Uranium enrichment is the process used to make fuel for nuclear power plants, but when extended it can also produce fissile material for an atomic bomb.
VOA: standard.2009.11.28
But, in effect, off-shore, outside of Iran, so that this would satisfy the concerns of others like the United States and the Europeans that Iran couldn't secretly use this process to create a stash of what's called fissile material for a nuclear weapon.