Brief History of Nuclear Accidents Worldwide

This fact sheet outlines seven major nuclear accidents occurring between 1957 and 2011, including the Fukushima Dai-ichi, Chernobyl, and Three Mile Island disasters. It describes the technical failures, human errors, and environmental impacts associated with each event, ranging from partial fuel meltdowns to catastrophic explosions and large-scale radioactive releases.

• The March 11, 2011, accident at the Fukushima Dai-ichi plant in Japan was caused by an earthquake that cut external power and a tsunami that disabled backup diesel generators. This led to the failure of reactor cooling systems, hydrogen explosions in three reactor buildings, and the melting of fuel in three reactor cores, resulting in the evacuation of nearly 500,000 residents.
• The April 26, 1986, Chernobyl disaster in the former Soviet Union is described as the world's worst nuclear disaster. It was caused by a power surge during a reactor systems test where safety precautions were ignored, leading to an explosion that destroyed Unit 4 and forced the relocation of approximately 220,000 people.
• The March 28, 1979, accident at Three Mile Island Unit 2 in the USA is the most serious nuclear accident in U.S. history. It involved a partial meltdown caused by failures in the non-nuclear secondary system and a stuck-open relief valve, compounded by operators' failure to correctly identify the problem due to a hidden indicator light.
• Other significant historical accidents include the 1966 Enrico Fermi Unit 1 partial meltdown caused by coolant flow blockage, the 1961 SL-1 steam explosion caused by the improper withdrawal of a control rod, the 1959 Sodium Reactor Experiment partial meltdown due to oil-like fluid leakage, and the 1957 Windscale fire in the UK, which is considered the worst accident to occur in the West and is attributed with more than 200 cancer deaths.

APA

Union of Concerned Scientists (2013). Brief History of Nuclear Accidents Worldwide. https://www.ucs.org/resources/brief-history-nuclear-accidents-worldwide

Chicago

Union of Concerned Scientists. Brief History of Nuclear Accidents Worldwide. 2013. https://www.ucs.org/resources/brief-history-nuclear-accidents-worldwide.

Wikipedia

{{cite report |author=Union of Concerned Scientists |title=Brief History of Nuclear Accidents Worldwide |date=1 October 2013 |url=https://www.ucs.org/resources/brief-history-nuclear-accidents-worldwide |access-date=23 October 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{unionofconcernedscientists2013brief, author = {{Union of Concerned Scientists}}, title = {{Brief History of Nuclear Accidents Worldwide}}, institution = {Union of Concerned Scientists}, year = {2013}, month = oct, url = {https://www.ucs.org/resources/brief-history-nuclear-accidents-worldwide}, urldate = {2026-10-23}, note = {Indexed by Climate Insights Directory} }