PAKISTAN INSTITUTE OF ENGINEERING AND APPLIED SCIENCES

FUNDAMENTALS OF NUCLEAR ENGINEERING

Cross-section Practice Problems

1. In a reactor U3Si2 is used as fuel with Uranium enriched to

19.99 weight percent of U-235. The density of fuel is 3.5898

g/ cm3. Find the number density of Si, 235U and 238U.

2. Natural Uranium contains 99.28 weight percent of U-238 (a =

2.71 barns) and 0.72 weight percent of U-235 (a = 683

barns). Density of natural Uranium metal is 19 g/cm3.

Determine the macroscopic and microscopic absorption cross-

section of Uranium metal.

3. SS-304 has density of 7.86 g/cm3. Its composition by weight is

as follows: Carbon-12 0.08% (a = 0.0034 b), Chromium-52

19% (a = 3.1 b), Nickel-59 10% (a = 4.43 b) and remainder

is Iron-56 (a = 2.55 b). Find the macroscopic absorption

cross-section of SS-304.