Updated Thursday, November 29, 2012 at 05:48 AM
The head of the U.N. nuclear agency says he cannot provide a "credible assurance" for Tehran's claims that all of its atomic activities are peaceful.
Speaking Thursday at a board meeting of the 35-country International Atomic Energy Agency, Yukiya Amano also expressed concern over Iran's "activities" at Parchin, southeast of Tehran.
His experts want to visit the site amid suspicions that it was used for secret tests related to nuclear weapons developments. His language is diplomatic shorthand for an alleged cleanup at the site.
Iran denies any interest in nuclear weapons and says it never tried to develop them. It dismisses concerns that it is enriching uranium for possible use as the core of a warhead, saying it wants only to produce reactor fuel.
The diagram shows a bell curve and has variables of time in micro-seconds and power and energy, both in kilotons _ the traditional measurement of the energy output, and hence the destructive power of nuclear weapons. The curve peaks at just above 50 kilotons at around 2 microseconds, reflecting the full force of the weapon being modeled. The Farsi writing at the bottom translates "changes in output and in energy released as a function of time through power pulse."
In this April 8, 2008 photo provided by the Iranian President's Office, Iranian President Mahmoud Ahmadinejad, center, visits the Natanz Uranium Enrichment Facility some 200 miles (322 kilometers) south of the capital Tehran.