A general view of the Arak heavy-water project
A general view of the Arak heavy-water projectReuters

Iran has breached another limit of its 2015 nuclear deal with major powers by accumulating slightly more than 130 tons of heavy water, a substance used in a type of reactor it is developing, the UN nuclear watchdog said in a report seen by Reuters on Monday.

Heavy water is not as sensitive as uranium, which Iran is enriching in a quantity and to a level of purity beyond limits in the deal. However, the 2015 deal says Iran should not have more heavy water than it needs, specifying this is estimated to be 130 metric tons.

“On 16 November 2019, Iran informed the Agency that its stock of heavy water had exceeded 130 metric tons,” the International Atomic Energy Agency (IAEA) said in a report to member states obtained by Reuters.

“On 17 November 2019, the Agency verified that the Heavy Water Production Plant (HWPP) was in operation and that Iran’s stock of heavy water was 131.5 metric tons,” added the agency.

Heavy water is, among other things, used as a moderator to slow down reactions in the core of nuclear reactors like one Iran has been developing at Arak.

Iran has gradually scaled back its compliance with the 2015 deal in response to US President Donald Trump’s withdrawal from the agreement last May.

Most recently, the Islamic Republic restarted uranium enrichment at the underground Fordow facility in violation of the deal.

Britain, France and Germany have been trying to save the nuclear deal and have vowed to help Iran evade the economic sanctions imposed by the US, shielding companies doing business with the rogue state in an effort to preserve the Iran nuclear deal.

The chief of Iran's atomic agency recently blamed Europe for his country scaling back its commitments under the deal, saying their broken promises gave the Islamic Republic little choice.