Iran’s Breaches of the Nuclear Deal

October 2, 2019

On July 1, 2019, Tehran began to breach the nuclear deal brokered with the world’s six major powers in 2015. Between July and September, it exceeded the limits three times:

•    In July, Iran surpassed the limits on its stockpile of low-enriched uranium. 
•    A week later, it increased enrichment from 3.67 percent to 4.5 percent. 
•    In September, it began using advanced centrifuges to enrich uranium. 

None of the breaches has posed an immediate threat; they did not bring Iran closer to building a bomb. They could also be reversed quickly. Iran made the incremental and calibrated moves to pressure European countries to do more to offset the negative impact of U.S. sanctions, which were reimposed in November 2018. “This has a political strategic significance,” said Abbas Araghchi, Iran’s deputy foreign minister.

The agreement, known as the Joint Comprehensive Plan of Action (JCPOA), was brokered between Iran and six world powers – Britain, China, France, Germany, Russia, and the United States. Between mid-2015 and mid-2019, Tehran had complied with the JCPOA, even after President Trump abandoned it in May 2018. The U.S. sanctions have taken a serious toll on Iran’s oil sales, the government’s main source of revenue.  

In May 2019, Iranian officials announced that Tehran would gradually reduce its commitments under the JCPOA until Europe offered economic incentives for Iran to stay in the deal. On June 28, Britain, France and Germany announced progress on a “special purpose vehicle”— known as INSTEX — to bypass U.S. sanctions and facilitate trade with Iran. But Iranian officials claimed that INSTEX was ineffective. “Thus far, this last one (INSTEX) even in practice hasn’t been able to stand on its feet,” President Hassan Rouhani said on September 26.  

In late September, the European Union warned Iran that any further breaches could force Britain, France and Germany to start withdrawing from the deal. Tehran warned that it would take a fourth step on November 7. The following is a rundown of Iran’s breaches of the JCPOA.  


First Breach 

Under the nuclear deal, Tehran was allowed to stockpile only 300 kilograms of low-enriched uranium. It was expected to sell or exchange any surplus. But on May 3, 2019, the United States vowed to sanction any country or company that helped Iran sell or exchange surplus, which left it with few alternatives to remain in compliance with the JCPOA. In retaliation, Tehran announced it would no longer honor the limit on its stockpile. On July 1, it accelerated the rate of production fourfold. 

“We had previously announced this and we have said transparently what we are going to do,” Foreign Minister Mohammad Javad Zarif said on July 1. “We consider it our right reserved in the nuclear deal.” Iran also vowed to increase its uranium enrichment closer to weapons-grade levels if Europe failed to provide economic relief promised in the JCPOA. 

The breach did not pose an immediate proliferation threat, according to the Arms Control Association’s Kelsey Davenport. Iran would need to produce at least 1,050 kilograms of highly-enriched uranium —nearly four times its stockpile at the time—to develop a nuclear weapon. If Iran produced enough fissile material for a bomb, it would still need to convert the gas into powder and then fabricate it into a metallic form to create the fissile core of a nuclear warhead. The uranium would then have to be fitted with explosives and integrated into a delivery system, such as a ballistic missile. The strict monitoring mechanisms set up in the JCPOA would also provide early warnings if Tehran decided to build a bomb.  

Iran could quickly reverse the step by diluting the excess enriched uranium, which would return it to a natural level—and which is not restricted in the JCPOA. Tehran could undo the break in days or weeks.  


Second Breach 

On July 7, Iran announced that was increasing enrichment from 3.67 percent--a level suitable for fueling nuclear power reactors--to 4.5 percent. 


The slight breach, by itself, did not pose a short-term proliferation risk. Enrichment was still well below weapons-grade, which is more than 90 percent enriched uranium. It was also significantly lower than the 20 percent enrichment that Iran had reached in 2010, before the JCPOA in 2015. It would also still take Iran at least a year to amass enough weapons-grade fuel for a weapon; before the deal, the so-called “breakout time” was about two to three months. 

Click here for more information on the first and second breaches. 


Third Breach 

On September 25, Iran again breached the JCPOA by installing advanced centrifuges—20 IR-6s and 20 Ir-4s—to enrich uranium at the Natanz facility near Isfahan. The IR-6 centrifuge can enrich uranium ten times faster than the IR-1, according to Iranian officials. Centrifuges cascade together to produce fissile material. A report by the IAEA also verified that Iran had installed a cascade of 164 IR-4 and 164 IR-2m centrifuges.   

Iran’s third breach of the agreement was more significant than the previous two. It accelerated the production of fissile material and decreased the breakout time needed to develop a nuclear weapon. With advanced centrifuges, Tehran could start stockpiling enriched material for an eventual bomb. “Under current circumstances, the Islamic Republic of Iran is capable of increasing its enriched uranium stockpile as well as its enrichment levels and that is not just limited to 20 percent,” Behrouz Kamalvandi, the spokesperson the Atomic Energy Organization of Iran, said. “We are capable inside the country to increase the enrichment much more.”