I used ("sacrificed") some of my grey cells thinking how to adapt that nuclear simulator, and make a IC2/GT nuclear reactor that would be FUN to run.
That nuclear simulator gives players problem to solve which would not exist in MC world, because if we lack in anything we can just make more of it. So, design has to give players choices with good and bad outcomes (it's a game and it is supposed to be PLAYED).
Since I already redesigned IC2 reactor to achieve it's original goal which was a "minigame" power generator, I decided to use that design and merge it with that nuclear simulator. (Madman's reactor my old idea)
Quickly though I found a little problem. We do not have a proper "coolant" in Minecraft. Since we want our nuclear reactor to be a system of multiblock structures, we need something that would not immediately cool thing down. We need a thing that would "carry" "heat" from one place to the other (heat from reactor core to the boiler).
Now, we can not use forge fluids, because they do not carry information like "heat" (no idea if that is true). So, maybe we could somehow adapt EU api to do it?
So, we need a coolant API that would allow it to flow through a pipe at "adjustable speed" (so we can control the flow of coolant) and carrying a "charge" (heat in our care).
So how would this thing even work?
Step by step.
First we need reactor chamber, a core of our multi multiblock system. We put fuel rods there, we turn it on, they start to react and we are getting heat. Or rather, chamber is taking heat. Soon that heat is too much for chamber to hold together and we want to "move" that heat somewhere else. to be more precise, to the boiler.
And this is where we use our "coolant". So, we make a loop. Reactor chamber -> boiler -> excess heat dissolver -> coolant tank -> pump -> reactor chamber.
I would like all of those things to use IC2 reactor heat exchanger components. So in reality it works like this. In reactor chamber heat exchangers move heat from chamber to coolant. The slower coolant flow, the more heat it'll receive from chamber.
Than at the boiler heat exchangers move heat from coolant to boiler. If the coolant is still too hot after visiting boiler it can boo cooled down at emergency heat dissolver and get back through pump to the loop. Coolant tank is there to replenish any lost coolant from loop.
Now, because it always take time to heat something up, or cool something down. In order to get our boiler to make more steam and our fuel to be more efficient, we want to keep our coolant in the loop very hot. After all, the hotter it is, the more efficient our system is. But that temperature comes with danger.
It makes components to fail. Pretty much all of the reactor system parts have heat toleration and can fail in some way when exposed to that heat for period of time. Se, one main loop with coolant would not be enough. To make this reactor work efficiently and still be prepared for any "mechanical parts malfunction" you would need to make more coolant loops. That would be turned on and off at emergency.
So this is my quick from the head suggestion for GT specific nuclear reactor.
My extremely tired brain looks at this and likes where it's going but can't fully process it yet.
What it can do though is say that Forge Fluids can have Temperatures assigned to the Fluids themselves. (Water has a fixed temperature, Lava has a fixed temperature, Steam has a fixed temperature, every Fluid in the Forge Fluid Registry has a fixed temperature.) So knowing this, you could theoretically create (for example) "Cold Coolant", "Warm Coolant", "Heated Coolant," and "Superheated Coolant" Fluids, that could then be run through a Heat Exchanger block or multiblock, and be cooled from Heated or Superheated down to Heated, Warm, or Cold, depending on how much Coolant fluid was flowing through the Exchanger and/or how much fluid it contained at a given time. And then some multiple of the volume of Coolant run through or contained in the Exchanger and which heat state it was, Energy or Steam could be produced and sent out. (Energy simpler but less efficient; Thermocouples are nice little things. Steam more preferable, more efficient IRL AFAIK, and already a precedent in larger energy generation systems.)
... Ya know this whole Heat Exchanger idea is suddenly starting to sound a whole lot like a more complicated form of the old GT Thermal Boilers from 1.6.
Side note: might want to look at how Big Reactors does its Steam Turbines... I've wanted to look at that for months but never got around to it