Eta (Reproduction Factor) Impact of Fuel Leg Change

[ms.shafeie]

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

 

[Astronuc]

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

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