Yes, both USA and Soviet experimented with nuclear powered planes during the 60s. The problem was how to shield the pilots from radioactivity. https://en.wikipedia.org/wiki/Nuclear-powered_aircraft

They also experimented with nuclear powered drones. https://www.popularmechanics.com/military/research/a33565112...

And Russia now claims to have a nuclear engine that can make a cruise missile fly for days. https://en.wikipedia.org/wiki/9M730_Burevestnik

What if there were a reactor type which would require no, or much less shielding because all it emits is mostly hard ultraviolet light?

[0] https://en.wikipedia.org/wiki/Nuclear_lightbulb

I read that as using UV light to transfer energy to the working fluid, not that the actual nuclear reaction itself would be any different to any other nuclear reactor.

Even when it reads "It would be operated at temperatures of up to 22,000°C where the vast majority of the electromagnetic emissions would be in the hard ultraviolet range." ?

edit: Sigh.. disregard, cf. https://web.archive.org/web/20080109011832/http://www.nuclea...

Another problem is crashes or accidents