Transcript Status of Attila for the Advanced Test Reactor (ATR) D. Scott Lucas INL

Status of Attila for the
Advanced Test Reactor (ATR)
D. Scott Lucas
INL
Discussion
• ATR
• Present ATR Neutronics Analysis
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Why Change?
LDRD Status
Results
Plans
• Funding
Acknowledgements & Contributors
• Transpire, Inc., Allen Barnett, Todd Wareing, John
McGee, Jim Morel
• Hans Gougar, Alan Schilk, Bruce Schnitzler
• Josh Peterson, Derek Hounshel
• Cristian Rabiti
• Jim Parry, George Griffiths
• ATR Staff
• Peter Cebull, HPC, S. Lucas Jr., HPC
ATR
• Largest materials test reactor (<250MWt)
• HEU in al matrix, plate fuel, water cooled, Be
reflector
• Loaded with a mixture of new and recycled elements
• Not very symmetric, highly heterogeneous
• 9 flux traps, some with independent coolant loops
• Variable operating cycles (2-60 days)
• Positive void coefficient in loops
Description
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Present ATR Analysis
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PDQ 2D XY R-Theta Neutron Diffusion
4 Energy Groups
Fixed Mesh
1960’s Advanced Weighted
Residual Collocation Method
• PDQ Approaching 40 Years of Age
National User Facility
• Use ATR for Tests, NGNP, GNEP, Westinghouse,
AREVA, GE
• More up to date codes than PDQ, Monte Carlo,
Deterministic
• Advanced Tests – Highly Enriched Fuels, More
Complicated Geometries
• Both MCNP & Attila use SolidWorks
• Will be able to Exchange Models and Verify between
MCNP & Attila
For the Reactor Physicist…Attila
• Solves the discrete ordinates (Sn) transport
equation on a 3D unstructured finite element
mesh
• Discontinuous Galerkin method for higher order
flux and current solution (3rd order accurate)
• Source Iteration with Diffusion Synthetic
Acceleration
For the Core Safety Analyst…
• FE mesh generated on a CAD model (Solidworks)
• Output amenable to visualization techniques
(VisIt)
• Demonstrated on many platforms (~Opteron)
• Depletion module
Zeus Critical Assembly
• The Zeus critical assembly is located at Los Alamos
National Laboratory
• Experiments have been performed to measure the
reactivity worth of small samples of 233U, high
enriched U (HEU), Pu, and 237Np
• The MCNP Monte Carlo code has been used to
predict the reactivity of these samples, but was too
time consuming to obtain statistically adequate
results
• Attila has been used to predict the reactivity worth
of these samples
ZEUS
ZEUS
Sample
Experiment
Attila
Monte Carlo
233U
0.08 ± 0.01
0.13
0.16 ± 0.05
HEU
0.05 ± 0.01
0.06
0.06 ± 0.05
237Np
-0.04 ± 0.01
-0.06
0.02 ± 0.05
Pu
0.05 ± 0.01
0.07
0.08 ± 0.05
Attila Model – LDRD Status
INL LDRD Accomplishments
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2D/3D CIC 94 Benchmarks
Comparisons to Criticality Experiments
MCNP, MCNPX
Fresh Core
Takeda Fast Reactor 1-4
Depletion
Serial
Parallel
5 Students Trained this summer on SW &Attila
(Never Again)
Parallel (DMP) Test INL
• 623,000 Tet 3D Model
• 8 hours on locally parallel
version – 2 cpus
• 16 hours on 1 cpu
• 1 hour 23 minutes on 16
Distributed Memory cpus
at Transpire
• 15 Minutes on 64 CPU’s ICESTORM
• Theoretically Linear up to
100 cpus
HPC
procs
walltime (min)
walltime - slow
1
554
554
2
285
292
4
144
158
8
77
90
16
45
58
24
29
49
32
24
43
40
20
40
48
17
40
56
15
39
64
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37
HPC
600
Walltime (min)
500
400
custom MPI
supplied MPI
300
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100
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20
40
Number of Processes
60
80
Yet Another Pretty Picture
XS Libraries
• Main Library = SCALE 27 Group, 22 Neutron Energy
Groups, 5 Photon Groups
• AMPX Format, Attila conversion Tool
• SCALE 44 & 238 Group Library
• XS BakeOff
• NEWT Code – INL - Jim Parry to generate region
specific XS Libs
• HELIOS – Studsvik – INL George Griffiths
Shim Sections – Five Degrees
Model for Heat Loads
XS Library Comparisons – CIC94
CIC 94 XS Comparison
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Power (MWt)
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ATR
7
ATRC
Attila Transpire
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Scale 5 Grps
Scale 27 Grps
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4
3
1
11
21
Fuel Assembly #
31
AFIF
AFIF
Other Tasks Performed
• Script for changing material properties in input file
done
• Placed angular sections in Be of Shim for reference
points
• Run 2D/3D CIC 94 Comparisons with 19 plate fuel
• Use 2D/3D Models with 19 plate fuel for Core Wide
Flux Maps
• Comparing to earlier CIC configurations
• Comparing to Flux Map reports
• Updating Neutronics Reqt’s per PDQ & CSAP
• CRADA Proposal
CIC Data Comparisons
CIC94 2DQTR Comparisons with SCALE XS
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Relative Power
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CIC94 Data
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Attila 2D
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2
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6
Elem ent #
8
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12
19 Plate Fuel for 2D/3D
Being placed in Rx Model and meshed
Attila Work
• Four Year Project
• 0.5 Million for Balance of Fiscal Year
Possible Attila Calculations
Excessive reactivity at startup with everything inserted
Excessive reactivity at end of cycle
50/50 60/40 70/30 for 0 3, 17 and 38 days
Relative axial power peak for three different scenarios
Relative fuel peak power for the three scenarios
Shim rod reactivates
Regulating rod reactivity
Safety rod reactivity
OSCC reactivates
80/20 power
Amount of Boron burned through cycle
Change in reactivity from the burn of boron
Take into consideration reflector poisoning
Fuel temperature coefficient
Moderator temperature coefficient (BOC) (EOC)
Power coefficient
Delayed neutron fraction
Safety rod worth
Stuck safety rod worth
Neck shim worth
Burnable poison (BOC)
Change in reactivity associated with flooding of different
loops for the 50/50 60/40 and 70/30 cases
Thermal and Fast neutron flux (>1MeV) in multiple
locations including OS I holes and drop tube
Consumption and buildup of U and Pu isotopes
Boron worth as a function of burnup
Power in the 40 fuel elements for the 50/50 60/40 70/30 at
(BOC) and (EOC)
Reactivity for a depleted and new regulating rod
Summary
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Sectional Hf in Shims done, gives good results
19 Plate Fuel has been meshed, runs in process
Beta - Parallel Attila Tested and running 2D/3D Models
Parallel Burnup in progress
Need to eventually define reqt’s for T/H and Fluids to interface
with Attila for Heat Loads
Harvesting LDRD Funds
Generate XS Comparison between NEWT/HELIOS
Burn Library
CIC 94 Complete Cycle with Burn