People who dismiss the threat of small nuclear devices are being dangerously naive. Realize that airplanes full of passengers where once thought to never be used as weapons and you can see how stupid it is to claim an actual weapon – which has no other purpose than to massively destroy – is not a concern. I ran across this article and my jaw literally dropped as I read one of the dumbest claims I have ever seen (and of course it was all about Jack Bauer):

Jack Bauer may lose 24 hours of sleep worrying about suitcase nukes, but should his viewers?

Probably not, nuclear weapons experts say.

Nuclear bombs cleverly concealed in suitcases don’t exist in real life. Even so, they have long been a popular Hollywood plot point.

Actually, nuclear bombs can fit into suitcases (or more likely shipping crates used for golf clubs or large suitcases). And since they can appear to be camera equipment, surveying equipment, etc they can be hidden in plain sight. The nuclear ‘experts’ are rationalizing, they are not being accurate. For example, check out these conflicting statements:

Nikolai Sokov of the Center for Non-proliferation Studies in Monterey, Calif., says there is no evidence any scientist has been able to create a suitcase-contained nuclear device.

…

Such devices had similar characteristics to the theoretical suitcase nukes, Sokov notes, including:

•Small size, perhaps measuring 23 inches long by 8 inches tall and weighing less than 70 pounds.

•Explosive yields from plutonium explosions under 1 kiloton, less than one-tenth as strong as the bomb dropped on Hiroshima in 1945.

Sounds like you could get two of those in a golf bag carrier. The weight is the problem. But if you are not passing through any airport security systems with the thing assembled, then you have no barriers. And then there is this completely ridiculous claim:

Battery life is one glaring sticking point, Thornton and others say. Any device lost in the early ’90s would be battery dead by now, as well as missing a few dozen maintenance checks. (24 plot spoiler alert: The story revolves around the villain seeking to somehow revive the batteries in his suitcase nukes.)

The one technology that has grown by leaps and bounds since the 1990’s is battery technology (not surprisingly pushed by the electric car iinvestments to reduce fuel consumption). Replacing batteries is trivial – you just need to match voltage and impedence and you are there. And today’s trickle charge batteries can go on for many, many months. If this is their explanation of why we shouldn’t be worried then they are truly naive or they are selling a story. For some reason these people think we should rate one threat higher than the other – which is insane. We treat all threats equally dangerous and not lose sight of any of them. Because I happen to agree that their preferred concern is truly a concern:

Other experts, including Sokov, warn that a “dirty bomb” seems a more likely form of nuclear terrorism, albeit a less deadly one. A dirty bomb would blow up some radioactive material, perhaps discarded medical diagnostics such as radioactive cesium, in a crowded place. It would kill some people with the explosion and contaminate the area. The technical expertise needed to create such a bomb is much less, Sokov says.

Zimmerman views the poisoning of ex-Russian agent Alexander Litvinenko in November as genuine nuclear terrorism, in part because Russians implicated in the death reportedly have left traces of polonium-210 across Europe, enough to trigger health concerns.

But here again they miss the real danger. What if Litvinenko was exposed during a Po-210 smuggling effort. What if his deadly dose is a small fraction of the material that transitted London last October. His deadly dose would probably not be visible to the human eye if it was sitting in a petri dish in pure form. So why is it there were three ‘consignments’ brought through London. A volume of Po-210 the size of a packet of sugar could kill millions. How many trips does it take to move a packet of sugar? Not three.

These folks are right, the dirty bomb is a serious danger AND it is closer to the grasp of terrorists than a full up nuke. The barrier is not batteries but technological expertise and experience. However, the more expertise and experience you can garner the more damage you can do.