SILEX Laser Isotope Separation Technology

The SILEX Laser Isotope Separation (LIS) technology was invented by Silex Systems scientists Dr Michael Goldsworthy (our CEO) and Dr Horst Struve (retired) in the 1990s at its Lucas Heights facility south of Sydney, Australia.

Initially, the Silex team investigated LIS techniques for several stable elements, including Chlorine, Molybdenum, Carbon, Oxygen and Silicon. Being the single largest commercial isotope market in the world, activities also focused increasingly on Uranium enrichment. It is worth noting that Australia has the largest uranium reserves in the world (around one-third of the total) however, Australia only mines uranium and sells it as uranium oxide (‘yellowcake’) – with no further processing permitted.

Several of the stable element isotopes noted above already have existing commercial markets and production is achieved via traditional methods such as cryogenic distillation (carbon and oxygen) and gas centrifuge (others listed above). There are emerging markets for isotopes in the medical radiopharmaceutical industry, such as Ytterbium and Molybdenum. The SILEX technology can potentially be applied to the enrichment of some of these valuable isotopes.

Today, Silex is actively pursuing two applications of the SILEX LIS Technology:


Through our 51% owned subsidiary Global Laser Enrichment (GLE), the path to market for our uranium enrichment technology is currently based on the planned multi-purpose Paducah Laser Enrichment Facility (PLEF) in the United States to produce all three grades of nuclear fuel required for current and future nuclear plants:

  • PLEF UF6 Production: via enrichment of US Department of Energy (DOE) owned inventories of depleted UF6 tails (at the proposed PLEF) to produce uranium (in the form of converted UF6) at a natural U235 assay of ~0.7%;
  • PLEF LEU Production: production of low enriched uranium (LEU) (U235 assays up to 5%) and LEU+ (assays from 5% to 10%) from natural grade UF6 with additional SILEX enrichment capacity – to supply fuel for existing reactors;
  • PLEF HALEU Production: production of high assay LEU (HALEU) (U235 assays up to ~20%) via enrichment with SILEX technology to supply fuel for next generation advanced reactors, including SMRs.

Underpinning GLE’s commercialisation of the SILEX technology at the PLEF is the 2016 agreement between GLE and the DOE, which through the acquisition of over 200,000 metric tonnes of depleted tails owned by the DOE, provides the feedstock for the production of natural grade uranium hexafluoride (UF6) over three decades.

The output of the proposed plant would be sold into the global uranium market at an expected production rate equivalent to a uranium mine with an annual output of up to 5 million pounds of uranium oxide, which would rank in the top 10 of today’s uranium mines by production volume. Preliminary analysis by Silex of PLEF UF6 Production indicates it could rank equal to a ‘Tier 1’ uranium project based on current estimates of the low cost of production and longevity.

Uranium ESG focus – nuclear power for a clean energy future

Our key application – uranium production and enrichment, is core to our ESG focus. In an energy-hungry, carbon-constrained world, nuclear energy offers the unique possibility to produce emissions-free baseload energy at very competitive costs to renewables, whilst providing stability to the world’s electricity grids. Nuclear is the perfect complement to renewables.


Silex is developing its SILEX laser enrichment technology for the production of highly enriched ‘Zero-Spin Silicon’ – an enabling material for silicon quantum computing. Quantum computing will transform humanity’s computing capabilities, allowing complex and difficult global issues to be solved, such as:

  • more powerful modelling of global climate systems to help develop climate change mitigation and adoption strategies; and
  • more powerful modelling of diseases and pharmaceutical / vaccine development, such as in the case of COVID-19.

Silicon ESG focus – next-generation computing to solve global challenges

Quantum computers, expected to be thousands of times more powerful than the most advanced conventional computers, will open new frontiers and opportunities in many industries, including medicine, artificial intelligence, cybersecurity and global financial systems. Quantum computing will have the capability to solve many of humanity’s most vexing challenges.

Subscribe to our announcements