Iran, world powers reach nuclear accord

Understanding outlines limits on Iran’s nuclear programme so it cannot lead to atomic weapons.

The United States, Iran and five other world powers on Thursday announced an understanding outlining limits on Iran’s nuclear programme so it cannot lead to atomic weapons, directing negotiators toward achieving a comprehensive agreement within three months.

Reading out a joint statement, European Union foreign policy chief Federica Mogherini said a “decisive step” after more than a decade of negotiations had been achieved. Iranian Foreign Minister Mohammad Javad Zarif followed with the same statement in Farsi. U.S. Secretary of State John Kerry and the top diplomats of Britain, France and Germany also briefly took the stage behind them.

In a tweet, Mr. Kerry said there was an agreement “to resolve major issues on nuclear programme. Back to work soon on a final deal”.

Ms. Mogherini said the seven nations would now start writing the text of a final accord. She cited several agreed-upon restrictions on Iran’s enrichment of material that can be used either for energy production or in nuclear warheads. She said Iran won’t produce weapons-grade plutonium.

Crucially for the Iranians, economic sanctions related to its nuclear programmes are to be rolled back after the U.N. nuclear agency confirms compliance.

Key issues in Iran nuclear talks with world powers

>BREAK-OUT TIME

The goal of the negotiations is an arrangement whereby Iran would need at least one year to produce enough fissile material -- high enriched uranium or plutonium -- for a single atomic weapon, should Tehran choose to produce one. That is known as the “break-out” time.

DURATION OF DEAL U.S. President Barack Obama has said that Iran will need to accept limits on its nuclear programme for at least 10 years. Recently Iran had wanted eight years and the U.S. 20 years. They have compromised at 10 years.

URANIUM ENRICHMENT

Originally Iran wanted to maintain all of its uranium enrichment centrifuges, machines that purify uranium for use as fuel in power plants or, if very highly enriched, in weapons. That was around 10,000 operational out of nearly 20,000. The U.S. and others wanted to reduce that number to several hundred. Now, Iran wants to keep around 9,000 while western official are talking 6,000.

RESEARCH AND DEVELOPMENT Iran’s desire to pursue > research and development into advanced centrifuges is one of the biggest sticking points in the talks. Western powers are extremely uncomfortable with allowing Tehran to continue developing more efficient centrifuges that would shorten the break-out time.

PLUTONIUM

Western powers had originally wanted Iran to dismantle a heavy-water reactor at Arak that could yield significant quantities of plutonium. Tehran refused to do so but has agreed to the idea of converting or operating it in a way that ensures the amount of plutonium it could yield would be insignificant. Iran has also agreed not to pursue technology for extracting plutonium from spent fuel.

FORDOW An underground enrichment plant that Iranian officials say they have agreed to convert into an R&D plant. Western officials would like this site converted into something that has nothing to do with enrichment.

STOCKPILES

Iran's uranium stockpiles are an important issue because the less uranium Tehran has on hand, the more centrifuges it can maintain. Originally, Iran wanted to enrich 2.5 tonnes per year, but could settle at half a tonne. Western officials say that allowing Iran to produce more than 250 kg a year would be problematic. The remainder would be relocated to Russia or another country

SANCTIONS The speed of lifting sanctions is another major sticking point in the talks. Iran wants all U.S, European Union and United Nations sanctions lifted immediately. U.S. says sanctions should be lifted gradually. This has become a sensitive issue in the U.S., as Republicans controlling both houses of Congress have threatened to impose new U.S. sanctions on Tehran against the advice of Obama. Obama has said he would veto any new sanctions steps for fear they would torpedo the delicate negotiations. Obama can use executive authority to suspend sanctions but many U.S. measures can only be terminated by Congress.

POSSIBLE MILITARY DIMENSIONS

The Western powers say it is vital that Iran fully cooperate with a U.N. International Atomic Energy Agency (IAEA) investigation into past nuclear activities that could be related to making weapons. Iran has said these “possible military dimensions” (PMD) are an issue it will not budge on.

MONITORING Any deal would require a vigorous monitoring framework to ensure Iranian compliance. Iranian officials say they reject Western demands unlimited inspection powers for the IAEA.