Homeland security: radiation detector overload

The New Yorker reviews the state of the art in American nuclear weapon defense ...

The New Yorker: Can the United States be made safe from nuclear terrorism?

...The federal government has distributed more than fifteen hundred radiation detectors to overseas ports and border crossings, as well as to America’s northern and southern borders, domestic seaports, Coast Guard ships, airports, railways, mail facilities, and even some highway truck stops. More detectors are being distributed each month... In the United States alone, the sensors generate more than a thousand radiation alarms on an average day, all of which must be investigated.

The world, it turns out, is awash in uncontrolled radioactive materials. Most are harmless, but a few are dangerous, and many detectors are still too crude to distinguish among different types of radiation; they ring just as loudly if they locate nuclear-bomb material or contaminated steel or, for that matter, bananas, which emit radiation from the isotope potassium-40. So far, the result has been a cacophony of false alarms, which, in most cases, are caused by naturally occurring radiation that has found its way from soil or rock into manufactured products such as ceramic tiles. In addition, people who have recently received medical treatments with radioactive isotopes such as thorium can set off the detectors. At baseball’s All-Star Game in Detroit in 2005, unobserved NEST scientists screened tens of thousands of fans entering the stadium, and their sensors rang just once—reacting to the former Secretary of Energy Spencer Abraham, who was radioactive from a recent doctor’s visit...

This is more than the boy who called wolf. This is the boy's choir calling wolf -- continuously.

It's a fascinating article. I suspect there's no real defense against a technologically competent enemy, but fortunately al Qaeda appears to be quite hostile to geeks and intellectuals. It reminds me a bit of Germany's attitude towards its Jewish scientists, who subsequently joined the Manhattan project. There may be defenses against duller enemies.

Of all the defenses we might have, I suspect the best is at the retail end of the nuclear weapons and waste industry. There may be "legitimate" vendors out there (fewer now that Pakistan is keeping a lower profile), but they are probably outnumbered 100:1 by undercover security agents.