"Bellefonte Nuclear Power Plant" by Tennessee Valley Authority - tva.com. Licensed under Public Domain via Wikimedia Commons.
According to the International Atomic Energy Agency(IAEA), an accident is any unintended event, including operating errors, equipment failures or other mishaps, the consequences or potential consequences of which are not negligible from the point of view of protection or safety. Source: IAEA (Retrieved March 13, 2018).