Hello,

I’m modelling TRISO fuel particles in a box (1cmx1cmx1cm). I have taken the example from this post Simulation Triso - #2 by mkreher13. I ran the example first and got kinf ~ 1.06. I have then changed the material compositions and TRISO particle radii for the specific problem I am modelling. The kinf for this problem is ~0.69. Given that the problem is a box with reflective BC I would expect the kinf > 1. All that I have changed from the example is the material compositions and particle radii so I don’t understand this result. I have modelled the same problem in Serpent and got kinf~1.38 which is what I would expect from this problem. I have attached my file.

triso_box_v2.py (3.4 KB)

Best wishes,

Emma