Eerie

Using the 40 kiloton W33 warhead in high-yield mode, we do 6dx17,889 cr ex linked 6dx11,628 burn ex rad sur.

The radius of effect from p. B414 is 2x the dice in yards, or 214,668 yards or 122 miles for the explosion.  139,536 yards or 80 miles for the flash.

The average roll of 21 on 6d gets 375,669 points of crushing damage from the explosion and 244,188 for the flash.

This is at ground zero.  So don't stand there if you can help it.

But the damage falls off fast!

Nukemap says the radius of the fire ball is just 1,270 ft or 423 yards.

You divide the crushing explosion damage by 3x the yards from ground zero.  The burn explosion damage is divided by 2x the yards from ground zero.

So at 423 yards you take 296 points from the explosion and 289 from the flash.

Heavy blast damage (20 psi) goes out to 2,440 ft, or 813 yards.  Thats 154 points from the explosion and 150 from the flash.

Moderate blast damage (5 psi) goes out to 0.97 miles, or 1,707 yards.  That's 75 points from the explosion and 72 from the flash.

Radiation radius (500 rem) is 0.98 miles or 1,724 yards.  That's 73 points from the explosion and 71 points from the flash.

Thermal radiation radius (3rd degree burns) is 1.62 miles or 2,851 yards.  That's 44 points from the explosion and 43 points from the flash.

Light blast damage (1 psi) goes out to 2.5 miles or 4,400 yards.  That's 28 points from the explosion and 28 from the flash.

At the theoretical max blast circle, you take 0.58 points of damage from the blast.

At the theoretical max flash circle you take 0.9 points of damage from the blast and 0.88 from the flash.  Someone could punch you harder than that! 

For a bit of perspective:

An M67 fragmentation grenade does 9d[2d] cr ex.  That does an average of 32 points at the detonation point.

Don't be around nukes when they go off!

This, mostly, GURPS. 

The W79 Mod 0 dialed all the way up does: 6x2,966 cr ex linked 6dx1,928 burn ex rad sur.  Average damages of 62,286 and 40,488 each.

Fireball: 100 yards - 208 from blast, 202 from flash.
Heavy: 246 yards - 84 from blast, 82 from flash.
Moderate: 517 yards - 40 from blast, 39 from flash.
Thermal: 581 yards - 36 from blast, 35 from flash.
Radiation: 933 yards - 22 from blast, 22 from flash.
Light: 1,320 yards - 16 from blast, 15 from flash.

Dialed down it's: 6dx283 cr ex linked 6dx1,928 burn ex rad sur.  Average damages of 5,943 and 40,488 each.

Fireball: 38 yards - 52 from blast, 532 from flash.
Heavy: 110 yards - 18 from blast, 184 from flash.
Moderate: 232 yards - 9 from blast, 87 from flash.
Thermal: 255 yards - 8 from blast, 79 from flash.
Light: 596 yards - 3 from blast, 34 from flash.
Radiation: 613 yards - 3 from blast, 33 from flash.

These too, GURPS!