In-Vessel Coil System Conceptual Design Review – September, Vertical Stability Coil Structural Analyses P. Titus, July

In-Vessel Coil System Conceptual Design Review – September, MaterialSm1.5Sm 316 LN SST183Mpa (26.6 ksi)275Mpa (40ksi) 316 LN SST weld 160MPa(23.2ksi)241MPa(35ksi) Criteria for IV Coils Will be Appendix D of the In-Vessel Component Criteria Copper: Stainless Steel: This will be Fatigue Driven. Primary Loads are Supported by the Case, Thermal Stresses are Self Relieving Failure is Leak Due to Crack Propagation Also Fatigue Driven, but Must Support Primary Loads

In-Vessel Coil System Conceptual Design Review – September, ( )* 5/9 =25.1 deg C Joule Heating Loads (M. Mardenfeld Early Results) Latest results are the same or less than 25deg C except the double turn failure results. Charlie’s Design Point is now 20 deg

In-Vessel Coil System Conceptual Design Review – September, Structural Model Features 4 Model is a 10 degree cyclic symmetry model Coils are supported every 5 degrees with Clamps Temperatures modeling the Joule heat and nuclear heat Based on Nuclear Heat from Russ Feder Radial forces are computed from SQRT(1.2) MN/40 degree sector. Vertical forces are computed from SQRT(1.2) MN/40 degree sector Radial and Vertical Forces are applied concurrently Sliding gap-friction is modeled between Spine, Sheath, MgO and conductor. A Retainer Clamp is Used Rather than Weld or Braze.

In-Vessel Coil System Conceptual Design Review – September, The 2D model is swept through 10 degrees. Then regions between clamps and bolts are deleted to form the model. Present Design Iteration Mesh Generation “Feet” Modeling Welds and Vessel Connection

In-Vessel Coil System Conceptual Design Review – September, VS Structural Model Gap Elements between all MgO conductor Components SST “Spine” Displacement Constraints Model Cyclic Symmetry Gap Elements at Clamps

In-Vessel Coil System Pre-Preliminary Design Review – July Temperature from Joule Heat/Water Cooling input as a Boundary Condition

In-Vessel Coil System Conceptual Design Review – September, Nuclear Heat taken from Russ Feder’s Calculation Temperatures are calculated from a Steady State Heat Conduction Analysis

In-Vessel Coil System Pre-Preliminary Design Review – July Modeling Nuclear Heat

In-Vessel Coil System Pre-Preliminary Design Review – July Electromagnetic Loads VSFORCE= e6**.5 Some Analyses Still Use the Previous 2 MN in Each Direction

In-Vessel Coil System Conceptual Design Review – September, Disruption Inductively Driven Electromagnetic Loads 11 Around the upper VS ELM the vessel current density is 10 amps per mm^2 with the case If the current density is the same in the case as in the vessel, The case currents are as high as 10*20231=202kA Currents are comparable to Nominal 240kA currents – Thus forces are.

In-Vessel Coil System Conceptual Design Review – September, /solu bfe,all,temp,1,380 !100C esel,real,11,14 $nelem bfe,all,temp,1,400 ! Conductors 20C hotter Nall $eall Solve $save /title, Disruption + Normal Operating Loads 2e6/40deg esel,mat,1 $nelem f,all,fz,vsforce/4/46656 ! there are nodes in the conductors and 2e6 is for 40 degrees f,all,fx,-vsforce/4/46656 Nall $eall Solve $save /title, Disruption + Normal Operating Loads +Nuclear ldread,temp,last,,,,therm,rth Nall $eall Solve $save /title, Lorentz+Shared Ves Disrup Current + Normal Operating Loads 2*2e6/40deg esel,mat,2 $nelem f,all,fz,2*vsforce/4/52486 f,all,fx,-2*vsforce/4/52586 Nall $eall Solve $save Fini $/exit 1.2e6 N per 40 degree sector Vector Sum of Radial and Vertical Directions are used An additional 1.2e6 N Vector Sum of Radial and Vertical Directions are applied on the case to simulate loads from shared vessel currents LDREAD Temps from Nuclear Radiation Thermal Analysis

In-Vessel Coil System Conceptual Design Review – September, M25 Bolts – Bolt Preload + Joule Heat Load Step ~100 MPa Bolt Preload ~400 MPa Preload Eliminated Clamp Lift-Off

In-Vessel Coil System Conceptual Design Review – September, CDR Model Response, No Shared Vessel Currents

In-Vessel Coil System Conceptual Design Review – September, CDR Model Response, With Shared Vessel Currents

In-Vessel Coil System Pre-Preliminary Design Review – July PDR Model Response, With Shared Vessel Currents Lower Bolt Preload is Required

In-Vessel Coil System Conceptual Design Review – September, With the Full Current Inventory (1.2MN/40deg) in Conductors and Spine, Stresses in the Spine are Acceptable MaterialSm1.5Sm 316 LN SST183Mpa (26.6 ksi)275Mpa (40ksi) 316 LN SST weld 160MPa(23.2ksi)241MPa(35ksi)

In-Vessel Coil System Conceptual Design Review – September, Conductor Stresses -Will be qualified by fatigue analysis Conductor Stress With Joule Heat

In-Vessel Coil System Conceptual Design Review – September, Conductor Stresses -Will be qualified by fatigue analysis These Results are for the CDR 2MN Loading in Each Direction Conductor Stress With Joule Heat and Normal Operating Lorentz Loads Tensile Stresses are Low

In-Vessel Coil System Conceptual Design Review – September, Weld Stresses at the Clamp Body CDR Design at 2MN – Design Similar to PDR Design The peak weld stress of ~70 MPa tension is modest. It will provide some headroom for fatigue evaluations.

In-Vessel Coil System Conceptual Design Review – September, Weld Stresses CDR Design at 2MN – Design Similar to PDR Loads Per 10 Degree Model Section, Summed Over All All Welds LOAD STEP= 4 SUBSTEP= 1 TIME= LOAD CASE= 0 THE FOLLOWING X,Y,Z SOLUTIONS ARE IN THE GLOBAL COORDINATE SYSTEM FX FY FZ Radial VerticalToroidal TOTAL VALUES E E

In-Vessel Coil System Conceptual Design Review – September, Peak Clamp to Vessel Weld Stress CDR Design at 2MN – Design Similar to PDR MaterialSm1.5Sm 316 LN SST 183Mpa (26.6 ksi) 275Mpa (40ksi) 316 LN SST weld 160MPa(23.2ksi) 241MPa(35ksi) Peak Weld Stress Meets “Average” Static Stress Criteria

In-Vessel Coil System Conceptual Design Review – September, Mounting Bolt Stress With Adequate Preload (400 MPa), The Bolt Alternating Stress is Low.

In-Vessel Coil System Pre-Preliminary Design Review – July Joggle Model Joggle Model

In-Vessel Coil System Pre-Preliminary Design Review – July Only Copper is Modeled Only Toroidal Field is Applied Fixity is assumed where the conductor enters the splines Turns need to be shortened to Reduce the length that crosses the toroidal field

In-Vessel Coil System Conceptual Design Review – September, VS Fault Conditions (OneD Analysis) Only Radiative Cooling, 20 Minute Cooldown Between Pulses Tube Surface Temp Radiating to 373K, Tube emissivity =.3, Vessel emissivity =.8, Nuclear Heat = 1.4MW/m^3, Tube Thickness = 1.9mm 500 sec 1000 sec 1500 sec 650 K 875K 1050K Stresses Due to These TBD

In-Vessel Coil System Conceptual Design Review – September, Conclusions The VS coil conceptual design is In a comfortable design space to finish preliminary and go forward final design Conductor thermal stresses are low because of the axisymmetry of the winding (no corner bends as in the ELM). Lead break-outs will have to preserve this feature Case stresses are high under the clamp details but with some slight modifications, these will meet static and fatigue allowables. Bolt stresses during the disruption are within the allowables of high strength bolts. Preloading the bolts eliminates the alternating component. Assuming shared vessel currents during the disruption, may be overly conservative. Should current density be halved? Does Proximity to the ELM Coils Still Make the Clamp Bolting Challenging – Investigate Common ELM/VS Clamps?

VS Issues and Resolution Plan IssueResolutionPre/Post October PDR Interpretation of Loading (1.2MN Vector Sum) is Lower than CDR Shared Current Loads Are also lower because they are assumed comparable Resolve Interpretation of LoadsPre Conductor thermal stresses are low because of the axisymmetry of the winding (no corner bends as in the ELM). Lead break-outs will have to preserve this feature Interaction of conductor, MgO and Sheath at Lead Break- outs is very similar to elm coil corners – Will have a common solution/qualification. Pre “bump” over the lead break-out and the leads crossing the TF field will need supports at shorter spans Add brackets as required.Pre Uncertainty in MgO properties and behavior Characterization of MgO from testing underway needs to be folded into analysis Pre? 28 ITER IVC IDR July 2010

In-Vessel Coil System Conceptual Design Review – September, Clamp Bolt Stress Comparable to FEA Results