Enriched uranium may contain fissionable contents of the order of
A
1-99%
B
1-25%
C
1-50%
D
1-75%
Correct Answer: 1-99%
Natural uranium is 99.284% 238U isotope, with 235U only constituting about 0.711% of its mass. 235U is the only nuclide existing in nature (in any appreciable amount) that is fissile with thermal neutrons.