In a complete nuclear meltdown, radiation would reach the First Coast, from Japan. Don't get too concerned about the possibility though. Radiation levels would be significantly less than those seen from x-rays and even kitchen appliances. Locations that would have to take precautionary measures would be those areas west of the Rocky Mountains.
Possible Nuclear Fallout
What both helps and hurts the First Coast is the jet stream or winds in the upper layers of the atmosphere. In the Northern Hemisphere, major wind patterns travel from west to east. They also zigzag and loop around, similar to a roller coaster track. This sloped path gives the radiational particles enough time and space to dissipate. The Rocky Mountains would basically serve as a divider between the questionable zone, to the west, and the no threat zone, to the east.
Jet Stream Pattern
Once again, the threat to the United States would only happen in a full blown nuclear meltdown and catastrophe.