Iran’s Stock of near 20 Percent LEU under the Extension of the Joint Plan of Action | Institute for Science and International Security

Despite the fact that Iran no longer has a stock of near 20 percent low enriched uranium (LEU) in hexafluoride form, it retains a significant portion of this material in the form of oxide. Under the July 2014 extension of the interim deal of the Joint Plan of Action, Iran pledged to convert 25 kilograms of LEU oxide into fuel assemblies for the Tehran Research Reactor. The goal of this step was to reduce the ease of reconverting this uranium oxide and using it in a breakout to nuclear weapons. However, only about 5-10 kilograms of this near 20 percent LEU actually ended up in the fuel. In the most recent extension, Iran committed to use another 35 kilograms for that purpose. Although the efficiency rates are expected to be higher this time, Iran will still retain large amounts of near 20 percent LEU in both oxide powder and in scrap, in-process material and in waste. The figure below shows that far more LEU, almost triple the amount, is ending up in scrap and waste than in fuel assemblies. The bulk of this LEU is recoverable and usable in fuel or in a breakout to nuclear weapons.