242:, diluted about 100 fold by a carrier gas (which can be argon or nitrogen), is cooled to about 80 K by adiabatic expansion through a nozzle into vacuum. Initially there are still collisions (which are necessary for cooling). But after traveling about 10 nozzle diameters, due to the expansion, they are so rare that condensation can no longer take place. Avoiding collisions is also necessary to suppress any collisional transfer of energy between the isotopes. Such a molecular beam method is used in all cases, where spectral narrowing is needed for selective excitation.
225:
53:
or being used for multiple applications around the world. Slight variations in operating parameters, equipment arrangements, lasers and their capabilities, may exist from one SILEX-type process to the next (and be called by a different name), but the physical separation concept remains the same if condensation repression is utilized, especially when compared to that used by AVLIS or MLIS.
213:
335:
hide a production facility for bomb uranium. The attractiveness is even enhanced by the claims of GLE that a SILEX plant is faster and cheaper to build, and consumes considerably less energy. Scientists therefore expressed their concerns repeatedly that SILEX could create an easy path towards a nuclear weapon.
375:
states that the technology will be smaller, less energy-intensive, and more difficult to control once it is a viable alternative to current methods of enrichment. Ms. Walsh also states that the development of the technology has been protracted, and that there are significant governmental interests in
334:
Compared to current enrichment technologies, SILEX obtains a higher enrichment. Hence fewer stages are necessary to reach bomb grade uranium (> 90% U). According to GLE, each stage requires as little as 25% of the space of the conventional methods. Hence it would facilitate to rogue governments to
294:
lasers and with the stimulated Raman shifter the state of technology is 2–4 kHz. In order not to leave large parts of the molecular beam unirradiated, one needs at least 20 kHz (according to Urenco several tens of kHz), unless pulsed nozzles are used. The nozzles themselves must have slit
52:
While the
Australian company Silex Systems Limited is the most prominent developer of this technology (as part of the Global Laser Enrichment consortium), the acronym SILEX really only refers to a physical separation concept utilizing condensation repression that is well known and under development
566:“Agreement for Cooperation between the Government of Australia and the Government of the United States of America concerning Technology for the Separation of Isotopes of Uranium by Laser Excitation (SILEX Agreement), Agreed Minute and Exchange of Notes (Washington, 28 October 1999). ATS 19 of 2000”
228:
Schematic of a stage of an isotope separation plant for uranium enrichment with laser. An infrared laser with a wavelength of approx. 16 μm radiates at a high repetition rate onto a UF6 carrier gas mixture, which flows supersonically out of a laval nozzle. The excited component moves away from the
37:) is a process for enriching uranium to fuel nuclear reactors that may also present a growing nuclear weapons proliferation risk. It is strongly suspected that SILEX utilizes laser condensation repression to excite a vibrational mode of the uranium-235 isotope in uranium hexaflouride (UF
267:. The enrichment factor is the better, the larger the transmitted fraction (i.e. the smaller the depletion and the smaller the cut). That is, SILEX uses a separation nozzle, modified by a laser and profiting from selective repression of cluster formation ("condensation").
262:
does. Due to their higher thermal velocity, the free molecules leave the axis of the molecular beam faster than the clusters. The latter are therefore enriched in the part transmitted by a skimmer nozzle downstream, whereas the non-transmitted fraction is enriched in the
56:
Princeton physicist Ryan Snyder has suggested that this process may lead to the further proliferation of nuclear weapons by providing a new and increasingly accessible technological pathway and undetectable signatures (small area footprint and high energy efficiency).
45:. This differs greatly from previous methods of laser enrichment explored for their commercial prospects: one using atomic uranium (Atomic Vapor Laser Isotope Separation (AVLIS)) and another molecular method that uses lasers to dissociate a fluorine atom from UF
237:
is around 16 μm. At room temperature its width (around 20 cm) is much larger than the isotopic shift (0.6 cm). The broadening is due to thermally populated excited vibrational and rotational states. To allow for selective excitation, the
355:, which states that classification can only be assigned to information "owned by, produced by or for, or is under the control of the United States Government". This is the only known case of the Atomic Energy Act being used in such a manner.
582:
298:
GLE informs that they reach separation factors of 2–20, the higher values probably coupled to a poorer depletion (which is not given). This is sufficient for enrichment from natural uranium (0,72 % U) to reactor grade
187:
In 2021, Silex
Systems took majority ownership (51%) of GLE, with Cameco (49%) as minority owner. Under an agreement between GLE and the US Department of Energy, GLE will re-enrich to natural levels several hundred
245:
With SILEX, the pressure and nozzle diameter are chosen large enough to provide a sufficient number of collisions immediately after the nozzle, to allow for formation of clusters (UF6•G) with the carrier gas G.
145:
In 2008, GEH spun off Global Laser
Enrichment (GLE) to commercialise the SILEX Technology and announced the first potential commercial uranium enrichment facility using the Silex process. The U.S.
1122:
470:
351:, all information not specifically declassified is classified as Restricted Data, whether it is privately or publicly held. This is in marked distinction to the national security classification
118:
Silex
Systems concluded the second stage of testing in 2005 and began its Test Loop Program. In 2007, Silex Systems signed an exclusive commercialization and licensing agreement with
578:
159:
Between 2011 and 2012, GLE applied for and received a permit to build a commercial enrichment plant at
Wilmington. The plant would enrich uranium to 8% U, the upper end of
69: (MLIS) variants began in the 1970s. The key physical process in all of them is an infrared laser, which vibrationally excites only one of the isotopes in gaseous
640:
499:
754:
84:
After initial euphoria, laser isotope separation research was mostly abandoned during the 1990s, mainly because it still required extensive and uncertain
527:
41:), allowing this lighter molecule to move more rapidly to the outer rim of a gaseous jet and resist condensing compared to the heavier, unexcited UF
348:
166:
In 2014, both GLE and Silex
Systems restructured, with Silex halving its workforce. In 2016 GEH withdrew from GLE, writing off their investment.
670:
523:
385:
104:
347:
classified "certain privately generated information concerning an innovative isotope separation process for enriching uranium". Under the
364:
390:
344:
170:
66:
821:
607:
779:
1115:
Snyder, R., "A Proliferation
Assessment of Third Generation Laser Uranium Enrichment Technology," Science & Global Security:
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310:
Using other lasers with suitable wavelengths, SILEX can also be used for the isotopic enrichment of other elements such as
1024:
174:
146:
800:
258:
is selectively excited at 628.3 cm, then this molecule does not aggregate with G, whereas the nonexcited heavier UF
119:
1137:
895:
Ronander, Einar; Rohwer, Erich G. (1993-05-04). Fotakis, Costas; Kalpouzos, Costas; Papazoglou, Theodore G. (eds.).
278:
laser wavenumber of 982.1 cm (10R30 line), one receives 627.8 cm. This is only close to the Q-branch of UF
728:
123:
514:
368:
127:
372:
184:
In 2018, Silex
Systems abandoned its plans for GLE, intending to repatriate the SILEX technology to Australia.
108:
896:
290:
lasers would cause additional problems with the pulse repetition rate. With common (atmospheric-pressure) CO
73:. This requires a wavelength near 16 μm. Traditional MLIS then continued to excite the molecules unto
197:
93:
49:(Molecular Laser Isotope Separation (MLIS)), allowing the enriched product to precipitate out as a solid.
177:
to GLE for re-enrichment (from 0.35 to 0.7 % U) using the SILEX process over 40 years at a proposed
932:
78:
987:
904:
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662:
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axis of the molecular beam faster than the unexcited tailings stream which is separated at a skimmer.
160:
112:
70:
568:. Australasian Legal Information Institute, Australian Treaties Library. Retrieved on 15 April 2017.
115:
for cooperative SILEX research and development. However, in 2003 USEC backed out from the project.
303:
3% U). The pioneer works of the van den Bergh group obtained only much smaller enrichments with SF
920:
877:
565:
976:"Isotopically Selective Condensation and Infrared-Laser-Assisted Gas-Dynamic Isotope Separation"
848:
Takami, Michio; Oyama, Toshiyuki; Watanabe, Tsunao; Namba, Susumu; Nakane, Ryohei (1984-02-01).
156:
In 2010, concerns were raised that the SILEX process poses a threat to global nuclear security.
522:. 6th Int'l. Symp. on Adv. Nucl. Energy Research (Mito, Japan; 23–25 March 1994). Tokyo:
1044:
1005:
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Zellweger, J. -M.; Philippoz, J. -M.; Melinon, P.; Monot, R.; van den Bergh, H. (1984-03-19).
960:
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clusters are practically not formed due to the much lower density of UF6 compared to G.) If UF
201:
178:
153:, Canada, the world's largest uranium producer, joined GE and Hitachi as a part owner of GLE.
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W. Eberhardt (DESY), W. Fuss (MPQ), F. Lehner (DESY), and R. Snyder (IFSH) (2019-11-04).
991:
908:
149:(NRC) approved a license amendment allowing GLE to operate the Test Loop. Also in 2008,
691:
282:(center at 628.3 cm, width 0.01 cm ) and is even closer to the Q-branch of UF
89:
1131:
924:
881:
545:
419:"A Proliferation Assessment of Third Generation Laser Uranium Enrichment Technology"
443:
418:
1116:
1000:
975:
103:
In
November 1996, Silex Systems Limited licensed its technology exclusively to
371:
uses "Laser
Uranium Enrichment" as a core plot device. The female protagonist
315:
286:. GLE does not inform, how they do the necessary fine tuning. High-pressure CO
224:
1048:
1009:
873:
452:
97:
897:"Multikilowatt TEA-CO2 laser system for molecular laser isotope separation"
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laser needs at least 20 MW. With a Raman shift of 354.3 cm and a CO
323:
139:
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until 2013, and GLE plans to build their new plant on the same spot.
150:
135:
17:
85:
544:. Sustainable Energy & Anti-Uranium Service Inc. Archived from
485:
1121:
Snyder, R., "Proliferation Risks of Laser Enrichment of Uranium,"
223:
212:
211:
850:"Cold Jet Infrared Absorption Spectroscopy: The ν 3 Band of UF 6"
376:
maintaining the secrecy and classified status of the technology.
542:"Silex Systems Ltd: New Laser Technology for Uranium Enrichment"
899:. 9th International Symposium on Gas Flow and Chemical Lasers.
755:"Toshiba's U.S. unit bankruptcy dims Japan's nuclear ambitions"
189:
690:
Nuclear Regulatory Commission announcement |date=2012-09-19|
488:. Deutsches Elektronen-Synchrotron (DESY) and European XFEL.
1110:
233:
The shortest-wavelength fundamental vibration of gaseous UF
822:
Silex gets go ahead to enrich stockpiles to enrich uranium
729:"GE-Hitachi Exits Nuclear Laser-Based Enrichment Venture"
122:(GE), transferring their test loop to GE's facility in
142:- the two largest nuclear power utilities in the USA.
1023:
Boureston, Jack; Ferguson, Charles D. (2005-03-01).
780:"US DOE sells depleted uranium for laser enrichment"
579:"The Biggest Nuclear Operators In The United States"
471:"Proliferation Risks of Laser Enrichment of Uranium"
295:
form, in order to provide enough absorption length.
1086:"A glimpse of the SILEX uranium enrichment process"
692:
http://pbadupws.nrc.gov/docs/ML1226/ML12263A046.pdf
704:"Lasers point to the future of uranium enrichment"
1088:. Secrecy News, Federation of American Scientists
1066:. Secrecy News, Federation of American Scientists
722:
720:
663:"Laser Advances in Nuclear Fuel Stir Terror Fear"
633:"Australian laser 'threatens nuclear security'"
1117:https://doi.org/10.1080/08929882.2016.1184528
107:(USEC) for uranium enrichment. In 1999, the
8:
604:"Cameco Joins GE Hitachi Enrichment Venture"
498:: CS1 maint: multiple names: authors list (
100:continued research on the SILEX technique.
31:Separation of isotopes by laser excitation
999:
442:
216:Infrared absorption spectra of the two UF
402:
173:agreed to sell about 300,000 tonnes of
1025:"Laser Enrichment: Separation anxiety"
941:
930:
835:"Global Laser Enrichment | Silex"
801:"Silex Systems out of GLE restructure"
524:Japan Atomic Energy Research Institute
491:
77:, at which point they crystallized as
386:Atomic vapor laser isotope separation
134:for uranium enrichment services with
7:
1064:"DOE classifies privately held info"
626:
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105:United States Enrichment Corporation
27:Method of producing enriched uranium
1084:Steven Aftergood (23 August 2007).
854:Japanese Journal of Applied Physics
486:"FELs and Laser Isotope Separation"
365:Australian Broadcasting Corporation
803:. World Nuclear News. 13 June 2018
513:Schneider, K. R. (Mar 1995).
391:Molecular laser isotope separation
171:United States Department of Energy
67:molecular laser isotope separation
25:
1062:Steven Aftergood (26 June 2001).
1029:Bulletin of the Atomic Scientists
753:Yasuhara, Akiko (31 March 2017).
782:. World Nuclear News. 2016-11-11
661:Broad, William J. (2011-08-20).
824:, AuManufacturing, 19 Jan 2021.
673:from the original on 2012-11-03
643:from the original on 2012-08-29
631:McMurtrie, Craig (2010-04-13).
610:from the original on 2012-08-09
585:from the original on 2012-11-07
581:. Investopedia US. 2011-03-28.
526:. pp. 280–289 – via
473:. National Academy of Sciences.
200:plant. That plant operated in
1:
706:. Gizmag.com. 6 November 2013
444:10.1080/08929882.2016.1184528
423:Science & Global Security
175:depleted uranium hexafluoride
147:Nuclear Regulatory Commission
1123:National Academy of Sciences
903:. Heraklion, Greece: 49–52.
727:Patel, Sonal (1 June 2016).
120:General Electric Corporation
1001:10.1103/PhysRevLett.52.1055
961:"LIS: The view from Urenco"
469:Snyder, Ryan (2021-05-18).
417:Snyder, Ryan (2016-05-03).
181:Laser Enrichment Facility.
1159:
124:Wilmington, North Carolina
959:k. r., Schneider (1995).
516:LIS: The view from Urenco
220:isotopes at 300 and 80 K.
128:GE Hitachi Nuclear Energy
79:uranium-235 pentafluoride
1111:http://www.silex.com.au/
111:and Australia signed an
1109:Silex Systems Limited:
980:Physical Review Letters
435:2016S&GS...24...68S
343:In June 2001, the U.S.
339:Security classification
196:tailings from the last
65:Development of various
940:Cite journal requires
606:. Cameco. 2008-06-20.
330:Proliferation concerns
230:
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94:technological maturity
1143:Nuclear proliferation
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345:Department of Energy
198:diffusion enrichment
161:low-enriched uranium
113:international treaty
71:uranium hexafluoride
992:1984PhRvL..52.1055Z
909:1993SPIE.1810...49R
866:10.1143/JJAP.23.L88
1138:Isotope separation
667:The New York Times
231:
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151:Cameco Corporation
1041:10.2968/061002005
917:10.1117/12.144664
349:Atomic Energy Act
179:Paducah, Kentucky
132:letters of intent
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75:dissociation
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30:
29:
860:(2A): L88.
90:centrifuges
1132:Categories
1092:2007-08-23
1070:2007-08-23
786:2016-11-15
710:2013-11-06
677:2012-08-28
647:2012-08-28
637:ABC Online
614:2012-08-28
589:2012-08-28
552:2006-04-21
397:References
316:molybdenum
1049:0096-3402
1010:0031-9007
874:0021-4922
453:0892-9882
363:The 2014
98:Australia
925:94250559
882:93245695
671:Archived
641:Archived
608:Archived
583:Archived
494:cite web
380:See also
369:The Code
312:chlorine
190:kilotons
988:Bibcode
905:Bibcode
807:14 June
764:1 April
738:1 April
431:Bibcode
324:silicon
208:Process
202:Paducah
140:Entergy
86:R&D
61:History
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923:
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872:
451:
367:drama
320:carbon
136:Exelon
921:S2CID
878:S2CID
733:POWER
520:(PDF)
35:SILEX
18:SILEX
1045:ISSN
1006:ISSN
946:help
901:1810
870:ISSN
809:2018
766:2017
740:2017
528:INIS
500:link
449:ISSN
322:and
301:>
138:and
1037:doi
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318:,
250:•UF
246:(UF
192:of
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