I'm writing a story in which at least two nuclear explosions happen on both the east and west coast of the United States. What I need to know is how far will the radiation spread inland and how long will it take it to fade? I know the answer to the last question depends on the weather but any estimation would be helpful.
I've attempted to Google for this but I'm having a hard time coming up with good search words and putting what I do find into plain English.
Thank you in advance!
ETA: Sorry, two nuclear bombs on each coast. I want them as big as they come and positioned to do as much damage as possible.