The International Atomic Energy Agency’s (IAEA) June 5 report assessing Iran’s compliance with the 2015 nuclear deal noted that Tehran’s stockpile of low enriched uranium continues to increase beyond limits set by the accord, known as the Joint Comprehensive Plan of Action (JCPOA).
While the stockpile growth is concerning, the IAEA report states that Iran continues to comply with the JCPOA’s monitoring and verification measures, which provide assurance that if Tehran were to take further steps to violate the deal or dash toward a bomb, its activities would be quickly detected.
In short, Iran continues to transparently breach the nuclear deal to create leverage in response to the U.S. sanctions campaign and the failure of the remaining P4+1 parties (China, France, Germany, Russia, the United Kingdom, and the EU) to deliver meaningful economic relief. The breaches are troubling, but do not indicate a decision to pursue nuclear weapons and are quickly reversible should Iran decide to return to compliance with the JCPOA.
Specifically, the June 5 report noted that Iran’s stockpile of enriched uranium increased by about 551 kilograms since the March report, bringing the total stockpile to 1,571 kilograms of uranium enriched to less than 4.5 percent uranium-235, nearly all of which is in the form of uranium hexafluoride gas (UF6). Of the 551 kilograms produced over the past three months, 214.6 kilograms consists of uranium enriched to less than 2 percent. That brings the total amount of uranium enriched to less than 2 percent to 483 kilograms.
While any uranium enriched in excess of the stockpile limit (300 kilograms of uranium enriched to 3.67 percent UF6) is still a concerning breach of the restrictions established by the JCPOA, producing enriched uranium at the 2 percent enrichment level poses far less risk and does not significantly alter the so-called breakout time, or time it would take to produce enough weapons-grade uranium for one bomb (25 kilograms of uranium enriched to greater than 90 percent uranium-235).
Setting aside the 483 kilograms of uranium enriched to less than 2 percent uranium-235, Tehran has produced about 1,088 kilograms of uranium enriched to between 2 and 4.5 percent, mostly in the form of UF6, which is enough reactor-grade material for one bomb. If Iran were to further enrich this material to weapons-grade using its IR-1 centrifuges currently installed and enriching at Natanz and Fordow, it would likely take at least 3-4 months to produce enough weapons-usable nuclear material for one bomb.
While this timeline is short in comparison with the 12-month breakout when the JCPOA was fully implemented, Iran does not appear to be making a “dash” to try to acquire a nuclear weapon and the IAEA has said there is no evidence that Iran is diverting nuclear material for covert purposes. Even if Iran did decide to pursue nuclear weapons, further time would be needed to weaponize the material and any move by Iran to enrich to higher levels would be quickly detected by the IAEA.
Also, while it is clear that Iran undertook activities in the past related to developing a nuclear explosive device, Tehran has not verified its design with a nuclear test, and it is unlikely that Tehran would “breakout” to produce only one bomb. So, while the increase in the stockpile of low enriched uranium is concerning, it is not yet an urgent proliferation risk and there remains time to restore full compliance with the JCPOA.
The June 5 report confirmed that while Iran is breaching the 3.67 percent uranium-235 enrichment level set in the JCPOA by enriching to 4.5 percent, there is no enrichment up to 20 percent. The U.S. decision to terminate the sanctions waiver allowing Iran to import 20 percent enriched uranium fuel for its Tehran Research Reactor in May raises concern that Iran may use fueling for the TRR as a justification to resume 20 percent enrichment down the road. Uranium enriched to 20 percent poses a far more significant proliferation risk as it can be much more quickly enriched to weapons-grade. However, the IAEA noted that Iran received a shipment of fuel for the TRR in April 2020, which should allay any immediate need for 20 percent enriched fuel. Iran last received a shipment of 20 percent enriched fuel in 2018.
The report also noted that Iran has not taken steps to act on its Jan. 5 announcement that the country’s nuclear program would no longer be “subject to any restrictions” and that there have been no changes to JCPOA-related monitoring and verification activities. The IAEA “maintained its verification and monitoring activities” during the Covid-19 crisis, according to the report.
According to the IAEA report, Iran continues to breach:
Iran is still abiding by some provisions of the JCPOA. According to the IAEA report:
The IAEA issued a second report June 5 on Iran's implementation of its safeguards agreement. That report is discussed in "Iran’s Failure to Comply with IAEA Investigation Raises Concerns."