Iran and six world powers said on April 2 that they had reached an agreement on "key parameters" of a comprehensive nuclear agreement that must be finalized by June 30.
Here are five things to know about the announced commitments.
'Breakout' Time
The commitments would extend the amount of time Iran would need to enrich enough uranium for one nuclear weapon -- known as “breakout” time -- to “at least one year” for a duration of 10 years, according to a U.S. fact sheet released on April 2.
Iran’s current breakout time is estimated at two to three months.
Kelsey Davenport, director for Nonproliferation Policy at the Arms Control Association, says that “from a nonproliferation standpoint, the parameters established in this deal are very strong.”
“This deal effectively blocks Iran’s pathways to a weapon using both uranium and plutonium, and it puts in place stringent monitoring and verification to ensure that any deviation from the agreement or any covert program will be immediately detected,” she told RFE/RL.
Centrifuges
Centrifuges can be used to enrich uranium for energy, medical, and scientific purposes, as well as for nuclear weapons.
Under the parameters announced on April 2, Iran would cut the number of its installed centrifuges from around 19,000 currently to 6,104, according to the U.S. fact sheet. Of these centrifuges, 5,060 would be allowed to enrich uranium for 10 years.
All of these 6,104 centrifuges would be first-generation IR-1 models that enrich much less efficiently than newer models.
The excess centrifuges would be placed in storage and monitored by the International Atomic Energy Agency (IAEA), the UN’s nuclear watchdog.
Enrichment
Tehran agreed to enrich uranium significantly below levels needed for nuclear weapons, and to reduce its current stockpile of around 10,000 kilograms of low-enriched uranium to 300 kilograms for 15 years, the U.S. fact sheet says.
A bank of Iranian centrifuges at a facility in Natanz in 2012
Iran would also be required to forego building new facilities to enrich uranium for the next 15 years.
The commitments would also introduce enrichment restrictions at Iran’s Natanz facility, preventing it from using newer-model centrifuges and placing those currently installed at the facility in storage for 10 years under IAEA monitoring.
Verification
Iran has agreed to give the IAEA “regular access” to all of its nuclear facilities, as well as to the supply chain feeding Tehran’s nuclear program, the U.S. fact sheet says. The IAEA would also be allowed to inspect uranium mines and monitor manufacturing and storage facilities related to the program.
Iran would also be required to allow IAEA inspectors to “investigate suspicious sites or allegations” of covert facilities for enrichment, conversion, and centrifuge and yellowcake production inside the country.
Mark Fitzpatrick, director of the Nonproliferation and Disarmament Program at the London-Based International Institute for Strategic Studies (IISS), says the agreement would create a strict verification infrastructure.
“It would be detected very quickly if Iran were to use any of its declared facilities,” Fitzpatrick told RFE/RL. “If Iran were to try to hide something, that would also very likely be detected because this deal -- the parameters -- include a lot of verification measures that go beyond the normal IAEA monitoring.”
These measures include access to centrifuge production storage and to procurement channels for equipment and material, he added.
“So that’s a new kind of measure that has never been implemented in any other IAEA agreement,” he said.
Sanctions
The U.S. fact sheet states that Iran will be granted relief from sanctions if it “verifiably abides by its commitments.”
This relief would include a suspension of U.S. and EU nuclear-related sanctions and a lifting of all UN Security Council resolutions concerning Iran’s nuclear activities once Tehran fulfills its obligations to address “all key concerns.”
The UN Security Council, however, would introduce a new resolution that leaves in place key provisions of the earlier resolutions dealing with “the transfers of sensitive technologies and activities.”
If Iran does not fulfill its commitments, the U.S. and EU sanctions would “snap back into place,” according to the fact sheet. If Tehran’s noncompliance cannot be resolved through a dispute resolution process stipulated in the agreement, UN sanctions could be reimposed, as well.
U.S. sanctions on Iran related to “terrorism, human rights abuses, and ballistic missiles” would remain in place, according to the U.S. fact sheet.
Davenport says that once the deal is implemented, “Iran will see relief from sanctions quite quickly.”
“The final lifting of many of the sanctions, particularly from the U.S. and UN sides, will come later as Iran works with the International Atomic Energy Agency to resolve some of the agency’s outstanding concerns about its past actions,” Davenport told RFE/RL. “But Iran will certainly see relief in the short term based on these parameters.”