Now that CASUCs are gone, building a viable reactor requires a much more complex internal layout than before. A lot of parts have to go in the right places, and so on.
This makes the tedium of refueling every 2.4 hours or so even more irritating, and quite honestly makes reactors a waste of time compared to wind mill spam. Reactors are fun, but you'll get more consistent power output per hour of gameplay spamming those windmills.
Real life nuclear reactors have a big advantage : once fueled, they can run for years without refueling. The latest reactors used in aircraft carriers can power the ship for 25 years before refueling.
I suggest the following changes :
Increase fuel life in reactors by 10 to 20 times. This means they would last between 24-48 hours without refueling, at least.
To avoid disrupting uranium rarity and balance, increase the uranium ore needed to make fuel by a similar factor. For instance, the new uranium refining method would be macerate the ore, then place a stack of 20 uranium dust in the compressor to get the uranium ingot.
Add a new reactor component : the "U-235 target plate". This would be made by compressing a bunch of uranium ingots together. This target plate would then need to be placed in the reactor and exposed to a HUGE flux of neutrons, much more than are needed for breeding. (so it would require a skilled, advanced reactor design)
After enough neutron exposure, the target plate becomes a "plutonium plate". You would be able to make plutonium fuel cells from this plate, which would last almost forever inside a reactor, and they would be a required component for the nuclear bomb. (instead of the current lame recipe).
Making the nuclear bombs this much more complex and expensive would possibly make them more viable on multiplayer servers since griefers can't log in and get them in 1 hour.