Yeah, I think for an active reactor I'll buffer water through an iron tank that's sourced from at least 2 eIO reservoirs. With all this steam I'm going to be producing I may as well upgrade my maxed out iron tank to a steel tank heh.
As for power conversion it looks like I might be better off building the GT turbine instead as I really don't want to make quite that much industrial TNT to do the galacticraft route right now and I haven't even started to dabble in pneumaticraft. I guess I could do one smaller BR turbine though and use that to power my AE2 ME network. It's sort of nice how the AE2 Power Accepter will take any type of power. It's unfortunate that I don't see a way to get to spit power back out.
Well, one thing about this active BR reactor, is that I ought to be able to scrap my plans to create a titanium boiler, so that's good I guess. It also means I need to mine more yellorium. After I had half a chest full of it I sort of started skipping it. Does any of the uranium/plutonium work in BR? I've got a pitchblende vein 100m from my base. I just built a BC quarry and plan to deploy it tonight. I need rocky bees!
I don't think 2 reservoirs will cut it. I seem to recall having something like 10 of the damn things and them not keeping up with a 5x5x2 (interior) throttled to 80% closed. Might have been a 5x5x3. Seriously the things destroy water.
I don't know of any way to translate GT fissionables to yellorium, but others might.