Do people in the US. really Need to worry about Radiation plumes from the Fukishima Reactors?

There's no need to be worried about the radiation affecting your health at all. They're really only worried about places within 50 miles of the reactors. I strongly discourage you from using iodine and stuff, because it will probably damage your body, and there's no need to anyway. We're too far away for it to be a danger to us.