In response to the sabotage of an Israeli-affiliated Iranian nuclear site last weekend, Iran began enriching its uranium supply to 60 percent purity – the level the country has ever reached for a weapon.
Iran’s move, reported in state media on Friday, made good the threats Iranian officials announced following the sabotage that threw a new cloud over the talks to save the 2015 deal that broke the nuclear Limits Iran’s ability to trade in exchange for the relief of sanctions.
Iranian President Hassan Rouhani went further and, when those talks resumed in Vienna, boasted that his scientists could easily enrich uranium to 90 percent purity – weapons grade fuel – despite the fact that, as Iranian leaders have repeatedly stressed, he did insisted that Iran “never aspires to make an atomic bomb. “
What is the significance of uranium purity, which is at the heart of the deal the negotiators are trying to save? And why is Iran making these claims? Some basic questions and answers:
What is the goal of uranium enrichment?
Uranium contains a rare radioactive isotope called U-235, which can power nuclear reactors with low enrichment and atom bombs with much higher propulsion. The goal of uranium enrichment is to increase the percentage of U-235, which is often achieved through the use of centrifuges – machines that spin some form of unrefined uranium at high speed.
Under the nuclear deal known as the Joint Comprehensive Plan of Action, Iran was allowed to keep up to 300 kilograms of uranium, which was enriched to 3.67 percent for civilian nuclear power. Iran also agreed to stop enriching uranium above 5 percent and shut down hundreds of centrifuges. The uranium supply fell well below the amount needed to make a single bomb.
Why does Iran have more enriched uranium now?
After President Donald J. Trump rejected the Iran deal in 2018, imposed economic sanctions on Iran, and imposed further penalties, Iran took a tiered series of steps from complying with the deal to retaliation – increasing its uranium supply by 3.67 percent , Adding centrifuges and increasing uranium purity in part of the supply to 20 percent and restricting international inspectors’ access to some nuclear sites. Meanwhile, the country said these were easily reversible acts.
What makes the 60 percent enrichment level particularly threatening is that the difficult enrichment process becomes much easier and requires fewer centrifuges when it gets to the higher purities. In other words, a purity of 90 percent is much easier from 20 percent and even easier from 60 percent.
How much enriched uranium does Iran have now?
According to the International Atomic Energy Agency, the United Nations nuclear surveillance arm, Iran had amassed 2,967.8 kilograms of uranium in February – roughly 14 times the nuclear deal limit and theoretically enough to power about three atomic bombs if refined to weapon quality. The stock contains 17.6 kilograms, enriched to 20 percent – also banned until 2030.
Did last weekend’s sabotage affect Iran’s ability to enrich uranium?
Almost certainly yes. While Iranian officials have come up with conflicting reports about the extent of centrifuge damage at Natanz, the sabotaged enrichment complex, at least one has claimed that several thousand machines have been destroyed. But Iran also has a second well-known enrichment site, an underground facility called Fordow, which houses around 1,000 centrifuges. Some were used earlier this year to enrich uranium to 20 percent.
Nuclear experts estimate that Iran would have to use around 500 centrifuges for this task in order to enrich uranium with a purity level of 20 percent to 60 percent. Around 100 more spinning machines would be needed to further increase the degree of cleaning to 90 percent.
In an interview, Olli Heinonen, a former chief inspector of the International Atomic Energy Agency, said Iran could theoretically enrich from 60 percent to 90 percent in a week, compared to a month or so if it went up from 20 percent.
“It’s not a big difference. At this point, this is a demonstration, ”he said of Iran’s 60 percent risk of enrichment. “They want to show that they can.”
Does that mean Iran could be producing a bomb in a week?
No. Dr. Heinonen and others said it was far more difficult to turn 90 percent enriched uranium into the core of an atomic bomb. It could take months. And such an estimate does not include the technology, testing, and time required to mount the weapon on a missile warhead, which could take much longer.
Why should Iran point out such capabilities?
The danger of militarizing its nuclear capabilities has always been a negotiating tool for Iran – both in the talks that led to the 2015 agreement and in the ongoing negotiations. At the same time, Tehran has made it clear that it wants to reach an agreement that will end the onerous American sanctions that are severely hampering Iranian oil sales and international financial transactions. This partly explains Iran’s reluctance to take military revenge on attacks on its nuclear sites.
“Iran sees itself as a boxer in the ring,” said Mehrzad Boroujerdi, an Iran expert, professor and director of the School of Public and International Affairs at Virginia Tech. “People hit left and right without damaging the other side.”
With the 60 percent gain, Boroujerdi said, “Iranian leaders are trying to fall back on their aces.”
