Quick Guides
Writing Input
KOMODO input is designed to be self-explanatory. It has several input cards marked by %, for example: %mode, %geom, %xsec, and so on. Some cards are mandatory for any problems. While some cards are conditional depending on the problems at hand and some cards are optional. Comments are marked by !. For example, the following is the IAEA3D input, where you can find its specification here.
! IAEA3D input data
! NODE SIZE = 10 cm
! PARCS K-EFF : 1.029096
! KOMODO K-EFF : 1.029082 (ERROR = 1.4 PCM)
! Mode card
%MODE
FORWARD
! Case card
%CASE
IAEA3D
10 CM NODE SIZE
! Cross-sections card
%XSEC
2 5 ! Number of groups and number of materials
! sigtr siga nu*sigf sigf chi sigs_g1 sigs_g2
0.222222 0.010 0.000 0.000 1.0 0.1922 0.020
0.833333 0.080 0.135 0.135 0.0 0.000 0.7533 ! MAT1 : Outer Fuel
0.222222 0.010 0.000 0.000 1.0 0.1922 0.020
0.833333 0.085 0.135 0.135 0.0 0.000 0.7483 ! MAT2 : Inner Fuel
0.222222 0.0100 0.000 0.000 1.0 0.1922 0.020
0.833333 0.1300 0.135 0.135 0.0 0.000 0.7033 ! MAT3 : Inner Fuel + Control Rod
0.166667 0.000 0.000 0.000 0.0 0.1267 0.040
1.111111 0.010 0.000 0.000 0.0 0.000 1.1011 ! MAT4 : Reflector
0.166667 0.000 0.000 0.000 0.0 0.000 0.040
1.111111 0.055 0.000 0.000 0.0 0.000 0.000 ! MAT5 : Reflector + Control Rod
%GEOM
9 9 19 ! number of assembly in x, y, z directions
10.0 20.0 20.0 20.0 20.0 20.0 20.0 20.0 20.0 !x-direction assembly size in cm
1 8 8 8 8 8 8 8 8 !x-direction assembly divided into 2 (10 cm each)
20.0 20.0 20.0 20.0 20.0 20.0 20.0 20.0 10.0 !y-direction assembly size in cm
8 8 8 8 8 8 8 8 1 !y-direction assembly divided into 2 (10 cm each)
19*20.0 !z-direction assembly in cm
19*1 !z-direction nodal is not divided
4 !np number of planar type
1 13*2 4*3 4 !planar assignment (from bottom to top)
! Planar_type_1 (Bottom Reflector)
4 4 4 4 4 4 4 4 4
4 4 4 4 4 4 4 4 4
4 4 4 4 4 4 4 4 4
4 4 4 4 4 4 4 4 4
4 4 4 4 4 4 4 4 0
4 4 4 4 4 4 4 4 0
4 4 4 4 4 4 4 0 0
4 4 4 4 4 4 0 0 0
4 4 4 4 0 0 0 0 0
! Planar_type_2 (Fuel)
3 2 2 2 3 2 2 1 4
2 2 2 2 2 2 2 1 4
2 2 2 2 2 2 1 1 4
2 2 2 2 2 2 1 4 4
3 2 2 2 3 1 1 4 0
2 2 2 2 1 1 4 4 0
2 2 1 1 1 4 4 0 0
1 1 1 4 4 4 0 0 0
4 4 4 4 0 0 0 0 0
! Planar_type_3 (Fuel+Partial Control Rods)
3 2 2 2 3 2 2 1 4
2 2 2 2 2 2 2 1 4
2 2 3 2 2 2 1 1 4
2 2 2 2 2 2 1 4 4
3 2 2 2 3 1 1 4 0
2 2 2 2 1 1 4 4 0
2 2 1 1 1 4 4 0 0
1 1 1 4 4 4 0 0 0
4 4 4 4 0 0 0 0 0
! Planar_type_4 (Top reflectors)
5 4 4 4 5 4 4 4 4
4 4 4 4 4 4 4 4 4
4 4 5 4 4 4 4 4 4
4 4 4 4 4 4 4 4 4
5 4 4 4 5 4 4 4 0
4 4 4 4 4 4 4 4 0
4 4 4 4 4 4 4 0 0
4 4 4 4 4 4 0 0 0
4 4 4 4 0 0 0 0 0
! Boundary conditions
! 0 = zero-flux
! 1 = zero-incoming current
! 2 = reflective
! (east), (west), (north), (south), (bottom), (top)
1 2 2 1 1 1
%ITER
1200 5 1.e-5 1.e-5 15 40 20 80 ! 5 inner iterations per outer, and fission extrapolate every 15 outer iterations
! NOTE: Writing 19*20.0 is equivalent to write 20.0 nineteen times in a row
In the above example, there are
- Two mandatory cards :
%MODEand%GEOM - One conditional card:
%XSEC - One optional card :
%CASE
You find the detailed description for each card here, but we will explain them briefly now
%MODE Card
This is the mode of KOMODO calculation. Since here we want to calculate static forward calculation (eigenvalue problem) the calculation mode is FORWARD. The detailed description of this card is here.
%CASE Card
This card is optional. This describes the problem at hand. The detailed description of this card is here.
%XSEC Card
This card is conditional, necessary only if %XTAB card is not present. This card tells KOMODO the cross sections data for the problem. The cross section data must be given for each group and for each material as shown in the example. The description of the cross sections data can be seen in the comments. The detailed description of this card is here.
%GEOM Card
This card is describes the geometry of the problem. It quite similar to other reactor core simulator which you can easily understand if you have background on nuclear engineering. The description of the inputs given in the comments. The detailed description of this card is here.
Running a Test
In Linux or other Unix based OS, you can run KOMODO using command
komodo [INPUT_FILE_PATH_NAME]
for example, you can run IAEA3Ds input by
komodo /home/imronuke/smpl/static/IAEA3Ds
While in Windows, for example, you can run as follow
komodo C:\Users\imronuke\Downloads\KOMODO-master\smpl\static\IAEA3Ds
Reading Output
After you run a test, you should see in the summary of the output in terminal as follow
###########################################################
# KOMODO 1.2 #
# ABU DHABI POLYTECHNIC REACTOR SIMULATOR #
###########################################################
CALCULATION MODE : FORWARD CALCULATION
CASE ID : IAEA3D
10 CM NODE SIZE
NODAL KERNEL : SEMI-ANALYTIC NODAL METHOD
reading input ... done
==============================================================================
CALCULATION RESULTS
==============================================================================
Itr k-eff Fis.Src Error Inner Error
----------------------------------------------------
1 0.981424 5.47871E-01 8.55259E+03
2 1.001319 2.41976E-01 8.56379E+00
3 1.009804 1.67297E-01 6.27992E-01
4 1.013500 1.33833E-01 1.44559E-01
...FISSION SOURCE EXTRAPOLATED...
5 1.026980 2.65156E+00 1.31348E-01
.
.
.
15 1.028565 5.05638E-01 6.73943E-02
16 1.028253 6.31685E-02 4.20531E-01
17 1.028196 3.63469E-02 4.93252E-01
18 1.028082 2.21127E-02 2.48688E-01
19 1.028020 1.29756E-02 6.24972E-02
...FISSION SOURCE EXTRAPOLATED...
20 1.027400 3.54750E-01 2.34432E-02
21 1.027655 6.04390E-02 3.09183E-01
.....NODAL COUPLING UPDATED.....
MAX. CHANGE IN NODAL COUPLING COEF.= 3.16843E-01 AT NODE I = 6, J = 4, K = 19
22 1.028084 5.88420E-02 1.59061E-01
23 1.032373 1.30872E-01 4.33336E-01
.
.
.
127 1.029082 1.20168E-05 8.28493E-05
128 1.029082 9.48481E-06 2.04727E-05
129 1.029082 7.46358E-06 9.66768E-06
MULTIPLICATION EFFECTIVE (K-EFF) = 1.029082
CPU time breakdown in seconds
Input reading time : 0.0078 ( 5.0%)
XSEC processing time : 0.0003 ( 0.2%)
CMFD time : 0.0893 (57.1%)
Nodal update time : 0.0590 (37.7%)
T-H time : 0.0000 ( 0.0%)
------------------------------------------
Total time : 0.1565
KOMODO EXIT NORMALLY
If you get KOMODO EXIT NORMALLY in the end of the terminal output, it means you successfully run KOMODO. Since it is a forward (eigenvalue) problem, you will see the outer iterations as they evolve and you will see also the effective multiplication factor as well as CPU time breakdown. The detailed output, such as radial and axial power distribution, can be found in the same file name as input but with an .out extension.
It is always a good idea to see this output file to ensure that you had written input correctly. KOMODO echoes your input and re-describe the input to make sure that this is the problem you want to solve. KOMODO may run well without any error but it gives you wrong results. This might happen if the input is not consistent with the problem specification.