relating to my latest thread here: Weird Fission Reaction Rate Calculated in Epithermal Assembly Depletion
I found that Fission Value acquire from MeshFilter (Left) and CellFilter (Right) Tally is different which lead to the difference in Axial Peaking Factor show in this figure
Result got from MeshFilter is similar to the Result from Serpent (from literature) in every time step from 0 to 90Mwd/kg. While the Result from CellFilter is the same result with results.get_reaction_rate for defined material_ids. The differences can be observed clearly in the internal blanket zone.
as I’m doing the Multiphysics calculation loop. It is much easier for me to use the results.get_reaction_rate or at least CellFilter because it gives results in the form of an array that matches my axial block numbers which means my geometry height can be parametrized later.
bounds = [-11.41225,-11.41225,0,11.41225,11.41225,102.5] tallies_file = openmc.Tallies() mesh_axial = openmc.RegularMesh(mesh_id=1) mesh_axial.dimension = [1,1, 205] mesh_axial.lower_left = bounds[:3] mesh_axial.upper_right = bounds[3:] mesh_f_axial = openmc.MeshFilter(mesh_axial) tally_axial = openmc.Tally(name='axial peaking') tally_axial.filters = [mesh_f_axial] tally_axial.scores = ['fission']
tally_axial_2 = openmc.Tally(name='APF') tally_axial_2.filters = [openmc.CellFilter([LFB1_cell,LFB2_cell,LFB3_cell,LFB4_cell,LFB5_cell,LFB6_cell,LFB7_cell,LFB8_cell,\ IBB1_cell, IBB2_cell, IBB3_cell, IBB4_cell, IBB5_cell, IBB6_cell, IBB7_cell, IBB8_cell,\ UFB1_cell, UFB2_cell, UFB3_cell, UFB4_cell, UFB5_cell, UFB6_cell, UFB7_cell, UFB8_cell,\ UBB1_cell, UBB2_cell, UBB3_cell, UBB4_cell, UBB5_cell, UBB6_cell, UBB7_cell, UBB8_cell,UBB9_cell,UBB10_cell])] tally_axial_2.scores = ['fission']
The differences appear after 0 Mwd/kg
Any reason behind this difference ?