"In my home there are few publications that we actually get hard copies of, but [Arms Control Today] is one and it's the only one my husband and I fight over who gets to read it first."

– Suzanne DiMaggio
Senior Fellow, Carnegie Endowment for International Peace
April 15, 2019
Iran Forges Ahead on Enrichment

Peter Crail

Iran is finalizing its installation of a second set of 3,000 gas centrifuges at its commercial-scale uranium-enrichment facility and is preparing to install a third set, according to a Nov. 19 report by the International Atomic Energy Agency (IAEA). Tehran is therefore showing no sign of suspending its uranium-enrichment efforts, contrary to UN Security Council demands. Meanwhile, Iran is also continuing to develop its ballistic missile capabilities, but it is unclear whether it is successfully employing more-advanced missile technologies.

Iran Steadily Expands Enrichment

According to the IAEA report, Iran is currently operating close to 3,800 centrifuges in two separate units of its commercial-scale uranium-enrichment facility at Natanz. When completed, this facility is intended to house roughly 48,000 centrifuges, divided into 16 units each with about 3,000 machines. A senior UN official stated during a Nov. 19 background briefing that Iran is close to running another 2,100 centrifuges and can likely begin feeding them with uranium hexafluoride by the end of the year, for a total of about 5,900.

Uranium hexafluoride is the feedstock used in the uranium-enrichment process. It can be enriched to low levels to fuel nuclear reactors or high levels for potential use in nuclear weapons.

Using this feedstock, Iran has accumulated about 630 kilograms of low-enriched uranium (LEU) hexafluoride. Although this material is only enriched to the levels needed for nuclear power reactors, there is no apparent need for such material at this time. Russia has agreed to provide Iran's first and only nuclear power reactor with fuel.

If reintroduced into its centrifuges, Iran would be capable of rapidly enriching this material to higher levels suitable for weapons. David Albright, president of the Institute for Science and International Security, estimates that Iran would need to process 1,030-1,180 kilograms of LEU hexafluoride in its centrifuges under optimal conditions to produce enough highly enriched uranium (HEU) for a nuclear weapon. (See ACT, November 2007.)

At this time, however, all nuclear material at Iran's declared facilities are subject to IAEA monitoring. Moreover, a December 2007 National Intelligence Estimate judged "with moderate confidence that Iran probably would use covert facilities rather than its declared sites" to produce HEU for nuclear weapons.

A senior UN official said Nov. 19 that the IAEA has not received concrete information of clandestine uranium-enrichment facilities operating elsewhere in the country. At the same time, the agency has consistently noted that it cannot rule out the presence of undeclared nuclear activities unless Iran implements an additional protocol to its safeguards agreement providing greater access to inspectors. Iran stopped implementing its version of the 1997 Model Additional Protocol in 2005.

Iran is also continuing to operate its centrifuges near their expected capacity. Iranian officials claimed in 2006 that its first-generation centrifuges had a feed rate of about 70 grams of uranium hexafluoride per hour, and the IAEA assessed that Iran was operating its centrifuges "close to" this rate during inspections in August. (See ACT, October 2008.) The centrifuges have continued to operate at this rate in the succeeding months as well.

Iran's first-generation centrifuge is based on Pakistan's P-1 centrifuge. Pakistani nuclear official Abdul Qadeer Khan secretly acquired the technology for the P-1 centrifuge from the European enrichment consortium Urenco during the 1970s. Khan in turn provided the technology to Iran and other countries during the 1980s and 1990s.

In addition to the P-1 centrifuge, Iran acquired a more advanced design, the P-2, which can enrich uranium about 2.5 times faster than the P-1. (See ACT, November 2007.) Iran is currently conducting tests of two designs based on the P-2 model, named the IR-2 and IR-3, at a pilot enrichment facility also located at Natanz. Iran is only feeding these test centrifuges with limited amounts of uranium hexafluoride.

Beyond the two units containing operating centrifuges, the report notes that Iran has been preparing three more units for centrifuge installation. Iran told the agency that it intends to begin installing P-1 machines at one of these units at the beginning of 2009.

Iran does not appear ready to begin installing its more advanced centrifuge models just yet. The senior UN official stated that although it may be possible for Iran to install its IR-2 or IR-3 centrifuges at any of the units it is currently preparing for installation, "it would be quite a surprise" due to Iran's inability to run them proficiently at this time.

Although Iran has stated plans to continue introducing centrifuges into its commercial-scale facility, it is unclear how many additional machines Iran is equipped to install. The senior UN official noted that, prior to the resumption of Iran's enrichment program in 2006, the IAEA assessed that Iran manufactured enough components for about 10,000 P-1 centrifuges. Because Iran does not have an additional protocol in force, the agency does not have access to Iran's centrifuge manufacturing sites and cannot judge how many additional centrifuges Iran has manufactured since then.

Tehran's continued work on its enrichment program is being carried out in violation of five UN Security Council resolutions. Three of those resolutions have imposed penalties targeted at persons and entities believed to be involved in Iran's nuclear and missile programs. (See ACT, April 2008.)

IAEA Receives Less Cooperation From Tehran

Although Iran's declared enrichment operations are carried out under IAEA monitoring, the report noted two areas in which Iran has not provided cooperation.

Iran did not allow the agency to carry out an Oct. 26 visit to the site of its heavy-water reactor at Arak, which has been under construction since 2006. The agency claims that it retains the right to visit the facility even though Iran suspended its implementation of a subsidiary agreement to provide early design information to the IAEA. Iran did allow such a visit in August.

As a result of this denial, the agency has to rely on satellite imagery to assess progress on the construction of the reactor. The senior UN official said it would be some time before the facility was operational. The UN Security Council has demanded that Iran halt this construction due to concerns that it may be used to produce plutonium for nuclear weapons.

Iran has also failed to provide additional information requested by the agency regarding alleged Iranian activities that the IAEA said points to "possible military dimensions to Iran's nuclear program." In its May 26 report, the agency outlined a series of questions regarding these activities that the agency posed to Iran in the preceding months. (See ACT, June 2008.) A senior UN official said Nov. 19 that Iran has not provided any cooperation in answering these questions in recent months.

Iran Continues Solid-Fuel Missile Work

In addition to building up its nuclear capacity, Iran has continued work on its ballistic missile program. Iran Nov. 12 tested a two-staged missile named the Sajjil that Iranian officials said has a range of about 2,000 kilometers and uses solid fuel. The Sajjil has the same appearance and claimed capabilities of a missile Iran tested last November, called the Ashura. (See ACT, January/February 2008.) Uzi Rubin, former director of the Israel Missile Defense Organization, told Arms Control Today Nov. 20 that the Sajjil is simply a different name for the same system.

The test demonstrates Iran's continued pursuit of a solid-fueled, medium-range ballistic missile capability. The use of solid fuel provides some advantages over Iran's liquid-fueled systems, which have comprised much of Iran's medium-range ballistic missile arsenal. Among these advantages are a shorter launch time, easier handling and storage, and the possibility of deploying smaller missiles. Iran has also said that its liquid-fueled Shahab-3 missile has a range of 2,000 kilometers.

At this range, Iran would be capable of striking targets outside the region, including parts of the Balkans and eastern Europe.

It is not clear if Iran can reach these distances. Striking such ranges and beyond will likely require Iran to master the process of staging, in which additional sets of engines are stacked on top of one another, firing at different times along the missile's flight path. Iran is not known to have successfully tested a multiple-stage rocket or missile. Its most recent tests of such systems, in November 2007 and in August 2008, both failed. (See ACT, September 2008.) The Sajjil test was reportedly unsuccessful.

Following the test, Washington reiterated its call for establishing a missile defense system in Europe. Pentagon spokesperson Bryan Whitman told reporters Nov. 13, "This testing is another reminder of the importance of establishing a missile defense site in Poland and in the Czech Republic to defend the U.S. and Europe against a threat that is developing in Iran." The U.S. missile defense proposal is designed to intercept missiles with longer ranges than the systems that Iran has tested to date.