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Caden
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- What does MCNP do with extra neutrons when keff > 1.0?
I am running some depletion calculations and have noticed odd behavior when keff is much greater or lower than one in the number of absorption's taking place on the outside the reactor. MCNP seems to be deleting the neutrons after it has reached the number of fissions required for the power level.
To test this I made an unrealistic reactor with a keff of 1.4 and a near infinite neutron capture blanket. I caught 70% of the neutrons created. By dropping keff to 1.0 in the same geometry by reducing the amount of fuel, I caught 100% of the neutrons created.
To me this implies that when keff > 1.0 any extra neutrons that would cause fissions in the fuel are deleted making it appear as though I am capturing less neutrons at higher keff.
If anyone can confirm what is going on that would be helpful.
Thanks
To test this I made an unrealistic reactor with a keff of 1.4 and a near infinite neutron capture blanket. I caught 70% of the neutrons created. By dropping keff to 1.0 in the same geometry by reducing the amount of fuel, I caught 100% of the neutrons created.
To me this implies that when keff > 1.0 any extra neutrons that would cause fissions in the fuel are deleted making it appear as though I am capturing less neutrons at higher keff.
If anyone can confirm what is going on that would be helpful.
Thanks