The Washington Post reports:

A major expansion underway inside Iran’s most heavily protected nuclear facility could soon triple the site’s production of enriched uranium and give Tehran new options for quickly assembling a nuclear arsenal if it chooses to, according to confidential documents and analysis by weapons experts.

Inspectors with the International Atomic Energy Agency confirmed new construction activity inside the Fordow enrichment plant, just days after Tehran formally notified the nuclear watchdog of plans for a substantial upgrade at the underground facility built inside a mountain in north-central Iran.

Iran also disclosed plans for expanding production at its main enrichment plant near the city of Natanz. Both moves are certain to escalate tensions with Western governments and spur fears that Tehran is moving briskly toward becoming a threshold nuclear power, capable of making nuclear bombs rapidly if its leaders decide to do so.

At Fordow alone, the expansion could allow Iran to accumulate several bombs’ worth of nuclear fuel every month, according to a technical analysis provided to The Washington Post. Though it is the smaller of Iran’s two uranium enrichment facilities, Fordow is regarded as particularly significant because its subterranean setting makes it nearly invulnerable to airstrikes.

It also is symbolically important because Fordow had ceased making enriched uranium entirely under the terms of the landmark 2015 Iran nuclear agreement. Iran resumed making the nuclear fuel there shortly after the Trump administration unilaterally withdrew from the accord in 2018.

Iran already possesses a stockpile of about 300 pounds of highly enriched uranium that could be further refined into weapons-grade fuel for nuclear bombs within weeks, or perhaps days, U.S. intelligence officials say. Iran also is believed to have accumulated most of the technical know-how for a simple nuclear device, although it would probably take another two years to build a nuclear warhead that could be fitted onto a missile, according to intelligence officials and weapons experts.

Iran says it has no plans to make nuclear weapons. But in a striking shift, leaders of the country’s nuclear energy program have begun asserting publicly that their scientists now possess all the components and skills for nuclear bombs and could build one quickly if so ordered. In the past two years, Fordow has begun stockpiling a kind of highly enriched uranium that is close to weapons-grade, with a purity far higher than the low-enriched fuel commonly used in nuclear power plants. [Continue reading…]