Iran’s Breach Too Far

On July 7, Iran announced that it would begin enriching uranium beyond the 3.67 percent cap it agreed to as part of the 2015 nuclear deal. Every 60 days, moreover, it would incrementally raise that level unless the remaining parties to the deal convince Washington to ease its crippling sanctions or else find some other way to protect Iran from their effects.

Although the incremental approach is likely designed to get everyone back to the negotiating table, its prospects for success are slim. Since the signing of the nuclear agreement, called the Joint Comprehensive Plan of Action (JCPOA), Iran’s advances in nuclear technology have drastically reduced the time it needs to create a nuclear weapon. That means there is precious little time for diplomacy to work. Any subsequent breaches by Iran could bring it dangerously close to a nuclear weapon, which could push the Europeans to abandon the deal entirely and even provide support for a U.S.-led strike on Iranian facilities.

Before the JCPOA, experts believed that Iran’s breakout point—the point at which the country would possess sufficient weapons-grade uranium for a nuclear bomb—was one year. Beyond that, it would need approximately an additional five months to a year to build a deployable weapon. The nuclear deal was meant to keep that timeline from getting any shorter.

With the most conventional method of creating a nuclear weapon, a bomb requires 25 kilograms of uranium enriched to 90 percent. You can make that 25 kilograms out of 1,050 kilograms of low enriched uranium (LEU). Under the JCPOA, Iran was allowed to maintain a store of only 300 kilograms of LEU at any one time, which meant that it had to ship the vast majority of what it had created outside the country. Before it breached the 3.67 percent enrichment cap, Iran had already broken the deal on July 1 by exceeding the 300-kilogram limit, as confirmed by the International Atomic Energy Agency.

The clock is running down far faster than it was before the JCPOA.

With this first breach, the countdown to 1,050 kilograms began. The problem is that the clock is running down far faster than it was before the JCPOA. Under that agreement, Iran was permitted to keep 6,104 centrifuges operational. Up through January 2019, it had kept 5,060 running, and all of them were Iran’s most basic IR-1 model. The remaining 14,000 IR-1 centrifuges and 1,000 IR-2 centrifuges were put in storage.

The Iran deal did not restrict Iranian development of more efficient centrifuges, nor did it explicitly prohibit Iran from developing its ballistic missiles to carry nuclear warheads—and in the last few years, the country has done both.

At the time of the JCPOA’s signing, the relatively rudimentary technology of the IR-1 had a breakdown rate of about 40 percent. That’s because the stresses placed on the centrifuge’s parts from spinning at high speeds—as well as destructive vibrations—cause their parts to crack or fail in other ways. Since Iran was prohibited from manufacturing new centrifuges, it was assumed that Iran’s time to reach the breakout point would thus remain the same—or even recede into the distance, if some of the mothballed centrifuges were rendered inoperable due to the passage of time.

But the Atomic Energy Organization of Iran (AEOI) now claims that its scientists have reduced the IR-1’s breakdown rate to a mere 1 percent. By slashing the rate, Iran maintains a significantly higher number of IR-1 centrifuges than Western negotiators expected. Iran has thus become dangerously more efficient in its quest to enrich uranium and potentially make a bomb.

Meanwhile, for the last 12 years, including after it signed the nuclear agreement, Iran has been developing the IR-4 centrifuge, which has four to five times the enrichment capacity as the IR-1. On Jan. 30, Ali Akbar Salehi, the head of the AEOI, declared in a television interview with Iran’s Channel 2 that Iran’s testing of the IR-4 centrifuge had been completed and that Iran could “easily manufacture them on an industrial scale.” It is also working on the IR-6, which may have up to 10 times the enrichment capacity of the IR-1, and the IR-8, which has about 20 times the enrichment capacity, according to the AEOI. On April 10, Iranian President Hassan Rouhani even announced the installation of a cascade of 20 IR-6 centrifuges at the enrichment facility at Natanz. Salehi boasted that Iran’s effort to develop these higher-capacity centrifuge models for mass production had advanced unimpeded by the nuclear deal, which had banned building them but not the capacity to mass produce them.

Under the pre-JCPOA countdown clock, assuming no secret programs or outside help, Iran would now be one year away from breakout point and about one and a half years away from a deliverable nuclear weapon. But given the advances of Iran’s nuclear program under the JCPOA, Iran’s breakout could now be only four months—or less, if a few thousand of its more sophisticated centrifuges are brought online. In this case, Iran’s time to a deployable nuclear weapon could be six months or less.

The six-month timetable may push the remaining parties to the deal, particularly in Europe, to abandon the JCPOA and come to the United States’ side. The turning point may be if Iran activates a combination of IR-1 and more sophisticated centrifuges to enrich uranium to 20 percent. A stockpile of 20 percent enriched uranium would cut Iran’s estimated breakout time by more than half.

As Tehran races toward the breakout point, it has also cut the time available for diplomacy to succeed. Any further provocations may be a breach too far.