UNITED NATIONS -- Iran is being accused of illicitly stepping up purchases for its heavy water reactor, which if completed will produce enough plutonium for several nuclear weapons a year, U.N. diplomats said Tuesday.
What to do with the research reactor, which is under construction in the city of Arak, is among the disagreements between Iran and the U.S. at ongoing talks meant to put long-term curbs on Tehran's nuclear program in exchange for sanctions relief.
The U.S. and its partners want Iran to agree to re-engineer Arak to a light-water reactor that produces only minuscule amounts of plutonium. The Iranians would rather re-engineer it to produce less plutonium -- but that process is reversible, and therefore opposed by the Americans.
The allegation against Iran by an unnamed country, if true, would suggest that Tehran is rejecting the U.S. reconfiguration into a light-water reactor.
The accusation was contained in a report to the Security Council sanctions committee prepared by experts monitoring sanctions against Iran, according to two diplomats familiar with the report. They spoke anonymously because the report hasn't been made public.
Behrouz Kamalvandi, spokesman for the Atomic Energy Organization of Iran, said he had no information about the purchase of any new equipment for Arak. "Iran has agreed not to set up new equipment in Arak facility and it has not done so ever since," he said.
The Security Council has imposed four rounds of sanctions against Iran because of concerns it is seeking to develop nuclear weapons and its refusal to suspend enrichment. Tehran claims its nuclear program is peaceful and exists only to produce energy for civilian use.
The sanctions, which have chipped away at Iran's economy, include a ban on the import of nuclear and missile-related materials. If the overseas purchases for Arak are confirmed, they would violate sanctions.
In theory, purchases for the Arak reactor could be a deal breaker in negotiations between Iran and six major powers on a long-term nuclear deal. But the Americans appear determined to try and work out an agreement nonetheless, even while acknowledging that Iran is trying to evade sanctions on its nuclear program.
State Department spokeswoman Marie Harf said Washington not only knows -- and is concerned -- about "Iran's illicit procurement activities," but has spoken about them publicly and has imposed penalties on companies involved.
"Indeed it is in part precisely because of our concerns about Iran's procurement activities that we believe it is vital to see if we can conclude a comprehensive agreement that gives us transparency into Iran's nuclear program," she said.
Harf noted that Iran has upheld its commitments under last year's interim deal signed in Geneva between Iran and world powers and aimed at testing Tehran's claim that it does not seek atomic weapons.
A yearlong effort by the two sides to seal a nuclear deal by a Nov. 24 deadline failed and talks have been extended for seven months. Among the major unresolved issues are how many -- and what kind -- of centrifuges which can enrich uranium Iran should be allowed to have.
Diplomats said the expert panel's report cites a "relative decrease" in procurement related to centrifuge enrichment by Iran in recent months.