There have been more than 20 nuclear and radiation accidents involving fatalities. These involved nuclear power plant accidents, nuclear submarine accidents, radiotherapy accidents, and other mishaps.
4,000 fatalities – Chernobyl disaster, Ukraine, April 26, 1986. 56 direct deaths (47 accident workers, and nine children with thyroid cancer), and it is estimated that there were 4,000 extra cancer deaths among the approximately 600,000 most highly exposed people.
Estimates of the total number of deaths potentially resulting from the Chernobyl disaster vary enormously: Thirty one deaths are directly attributed to the accident, all among the reactor staff and emergency workers. A UNSCEAR report places the total confirmed deaths from radiation at 64 as of 2008. The World Health Organization (WHO) suggests it could reach 4,000 civilian deaths, a figure which does not include military clean-up worker casualties. A 2006 report predicted 30,000 to 60,000 cancer deaths as a result of Chernobyl fallout. A Greenpeace report puts this figure at 200,000 or more. A Russian publication, Chernobyl, concludes that 985,000 premature cancer deaths occurred worldwide between 1986 and 2004 as a result of radioactive contamination from Chernobyl.
Frank N. von Hippel, a U.S. scientist, has suggested, as "a very preliminary order-of-magnitude guesstimate," that "one might expect around 1,000 extra cancer deaths related to the Fukushima Daiichi accident."
As of June 2012, the exact chain of events which included the explosions at the Fukushima Diiachi plant are still not known. The total amount of radiation released is also not known for certain, and the impacts on human health and the environment, and hence the likely number of deaths, cannot be determined with the information available.
200+ fatalities – Mayak nuclear waste storage tank explosion, (Chelyabinsk, Soviet Union, 29 September 1957), figure is a conservative estimate, 270,000 people were exposed to dangerous radiation levels. Over thirty small communities had been removed from Soviet maps between 1958 and 1991.
33+ cancer fatalities (estimated by UK government) – Windscale, United Kingdom, October 8, 1957. Fire ignites plutonium piles and contaminates surrounding dairy farms.. Windscale was an air-cooled graphite-moderated reactor with no containment structure. A significant contributing factor was that the graphite caught fire.
- 17 fatalities – Instituto Oncologico Nacional of Panama, August 2000 – March 2001. Patients receiving treatment for prostate cancer and cancer of the cervix receive lethal doses of radiation.
- 13 fatalities – Radiotherapy accident in Costa Rica, 1996. 114 patients received an overdose of radiation from a Cobalt-60 source that was being used for radiotherapy.
- 11 fatalities – Radiotherapy accident in Zaragoza, Spain, December 1990. Cancer patients receiving radiotherapy; 27 patients were injured.
- 10 fatalities – Soviet submarine K-431 reactor accident, August 10, 1985. 49 people suffered radiation injuries.
- 10 fatalities – Columbus radiotherapy accident, 1974–1976, 88 injuries from Cobalt-60 source.
- 9 fatalities – Soviet submarine K-27 reactor accident, 24 May 1968. 83 people were injured.
- 8 fatalities – Soviet submarine K-19 reactor accident, July 4, 1961. More than 30 people were over-exposed to radiation.
- 8 fatalities – Radiation accident in Morocco, March 1984.
- 7 fatalities – Houston radiotherapy accident, 1980.
- 5 fatalities – Lost radiation source, Baku, Azerbaijan, USSR, October 5, 1982. 13 injuries.
- 4 fatalities – Mihama Nuclear Power Plant accident, August 9, 2004. Hot water and steam leaked from a broken pipe (not actually a radiation accident). 
- 4 fatalities – Goiânia accident, September 13, 1987. 249 people received serious radiation contamination from lost radiography source.
- 4 fatalities – Radiation accident in Mexico City, 1962.
- 3 fatalities – SL-1 accident (US Army) 1961.
- 3 fatalities – Samut Prakan radiation accident: Three deaths and ten injuries resulted when a radiation-therapy unit was dismantled, February 2000.
- 2 fatalities – Tokaimura nuclear accident, nuclear fuel reprocessing plant. Japan, September 30, 1999.
- 2 fatalities - Meet Halfa, Egypt, May 2000; two fatalities due to radiography accident.
- 1 fatality – Mayapuri radiological accident, India, April 2010.
- 1 fatality – Daigo Fukuryū Maru March 1, 1954
- 1 fatality – Louis Slotin May 21, 1946
- 1 fatality – Harry K. Daghlian, Jr., August 21, 1945 at Los Alamos National Laboratory in New Mexico.
- 1 fatality – Cecil Kelley criticality accident, December 30, 1958 at the Los Alamos National Laboratory.
- 1 fatality – Malfunction INES level 4 at RA2 in Buenos Aires, Argentina, operator Osvaldo Rogulich dies days later.
- 1 fatality - San Salvador, El Salvador, 1989; one fatality due to violation of safety rules at 60Co irradiation facility.
- 1 fatality - Soreq, Israel, 1990; one fatality due to violation of safety rules at 60Co irradiation facility.
- 1 fatality - Tammiku, Estonia, 1994; one fatality from disposed 137Cs source.
- 1 fatality - Sarov, Russia, June 1997; one fatality due to violation of safety rules.
- ^ Benjamin K. Sovacool. The costs of failure: A preliminary assessment of major energy accidents, 1907–2007, Energy Policy 36 (2008), p. 1806.
- ^ Benjamin K. Sovacool. A Critical Evaluation of Nuclear Power and Renewable Electricity in Asia, Journal of Contemporary Asia, Vol. 40, No. 3, August 2010, p. 396.
- ^ "IAEA Report". In Focus: Chernobyl. http://www.iaea.org/NewsCenter/Focus/Chernobyl/. Retrieved 2008-05-31.
- ^ Hallenbeck, William H (1994). Radiation Protection. CRC Press. p. 15. ISBN 0-87371-996-4. "Reported thus far are 237 cases of acute radiation sickness and 31 deaths."
- ^ "Chernobyl: the true scale of the accident". Chernobyl’s Legacy: Health, Environmental and Socio-Economic Impacts. http://www.who.int/mediacentre/news/releases/2005/pr38/en/index.html. Retrieved 2011-04-15.
- ^ "Torch: The Other Report On Chernobyl- executive summary". European Greens and UK scientists Ian Fairlie PhD and David Sumner - Chernobylreport.org. April 2006. http://www.chernobylreport.org/?p=summary. Retrieved 2011-08-20.
- ^ "The Chernobyl Catastrophe - Consequences on Human Health". Greenpeace. 18 April 2006. http://www.greenpeace.org/international/Global/international/planet-2/report/2006/4/chernobylhealthreport.pdf. Retrieved 15 December 2008.
- ^ Alexey V. Yablokov; Vassily B. Nesterenko; Alexey V. Nesterenko (2009). Chernobyl: Consequences of the Catastrophe for People and the Environment (Annals of the New York Academy of Sciences) (paperback ed.). Wiley-Blackwell. ISBN 978-1-57331-757-3.
- ^ Frank N. von Hippel (September/October 2011 vol. 67 no. 5). "The radiological and psychological consequences of the Fukushima Daiichi accident". Bulletin of the Atomic Scientists. pp. 27–36. http://bos.sagepub.com/content/67/5/27.full.
- ^ Samuel Upton Newtan. Nuclear War I and Other Major Nuclear Disasters of the 20th Century 2007, pp. 237–240.
- ^ a b Perhaps the Worst, Not the First TIME magazine, May 12, 1986.
- ^ a b Benjamin K. Sovacool. A Critical Evaluation of Nuclear Power and Renewable Electricity in Asia, Journal of Contemporary Asia, Vol. 40, No. 3, August 2010, p. 393.
- ^ Investigation of an accidental Exposure of radiotherapy patients in Panama - International Atomic Energy Agency
- ^ a b c d e Johnston, Robert (September 23, 2007). "Deadliest radiation accidents and other events causing radiation casualties". Database of Radiological Incidents and Related Events. http://www.johnstonsarchive.net/nuclear/radevents/radevents1.html.
- ^ Medical management of radiation accidents pp. 299 & 303.
- ^ a b Strengthening the Safety of Radiation Sources p. 15.
- ^ The Worst Nuclear Disasters
- ^ a b Ricks, Robert C. et al. (2000). "REAC/TS Radiation Accident Registry: Update of Accidents in the United States". International Radiation Protection Association. p. 6. http://www.irpa.net/irpa10/cdrom/00325.pdf.
- ^ Lost Iridium-192 Source
- ^ Facts and Details on Nuclear energy in Japan
- ^ The Radiological Accident in Goiania p. 2.
- ^ a b Pallava Bagla. "Radiation Accident a 'Wake-Up Call' For India's Scientific Community" Science, Vol. 328, 7 May 2010, p. 679.
- ^ Benjamin K. Sovacool. A Critical Evaluation of Nuclear Power and Renewable Electricity in Asia, Journal of Contemporary Asia, Vol. 40, No. 3, August 2010, p. 399.
- ^ a b c d e István Turai and Katalin Veress (2001, Vol.7. No.1.:3-14). "Radiation Accidents: Occurrence, Types, Consequences, Medical Management, and the Lessons to be Learned". CEJOEM. http://www.omfi.hu/cejoem/Volume7/Vol7No1/CE01_1-01.html.
- ^ McInroy, James F. (1995), "A true measure of plutonium exposure: the human tissue analysis program at Los Alamos", Los Alamos Science 23: 235–255, http://library.lanl.gov/cgi-bin/getfile?23-11.pdf