Chain Reactions
For the fissioning of uranium-238, we have the average number of neutrons/fission = 2.5. This means, for k=1, we need Pf = .4 .
On the nuclear data sheet, page 2, we have listed some information about ?i’s.
Recall that Pf = ?f / (?f + ?a + ?esc)
(we don’t include ?scattering since this does not remove the neutron).