TCS Daily

Paper Tigers

By Iain Murray - June 11, 2002 12:00 AM

"The atom bomb is a paper tiger which the United States reactionaries use to scare people. It looks terrible, but in fact it isn't."
Mao Tze-Dong's 1946 statement could be applied with far more validity to today's paper tiger, the so-called "dirty nuke". People are worried that terrorists might combine conventional explosives with radioactive material to create a more effective weapon. Recognition of the ready availability of radiological medical waste - experts on CNN and Fox News have called attention to Strontium-90, for instance - combined with the arrest of Jose Padilla for planning such an attack have helped to foster a climate of worry that a nuclear disaster is looming. Yet the threat is as flimsy as Chairman Mao suggested.

The nuclear destruction of Baltimore in the hit movie "The Sum of All Fears" cannot be helping, but a "dirty nuke" would look nothing like that. The blast would be as limited as any conventional terrorist bomb, like the one in Oklahoma City that killed 168 people. Nor would many people be killed by radiation. The problem with radioactive material as a weapon is that it decays over time - what is known as the "half-life". Generally, the shorter the half-life, the more deadly the material. However, what's deadly for the target is also deadly for the bomber. Without a specially equipped lab and sophisticated containment devices, the material would probably kill the bomb-makers and could even melt the container.

Using materials less deadly to the maker, the problem is that not enough radiation is emitted to kill large numbers of people. A material like caesium-137, with a half-life of 30 years, would not kill many extra people. Most could simply walk out of the affected area after the blast and not suffer particularly badly. If people ingested fallout then they might develop cancer or suffer other ill effects later, but immediate radiation sickness would not be a particular worry. This is one of the reasons the Iraqis abandoned their program aimed at creating dirty nukes in 1987. As the New York Times commented, "the radiation levels were considered too low to achieve the grisly objectives" (William J. Broad, "Document Reveals 1987 Bomb Test by Iraq," New York Times, Apr. 29, 2001).

However, the lack of immediate deadliness could be viewed as a strength of dirty bombs. Radioactive contamination would mean that an area became unusable, as staying in it for any length of time would be deadly. An area attacked by a bomb using uranium-234 would remain uninhabitable for thousands of years. Dirty bombs could therefore be very useful as economic weapons. Much has been made of scenarios where terrorists explode such bombs in The Mall in Washington DC. There would indeed be a significant psychological effect of having large areas of the national capital cordoned off, but the only practical effect would be to prevent people going to museums. A dirty bomb exploded at an airport like JFK, however, could have significant economic impact. Getting the right target becomes very important if you are going to use a dirty bomb primarily as an economic weapon.

Even so, new airports can be built relatively quickly. Fallout can be cleaned up. Economic effects may be severe, but they will be temporary. The nightmare scenarios mentioned wherein the entirety of Manhattan is rendered uninhabitable would require huge bombs with very large amounts of radioactive material, and can probably be discounted as fantasy.

Moreover, the sort of radioactive material available is an important element in assessing the scale of the threat posed by dirty nukes. Many commentators have mentioned strontium-90 as being readily available in medical waste. This is true, but strontium-90 is neither one thing nor the other when it comes to the effects it would have. It would not be deadly initially - the most harm would come to those people unlucky enough to ingest the material and have it affect their bone marrow. Others would suffer burns no worse or longer lasting than those from other heat sources. On the other hand, as radioactive materials go, strontium-90 would not contaminate for very long. Any area affected would be inhabitable again in about 30 years, a tiny period in the lifetime of cities and certainly miniscule by comparison with radium-226, which would continue to affect the area for 1.5 million years. The effect would be not so much "Keep out" as "Closed for repairs".

Dirty nukes are therefore useful really only for their significant disruptive power. At the moment, however, there is substantial added value to the terrorist from the fear their possible use engenders. The panic this fear could produce in the event of one being used might kill more than the explosion. That is why it is best to think of them as paper tigers. The more we know about what they really are, the less frightening they become.



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