The agency said the team from the International Atomic Energy Agency (IAEA) visited the heavy-water reactor site in Arak, which is currently under construction. Heavy water is used in one type of nuclear-fuel production process.
Iran agreed earlier this month to let the IAEA inspectors visit the Arak complex. The move is a key step in efforts to allay concerns about Iran's nuclear program.
On August 6, IAEA inspectors are scheduled to continue their investigation with visits to the Natanz uranium-enrichment plant and a uranium-ore conversion plant near Isfahan. The two plants conduct separate stages of the nuclear fuel-making process.
(Reuters, AFP)