Natanz Enrichment Complex

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Last Updated: July 7, 2017
Other Name: N/A
Location: Natanz, Iran
Subordinate To: Atomic Energy Organization of Iran (AEOI)
Size: Nine buildings
Facility Status: Operational

Natanz is Iran's primary enrichment facility and houses both the commercial Fuel Enrichment Plant (FEP) and the Pilot Fuel Enrichment Plant (PFEP). [1] The facility consists of three underground buildings, two of which are designed to hold 50,000 centrifuges, and six above ground buildings. Two of the above ground buildings are 2,500 meter halls used for gas centrifuge assemblies. [2] The nuclear material and enrichment equipment located at the FEP and PFEP are under IAEA safeguards. [3]

Iran covertly moved its gas centrifuge research, development, and assembly operations to Natanz from the Kalaye Electric Company in 2002. [4] The operation did not remain secret for long, however, because the opposition group The National Council of Resistance of Iran publicly identified the site in August 2002. The revelations prompted Gholam Reza Aghazadeh, President of the Atomic Energy Organization of Iran, to reveal Iran's intention to develop the full nuclear fuel cycle at the 2002 IAEA General Conference. [5] During IAEA Director General Mohammed El-Baradei's follow-up visit in February 2003, Tehran officially declared that it was constructing the FEP and the PFEP at Natanz. [6]

In October 2003, France, Germany, the United Kingdom, the European Union and Iran commenced negotiations on suspending Iran’s enrichment and conversion activities. [7] In addition to ceasing such activities, Iran agreed to halt manufacturing and assembling centrifuge parts at its enrichment installations. [8] The suspension was maintained through the duration of talks with the E3 and EU in November 2004. [9] Following the election of the conservative President Mahmoud Ahmadinejad in August 2005, however, Iran began to backtrack on cooperative agreements with the IAEA. On January 10, 2006, Iran broke the seals safeguarding Natanz and resumed its enrichment program. Shortly thereafter, Iran introduced UF6 into the gas centrifuges at the PFEP, and by February 2007 it had started feeding UF6 into the cascades installed at the FEP. [10]

With negotiations over Iran’s nuclear program deadlocked in 2006, the George W. Bush administration initiated a cyber-warfare operation, code-named “Olympic Games,” aimed at sabotaging Iran’s growing enrichment activities through a slow barrage of cyber-strikes. [11] Popularly known as “Stuxnet,” the virus, which was developed with the help of Israeli intelligence agencies, targeted the computer systems that commanded the centrifuges at Natanz. Designed to produce continuous, incremental damage rather than a catastrophic, one-hit strike, the virus caused the centrifuge rotors to spin uncontrollably fast. These substantial increases in velocity led to a destructive rise in the rotor wall pressure, thereby causing the centrifuges to break. [12] After assuming office in 2009, President Obama intensified the program, gradually increasing the rate and severity of attacks on Natanz’s enrichment complex. According to IAEA reports, between the end of 2009 and early 2010 Iran decommissioned and replaced approximately 1,000 centrifuges at Natanz due to damage from the Stuxnet virus. [13] In November 2010, Iran temporarily suspended enrichment activities at the FEP amid growing issues with centrifuge operations. Estimates of Stuxnet’s success vary, as some Obama administration officials believe the cyber-attack delayed Iran’s nuclear development by 18 months to two years. Other assessments are more critical of Stuxnet’s significance and point to the quick recovery of centrifuge activity at Natanz following the facility’s brief shutdown. [14]

As negotiations over Iran’s nuclear program proceeded in fits and starts, the Iranian government notified the IAEA in January 2013 that it planned to install more than 3,000 of the country’s advanced centrifuges, the IR-2m. [15] More durable and efficient than the IR-1 model, these centrifuges were capable of significantly increasing Iran’s output of enriched uranium. [16] The declaration signaled another step by Iran towards expanding its enrichment program in violation of IAEA Board of Governors and UN Security Council resolutions.

On November 24, 2013, Iran and the P5+1 (China, France, Germany, Russia, the United Kingdom and the United States) concluded a Joint Plan of Action (JPOA) to place a temporary freeze on Iran’s nuclear program and lay the groundwork for a more sweeping, long-term agreement. Under the JPOA, Iran agreed to cap its uranium enrichment operations at Natanz, begin diluting its LEU stockpile, and discontinue the installation of new centrifuges at the FEP. It also gave the IAEA broader access to the facilities at Natanz. [17]

Using the JPOA as a foundation for a more comprehensive agreement, Iran and the P5+1 concluded the Joint Comprehensive Plan of Action (JCPOA) on July 14, 2015, a far-reaching 25-year settlement that constrained Iran’s nuclear capacity in exchange for sanctions relief. In accordance with the JCPOA, Iran agreed to remove approximately two-thirds of Natanz’s centrifuges, limit uranium enrichment to 3.67 percent, and down-blend or sell the majority of its LEU stockpile. Iran is also required to provide the IAEA daily access to Natanz for continuous monitoring of enrichment activities and centrifuge production. [18]

Sources:
[1] Institute for Science and International Security (ISIS), "Nuclear Sites: Facilities: Natanz," ISIS Nuclear Iran, www.isisnucleariran.org.
[2] Institute for Science and International Security (ISIS), "Nuclear Sites: Facilities: Natanz," ISIS Nuclear Iran, www.isisnucleariran.org.
[3] International Atomic Energy Agency, "Implementation of the NPT Safeguards Agreement and relevant provisions of Security Council Resolutions 1737 (2006), 1747 (2007), 1803 (2008), and 1835 (2008) in the Islamic Republic of Iran," Report by the Director General, August 28, 2009, www.iaea.org.
[4] Institute for Science and International Security (ISIS), "Nuclear Sites: Facilities: Natanz," ISIS Nuclear Iran, www.isisnucleariran.org.
[5] International Atomic Energy Agency, "Implementation of the NPT Safeguards in the Islamic Republic of Iran," Report by the Director General, June 6, 2003, www.iaea.org.
[6] International Atomic Energy Agency, "Implementation of the NPT Safeguards in the Islamic Republic of Iran," Report by the Director General, June 6, 2003, www.iaea.org.
[7] "Statement by the Iranian Government and Visiting EU Foreign Ministers," IAEA and Iran, International Atomic Energy Agency, October 21, 2003, www.iaea.org.
[8] Daniel H. Joyner, Iran’s Nuclear Program and International Law, (New York: Oxford University Press, 2016), p. 216.
[9] "Paris Agreement: Agreement between Iran, Germany, United Kingdom and France," Diplomatic News, Republique Francaise, November 14, 2004, www.ambafrance-ir.org.
[10] International Atomic Energy Agency, "Implementation of the NPT Safeguards Agreement in the Islamic Republic of Iran," Report by the Director General, April 28, 2006, www.iaea.org; International Atomic Energy Agency, "Implementation of the NPT Safeguards Agreement and Relevant Provisions of Security Council Resolution 1737 (2006) in the Islamic Republic of Iran," Report by the Director General, February 22, 2007, www.iaea.org.
[11] David E. Sanger, “Obama Ordered Wave of Cyberattacks against Iran,” The New York Times, June 1, 2012, www.nytimes.com.
[12] Ralph Langer, “Stuxnet’s Secret Twin, Foreign Policy, November 19, 2013, www.foreignpolicy.com.
[13] Atika Shubert, “Cyber warfare: A different way to attack Iran’s reactors,” CNN, November 8, 2011, www.cnn.com.
[14] David E. Sanger, “Obama Ordered Wave of Cyberattacks against Iran,” The New York Times, June 1, 2012, www.nytimes.com.
[15] “Iran to upgrade nuclear program with faster IR-2m centrifuges to speed uranium enrichment, diplomats say,” CBS News, January 31, 2013, www.cbsnews.com.
[16] Kelsey Davenport, “Iran Installs Advanced Centrifuges,” Arms Control Today, February 28, 2013, www.armscontrol.org.
[17] “Joint Plan of Action,” November 24, 2013, accessed at https://assets.documentcloud.org.
[18] “The Iran Nuclear Deal: A Definitive Guide,” Belfer Center for Science and International Affairs, August 2015, www.belfercenter.org; “Section 3: Understanding the JCPOA,” Arms Control Association, August 10, 2015, www.armscontrol.org.

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This material is produced independently for NTI by the James Martin Center for Nonproliferation Studies at the Middlebury Institute of International Studies at Monterey and does not necessarily reflect the opinions of and has not been independently verified by NTI or its directors, officers, employees, or agents. Copyright 2017.