The International Atomic Energy Agency (IAEA), the UN nuclear watchdog, on Tuesday voiced concern that Iran had not clarified queries over possible undeclared nuclear activity, adding that its enriched uranium stockpile was 16 times over the limit, AFP reports.
The two reports issued by the IAEA are the first substantive reports since Iran suspended some inspections in February.
Last week the IAEA said it had extended a temporary agreement with Iran until June 24 which has allowed many inspections to continue.
The report said IAEA director general Rafael Grossi was “concerned that the technical discussions between the agency and Iran have not yielded the expected results,” referring to exchanges on the sites where undeclared nuclear activity may have occurred.
The conclusion comes despite a “proactive and focused effort” launched by the IAEA in April “to break the impasse” over the sites.
The IAEA says that the results of its inspection work have established “a clear indication that nuclear material and/or equipment contaminated by nuclear material has been present” at three undeclared locations, with most of the activity in question dating back to the early 2000s.
The agency also said Iran has failed to answer questions regarding a fourth site where natural uranium may have been present between 2002 and 2003 in the form of a metal disc.
Last year, the IAEA found uranium particles at two Iranian sites it inspected after months of stonewalling.
Although the sites where the material was found are believed to have been inactive for nearly two decades, opponents of the 2015 nuclear deal Iran signed with world powers say evidence of undeclared nuclear activities shows that Iran has not been acting in good faith.
Iran said last month it had supplied the IAEA with documents explaining the discovery of suspect enriched uranium traces.
In late April, Grossi said that his agency is still trying to clarify answers from Iran on outstanding questions involving traces of human-made enriched uranium at three sites in the country, and also acknowledged that Iran’s ability to enrich uranium since the collapse of the 2015 nuclear deal had expanded as it uses more-advanced centrifuges.
In a separate report on Monday, the IAEA said Iran’s stockpile of enriched uranium is around 16 times the limit laid down in the 2015 deal with world powers.
It gave an estimate of a stockpile of 3,241 kilograms (7,145 pounds) but said that it was not able to verify the total.
The limit laid down in the 2015 deal was 300 kilograms of uranium in a particular compound form, the equivalent of 202.8 kilograms of uranium.