I can confirm theprolo and Torezu's ideas..
I long have had the same idea of using cc to manage the reactor.. But good old wiring and brains got mine safe - really safe. My 6 core reactor uses 3 ice rows and 3 uranium rows. It never hits a temprature above 1500. Also thermal monitors are setup on each reactor. If they go over the 1500 heat threshold, it will shut down all the reactors untill I reset the system manually. Also each reactor can be turned on individually. Another safty measure is that if the MFSU's are full, the system only stop temporarly, it produces power again as soon as the MFSU are emptying again.
Alot of wiring, but it pays off in the end.