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

ITER In-Vessel Coils (IVC)Interim Design Review

Thermal Structural FEA of Feeders

A Brooks

July 27, 2010

July 26-28, 2010 1ITER_D_353BL2

Middle and Lower ELM FeedersAnalysis 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 26-28 July 2010

Feeder Geometry

Modeling Interface is up to but not including Couplings

CATIA Model Exported as Step File and Imported into ProE3ITER IVC IDR 26-28 July 2010

Modeling• Modeling used section data and sweeping curves from

CAD Model to create mesh using FORTRAN Codes

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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

OH/PF Coil Geometry and CurrentsCoil Rc Zc Dr Dz MA-TurnsOH1 1.688 5.071 0.749 1.979 4.03OH2 1.688 3.043 0.749 1.979 -10.98OH3 1.688 1.014 0.749 1.979 -18.11OH4 1.688 -1.014 0.749 1.979 -18.24OH5 1.688 -3.043 0.749 1.979 -8.99OH6 1.688 -5.071 0.749 1.979 5.94PF1 3.954 7.557 0.968 0.976 5.07PF2 8.309 6.53 0.649 0.595 -2.22PF3 11.935 3.265 0.708 1.125 -6.23PF4 11.905 -2.243 0.649 1.125 -5.05PF5 8.395 -6.73 0.82 0.945 -7.39PF6 4.287 -7.557 1.633 0.976 17.67

Initial Scenario Data UsedOther Scenarios need to be considered

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Material Properties

• Preliminary Analysis – Using Linear Properties

Material Properties (at 100C for linear checkout) CuCRZr MgO SS

Electrical Resitivity rsvx 1 2.71E-08 2.71E+01 7.70E-07 Ohm-mRelative Permeablity murx 1 1 1 1Elastic Modulus ex 1 1.25E+11 3.00E+11 1.93E+11 MpaPoisson's Ratio nuxy 1 0.3 0.3 0.3Thermal Expansion Coef alpx 1 1.71E-05 1.28E-05 1.65E-05 m/m-CDensity dens 1 8854 2200 7899 kg/m3Thermal Conductivity kxx 1 333 2.36 15.48 w/m-CHeat Capacitance c 1 383 940 513 J/kg-C

6ITER IVC IDR 26-28 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

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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

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Applied Nuclear Heating Heat Generation Rates

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Resulting Steady State Temperatures

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Mid Section of Feeders

Resulting Steady State Temperaturesat ends of Feeder Tees

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With Cold Inlet Water in Bottom Turn, Hot Spot is on TopWith Cold Inlet Water in Top Turn, Hot Spot is on Bottom

Water Pressure in Tubes

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Toroidal Field

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1/R Field plusself field fromfeeders

Vertical Field

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Without Plasma With Plasma

Initial Results ignoredplasma field, but for outboard componentsvertical field is increased

Radial Field

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Without Plasma With Plasma

As is radial field

Global Von Mises Stresses

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Global Displacements

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EM Thermal

EM vs Thermal Loads Impact onVon Mises Stress

View from Back

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EM Thermal

EM vs Thermal Loads Impact onDisplacements

Von Mises Stress at Mid Section

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Temperature GradientBetween base and VVAnd assumption of fixedSupport causes large stress

Von Mises Stress at Lower End Section

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Local stress concentrationat weld

Von Mises Stress in Tubes at Mid ELM

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High Outer fiber stressFrom bending of Unsupported tube

Von Mises Stress at Mid Section with Perfect Thermal Contact to VV

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Stress in SS base drops significantly278=>150 MPa

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Von Mises Stress at Lower Section with Perfect Thermal Contact to VV

Local stress concentrationat weld stillpersists

Von Mises Stress at Lower Section with Perfect Thermal Contact to VV

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Only minor change inOuter fiber stressFrom 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

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Calculated Stress in Fully SupportedSection (left)

Sm Endurance Limit (No Defects)

Conductor, Intermediate Strength CuCrZr

74 MPa 133 MPa 96 MPa

Conduit, 316LN 131 MPa 147 MPa 196 MPa

Support, 316LN 150 MPa 147 MPa 196 Mpa

MgO 163 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

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Issues and Resolution Plan

Issue Resolution Pre/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 Welds Refine 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 26-28 July 2010