Only one that I know of, but that's still probably more than ancient Greece.

https://fivethirtyeight.com/features/how-do-you-put-out-a-su...

It's an interesting bit of trivia that St. Louis had one of the nation's first cyclotrons used for atomic research, but radiation is the gift that keeps on giving. We're more or less stuck with it now, though; too bad we aren't using more for energy. Why, my pops has stories of scrubbin' the hot room floor what'd raise your hairs...of course, that was back on the East coast. Grandpop always was fond of hands-on lessons.

Well. Hands-on lessons, ignoring the IRS, and losing his company's license to produce radioactive material. Still, he considered it a win when he was still cogent because 'those boys at oak ridge saved him from the draft.' Can't argue with that. Or at least, I sure as hell can't, especially since my other grandpop served in the Pacific theater and was very quiet about the whole thing besides using certain, uh, racial epithets to his death.

Let's all stop and appreciate the lack of serious global conflict around now, yeah?