The department received 215 reports of nuclear trafficking and related criminal activity worldwide in 2005, versus 100 incidents in 2000, said Jarrod Agen, a Homeland Security spokesman. The incidents included illegal diversion, purchase, sale, transport or storage of nuclear material.
"Only a handful of the known illicit nuclear/radiological trafficking incidents involved weapons-usable nuclear materials," Agen said. "Of the known smuggling incidents to date, the vast majority were profit-motivated scams involving bogus materials."
The number of trafficking incidents recorded by the U.S. Department of Homeland Security was more than double that reported in August by the International Atomic Energy Agency.
The Geneva-based U.N. nuclear watchdog said it had received reports of 103 incidents of illicit trafficking and other unauthorized activities involving nuclear and radioactive materials in 2005.
It cited a 2005 New Jersey case in which a lab inadvertently disposed of 0.1 ounce (3.3 grams) of highly enriched uranium. A lab worker failed to locate one of several samples in a shipment and apparently threw it away with the packaging, which was buried at a landfill. The lab was later fined $3,250 by the Nuclear Regulatory Commission.
The Homeland Security figures include IAEA reporting as well as other information obtained by intelligence and law enforcement agencies, Agen said.
"What has doubled is the number of reported events," he said. "This is due mainly to an increase in awareness, more comprehensive reporting and an increase in the number of number of detection devices."
Since the September 11 attacks, security awareness has become higher worldwide, and the United States has increased the number and sophistication of screening machines across the country.
"We screen about 80 percent of all cargo that comes into the U.S. through radiation portal monitors, and by the end of next year we will be at 100 percent," Agen said. "That gives you an indication of how seriously we take screening for radioactive material."