Russia's Atomstroyexport said it finished the so-called "hot operational testing" that was in the final stage before the fall opening of the facility, RIA Novosti reported Thursday.
"Efficiency tests of the reactor equipment and supporting technological systems was held," Atomstroyexport officials said in a statement.
In June, Iran's nuclear chief, Ali Akbar Salehi said the Bushehr facility would be operational in mid-September. Russian officials said construction of the plant wasn't affected by U.N. sanctions against Iran for its nuclear operations that Western countries fear are for development of a nuclear weapon. Iran maintains its nuclear operations are for peaceful purposes.