“Tens of kilograms, maybe up to 220 pounds of raw uranium, have been stolen by people who hoped to sell it at profit because of their ignorance,” he said. “Only some 10 percent of these materials have been found.”

Federal Atomic Energy Agency chief Alexander Rumyantsev said the nation’s nuclear facilities are safe from terror attacks and thefts but acknowledged controls over radioactive materials at clinics and industrial plants have been loose.

Rumyantsev admitted authorities have been negligent in disposing worn-out equipment involving lethal radioactive isotopes. Such equipment, used for cancer treatment in clinics and for various industrial purposes in manufacturing industries, has been carelessly dumped across Russia, he said.

“Such equipment has been found in dumpsites, among garbage,” Rumyantsev said. He added that Russian and U.S. officials had taken joint efforts to strengthen control over medical and industrial radioactive sources. The Russian government has recently toughened legislation to help track down radioactive equipment. Many experts warn that medical and industrial radioactive devices could be used by terrorists for making a radiological dispersal device, or dirty bomb. Unlike nuclear warheads that are designed to kill and destroy through a huge nuclear blast, dirty bombs – which thus far no one has employed – would rely on conventional explosives to spread radioactive material. Rumyantsev said all Russian nuclear facilities, including nuclear power plants and waste storage facilities, are securely guarded by heavily armed Interior Ministry troops, Associated Press reported.