Last December, two small teams slipped nearly simultaneously into the United States. One moved across the Canadian border, the other entered from Mexico; both carried cesium-137, a material commonly associated with dirty bombs. Radiation detectors flagged them at both points of entry, but the smugglers produced fake documents, ostensibly issued by the U.S. Nuclear Regulatory Commission, legitimizing their cargo. They were allowed to enter the country.
The individuals weren’t terrorists. They were employees of the Government Accountability Office, the investigative arm of Congress, and they were testing the state of American security. Their report, released Tuesday at a Senate hearing, accuses the government of allowing enough material for “two dirty bombs” into the United States. Predictably, senators of both parties have expressed outrage. Republican Norm Coleman said the report suggested “a massive blind spot.” Democrat Carl Levin described it as “an alarming wake-up call.”
But such panic is overstated—and worse, potentially harmful. The GAO operation, while exposing one important flaw in our border security system, came nowhere close to showing that terrorists could import a dirty bomb that would do serious damage, or, actually, any damage at all. The materials smuggled in would barely be enough to contaminate a studio apartment, let alone a substantial part of an American city. And if the United States continues to hold itself to the unrealistic standards the GAO has implicitly established, it will weaken, not improve, its security.
After Tuesday’s hearings, The Washington Post published details about the materials used in the GAO plot that had been left out of the report. According to the Post, the GAO employees smuggled 150 microcuries (a unit of radioactivity) of cesium-137 across each border point. Simple simulations using the government-developed software HOTSPOT show that if that amount were dispersed in light winds using a pound of explosives—ideal conditions for a terrorist attack—no area would be contaminated above even the strictest federal safety standards. Even if (unrealistically) someone remained within half a city block of the dirty bomb explosion for 30 years, he would gain only an extra one-in-a-million chance of death from cancer. Using more explosives would make the radiological danger even smaller, as would assuming stronger winds; in both cases, the material would be spread so broadly that it would pose little danger at any one place. (One might wonder whether many instances of low-level smuggling could add up to a dangerous bomb. But to detonate anything significant, a terrorist group would probably need one curie of cesium-137, about 10,000 times as much material as was used in the GAO test. If each of 10,000 smuggling attempts had a 99.9 percent chance of success, but if a single interception led to defeat of the whole terrorist plot, the scheme would have a 0.005 percent chance of succeeding.)
Of course, such sting operations have value: In this case, they tested radiation detectors at the border. More significantly, the GAO sting identified an important problem: The documents permitting possession of radioactive sources can be too easily faked. The Nuclear Regulatory Commission is working to fix the problem, and it should move as quickly as possible. But solving it shouldn’t distract us from other pressing needs—such as stricter security requirements for strongly radioactive materials and development of non-radioactive technologies to replace highly radioactive sources—that will be required to deal with the dirty-bomb problem.
There is also a danger that hysteria surrounding the GAO report will lead to a focus on stopping small amounts of radioactive materials from entering the United States rather than stopping terrorists with radioactive materials from entering the United States. Those who participated in the GAO study carried American passports and drivers’ licenses; most terrorists would probably be carrying passports from foreign countries (as were the September 11 hijackers). We can’t ignore the fact that stopping nuclear terrorism means stopping nefarious individuals with nefarious materials—for instance, by improving databases of suspected terrorists and linking them with radiation detection equipment—not simply stopping nefarious materials themselves.
Moreover, millions of radioactive sources exist in the United States, and many times more around the world. As countless scholars have noted, it is impossible to secure them all or to interdict all that are stolen. If the standard used by the GAO is applied in other efforts to prevent dirty bombs—if, for instance, the government attempts to secure every source the size of the one used by the GAO—then the United States will experience one of two outcomes. If it succeeds in controlling the materials, the costs will be enormous, and the side effects will be crippling to the many industries that rely on small amounts of radioactive materials. If, on the other hand, it determines that controlling so many sources is impossible, it may give up, leaving the most potent sources—which number many fewer—dangerously unsecured. It may be satisfying now to call for absolute security, as the senators who ordered the GAO report are effectively doing. But more realistic, attainable goals will leave us much safer in the long run.