I know it's rude to double-post, but Kongregate doesn't offer a way to alter previous posts. Two things: First, a modification upon kNIGHT0wl's original idea with the slider: allow us to manually parse through the frames. what this means is that, when the reaction's paused, we can hiut a key and it'll advance the simulation by one tick. Second: For all you mid-game players (and quite possibly early, haven't tested) Here's my big contribution: a cooling system that doesn't rely on either exotic particles OR direct contact. In this case, X=vent and O=outlet.
X
XOXX
XXXOX
OXXX
XOX
X
basically, what this does is it pipes immense amounts of heat right through the reactor in less than one tick. the only precaution needed is some plating in the event of an overload.
When placing large amounts of fuel cells (as I do often with my setup,) I find it a time consuming process to manually place every one. To this end, I suggest that 'flood-fill' option be added. merely click and drag to select multiple cells.