May day, May day
In mid-May, Chalk River abruptly shut down after a small leak was discovered. The reactor isn’t expected to restart until the first quarter of 2010. Then in July, the U.S. backup supplier—the Dutch Petten reactor—also shut down briefly for routine maintenance.

Suddenly, the supply of TC-99m isotopes used in some 46,000 procedures each day in this country was in jeopardy. Nuclear medicine providers predicted dire consequences for patients. “It’s possible that some deaths could occur,” Michael Graham, M.D., president of the Society for Nuclear Medicine, told reporters. “Some people will be operated on that don’t need to be, and vice versa.”

Hospitals around the country braced for the worst.

Disaster waiting to happen
For decades, U.S. security experts have braced for another kind of disaster with the same uranium. The United States began circulating highly enriched uranium around the world in the 1950s under its Atoms for Peace program, which promoted civilian nuclear development. Though any alleged disappearance of uranium is difficult to confirm, growing concerns about the potential for theft prompted the government to reverse course in the 1970s. It began retrieving distributed uranium, especially from countries where terrorism was a threat, such as Serbia and Bulgaria.

The government also stopped shipping highly enriched uranium—with one notable exception: distribution continued for production of medical isotopes. Today that distribution poses an increasingly attractive target for terrorists. “This 1950s-era policy simply does not work in a post-9/11 world,” says U.S. Rep. Edward J. Markey, D.-Mass., a long-time advocate for nuclear safety. “It is dangerous and unnecessary and must come to an end.”

Only about three percent of highly enriched uranium is actually consumed in the processing. The remainder, waste that can still be used to make nuclear weapons, is stored at the reactor facilities. While in recent years the United States has spent millions to upgrade its own storage of highly enriched uranium, security at foreign reactors isn’t nearly as good.

“It’s bomb-grade material,” says Alan J. Kuperman, director of the Nuclear Proliferation Prevention Program at the University of Texas, “but it’s not guarded like bomb-grade material.”

The alternative
The most logical solution, from a security standpoint, would be to switch production sources from highly enriched uranium to low-enriched uranium. The lower-grade metal yields medical isotopes of equivalent quality and can’t be converted into nuclear weapons.

Past efforts to make this change, however, met resistance, in part because converting existing reactors to be able to use low-enriched uranium will be expensive. Among those opposing the change in Washington was MDS Nordion, a Canadian company that supplies 40 percent of the world’s supply of medical isotopes from Chalk River.

Earlier this decade, when Congress was considering extending restrictions on exports of highly enriched uranium, MDS Nordion and another isotope manufacturer launched an extensive lobbying campaign to ease the restrictions, according to the Washington Post. Leading the effort in Congress to keep the uranium in circulation was Richard Burr, R-N.C., then a U.S. representative and now a senator.

The effort succeeded. The 2005 Energy Policy Act, signed by President George W. Bush, exempted material used for medical isotopes from the restrictions—effectively undermining, critics said, a quarter-century of U.S. efforts to halt the global trade.

But the 2005 energy act contained something else: A request that the National Academy of Sciences (NAS) determine the technological and economic feasibility of producing medical isotopes with low-enriched uranium. In January, accompanying its bleak appraisal of current sources of medical isotopes, the NAS concluded that the isotopes can indeed be produced from low-enriched uranium.