By Andrea Stricker
December 11, 2019
Nuclear inspectors reported in late November that Iran had exceeded the 2015 nuclear deal’s limit on stockpiles of heavy water, a commodity employed in nuclear reactors. This move is part of the Iranian regime’s incremental effort to reduce compliance with the nuclear deal in order to extract sanctions relief.
Iran produces heavy water domestically for a reactor called the IR-40, located in the city of Arak. Heavy water itself does not pose a proliferation risk, but the natural uranium fuel used to run certain reactors combines with the use of heavy water to quickly produce high-quality plutonium. The 2015 nuclear deal, formally known as the Joint Comprehensive Plan of Action (JCPOA), capped the amount of heavy water Iran can stockpile at 130 metric tons, the quantity required annually for the IR-40. The JCPOA also required the reorientation of the reactor to limit the risk of plutonium production. However, Iran has threatened to stop this reorientation and resume building a reactor that can quickly produce large amounts of a quality of plutonium suitable for nuclear weapons. Iran’s heavy water overage and announcement of advances in heavy water technology are likely intended to augment that threat.
Under the terms of the JCPOA, Iran is permitted to sell heavy water on the international market. In 2016, the JCPOA’s executive body, the Joint Commission, authorized the interim storage of Iran’s heavy water in Oman before the water’s sale to a foreign buyer. The commission also interpreted the JCPOA to mean that heavy water held temporarily abroad did not count toward the 130-ton cap. This effectively incentivized Iran to overproduce heavy water for sale abroad.
In May 2019, the Trump administration addressed this flaw in the JCPOA by tightening the sanctions waiver that permitted temporary storage in Oman. According to a U.S. official speaking on background, Oman has cooperated with the United States and has not accepted any more Iranian heavy water or returned any of the stockpile to Iran. Yet nuclear inspectors from the International Atomic Energy Agency (IAEA) have never safeguarded the heavy water in Oman or accounted for quantities that remain. Inspectors reported, however, that Iran exported heavy water on four occasions since May, sending abroad a total of 2.9 metric tons. The IAEA does not name the recipients. In November, the IAEA also reported that Iran had 131.5 metric tons of heavy water, or 1.5 more than the JCPOA allows.
It is unknown who is currently buying Iran’s heavy water. Russia is the most likely candidate, although the buyer could be another party to the JCPOA. Following a June meeting of the Joint Commission, the Russian Foreign Ministry stated, “[T]he participating countries are instructed to work out practical measures that would allow Iran to export … heavy water contrary to U.S. sanctions.”
Washington should now act to prevent any further exports of heavy water by Iran. Tehran deserves no further windfalls given its noncompliance with its nuclear safeguards agreements, violations of the JCPOA, and regular threats to make additional nuclear advancements. Washington should identify who is buying Iran’s heavy water and use the threat of sanctions to end this practice. Although the administration has not stated it would also sanction direct purchases of Iranian heavy water, it could do so on the basis that the United States prohibits most financial transactions with Iran, sanctions its shipping and aviation industries, and bans purchases from Iran relevant to proliferation, even those by foreign governments.
The administration could take these actions now or during its next consideration of Iran nuclear waivers in January 2020. Tehran should stop operating its heavy water production plant and should dispose of the excess. The administration should also urge the IAEA to account for any heavy water that remains in Oman.
Taking action against Iran’s heavy water violations would reinforce the broader message that Washington will not tolerate Iran’s nuclear threats.
Foundation for Defense of Democracies