So I've been working on breeder reactors extensively. This is my best design so far. Note that 4 uranium cells recharge 142 cells in one go. I invented this design in survival first, then refined it to max theoretical efficiency with the planner. Only 2 meltdowns led to this design! On a side note I cranked the IC2 configs up: 100 blast size for nukes (up from 35), and 125 for reactors (up from 45). Nuclear explosions need to be devastating. Planner Link Spoiler I have an unhealthy obsession with reactor efficiency and love a little risk. I'm not looking for a better pre-planned design to copy. I am looking for other subtle hints about directions to go if it can be made better; note that my component usage is restricted to only a few types of things. I didn't have materials to do TONS of experimentation, so this is where I'm at, and none of my experiments with other component types worked as well as this. I hesitate to use single-use coolants because of the maintenance factor, but if they can be lower maintenance than replacing the cells, I'd consider it. I've done this entirely in survival only without looking at any cheat images, and intend to continue that way, but I think I've reached max efficiency without some new inspiration.