(This idea probably already came up, but i didn't see it)
mods used: IC², Redpower2(+ some planned features)
1 UUM = 166.000 EU +34 scrap
1 urancell = 6.000.000 eu
(in this reactor:
6uum(<= don't know exact number)+ 2 tin(+time)+ 8coal=>8 uran cells
This is obviously (semi-)self-sustaining.
Coal and tin should be added from outside(mine, scrapbox factory), because it is far too expensive to produce them through uum.
could be powered by photovoltaics or watermills and get their scrap out of cobble generators.
I thought of a system to replace all bukets in 2 ticks(with the retriever+ thats 90 buckets/second :3).
It would get stopped every half cycle to replace the breeded cells with fresh cells.
Every full cycle the reactor is stopped, but now you've got to reset it manually (because the engeneering for this would be pretty complicated) and turn it on again.
would be done manually, as you would only really need auto crafting if you would automate the reset after each full cycle( i'll look into that as soon as RP2 releases crafting machine, because i need RP2 overflow handling to get the overflow uum with out giant systems out of the cycle.).
The overflow of uum could be crafted into needed recources or again be turned into uran and then energy.
A complete machine like this could break a server's economy, so i wouldn't recommend building it.