Things TLs 7-9 would be interesting to see WITHOUT

[The Colonel]

Originally Posted by Mailanka

Here's one I've been considering for an alien race: the presence of nuclear power, but not nuclear weapons. I'm not sure how plausible that is, though. Any thoughts?

The only thing I can think of off the top of my head would be for nuclear power to have developed from radiothermal power by engineering experimentation rather than being developed from physical principles... a nuclear reactor and a bomb are very different beasts and whilst you might know from experience that you get a hell of a mess if you lose control of your core the idea that you could turn that into a practicable weapon might not be inutitive if you don't know the physics.