HOWTO Build a Nuclear Device

[Tim May]

On Friday, November 16, 2001, at 08:20 PM, !Dr. Joe Baptista wrote:

> One thing that is bothering me these days are all the reports coming out
> of Afganistan that nuclear bomb making plans were found.  Big
> deal.  Anyone on the planet can make a nuclear device if they have the
> appropriate materials.  The hard part is staying alive due to exposure
> while manufacturing the device.
>
> If however death is not an issue then the process itself becomes easy to
> accomplish.

Tom Clancy did a good job of describing how to make a low-yield nuke in 
one of his novels, the one about a nuke in the Denver stadium. (I think 
it was "The Sum of All Fears.") It's been many years since I read it, 
but my recollection is that one of  the actors gets sick.

As Eric C. pointed out in his follow-up to your article, this business 
of "staying alive" is probably the easiest of the problems to solve. The 
biggest hazard is from ingestion of the materials, either from some 
grinding or machining stage, or liquid compounds (molding the 
fissionables).

(The "apron" you mention at some point is almost totally beside the 
point. Working in a good fume hood or laminar flow hood would be a 
better safety precaution. Wearing a moonsuit and gloves would be extra 
protection. Not eating sandwiches or Doritos while mixing the stuff also 
helps.)

> Materials
> ---------
>
>  4 stainless steal salad bowls (5 - 8 inch diameter)
> 10 pounds of U-235 (Plutonium)
>  1 containment cylinder in which to fit the salad bowls
>  ? some explosives - C4 platic works best - but TNT or gun powder is
> acceptable.
>

> Divide the U-235 into two five pound masses.  Beat it evenly into the
> inside of one of your salad bowls.  U-235 is malleable like gold so you
> should have no problem shaping it.  Do the same with the other U-235 
> mass
> and shape it into the other salad bowl.
>
> C4 explosives work best.  You simply mold the C4 into the other two 
> salad
> bowls.  This is the most dangerous part of the project.  Improper 
> handling
> of C4 can cause an explosion.  But gun powder is just as effective.


Why so complicated on the detonation geometry? Without doing some 
experiments and getting the fast ignition triggers (on the real 
munitions list), I'd doubt strongly that your scheme would work the 
first time.

And gunpowder is almost guaranteed to not work.
>
>
> Anyone on this planet can build a nuclear device.  So the only issue in
> building the device is the will to die for a cause.  And the only 
> thing I
> find unfortunate in all of this is that there are so many causes that
> people are willing to die for.  And war will not make those reasons go
> away - it will only encourage them.
>

It's really _not_ this easy. It took China and India a while before they 
successfully tested an A-bomb (many years after they had the raw 
materials from their reactor programs). It may have taken the South 
Africans and Israelis a few years after getting materials, too. So, why 
didn't they just hammer U-235 into stainless steel mixing bowls and do 
it the way "anyone on this planet can build a nuclear device," one 
wonders.

I'd guess that the "tall pipe" version is the most buildable of the 
basement nukes. (In a nutshell: a tall drainpipe, perhaps 40 feet tall. 
Set up in an apartment building, warehouse, etc. At the base the pipe is 
reinforced with copious amounts of concrete. The subcritical masses are 
at opposite ends of the pipe. The mass on top is piled on with several 
hundred pounds of ballast, to "tamp" the early critical mass action. To 
explode the bomb, drop the mass from the top of the pipe. The critical 
mass is briefly contained by the concrete collar around the pipe and the 
inertial mass above. Is it enough to produce a real chain reaction? 
Well, it's all relative. Still, not very efficient.)