N9 3- 26 9_)-[

Next Generation SystemModeling of NTR Systems

John J. Buksa and William J. RiderLos Alamos National Laboratory

October 22, 1992

Los Alamos

Introduction

_] NTR Modeling Challenges

Current Approaches

O Shortcomings of Current Analysis Methods

O Future Needs

O Present Steps Toward These Goals

, l

NTP: Systems Mochila 8 712

Los AlamosNP-TIM-92

https://ntrs.nasa.gov/search.jsp?R=19930017772 2019-03-20T11:16:25+00:00Z

Figure l. The Coupled Cores in Klva-3, PaJsrito Site."Test Klwl" t8 on the left, and PARK_ is 0a the right.

_.--:: ^" 713 NTP: Systems Modeling

ENGINE COUPLING PHENOMENA

1'(2,22M=V)

Los Alamos

Hyb_ Symm for Crm Vehk:kDHyb-l_lllob (NTRMAh(Chem)

NTP: Sy_ Modelin8 714 _ I_P-TIM-92

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NP-TIM-92 "715 NTP: Systems Modeling

Intr&iucUon: Modeling Applications

I I IIt ii i II

• Design: performance (SS operation) and lifetime (fuel / criticality)

• Startup and Shutdown

(two phase T-H, neutronics, kinetics, heat transfer, low strain rate hydro)

• Water Immersion

(kinetics, neutmnics, all hydro)

• Impaction

(kinetics, neutronics, high strain rate hydro)

• Engine-Out Operations

(all except high strain rate hydro)

Los Alamos

NJOY/TRANSX i

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Flux Spectra

Reaction Rltll

Power Distribution

N'rP:Syste_Mo_lins ? 16 NP-TIM-_

DETAILED MCNP MODELING OF NUCLEAR THERMALROCKETS - WESTINGHOUSE NRX-A6 REACTOR

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Los Alamos

Thermal-Hydraullc Analysis Methods

NP-TIM-92

• Extensive experience in both space and terrestrial reactors• TRAC

- Developed tot LOCA analysis of PWRs

- Highly developed models for two-phase flow

Low/zero gravity models are available

Useful for facility/more genera/system ana/ys|s• HERA

Developed for solid core terrestrial reactors

Useful for the thermal analysis of general systems including spacenuclear systems

• KLAXON

- New thermal hydraulic systems code designed specifically for gascooled, space reactors

• THROHPUT

State-of-the-art heat pipe modeling from startup to shutdown

Los Alamos

717 NTP:System| Modelins

Kxample TRAC Nodlng Diagram

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Thermal-Hydraulic Modeling: Prismatic Fuel

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HERA: HElium/Hydrogen Reactor Analysis

Used to model reactor core and core components with axially homogeneous

construction

Three-dimensional, fully transient, arbitrary user defined geomatdes

Programmed to be computationally efficient, espedally on vector

supercomputers

Currently exists in stand-alone mode and coupled to TRAC. Connection

to KLAXON is planned

PATRAN grid generator and visualization translators currently being written

Coupling to Storm's corrosion model envisioned _ Core Ufetlme

Component and core T-H model planned (fuel element, support element,

and periphery)

,. Los Alamos

Methodology: New

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PATRAN._[,Translator__{ HERA _ Post' • J/ I Translator

Absqus HERA I Tamp flle' L

file input file PATRAN

input file _I|

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NP-lTM-92 721 IqTP: Systems Moiling

KLAXONGAS-COOLED REACTOR SYSTEMS MODELING CODE

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Time-dependent analysis of systems operating with compressible gas

working fluids. TRAC-like pipe, plenum, etc. component models, filland break capabilities, and advanced flow modeling numerics forshock following in nozzles. ,.o

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Future Development

- Connection to HERA _ o0

- Validation with "_

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NTP: Symtems Modeling 722 IqP-'IIM-92

THROHPUTHEAT PIPE MODELING CODE

Transient thermal-hydraulic heat plpe modeling code wlth:

- Multi-region capability (wall,fluid, mixed, gas)

- 2-D convection andconduction heat transfer

- Li melt model

- Gravity and non-gravitycapillary pressure models

Future development:Benchmarking and validationwith LANL experiments

Heat Pipe Operation

Los Alamos3/112

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NP-TIM-92 723 NTP: Syst_ns Modeling

I I I III

Future Needs

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C) Better All Around Resolution of Problems

System Design Optimization Tools

O Complete Utilization of Modern Technology(Computers and Algorithms)

O Use of Integrated Physics Codes

Los Alamos

LOS ALAMO6 NA'I1OI_M. LABORATORY _]__ _)_)i I I i, , I i, •

Los Alamos Perspective ,

• Emphasis on Simulation Instead of Testing

-- current ES&H environment dictates reduced testing

of nuclear systems

• Interagency NTP Modeling Team

Role, Impact, Importance, Visibility

• Effort Should be Commensurate With the SEI

--- ambitious, high profile, high tech, national

importance 724NTP: Systeml Moiling

NP-TIM-92

I! °• 88

Advanced Architecture: Description

common file storage wod_tat_

USER

DRIVEN DRIVEN

PHYSICSMoDELS [ VISUALIZATION' OUTPUT

_xcomputem gr_ohtc_l

COMPUTER

Los Alamos

NTP: Sy,=tem= ModelingNP-TIM-92 725

Advanced Architecture: Potential Physle_ l_clmges

.. Neutronlcs (includingcross-sections, doslmetry)

• Spatial Kinetics

• Generation/Deplatton

• ThermC-Hydrsu_(t.,ophase)

• Low Strain Rate Hydro

• High Straln Rate Hydro (solid and fluid)

• Heat transfer (conduction, radiation)

• Chemistry/Materials

Los Alamos

NTP:SystemsMo_UnS 726 m,-TU4-_

Other Laboratory Capability

Fluid dynamics codes

Developed for a large range of physical sltuatlons varylng fromIncompressibleto hlghly compresslble flows

Advanced methodologies

High Strain Rate Solid/Hydrodynamics

Applicable to events Involving reactor impaction/disassembly

Examples: launch accidents, reentry, water immersion

Coupled directlyto other physical phenomena (neutronics for Instance)

Advanced methodologies

High Performance ComputingOne of two DOE centers of excellence

ICN (3 CMs, 7 Cray YMPs)

ACL

Los Alamos

ADVANCED COMPUTINGLABORATORY

Acting as a university/industrial/laboratory interface forstate of the art computations, emphasizing:

• State of the art hardware for massively parallelcomputation (largest CM-2s and CM-5 in the nation)

• Wide area gigabit network for distributed parallelcomputing (using ANSI standard: HIPPI)

• Advanced scientific visualization using high speednetworking and parallel computational methods

• Software tools/algorithms development for distributedparallel computation (NSF Science & Tech. center: CRPC)

• Emphasizing "real" applications running in parallelenvironment (Grand Challenges and beyond)

NT-TIM-92 727 L_ sAqe_e,3=_

Purposes of the ACL

• To respond to the rapid changes in hardware and software

• To investigate new "Grand Challenge" computingenvironments

• To provide more "access" to Los Alamos from the outsideworld

• Provide high performance testbed for networking andvisualization

• Stimulate practical algorithm development for massively

parallel computing

• Function as one of the Dept of Energy High Performance

Computing Research Centers

Los Alamos

Table 1: TODAY

Porous Mediaflow

Novel Materials 2-d molecular

dynamics

3-d multimaterial

hydro (2003 pts)

transport scalingPlasma physics

Global Ocean decade, 20 levels,1/2 °

Brain Topology 3-d reconstruction

QCD quenched lattice(32x32x32x64)

1014

1015

1015

l0 is

10 t3

1016

500 Mbytes

8 GBytes

18 GBytes

500 MBytes

64 GBytes

100GBytes

200 GBytes

250 GBytes

200 MBytes 10 OBytes

500 MBytes 500 MBytes

tore: systems Mode_ 728 I t_e Alamne I_P'11M-92

Table 1: TOMORROW

Porous Media

Novel Materials

3-d immiscibleflow

3-d molecular

dynamics

3-d mulfimatcrial

hydro (10003 pts)

Plasma physics numerical Tokamak

,Global Ocean century, 40 levels,1/4°

Brain Topology 3-d reconstruction

QCD quenced lattice(64x64x64x128)

1018

i0 Is

10 TM

1017

1015

10 TM

1 Tbytes 4 TByt_

20 Gbytcs 3 TBytes

1 TBytcs 20TBytes

1 TBytes 100 TBytes

4 GBytes 20 TBytes

15 GBytes 1 TBytes

8 GBytes 8 TBytes

Los Alamos

NP-TIM-92

• QCD

Applications on the CM-2

• Condensed Matter Physics

• Free Lagrange Hydrodynamics

• Global Ocean Model

• Lattice Gas (porous media)

• Oil Reservoir: Mobil (11Gflops sustained)

• Tokamak Fluid Turbulence

• Fokker Planck

• Crystal Formation

• Many Body Problem

• Plasma Particle Simulations

• Molecular Dynamics

• Neural Networks

729 k,l_s#do_l_s

flF POOR

Existing ACL HIPPI Network

Fiber Link

Data

CM-5

Los Alamos

PAGOSA

O A 3-D Multi-Materlal Hydrodynamics Code on theConnection Machlne

High-Speed Hydrodynamics and High-RateDeformation of Solids

0 Eulerian, Second-Order Predictor CorrectorLagrangian Step with Third-OrderHigh.ResolutionAdvection

High-Resolution Interface ReconstructionAlgorithm

0 Highly Efficient for the Connection Machine

Los Alamos

N'rP: Systenm Modeling 730 m,-Tnvl-92

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Conclusions

C1Current Modeling Approaches are GenerallyInadequate

CI In the Future Modeling will be Relied on Heavily

O Los Alamos has begun to Lay the Groundwork forFuture Modeling Capabilities

NP-TIM-92

Los. Alamos731 N'rP: Systems Modeling