Reproduction Factor

ms.shafeie

why does eta(Reproduction Factor) fall down when we change fuel leg from maximum level of yield?

Astronuc

I don't quite follow the question, specifically the part "when we change fuel leg from maximum level of yield". Please elaborate on this statement.

η = Ʃ_i (v_i Ʃ_f,i) / Ʃ_a, where Ʃ_a is the weighted sum of the macroscopic absorption cross-section of the fuel material mixture. The index i refers to the fissile (and fertile) species. Fertile nuclides fission mainly with fast neutrons.

There are neutron energy spectral effects and temperature effects. If v (nu) increases, the fission cross-section decreases and the absorption increases (due to increased resonance absorption). One has to look at the fissile and fertile species, as well as other materials and coolant.

ms.shafeie

thanks alot for ur good respond to my question.ur suggetion is right and I try to solve my problem in asking questions.