IAEA revisits Syria reactor in uranium traces probe

VIENNA (Reuters) - U.N. inspectors revisited a Damascus nuclear research reactor on Tuesday to take more swipe samples after judging Syria's initial explanation for uranium traces found there to be doubtful.

An International Atomic Energy Agency official confirmed inspectors were at the site a day after an IAEA report said tests of samples taken in August 2008 showed the traces did not come from Syria's declared nuclear inventory, as it maintained.

The report also said Syria was still blocking follow-up IAEA access to a desert site of what U.S. intelligence reports said was a nascent, North Korean-designed nuclear reactor geared to yield atomic bomb fuel, before Israel bombed it in 2007.

The Vienna-based IAEA has been checking whether there could be a link between the Damascus and Dair Alzour sites since discovering mysterious particles of processed uranium at both.

Some analysts have said the findings raised the question of whether Syria used some natural uranium intended for the alleged reactor at Dair Alzour in tests applicable to learning how to separate out bomb-grade plutonium from spent nuclear fuel.

Syria, an ally of Iran which is under IAEA investigation over nuclear proliferation suspicions, has denied ever having an atom bomb programme and has said the intelligence is fabricated.

Syria told the IAEA earlier this month that the traces at the Damascus site could have come from domestically-produced uranium concentrate known as "yellow cake", or from imports of commercial uranyl nitrate which it had not declared to the IAEA.

Tuesday's inspector trip aimed to verify that assertion.

Syria at first told the IAEA that the traces found last year came with contaminated equipment used at the site, but IAEA test results did not stand up this explanation, and the particles could not be traced to Syria's declared inventory.