Geometry error

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Barbara
Posts: 1
Joined: Fri May 07, 2021 8:09 pm
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Geometry error

Post by Barbara » Wed May 26, 2021 9:04 pm

Hey all,

I am a serpent code beginner and I am modeling a small PWR core. I got the following error:

[bolivei@rdfmg SERPENT]$ Geometry error: undefined region.
geometry definition in the input.

Level 0 / universe 0 :
Cell universe / cell 300
(x,y,z) = 3.34820E+01 1.11502E+01 1.55145E+02
(u,v,w) = 0.00000E+00 0.00000E+00 1.00000E+00

Level 1 / universe 300 :
Lattice universe / region 7
(x,y,z) = 3.34820E+01 1.11502E+01 1.55145E+02
(u,v,w) = 0.00000E+00 0.00000E+00 1.00000E+00

Geometry errors caused by undefined regions can be
ignored by using the "set lost" input option:

http://serpent.vtt.fi/mediawiki/index.p ... l#set_lost

Simulation aborted.

My input model:

% --- INPUT C5G7 Barbara
c5g7.inp
set title "C5G7 TD source generation"


% --- Cross section library file path:

set acelib "/cm/shared/apps/ncsu/SERPENT/xsdata/endfb71/sss_endfb71u.xsdata"
set declib "/cm/shared/apps/ncsu/SERPENT/xsdata/endfb71/sss_endfb71.dec"
set nfylib "/cm/shared/apps/ncsu/SERPENT/xsdata/endfb71/sss_endfb71.nfy"
set sfylib "/cm/shared/apps/ncsu/SERPENT/xsdata/endfb71/sss_endfb71.sfy"

% set savesrc "./source" % save neutron source for transient

% ------------------------------------------------------------

% --- Material definitions:

% UO2
mat UO2 sum tmp 293.15
92235.86c 8.6500E-4
92238.86c 2.2250E-2
8016.86c 4.6220E-2


% MOX 4.3 wt % enrichment
mat MOX4 sum tmp 293.15
92235.86c 5.0000E-5
92238.86c 2.2100E-2
94238.86c 1.5000E-5
94239.86c 5.8000E-4
94240.86c 2.4000E-4
94241.86c 9.8000E-5
94242.86c 5.4000E-5
95241.86c 1.3000E-5
8016.86c 4.6300E-2

% MOX 7.0 wt % enrichment
mat MOX7 sum tmp 293.15
92235.86c 4.7493E-5
92238.86c 2.1462E-2
94238.86c 2.4452E-5
94239.86c 9.5151E-4
94240.86c 4.0069E-4
94241.86c 1.5682E-4
94242.86c 8.7024E-5
95241.86c 1.9724E-5
8016.86c 4.6300E-2

% MOX 8.7 wt % enrichment
mat MOX8 sum tmp 293.15
92235.86c 4.7052E-5
92238.86c 2.1063E-2
94238.86c 3.0390E-5
94239.86c 1.1800E-3
94240.86c 5.0056E-4
94241.86c 1.9490E-4
94242.86c 1.0816E-4
95241.86c 2.5645E-5
8016.86c 4.6300E-2


% --- Al Clad
mat ALCLAD sum tmp 293.15
13027.86c 6.0000E-2

% --- Zr Clad
mat ZRCLAD sum tmp 293.15
40090.86c 2.21235E-2
40091.86c 4.82460E-3
40092.86c 7.37450E-3
40094.86c 7.47340E-3
40096.86c 1.20400E-3

% --- Control rods
mat CR sum tmp 293.15
47107.86c 2.27105E-2
47109.86c 2.27105E-2
49115.86c 8.00080E-3
48113.86c 2.72410E-3

% --- Water:

mat water sum tmp 293.15 moder lwtr 1001
1001.86c 6.70000E-02
8016.86c 3.35000E-02
5010.86c 5.53220E-06
5011.86c 2.22678E-05

%therm lwe6 lwe6.00t
therm lwtr lwtr.20t

% --- Fission chamber:

mat FC sum tmp 293.15
1001.86c 6.70000E-02
8016.86c 3.35000E-02
92235.86c 1.00000E-08
5010.86c 5.53220E-06
5011.86c 2.22678E-05


% ------------------------------------------------------------

% --- Parameters ("param block"):

% --- Set power level

set power 1.0

% --- Neutron population and criticality cycles:

set pop 8000 800 200

% --- Boundary conditions

set usym 0 1 2 0.0 0.0 0 90

% ------------------------------------------------------------

% --- Geometry ("geom block"):

% --- UO2 fuel pin
pin 1
UO2 0.4095
void 0.4180
ZRCLAD 0.4750
void 0.4800
ALCLAD 0.5400
water

% --- 4.3 MOX fuel pin
pin 2
MOX4 0.4095
void 0.4180
ZRCLAD 0.4750
void 0.4800
ALCLAD 0.5400
water

% --- 7.0 MOX fuel pin
pin 3
MOX7 0.4095
void 0.4180
ZRCLAD 0.4750
void 0.4800
ALCLAD 0.5400
water

% --- 8.7 MOX fuel pin
pin 4
MOX8 0.4095
void 0.4180
ZRCLAD 0.4750
void 0.4800
ALCLAD 0.5400
water

% --- CR guide tube
pin 5
water 0.3400
ALCLAD 0.5400
water

% --- fission chamber/central guide tube
pin 6
FC 0.3400
ALCLAD 0.5400
water


% --- UOX-assembly ("unit 100"):

surf 1000 cuboid -10.71 10.71 -10.71 10.71 0.0 365.76

cell 100 100 fill 110 -1000
cell 101 100 water 1000

% --- MOX-assembly ("unit 200"):

surf 2000 cuboid -10.71 10.71 -10.71 10.71 0.0 365.76

cell 200 200 fill 210 -2000
cell 201 200 water 2000

% --- Core lattice ("global unit 0"):

surf 3000 cuboid -42.84 42.84 -42.84 42.84 0.0 408.6

cell 300 0 fill 300 -3000
cell 301 0 outside 3000


% --- Water reflector:

surf 4000 cuboid -10.71 10.71 -10.71 10.71 0.0 21.42


cell 400 400 water -4000
cell 401 400 water 4000

% ------------------------------------------------------------

% --- Lattices ("array block"):

% --- UO2 pin lattice:

lat 110 11 0.0 0.0 0.0 17 17 1 1.26 1.26 365.76

1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 % 1
1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 % 2
1 1 1 1 1 5 1 1 5 1 1 5 1 1 1 1 1 % 3
1 1 1 5 1 1 1 1 1 1 1 1 1 5 1 1 1 % 4
1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 % 5
1 1 5 1 1 5 1 1 5 1 1 5 1 1 5 1 1 % 6
1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 % 7
1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 % 8
1 1 5 1 1 5 1 1 6 1 1 5 1 1 5 1 1 % 9
1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 % 10
1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 % 11
1 1 5 1 1 5 1 1 5 1 1 5 1 1 5 1 1 % 12
1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 % 13
1 1 1 5 1 1 1 1 1 1 1 1 1 5 1 1 1 % 14
1 1 1 1 1 5 1 1 5 1 1 5 1 1 1 1 1 % 15
1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 % 16
1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 % 17

% --- MOX pin lattice:

lat 210 11 0.0 0.0 0.0 17 17 1 1.26 1.26 365.76


2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 % 18
2 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 2 % 19
2 3 3 3 3 5 3 3 5 3 3 5 3 3 3 3 2 % 20
2 3 3 5 3 4 4 4 4 4 4 4 3 5 3 3 2 % 21
2 3 3 3 4 4 4 4 4 4 4 4 4 3 3 3 2 % 22
2 3 5 4 4 5 4 4 5 4 4 5 4 4 5 3 2 % 23
2 3 3 4 4 4 4 4 4 4 4 4 4 4 3 3 2 % 24
2 3 3 4 4 4 4 4 4 4 4 4 4 4 3 3 2 % 25
2 3 5 4 4 5 4 4 6 4 4 5 4 4 5 3 2 % 26
2 3 3 4 4 4 4 4 4 4 4 4 4 4 3 3 2 % 27
2 3 3 4 4 4 4 4 4 4 4 4 4 4 3 3 2 % 28
2 3 5 4 4 5 4 4 5 4 4 5 4 4 5 3 2 % 29
2 3 3 3 4 4 4 4 4 4 4 4 4 3 3 3 2 % 30
2 3 3 5 3 4 4 4 4 4 4 4 3 5 3 3 2 % 31
2 3 3 3 3 5 3 3 5 3 3 5 3 3 3 3 2 % 32
2 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 2 % 33
2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 % 34

% --- Core lattice:

lat 300 11 0.0 0.0 0.0 3 3 1 21.42 21.42 408.6


100 200 400
200 100 400
400 400 400


% ------------------------------------------------------------
% Detectors
% ------------------------------------------------------------

det 1 dl 300

det 2 dm UO2

det 3 dm MOX4

det 4 dm MOX7

det 5 dm MOX8

% ---- Detector for tallying the flux energy spectrum

det EnergyDetector de EnergyGrid

% ---- Define the energy grid to be used with the detector
% Grid type 3 (bins have uniform lethargy width)
% 500 bins between 1e-11 MeV and 2e MeV

ene EnergyGrid 3 500 1e-11 2e1

% ---- Detector that calculates the pin power distribution in the core:
% Name of detector is pinpowers.
% The detector uses response number -8 (fission heat deposition)
% of the material at the interaction site (keyword:void)
% The detector has 34 bins in the x-direction between -21.42 cm and 21.42 cm
% The detector has 34 bins in the y-direction between -21.42 cm and 21.42 cm

det pinpowers dr -8 void dx -21.42 21.42 34 dy -21.42 21.42 34



% --- Geometry and mesh plots:

plot 3 1200 1200 [ 0.0 -80 80 -80 80 ]

Ana Jambrina
Posts: 553
Joined: Tue May 26, 2020 5:32 pm
Security question 1: No
Security question 2: 7

Re: Geometry error

Post by Ana Jambrina » Wed May 26, 2021 9:59 pm

There are several problems in your geometry (you can have a better idea of what is going on from the plot).
- Define the assembly surface (for each lattice) as a 2D infinite square surface, 'sqc' (see: Surface types).
- Check the core lattice definition.
- Check the boundary conditions: the global (at the geometry outer boundary ‘bc’ card) vs symmetry boundary conditions (universe symmetry through angle/wedge symmetry, ‘usym’ card).
- Check the 'plot' card definition (brackets in the syntax definition mean optional input values; the brackets themselves should not be included).

The tutorial Part 5 provides an overview of how to build a simple Serpent model for a 3D research reactor. Also, some of the Wiki examples, e.g., 2D PWR MOX/UOX show a set up for a 2D PWR MOX/UO2 core.
- Ana

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