To build a nuclear bomb, Iran would need much more than weeks

The first question of Tuesday night’s vice presidential debate was whether the candidates would support or oppose a preemptive strike against Iran by Israel.

In it, the governor Tim Walz and the senator JD Vance They considered the issue urgent because Iran has “dramatically reduced the time it would take to develop a nuclear weapon,” reducing its acquisition time to “one or two weeks.”

The premise behind Margaret Brennan’s question of CBS Newsone of the debate moderators, highlights a popular confusion about what it takes to build a usable nuclear bomb.

Nuclear experts said Wednesday that it would take Iran not weeks to build a nuclear weapon, but months and possibly even a year.

Brennan’s question, they added, began the debate with a fake note.

“I don’t think there’s any danger that Iran will start exploding nuclear weapons this year,” said Houston G. Wood, professor emeritus of mechanical and aerospace engineering at the University of Virginia.

Wood, a specialist in atomic centrifuges and other nuclear matters, estimated that it would take until Iran one year in designing a weapon once it had enough nuclear fuel.

“It would probably take many months,” said Siegfried S. Hecker, former director of the Los Alamos weapons laboratory in New Mexico, “not weeks.”

Experts said the CBS question confused the time it would likely take Iran to make a highly enriched uranium bomb with the overall process of weaponizing it.

Once enough uranium metal is produced, it must be carefully machined to form the core of an atomic bomb, which is then placed between the other parts of a nuclear warhead that would be placed on a missile.

“You need advanced metallurgy and engineering,” Hecker, who served as director of Los Alamos from 1986 to 1997, said in an interview.

The process is more difficult than you might expect.

Nuclear workers, for example, face health risks because tiny radioactive particles created during the shaping of nuclear parts could, unless they are careful, settle in their lungs and stimulate cancerous growths.

The CBS question, although based on a false premise, seemed appropriate for the moment because Iran fired 180 missiles against Israel on Tuesday night in a dramatic escalation of the conflict between the two countries.

Israel has vowed to retaliate, and the president Joe Biden He said Wednesday that he would not favor an attack on Iran’s nuclear infrastructure.

The widespread misunderstanding of the state of Iran’s nuclear capabilities stems from numerous recent public reports that gave detailed timelines for the production of fuel for a nuclear bomb.

But those reports offer few details about the other steps Iran must complete to build a nuclear weapon, including feats of atomic purification, engineering, manufacturing and testing.

Public reports focus on what weapons experts call nuclear leak:

the time it would take for a potential atomic power to acquire atomic fuel equivalent to a bomb.

An August report from the Institute for Science and International Security, a private Washington group that closely follows nuclear proliferation, for example, stated that Iran had developed its expertise in fuel manufacturing to the point that it could now “explode quicklyin a matter of days.”

The institute’s president, David Albright, did not respond to questions about the group’s timeline for Iran.

If Iran were to achieve the explosion, it would face a series of other crucial steps before producing a nuclear warhead.

One of them would be to develop a system of electronic triggeror to activate a group of conventional explosives that compress the nuclear core, initiating the chain reaction that emits bursts of atomic energy.

Additionally, the entire warhead must be rigorously tested to ensure that it can withstand the extraordinary heat and the shocks of atmospheric re-entry.

Nuclear experts say the lengthy process also often culminates with the explosive testing of a bomb underground to ensure that the warhead will detonate as expected in a war.

A March study by the Congressional Research Service cited federal reports that said Iran needed between one and two weeks to produce enough enriched uranium for a single weapon.

But that study also cited testimony from Gen. Mark Milley, former chairman of the Joint Chiefs of Staff, that Iran would need “several months to produce a real nuclear weapon.”

And he said that “the US intelligence community assesses that Iran has not resumed work on its weapons research.”

Finally, the Congressional study noted that reports from the International Atomic Energy Agency, the United Nations watchdog that monitors Iran’s nuclear progress, suggested that Iran “does not yet have a viable nuclear weapon design or system.” of appropriate explosive detonation”.

Wood said many additional factors come into play in assessing the real threat that Iran’s nuclear program could pose to Israel.

“You don’t want to shoot a gun and then run out of ammunition,” he said in an interview. Iran, Wood suggested, might want to possess an arsenal of a half-dozen or more weapons before testing one underground or detonating one in war.

The big problem for court martials and arms control, he added, is that “having that first one is a game changer.”