Updated February 2, 2009
Iran’s bank of rapidly spinning centrifuges has produced a stockpile of low-enriched uranium, able to fuel nuclear reactors, but able also to fuel nuclear weapons if further enriched by re-circulating it through the centrifuges. The re-circulation raises the concentration of the uranium isotope U-235, which fissions in nuclear weapons such as the one dropped on Hiroshima.
Based on the amount of low-enriched uranium Iran has stockpiled, and the amount it is believed to be producing each month, the Wisconsin Project estimates that by December 2008, Iran had accumulated enough U-235 to fuel one bomb quickly. "Quickly," in this context, means two to three months – about the time it would take Iran to raise the level of U-235 in its uranium stockpile from 3.8 percent to over 90 percent.
As Iran increases the number of centrifuge machines it is operating, and increases its stockpile of low-enriched uranium, it will consolidate its status as a "virtual" nuclear weapon state.
Iran's progress towards this status as of February 1, 2009 is estimated below:
http://www.iranwatch.org/ourpubs/art...timetable.html