opal reactor full 3-d calculations including...
TRANSCRIPT
OPAL Reactor Full 3-D Calculations including
refueling
5th International Serpent User Group Meeting in Knoxville , USA, 13-16 Oct 2015
By Diego FerraroNuclear Engineering Department – INVAP S.E. - Argentina
Presentation Overview
1- Introduction – Why using Serpent in INVAP?
2- Serpent coupling with INVAP Calculation line
3- OPAL Reactor: Full 3-D Serpent model
4- Full 3-D model in Serpent with Refueling
using diverse approaches
5-Conclusions
2
5th International Serpent User Group Meeting in Knoxville, USA, 13-16 Oct 2015
1- Introduction – Why Serpent?
• Monte - Carlo Codes are used mainly in the Nuclear Engineering Department:
Criticality Calculations (Reactors, Fuel Storages)
Shielding Calculations (Coupled N,P)
Ex-Core Facilities design & performance evaluation in RR
Code to Code comparisons
Detailed flux profile calculations
• INVAP deterministic Calculation Line (CONDOR CP/HRM cell code +
CITVAP finite differences diffusion core code) is coupled with MCNP/Serpent
through NDDUMP code (internal development) Evaluations can be
performed with burnup dependence
• NDDUMP can handle composition changes: fuel management &
thermalhydraulic feedback & control rod position3
5th International Serpent User Group Meeting in Knoxville, USA, 13-16 Oct 2015
1- Introduction – Why Serpent?
• Original motivation to use Serpent (2010) in INVAP:
Obtain condensed parameters (macroscopic XS) for in-core and ex-core
devices with high heterogeneity for Research Reactors.
Additional comparisons for burnup dependent cell-level calculations for MTR
including burnable poisons with a different physical approach.
• Today’s motivation to use Serpent in INVAP:
Increase in Serpent Capabilities + Parallelization Complex core models
can be developed and compared with other calculations.
Core-level Calculations using compositions obtained from other codes.
Additional comparisons including burnup at cell-level calculations for diverse
fuel designs (both MTR or NPP) using a different physical approach.
Full core MonteCarlo calculations including refueling for Research Reactors.
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5th International Serpent User Group Meeting in Knoxville, USA, 13-16 Oct 2015
2 –Coupling with INVAP Calculation Line
5
+ External code
(developed in C)
to perform
simple refueling
using Serpent 2
restart file
(NEW)
5th International Serpent User Group Meeting in Knoxville, USA, 13-16 Oct 2015
INVAP neutronic Calculation Line:
3- OPAL Reactor: Full 3-D Serpent model
• The OPAL Research Reactor.
State of art 20MWth multi-purpose open-
pool type Research Reactor located at Lucas
Heights, Australia.
It was designed and built by INVAP between
2000 and 2006 and it is owned and operated
by ANSTO.
6
Irradiation facilities in the Reflector Vessel: Cold Neutron
Source (+ two beams), a thermal neutron source (+ 2
beams), 17 vertical irradiation tubes, pneumatic RIGs, 6
NTDs facilities.
It was designed, commissioned and performance tested
using INVAP´s calculation line (CONDOR + CITVAP) +
MCNP4C.
Data available in IAEA Research Reactor
Benchmarking Database (Tech. Report Series Nro 480).
Compact core of 16 LEU MTR-type fuels with Cd wires as BP, cooled and
moderated by light water and reflected by heavy water contained in a
Reflector Vessel.
5th International Serpent User Group Meeting in Knoxville, USA, 13-16 Oct 2015
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Previous works:
• A 3-D full core model for OPAL Research Reactor was developed for
Serpent 2 v1.21. Automatic Input generation through and spreadsheet.
• Main components for first Core configuration were modeled:
3 Fuel types (MTR), 5 CR, Chimney, Reflector Vessel.
• Simplified models for most relevant experimental facilities are included:
17 vertical irradiation tubes
Simplified model for the Cold Neutron Source & Cold neutron beams.
2 Thermal neutron beams.
• Results for these models are compared with experimental data from Reactor
Commissioning & Other codes:
Presented in 16th IGORR 2014/IAEA Technical Meeting: “ OPAL Reactor
Full 3-D Calculations using the MonteCarlo Code Serpent 2” – D. Ferraro
and E. Villarino – Nov 2014
Critical positions (from Reactor Commissioning).
Kinetic parameters.
In-core thermal flux profiles.
Full core burnup (1st cycle).
3- OPAL Reactor: Full 3-D Serpent model
5th International Serpent User Group Meeting in Knoxville, USA, 13-16 Oct 2015
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Full model x-y cut – 4 cm below core centre
Full model x-y cut – 4 cm below core centre
Full model y-z cut – CR and CNS details
Previous model characteristics:
3- OPAL Reactor: Full 3-D Serpent model
5th International Serpent User Group Meeting in Knoxville, USA, 13-16 Oct 2015
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Critical points:† Measurement from Reactor Commissioning (CR calibrations):
-700
-600
-500
-400
-300
-200
-100
0
0 5 10 15 20 25 30
Cal
cula
ted
rea
ctiv
ity [
pcm
]
Case Number
Calibration CR 1&4
Calibration CR 5
Calibration CR 2&3
CasesSerpent
2 [pcm]MCNP [pcm]
CONDOR-
CITVAP [pcm]
CR 1 & 4 -400 -360 -300
CR 5 -340 -370 -130
CR 2 & 3 -500 Not Calculated -240
All 74 cases -420 -390 -220
Calculations
Cold w/o Xe,
1st Core Fresh.
Comparison with other codes (from Commissioning):
Fairly good
agreement!
3- OPAL Reactor: Full 3-D Serpent model
†Ref. 16th IGORR 2014/IAEA Technical Meeting – “ OPAL Reactor Full 3-D Calculations using the MonteCarlo
Code Serpent 2” – D. Ferraro and E. Villarino
5th International Serpent User Group Meeting in Knoxville, USA, 13-16 Oct 2015
10
Kinetic Parameters:† Measurements from OPAL Reactor Commissioning:
Neutron decay constant was measured for a 15FA core configuration using
the Feynman-α method.
This configuration was modeled with Serpent. IFP method was used.
Kinetic Parameters for 16 FA configuration: The final 16FA was
calculated and compared with calculations:
Good agreement
with Calculated
values (<4%).
Kinetic Parameter CONDOR-CITVAP MCNP Serpent 2 (IFP)
βeff [pcm] 768 770 766
Λ [μs] 171 172 177
α [1/s] 45 45 44
Kinetic
ParameterMeasurement
Serpent 2
(IFP)MCNP
α [1/s] 38.1 38.8 37.2
Good agreement with calculated and
measured values (<3%).
3- OPAL Reactor: Full 3-D Serpent model
†Ref. 16th IGORR 2014/IAEA Technical Meeting – “ OPAL Reactor Full 3-D Calculations using the MonteCarlo
Code Serpent 2” – D. Ferraro and E. Villarino
5th International Serpent User Group Meeting in Knoxville, USA, 13-16 Oct 2015
11
In-Core Thermal Flux:†
Measurements from commissioning at low power (36kW±6)
Modeled in Serpent considering CR positions
Mesh detectors included
Overall power set to 36kW
Relevant positions considered
Axial profiles included
0.E+00
5.E+10
1.E+11
2.E+11
2.E+11
3.E+11
3.E+11
4.E+11
4.E+11
5.E+11
5.E+11
-30 -25 -20 -15 -10 -5 0 5 10 15 20 25 30
Ther
mal
Flu
x (
E<
0.6
25eV
) [
n/c
m2s]
Axial position [cm]
A2 - measured
A2 - Calculated Serpent 2
A2 - CONDOR-CITVAP
0.E+00
5.E+10
1.E+11
2.E+11
2.E+11
3.E+11
3.E+11
4.E+11
4.E+11
5.E+11
-30 -25 -20 -15 -10 -5 0 5 10 15 20 25 30
Th
erm
al F
lux
(E
<0
.62
5eV
) [
n/c
m2
s]
Axial position [cm]
D2 - measuredD2 - Calculated Serpent 2 D2 - CONDOR-CITVAP
Positions in FA in D2 and A2
3- OPAL Reactor: Full 3-D Serpent model
†Ref. 16th IGORR 2014/IAEA Technical Meeting – “ OPAL Reactor Full 3-D Calculations using the MonteCarlo
Code Serpent 2” – D. Ferraro and E. Villarino
5th International Serpent User Group Meeting in Knoxville, USA, 13-16 Oct 2015
12
4- Full 3-D model in Serpent with
Refueling using diverse approaches
New challenge:
• Can we perform full 3-D Burnup calculation in Serpent for a state of art
Research Reactor including refueling?
To perform this task an external code that operates with the Serpent 2
restart file was developed
• The results obtained were compared for cycles 7 to 12 of OPAL reactor
using the diverse approaches available in INVAP Calculation line:
1. CONDOR (HRM- 2D) + CITVAP (finite difference diffusion 3-D) model.
2. CONDOR (HRM- 2D) + CITVAP (finite difference diffusion 3-D) model
compositions inserted in Serpent 2.1.24 model using NDDUMP code.
3. Full 3-D Model in Serpent 2.1.24, including refueling using an external
code that operates with restart file to perform refueling.
5th International Serpent User Group Meeting in Knoxville, USA, 13-16 Oct 2015
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20 axial subdivisions.
Plates and BP (Cd wires) evolved independent in CONDOR.
69 energy groups at cell level, 3 groups at core level.
¼ FA Condor cell model CITVAP model x-y cut
4- Full 3-D model in Serpent with
Refueling using diverse approaches
1- CONDOR (HRM- 2D) + CITVAP (finite difference diffusion 3-D) model
5th International Serpent User Group Meeting in Knoxville, USA, 13-16 Oct 2015
Standard cell + core level approach.
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10 axial subdivisions, no division in plates or Cd wires radii for
each axial zone
4- Full 3-D model in Serpent with
Refueling using diverse approaches
2- CONDOR (HRM- 2D) + CITVAP (finite difference diffusion 3-D) model
compositions inserted in Serpent model using NDDUMP code
Compositions from CONDOR+CITVAP
are inserted in Serpent input using
INVAP’s developed NDDUMP code.
5th International Serpent User Group Meeting in Knoxville, USA, 13-16 Oct 2015
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10 axial subdivisions
Automatic division of depletion
zones: division in plates & Cd
wires
4 radii for each Cd wire
9760 depleted materials
Parallel calculation (OMP)
4- Full 3-D model in Serpent with
Refueling using diverse approaches
3- Full 3-D Model in Serpent, including refueling using an external code
that operates with restart file
Full Serpent model + external refueling using
Restart file processing.
5th International Serpent User Group Meeting in Knoxville, USA, 13-16 Oct 2015
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4- Full 3-D model in Serpent with
Refueling using diverse approaches
3- Full 3-D Model in Serpent, including refueling using an external
code that operates with restart file (cont)
How do we perform refueling
Burn with
SerpentSave restart file
(f.e. rest1.res)
Get a new restart
file where refuel
compositions are
included using a
ad-hoc code
(f.e. rest2.res)
Read restart
file in Serpent
(rest2.res)
Details to be considered:
moving different FA types
easy input to process restart file
5th International Serpent User Group Meeting in Knoxville, USA, 13-16 Oct 2015
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4- Full 3-D model in Serpent with
Refueling using diverse approaches
Obtained results for Cycles 7 to 12 – All Rods Out:
Good Agreement between 3 approaches !
Differences in Serpent in NDDUMP due to Cd wires modeling
Full 3-D modeling in Serpent + Refueling is possible for RR
1500
2000
2500
3000
3500
4000
4500
5000
5500
6000
6500
0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120 125 130 135 140 145 150 155 160 165
Exce
ss R
eac
tivi
ty [
pcm
]
FPD
Serpent full 3-D model - 9760 materials
Serpent Calculation using CONDOR-CITVAP Compositions (obtained with NDDUMP)Condor + CITVAP
5th International Serpent User Group Meeting in Knoxville, USA, 13-16 Oct 2015
Cycle 07
Cycle 12
3 types of FA with
diverse U load BP1 FA type
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4- Full 3-D model in Serpent with
Refueling using diverse approaches
We can also check measured critical positions (f.e. Cycle 12) using
the Serpent restart file and reported CR positions.
Very good agreement with experimental results (< 1000 pcm)!
Full 3-D modeling in Serpent + Refueling + critical position
check is possible for RR
5th International Serpent User Group Meeting in Knoxville, USA, 13-16 Oct 2015
-1500
-1250
-1000
-750
-500
-250
0
250
500
750
1000
1250
1500
1750
2000
135 140 145 150 155 160Re
acti
vity
[p
cm]
FPD
Cycle 12 - burn with Serpent - critical CR positions
Some CR
positions with
Xenon not in
equilibrium
19
4- Full 3-D model in Serpent with
Refueling using diverse approaches
Further comments (regarding calculation aspects) in Serpent:
1. Calculation time:
For each cycle 6E4 min of [email protected] 15h in a 64CPUs node in (OMP mode)
Full 6 cycles can be calculated within 1 week in a 64CPUs node in (OMP mode)
2. Memory Requirements:
3. Factors affecting efficiency:
Case Full Serpent model Serpent + NDDUMP model
# burn materials 9760 None
MAT_MEMSIZE [Mb] 56521.80 1243.01
XS_MEMSIZE [Mb] 2633.57 643.23
0.0E+00
1.0E+04
2.0E+04
3.0E+04
4.0E+04
5.0E+04
6.0E+04
0.00
0.20
0.40
0.60
0.80
1.00
1.20
26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52
Tota
l CP
U t
ime
[min
s]
OM
P F
ract
ion
Burnup FPD
Cycle 08 OMP Fraction
Cycle 08 - no depout 3 OMP Fraction
Cycle 08 Total running time
Cycle 08 - no depout 3 Total running time
5th International Serpent User Group Meeting in Knoxville, USA, 13-16 Oct 2015
Depout
Mesh plots
Others...
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5- Conclusions
• All main parameters for OPAL Reactor measured during commissioning
were calculated in past works, good agreement was encountered compared
with experimental data and with results from INVAP deterministic
Calculation line and independent MCNP models.
• Full core calculations including burnup and refueling can be carried
out for MTR reactors using Serpent:
A code to perform refueling using Serpent restart files was developed
and tested.
Good agreement with other calculation schemes & experimental data.
High memory & CPU resources requirements.
• Serpent 2 can be used as independent Calculation Line at diverse
levels: Cell, Full Core, Full Core using external compositions, etc.
5th International Serpent User Group Meeting in Knoxville, USA, 13-16 Oct 2015
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• A Validation effort can be carried out by Serpent Users? How
can we contribute?
• Detailed Data is available in IAEA or CEA framework for
several Research Reactors & NPP (IAEA benchmarking
database Series 480 + IAEA CRP for burnup + NEA
International Handbook of Evaluated Reactor Physics
Benchmark Experiments - IRPhEP, etc) Should users
develop a Serpent benchmarks database?
5th International Serpent User Group Meeting in Knoxville, USA, 13-16 Oct 2015
5- Conclusions
Questions?
Thanks for your attention!