If the EMP from an atomic explosion is SO massive that one single bomb/EMP will 'totally destroy the United States Power Grid and kill "up to" 90% of all Americans ...
THEN - How the hell did the Enola Gay manage to keep flying after dropping the A-Bomb ?
It was at 30,000 feet (~5 miles altitude), and 11.5 miles horizontal distance from the explosion.
Go ahead - make your bomb 100 times bigger - do the math - energy density is directly proportional to r^2.
A little trig 50 miles up, 100 miles away - how does the SQUARE of that distance compare to the SQUARE of the distance the Enola Gay was from drop zone ? How about 2200 miles away and 100 miles in elevation ?
If ya really wanna crunch the numbers, go ahead.
IT DOES NOT COMPUTE - the EMP doomsday stuff is horsefeathers.
BTW: The Enola Gay kept flying.
http://nuclearweaponarchive.org/Usa/EnolaGay/EnolaGay.html
The Enola Gay rendezvoused with the observation planes over Iwo Jima at 0605. Little Boy was armed at 0730. At 0741 Tibbets began the climb to the drop altitude above 30,000 feet. The Enola Gay came within sight of the Empire, as bombing crews called it, at about 0750 as it approached the southern tip of Shikoku Island.
The weather plane over the primary target radioed good conditions at 0830 and Tibbets announced that Hiroshima would be their destination. At 0909 Hiroshima came into view. At 0913.30 the bombadier, Thomas Ferebee, took control of plane in preparation for release. At 0914.17 the Aioi Bridge appeared in the Norden bombsight cross-hairs and Ferebee initiated the automatic release sequence. At 0915.17 Little Boy dropped away. The fall to the burst altitude of 600 meters lasted 43 seconds, at that moment Little Boy had a vertical velocity of 335 meters/second, just a bit faster than sound.
As soon as the bomb was released Tibbets took control and the Enola Gay began its escape maneuver. Eleven and a half miles from the detonation point and nearly a minute after the explosion the plane was rocked by the shock wave travelling directly out from the fireball, and then several seconds later it was struck by a second weaker shock reflected from the ground. Aside from the sighting of a single fighter, the flight back from the mission was uneventful. The mushroom cloud, which had climbed to 40,000 feet, was visible from the plane for almost an hour and a half, finally being lost from sight at 1041, 363 miles from Hiroshima.
http://www.atomicheritage.org/history/project-silverplate
Modifications - Mechanical to accomodate size and weight of the bombs - no special 'emp hardening' mentioned at all. Radios kept working also. New Nuclear bombs can be 'optimized for EMP yield' ... Really - that is going to be their argument ? I will call BS on that being a major factor also.
Finally, brethren, whatsoever things are true, whatsoever things are honest, whatsoever things are just, whatsoever things are pure, whatsoever things are lovely, whatsoever things are of good ...