Board Thread:Questions and Answers/@comment-138.217.68.181-20121227061218/@comment-96.251.196.172-20121227085542

It may be that you don't have enough chambers for the reactor. All sides of the Nuclear Reactor must have 1 Reactor Chamber on each side in order to have the full GUI to fit however many uranium cells, ice, coolant cells, ect. you want in it. If that doesn't fix the problem, take the nuclear reactor and the reactor chambers back, then set it up once again. Hope this fixes the problem. :)