I think the nuclear reactor as it is (needing fuel) should not be our highest tier reactor. I do think though it should run longer then a bioreactor full of fish even so it puts out ten times the power per minute in comparison.

I dunno if the whole nuclear reactor balancing can be done by pure value tuning.

But the other things.would just make the reactor even more unappealing to players. Yes maybe you should need to equip the Rad-suit to handle rods and if you do without you get constant damage. I don't see that reactor incidents would make the reactor any more worthwhile. Please2not make nuclear the bogey man in the closet, it's really one of the best power sources out there, and if we felt like it, there's even reactor designs (called breeder reactors) that use spent nuclear fuel from earlier reactors, and there's also others that would shut themselves down and seal themselves off, even without power and without coolant ( molten salt reactors). What if I took a swim in a typical spent nuclear fuel pool? TL DR: the only safer source of power than nuclear is Hydro, and then only if you're in the US.

other risk: radiation could attract leviathans.

nuclear risk: the reactor could loose 1% repair each day and create incidents below 50% repair, blowing up the base at 0%.

waste disposal: burned rods should radiate for a week before vanishing (not years like in RL), making a seperate disposal base necessary.

radiation: rods and the reactor room should be radioactive and bulkheads needed to seal the reactor from the base.

power level: (already getting reworked).

longevity: the rods should run for a week but need far more uranite (20x or more).

We could just label it 'Superadvanced Bioreactor' - no difference, other than needing uranite instead biomaterial. Summary: The nuclear reactor doesn't feel 'nuclear' at all, with advantages as well as disadvantages. We have no nuclear waste disposal problem other than having a special bin to drop the rods into it with no other disadvantages. Only a difference from power to the bioreactor and the complexity to forge rods for it to work. We have no 'nuclear' power level and length, no 'nuclear' risk and not even radiation distinguishing the reactor from the others. They act more like coal rods with being labeled nuclear than displaying true nuclear power. So the rods burn down much too fast and many players don't like that. Even considering the nuclear tech in the game future is less good, the rods should work for the whole game time. In real life nuclear reactors can run the reactor rods for a few years before replacing them.

Subnautica cyclops thermal reactor