Is there any possibility of this happening in a future version?
What I have in mind is: having to build a reactor core with actual blocks, rather than putting cells into the current chambers, having to cool it down with coolant (water? processed water? Finally a good use for pumps!), and, finally, harvesting the heat (steam?) via thermal generators (turbines?).
I think it would be fun, but I have no idea if these kinds of mechanics are even possible in minecraft currently.