Make the Uranium-235 production similar to how productivity modules function. Such as for every 1000(?) uranium ore you get 1 Uranium-235 and 1000 Uranium-238. To me it feels like the randomness of the centrifuge does not fit in with the rest of the game.

My suggestion about balancing would be to make it only work with low-tier chests. That way you would sacrifice capacity if you used one.