Same Flux distribution

Hello everyone,
I am trying to determine the axial flux distribution for a BWR assembly. To achieve this, I have created a mesh filter and an energy filter. The code is:

tallies_file = openmc.Tallies()

mesh = openmc.RegularMesh(mesh_id=1)
mesh.dimension = [1, 1, 381]
mesh.lower_left = [5.951855, 5.951855, -169.6]
mesh.upper_right= [7.63016, 7.63016, 211.4]
#mesh.width = [1.678305, 1.678305, 1]
mesh_filter = openmc.MeshFilter(mesh)
energy_filter = openmc.EnergyFilter([0.0, 1.0])

tally = openmc.Tally(name=‘flux’)
tally.filters = [mesh_filter, energy_filter]
tally.scores = [‘flux’]
tallies_file.append(tally)

I then loaded the statepoint file, extracted the flux tally, and plotted the axial flux distribution. The code is:

Load the statepoint file

sp = openmc.StatePoint(“statepoint.200.h5”)

Extract the flux tally

tally = sp.get_tally(name=‘flux’)

Extract the flux data for all particle types

flux_data = tally.get_slice(scores=[“flux”])

Extract the values of the flux data

flux_values = flux_data.mean.ravel()

Plot the axial flux distribution

plt.plot(flux_values)
plt.xlabel(“Axial Position”)
plt.ylabel(“Flux”)
plt.show()
However, I am encountering an issue where the plot consistently displays the same flux distribution for all fuel rods within the assembly, regardless of any variations in fuel or burnable absorbers. I am uncertain as to the cause of this discrepancy and would greatly appreciate any guidance in resolving this issue.
Thanks,
Niloy

Hello Niloy,

How do you check the flux in different pins? Do you define different tallies changing the lower_left and upper_right attribute?
Why don’t you use a CellFilter or a MaterialFilter to select the desired pins? It should be easier to track in which pin you are collecting the scores

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