IAEA says Iran nuclear arms studies “serious concern”

Reuters: Iran's alleged research into designing nuclear warheads remains a matter of serious concern and needs "substantive explanations", the U.N. nuclear watchdog said on Monday.

VIENNA (Reuters) – Iran's alleged research into designing nuclear warheads remains a matter of serious concern and needs "substantive explanations", the U.N. nuclear watchdog said on Monday.

The International Atomic Energy Agency (IAEA) also said in its latest report on Iran that Tehran had 3,500 centrifuges operational at its Natanz underground nuclear facility.

The agency said it had not been given access to Iranian nuclear-related sites that it asked to see in April.

The agency has pressed Tehran for answers following Western intelligence alleging that Iran had covertly studied how to design atomic bombs. Iran has dismissed the intelligence as baseless, forged or irrelevant.

In a report in February, the IAEA said Iran had 3,000 older P-1 centrifuges running at very low capacity at the Natanz enrichment plant. A small number of "new generation" centrifuges, supposedly able to enrich 2-3 times as fast, were being tested in the above-ground pilot wing there.

Iran announced in April it had begun installing 6,000 new centrifuges at Natanz.

But later that month, IAEA chief Mohamed ElBaradei said 3,300 and 3,400 centrifuges of the 1970s vintage P-1 type operational at Natanz.

(Reporting by Karin Strohecker; Editing by Giles Elgood)