A top Iranian nuclear official said that traces of enriched uranium discovered at an underground bunker came from a "routine technical issue," the country's official IRNA news agency reported Saturday.
Ali Asghar Soltanieh, Tehran's envoy to the International Atomic Energy Agency, was responding to a report by the U.N. nuclear watchdog that said it had found radioactive traces at an Iranian nuclear site. The uranium found had been enriched to a level that is slightly closer to the threshold needed for nuclear weapons than Iran's previous highest-known enrichment grade.
The IAEA said in the confidential report obtained Friday by the Associated Press that it was asking Tehran for a full explanation about the traces. But the report was careful to avoid any suggestion that Iran was intentionally increasing the level of its uranium enrichment.
Tehran said the find was a technical glitch, according to the report. Analysts and diplomats said Iran's version sounded plausible.
The West suspects Iran is pursuing a weapons program. Tehran denies the charge, saying its nuclear program is aimed at peaceful purposes.
Soltanieh said the report on Iran's nuclear activities was "historic evidence" that proved the peaceful nature of Iranian nuclear activities, while the uranium discovery was blown out of proportion.
"This issue shows that some intend to damage the existing constructive cooperation between Tehran and the International Atomic Energy Agency," he was quoted as saying.
The higher the enrichment, the easier it becomes to re-enrich uranium to the 90 percent needed for weapons grade. As a result, the finding of traces at 27 percent at the Fordo enrichment plant in central Iran sparked international interest.
Iran denies any plans to develop nuclear weapons, but has for years declined offers of reactor fuel from abroad, including more recent inducements of 20-percent material if it stops producing at that level.