High enriched uranium is defined as greater than 20 percent U-235. Which option correctly matches this definition?

High enriched uranium is defined as greater than 20 percent U-235. Which option correctly matches this definition?

• A. Less than 20% concentration of U-235
• B. Greater than 20% concentration of U-235
• C. Around 3-5% U-235
• D. Around 90% U-235

Answer: (B)

High enrichment means the amount of U-235 in uranium is lifted well above natural levels. Natural uranium is about 0.7% U-235, and civilian reactor fuel typically sits around 3–5% U-235. When the U-235 fraction exceeds about 20%, it’s classified as highly enriched uranium. So the statement describing a greater than 20% concentration of U-235 matches this definition. Note that very high enrichment, like around 90% U-235, is an example of the extent high enrichment can reach, but the defining point is passing the 20% threshold.

High enrichment means the amount of U-235 in uranium is lifted well above natural levels. Natural uranium is about 0.7% U-235, and civilian reactor fuel typically sits around 3–5% U-235. When the U-235 fraction exceeds about 20%, it’s classified as highly enriched uranium. So the statement describing a greater than 20% concentration of U-235 matches this definition. Note that very high enrichment, like around 90% U-235, is an example of the extent high enrichment can reach, but the defining point is passing the 20% threshold.