Which statement about enrichment categories is accurate?

Which statement about enrichment categories is accurate?

• A. LEU is less than 20% U-235; HEU is greater than 20% U-235; Reactor grade is 3-5%; Weapons grade is about 90%
• B. LEU is greater than 20%; HEU is less than 20%; Reactor grade is 3-5%; Weapons grade is 90%
• C. LEU is 50%; HEU is 50%; Reactor grade is 3-5%; Weapons grade is 90%
• D. LEU is 3-5%; HEU is 90%; Reactor grade is 50%; Weapons grade is 99%

Answer: (A)

Enrichment categories classify uranium by how much U-235 it contains, which determines how easily it fissions and whether it’s suitable for civilian use or weapons. Low-enriched uranium has less than 20% U-235, which is typical for most civilian reactors because it provides manageable reactivity and safety. Highly enriched uranium contains more than 20% U-235, increasing reactivity and raising proliferation concerns. Reactor-grade uranium is usually around 3–5% U-235, a common fuel level for many reactors and still considered LEU. Weapons-grade uranium is about 90% U-235, offering the high fissile concentration needed for weapons applications. The statement that aligns with these standard ranges—LEU under 20%, HEU over 20%, reactor-grade near 3–5%, and weapons-grade around 90%—is the best description.

Enrichment categories classify uranium by how much U-235 it contains, which determines how easily it fissions and whether it’s suitable for civilian use or weapons. Low-enriched uranium has less than 20% U-235, which is typical for most civilian reactors because it provides manageable reactivity and safety. Highly enriched uranium contains more than 20% U-235, increasing reactivity and raising proliferation concerns. Reactor-grade uranium is usually around 3–5% U-235, a common fuel level for many reactors and still considered LEU. Weapons-grade uranium is about 90% U-235, offering the high fissile concentration needed for weapons applications. The statement that aligns with these standard ranges—LEU under 20%, HEU over 20%, reactor-grade near 3–5%, and weapons-grade around 90%—is the best description.