October 29, 2012

The Iranian Nuclear Program: Timelines, Data, and Estimates V4.1

Maseh Zarif

This assessment is version 4.1 of a recurring analysis of Iran’s nuclear program.

KEY POINTS

IRAN’S ENRICHMENT CAPABILITIES ARE NO LONGER THE PRIMARY BOTTLENECK IN A NUCLEAR BREAKOUT SCENARIO.

  • Iran can produce one bomb’s worth of fissile material faster than it likely can deploy a functioning nuclear device. Tracking Iran’s uranium enrichment activities now addresses only Iran’s intentions and the size of its projected arsenal.

  • Obtaining fissile material in the form of weapons-grade uranium or plutonium is the most technically demanding step in acquiring a nuclear weapons capability. Designing an explosive device (which consists of non-nuclear components) and a delivery system for the device are comparatively less technically challenging. Those efforts can also proceed parallel to enrichment.

  • Iran has the infrastructure and material to produce weapons-grade uranium. It has enough enriched uranium to produce fuel for five nuclear weapons after conversion to weapons-grade. Its expanding enrichment activities have significantly reduced the time required for it to produce weapons-grade uranium. The key accelerants for this shrinking timeline have been its growing stockpiles of low- and medium-enriched uranium, which is 90% of the way to weapons-grade, and an increasing number of centrifuges enriching.

Nuclear Program Expansion

  • Iran has installed many more centrifuges at the hardened Fordow facility than are now actually spinning, providing a reserve and/or surge capacity that will be difficult for Israel to destroy.

  • The recent installation of 1,076 additional centrifuges at Fordow has more than doubled capacity at that facility. 

  • Iran’s uranium enrichment is at historically high rates despite increasing sanctions and damage to the Iranian economy.

  • Iran will likely have enough near-20% enriched uranium to rapidly produce fissile material for 2 nuclear weapons by late 2013/early 2014. 

  • Iran recently told the International Atomic Energy Agency (IAEA) that it plans to begin operating the Arak heavy water reactor in Q3 2013. This reactor will be capable of producing two warheads’ worth weapons-grade plutonium per year once operational.

Breakout Timelines

  • Iran needs 3.7 MONTHS to produce 25 kg of weapons-grade uranium and 1.9 MONTHS to produce 15 kg weapons-grade uranium at the buried Fordow and pilot Natanz enrichment facilities.* It can cut these times significantly using the newly installed centrifuges at Fordow. 

  • Iran needs 0.8-2.2 MONTHS to produce 25 kg weapons-grade uranium and 1-4 WEEKS to produce 15 kg weapons-grade uranium at the main Natanz enrichment facility.* The higher end of the range accounts for a three-step conversion process.

  • The existence of undeclared (covert) enrichment sites would have a significant impact on breakout estimates.

  • Estimates of the time Iran needs to build a nuclear device to use this fissile material are all longer than these timelines.

  • Evidence of significant Iranian enrichment beyond 20% will strongly suggest not only that the decision to weaponize has been made, but also that the Iranians believe that they will shortly have a viable warhead in which to place weapons-grade uranium.

*Estimates assume Natanz and Fordow are used with the operational capacity reflected in the August 2012 IAEA report. Iran may need 15-25 kg weapons-grade uranium for an implosion-type bomb design depending on its level of technical ability (high technical ability would require less material). 

This product is an exposition of the technical data contained in numerous International Atomic Energy Agency (IAEA) reports informed by the discussions of experts in the field of nuclear proliferation. It is a work in progress in that it will be revised continuously based on new information from the IAEA reports and other sources and on feedback from readers. We welcome your informed commentary on the technical considerations presented in this document. Please send your comments, with references to source-date or documentation, to [email protected].

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