NTI - Global Security Newswire, 7 Oct 2008.

WASHINGTON — Relying on highly enriched uranium to produce medical isotopes leaves the United States vulnerable to acts of nuclear terrorism and a drastic shortage of one crucial material in coming years, experts warned yesterday (see GSN, June 19, 2006).

As there is no reasonable alternative to using technetium 99m for a widespread cardiac diagnostic test, the answer to these risks lies in employing facilities that produce the nuclear isomer without also creating a proliferation threat, they argued.

Four non-U.S. companies use highly enriched uranium to produce 95 percent of the global supply of technetium 99m, said Andrew Einstein, a clinical medicine professor at Columbia University in New York.

The United States each year sends 20 kilograms of weapon-grade uranium to a reactor at Chalk River, Ontario, where it is used to create much of the U.S. supply of technetium. The problem is that the waste produced through this work retains 95 percent of the original highly enriched uranium, creating the danger that it could be put to bad uses in the wrong hands.

There are increasing signs that terrorist organizations hope to use an improvised nuclear weapon, said Cristina Hansell, director of the Newly Independent States Nonproliferation Program at the James Martin Center for Nonproliferation Studies. Their intent is to craft a devastating weapon rather than a less-lethal radiological “dirty bomb,” she said.

“For that sort of device, highly enriched uranium is the material of choice. Plutonium is a fissile material but it [takes] a lot more complex technology to create a device that would make that explode efficiently,” Hansell said during a Capitol Hill discussion organized by the American Association for the Advancement of Science. “Using that simple gun-type device you need highly enriched uranium.”

Terrorists are unlikely to enrich uranium themselves, so they would have to find an available source, Hansell said. Civilian sites around the world contain roughly 50 metric tons of weapon-grade uranium and generally have lower levels of security than military sites, she said.

The amount of material needed for a weapon would drop as the enrichment level increased. Major producers of technetium use material that is enriched to 93 percent, “easily weapons-useable material,” according to Hansell.

There has been significant progress around the world in converting research and other reactors to using low-enriched uranium, which would not provide fuel for nuclear explosions, Hansell said (see GSN, Oct. 3). However, “the portion of HEU that’s going to medical isotopes is increasing as these other uses are decreased and more and more medical isotopes are needed,” she added.

That need is growing even as the supply of technetium faces significant drop-offs in the next few years, Einstein said. The 51-year-old National Research Universal reactor at Chalk River is not expected to last beyond 2014; Canada terminated the project for a replacement facility and no new plant is anticipated, he said.

Atomic Energy of Canada Ltd., which operates the Chalk River site, did not respond by deadline to a request today for comment.

Meanwhile, the Dutch reactor that is the United States’ second-highest supplier of the parent compound of technetium shut down in August and will resume operations no earlier than this month. The subsequent shortage of technetium in the last two months in Europe and the United States “is really a harbinger for the future,” Einstein said.

There are no good options for conducting the stress tests used to diagnosis heart problems without the isomer, he said. The four potential alternatives have a variety of drawbacks, including an increased potential for causing cancer in patients, failing to detect some cases of cardiac disease and death due to the invasive nature of one procedure.

Possible Answers

There are potential legislative responses to this twinned terrorism and medical threat, said Alan Kuperman, a public affairs professor at the University of Texas at Austin. He said, though, that Washington’s record to date is mixed.

The “original sin” of U.S. HEU proliferation was the Atoms for Peace program that in the 1950s began providing weapon-grade uranium to other nations for reactor fuel and medical isotope production, according to Kuperman. In some years through the 1970s, the United States sent 3 tons of uranium to other nations, enough for “dozens, dozens, dozens” of weapons, he said (see related GSN story, today). “We exported this stuff, bomb-grade uranium, like doughnuts or something. It’s just remarkable,” he said.

Washington began to reverse the trend in the 1970s through a program to produce low-enriched uranium fuel that would meet the same civilian needs without the threat of being used in weapons. Some existing reactors were converted for LEU use while new plants were built with that specification.

Among those to resist the effort were producers of medical isotopes, Kuperman said.

The 1992 U.S. Energy Policy Act set three conditions for export of bomb-grade uranium to any reactor — the facility at the time could not be capable of using low-enriched uranium, it had agreed to make the switch as soon as possible, and the U.S. government was assisting the conversion effort. That legislation contributed to a major decline in U.S. weapon-grade uranium exports, but it was undone by a 2005 bill that eliminated the 13-year-old restrictions, Kuperman said (see GSN, July 29, 2005). Lawmakers in Washington “rolled over” for the Canadian reactor that was reluctant to modify its fuel, he said.

“They resisted conversion basically because it was inconvenient. A little bit of cost, but mainly, 'It ain't broke, don't fix it,’” Kuperman said.

So Canada ended its LEU conversion plan for the Chalk River site and U.S. exports of highly enriched uranium now appear to be again on the rise, “potentially to continue in perpetuity,” he said.

While the later bill made it easier to export highly enriched uranium, the amount actually shipped by the United States has not increased significantly, said Nuclear Regulatory Commission spokesman Dave McIntyre: “It’s just a function of demand.” Specific figures were not immediately available.

There are a number of options to address the situation, according to Kuperman, including restoration of the 1992 HEU export regime.

The government could also support development of a U.S. technetium production capacity that would involve low-enriched uranium, Kuperman said. Representatives from the University of Missouri and the power-generation firm Babcock & Wilcox indicated at the discussion that their firms could together supply 100 percent of the necessary U.S. supply of technetium 99m.

However, both would need some form of help from the government. For the university, it would be up to $40 million in startup costs. The private firm would prefer to handle the capital but would look for assistance on dealing with waste and the regulatory process.

Additionally, Congress could establish “preferences” for medical isotopes that are produced through use of low-enriched uranium rather than its weapon-grade counterpart, Kuperman said. That could come through temporary subsidization of LEU processes or through prohibitions on use of HEU-made isotopes if there is an LEU-based alternative.

“In the long run I think we won’t have any production of isotopes with HEU, and so we could phase out the subsidy,” Kuperman said. “But In the short run, we should give an advantage to the technology that is not vulnerable to nuclear terrorism.”

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