As Iran Allows the UN Access to Suspected Nuclear Sites, Its Uranium Stockpile Is Growing

Iran has agreed to the IAEA accessing possible nuclear sites even as it has accumulated 10x the amount of low-enriched uranium permitted in the 2015 nuclear deal.

6 min readSep 7, 2020


by Stephanie Liechtenstein. Read more on PassBlue.

Javad Zarif, Iran’s foreign minister, right, and Rafael Grossi, head of the International Atomic Energy Agency, left, meeting in Tehran, Aug. 25, 2020.

VIENNA — The International Atomic Energy Agency has just reported that Iran’s stockpile of low-enriched uranium continues to grow. The stockpile now exceeds the limit set in the 2015 nuclear deal tenfold.

According to the confidential quarterly IAEA report, distributed to member states on Sept. 4 and seen by PassBlue, as of Aug. 25, Iran had stockpiled 2105.4 kilograms of low-enriched uranium, an increase of 533.8 kilograms since the previous quarterly report, in June. The nuclear deal, or Joint Comprehensive Plan of Action (JCPOA), allows Iran to keep a stockpile of 202.8 kilograms only.

Yet the stockpile is still far below the amount of enriched uranium Iran had accumulated before the conclusion of the JCPOA, signed in 2015 with the world’s major powers — Britain, China, France, Germany, Russia and the United States (which left the deal in 2018).

In addition, the IAEA also reported that Iran had enriched its uranium to a purity of up to 4.5 percent, above the 3.67 percent limited under the JCPOA. To build a nuclear bomb, however, Iran would still have to further enrich its uranium to a purity of 90 percent, nuclear experts say.

The Institute for Science and International Security, a Washington think tank, warned in its most recent study that the IAEA’s new findings mean that Iran’s estimated breakout time as of late September 2020 could be “as short as 3.5 months.” Breakout is defined as the time that Iran would need to build a nuclear weapon.

“A new development is that Iran may have enough low-enriched uranium to produce enough weapon-grade uranium for a second nuclear weapon, where the second one could be produced more quickly than the first, requiring in total as little as 5.5 months to produce enough weapon-grade uranium for two nuclear weapons,” the study continued.

Yet despite Iran’s incremental violations of the nuclear deal, which Tehran began in reaction to the US withdrawal from the JCPOA in May 2018, the remaining signatories want to keep the deal alive and continue its implementation. In their view, Iran is still cooperating with the UN nuclear agency, which is based in Vienna.

Mark Hibbs, a fellow at the Carnegie Endowment for International Peace, told PassBlue that “as long as Iran continues to signal that its actions are reversible, the other parties in the accord will not leave it.”

This was also underlined during the most recent meeting of the JCPOA Joint Commission in Vienna on Sept. 1, where Chinese, European and Russian diplomats pushed back against US attempts to snap back sanctions against Iran in the UN Security Council on Aug. 20 and reiterated the importance of preserving the agreement.

On this point, Gaukhar Mukhatzhanova, director of the International Organizations and Non-Proliferation Program at the James Martin Center for Nonproliferation Studies and currently based at the Vienna Center for Disarmament and Nonproliferation, told PassBlue that in her view, “The growing stockpile of low-enriched uranium is of concern, but not a reason for the remaining parties to abandon the JCPOA.” She thinks “there is really nothing to be gained in terms of nonproliferation in completely destroying the JCPOA now.”

On the breakout-time calculation, she also cautioned that this was based on an assumption that Iran “races for the bomb.” The calculation “only tells us how soon, approximately, a country might have enough weapons-grade material for one nuclear explosive device — how long it would take them to turn that material into a bomb is a different story,” she said.

Meanwhile, in separate developments, the IAEA on Sept. 4 issued a second confidential report, also seen by PassBlue, confirming that Iran had begun to provide agency inspectors access to one site in the country, where undeclared nuclear material may have been stored or nuclear activities may have taken place as far back as 2003.

According to this second report, which is unrelated to the more recent one, inspectors this month took environmental samples at the site in question to analyze them at various laboratories, including at the agency’s own site at Seibersdorf, Austria. The results of the analysis have not been released yet.

The report also said that the agency “will conduct a complementary access, under the Additional Protocol, at the second specified location later in September 2020 on a date already agreed with Iran, to take environmental samples.”

This second report is about Iran’s commitments under the Nuclear Non-Proliferation Treaty (NPT), the Comprehensive Safeguards Agreement and Additional Protocol. These international agreements commit Iran to ensure that all declared nuclear material is for peaceful uses only, and that there is no other undeclared nuclear material or activity present in the country.

The agency started asking questions about possible undeclared nuclear material and activity in Iran in 2019, when Israel provided the IAEA with fresh intelligence, obtained by Mossad agents during a covert operation inside Iran in January 2018.

Iran had, however, stonewalled the UN agency for several months and denied it access to the sites where the nuclear activity or material was suspected to have existed. Tehran maintained that the investigation into its past nuclear program was explicitly closed by the IAEA in 2015.

This led the 35-member board of governors of the UN agency to adopt a resolution in June, slamming Iran and calling on it to “fully cooperate with the agency.”

At the time, some experts warned that if Iran failed to cooperate for much longer, the fight could intensify and lead the board to refer the case to the UN Security Council to consider reimposing UN sanctions against Iran. Such a move would most likely have dealt a fatal blow to the JCPOA.

However, this possibility is off the table, at least for the time being, since Iran agreed to grant the UN agency’s inspectors access to the sites in question.

The details of the deal were hammered out during a two-day visit to Iran by the IAEA director general, Rafael Grossi, at the end of August, where he met with Iranian President Hassan Rouhani; the foreign minister, Javad Zarif; and the head of the Atomic Energy Organization of Iran, Ali Akbar Salehi. This was Grossi’s first visit to Iran since being appointed director general in December 2019. The trip occurred less than two weeks after Grossi held a meeting in Vienna with US Secretary of State Mike Pompeo, where “the need for Iran to respond to the IAEA’s requests for information and access” was also discussed.

After Grossi’s discussions in Iran, a joint statement was issued in which the two sides said that they had “reached an agreement on the resolution of the safeguards implementation issues specified by the IAEA, in good faith.”

The joint statement also underlined that “in this present context,” the IAEA did not have any more questions for Iran or additional requests to access locations.

Yet speaking to reporters at the Vienna airport on Aug. 26 after returning from Tehran, Grossi clarified that he “could imagine” requiring more access and having additional questions in the future if he had “information that warrants it.”

This means that while the agreement achieved by Grossi may have averted escalating tensions on the matter before the US presidential election on Nov. 3, it is not necessarily the end of the story. If other leads open up, the agency may need to ask for further access.

On this point, Hibbs told PassBlue that he thinks “Iran’s climb-down will permit the IAEA to get information it needs.” But he concedes that the main question will be whether the agreement will hold, “as the Iran-IAEA relationship since 2003 has been papered with good intentions that bought Iran time and had to be repeatedly renewed.”

Mukhatzhanova has a slightly more positive outlook. She told PassBlue that it is now important to wait for the IAEA reporting on its analysis of samples collected in Iran. Should the agency have more questions as a result of its findings, a more definitive assessment about the level of cooperation by Iran should be made.

Originally published at on September 7, 2020.




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