Enriched Uranium
Uranium in which the relative concentration of the fissile isotope Uranium-235 has been increased above its natural abundance (~0.72%).
Governing formula
% U-235 Concentration (Low Enriched: 3–5%, High Enriched: >20%)
SI unit
Weight Percent (% ²³⁵U)
In depth
Natural uranium consists of ~99.28% non-fissile U-238 and ~0.72% fissile U-235. Isotope separation techniques (gas centrifuges or gaseous diffusion) exploit mass differences to enrich U-235 concentration for reactor fuel (3–5%) or weapons (>90%).
Examples in the real world
Low-enriched uranium (LEU) fuel pellets containing 4% U-235 utilized in commercial light-water nuclear power reactors.