Ah, my favorite topic. There was a $1B (1950s dollars) program in the 1950s to make these. It led to vast nuclear development. Some good reading and pictures on it are in this huge report [1]. I particularly like this image: https://whatisnuclear.com/img/nuclear_rocket.jpg

Another fun fact, if you've heard of molten salt reactors (MSR) or the associated thorium fuel cycle, you should know that almost all of the tech development related to those projects came from the program to develop nuclear-powered aircraft. The first MSR was called the Aircraft Reactor Experiment (ARE) [2]. The second one, the famed MSRE, was built in the building that had been entirely funded and built for the air force project, using mostly parts and certainly the expertise built by it.

[1] https://www.osti.gov/biblio/1048124-comprehensive-technical-...

[2] https://en.wikipedia.org/wiki/Aircraft_Reactor_Experiment