How long would it take Iran to develop nukes? No one knows the answer for sure

Experts aren’t sure how long it would take Iran to develop a nuclear weapon.

The timeframe is key to the debate surrounding the administration’s negotiations with Iran and other countries on a nuclear deal that would place limits on Iran’s program in exchange for the lifting of sanctions.

{mosads}The Senate this week approved legislation that will allow Congress to review a deal — and to vote to disapprove it. The House will take up the bill next week.

A key factor that lawmakers will consider is the risk that Iran will obtain nuclear weapons, and they will want to know whether any deal negotiated with Iran is extending the time Tehran would need to develop a bomb.

“How far along is Iran in the weaponization process?” Rep. Eliot Engel (N.Y.), the ranking Democrat on the House Foreign Affairs Committee, said at an April hearing. “If Iran were to enrich enough fissile material to achieve a ‘breakout,’ how long would it then take them to then build a warhead and mate it to missile?  We must have answers to these questions.”

The Obama administration has warned that Iran needs just two or three months of “breakout time,” or, time it would take for Iran to have enough fissile material to build a nuclear weapon. 

But it would still take more time for Iran to create a weapon.

“What this means is that even if Iran crosses that line, it would still have a long way to go to have a nuclear weapon it can use, let alone a stockpile of nuclear weapons,” said Ariane Tabatabai, an associate at the Belfer Center’s International Security Program.

President Obama said in March 2013 that it would take over a year for Iran to actually develop a nuclear weapon. 

The year-long assessment tracks with an estimate from Israeli Prime Minister Bibi Netanyahu. In a September 2012 address at the United Nations, he indicated it would take about a year for Iran to develop a bomb.Later that year, he switched to the earliest time estimated to get enough fissile material, which at the time he said was “six months.” 

People get confused between the two definitions, of getting enough material and developing a bomb, said Frank Von Hippel, professor and co-director of Princeton University’s Program on Science and Global Security.

There are multiple steps to getting a nuclear bomb, and producing enough weapons grade uranium is just the first step, said Hans Kristensen, director of the Nuclear Information Project at the Federation of American Scientists.

Iran would also have to develop a warhead, get the uranium into the warhead, and have a way to deliver it, he said. Even then, it’s not clear whether the weapon would work, since Iran has never done any nuclear weapons testing. 

Experts say they can’t assess how close Iran is to actually completing those steps, without knowing what past research it has done, and how far it went.  

The agreement being negotiated is supposed to address the issue, commonly referred to as “past military dimensions” of Iran’s nuclear program. 

Lawmakers have called for answers on how long it would actually take. 

“We need to know how far along Iran progressed in their weaponization so that we can understand those consequences as it relates to other breakout time issues,” Sen. Bob Menendez (D-N.J.), co-sponsor of the Iran bill, said Thursday. 

Negotiators last month reached a framework agreement on a deal that would extend Iran’s breakout time to a year. Negotiators are not trying to fill in all the details on a deal by June 30.

“The breakout time has become the main criterion for judging how much Iran scales back its nuclear program under a deal but it is far from being fully reliable,” said Tabatabai.

The “worst case assumption” is that Iran could build a nuclear bomb as soon as Iran obtains enough weapons-grade uranium, Von Hippel said.

He said Iran has done some research on warhead design, but without knowing how far it got, it’s impossible to know. 

“Nobody knows the answer,” he said.