This was the original (1040s, Fermi) idea, hence reactors in Idaho (after becoming alarmed that they had constructed a reactor in downtown Chicago). I think however there's a reason this isn't done now: it acknowledges that large reactors aren't safe (which they're not), therefore begs the question why build them at all. For the idea to become viable, climate change would need to become a much more immediate pressing concern, allowing the trade off to be made between irradiating some Utah desert vs boiling the planet.