Iran’s Nuclear Program: Status
Congressional research reportDec 20, 2019
Ask Donna
What actually matters in this document.
Text
Iran’s Nuclear Program: Status
Paul K. Kerr
Analyst in Nonproliferation
Updated December 20, 2019
Congressional Research Service
7-....
www.crs.gov
RL34544
Iran’s Nuclear Program: Status
Summary
Iran’s nuclear program began during the 1950s. The United States has expressed concern since
the mid-1970s that Tehran might develop nuclear weapons. Iran’s construction of gas centrifuge
uranium enrichment facilities is currently the main source of proliferation concern. Gas
centrifuges can produce both low-enriched uranium (LEU), which can be used in nuclear power
reactors, and weapons-grade highly enriched uranium (HEU), which is one of the two types of
fissile material used in nuclear weapons.
Is Iran Capable of Building Nuclear Weapons?
The United States has assessed that Tehran possesses the technological and industrial capacity to
produce nuclear weapons. But Iran has not yet mastered all of the necessary technologies for
building such weapons. Whether Iran has a viable design for a nuclear weapon is unclear. A
National Intelligence Estimate made public in 2007 assessed that Tehran “halted its nuclear
weapons program” in 2003. The estimate, however, also assessed that Tehran is “keeping open
the option to develop nuclear weapons” and that any decision to end a nuclear weapons program
is “inherently reversible.” U.S. intelligence officials have reaffirmed this judgment on several
occasions.
Obtaining fissile material is widely regarded as the most difficult task in building nuclear
weapons. As of January 2014, Iran had produced an amount of LEU containing up to 5%
uranium-235, which, if further enriched, could theoretically have produced enough HEU for as
many as eight nuclear weapons. Iran had also produced LEU containing nearly 20% uranium235; the total amount of this LEU, if it had been in the form of uranium hexafluoride and further
enriched, would have been sufficient for a nuclear weapon.. After the Joint Plan of Action, which
Tehran concluded with China, France, Germany, Russia, the United Kingdom, and the United
States (collectively known as the “P5+1”), went into effect in January 2014, Iran either converted
much of its LEU containing nearly 20% uranium-235 for use as fuel in a research reactor located
in Tehran, or prepared it for that purpose. Iran has diluted the rest of that stockpile so that it
contained no more than 5% uranium-235. In addition, Tehran has implemented various
restrictions on, and provided the IAEA with additional information about, its nuclear program
pursuant to the July 2015 Joint Comprehensive Plan of Action (JCPOA), which Tehran concluded
with the P5+1.
Although Iran claims that its nuclear program is exclusively for peaceful purposes, the program
has generated considerable concern that Tehran is pursuing a nuclear weapons program. The U.N.
Security Council responded to Iran’s refusal to suspend work on its uranium enrichment program
by adopting several resolutions that imposed sanctions on Tehran. Despite evidence that sanctions
and other forms of pressure have slowed the program, Iran continued to enrich uranium, install
additional centrifuges, and conduct research on new types of centrifuges. Tehran has also worked
on a heavy-water reactor, which was a proliferation concern because its spent fuel would have
contained plutonium—the other type of fissile material used in nuclear weapons. However,
plutonium must be separated from spent fuel—a procedure called “reprocessing.” Iran has said
that it will not engage in reprocessing.
Who Is Monitoring Iran’s Nuclear Program?
The International Atomic Energy Agency (IAEA) monitors Iran’s nuclear facilities and has
verified that Tehran’s declared nuclear facilities and materials have not been diverted for military
purposes. The agency has also verified that Iran’s compliance with the JCPOA. On the JCPOA’s
Implementation Day, which took place on January 16, 2016, all of the previous Security Council
resolutions’ requirements were terminated. The nuclear Nonproliferation Treaty (NPT) and U.N.
Congressional Research Service
Iran’s Nuclear Program: Status
Security Council Resolution 2231, which the council adopted on July 20, 2015, compose the
current legal framework governing Iran’s nuclear program. Iran has continued to comply with the
JCPOA and Resolution 2231. Iran and the IAEA agreed in 2007 on a work plan to clarify
outstanding questions regarding Tehran’s nuclear program, most of which concerned possible
Iranian procurement activities and research directly applicable to nuclear weapons development.
A December 2015 report to the IAEA Board of Governors from then-agency Director-General
Yukiya Amano contains the IAEA’s “final assessment on the resolution” of these outstanding
issues.
How Soon Could Iran Produce a Nuclear Weapon?
Then-Under Secretary of State for Political Affairs Wendy Sherman explained during an October
2013 hearing of the Senate Committee on Foreign Relations that Iran would need as much as one
year to produce a nuclear weapon if the government decided to do so. At the time, Tehran would
have needed two to three months to produce enough weapons-grade HEU for a nuclear weapon.
Iran’s compliance with the JCPOA increased that time frame to one year, according to U.S.
officials. These estimates apparently assume that Iran would use its declared nuclear facilities to
produce fissile material for a weapon. However, Tehran would probably use covert facilities for
this purpose; Iranian efforts to produce fissile material for nuclear weapons by using its known
nuclear facilities would almost certainly be detected by the IAEA.
Congressional Research Service
Iran’s Nuclear Program: Status
Contents
Background ..................................................................................................................................... 1
Proliferation Concerns .............................................................................................................. 1
Scope and Purpose of Iran’s Nuclear Program ......................................................................... 3
Recent Nuclear Controversy............................................................................................................ 6
Iran’s Cooperation with the IAEA ........................................................................................... 11
Possible Military Dimensions ............................................................................................ 11
Other IAEA Cooperation Issues........................................................................................ 14
Status of Iran’s Nuclear Facilities ................................................................................................. 17
Uranium Enrichment Facilities ............................................................................................... 18
Natanz Commercial Facility ............................................................................................. 19
Natanz Pilot Facility ......................................................................................................... 20
Fordow Enrichment Facility ............................................................................................. 22
Enriched Uranium Containing Nearly 20% Uranium-235................................................ 24
Future Centrifuge Facilities .............................................................................................. 25
Inconsistent Progress ........................................................................................................ 26
Uranium Conversion ............................................................................................................... 27
Plutonium ................................................................................................................................ 28
Arak Reactor and Redesign .............................................................................................. 29
Bushehr Reactor ................................................................................................................ 31
Possible Future Reactors ................................................................................................... 32
Fuel Manufacturing Facilities ................................................................................................. 33
Uranium Mines and Mills ....................................................................................................... 33
Effects of Sanctions and Sabotage on Iran’s Enrichment Program ............................................... 33
Sanctions ................................................................................................................................. 33
Sabotage .................................................................................................................................. 35
Nuclear Weapon Development Capabilities .................................................................................. 36
Timelines ................................................................................................................................. 40
Declared Versus Undeclared Nuclear Facilities ................................................................ 42
Does Iran Have a Nuclear Weapons Program? .............................................................................. 43
Government Estimates ............................................................................................................ 46
Living with Risk...................................................................................................................... 49
Other Constraints on Nuclear Weapons Ambitions ................................................................. 50
Appendixes
Appendix A. Iranian Statements on Nuclear Weapons .................................................................. 52
Appendix B. Organization of Iran’s Nuclear Program .................................................................. 54
Appendix C. Multilateral Diplomacy Concerning Iran’s Nuclear Program .................................. 58
Appendix D. Trump Administration Joint Cooperative Plan of Action Policy ............................. 71
Appendix E. Possible Military Dimensions of Iran’s Nuclear Program ....................................... 75
Appendix F. Iranian Centrifuge Workshops and Related Entities ................................................. 78
Appendix G. Post-2003 Suppliers to Iran’s Uranium Enrichment Program ................................. 82
Congressional Research Service
Iran’s Nuclear Program: Status
Contacts
Author Contact Information .......................................................................................................... 85
Congressional Research Service
Iran’s Nuclear Program: Status
Background
Iran’s nuclear program began during the 1950s. Construction of a U.S.-supplied research reactor,
called the Tehran Research Reactor (TRR), located in Tehran began in 1960; the reactor went
critical in 1967.1 During the 1970s, Tehran pursued an ambitious nuclear power program.
According to contemporaneous U.S. documents, Iran wanted to construct 10-20 nuclear power
reactors and produce more than 20,000 megawatts of nuclear power by 1994.2 Iran also began
constructing a light-water nuclear power reactor near the city of Bushehr, and it considered
obtaining uranium enrichment and reprocessing technology.
Proliferation Concerns
Iran took steps to demonstrate that it was not pursuing nuclear weapons. For example, Tehran
signed the nuclear Nonproliferation Treaty (NPT) in 1968 and ratified it in 1970. Iran also
submitted a draft resolution to the U.N. General Assembly in 1974 that called for establishing a
nuclear-weapons-free zone in the Middle East. Nevertheless, mid-1970s U.S. intelligence reports
expressed concern that Iran might pursue a nuclear weapons program.3 Although Iran cancelled
its nuclear program after its 1979 revolution, a 1981 Department of State draft paper argued that
Iran might develop a nuclear weapons program in response to a then-suspected Iraqi nuclear
weapons program, although Iran was not one of several countries of “near to medium term
proliferation concern” cited in the paper.4
Tehran “reinstituted” its nuclear program in 1982.5 According to International Atomic Energy
Agency (IAEA) reports, Iran conducted experiments during the 1980s and early 1990s related to
uranium conversion, heavy-water production, and nuclear reactor fuel fabrication. A 1985
National Intelligence Council report, which cited Iran as a potential “proliferation threat,” stated
1 The United States and Iran signed a nuclear cooperation agreement in 1957; it entered into force in 1959. The two
countries negotiated another such agreement during the 1970s, but it was never concluded. For a summary of these
negotiations, see William Burr, “A Brief History of U.S.-Iranian Nuclear Negotiations,” Bulletin of the Atomic
Scientists, January/February 2009.
2 The United States was willing to supply Iran with reprocessing technology, according to 1975 and 1976 National
Security Council documents. Tehran also had a 1976 contract for a pilot uranium-enrichment facility using lasers (see
Implementation of the NPT Safeguards Agreement and Relevant Provisions of Security Council Resolutions 1737
(2006) and 1747 (2007) in the Islamic Republic of Iran, Report by the Director General, GOV 2007/58, November 15,
2007. In addition, according to a 1976 State Department cable, Iran engaged in uranium exploration in Iran and other
countries, planned to reprocess spent reactor fuel in the future, and had contemplated building its own enrichment
facility (U.S. Embassy Tehran Airgram A-76 to State Department, “The Atomic Energy Organization of Iran,” April
15, 1976).
3 Prospects for Further Proliferation of Nuclear Weapons, Special National Intelligence Estimate, August 23, 1974. A
1975 Department of State memorandum referred to the “uncertainty over” Iran’s “long-term objectives despite its NPT
status” (“Memorandum for the Assistant to the President for National Security Affairs: Department of State Response
to NSSM 219 [Nuclear Cooperation with Iran],” April 18, 1975). A 1975 CIA report identified Iran as one state with
the “potential … to cross the explosives threshold within the next ten years.” (Managing Nuclear Proliferation: The
Politics of Limited Choice, Research Study, CIA, December 1975.) A 1988 CIA report (Middle East-South Asia:
Nuclear Handbook) indicated that Iran had conducted nuclear weapons “design work” before the 1979 revolution.
4 “Request for Review of Draft Paper on the Security Dimension of Non-Proliferation,” Special Assistant for Nuclear
Proliferation Intelligence, National Foreign Assessment Center, Central Intelligence Agency, to Resource Management
Staff, Office of Program Assessment et al., April 9, 1981. Iraq pursued nuclear, chemical, and biological weapons
during the 1980s. The paper argued that Iraq’s nuclear program was “intended to provide the option of developing
nuclear explosives in the future.”
5 Middle East-South Asia: Nuclear Handbook, CIA, May 1988.
Congressional Research Service
1
Iran’s Nuclear Program: Status
that Tehran was “interested in developing facilities that ... could eventually produce fissile
material that could be used in a [nuclear] weapon.” The report, however, added that it “would
take at least a decade” for Iran to do so.6 A 1986 CIA report went further, citing “the advantage of
long-range missiles to deliver warheads quickly, virtually without warning, and-unlike aircraftwithout facing any defense” as a “factor” that would incentivize Iranian development of nuclear
weapons “in the late 1990s.”7 A 1995 U.S. intelligence report stated that Iran was “aggressively
pursuing a nuclear weapons capability and, if significant foreign assistance were provided, could
produce a weapon by the end of the decade.”8 Somewhat less urgently, an Arms Control and
Disarmament Agency report covering 1995 observed that “Iran's rudimentary program has
apparently met with limited success so far, [but] we believe Iran has not abandoned its efforts to
expand its nuclear capabilities with a view to supporting nuclear weapons development.”9
In 1996 congressional testimony, then-Director of Central Intelligence John Deutch described
Iranian efforts to acquire from the former Soviet Union fissile material for a nuclear weapon:
In an attempt to shorten the timeline to a weapon, Iran has launched a parallel effort to
purchase fissile material, mainly from sources in the former Soviet Union.
Iranian agents have contacted officials at nuclear facilities in Kazakhstan on several
occasions, attempting to acquire nuclear-related materials. For example, in 1992, Iran
unsuccessfully approached the Ulba Metallurgical Plant to obtain enriched uranium.
In 1993, three Iranians believed to have had connections to Iran’s intelligence service
were arrested in Turkey while seeking to acquire nuclear material from smugglers from
the former Soviet Union.10
More recently, the Iranian government has said that it plans to expand its reliance on nuclear
power to generate electricity. This program will, Tehran says, reduce Iran’s oil and gas
consumption and allow the country to export additional fossil fuels; the previous Iranian regime
also made this argument.11 Iran has begun to operate the Bushehr reactor, and Tehran says it
intends to build additional reactors to generate 20,000 megawatts of power within the next 20
years.12 The 2015 Joint Comprehensive Plan of Action (JCPOA) requires Iran to refrain from
6 The Dynamics of Nuclear Proliferation: Balance of Power and Constraints, National Intelligence Council, September
1985. A 1985 CIA report articulated a more sanguine view, observing that “there is no evidence that Iran is resuming
nuclear research to develop nuclear weapons.” (“Overview of Iran's Renewed Efforts for Nuclear Development,”
Central Intelligence Agency Directorate of Intelligence, August 5, 1985).
7 Iran-Iraq: Ballistic Missile Warfare and Its Regional Implications, An Intelligence Assessment, Central Intelligence
Agency Directorate of Intelligence, March 1986.
8 The Weapons Proliferation Threat, Nonproliferation Center, March 1995.
9 A 1994 report from the same agency contains identical language. (U.S. Arms Control and Disarmament Agency,
Threat Control through Arms Control, Report to Congress, 1994.) A 1992 Arms Control and Disarmament Agency
report refers to “Iran's efforts to acquire from other countries nuclear weapons technology.” (U.S. Arms Control and
Disarmament Agency, Adherence to And Compliance with Agreements, June 24, 1992.)
10 Statement for the Record by John Deutch, Director of Central Intelligence, to the Permanent Subcommittee on
Investigations of the Senate Committee on Government Affairs, March 20, 1996.
11 For example, according to a 1976 State Department cable, the President of the Atomic Energy Organization of Iran
cited these arguments as reasons for starting an ambitious nuclear program (U.S. Embassy Tehran Airgram A-76 to
State Department, 1976). Ambassador Ali Asghar Soltanieh, then Iran’s Permanent Representative to the International
Atomic Energy Agency, has explained that nuclear power would only meet “perhaps a small portion” of the projected
national electricity demand (“Interview with Iran’s Ambassador to IAEA,” Campaign Against Sanctions and Military
Intervention in Iran, June 29, 2008; published July 2, 2008).
12 “Iran to Follow Nuclear Timetable Regardless of IAEA Reports—Official,” Islamic Republic of Iran News Network,
February 25, 2009. A spokesperson for the Atomic Energy Organization of Iran stated on January 11, 2016, that the
country “needs to generate 20,000 megawatts of nuclear electricity” and should produce 12,000 megawatts of nuclear
Congressional Research Service
2
Iran’s Nuclear Program: Status
building heavy-water-moderated reactors for 15 years. Pursuant to the agreement, Iran has
pledged to refrain from constructing any such reactors indefinitely. Iranian officials say that
Tehran has begun design work on its first indigenously produced light-water reactor, to be
constructed at Darkhovin. According to official U.S. and Iranian sources, France agreed to
construct the reactor during the 1970s but ended the project after the 1979 revolution in Iran.13
Atomic Energy Organization of Iran (AEOI) President Ali Akbar Salehi stated in September 2016
that “we are almost about to sign a contract for designing” the reactor, “but it will take a rather
long time.”14
Scope and Purpose of Iran’s Nuclear Program
Iranian officials have repeatedly asserted that the country’s nuclear program is exclusively for
peaceful purposes (see Appendix A). Nevertheless, prior to the JCPOA, the United States and
other governments argued that Iran may be pursuing, at a minimum, the capability to produce
nuclear weapons. Discerning a peaceful nuclear program from a nuclear weapons program can be
difficult because much nuclear technology is dual-use. In addition, a military nuclear program
may coexist with a civilian program, even without an explicit governmental decision to produce
nuclear weapons. Jose Goldemberg, Brazil’s former secretary of state for science and technology,
observed that a country developing the capability to produce nuclear fuel
does not have to make an explicit early [political] decision to acquire nuclear weapons. In
some countries, such a path is supported equally by those who genuinely want to explore
an energy alternative and by government officials who either want nuclear weapons or just
want to keep the option open. 15
Some analysts argue that several past nuclear programs, such as those of France, Sweden, and
Switzerland, illustrate this approach.16 A Swedish official involved in that country’s nuclear
weapons program “argued that the main aim should be the generation of nuclear energy, with
plutonium production, which would make possible the manufacture of nuclear weapons as a sideeffect.”17
The main source of proliferation concern generated by Iran’s nuclear program has been Tehran’s
construction of gas centrifuge uranium-enrichment facilities. Gas centrifuges enrich uranium by
spinning uranium hexafluoride gas at high speeds to increase the concentration of the uranium235 isotope. Such centrifuges can produce both low-enriched uranium (LEU), which can be used
electricity by 2025 (Sara Ma’sumi, Interview with Behruz Kamalvandi, “Less Than Seven Day to the Implementation
of the JCPOA [Joint Comprehensive Plan of Action],” E’temad, January 11, 2016).
13 “Iran Asks France to Remain Committed to N. Power Plant Construction Deal,” FARS News Agency, October 28,
2014. Director of Central Intelligence, Joint Atomic Energy Intelligence Committee, Iran’s Nuclear Program: Building
a Weapons Capability, February 1993. France completed 5% of the project, according to former President of Iran’s
Atomic Energy Organization Reza Amrollahi (“If We Want Nuclear Energy, We Should Not Make a Fuss,” Sharq,
September 7, 2013).
14 “Iran to Build More Power Plants—Nuclear Chief,” IRTV2, September 10, 2016.
15 Jose Goldemberg, “Looking Back: Lessons From the Denuclearization of Brazil and Argentina,” Arms Control
Today, April 2006.
16 See James Acton, “The Problem with Nuclear Mind Reading,” Survival, February-March 2009, pp. 119-142; Paul M.
Cole, “Atomic Bombast: Nuclear Weapon Decision-making in Sweden 1945-1972,” The Henry L. Stimson Center,
1996; “Neutral States: Sweden and Switzerland,” in T.V. Paul, Power Vs. Prudence: Why Nations Forgo Nuclear
Weapons (Montreal: McGill University Press), 2000, pp. 84-98; and Bruno Tertrais, “Has Iran Decided to Build the
Bomb? Lessons from the French Experience,” January 30, 2007.
17 Thomas Jonter, “The Swedish Plans to Acquire Nuclear Weapons, 1945-1968: An Analysis of the Technical
Preparations,” Science & Global Security, 18:61-86, 2010.
Congressional Research Service
3
Iran’s Nuclear Program: Status
in nuclear power reactors, and highly enriched uranium (HEU), which is one of the two types of
fissile material used in nuclear weapons. HEU can also be used as fuel in certain types of nuclear
reactors.18 Iran also has a uranium-conversion facility, which converts uranium ore concentrate
into several compounds, including uranium hexafluoride.19 This program is currently constrained
by the JCPOA. German Minister of State Niels Annen argued in a February 19, 2019, speech that
the JCPOA “effectively prevents Iran from acquiring a nuclear weapon for as long as the
agreement stands.”20
However, following the May 8, 2018, U.S. announcement that the United States would no longer
participate in the JCPOA and would reimpose sanctions that had been suspended pursuant to the
agreement, Iranian President Hassan Rouhani ordered the AEOI to “go ahead with adequate
preparations to resume enrichment at the industrial level without any limit.”21 A year later,
Rouhani announced additional Iranian responses. (see Appendix C, “Multilateral Diplomacy
Concerning Iran’s Nuclear Program”).
Iran claims that it wants to produce LEU fuel for its planned light-water nuclear power reactors,
as well as the Tehran Research Reactor (TRR) and other planned future research reactors. The
latter reactors will be used to produce isotopes for medical purposes, according to Tehran.
Although Iran has expressed interest in purchasing nuclear fuel from other countries, the
government asserts that the country should have an indigenous enrichment capability as a hedge
against possible fuel supply disruptions.22 President Rouhani ordered AEOI President Salehi on
December 13, 2016, to provide a plan “for designing and manufacturing nuclear-propulsion
system to be used in maritime transportation,” as well as producing fuel for such a system.23
However, Iranian officials have indicated that Tehran would not produce enriched uranium
exceeding JCPOA-established enrichment limits.24 In a January 2018 letter, Iran informed the
IAEA of the government’s “decision … to construct naval nuclear propulsion in future.”25 Tehran
explained in an April 2018 letter to the agency that “[f]or the first five years, no [nuclear] facility
will be involved” and the “[n]uclear fuelled engines/reactors will be used for civilian purpose.”26
Salehi stated in early February 2019 that at the project will take “at least 15 years” to complete.27
18 Highly enriched uranium used in nuclear weapons typically contains about 90% uranium-235, whereas low-enriched
uranium used in nuclear reactors typically contains less than 5% uranium-235.
19 For a detailed description of the nuclear fuel cycle, see CRS Report RL34234, Managing the Nuclear Fuel Cycle:
Policy Implications of Expanding Global Access to Nuclear Power, coordinated by Mary Beth D. Nikitin.
20 “Opening Remarks by Minister of State Niels Annen at the SWP Conference on U.S. Foreign Policy under the
Trump Administration,” February 19, 2019.
21 “Iran Accepts Remaining in JCPOA Under Condition,” Islamic Republic News Agency, May 9, 2018.
22 What Are Iran’s “Practical Needs” and Why Does Iran Want to Fuel Reactors on Its Own?, nuclearenergy.ir, July
2014. “Soltaniyeh: Iran Has No Alternative but to Enrich Uranium,” Islamic Republic News Agency, October 2, 2008;
“Interview with Iran’s Ambassador to IAEA,” 2008.
23 “Following U.S Delay, Negligence and Violation of JCPOA; President Orders FM, AEOI Head to Implement Legal
Procedures, Produce Nuclear Fuel, Propulsion System,” December 13, 2016. Available at http://president.ir/en/96776.
24 “Iran Nuclear Propulsion Bids to ‘Heed’ 2015 Deal,” Tasnim News Agency Website, December 26, 2016; “Salehi
Discusses Nuclear Propulsion Systems, Content of Rouhani’s Order with Amano”, Islamic Republic News Agency,
December 21, 2016; “AEOI Official: Russia, China Willing to Build Small N. Reactors in Iran,” FARS News Agency,
January 23, 2018.
25 Verification and Monitoring in the Islamic Republic of Iran in Light of United Nations Security Council Resolution
2231 (2015), Report by the Director General, International Atomic Energy Agency, GOV/2018/7, February 22, 2018.
26 Verification and Monitoring in the Islamic Republic of Iran in Light of United Nations Security Council Resolution
2231 (2015), Report by the Director General, International Atomic Energy Agency, GOV/2018/24, May 24, 2018.
27 “Iran Vows to Expand Nuclear Industry,” FARS News Agency, February 1, 2019.
Congressional Research Service
4
Iran’s Nuclear Program: Status
A reactor moderated by heavy water, which Iran was constructing at Arak, has also been a source
of concern. Although Tehran says that the reactor is intended for the production of radioisotopes
for medical purposes, the reactor previously under construction was a proliferation concern
because its spent fuel would have contained plutonium well-suited for use in nuclear weapons.
Spent nuclear fuel from nuclear reactors contains plutonium, the other type of fissile material
used in nuclear weapons. In order to be used in nuclear weapons, however, plutonium must be
separated from the spent fuel—a procedure called “reprocessing.” Iran has said that it will not
engage in reprocessing. This reactor is designed to use natural uranium fuel, which does not
require enrichment. Iran has rendered the Arak reactor’s original core inoperable pursuant to the
JCPOA, which also commits Tehran to redesign and rebuild the reactor based on a design agreed
to by the P5+1.
In addition to the dual-use nature of the nuclear programs described above, Iran’s inconsistent
cooperation with the IAEA contributed to suspicions that Tehran had a nuclear weapons
program.28 In the past, Iran has taken actions that interfered with the agency’s investigation of its
nuclear program, including concealing nuclear activities and providing misleading statements.
Then-IAEA Director-General Mohamed ElBaradei explained in a 2008 interview that Iran’s
cooperation lagged behind IAEA demands:
[T]hey [the Iranians] have concealed things from us in the past, but that doesn’t prove that
they are building a bomb today. They continue to insist that they are interested solely in
using nuclear power for civilian purposes. We have yet to find a smoking gun that would
prove them wrong. But there are suspicious circumstances and unsettling questions. The
Iranians’ willingness to cooperate leaves a lot to be desired. Iran must do more to provide
us with access to certain individuals and documents. It must make a stronger contribution
to clarifying the last unanswered set of questions—those relating to a possible military
dimension of the Iranian nuclear program. 29
Consistent with ElBaradei’s statement, then-IAEA Director-General Yukiya Amano explained in
a 2012 interview that the IAEA did not claim that “Iran [has] made a decision to obtain nuclear
weapons.”30 Notably, Tehran has implemented various restrictions on, and provided the IAEA
with additional information about, its uranium enrichment program and heavy-water reactor
program pursuant to the JCPOA.
Iran and the IAEA agreed in August 2007 on a work plan to clarify the outstanding questions
regarding Tehran’s nuclear program, most of which concerned possible Iranian procurement
activities and research directly applicable to nuclear weapons development. A December 2015
report to the IAEA Board of Governors from Amano contains the IAEA’s “final assessment on
the resolution” of these outstanding issues.31
Iran also has extensive programs to develop ballistic missiles and cruise missiles. (For more
details on Iran’s ballistic missile program, see CRS Report R42849, Iran’s Ballistic Missile and
Space Launch Programs, by Steven A. Hildreth.)
28 For a detailed description of Iran’s compliance with its international obligations, see CRS Report R40094, Iran’s
Nuclear Program: Tehran’s Compliance with International Obligations, by Paul K. Kerr.
29 “Interview with IAEA Boss Mohamed ElBaradei,” Der Spiegel, June 11, 2008.
30 Jay Solomon and David Crawford, “An Interview With IAEA’s Yukiya Amano,” Wall Street Journal, June 9, 2012.
31 Final Assessment on Past and Present Outstanding Issues Regarding Iran’s Nuclear Programme, GOV/2015/68,
December 2, 2015.
Congressional Research Service
5
Iran’s Nuclear Program: Status
Recent Nuclear Controversy
The public controversy over Iran’s nuclear program began in August 2002, when the National
Council of Resistance on Iran (NCRI), an Iranian exile group, revealed information during a press
conference (some of which later proved to be accurate) that Iran had built nuclear-related
facilities at Natanz and Arak that it had not revealed to the IAEA. The United States had been
aware of at least some of these activities, according to knowledgeable former officials.32 During
the mid-1990s, Israel’s intelligence services detected Iranian “efforts to develop a military nuclear
industry,” according to a 2004 Israeli Knesset committee report.33
Iran ratified the nuclear Nonproliferation Treaty (NPT) in 1970. States-parties to the treaty are
obligated to conclude a comprehensive safeguards agreement with the IAEA; Tehran concluded
such an agreement in 1974. In the case of nonnuclear-weapon states-parties to the treaty (of
which Iran is one), such agreements are designed to enable the IAEA to detect the diversion of
nuclear material from peaceful purposes to nuclear weapons uses, as well as to detect undeclared
nuclear activities and material. As a practical matter, however, the IAEA’s ability to inspect and
monitor nuclear facilities, as well as obtain relevant information, pursuant to a comprehensive
safeguards agreements is limited to facilities that have been declared by the government.34
Additional Protocols (see text box below) to IAEA safeguards agreements increase the agency’s
authority to inspect certain facilities and demand additional information from states-parties,
thereby augmenting the agency’s ability to investigate clandestine nuclear facilities and
activities.35 The IAEA’s statute requires the agency’s Board of Governors to refer cases of
noncompliance with safeguards agreements to the U.N. Security Council. Prior to the NCRI’s
revelations, the IAEA had expressed concerns that Iran had not been providing the agency with
all relevant information about its nuclear programs, but the IAEA had never found Iran in
violation of its safeguards agreement.
32 CRS analyst interview with knowledgeable former U.S. official, October 3, 2019. Gary Samore, Former Senior
Director for Nonproliferation and Export Controls on the National Security Council, personal communication June 5,
2008; Former Director of Central Intelligence George J. Tenet, “DCI Remarks on Iraq’s WMD Programs,” February 5,
2004. According to former Deputy Secretary of State William Burns, the U.S. intelligence community “began to track”
these sites in “late 2001.” (William J. Burns, The Back Channel: A Memoir of American Diplomacy and the Case for
Its Renewal [New York: Random House], 2019, p. 706.)
33 Report—Volume 1 (Unrestricted section), The Committee of Enquiry into the Intelligence System in Light of the
War in Iraq, The Knesset Foreign Affairs and Defence Committee, March 2004.
34 The IAEA does have other investigative tools, such as monitoring scientific publications from member-states. For
more information, see CRS Report R40094, Iran’s Nuclear Program: Tehran’s Compliance with International
Obligations, by Paul K. Kerr.
35 NPT states are not required to conclude Additional Protocols. However, applicable U.N. Security Council resolutions
require Iran to conclude such a protocol.
Congressional Research Service
6
Iran’s Nuclear Program: Status
Selected Provisions of the IAEA Model Additional Protocol
Additional protocols to comprehensive safeguards agreements increase the IAEA’s ability to investigate undeclared
nuclear facilities and activities in nonnuclear-weapon states by increasing the agency’s authority to inspect certain
nuclear-related facilities and demand information from member states.
Information
Article 2 of the Model Additional Protocol requires a state to provide the IAEA with information about a variety
of nuclear-related activities. The information most relevant to Iran’s enrichment and heavy water reactor
programs (the programs of greatest proliferation concern for the international community) would be a “general
description of and information specifying the location of nuclear fuel cycle-related research and development
activities not involving nuclear material.” These activities include those “specifically related to any process or
system development aspect” of uranium enrichment and spent fuel reprocessing. The Protocol also requires the
state to “make every reasonable effort to provide” the IAEA with a “general description of and information
specifying the location of nuclear fuel cycle-related research and development activities not involving nuclear
material which are specifically related to enrichment.”
The Protocol also requires the state to provide a “description of the scale of operations for each location engaged
in the activities specified in Annex I” to the Protocol. This Annex covers a variety of activities related to
enrichment, reprocessing, and nuclear reactors.
Locations
Depending on the type of facility, the IAEA may request access to a location in order to “assure the absence of
undeclared nuclear material and activities” in the facility or to “resolve a question relating to the correctness and
completeness” of Iran’s declaration pursuant to Article 2 of the Model Additional Protocol. The methods and
activities (e.g., environmental sampling, radiation detection) that IAEA inspectors may undertake when accessing
such a location vary depending on the facility’s type. In general, the Protocol would allow the IAEA access to the
following types of nuclear locations:
Uranium mines, uranium mills, and uranium ore processing facilities located at the mines.
Locations around and including facilities with nuclear material that Iran has declared under its
safeguards agreement. In Iran, these would include entire facilities where declared nuclear material
is located; such facilities are normally within a perimeter boundary, such as a security fence.
Locations of nuclear fuel cycle-related research and development activities not involving nuclear
material.
Locations engaged in activities specified in Annex I of the Model Additional Protocol. These
activities include the manufacture of some components related to enrichment, reprocessing, and
nuclear reactors.
In fall 2002, the IAEA began to investigate Iran’s nuclear activities at Natanz and Arak;
inspectors visited the sites the following February. During a June 2003 meeting, the IAEA board
first expressed “concern” about Iran’s past undeclared nuclear activities and urged Tehran to
cooperate with the agency’s investigation. The IAEA board’s first resolution, which was adopted
during a September 2003 meeting, called on Tehran to increase its cooperation with the agency’s
investigation and to suspend its uranium enrichment activities. (For more detail about Iran’s
nuclear organization, see Appendix B).
President Rouhani identified the Atomic Energy Organization of Iran (AEOI) as “the authority
that was,” prior to the June 2003 IAEA board meeting, “basically handling all political and
technical issues concerning” the agency’s investigation of Iran’s nuclear program.36 Following
that meeting, Iran’s Supreme National Security Council created the Supreme Nuclear Committee,
which was composed of officials from various agencies, including the AEOI and the ministries of
36 “Beyond the Challenges Facing Iran and the IAEA Concerning the Nuclear Dossier,” Rahbord, September 30, 2005,
pp. 7-38.
Congressional Research Service
7
Iran’s Nuclear Program: Status
defense, foreign affairs, and intelligence.37 After the IAEA board adopted its September 2003
resolution, the government placed Rouhani, who was the head of the Supreme National Security
Council at the time, in charge of the negotiations concerning Iran’s nuclear program. Rouhani
explained the resulting nuclear decisionmaking process in 2011:
Even though some people thought the nuclear team was operating with complete
prerogatives, the facts were otherwise. The work procedure for every issue was that we
first had to discuss the matter in the Supreme Nuclear Committee, then we took that result
to the Meeting of Leaders, and finally we acted in accordance with the decision of the
leaders.38
In October 2003, Iran concluded an agreement with France, Germany, and the United Kingdom,
collectively known as the “E3,” to suspend its enrichment activities, sign and implement an
Additional Protocol to its IAEA safeguards agreement, and comply fully with the IAEA’s
investigation.39 As a result, the IAEA board decided to refrain from referring the matter to the
U.N. Security Council, despite U.S. advocacy for such a referral.40 Statements from current and
former Iranian officials indicate that, during fall 2003, Tehran feared that the United States might
use Security Council referral as a means to undertake military action or other coercive measures
against Iran.41 Rouhani argued in February 2005 that the United States would not take such action
as long as Iran was cooperating with the IAEA and negotiating with the E3.42
After October 2003, Iran continued some of its enrichment-related activities, but Tehran and the
E3 agreed in November 2004 to a more detailed suspension agreement. During negotiations
between fall 2003 and summer 2005, both Iran and the E3 offered a number of proposals,
although the two sides never reached agreement.43 The IAEA’s investigation, as well as
information Tehran provided after the October 2003 agreement, ultimately revealed that Iran had
engaged in a variety of clandestine nuclear-related activities, some of which violated Iran’s
safeguards agreement. These activities included plutonium separation experiments, uranium
enrichment and conversion experiments, and importing various uranium compounds.
Current and former Iranian officials have depicted a government deeply divided during this time
over diplomatic approaches regarding its nuclear program. For example, Seyed Hossein
Mousavian, who was Iran’s spokesperson during the government’s 2003-2005 negotiations with
France, Germany, and the United Kingdom, explained that in 2003 “there were two schools of
37 Dr. Hasan Rouhani, National Security and Nuclear Diplomacy (Tehran: Center for Strategic Research), 2011, pp. 24-
28. The Supreme Council on New Technologies, which Iran formed in 1998 to focus on the nuclear program, “rarely
met” after the June 2003 IAEA board meeting, according to Rouhani.
38 Rouhani 2011, p. 245.
39 The text of the agreement is available at http://www.iaea.org/NewsCenter/Focus/IaeaIran/
statement_iran21102003.shtml. Iran signed its Additional Protocol in December 2003, but has not ratified it.
40“Ex-chief Negotiator Says Iran Leaders Decided to Suspend Nuclear Enrichment,” Aftab-e Yazd, April 7, 2009; John
Bolton, Surrender Is Not an Option: Defending America at the United Nations and Abroad (New York: Threshold
Editions), 2008, p. 139; Christopher Ford, “A New Paradigm: Shattering Obsolete Thinking on Arms Control and
Nonproliferation,” Arms Control Today, November 2008. For more details about noncompliance with IAEA safeguards
agreements and Security Council referral, see CRS Report R40094, Iran’s Nuclear Program: Tehran’s Compliance
with International Obligations, by Paul K. Kerr.
41 Aftab-e Yazd, April 7, 2009; Keyhan, July 23, 2005; David Patrikarakos, Nuclear Iran: The Birth of an Atomic State
(New York: I.B. Tauris), 2012, p. 181; Seyed Hossein Mousavian, The Iranian Nuclear Crisis: A Memoir (Washington,
DC: Carnegie Endowment for International Peace), 2012, p. 76.
42 “Iranian Official Rowhani Gives Interview, Discusses Talks With EU, Criticizes U.S.,” Tehran Vision of the Islamic
Republic of Iran Network 2, February 7, 2005.
43 These proposals are available at http://www.armscontrol.org/factsheets/Iran_Nuclear_Proposals.
Congressional Research Service
8
Iran’s Nuclear Program: Status
thought in Iran. One group advocated engagement with the West, while others were proponents of
resistance.”44 President Rouhani, who headed the 2003-2005 negotiations, explained during a July
2005 interview that certain parts of the Iranian government opposed the diplomatic track, adding
that “[t]he problems included both disharmony and sabotage.”45 Indeed, Rouhani later argued that
Iran’s Supreme National Security Council took charge of the diplomacy concerning the nuclear
program because
the Foreign Ministry was not able to be responsible for this task in a good way because
some organizations did not pay sufficient attention to this ministry’s decisions, especially
since there had been disagreements for months between the Foreign Ministry and the
Atomic Energy Organization.46
In a 2005 article, an Iranian Foreign Ministry official explained that the decision to delegate
responsibility for the nuclear issue to the Supreme National Security Council was
aimed at creating domestic consensus and preventing any possible discrepancies in the
decision making process and its implementation at the national level. It was demonstrated
in practice that this decision was crucial in preventing the friction between the government,
parliament and all other relevant agencies.47
Iran resumed uranium conversion in August 2005 under the leadership of then-President
Ahmadinejad, who had been elected two months earlier. On September 24, 2005, the IAEA Board
of Governors adopted a resolution that, for the first time, found Iran to be in noncompliance with
its IAEA safeguards agreement. The board, however, did not refer Iran to the Security Council,
choosing instead to give Tehran additional time to comply with the board’s demands. Iran
announced in January 2006 that it would resume research and development on its centrifuges at
Natanz. In response, the IAEA board adopted a resolution on February 4, 2006, that referred
Iran’s case to the Security Council. Two days later, Tehran announced that it would stop
implementing its Additional Protocol.
In March 2006, the U.N. Security Council President issued a statement, which was not legally
binding, that called on Iran to “take the steps required” by the February IAEA board resolution.
The council subsequently adopted six resolutions concerning Iran’s nuclear program: 1696 (July
2006), 1737 (December 2006), 1747 (March 2007), 1803 (March 2008), 1835 (September 2008),
and 1929 (June 2010). The second, third, fourth, and sixth resolutions imposed a variety of
restrictions on Iran. In addition, these resolutions required Tehran to cooperate fully with an
ongoing IAEA investigation of its nuclear activities, suspend its uranium enrichment program,
suspend its construction of a heavy-water reactor and related projects, and ratify the Additional
Protocol to Iran’s IAEA safeguards agreement. Resolution 1929 also required the government to
refrain from “any activity related to ballistic missiles capable of delivering nuclear weapons” and
to comply with a modified provision (called code 3.1) of Iran’s subsidiary arrangement to its
IAEA safeguards agreement. Beginning in June 2006, Iran held multiple rounds of talks with
China, France, Germany, Russia, the United Kingdom, and the United States, collectively known
44 Ali Vaez, “Seyed Hossein Mousavian: The West is Pushing Iran in the Wrong Direction,” Bulletin of the Atomic
Scientists, November 18, 2011.
45 Mehdi Mohammadi,“Nuclear Case From Beginning to End in Interview with Dr. Hasan Rowhani (Part 1): We Are
Testing Europe,” Keyhan, July 23, 2005
46 Rouhani 2011, p. 71.
47 Hamid Baeidi-Nejad, “Khatami’s Nuclear Policy,” Iranian Journal of International Affairs, vol. 18, No. 1 (Spring
2005), p. 61. An Iranian Foreign Ministry official with the same name was a participant in Iran’s negotiations regarding
its nuclear program.
Congressional Research Service
9
Iran’s Nuclear Program: Status
as the “P5+1,” concerning various proposals for resolving the nuclear dispute. Saeed Jalili, thenhead of Iran’s Supreme National Security Council, conducted Iran’s nuclear negotiations.
Following his June 2013 election, Iranian President Rouhani delegated the “nuclear negotiations
portfolio” to the Foreign Ministry, he explained in a September 2013 interview.48 The AEOI
continued to be responsible for Tehran’s negotiations with the IAEA and Supreme Leader
Ayatollah Ali Khamene’i was the ultimate decisionmaker regarding Iran’s diplomacy concerning
the Joint Comprehensive Plan of Action. Then-Under Secretary of State for Political Affairs
Wendy Sherman explained during a December 2013 hearing that Khamene’i “is the only one who
really holds the nuclear file—makes the final decisions about whether Iran will reach a
comprehensive agreement to forego much of what it has created in return for the economic relief
it seeks.”
The Supreme Leader remained in charge of decisions regarding the nuclear program following
Rouhani’s 2013 election. Deputy Foreign Minister Seyed Abbas Araqchi explained in July 2016
that the nuclear issue was “under the senior management” of Khamene’i, adding that
With regards the major foreign policy issues the more the decision making progresses and
enters important levels the higher the level of engagement; it moves up from the ministry
to the administration level and from the administration to the level of Supreme National
Security Council and at the end to the supreme leader.49
Iran and the P5+1 met three times before concluding an agreement called the Joint Plan of Action
(JPA) on November 24, 2013. This agreement placed certain limitations on Iran’s nuclear
program and established an approach toward reaching a long-term comprehensive solution to
international concerns regarding Iran’s nuclear program. The two sides began implementing the
JPA on January 20, 2014. The P5+1 and Iran reached a framework of a Joint Comprehensive Plan
of Action (JCPOA) on April 2, 2015, and finalized the JCPOA on July 14, 2015. The parties
began implementing the JCPOA on January 16, 2016. On that day, all of the previous Security
Council resolutions’ requirements were terminated. The NPT and U.N. Security Council
Resolution 2231 compose the current legal framework governing Iran’s nuclear program.50
On May 8, 2018, President Donald Trump announced that the United States would no longer
participate in the JCPOA. The United States subsequently reimposed sanctions that had been
suspended pursuant to the agreement. Other P5+1 countries immediately reiterated their support
for the JCPOA and announced that they intend to fulfill their JCPOA commitments and protect
their companies from the effects of any U.S.-imposed sanctions. President Rouhani has pledged
to continue implementing the accord, provided Iran continues to receive the economic benefits of
the agreement. (For more information about multilateral diplomacy concerning Iran’s nuclear
program, including the JCPOA’s status, see Appendix C. For more information about the Trump
administration’s JCPOA policy, see Appendix D.)
48 “Iranian President Hassan Rouhani Speaks with NBC News’ Ann Curry in Tehran,” September 18, 2013. A Foreign
Ministry spokesperson told an Iranian news agency that the Supreme National Security Council would continue
coordinating the talks, but the foreign ministry would have the lead. (“FM: Iran Restructuring Team of Negotiators in
Upcoming N. Talks with World Powers,” FARS News Agency, September 9, 2013.)
49 “The Current Restrictions Have Nothing to do with the JCPOA,” Iran Newspaper, July 13, 2016.
50 “Joint Statement by EU High Representative Federica Mogherini and Iranian Foreign Minister Javad Zarif,” January
16, 2016.
Congressional Research Service
10
Iran’s Nuclear Program: Status
Iran’s Cooperation with the IAEA
As noted, the IAEA investigation of Iran’s nuclear program began in 2002. Iran and the IAEA
agreed in August 2007 on a work plan to clarify the outstanding questions regarding Tehran’s
nuclear program.51 Most of these issues,52 which had contributed to suspicions that Iran had been
pursuing a nuclear weapons program, were essentially resolved by June 2008. However, thenIAEA Director-General ElBaradei told the IAEA Board of Governors on June 2, 2008, that there
is “one remaining major [unresolved] issue,” which concerns questions regarding “possible
military dimensions to Iran’s nuclear programme.”
Possible Military Dimensions
Iran and the IAEA subsequently held a series of discussions regarding these issues. The agency
provided Iran with documents or, in some cases, descriptions of documents, which had been
provided to the IAEA by several governments. The documents indicated that Iranian entities may
have conducted studies related to nuclear weapons development. The subjects of these studies
included uranium conversion, missile reentry vehicles for delivering nuclear warheads, and
conventional explosives used in nuclear weapons. Iranian officials have claimed that the
documents are not authentic,53 but ElBaradei told the IAEA board on June 17, 2009, that there
was “enough in these alleged studies to create concern in the minds of our professional
inspectors.” Iranian officials acknowledged that some of the information in the documents is
accurate, but they argued that the activities described were exclusively for nonnuclear purposes.54
Tehran has provided some relevant information about these matters to the IAEA, but ElBaradei
reported in August 2009 that the government should “provide more substantive responses” to the
IAEA, as well as “the opportunity to have detailed discussions with a view to moving forward on
these issues, including granting the agency access to persons, information and locations identified
in the documents.”55
Then-IAEA Director-General Amano issued a report to the IAEA board in November 2011 stating
that Iran had not “engaged with the agency in any substantive way” on the alleged studies since
51 The text of the work plan is available at http://www.iaea.org/Publications/Documents/Infcircs/2007/infcirc711.pdf.
52 These issues included plutonium experiments, research and procurement efforts associated with two types of
centrifuges, operations of a uranium mine, and experiments with polonium-210, which (in conjunction with beryllium)
is used as a neutron initiator in certain types of nuclear weapons.
53 In a September 28, 2008, letter to the IAEA, Iran described some characteristics of the documents discussed above.
The letter stated that some of the information from the United States was shown to Iranian officials as PowerPoint
presentations. In addition, some of the documents are “in contradiction with typical standard Iranian documentation”
and lack “classification seals,” the letter said. See, Permanent Mission of the Islamic Republic of Iran, Explanatory
Comments by the Islamic Republic of Iran on the Report of the IAEA Director General to the September 2008 Board of
Governors (GOV/2008/38), September 28, 2008. INFCIRC/737. Iran also complained that the IAEA has not provided
Tehran with original versions of some documentation related to the alleged “military dimensions” of Iran’s nuclear
program. Several reports from ElBaradei have stated that the agency has not had permission to provide this
documentation from the governments that provided it. In his November 2009 report, ElBaradei again called on such
governments to authorize the IAEA to share additional information with Iran.
54 Implementation of the NPT Safeguards Agreement and Relevant Provisions of Security Council Resolutions 1737
(2006), 1747 (2007) and 1803 (2008) in the Islamic Republic of Iran, Report by the Director General, GOV/2008/15,
May 26, 2008.
55 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,
GOV/2009/55, August 28, 2009.
Congressional Research Service
11
Iran’s Nuclear Program: Status
August 2008.56 According to this report, which provided the most detailed account to date of the
IAEA’s evidence regarding Iran’s suspected nuclear weapons-related activities, the agency has
“credible” information that Iran has carried out activities “relevant to the development of a
nuclear explosive device,” including
acquisition of “nuclear weapons development information and documentation,”
work to develop “an indigenous design of a nuclear weapon including the testing
of components,”
efforts “to procure nuclear related and dual use equipment and materials by
military related individuals and entities,”
and work to “develop undeclared pathways for the production of nuclear
material.”
Although some of these activities have civilian applications, “others are specific to nuclear
weapons,” the report notes. Most of these activities were conducted before the end of 2003,
though some may have continued. (See Appendix E and “Nuclear Weapon Development
Capabilities” for more details.)
The IAEA Board of Governors adopted a resolution on November 18, 2011, stating that “it is
essential” for Iran and the IAEA “to intensify their dialogue aiming at the urgent resolution of all
outstanding substantive issues.” IAEA and Iranian officials met 10 times between January 2012
and May 2013 to discuss what the agency termed a “structured approach to the clarification of all
outstanding issues related to Iran’s nuclear programme.”57 However, during an October 2013
meeting, IAEA officials and their Iranian counterparts decided to adopt a “new approach” to
resolving these issues. Iran signed a joint statement with the IAEA on November 11, 2013,
describing a “Framework for Cooperation.” According to the statement, Iran and the IAEA
agreed to “strengthen their cooperation and dialogue aimed at ensuring the exclusively peaceful
nature of Iran’s nuclear programme through the resolution of all outstanding issues that have not
already been resolved by the IAEA.” Tehran subsequently provided the IAEA with information
about several of the outstanding issues and later agreed in May 2014 to provide information to the
agency by August 25, 2014, about five additional issues, including alleged Iranian research on
high explosives and “studies made and/or papers published in Iran in relation to neutron transport
and associated modelling and calculations and their alleged application to compressed materials.”
Iran subsequently provided information about four of these issues.58
Road Map to Assessing Possible Military Dimensions
The July 2015 JCPOA states that Tehran was to “complete” a series of steps set out in an IranIAEA “Roadmap for Clarification of Past and Present Outstanding Issues.” According to thenIAEA Director-General Amano, this road map, which the two sides concluded in July 2015, set
out “a process” under the November 2013 JPA “to enable the Agency, with the cooperation of
Iran, to make an assessment of issues relating to possible military dimensions to Iran’s nuclear
56 Implementation of the NPT Safeguards Agreement and Relevant Provisions of Security Council Resolutions in the
Islamic Republic of Iran, GOV/2011/65, November 8, 2011.
57 A September 2012 IAEA Board of Governors resolution reiterated the board’s support for the agency’s negotiations
with Tehran, and stated that “Iranian cooperation with IAEA requests aimed at the resolution of all outstanding issues
is essential and urgent in order to restore international confidence in the exclusively peaceful nature of Iran’s nuclear
programme.”
58 Implementation of the NPT Safeguards Agreement and Relevant Provisions of Security Council Resolutions in the
Islamic Republic of Iran, Report by the Director General, GOV/2015/34, May 29, 2015.
Congressional Research Service
12
Iran’s Nuclear Program: Status
programme.”59 According to a December 2, 2015, report to the IAEA Board of Governors from
Amano, “[a]ll the activities contained in the road-map were implemented in accordance with the
agreed schedule.”60 The road map required Amano to present this report, which contains the
agency’s “final assessment on the resolution” of the aforementioned outstanding issues.
In response, the board adopted a resolution on December 15, 2015, that notes Iran’s cooperation
with the road map and “further notes that this closes the Board’s consideration” of the
“outstanding issues regarding Iran’s nuclear programme.”61 Because the IAEA has verified that
Iran has taken the steps required for Implementation Day to take effect, the board is no longer
focused on either Iran’s compliance with past Security Council resolutions or past issues
concerning Iran’s safeguards agreement. Instead, the board is focused on monitoring and
verifying Iran’s JCPOA implementation “in light of” United Nations Security Council Resolution
2231, which the council adopted on July 20, 2015. The December 2015 IAEA resolution requests
the Director General to issue quarterly reports to the board regarding Iran’s “implementation of
its relevant commitments under the JCPOA for the full duration of those commitments.” The
Director General is also to report to the IAEA Board of Governors and the Security Council “at
any time if the Director General has reasonable grounds to believe there is an issue of concern”
regarding Tehran’s compliance with its JCPOA or safeguards obligations.62
Parchin
Parchin is an Iranian military site. As part of its investigation into “possible military dimensions”
of Iran’s nuclear program, the IAEA requested that Tehran respond to information which the
agency obtained from unnamed governments regarding activity at the military site. Information
provided to IAEA indicated that in 2000 “Iran constructed a large explosives containment vessel”
at Parchin to conduct experiments related to the development of nuclear weapons, according to
Amano’s November 2011 report.63 The report did not say whether Iran actually built the vessel or
conducted these experiments. IAEA inspectors visited the site twice in 2005, but they did not visit
the location “believed to contain the building which houses the explosives chamber.”64 The
agency requested access to this latter building in February 2012, but Iran did not provide such
access until September 2015 as part of the road map described above. At that time, IAEA officials
conducted and supervised verification activities, including “visual observation and environmental
sampling,” but they “did not observe a chamber or any associated equipment inside the
59 For more information about the Joint Plan of Action and the JCPOA, see CRS Report R43333, Iran Nuclear
Agreement, by Kenneth Katzman and Paul K. Kerr.
60 Final Assessment on Past and Present Outstanding Issues Regarding Iran’s Nuclear Programme, GOV/2015/68,
December 2, 2015.
61 Joint Comprehensive Plan of Action Implementation and Verification and Monitoring in the Islamic Republic of Iran
in Light of United Nations Security Council Resolution 2231 (2015), Resolution Adopted by the Board of Governors,
GOV/2015/72, December 15, 2015.
62 The JCPOA and U.N. Security Council Resolution 2231 contain a variety of reporting provisions for the IAEA. For
example, the resolution requests the agency’s Director General
to provide regular updates to the IAEA Board of Governors and, as appropriate, in parallel to the
Security Council on Iran’s implementation of its commitments under the JCPOA and also to report
to the IAEA Board of Governors and in parallel to the Security Council at any time if the Director
General has reasonable grounds to believe there is an issue of concern directly affecting fulfilment
of JCPOA commitments.
63 GOV/2011/65.
64 Ibid.
Congressional Research Service
13
Iran’s Nuclear Program: Status
building.”65 Iranian officials told their IAEA counterparts in October 2015 that the building in
question “had always been used for the storage of chemical material for the production of
explosives,” but the “information available” to the IAEA, “does not support Iran’s statements on
the purpose of the building.”66 Beginning in February 2012, Iran apparently undertook efforts to
remove evidence of past nuclear-related activities at the site. These efforts, which included
landscaping, refurbishing buildings, demolishing buildings, and removing and replacing external
wall structures, “seriously undermined the Agency’s ability to conduct effective verification,”
according to Amano’s December 2, 2015, report.
Iranian officials have implied that the government’s refusal to allow IAEA post-2005 access to
Parchin was due to Defense Ministry resistance. Fereydoun Abbasi-Davani, then-AEOI President,
indicated in 2012 that allowing inspectors to the site was the Iranian military’s decision.67
Rouhani in 2011 described a contentious internal debate regarding access to Parchin:
In the area of Agency inspections and especially the inspections of military centers such as
Parchin, this was debated for months inside the country and this issue was therefore raised
in various meetings over the circumstances in which these inspections would take place.
There was serious opposition to the Agency’s request to inspect Parchin; the nation’s
domestic political climate was vigorously opposed to inspectors inspecting Parchin and
military centers in general.68
For more information about the Parchin site, see Appendix E.
Other IAEA Cooperation Issues
Iran cooperated with the IAEA in other respects, albeit with varying consistency. The IAEA was
(and still is) able to verify that Iran’s declared nuclear facilities and materials have not been
diverted for military purposes. Moreover, Tehran provided the agency with “information similar
to that which Iran had previously provided pursuant to the Additional Protocol,” ElBaradei
reported to the IAEA board in February 2008, adding that this information clarified the agency’s
“knowledge about Iran’s current declared nuclear programme.”69 Iran, however, provided this
information “on an ad hoc basis and not in a consistent and complete manner,” the report said.
Indeed, the IAEA requested in April 2008 that Iran provide “as a transparency measure, access to
additional locations related ... to the manufacturing of centrifuges, research and development
(R&D) on uranium enrichment, and uranium mining.”70 Tehran provided such access pursuant to
the 2013 JPA.
ElBaradei’s February 2008 report underscored the importance of full Iranian cooperation with the
IAEA investigation, as well as Tehran’s implementation of its Additional Protocol:
Confidence in the exclusively peaceful nature of Iran’s nuclear programme requires that
the Agency be able to provide assurances not only regarding declared nuclear material, but,
equally importantly, regarding the absence of undeclared nuclear material and activities in
Iran.... Although Iran has provided some additional detailed information about its current
activities on an ad hoc basis, the Agency will not be in a position to make progress towards
65 GOV/2015/68.
66 Ibid.
67 “Iran: Military Decides if IAEA Can Visit Parchin,” Reuters, February 29, 2012.
68 Rouhani 2011, p. 244.
69 GOV/2008/4.
70 GOV/2008/15.
Congressional Research Service
14
Iran’s Nuclear Program: Status
providing credible assurances about the absence of undeclared nuclear material and
activities in Iran before reaching some clarity about the nature of the alleged studies, and
without implementation of the Additional Protocol.71
The IAEA also asked Iran to “reconsider” its March 2007 decision to stop complying with a
portion of the subsidiary arrangements for its IAEA safeguards agreement.72 That provision
(called code 3.1), to which Iran agreed in February 2003, requires Tehran to provide design
information for new nuclear facilities “as soon as the decision to construct, or to authorize
construction, of such a facility has been taken, whichever is earlier.” Previously, Iran was required
to provide design information for a new facility 180 days before introducing nuclear material into
it.73 Iran invoked the March 2007 decision when it withheld from the IAEA until September 2009
“preliminary design information” for the planned Darkhovin reactor; the agency first requested
the information in December 2007. Although Iran provided the agency with preliminary design
information about the Darkhovin reactor in a September 22, 2009, letter, the IAEA requested
Tehran to “provide additional clarifications” of the information.74 Amano reported in September
2010 that Iran had “provided only limited design information with respect to” the reactor.75
Arak Reactor
Tehran also refused to provide updated design information for the Arak reactor—a decision
which, according to a May 2013 report from Amano, had “an adverse impact on the Agency’s
ability to effectively verify the design of the facility.”76 As part of the JPA, Iran submitted this
information to the IAEA on February 12, 2014.77 Pursuant to the JCPOA, Iran has committed to
redesign and rebuild the Arak reactor based on a design agreed to by the P5+1 so that it will not
produce weapons-grade plutonium. Iran has rendered the reactor’s original core inoperable.
Iran had also refused to allow IAEA officials to conduct an inspection of the Arak reactor in order
to verify Iranian-provided design information. ElBaradei argued in a June 2009 report to the
IAEA board that this continued refusal “could adversely impact the Agency’s ability to carry out
effective safeguards at that facility,” adding that satellite imagery was insufficient because Iran
has completed the “containment structure over the reactor building, and the roofing for the other
buildings on the site.”78 However, IAEA inspectors visited the reactor facility in August 2009 to
71 Implementation of the NPT Safeguards Agreement and Relevant Provisions of Security Council Resolutions 1737
(2006) and 1747(2007) in the Islamic Republic of Iran, Report by the Director General, GOV/2008/4, February 22,
2008.
72 According to the 2001 IAEA Safeguards Glossary, subsidiary arrangements describe the “technical and
administrative procedures for specifying how the provisions laid down in a safeguards agreement are to be applied.”
73 For more detail about Iran’s safeguards obligations and reporting requirements, see CRS Report R40094, Iran’s
Nuclear Program: Tehran’s Compliance with International Obligations, by Paul K. Kerr.
74 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,
GOV/2008/59, November 19, 2008.
75 Implementation of the NPT Safeguards Agreement in Relevant Provisions of Security Council Resolutions in the
Islamic Republic of Iran, Report by the Director General, GOV/2010/46, September 6, 2010. IAEA reports since 2012
do not appear to address this issue.
76 Implementation of the NPT Safeguards Agreement and Relevant Provisions of Security Council Resolutions in the
Islamic Republic of Iran, Report by the Director General, GOV/2013/27, May 22, 2013.
77 Implementation of the NPT Safeguards Agreement and Relevant Provisions of Security Council Resolutions in the
Islamic Republic of Iran, Report by the Director General, GOV/2014/10, February 20, 2014.
78 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,
GOV/2009/35, June 5, 2009.
Congressional Research Service
15
Iran’s Nuclear Program: Status
verify design information, according to ElBaradei’s report issued the same month. IAEA
inspectors had last visited the reactor in August 2008. Inspectors have visited the facility several
more times, according to reports from Amano.
Fordow Fuel Enrichment Plant
In addition, Iran failed to notify the IAEA until September 2009 that it was constructing a
uranium enrichment facility, called the Fordow Fuel Enrichment Plant, near the city of Qom. Iran
revealed in September 2009 that it had been constructing the facility and provided some details
about it to the IAEA in a September 21, 2009, letter. Four days after the IAEA received the letter,
British, French, and U.S. officials revealed that they had previously developed intelligence on the
facility. The three governments provided a detailed intelligence briefing to the IAEA after the
agency received Iran’s letter. U.S. officials have said that, despite its letter to the agency, Iran
intended for the facility to be kept secret. Tehran placed the facility under IAEA safeguards after
its September 2009 letter. (For more details, see the “Fordow Enrichment Facility” section
below.) Pursuant to the JCPOA, Iran has begun to convert its Fordow enrichment facility into “a
nuclear, physics, and technology centre” in which no nuclear material will be present.
In a letter published on October 1, 2009, the IAEA asked Iran to provide additional information
about the facility, including “further information with respect to the name and location of the pilot
enrichment facility, the current status of its construction and plans for the introduction of nuclear
material into the facility.” The letter also requested that Tehran provide IAEA inspectors with
access to the facility “as soon as possible.” IAEA officials inspected the facility and met with
Iranian officials in late October 2009. According to a November 2009 report from ElBaradei to
the IAEA board, Tehran “provided access to all areas of the facility,” which “corresponded with
the design information provided by Iran” a week before the visit. IAEA officials have since
conducted regular inspections of the facility. Although Iran provided additional design
information about the facility to the IAEA, the agency still had questions about the facility’s
“purpose and chronology” and wished to interview other Iranian officials and review additional
documentation, according to ElBaradei’s report. Amano reported in May 2012 that Iran had
provided the IAEA with some requested information regarding the Fordow construction decision,
but the agency still wanted more information from Tehran.79 Tehran, according to Amano’s
November 2015 report, has not yet provided all of this information.80 Subsequent IAEA reports
have not addressed the issue.
Heavy-Water Reactor
The IAEA has also requested additional information about Iran’s production of heavy water. As
noted, Iran is constructing a heavy-water nuclear reactor. ElBaradei’s November 2009 report
states that, during an inspection of Iran’s uranium conversion facility the previous month, IAEA
inspectors “observed 600 50-litre drums said by Iran to contain heavy water.”81 The inspectors
visited the facility to verify updated design information submitted by Iran in August 2009. The
inspectors observed the drums after gaining access to an area of the facility that agency inspectors
79 Implementation of the NPT Safeguards Agreement and Relevant Provisions of Security Council Resolutions in the
Islamic Republic of Iran, Report by the Director General, GOV/2012/23, May 25, 2012.
80 Implementation of the NPT Safeguards Agreement and Relevant Provisions of Security Council Resolutions in the
Islamic Republic of Iran, GOV/2015/65, Report by the Director General, November 18, 2015.
81 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,
GOV/2009/74, November 16, 2009.
Congressional Research Service
16
Iran’s Nuclear Program: Status
had not previously visited.82 Tehran told the IAEA that the water originated in Iran and permitted
agency inspectors to count the number of drums and weigh a “small number of randomly selected
drums.”83 For a time, Tehran did not permit the agency to take samples of the heavy water, but the
government did allow such access in February 2014.84 Similarly, Iran for some time did not grant
repeated IAEA requests for “further access” to the country’s heavy-water production plant since
agency inspectors visited the facility in August 2011.85 However, Iran granted such access in
December 2013.86
The IAEA apparently resolved a discrepancy discovered during an August 2011 inspection of an
Iranian research laboratory that had been used to conduct uranium conversion experiments. IAEA
measurements revealed that Iran had overstated the amount of material in the facility, described in
Amano’s November 2011 report as “natural uranium metal and process waste,” by almost 20
kilograms.87 Iran and the IAEA appear to have resolved the issue in 2013.88
Status of Iran’s Nuclear Facilities
Some nongovernmental experts and former U.S. officials have argued that, rather than producing
fissile material for nuclear weapons indigenously, Iran could obtain such material from foreign
sources.89 A November 2007 National Intelligence Estimate (NIE) states that the intelligence
community “cannot rule out that Iran has acquired from abroad—or will acquire in the future—a
nuclear weapon or enough fissile material for a weapon.”90 A senior intelligence official
characterized such acquisition as “an inherent option” for Iran.91 However, Tehran’s potential
ability to produce its own fissile material is a greater cause of concern; the official explained that
“getting bits and pieces of fissile material from overseas is not going to be sufficient” to produce
a nuclear arsenal.92 As noted, uranium enrichment facilities can produce highly enriched uranium
(HEU), which is one of the two types of fissile material used in nuclear weapons. The other type
is plutonium, which is separated from spent nuclear reactor fuel.
According to a November 14, 2013, IAEA report, Iran had generally stopped expanding its
enrichment and heavy-water reactor programs during the negotiations leading up to the JPA,
82 CRS analyst interview with a U.S. official, December 17, 2009.
83 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,
GOV/2010/10, February 18, 2010.
84 Implementation of the NPT Safeguards Agreement and Relevant Provisions of Security Council Resolutions in the
Islamic Republic of Iran, Report by the Director General, GOV/2015/15, February 19, 2015.
85 Ibid.
86 GOV/2015/65.
87 Ibid.
88
GOV/2013/27.
89 See, for example, then-Under Secretary of State for U.S. Arms Control and International Security Robert Joseph’s
testimony before the Senate Committee on Foreign Relations, February 9, 2006, and then-Director of Research Institute
for National Strategic Studies National Defense University Stephen Cambone’s testimony before the Senate Committee
on Governmental Affairs, September 21, 2000.
90 Iran: Nuclear Intentions and Capabilities, National Intelligence Estimate, November 2007.
91 “Unclassified Key Judgments of the National Intelligence Estimate: Iran: Nuclear Intentions and Capabilities,”
background briefing with senior intelligence officials, December 3, 2007.
92 Ibid.
Congressional Research Service
17
Iran’s Nuclear Program: Status
which the parties finalized later that month.93 That agreement essentially froze most aspects of
Iran’s nuclear program to allow time to negotiate the July 2015 JCPOA. When the JPA went into
effect in January 2014, Iran had enough uranium hexafluoride containing up to 5% uranium-235
to yield—if further enriched—weapons-grade HEU for as many as eight nuclear weapons.94 If it
had been further enriched, the total amount of Iranian uranium hexafluoride containing 20%
uranium-235 would have been sufficient for a nuclear weapon. Pursuant to the JCPOA, Iran has
restricted and/or dismantled various portions of its nuclear program. Iran currently lacks enough
low-enriched uranium hexafluoride to produce a nuclear weapon.
Since the JCPOA’s Implementation Day, Iran has imported items for its nuclear program via a
JCPOA-established “procurement channel,” which, according to the agreement, is to last for a
duration of 10 years.95 A Procurement Working Group, which is part of the JCPOA-established
Joint Commission, reviews proposals for nuclear-related transfers to Iran. The working group
provides its recommendations to the UN Security Council, which approves any exports. The
JCPOA requires Iran to provide the IAEA with “access to the locations of intended use of all
items, materials, equipment, goods and technology” listed in the NSG’s “Guidelines for Nuclear
Transfers.”96 Tehran is also to permit exporting governments to “verify the end-use of all items,
materials, equipment, goods and technology” listed in the NSG’s “Guidelines for Transfers of
Nuclear-Related Dual-Use Equipment, Materials, Software, and Related Technology.”97
According to a December 2019 report by Marc Pecsteen de Buytswerve, Security Council
Facilitator for the Implementation of Resolution 2231(2015), the Security Council had received
44 nuclear-related export proposals since Implementation Day; the council approved 30 of those
proposals and disapproved five. Nine proposals were withdrawn by the submitting states.98 The
report states that “the procurement channel continues to function, and the Joint Commission
continues to review proposals.” However, the number of export proposals has decreased
significantly since the May 2018 U.S. withdrawal from the JCPOA; de Buytswerve’s report states
that the group had received no new proposals during the previous six-month period.99
Uranium Enrichment Facilities
Iran has used three centrifuge facilities to enrich uranium: a pilot centrifuge facility and a larger
commercial facility, both located at Natanz, and the Fordow centrifuge facility located near the
city of Qom. Iran has also had a variety of facilities and workshops involved in the production of
centrifuges and related components. (See Appendix F and CRS Report R42443, Israel: Possible
Military Strike Against Iran’s Nuclear Facilities, coordinated by Jim Zanotti.) During a July 31,
93 Implementation of the NPT Safeguards Agreement and Relevant Provisions of Security Council Resolutions in the
Islamic Republic of Iran, Report by the Director General, GOV/2013/56, November 14, 2013.
94 Colin Kahl, Deputy Assistant to the President and National Security Adviser to the Vice President, “Arms Control
Association Annual Meeting: Unprecedented Challenges for Nonproliferation and Disarmament,” May 14, 2015.
95 Information about the procurement channel is available at https://eeas.europa.eu/delegations/iran/8711/jcpoaprocurement-channel_en.
96 INFCIRC/254/Rev.12/Part 1.
97 INFCIRC/254/Rev.9/Part 2.
98 Eighth Six-Month Report of the Facilitator on the Implementation of Security Council Resolution 2231 (2015),
S/2019/952/Rev.1, December 16, 2019.
99 Ibid. A June 2019 letter from Russia to the UN Security Council suggests that the United States is attempting to
prevent transfers via the channel (Letter dated 11 June 2019 from the Chargé d’affaires of the Permanent Mission of
the Russian Federation to the United Nations Addressed to the Secretary-General and the President of the Security
Council, S/2019/482, June 12, 2019).
Congressional Research Service
18
Iran’s Nuclear Program: Status
2015, press briefing about possible Iranian undeclared nuclear facilities, then-U.S. Secretary of
Energy Ernest Moniz stated that “we feel pretty confident that we know their current
configuration.”100
Natanz Commercial Facility
This facility was to have held approximately 50,000 centrifuges.101 Former Vice President
Gholamreza Aghazadeh, who also headed the AEOI until July 2009, explained in February 2009
that Iran intended to install all of the centrifuges by 2015.102 Iran began enriching uranium in the
facility after mid-April 2007; as of November 5, 2013, the facility had produced 10,357
kilograms of low-enriched uranium hexafluoride containing up to 5% uranium-235. This quantity
of LEU, if it had been further enriched, would have yielded enough weapons-grade HEU for as
many as eight nuclear weapons.103 As of October 31, 2015, the facility had produced 15,525
kilograms of uranium hexafluoride containing up to 5% uranium-235. However, Iran had only
approximately 8,305 kilograms of this material because the rest had been converted into various
other chemical forms.104
Individual centrifuges are linked together in cascades; each cascade in the commercial facility
contained either 164 or 174 centrifuges. As of May 17, 2015, Tehran had installed about 15,400
first generation (IR-1) centrifuges, approximately 9,150 of which were enriching uranium. Iran
had also installed about 1,000 centrifuges of greater efficiency, called IR-2m centrifuges, in the
facility. The IR-2m centrifuges were not enriching uranium.105 Amano reported in February 2017
100 See also Colin H. Kahl, “Not Time to Attack Iran: Why War Should Be a Last Resort,” Foreign Affairs, January 17,
2012.
101 A 2008 IAEA report states that Iran was planning to install 16 cascade units, each containing 18 164-centrifuge
cascades. The total number of centrifuges would have been 47,232. Iran, however, installed some cascades containing
174 centrifuges (Implementation of the NPT Safeguards Agreement and Relevant Provisions of Security Council
Resolutions 1737 [2006], 1747 [2007] and 1803 [2008] in the Islamic Republic of Iran, Report by the Director
General, GOV/2008/15, May 26, 2008). According to September 25, 2009, Obama Administration talking points, the
facility “is designed to house 54,000 centrifuges.” Gholamreza Aghazadeh, who headed Iran’s Atomic Energy
Organization (AEOI), said in February 2009 that Iran would install 50,000 centrifuges (“Iran to Follow Nuclear
Timetable Regardless of IAEA Reports—Official,” Islamic Republic of Iran News Network, February 25, 2009). A
2012 AEOI report gives the facility’s “overall capacity” as 48,000 centrifuges (Nuclear Industry in Iran: An Overview
on Iran’s Activities and Achievements in Nuclear Technology, Atomic Energy Organization of Iran, 2012, p. 16).
102 Islamic Republic of Iran News Network, February 25, 2009.
103 Colin Kahl, Deputy Assistant to the President and National Security Adviser to the Vice President, “Arms Control
Association Annual Meeting: Unprecedented Challenges for Nonproliferation and Disarmament,” May 14, 2015. See
also calculations from Iran’s Nuclear, Chemical, and Biological Capabilities: A Net Assessment, International Institute
for Strategic Studies [IISS], 2011, p. 72. This number of nuclear weapons probably assumes that 25 kilograms of
uranium-235 (approximately 27.8 kilograms of uranium containing 90% uranium-235) would be necessary for one
HEU-based nuclear weapon. The IAEA term for this amount of uranium is “significant quantity,” defined as the
“approximate amount of nuclear material for which the possibility of manufacturing a nuclear explosive device cannot
be excluded.” The latter report points out that Iran would likely need to produce more uranium-235 to build its first
nuclear weapon because “the fabrication of an initial bomb would involve an amount of unavoidable wastage” (p. 69).
Some types of weapons could be developed using less uranium-235. The term “significant quantity” should be
understood in the context of IAEA safeguards objectives. One such objective, according to the agency, is the “timely
detection of diversion of significant quantities of nuclear material from peaceful nuclear activities to the manufacture of
nuclear weapons or of other nuclear explosive devices or for purposes unknown.”
104 GOV/2015/65. Iran’s Fordow centrifuge facility also produced low-enriched uranium hexafluoride containing up to
5% uranium-235 (see “Fordow Enrichment Facility”). In addition, Iran produced uranium hexafluoride of a similar
isotopic composition by converting low-enriched uranium hexafluoride containing nearly 20% uranium-235.
105 Implementation of the NPT Safeguards Agreement and Relevant Provisions of Security Council Resolutions in the
Islamic Republic of Iran, GOV/2015/34, Report by the Director General, May 29, 2015.
Congressional Research Service
19
Iran’s Nuclear Program: Status
that, pursuant to its JCPOA commitments, Iran had 5,060 IR-1 centrifuges installed in the facility
and had removed all other centrifuges.106 Iran shipped out most of its LEU to Russia on
December 28, 2015, to reduce its stockpile to the required levels.107 Until July 1, 2019, IAEA
reports stated that Iran’s total stockpile of low-enriched uranium hexafluoride did not exceed 300
kilograms since Tehran began implementing its JCPOA commitments.108 But the agency reported
on that date, however, that it had verified that this stockpile had exceed the 300 kilogram limit.109
As of August 19, 2019, Iran’s stockpile of low-enriched uranium hexafluoride was
approximately 372 kilograms, based on information from a November 11 report by IAEA Acting
Director General Cornel Feruță.110
Until July 2019, IAEA reports stated that Iran had been producing enriched uranium hexafluoride
continuing no more than 3.67% uranium-235, as mandated by the JCPOA. According to a July 8
IAEA report, the agency verified that the uranium-235 content of Tehran’s LEU exceeded the
JCPOA-mandated limits. “Iran informed the Agency that, based on the operator’s assessment, the
[LEU] enrichment level … is about 4.5%,” the report says.111 Tehran has since been “enriching
uranium up to” this concentration of uranium-235.112 AEOI spokesperson Behrouz Kamalvandi
stated in a November press conference that the AEOI “is capable of enriching uranium to 5, 20 or
60 per cent.”113
Natanz Pilot Facility
Iran began enriching uranium up to 20% uranium-235 in the Natanz pilot facility in February
2010. Iranian officials stated that this enriched uranium was to serve as fuel in Iran’s Tehran
Research Reactor (TRR), as well as future such research reactors.114 Construction of the U.S.supplied TRR began in 1960, and it went critical in 1967. Initially fueled by U.S.-supplied HEU,
106 Verification and Monitoring in the Islamic Republic of Iran in Light of United Nations Security Council Resolution
2231 (2015), GOV/2017/10, Report by the Director General, February 24, 2017.
107 “Press Release on the Export of Enriched Uranium from Iran Assisted by Russia as Part of Preparation for JCPOA
Implementation,” Ministry of Foreign Affairs of the Russian Federation, December 29, 2015. Daily Press Briefing,
Department of State, December 28, 2015. Ambassador Stephen Mull, then-Coordinator for Implementation of the
JCPOA, told the Senate Foreign Relations Committee on December 17, 2015, that the exported material “will end up at
a safeguarded facility” in Russia.
108 Verification and Monitoring in the Islamic Republic of Iran in Light of United Nations Security Council Resolution
2231 (2015), Report by the Director General, International Atomic Energy Agency, GOV/2019/10, February 22, 2019.
109 Verification and Monitoring in the Islamic Republic of Iran in Light of United Nations Security Council Resolution
2231 (2015), GOV/INF/2019/8, Report by the Director General, July 1, 2019. Based on information in the report,
Iran’s stockpile of low-enriched uranium hexafluoride was approximately 304 kilograms.
110 Verification and Monitoring in the Islamic Republic of Iran in Light of United Nations Security Council Resolution
2231 (2015), Report by the Director General, International Atomic Energy Agency, GOV/2019/55, November 11,
2019. The stockpile’s composition as of November 3 was approximately 213 kilograms of LEU containing as much as
3.67% uanium-235 and 160 kilograms of LEU containing as much as 4.5% uranium-235.
111 Verification and Monitoring in the Islamic Republic of Iran in Light of United Nations Security Council Resolution
2231 (2015), GOV/INF/2019/9, Report by the Director General, July 8, 2019.
112 GOV/2019/55.
113 “Iran Capable of Enriching Uranium Up to 60 per Cent – Official,” BBC Monitoring, November 10, 2019.
114GOV/2012/23. Iran will need to provide fuel for “at least 4 other research reactors,” according to the text of a June
Iranian proposal to the P5+1 (“Full Text of Iran’s Proposals to Six World Powers in Moscow Talks,” Fars News
Agency, July 7, 2012). Abbasi stated in an April 2012 interview that Iran plans to design and build another 10 megawatt
“strong pool reactor.” He indicated that the reactor would also use fuel enriched to the level of the TRR fuel, but he
provided no additional details (“Nuclear Chief: Iran Sees No Reason For Suspending Fordo Activities,” Iranian
Students’ News Agency, April 8, 2012).
Congressional Research Service
20
Iran’s Nuclear Program: Status
the reactor was converted to use LEU fuel in 1994 after Argentina agreed to supply the reactor
with such fuel in 1987.115 Fereydun Abbasi-Davani, then-President of the Atomic Energy
Organization of Iran, stated in a 2012 interview that once Iran had “enough” uranium enriched to
this level, the country would use its enrichment facilities to produce enriched uranium containing
3.5% uranium-235.116
Centrifuge Research and Development
Iran has tested several types of more-advanced centrifuges in the pilot facility; these centrifuges
could increase the other enrichment facilities’ capacity.117 Tehran has altered this facility to
comply with the JCPOA’s limits on Iranian centrifuge research and development.118 Iran’s
development of new centrifuges has apparently been less successful than development of the IR-1
centrifuge;119 past estimates from Iranian officials regarding the deployment of more-advanced
centrifuges have been excessively optimistic.120 According to a 2012 report from a U.N. panel of
experts, the advanced centrifuge program’s lack of success may have been “the result of sanctions
limiting” Tehran’s “ability to procure items necessary for its centrifuge programme,” as well as
“[o]ther variables, including design and manufacturing limitations, or a shortage of other
necessary materials.”121
The JCPOA contains a detailed description of centrifuge research and development (R&D) that
Iran is permitted to conduct under the agreement. Iran is to conduct centrifuge R&D with uranium
only at the Natanz pilot facility and will conduct mechanical testing of centrifuges only at the
pilot facility and the Tehran Research Centre. Iran submitted an “enrichment R&D plan” to the
IAEA in January 2016 as part of Tehran’s initial declaration for its Additional Protocol.122 Iranian
adherence to that plan is a JCPOA requirement. Beginning in September 2019, Iran has installed,
115 This information is contained in a February 18, 2010, letter from Iran to the IAEA (GOV/INF/2010/5). An undated
paper from an AEOI official places the conversion date at November 1993 (Mohammad Zaker, “Conversion and Start
Up of Tehran Research Reactor with LEU Fuel,” no date given. Available at http://www.iaea.org/inis/collection/
NCLCollectionStore/_Public/35/044/35044382.pdf).
116 Iranian Students’ News Agency, April 8, 2012.
117 Iran has experimented with a variety of advanced centrifuges. A June 2009 report from ElBaradei states that Iran
was testing four other more-advanced centrifuges; Iran informed the IAEA in February 2012 that it intended to install
three new types of centrifuges, according to a 2012 IAEA report (Implementation of the NPT Safeguards Agreement
and Relevant Provisions of Security Council Resolutions in the Islamic Republic of Iran, Report by the Director
General, GOV/2012/9, February 24, 2012). Iran’s IR-2m could “improve the enrichment of the Iranian centrifuges
threefold,” according to a 2012 Israeli intelligence report (Report 9342, Iran/Nuclear/Program Status, October 22,
2012. Available at http://www.aljazeera.com/news/2015/02/leaks-netanyahu-misled-iran-nuclear-programme-guardianiran-nuclear-speech-2012-150218165622065.html).
118 Verification and Monitoring in the Islamic Republic of Iran in Light of United Nations Security Council Resolution
2231 (2015), Report by the Director General, GOV/INF/2016/1, January 16, 2016.
119 Analyst interview with U.S. official, June 25, 2009; “Iran May Be ‘Struggling’ with New Nuclear Machines,”
Reuters, February 28, 2012.
120 For example, then-Atomic Energy Organization President Aghazadeh indicated in February 2009 that at least one
new type of centrifuge would be installed in the “near future” (Islamic Republic of Iran News Network, February 25,
2009). Then-Atomic Energy Organization President Ali Akbar Salehi stated in a December 2009 interview that Iran
hoped to have the new types of centrifuges operational by early 2011 (“Iran to Produce New Generation of
Centrifuges—Nuclear Chief,” Fars News Agency, December 18, 2009).
121 Final Report of the Panel of Experts Established Pursuant to Resolution 1929 (2010), June 12, 2012.
122 Verification and Monitoring in the Islamic Republic of Iran in Light of United Nations Security Council Resolution
2231 (2015), Report by the Director General, GOV/2016/8, February 26, 2016.
Congressional Research Service
21
Iran’s Nuclear Program: Status
as well as begun testing with uranium hexafluoride, quantities and types of advanced centrifuges
at this facility in violation of its JCPOA commitments.123
Fordow Enrichment Facility124
In December 2011, Iran began enriching uranium up to 20% uranium-235 in the Fordow Fuel
Enrichment Plant, according to IAEA reports. As of November 1, 2013, Iran was feeding uranium
hexafluoride into four cascades (696 centrifuges) of IR-1 centrifuges125 and had installed a total
of 2,710 IR-1 centrifuges in the facility. Tehran had planned to install a total of 16 cascades
containing approximately 3,000 centrifuges. Tehran told the IAEA that the facility would be
configured to produce both uranium enriched to 5% uranium-235 and 20% uranium-235. Iran
also told the IAEA that “the facility could be reconfigured to contain centrifuges of more
advanced types should Iran take a decision to use such centrifuges in the future.”126
Iran agreed under the JCPOA to convert the facility into “a nuclear, physics, and technology
centre.” Pursuant to this commitment, Iran decreased the number of IR-1 centrifuges to 1,044 and
removed all nuclear material from the facility. Beginning in November, however, Iran transferred
uranium hexafluoride to the facility and began enriching uranium in two cascades, each of which
contain 174 IR-1 centrifuges; the JCPOA prohibits both of these activities.127
Pursuant to its JCPOA commitments, Iran has modified two cascades “for the production of
stable isotopes” for medical and industrial uses.128 However, the Russian company TVEL stated
on December 6 that it had cancelled its work on these modifications, which the company had
conducted since 2017, because Iran had begun in November to feed uranium hexafluoride into
other cascades in the same facility (see below). “Uranium enrichment and stable medical isotope
production cannot be sustained in the same room,” the statement explained, adding that “[a]ir and
equipment are exposed to [uranium hexafluoride] leftovers, making the produced stable medical
isotopes unsuitable for medical purposes.”129 Russian and Iranian officials have stated that the
two governments are attempting to resolve this issue.130 According to an article published
December 9, Kamalvandi stated that Iran “can continue production of stable isotopes even
123 GOV/2019/55; Verification and Monitoring in the Islamic Republic of Iran in Light of United Nations Security
Council Resolution 2231 (2015), Report by the Acting Director General, GOV/INF/2019/10, September 8, 2019.
124 Unless otherwise noted, this section is based on a September 21, 2009, letter from Iran to the IAEA and September
25, 2009, background briefings from U.S. officials, along with associated Obama Administration talking points. See
also CRS Report R43333, Iran Nuclear Agreement.
125 GOV/2012/23.
126 GOV/2009/74.
127 GOV/2019/55.
128 GOV/INF/2016/1. An AEOI official announced in late August 2016 that Iran had opened a “semi-industrial unit” at
its uranium conversion facility in order to “produce raw materials for stable isotopes” (“Iran Opens Stable Isotope
Materials Production Unit,” Mehr News Agency, August 29, 2016).
129 “TVEL Company Statement Regarding Fordow Project, Iran,” December 6, 2019.
130 “Iran Says Talks With Russia on Stable Isotopes in Progress,” Fars News Agency, December 5, 2019. “Russia to
Analyze Impact of U.S. Restrictions on Fordow Nuclear Project – Senior Diplomat,” ITAR-TASS, December 5, 2019. A
Chair’s statement following a December 6 meeting of the JCPOA-established Joint Commission explained that the
remaining JCPOA parties “expressed strong support to the efforts of Russia to continue implementation of the stable
isotope project.” (Chair’s Statement Following the 6 December Meeting of the Joint Commission of the JCPoA,
December 6, 2019.)
Congressional Research Service
22
Iran’s Nuclear Program: Status
without the Russians,” adding that Tehran is “building a center” at the Fordow facility “which
will be constructed a few months later to produce stable isotopes without using centrifuges.”131
As noted, Iran revealed in September 2009 that it had been constructing the facility. That same
month, Tehran provided some details about the facility to the IAEA. The United States had been
“observing and analyzing the facility for several years,” according to September 25, 2009, Obama
Administration talking points, which added that “there was an accumulation of evidence” earlier
in 2009 that the facility was intended for enriching uranium.132 Some of this evidence apparently
indicated that “Iran was installing the infrastructure required for centrifuges earlier” in 2009.133
U.S. officials have not said exactly when Iran began work on the facility, which is “located in an
underground tunnel complex on the grounds of an Islamic Revolutionary Guard Corps” base near
the Iranian city of Qom. Nevertheless, the Atomic Energy Organization of Iran (AEOI), rather
than the Iranian military, is responsible for the development and management of the facility,
according to the September 2009 U.S. talking points described above.134 According to a
November 2009 report from then-IAEA Director-General ElBaradei, Iran informed the IAEA that
construction on the site began in the second half of 2007.135 However, citing information in its
possession that appears to contradict Tehran’s claim, the IAEA asked Iran to provide more
information about the facility’s chronology.136
U.S. officials suggested that the facility may have been part of a nuclear weapons program.
President Obama stated on September 25, 2009, that “the size and configuration of this facility is
inconsistent with a peaceful program.” But the Administration’s talking points were somewhat
more vague, stating that the facility “is too small to be viable for production of fuel for a nuclear
power reactor,” although it “could be used” for centrifuge research and development or
“configured to produce weapons-grade uranium.”137 The facility “would be capable of producing
approximately one weapon’s worth” of HEU per year, according to the talking points.138
Iran’s failure to inform the IAEA of the Fordow plant’s existence until well after Tehran had
begun constructing it raised concerns that the country may have had other covert nuclear
facilities. A November 2009 IAEA Board of Governors resolution stated that Iran’s declaration of
the Fordow facility “reduces the level of confidence in the absence of other nuclear facilities and
gives rise to questions about whether there are any other [undeclared] nuclear facilities under
construction in Iran.” Furthermore, then-UK Foreign Office Minister Alistair Burt told Parliament
in February 2012 that the Fordow facility “which Iran initially kept secret from the IAEA, also
131 “AEOI Spokesman: Iran Capable of Producing Stable Isotopes Without Russia’s Help,” Fars News Agency,
December 9, 2019.
132 “Q&A on the Qom Enrichment Facility,” September 25, 2009, available at
https://www.iranwatch.org/sites/default/files/us-wh-qomqandas-0909.pdf.
133 A 2011 Fact Sheet from the State Department indicates that construction on the facility began as early as 2006 (U.S.
Department of the Treasury, “Fact Sheet: E.O. 13382 Designations on Iran,” November 21, 2011).
134 “Q&A on the Qom Enrichment Facility,” September 25, 2009.
135 GOV/2009/74.
136 Majlis speaker Ali Larijani, who was formerly Iran’s lead nuclear negotiator, indicated that Iran had been
constructing the facility for approximately three years. (“Iran Speaker Says Country has Fully Mastered Nuclear
Technology,” Islamic Republic News Agency, September 27, 2009.)
137 “Q&A on the Qom Enrichment Facility,” September 25, 2009.
138 Ibid. Such estimates depend on several variables, including the number and type of centrifuges used, as well as the
degree to which the uranium hexafluoride feedstock is enriched. This particular estimate appears to assume the use of
3,000 IR-1 centrifuges; the other assumed parameters are unclear. For more information on the facility’s potential
weapons-grade HEU production capability, see Iran’s Nuclear, Chemical and Biological Capabilities: A Net
Assessment, February 2011, p. 67.
Congressional Research Service
23
Iran’s Nuclear Program: Status
raises our concerns that there may also be other, undeclared sites in Iran that could be engaged in
work” related to nuclear weapons.139
Tehran’s shifting explanations regarding the facility’s purpose also raised concerns that Iran
would, in the future, use the facility to produce fissile material for nuclear weapons. Iran’s 2009
letter to the IAEA described the Fordow facility as a “new pilot fuel enrichment plant” that would
produce uranium enriched to no higher than 5% uranium-235. Tehran subsequently changed the
plant’s stated purpose several times. For example, Tehran, as noted, later told the IAEA that the
facility would be configured to produce both uranium enriched to 5% uranium-235 and 20%
uranium-235. Apparently suggesting that Iran might later produce uranium containing higher
levels of uranium-235, a U.S. official told the IAEA Board of Governors on March 8, 2012, that
“[w]e cannot help but wonder ... whether Iran has finally informed us of the ultimate purpose of
this facility.”140
For its part, Iran has asserted that the facility is for peaceful purposes and that the government has
acted in accordance with its international obligations. As noted, Tehran argued that it was
producing enriched uranium containing up to 20% uranium-235 for use as fuel in research
reactors, to be used to produce isotopes for medical purposes. Regarding the facility’s secret
nature, Iranian officials argued that Tehran was not previously obligated to disclose it to the
IAEA141 and stated on several occasions that the facility was concealed to protect it from military
attacks.142 Iran told the IAEA in 2009 that the Fordow facility was to serve as a “contingency
enrichment plant, so that the enrichment activities shall not be suspended in the case of any
military attack.”143 The Natanz commercial facility “was among the targets threatened with
military attacks,” Iran explained.144 Iranian officials stated during a June 2012 meeting with the
P5+1 that the Fordow facility is “not a military base” and is “not located on a military base.”145
Enriched Uranium Containing Nearly 20% Uranium-235
As noted, Iran argued that it was producing LEU containing nearly 20% uranium-235 for use in
research reactors; as of January 20, 2014, when the Joint Plan of Action (JPA) went into effect,
Tehran had used the Natanz pilot facility and the Fordow facility to produce a total of 447.8
kilograms of uranium hexafluoride containing up to 20% uranium-235.146 Iran’s production of
uranium enriched to this level has caused concern because such production requires
approximately 90% of the effort necessary to produce weapons-grade HEU, which contains about
90% uranium-235.147 If further enriched, this amount of material would have been sufficient for a
139 “Written Answers to Questions,” Daily Hansard, February 7, 2012.
140 “U.S. Statement to the Board of Governors on Iran,” March 8, 2012.
141 For more information, see CRS Report R40094, Iran’s Nuclear Program: Tehran’s Compliance with International
Obligations, by Paul K. Kerr.
142 See, for example, “Iranian Nuclear Negotiator Says 5+1 Talks ‘Positive,’” Islamic Republic of Iran News Network,
October 1, 2009.
143 GOV/2009/74.
144 Ibid.
145 “Full Text of Iran’s Proposals to Six World Powers in Moscow Talks,” Fars News Agency, July 7, 2012. Rouhani
argued in February 2005 that Iran could enrich uranium “under mountains,” explaining that “[i]f we go there, no
American bomb or missile can be effective.” “Iranian Official Rowhani Gives Interview, Discusses Talks With EU,
Criticizes U.S.,” Tehran Vision of the Islamic Republic of Iran Network 2, February 7, 2005.
146 GOV/2014/10.
147 Former IAEA Deputy Director General Olli Heinonen, “Dealing with a Nuclear Iran: Redlines and Deadlines,”
Center for Strategic and International Studies, February 6, 2013; U.S. Secretary of Energy Ernest Moniz, Senate
Congressional Research Service
24
Iran’s Nuclear Program: Status
nuclear weapon. Iran would need approximately 215 kilograms of uranium hexafluoride
containing 20% uranium-235 to produce approximately 27.8 kilograms of uranium containing
90% uranium-235—a sufficient amount of weapons-grade HEU for a nuclear weapon.148 This is a
conservative estimate; the specific characteristics of Iran’s enrichment facilities may necessitate
using more than 215 kilograms of such material. Then-Director of National Intelligence James
Clapper suggested during a February 16, 2012, Senate Armed Services Committee hearing that “a
number of factors” could impede Tehran’s ability to produce weapons-grade HEU from uranium
enriched to 20% uranium-235.149
As of January 20, 2014, approximately 160 kilograms of the LEU described above was in the
form of uranium hexafluoride and, therefore, available to be further enriched in the near term.150
Since that date, Iran has either converted much of that material for use as fuel in the Tehran
Research Reactor or prepared it for that purpose.151 Iran diluted the rest of that stockpile so that it
contained no more than 5% uranium-235. AEOI spokesperson Kamalvandi said in February 2014
that Iran had “the necessary reservoirs of fuel for 5 years for the Tehran research reactor.”152
Future Centrifuge Facilities
Iranian officials indicated in the past that Tehran intended to construct 10 additional centrifuge
plants—a goal that many analysts argued was virtually unachievable. Then- Atomic Energy
Organization (AEOI) President Ali Akbar Salehi stated in 2009 that Iran is investigating locations
for the sites. (Salehi was president of the organization from 2009 to 2010; he became president
again in August 2013.)153 In 2012, then-AEOI President Abbasi argued that “mastering”
centrifuge enrichment technology would enable Iran to “develop [centrifuge] sites in various
locations to avoid any threat by foreign enemies.” According to the JCPOA, Iran is to enrich
uranium only at the Natanz commercial facility for 15 years.154 Expiration of the agreement’s
enrichment restrictions will be “followed by gradual evolution, at a reasonable pace” of Iran’s
enrichment program. According to the JCPOA, Iran’s centrifuge-testing program may proceed
under strict limits, which will begin to ease approximately eight years after the beginning of the
agreement’s implementation. An AEOI spokesperson stated in January 2016 that Iran’s nuclear
Committee on Armed Services, “Impacts of the Joint Comprehensive Plan of Action (JPCOA) on U.S. Interests and the
Military Balance in the Middle East,” July 29, 2015.
148 This number of nuclear weapons assumes that 25 kilograms of uranium-235 (approximately 27.8 kilograms of
uranium containing 90% uranium-235) would be necessary for one HEU-based nuclear weapon. The IAEA term for
this amount of uranium is “significant quantity,” defined as the “approximate amount of nuclear material for which the
possibility of manufacturing a nuclear explosive device cannot be excluded.” Some types of weapons could be
developed using less uranium-235.
149 “Current and Future Worldwide Threats to the National Security of the United States,” Senate Armed Services
Committee, February 16, 2012.
150 GOV/2014/10. In addition to the 43 kilograms of this material that is being prepared for use as fuel, Iran has altered
another 1.6 kilograms of the material, which now contains less than 5% uranium-235.
151 This process has generated scrap that contains LEU with up to 20% uranium-235. Iran also retains 0.6 kilograms of
uranium hexafluoride containing up to 20% uranium-235, which “had been used as reference material for mass
spectrometry” (Implementation of the NPT Safeguards Agreement and Relevant Provisions of Security Council
resolutions in the Islamic Republic of Iran, Report of the Director General, International Atomic Energy Agency,
GOV/2015/34, May 29, 2015).
152 Sara Massoumi, Hamed Shafiei, “20% Enrichment Is Not Iran’s Need Today,” Iranian Diplomacy, February 8,
2014.
153 Fars News Agency, December 18, 2009.
154 After 10 years Iran may produce enriched uranium at the pilot centrifuge facility as part of R&D work.
Congressional Research Service
25
Iran’s Nuclear Program: Status
program “will begin to accelerate from the 13th or 14th year onwards,”155 adding that Tehran plans
to increase its enrichment capacity by approximately “20-fold” by the end of the 15th year.156 Iran
plans to produce enough enriched uranium to fuel five or six nuclear reactors, Deputy Foreign
Minister Araqchi stated in August 2015.157
AEOI spokesperson Kamalvandi explained in June 2018 that Iran would begin the process of
“manufacturing and assembly of centrifuge rotors,” which are critical components of such
machines.158 Iran “will begin building a centrifuge rotor plant,” he noted.159 In addition, Salehi
announced in June that Iran has completed building a centrifuge assembly center in the Natanz
facility; Tehran had not previously disclosed this facility publicly.160 The facility’s completion
“does not mean that we are going to produce these centrifuges now,” Salehi said in September
2018, adding that the facility provides Iran with the capability to mass-produce such centrifuges,
should the government decide to do so.161 Feruță’s November 2019 report indicates that Tehran is
manufacturing centrifuges in violation of the JCPOA.162
Inconsistent Progress
A senior U.S. intelligence official said in 2007 that a country needs to be able to “operate large
numbers of centrifuges for long periods of time with very small failure rates” in order to be able
to “make industrial quantities of enriched uranium.”163 Iran’s record indicates that the country has
not always met this standard. The 2007 National Intelligence Estimate stated that Iran still faced
“significant technical problems operating” its centrifuges. Although a 2008 report to Congress
submitted by the Deputy Director for National Intelligence described the amount of LEU that Iran
produced in 2008 as a “significant improvement” over the amount it had produced during the
previous year,164 data from an August 2015 Institute for Science and International Security report
indicate that the average per-centrifuge performance at that facility peaked in 2010 and
subsequently fluctuated.165
The extent to which Iran’s progress is sustainable is open to question. Former Pakistani nuclear
official Abdul Qadeer Khan described Pakistan’s first-generation centrifuges as “unsuccessful” in
155 Specifically, the JCPOA states that “Iran will commence, upon start of implementation of the JCPOA,” testing of
Iran’s IR-6 and IR- 8 centrifuges “on single centrifuge machines and its intermediate cascades and will commence the
testing of up to 30 centrifuges machines from one and a half years before the end of year 10. Iran will proceed from
single centrifuges to small cascades to intermediate cascades in a logical sequence.”
156 Interview with Behruz Kamalvandi, January 11, 2016.
157 “AEOI: Iran Starts Injecting UF6 into IR-8 Centrifuges,” Fars News Agency, January 28, 2017.
158 “Nuclear Chief: Iran To Start New Centrifuge Production In Natanz Tomorrow,” Fars News Agency, June 5, 2018.
159 “Iran to Inform IAEA of Plan to Boost Enrichment —Fuller Report,” Iranian Students’ News Agency, June 4, 2018.
160 “Iran Completes Facility to Build Advanced Centrifuge,” Islamic Republic of Iran Broadcasting, July 18, 2018.
161 Jon Gambrell and Nasser Karimi, “AP Interview: Iran Nuclear Chief Hopes Deal Will Survive,” The Associated
Press, September 11, 2018.
162 GOV/2019/55. Specifically, Iran has produced components to “manufacture centrifuges … for activities beyond
those specified in the JCPOA, such as the installation of the new cascades” at the Natanz Pilot Facility.
163 Background briefing with senior intelligence officials, December 3, 2007.
164 Unclassified Report to Congress on the Acquisition of Technology Relating to Weapons of Mass Destruction and
Advanced Conventional Munitions, Covering 1 January to 31 December 2008.
165 David Albright, Serena Kelleher-Vergantini, Andrea Stricker, and Daniel Schnur, ISIS Analysis of the IAEA Iran
Safeguards Report, Institute for Science and International Security, August 27, 2015. Calculating the average
performance of Iran’s centrifuges became more difficult after November 2010, when the IAEA stopped reporting
information about the Natanz commercial facility’s average product enrichment level.
Congressional Research Service
26
Iran’s Nuclear Program: Status
a 1998 interview.166 Furthermore, Mark Fitzpatrick of the International Institute for Strategic
Studies observed that “[i]t can be years before it is clear whether an enrichment programme is
working well,” observing that centrifuges at a Japanese enrichment facility “started to crash seven
years after installation.”167 And, as noted, Iran has struggled to develop and deploy moreadvanced centrifuges. Nevertheless, historical experience indicates that sustained operation of gas
centrifuges appears to be a manageable task for governments with even modest technical
capabilities.168 According to a U.S. Nuclear Regulatory Commission document, some centrifuges
of simple design “have operated 30 years with a failure rate of less than one percent.”169 (See also
“Effects of Sanctions and Sabotage on Iran’s Enrichment Program.”)
Uranium Conversion
As noted, uranium conversion is a process whereby uranium ore concentrate is converted into
several compounds, including uranium hexafluoride—the feedstock for Iran’s centrifuges. Iran
produced approximately 541 metric tons of uranium hexafluoride between March 2004 and
August 10, 2009, using both imported uranium ore concentrate and domestically produced
uranium ore concentrate.170 Iran has not produced any uranium hexafluoride since August 2009,
according to IAEA reports, although Tehran has transferred domestically produced uranium ore
concentrate to the uranium conversion facility. The 2012 U.N. Panel of Experts report concluded
that, based on data from Amano’s February 2012 report, Iran had “an ample supply of uranium
hexafluoride to maintain current levels of enrichment for the foreseeable future.”171 On June 27,
2018, Iran’s official news agency announced that Iran has resumed operations at the conversion
facility.172
According to a report from the Director of National Intelligence to Congress covering 2011, Iran
had “almost exhausted” its supply of imported uranium ore concentrate.173 Tehran apparently did
not import any more such material prior to December 2015. According to the 2012 U.N. Panel of
Experts report, “a number” of governments believed that Tehran was “seeking new sources of
uranium ore to supply its enrichment efforts”; the report added that “the Panel is not aware of any
confirmed cases of actual transfers.”174 British Foreign and Commonwealth Office official Tobias
Ellwood informed Parliament in June 2015 that the British government was “not aware of” any
166 “A Talk with A.Q. Khan: Pakistan’s Top Nuclear Scientist Talks About Nuclear Weapons,” Jane’s Foreign Report,
July 24, 1998.
167 Mark Fitzpatrick, The Iranian Nuclear Crisis: Avoiding Worst-Case Outcomes, Adelphi Paper 398, International
Institute for Strategic Studies, May 2008, p. 50.
168 R. Scott Kemp, “The Nonproliferation Emperor Has No Clothes: The Gas Centrifuge, Supply-Side Controls, and the
Future of Nuclear Proliferation,” International Security, Spring 2014, vol. 38, no. 4, pp. 39-78.
169 USNRC Technical Training Center: Uranium Enrichment Processes, Module 4.0 of the Uranium Enrichment
Processes Directed Self-Study Course 9/08 (Rev 3), Directed Self Study. The document appears to have been published
in 2008.
170 Based on data from GOV/2009/74. Iran imported 531 metric tons of uranium ore concentrate in 1982, according to
Implementation of the NPT Safeguards Agreement in the Islamic Republic of Iran, Report by the Director General,
GOV/2003/75, November 10, 2003.
171 Panel of Experts, 2012.
172 “Iran UF6 Factory Resumes Work,” Islamic Republic News Agency, June 27, 2018.
173 Unclassified Report to Congress on the Acquisition of Technology Relating to Weapons of Mass Destruction and
Advanced Conventional Munitions, Covering 1 January to 31 December 2011.
174 Panel of Experts, 2012.
Congressional Research Service
27
Iran’s Nuclear Program: Status
recent reports that Iran had attempted to purchase foreign uranium.175 Former State Department
official Richard Nephew wrote in September 2015 that there had “not been any verified transfer
of uranium to Iran aside from fuel for the Bushehr power reactor.”176 In late December 2015, Iran
imported between 200 and 220 metric tons of uranium ore concentrate in exchange for LEU that
Iran shipped to Russia in order to reduce its stockpile to JCPOA-required levels.177 The IAEA
verified Iran’s receipt in February 2017 of approximately 125 metric tons of uranium ore
concentrate.178 During March 2017, Iranian officials stated that the country had imported between
382 and 384 metric tons of this material since concluding the JCPOA.179 The imported uranium
ore concentrate is to serve as fuel for the Bushehr reactors, according to Iranian officials.180
Prior to 2009, Tehran apparently improved its ability to produce centrifuge feedstock of sufficient
purity for light-water reactor fuel; information in a 2010 IAEA report indicated that Iran was
purifying its centrifuge feedstock.181 Whether Iran is currently able to produce feedstock pure
enough for weapons-grade HEU is unclear, however.
Plutonium
Iran acknowledged to the IAEA in 2003 that it had conducted plutonium-separation
experiments—an admission that contributed to suspicions that Iran could have a program to
produce plutonium for nuclear weapons. The IAEA, however, continued to investigate the matter;
then-IAEA Director-General ElBaradei reported in August 2007 that the agency had resolved its
questions about Iran’s plutonium activities.182 As noted above, Iran has said that it does not plan
to engage in reprocessing, and then-IAEA Director-General Amano’s November 2011 report
described an “absence of any indicators that Iran is currently considering reprocessing irradiated
nuclear fuel to extract plutonium.”183 Amano’s November 2015 report states that the agency could
“confirm that there are no ongoing reprocessing related activities” at the Iranian facilities to
which the agency has access.184
175 Iran: Nuclear Weapons: Written Question-1913. Answered by Tobias Ellwood on June 15, 2015.
176 Richard Nephew, “How the Iran Deal Prevents a Covert Nuclear Weapons Program,” Arms Control Today,
September 2015.
177 Interview with Behruz Kamalvandi, January 11, 2016. “Atomic Chief: Iran Completes Swap of Surplus Enriched
Uranium with Russia,” Vision of the Islamic Republic of Iran Network,” December 29, 2015; Secretary of State John
Kerry,” Arms Control and International Security: An Update on Progress Toward Implementation Day of the JCPOA,”
December 28, 2015.
178 GOV/2017/10.
179 “Iran Plans to Buy 950 Tonnes of Yellowcake from Kazakhstan: Salehi,” IRIB News Agency, March 7, 2017; “Iran’s
Atomic Chief Calls Critics of Nuclear Deal ‘Unfair,’” IRIB News Agency, March 10, 2017.
180 “Iran to Use Russian Yellow Cake at Esfahan, Bushehr Sites—Official,” Iranian Young Journalists’ Club Website,
February 26, 2017.
181 IISS Strategic Comments, “Nuclear Iran: How Close Is It?,” September 2007; Paul Kerr, “Iran Continues Security
Council Defiance,” Arms Control Today, June 2007; analyst interview with State Department official October 28,
2008. 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,
GOV/2010/28, May 31, 2010. A footnote in the report states that some enriched uranium hexafluoride “was present in
the feed purification cylinder.”
182 Implementation of the NPT Safeguards Agreement in the Islamic Republic of Iran, Report by the Director General,
GOV/2007/48, August 30, 2007.
183 GOV/2011/65.
184 Ibid.
Congressional Research Service
28
Iran’s Nuclear Program: Status
The JCPOA prohibits Iran from reprocessing spent reactor fuel, except to produce “radio-isotopes
for medical and peaceful industrial purposes.” The JCPOA text states that Iran “does not intend”
to engage in reprocessing after the 15-year period expires and specifies Iran’s intention to
ship out all spent fuel for all future and present nuclear power and research reactors, for
further treatment or disposition as provided for in relevant contracts to be concluded
consistent with national laws with the recipient party.
According to the IAEA, Iran has adhered to this requirement.
Arak Reactor and Redesign185
Iran says that its reactor under construction at Arak is intended for the production of medical
isotopes and various other purposes. According to a 2008 presentation by Ambassador Soltanieh,
the reactor, which was originally designed to be moderated by heavy water, is to substitute for the
“outdated” Tehran Research Reactor (TRR), which has been in operation since 1967.186 As noted,
Iran subsequently decided to refuel the TRR. According to a 2012 AEOI report, the reactor has
several objectives:
a suitable replacement for the aging Tehran Research Reactor using local
engineers and scientist [sic] with the least dependency to foreign countries;
medical, industrial and research radioisotope production of [sic] the country;
performing research in the fields of neutron physics, reactor chemistry, thermalhydraulics, and health physics;
obtaining technological and scientific experience in design and construction of
nuclear reactors using local experts within the country;
training of specialists in the nuclear field; and
enhancing the technological levels of the local industries in design and
manufacturing of various components such as reactor vessels, heat exchangers,
pumps, etc. using nuclear standards.187
Iran told the IAEA in 2012 that the reactor was scheduled to begin operating during the second
half of 2013.188 The project was about 75% complete as of July 2011.189 Iran suspended several
aspects of the reactor’s construction pursuant to the 2013 Joint Plan of Action.190
The originally designed Arak reactor was a proliferation concern because its spent fuel would
have contained plutonium better suited for nuclear weapons than the plutonium produced by
light-water moderated reactors, such as the TRR and Bushehr reactor. The original Arak reactor, if
it had been completed, could have produced enough plutonium for between one and two nuclear
185 Iran informed the IAEA in April 2017 that Tehran was renaming the facility the “Khondab Heavy Water Research
Reactor.” (Verification and Monitoring in the Islamic Republic of Iran in Light of United Nations Security Council
Resolution 2231 [2015], Report by the Director General, International Atomic Energy Agency, GOV/2017/24, June 2,
2017).
186 “Iran’s Exclusively Peaceful Nuclear Programs and Activities,” Briefing for NGOs, May 5, 2008.
187 Nuclear Industry in Iran: An Overview on Iran’s Activities and Achievements in Nuclear Technology, Atomic
Energy Organization of Iran, 2012, p. 29.
188 GOV/2012/23.
189 Nuclear Industry in Iran, p. 29.
190 Iran pledged to refrain from commissioning the reactor, transferring fuel or heavy water to the reactor site, testing
and producing additional reactor fuel, and installing remaining reactor components.
Congressional Research Service
29
Iran’s Nuclear Program: Status
weapons per year.191 In addition, Iran would have been able to operate the reactor with natural
uranium and, therefore, would not have been dependent on supplies of enriched uranium.
The JCPOA requires Tehran to render the Arak reactor’s original core inoperable. Iran has met
this requirement.192 According to former U.S. officials Eric Brewer and Richard Nephew, “the
path to actually completing and starting” the Arak reactor according to its previous design “would
be a long and uncertain one.”193 The agreement also commits Tehran to redesign and rebuild the
Arak reactor based on a design agreed to by the P5+1 so that the reactor will not produce
weapons-grade plutonium. Tehran is “trying to complete the project in five years,” an AEOI
spokesperson said in January 2016.194 AEOI President Salehi stated in September 2016 that China
will supply the reactor’s first fuel load “in the next five-year time.”195 Iran will subsequently
produce the reactor fuel, he said. Iran is to export the spent fuel from this reactor and all other
nuclear reactors. In addition, the JCPOA requires Iran to refrain from building heavy-watermoderated reactors for 15 years, and Tehran has pledged to refrain from constructing any such
reactors indefinitely.
According to IAEA reports and Iranian officials, Iran began to operate its heavy-water production
plant located near Arak in August 2006.196 IAEA reports since the start of JCPOA implementation
indicate that the plant, which is to produce heavy water for the reactor and deuterated solvents, is
operating.197 Pursuant to the JCPOA, Tehran has committed to refrain from accumulating heavy
water “beyond Iran’s needs.” Iran is to “sell any remaining heavy water on the international
market for 15 years.” According to the agreement, these “needs” are 130 metric tons of “nuclear
grade heavy water or its equivalent in different enrichments” prior to commissioning the
redesigned Arak reactor and 90 metric tons after the reactor is commissioned.198
Iran’s stock of heavy water has exceeded 130 metric tons on three occasions since the JCPOA
began implementation. On February 17, 2016, the IAEA verified that Tehran’s heavy-water stock
had exceeded 130 metric tons; on November 8, 2016, the IAEA verified that Iran’s stock of heavy
water had again exceeded the JCPOA limit. Iran resolved the issue on both occasions by
exporting the excess heavy water. Tehran sent this material to Russia and the United States,
shipping at least some of it via Oman.199 Iran told the IAEA on June 18, 2017, that it had
transferred 19.1 metric tons of heavy water to a destination outside the country.200 According to
191 Colin Kahl, Deputy Assistant to the President and National Security Adviser to the Vice President, “Arms Control
Association Annual Meeting: Unprecedented Challenges for Nonproliferation and Disarmament,” May 14, 2015.
192 GOV/INF/2016/1.
193 Eric Brewer and Richard Nephew, “Seeing Red in Trump’s Iran Strategy,” Arms Control Today, July/August 2019.
194 Interview with Behruz Kamalvandi, January 11, 2016.
195 IRTV2, September 10, 2016.
196 “‘Peaceful’ Iran Has a Transparent Nuclear Program: Ahmadinejad; Arak Heavy Water Plant Launched,” Mehr
News Agency, August 26, 2006; “Iran’s Heavy Water Research Reactor Project on Track, Says Official,” Fars News
Agency, August 26, 2006. A 2005 IAEA report (GOV/2005/67) describes the plant as “currently being commissioned”;
a 2007 IAEA report (GOV/2007/8) states that the plant is operational.
197 Nuclear Industry in Iran, p. 27.
198 The plant has a “maximum annual capacity” of 20 metric tons, Iran informed the IAEA in 2017. A special assistant
to AEOI President Salehi asserted in October 2019 that the facility can produce “up to 25” metric tons of heavy water
annually (“Secondary Circuit of Iran’s Arak Nuclear Reactor to Be Operational Within Two Weeks: Official,” Reuters,
October 20, 2019).
199 Iran has also shipped “a smaller amount to other countries,” a spokesperson for Iran’s Atomic Energy Organization
said in March 2018 (“Iran to Unveil ‘Heavy Water Achievements’ on 9 April,” Fars News Agency, March 26, 2018).
200 Verification and Monitoring in the Islamic Republic of Iran in Light of United Nations Security Council Resolution
2231 (2015), Report by the Director General, International Atomic Energy Agency, GOV/2017/35, August 31, 2017.
Congressional Research Service
30
Iran’s Nuclear Program: Status
an April 2018 State Department report covering 2017, “[m]ost Iranian excess heavy water has
been sold and delivered to international buyers; the remainder is awaiting sale and is stored in a
location outside Iran, under IAEA seal, though it remains Iranian property.”201 Tehran has
continued to ship heavy water outside Iran.202 The IAEA verified on November 17, 2019, that Iran
had 131.5 metric tons of heavy water.203
Bushehr Reactor
Iran is also operating a 1,000-megawatt nuclear power reactor, moderated by light water, near the
city of Bushehr. The original German contractor, which began constructing the reactor in 1975,
abandoned the project following Iran’s 1979 revolution.204 Russia agreed in 1995 to complete the
reactor, but the project subsequently encountered repeated delays; both Russian and Iranian
officials attributed those delays to technical issues. In February 2005, Moscow and Tehran
concluded an agreement stating that Russia would supply fuel for the reactor for 10 years.
Atomstroyexport, a subsidiary of Rosatom, the Russian company, sent the first shipment of LEU
fuel to Iran on December 16, 2007, and the reactor received the last shipment near the end of
January 2008. The fuel, which is under IAEA seal, will contain no more than 3.62% uranium-235,
according to an Atomstroyexport spokesperson.205 An August 2014 IAEA inspection revealed that
the reactor “was operating at 100% of its nominal power.”206
Before 2002, the United States had urged Moscow to end the project, citing concerns that it could
aid an Iranian nuclear weapons program by providing the country with access to nuclear
technology and expertise.207 However, U.S. officials said in 2002 that Washington would drop
these public objections if Russia took steps to mitigate the project’s proliferation risks. The 2005
deal requires Iran to return the spent nuclear fuel to Russia.208 This measure is designed to ensure
that Tehran will not separate plutonium from the spent fuel. Moscow argues that the reactor will
The report does not name the heavy water’s destination.
201 Adherence to and Compliance with Arms Control, Nonproliferation, and Disarmament Agreements and
Commitments, Department of State, April 2018.
202 Verification and Monitoring in the Islamic Republic of Iran in Light of United Nations Security Council Resolution
2231 (2015), Report by the Acting Director General, GOV/INF/2019/17, November 18, 2019; GOV/2019/55.
203 GOV/INF/2019/17.
204 The contractor, Kraftwerk Union, completed about 85% of the first reactor and 55% of the second (“Iran’s Nuclear
Ambitions: Persistence Despite Manpower Problems,” Central Intelligence Agency Directorate of Intelligence, October
1986).
205 “Atomstroyexport Completes Latest Shipment of Fuel to Bushehr Nuclear Plant,” Interfax, December 28, 2007.
206 Implementation of the NPT Safeguards Agreement and Relevant Provisions of Security Council Resolutions in the
Islamic Republic of Iran, Report by the Director General, GOV/2014/43, September 5, 2014.
207 For example, then-Deputy Assistant Secretary of Defense Marshall Billingslea testified before the Senate on July
29, 2002, that the United States was “concerned that the Bushehr nuclear power project is, in reality, a pretext for the
creation of an infrastructure designed to help Tehran acquire atomic weapons.” Similar concerns are expressed in a
2005 State Department report (Adherence to and Compliance with Arms Control, Nonproliferation, and Disarmament
Agreements and Commitments, U.S. Department of State, August 2005, p.77.) Then-Under Secretary of State for
International Security and Arms Control John Bolton told the House International Relations Committee in June 2003
that Iran could build “over 80 nuclear weapons” if it had access to sufficient fuel, operated the reactor for five to six
years, and chose to withdraw from the NPT. During a June 12, 2008, House Foreign Affairs Committee hearing, thenActing Under Secretary of State for Arms Control and International Security John Rood agreed with a Department of
Energy assessment that the reactor’s spent fuel would contain enough plutonium for between 50 and 60 nuclear
weapons. These estimates assume that Iran possesses a reprocessing facility, which the country does not have.
208 Estimates for the length of time the spent fuel must stay in Iran to cool range from two to five years. See Paul Kerr,
“Iran, Russia Reach Nuclear Agreement,” Arms Control Today, April 2005.
Congressional Research Service
31
Iran’s Nuclear Program: Status
not pose a proliferation risk because it will operate under IAEA safeguards. It is worth noting that
light-water reactors are generally regarded as more proliferation-resistant than other types of
reactors. Although the U.N. Security Council resolutions restricted the supply of nuclear-related
goods to Iran, they did permit the export of nuclear equipment and fuel related to light-water
reactors.
Experts have expressed strong doubts regarding Iran’s ability to produce fuel for the reactor.209
According to a July 2014 Iranian government report, Russia and Iran may renew the fuel supply
agreement, but they are also “engaged in negotiations ... to engage in cooperative arrangements
for the domestic manufacturing of fuel for the facility after the expiration of the current
contract.”210 According to an interview published in April 2017, AEOI Deputy Director Pezhman
Rahimian stated that the two governments had almost completed a “road map” for such
manufacturing.211
Possible Future Reactors
Iran and Russia signed a contract in November 2014 for the construction of two additional lightwater nuclear power reactors in Bushehr, according to Rosatom, the Russian company.212 The
project’s construction began in September 2016 and is expected to take 10 years to complete.213 A
Rosatom official told the IAEA General Conference in September 2018 that “[p]ractical work to
build the second and third” Bushehr power plant units “has begun.”214 These reactors are to be in
operation by 2025 and 2027.”215
Iran was also “negotiating with China for building two 100 megawatt power plants,” Salehi
stated in a July 2015 speech.216 Iran informed the IAEA in an October 2017 letter that Tehran had
decided to “design and construct a critical facility (Light Water Critical Reactor) … for research
purposes in near future.” Iran “provided preliminary design information for the facility,” which
indicates that the reactor fuel is to contain “up to 3.67%” uranium-235.217
209 See, for example, Robert Einhorn, “Will Iran Play Ball in Nuke Talks?,” The National Interest, January 14, 2015.
210 What Are Iran’s “Practical Needs”?, NuclearEnergy.ir, July 2014.
211 Hadi Mohammadi: “Tehran Reactor's Fuel Is Entirely Made in Iran; Country's Yellow Cake Stockpile Has
Doubled,” Khorasan, April 8, 2017.
212 “The Foundation Stone Ceremony Held on the Bushehr Phase II Construction Site (Iran),” Communications
Department of ROSATOM, September 13, 2016. Available at http://tinyurl.com/jsc9z89.
213 Ibid. “Inauguration of Two New Power Plant Units Construction in Bushehr,” Atomic Energy Organization of Iran,
September 18, 2016. Available at http://tinyurl.com/h7bl7jl.
214 “Rosatom Starts Work at third Bushehr NPP Unit in Iran,” Interfax, September 17, 2018.
215 “Iran’s Two New Power Plant Units to Be Operational by 2027,” Vision of the Islamic Republic of Iran Network 1,
November 10, 2019. The second reactor “is scheduled to come on stream in 6 years, while the third unit will be
finished in 8 years,” according to a November Fars News Agency report (Iran’s Nuclear Electricity Capacity to Hit
3000 MW by 2027,” Fars News Agency, November 10, 2019).
216 “Excerpts of the Speech Presented by H.E Dr. A.A.Salehi, President’s Deputy and Head of AEOI in the Presence of
Organization’s Personnel,” July 20, 2015. Available at http://tinyurl.com/gllptz5.
217 GOV/2007/48.
Congressional Research Service
32
Iran’s Nuclear Program: Status
Fuel Manufacturing Facilities
Iran intended its fuel manufacturing plant to produce fuel for the Arak and Darkhovin reactors.218
The plant started the process of producing fuel for the pre-JCPOA Arak reactor.219 Iran’s Fuel
Plate Fabrication Plant has produced fuel for the Tehran Research Reactor.220
Uranium Mines and Mills
Iran has a uranium mill and a uranium mine located at a site called Bandar Abbas, which is
sometimes referred to as Gchine. Iran also has a uranium mine at a site called Saghand and an
associated uranium mill called the Ardakan Yellowcake Production Plant. Salehi stated in a
January 30, 2019, interview that Tehran plans to construct several more such mills. Iranian
officials acknowledge that the country’s uranium deposits are insufficient for its planned nuclear
power program.221 These reserves are sufficient, however, to produce 250-300 nuclear weapons,
according to a past U.S. estimate.222 Salehi indicated in February 2019 that Iran continues to
explore for uranium.223
Effects of Sanctions and Sabotage on Iran’s
Enrichment Program
A number of governments employed sanctions and, apparently, sabotage to impede Iran’s nuclear
program.
Sanctions
Iran has tried to improve its capabilities to produce materials and components for its centrifuge
program, according to former IAEA Deputy Director General Olli Heinonen.224 Some Iranian
officials have claimed that the country can manufacture centrifuges on its own. For example,
then-Iranian Ambassador to the IAEA Ali Asghar Soltanieh said in 2012 that Iran “has ‘fully
mastered’ the nuclear energy technology and can produce all the 90 pieces of a centrifuge
machine on its own and without foreign assistance.”225 However, other Iranian officials have
suggested that Tehran is not yet able to produce all of the necessary centrifuge components. ThenPresident of Iran’s Atomic Energy Organization Abbasi stated during a 2012 television broadcast
that “Iran could not claim that it did not need other countries” for its enrichment program, adding
that “domestic production of all items was not economically viable.”226 AEOI Director Salehi
218 “Aqazadeh: Iran Heralds Peaceful Nuclear Program,” Islamic Republic News Agency, April 8, 2008.
219 GOV/2015/65.
220 Ibid.
Installation of Centrifuges Continues in Natanz—Iran Nuclear Official,” Iranian Students’ News Agency, April 17,
2007; Thomas W. Wood, Matthew D. Milazzo, Barbara A. Reichmuth, and Jeffrey Bedell, “The Economics Of Energy
Independence For Iran,” Nonproliferation Review, vol. 14, No. 1, March 2007.
222 Paul Kerr, “Iran Nuclear Abilities Limited,” Arms Control Today, September 2005.
223 “Iran Opens Heavy Oxygen Isotope Plant,” FARS News Agency, February 5, 2019.
224 Analyst interview, January 18, 2012.
225 “Nuclear Official Stresses Iran’s Domestic Capability to Produce Centrifuge Machines,” FARS News Agency,
December 3, 2012.
226 “Nuclear Chief Says West Aware of Significance of Iran Achievements,” Vision of the Islamic Republic of Iran
221
Congressional Research Service
33
Iran’s Nuclear Program: Status
stated in 2014 that Iran was purchasing some items for its nuclear program “from some
developing and growing Eastern countries.”227
Non-Iranian sources also cast doubt on the self-sufficiency claims described above. A 2014 U.N.
Panel of Experts report observed that the “quality of such [Iranian-produced] equipment is not
known.”228 Moreover, then-Principal Deputy Assistant Secretary of State for International
Security and Nonproliferation Vann Van Diepen said that Iran in 2014 was still attempting to
“procure items” for the nuclear program.229 Nevertheless, according to the 2014 Panel of Experts
report, several governments told the panel that, since mid-2013, there had been a “been a decrease
in the number of detected [Iranian] attempts ... to procure items for prohibited programmes, and
related seizures.”230 A 2015 Panel of Experts report states that the panel had not “identified cases
of procurement for activities prohibited” by Security Council resolutions in force at the time.231
No governments reported any such cases, the report adds. It is worth noting that a special
assistant to AEOI President Salehi asserted in October 2019 that “[o]ne-hundred percent of Iran's
nuclear industry activities have been indigenized and today, we are self-sufficient in designing
and manufacturing various kinds of centrifuges”232
According to various sources, international sanctions complicated Iranian efforts to obtain
components and materials for its centrifuge program. For example, the U.N. Panel of Experts
2011 report stated that “sanctions are constraining Iran’s procurement of items related to
prohibited nuclear and ballistic missile activity and thus slowing development of these
programmes.”233 Similarly, the 2012 U.N. Panel of Experts report observed that “[s]anctions are
slowing the procurement by the Islamic Republic of Iran of some critical items required for its
prohibited nuclear programme.”234 A June 2013 report from the same panel suggested that this
condition still existed, arguing that “Iran’s reliance on procurement abroad continues to provide
the international community with opportunities to limit Iran’s ability to maintain and expand
certain activities.”235 Then-UK Foreign Secretary William Hague wrote in 2013 that “[w]e judge
that sanctions have been effective in slowing the nuclear programme to some degree.”236
U.S. officials have argued that the sanctions have impeded Iran’s ability to acquire technology for
its nuclear programs. Then-State Department Special Advisor for Nonproliferation and Arms
Control Robert Einhorn told a Washington audience in 2011 that “[w]e believe Iran has had
difficulty in acquiring some key technologies and we judge this has had an effect of slowing some
of its programs.”237 Similarly, then-National Security Adviser Tom Donilon argued in 2011 that
“[s]anctions and export control efforts have made it more difficult and costly for Iran to acquire
Network 2, February 15, 2012.
227 “Some in East Colluding with West in Iran Nuclear Sabotage: AEOI,” Press TV, August 25, 2014.
228 Final Report of the Panel of Experts Established Pursuant to Resolution 1929 (2010), June 11, 2014.
229 William Maclean, “Iran Pursuing Banned Items for Nuclear, Missile Work: U.S. Official,” Reuters, March 16, 2014.
230 Panel of Experts, 2014.
231 Final Report of the Panel of Experts Established Pursuant to Resolution 1929 (2010), June 2, 2015.
232 “Official: Iran’s Fordow Nuclear Site at Full Swing,” Fars News Agency, October 29, 2019.
233 Panel of Experts Established Pursuant to Resolution 1929 (2010): Final Report, June 2011.
234 Panel of Experts, 2012.
235 Final report of the Panel of Experts Established Pursuant to Resolution 1929 (2010), June 5, 2013.
236 Letter to Richard M. Ottaway MP, May 14, 2013.
237 Robert J. Einhorn, “The Impact of Sanctions on Iran’s Nuclear Program,” Arms Control Association, March 9,
2011.
Congressional Research Service
34
Iran’s Nuclear Program: Status
key materials and equipment for its enrichment program, including items that Iran can’t produce
itself.”238
However, the extent to which sanctions slowed Tehran’s program is unclear. Donilon also cited
“mistakes and difficulties in Iran” as obstacles to the program’s progress. Former IAEA Deputy
Director General Heinonen stated that “[w]e do not know” whether Iran’s delays in deploying
advanced centrifuges are attributable to “lack of raw materials or design problems,” according to
a 2012 press report.239 Furthermore, reports from the Office of the Director of National
Intelligence covering 2009-2011 stated that “some obstacles slowed” the progress of Iran’s
nuclear program during those years, but the report did not name those obstacles.240
Sabotage
The extent to which alleged efforts by the United States and other governments, including
Israel’s, to sabotage Iran’s centrifuge program have affected Tehran’s nuclear program is unclear.
The New York Times reported in 2009 that such efforts have included “undermin[ing] electrical
systems, computer systems and other networks on which Iran relies,” according to unnamed
senior U.S. and foreign government officials.241 One effort involved foreign intelligence services
sabotaging “individual power units that Iran bought in Turkey” for Tehran’s centrifuge program.
“A number of centrifuges blew up,” according to the Times.242 Western governments have
reportedly made other efforts to sabotage centrifuge components destined for Iran, according to
some nongovernmental experts.243 Iranian officials have asserted that Western countries have
tampered with components in transit to Iran’s enrichment facilities, directly sabotaged those
facilities, and conducted espionage in the country.244 In addition, New York Times reporter James
Risen wrote in 2006 that, according to unnamed U.S. officials, the United States engaged in a
covert operation to provide Iran with flawed blueprints for a device designed to trigger a nuclear
explosion.245
The United States and Israel have also reportedly executed cyberattacks on Iran’s nuclear
facilities. Perhaps the best known of these used the Stuxnet computer worm, which was
discovered in 2010 and probably developed by a government to attack Iran’s enrichment
238 Tom Donilon, “Iran and International Pressure: an Assessment of Multilateral Effort to Impede Iran’s Nuclear
Program,” The Brookings Institution, November 22, 2011.
239 “Iran May Be ‘Struggling’ with New Nuclear Machines,” Reuters, February 28, 2012.
240 Unclassified Report to Congress on the Acquisition of Technology Relating to Weapons of Mass Destruction and
Advanced Conventional Munitions, Covering 1 January to 31 December 2009; Unclassified Report to Congress on the
Acquisition of Technology Relating to Weapons of Mass Destruction and Advanced Conventional Munitions, Covering
1 January to 31 December 2010; Unclassified Report to Congress on the Acquisition of Technology Relating to
Weapons of Mass Destruction and Advanced Conventional Munitions, Covering 1 January to 31 December 2011.
241 David E. Sanger, “U.S. Rejected Aid for Israeli Raid on Nuclear Site,” New York Times, January 11, 2009.
242 David E. Sanger and William J. Broad, “U.S. Sees an Opportunity to Press Iran on Nuclear Fuel,” New York Times,
January 3, 2010. Iranian officials alluded to this incident, according to a January 2007 Iranian press report (Ayande-ye
Now, January 6, 2007).
243 James Blitz, Roula Khalaf, and Daniel Dombey, “Suggestions of Iran Nuclear Sabotage,” Financial Times, July 22,
2010.
244 “Iran Atomic Energy Officials Discuss ‘Thwarted’ Nuclear ‘Sabotage’ Attempts,” Tehran Hamshahri Online,
September 6, 2014. Foreign Minister Zarif stated that there had been no such sabotage since concluding the JCPOA
(“Zarif Series: On the Nuclear Deal, US Relations,” July 19, 2017. Available at
http://iranprimer.usip.org/blog/2017/jul/19/zarif-series-nuclear-deal-us-relations).
245 James Risen, State of War: The Secret History of the CIA and the Bush Administration (New York: Free Press),
2006.
Congressional Research Service
35
Iran’s Nuclear Program: Status
facilities.246 Some governments have reportedly assassinated Iranians associated with Iran’s
nuclear program.247 The United States also may have obtained information from Iranian officials
who defected as part of a CIA program to induce them to do so.248
Nuclear Weapon Development Capabilities
Statements from the U.S. intelligence community indicate that Iran has the technical capability to
produce nuclear weapons. For example, the 2007 National Intelligence Estimate (NIE) assessed
that “Iran has the scientific, technical and industrial capacity eventually to produce nuclear
weapons if it decides to do so.”249 More recently, then-Director of National Intelligence Clapper
stated during a February 2016 Senate Armed Services Committee hearing that Iran “does not face
any insurmountable technical barriers to producing a nuclear weapon.”250
Obtaining fissile material is widely regarded as the most difficult task in building nuclear
weapons. As noted, Iran is enriching uranium, but whether and to what extent Tehran has taken
the other steps necessary for producing a nuclear weapon is unclear. A 2008 report from former
IAEA Director-General ElBaradei points out that the IAEA, with the exception of a document
related to uranium metal, has “no information ... on the actual design or manufacture by Iran” of
components, nuclear or otherwise, for nuclear weapons.251 However, according to then-IAEA
Director-General Amano’s November 2011 report, the IAEA has “credible” information that Iran
has carried out activities “relevant to the development of a nuclear explosive device.”252 These
include acquisition of “nuclear weapons development information and documentation” and work
to develop “an indigenous design of a nuclear weapon including the testing of components.”
Although some of these activities have civilian applications, “others are specific to nuclear
weapons,” the report notes.253 Most of the report provides additional details about Iranian
activities applicable to nuclear weapons development that were described in previous IAEA
246 David Albright, Paul Brannan, Andrea Stricker, Christina Walrond, and Houston Wood, Preventing Iran From
Getting Nuclear Weapons: Constraining Its Future Nuclear Options, Institute for Science and International Security,
March 5, 2012; R Scott Kemp, “Worm Holes—Virus Attacks Iran’s Enrichment Operation,” Jane’s Intelligence
Review, September 15, 2011; David E. Sanger, “Obama Order Sped Up Wave of Cyberattacks Against Iran,” New York
Times, June 1, 2012; Ellen Nakashima, Greg Miller, Julie Tate, “U.S. and Israel Created ‘Flame’,” Washington Post,
June 20, 2012. For more information about Stuxnet, see CRS Report R41524, The Stuxnet Computer Worm: Harbinger
of an Emerging Warfare Capability, by Paul K. Kerr, John W. Rollins, and Catherine A. Theohary. See also, Geoff
McDonald, Liam O. Murchu, Stephen Doherty, Eric Chien, Stuxnet 0.5: The Missing Link, Symantec Security
Response, February 26, 2013; and Ralph Langner, To Kill a Centrifuge: A Technical Analysis of What Stuxnet’s
Creators Tried to Achieve, The Langner Group, November 2013.
247 See, for example, Ulrike Putz, “Sabotaging Iran’s Nuclear Program,” Der Spiegel, August 2, 2011; Artin Afkhami,
“Tehran Abuzz as Book Says Israel Killed 5 Scientists,” New York Times, July 11, 2012.
248 Greg Miller, “CIA Has Recruited Iranians to Defect; The Secret Effort Aims to Undermine Tehran’s Nuclear
Program,” Los Angeles Times, December 9, 2007.
249
Iran: Nuclear Intentions and Capabilities, November 2007.
250 Statement for the Record Worldwide Threat Assessment of the US Intelligence Community, Senate Armed Services
Committee, February 9, 2016.
251 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,
GOV/2008/59, November 19, 2008.
252 GOV/2011/65.
253 An annex to the report details these activities and provides a detailed explanation of the suspected weapons
program’s organizational structure.
Congressional Research Service
36
Iran’s Nuclear Program: Status
reports, although it does contain some previously unreported material.254 The program’s purpose
was “to develop a nuclear warhead for the Shahab-3 missile,” a senior Administration official
stated during a November 8, 2011, briefing about Amano’s November 2011 report.255 A 2012
Department of Defense report described Amano’s report as containing “extensive evidence of
past and possibly ongoing Iranian nuclear weapons-related research and development work.”256
(See Appendix E for more details about the IAEA’s information regarding suspected military
aspects of Iran’s nuclear program.)
Amano’s November 2011 report states that, according to information available to the IAEA,
Iranian activities related to building a nuclear explosive device “took place under a structured
programme” prior to the end of 2003. That program, however, “was stopped rather abruptly
pursuant to a ‘halt order’ instruction issued in late 2003 by senior Iranian officials,” the report
says. The weapons-related activities were consolidated under the “AMAD Plan” and “appear to
have been conducted during 2002 and 2003.” Nevertheless, “[t]here are also indications that some
activities relevant to the development of a nuclear explosive device continued after 2003, and that
some may still be ongoing,” according to the report. According to an August 2014 State
Department announcement, Iran established the Organization of Defensive Innovation and
Research (SPND), which “is primarily responsible for research in the field of nuclear weapons
development,” in 2011. The SPND “took over some of the activities related to Iran’s undeclared
nuclear program,” the announcement said.257 According to a 2012 Israeli intelligence report, the
SPND
was established for the purposes of preserving the technological ability and the joint
organizational framework of Iranian scientists in the area of R&D of nuclear weapons, and
for the purposes of retaining the skills of the scientists. This is [to] allow renewal of the
activity necessary to produce weapon immediately when the Iranian leadership decides to
do so.258
This report also indicates that Iran had not restarted the nuclear weapons program.
During a March 2019 press briefing, a senior U.S. official described the SPND as
an organization, chunks of which seem to have been created precisely in order to employ
people on dual-use things that could easily be repurposed into the very kind of work that
was being done before on the weapons program and…in a sense, to keep their skills sharp
and available to the Iranian clerical regime.259
Amano’s December 2, 2015, report assesses that Iran conducted “a range of activities relevant to
th
This text is long and has been trimmed here. Open the source document for the complete record.
This is a copy of a public record, reproduced as it was published. It is not legal advice, and it may not be the version a court would rely on. Check the official source before you cite it.