1. US ITER TBM Overview of DCLL R&D and Predictive Capability Activities Compiled by Neil Morley of UCLA 2006 US-Japan Workshop on Fusion High Power Density Components and System Inn on the Alameda, Santa Fe, New Mexico, USA November 15-17, 2006

2. US ITER TBM Outline  R&D Strategy and Prioritization  Main DCLL R&D Categories  Introduction to Predictive Capabilities  Summary

3. US ITER TBM R&D tasks directly contribute to satisfying design, qualification, safety, and operation requirements R&D tasks have been reviewed based on: –Forming basis for important design, material, and fabrication decisions –addressing safety issues and reliability risks that must be resolved for qualification of the first TBMs –planning, operating and analyzing US TBM experiments in ITER ITER TBM Acceptance Requirements TBMs must be Tested in H-H Phase TBMs must be DEMO Relevant TBMs must not interfere with operation, availability, or safety

4. US ITER TBM ITER & DEMO requirements and risks have a strong impact on TBM design and R&D decisions  DEMO relevance: –Materials and fabrication techniques should extrapolate to radiation environment –TBM designs and loading should extrapolate to DEMO sizes and performance needs  Qualification, safety, and reliability requirements: –Intense and early R&D on RAFS fabrication –Inclusion of prototype fabrication and several partially integrated mockup tests –Verified predictive capabilities will be required to establish allowable operating points from safety perspective –TBM is an experiment, but must know a lot abut how it will behave  Testing TBMs in the ITER H-H phase: –H-H phase TBM should use prototypical D-T phase TBM materials, fabrications, and designs –Predictive capability must extrapolate H-H operating conditions to D-T phase TBM operation

5. US ITER TBM R&D and Predictive Capabilities progress together - coordinated with design milestones Basic Properties Single/Multiple Effects Testing Partially-Integrated Mockup Testing Final Design Qualification Integrated Simulation Title3DesRev StartPrototype June FY2008 2009 2010 2011 20122013 DetDesFinalRev Sep Prototype Done April FinDes Chng Dec StartTBMfab June PrelDes Rev July BidPack August FabRoute Dec Models and Theory Simulation Codes Integration and Benchmarking

6. US ITER TBM 1. US ITER Proj. DCLL R&D Tasks are included under 3 main WBS elements 1.8 US ITER TBM 1.8.1 DCLL 1.8.1.1 Test Module 1.8.1.5 Design Integration 1.8.1.4 Tritium Systems 1. Thermofluid MHD 2. SiC FCI Fabrication and Properties 3. SiC/FS/PbLi Compatibility & Chemistry 4. FM Steel Fabrication & Materials Prop. 5. Helium System Subcomponents Tests 6. PbLi/H 2 O Hydrogen Production 7. Be Joining to FS 8. Advanced Diagnostics 9. Partially Integrated Mockups Testing 1.Model Development and Testing 2.Fate of Tritium in PbLi 3.Tritium Extraction from PbLi 4.Tritium Extraction from He 1.He and PbLi Pipe Joints 2.VV Plug Bellows Design DCLL R&D tasks vary considerably in cost and scope

7. US ITER TBM DCLL Unit Cell

8. US ITER TBM Key DCLL R&D Items  PbLi Thermal fluid MHD Key impacts on thermal and power extraction performance  SiC FCI development including irradiation low fluence effects Key impacts on DCLL lifetime, thermal and power extraction performance  RAFS/PbLi/SiC compatibility & chemistry Impacts DCLL lifetime and thermal performance  Tritium extraction and control Critical element for high temperature PbLi such as in DCLL  High temperature heat exchanger Critical element for high temperature DCLL  He system subcomponents analyses and tests, He distribution and 1-sided heat transfer enhancement Key impacts on DCLL thermal and power extraction performance  RAFS fabrication development and materials properties including low fluence effects Credibility of the RAFS structural material and DCLL design  Integrated Mockup leading to Test Blanket Module testing in ITER Credibility of the RAFS structural material and DCLL design

9. US ITER TBM RAFS Fabrication – determine detailed material and fabrication specification Basic Properties Single and Multiple Effects Testing Partially-Integrated Mockup Testing Final Design Fabrication Qualification Material alloy specification Fabrication procedures Properties - base metal & joints NDE tests and test procedures StartPrototype June FY2007 2008 2009 2010 20112012 FabRoute Dec Init R&D Oct Produce H-H TBM that meet design specifications schedule, qualification testing and safety requirements, Irradiation effects Mockup fabrication support Coordinated by R. Kurtz and A. Rowcliffe

10. US ITER TBM Fabrication discussions with US Industry have shown strong capabilities and interest

11. US ITER TBM Partially-Integrated Testing is a key part of qualification of experimental components Basic Properties Single and Multiple Effects Testing Partially-Integrated Mockup Testing Final Design Fabrication Qualification FW Heat Flux Tests PbLi Flow and Heat Transfer Tests Pressurization and Internal LOCA Tests Testing needed to: demonstrate performance provide “practice” fabrications support safety/qualification dossier data to verify Predictive Capabilities in complex geometry Existing US Facilities used in plan and cost estimate Title3DesRev StartPrototype June FY2008 2009 2010 2011 20122013 DetDesFinalRev September PrototypeDone April FinDesChng December StartTBMfab June BidPack August Coordinated by R. Nygren

12. US ITER TBM FCI development and Thermofluid MHD are highly inter-related DCLL R&D efforts Basic Properties Single and Multiple Effects Testing Partially-Integrated Mockup Testing Final Design Fabrication Qualification FCI properties and fab. FCI and MHD together determine : PbLi flow conditions and blanket temperatures / thermal loads FCI required/achievable properties Title3DesRev StartPrototype June FY2008 2009 2010 2011 20122013 DetDesFinalRev September PrototypeDone April FinDesChng December StartTBMfab June PrelDesRev July BidPack August FabRoute Dec Modeling Tools Manifold experiments FCI flow and HT experiments FCI irradiation Coordinated by Y. Katoh and S. Smolentsev Simulation FCI mockup

13. US ITER TBM SiC/SiC Flow Channel Insert  Decoupling PbLi & Fe  Electric insulation  Thermal insulation  Low primary stress  Robust to thermal stress -  T ~200C FCI/SiC Devel. & Fabrication  Tailoring k and   k(T),  (T)  Irradiation effect  Fabrication issues Thermofluid MHDStructural Analysis FCI is the key element of DCLL – its performance and fabrication must be explored prior to ITER testing  Effectiveness of FCI as electric/thermal insulator  MHD pressure drop and flow distribution  MHD flow and FCI property effects on T  FCI stresses  FCI deformations ITER DT ITER DT: Max stress <45 MPa ITER TBM  3D FCI features MHD Experiments  Manifolds UCLA Manifold Flow distribution Experiment (~1m length)

14. US ITER TBM FCI in DCLL Blanket Module  FCI is a key feature that: –Distinguishes DCLL blanket. –Makes DCLL concept attractive for DEMO and power reactors.  Two important FCI functions: –Thermally insulate Pb-Li so that the Pb-Li temperature can be considerably higher than the maximum operation temperature for steel structures. –Electrically insulate Pb-Li flow from steel structures.

15. US ITER TBM Key Requirements to FCI 1.Adequate tranverse thermal insulation –K th = 2~5 W/m-K for US DCLL TBM (assuming 5 mm FCI) 2.Adequate transverse electrical insulation –  el = 5~100 S/m for US DCLL TBM (assuming 5 mm FCI) 3.Chemical compatibility with Pb-Li –Up to the highest possible temperatures, in a flow system with strong temperature gradients, and contact with FS at lower temperature. 4.Hermeticity –Pb-Li must not “soak” into cracks or pores in order to avoid increased electrical conductivity, high tritium retention, or explosively vaporized pockets. –In general, sealing layers are required on all surfaces of the inserts. 5.Mechanical integrity –Primary and secondary stresses must not endanger integrity of FCI 6.Maintain 1-5 in a practical operation environment –Neutron irradiation in D-T phase –Developing flow conditions, temperature & field gradients –Repeated mechanical loading upon VDE and disruption events

16. US ITER TBM SiC/SiC as FCI Material  SiC/SiC has been identified to be the most promising material for FCI –Industrial maturity, radiation-resistance, chemical compatibility, etc. –Being qualified as the control rod material in US-DOE Next Generation Nuclear Power program. Tyranno-SA/PyC/FCVI

17. US ITER TBM Why are Differential Swelling and Creep Important for FCIs? ~8x10 -6 K -1  Low temperature swelling (S) in SiC –Occurs at < ~1000ºC –Negative correlation with temperature –Start at onset of irradiation –Saturate by ~1 dpa  Differential swelling (dS/dT·dT/dx) –~twice more significant than CTE –Unconstrained strain reaches 0.1%, typical unirradiated fracture strain for SiC, at  T = 120K.  Irradiation creep may eliminate the secondary stress issues –Transient irradiation creep strain exceeding 0.2% is reported for SiC. –Strong swelling-creep coupling likely exists. –No data available. Irradiation temperature-dependence of saturated swelling in SiC

18. US ITER TBM Transverse electrical conductivity measurements in 2D composite  Data for in-plane  of typical fusion grade 2D-SiC/SiC shows relatively high values ~500 S/m, likely due to highly conducting carbon inter-phase  New measurements on same material shows SIGNIFICANTLY lower  in transverse direction – 2 to 3 orders lower at 500C  The low  transverse apparently reflects the extreme anisotropy of the CVI-deposition process for SiC/SiC composite made with 2D-woven fabric layers.  Thermal conductivity still a challenge 2D SiC composite, in-plane Monolithic SiC DCLL TBM Target 2D SiC composite, transverse DC electrical conductivity measurements of 2D-Nic S/CVI-SiC composite. Measurements were made in both argon-3% H2 or dry argon. Vacuum-evaporated Au-electrodes on disc faces.

19. US ITER TBM Approach & Potential Design Benefits of SiC Foam for flow channel inserts  Improved manufacturability and lower cost compared to SiC/SiC  High strength, stiffness, and thermal stress resistance  Lower thermal conductivity than SiC/SiC  Ultramet will fabricate a flow channel insert composed of an open-cell CVD SiC foam primary structure with thin, integrally bonded and impermeable CVD SiC facesheets. ULTRAMET-DMS proposed Flow-Channel Insert configuration CVD SiC closeout layers applied to SiC foam (5X)

20. US ITER TBM Testing of foam samples in role as flow channel inserts  Disk samples (~70 mm diameter) held in contact with LM on both sides  100 C thermal gradient and variable electric current applied to the sample  Measurements of electrical and thermal conductivity as a function of thermal cycles  Looking for penetration of LM into SiC Testing rig at UCLA

21. US ITER TBM Summary of electrical and thermal conductivity measurements on SiC foam in contact with LM – no penetration observed in 100 h tests Foam SampleArea (m2)Thickness (m)Average Electrical Conductivity (S/m) Average Electrical Conductivity (W/m.k) SiC #2 With Prewetting 3.79E-039.01E-032.166.25 SiC #2 W/O Prewetting 3.79E-039.01E-036.116.25 SiC #3 With Prewetting 3.67E-031.04E-021.72E-016.78 SiC #3 W/O Prewetting 3.67E-031.04E-021.84E-016.78 SiC #4 W/O Prewetting 3.54E-031.60E-022.79E-014.53

22. US ITER TBM Compatibility of SiC With PbLi at 800 - 1200°C 17Li-Pb Mo Capsule Mo Wire Spacer SiC Crucible & Lid SiC Specimen Holder Al 2 O 3 Spacer CVD SiC Specimen Outer SS, Inconel or 602CA Capsule Before/During Test  No significant mass gains after any capsule test.  Si in PbLi only detected after highest temperature tests.  Si could come from CVD SiC specimen or capsule.  Results suggest maximum temperature is <~1100°C  Research Needs: Testing in flowing LiPb environment. Testing of SiC composites with sealing layers. Static Capsule Tests 902580650<6018.55%800°C 5000 h 2007890102518515.99%1100°C 2000 h 45016620269037015.62%1200°C 9035501160<3016.27%1100°C 10040901850<3017.49%800°C 1000 h <401270<170<40n.d.Starting NOCSiLiTest Concentrations in appm

23. US ITER TBM Thermofluid/MHD issues of DCLL Issues: oImpact of 3-D effects on pressure drop & flow distribution  Flows in the manifold region  Flows in non-uniform, 3-component ITER B-field  Pressure equalization via slots (PES) or holes (PEH)  FCI overlap regions  FCI property variations oCoupled Flow and FCI property effects on heat transfer between the PbLi and He and and temperature field in the FCI and Fe structure oFlow distribution, heat transfer, and EM loads in off-normal conditions In the DCLL blanket, the PbLI flows and heat transfer are affected by a strong magnetic field DCLL DEMO B-field

24. US ITER TBM Current DCLL design based on 2D fully developed Thermofluid MHD analysis Characterization of the general MHD phenomena in the blanket 2D simulations showing:  Effectiveness of the FCI as electric/thermal insulator  Preferred pressure equalization slot location on FCI Preliminary identification of SiC FCI properties (  and k) Estimates of the MHD pressure drop in the system MHD pressure drop reduction for different slot locations

25. US ITER TBM Current status of Thermofluid MHD R&D and PC (Cont’d.) Preliminary 3-D heat transfer analysis for DEMO, ITER HH and DT blanket modules Coupling between: - Thermofluid/MHD  Structural Analysis - Thermofluid/MHD  He Thermofluid Good start on 3-D parallel MHD software (HIMAG) and a number of research codes addressing specific MHD/heat transfer issues Temperature. ITER DT High Ha number flow computation DEMO: Ha=15,000; Re=84,000;  =100 S/m

26. US ITER TBM US strategy for DCLL Thermofluid MHD R&D Two goals: 1.To address specific 1 st ITER TBM issues via experiments and modeling 2.To develop a verified PC, enabling design and performance predictions for all ITER TBMs and DEMO blanket Two lines of activity: 1.Experimental database. Obtain experimental data on key MHD flows affecting operation and performance of the blanket for which there is little/no data available. Flow distribution in manifolds FCI effectiveness and 3D flow issues Coupled heat transfer / velocity field issues 2.Modeling tools. Develop 2D and 3D codes and models for PbLi flows and heat transfer in specific TBM/DEMO conditions. Benchmark against existing and new analytical solutions, experimental data and other numerical computations. HIMAG – arbitrary geometry 3D fully viscous and inertial parallel MHD solver 2D models and codes for specific physics issues – MHD turbulence and natural convection

27. US ITER TBM 3D HIMAG Benchmark Case against Experimental Pipe Flow Data at Ha = 6600 Case-1 B max = 2.08 T Ha = 6640 N = 11061 Re = 3986 U = 0.07 m/s Case-2 B max = 1.103 T Ha = 3500 N = 770 Re = 15909.1 U = 0.2794 m/s a = 0.0541m t = 0.00301 m x = -20a x = 15a x y z B ( C.B.Reed et al, 1987)

28. US ITER TBM Velocity profiles along the channel

29. US ITER TBM Flow Streamlines with electric potential contours Pressure drop comparison to experimental data

30. US ITER TBM Application of HIMAG to Manifold Problem  3D complex geometry and strong MHD interaction – what is the flow distribution?

31. US ITER TBM MHD effects control the flow distribution due to M- shaped velocity profile formation Ha = 1000 Re = 1000 N = 1000

32. US ITER TBM Center channel has larger flow  center channel +11.8%  side channels -5.9%  Dependence on Ha, Re and geometry must be studied – Likely to be more imbalanced at higher Ha Ha = 1000 Re = 1000 N = 1000

33. US ITER TBM MTOR Laboratory at UCLA JUPITER 2 MHD Heat Transfer Exp. in UCLA FLIHY Electrolyte Loop BOB magnet QTOR magnet and LM flow loop

34. US ITER TBM MHD Manifold Flow Distribution Experiment  ~1 m in length  Fits into BOB magnet with in-situ MHD pumping sections  Potential and pressure taps for measuring flow distribution and pressure drop  Potentially part of Jupiter III collaboration with Japan

35. US ITER TBM z x y B Inflow Outflow FCI 1.4 m1.66 m 0.3 m 0.139 m 120 mm RAFS wall 4 mm thick SiC wall 5 mm thick 139 mm z y 2 mm gap 5 mm DCLL Geometry (not to scale) for HIMAG Simulations

36. US ITER TBM 2D models for turbulence and mixed convection  Effects important for flows with strong temperature gradients, velocity jets and poorly conducting walls  Motions tend to become 2D at such high interaction parameter High Ha number flow computation DEMO: Ha=15,000; Re=84,000;  =100 S/m

37. US ITER TBM A verified predictive capability is considered a top level deliverable for a TBM program A ultimate goal of R&D and ITER testing is to provide a verified Predictive Capability (PC) that can: –Meet ITER QA verification requirements –Perform the analysis required for the design and qualification of any TBM in ITER, and –Enable interpretation and extrapolation of experimental results from laboratory experiments and from ITER TBMs. PC Analogy: The TBM can be considered the hardware, and the Predicative Capability the software necessary to exploit the hardware Basic Properties Single/Multiple Effects Testing Partially-Integrated Mockup Testing - Final Design - Qualification - Integrated Simulation Models & Theory Simulation Codes Integration and Benchmarking

38. US ITER TBM PC is included as a main branch of the WBS – similar to EU and other parties

39. US ITER TBM “Models and codes” includes simulation codes and complex physical and solid models 1.8.3.1Models and Codes 1.8.3.1.1MHD Thermofluid 1.8.3.1.2Solid breeder thermomechanics 1.8.3.1.3Tritium Permeation 1.8.3.1.4CAD 1.8.3.1.5Neutronics 1.8.3.1.6Structural/Stress 1.8.3.1.7Thermal-hydraulics...both simulation codes, and sophisticated input and models for existing codes are included DCLL solid model showing manifold region geometry in 1.8.1.1.3.1 Turbulent fluctuations in DCLL flow channel in 1.8.1.1.2.1.1

40. US ITER TBM Predictive Capabilities tasks are linked to associated R&D and Engineering Analysis activities Sample from PC Schedule: showing references to linked R&D tasks Predictive capability sufficient for design and qualification are important R&D tasks – as well as an important deliverable needed for TBM experiment operations

41. US ITER TBM Data/Code Integration, or Virtual TBM, is key for planning and interpreting ITER TBM experiments Integration of the various PC tools and data into an effective, coupled suite of capabilities that:  exchange data in a seamless and error-free manner,  are compatible with modern clusters and parallel execution  allow coupled simulation of the TBM experiments, including phenomena that are usually considered and modeled separately 1.8.3.3Data/Codes Integration 1.8.3.3.1 Integrated Strategy Development 1.8.3.3.2 Executive Routines and Data Structure 1.8.3.3.3 Integration of Simulation Capabilities and Associated Data 1.8.3.3.4 Integrated Code Benchmarking and Application –Complex designs, CAD –neutronics, –coolant flow and heat transfer –structural response, –tritium breeding, permeation and extraction

42. US ITER TBM Selection Phase Choosing analysis types (selection of codes) Choosing CAD files for different analysis Establish analysis hierarchy Preprocessor Phase CAD inputs Starting preprocessing modules for selected codes Setting up different meshes, input files Interaction control Setting up code interaction parameters and timing controls (How often to write load file, coordinate time steps between different codes) Choosing between tandem run or sequential run between codes (preserving the analysis hierarchy) Solution Phase Grid mapping / Data Ex The required interpolation routines should start when mapping is required Post processing Starting post processing modules for the different software. All results file at the same time level should be analyzed together Some analysis parameters should be able to be changed at this stage and the solution recomputed from the current level to observe the change Example Virtual TBM flow chart

43. US ITER TBM Activity Schedule for Data/Codes Integration

44. US ITER TBM Summary of the US TBM R&D / PC Activities and Technical Plan  The US TBM R&D plan is designed to provide the basis for important design, fabrication and qualification decisions. –R&D is needed to insure against risks to whole machine ($10B), not just this component - must be conservative! –If building one blanket module, or blankets for the whole machine, R&D is the essentially the same – subsequent TBM projects will be lower cost  A verified predictive capability is considered a top level deliverable  Main DCLL R&D activities include –RAFS fabrication and Partially-integrated Mockup Testing and prototypes make up >50% of projected costs –FCI development, and thermofluid MHD database and simulation tools –Other smaller activities in diagnostics, He thermofluid, PbLi compatibility and reactivity, and tritium