Iran underlined its disregard Friday for the U.N. deadline to halt uranium enrichment — now expired — when its president vowed never to give up its nuclear program and accused the West of misrepresenting Tehran's nuclear activities.

History

Iran's nuclear program began in the Shah's era, including a plan to build 20 nuclear power reactors. Two power reactors in Bushehr, on the coast of the Persian Gulf, were started but remained unfinished when they were bombed and damaged by the Iraqis during the Iran-Iraq war.

Following the revolution in 1979, all nuclear activity was suspended, though subsequently work was resumed on a somewhat more modest scale.

The current nuclear program is headed by the president, the commander of the Iranian Revulutionary Gaurd Corps (IRGC), the head of the Defense Industries Organization, and the head of Iran's Atomic Energy Organization (IAEO).

Iran ratified the Nuclear Nonproliferation Treaty in 1970 and since February 1992 has allowed the IAEA to inspect any of its nuclear facilities. Prior to 2003 no IAEA inspections had revealed Tehran's violations of the NPT.

In February 2003, Iranian President Mohammad Khatanmi reportedly announced a program for a complete nuclear fuel cycle, which was to consist of these components:

Mining uranium in Saghand (200 kilometers, 125 miles from Yazd) from 350 meters (1160 feet) deep.

Preparing Yellow Cake in Ardekan near Yazd (at a site known as Ardekan Nuclear Fuel Unit)

UCF Facility in Isfahan site. At the Uranium Conversion Facility (UCF) in Isfahan, using the yellow cake prepared in the Ardekan, a number of by-products including uranium hexofloride (UF6), metallic uranium, and uranium oxide (Uo2) are produced. These are later used for uranium enrichment.

Natanz Uranium Enrichment Facility. Using the yellow cake and the products of the Isaheur UCF unit, uranium is enriched using the centrifuge equipments, and nuclear fuel pellets are to be eventually produced in Natanz. These pellets could then be used to form the fuel rods

• Locations

Bushehr: Nuclear power station

Iran's nuclear program began in 1974 with plans to build a nuclear power station with German assistance. The project was abandoned because of the Islamic revolution, but revived in 1992 when Tehran signed an agreement with Russia to resume work at the site.

Isfahan: Uranium conversion plant

Iran is building a plant here to convert uranium ore into three forms: hexafluoride gas (used in gas centrifuges), uranium oxide (used to fuel reactors, albeit not the type Iran is constructing) and metal (often used in the cores of nuclear bombs).

The International Atomic Energy Agency is concerned about the metal's use, as Iran's reactors do not require it as fuel.

Natanz: Uranium enrichment plant

Iran suspended work on its uranium enrichment plant at Natanz in 2003, but has recently reopened the facility.

In 2003, a leaked IAEA report said that weapons-grade uranium had been found in samples taken from the site. Iran blamed contaminated imported equipment and an independent report later confirmed this.

According to some estimates, when complete, Natanz could house some 50,000 advanced gas centrifuges, which would produce enough weapons-grade uranium to produce more than 20 weapons per year.

Other estimates suggest the plant will have a total of 5,000 centrifuges when initial stages of the project are completed. With that number, Iran would be able to produce sufficient enriched uranium to make a small number of nuclear weapons each year.

Arak: Heavy water plant

The apparent existence of a heavy water facility near the town of Arak first emerged with the publication of satellite images by the U.S.-based Institute for Science and International Security in December 2002.

Heavy water is used to moderate the nuclear fission chain reaction either in a certain type of reactor — albeit not the type that Iran is currently building — or produce plutonium for use in a nuclear bomb.

(Sources: Global Security, BBC News)