Nuclear power plant accidents and incidents with multiple fatalities and / or more than US $100 million in property damage, 1952 - 2011 Date Location of accident Description of accident or incident Dead Cost ($ US millions 2006) INES level 000000001957 - 09 - 29 - 0000 September 29, 1957 Mayak, Kyshtym, Russia The Kyshtym disaster was a radiation contamination incident that occurred at Mayak, a Nuclear fuel reprocessing plant in the Soviet Union. 6 000000001957 - 07 - 26 - 0000 July 26, 1957 Simi Valley, California, United States Partial core meltdown at Santa Susana Field Laboratory 's Sodium Reactor Experiment. 0 32 000000001957 - 10 - 10 - 0000 October 10, 1957 Sellafield aka Windscale fire, Cumberland, United Kingdom A fire at the British atomic bomb project destroyed the core and released an estimated 740 terabecquerels of iodine - 131 into the environment. A rudimentary smoke filter constructed over the main outlet chimney successfully prevented a far worse radiation leak and ensured minimal damage. 0 5 000000001961 - 01 - 03 - 0000 January 3, 1961 Idaho Falls, Idaho, United States Explosion at SL - 1 prototype at the National Reactor Testing Station. All 3 operators were killed when a control rod was removed too far. 22 000000001966 - 10 - 05 - 0000 October 5, 1966 Frenchtown Charter Township, Michigan, United States Partial core meltdown of the Fermi 1 Reactor at the Enrico Fermi Nuclear Generating Station. No radiation leakage into the environment. 0 132 000000001969 - 01 - 21 - 0000 January 21, 1969 Lucens reactor, Vaud, Switzerland On January 21, 1969, it suffered a loss - of - coolant accident, leading to a partial core meltdown and massive radioactive contamination of the cavern, which was then sealed. 0 5 000000001975 - 01 - 01 - 0000 1975 Sosnovyi Bor, Leningrad Oblast, Russia There was reportedly a partial nuclear meltdown in Leningrad nuclear power plant reactor unit 1. 000000001975 - 12 - 07 - 0000 December 7, 1975 Greifswald, East Germany Electrical error causes fire in the main trough that destroys control lines and five main coolant pumps 0 443 000000001976 - 01 - 05 - 0000 January 5, 1976 Jaslovské Bohunice, Czechoslovakia Malfunction during fuel replacement. Fuel rod ejected from reactor into the reactor hall by coolant (CO). 000000001977 - 02 - 22 - 0000 February 22, 1977 Jaslovské Bohunice, Czechoslovakia Severe corrosion of reactor and release of radioactivity into the plant area, necessitating total decommission 0 1,700 000000001979 - 03 - 28 - 0000 March 28, 1979 Three Mile Island, Pennsylvania, United States Loss of coolant and partial core meltdown due to operator errors. There is a small release of radioactive gases. See also Three Mile Island accident health effects. 0 2,400 5 000000001984 - 09 - 15 - 0000 September 15, 1984 Athens, Alabama, United States Safety violations, operator error, and design problems force a six - year outage at Browns Ferry Unit 2. 0 110 000000001985 - 03 - 09 - 0000 March 9, 1985 Athens, Alabama, United States Instrumentation systems malfunction during startup, which led to suspension of operations at all three Browns Ferry Units 0 1,830 000000001986 - 04 - 11 - 0000 April 11, 1986 Plymouth, Massachusetts, United States Recurring equipment problems force emergency shutdown of Boston Edison 's Pilgrim Nuclear Power Plant 0 1,001 000000001986 - 04 - 26 - 0000 April 26, 1986 Chernobyl, Chernobyl Raion (Now Ivankiv Raion), Kiev Oblast, Ukraininan SSR, Soviet Union Overheating, steam explosion, fire, and meltdown, necessitating the evacuation of 300,000 people from Chernobyl and dispersing radioactive material across Europe (see Effects of the Chernobyl disaster) 30 direct, 19 not entirely related and 15 minors due to thyroid cancer, as of 2008. (3) 6,700 7 000000001986 - 05 - 04 - 0000 May 4, 1986 Hamm - Uentrop, West Germany Experimental THTR - 300 reactor releases small amounts of fission products (0.1 GBq Co-60, Cs - 137, Pa - 233) to surrounding area 0 267 000000001987 - 03 - 31 - 0000 March 31, 1987 Delta, Pennsylvania, United States Peach Bottom units 2 and 3 shutdown due to cooling malfunctions and unexplained equipment problems 0 400 000000001987 - 12 - 19 - 0000 December 19, 1987 Lycoming, New York, United States Malfunctions force Niagara Mohawk Power Corporation to shut down Nine Mile Point Unit 1 0 150 000000001989 - 03 - 17 - 0000 March 17, 1989 Lusby, Maryland, United States Inspections at Calvert Cliff Units 1 and 2 reveal cracks at pressurized heater sleeves, forcing extended shutdowns 0 120 000000001992 - 03 - 01 - 0000 March 1992 Sosnovyi Bor, Leningrad Oblast, Russia An accident at the Sosnovy Bor nuclear plant leaked radioactive gases and iodine into the air through a ruptured fuel channel. 000000001996 - 02 - 20 - 0000 February 20, 1996 Waterford, Connecticut, United States Leaking valve forces shutdown Millstone Nuclear Power Plant Units 1 and 2, multiple equipment failures found 0 254 000000001996 - 09 - 02 - 0000 September 2, 1996 Crystal River, Florida, United States Balance - of - plant equipment malfunction forces shutdown and extensive repairs at Crystal River Unit 3 0 384 000000001999 - 09 - 30 - 0000 September 30, 1999 Ibaraki Prefecture, Japan Tokaimura nuclear accident killed two workers, and exposed one more to radiation levels above permissible limits. 54 000000002002 - 02 - 16 - 0000 February 16, 2002 Oak Harbor, Ohio, United States Severe corrosion of control rod forces 24 - month outage of Davis - Besse reactor 0 143 000000002004 - 08 - 09 - 0000 August 9, 2004 Fukui Prefecture, Japan Steam explosion at Mihama Nuclear Power Plant kills 4 workers and injures 7 more 9 000000002006 - 07 - 25 - 0000 July 25, 2006 Forsmark, Sweden An electrical fault at Forsmark Nuclear Power Plant caused one reactor to be shut down 0 100 000000002011 - 03 - 11 - 0000 March 11, 2011 Fukushima, Japan A tsunami flooded and damaged the plant 's 5 active reactors, drowning two workers. Loss of backup electrical power led to overheating, meltdowns, and evacuations. One man died suddenly while carrying equipment during the clean - up. The plant 's 6th reactor was inactive at the time. 2 + 7 12 September 2011 Marcoule, France One person was killed and four injured, one seriously, in a blast at the Marcoule Nuclear Site. The explosion took place in a furnace used to melt metallic waste.
where was the most serious global nuclear power plant accident in 1986
Chernobyl, Chernobyl Raion (Now Ivankiv Raion), Kiev Oblast, Ukraininan SSR, Soviet Union