it might be better to split this into two mods, one for power generation and another for combat.

power

how does the UPS compare to vanilla?

combat

uranium rounds - depleted uranium is used in armor piercing bullets solely for density. being depleted, it has no nuclear effects. similar could be said for uranium cannon shells.
nuclear artillery would be a very welcome combat addition
uranium fusion reactor - what? shouldn't nuclear be a lower tier than fusion?

bugs

U-234 Aplha decay

wiki

https://en.wikipedia.org/wiki/Depleted_uranium

Natural uranium contains about 0.72% 235U, while the DU used by the U.S. Department of Defense contains 0.3% 235U or less. The less radioactive and non-fissile 238U constitutes the main component of depleted uranium. Uses of DU take advantage of its very high density of 19.1 grams per cubic centimetre (0.69 lb/cu in) (68.4% denser than lead).

Hey, thanks for the input!

UPS-wise, the stats are the same of vanilla of course, fluids handling is still there. I haven't thought about making some kind of optimizations that does not require to rewrite reactors as nuclear boilers and cut the entire heat/steam/water part to save performance (but this will also remove the buffer mechanic).

I wouldn't split it into separate mods because weapons and fuels are the outlet for nuclear waste, so it's basically needed to make the whole uranium thing kinda balanced instead of having chests of waste just pile up and do nothing in the map.

That said, I use U236 since there's no loop to get it back into something else yet, but I can add U234 to be even more realistic and have U236 be reprocessed into U234, I like that, but I'll have to do some research ;)

P.S. yeah i might change portable reactors to be "fissile" instead of "fusion", I just went for it because vanilla's was called like that and I didn't question it in the first place

another couple thoughts:

you could create an RTG/SMR and add them to satellites, replacing solar/accum

the reason i mentioned depleted uranium was because the u-236 icon is glowy and i thought that meant fissile, but apparently it isn't. i'd suggest icons which clearly show which is waste and which is fuel