ITER In-Vessel Coils (IVC) Interim Design Review Thermal Structural FEA of Feeders A Brooks July 27, 2010 July 26-28, 20101ITER_D_353BL2

Middle and Lower ELM Feeders Analysis Status Overview Geometry Modeling & Meshing –Feeders –Background Field Coils Material Properties Boundary Conditions –Temperature –Implied Structural Supports Loading –Ohmic Heating –Nuclear Heating –Lorentz Forces –Water Pressure Preliminary Results Stress Allowables and Acceptance Criteria (TBD) Ongoing Analyses Issues and Resolution Plan 2ITER IVC IDR July 2010

Feeder Geometry Modeling Interface is up to but not including Couplings CATIA Model Exported as Step File and Imported into ProE 3ITER IVC IDR July 2010

Modeling Modeling used section data and sweeping curves from CAD Model to create mesh using FORTRAN Codes 4ITER IVC IDR July 2010

PF and TF Field Drivers PF Coils Modeled Explicitly in ANSYS TF Coil uses 1/R from Center Filament to Provide 5.3T at 6.2m Initial Scenario Data Used Other Scenarios need to be considered 5ITER IVC IDR July 2010

Material Properties Preliminary Analysis – Using Linear Properties 6ITER IVC IDR July 2010

Boundary Conditions Preminary Analyses Assumed MgO bonded to Cu Tube and SS Sheath –Impact of debonding to be addressed using low shear modulus Supports not modeled explicidly, constraints added at support locations –Initial runs assumed tee fully bonded to VV structurally but isolated thermally (conservative?) –Tube Ends Fully Constrained at Couplings (assumes support will exist) Only Cooling from Water Tubes –ID held at fixed temperature: 100C at inlet, 130 at outlet –Radiation from outer surfaces to VV and surroundings not included –Conduction cooling to VV ignored 7ITER IVC IDR July 2010

Loading Ohmic Heating 15 kA DC Current in Cu –Directions chosen to induce worse moments of Tee Section – Top Turns in one direction, bottom opposite –Note: Since Temperature is constrained at ID (perfect cooling) Ohmic heating has only small effect on Cu transverse temperature gradients. Nuclear Heating assumes 1.4 MW/m2 at Plasma facing surface and decays as e -x/  where  cm Lorentz Forces from 15kA crossed with local field from OH/PF and TF (see plots) 4.4 MPa (638psi) Water Pressure in Tubes 8ITER IVC IDR July 2010

Applied Nuclear Heating Heat Generation Rates 9ITER IVC IDR July 2010

Resulting Steady State Temperatures 10ITER IVC IDR July 2010 Mid Section of Feeders

Resulting Steady State Temperatures at ends of Feeder Tees ITER IVC IDR July With Cold Inlet Water in Bottom Turn, Hot Spot is on Top With Cold Inlet Water in Top Turn, Hot Spot is on Bottom

Water Pressure in Tubes 12ITER IVC IDR July 2010

Toroidal Field 13ITER IVC IDR July /R Field plus self field from feeders

Vertical Field 14ITER IVC IDR July 2010 Without PlasmaWith Plasma Initial Results ignored plasma field, but for outboard components vertical field is increased

Radial Field 15ITER IVC IDR July 2010 Without PlasmaWith Plasma As is radial field

Global Von Mises Stresses 16ITER IVC IDR July 2010

Global Displacements ITER IVC IDR July

ITER IVC IDR July EM Thermal EM vs Thermal Loads Impact on Von Mises Stress View from Back

ITER IVC IDR July EMThermal EM vs Thermal Loads Impact on Displacements

Von Mises Stress at Mid Section 20ITER IVC IDR July 2010 Temperature Gradient Between base and VV And assumption of fixed Support causes large stress

Von Mises Stress at Lower End Section 21ITER IVC IDR July 2010 Local stress concentration at weld

Von Mises Stress in Tubes at Mid ELM 22ITER IVC IDR July 2010 High Outer fiber stress From bending of Unsupported tube

Von Mises Stress at Mid Section with Perfect Thermal Contact to VV ITER IVC IDR July Stress in SS base drops significantly 278=>150 MPa

ITER IVC IDR July Von Mises Stress at Lower Section with Perfect Thermal Contact to VV Local stress concentration at weld still persists

Von Mises Stress at Lower Section with Perfect Thermal Contact to VV ITER IVC IDR July Only minor change in Outer fiber stress From bending of Unsupported tube

Stress Allowables and Acceptance Criteria Need to ensure compliance with Appendix D of the In-Vessel Component Criteria specifies the Stress Acceptance Criteria. Not there yet for unsupported tubes and welds. MgO TBD ITER IVC IDR July Calculated Stress in Fully Supported Section (left) SmEndurance Limit (No Defects) Conductor, Intermediate Strength CuCrZr 74 MPa133 MPa96 MPa Conduit, 316LN131 MPa147 MPa196 MPa Support, 316LN150 MPa147 MPa196 Mpa MgO163 MPa??

Ongoing Analyses Alternate Support Concepts need to be evaluated to reduce stresses –For Tee –For Tubes Additional Load Cases need to be identified and run –Normal Operating Scenarios –Disruption Scenarios –Transient Response Characterization of MgO, which is in progress, needs to be folded into analyses –Material Properties –Interface behavior with Cu Tube and SS Casing ITER IVC IDR July

Issues and Resolution Plan IssueResolutionPre/Post October High Stresses in unsupported region of tubes Design will need to provide additional supports while not over constraining and restrict thermal expansion Pre High Stresses in WeldsRefine modeling and/or increase weld section. Solving above support of tubes may also relieve local stress Pre High Stresses in Base Support if poor thermal connection to VV while rigidly held Need to ensure supports to VV provide adequate heat sinking. Pre Uncertainty in MgO properties and behavior Characterization of MgO from testing underway needs to be folded into analysis Pre? 28ITER IVC IDR July 2010