Cold War Era US Pursuit of a Nuclear-Powered Bomber Ends in 1961 Cancellation
During the 1950s the US Air Force explored nuclear propulsion for bombers, but technical hurdles and the rise of ICBMs led to the program’s termination in 1961.
In the early Cold War, before intercontinental ballistic missiles were dependable, the US Air Force launched the Nuclear Energy for the Propulsion of Aircraft (NEPA) project, later renamed Aircraft Nuclear Propulsion (ANP), to develop a nuclear-powered strategic bomber. The concept promised virtually unlimited endurance, offering a continuous airborne deterrent against the Soviet Union. Engineers examined a shielded reactor feeding a heat exchanger and an unshielded reactor that directly heated airflow, the latter producing highly radioactive plume.
The program’s most notable technical achievement was the Aircraft Reactor Experiment, the first molten-salt reactor, which ran at 2.5 MW thermal for 221 hours. Despite these advances, the weight of the reactor, crew shielding needs, and the risk of a nuclear accident in a crash proved prohibitive. The deployment of operational ICBMs in 1959 rendered the nuclear bomber concept obsolete, and on March 26 1961 President John F. Kennedy ordered the program’s cancellation. No nuclear-powered aircraft has been built since, though Russia has recently unveiled a nuclear-powered cruise missile.
Why it matters
It shows how Cold War strategic priorities drove risky tech experiments that were later abandoned as missile technology advanced.
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