Wait a minute. Time out. Back the aeroplane up. There are nukes in F4AF?
Yes, but it's useless. All it really does is cause the campaign to crash. The animations for it aren't even accurate, correct, or modeled. The effect is basically just a large radius explosion. Take a standard 2000 JDAM, multiply the dmg & radius several hundred times, and you get the F4AF nuke.
If you want to experiment with it, create a Tactical Engagement in 2010 NK. Drop down a few dozen tank and infantry columns. Add some SAMs if you're feeling saucy. Create your package and load it with the nuclear bomb. Burn 400 to 29.9 (contrails start @ 30), fly to where you know the dots you just created are, roll in, and bomb them. Accuracy not required. There's also some nuclear free fall bombs for red side bombers if you know how to switch over and fly as the OPFOR.