I am a PhD student at University of Tennessee, Knoxville. Right now I am trying to actively learn OpenMC, as an exercise I am conducting a verification study. I am evaluating TBR for multiple solid breeder concepts (8 different breeders and 3 multiplier - Be, Be12Ti, Be12V) and comparing them to MCNP results published in this paper .
In a short summary, the tokamak design in reduced to infinite shells. Source(14 MeV, 100cm radius) is surrounded by homogenized blanket. It starts off as just breeder+multiplier, and then other materials are added within the blanket region with a relative volume fraction while maintaining 200cm width throughout.
note: Geometry and Cross-sections were kept consistent throughout.
Through the simulations, I have received a pretty decent agreement with the MCNP data, but I noticed some huge difference in handful of cases (9/24 cases). I would be open to meeting on zoom or sharing more comparisons. I had some questions, I am posting some of them.
- In all 8 breeders with Be, the OpenMC evaluation is significantly higher than MCNP. (I have rechecked the code multiple time and as other multipliers show reasonable agreement, I am inclined to trust the code for now). In the comparisons below, there are no materials added in the breeding zone. I was wondering what would be best way to move forward and what other things can be checked, I think I am stuck here.
I also wanted to visualize where the neutrons are being absorbed in the geometry, if I could be directed to the relevant documentation, that would be really helpful
Can a simulation be run with two different cross sections, if yes, how? if not, is there a way around it?
I apologize for the long post. Let me know if you would be interested in looking at more comparisons to get a better picture of the questions.