Iran Faces Difficult Choice After U.S. Narrows Nuclear Sanctions Waivers

The U.S. government on Friday renewed only five out of the seven nuclear sanctions waivers that allow other parties to the nuclear deal with Iran to pursue civilian nuclear cooperation projects. By revoking the waivers that enabled Iran to ship abroad excess supplies of enriched uranium and heavy water, the U.S. has confronted Iran with a difficult choice regarding whether it should continue to comply with certain key terms of the deal.

Under the terms of what is formally known as the Joint Comprehensive Plan of Action (JCPOA), Iran may stockpile no more than 300 kilograms of low-enriched uranium (LEU), i.e. uranium hexafluoride enriched up to a 3.67 percent concentration of the U-235 isotope, and no more than 130 metric tons of heavy water. Thanks to a waiver that allowed it to export excess LEU to Russia, Iran maintained the option to continue enriching uranium under the JCPOA. A waiver also enabled Iran to ship excess heavy water to Oman for storage, from where it could be sold to foreign customers.

By revoking the waivers, the U.S. is pressuring Iran to stop the production of LEU and heavy water. Currently, there is an oversupply of LEU and heavy water in the global marketplace, which means that Iran would be unlikely to find customers even if it were allowed to export these items.

With regard to LEU, Iran has several months before it needs to make a decision on whether to continue enrichment. According to the latest International Atomic Energy Agency (IAEA) report, Iran’s total inventory of LEU was only about four-fifths of the permitted amount and growing by only several kilograms per month. Thus, Iran can continue to enrich for several months before approaching the cap set by the JCPOA.

At that point, Iran could stop observing the JCPOA’s 300-kilogram limit on LEU. Iran could simply pass this quantitative limit or even start to enrich uranium to higher levels (e.g. to a 20 percent concentration of the U-235 isotope), as it has done in the past. As part of this approach, Iran may trigger the JCPOA’s dispute resolution mechanism, claiming that the other parties to the deal have failed to ensure Iran can produce LEU. The U.S. would presumably block this complaint when it reaches the UN Security Council, yet the JCPOA permits a frustrated complainant to stop abiding by the deal “in whole or in part.” In this manner, Iran could build a case that its violation is justified.

With regard to heavy water, Iran faces a similar choice, but has less time to decide. The latest IAEA inventory showed it having 124.8 metric tons, so it will reach the 130 metric ton limit soon if its production continues. Iran could stop production, but this would amount to surrendering a key concession made by the JCPOA – and one that shows why the deal was flawed from a nonproliferation perspective. Alternately, Iran could continue production while triggering the dispute resolution mechanism. Iran would likely have to store the excess heavy water at home, since Oman is unlikely to welcome it in the absence of a sanctions waiver.

If Iran chooses to violate its JCPOA commitments, some European parties to the deal may voice displeasure, but ultimately accept the violations de facto rather than risk the complete implosion of the deal. Others may seek to hold Iran to its caps. Iran may also seek to dampen the European response by stressing that its retaliatory measures do not violate either its Comprehensive Safeguards Agreement or the Additional Protocol, but only the JCPOA. In that vein, Iran may also restrict IAEA monitoring of its uranium mining and centrifuge manufacturing facilities, which would breach the JCPOA but not those other agreements.

Ignoring such violations would be a risky approach from a nonproliferation perspective, since a growing LEU stockpile would reduce the “breakout time” Iran needs to produce a nuclear weapon. Given that the international community has only a partial picture of Iran’s current weapons design and manufacturing capabilities, allowing Iran’s breakout time to diminish would be especially dangerous. To avoid walking down this slippery slope, the parties to the JCPOA should not tolerate any violations by Iran.

Olli Heinonen is a senior advisor on science and nonproliferation at the Foundation for Defense of Democracies (FDD), where he also contributes to FDD’s Center on Economic and Financial Power (CEFP). Follow FDD on Twitter @FDD and @FDD_CEFP. FDD is a Washington, DC-based, nonpartisan research institute focusing on national security and foreign policy.