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# Blast radius of a nuclear explosion?

Updated: 9/27/2023

Wiki User

12y ago

it depends mainly on the amount or weight of the nuclear bomb.....that is ....the amount of radioactive uranium and plutonum inside it....diff weights have different blast radiuses.....the heavier the bomb the larger the explosion.

Actually it has nothing whatsoever to do with the weight of the bomb, It depends on:

• yield
• burst height/depth
• weather (e.g. inversion layer above burst)
• What level of overpressure you want to measure as the "blast radius"

The amount of uranium or plutonium in the bomb is usually an insignificant fraction of the weight of a nuclear bomb or warhead. Fatman had about 10 pounds of plutonium yet weighed 10,000 pounds. The remaining 9,990 pounds consisted mostly of depleted uranium, conventional explosives, electronics, and a steel ballistic casing!

One bomb can easily be much lighter than another and have a higher yield, if its materials usage is more efficient. This is a major goal of nuclear weapon designers.

The three usual overpressure zones nuclear weapons planners are concerned with are the 1000 psi zone (which is generally the requirement to knock out a hardened missile silo), the 20 psi zone (which destroys steel reinforced buildings), and the 5 psi zone (which destroys normal buildings). In particular, the 5 psi zone is used for casualty calculations, since the number of survivors of inside the 5 psi zone is roughly equivalent to the deaths outside that zone, for a typical area with an even population distribution.

For a 1 MT weapon detonated at the optimal distance from the ground to produce the maximum radius of the PSI zone in question, here are the appropriate distances from ground zero: 3.2 miles (5 psi), 1.4 miles (20 psi), 0.5 mile (1000 psi). The power of a nuclear weapon goes up with the cube root of the yield - so, if you want a weapon that has twice the area of effect, it needs to have 8 times the yield. So, a 1kT weapon has 0.1 of the area of effect of a 1MT weapon, while a 125kT weapon has 0.5 the area of effect compared to a 1 MT weapon.

Wiki User

12y ago