How to Handle WIMS Reactor Physics Codes for Radial Neutron Flux Analysis?

[PhotonEd]

Hello hope someone can help me
I need to do WIMS reactor physics codes analysis for
1) divide fuel pin into radial equal-volume sub regions
2) preform criticality calculations to obtain radial fast and thermal neutron flux (use 0.615eV energy cut off between fast and thermal regions)
I will need advise on obtaining flux for the regions as the output file is not showing the 2 group flux, please see the below for some of the input files, many thanks

regards

1) equal section setup as below in .pwrpin file for wimsbuilder

FUEL MATERIAL 1
DENSITY 10.40
TEMP FUELTEMP
COMPOSITION \
U235 1.0997472E-03 \
U238 2.1525591E-02 \
U234 1.0409077E-05 \
U236 3.2482827E-07 \
O 4.5272144E-02

FUEL MATERIAL 2
DENSITY 10.40
TEMP FUELTEMP
COMPOSITION \
U235 1.0997472E-03 \
U238 2.1525591E-02 \
U234 1.0409077E-05 \
U236 3.2482827E-07 \
O 4.5272144E-02

CLAD MATERIAL 3
DENSITY 6.5
TEMP CLADTEMP
COMPOSITION Zr 100

COOLANT MATERIAL 4
DENSITY COOLDENS
TEMP COOLTEMP
COMPOSITION H 11.18983 O 88.81017

ANNULUS 1 RADIUS 0.40950 MATERIAL 1
ANNULUS 2 RADIUS 0.42950 MATERIAL 2
ANNULUS 3 RADIUS 0.47500 MATERIAL 3
ANNULUS 4 MATERIAL 4

2) for energy cut off and group split in .route file

....
ifelse(BRANCH,YES,[CRITIC 8 5],[CRITIC 2 5])
buckling 6 0.00022314 0.000065641 0.00001 0.0
begin
COND 5 6
energy 0.615 *This is for the Energy cut-off (2-groups)
begin
SMEAR 6 7
newmat 1 allm
begin
EDIT 7
groups SPLIT * this is to print for 2 grroup
nuclides Pu239 Pu241
...

 

[PhotonEd]

To anyone of interested
EDIT should be on card 6 before SMEAR as otherwise it will just print out the "smeared" 1 group (1 group) and not the 2 groups (fast ad thermal) as required
codes as of the below
:)

...
ifelse(BRANCH,YES,[CRITIC 8 5],[CRITIC 2 5])
buckling 6 0.00022314 0.000065641 0.00001 0.0
begin
COND 5 6 * Energy cut-off (2-groups)
energy 0.615 0 * Energy cut-off (2-groups)
begin * Energy cut-off (2-groups)

EDIT 6
groups SPLIT * print option for 2gr
begin

SMEAR 6 7
newmat 1 mat 1
*newmat 1 allm
begin
...

 

[raining Pete]

Hello there,

I am not an expert in WIMS reactor physics codes, but I can try to provide some advice based on the input files you have shared.

For the first part of your task, dividing the fuel pin into radial equal-volume sub regions, it seems like you have already set up the sections in the .pwrpin file using the ANNULUS command. However, it is not clear from the input files how many sub-regions you have defined and if they are truly equal in volume. You may need to double check the dimensions and make sure they are accurately defined.

For the second part, performing criticality calculations to obtain radial fast and thermal neutron flux, it seems like you have specified the energy cut off between the fast and thermal regions in the .route file. However, it may be helpful to check the output file to make sure the energy cut off is being applied correctly.

Regarding obtaining the flux for the regions, it is not clear which output file you are referring to. It may be helpful to consult the WIMS documentation or reach out to other experts in the field for guidance on how to obtain the flux for the defined regions.

I hope this helps a bit. Best of luck with your analysis!