FACT CHECK: Iran’s nuclear weapons capability: A May report by the Institute for Science and International Study, which analyzed data collected by the International Atomic Energy Agency, said that Iran had produced roughly seven tons of low-grade enriched uranium.

“This total amount of 3.5 percent low enriched uranium hexafluoride, if further enriched to weapon grade, is enough to make over five nuclear weapons,” the institute reported.
Uranium enrichment percentages refer to concentrations of uranium-235, the radioactive isotope that produces nuclear reactions. Nuclear power plants operate with concentrations of 3 to 5 percent; nuclear weapons require 90 percent.

Between the two extremes is 19.75 percent enriched uranium, which is used in research reactors. The Institute for Science and International Study reported in June that if Iran further enriched its supply of this concentration of uranium, it could produce less than half of the weapons-grade uranium it would need to make a bomb. At its current rate of production, the institute estimated that Iran will have enough 19.75 percent enriched uranium in February 2013 to make a bomb.

Earlier this month, the Institute for Science and International Study estimated that Iran could produce enough weapons-grade uranium to make a bomb in less than a month, if it devoted its full resources to that purpose.

“Although Iran’s breakout times are shortening, an Iranian breakout in the next year could not escape detection by the [International Atomic Energy Agency] or the United States,” the institute reported. by Callum Borchers, Globe... 10/23/2012 1:57:35 AM