author profiles for this publication at: https://www.researchgate.net/publication/382917552Lasers Point To The Future Of Uranium EnrichmentArticle · August 2024CITATIONS0READS99 authors, including:Bulbul KhanThe Institution of Engineers (India)90 PUBLICATIONS 1 CITATIONSEE PROFILESk Ahamed AliThe Institution of Engineers (India)83 PUBLICATIONS 1 CITATIONSEE PROFILEFredrick KayusiPwani University57 PUBLICATIONS 64 CITATIONSSEE PROFILERajesh KUMAR GuptaThe Institution of Engineers (India)69 PUBLICATIONS 1 CITATIONSEE PROFILEAll content following this page was uploaded by Bulbul Khan on 07 August 2024.The user has requested enhancement of the downloaded file.1Lasers Point To The Future Of Uranium EnrichmentLaser enrichment of isotopes has major potential to reduce the cost of nuclear powerWith the world’s first laser enrichment plant having received aconstruction and operating license from the US Nuclear RegulatoryCommission in 2012, the stage has been set for a radical change inthe industry. So how does laser enrichment work, and whatcommercial benefits, along with proliferation concerns, does this newprocess present compared to current methods?Nuclear power plants generally benefit from uranium enrichment. Byincreasing the abundance of U-235 in uranium fuel rods from thenatural abundance of 0.71 percent to 3 percent or greater, fewercompromises need be made to reach gigawatt power levels. A fewreactors use uranium enriched to about 20 percent U-235, and at theextreme, some nuclear submarines use fuel enriched to about 93percent.Nuclear weapon designs based on uranium fission always benefitfrom uranium enrichment. Few proliferation concerns arose when theexpensive and technically demanding method of gaseous diffusionwas the only practical approach to enrichment, as only nation-stateswith enormous resources were likely to be able to use that process toobtain weapons-grade fuel. Given centrifuge and now laser-basedenrichment technologies, this is no longer the case.Three general types of uranium enrichment have beendeveloped into large-scale processes: gaseous diffusion,centrifuge cascades and now laser-based enrichment. Ofthese, gaseous diffusion facilities have been considered tobe too large, expensive, and technically demanding torepresent a significant proliferation hazard. Such facilitiesare now obsolete and currently the dominant technology foruranium enrichment is the high-speed centrifuge cascade.Now that laser-based enrichment methods have arrived.CentrifugesA gas centrifuge is a hollow cylindrical tube that is rapidly rotatingaround its long axis. The rotation produces a centrifugal force on auranium hexafluoride gas in the cylinder, which acts to force the gastoward the wall of the centrifuge.This force is stronger on uranium hexafluoride containing U-238 thanon the same material that contains U-235. As a result, the gas near thecentrifuge wall is enriched in U-238, while the gas near the axis ofrotation is enriched in U-235. The largest centrifuges used in uraniumenrichment hold only about 15 grams of uranium, so an enrichmentplant must include many parallel paths to produce commerciallyviable quantities of enriched uranium.Typically, an enrichment cascade would require about sevenstages to produce uranium enriched to five percent U-235,and about 20 stages to produce weapons-grade U-235.Centrifuge cascades have been the main route towardnuclear proliferation, most notably in Pakistan, Iraq, Iran,Libya, and North Korea.Laser isotope separationThe new player in the game is enrichment techniques that depend onlaser excitation to separate isotopes. The basis for all laser-basedenrichment schemes is that the amount of energy required to put auranium hexafluoride molecule containing an atom of U-235 into anexcited state is slightly smaller (by about 0.1 percent) than the energyrequired when the uranium atom is U-238. It turns out that carefullytuned photons from a 16 micron laser will excite the U-235 containingmolecules, but not the U-238 containing molecules. As onlymolecules containing U-235 are in an excited state, this gives ahandle with which to differentiate, and eventually to separate, the twoisotopes.To be built by GE and Hitachi, the first commercial-scale U-235 laserenrichment facility licensed for production will use an Australian-developed laser enrichment technology known as Separation ofIsotopes by Laser Excitation (SILEX). Currently Silex has completedits phase I test loop program at GE-Hitachi Global Laser Enrichment’s(GLE) facility in North Carolina. When the commercial plant is built, itstarget enrichment level will be 8 percent, which puts it on the upperend of low-enriched uranium.SILEX is only one of a number of new approaches that have beeninvestigated for uranium enrichment. The SILEX process [PDF] wasdeveloped by Dr. Michael Goldsworthy and Dr. Horst Struve.As part of licensing the technology to the United States EnrichmentCorporation, details of the SILEX are classified under the provisionsof the US Atomic Energy Act. So while we don't have the whole storyon the details of the process, it's reasonable to assume that onlyabout three stages of enrichment are needed to produce five percentenriched uranium from ore, and only about seven stages to producefully weapons-grade enriched uranium. Estimates suggest that alaser-based uranium enrichment plant would have an initial cost, size,and power requirement about one-fifth that of an equivalentcentrifuge-based enrichment plant. The operating cost would also beexpected to be far smaller.Simpler, smaller, and less costly are characteristics that give laserenrichment of isotopes major potential to reduce the cost of nuclearpower. However, these same characteristics also make suchprocesses pose a substantial danger for widespread proliferation.Time will tell which potential future will win out, or if both hopes andconcerns are valid.By Dr. Bulbul Ahammed,Ph.D In Mechanical Engineer,Assistant professor,Premier University Of Technology,44 Sonargaon Janapath, Dhaka 1230,Bangladesh.
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