Nuclear nonproliferation and Iran's nuclear medical reactor

by Salman Hameed

I'm catching up on back issues of Science and Nature. Here is the news story about the concerns of a nuclear medical reactor in Iran. Now, I have said this multiple times - but here it is again. Nuclear weapons are, of course, awful and should not be pursued by any nation (see . At the same time, it is hypocritical of nuclear powers to place their opposition to Iranian nuclear program in any sort of ethical/moral or even security context. This is particularly true of the US, which has increased its funding for nuclear weapon facilities just this current year (see the link in this earlier post).

Here is a piece from Science (Jun 21st):

If all goes to plan, Iran next year will switch on a facility that gives nuclear nonproliferation analysts goose bumps: the Arak heavy water reactor in the central province of Markazi. Iranian officials have long stated that a chief aim of the fission reactor, known as the IR-40, is to make radioisotopes for medicine. But it also will yield something far more troubling: about 10 kilograms of plutonium a year, enough for one or two atomic bombs. 

Locked in a standoff with the United States and allies over its nuclear ambitions, Iran has steadfastly averred that the objectives of its sprawling nuclear program are peaceful: to generate electricity and produce radioisotopes for industry and medicine. But what if Iran didn't need the controversial IR-40 to make medical isotopes? A new report by nuclear specialists highlights that possibility, laying out alternatives that avoid uranium and production of plutonium, the fissile material in nuclear bombs. 

Medical isotopes are a ripe topic for diplomacy. In remarks on 17 June reported by Fars News Agency, Iran's President-elect, moderate cleric Hassan Rouhani, said that his nation is prepared to "increase transparency" of its nuclear program and "enhance mutual confidence [-building] between Iran and other countries." One confidence-building measure, diplomats say, might be expanding medical isotope production via ways that don't facilitate making bombs. If U.S. negotiators "can sell the idea of Iran participating in advanced nuclear technologies [that steer clear of fissile material], then maybe you've got something," says Mark Jansson, special projects director at the Federation of American Scientists in Washington, D.C. 

Radioisotopes are widely used in medical imaging and cancer treatment. Considered a dividend of nuclear technology, they were an important reason that nuclear powers in the 1950s and 1960s promoted the construction of research reactors around the world. However, many medical isotopes are made in reactors that use highly enriched uranium (HEU), which contains at least 20% of the fissile isotope uranium-235 (U-235)—enough to be "weapons ready." So arms control advocates are loath to see HEU-powered reactors spread, and have successfully shut down some located in unstable regions. 

In Iran, technicians already make medical isotopes in an aging reactor that uses uranium enriched to 19.75% U-235—a hair below bomb-grade. The IR-40 would replace that reactor, but use natural uranium, which is mostly U-238, and not HEU. That worries arms control specialists because bombarding natural uranium with neutrons turns out to be a very efficient way to generate plutonium. 

Several alternative methods of generating desired medical isotopes would make it harder for would-be proliferators to lay hands on weapon-grade fissile material, argues the 13 June report from the Center for Science, Technology, and Security Policy of AAAS (publisher of Science). The technical approaches include an expanded reliance on cyclotrons or spallation neutron sources. High demand for short-lived isotopes used in positron emission tomography, coupled with technical advances in miniaturizing accelerators, has driven down costs. "Accelerator technology is far less expensive and more capable than in the past," write authors Derek Updegraff and Seth A. Hoedl, analysts at AAAS.                  
...
If nonproliferation is the objective, cost may not be a showstopper. In the wake of last week's Iranian elections, U.S. officials hope to revive nuclear talks, which broke down in April. Rouhani, a former nuclear negotiator in Iran's talks with the West, has not signaled any major policy shift. And the window for a deal on IR-40 may be closing. After Iran has spent 10 years planning the facility, "it will be hard to convince them to walk away" from the reactor, Jansson predicts. But proliferation risks could be reduced, he notes, by fueling it with low-enriched uranium, which would yield less plutonium. 

Whatever happens with IR-40, the long-term implications of alternative isotope technology are broader than Iran, says Pierce Corden, a disarmament expert and visiting scholar at AAAS who initiated work on the report. "There may be other problematic situations in the future," he says.                   

Read previous posts on Iran's nuclear program:
Boneheaded US sanctions on reviewing Iranian science manuscripts
The Sacred Value of Iranian Nukes
Scientists must speak up against assassinations of scientists
Oped on Iran's nuclear program
A photo-tour of an Iranian nuclear plant
More restrictions for Iranian-born scientists - The Dutch edition