Large Nuclear-Powered Subsonic Aircraft for Transoceanic Commerce (1971) [pdf]
ntrs.nasa.gov
ntrs.nasa.gov
Had the pleasure to see the nuclear engines (intended for bombers) described in the video when road-tripping through Idaho some years back.
Go for the Experimental Breeder Reactor 1 but stay and have a picnic near a pair of hulking relics of the Cold War: https://en.wikipedia.org/wiki/Aircraft_Nuclear_Propulsion