A nuclear-security expert is calling on the U.S. government to better regulate the private-sector transport of radiological sources that could be seized by terrorists.
"Given the scale of damage that a 'dirty-bomb' could cause, it's difficult to understand why there are still no armed escorts required for category 1 transports," said Tom Bielefeld, a physicist and security-policy expert at the Harvard University Belfer Center's Project on Managing the Atom.
Category 1 sources are the most deadly of five radiological categories ranked by the International Atomic Energy Agency. Individuals who come into close contact to unshielded category 1 sources can die of radiation contamination within a few minutes to an hour, Bielefeld wrote in a Thursday analysis for the Bulletin of the Atomic Scientists.
The 3,000 curies of cobalt-60 contained in a briefly stolen truck last month in Mexico by armed thieves -- who turned out to be more interested in the truck than the cargo -- was a category 1 source.
While not quite as dangerous as category 1 sources, category 2 materials can cause irreversible injuries or even death if individuals are exposed to them for long enough.
Though the radioactive material in the Mexico case eventually was located and retrieved, there is a chance that similar or more dangerous incidents could take place in the United States, said Bielefeld.
He offered a number of suggestions for limiting the risk of a terrorist group seizing category 1 sources and other lower-grade radioactive materials while they are being transported by vehicle across the country, including:
-- A requirement by the U.S. Nuclear Regulatory Commission that a "real-time location-tracking system" be installed in all vehicles transporting either category 1 or category 2 sources;
-- A mandate in all 50 U.S. states that trucks transporting category 1 sources have an armed escort;
-- Assistance by states to radioactive transport licensees in identifying secure parking areas where drivers can safely rest;
-- Better training of truck drivers in how to respond, should their vehicles come under attack; and
-- Outfitting trucks with inexpensive security devices, such as vehicle-disabling systems and duress buttons.
"On the road, there are fewer technical protection measures available than inside buildings, so security depends even more on the people in charge: the drivers," Bielefeld said. "They must be vigilant and prepared. This is primarily the responsibility of their bosses, who, in turn, must be able to rely on adequate rules and specific guidance from the regulator."