UN sees small but significant Iranian nuke deal violation

VIENNA — The United Nations agency monitoring the nuclear pact between Iran and six world powers said Wednesday that Iran is in violation of the deal meant to curb its ability to make atomic arms by storing marginally more heavy water than the agreement allows.

Heavy water is a concern because it is used to cool reactors that can produce substantial amounts of plutonium. That, in turn, can be applied to making the fissile core of nuclear warheads.

The U.N’s International Atomic Energy Agency said in a confidential report obtained by The Associated Press that Iran had exceeded the heavy water allotment of 143.3 tons only slightly — by 220 pounds. The report also noted Iran had served notice it would resolve the issue by exporting 5 metric tons, substantially more than the excess amount.

Wednesday’s report said the agency verified the overhang on Tuesday, just days after IAEA chief Yukiya Amano “expressed concerns” to top Iranian officials.

A senior diplomat familiar with the issue said the Iranians had told the IAEA the shipment would be leaving their country within the next few days. The diplomat requested anonymity because he was not authorized to speak on the record about Iran’s nuclear program.

Still, with both sides closely watching for violations, the breach was sensitive even beyond the technical uses of heavy water, especially since it was the second such breach since implementation of the deal curbing Iran’s nuclear program in exchange for sanctions relief.

In February, a month after the deal went into effect, the agency noted for the first time that Iran had exceeded its allotted limit of heavy water. The amount was greater in that case.