The Calutron was a kind of hybrid particle accelerator/mass spectrometer, made by retrofitting a cyclotron. It was built for the Manhattan Project as a way to enrich uranium, since gas centrifuges didn't exist yet.
I could imagine that in-game it could work as either a cheaper alternative to the Cyclotron, or as a quicker but less energy-efficient alternative to the gas centrifuge (although the SILEX already kinda exists for that)... Or perhaps it can have its own unique function in the mod, idk.
I also wish that Atomic Piles and other such 1st generation nuclear reactors had more use, currently there's no way to automate them, and they're just good for turning uranium into plutonium, which isn't all too useful all things considered. Perhaps Gen 1 reactors can work as an alternative path to getting bismuth without needing an RBMK or Lead-209 RTGs?