This week, Iran and the world powers reached a nuclear agreement that will severely restrict Iran's nuclear program. It will also impose an invasive inspections and monitoring regime to make sure Iran is holding to its commitments under the deal. And, in return, Iran will get relief from international economic sanctions. But, at its core, this deal is really about limiting Iran's nuclear program. Here are the very basics of what that program will look like under the conditions of the deal, once it comes into force:
Centrifuges: Iran will give up most of its centrifuges
Centrifuges are pieces of equipment used to enrich uranium, a natural ore, into nuclear fuel. Iran currently has about 20,000 centrifuges, so it will have to give most of them up. It will also be allowed to use only its old, first-generation centrifuges. This means Iran will have a much smaller nuclear program, in terms of its ability to create nuclear fuel or, potentially, nuclear material for a bomb.
Enrichment: Iran can only enrich uranium to energy-grade material
Iran will be allowed to turn raw uranium into the kind of fuel that can be used for a nuclear power plant: uranium that is enriched to 3.67 percent. It is barred from enriching beyond that, and its nuclear material will be stopped far short of the 90 percent enrichment needed for a nuclear bomb.
Uranium: Iran will have to give up most of its stockpile
Currently, Iran has a stockpile of 10,000 kilograms, or about 22,000 pounds. It now has to give up a stunning 97 percent of its nuclear stockpile, almost all of it. This means that Iran will have a lot less nuclear material on hand, so that if it ever decides to break the agreement and build a bomb it will have very little capacity to do so. The upshot is that Iran's "breakout time" — the time it would take them to put together enough weapons-grade uranium for one bomb — has been extended from about 3 months to a full year.
Facilities: Enrichment only at Natanz, research at Fordow, and a plant at Arak
The US wanted Iran to close most of its nuclear facilities; Iran wanted to keep using them all for nuclear development. They compromised: Iran can use only the Natanz facility, which will be under heavy inspections and monitoring, for enriching uranium. It can keep its hardened facility at Fordow, but just for research, and it can't use fissile material there. The Arak facility matters because Iran has used it to develop plutonium, another nuclear fuel that can be used for energy or for a weapons program. Iran will be required to restructure its plutonium plant at Arak such that it will only make energy-grade plutonium, and will ship out its spent plutonium. The Arak facility will also be monitored.