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

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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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