Iran Continues to Stockpile Uranium

July/August 2020
By Kelsey Davenport

Iran’s stockpile of low-enriched uranium (LEU) continues to grow in violation of the limits imposed by the 2015 nuclear deal, but the country is abiding by the monitoring and verification mechanisms put in place by the accord, the International Atomic Energy Agency (IAEA) reported.

An International Atomic Energy Agency camera monitors activity at Iran's Uranium Conversion Facilities in 2005. As Iran has violated the uranium production limits of the 2015 nuclear deal, it has not curtailed the agency's inspection efforts. (Photo: Behrouz Mehri/AFP/Getty Images)According to an IAEA report on June 5 on Iran’s implementation of the 2015 nuclear agreement, known as the Joint Comprehensive Plan of Action (JCPOA), Iran has stockpiled 1,571 kilograms of uranium enriched to a level of less than 5 percent uranium-235, significantly more than the 202 kilograms of uranium enriched to 3.67 percent (the equivalent of 300 kilograms of uranium gas enriched to 3.67 percent) allowed by the accord. When the IAEA last reported on Iran’s implementation of the JCPOA in March, the stockpile was 1,020 kilograms.

Kazem Gharib Abadi, Iranian ambassador to the IAEA, emphasized in a June 16 statement to the agency’s Board of Governors that Tehran is ready to “reverse all remedial actions” taken to reduce compliance with its JCPOA obligations if the other parties to the deal take “credible practical steps” to implement their obligations under the accord. He said that “words do not ensure” that Iran benefits from the deal and that actions are needed.

Iran first announced it would begin taking steps to breach limits set by the nuclear deal in May 2019, one year after U.S. President Donald Trump withdrew the United States from the agreement and reimposed sanctions on Iran lifted by the accord. (See ACT, June 2019; June 2018.) Iranian officials have continued to reiterate that Tehran will return to compliance with the deal if its demands on sanctions relief are met.

Gharib Abadi singled out the three European parties to the deal (France, Germany, and the United Kingdom) and accused them of succumbing to U.S. bullying and urged them to take steps to meet their obligations under the JCPOA “before it’s too late.”

In a June 19 statement, the foreign ministers of the three European states said they met their obligations to lift sanctions under the deal and “have gone beyond the commitments required by the agreement to support legitimate trade.”

They urged Iran “to pursue substantial discussions and actions in coordination with us” to preserve the deal. The statement said the three countries will seek a ministerial meeting to take stock of the dispute resolution mechanism process. In January, the three countries triggered the process outlined in the nuclear deal to address Iran’s breaches of the accord.

Although Iran continues to breach JCPOA limits, Tehran has refrained from taking new actions that violate the agreement, despite having announced on Jan. 5 that it would no longer adhere to any restrictions on its nuclear activities.

Nevertheless, the IAEA “has not observed any changes to Iran’s implementation of its nuclear-related commitments in connection with” the Jan. 5 announcement, said agency Director-General Rafael Mariano Grossi on June 15.

The United States took no solace in that finding. The IAEA report “makes clear that Iran has continued to expand its proliferation-sensitive activities and is showing no signs of slowing its destabilizing nuclear escalation,” said Jackie Wolcott, U.S. ambassador to the IAEA, on June 16. Iran’s actions are “transparent attempts at extortion” and are designed to “raise tensions rather than defuse them,” she said.

Wolcott may have been referring to the growing size of the LEU stockpile and Iran’s expansion of enrichment activities using advanced centrifuges.

Of the 1,571 kilograms of uranium enriched to less than 5 percent U-235, the IAEA noted that 483 kilograms are enriched to about 2 percent, a level that does not significantly affect Iran’s ability to produce weapons-grade material for a nuclear bomb, should Tehran make the decision to do so.

Yet, with 1,088 kilograms of material enriched to between 3.67 and 4.50 percent, Iran now has enough LEU that, if enriched to weapons grade, is sufficient for one nuclear bomb. If Iran were to use the 5,060 IR-1 centrifuges at Natanz and the 1,044 IR-1 centrifuges at Fordow to pursue weapons-grade enrichment, it could produce enough material for a bomb in three to four months, according to expert assessments. When the JCPOA was fully implemented, that timeline was 12 months.

Such an effort would be quickly detected, however, as the IAEA report noted that Iran continues to cooperate with the verification and monitoring mechanisms put in place by the JCPOA, including tracking of enrichment levels in real time.

The IAEA also reported that Iran continues to breach limitations put in place by the JCPOA on research and development of advanced centrifuge machines. According to the June 5 report, Iran is withdrawing enriched uranium from cascades of 164 IR-2 and IR-4 centrifuges and a cascade of 135 IR-6 centrifuges. Under the JCPOA, Iran is only permitted to test a small number of advanced machines with uranium and is prohibited from withdrawing any enriched material.

The IAEA report noted that Iran has not resumed construction on the Arak reactor based on its original, more proliferation-sensitive design or resumed uranium enrichment to 20 percent.

In May, U.S. Secretary of State Mike Pompeo terminated sanctions waivers allowing international cooperation on conversion of the Arak reactor and the import of 20 percent-enriched uranium fuel for Iran’s research reactor. (See ACT, June 2020.) The parties to the JCPOA are required under the deal to assist with the conversion and the transfer of 20 percent-enriched uranium fuel to Iran. Without the waivers, however, any continued cooperation could be penalized by the United States.

Gharib Abadi said that the “unlawful conduct” of the United States is “endangering international cooperation in the field of nuclear energy and technology” and a “clear contradiction” of UN Security Council Resolution 2231. Resolution 2231 endorsed the nuclear deal.

Iranian officials have threatened to resume work on the Arak reactor based on the original design, which would produce enough plutonium for about two nuclear weapons per year, if the international cooperative efforts to convert the reactor were halted. Iran has also threatened to resume enriching uranium to 20 percent, a level that poses much more of a proliferation risk than the current enrichment level of less than 5 percent, if necessary to produce fuel for its research reactor.

The IAEA report said Iran received a shipment of 20 percent-enriched uranium for the Tehran Research Reactor in April, prior to Pompeo’s announcement.