I do use scrap, I have several quarries running 24/7 to produce enough scrap. Still not enough though. I've tried fluid reactors before, but the kinetic steam generators always make explosions sounds and shoot out steam particles. I will try again, and I'll post again with the results.
You have to ensure the reactor is making enough hot coolant to keep up with the demand from the liquid heat exchangers. That's been my big pitfall: I can't get a hot enough reactor design. But Aroma was just telling me that you can copy and paste the URL for all those dead-linked reactor schematics into the reactor design simulator and it will show the design so that's pretty awesome.