I want to determine the maximum and minimum k_eff values within an assembly to calculate their difference. However, I only seem to get an average k_eff. Does OpenMC have this feature, and how can I implement it?
I’m not sure that I totally understand your question. keff is an integral quantity by definition, so it is integrated over the whole problem domain. What are you trying to understand about the system that you’re modeling?
You could get a rough estimate by using tallies to track the rate of reactions across a mesh, then you’d want to be calculating \mathrm{\frac{Neutrons\>Created}{Neutrons\>Destroyed}} per mesh node
The following link may be helpful, it outlines all the possible Reaction Score tallies that can be tracked with OpenMC.