Today’s fleet of nuclear power plants have uranium enrichment requirements that vary by plant size and design. The diversity of fuel designs and levels of enrichment is increasing with the advent of new nuclear reactor technologies lead by small modular and advanced reactors. Having the flexibility to address a broad spectrum of enrichment needs is important to the future growth and diversity of both the domestic and global nuclear fuel supply chains.
Uranium is a naturally occurring element found in deposits around the world. This element is the primary fuel for nuclear power plants that produce a substantial share of the world’s clean energy. Natural uranium is dominated by two isotopes, U-235 (~0.7%) and U-238 (~99.3%), and it is the scarce U-235 isotope that undergoes splitting (or “fission”) to produce energy in a nuclear reactor. In order to increase the concentration of the fissile isotopes and make the material more useful for nuclear fuel, uranium typically undergoes a process of concentrating (or “enriching”) the U-235 isotope to approximately 5% or greater. Uranium enrichment is a technically difficult process and traditionally accounts for around 30% of the cost of nuclear fuel and approximately 5% of the total cost of the electricity generated by nuclear power.
Historically, uranium has been enriched via the first-generation gaseous diffusion process (now obsolete) or using second-generation gas centrifuge technology, both of which rely on subtle molecular weight differences to separate the uranium isotopes and are relatively inefficient.
Uranium Enrichment Using Lasers
Uranium can also be enriched by separating the isotopes with lasers. Lasers produce precise wavelengths of light, which can then be used to increase the energy of atomic or molecular species consisting of a specific isotope (“laser excitation”), changing their properties and allowing them to be separated. In the case of uranium, the U-235 isotopes are selectively excited and harvested separately from the more common U-238 isotopes, resulting in an increased concentration of U-235 over the initial uranium feedstock. The enriched product can then be used to produce fuel for generating nuclear energy, including for new reactor types that require higher enrichment levels.
SILEX and GLE
The Separation of Isotopes by Laser EXcitation (SILEX) process is a unique laser-based uranium enrichment process that has the potential to economically separate enrich uranium isotopes through highly selective laser excitation of the fluorinated form of uranium – the 235UF6 isotopic molecule. The SILEX process is substantially more efficient than existing methods of uranium enrichment and is the only third-generation enrichment technology at an advanced stage of commercialization today.
Since 2006, GLE has held the exclusive global rights to commercialize the SILEX technology for the purpose of uranium enrichment, and has been advancing the SILEX process in collaboration with Silex Systems at GLE’s Wilmington, North Carolina Test Loop facility, and at Silex’s facility in Sydney, Australia. As part of its commercialization efforts, GLE plans to integrate the its technology in the Test Loop facility with a balance-of-plant-infrastructure that is shared by existing commercial uranium conversion and enrichment facilities. The result is expected to be a compelling and flexible new source of cost-effective, US-based laser enrichment capability which can supply natural grade uranium and enriched uranium to fuel the requirements of existing and emerging nuclear plant designs.