Iran has not yet decommissioned the Arak heavy water reactor, one of its obligations under the nuclear deal with world powers to win a reprieve from sanctions.
IR-40 is an Iranian 40 megawatt (thermal) heavy water reactor under construction near Arak. The International Atomic Energy Agency (IAEA) was informed on May 5, 2003 that construction would begin in June 2004. Iran announced that the reactor will begin nuclear operation in 2014.
The precise date for lifting sanctions, known as Implementation Day, has not been determined and depends on a report by the U.N. nuclear watchdog, verifying Iran has kept its promises under the deal.
Iranian officials expect to finish implementing the July 14 deal, known as the Joint Comprehensive Plan of Action (JCPOA) in the coming days. Iran has already shipped most of its enriched uranium stockpile to Russia, and must still mothball most of its centrifuges and decommission the Arak reactor.
Once the United Nations confirms Iran has done this, international sanctions against Iran will be lifted, paving the way for an influx of foreign investment and a rapid increase in crude oil exports.