O.Petit, E.Dumonteil, F.X.Hugot, Y.K.Lee, A.Mazzolo, C ... · 2 CEA/DEN/DM2S/SERMA 2 TRIPOLI-4...

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1CEA/DEN/DM2S/SERMATRIPOLI-4 Monte Carlo code overview

ICRM meeting, November 27-28, 2006

TRIPOLI-4A 3D CONTINUOUS-ENERGY MONTE CARLO TRANSPORT CODE

O.Petit, E.Dumonteil, F.X.Hugot, Y.K.Lee, A.Mazzolo, C.Jouanne, C.M. Diop and J.C.Trama.

DEN/DM2S/SERMACEA/Saclay

91191 Gif-sur-Yvette CedexFRANCE

[email protected]@cea.fr

[email protected]

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1. A brief history2. Application fields3. General features4. Structure of the code5. Geometry description6. Nuclear data, processing, libraries7. Variance reduction8. Green functions9. Benchmarking10. User interface

TRIPOLI-4 : Outline

TRIPOLI-4 overview

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TRIPOLI-1 1976 : J.C. Nimal, S. Katz.

TRIPOLI-2 1982 : J.C. Nimal, T. Vergnaud, L. Bourdet, J. Gonnord, G. Dejonghe.

TRIPOLI-3 1996 : J.C. Nimal, T. Vergnaud, M. Chiron.

TRIPOLI-4 1990 : J.P. Both, Y. Pénéliau, B. Roesslinger,

Y.K. Lee, O. Petit, A. Mazzolo, C. Jouanne, E. Dumonteil, F.X. Hugot.

C.M. Diop : since 1995

J.C. Trama : since 2006.

1. TRIPOLI-4 : A brief history

TRIdimensionnel POLYcinétiqueA Particle Transport Monte Carlo Code in 3D Geometry

Available from the OECD / NEA data bank since 2003

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Shielding studiesCore and criticality studiesInstrumentation studiesPhysical analysis, numerical experiment Reference and Project Tool

. Power Reactor (PWR, FBR, BWR, ...)

. Dismantling

. Fabrication, Reprocessing, Transport of fuel

. Research reactors

. Nuclear Wastes

. Transmutation, Hybrid System

. Thermonuclear Fusion

. Particle Accelerators

. Medicine

. Industrial plants, …

2. TRIPOLI-4 : Application fields

Neutron and gamma dose ratecalculations inside PWR reactors

OSIRIS : conception of experimentsin OSIRIS research reactor

Dampierre PWRKeff calculation and

ex-core response calculationversus erroneous assembly loading

concrete

Reactor pitHeat insulator

pressure vesselwater

barrel

bafle assembly

water

assemblies

Neutron fluence calculation on PWR vessel

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• 3D• Continous energy pointwise cross-sections (20 MeV)• Multigroup self-shielded cross-sections (20 Mev)• Neutron, gamma, coupled (n,γ)• Electron, positron, cascad shower (GeV)• Parallelization

φ = TCφ + TS

• Subcritical problem

• Critical problem

• Time dependent problem

• Perturbations

Specificities for neutrons :

3. TRIPOLI-4 : General features

Physical quantities :

• Flux of particles : φ• Current of particles : J• Reaction rates• Damages• Dose rates• Keff

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Modules Description Languages # of lines

Cplus Memory management library C++ 8kGeom Geometry library C 30kEndl ENDL data management library C++ 4kIpc Parallel computing library C++ 20kNjoy ENDF file management for Njoy F77,F90 100kTripoli4 Monte Carlo core code library C++, yacc, lex 280k

4. TRIPOLI-4 : Stucture of the code

Available platforms :

Linux 32 and 64 bits, Solaris, OSF1, IBM Aix

Parallelism : heterogeneous networks, massively parallel machines.

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Predefined shapes and combinatorial operators :Reunion, smash, intersection, substractionRotationRepetition of basic pattern

Lattices, Lattices of lattices :

Or definition by surfaces :

Combination of both descriptions is possible.

5. TRIPOLI-4 : 3D Geometry description

User friendly interface

2D cut

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→ Evaluated Photon Data Library

Photons :

Electrons, positrons :

→ Evaluated Electron Data Libray

Photoionization, photoexcitation, coherent and incoherent scattering and pair production

Relaxation of ionized atoms back to neutrality

→ Evaluated Atomic Data Library

Transport of electrons. Production of secondary particles :Photons due to Bremsstrahlung and primary electrons due to inelastic scattering

6. TRIPOLI-4 : Nuclear data

Neutrons :All libraries in ENDF-B6 Format : ENDFBVIR8, ENDFBVII, JEF2.2, JEFF3.1, JENDL3.3…

Energy range from 10-5 eV to 20 MeV

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Nuclear data processing by NJOY99.x1. Reconstruction at 0 K (RECONR, ε = 0.001)2. Doppler Broadening at T K (BROADR, ε = 0.001)3. Treatment of Thermal Neutron scattering data for materials (THERMR)

→ Pointwise cross section library (PENDF)

→ Unresolved Range : Probability Tables by CALENDF code.

TRIPOLI-4 : Nuclear data processing

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TRIPOLI-4 generates XDR portable binary and angular distributionfiles the first time it reads a PENDF and an ENDF file

TRIPOLI-4 : Nuclear data libraries

TRIPOLI-4

Evaluation

RECONRBROADRTHERMR

PENDF

Deterministic code libraries(e.g. from APOLLO-2)

CALENDF PT

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The biasing scheme in TRIPOLI-4 :

• An importance map I(P) is automatically pre-computed on a (r,E) grid; the adjoint flux form is used as a hint (INIPOND module).

• Importance definition :

• Biasing parameters K and directions of interest are calculated

(related to importance by : ).

• In each cell and each group is computed by :

- a shortest path algorithm (for discrete « attractors »)

- or an analytical form, e.g. cylindrical (for a surface « attractor »)

),,()(),(),,( Ω××=Ωrrrrr ErIEIErIErI des

IIK ∇

=Ωr

r0

0Ωr

),( ErIsr

7. TRIPOLI-4 : Variance Reduction

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Examples of iso-importances produced :

TRIPOLI-4 : Biasing

Iron

Water

Neutron source

Detector

Discrete detectors for « passing-round » problems

Detector surfacefor uniform FOM on a surface

Detector surface

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Exponential transform is used for the transport sampling :

Biased cross-sections are :

Russian roulette and splitting are played

Biasing of the source

The beginning of the simulation is used to adjust Iref

from group to group (using weight discrepancies).

0* Ω⋅Ω−Σ=Σ

rrKtt

TRIPOLI-4 : Biasing

Ω0

ΩSource Resultregion

∫ ΩΩ+Σ−ΩΣ=Ω→ dsEsrErErrT tt )',',''(exp)',',()',','( ***

wrt. the Iref map.

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Example of β values (biasing’s strength adjustment) :PONDERATION

NEUTRONDECOUPAGE 6

20. 8. 4.5 2. 1. 1.E-11

DETECT_RHO 1 220.5 [β]MAILLAGE 69 1 21

4.68 1.5715 5.65 3REPERE CYLINDER

-0.001 -0.001 -50.1 β = 0 β = 0.1 β = 1100 -0.02 0

β FOM Efficiency0. 0. 1 0. 0.05 1

FIN_MAILLAGE 0.1 0.15 3INIPOND AUTO 0.5 3.66 70OMEGA SET_OMEGA CYLINDER 0 0 1 0 0 0 1.0 5.33 100FIN_INIPOND 1.4 16.00 300

FIN_PONDERATION 2.0 12.50 240

TRIPOLI-4 : Biasing

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Directsource Detector

Adjointsource

Adjointdetector D

= S(P) (P) dP+χ∫I

D= h(P) (P) dPχ∫I

8. TRIPOLI-4 : Green functions

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Large storageEasy and fast re-use of Green functions

Small storageEasy and fast re-use

of adjoint flux

Large storage

BiasingBiasingBiasing

One transport calculation for several source distributions

Two steps scheme (first step requires time to compute Green functions)

One transport calculation for several source distributions

One transport calculation for eachsource distribution

multi-detectorsmulti-scorings

one detectormulti-detectorsmulti-scorings

continous energymultigroupcontinous energy

« Green functions pseudo-adjoint»« Classical »adjoint

Direct biased

D= h(P) (P) dPχ∫I

D= S(P) (P) dP+χ∫I

0' '

( ) ( , , ' , ') ( ', ') ' '( ) k

r Z E E

N r G r E r Z E s r E dr dE dEN r∈

= ∈∫ ∫ ∫I

TRIPOLI-4 : Green functions

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« initial » data :

• position r• energy E• source intensity S(r,E)• weight W

« final » data :

• energy E’• contribution χ• weight W’

assembliesbafle assemblywater

concrete

pressure vessel

barrel

reactor pit

heat insulator

capsules

Example : neutron fluence calculation :

Exploitation : Simulation M.C :264 s > 2 days

2.7693E+10 (1.05%) 2.7695E+10 (0.51%)

TRIPOLI-4 : Green functions

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Ben

chm

ark

IAEA

(LL

NL

-Cul

len,

200

4) “How accurately can we calculate

thermal systems ?”

- K-inf and S(α,β) : s +/-0.0001- U-235 : 0.98%, 3.5% and 70%

- Monte Carlo codes :TRIPOLI-4.3 MVP MCNP-4C MCNP-5KENO-5 COGMCU MONK-8TART04 VIM RCP RACER

Publication: IAEA-INDC(USA) – 107, May, 2004

9. TRIPOLI-4 : Benchmarking

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• Industrialization : CAO / SALOME Project

10. TRIPOLI-4 : User interface

O.Petit, E.Dumonteil, F.X.Hugot, Y.K.Lee, A.Mazzolo, C ... · 2 CEA/DEN/DM2S/SERMA 2 TRIPOLI-4...

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