| 2011 | Fukushima | 5 | Japan | Reactor shutdown after the 2011 Sendai earthquake and tsunami; failure of emergency cooling caused an explosion |
| 2011 | Onagawa |
| Japan | Reactor shutdown after the 2011 Sendai earthquake and tsunami caused a fire |
| 2006 | Fleurus | 4 | Belgium | Severe health effects for a worker at a commercial irradiation facility as a result of high doses of radiation |
| 2006 | Forsmark | 2 | Sweden | Degraded safety functions for common cause failure in the emergency power supply system at nuclear power plant |
| 2006 | Erwin |
| US | Thirty-five litres of a highly enriched uranium solution leaked during transfer |
| 2005 | Sellafield | 3 | UK | Release of large quantity of radioactive material, contained within the installation |
| 2005 | Atucha | 2 | Argentina | Overexposure of a worker at a power reactor exceeding the annual limit |
| 2005 | Braidwood |
| US | Nuclear material leak |
| 2003 | Paks | 3 | Hungary | Partially spent fuel rods undergoing cleaning in a tank of heavy water ruptured and spilled fuel pellets |
| 1999 | Tokaimura | 4 | Japan | Fatal overexposures of workers following a criticality event at a nuclear facility |
| 1999 | Yanango | 3 | Peru | Incident with radiography source resulting in severe radiation burns |
| 1999 | Ikitelli | 3 | Turkey | Loss of a highly radioactive Co-60 source |
| 1999 | Ishikawa | 2 | Japan | Control rod malfunction |
| 1993 | Tomsk | 4 | Russia | Pressure buildup led to an explosive mechanical failure |
| 1993 | Cadarache | 2 | France | Spread of contamination to an area not expected by design |
| 1989 | Vandellos | 3 | Spain | Near accident caused by fire resulting in loss of safety systems at the nuclear power station |
| 1989 | Greifswald |
| Germany | Excessive heating which damaged ten fuel rods |
| 1986 | Chernobyl | 7 | Ukraine (USSR) | Widespread health and environmental effects. External release of a significant fraction of reactor core inventory |
| 1986 | Hamm-Uentrop |
| Germany | Spherical fuel pebble became lodged in the pipe used to deliver fuel elements to the reactor |
| 1981 | Tsuraga | 2 | Japan | More than 100 workers were exposed to doses of up to 155 millirem per day radiation |
| 1980 | Saint Laurent des Eaux | 4 | France | Melting of one channel of fuel in the reactor with no release outside the site |
| 1979 | Three Mile Island | 5 | US | Severe damage to the reactor core |
| 1977 | Jaslovské Bohunice | 4 | Czechoslovakia | Damaged fuel integrity, extensive corrosion damage of fuel cladding and release of radioactivity |
| 1969 | Lucens |
| Switzerland | Total loss of coolant led to a power excursion and explosion of experimental reactor |
| 1967 | Chapelcross |
| UK | Graphite debris partially blocked a fuel channel causing a fuel element to melt and catch fire |
| 1966 | Monroe |
| US | Sodium cooling system malfunction |
| 1964 | Charlestown |
| US | Error by a worker at a United Nuclear Corporation fuel facility led to an accidental criticality |
| 1959 | Santa Susana Field Laboratory |
| US | Partial core meltdown |
| 1958 | Chalk River |
| Canada | Due to inadequate cooling a damaged uranium fuel rod caught fire and was torn in two |
| 1958 | Vinča |
| Yugoslavia | During a subcritical counting experiment a power buildup went undetected - six scientists received high doses |
| 1957 | Kyshtym | 6 | Russia | Significant release of radioactive material to the environment from explosion of a high activity waste tank. |
| 1957 | Windscale Pile | 5 | UK | Release of radioactive material to the environment following a fire in a reactor core |
| 1952 | Chalk River | 5 | Canada | A reactor shutoff rod failure, combined with several operator errors, led to a major power excursion of more than double the reactor's rated output at AECL's NRX reactor |
