Let's hope Chernobyl won't repeat itself.
Scientist: Hey lets test out all our safety features and turn them off with our technology nothing will go wrong.
Anyways, if there were a high level of radiation and it did happen consider that not only your 250mile radius would be affected but lake Michigan as well. It takes up to thousands of years for a substance like plutonium to take up a half-life.
I remember a while back in 2010, Canada was shipping nuclear waste over the great lakes, across the ocean to Norway for it to be stored. If a single waste were to be spilled, our fresh water would be polluted with radiation.