Okay, this might be entirely me missing something, but I've done all the research I can figure out how to do. I have a completed fission reactor, and put fuel in it. Nothing happens - no progress, no RF produced, nothin'. I looked back at Nuclearcraft wiki, and it shows use of a fuel rod, which appears not to be included in this pack. I'm at a loss.

Give the controller a redstone signal

That was it. Thanks!