Iran has reiterated that it is a "nuclear power" because it has enriched uranium to 20 percent for use in a medical research reactor. Iran has a stockpile of low-enriched uranium (less than 5 percent). With 20 percent enrichment, it could move quickly to making weapons-grade uranium enriched at 90 percent. Below is a simplified explanation of the enrichment process. Iranian leaders consistently say they are not interested in nuclear weapons.
SOURCE: armscontrolwonk.com | Glenn Kessler and Laura Stanton/The Washington Post - February 12, 2010