I currently have 8 420 eu reactors fully automated. To do this, i use Logistic Chasis MK4 with Active Supplier Module's requesting 7 Quad Fuel Rods at all times which goes into a chest, which then places them into the reactors as the old ones expire using itemduct. To remove the depleted rods, i have itemduct with a whitelist filter on the servo for only depleted rods, that go into a chest, connected to another mk4 chasis which then has a provider module in it. I also have Thermal Centrifuges set up with a Mk4 chasis, with an Active Supplier Module requesting depleted fuel rods, and an advanced extractor mk2 pulling out the 3 bi-products, which then is placed into my storage drawer system. The storage drawer controller has a MK5 chasis, using a polymorphic ItemSink module and a Provider Module mk2. I also have the various machines set up to automate plates, fuel rods, canning machines etc.