Arak Nuclear Complex

This page is part of the Facilities Collection.

The Arak Nuclear Complex is comprised of a heavy water experimental reactor and an adjacent heavy water production plant.

Iran tried to purchase a heavy water moderated reactor in the 1990s. Tehran secretly approached at least four nuclear suppliers, but was repeatedly turned down. After unspecified foreign experts provided technical assistance, Iran began constructing the reactor on its own. ¹ Starting in August 2008, Iran stopped permitting IAEA visits to the construction site. After Iran completed construction of the reactor vessel’s containment dome, the IAEA was unable to remotely monitor construction progress. ² Following repeated requests, Iran provided the IAEA with access to the IR-40 reactor in August 2009, at which time the IAEA was able to carry out Design Information Verification (DIV). ³ The IAEA confirmed that the facility “at its current stage of construction conforms to the design information provided by Iran as of January 24, 2007.” ⁴ At the time of the inspection, Iran estimated that the plant was approximately 63% completed, including installation of the reactor vessel’s containment dome. ⁵

In May 2013, Iran informed the IAEA of its plans to produce 55 fuel assemblies by August 9, 2013. In its May 2013 report, the IAEA highlighted Iran’s failure to provide an updated Design Information Questionnaire (DIQ) for the reactor since 2006, thereby falling short of meeting its obligations under the modified Code 3.1 of the General Part of the Subsidiary Arrangements to its Safeguards Agreement. The report further underlined the impact of this failure on the IAEA’s ability to verify the design of the facility, and to implement an effective safeguards approach in light of the approaching date of the IR-40’s operation. ⁶

The Heavy Water Production Plant (HWPP) provides heavy water for the IR-40 reactor. It began operation in November 2004 and can produce up to 16 metric tons of heavy water per year. ⁷

The existence of the HWPP remained secret until August 14, 2002, when the National Council of Resistance of Iran revealed the construction of at least two secret sites related to Iran’s nuclear program. ⁸ The allegations prompted IAEA Director General Mohammed El-Baradei to question Iranian authorities about the existence of a heavy water program. ⁹ During El-Baradei’s visit to Iran in February 2003, Iran officially declared that it was constructing the HWPP. ¹⁰ In November 2019, the IAEA announced that the HWPP was in operation, and that Iran had a current heavy water stockpile of 131.5 metric tons.¹¹

In a letter dated January 27, 2012, the IAEA requested that Iran provide an updated DIQ for the IR-40 Reactor. ¹² In November 2012, the Agency conducted a Design Information Verification (DIV) at the site and reported that, “the installation of cooling and moderator circuit piping was continuing.” ¹³ Iranian media quoted the head of the AEOI saying that Iran planned to test the reactor in 2013 using dummy fuel, and to commence operations the following year. ¹⁴

In the interim 2013 Joint Plan of Action (JPOA), Iran agreed to halt construction on the IR-40 for six months while promising to provide a DIQ to the IAEA. Iran would later be required to work with the IAEA to conclude an agreed safeguards approach for the facility. ¹⁵ In exchange for these concessions, the United States and European Union agreed to lift sanctions imposed on certain Iranian industries, and the United States also agreed to refrain from imposing further nuclear-related sanctions in the near future. ¹⁶

Under the JCPOA, Iran will rebuild the Arak Nuclear Facility to satisfy concerns over the potential for spent fuel reprocessing. According to article eight of the JCPOA, the new design will prevent the facility from producing and reprocessing weapons-grade plutonium. Instead, the redesigned facility will host peaceful medical and industrial nuclear research. All spent fuel from Arak will be shipped out of Iran to a destination to be negotiated. ¹⁷ Based on previous bilateral agreements on spent fuel between Iran and Russia, Russia will likely be the final destination for spent fuel from the Arak facility. ¹⁸

In accordance with the JCPOA, Iran must fill the calandria, or reactor core, at the Arak facility with cement to render it unusable. ¹⁹ On January 16, 2016, the IAEA Board of Governors released a report by the Director General, which confirmed that Iran had removed and “rendered inoperable” the Arak facility’s calandria. ²⁰

Since the passage of United Nations Security Council Resolution (UNSCR) 2231 (2015), the IAEA has issued periodic reports on Iran’s compliance with the JCPOA’s provisions. ²¹ The IAEA’s reports have consistently confirmed that Iran is not pursuing construction of the IR-40 based on its original design. ²² The IAEA also verified that Iran was “not producing or testing natural uranium pellets, fuel pins or fuel assemblies specifically designed for the support of the IR-40 Reactor as originally designed.” ²³ The JCPOA requires Iran to store its existing pellets under IAEA supervision until they can be used in the redesigned reactor. ²⁴

The Arak facility’s redesign is a cooperative project to be implemented by a P5+1 working group. Iran assumed full responsibility for the reconstruction; other members of the working group must provide consensus on the final design. The new facility design must use up to 3.67 percent enriched uranium in the form of UO2 (uranium dioxide), with a maximum approximate mass of 350kg. ²⁵ Any heavy water that is not required for the redesigned Arak reactor or other Iranian nuclear projects may be exported for 15 years after the signing of the JCPOA. This covers material in excess of 130 tons before the recommissioning of the IR-40 and in excess of 90 tons after said recommissioning. The IAEA has the authority to monitor heavy water storage and production to ensure Iran’s compliance. ²⁶

On April 12, 2017, the Chinese and Iranian ambassadors signed an agreement in Vienna to cooperate on the reconstruction of the Arak reactor. The commercial agreement between the China National Nuclear Corporation and the AEOI concerned the Arak facility’s preliminary design and design-related consultation services. ²⁷ This deal satisfies annex one provisions of the JCPOA and settles doubt over whether Iran would pursue the redesign with the aid of its own companies or engage the assistance of one of the parties to the JCPOA.