1946    The first in Europe artificial, self-sustaining nuclear chain reaction was initiated within Soviet nuclear reactor F-1.

1954    The U.S. Navy submarine {{USS|Nautilus|SSN-571|6}} is commissioned as the world's first nuclear reactor powered vessel.

1979    Operators of Three Mile Island's Unit 2 nuclear reactor outside of Harrisburg, Pennsylvania fail to recognize that a relief valve in the primary coolant system has stuck open following an unexpected shutdown. As a result, enough coolant drains out of the system to allow the core to overheat and partially melt down.

1981    The Israeli Air Force destroys Iraq's Osiraq nuclear reactor during Operation Opera. The facility could have been used to make nuclear weapons.