Centrifuge Suggestion

[WanderingLynx]

Maybe you could make the centrifuge work 2-3x faster when upgraded.

[WanderingLynx]

Another idea would be to have a chance to make ultra-enriched uranium or plutonium once the machine reaches 100% enriched, which would have extra heat production in the fission reactor.

[ICY105]

Right now, anything above 40% enriched is considered 'unsafe' and cannot be used in a reactor. Anything above 70% enriched is considered weapons grade and in the future will be used to make bombs, so an 'ultra enriched' fuel cell doesn't make a whole lot of sense. I could make it faster, but throws off the game balance a bit.
My leading idea is that if I ever implement more types of fuel, it will require an upgraded centrifuge to refine those fuels, but I don't have enough fuel dependent variables right now to justify adding more fuels.