Iran has resumed uranium enrichment at its underground Fordow facility, taking the next step in its stage-by-stage move away from its nuclear deal with the west.

The country’s atomic energy organisation said early on Thursday that uranium gas had successfully been injected into 1,044 centrifuges, in the presence of UN inspectors.

The centrifuges have previously spun empty under the terms of the 2015 deal, known as the Joint Comprehensive Plan of Action (JCPOA), when Iran agreed to limit its nuclear activities in return for the lifting of economic sanctions.

The Iranian president, Hassan Rouhani, had said on Wednesday the step was reversible and did not specifically say if the injection of gas would be used to speed the enrichment of uranium.

However, Kazem Gharibabadi, Iran’s ambassador to the International Atomic Energy Agency, later said Iran had informed the IAEA about “the start of injecting UF6 [uranium hexafluoride] into centrifuges at Fordow”.

Q&A What is the Iran nuclear deal? Show Hide In July 2015, Iran and a six-nation negotiating group reached a landmark agreement known as the Joint Comprehensive Plan of Action that ended a 12-year deadlock over Tehran’s nuclear programme. The deal, struck in Vienna after nearly two years of intensive talks, limited the Iranian programme, to reassure the rest of the world that it cannot develop nuclear weapons, in return for sanctions relief.

At its core, the JCPOA is a straightforward bargain: Iran’s acceptance of strict limits on its nuclear programme in return for an escape from the sanctions that grew up around its economy over a decade prior to the accord. Under the deal, Iran unplugged two-thirds of its centrifuges, shipped out 98% of its enriched uranium and filled its plutonium production reactor with concrete. Tehran also accepted extensive monitoring by the International Atomic Energy Agency (IAEA), which has verified 10 times since the agreement, and as recently as February, that Tehran has complied with its terms. In return, all nuclear-related sanctions were lifted in January 2016, reconnecting Iran to global markets. The six major powers involved in the nuclear talks with Iran were in a group known as the P5+1: the UN security council’s five permanent members – China, France, Russia, the UK and the US – and Germany. The nuclear deal is also enshrined in a UN security council resolution that incorporated it into international law. The 15 members of the council at the time unanimously endorsed the agreement. On 8 May 2018, US president Donald Trump pulled his country out of the deal. Iran announced its partial withdrawal from the nuclear deal a year later. Saeed Kamali Dehghan, Iran correspondent

In the nuclear deal, which has been unravelling since Donald Trump pulled the US out last year, Iran agreed to refashion its Fordow plant as a centre for the production of stable isotopes, which have applications in industry, agriculture and medicine.

Iran says its nuclear programme is entirely for civil nuclear purposes, but the move will add to existing US Congress pressure to remove US waivers for research at the Fordow site.

The US has always seen Fordow as a covert and highly fortified facility intended for the production of enough uranium for one or two nuclear weapons per year.

Iran, confirming a plan first announced in September, also said on Monday it was going ahead with a tenfold increase in its enriched uranium production at its Natanz facility.

Rouhani said the steps taken so far – including going beyond the deal’s enrichment and stockpile limitations – could be reversed if Europe offered a way to avoid US sanctions choking off its crude oil sales abroad.

“All of the steps Iran has taken to reduce its commitments to the nuclear deal are reversible and Iran will uphold all of its commitments under the deal when the remaining signatories – France, Britain, Germany, Russia and China – do the same.” He said the United Nations nuclear agency would still be allowed to inspect Iran’s activities, including work at Fordow.

Rouhani added: “We know their sensitivity with regards to Fordow. With regard to these centrifuges, we know. But at the same time when they uphold their commitments we will cut off the gas again … so it is possible to reverse this step.”

He said Iran would continue to negotiate with European powers behind the scenes to reach an agreement on how Europe could build trade with Iran and circumvent US secondary sanctions. “We can’t unilaterally accept that we completely fulfil our commitments and they don’t follow up on their commitments,” he said.

In an attempt to further calm European reaction, Rouhani’s chief of staff told the Iranian Mehr news agency that the nuclear deal was still in place and that “there’s a long way before our complete withdrawal”.

Centrifuges are machines that spin at supersonic speeds to separate atomic elements. They can be used to enrich uranium as well as other elements, such as xenon and iridium, for medical and industrial purposes.

Feeding uranium gas into spinning centrifuges allows for the separation of a highly radioactive form of uranium, U-235, which can be split to produce power in nuclear reactors.

If the use of gas at Fordow is intended to enrich uranium, the step has the potential to put Iran much closer to 20% uranium enrichment.

U-235 must make up 3-5% of uranium to be of commercial use for nuclear power and a 85-90% concentration for a nuclear weapon. But the most laborious part of enrichment is between 0-20% – once this level is reached, enrichment can be boosted to 90% quite rapidly.



Iran says it currently produces uranium enriched at 4.5% U-235, in breach of the 3.67% limit set by the nuclear deal, but nowhere near the 20% level required for research reactors.

Ilan Goldenberg, Middle east security director at Centre for a New American Security, said: “Rouhani’s announcement that Iran will start spinning 1,000 centrifuges at Fordow is by far the most significant step Iran has taken outside the JCPOA, and another sign that Trump’s maximum pressure campaign is failing.”

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Iran has gradually shelved its commitments made under the deal with world powers in response to the US maximum economic sanctions programme imposed last year. That programme has blocked Iran’s oil exports, damaged its currency and interfered with the flow of medicines.



Reactions to the Iranian decision from JCPOA signatories were initially hostile. The Kremlin said on Tuesday it was concerned by Iran’s intention to further scale back its commitment to the 2015 nuclear deal, and that Moscow would like the deal to remain in place.

The French government said the announcement was a breach of the JCPOA, but would await the formal report from the IAEA on the decision’s implications.

JCPOA’s collapse coincided with a tense summer of attacks on oil tankers and Saudi oil facilities that the US blamed on Iran. Tehran denied the allegation, though it did seize oil tankers and shoot down a US military surveillance drone.