IR-40

IR-40 is an Iranian 40 megawatt (thermal) heavy water reactor under construction in Arak. While the basic design was completed in 2002, the IAEA was informed on May 5, 2003 that construction would begin in June 2004. The reactor was originally going to be constructed at a location in Esfahan, though after the designs were completed, the Iranian leadership decided to build instead at its present location in Arak. In August 2006, mixed reports came out about when the reactor would go into operation, one stating that the plant would start up in 2009, while another reported that operation would be postponed until 2011. Press reports indicate that Iranian President Mahmoud Ahmadinejad visited the reactor in June 2013, on the occasion of the reactor vessel installation which is the final precursor prior to commencement of operation. Iran advised the International Atomic Energy Agency (IAEA) that the reactor will begin nuclear operation in 2014.

In full operation, it is expected that the reactor will produce from 10 kg to 12 kg of plutonium a year within its spent nuclear fuel. Iran is also constructing hot cells at the IR-40. Aspects of IR-40's design will also serve as a prototyping and testbed for the larger 336 megawatt Darkhovin Nuclear Power Plant under construction near Ahvaz. The IAEA has reported that it found no indication of ongoing reprocessing activities, but also that Iran has denied access to the IR-40 for design information verification, despite the IAEA's right to conduct such verification. Iran states that the reactor will only be used for R&D, medical and industrial isotope production. On June 16, 2010 Iran announced plans to fabricate fuel for the Tehran Research Reactor by September 2011 and to build a new 20 MW reactor for radioisotope production within five years.

History
Iran's leadership decided to begin designing IR-40 in the 1980s, amid concerns that their plans at uranium enrichment would fail. After Iran was unable to get a reactor from abroad, they allegedly received blueprints for a research reactor from Russia, which they used to domestically design the larger IR-40 reactor. The current Iranian research reactor, TRR, is nearing the end of its operational life having been in use since 1967.

Role in Iran's nuclear program
While Iran claims that IR-40 will be used solely for research and development, production of both short and long lived radioisotopes, and training; there are some proliferation concerns about the reactor's ability to produce enough plutonium for several nuclear weapons each year.

Proliferation concerns
Natural uranium fueled heavy water reactors have been identified as a design very efficient for producing weapons-grade plutonium usable for construction of nuclear weapons. Analysis suggest that Iran could extract 8–10 kilograms of high purity Pu-239 annually from fuel irradiated in IR-40. This, according to the IAEA, is sufficient weapons-grade material to produce 1 to 2 nuclear weapons annually.

As a result of concerns that this plutonium would support weapons development, the IAEA Deputy Director-General for Safeguards, Olli Heinonen proposed an IR-40 reactor redesign to a reactor using slightly enriched uranium fuel rather than natural uranium. Use of enriched uranium fuel combined with extended operations would reduce the reactor's ability to produce weapons-grade plutonium.

Iran has indicated they do not intend to reprocess the IR-40 fuel to recover weapons-grade plutonium. The planned hot cell facility at the Arak site is described as capable of handling irradiated fuel and targets (such as targets for production of medical radioisotopes) from the IR-40. It has been argued that the facility has insufficient capability to reprocess irradiated fuel. However proliferation experts have expressed concern that once sufficient fuel has been irradiated Iran may modify this facility or build a separate reprocessing facility to recover weapons-grade plutonium.