Iranian President's Office/AP/File
3. Natanz uranium fuel enrichment plant
The existence of the Natanz plant, Iran’s key uranium enrichment site, was also disclosed in 2002 by the MEK. Located in central Iran, it is a key uranium enrichment site and is now the primary site for Iran’s centrifuge program. It holds about 8,000 centrifuges for making nuclear fuel in its underground facility, although a 2011 IAEA report states that about 1,000 centrifuges were damaged by the Stuxnet computer virus. Later reports indicated that those centrifuges were quickly replaced.
The Natanz site is one of the most controversial sites in the country. Iran claims it aims only to produce nuclear power peacefully, and the low-enriched uranium refined to 3.5 percent purity at Natanz is meant to fuel nuclear reactors. But when enriched to far higher levels, such as 90 percent, the material can be used to make a nuclear weapon. So far, Iran has shown it can enrich to almost 20 percent and says it is stopping there.