The History Channel did a 2 hour special called "Day After Disaster". It was low on doom and gloom and high on expert testimony.

One important thing to remember is the size of particulate. A grain of sand with 100 time the mass of a spec of dust will hold radiation that much longer.

here's a link to the special on youtube

http://www.youtube.com/watch?v=doQY4xRXJJ4