The US built a secret replica of Iran's nuclear facilities ...

In its tense negotiations over slowing Iran's nuclear development, the United States isn't just walking a diplomatic tightrope. It's walking a technological one, too, trying to allow Iran to continue researching only those technologies that can be used for peaceful purposes like energy, and none that could be weaponized.

Thankfully, the diplomats have some help. At Oak Ridge National Lab in Tennessee, the U.S. has a secret mock-up of Iran's nuclear capabilities, The New York Times says. Here, government scientists try to determine what Iran can and cannot do with its current technologies by trying to do it themselves, and then provide negotiators with their best guesses as to which technologies Iran should and shouldn't be allowed to keep.


A prime target of the effort was redesigning Iran's still-under-construction nuclear reactor at Arak, a sprawling complex ringed by antiaircraft guns. The question was how to prevent the reactor from producing weapons-grade plutonium, a main fuel of atom bombs. Iran insisted the reactor was being built to produce medical isotopes for disease therapy.

In that case, Iran proposed a way to redesign the facility and then Argonne National Laboratory had to evaluate that proposal. The scientists added a few tweaks based on their research that should prevent Arak from being used to develop weapons-grade plutonium.

The next round of talks starts tomorrow in Vienna. If the diplomats get the job done and the deal gets signed, they have scientists and their mock-up Iranian nuclear reactors to thank
http://www.popularmechanics.com/science/energy/a15214/us-replica-iran-nuclear-plant/