Counterterrorism experts have long warned that unsecured radiological materials such as cesium-137 — commonly used in the medical community — could fall into terrorist hands and be used to manufacture so-called dirty bombs.
But there is a less known medical isotope made from bomb grade uranium that could pose a far greater threat, a group of nonproliferation scholars said at a Capitol Hill briefing.
Christina Hansell, director of the Newly Independent States Non-Proliferation Program, said leftover material from the manufacture of Tc-99n — used for diagnosing ailments such as heart conditions — could be used by terrorists to make a nuclear bomb. Such a weapon poses a far greater risk than just a radiological dispersal device, the technical term for a dirty bomb.
“I’m talking about real nuclear terrorism with an improvised nuclear device,” she said at the talk sponsored by the Center for Science, Technology and Security Policy.
Commercial facilities that store the uranium — all of them located overseas — are more vulnerable than military facilities that store nuclear material, she said.
Andrew Einstein, assistant professor of clinical medicine at Columbia University College of Physicians and Surgeons, said the United States has no capacity to domestically produce the Tc-99n isotope. Yet these suppliers are using U.S. produced uranium. The United States must then turn around and import 100 percent of its Tc-99n needs from a handful of overseas suppliers, he said.
But there are safer options to make the isotopes without using highly enriched uranium, said the speakers. It is possible to use low-enriched uranium to produce the same medical materials.
A research reactor at the University of Missouri has the ability to produce the isotopes without the use of bomb-grade material in the production process, said Hansell. This reactor could alone meet 50 percent of the U.S. Tc-99n demand, she added.
Alan Kuperman, director of the Strauss Center’s Nuclear Proliferation Prevention Program, recommended that Congress pass legislation prohibiting the export of highly enriched uranium. It would not be difficult for facilities to produce the isotopes using low-enriched uranium, which is non-weapons grade, he said.