i need a help in solving ,using 1 group approxmation , estimate the critical size of cube consisting of 75% zirconium-91 and 25% plutonium--239 by volume , when the cube is surrounded by a vacumm.(adsbygoogle = window.adsbygoogle || []).push({});

zr-91

microscopic cross section (capture)=0.00335

microscopic cross section (scattering )=5.89

density=6.4 g/cm3

Mass=90.9056 g/mol

pu-239

v=2.98 n/fission

microscopic cross section (fission)=1.81

microscopic cross section (capture)=0.05

microscopic cross section (scattering )=7.42

density=19 g/cm3

Mass=239.0522 g/mol

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# One group neutron diffusion calculation

**Physics Forums | Science Articles, Homework Help, Discussion**