I blatantly stole this from /u/AccidentalChef's Reddit post (https://www.reddit.com/r/factorio/comments/7sp1zp/simplest_possible_kovarex/), and modified it a bit to make use of a few beacons and able to tile easily. I also added some provider chests to capture overflow of U-235/U-238 and I use bots to put them into buffers next to this array and they feed Nuclear Fuel and Uranium Fuel Cells.
I run 2 of these stacked in a small base, as in the picture, but you could run as many as you want hypothetically. There are better options for sure, but I liked the look of this and thought I'd share my modification to his/her design. There may be some leftover Speed2 beacons in there, but I think I got all of them upgraded to Speed3.
Questions/comments are welcome!