Hiho,
I haven't seen anyone with this idea on this forum so i show you my tin-eating reactor (because i heard some waste it in geothermals or coal-fuel)
Coolant Cells are WAY cheaper than using Ice for cooling considering that they can take 10.000 Heat before melting (except that you need Tin).
with this basic,save,easy-design you can make 84 Mio EU with one stack of Tin with Uran effectivity 3.0 (edit: pardon i meant 2 stacks of tin, still half a million per piece)
setup:
A Pump fills the Cells with water and BC/RP bring them into an Extractor (use some overclocker upgrades to make sure it produces the 14(or another amount when you change the reactor)
needed coolant cells in 5 min)
let a transposer pull them into a chest (they dont stack so they have to be stored anywhere else than the extractor)
VERY IMPORTANT: to reduce heat leaking into the hull when all the cells break in the same moment you should put the last transposer on high frequency and short(no) tube (or even use more than one)
(will maybe send a screenshot later)
safety suggestion: (because some heat WILL leak)
when you leave this thing alone make sure theres enough tin (or empty cells) for a full cycle
put some ice in the reactor as a buffer
water around the reactor helps to compensate the heat that gets into the reactor when refilling it
you could make a redstone timer that turns the reactor off when the cells are burnt until it is refilled
use thermal monitor addon
variants:
the reactor i use kills all the coolants all together, other designs could make them die one after the other to reduce heat leaks (but stopping the reactor while refilling will be very difficult)
higher effektivity is possible but will reduce the EU per Tin (just make sure every uranium still has at least one coolant cell)
higher EU per Tin is reached when the Uranium is surrounded by more Coolants
hope you like the idea, and if you do so show my your setups