UUM is not meant for fuel production. Although you have the ability to produce it for whatever you wish (for example, breeding plutonium for RTGs).
Let me put it another way. A state of the art reactor made with almost a thousand copper, as well as several hundred iron, fueled by effectively 12 uranium ore per cycle, can't even generate enough UU matter in a complete cycle to make a single diamond. It could also make almost a stack of rubber. Regardless of what I'm making with UU matter, with the power requirements involved it is more efficient to simply not waste the time on this mod. In the time I could gather the uranium to run my reactor, I could easily just gather whatever the UU matter would replicate. This is not even mentioning the time spent making the reactor itself. IC2 might as well introduce a new tool-the fluffy mittens. They require 8 hours of work to craft, after which they allow you to do whatever you normally would, but at a 50% slower rate! How novel!
Edit:Double checking math, more to follow.
Edit 2, it appears to be taking 10m EU to make 1 bucket of UUM. My reactor generated just above 100M EU in its first full cycle consuming 3 quad cells (12 total cells). That translates to roughly 8.333 million EU per cell, and at 3 ore per 2 refined fuel, 5.56m eu per ore. In order to make 1 UUM you're looking at 1.8 uranium ore. At this we're looking at the following exchange rates, which generously ignore the power requirements of the scanner and replicator-
1 lapis=4.4 uranium ore
1 gold=9.9 uranium ore
1 diamond=18.2 uranium ore
1 redstone-0.76 uranium ore
1 uranium ore=12 uranium ore
1 copper=0.63 uranium ore
If my math is incorrect, I'd be happy to find out but to me it seems like this entire mod is a timesink with no actual return. I am now a few days of time and quite a bit of resources behind when I started trying this mod out and I have no useful or interesting things to show for it. It would take a month of playing with no other uses for uranium to make the production of a reactor worthwhile. Just to repay the copper that went into my reactor design, ignoring the material and power costs of the other machines required to use UU matter, I would have to hope to find 520 uranium ore. Accounting for the entire process would push that figure up by another 30% or so. On top of that, copper is one of the cheapest to make items. If I find some free time I might come back and calculate the entire amount of uranium ore required to break even on production of this system.
My reactor design-
http://www.talonfiremage.pwp.b…tkgvt4wa7klu3kvkqhwmrdnnk
Reactor resources cost in uranium-
copper-520 uranium
tin- 82 uranium
iron- 399 uranium
gold- 276 uranium
rubber- less than 1 uranium
Redstone- 3 uranium
lapis- 8 uranium
total= roughly 1288 uranium ore