Lightbridge’s metal fuel differs from the alloy fuel that has been historically evaluated for fast reactor applications. Previous investigations into metal nuclear fuels focused on low alloy compositions such as U-10Zr wherein the concentration of uranium is significantly higher than the alloy constituent. The Lightbridge Zr-U alloy is a high-alloy fuel comprised of U-50Zr. One of the primary differences, with respect to irradiation characteristics, of Lightbridge’s metal fuel compared to U-10Zr is a significant reduction in irradiation-induced swelling. The U-10Zr fuels exhibit high radiation-induced swelling (typically, ~30 volume percent within 2 atom percent burnup) while swelling in the Lightbridge metal fuel is expected to be around 1 volume percent per atom percent burnup.
Lightbridge’s metal fuel technology came out of the research and development work for our thorium-based seed-and-blanket fuel assembly. The metallic seed rods used in our seed-and-blanket design are capable of operating safely at increased power density compared to standard uranium oxide fuel. Lightbridge determined that a fuel assembly comprised of only metallic fuel rods could provide significant benefits to a nuclear power plant.
© 2009 Lightbridge 
