The Iranian Nuclear Program      Timelines, Data, and Estimates                                Maseh Zarif                ...
Recent DevelopmentsStart of Advanced Centrifuge Installation        IAEA inspectors observed that Iran installed 180 IR-2m...
Status of Near-20% Enriched UraniumIran has enough near-20% enriched uranium with which to produce weapons-gradeuranium (W...
Enrichment Program Assessment   IRAN’S ABILITY TO PRODUCE FISSILE MATERIAL IS NO LONGER THEPRIMARY BOTTLENECK FOR ITS DEVE...
Breakout TimelinesTime needed to produce fuel for 1 nuclear weapon:   Iran needs 3.6 months to produce 25 kg of weapons-gr...
Iran has outfitted the hardened Fordow enrichment facility with more than 2,000IR-1 centrifuges that are not yet operating...
Iran’s 3.5% Enriched Uranium Production at Natanz Assessment: Stuxnet derailed the 2009 Iranian effort to expand enrichmen...
Near-20% Enriched Uranium Production and Projected Growth at Fordow/Natanz                                                ...
Italicized dates are estimates;bold dates are fixedListed inspection windows are                                          ...
Making an Atomic Bomb (Concept)                                Acquire Weapons-grade                                      ...
Making an Atomic Bomb (Status as of FEB 2013)                                                         ay                  ...
Why Enrichment Accelerates at Higher Concentration of U-235                                                         Centri...
Iran’s Known Uranium Enrichment FacilitiesFordow Fuel Enrichment Plant (FFEP)As of FEB 2013:    696 IR-1 centrifuges produ...
Natanz Enrichment FacilitiesPilot Fuel Enrichment Plant (PFEP)                                                            ...
Fordow Enrichment Facility: Status and Construction                  Image taken SEP 14 2012                              ...
Scope, Assumptions and Technical Points                                                                    Page 16        ...
ScopeThis product is an exposition of the technical data contained in numerousIAEA reports informed by the discussions of ...
Breakout ScenariosWorst-case  The worst-case scenarios assume that Iran devotes all operational centrifuges at Natanz (as ...
Atomic Weapons DataSmall atomic weapons can be built from cores consisting of 10-25 kg of uranium enriched to ~90% U-235 (...
Projections for the May 2013 IAEA Report IR-1 centrifuges being fed at Natanz FEP: ~9,000 Total 3.5% LEU produced at Natan...
SourcesInternational Atomic Energy Agency (IAEA) – The IAEA publishes quarterly reports on Iran’s nuclear program and enri...
For more on Iran, visit www.irantracker.org
Upcoming SlideShare
Loading in …5
×

The Iranian Nuclear Program: Timelines, Data, and Estimates V6.0

10,269 views

Published on

This assessment is the eighth version of a recurring analysis of Iran’s nuclear program. 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 INP@aei.org.

0 Comments
0 Likes
Statistics
Notes
  • Be the first to comment

  • Be the first to like this

No Downloads
Views
Total views
10,269
On SlideShare
0
From Embeds
0
Number of Embeds
4,619
Actions
Shares
0
Downloads
60
Comments
0
Likes
0
Embeds 0
No embeds

No notes for slide

The Iranian Nuclear Program: Timelines, Data, and Estimates V6.0

  1. The Iranian Nuclear Program Timelines, Data, and Estimates Maseh Zarif Deputy Director and Iran Team Lead AEI Critical Threats Project Version 6.0 FEBRUARY 2013 Current as of FEB 28 2013 using data from IAEA report dated FEB 21 2013 www.criticalthreats.org Copyright © 2013 by the AEI Critical Threats Project
  2. Recent DevelopmentsStart of Advanced Centrifuge Installation IAEA inspectors observed that Iran installed 180 IR-2m centrifuges at the Natanz enrichment facility. These machines have an output rate several times greater than first-generation centrifuges. The deployment of IR-2m centrifuges in significant quantities will drastically reduce the time required for weapons-grade (~90% enriched) uranium production and, therefore, increase the risk that Iran will be able to produce such material undetected.Significant Installation of First-Generation Centrifuges Iran increased its enrichment capacity by installing more than 2,200 additional first-generation centrifuges at the Natanz enrichment facility between November 2012 and February 2013. This mass installation will further cut the time needed to produce weapons-grade uranium. It also indicates that Iran is still able to produce centrifuges in significant quantities despite sanctions and interdiction efforts.Stockpiling for Second Bomb’s Worth of ~20% Enriched Uranium Iran is producing near-weapons grade (~20% enriched) uranium at rate of about 10 kilograms per month. It has converted to powder and sent to the Tehran Research Reactor only a small fraction of this material thus far. Iran has stockpiled, in gas and powder forms, enough 20% uranium to rapidly convert to fuel for one bomb. It is now on its way to accumulating a second bomb’s worth of 20% uranium.Stonewalling the IAEA Iran failed to cooperate with IAEA officials regarding the IAEA’s investigation into weaponization activities over the course of 3 meetings held since November 2012. The IAEA has said that its information indicates that some weaponization-related activities continued after 2003 and that some activities may still be ongoing.Alternative Fissile Material Acquisition Path The IAEA observed continued installation work at the Arak (IR-40) reactor, scheduled to “go hot” in 2014. This reactor, once operational, will be capable of producing plutonium for two weapons every year after reprocessing. Page 2 Copyright © 2013 by the AEI Critical Threats Project
  3. Status of Near-20% Enriched UraniumIran has enough near-20% enriched uranium with which to produce weapons-gradeuranium (WGU) for one warhead. Some of this material is currently stored in oxidepowder form, which can be converted back into a gas for weapons-grade enrichment. NEAR-20% ENRICHED URANIUM 141 kg needed to produce one warhead’s worth of WGU 189 kg produced as of February 2013 IAEA report (see pie chart for breakdown) 181.5 kg available in gas, oxide powder, or intermediary form 6.5 kg * 1 kg Converted into U3O8 fuel Enriched down to <4% plates and sent to the Tehran Research Reactor (as of February 2013) 68.5 kg 113 kg Fed into process for Stored as enriched conversion to U3O8 uranium gas (available for WGU (available now for WGU production after re- production) conversion to gas form)** Total near-20% enriched uranium produced: 189 kg* The IAEA reports that Iran has sent 5 fuel assemblies containing near-20% LEU to the Tehran Research Reactor. Each assembly has at most 1.3 kg LEU.**Methods for converting near-20% material in U3O8 form back into a gas “are standard processes in the nuclear industry and Iran uses them as part ofits uranium ore processing.”1 The conversion can be done using specialized facilities and can be accomplished in “days to weeks.”2 The near-20% LEU canonly be classified as unusable in a breakout once the fuel assemblies containing the U3O8 are inserted and irradiated in a reactor core. Only a smallfraction of Iran’s near-20% LEU in the form of U3O8 has been manufactured into fuel assemblies and placed into or irradiated in a reactor core.1) Gregory Jones, “Fueling the Tehran Research Reactor: Technical Considerations on the Risks and Benefits,” NPEC, October 12, 2009.2) Ibid. Page 3 Copyright © 2013 by the AEI Critical Threats Project
  4. Enrichment Program Assessment IRAN’S ABILITY TO PRODUCE FISSILE MATERIAL IS NO LONGER THEPRIMARY BOTTLENECK FOR ITS DEVELOPMENT OF A NUCLEAR WEAPON. Obtaining fissile material in the form of weapons-grade uranium or plutonium is the most technically demanding step in developing a nuclear weapon. The parallel steps of designing an explosive device and a delivery system are comparatively less technically challenging. Iran, due to its enrichment program expansion since 2009, can now produce one bomb’s worth of fissile material faster than estimates of the time needed to build a nuclear device to mate the material with. Potential timelines for weapons-grade uranium production could contract further due to increasing centrifuge numbers and types. Iran’s low-enriched uranium stockpile is currently adequate for fueling a small arsenal of nuclear weapons after further conversion to weapons-grade. Enrichment up to weapons-grade uranium (~90% enriched) is one key indicator of Iranian weaponization. Evidence of enrichment beyond research reactor-grade uranium (~20% enriched), material that is 90% of the way to weapons-grade, will strongly suggest not only that the decision to weaponize has been made, but also that the Iranians believe they have (or will shortly have) a viable device. Page 4 Copyright © 2013 by the AEI Critical Threats Project
  5. Breakout TimelinesTime needed to produce fuel for 1 nuclear weapon: Iran needs 3.6 months to produce 25 kg of weapons-grade uranium and 1.9 months to produce 15 kg weapons-grade uranium at the hardened Fordow enrichment facility.* It can cut these times significantly using the centrifuges installed but not yet operating at the Fordow facility. Iran needs 4-10 weeks to produce 25 kg of weapons-grade uranium and 1-5 weeks to produce 15 kg of weapons-grade uranium at the main Natanz enrichment facility.* The higher end of the range accounts for a three-step conversion process.Estimates of the time Iran needs to build a nuclear device to use this fissile material aregenerally longer than the timelines above.The existence of undeclared (covert) enrichment sites would have a significant impacton breakout estimates.*All enriched uranium figures are given in terms of solid uranium (where 1 kg uranium hexafluoride is equal to ~0.67 kgelemental uranium). Estimates assume Natanz and Fordow are used with the operational capacity reflected in the February2013 IAEA report. Iran may need 15-25 kg of weapons-grade uranium for an implosion-type bomb design depending on itslevel of technical ability (high technical ability would require less material). See pages 18, 19, and 21 for further detail. Page 5 Copyright © 2013 by the AEI Critical Threats Project
  6. Iran has outfitted the hardened Fordow enrichment facility with more than 2,000IR-1 centrifuges that are not yet operating. This reserve and/or surge capacitygives Iran the ability to produce near-20% enriched uranium at a faster rate andthe means to convert that stockpile to weapons-grade uranium (WGU) morerapidly in a deeply buried site. Time needed to produce WGU Time needed to produce near- for 1 warhead from near-20% 20% enriched uranium feed enriched uranium at Fordow for WGU for second warhead* Using 696 centrifuges (4 cascades) currently enriching 4.7 MONTHS 14 MONTHS Using 1,392 centrifuges (8 cascades) 2.4 MONTHS 8.6 MONTHS Using 2,784 centrifuges (16 cascades) 1.2 MONTHS 4.7 MONTHS*Assumes constant production of near-20% enriched uranium at smaller pilot facility at Natanz Page 6 Copyright © 2013 by the AEI Critical Threats Project
  7. Iran’s 3.5% Enriched Uranium Production at Natanz Assessment: Stuxnet derailed the 2009 Iranian effort to expand enrichment capability for roughly one year, but the enrichment expansion effort recovered in mid-2010. Neither direct actions nor sanctions have had a visible effect on the enrichment program. Even the Stuxnet success does not appear to have derailed the steady growth of the enriched uranium stockpile. Iran is running its highest number of centrifuges and production rates since the enrichment program began. It has produced enough enriched uranium since 2009 to fuel a small arsenal of nuclear weapons after conversion to weapons grade. New U.S./ Iranian Centrifuges Centrifuges 3.5% LEU UN/EU Stuxnet Scientist enriching installed but produced sanctions Killed not operating Heading Kilograms LEU # centrifugesEnrichment data source: IAEA quarterly reports Page 7 Copyright © 2013 by the AEI Critical Threats Project
  8. Near-20% Enriched Uranium Production and Projected Growth at Fordow/Natanz Amount 705 Projected production level enough needed to produce WGU for three nuclear for: bombs by late 2013. Iran would 4 564 need to begin enriching gradually weapons in installed Fordow cascades toKilograms 19.75% LEU Iran will have produced 282 kg meet this threshold. ~20% enriched uranium by fall 2013 3 423 under steady-state conditions-- weapons enough to produce WGU for two nuclear bombs designed with a low 2 282 level of technical capability. weapons 1 141 weapon 189 kg (as of FEB 2013) 0 May-12 Jul-12 Oct-12 Jan-13 May-13 Jul-13 Oct-13 Jan-14BLACK: Reported productionRED: Steady-state enrichment (a)GREEN: Gradual enrichment expansion in available centrifuges at Fordow (b)PURPLE: Rapid enrichment expansion at Fordow (c)(a) 1,024 centrifuges currently enriching (2 cascades with 328 total IR-1 centrifuges at PFEP and 4 cascades with 696 total IR-1 centrifuges at Fordow)(b) Same as (a) but Iran begins turning on 2 additional cascades at Fordow every two months in March 2013.(c) Iran begins enriching in all 16 cascades installed at Fordow in March 2013. Page 8 Copyright © 2013 by the AEI Critical Threats Project
  9. Italicized dates are estimates;bold dates are fixedListed inspection windows are Key Upcoming Eventsapproximate. The IAEA may beconducting inspections outsideof these windows. 11/27/2013 Approx. date by which Iran—at current rates—will have produced enough near-20% enriched uranium for a second warhead 4/23/2013 - 5/14/2013 7/30/2013 - 8/20/2013 10/18/2013 - 11/8/2013 IAEA Inspection Window IAEA Inspection Window IAEA Inspection Window 3/1/2013 4/1/2013 5/1/2013 6/1/2013 7/1/2013 8/1/2013 9/1/2013 10/1/2013 11/1/2013 12/1/2013 1/1/2014 2/1/20143/4/2013 6/3/2013 9/9/2013 11/28/2013IAEA BOG IAEA BOG IAEA BOG IAEA BOG meets meets meets meets 5/24/2013 8/30/2013 11/18/2013 IAEA Report IAEA Report IAEA ReportIAEA BOG = International AtomicEnergy Agency Board of Governors Page 9 Copyright © 2013 by the AEI Critical Threats Project
  10. Making an Atomic Bomb (Concept) Acquire Weapons-grade Parallel processes Design Parallel processes Acquire delivery Uranium warhead vehicle Centrifuge Acquire weapon cascade design LEU gas Fed back into produces UF6 gas Shahab-3(3.5% U-235) 19.75% U-235 missile Fed back into produces Develop detonator technology Centrifuge Centrifuge cascade Two-step cascade Test design uranium Fed through produces and engineering enrichment then UF6 gas process UF6 gas 0.7% U-235 90% U-235 Build weapon Converted to Processed into Test weapon Mate warhead with delivery vehicle Natural uranium High-enriched elemental uranium (Process complete) solid metal (90% U-235) Page 10 Copyright © 2013 by the AEI Critical Threats Project
  11. Making an Atomic Bomb (Status as of FEB 2013) ay ay w Acquire Weapons-grade Design Acquire delivery w ne Parallel processes Parallel processes r r de warhead vehicle de Uranium Do Un Un Centrifuge Acquire weapon cascade design ay Shahab-3 w ne ne ne LEU gas Fed back into produces UF6 gas r(3.5% U-235) 19.75% U-235 missile Do Do de Do Un Fed back into produces NB: All estimates of Iran’s Develop detonator ay nuclear status and technology w Centrifuge capabilities assume that Centrifuge r there are no clandestine de cascade cascade facilities, and that the Un IAEA has full access to all Test design Fed through produces declared facilities. The and engineering first assumption is impossible to verify. The d then te second assumption is or ne UF6 gas known to be false. UF6 gas ep 0.7% U-235 Do 90% U-235 tr Build weapon d te No or Converted to Processed ep into tr No Mate warhead with g ne Test weapon in g d in Do te delivery vehicle ar or Natural uranium ar ep ep High-enriched (Process complete) ep Pr tr elemental uranium Pr No solid metal (90% U-235) Page 11 Copyright © 2013 by the AEI Critical Threats Project
  12. Why Enrichment Accelerates at Higher Concentration of U-235 Centrifuge 1,373 kg cascade 116 kg LEU gas Fed back into produces UF6 gas (3.5% U-235) 19.75% U-235 559 SWU The work and time required to Fed back into 37 days enrich uranium from its natural produces concentration (0.7%) to 3.5% Centrifuge 5,060 SWU 115 SWU Centrifuge LEU is an order of magnitude cascade 331 days 8 days cascade greater than that required to enrich 20% LEU to weapons- Fed through produces grade concentrations (~90% U- 235). 14,187 kg 15 kg That is because centrifuges UF6 gas UF6 gas 0.7% U-235 90% U-235 must spin more than 14,000 kg of uranium ore to produce Processed Converted to 1,373 kg of 3.5% LEU, but only into 116 kg of 20% LEU to produce 15 kg of weapons-grade uranium. Natural uranium High-enriched elemental uraniumSWU = Separative work unit, a measure of the amount of effort solid metal (90% U-235)required to process nuclear material. The SWU requirement isused to determine the time needed to enrich uranium with a givennumber of centrifuges operating at a given efficiency. Page 12 Copyright © 2013 by the AEI Critical Threats Project
  13. Iran’s Known Uranium Enrichment FacilitiesFordow Fuel Enrichment Plant (FFEP)As of FEB 2013: 696 IR-1 centrifuges producing near- 20% LEU 2,014 IR-1 centrifuges installed but not yet enriching Facility producing near-20% low- enriched uranium (LEU) 662 kg <5% LEU converted to 88 kg near-20% LEU Natanz Fuel Enrichment Plant (FEP) As of FEB 2013: 145 ~9,000 IR-1 centrifuges producing <5% LEU km ~3,669 additional IR-1 centrifuges installed but not yet enriching 180 IR-2m centrifuges installed but not yet enriching Facility producing 3.5% enriched LEU 64,117 kg natural uranium converted Pilot Fuel Enrichment Plant (PFEP) to 5,597 kg <5% LEU As of FEB 2013: 328 IR-1 centrifuges producing near- 20% LEU 2 IR-1, 9 IR-2m, 29 IR-4, and 8 IR-6 centrifuges installed and intermittently fed Facility producing near-20% LEU ` 856 kg <5% LEU converted to 101 kg near-20% LEU Page 13 Copyright © 2013 by the AEI Critical Threats Project
  14. Natanz Enrichment FacilitiesPilot Fuel Enrichment Plant (PFEP) Natanz Fuel Enrichment Plant (FEP)As of FEB 2013: As of FEB 2013: 328 IR-1 centrifuges producing near- ~9,000 IR-1 centrifuges producing 20% LEU <5% LEU 2 IR-1, 9 IR-2m, 29 IR-4, and 8 IR-6 ~3,669 additional IR-1 centrifuges centrifuges installed and intermittently installed but not yet enriching fed 180 IR-2m centrifuges installed but Facility producing near-20% LEU not yet enriching 856 kg <5% LEU converted to 101 kg Facility producing 3.5% enriched LEU near-20% LEU 64,117 kg natural uranium converted to 5,597 kg <5% LEU Underground halls under construction FEB 2003 Page 14 Copyright © 2013 by the AEI Critical Threats Project
  15. Fordow Enrichment Facility: Status and Construction Image taken SEP 14 2012 Image from MAR 24 2005 (Google Earth)Pleiades, Apollo Mapping Areas covered in 2005 appear as entrances to New above- underground facilities in 2009 ground facility appears between Fordow Fuel Enrichment Plant (FFEP) 2005 and As of FEB 2013: 2009 696 IR-1 centrifuges producing near- 20% LEU Ridgeline rises 2,014 IR-1 centrifuges installed but not roughly 200 feet yet enriching from entrances Facility producing near-20% low- enriched uranium (LEU) to peak. 662 kg <5% LEU converted to 88 kg near-20% LEU Image from NOV 24 2009 (Google Earth) Page 15 Copyright © 2013 by the AEI Critical Threats Project
  16. Scope, Assumptions and Technical Points Page 16 Copyright © 2013 by the AEI Critical Threats Project
  17. ScopeThis product is an exposition of the technical data contained in numerousIAEA reports informed by the discussions of experts in the field of nuclearproliferation. It is a work-in-progress in that it will be revised continuouslybased on new information from the IAEA and other sources and on feedbackfrom readers. It is focused entirely on technical feasibility and does not assessIranian intentions to pursue breakout scenarios.We welcome your informed commentary on the technical considerationspresented in this document. Please send your comments, with references tosource-data or documentation, to INP@AEI.ORG. Page 17 Copyright © 2013 by the AEI Critical Threats Project
  18. Breakout ScenariosWorst-case The worst-case scenarios assume that Iran devotes all operational centrifuges at Natanz (as of FEB 2013) to producing first additional 19.75% LEU and then 90% highly-enriched uranium (HEU), ceasing production of 3.5% LEU. Such actions would be visible to inspectors and so would most likely occur between inspections. Iranian nuclear policy and strategy does not appear to be going down this road. The scenarios assume ~9,000 centrifuges spinning (the number being fed uranium as of FEB 2013) operating with an efficiency of 0.9 separative work units (SWU)/centrifuge/year (roughly the efficiency they have demonstrated). 15 kg requirement: Iran begins to race to breakout by producing 116 kg total of 19.75% LEU and then enriching that material to 90% HEU. 25 kg requirement: Iran begins to race to breakout by producing 193 kg total of 19.75% LEU and then enriching that material to 90% HEU. If Iran breaks out using a three-step process, it would need to produce 240 kg total of 19.75% LEU in total, then enrich to 60% HEU and then to 90% HEU to yield 15 kg. Assuming Iran needs 25 kg 90% HEU, it would need to produce 399 kg total of 19.75% LEU before it could convert to 60% HEU and then 90% HEU. These calculations assume tails assays of 2.0% and 9.3% for the two steps in the first process and 2.0%, 12.0%, and 41.1% for the three steps in the second process (see page 22). These data are derived from the Natanz facility; the Fordow installations are notably more efficient with lower tails assays.Most Likely The ~9,000 centrifuges being fed in the main cascade hall at Natanz continue to produce 3.5% LEU and are not diverted to higher-level enrichment. Iran uses 85 kg 19.75% LEU to produce 15 kg 90% HEU or continues enriching to 19.75% until it has amassed approximately 141 kg 19.75% LEU, which can yield 25 kg 90% HEU. Enrichment to 19.75% occurs in 4 cascades totaling 696 IR-1 centrifuges at Fordow (2 sets of 2 interconnected cascades) and 2 cascades totaling 328 IR-1 centrifuges at the Natanz PFEP (all currently operational). Enrichment from 19.75% to 90% occurs in 6 cascades at Fordow in one step using a tails assay of 4.6%. The difference in the tails between the worst-case and most likely breakout scenarios reflects the fact that the cascades at Fordow, like the ones at Natanz PFEP, are interconnected in pairs. Page 18 Copyright © 2013 by the AEI Critical Threats Project
  19. Atomic Weapons DataSmall atomic weapons can be built from cores consisting of 10-25 kg of uranium enriched to ~90% U-235 (weapons-grade HEU). We use 15 kg and 25 kg to assess breakout timelines.The explosive yield of a 15 kg core is on the close order of 15 kilotons.Uranium can be enriched to HEU in a two-step or a three-step process.Both processes begin by enriching natural uranium (0.7% U-235) to 3.5% LEU.The two-step process enriches from 3.5% LEU to 19.75% LEU, and then from 19.75% LEU directly to90% HEU.The three-step process proceeds from 3.5% LEU to 19.75% LEU, from 19.75% LEU to 60% HEU, andthen from 60% HEU to 90% HEU.The most important difference between these processes is the amount of LEU required initially—thetime required to enrich from 19.75% to 90% is virtually the same for either process.The two-step process for producing 15 kg weapons-grade HEU requires 85 kg of 19.75% LEU usinginterconnected cascades (such as at Fordow) or 116 kg using non-interconnected cascades (such asthose at Natanz). Producing 25 kg weapons-grade HEU in a two-step process requires 141 kg of19.75% LEU using interconnected cascades or 193 kg using non-interconnected cascades. The three-step process requires significantly more in non-interconnected cascades (such as at Natanz).There is disagreement among experts about Iran’s ability to execute a two-step process with itscurrent technology and cascade configuration.If Iran were forced to use a three-step process, the primary delay would result from the timerequired to produce the additional 19.75% LEU, a factor that Iran could affect either by bringing morecentrifuge cascades online or by beginning to enrich with more efficient centrifuges, some of whichare already installed but not yet producing enriched uranium. Page 19 Copyright © 2013 by the AEI Critical Threats Project
  20. Projections for the May 2013 IAEA Report IR-1 centrifuges being fed at Natanz FEP: ~9,000 Total 3.5% LEU produced at Natanz FEP: 5,567 kg* IR-1 centrifuges being fed for 19.75% enrichment at Natanz and Fordow: 1,024 Total 19.75% LEU produced at Natanz PFEP and Fordow FEP: 219 kg** PREVIOUS PROJECTIONS 3.5% LEU We previously estimated that Iran would produce an additional 467 kg of 3.5% enriched uranium at Natanz during the last reporting period. The IAEA reported that Iran produced about 497 kg 3.5% enriched uranium during the period. 19.75% LEU We previously estimated that Iran would produce an additional 29 kg of 19.75% enriched uranium at Natanz and Fordow during the last reporting period. The IAEA reported that Iran produced about 33 kg 19.75% enriched uranium. The error is attributed to increased production rate per centrifuge at Fordow.*Assuming IAEA measurement on MAY 4 2013**Assuming IAEA measurement on MAY 11 2013 Page 20 Copyright © 2013 by the AEI Critical Threats Project
  21. SourcesInternational Atomic Energy Agency (IAEA) – The IAEA publishes quarterly reports on Iran’s nuclear program and enrichment progress. Enriched uranium stockpile,centrifuge count, potential inspection windows, and other technical data provided by the IAEA are used in our analysis to determine historical rates of productionand to serve as a basis for building projections. IAEA reports on Iran are available at http://www.iaea.org/newscenter/focus/iaeairan/iaea_reports.shtml.World Information Service Project on Energy (WISE) – WISE provides a uranium enrichment calculator for calculating the separative work required to achieve specificlevels of U-235 concentration. The calculator uses manual inputs of feed, product, and tails figures to calculate separative work units (SWU). The resultant SWUserves as the basis for calculating time requirements. This assessment uses the WISE calculator to determine the SWU required for enriching at various levels. Theonline calculator is accessible at http://www.wise-uranium.org/nfcue.html.Gregory Jones, Nonproliferation Education Policy Center (NPEC) – Gregory Jones provided the estimated tails percentage figures for enriching to weapons-gradeuranium levels for two-step and three-step batch recycling methods (starting with 3.5% LEU) at the Natanz FEP and two-step batch recycling (from 3.5%) at NatanzPFEP/Fordow FEP, where cascades are interconnected. Jones has written that the technical assumption underlying an Iranian attempt to break out using two-stepbatch recycling without reconfiguration (from 3.5%) may not be feasible. The alternative Iranian breakout approach he suggests, adding an intermediary stepbetween 19.75% and 90% enrichment, is one that we have relied on in our analysis. Jones’s analyses are available at http://www.npolicy.org/.Jones has written that the process for Iran to convert the U3O8 enriched up to 20% created for fuel plates back to 20% enriched UF6 gas for use in a breakout“involves dissolution by nitric acid, followed by purification by solvent extraction. These are standard processes in the nuclear industry and Iran uses them as part ofits uranium ore processing...The time required from the removal of the fresh TRR fuel from safeguards to the time to produce 19.75% enriched uranium hexafluoridewould be only ‘days to weeks.’ [citing Albert Wohlstetter et al, Swords from Plowshares, Chicago University Press, 1979]” The report is available at http://www.npolicy.org/article_file/Fueling_the_Tehran_Research_Reactor-Technical_Considerations_on_the_Risks_and_Benefits.pdf.Further on this topic, Henry Sokolski, NPEC, has written that Iran could withdraw 19.75% enriched uranium from fuel plates in the form of UF6 gas in 1-2 weeks. Seehttp://www.nationalreview.com/corner/188387/fueling-around-iran-and-bomb/henry-sokolski.Institute for Science and International Security (ISIS) – ISIS has contributed to a technical debate among experts regarding the feasibility of two-step and three-stepbatch recycling methods. ISIS analyses are available at http://isis-online.org/.Alexander Glaser, “Characteristics of the Gas Centrifuge for Uranium Enrichment and Their Relevance for Nuclear Weapon Proliferation,” Science and Global Security(16:1-25, 2008) – Glaser’s analysis of the P-1 centrifuge—the foundation of Iran’s IR-1 centrifuge program—is the basis for two-step batch recycling projections forenriching to weapons-grade uranium. A key aspect of Glaser’s analysis in this paper was that 90% HEU can be produced in one step from 19.7% LEU without theneed to reconfigure the arrangement of cascades. In October 2011, according to Gregory Jones, Glaser said he had “been made aware of certain phenomena thatare not taken into account” in his 2008 analysis and that “We now find that the most credible scenarios involve some kind of cascade reconfiguration.” See GregJones, “Earliest Date Possible for Iran’s First Bomb,” Nonproliferation Education Policy Center, December 6, 2011, http://npolicy.org/article.php?aid=1124&rid=4.For Glaser’s original analysis, see http://www.princeton.edu/sgs/publications/sgs/archive/16-1-Glaser.pdf.International Commission on Nuclear Non-Proliferation and Disarmament (ICCND) – The ICCND notes that a basic implosion-type nuclear weapon design with anexplosive yield of 15 kilotons would require 15 kg of weapons-grade uranium. We use this figure as the minimum 90% HEU Iran would produce to fuel one bomb.See http://icnnd.org/Reference/reports/ent/part-ii-4.html.Thomas B. Cochran and Christopher E. Paine, “The Amount of Plutonium and Highly-Enriched Uranium Needed for Pure Fission Nuclear Weapons,” NationalResources Defense Council, April 13, 1995. – Cochran and Paine assert that the “significant quantity” measurement of 25 kg weapons-grade HEU used by the IAEAgreatly overestimates the amount of fissile material required to fuel a basic implosion-type nuclear explosive device. They estimate that a state with a low technicalcapability can produce a bomb with an explosive yield of 20 kilotons with 16 kg weapons-grade HEU. See: http://www.nrdc.org/nuclear/fissionw/fissionweapons.pdf. Page 21 Copyright © 2013 by the AEI Critical Threats Project
  22. For more on Iran, visit www.irantracker.org

×