Jeffrey LewisSuitcase Nukes

A while back, a reader asked me whether or not “suitcase nukes” actually existed. I expressed my skepticism, but deferred to a more knowledgeble colleague.

Now, AP’s Katherine Shrader has a very nice, readable deconstruction of the rise and fall of the suitcase-nukes-scare:

“The suitcase nuke is an exciting topic that really lends itself to movies,” said Vahid Majidi, the assistant director of the FBI’s Weapons of Mass Destruction Directorate. “No one has been able to truly identify the existence of these devices.”

I also recommend Carey Sublette’s excellent essay, Alexander Lebed and Suitcase Nukes.


  1. Yale Simkin (History)

    It is quite important to differentiate between the possibility of suitcase-sized bombs and whether terrorists possess actual diverted inventory of a possible Russian design.

    It is important to note 2 things…

    1) The AP story was chock-a-block (… I always wanted to use that word!…) with technical error. It is scary if Majidi, who is responsible for protecting us from this stuff, could state such nonsense and have his numbers so screwy.

    2) Sublette’s essay was on the Lebed issue – NOT on the very real existance of very small bombs which can fit in a large suitcase. Within his essay is a link to a discussion of the actual possibilities.

    What is possible? Real, actual, touchable nuclear artillery shells, using linear implosion, were manufactured in large numbers and most certainly would fit in a small suitcase and at less than 50 kilograms, be carryable by a strong individual. As Carey points out:

    It is clear that any of the 155 mm artillery shells, if shortened by omitting the non-essential conical ogive and fuze would fit diagonally in the package that Lebed describes…

    Mock-up of W48

    These very real artillery shell are the basis for the mockup shown in Jeffery’s post.

    I do agree with the premise of the article that the most likely terrorist risk would not be from one of these micronukes, but something much bulkier (but still concealable and transportable)

    A “homebuilt” uranium gun is well within the skill level of competent groups. In “The Curve of Binding Energy” Ted Taylor gives rather detailed descriptions of a device which would fit in a golfbag and weigh a couple hundred kilograms yielding 1 kiloton.

  2. Anya L (History)

    The Weldon picture is priceless…

  3. Alex W. (History)

    To me the oddest bit about the idea that the Russians had created dozens of nukes in suitcases and brought them over to US cities and the like is that you’d have to inherently keep it secret for it to not create panic in the host country (and after they tried putting nukes as close as Cuba, it seems unlikely that they would actually have them placed inside US cities without major political repercussions), but keeping it too secret would mean it had zero value as a psychological deterrent. As Dr. Strangelove said, “Of course, the whole point of a Doomsday Machine is lost, if you keep it a secret!” Suitcase nukes would be an ideal weapon, perhaps, for terrorists, but they don’t seem to me like they would be all that useful for nation states. (And in the category of nation-state sponsored terrorism, I think you’d usually be happy with something less conspicuous as a nuke.)

  4. SQ

    Just letting people believe in the existence of pre-planted nuclear devices could have some of the desired psychological effects. Similar rumors have described a nuclear device hidden in the Soviet embassy — presumably transported by diplomatic pouch.

    In either case, the extraordinary risks involved make the story quite doubtful. The difficulty of maintaining any such device in working order for very long makes the story downright implausible.

  5. cenoxo

    Perhaps suit/briefcase nukes are red herrings.

    Low-yield, relatively small nuclear warheads were used in the atomic Davy Crockett shell, the ‘backpackable’ Special Atomic Demolition Munition (SADM), and its big sister MADM . These were designed, built, and deployed decades ago. Even if they’re no longer available (to be stolen or lost), couldn’t something similar be recreated with today’s technology?

    Devices in this class — or those weighing less than few hundred pounds — would still be small enough to be transported easily in ordinary vehicles, and hidden in millions of inconspicuous locations (i.e., the vending machine in Sum of All Fears, parked in a garage, or stored in an old trunk.)

  6. PDW

    US backpack sized bombs existed and were called Special Atomic Demolition Munition, SADM, or Medium Atomic Demolition Munition, MADM.(see e.g.

    As their names suggests these weapons did not have a pure deterrent function but were supposed to be used as tactical weapons to destroy high value military targets (e.g. bridges.) As far as I know they were prepositioned in NATO countries. It seems likely that Russia also had such weapons in its arsenal.
    Wether such Rusian weapons still exist and if it is likely that terrorists would be able to obtain such bombs is of course a different matter.

  7. Mark Gubrud

    One can imagine that suitcase nukes or prepositioned nukes would be useful for zero-warning decapitation in a surprise attack, or as a deterrent in some scenarios, e.g. that their existence could be revealed in case of a very severe crisis, if one feared a first strike from the other side (you could tell them where one was hidden, and that there were others).

    However, the possibility of one of the bombs being detected in peacetime, or that one might pass out of your control due to a defection, sale to a terrorist, or mental breakdown of an agent responsible for one or more of the weapons, would seem likely a compelling argument against deployment of such weapons except possibly, again, in anticipation of a possible crisis situation in which such weapons would be useful.

    My conclusion would be that it is possible for weapons to have been made for this purpose, but unlikely that they would ever have been deployed, e.g. prepositioned, or even released from a secure facility.

  8. Gridlock (History)

    I understood it to be a former president who offhandedly described the nuclear weapon on the second floor of the Soviet embassy in DC, but then I heard this a few years back and the details escape me – however I must be asking in the right place?

    (I couldn’t find my original source for the embassy story, but this was interesting reading – the Russians attacked a USN Officer with a laser?)

  9. Tom (History)

    Correct me if I’m wrong but isn’t plutonium oxidation a serious issue with smaller weapons?

    If these (alleged) weapons were manufactured in the 1970s and have been (potentially) out of maintenance for a decade and a half would they even be serviceable?

    Not saying you couldn’t re-use the components in some other home-brewed device but without a depot overhaul could they be used as is at this stage?

  10. Rob (History)

    It makes no difference at the moment. If the Russian did at one time have so-called suitcase nukes they don’t now.

    And even if a few are missing the likelihood that they can be used now is very small if not impossible. Maintenance and the shelf-life on these critters like the SADMs was extraordinary…

    Besides Curt Weldon goes to sleep at night worrying about the one under his bed.

    If UBL had one we would also know it by the big hole in the ground where NYC or any city for that matter once was….

    We better start worrying about the 410MT of HEU that is poorly secured in the Federation before we have any big holes where a city once was. That is the threat! Besides us mis-placing a few W80-1 by accident….

  11. SQ

    For whatever it may be worth:

  12. Allen Thomson

    Not exactly suitcase bombs, but some history on worries about clandestine nuclear attack:

  13. Gridlock (History)

    The Memory Hole, that was it – cheers.

    That Kennedy, always saying the wrong thing to the wrong people…

  14. Rwendland (History)

    At least no-one has recently suggested that the mythical lightweight Californium suitcase nuke (lower critical mass) has ever been made!

    But to go off at a tangent, hopefully without creating urban-myth fodder, can anyone explain why the UK Ministry of Defence offers “californium production” as a significant use for a substantial part of 4.2 tonnes of plutonium that the UK supplied to the US between 1964-1969? I always thought only gram quantities of Californium had ever been isolated, so I’ve always been puzzled by this MoD statement – though I have no understanding of Californium production; maybe it is easy to explain. Source: see paras 30-34 of Plutonium and Aldermaston – An Historical Account

    The background is that the UK plutonium in Barter B under the 1958 US-UK Mutual Defence Agreement came from both military and civil magnox reactors. The US undertook not to use the civil plutonium for weapons – explaining this the UK MoD says: “Civilian programmes include californium production and reactor research.”, so californium production is the first mentioned use of this civil plutonium.

    The UK MoD does not say how much of this 4.1 tonnes barter came from civilian reactors, but as UK military reactors produced I think roughly 500kg/year, in the 5 years full production of the UK military reactors would be less than the 4.1 tonnes. Also the other 2 barters which came entirely from military reactors were for only 0.5+0.8 tonnes. So probably the majority of the 4.1 tonnes came from civil reactors. 2+ tonnes of plutonium is a lot to use for “programmes [that] include californium production and reactor research.” If californium production was a minor use, why explicitly mention it?

    Can anyone offer an easy explanation?

    extra info: If we look at the US version of this report, it says foreign supplies of plutonium were ‘primarily fuel grade plutonium’, that 692kg plutonium was used in fission and transmutation 1964-74, and ‘plutonium that was transformed to other materials such as Plutonium-242, Plutonium-244, Americium, Curium, and Californium-252. Californium-252 was produced in the Savannah River Site reactors and in the Oak Ridge National Laboratory (ORNL) High Flux Isotope Reactor in the late 1960’s. Californium-252 is an excellent spontaneous fission neutron source for oil well logging, industrial radiography, reactor start-up, nuclear physics research, and medical applications.’

  15. Enoch (History)

    “Curt Weldon goes to sleep at night worrying about the one under his bed.”

    I think he’s more worried about whether there’s an FBI agent under his bed and his daughter’s bed.

  16. Carey Sublette (History)

    But to go off at a tangent, hopefully without creating urban-myth fodder, can anyone explain why the UK Ministry of Defence offers “californium production” as a significant use for a substantial part of 4.2 tonnes of plutonium that the UK supplied to the US between 1964-1969? I always thought only gram quantities of Californium had ever been isolated, so I’ve always been puzzled by this MoD statement – though I have no understanding of Californium production; maybe it is easy to explain.

    Indeed it is. High atomic mass transuranics are created by multiple neutron captures, starting (ultimately) with U-238. To make Cf-252 this requires 14 successive captures.

    The problem is: at each stage of this 14-step process the production rate is a fraction of the production rate of the previous product in the chain of captures. When you multiply the starting product production rate by a fraction fourteen times you end up with a very small number. To get significant amounts of product 14 you need very large amounts of starting material. To make grams of Cf-252 you need tons of starting material, plus years of irradiation in a high flux reactor.

    The fuel grade plutonium makes a good starting material because it contains a relatively high concentration of Pu-242, which is already four steps along the production chain.

  17. Alex W. (History)

    Apropos of nothing, there is a nice video about the SADM on YouTube now:

    (for lots more, see

  18. Rwendland (History)

    Carey, thanks muchly for that Cf-252 production explanation. As this Pu was from a military exchange, I had wondered if the Pu was for producing enough Cf-251 for military research, eg measuring Cf-251 critical mass. Sounds very unlikely.

    Incidentally, there is a published estimate of theoretical Cf critical masses in Evaluation of nuclear criticality safety data and limits for actinides in transport – C4/TMR2001/200-1 eg 5.46kg for bare sphere Cf-251.

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