Airforce Nuclear Bomber Program
With the Navy having their nuclear subs and ships and the army developing portable reactors the Air force decided to get into the reactor business by developing the nuclear bomber. The requirements for this reactor were very unique in order to power a Turbo Engine.
The first requirement was very high temperature > 1500 degF, light weight design, compact, minimal shielding, and easy to operate.
The contract was given to Oak Ridge National Labs and the birth of the Molten Salt Reactor came about.