Nuclear Detection Flaws

In 2002 the Bush administration began a $300 million radiation defense system. The system is intended to screen border traffic between the United States and Canada for radioactive substances. While defending the United States against radioactive-based attacks (such as nuclear weapons or dispersal of radioactive material) is a laudable goal, these efforts have failed. In fact, they have done worse than fail.

Newsweek recently published an article on this defense system that presented two very important facts. First, the system has had 1.5 million false positives in the course of screening 270 million vehicles. While the sensors have been set off by tile, cat litter, granite and even bananas, the majority of these false positives are from patients who have undergone medical procedures involving nuclear isotopes. The patients are, in effect, radioactive and hence are picked up by the sensors. While the sensitivity of the sensors is certainly encouraging, the fact that they cannot distinguish between patients and possible weapons is less encouraging. Of course, it could be the case that there simply is no effective way to distinguish between real threats and false positives using such sensors.

The second fact of concern is that of the 1.5 million positives, all of them have been false. Thus, no terrorists have been caught using this system. On one hand, this can be seen as a positive thing. Perhaps the deterrence factor of the system has kept terrorists from even making the attempt. On the other hand, maybe this is a bad thing. Perhaps terrorists (or others) have smuggled radioactive material across the border without being caught. In “Detecting Nuclear Smuggling” (Scientific American, April 2008 pages 98-104) Thomas Cochran and Matthew McKinzie discuss the unreliability of nuclear detectors. To illustrate their point, they helped ABC news smuggle depleted uranium through such detectors. While the authors go into some technical details in making there case, it is easy enough to make a general and intuitive case for why nuclear smuggling would be so easy.

While I am not a physicist, I know that radiation detectors work by detecting emitted radiation. To use an analogy, they can be compared to an eye seeing light or a nose detecting a scent. In the case of the eyes, if all emitted light is blocked, it cannot be detected. In the case of scent, if the particles coming off the substance can be contained, then it cannot be detected by smell (one might recall the commercials for zip lock bags demonstrating this). In the case of radiation, if the emissions are blocked, then the substance cannot be detected in that manner. Blocking radiation is a relatively simple thing and anyone who had read Superman comics knows how to do it: lead. Naturally, the actual concealing of radioactive material can be a bit more complex, but it is a simple matter of shielding and does not require any advanced technology or special equipment. In short, anyone who can gain access to radioactive material will certainly be able to have access to shielding material as well as a basic grasp of how to use it.

Radiation detectors would be useful against terrorists who lack the most basic grasp of how radiation detection works or in cases where the shielding is not adequate. However, it seems likely that these cases would be extremely rare.

It might be thought that such shielded containers would be easy to spot. However, as ABC news proved, it seems easy enough to get them through ports. Shielded containers could be disguised as any number of harmless items (metal machine parts, for example) that would pass visual inspection during border crossings. Of course, if we have to rely on visual inspection, it makes little sense to have spent $300 million on a system that is almost useless.

The nuclear detection flaws are just yet another example of what Bush’s war on terror has done in terms of defending America: we have spent millions of dollars building a system that inconveniences people needlessly and cannot really protect us. While it might catch very stupid  or ignorant terrorists, it hardly seems worth the cost.

Of course, the stated intent is a good one: protecting the United States from nuclear danger. Radiation weapons do present a potential for serious damage and we should have defenses against them. However, we need to spend our resources on defenses that work rather than ones that do not.

It might be argued that the defense would work, provided that people like Cochran McKinsie and myself did not betray America by drawing attention to the fact that the system cannot work. In reply, I think that the terrorists would figure that out on their own. Also, a citizen has a moral duty to point out wasted resources and inffective defenses. Basing a $300 million defense on the hopes that no one will notice or say that it cannot work is hardly good strategy.

We do need a defense against radiation weapons. Unfortunately, the current system is not the defense we need. Thanks again, George, for burning through so much cash with so little to show for it.