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former Chairman of the Joint Chiefs of Staff
Bridging the Uranium-Enrichment Gap
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Daryl G. Kimball

A long-sought, comprehensive deal between Iran and the P5+1 (China, France, Germany, Russia, the United Kingdom, and the United States) to ensure Iran’s nuclear program is exclusively peaceful is within reach. Both sides have been negotiating seriously, but some big gaps must still be bridged before the Nov. 24 deadline.

To succeed, both sides must seek creative trade-offs, particularly on the toughest issue: Iran’s uranium-enrichment capacity.

In previous rounds of talks, the two sides reached a basic understanding on several key issues, including strengthening International Atomic Energy Agency (IAEA) inspections to guard against a secret weapons program and modifying the Arak heavy-water reactor project to drastically cut its plutonium output.

The two sides also agreed that Iran need not enrich uranium to levels above 5 percent fissionable uranium-235 and that the Fordow enrichment plant would be limited to a research role, but they could not bridge their differences regarding the overall scale of Iran’s enrichment program.

Today, Iran has about 18,000 IR-1 first-generation centrifuge machines at two sites, of which about 10,200 are operational. Iran has also installed 1,008 more-advanced IR-2M centrifuges at the Natanz enrichment plant.

Theoretically, Iran’s operating IR-1 machines could allow Tehran to use natural uranium to produce a quantity of weapons-grade uranium gas sufficient for one nuclear bomb (25 kilograms) in about two to three months if such an effort were not detected and slowed or halted first. Even so, if Iran tried to build a militarily significant nuclear arsenal, it would take considerably more than a year.

For the next several years, Iran’s practical needs for enrichment are limited. Iran already has enough fuel for its Tehran Research Reactor, which produces medical isotopes, for several years. If the Arak reactor is modified to use 3.5 percent-enriched uranium fuel, it might require no more than 1,000 IR-1 centrifuges to provide for its fuel requirements.

Iran’s light-water reactor at Bushehr, which has a power-generation capacity of about 1,000 megawatts electric, uses fuel supplied by Russia under a 10-year deal that could be extended past its 2021 end date. Russia is obliged to supply fuel unless Iran chooses not to renew the contract. But Iran’s leaders are under heavy political pressure to reduce the country’s reliance on foreign energy suppliers and to maintain a uranium-enrichment program that could be expanded if and when the country’s nuclear energy needs grow.

By the close of the last round of talks in July, Iran was still pushing for an industrial-scale enrichment capacity. The P5+1 was insisting on a drastic reduction of Iran’s enrichment capacity—to about 1,500 IR-1 centrifuges—for an extended period.

Negotiators can square the circle in a number of ways. The International Crisis Group and the Arms Control Association recently outlined a formula that would increase the time Iran would require to produce enough weapons-grade material for one bomb and still would provide Iran with more than sufficient capacity for its civilian nuclear program over a period of 11 to 16 years. Key elements of the proposal include:

• Reducing Iran’s current enrichment capacity by half for a period of three to five years. Combined with a reduction in the size of Iran’s enriched-uranium stocks, this would increase the time it would take Iran to produce enough weapons-grade enriched-uranium gas to 12 months or more. Iran’s operating enrichment capacity could return to current levels by 2021 and for the duration of any agreement, but only if Iran can demonstrate that it has discontinued any experiments with possible military dimensions.

• Limiting Iran’s working stockpile of low-enriched uranium hexafluoride gas to less than 200 kilograms and converting any excess into an oxide powder, which is more proliferation resistant, for removal to a third country, conversion into fuel for the Arak reactor or a light-water reactor, or some combination of those options. Iran would be barred from building a reconversion line that could reverse the process.

• Removing and storing under IAEA seal most of Iran’s IR-1 centrifuges and replacing some with a smaller number of IR2-M centrifuges. Research on machines that are even more advanced would be limited over the course of any agreement. This would allow Iranian scientists to make the desired shift to more cost-effective machines, but still constrain Iran’s overall enrichment capacity.

• Providing strong guarantees to Iran to help meet its future energy needs, including predelivery of fuel for operation of the Bushehr reactor beyond 2021. By that time, the IAEA and Iran could begin a technical assistance project on reactor fuel fabrication.

Such an agreement may not deliver everything each side wants, but it would deliver what each side needs. The P5+1 would put in place significant, verifiable, long-term constraints on Iran’s capacity to build nuclear weapons and be able to detect and deter any such effort before Tehran could do so. Iran would be able to ease the burden of nuclear-related sanctions and pursue a realistic civilian nuclear program. It is a win-win formula that both sides should embrace. ACT