NEUDOS Kirk Oct 2009 Neutrons
-
Upload
david-ten-kao-yuan -
Category
Documents
-
view
570 -
download
3
Transcript of NEUDOS Kirk Oct 2009 Neutrons
Overview of Neutron
Transport Codes
11th NEUTRON AND ION DOSIMETRY
SYMPOSIUM (NEUDOS-11)
Capetown, South Africa
October 16, 2009
Presented by:
Bernie Kirk
Director, Radiation Safety Information
Computational Center (RSICC)
Nuclear Science and Technology Division
2 Managed by UT-Battellefor the U.S. Department of Energy
SUMMARY
BACKGROUND
STOCHASTIC VERSUS DETERMINISTIC METHODS
MONTE CARLO SOFTWARE
DETERMINISTIC SOFTWARE
CONCLUSION
Science News
ScienceDaily Oct. 1, 2009
Spallation Neutron Source First Of Its Kind To Reach Megawatt Power
— The Department of Energy's Spallation Neutron Source (SNS), already the world's most powerful facility for pulsed neutron scattering science, is now the first pulsed spallation neutron source to break the one-megawatt barrier.
An image made possible by a
phosphorescent coating
colorfully illustrates one
megawatt of power striking
the Spallation Neutron
Source's mercury target.
(Credit: Image courtesy of
DOE/Oak Ridge National
Laboratory)
Supercomputers Twenty Years Ago
5 Managed by UT-Battellefor the U.S. Department of Energy
Stochastic Method (Monte Carlo)
Deterministic Method
Radiation Transport
' '
''',',',',
,,,,4
1,,,,
E
s
tf
ddEErEEr
ErErErSErSEr
Neutron Transport Equation
6 Managed by UT-Battellefor the U.S. Department of Energy
MONTE CARLO SOFTWARE
Electron/Photon
Transport
EGS5
PENELOPE
EgsNRC
NEUTRON Transport
SCALE – MONACO, MAVRIC, KENO
MCNP/MCNPX
TRIPOLI
VIM
TART
SERPENT
High
Energy
Transport
PHITS
GEANT4
FLUKA
MCNPX
SHIELD
NEUTRON Transport
SCALE - DENOVO
PARTISN
PENTRAN
DETERMINISTIC
SOFTWARE
Non-commercial Software
7 Managed by UT-Battellefor the U.S. Department of Energy
SCALE
http://www.ornl.gov/sci/scale/
Developed at Oak Ridge National Laboratory
Contact: Brad Rearden, [email protected]
Available:
RSICC http://rsicc.ornl.gov
NEADB http://www.nea.fr/html/databank/welcome.html
8 Managed by UT-Battellefor the U.S. Department of Energy
SCALE Standardized Computer Analyses for Licensing Evaluation
• SCALE is a modular code system that uses automated sequences to provide:
– Problem-dependent cross-section processing
– Reactor / lattice physics analysis
– Criticality safety analysis
– Sensitivity/uncertainty analysis
– Radiation shielding analysis
– Spent fuel and HLW characterization
– Advanced 3-D visualization and automated user interface
• Distributed and used worldwide for > 25 years
• Developed at Oak Ridge National Laboratory
9 Managed by UT-Battellefor the U.S. Department of Energy
D&D
Material processing and fabrication Commercial and
research reactors
Recycling
StorageTransport
SCALE provides mature and
flexible software for nuclear
analysis of nearly any application
within the nuclear fuel cycle
SCALE is used
worldwide (~30
nations) by
regulators,
vendors, utilities,
cask designers,
R&D labs,
safeguard
agencies
10 Managed by UT-Battellefor the U.S. Department of Energy
MONACO/MAVRIC (SCALE)
Developed at Oak Ridge National Laboratory
Contact: Douglas Peplow, [email protected]
11 Managed by UT-Battellefor the U.S. Department of Energy
• Neutron/Photon
• general-purpose, fixed source, multigroup Monte Carlo shielding
• multigroup transport methods are inherited from
Monaco’s predecessor, MORSE
Monaco – Multigroup Monte Carlo
12 Managed by UT-Battellefor the U.S. Department of Energy
• geometry data as sets of quadratic equations -same geometry package as KENO-VI
• Flexible, friendly user input
– Source description is separable:
space, energy, direction
– Region tallies, mesh tallies, point detector tallies
– Integrates fluxes with response functions (dose)
• Variance Reduction capabilities
– Weight windows based on region/energy
– Mesh-based weight windows
• MeshView plotting software
– Plot calculated responses on mesh grid
Monaco – Multigroup Monte Carlo
13 Managed by UT-Battellefor the U.S. Department of Energy
MAVRIC – Monaco with Automated
Variance Reduction using Importance
Calculations
• Intended for challenging, deep-penetration problems
• CADIS (Consistent Adjoint Driven Importance Sampling)
– Denovo is used to calculate the coarse-mesh adjoint flux for a specific tally
– Creates importance map (space, energy) and biased source
– Monaco is then optimized for that specific tally
• Forward Weighted CADIS
– Denovo estimates forward fluxes, used in the adjoint source
– Helps balance relative uncertainties across multiple tallies or large mesh tallies
14 Managed by UT-Battellefor the U.S. Department of Energy x-distance (cm)
y-d
ista
nce
(cm
)
0 20 40 60 80 100 120 140 1600
20
40
60
80
100
120
140
160
Biased
8.4E-02
3.7E-02
1.6E-02
7.1E-03
3.1E-03
1.4E-03
6.1E-04
2.7E-04
1.2E-04
5.2E-05
2.3E-05
1.0E-05
Example: PWR Ex-Vessel Thermal (10B) Detector Response
Detector
Core
Cavity Pressure vessel
Downcomer
Neutron pads
Baffle plates
Flow channel
Core barrel
Concrete shield
Monte Carlo model Deterministic model
x-dimension (cm)
y-d
ime
nsio
n(c
m)
50 100 150 200 250 300
50
100
150
200
250
300
adjoint
5.00E+30
7.46E+29
1.11E+29
1.66E+28
2.48E+27
3.70E+26
5.51E+25
8.23E+24
1.23E+24
1.83E+23
2.73E+22
4.07E+21
6.08E+20
9.07E+19
1.35E+19
2.02E+18
3.01E+17
4.49E+16
6.70E+15
1.00E+15
Adjoint data
Calculate/apply VR Parameters
CASE
CPU TIME TO
ACHIEVE RE=1%
(h)
SPEEDUP
No VR 8.86E+4 (10.1 yrs) 1
Manual VR 13.6 6500
CADIS VR 1.02 87000
Required ~3 weeks by an experienced MC practitioner using all applicable
MCNP4C VR capabilities
Faster Results
CADIS Methodology for
Automated Variance Reduction
15 Managed by UT-Battellefor the U.S. Department of Energy
MAVRIC: Dose Rates from Cask Array
Analog calculation:
560 hours, poor resolution in mesh tally
Automated variance reduction: 109 hours,
80% voxels < 5% rel unc
97% voxels < 10% rel unc
16 Managed by UT-Battellefor the U.S. Department of Energy
KENO (SCALE)
Developed at Oak Ridge National Laboratory
Contact: Sedat Goluoglu, [email protected]
17 Managed by UT-Battellefor the U.S. Department of Energy
KENO Multigroup Monte Carlo Code
for Criticality Calculations
• KENO was first developed during 1960’s and is internationally accepted tool for criticality safety analysis
• SCALE has two versions
– KENO.Va: restricted geometries, but faster
– KENO-VI: general geometry; rotations; intersections
• Multigroup method runs much faster than continuous energy, but requires self-shielding corrections to XS’s
18 Managed by UT-Battellefor the U.S. Department of Energy
SCALE 6: Criticality
Safety Enhancements
• Continuous energy capability incorporated in KENO
• ENDF/B-VI and ENDF/B-VII libraries included.
LEU
0.95
0.96
0.97
0.98
0.99
1
1.01
1.02
0 50 100 150 200 250
Benchmark number (arbitrary)
Ke
ff
-2.0
-1.5
-1.0
-0.5
0.0
0.5
1.0
1.5
2.0
2.5
3.0
(C-B
)/B
%
Calculated Percent difference
CE validation results for LEU benchmarks
CE vs. Multigroup
19 Managed by UT-Battellefor the U.S. Department of Energy
Explicit 3D neutron
transport model of
application
keff,
EALF,
etc.
neutron flux
continuous-energy
or
multi-group
reaction rates
20 Managed by UT-Battellefor the U.S. Department of Energy
SCALE: KENO-VI and MAVRIC Coupling
Step 2:
•Use MAVRIC to model particle transport
•Use KENO-VI fission distribution as the
source for MAVRIC
•Calculate detector responses, dose rates
at specific points or mesh tallies of dose
rates
layers of UF4
West wing of the ORCEF,
building 9213Step 1:
•Use KENO-VI to model the
criticality accident and save the
fission distribution as a mesh
source
Dose in rem per 1019 fissionsSpeedups of 3000 to 4500
21 Managed by UT-Battellefor the U.S. Department of Energy
MCNP/MCNPX
http://mcnp-green.lanl.gov/
Monte Carlo N-Particle
Developed at Los Alamos National Laboratory
Contact: Tim Goorley, [email protected]
Available:RSICC http://rsicc.ornl.gov
NEADB http://www.nea.fr/html/databank/welcome.html
22 Managed by UT-Battellefor the U.S. Department of Energy
MCNP/MCNPX
neutron, photon, electron, or coupled neutron/photon/electrontransport
radiation protection and dosimetry,
radiation shielding, radiography
medical physics,
nuclear criticality safety,
Detector Design and analysis,
nuclear oil well logging,
Accelerator target design
Fission and fusion reactor design
decontamination and decommissioningCalculate
– Flux, Current, Energy or Charge Deposition,
Heating, Reaction
Rates, Response Functions, Radiographs, Mesh
Tallies (E, θ, t bins)
– keff, prompt neutron lifetime, fission
distributions, η, ν, Ē of
neutrons causing fission, neutron balance per
cell and nuclide.
23 Managed by UT-Battellefor the U.S. Department of Energy
MCNP History
• 50+ years of code development!
– World recognized experts in several fields
• Impressive physics, geometry, tally, variance reduction capabilities
• Modern Teraflop supercomputers can drive Monte Carlo calculations not dreamed possible more than a decade ago
• Now used for design of many systems (criticality example)
1960s: K-effective
1970s: K-effective, detailed assembly power
1980s: K-effective, detailed 2D whole-core
1990s: K-effective, detailed 3D whole-core
2000s: K-effective, detailed 3D whole-core,
depletion, reactor design parameters
1992 200919771940s
24 Managed by UT-Battellefor the U.S. Department of Energy
MCNP / MCNPX Teams
• MCNP
• Deputy Group Leader: Jeremy Sweezy
• Project Lead: Tim Goorley
• Tom Booth
• Forrest Brown
• Jeff Bull
• Art Forster
• John Hendricks
• Grady Hughes
• Roger Martz
• Stepan Mashnik
• Avneet Sood
• Tony Zukaitis
• MCNPX
• Team Lead: Gregg McKinney
• Project Lead: Laurie Waters
• Joe Durkee
• Jay Elson
• Michael Fensin (N-4)
• John Hendricks (X-3)
• Shannon Holloway (T-2 CINDER)
• Michael James
• Russell Johns
• William Johnson
• Toshihiko Kawano (T-2 CGM)
• Denise Pelowitz
25 Managed by UT-Battellefor the U.S. Department of Energy
MCNP/X Present
• MCNP5 1.51 and MCNPX 2.6.0
– released through RSICC
– Export Controlled source code (by Department of Energy)
• Active merger effort to produce MCNP6
– ~$5M since 2006
– 3 people / year
– All capabilities of both codes
– Friendly Alpha testing has already begun at LANL
– Anticipated merger by June / July
– Beta available within LANL (Internal milestone in Sept 2009)
– Begin robust V&V for ultimate release to RSICC summer 2010
– Subsequent elimination of duplicate features
26 Managed by UT-Battellefor the U.S. Department of Energy
New Features 2008
• MCNP5 version 1.51
– Variance Reduction with Pulse Height Tallies
– Temperature dependant (Doppler Broadened) libraries with preprocessor makxsf
– Memory improvements for large lattices
– Long file names & tabs
– Test suites that compare to experiments
– OpenMP threading on all platforms (alone or in combination with MPI)
• MCNPX 2.6.0
– Heavy Ion transport for 2000+ ions (LAQGSM, CEM)
– Burnup / Depletion with full integration of CINDER 90
– Delayed neutron and gammas from CINDER90 decay products
– Muon capture interactions
– Charged ions from neutron capture
– Fission Matrix criticality source convergence acceleration
– Weight windows improvements
– Residual nuclei tally
– Spontaneous photon sources
• Nuclear Data from ENDF/B-VII
27 Managed by UT-Battellefor the U.S. Department of Energy
Recent Capabilities
Simulated Radiographs
Decay Chains &
their emissionsBackground
Neutron and Photon
Radiation from lat,
long, and elevation
28 Managed by UT-Battellefor the U.S. Department of Energy
Monte Carlo Applications Tool Kit
(MCATK)
• From scratch Monte Carlo radiation transport code in C++, using Agile-like processes, unit testing, pair programming, modular design
• Driven by desire to utilize GPUs & new hardware (which doesn’t always have a FORTAN 90 compiler), as well as maintain MC expertise in new staff
• Intended to replace portions of MCNP
• Leverages Commercial + Open Source Software
– Eclipse Development Environment
– Unit Test++
– QT
– Doxygen
– Boost
GUI tool to view geometry
29 Managed by UT-Battellefor the U.S. Department of Energy
MCNP Unstructured Mesh
• track and tally on unstructured mesh
• mesh objects are mix of 4, 5 & 6 sided solids
• Boundaries of solids can be bi-linear.
• Mesh can be added into regular 3-D MCNP geometry
• Already in MCNP6, works in parallel
• Quadratic surfaces under development
• Want to expand to CAE codes other than ABAQUS
• Is currently used for thermo-mechanical analysis
Energy
Deposition
30 Managed by UT-Battellefor the U.S. Department of Energy
Low Energy Threshold
• Current lower energy limit of photons and electrons is 1 keV
• Not sufficient for smaller geometries desired by medical community
• Also necessitates improved L-M-N shell fluorescence
Millimeter or sub-millimeter
patient –based geometry is
frequent in user community
R&D Topics!
31 Managed by UT-Battellefor the U.S. Department of Energy
Improved Variance Reduction
• Long time goal of linking together deterministic SN adjoint solutions to feed into foreward Monte Carlo calculations
• Variance Reduction needs reexamination. Many methods were developed to gain information in a few specific locations, not everywhere
• Continuous Energy Adjoint
• Not all pieces work together
MCNP5
PARTISN
Generated ImportancesGeometry
R&D Topics!
Dose from Hiroshima
nuclear weapon
detonation in Times
Square, NY for FEMA.
32 Managed by UT-Battellefor the U.S. Department of Energy
Criticality Efforts
• Relative Entropy Of Fission Source Distribution
• Dominance Ratio
• Beta-Effective
• Source Shape Effects on Perturbations
• Probability of Initiation
“Stochastic Geometry” for HTGRs: Fuel
kernel displaced randomly within lattice
element each time that neutron enters
0.00
0.02
0.04
0.06
0.08
0.10
0.12
0.14
0.16
0.18
0.00 0.10 0.20 0.30 0.40 0.50
Fractional density change
Re
ac
tiv
ity
(k
/kk
')
2 MCNP runs
MCNP 2nd-order
2nd+PS(5-cycle)
2.741cm
6 cm
Perturbed
region
Godiva central perturbation
Exact, 2
MCNP
runs
Standard MCNP,
2nd order perturbation
Modified MCNP,
With source-shape
Effects on perturbation
R&D Topics!
33 Managed by UT-Battellefor the U.S. Department of Energy
TRIPOLI
Developed at Commissariat à l’Énergie Atomique, Saclay
Contact: Jean-Christophe Trama, (Jean-
O Petit, É Dumonteil, FX Hugot, YK Lee, A Mazzolo, C Diop
Available:RSICC http://rsicc.ornl.gov
NEADB http://www.nea.fr/html/databank/welcome.html
34 Managed by UT-Battellefor the U.S. Department of Energy
A long history at CEA, representing a large Monte Carlo
expertise since the 1960s
The fourth generation of the code,TRIPOLI-4, is a 3D
pointwise Monte Carlo code for radioprotection and
shielding, core physics, criticality and nuclear
instrumentation studies.
TRIPOLI-4 represents more than one and half hundred
person-years of capitalized experience, devoted to
research & development as well as industry.
TRIPOLI
35 Managed by UT-Battellefor the U.S. Department of Energy
CEA (core physics, radioprotection, criticality studies
through the CRISTAL package)
EDF (core physics, radioprotection)
IRSN (criticality studies through the CRISTAL package)
AREVA NC (criticality studies through the CRISTAL
package)
AREVA TA (core physics, radioprotection)
NURESIM European project : TRIPOLI-4 reference Monte
Carlo tool
TRIPOLI-4: a reference tool for radioprotection and
shielding, core physics, and criticality studies
www.nuresim.com
36 Managed by UT-Battellefor the U.S. Department of Energy
3D, Monte-Carlo code to compute transport related
quantities (flux, current, reaction rate, keff etc.)
Directly reads pointwise cross sections (pendf files), can
easily mix isotopes from different evaluations
Easy-to-use automated variance reduction tools
especially designed for deep penetration problems
Robust and efficient parallelism capability
(heterogeneous workstation network as well as massive
HPC systems)
Highly qualified 0-20 MeV neutrons and photons nuclear
energy calculations (reactors, plants and labs)
TRIPOLI-4 : main characteristics
CASCAD fuel storage
Reactor simulation
37 Managed by UT-Battellefor the U.S. Department of Energy
Mainly written in C++
Available on various Unix and Linux
Easy-to-understand key-word based input system,
supplemented by 3D mouse-driven man-machine interface
(Salomé)
Probability table in the URR range from CEA CALENDF
code (also available from NEA)
Externally coupled with depletion code, CFD code
TRIPOLI-4 : some technical features
TERA, supercomputer, © CEA
38 Managed by UT-Battellefor the U.S. Department of Energy
TRIPOLI-4 directly reads pendf files from various
evaluations
Presently, evaluations from JEF2.2, JEFF3.0 3.1 3.2,
ENDF/B-VI.4 B-VI.8, B-VII.0, JENDL33 may be used
(available from NEADB and RSICC)
TRIPOLI-4 reads PT files from the CEA CALENDF code,
for the Unresolved Resonance Range (URR)
Examples of data libraries already in use are
JEFF3.1 : 381 isotopes + 140 PT in the URR
ENDF/B-VII : 393 isotopes + 252 PT in the URR
JENDL33 : 337 isotopes + 209 PT in the URR
It is possible to easily use a user-defined nuclear data set,
with isotopes coming from different evaluations
TRIPOLI-4 : a focus on nuclear data
management
39 Managed by UT-Battellefor the U.S. Department of Energy
Variance reduction techniques are necessary to obtain acceptable
Figure of Merit (FOM)
Deep penetration problems are almost impossible to calculate
without them.
Variance reduction techniques are statistical tools to help the user
sample from a modified physics to reach the desired results.
The automated reduction variance built in the INIPOND TRIPOLI-
4 module allows to easily run a deep penetration problem.
TRIPOLI-4 : a focus on automated
variance reduction
40 Managed by UT-Battellefor the U.S. Department of Energy
Predefined shapes and combinatorial operators :
Reunion, smash, intersection, substraction
Rotation
Repetition of basic pattern
Lattices, Lattice of lattices :
Or definition by surfaces :
Combination of both descriptions is possible.
User friendly interface
2D cut
TRIPOLI-4 : a focus on geometry description
41 Managed by UT-Battellefor the U.S. Department of Energy
41 Managed by UT-Battellefor the U.S. Department of Energy
VIM
http://www.vim.anl.gov/
Developed at Argonne National Laboratory
Contact: Roger Blomquist, [email protected]
Available:RSICC http://rsicc.ornl.gov
NEADB http://www.nea.fr/html/databank/welcome.html
42 Managed by UT-Battellefor the U.S. Department of Energy
42 Managed by UT-Battellefor the U.S. Department of Energy
VIM
•Continuous Energy Neutron/Photon Transport Code System for criticality, reactor physics, and shielding
•Geometry options are infinite medium, combinatorial geometry, and hexagonal or rectangular lattices of combinatorial geometry unit cells, and rectangular lattices of cells of assembled plates
•Variance reduction using splitting/Russian roulette, non-terminating absorption with nonanalog weight cutoff energy
43 Managed by UT-Battellefor the U.S. Department of Energy
43 Managed by UT-Battellefor the U.S. Department of Energy
VIM Background
•Developed to analyze ANL critical experiments and benchmark ANL diffusion, transport, and spectrum analytical tools
•Nuclear data processed using ANL codes independent of others:
–Not NJOY
–Some other codes use ANL-developed methods (e.g., URR probability tables in MCNP)
•Earlier VIM verification & validation:
–Extensive benchmarking with ZPR/ZPPR criticals and ICSBEP
–Earlier libraries verified by inter-code comparisons with MC2-2 fast reactor spectrum code in great detail, MCNP, etc.
44 Managed by UT-Battellefor the U.S. Department of Energy
44 Managed by UT-Battellefor the U.S. Department of Energy
Recent VIM Enhancements
CODE
• FORTRAN 95, with nuclear data in structures
• Eliminated archaic memory management routines
• Improved input diagnostics
• Slicer geometry input color display
• Enhanced precision to reduce tracking errors and differences between platforms
Data Library
• Eliminated intermediate codes previously used to access processed nuclear data libraries
• Default libraries now ASCII, with provenance information in header records
• Increased angular distribution detail and accuracy
• Total fission spectra used, not prompt only
• ENDF/B-VII.0, tested on fast and intermediate systems
45 Managed by UT-Battellefor the U.S. Department of Energy
45 Managed by UT-Battellefor the U.S. Department of Energy
ICSBEP HEU-MET Benchmark
Cases: VIM vs. MCNP
003-1
1c
HM
I001
065
061
028
027
022
021
018
015
014
013
012
008
003-1
2
003-1
1d
003-1
1b
003-1
1a
003-1
0g
003-1
0f
003-1
0e
003-1
0d
003-1
0c
003-1
0b
003-1
0a
HM
F001
-100
-50
0
50
100
150
k(V
IM)
- k(M
CN
P)
(pcm
)
46 Managed by UT-Battellefor the U.S. Department of Energy
TART
http://home.comcast.net/~redcullen1/speed.htm
Developed at Lawrence Livermore National Laboratory
Contact: Dermott E. Cullen, [email protected]
Available:RSICC http://rsicc.ornl.gov
NEADB http://www.nea.fr/html/databank/welcome.html
47 Managed by UT-Battellefor the U.S. Department of Energy
Pedigree of TART
•Livermore production code for 40 years
•Livermore’s equivalent of MCNP
•Only recently released outside Livermore
•TART2000
• Coupled Neutron-Photon
• 3-D Combinatorial Geometry
• Time Dependent
• Energy Range: Very Low up to 1 GeV
48 Managed by UT-Battellefor the U.S. Department of Energy
TART Features
• Very fast
•Uses Latest ENDF/B data
• neutrons & photons
• Runs on ANY computer•UNIX Workstations
•Windows/Linux PC
• Power MAC
•Very user friendly•Only about 15-20 % is the Monte Carlo code
•The remainder is tools to make your job easier
49 Managed by UT-Battellefor the U.S. Department of Energy
•The TART System is a complete
system
•It helps you prepare and check
input
•Runs your Monte Carlo
calculations
•Source and criticality problems
•Interactive graphics is extensively
used
•In input preparation and
checking
•Overlaying results on your
geometry
•Viewing neutron and photon
data
TART Features
50 Managed by UT-Battellefor the U.S. Department of Energy
•A well known advantage of Monte
Carlo is its ability to handle
complicated geometry.
•TART tries to optimize this advantage
•Other codes allow first & second
degree surfaces - planes,
spheres, cylinders,…
•TART allows third & fourth
degree surfaces - cubic & quartic
splines, fine and detailed
surfaces, torus
•There is no limit to the detail of
geometry
•Everything is dynamically
dimensioned
•Here’s an example of a
complete seven story building
TART Features
Example of a complete
seven story building
51 Managed by UT-Battellefor the U.S. Department of Energy
• continuous energy neutrons
• and continuous energy kinematics
• but multigroup cross sections
• 700 groups: 50 per energy decade
• Multiband parameters in all group
• Because sampling continuous energy cross
sections converges too slowly and isn’t
necessary, TART uses self-shielding theory and
the multiband method
TART Features
52 Managed by UT-Battellefor the U.S. Department of Energy
52 Managed by UT-Battellefor the U.S. Department of Energy
SERPENT
http://montecarlo.vtt.fi
Developed at VTT Technical Research Centre , Finland
Contact: Jaakko Leppanen, [email protected]
Available:RSICC http://rsicc.ornl.gov
NEADB http://www.nea.fr/html/databank/welcome.html
53 Managed by UT-Battellefor the U.S. Department of Energy
The Serpent Computer Code
• Serpent - a continuous-energy Monte Carlo reactor physics burnup calculation code
• Developed at VTT Technical Research Centre of Finland since 2004 (until Oct. 2008 under working title ”PSG”)
• Mainly intended for, but not limited to lattice physics calculations:
− Generation of homogenized multi-group constants for deterministic reactor simulator codes
− Fuel cycle studies
− Reactor physics calculations traditionally handled using deterministic lattice transport codes
• Universe-based three-dimensional geometry model – allows the description of practically any 2D or 3D fuel or reactor core configuration
Fig 1. MOX assembly surrounded by UOX
assemblies in a PWR reactor lattice
http://montecarlo.vtt.fi
54 Managed by UT-Battellefor the U.S. Department of Energy
• Interaction physics:
− Continuous-energy cross sections read from ACE format data libraries and reconstructed on a unionized energy grid
− Neutron interactions modeled using classical collision kinematics and ENDF reaction laws
− Unresolved resonance cross sections sampled from probability tables
• Tracking:
− K-eigenvalue criticality source calculation
− Neutron transport based on the combination of conventional surface tracking and the Woodcock delta-tracking method
• Burnup calculation:
− Fully automated built-in depletion routines
− The Bateman depletion equations solved using the transmutation trajectory analysis (TTA) or the Chebyshev rational approximation method (CRAM)
− Radioactive decay and fission yield data read from standard ENDF format files
Serpent Capabilities
55 Managed by UT-Battellefor the U.S. Department of Energy
• Capabilities include:
− Homogenized multi-group constants, including cross sections, assembly discontinuity factors, scattering matrices, diffusion coefficients and point-kinetic and effective delayed neutron parameters calculated by default
− Unlimited number of depleted material zones in burnup calculation
− Various user-defined ”detector” (tally) features
• Main limitations:
− Transport simulation limited to neutrons
− K-eigenvalue criticality source calculation, fixed source mode not available
− Memory usage may become a limiting factor in large burnup calculation problems
− Delta-tracking necessitates the use of the collision flux estimator poor efficiency for reaction rates tallies integrated over small cells or regions oflow collision density
Fig 2. The VENUS-2 reactor core
Serpent Limitations
56 Managed by UT-Battellefor the U.S. Department of Energy
• Parallel calculation using MPI
• Built-in Doppler-broadening preprocessor routine
• B1 fundamental mode calculation and leakage models currently under development
• Geometry models for handling random particle and pebble distributions in HTGR calculations
• Serpent is optimized for performance in lattice physics calculations:
− Efficient geometry routine based on delta-tracking
− Unionized energy grid used for all cross sections minimizes the number of grid search iterations
− Additional tricks to speed up burnup calculation
Full-scale LWR assembly burnup calculations (1
can be completed in about 4 hours on a 2.6 GHz Linux PC cluster using 4 CPU’s in the MPI mode
Fig 3. 15,000 microscopic TRISO particles
randomly dispersed inside a PBMR-type fuel
pebble (explicit particle fuel model)
(1 A standard 17 x 17 PWR fuel assembly with burnable absorber pins.
Materials divided into 65 depletion zones, a total of 42 burnup steps run
with predictor-corrector calculation, 3 million neutron histories per each
transport cycle.
Additional Features of Serpent
57 Managed by UT-Battellefor the U.S. Department of Energy
57 Managed by UT-Battellefor the U.S. Department of Energy
DENOVO (SCALE)
Developed at Oak Ridge National Laboratory
Contact: Tom Evans, [email protected]
AvailabilityRSICC http://rsicc.ornl.gov
NEADB http://www.nea.fr/html/databank/welcome.html
58 Managed by UT-Battellefor the U.S. Department of Energy
Denovo
• State of the Art Transport Methods
massively parallel deterministic radiation transport code
–3-D regular grid, Discrete Ordinates (SN)
–Multigroup energy, anisotropic PN scattering
–6 spatial discretization algorithms (linear & tri-linear discontinuous FE, Step-characteristics, theta-weighted diamond, diamond difference + fixup)
• High Performance, Modern, Innovative Solvers
–GMRES, BiCGStab. or Source Iteration options on within-group solves
–DSA-preconditioning (SuperLU/ML-preconditioned CG)
–Transport Two-Grid upscatter acceleration of Gauss-Seidel MG iteration
–Parallel first collision approximation
–Eigenvalue (keff) and fixed-source problem modes
–Krylov solvers provided by Trilinos Library
58
59 Managed by UT-Battellefor the U.S. Department of Energy
DENOVO APPLICATIONS
Zones Angles Groups State Size
(GB)
Output
(GB)
Time
(m)
103.7M S24/P3 27 568.741 83.457 46.97
1,047.8M S24/P3 27 5,746.180 843.189 79.43
PWR Facility Modeling
Nuclear Energy:
LWR analyses
Fusion:
ITER analyses
285M cell, S24/P3 model of the International Thermonuclear Experimental Reactor (ITER)
59
60 Managed by UT-Battellefor the U.S. Department of Energy
DENOVO
• Parallel Algorithms
–Koch-Baker-Alcouffe (KBA) wavefront solve
–Domain replicated & decomposed options for parallel first-collision source
–Multi-level decompositions in energy and angle under development
–Parallel I/O for massive problems
• Advanced Visualization and Run-Time Environment
–Python front-end allows high-degree of flexibility in prescribing input/output
–Direct connection to SCALE geometry and data
–HDF5 output directly interfaced with Visit
60
61 Managed by UT-Battellefor the U.S. Department of Energy
Denovo
• Advanced Methods– GMRES (with DSA preconditioning) within-group
solver
– Transport, Two-Grid accelerated Gauss-Seidel for multi-group
– Koch-Baker-Alcouffe (KBA) parallel domain-decomposition
– Trilinos parallel solver package for highly efficient Krylov solvers and as an interface to the SuperLUdirect solver library
– Parallel first-collision source
– 5 different spatial differencing schemes
– Multiple input front-ends including Python
– High-performance parallel I/O using HDF5
KBA Parallel Sweep
1. Sweep each block starting
in corner of octant.
2. Communicate outgoing
fluxes to neighboring (x,y)
blocks.
3. Continue sweep in z-
direction.
4. MPI communication
across blocks.
5. OpenMP on angles within
block.
Denovo can run on PCs, workstation clusters, supercomputers
Jaguar – 1.64 PF Cray XT: 45,376 Quad-Core Processors, 362 TB memory
Denovo is designed to run
high resolution problems
scaled to thousands of cores.
Weak Scaling
Denovo’s parallel algorithms
are very efficient on cluster-
level platforms as well.
Strong Scaling
62 Managed by UT-Battellefor the U.S. Department of Energy
Cancer Therapy Planning with Denovo
Denovo generates a model directly from CT
scans:
576,600 voxels
lung/chest scan from UNC medical center
Using this model, Denovo can perform fast
and accurate radiation transport calculations:
S8 angular quadrature
P3 scattering
40 energy groups
Calculation took 438 seconds on a 16
CPU AMD 64 Linux cluster
63 Managed by UT-Battellefor the U.S. Department of Energy
Therapy Plan
Denovo outputs data that can be read directly by VisIt
inline, real-time visualization
dynamic visualization for modulated therapy planning
2D/3D contours, color plots, etc.
contours at 80, 70, 50, 30, and 10%
64 Managed by UT-Battellefor the U.S. Department of Energy
Denovo Capabilities for Treatment
Planning
• Coupled photon-electron transport
– Galerkin quadrature + CEPXS cross sections implemented
– in testing and verification phase
• Boltzmann-Fokker-Planck planned for this year
• Photo-neutron library scheduled for testing Fall 09
– estimate neutron full-body doses to personnel and patients
• Coupled proton-neutron-photon physics planned after BFP implementation
– used for proton therapy planning
– occupational neutron dose calculations
65 Managed by UT-Battellefor the U.S. Department of Energy
65 Managed by UT-Battellefor the U.S. Department of Energy
PENTRAN
http://www.hswtech.com/
Developed at HSW Technologies LLC, University of Florida
Contact: Ali Haghighat, [email protected] Sjoden, [email protected]
Availability – coming soon to university participants onlyRSICC http://rsicc.ornl.gov
66 Managed by UT-Battellefor the U.S. Department of Energy
PENTRANTM (Parallel Environment Neutral-particle TRANsport)
Code System
Pre-processing
PENMSH-XP (prepares mesh/material/source distributions &
PENTRAN input file)
PENTRAN (Parallel 3-D, Sn transport code)
Post-processing
PENDATA (prepares tables of flux, source, and material distributions by
processing parallel-partitioned output files)
PENPRL (determines flux values at any arbitrary position by performing
3-D linear interpolation)
67 Managed by UT-Battellefor the U.S. Department of Energy
• PENTRAN code system was developed by Glenn Sjoden and
Alireza Haghighat in 1996.
• ANSI FORTRAN F77/f90 with MPI library, over 37,000 lines
• Industry standard FIDO input
• Licensed via HSW Technologies LLC
• Solves 3-D Cartesian, multigroup, anisotropic transport problems
• Forward and adjoint mode
• Fixed source, criticality eigenvalue problems
• Parallel processing algorithms
• Hybrid phase-space decomposition in angle, energy, and/or spatial
variables
• Parallel I/O
• Partitioned memory for memory intensive arrays (angular fluxes, etc)
• Builds MPI processor communicators
• Automatic scheduling using a decomposition weighting vector
68 Managed by UT-Battellefor the U.S. Department of Energy
Numerical formulations
– Adaptive Differencing Strategy
DZ DTW EDI
Upgrade condition: Negative solution w ≥ .96
Diamond Zero Fixup (DZ); Directional Theta-Weighted (DTW); Exponential-Directional Iterative (EDI)
– Fully discontinuous variable meshing
between coarse meshes: Uses a novel
higher order mesh coupling scheme:
Taylor Projection Mesh Coupling (TPMC)
– Acceleration
• Coarse-mesh Rebalance (CMR) techniques; multi-grid (MG);
Combined CMR & MG; Synthetic Even Parity Simplified Sn (EP-SSn);
Preconditioned EP-SSn/Sn
69 Managed by UT-Battellefor the U.S. Department of Energy
Numerical formulations (cont.)
– Iterative
• Multigroup & One-level Source Iteration (SI)
• Red-Black and Block Jacobi iteration
– Anisotropic scattering with arbitrary order,
– Angular quadrature set:
• Level symmetric (up to S20) with ordinate splitting (OS)
• Pn-Tn (arbitrary order) with OS
– Vacuum, reflective, and albedo boundaries
– Volumetric & planar angular sources
Other versions
– Medical Application:
– PENTRAN-MP (Radiation dose – photon & electron);
– PENTRAN-CRT (Hybrid Sn & Characteristic Ray Trace) (under
testing & evaluation)
– Core physics: PENTRAN with PENBURN (3-D fuel burnup)
70 Managed by UT-Battellefor the U.S. Department of Energy
Benchmarking: VENUS-3 benchmark facility, Kobayashi 3-D benchmarks,
C5G7 MOX Criticality benchmark, Ganapol TIEL benchmarks
Applications
– BWR Core-Shroud
– Pulsed Gamma Neutron Activation
Analysis (PGNAA) device
– X-Ray room
– Time-of-Flight (TOF)
– Spent fuel storage cask
– UF Training Reactor (UFTR) - Water tank Characterization
– UFTR - Thermal column optimization
– SNM Detection optimization
– Whole body Medical Phantom dosimetry (PENTRAN-MP)
– SiC Power Monitoring Assessment
– LWR 3-D fuel burnup calculation for whole core (PENTRAN with PENBURN)
– Full-core PWR (IBM blueGene/P) (tested on 4096 cores)
– Development of Spent fuel pool monitoring tool
– Cargo Monitoring Assessments
Performance: Achieved high parallel fractions in a range of 96-99%
71 Managed by UT-Battellefor the U.S. Department of Energy
71 Managed by UT-Battellefor the U.S. Department of Energy
PARTISN
Developed at Los Alamos National Laboratory
Contact: Randy Baker, [email protected]
Availability:RSICC http://rsicc.ornl.gov
NEADB http://www.nea.fr/html/databank/welcome.html
72 Managed by UT-Battellefor the U.S. Department of Energy
72 Managed by UT-Battellefor the U.S. Department of Energy
PARTISN
PARallel, TIme-Dependent SN
Evolutionary successor to DANTSYS (ONEDANT, TWODANT,
THREEDANT)
PARTISN 5.97: Time-Dependent
Parallel Neutral Particle Transport Code System
Solves the time-independent or dependent multigroup discrete ordinates
form of the Boltzmann transport equation in several different geometries
73 Managed by UT-Battellefor the U.S. Department of Energy
73 Managed by UT-Battellefor the U.S. Department of Energy
PARTISN
Uses MPI (message passing interface)
Designed for UNIX, Linux or Windows systems
solves the transport equation on orthogonal (single level or block-
structured AMR) grids in 1-D (slab, two-angle slab, cylindrical, or
spherical), 2-D (X-Y, R-Z, or R-T) and 3-D (X-Y-Z or R-Z-T) geometries
74 Managed by UT-Battellefor the U.S. Department of Energy
Supercomputers Today
Million-fold increase in computing and data
capabilities
2004
2006
2007
2008
2009
2011
2015
2018
Cray ―Baker‖8/12-core, dual-
socket SMP 1000 TF (1 PF)
DARPA HPCS20 PF
Future system
100–250 PF
Cray XT4119 TF
Cray XT3 Dual-core
54 TF
Cray XT4 Quad-core
263 TF
Cray X13 TF
Cray XT3Single-core
26 TF
Future system1000 PF(1 EF)
Cray XT4Quad-core
166 TF
Cray ―Baker‖8-core, dual-socket SMP
1379 TF (1.4 PF)
2005
Slide courtesy of Jeff Nichols, Oak Ridge National Laboratory
Cost as low as
$0.13 / gigaflop
for the 40nm GPU
from ATI.
75 Managed by UT-Battellefor the U.S. Department of Energy
75 Managed by UT-Battellefor the U.S. Department of Energy
Shielding Aspects of Accelerators and Target Irradiation
Facilities (SATIF-10)
http://indico.cern.ch/conferenceDisplay.py?confId=62629
76 Managed by UT-Battellefor the U.S. Department of Energy
76 Managed by UT-Battellefor the U.S. Department of Energy
Computational Medical Physics Working Group
http://cmpwg.ans.org
77 Managed by UT-Battellefor the U.S. Department of Energy
77 Managed by UT-Battellefor the U.S. Department of Energy
Monte Carlo 2010 and Supercomputing 2010
http://sna-mc-2010.org/
October 17-20, 2010
Tokyo, Japan