“CAD-centric” Integrated Multi-physics Simulation Predictive Capability for Plasma Chamber Nuclear Components 1 Others working on separate parts of the subject M. Abdou, M. Ulrickson (and team), M. Sawan (and team), M. Youssef, B. Merrill A. Ying (UCLA), R. Reed (graduate student), R. Munipalli (HyPerCom) Unlike FSP, the integrated modeling is progressed in a smaller scale fashion FNST meeting August 2, 2010 UCLA Aligned with ReNew Thrust 15 Acknowledgements to graduate(d) students M. Narula, R. Hunt, and H. Zhang (UCLA)

22 Integrated Simulation Predictive Capability (ISPC) as a part of ReNeW Thrust 15: Creating integrated models for attractive fusion power systems ReNeW Thrust 15 Integrated Model Objectives: Develop predictive modeling capability for nuclear components and associated systems that are science-based, well- coupled, and validated by experiments and data collection. Extend models to cover synergistic physical phenomena for prediction and interpretation of integrated tests and for optimization of systems. Develop methodologies to integrate with plasma models to jointly supply first wall and divertor temperature and stress levels, electromagnetic responses, surface erosion, etc. Today’s Trend in Simulation: –Treat complexity of entire problem Extreme geometric complexity Multi-physics, Multi-scales –Inter-disciplinary approach Modernize codes & Interpret phenomena from interrelated scientific disciplines –High accuracy & thorough understanding at each level –Interactive visualization and post processing (Intelligent Expert System)

“ITER Baking in progress” An integrated model tool potentially contributes to more efficient FNST R&D 3 FW/BLKT temperature response with time with water inlet temperature at 10K/h ramp-up rate. The time-dependent BLKT outlet temperature can be used in RELAP5 system code for heating control analysis. The flow pattern and associated heat transfer inside a FW/BLKT is very complex, which RELAP5 cannot model. Provide high level of accuracy and substantially reduce risk and cost for the development of complex plasma chamber in-vessel components Facilitate simulation of normal and off normal operational scenarios. Offer capabilities for system optimization Allow insight and intuition into the interplay between key multi-physics phenomena (occurring at a level where instruments cannot be installed.) Better understand the state of the operation through limited diagnostics BLKT-12 CATIA model FW (Be) Shield Module

CAD-centric modeling tools are being used in the US ITER FW/Blanket Shield Design (design by analysis) (led by Mike Hechler-ORNL and Mike Ulrickson-SNL) 4 Snapshots of velocity magnitudes at different pipes (BLKT-12 SM) Nuclear heating profile X-Y plane (8 cm above mid-plane) FW/BLKT-12 CFD/thermo-fluid Mechanical load under a disruption

Design by analysis incorporating CAD model becomes even more important in regard to first wall panels shaped as local limiters 5 The heat flux profile is extremely non-uniform: heat flux as high as 5 MW/m 2 (7.5 MW start-up and ramp down), 40% of wall EHF modules A shaped FW design brings forth the importance of using “prototype” in the analysis locationPeak heat flux Rows or panels affected Inboard : start-up4.4 MW/mm²3,4 Outboard3.6 MW/m²14,15,16,17 Shine thru4.0 MW/m² 6 panels on rows 15,16 Top4.6 MW/m² CuCrZr Von Mises (Pa) In recent design, slot was removed CuCrZr Reference: R. Mitteau et. al., Heat loads and shape design of the ITER first wall, ISFNT-9 (2009) ITER FW/shield design still evolving

Simulation performed on an engineering CAD model allows practical design assessments 6 ISPC can potentially reduce risk and cost of the component development Mid-plane nuclear heating (gamma: left; neutron: right) W/cc Location of the instrument and the associated perturbation to the data Analysis with a detailed geometric drawing with instrumentations in-place needed Thermomechanics Analysis  Proper manifold designs to provide uniform flow distributions among many parallel flow paths  Adequate cooing to all parts DCLL He-coolant inlet manifold He-velocity High temperature at upper structures PbLi velocity Velocity :m/s Stress concentration Initial results with simplified geometry & operating condition Inlet to 2 nd FW cooling panel

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What numerical software are available for CAD-centric integrated model? 8 Attila: Commercial Software Tetrahedral mesh MCNP – MCAM Community Developed Orthogonal mesh DAG-MCMP MOAB & CGM CADVoxels MCNP(X) MCNPX Native Geometry (Other) (many neutronics codes available: deterministic or Monte Carlo) Hybrid code ADVANTG (MCNP + Denovo) ITER FW Panel Attila is now being used to calculate radioactivity of components ITER 40 o A-lite Neutronic model Total (neutron + photon) flux ORNL

9 Solving individual physics using its optimized numerical technique and running simultaneously with a smart transfer of information Sample analysis codes and mesh requirements in ISPC Physics Analysis code Mesh specification NeutronicsMCNPMonte Carlo mesh tally (cell based) AttilaUnstructured tetrahedral mesh (node based) Electro- magnetics OPERA (Cubit) Unstructured tetrahedral (Hex-) mesh (node based) ANSYSUnstructured Hex/Tet mesh (node based and edge based formulations) CFD/ Thermo- fluids SC/TetraUnstructured hybrid mesh (node based) Fluent/CFX etc. Unstructured hybrid mesh (cell based) MHDHIMAGUnstructured hybrid mesh (cell based) Structural analysis ANSYS/ ABAQUS Unstructured second order Hex/Tet mesh (node based) Species transport COMSOL or others: TMAP, ASPEN Unstructured second order mesh (node based) SafetyRELAP5-3D MELOCR System representation code Imprinting A F B C E D Merging DAG-MCNP (UW) Overcoming CAD discrepancy (e.g. overlapping) is common source of difficulty for MCNP Adopting one numerical technique for all simulations in ISPC can limit the size of the problem and is undesirable.

10 A multi-disciplinary effort Verification & Validation Material database/Constitutive equations/ Irradiation effect CAD- Geometry Mesh services Adaptive mesh/ mesh refinement Visualization Data Management: Interpolation Neutral format Time step control for transient analysis Partitioning Parallelism Neutronics Radiation damage rates Thermo- fluid Species (e.g. T 2 ) tran s port Electro- magnetics MHD Coupled effect Special module Radioactivity Transmutation Safety e.g. source Structure/ thermo- mechanics Integration of computational software forms the heart of FNST performance prediction Data mapping and interpolation across various analysis meshes/codes has to be fast, accurate and satisfy physical conservation laws Large scale simulation, leading-edge high performance computing, advanced computational methods, and the development and application of new mathematical models

Maintain consistency in the geometric representation among the analysis codes The CAD-based solid model is the common element across physical disciplines specialized user FUNction Data Mapping Script CAD Model Neutronics Thermo-fluid & LM MHD Electromagnetics DMS FW/Plasma Facing Surface Phenomena DMS FUN Specialized physics models FUN Neutron source profile q” FW/PFC Thermo-fluid profile Stress/Deformation- Analysis Species Transport 3-D design iterative assessment important Safety or Transient events FUN * * Structural Support ISPC Design Process Flow Tremendous work for ITER FW/SB at SNL

12 Jet impingement He inlet He outlet Need experimental data for code verification & validation RF-CHF Within ITER project, some R&D being carried out and providing data for design support and code benchmark TCs installed in the mockup have provided data US-CHF mock-up Verification/validation needed on integration method Temperature and He flow characteristics under 10 MW/m 2

“How to” incorporate a bigger resource into ISPC? 13 Similar efforts are being pursued in various fields: within DOE Vision 21 project (Improved asset optimization by integrating ASPEN PLUS and FLUENT) Nuclear Energy and Simulation Hub FSP (Fusion Simulation Project) “to apply existing modeling and simulation capabilities to create a user environment that allows engineers to create a simulation of a currently operating reactor that will act as a "virtual model" of that reactor.---” Nuclear Energy Innovation Hub Advanced computational tools are continuously being developed in various projects: SciDAC, ITAPS, CCA, etc. Look for synergism Not re-inventing the wheel but riding on state-of-the-art methodology

Next Steps How do you see this moving forward? 14 Three activities (ITER FW/shield design, TBM program, and FNSF assessment study) provide mechanism, panorama, and opportunity for the development/ benchmark/test of the idea to the extent possible. However, a substantial effort requires FSP-like or NESH-like commitment Near term goal Continue to build/enhance interface and data management (increase degree of automation) Establish test cases to further explore the limit of the capability Example test cases Enhance existing neutronics computational platform for TBM radioactive dose calculations extended to ITER port cell area FNSF tritium breeding assessment through a complete 3-D base breeding blanket exploratory design analysis Develop schemes to link to plasma facing surface phenomena, and address FW tritium inventory and permeation losses Periodic recovery of implanted tritium has an impact on the TBR requirement; however, its degree of impact is affected by losses from tritium permeation into FW coolant

15 Summary Adopt the state-of-the-art computer technique, high-powered computing, advanced modeling and simulation that is 3-dimensional, high-resolution Develop highly integrated predictive capabilities for many cross-cutting scientific & engineering disciplines and deliver faster and more detailed insights into the R&D of in-vessel FNST components and systems The goal of an integrated simulation effort then is to be able to model and design a complete DEMO system including irradiation effects, thermofluid/MHD, temperatures and mechanical loads, tritium accountability in entire system (tritium retention, and tritium production and transport processes), and FW/divertor erosion. Imagine if critical performance parameters can be projected and examined in advance----