MILNET - Suitcase Nukes

Also highlighting this issue is the timely release of the motion picture Peacemaker, a thriller based upon a Bosnian terrorist getting his hands on a the primary device in a thermonuclear weapon. The primary in this case is shown to be a cylinder about 1 foot long and 4 or 5 inches in diameter. In the final scenes of the film, we see a minature metal ball with a texture similar to a soccer ball, the panels supposedly being the shaped charge necessary on the outside to create a compression of plutonium to attain a critical mass. Tiny wires protrude from each panel, and our heroes are attempting to dismantle the devilish device. Whew!

Here are some answers to some simple questions...answers from Carry Sublette the author of the Nuclear Weapons FAQ posted on MILNET.

Notes surrounded with [ .. ] are editorial comments by MILNET.

Q: I have taken the position in the past that the physics are such that only a weapon with little or no shielding would be possible to fit in this size.

A: This [...a weapon of with little or no shielding would be possible to fit in this size] is true, but not of much consequence. Few nuclear weapons incorporate much shielding of any kind.

Q: Taking into account the physical size of a critical mass (a grapefuit sized mass of 6.8 kg?), the gun device, or surrounding shaped charges would mean the device would have to be the size of a large steamer trunk rather than a suitcase.

A: The closest thing to a "suitcase bomb" (i.e. designed to be man-carried) was the W-54 SADM which was a cylinder 40 cm by 60 cm, and weighed 68 kg (the actual warhead portion weighed only 27 kg). The yield was up to 1 Kt. In fact it has been called a "suitcase bomb"; I refer to it as a "steamer trunk bomb" in the attached article

But as I indicate, the actual part that goes "boom" was much lighter and could be packaged differently. In fact, if we look at the other W-54 variants a much lighter and more compact design emerges.

As the Davy Crockett warhead (yield only 10-20 tons), its mass was only 23 kg. The warhead was basically egg-shaped with the minor axis of 27.3 cm and a major axis of 40 cm [50 cm is around a foot and a half].

But some of the test devices used to develop the W-54 were smaller still:
shots Hamilton and Humboldt on 15 October and 29 October 1958 fired in Hardtack Phase II weighed only 16 kg. These devices were 28 cm by 30 cm. These two devices had yield of only 10 tons or so, but adding fissile material to bring the yield up to hundreds of tons would have only required a few more kilograms.

[General] Lebed specified a suitcase thickness [height of the weapon carrying case] of 20 cm, a little thinner than the minimal dimensions listed above. But the linear implosion technology used to make atomic artillery shells could easily make weapons slim enough to fit in this dimension. We have fielded 20.3 cm and 15.5 cm atomic artillery shells, and 10.5 cm is known to be feasible. These systems are probably heavier than the implosion technology used for the W-54, but how much does a 155 mm or 105 mm artillery shell weigh anyway? Probably more than half that weight is steel shell casing anyway.

Q: How long could someone be exposed to a device of this type (shielded and unshielded)?

A: Close proximity to a bomb's worth of plutonium 40 hours a week may violate OSHA guidelines.

I'm *not* being flip here, this is an important worker safety issue where bombs and components are fabricated and assembled. The only "shielding" are rubber gloves, and a plexiglas window. Weapon grade plutonium can be handled without undue concern, but temporary rotation to other jobs is sometimes required to keep down exposure levels. Similarly, the submarine deployed W80-0 warhead used "supergrade" plutonium because of neutron exposure problems for sub crews who work 12 hour days in close proximity to warheads for a couple of months at a time.

In short - there is no practical limitation for relatively short term exposure (like a sabotage mission).

Carey

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So as you can see the suitcase weapon is both possible and could be as lethal as the designer decides. If you read the article that accompanies Carey's reply, you will see that a 10 ton weapon could be quite small, and simply by adding some additional fissile material, you could push the yield up to 200 tons, which would having a killing radius (100% lethal radiation exposure) of some 450 meters (around a quarter of a mile, slightly larger than a football field).

If a 200 ton yield weapon were set of in the stands of a football stadium, everyone not at the concession stands (typically behind the concrete pilings of the structure) would be dead within 48 hours if not instantly. Those visiting the bathrooms or getting a hot dog would be extremely ill almost immediately, and would have a 50% or better chance of dieing within a few days of the incident. Few in the stadium anywhere would survive. There would also be some fallout effects as well as site toxicity, such that fireman, police, and other rescue workers would also suffer, adding to the casualty list. In other words, it would be a major disaster, not just a loud bang.

And in Carey's opinion, this weapon would still be small enough to be lugged around. Worst case it could be part of someone's luggage on a train, or simply kept in the trunk of a rental car. Lord knows I've carried heavy enough suitcases before.

And clearly if someone were going about transporting a small weapon, they would be doing so for the purpose of enciting terror, or at a minimum targeting the morale of their enemy. Striking fear into the populace of military opponent is a typical propoganda method used by military leaders in or out of war.

Therefore it would seem quite possible for such weapons to have been produced by the Soviets or the U.S. during the height of the cold war.