15. Create Integrated Modelsand Designs for Attractive

Fusion Power SystemsPresented by A. René Raffray (UCSD)

L. El-Guebaly (UW), W. Meier (LLNL), W. Reiersen (USIPO),M. Sawan (UW), P. Sharpe (INL), L. Waganer (Consultant),

S. Willms (LANL), A. Ying (UCLA) andthe Harnessing Fusion Power Theme Group

Research Needs Workshop (ReNeW)Bethesda, MD

June 8-13, 2009

Scope of the thrust

This thrust includes two primary aspects:1. Integration of physics and engineering models

focused on power extraction and fuel cyclesystems (fusion nuclear science and technology)

2.Advanced design studies for DEMO and FusionNuclear Science Facilities (FNSF)

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Issues addressed in this Thrust

• What modeling and system simulation tools andvalidating experiments are required to underpin andguide the research needed to harness fusion power?

• How can these separate physics, nuclear, andengineering models be most effectively coupled toaddress highly integrated fusion system behavior?

• What advanced design studies are needed to identifyand propose solutions for system integration issues andoperating parameter spaces for future fusion facilities onthe path to fusion power?

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Integrated Modeling Activities

• Develop science-based, increasingly coupled, predictive modelingcapability for plasma chamber components and related systems withstringent validation by experiments and data collection.

• Extend models to cover synergistic physical phenomena forprediction and interpretation of integrated tests (e.g., ITER TBM)and for optimization of components and systems.

• Develop methodologies to integrate with plasma models to jointlysimulate key first wall and divertor temperature, electromagneticresponses, etc.

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Goal is predictive capability for fusionnuclear science & technology aspects of

FNSF and DEMO

Example of integrated code integration forplasma chamber and power extraction

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• Predicting the performance of a plasma chamber nuclear component atpresent involves many technical disciplines and many computationalmodels and codes– Many of these codes/models already exist or will be developed as part of

Thrusts 13 and 14– e.g. MCNP for neutronics, CFD/thermofluid codes for FW surface

temperatures, and ANSYS for stress/deformation, etc.

• Because of the complex geometry of the fusion system, these codesshould be run in 3D with a true geometric representation in order toachieve high quality prediction.– Maintaining consistency in the geometric representation among the codes is

challenging.

• Using the output from a code as an input to the other code currentlyinvolves lots of human effort, and machine time.– It is a source of error.

• The proposed research thrust is to remedy this deficiency while giving amore realistic prediction of the phenomena and performances that occurin a fusion nuclear environment.

Careful representation of a geometrically complex fusioncomponent is essential to predict accurate performance

Direct Coupling of Neutronics with CAD Models (DAG-MCNP)

NWL map

ARIES-CS

ITER DCLLTBM

Mid-plane nuclearheating

Utilizing a combination of fusion specific researchcodes and off-the-shelf third party software

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Plasmaheat flux

Pb-Liflow FCI

Helium-cooledstructure

DCLLblanket

channels

MHD velocityprofile in theducts computedusing HIMAG

Example: - MHD flows with heat transfer and natural convection computed using codes developed in the fusion community (such as HIMAG.)

Sample analysis codes and mesh requirements in ISPC

Physics Analysis code Mesh specificationNeutronics MCNP Particle in cell (PIC)

Attila Unstructured tetrahedral mesh(node based)

Electro-magnetics

OPERA(Cubit)

Unstructured tetrahedral (Hex-)mesh (node based)

ANSYS Unstructured Hex/Tet mesh (nodebased and edge basedformulations)

CFD/Thermo-fluids

SC/Tetra &CFdesign

Unstructured hybrid mesh (nodebased)

Fluent(Gambit)

Unstructured hybrid mesh (cellbased)

MHD HIMAG Unstructured hybrid mesh (cellbased)

Structuralanalysis

ANSYS/ABAQUS

Unstructured second orderHex/Tet mesh (node based)

Speciestransport

COMSOL Unstructured second order mesh(node based)

Safety RELAP5-3DMELOCR

System representation code

- Traditional CFD/thermal analysis fornon-conducting flows performed usingoff-the-shelf third party software

Integrated Modeling Involves Four MajorElements

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• Fusion Research Code Development and Integration involving the multi-physicsphenomena occurring in a fusion nuclear chamber system

• Efficient and High Fidelity Data Interpolation Schemes across various analysis codes• A Computational Analysis Management, whereby relevant simulation data stored

and transmitted to multiple solvers in an appropriate format as well as madeavailable for post-processing

• Validation/Verification

Validation/Verification

CAD-Geometry

Mesh servicesAdaptive mesh/mesh refinement

Visualization

NeutronicsRadiationdamage rates

Thermo-fluid

Structure/thermo-mechanics

Species(e.g. T2)transport

Electro-magnetics

DataManagement:InterpolationNeutral format

MHD

Coupled effect

Specialmodule

Database/Constitutive equations

RadioactivityTransmutation

Time stepcontrol fortransientanalysis

PartitioningParallelism

Safety

Example of integrated code integration forplasma chamber and power extraction

9Ultimate Goal: Validated Predictive Capability for DEMO

IntegratedModelingSingle- and Multiple-

effect Experiments

Material DatabaseConstitutive Correlations/

Models

TBM Design and Data Interpretation

ITER TBMFNSF/CTFtest data

ValidationInitial Benchmark

FNSF/CTFChamber Design

• Compiles data base derived from fusion R&D in out-of-pile facilities and fission reactors• Provides high level of accuracy, substantially reduces risk and cost for the developmentof complex multi-dimensional system of the plasma chamber in-vessel components

• Provides a natural interface for Fusion Simulation Project (FSP)To FSP (PFC surfacetemperature andtopology)

Thrusts 13, 14Thrust 13

Thrust 13

Thrust 6

Thrusts 12, 13

Advanced Design Activities

• Assess and improve key aspects of fusion energy throughdetailed advanced design and integration activities forDEMO, laying out scientific basis and identifying researchefforts to close the knowledge gap to DEMO.

• Evaluate through advanced design and system simulationalternative configurations and designs through first stage ofFNSF effort.

• Perform advanced design simulation and modeling relatedto safety and environment, availability, maintenance andoverall system performance and optimization.

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Example from Thrust 13 Elements

Slide 11

Basic Properties /Separate Effects Testing

Multiple / Partially-IntegratedEffects Testing

Integrated FusionMockup Testing

DEMO ReadinessDatabase, Design Tools,Qualification / Licensing

Increasing time, complexity, integration, cost

Models and Theory

Simulation Codes

Integration andBenchmarking

Test FacilityPlanning &Preparation

ITER-TBM / FNSF Facilityand Test Article

Planning & Preparation

Decreasing number of concepts and options

Need More DetailedDEMO DesignDefinition as Goal forR&D Program

Need to assess most desirableconcept/capabilities of FNSF

Detailed DEMO Design Activities WillHelp Direct R&D

• ARIES on steroids (much more details needed)• Develops embodiments of systems/parameters/phenomena

associated with fusion as an energy source- Plasma physics, transient events, high energy neutrons, dpa, tritium permeation,

inherent safety, low activation, segment removal, etc...

• Enables assessment of key issues in an actual design context- Edge physics, PMI, TBR, fuel cycle, power balance, core maintenance, safety

assessments, and environmental impact, etc…

• Provides a vision of the next big goal- integrating force to focus and utilize the directed R&D efforts- The devil is in the details!

Specific Intent DEMO Design Activities Fully define all features, performance, operations, economics, safety

and environmental (attributes?) of the DEMO to demonstrate viability offusion – Use specifications as R&D performance metrics

Explore options including configurations, subsystems, maintenance,plasma (controls?) and operational procedures to select optimal R&Ddevelopment pathways and selection of optimal design

Assess options as risk mitigation programs The DEMO design effort will coordinate the basic scientific research

with the engineering efforts to yield relevant technologies - It will marrythe university and DOE laboratory efforts with industrial support

The DEMO design effort will commence as a somewhat more detailedconceptual design with a continual evolution into a morecomprehensive detailed design

Integrating Safety and EnvironmentalAspects

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• Safety benefits of fusion energy can allow deployment under the very restrictive“no-evacuation criteria” for nuclear facilities.

• Simulation tools for safety assessments must be developed, refined, and validatedfor fusion developmental facilities and eventual power systems. Scientificunderpinnings include:– robust and stable computational models suitable for short and long-term transients– integrated thermal, chemical, and electromagnetic phenomena possible during

postulated events– single-effects and integral experimentation to validate physical models

• Environmental benefits of fusion energy are exercised with an integrated materialslifecycle management strategy that:– minimizes the sizable amount of mildly activated materials anticipated for fusion power

plants– recycles and reuses activated materials within the nuclear industry– clears or free releases materials to the commercial market if materials contain traces of

radioactivity

The burden of proof, however, increasing relies on safety integrationthroughout the design process, along with adequate, proven tools for safetyassessment.

Integrating RAMI Aspects

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• The evolving design for DEMO would incorporate component designs thatpromote reliable operation, high availability, and maintainability.

• Studies would be performed to determine the development and testactivities, cost and schedule required to meet the DEMO availability goal.Results would be used to plan development and test activities (connectionwith Thrusts 13 and 14).

• Trade studies would be conducted to evaluate configuration options andcomponent design alternatives and select those options that promoteperformance, availability, and cost objectives. Results would be fed backto supporting experiments and test activities to provide needed focus.

• A clear map for coordinating design integration and development andtesting activities, and down-selecting between design options would bedeveloped and would include risk mitigation features.

Incorporating other Thrusts into DEMODesign Activities

Since all Thrusts are defining R&D leading to DEMO, all effortswill be applicable to the DEMO design activities

The DEMO design activities provide the ideal test bed toassess and “virtually validate” the merits of proposed anddeveloped processes, physics models, hardware and software

FNSF Effort as Proposed in Thrust 13

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• The role of a next step Fusion Nuclear Science Facility will be to fullyestablish the engineering feasibility, reliability, safety, fuel sustainability,and performance verification of the plasma chamber components withsignificant neutron flux and fluence, long continuous operating time, andwith the build-up of transmutation products in prototypic materials.

• Such a test program is envisioned to include both highly instrumentedscientific experiments geared towards understanding phenomena andbehavior as well as multiple concept modules for reliability statistics.

• The planning and design of such a facility is itself an intensive task, thelead time for which must be carefully considered in the overall timing of aDemo readiness program.

Evaluate through advanced design and system simulationalternative configurations and designs of FNSF

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• A number of different designs have been proposed (e.g.CTF/FDF/VNS/).

• The first stage of the FNSF effort should include:- defining the mission and requirements (what will be

accomplished in FNSF and will it be sufficient to then proceed toward commercial fusion?)

- conducting conceptual design/system study of different options to better assess their expected performance and capability and the extent to which how they address the research requirements.

Key fuel cycle and power extraction systems and systemsdesign aspects and processes that must be modeled

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Scale and Readiness

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- Medium size thrust (add structure to the list ofthrusts).

- Ready to start now.

- Can build on existing effort in advanced designand integrated modeling areas.

Benefits

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• The ultimate goal of fusion research is to provide a nearly unlimited, reliable,and safe source of power at an affordable cost.

• Development of effective fusion power is a cost-intensive process, fraughtwith many compounded complexities and increasingly costly experiments andtest facilities.

• These integrated models and designs offer a cost effective risk-mitigationoption for the fusion program at a fraction of the cost of single facility orexperiment.

• It also enables a wide range of design exploration and optimization over abroad spectrum of options and configurations for both DEMO and FNSF.

• Development of a computer-based simulation capability to display fusionplasma chamber behavior poses many challenges and opportunities forinnovations in development of efficient multi-physics algorithms, methods,and techniques as well as computer graphics and architectures.