Hitting the sweet spot: How many Iranian centrifuges?

With the deadline for a comprehensive nuclear agreement between Iran and the P5+1 (China, France, the United Kingdom, the United States, Russia, and Germany) right around the corner, the negotiating parties are starting to reveal more of their cards in hopes of striking a deal. Along with the creative solutions that the West has put on the table, there are now reports about it showing more flexibility on what remains the talks’ key sticking point: enrichment.

News reports indicate that the current numbers of centrifuges that the two sides are discussing fall in the range of about 4,000 to 5,000 of the machines. This is the “sweet spot” for both sides, when it comes to how many centrifuges Iran can have for enriching uranium.

How far both sides have come. The negotiations surrounding Iran’s enrichment capacity would make any Iranian rug merchant haggling in the bazaar proud. Many in the West were pushing for a few hundred centrifuges. This past summer, Iran’s Supreme Leader Ayatollah Khamenei (link in Persian) stirred things up when he put a specific number on his country’s enrichment goals. Given his status as Iran’s highest political authority, the large number he had announced made many nervous that a deal would no longer be reachable. Khamenei formulated Iran’s goal of enrichment capacity as 190,000 separative work units, or SWUs. (An SWU is a measure of the work expended during enrichment.)

For the country to be able to reach this number, Iran would likely need at least 190,000 and perhaps as many as about 243,000 first-generation centrifuges, known as IR-1 centrifuges. (The efficiency of these first-generation centrifuges varies a good deal, from about 0.78 SWU per unit per year to 0.9 SWU, but in the past couple of years most of them have been producing at the lower end of the scale. All of which means that Iran may need a lot more than first anticipated to reach the goal of 190,000 SWU produced annually.)

The news came at a time when most of those discussing Iran’s practical needs—how much fuel the country requires to keep its domestic nuclear energy program running—said they could be met with roughly 1,500 centrifuges, or fewer than one percent of Khamenei’s figure.

Tehran has made it clear that its goal is to have industrial-scale enrichment. But while fixing a clear and concrete goal, Khamenei’s speech also gave a lot of room for his negotiating team to maneuver. This part of the speech was lost in translation in the United States. Many in the arms control community and Congress focused on that 190,000 SWU figure, with those in favor of a deal becoming worried that this number would tie the hands of negotiators. Those opposing it cited this figure as a reason why the talks would fail.

In fact, what Khamenei had stated was: “Our officials say we need 190,000 SWU. It is possible this need is not for this year, the next couple of years, or the next five years, but this is the country’s undeniable need.”

The head of the Atomic Energy Organization of Iran, Ali Akbar Salehi, explained Khamenei’s statement, noting that 190,000 SWU would meet the Bushehr civilian nuclear power plant’s need for fuel for one year. This wouldn’t mean that Iran could take care of all of its fuel needs domestically, but it would give it a backup plan in case its suppliers fail again. This number, however, seems way above Bushehr’s needs alone.

Oddly, while fixing a redline, Khamenei’s statement also opens the doors wider for the negotiating team—and Iran’s nuclear industry in general—on the matter. It is significant that he doesn’t give a timeline for industrial-scale enrichment.

It is also significant that Iran has been adhering to the interim deal reached in November 2013. Even though it has more advanced and efficient technologies, such as the recently installed cascades of second-generation, IR-2m centrifuges (which produce approximately 5 SWU per machine per year, or more than four or five times that of an IR-1), Iran has chosen not to feed their new machines with natural uranium hexafluoride gas—a vital step to enrichment.

And in practical terms, Iran is nowhere close to being able to produce 190,000 SWU any time soon. Of the more than 190,000 IR-1 centrifuges needed, the country currently only has approximately 20,000—and only half of those are actually operating. While Iran also has a number of centrifuges even more advanced than the IR-2m under research and development at the Natanz Pilot Fuel Enrichment Plant, those centrifuges are not currently operating. And Tehran has undertaken to not install any new machines. Consequently, 190,000 SWU is not a number Iran can realistically attain any time soon.

Spinning out the implications. If the negotiating team accepts the 4,000- to 5,000-centrifuge proposal on the table, it can sell the deal back home in Iran using Khamenei’s guidelines, depending on the timeframe fixed in the final agreement. This is especially true if this proposal is part of a larger package that the team can stand behind. The current deal includes an attractive offer from the P5+1 on other sticking points, including the Arak heavy water reactor and the underground enrichment facility in Fordow.

But in Iran, the issue of enrichment is the most visible component of the nuclear talks. Many people may not be aware of the other sticking points such as Arak or Fordow, but virtually everyone in Iran is aware of the enrichment debate. Any limitation on enrichment will likely cause some factions to criticize the negotiating team, but no deal is possible without some kind of limitation. So far, the Rouhani government has let the issue of enrichment become the centerpiece of debate about the negotiations, and the only measure of the team’s success. But knowing that any deal of any kind would diminish Iran’s enrichment capacity, the government must step up and begin to publicize to the Iranian public the benefits of the other components of the agreement, such as the considerable concessions it is getting from the P5+1. This will allow the Iranian government to sell the deal as a whole, and not be judged by the number of centrifuges it is “losing.”  

During his 2013 presidential campaign, Hassan Rouhani famously declared that the centrifuges should spin, but that people’s lives should run too. He hadn’t said how many centrifuges should spin but this has become one of the key issues of the first eighteen months of his presidency. Something in the range of 4,000 to 5,000 centrifuges is a good compromise, a “win-win” formula for both sides. They’ll allow the Iranian negotiating team to go back to Tehran and state that they started negotiating at a time when their opponents at the bargaining table were pushing for Iran to be limited to a few hundred centrifuges, and that the Iranian team successfully kept over half of the current operating centrifuges. They can also say that they managed to keep Arak with some design modifications, and Fordow as a research facility. Meanwhile, the White House can tell Congress that it has effectively rolled back approximately half of Iran’s enrichment capacity.

For Iran, anything less than 4,000 centrifuges will be a hard pill to swallow. The Iranian parliament, or Majles, won’t roll out a red carpet for the negotiating team if it comes back with a lower number. Likewise, on the US side, selling more than 5,000 centrifuges to Congress would be extremely difficult. Many congressmen still believe any enrichment to be a major concession to Tehran, let alone about half of the country’s current number of operating centrifuges.

With nearly a month left until the November 24 deadline, the Iranian government should step up its promotional campaign to its people regarding the negotiations, and accept a number falling between 4,000 and 5,000 centrifuges.