Blast radius is large, but not that big. 4-8 mile diameter is more reasonable estimate. Depends on bomb eqiv weight.
Most of the weights we use now start at 20 megaton, and go up from there. Here is some information I got from the Office of Technology Assessment, Congress of the United States, Homeland Security on a detonation of one of our average devices, 25 megaton and distances from the initial. And this was an airburst:
25 Megaton Air Blast: Pressure Damage
Radius of destructive circle:
6.5 miles
12 pounds per square inch
The remains of some buildings’ foundations are visible. Some of the strongest buildings — those made of reinforced, poured concrete — are still standing. Ninety-eight percent of the population within this area are dead.
Radius: 10.7 miles
5 psi
Virtually everything is destroyed between the 12 and 5 psi rings. The walls of typical multi-story buildings, including apartment buildings, are completely blown out. As you move from the center toward the 5 psi ring there are more structural skeletons of buildings standing. Single-family residences within this this area have been completely blown away — only their foundations remain. Fifty percent of the population between the 12 and 5 psi rings are dead. Forty percent are injured.
Radius: 20 miles
2 psi
Any single-family residences that are not completely destroyed are heavily damaged. The windows of office buildings have been blown away, as have some of their walls. The contents of these buildings’ upper floors, including the people who were working there, are scattered on the street. A substantial amount of debris clutters the entire area. Five percent of the population between the 5 and 2 psi rings are dead. Forty-five percent are injured.
Radius: 30.4 miles
1 psi
Residences are moderately damaged. Commercial buildings have sustained minimal damage. Twenty-five percent of the population between the 2 and 1 psi rings are injured, mainly by flying glass and debris. Many others have been injured from thermal radiation — the heat generated by the blast. The remaining seventy-five percent are unhurt.
The radius of this is at around 30 miles, which make the diameter a little over 60 miles. So by making it a 60 mile diameter circle it creates an area of a little more than 2800 square miles from the immediate blast site.
But I believe the points within the post are consistent. Wish it wasn’t so.
rwood