2015
July 14 – Foreign ministers from Iran and the worlds six major powers — Britain, China, France, Germany, Russia and the United States — announced they had reached a final nuclear agreement, known as the Joint Comprehensive Plan of Action (JCPOA). Iran agreed to limit its nuclear activities in exchange for sanctions relief.
July 20 – The U.N. Security Council unanimously adopted resolution 2231 endorsing the final deal. The agreement and its annexes were also delivered to the U.S. Congress, beginning a 60-day review period.
July 20 – The European Union formally approved the JCPOA, following a vote of the European Union Foreign Affairs Council.
Sept. 17 – After weeks of heated debate, the deal’s opponents in the U.S. Congress failed to pass a resolution of disapproval to block the deal.
Sept. 17 – Secretary of State John Kerry announced that Ambassador Stephen D. Mull would serve as Lead Coordinator for Iran Nuclear Implementation.
Oct. 11-14 – Iran’s parliament voted to approve a resolution permitting the government to implement the JCPOA. On October 11, 139 lawmakers voted in favor of the bill’s general provisions, with 100 lawmakers against and 12 abstaining. And on October 13, parliament approved the details of the bill, with 161 lawmakers in favor and 59 against. Another 13 members of parliament abstained, 17 did not cast a vote, and 40 were not in attendance. The bill was ratified on October 14 by Iran’s Guardian Council, which is tasked with making sure legislation does not contradict religious laws or Iran's constitution.
Oct. 18 – Iran and the P5+1 countries marked the deal's Adoption Day. Iran began dismantling parts of its nuclear infrastructure, while the United States and European Union began preparations to lift or suspend certain sanctions.
Nov. 2 – Iran’s nuclear chief, Ali Akbar Salehi, announced that Iran had begun to shut down uranium enrichment centrifuges.
Nov. 17 – Iranian officials announced that the government had created a committee to monitor implementation of the JCPOA. The body would be called the Committee to Monitor and Supervise Implementation of the Joint Comprehensive Plan of Action.
Nov. 18 – The International Atomic Energy Agency (IAEA) released a report stating that Iran had removed 4,500 centrifuges at the Natanz and Fordo facilities. It still had to uninstall another 10,000 centrifuges to reduce its number of operable centrifuges to 5,000. Iran’s stock of low enriched uranium also increased to the equivalent of 12,639.6 kg, up by 460 kg since August. Under the nuclear agreement, Iran must eventually cut the stockpile to 300 kg.
Nov. 22, 2015 – The P5+1 countries issued a document outlining the redesign and reconstruction of Iran’s Arak nuclear reactor. It specified roles for each of the countries. Under the nuclear deal brokered in July 2015, Iran agreed to transform the reactor, not produce heavy water and not reprocess any plutonium at the facility for 15 years. The provision was intended to block a potential plutonium pathway to nuclear weapons.
Dec. 2 – The IAEA concluded that Iran had worked on a “range of activities relevant to the development of a nuclear explosive device,” despite its denial of any work on a nuclear weapons program. It reported that the most “coordinated” work was done before 2003. Some activities, however, continued until 2009.
Dec. 15 – The IAEA’s board decided to close the inquiry into the possible military dimensions of Iran’s nuclear program. The unanimous decision by the 35-nation group ended the 12-year probe while allowing inspectors to continue monitoring Tehran’s program.
Dec. 28 – Russia reportedly completed its withdrawal of enriched uranium from Iran, a key step towards decreasing Iran’s stockpile.