Making Highly Enriched Uranium
Alexander Glaser WWS556d Princeton University February 26, 2007
Revision 4
1 Sep 2002
200 meters
Fuel Enrichment Plant
(FEP)
(FEP)
Natanz Site, Iran, 2007
2 What is HEU?
3 Highly Enriched Uranium (visually) HEU (weapon-usable)
Natural uranium Low-enriched uranium Highly enriched uranium Weapon-grade uranium 0.7% U-235 typically 3-5%, 20% U-235 and above more than 90% U-235 but less than 20% U-235
U-235 Uranium U-238
4 Critical Mass of Uranium (for a beryllium-reflected metallic sphere)
300
250
200
150 144 kg
Critical Mass [kg] 100 LEU HEU 50 12 kg
0 0 20 40 60 80 100 Enrichment [wt%]
5 Characteristics of Highly Enriched Uranium
Easy to handle Easy to use in nuclear weapon or nuclear explosive device Difficult/Impossible to detect
Conventional Sub-critical chemical pieces of uranium-235 High-explosive Plutonium core propellant combined lenses compressed
Difficult to produce
6 Why Make HEU Anyway? (if there is so much of it around)
7 Global HEU Inventory 2007 (civilian and military combined)
Country National Stockpile (estimate)
China 22 MT______± 25% France 33 MT______± 20% India 0.2 MT______± 50% Pakistan 1.4 MT______± 15% Russia 770 MT______± 300 MT United Kingdom 24 MT______declared United States 467 MT______declared
Non-nuclear states 10 MT____ TOTAL (rounded) 1325 MT______± 310 MT
(total world-inventory of HEU is enough for 50,000-100,000 nuclear weapons)
Estimates from IPFM Global Fissile Material Report 2006, updated partially based on D. Albright (ISIS)
8 Global Distribution of Civilian HEU
Estimated total civilian inventory: about 50 metric tons
More than 10,000 kg 1,000 - 10,000 kg 100 - 1,000 kg 10 - 100 kg 1 - 10 kg Less than 1 kg (cleared)
9 Production of Enriched Uranium (Uranium Enrichment)
10 Global Enrichment Picture 2007
Country Name/Location Type Status Process Capacity [tSWU/yr]
Brazil Resende Commercial Under construction GC 120____ Lanhou 2 Commercial Under construction GC 500____ China Shaanxi Commercial In operation GC 500____ George Besse Commercial In operation GD 10800____ France George Besse II Commercial Planned GC 7500____ Germany Urenco Deutschland Commercial In operation GC 1800 (+2700)____ India Rattehalli Military In operation GC 4-10____ Iran Natanz Commercial Under construction GC 100-250____ Japan Rokkasho Commercial In operation GC 1050____ Netherlands Urenco Nederland Commercial In operation GC 2500 (+1000)____ Pakistan Kahuta Military In operation GC 15-20____ Angarsk Commercial In operation GC 2350____ Novouralsk Commercial In operation GC 12160____ Russia Zelenogorsk Commercial In operation GC 7210____ Seversk Commercial In operation GC 3550____ U.K. Capenhurst Commercial In operation GC 4000____ Paducah Commercial In operation GD 11300____ USA Piketon (USEC/DOE) Commercial Planned GC 3500____ Eunice (LES) Commercial Planned GC 3000____
11 Comparison of Enrichment Capacities Values for a reference facility with a capacity of 130 tSWU/yr
Material and separative work required to fuel a 1000 MWe light-water reactor Feed Product Time
150,000 kg U(nat) at 0.71% 20,000 kg LEU at 4% 1 year (Tails at 0.20%)
Material and separative work required to produce enough HEU for several bombs per year
Feed Product Time
150,000 kg U(nat) at 0.71% 654 kg HEU at 93% 1 year (25-50 bombs) (Tails at 0.30%)
150,000 kg U(nat) at 0.71% 100 kg HEU at 93% 40 days (4-8 bombs) (Tails at 0.65%)
020,000 kg LEU at 4% 100 kg HEU at 93% 08 days (4-8 bombs) (Tails at 3.55%)
Additional time is needed before HEU can be produced in a facility that previously produced LEU because the “old” uranium gas has to be “flushed out” from the equipment and the facility may have to be reconfigured
12 The Case of the Gas Centrifuge
13 Centrifuges for Uranium Enrichment
Source: IPFM 2006 Report tails feed product
top scoop
baffle
Enriched uranium Depleted uranium
center post casing
rotor
bottom scoop
electromagnetic motor
bottom bearing Source: Presentation by Mohammad Saeidi (AEOI)
14 Tails
Separating Unit
Separating Separating Unit Unit
Separating Separating Unit Unit
Separating Separating Unit Unit Product Separating Separating Unit Unit
Separating Separating Unit Unit
Separating Unit
Feed
Stage 1 Stage 2 Stage 3 Stage 4
15 Genealogy of the Gas Centrifuge
U.K. The Netherlands Germany
Urenco Russia
Iran France N. Korea USA (Iraq) China
(Libya) Pakistan Japan
India
Brazil
Australia
Original centrifuge R&D (pre-commercial, “Zippe-connection”) Technology transfer (confirmed or planned) Independent development or unconfirmed foreign assistance Status or achievement unclear Last revision: 02/2007
16 Why Are Centrifuges Different?
17 Crude Breakout Scenario (using an early-generation machine)
60
40
20
0 21 40 56 71 84 96 106 91 79 67 57 48 40 34 27 22 17 13 9 6 3
20
Number of machines in stage 40 Total number of machines in cascade: 987 Source: Urenco 60 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 Assumed characteristics of P-2-type machine Stage number
peripheral velocity = 485 m/s Performance of reference LEU-cascade rotor diameter = 15 cm rotor height = 100 cm Feed = 32.4 kg/d of UF6 w/ natural uranium separative power = 5 SWU/yr Product = 3.3 kg/d of UF6 w/ 4.4%-enriched uranium
18 Simple Breakout Scenario (using an early-generation machine)
100 86%
80 Serial batch operation: 10 cascades feed into 1 additional cascade 60
Simple batch operation:
hment [wt%] 1 cascade using 40 pre-enriched feed-stock Enric
20 26%
0 -2 0 2 4 6 8 10 12 Time [hours]
(compare to equilibrium time for gaseous diffusion process, which is on the order of months)
19 Detection of Undeclared Facilities
20 240 meters s er t 200 me
GRONAU centrifuge enrichment facility, Germany Current capacity: 1,800,000 SWU/a (to be expanded to 4,500,000 SWU/yr) Footprint of facility: 200 meters x 240 meters
Specific capacity of facility: 37.5 SWU/yr per square meter
Minimum capacity of facility to produce 25 kg of HEU annually: about 6,000 SWU/yr Hypothetical footprint: 160 square meters (42 ft x 42 ft)
21 Detectability of Undeclared Facilities
Detectability (Selected Criteria) Identifiable Thermal Effluents Structure Signature
Reactor Yes Yes No Plutonium Production Reprocessing No No (Yes)
Calutron/EMIS Uranium No Yes Yes Enrichment Gaseous diffusion Yes Yes Yes
Centrifuge No No No
22 What Are Our Options?
23 Possible Strategies to Limit the Front-End Proliferation Risks of the Nuclear Fuel Cycle
STRATEGY TARGET/OBJECTIVE
• Increase the effectiveness of (and the confidence in) safeguards Preclude covert misuse • Increase the ability to detect undeclared facilities Deter clandestine activities • Contain technology to existing or selected producers Know-how held by “trusted users” • Focus on the demand side (i.e. “devalue” nuclear weapons) Motivation
24 Global Nuclear Expansion Scenario (1500 GWe in 58 countries, based on 2003 MIT study)
More than 10 GWe installed At least 1 GWe installed
25 Enrichment Demand and Distribution (for 1500 GWe Global Nuclear Expansion Scenario)
37,200 17,650
20,850
36,600 27,750 12,750
2,850 3,150 5,100
2,850 2,250
24,450
5,400 4,800
10,300
11,050
tSWU/yr Total SWU-production in country Combined SWU-demand of countries importing all their enrichment services: 11,850 tSWU/yr
Global enrichment capacity: 1,500 x 150 tSWU/yr (225,000 tSWU/yr)
26 Containment Strategies
Have and have-not approaches Bush Proposal (2004) or other “criteria-based” proposals
Black Box approaches with or without “Poison Pills” and combined with multinational operation of facilities
Export Controls Deter, delay, detect procurement efforts
But to what extent are they durable? Underlying assumption that indigenous R&D efforts are irrelevant/insufficient
27 Timeline of Centrifuge Programs
Germany R&D as part of URENCO/ETC
Netherlands R&D as part of URENCO/ETC R&D Machine U.K. R&D as part of URENCO/ETC at least 2-5 SWU/yr Test cascade at least 100 machines Japan Pilot plant and further developments Australia Pakistan India Brazil Iran
1960 1970 1980 1990 2000 2010
DRAFT version, August 2006 - by Alexander Glaser, Princeton University (arrows indicate uncertain dates of respective events or milestones)
28 Possible Strategies to Limit the Front-End Proliferation Risks of the Nuclear Fuel Cycle
STRATEGY TARGET/OBJECTIVE
• Increase the effectiveness of (and the confidence in) safeguards Preclude covert misuse • Increase the ability to detect undeclared facilities Deter clandestine activities • Contain technology to existing or selected producers Know-how held by “trusted users” • Focus on the demand side (i.e. “devalue” nuclear weapons) Motivation
29 30