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LINK TO VIDEO With less than five months before the American Presidential elections, U.S. relations with the Islamic Republic of Iran seem to be moving on two parallel routes leading to heating up and cooling down. There has been a prisoner swap, with express calls on the American side to enlarge this opening for a comprehensive deal focusing on the nuclear dimension but not limited to it; but at the same time there are credible reports that the Iranian regime is moving its uranium stockpile dangerously close to a weapons-grade quantity. Do these currents contradict or complement one another? Panel: – Jonathan Hessen, Host. – Amir Oren, Analyst. – Olli Heinonen Former Deputy General IAEA and a Distinguished fellow, Stimson center, Washington DC (New York, USA). – Mr. Meir Javedanfar, Iran lecturer, IDC Herzliya (Central Israel).
Iran continued to take steps during the IAEA reporting period to violate the JCPOA’s limitations on advanced centrifuges. The following summarizes the deployment of advanced centrifuges in the six lines at the Natanz Pilot Fuel Enrichment Plant, or PFEP, their enrichment status, and their enrichment capacity, if known, as of the last reporting period.
Iran was no longer remixing the product and tails (waste), but collecting it separately, meaning that Iran accumulated enriched uranium at the PFEP. As of May 20, 2020, 483.1 kilograms (uranium mass) of uranium enriched up to two percent had been collected from lines 2 and 3 of the six lines at the PFEP. The IAEA does not provide the average enrichment of this material, although it can be safely assumed that it varies from just above natural uranium (0.71% uranium 235) up to 2% uranium 235. (This average value matters because the amount of separative work to make, for example, a quantity of two percent enriched uranium, is several times the amount needed to make that same quantity of one percent enriched uranium.) The IAEA did not reveal how much enriched uranium was collected in lines 4, 5, and 6 of the PFEP.
Lines 2 and 3 contained a variety of centrifuge types and numbers, many accumulating enriched uranium. The following is a summary, as of the end of the last reporting period, of all the centrifuges installed in lines 2 and 3, or about 90 in total, that were accumulating enriched uranium (so far about 483.1 kg, as mentioned above):
According to the IAEA report, as of June 1, Iran was testing the following single centrifuges with uranium hexafluoride in lines 2 and 3, but not accumulating enriched uranium:
Iran was also accumulating enriched uranium in lines 4, 5, and 6, in redeployed IR-2m and IR-4 centrifuge cascades (164 centrifuges each) and an IR-6 cascade (135 centrifuges). The IAEA did not specify how much enriched uranium had been produced so far, or its level of enrichment. This enriched uranium is likely included in the IAEA’s aggregate, reported amount of enriched uranium enriched up to 4.5 percent.
The redeployed cascades of 164 IR-2m and IR-4 centrifuges in lines 4 and 5 of the PFEP represent Iran’s most successful advanced centrifuge types. When previously operated in a production-scale cascade, each IR-2m centrifuge had an enrichment capacity of about 3.7 separative work units (SWU) per year. The total cascade thus has an estimated enrichment capacity of about 607 SWU per year. This is equivalent to about 675 IR-1 centrifuges operating in production cascades, where each IR-1 is assumed to have a capacity of 0.9 SWU per year. The IR-4 has a lower capacity than the IR-2m, estimated here as ten percent lower, or about 3.3 SWU per year per centrifuge. The production cascade would have a total output of about 540 SWU per year, or equivalent to about 600 IR-1 centrifuges. These two cascades represent a total capacity of about 1147 SWU/year, or the equivalent of about 1275 IR-1 centrifuges.
Line 6 at the PFEP held 135 IR-6 centrifuges in a single cascade (up from 72 during the last reporting period). Iran stated earlier that the line will hold 164 IR-6 centrifuges in a cascade. The IR-6 has a single machine estimated capacity of 6.8 SWU per year. No recent data are available publicly on its performance in this cascade. Assuming that the cascade value would be about 90 percent of the capacity achieved by an IR-6 operating by itself, 135 IR-6 centrifuges in cascade would have an output of about 826 SWU per year, and a cascade of 164 IR-6 would have total capacity of about 1000 SWU per year, or the equivalent of about 1115 IR-1 centrifuges.
Line 1 currently holds an inoperable cascade of IR-1 centrifuges. However, Iran reportedly announced planned modifications of line 1 that include removal of the inoperable centrifuges, apparently to clear space for upcoming R&D activities.
In addition, according to the quarterly report, Tehran was violating an additional JCPOA limitation by conducting mechanical testing of centrifuges at the Tehran Research Centre and a workshop at Natanz. According to the IAEA report, “On 27 May 2020, the Agency verified that, for periods of four to ten days, Iran had conducted mechanical testing of up to six IR-4 centrifuges simultaneously, and up to ten IR-6 centrifuges simultaneously” at these two locations.
As can be seen, Iran is developing a large number of centrifuges simultaneously, an unusual practice. The centrifuges at the PFEP include: IR-1, IR-2m, IR-3, IR-4, IR-5, IR-6, IR-6m, IR-6s, IR-6sm, IR-7, IR-8, IR-8s, IR-8B, IR-s, and IR-9. No information was provided in the IAEA report on how well these centrifuges work, their failure rates, or why so many of them are being developed. Typically, a centrifuge program with such characteristics is likely failing at developing a commercially viable centrifuge, although several of these centrifuges could work adequately in a nuclear weapons program, where efficiency, low failure rates, and low cost are not priorities.
n the breakout estimate, the following conditions are assumed:
Under these conditions, the breakout calculator gives an estimate of 3.1 months, with no initial set-up time added. Doing so would lengthen the estimate to about 3.5 months. In addition to the IR-2m re-deployment, a major factor is that most of the LEU is already enriched to 4.5 percent instead of 3.5 percent, a significant change from estimates performed before the JCPOA’s Implementation Day, since this one percent increase in enrichment can provide up to a 15 to 20 percent reduction in breakout time to produce 25 kilograms of weapon-grade uranium. The greater enrichment level also means that the production of 25 kilograms of weapon-grade uranium requires less LEU than if it were enriched to 3.5 percent: 900 kilograms of 4.5 percent LEU vs. 1250 kilograms of 3.5 percent LEU in hexafluoride mass. This last condition is particularly significant here, since it means that the existing amount of LEU is enough to reach the requisite amount of weapon-grade uranium without the need to also use some natural uranium to make a portion of the needed WGU. As a result, the process is strictly a three-step one instead of a three-step followed by a four-step one. This ability to use only three steps to reach weapon-grade, instead of four, is why the media often discusses a key threshold of about 1000 kg of LEU as significant