And I have a GT suggestion.
We already have a coolant for reactors. GT can add another coolant types for reactors. I am pretty sure, that there are several types, which are based on metals. Na-something. + Some metals in their molten state. mercury 100% had its uses in IRL nuclear reactors. Something like that.
I believe, these coolants could have simply a diferent multiplier for heat X hot coolant. default is 1 HU= 1mB of hot coolant. (If I am correct). So, these types would be able to eat more\less heat for different setups. I d like some better reactor components though.. or maybe better reactos. Naq maybe
In case you hadn't noticed, GT5u already has NaK and Helium coolant cells for nuclear reactors, and separate Naquadah reactors.