“CAD-centric” Integrated Multi-physics Simulation Predictive Capability for Plasma Chamber Nuclear Components

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

2. Integrated Simulation Predictive Capability (ISPC) as apart 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) 2

3. BLKT-12 CATIA model An integrated model tool potentially contributes to more efficient FNST R&D • 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 Shield Module • 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. FW/BLKT temperature response with time with water inlet temperature at 10K/h ramp-up rate. FW (Be) “ITER Baking in progress”

4. 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) Mechanical load under a disruption Snapshots of velocity magnitudes at different pipes (BLKT-12 SM) Nuclear heating profile CFD/thermo-fluid X-Y plane (8 cm above mid-plane) FW/BLKT-12

5. Design by analysis incorporating CAD model becomes even more important in regard to first wall panels shaped as local limiters ITER FW/shield design still evolving In recent design, slot was removed • The heat flux profile is extremely non-uniform: heat flux as high as 5 MW/m2 (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 Reference: R. Mitteauet. al., Heat loads and shape design of the ITER first wall, ISFNT-9 (2009) CuCrZr CuCrZr Von Mises (Pa)

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

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

9. Solving individual physics using its optimized numerical technique and running simultaneously with a smart transfer of information Imprinting A Merging F E B D C • Adopting one numerical technique for all simulations in ISPC can limit the size of the problem and is undesirable. Overcoming CAD discrepancy (e.g. overlapping) is common source of difficulty for MCNP Sample analysis codes and mesh requirements in ISPC DAG-MCNP (UW) 9

10. Special module Safety A multi-disciplinary effort • 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 Verification & Validation Structure/ thermo-mechanics Radioactivity Transmutation Species (e.g. T2)transport Thermo-fluid Electro-magnetics Neutronics Radiation damage rates e.g. source MHD Material database/Constitutive equations/ Irradiation effect Coupled effect Visualization Time step control for transient analysis Data Management: Interpolation Neutral format Mesh services Adaptive mesh/ mesh refinement Partitioning Parallelism CAD- Geometry

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

12. Need experimental data for code verification & validation 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 Jet impingement He inlet He outlet US-CHF mock-up Temperature and He flow characteristics under 10 MW/m2 RF-CHF Verification/validation needed on integration method

13. “How to” incorporate a bigger resource into ISPC? • 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) Advanced computational tools are continuously being developed in various projects: SciDAC, ITAPS, CCA, etc. Nuclear Energy Innovation Hub “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.---” • Look for synergism • Not re-inventing the wheel but riding on state-of-the-art methodology

14. Next StepsHow do you see this moving forward? • 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 capabilitiesfor many cross-cutting scientific & engineering disciplines and deliver faster and more detailed insights into the R&D of in-vessel FNST components and systems Imagine if critical performance parameters can be projected and examined in advance---- • 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.