final as Cancer and Uncounted/Hidden results may have/will occur.
Belgium
This list is incomplete. See also Laka Foundation's list of recent nuclear and radiological incidents in Belgium.| Date | Location | Description | Fatalities | Cost | INES rating |
| 2002 | Tihange, Belgium | "Safety injection during hot shutdown at Tihange 2 unit". | 2 | ||
| 2005 | Tihange, Belgium | "Inadequate protection relays and related setpoints". | 2 | ||
| 2006 | Fleurus, Belgium | "Severe health effects for a worker at a commercial irradiation facility as a result of high doses of radiation". | 4 | ||
| 2008 | Fleurus, Belgium | Iodine-131 release in the environment. | 3 | ||
| 2011 | Doel, Belgium | "Inadequate setting of the auxiliary feedwater turbopump". | 2 |
Canada
France
Germany
India
Japan
| Date | Location | Description | Fatalities | Cost | INES rating |
| 8 Jan 1975 | Mihama, Japan | Radioactivity released from Mihama nuclear power plant. | 0 | ||
| 2 Nov 1978 | Fukushima No I, Japan | Japan's first criticality accident at No 3 reactor, this accident was hidden for 29 years and reported on 22 Mar 2007 | 0 | ||
| 2 Apr 1979 | Tokaimura, Japan | Two workers suffer radioactive contamination at the Tokaimura complex. | 0 | ||
| 24–28 Jan 1981 | Tsuruga, Japan | 29 workers were exposed to radiation. | 0 | ||
| 8 Mar 1981 | Tsuruga, Japan | 56 workers were exposed to about 45 tonnes of radioactive waste which spilled from storage tanks at the Tsuruga Nuclear Power Plant. The waste was cleaned up with buckets and mops, and was also discharged into Tsuruga Bay via the town sewer. At the time, the plant had recorded 30 malfunctions since it was commissioned in 1970. | 0 | ||
| 31 Aug 1985 | Fukushima, Japan | Fire at Fukushima nuclear power plant during routine shutdown. | 0 | ||
| 23 Jun 1986 | Tokaimura, Japan | Twelve people suffer "slight" plutonium contamination while inspecting a storeroom. | 0 | ||
| 8 Feb 1991 | Fukui, Japan | Radioactivity was released from Mihama nuclear power plant after an emergency release valve failed. Officials said the release "did not pose a threat to humans or the environment." | 0 | ||
| 22 Feb 1993 | Fukushima, Japan | High-pressure steam accident kills one worker and injures two others. | 1 | ||
| December 1995 | Tsuruga, Japan | The fast breeder Monju Nuclear Power Plant sodium leak. State-run operator Donen was found to have concealed videotape footage that showed extensive damage to the reactor. | 0 | ||
| 11 March 1997 | Tokaimura, Japan | The Tokaimura nuclear reprocessing plant fire and explosion. 37 workers were exposed to low doses of radiation. Donen later acknowledged it had initially suppressed information about the fire. | 0 | ||
| 18 Jun 1999 | Shika, Japan | Wrong handling of some control rods set off an uncontrolled nuclear reaction. | 0 | 2 | |
| 30 Sept 1999 | Tokaimura, Japan | The criticality accident at the Tokai fuel fabrication facility. Hundreds of people were exposed to radiation and two workers later died. This is not a nuclear power plant accident, however. | 2 | 4 | |
| 2002 | Onagawa, Japan | Two workers were exposed to a small amount of radiation and suffered minor burns during a fire. | 0 | ||
| 9 Aug 2004 | Mihama, Japan | A main piping burst in the turbine building of the Mihama-3 station and killed persons present there; the subsequent investigation revealed a serious lack in systematic inspection in Japanese nuclear plants, which led to a massive inspection program. | 5 | 1 | |
| 2006 | Fukushima No1, Japan | A small amount of radioactive steam was released at the Fukushima Dai-ichi plant and it escaped the compound. | 0 | ||
| 16 Jul 2007 | Kashiwazaki, Japan | A severe earthquake hit the region where Tokyo Electric's Kashiwazaki-Kariwa Nuclear Power Plant is located and radioactive water spilled into the Sea of Japan; as of March 2009, all of the reactors remained shut down for damage verification and repairs. The plant with seven units is the largest single nuclear power station in the world, which now again is shut down due to the Fukushima accident. | 0 | 1 | |
| Dec 2009 | Hamaoka, Japan | Leakage accident of radioactive water. 34 workers were exposed to radiation | 0 | ||
| Mar 2011 | Fukushima Dai-ichi, Japan | The world's second INES 7 accident. A magnitude 9.0 earthquake and associated tsunami triggered cooling problems at Fukushima 1 & 2 stations with several reactors. Loss of coolant resulted in meltdowns in three units and hydrogen explosions caused their structural damage. Radioactive steam was released into the atmosphere, and highly radioactive water spilled into the ocean through utility trenches. Some immediate injuries resulted. 117 workers received committed effective doses above 100 mSv, and 6 workers received doses above the emergency dose limit of 250 mSv. | 2+; further near 1,600 died from evacuation stress | 1,200 - 2,100 | 7 |
| 6 June 2017 | Ibaraki Prefecture | The incident occurred at the Japan Atomic Energy Agency's Oarai Research and Development Center, after a bag containing radioactive material tore open while a check on radioactive storage inside a "controlled" room was performed. It resulted in internal radiation exposure in five workers, with one of them inhaling plutonium. However, no radiation was detected in the external environment. | 0 |
Pakistan
Russia
South Korea
Switzerland
Taiwan
Ukraine
United Kingdom
United States
| Date | Location | Description | Fatalities | Cost | INES |
| November 29, 1955 | Idaho Falls, Idaho, USA | Power excursion with partial core meltdown at National Reactor Testing Station's EBR-1 Experimental Breeder Reactor I | 0 | 5 | |
| July 26, 1959 | Simi Valley, California, USA | Partial core meltdown at Santa Susana Field Laboratory’s Sodium Reactor Experiment | 0 | 32 | |
| January 3, 1961 | Idaho Falls, Idaho, USA | Explosion at National Reactor Testing Station's SL-1 Stationary Low-Power Reactor Number One | 3 | 22 | 4 |
| October 5, 1966 | Monroe, Michigan, USA | Sodium cooling system malfunctions at Enrico Fermi demonstration breeder reactor causing some fuel elements to melt | 0 | 19 | 4 |
| August 11, 1973 | Palisades, Michigan, USA | Steam generator leak causes manual shutdown of pressurized water reactor | 0 | 10 | |
| March 22, 1975 | Browns Ferry, Alabama, USA | Fire burns for seven hours and damages more than 1600 control cables for one of the three nuclear reactors at Browns Ferry, disabling core cooling systems | 0 | 240 | 3 |
| November 5, 1975 | Brownsville, Nebraska, USA | Hydrogen gas explosion damages the Cooper Nuclear Station’s auxiliary building | 0 | 13 | |
| June 10, 1977 | Waterford, Connecticut, USA | Hydrogen gas explosion damages three buildings and forces shutdown of Millstone-1 Boiling Water Reactor | 0 | 15 | |
| February 4, 1979 | Surry, Virginia, USA | Surry Unit 2 shut down in response to failing tube bundles in steam generators | 0 | 12 | |
| March 28, 1979 | Middletown, Pennsylvania, USA | Loss of coolant and partial core meltdown, see Three Mile Island accident and Three Mile Island accident health effects | 0 | 2,400 | 5 |
| October 17, 1981 | Buchanan, New York, USA | 100,000 gallons of Hudson River water leaked into the Indian Point Energy Center Unit 2 containment building from the fan cooling unit, undetected by a safety device designed to detect hot water. The flooding, covering the first 9 feet of the reactor vessel, was discovered when technicians entered the building. Two pumps which should have removed the water were found to be inoperative. NRC proposed a $210,000 fine for the incident. | 0 | ||
| January 25, 1982 | Rochester, New York, USA | Steam generator-leak at the Ginna Nuclear Generating Station causes extensive injection of the high pressure emergency core cooling system | 0 | ? | |
| March 20, 1982 | Lycoming, New York, USA | Recirculation system piping fails at Nine Mile Point Unit 1, forcing two year shutdown | 0 | 45 | |
| March 25, 1982 | Buchanan, New York, USA | Damage to steam generator tubes and main generator resulting in a shut down Indian Point Energy Center Unit 3 for more than a year | 0 | 56 | |
| June 18, 1982 | Senaca, South Carolina, USA | Feedwater heat extraction line fails at Oconee 2 Pressurised Water Reactor, damaging thermal cooling system | 0 | 10 | |
| February 12, 1983 | Forked River, New Jersey, USA | Oyster Creek Nuclear Power Plant fails safety inspection, forced to shut down for repairs | 0 | 32 | |
| February 26, 1983 | Fort Pierce, Florida, USA | Damaged thermal shield and core barrel support at St Lucie Unit 1, necessitating 13-month shutdown | 0 | 54 | |
| September 15, 1984 | Athens, Alabama, USA | Safety violations, operator error, and design problems force six year outage at Browns Ferry Unit 2 | 0 | 110 | |
| March 9, 1985 | Athens, Alabama, USA | Instrumentation systems malfunction during start-up, which led to suspension of operations at all three Browns Ferry Units | 0 | 1,830 | |
| April 11, 1986 | Plymouth, Massachusetts, USA | Recurring equipment problems force emergency shutdown of Boston Edison's Pilgrim Nuclear Power Plant | 0 | 1,001 | |
| 1986 | Surry, Virginia, USA | Broken Feedwater pipe at Surry Nuclear Power Plant kills 4 | 4 | ? | |
| March 31, 1987 | Delta, Pennsylvania, USA | Peach Bottom units 2 and 3 shutdown due to cooling malfunctions and unexplained equipment problems | 0 | 400 | |
| December 19, 1987 | Lycoming, New York, USA | Malfunctions force Niagara Mohawk Power Corporation to shut down Nine Mile Point Unit 1 | 0 | 150 | |
| September 10, 1988 | Surry, Virginia, USA | Refuelling cavity seal fails and destroys internal pipe system at Surry Unit 2, forcing 12-month outage | 0 | 9 | |
| March 5, 1989 | Tonopah, Arizona, USA | Atmospheric dump valves fail at Palo Verde Unit 1, leading to main transformer fire and emergency shutdown | 0 | 14 | |
| March 17, 1989 | Lusby, Maryland, USA | Inspections at Calvert Cliff Units 1 and 2 reveal cracks at pressurized heater sleeves, forcing extended shutdowns | 0 | 120 | |
| November 17, 1991 | Scriba, New York, USA | Safety and fire problems force shut down of the FitzPatrick nuclear reactor for 13 months | 0 | 5 | |
| April 21, 1992 | Southport, North Carolina, USA | NRC forces shut down of Brunswick Units 1 and 2 after emergency diesel generators fail | 0 | 2 | |
| February 3, 1993 | Bay City, Texas, USA | Auxiliary feed-water pumps fail at South Texas Project Units 1 and 2, prompting rapid shutdown of both reactors | 0 | 3 | |
| February 27, 1993 | Buchanan, New York, USA | New York Power Authority shuts down Indian Point Energy Center Unit 3 after AMSAC system fails | 0 | 2 | |
| March 2, 1993 | Soddy-Daisy, Tennessee, USA | Equipment failures and broken pipes cause shut down of Sequoyah Unit 1 | 0 | 3 | |
| December 25, 1993 | Newport, Michigan, USA | Shut down of Fermi Unit 2 after main turbine experienced major failure due to improper maintenance | 0 | 67 | |
| 14 January 1995 | Wiscasset, Maine, USA | Steam generator tubes unexpectedly crack at Maine Yankee nuclear reactor; shut down of the facility for a year | 0 | 62 | |
| May 16, 1995 | Salem, New Jersey, USA | Ventilation systems fail at Salem Units 1 and 2 | 0 | 34 | |
| February 20, 1996 | Connecticut, USA | Leaking valve forces shutdown Millstone Nuclear Power Plant Units 1 and 2, multiple equipment failures found | 0 | 254 | |
| September 2, 1996 | Crystal River, Florida, USA | Balance-of-plant equipment malfunction forces shutdown and extensive repairs at Crystal River Unit 3 | 0 | 384 | |
| September 5, 1996 | Clinton, Illinois, USA | Reactor recirculation pump fails, prompting shut down of Clinton boiling water reactor | 0 | 38 | |
| September 20, 1996 | Senaca, Illinois, USA | Service water system fails and results in closure of LaSalle Units 1 and 2 for more than 2 years | 0 | 71 | |
| September 9, 1997 | Bridgman, Michigan, USA | Ice condenser containment systems fail at Cook Units 1 and 2 | 0 | 11 | |
| May 25, 1999 | Waterford, Connecticut, USA | Steam leak in feed-water heater causes manual shutdown and damage to control board annunciator at the Millstone Nuclear Power Plant | 0 | 7 | |
| September 29, 1999 | Lower Alloways Creek, New Jersey, USA | Major Freon leak at Hope Creek Nuclear Facility causes ventilation train chiller to trip, releasing toxic gas and damaging the cooling system | 0 | 2 | |
| February 16, 2002 | Oak Harbor, Ohio, USA | Severe corrosion of control rod drives in the reactor head forces 24-month outage of Davis-Besse reactor | 0 | 143 | |
| January 15, 2003 | Bridgman, Michigan, USA | A fault in the main transformer at the Donald C. Cook nuclear power plant causes a fire that damages the main generator and back-up turbines | 0 | 10 | |
| June 16, 2005 | Braidwood, Illinois, USA | Exelon's Braidwood Nuclear Generating Station leaks tritium and contaminates local water supplies | 0 | 41 | |
| August 4, 2005 | Buchanan, New York, USA | Entergy's Indian Point Energy Center Nuclear Plant leaks tritium and strontium into underground lakes from 1974 to 2005 | 30 | ||
| March 6, 2006 | Erwin, Tennessee, USA | Nuclear fuel services plant spills 35 litres of highly enriched uranium, necessitating 7-month shutdown | 0 | 98 | |
| November 21, 2009 | Harrisburg, Pennsylvania, USA | Twelve workers were contaminated after radioactive dust was mobilized at the Three Mile Island plant during pipe maintenance works. | 0 | ||
| January 7, 2010 | Buchanan, New York, USA | NRC inspectors reported that an estimated 600,000 gallons of mildly radioactive steam was intentionally vented after an automatic shutdown of Indian Point Energy Center Unit 2. The levels of tritium in the steam were below those allowable by NRC safety standards. | 0 | 0 | |
| February 1, 2010 | Vernon, Vermont, USA | Deteriorating underground pipes from the Vermont Yankee Nuclear Power Plant leak radioactive tritium into groundwater supplies | 0 | 700 | |
| August 2011 | Louisa county, Virginia, USA | A 5.8-earthquake in the region caused the loss of offsite power at the North Anna Nuclear Generating Station. Later in the incident, the plant lost an emergency diesel generator, leading to the activation of the so-called SBO diesel generator - an emergency situation. | 0 | ? | 2 |
| January 2014 | St. Lucie, Florida, USA | Flooding of the auxiliary building of the St. Lucie Nuclear Power Plant, caused by lacking proper flood barriers | 0 | ? | |
| July 2016 | Michigan, USA | Massive steam leak in the turbine building of Donald C. Cook Nuclear Plant, unit 2 | 0 | ? | |
| December 2019 | Nebraska, USA | One of the two safety related component cooling systems of Cooper Nuclear Station was unable to operate, because its service water system, that takes water from the river, was plugged with silt. | 0 | ? |