Arak Heavy Water Reactor (IR-40)

The IR-40 reactor at Arak is a heavy water reactor whose spent fuel can be reprocessed to yield weapons-grade plutonium, giving Iran a potential second path to nuclear weapons alongside uranium enrichment. Its construction drew sustained international concern throughout the 2000s.

Geography

History

Construction of the IR-40 began in the early 2000s and was the subject of years of negotiation. Under the 2015 JCPOA, Iran agreed to fill the reactor core with concrete, permanently disabling the original design, and to redesign it as a modernised research reactor with lower plutonium output with international assistance. The concrete filling was carried out in 2016.

Present Day

Following the US withdrawal from the JCPOA, Iran announced it would seek to restore the original IR-40 design. The redesigned reactor project has stalled without foreign technical assistance. The site remains a monitored facility under IAEA safeguards, though the future of the reactor is tied to the outcome of broader nuclear negotiations.