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Apr 15, 2010

Laser enrichment technology has been successfully completed

"This is a project clearly Steven Chu would love"
The initial phase of the test loop program for the SILEX laser enrichment technology has been successfully completed by Global Laser Enrichment (GLE).
The test loop facility is designed to demonstrate the commercial feasibility of the technology and is intended to advance the design of the equipment and processes for the proposed commercial production facility.
In January 2010, the NRC formally established a 30-month application review schedule. In February, during a public licensing meeting, the NRC indicated they were working to a 30-month schedule which would be completed in December 2011. This means that the commercial facility license could be received as early as January 2012, after which construction of the production plant could proceed.
This site has looked at the technical details of the SILEX enrichment process and compared it to gas centrifuge. The Silex laser uranium enrichment process has been indicated to be an order of magnitude more efficient than existing production techniques but again, the exact figure is classified.
The process is based on selective excitation of uranium hexafluoride (UF6) molecules that contain U-235 by laser light at a narrow spectral line near 16 µm. The CO2 lasers can generate 1 J pulses, but only at a limited repetition rate, and only a fraction of the pulse is in the pump band. Unspecified "additional nonlinear optical tricks" are needed to convert the CO2 pump light to the correct wavelength to pump the Raman cell. The lasers are 1% efficient and the Raman conversion 25% efficient, so the overall efficiency is 0.25%. With many details classified or proprietary, it is hard to quantify the processing. Lyman wrote that if a laser could illuminate a one-liter volume at an ideal repetition rate, it would take about 100 hours to produce one kilogram of U-235-assuming complete separation of the U-235 and U-238 isotopes. However, most processes require multiple stages of separation, and according to Lyman's comments, a 5000 Hz laser would be needed to process all the feed stream (a mixture of UF6 and an unidentified diluting gas.
Proliferation Fears In the journal Nature, there is an article Stop laser uranium enrichment It is written by Slakey (University of California Economics Prof) and Cohen (Law Professor). They argue that the Nuclear Regulatory Commission should prevent GE from building the SILEX commercial plant because the GE plant will perfect laser enrichment and allow others to steal the secrets.
* The mean US household savings from laser enrichment of uranium would probably be less than $2 a month * The technology could be misappropriated to secretly enrich uranium for weaponry * The US Nuclear Regulatory Commission should assess proliferation risks in the licensing process
The $3-4 billion per year in savings appears to only be a calculation of the one GE Silex plant. The ultimate savings could be from converting all nuclear enrichment  to Silex processes and the improvement economics could boost the use of nuclear energy. Improved enrichment would also allow economic re-enrichment of depleted uranium (the part that gets thrown away from current enrichment but still has 0.3% of the desirable uranium). The actual opportunity cost of not building SILEX would be far higher and the possible gain would be far less, because I do not think it would slow down the non-US programs that much. An example, is President Jimmy Carter stopped the US from developing reprocessing of Uranium back in the seventies. Yet reprocessing is still done by France, UK, Russia and Japan.

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