Ahmadinejad visits Iranian heavy water reactor site at heart of dispute with UN nuclear agency

Iran says President Mahmoud Ahmadinejad has visited a planned nuclear reactor that's part of a growing dispute between Tehran and the U.N.'s atomic agency.

The official IRNA news agency said Ahmadinejad's visit Sunday coincided with the beginning of operations to install the main cap at the heavy water reactor in Arak, about 255 kilometers (152 miles) southwest of Tehran.

Unlike Iran's lone Russian-built reactor, heavy water-type reactors do not need enriched uranium to operate. They also produce more plutonium, which could be used to make warhead material.

Iran insists it only seeks reactors for energy and medical use. The West and its allies fear Iran could develop nuclear weapons.

The U.N.'s International Atomic Energy Agency has urged Iran to suspend work on the reactor, which could begin operations next year.