“Highly enriched uranium (HEU) is anything enriched above 20% and weapon-grade uranium is commonly considered to have been enriched above 90% U-235. However, some research reactors use 90% enriched U-235 to produce medical isotopes, so there are civilian applications for this fuel too.”
“Highly enriched uranium (HEU) is anything enriched above 20% and weapon-grade uranium is commonly considered to have been enriched above 90% U-235. However, some research reactors use 90% enriched U-235 to produce medical isotopes, so there are civilian applications for this fuel too.”
https://armscontrolcenter.org/uranium-enrichment-for-peace-or-for-weapons/