nuclear-news

The News That Matters about the Nuclear Industry Fukushima Chernobyl Mayak Three Mile Island Atomic Testing Radiation Isotope

How lethal are Pakistan’s nuclear weapons? How much damage would there be to india?

How lethal are Pakistan’s nuclear weapons? How much area would be immediately destroyed in a single attack?

h/t Geoff Olynyk and Joseph Boyle for links and commentary

By destroy an area, I mean the radius within which buildings fall, things burn and people die immediately. I don’t mean the after effects of nuclear radiation, which I understand would affect a larger area. The objective of this question is chalk out a rough evacuation plan if some day there is a strong chance of a nuclear attack
 
The short answer, of course, is very lethal, like all nuclear weapons. Read on for more details.

So according to the Pakistan and weapons of mass destruction article on Wikipedia, Pakistan possesses four delivery mechanisms for a nuclear attack in the area:

  • Medium-range ballistic missile (MRBM). Range, 2500 km. Estimated yield 300–500 kt (kilotons of TNT equivalent).
  • Nuclear-tipped Babur cruise missiles. Range, 700 km. Yield – ?
  • Nuclear bombs carried by fighter-bombers. Estimated yield up to 150 kt.
  • Cruise missiles carried by fighter-bombers. Warhead estimated yield 20–25 kt.


The fighter-bombers likely drop 150 kt bombs or launch cruise missiles with 20–25 kt warheads. The most powerful warheads in Pakistan’s arsenal are estimated to have a yield 300–500 kt, delivered by the Ghauri-I MRBM:

Ghauri medium-range ballistic missiles.

Note that this would be a very similar yield to the U.S.’s most advanced warhead, the 475 kt W88. (Although the Pakistani one is probably much heavier due to the less advanced technology, and thus you can’t carry as many of them on a missile.)

As we start discussing the effects, keep in mind the pictures of the destruction in Hiroshima (the Little Boy bomb had a yield of 13 kt), and remember that a 500 kt weapon is nearly 40 times more powerful.

Effects of a 13 kt air burst.

They are also apparently working on a sea-launched cruise missile (a naval variant of the Babur) and a smaller nuclear warhead that can be put on Pakistan’s Chinese-made C-802 and C-803 anti-ship missiles, but these delivery mechanisms are not operational yet.

Taking the upper end of the estimated range of Pakistani warheads (500 kilotons) is convenient because the U.S. government published a bunch of graphs on the effects of a 500 kt blast in the report Nuclear Attack Environment Handbook (FEMA, August 1990). The graphics below are taken from here, which reproduces the FEMA book.

Here is an overview of the effects of a 500 kt surface burst:


There is heavy damage (5 psi overpressure) out to a radius of about 2.2 miles.

If they are smarter about it and detonate it 1.1 miles in the air (see Geoff Olynyk’s answer to Bombs: Why doesn’t the blast from a nuke take place on the ground?), the damage radius is larger:


There is now heavy damage out to a radius of 3.2 miles. The government also helpfully calculated the winds produced by a 500 kt air burst:


and a nice graph showing all the other fun effects (eardrums burst! serious glass wounds!) from a 500 kt air burst:


Finally, here are the radii at which you get flash burns from the light (thermal radiation) from a 500 kt air burst, depending on how clear of a day it is:


Okay, that’s enough detail. To actually answer your question, the overpressure at which buildings fall and people die immediately is about 20 psi, but it’s more likely than not that you’ll die at the 5 psi level also, due to flying debris, you getting thrown about, fire, glass, etc. Even if you survive, your eardrums will explode and you’ll probably die within a few hours anyway due to the burns.

So for a 500 kt weapon (upper estimate of Pakistani capability), with an air burst, that’s a radius of 0.6 miles (1.0 km) for the 20 psi overpressure, or 3.2 miles (5.1 km) for the 5 psi overpressure. Note that’s radius from the hypocenter (the point on the ground below where the warhead detonates).

But if you want a better chance of survival, just looking at the graphs above (I obviously have no personal experience with this), you’ll want to be more like 6–7 miles (9–11 km) away from the hypocenter.

There is lots more discussion of the effects of a 500 kt airburst at this company trying to sell you a fallout shelter‘s website:

  • Impact lethality out to just over 4 miles.
  • Impact skull fracture and serious glass wounds out to 5 miles.
  • Impact injuries out to over 6 miles, with 50% probability of 3rd degree burns, if in clear line-of-sight at the instant of initial flash.
  • Skin lacerations from glass fragments out to almost 9 miles, with 50% probability of 1st degree burns, if in clear line-of-sight at instant of initial flash.


They say the “lethal radius” is 2.2 miles, which corresponds to the 10 psi overpressure curve.

You can put these radii on your city using the widget here.
Ground Zero | Carloslabs (Choose the Joe-4 400 kt weapon.)

Finally, I note that for the smaller Pakistani weapons (say, the 20 kt nuclear-tipped airplane-launched cruise missile), the 5- and 20-psi overpressure radii will obviously be smaller; about 35% as large in radius. You can get a sense of the destruction from such a weapon by looking at pictures of Nagasaki (the Fat Man had a yield of 21 kt).

Also, I love how Quora now thinks I’m some sort of expert on nuclear weapons  because I’ve answered a few questions with links to Wikipedia. Every time I answer another one of these nuclear weapon questions on Quora, I’m more and more disgusted at humanity for building so many of them

 
 
Target a site with a nuclear device near you with this handy path of destruction programme;
 

  
 
 

May 30, 2013 - Posted by | Uncategorized

No comments yet.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.

%d bloggers like this: