Heavy Water Reactor

Arak Complex

Near the city of Arak is Iran’s heavy water production plant and a heavy water reactor, which remains under construction.  Iran originally intended to build a hot cell facility at Arak for the separation of “long-lived radioisotopes,” believed to be a euphemism for plutonium, but in 2004 Iran informed the IAEA that it was abandoning that plan.  Suspicions remain that Iran will reverse this decision and decide to build a plutonium separation plant after the reactor is operational.  It is currently expected to build hot cells to separate shorter-lived radioisotopes, such as cobalt-60 and iridium-192, for civilian applications.

Arak IR-40 Heavy Water Reactor

Iran has stated that it decided to construct a heavy water reactor in the 1980s.  In the 1990’s Iran received significant design assistance for the reactor from Russian entities.  It conducted certain testing activities at the Esfahan nuclear research center in the 1990s. The IR-40 reactor is designed to produce 40 megawatts thermal (MWth) of power and use natural uranium oxide fuel, which is being produced at the Esfahan conversion and fuel fabrication facilities.

The start date of the reactor is difficult to determine.  Officially, Iran has said that the reactor will achieve criticality in early 2014.  However, this date could be delayed because of problems acquiring necessary items overseas or in building the reactor.

If operating optimally, the IR-40 would produce about 9 kilograms of plutonium annually or enough for about two nuclear weapons each year. Before it could use any of the plutonium in a nuclear weapon, however, Iran would first have to separate the plutonium from the irradiated fuel.

Intermittently, Iran has allowed the IAEA access to the IR-40 reactor at Arak.  In recent years, Iran has justified its refusal to grant the Agency full access to the IR-40 reactor by saying that “since the IR-40 was not in a situation to receive nuclear material, no design-inventory-verification was required.” Iran has since softened its position and allowed the IAEA to visit the reactor.

Because Iran has completed the external structure of the IR-40 reactor, commercial satellite images can no longer monitor the progress of the reactor.  The IAEA continues to monitor construction through design inventory verifications.

Arak Hot Cells

Iran has denied that it intends to build a plant to separate plutonium from IR-40 reactor spent fuel.  However, Iran originally declared to the IAEA that there were plans to construct a building at the Arak site with hot cells for the production of long-lived radioisotopes, interpreted to mean plutonium.  Iran stated that they were planning to build hot cells for the production of “short lived” isotopes, and that it intended to construct the additional hot cells to produce “long lived” radioisotopes.  In May 2004, however, Iran revised its declaration for Arak, and eliminated plans to construct any hot cells for long-lived isotopes.

Arak Heavy Water Production Plant at Khondab

The existence of this facility was first revealed publicly by the Iranian opposition group, National Council of Resistance of Iran (NCRI), in August 2002.  ISIS then located the site in commercial satellite imagery after a wide-area search and published its findings in December 2002.1 

Iran’s heavy water production plant was commissioned in August 2006.  By United Nations Security Council resolution 1737 (2006), Iran was ordered to suspend all work on heavy water related projects.  However, Iran has not halted this work and maintains that it has no legal obligation to do so.

Iranian officials stated at a March 5-6, 2005 conference in Tehran that the plant was in its first stage of operation.  In 2010, imagery of the heavy water production plant analyzed by the IAEA indicated that it was operating by then.

Under traditional safeguards, heavy water production facilities are not subject to IAEA safeguards or inspection. Though Iran granted IAEA inspectors access on August 17, 2011, they were not permitted to obtain samples of Iran’s heavy water.  The IAEA monitors the status of the facility via satellite imagery.

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1 David Albright and Corey Hinderstein, “Iran Building Nuclear Fuel Cycle Facilities: International Transparancy Needed,” (Washington, DC: ISIS) December 12, 2002.