FIRE Vacuum Vessel and Remote Handling Overview B. Nelson, T. Burgess, T. Brown, D. Driemeyer, H-M Fan, K. Freudenberg, G. Jones, C. Kessel, P. Ryan, M. Sawan, M. Ulrickson, D. Strickler, D. Williamson FIRE Physics Validation Review March 31, 2004

31 March 2004FIRE Physics Validation Review: Vacuum Vessel and Remote Handling 2 Presentation Outline  Vacuum Vessel  Design requirements  Design concept and features  Analysis to date  Status and summary  Remote Handling  Maintenance Approach & Component Classification  In-Vessel Transporter  Component Replacement Time Estimates  Balance of RH Equipment  Design and analysis are consistent with pre-conceptual phase, but demonstrate basic feasibility of concepts

31 March 2004FIRE Physics Validation Review: Vacuum Vessel and Remote Handling 3 FIRE vacuum vessel

31 March 2004FIRE Physics Validation Review: Vacuum Vessel and Remote Handling 4 Vacuum vessel functions  Plasma vacuum environment  Primary tritium confinement boundary  Support for in-vessel components  Radiation shielding  Aid in plasma stabilization  conducting shell  internal control coils  Maximum access for heating/diagnostics

31 March 2004FIRE Physics Validation Review: Vacuum Vessel and Remote Handling 5 Vacuum vessel parameters  Configuration: Double wall torus  Shielding water + steel with 60% packing factor  Volume of torus interior53 m^3  Surface Area of torus interior112 m^2  Facesheet thickness15 mm  Rib thickness mm  Weight of structure, incl ports 65 tonnes  Weight of torus shielding100 tonnes  Coolant  Normal OperationWater, < 100C, < 1 Mpa  Bake-outWater ~150C, < 1 Mpa  Materials  Torus, ports and structure316LN ss  Shielding304L ss (tentative)

31 March 2004FIRE Physics Validation Review: Vacuum Vessel and Remote Handling 6 Vessel port configuration

31 March 2004FIRE Physics Validation Review: Vacuum Vessel and Remote Handling 7 Vessel ports and major components Divertor piping Cryopump Midplane port w/plug Divertor

31 March 2004FIRE Physics Validation Review: Vacuum Vessel and Remote Handling 8 Nuclear shielding concept  Vessel shielding, port plugs and TF coils provide hands-on access to port flanges  Port plugs weigh ~7 tonnes each as shown, assuming 60% steel out to TF boundary

31 March 2004FIRE Physics Validation Review: Vacuum Vessel and Remote Handling 9 Active control coils, segmented into octants IB and OB passive stabilizing conductor Active and passive stabilizing sys.  passive plates ~25 mm thick copper with integral cooling

31 March 2004FIRE Physics Validation Review: Vacuum Vessel and Remote Handling 10 Passive conductor is also heat sink  Copper layer required to prevent large temperature gradients in VV due to nuclear heating, PFCs  Passive plates are required in most locations anyway  PFCs are conduction cooled to copper layer  Reduces gradient in stainless skin  Extends pulse length VVPFC Tile Cu Passive stabilizer Cu filler (can be removed to allow space for mag. diag.) Gasket VV splice plate

31 March 2004FIRE Physics Validation Review: Vacuum Vessel and Remote Handling 11 FIRE and ITER first wall concepts similar BE, Cu, SSt Detachable FW panel Cooling integral with FW panel (requires coolant connections to FW) ITER FIRE BE, Cu, SSt Detachable FW tiles Cooling integral with Cu bonded to VV

31 March 2004FIRE Physics Validation Review: Vacuum Vessel and Remote Handling 12 VV octant subassy w/passive structure Vessel octant prior to welding outer skin between ribs Outboard passive conductor Inboard passive cond.

31 March 2004FIRE Physics Validation Review: Vacuum Vessel and Remote Handling 13 Vessel octant subassembly fab. (2)  Octant-to-octant splice joint requires double wall weld  All welding done from plasma side of vessel  Splice plates used on plasma side only to take up tolerance and provide clearance  Plasma side splice plate wide enough to accommodate welding the coil side joint

31 March 2004FIRE Physics Validation Review: Vacuum Vessel and Remote Handling 14 Vessel analysis  Vessel subjected to numerous loading conditions  Normal operation (gravity, coolant pressure, thermal loads, etc.)  Disruption (including induced and conductive (halo) loads  Other loads (TF current ramp, seismic, etc.)  Preliminary FEA analysis performed  Linear, static stress analysis  Linear, transient and static thermal analyses  Main issues are disruption loads, thermal stresses

31 March 2004FIRE Physics Validation Review: Vacuum Vessel and Remote Handling 15 Vacuum vessel mechanical loads

31 March 2004FIRE Physics Validation Review: Vacuum Vessel and Remote Handling 16 Disruption effects on VV  Disruptions will cause high loads on the VV due to induced currents and conducting (halo) currents flowing in structures  Direct loads on vessel shell and ribs  Direct loads on passive plates  Reaction loads at supports for internal components  Divertor assemblies and piping  FW tiles  Port plugs / in-port components (e.g. RF antennas)  Dynamic effects should be considered, including:  Transient load application  Shock loads due to gaps in load paths (gaps must be avoided)  All loads should be considered in appropriate combinations e.g. Gravity + coolant pressure + VDE + nuclear / PFC heating + Seismic + …

31 March 2004FIRE Physics Validation Review: Vacuum Vessel and Remote Handling 17 TSC runs confirm induced currents will concentrate in passive structures  Several TSC disruption simulations prepared by C. Kessel  VDE simulation used as basis for further analysis

31 March 2004FIRE Physics Validation Review: Vacuum Vessel and Remote Handling 18 VDE analysis based on TSC runs  TSC output used to create drivers for Eddycuff model of VV  Peak loads applied to ANSYS model of VV  Halo loads from TSC mapped directly onto VV model Copper Plates Inner Face Sheet Outer Face Sheet EDDYCUFF EM ModelANSYS Structural Model

31 March 2004FIRE Physics Validation Review: Vacuum Vessel and Remote Handling 19 Plasma Evolution (TSC), from earlier data I (A) 10-ms300-ms301-ms ms302.6-ms Reduced Filament Model (EDDYCUFF) TSC Filaments

31 March 2004FIRE Physics Validation Review: Vacuum Vessel and Remote Handling 20 Constant Current Vectors Proportional Current Vectors Typical Induced Eddy Currents

31 March 2004FIRE Physics Validation Review: Vacuum Vessel and Remote Handling 21 Current vs Time, Slow VDE (1 MA/ms)

31 March 2004FIRE Physics Validation Review: Vacuum Vessel and Remote Handling 22 Typical EM loads due to Induced Current Max force = -1 MN radial, +0.7 MN vertical per 1/16 sector (~11 MN tot)

31 March 2004FIRE Physics Validation Review: Vacuum Vessel and Remote Handling 23 Total Force vs time, induced + halo currents F(lbs) t(s) FZFZ FRFR 1 MA/ms VDE Case 2Case 1

31 March 2004FIRE Physics Validation Review: Vacuum Vessel and Remote Handling 24 Typ. EM Force distr. due to Halo Current Mapped directly from TSC to ANSYS, Halo current = 12-25% Ip Max force = MN radial, +1.2 MN vert. per 1/16 sector

31 March 2004FIRE Physics Validation Review: Vacuum Vessel and Remote Handling 25 Y X Z Pin 1 Reaction Fx=12662 Fz=10708 Pin 2 Reaction Fx= Fz=6614 Lug 1 Reaction Fx=35121 Fy=40107 Fz=6987 Lug 2 Reaction Fx= Fy= Fz=-6473 Forces are in pounds Divertor loads from current loop  Loads based on PC-Opera analysis *ref Driemeyer, Ulrickson

31 March 2004FIRE Physics Validation Review: Vacuum Vessel and Remote Handling 26 Combined stress, with VDE  Stresses due to gravity, coolant pressure, vacuum, VDE  VDE load includes direct EM loads on vessel (induced current and halo) and non-halo divertor loads 1.5Sm = 28 ksi (195 Mpa) VV Torus Ports Stress is in psi

31 March 2004FIRE Physics Validation Review: Vacuum Vessel and Remote Handling 27 Divertor attachment local stresses  Global model not adequate for analysis  Detailed model indicates adequate design Stress is in psi 1.5Sm = 28ksi (195 Mpa) Reinforced pins near connection points Increased hole Diameter to 0.7” Modified rib thickness to correct values Extended pins through the ribs and attached them to the outer shell

31 March 2004FIRE Physics Validation Review: Vacuum Vessel and Remote Handling 28 Nuclear heating and thermal effects  Vacuum vessel is subject to two basic heat loads:  Direct nuclear heating from neutrons and gammas  Heating by conduction from first wall tiles (which in turn are heated by direct nuclear heating and surface heat flux)  A range of operating scenarios is possible, but the baseline cases for analysis assume:  150 MW fusion power  100 W/cm^2 surface heat load assumed on first wall,  45 W/cm^2 is current baseline (H-mode)  > 45 W/cm^2 for AT modes  pulse length of 20 seconds (H-mode - 10T, 7.7 MA)  Pulse length of 40-ish seconds (AT mode - 6.5T, 5 MA)  Vessel is cooled by water  Flowing in copper first wall cladding  Flowing between walls of double wall structure

31 March 2004FIRE Physics Validation Review: Vacuum Vessel and Remote Handling 29 Heat loads on vessel and FEA model  Fusion power of 150 MW  Surface heat flux is variable, 0, 50,100, and 150 W/cm 2 analyzed D CB Tile, (36 mm) Cu cladding Double wall Vac Vessel A

31 March 2004FIRE Physics Validation Review: Vacuum Vessel and Remote Handling 30 2-D temp distr (100W/cm 2 surface flux) Inboard midplaneOutboard midplane 20 s pulse 40 s pulse 377 C 619 C 622 C 383 C Be limit ~ 600C

31 March 2004FIRE Physics Validation Review: Vacuum Vessel and Remote Handling 31 Peak Be temp vs heat flux, pulse length Be limit

31 March 2004FIRE Physics Validation Review: Vacuum Vessel and Remote Handling 32 Nuclear heating distribution* * Ref M. Sawan Neutron wall loading Volumetric heating: plasma side, ss coil side, ss divertor

31 March 2004FIRE Physics Validation Review: Vacuum Vessel and Remote Handling 33 Typical 3-D temp distribution in VV

31 March 2004FIRE Physics Validation Review: Vacuum Vessel and Remote Handling 34 VV thermal deformation and stress High stress region localized Stress < 3xSm ( 56 ksi) Typical Deformation Peak Stress is in psi

31 March 2004FIRE Physics Validation Review: Vacuum Vessel and Remote Handling 35 Combined stresses, 40 s pulse  Nuclear heating, gravity, coolant pressure, vacuum Max Stress = 23 ksi, < 3Sm (56ksi) Max Deflection = in. Stress is in psi

31 March 2004FIRE Physics Validation Review: Vacuum Vessel and Remote Handling 36 Combined stress, 10T, 7.7MA, 20 s pulse, with VDE is worst loading condition  Nuclear heating, gravity, coolant pressure, vacuum, slow VDE Stress is in psi 3xSm Max Stress = 58 ksi, > 3Sm (56ksi), but very localized

31 March 2004FIRE Physics Validation Review: Vacuum Vessel and Remote Handling 37 Combined stress, 6.5T, 5 MA, 40 s pulse, with VDE – not as severe as high field case  Nuclear heating, gravity, coolant pressure, vacuum, slow VDE Stress is in psi Max Stress = 46 ksi, < 3Sm (56ksi), also very localized

31 March 2004FIRE Physics Validation Review: Vacuum Vessel and Remote Handling 38 Preliminary VV stress summary (1) Normal, High field (10T, 7.7 MA), 20 s pulse operation – O.K.

31 March 2004FIRE Physics Validation Review: Vacuum Vessel and Remote Handling 39 Preliminary VV stress summary (2) High field (10T, 7.7 MA), 20 s pulse with VDE – a little high

31 March 2004FIRE Physics Validation Review: Vacuum Vessel and Remote Handling 40 Preliminary VV stress summary (3) Normal, Low field (6.5T, 5 MA), 40 s pulse operation – O.K.

31 March 2004FIRE Physics Validation Review: Vacuum Vessel and Remote Handling 41 Preliminary VV stress summary (4) Low field (6.5T, 5 MA), 40 s pulse with VDE – O.K.

31 March 2004FIRE Physics Validation Review: Vacuum Vessel and Remote Handling 42 Conclusions of vessel analysis  Can vessel achieve normal operation? YES  Can vessel achieve pulse length? YES  20 second pulse appears achievable  40 second pulse should be achievable but depends on surface heat flux distribution and Be temperature  Can vessel take disruption loads? ITS CLOSE  Some local stresses over limit, but local reinforcement is possible  Additional load cases must be run

31 March 2004FIRE Physics Validation Review: Vacuum Vessel and Remote Handling 43 What analysis tasks are next?  Optimized geometry and refined FEA models  Dynamic analysis with temporal distribution of VDE loads  Fatigue analysis, including plastic effects  Seismic analysis  Plastic analysis  Limit analysis

31 March 2004FIRE Physics Validation Review: Vacuum Vessel and Remote Handling 44 Longer term issues for FIRE  Refine design  Develop design of generic port plug  Optimize divertor attachments for stress, remote handling  Design internal plumbing and shielding  Re-design / optimize gravity supports  Perform needed R&D  Select/verify method for bonding of copper cladding to vessel skin  Select/verify method for routing of cooling passages into and out of cladding  Develop fabrication technique for in-wall active control coils  Perform thermal and structural tests of prototype vessel wall, with cladding, tubes, tiles, etc. (need test facility)  Verify assembly welding of octants and tooling for remote disassembly/reassembly (need test facility)

31 March 2004FIRE Physics Validation Review: Vacuum Vessel and Remote Handling 45 Remote Handling Overview

31 March 2004FIRE Physics Validation Review: Vacuum Vessel and Remote Handling 46 Remote Handling*  Maintenance Approach & Component Classification  In-Vessel Transporter  Component Replacement Time Estimates  Balance of RH Equipment *ref T. Burgess

31 March 2004FIRE Physics Validation Review: Vacuum Vessel and Remote Handling 47 Remote Maintenance Approach  Hands-on maintenance employed to the fullest extent possible. Activation levels outside vacuum vessel are low enough to permit hands-on maintenance.  In-vessel components removed as integral assemblies and transferred to the hot cell for repair or processing as waste.  In-vessel contamination contained by sealed transfer casks that dock to the VV ports.  Midplane ports provide access to divertor, FW and limiter modules. Port mounted systems (heating and diagnostics) are housed in a shielded assembly that is removed at the port interface.

31 March 2004FIRE Physics Validation Review: Vacuum Vessel and Remote Handling 48 Remote Maintenance Approach (2)  Upper and lower auxiliary ports house diagnostic and cryopump assemblies that are also removable at the port interface.  Remote operations begin with disassembly of port assembly closure plate.  During extended in-vessel operations (e.g., divertor changeout), a shielded enclosure is installed at the open midplane port to allow human access to the ex-vessel region.  Remote maintenance drives in-vessel component design and interfaces. Components are given a classification and preliminary requirements are being accommodated in the layout of facilities and the site.

31 March 2004FIRE Physics Validation Review: Vacuum Vessel and Remote Handling 49 Remote Handling, Classification of Components * Activation levels acceptable for hands-on maintenance Class 1Class 2Class 3Class 4* Divertor Modules Limiter Modules Midplane Port Assemblies - RF heating - diagnostics First Wall Modules Upper and Lower Horiz. Auxiliary Port Assemblies - cryopumps - diagnostics Vacuum Vessel Sector with TF Coil Passive Plates In-Vessel Cooling Pipes - divertor pipes - limiter pipes Toroidal Field Coil Poloidal Field Coil Central Solenoid Magnet Structure

31 March 2004FIRE Physics Validation Review: Vacuum Vessel and Remote Handling 50 In-Vessel Remote Handling Transporter Cantilevered Articulated Boom (± 45° coverage)  Complete in-vessel coverage from 4 midplane ports.  Local repair from any midplane port.  Handles divertor, FW modules, limiter (with component specific end- effector).  Transfer cask docks and seals to VV port and hot cell interfaces to prevent spread of contamination.

31 March 2004FIRE Physics Validation Review: Vacuum Vessel and Remote Handling 51 VV to Cryostat seal VV port flange Midplane port plug Connecting plate Cryostat panel Port plug designed for RH  Plug uses ITER-style connection to vessel, accommodates transfer cask

31 March 2004FIRE Physics Validation Review: Vacuum Vessel and Remote Handling 52 In-Vessel Remote Handling (2) Divertor and baffle handled as one unit

31 March 2004FIRE Physics Validation Review: Vacuum Vessel and Remote Handling 53  Six (6) positioning degrees of freedom provided by boom (2 DOF) and end-effector (4 DOF)  Module weight = 800 kg Divertor Handling End-Effector Transport positionInstallation position

31 March 2004FIRE Physics Validation Review: Vacuum Vessel and Remote Handling 54 Component Maintenance Frequency and Time Estimates * Includes active remote maintenance time only. Actual machine shutdown period will be longer by ~ > 1 month. ** Based on single divertor module replacement time estimate. † Based on midplane port replacement time estimate. Component or OperationRH ClassExpected FrequencyMaintenance Time Estimate* Divertor Modules 1 TBD replacements > 2 One module: 3.3 weeks Limiter ModulesAll (32) modules: 5.9 months Midplane Port AssembliesOne module: 3.3 weeks In-vessel Inspection Frequent deployment Bank (5?) modules: 3.5 weeks FW Modules 2 TBD replacements ≤ 2 One module: 3.3 weeks** Combined FW and Divertor ModulesAll (#TBD) modules: TBD Auxiliary Port Assemblies †12 month time target Vacuum Vessel Sector with TF Coil 3 Replacement not expected TBD, replacement must be possible and would require extended shutdown Passive Plates In-Vessel Cooling Pipes

31 March 2004FIRE Physics Validation Review: Vacuum Vessel and Remote Handling 55 Remote Handling Equipment Summary  In-Vessel Component Handling System  In-vessel transporter (boom), viewing system and end-effectors (3) for: divertor module, first wall / limiter module and general purpose manipulator  In-Vessel Inspection System  Vacuum compatible metrology and viewing system probes for inspecting PFC alignment, and erosion or general viewing of condition  One of each probe type (metrology and viewing) initially procured  Port-Mounted Component Handling Systems  Port assembly transporters (2) with viewing system and dexterous manipulator for handling port attachment and vacuum lip-seal tools  Includes midplane and auxiliary port handling systems

31 March 2004FIRE Physics Validation Review: Vacuum Vessel and Remote Handling 56 Remote Handling Equipment Summary (2)  Component & Equipment Containment and Transfer Devices  Cask containment enclosures (3) for IVT, midplane and auxiliary port  Double seal doors in casks with docking interfaces at ports and hot cell interfaces  Cask transport (overhead crane or air cushion vehicles TBD) and support systems  Portable shielded enclosure (1) for midplane port extended opening  Remote Tooling  Laser based cutting, welding and inspection (leak detection) tools for:  vacuum lip-seal at vessel port assemblies (2 sets)  divertor and limiter coolant pipes (2 sets)  Fastener torquing and runner tools (2 sets)  Fire Site Mock-Up  Prototype remote handling systems used for developing designs are ultimately used at FIRE site to test equipment modifications, procedures and train operators  Consists of prototypes of all major remote handling systems and component mock- ups (provided by component design WBS)

31 March 2004FIRE Physics Validation Review: Vacuum Vessel and Remote Handling 57 Some generic issues for ITER/FIRE  Develop ASME code for Fusion (Section III, Division 4) to avoid force fitting designs to Section III  Develop remote, in-vessel inspection systems  leak detection  metrology  Detection of incipient failure modes, like cracks  Create a qualification / test facility for in-vessel and in-port components to quantify and improve RAM  Thermal environment  Vacuum environment  Mechanical loading, shock, fatigue  Remote handling capability