TL;DR
Using high temp steam (nuclear reactor), should give bonus to coal liquefaction.What ?
At the moment, there is no reason to use nuclear reactors and heat exchangers for coal liquefaction over solid fuel in boilers, especially as solid fuel is a byproduct of coal liquefaction, as there is no difference in output for the extra steps involved.Easiest way to encourage this would be to boost efficiency of coal liquefaction when using a high temp steam source, especially if it increases output, as lower power input is negligible late game. Whether this is an increase in speed or bonus additional products created, I don't really mind, I'm not a number cruncher.
I think this would work well with the expansion as well.
The idea of transporting fuel cells from Nauvis to other planets, in order to boost Coal Liquefaction, with I presume the exception being Vulcanus as lava is hot enough to plug directly into a heat exchanger, is just a gameplay mechanic I find interesting, especially as uranium is native to Nauvis (with current knowledge).