Ex-IAEA official: In theory, Iran could reach weapons-grade enrichment in a week

With Iran’s announcement Friday that it has begun enriching uranium to 60 percent purity, a former top official at the UN’s nuclear watchdog said the Islamic Republic could potentially reach weapons-grade purity within the space of a week if it wanted to.

Olli Heinonen, an ex-deputy director-general of the International Atomic Energy Agency, stressed jumping from 60% to 90% in a week was theoretical, comparing it to the month or so needed to go from 20% to 60%. Enrichment at 20% is already a relatively short technical step away from weapons-grade levels of 90%.

However, Heinonen told the New York Times that Iran would still need months to produce a nuclear bomb even if it did so.

Heinonen also played down the significance of the latest increase in enrichment levels.

“It’s not a huge difference. At this point, this is a demonstration,” he said. “They want to show that they can do it.”

At 60% purity, Friday’s announcement marked the highest level to which Iran has enriched uranium. In January, it began enriching to 20%, a decade after its decision to begin enriching to that level nearly brought an Israeli strike targeting its nuclear facilities — tensions that only abated with the 2015 nuclear deal. Under that accord, Tehran was prohibited from enriching uranium beyond 3.67%.

The announcement came days after an attack at Iran’s Natanz nuclear facility that Iran has blamed on Israel, which damaged or destroyed thousands of centrifuges. Analysts have said the explosion that hit Natanz’s power supply is believed to have set back Iran’s ability to enrich uranium at large amounts by long months.

State TV referred to the decision to enrich to 60% as a “show of power against terrorist roguery.” Mahmoud Vaezi, the chief of staff for Iran’s president, similarly said it sent the message that Iran’s atomic program ”will not be stopped through the assassination of nuclear scientists and sabotage in nuclear facilities.”

The International Atomic Energy Agency, which monitors Iran’s nuclear program, did not immediately respond to a request for comment. Earlier this week, it sent its inspectors to Natanz and confirmed Iran was preparing to begin 60% enrichment at an above-ground facility at the site.

The Natanz attack appeared to be part of an escalating shadow war between Israel and Iran. Israeli authorities have not commented on the attack, for which Tehran has vowed revenge. But it has been widely ascribed to Israel, and unnamed intelligence officials cited in various Israeli reports have given specific details on the sabotage.

The move to increase enrichment could draw further Israeli action, as Prime Minister Benjamin Netanyahu has vowed never to allow Tehran to obtain a nuclear weapon.

Iran, which insists its nuclear program is peaceful, previously had said it could use uranium enriched up to 60% for nuclear-powered ships. However, the Islamic Republic currently has no such ships in its navy.

Israel is adamant that Iran is seeking a nuclear arsenal and duping the west. Iran frequently vows to destroy Israel.

The incident at Natanz and the Iranian decision to ramp up enrichment levels came amid ongoing talks in Vienna that are aimed at finding a way for the United States to reenter the nuclear agreement and have Iran comply again with its limits. The accord, from which former president Donald Trump withdrew the US in 2018, prevented Iran from stockpiling enough high-enriched uranium to be able to pursue a nuclear weapon in exchange for the lifting of economic sanctions.

The latest round of diplomatic negotiations aimed at ensuring the US’s return to the accord lasted for roughly two hours on Thursday afternoon, with Russia’s ambassador to the UN in Vienna, Mikhail Ulyanov, tweeting afterwards that the “general impression is positive.”

Israeli officials, led by Netanyahu, have adamantly opposed the US returning to the nuclear deal, putting Jerusalem at odds with the new White House administration.

Iran’s supreme leader on Wednesday dismissed initial offers being made at the talks in Vienna, describing them as “not worth looking at.”

Agencies contributed to this report.