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The ITER Magnet System:Status of Design and Procurement
� Introduction� ITER Magnet System Design� ITER Magnet System R&D� Main Manufacturing Challenges� Procurement Sharing and Schedule�Summary
H. Rajainmäki, A. Bonito-Oliva, C. Sborchia and A. VostnerF4E Magnet Group, Barcelona
Hannu Rajainmäki, Summer School, Kullaa, 17 June 2008 Slide 2
Intro – Tokamak
• ITER uses the TOKAMAK magnetic confinement concept:
Hannu Rajainmäki, Summer School, Kullaa, 17 June 2008 Slide 3
Intro - The core of ITER
Toroidal Field CoilNb3Sn, 18, wedged
Central SolenoidNb3Sn, 6 modules
Poloidal Field CoilNb-Ti, 6
Vacuum Vessel9 sectors
Port Plugheating/current drive, test blanketslimiters/RHdiagnostics
Cryostat24 m high x 28 m dia.
Blanket440 modules
Torus Cryopumps, 8
Major plasma radius 6.2 m
Plasma Volume: 840 m3
Plasma Current: 15 MA
Typical Density: 1020 m-3
Typical Temperature: 20 keV
Fusion Power: 500 MWMachine mass: 23350 t (cryostat + VV + magnets)- shielding, divertor and manifolds: 7945 t + 1060 port plugs- magnet systems: 10150 t; cryostat: 820 t
Divertor54 cassettes
Hannu Rajainmäki, Summer School, Kullaa, 17 June 2008 Slide 4
Intro – ITER in practice
• ITER tokamakbuilding - full of auxiliaries
Hannu Rajainmäki, Summer School, Kullaa, 17 June 2008 Slide 5
Intro – Superconducting Magnets
� The development of superconducting magnets for fusion started inthe 1970’s (for example the T-7 and T-15 at Kurchatov Institute with forced flow and flat cable embedded in Cu), in the quest to achieve higher magnetic fields and longer plasma pulses.
� Tore Supra and other superconducting devices with NbTisuperconductors started operation in 1980’s-1990’s.
� Advanced multi-strand Nb3Sn superconductors have been developed to increase the operating magnetic fields.
� Cable-in-conduit conductors (CICC) have been selected due to the large volume, energy and required stability for these magnets.
� The development to magnets for steady-state fusion devices has included the ITER Model Coils in the late 1990’s.
� Introduction� ITER Magnet System Design� ITER Magnet System R&D� Main Manufacturing Challenges� Procurement Sharing and Schedule�Summary
Hannu Rajainmäki, Summer School, Kullaa, 17 June 2008 Slide 7
48 superconducting coils:– 18 TF coils– 6 CS modules– 6 PF coils– 9 pairs of CC– Feeders
ITER Magnet System
41 GJ vs. 10.5 GJ magnetic energy in the 27 km Tunnel in the Large Hadron Collider at CERN
Hannu Rajainmäki, Summer School, Kullaa, 17 June 2008 Slide 8
Magnet Design Features
� TF & CS Coils use Nb3Sn superconductor due to large operating field (TF 11.8 T, CS 13.0 T)
� TF Coils wound in double pancakes, thin wall circular conductors embedded in stainless steel radial plates
� CS Coils wound in hexa- or quadru-pancakes with thick wall circular-in-square conductors
� PF Coils are manufactured in NbTi, since operating field is < 6.5 T, wound in double pancakes with circular-in-square conductors
� Stainless Steel Jackets are used in the superconducting coils and they are designed to operate at high operating fields and for a large number of cycles (60,000)
� Stainless Steel TF Coil Cases with their intercoil structures form the main support structure of the magnet system
� Composite Pre-compression Rings at the inner leg of the TF coils to relieve tensile stresses and fatigue in the structures
� High Strength Insulated Shear Keys and Bolts for the connection at inner and outer intercoil structures
Hannu Rajainmäki, Summer School, Kullaa, 17 June 2008 Slide 9
Main Design Issues
�� Large stored energyLarge stored energy � impact on conductor design and insulation voltages
�� Large current and forces:Large current and forces:� Conductor degradation under electro-magnetic load� Stringent mechanical requirements on conductor jackets� Large steel fabrication (welding, forging, etc.) with tight
tolerance requirements for support structures
�� Large nuclear heatingLarge nuclear heating on conductor � impact on cooling requirements
�� Neutron irradiationNeutron irradiation � impact on insulation selectionimpact on insulation selection
�� High electric voltage (in vacuum)High electric voltage (in vacuum) � impact on insulation selection and quality control procedures
Hannu Rajainmäki, Summer School, Kullaa, 17 June 2008 Slide 10
Conductor Concept
� High amperage conductor (large ampere turns and acceptable voltages)
� Large heat removal capability (nuclear heat, AC loss, …)� High stability (local disturbances and peak loads) � High mechanical strength (hoop and out of plane forces)� Quench protection (hot spot limitation)
RequirementsRequirements
SolutionSolution� Large number of parallel superconducting strands to enable high currents� Cabling with ~1/3 void between strands for coolant (supercritical He)� Outer jacket of high strength material to withstand high loads� Flexible design: variable currents by changing size
→→→→ Cable-in-Conduit Conductor
Hannu Rajainmäki, Summer School, Kullaa, 17 June 2008 Slide 11
Conductor DesignSub-cable Wrap Central Cooling Channel
Spiral
S/C Strand
Cu Strand
Cable Wrap
Jacket
Sub-cable
• All four magnet systems (CS, TF, PF and CC) are using the same concept • Strand type (NbTi or Nb3Sn) defined by max. field• Number of strands defined by nominal current, typically 1000 strands in 6 bundles• Supercritical He flows in void• Conductor operating conditions:
���� 5K with margin of 0.7K for Nb3Sn @ 11.8-13.0 T���� 5K with margin of 1.5K for NbTi @ 4.0-6.4 T
• Outer conduit material and shape (steel, round) defined by magnet design
Hannu Rajainmäki, Summer School, Kullaa, 17 June 2008 Slide 12
CICC is the most used option in CICC is the most used option in fusion magnetsfusion magnets
Hannu Rajainmäki, Summer School, Kullaa, 17 June 2008 Slide 13
Toroidal Field (TF) Coils
Nb3SnSuperconductor
5Operating temperature (K)
12.6Height (m)
~310Weight (t)
7Max. voltage (kV)
11Discharge time constant (s)
~400Centering force per coil (MN)
134Number of turns
68Operating current (kA)
11.8Max. conductor field (T)
~41Total stored energy (GJ)
18Number of coils
Design confirmation by Model Coil project launched in 1996
Hannu Rajainmäki, Summer School, Kullaa, 17 June 2008 Slide 14
TF Winding Pack
Radial Plate
Cover Plate
Conductor
Holes for VPIDP insulation
Hannu Rajainmäki, Summer School, Kullaa, 17 June 2008 Slide 15
TF - Joints and hydraulic connections
Very busy region….insulation must be applied by hand (typically resin wet glass/kapton & pre-made G10 sleeves…high risk area …intermediate Paschen tests
(or equivalent) needed to check quality insulation between assembly steps.
Electrical Joints
High voltage and sensors wiring
Helium inlets/outlets: high voltage
HV breakers
Hannu Rajainmäki, Summer School, Kullaa, 17 June 2008 Slide 16
TF - The impact of high voltage: selection of insulation type
0.10.01Co-wound QD tape to conductor
183.5 (7 for a few ms)
WP to ground
2.41.2 (2.4 for a few ms)
DP to DP
1.20.6 (1.2 for a few ms)
Turn to RP
Fault scenarioVf (kV)
Normal Operation (fast discharge) Vn
(kV)
Voltage during TF coil operation
…has driven decision to utilize of Kapton as insulation barrier ….
TF Coil Conductor
17 layers of Glass/Kapton
>3 layers of Glass/Kaptonhalf lapped
For NbSn coils (TF and CS) the insulation must be applied after the heat treatment
Hannu Rajainmäki, Summer School, Kullaa, 17 June 2008 Slide 17
TF - The impact of radiation & stress: selection of resin
• Existing industrial epoxies usable for VPI degrade at the design neutron fluence with no margin for operation
• New thermoset material (Cyanate Ester) presents one order of magnitude higher radiation hardness with ultimate far beyond the operational values at the expected fluence
⇓Main issues are:
• Very expensive … but small fraction of overall cost & possible to use blends.
• No experience with such resin on impregnation of (large) superconducting magnets.
Tests on-going at ASG (Genoa) to impregnate a 1m long mock-up with a blend CE-DGEBA (40-60%)
⇓⇓⇓⇓Still very modest compared to TF Still very modest compared to TF
coils !coils !
Hannu Rajainmäki, Summer School, Kullaa, 17 June 2008 Slide 18
Electromagnetic Forces on TF coils: – In-plane forces:
• 403 MN centripetal force• Outward forces in the outboard leg
which induce an outwards movement
– Out-of-plane forces:• Overturning moments
⇓⇓⇓⇓
TF -Mechanical Structure
• TF radial extension is mainly determined by the structure• Mostly Stainless Steel cross section• Critical current density of superconductor at operating conditions has only minor impact
Hannu Rajainmäki, Summer School, Kullaa, 17 June 2008 Slide 19
TF -The E.M forces are created by
• Friction between coils– Cylindrical closed vaulted shape
formed by the 18 wedged coils at the inner nose
• IIS– 13 shear keys located between
adjacent TF coils
• OIS– Upper and lower OIS– 4 bands of Intermediate OIS
• Pre-compression system reduces the stresses globally, especially the tension loads at the OIS, and reduces fatigue at the IIS shear keys
� Introduction� ITER Magnet System Design� ITER Magnet System R&D� Main Manufacturing Challenges� Procurement Sharing and Schedule�Summary
Hannu Rajainmäki, Summer School, Kullaa, 17 June 2008 Slide 21
TF Conductor Development – Stages
Procurement of Advanced StrandProcurement of Advanced Strand
Single StrandsSingle Strands Sub Size SamplesSub Size Samples Full Size SamplesFull Size Samples
Jacketed Jacketed StrandsStrands
Sub Size Sample Sub Size Sample ManufactureManufacture
Full Size Conductor Full Size Conductor ManufactureManufacture
Sub Size Sample Sub Size Sample TestingTesting
Cross Checking Cross Checking and and
Extended TestsExtended TestsFull Size Full Size
Sample TestSample Test
Full Size Sample Full Size Sample ManufactureManufacture
Bending Strain Bending Strain TestsTests
Conductor Procurement Qualification Samples
(CPQS)
Hannu Rajainmäki, Summer School, Kullaa, 17 June 2008 Slide 22
SULTAN: Test Facility for Conductors
•SULTAN (SUpraLeiter Test ANlage)
•Split solenoid coil: Allows tests in various magnetic field orientations up to 12 T field and 100 kA current
•Operated by CRPP (Switzerland)
•Unique in the world: All ITER full size conductors are to be qualified using SULTAN test results
Hannu Rajainmäki, Summer School, Kullaa, 17 June 2008 Slide 23
EFDA Dipole: Test Facility for Conductors
[A. Portone et al., presented at MT20, Philadelphia, accepted fo[A. Portone et al., presented at MT20, Philadelphia, accepted for publication in IEEE Trans. Appl. Supercond. 18]r publication in IEEE Trans. Appl. Supercond. 18]
Hannu Rajainmäki, Summer School, Kullaa, 17 June 2008 Slide 24
LN2-Shield
Current lead80kA - Pole
Current lead80kA + Pole
Bus bar type2
Cold storage vessel
TF-model coil TFMC
Support leg
Inter-coil structure
Auxiliary structure
Safety flap
Vacuum vessel
Bus bar type1
40 mm
80kA
TF Model Coil (TFMC) R&D during ITER-EDA
Conductor (LMI)
Dummy Double Pancake Complete TF Model Coil (AGAN Consortium)
Test in TOSKA (FzK)
Hannu Rajainmäki, Summer School, Kullaa, 17 June 2008 Slide 25
TFMC Test Results
ITER TF TFMC Peak field (T) 11.8 9.9 Conductor current (kA) 68 80 Number of turns 134 98 No. of double pancakes 7 5 Stored magnetic energy (MJ) 41,000 337 Coil height (m) 12.6 4.6 Total coil weight 310 40
� TFMC exceeded design values
� No degradation with cycling
� Conductor performance in coil less than expected from short sample tests→ conductor upgraded to recover margin
Tcs at 80 kA
[A. Ulbricht et al., Fus. Eng. Des. 73, 189[A. Ulbricht et al., Fus. Eng. Des. 73, 189--327 (2005)]327 (2005)]
Hannu Rajainmäki, Summer School, Kullaa, 17 June 2008 Slide 26
Degradation due to transverse load …
Electromagnetic force(accumulated)
Strand (bent by transverse load)
Strand
Conductor(CS model coil CICC)
Periodic bending deformation of strands in a large CICC
Large strain (low Ic) due to bending�Current transfer among filaments
εLarge strain
Large strain
Strand cross sectionCurrent transfer
Degradation of critical current and n index by strand bending
Hannu Rajainmäki, Summer School, Kullaa, 17 June 2008 Slide 27
Improvement of TF Conductor
29Void fraction (%)
10Central channel OD (mm)
43.7Conductor diameter (mm)
2Jacket thickness (mm)
1Cu ratio
0.82Strand diameter (mm)
1422Total number of strands
900Number of Nb3Sn strands
� Transverse load (bending) identified as main cause of degradation � Level of degradation depending on strand type (strain sensitivity)� Updated design with more strands, higher Jc and lower void fraction� First short sample tests in Sultan successful, final qualification in 2008
[P. Bruzzone et al., presented at MT20, Philadelphia, accepted f[P. Bruzzone et al., presented at MT20, Philadelphia, accepted for publication in IEEE Trans. Appl. Supercond. 18]or publication in IEEE Trans. Appl. Supercond. 18]
Hannu Rajainmäki, Summer School, Kullaa, 17 June 2008 Slide 28
Central Solenoid (CS) Coils
Nb3SnSuperconductor
5Operating temperature (K)
~980Total weight of all modules (t)
20Max. voltage to ground (kV)
535Turns per module
45Operating current (kA)
13Max. conductor field (T)
~6.4Total stored energy (GJ)
6Number of modules
Design confirmation by Model Coil project launched in 1994
� CS stack composed of 6 independently
powered modules wound in hexa-pancakes
Hannu Rajainmäki, Summer School, Kullaa, 17 June 2008 Slide 29
2m
Winding Structure
ConductorStructure
Outer Module(JA)
CS Insert Coil(JA)
Inner Module(US)
Cable (38 mmφ)3x3x4x5x6=1080
Central Tube
Initial Triplex
Nb3Sn Strand
Sub-Cable Lapping
Cable Lapping
Jacke t (Inco loy 908)
Insulation Tape
Model Coils for the CS Coils
Hannu Rajainmäki, Summer School, Kullaa, 17 June 2008 Slide 30
CS Model Coil: An International Cooperation
Nominal Operating Conditions- Current 46 kA- Magnetic Field 13 T
Hannu Rajainmäki, Summer School, Kullaa, 17 June 2008 Slide 31
CSMC Main Modules
CSMC: Inner module(provided by US)
CSMC: Outer module(produced by Japan)
[H. Tsuji et al., Nuclear Fusion 41, no 5, 645[H. Tsuji et al., Nuclear Fusion 41, no 5, 645--651 (2001)]651 (2001)]
Hannu Rajainmäki, Summer School, Kullaa, 17 June 2008 Slide 32
CSMC Results
Small degradation (0.1 to 0.2 K) saturated after a few cycles
CSMC successfully achieved design values
� Differences to present designPancake winding (not layer winding)Jacket material high Mn steel (not Incoloy)[Tsuji et al., ][Tsuji et al., ]
Hannu Rajainmäki, Summer School, Kullaa, 17 June 2008 Slide 33
Nb3Al Insert(JA)
TF Insert(RF)
CS Insert(JA)
CSMC Nb3Sn & NbTi Inserts
Hannu Rajainmäki, Summer School, Kullaa, 17 June 2008 Slide 34
Poloidal Field (PF) Coils• 6 PF coils independently powered, wound in double pancakes to:
���� Confine and shape the plasma���� PF1 & PF6 control plasma vertical displacement
• Conductor field limited to 6 T: NbTi sufficient• Coils are large (24 m diameter) but use of NbTi simplifies construction
Still open questions:Nb3Sn to gain flexibility ?Increase current in outer PF coils to gain in plasma stabilization ?
PF1
PF2
PF3
PF4
PF5PF6
Three different conductors depending on max. field:
•
Hannu Rajainmäki, Summer School, Kullaa, 17 June 2008 Slide 35
PF Conductor
51.9 x 51.951.9 x 51.953.8 x 53.8Circle in square316L jacket (mm)
35.335.337.7Cable diameter (mm)
2.702.85- no -Copper corediameter (mm)
424.7370.5366.8Total copper (mm2)
90.3(before 45.7)
144.5(before 80.5)
229.3Non copper (mm2)
72011521440Nr of sc strands
2.3(before 6.9)
2.3(before 4.4)
1.6Sc strand Cu:nonCu
0.730.730.73Strand diameter (mm)
(2sc+1cu)x3x4x5x63scx4x4x4x63scx4x4x5x6Cable pattern
PF2,3 and 4PF5PF1/6
Hannu Rajainmäki, Summer School, Kullaa, 17 June 2008 Slide 36
• Full size conductor (PF1 type) short sample tests in Sultan successful• Target achieved: 52 kA at 6.3 T with margin of 1.2 K• Problem: above 30 kA no transition, just quench
• “Sudden quench” independent from T or B. Originates from local peak fields(R. Wesche et al., Physica C 401, 113-117, 2004)
PF Conductor R&D
Long length performance checked by insert coil →
Hannu Rajainmäki, Summer School, Kullaa, 17 June 2008 Slide 37
PF Insert Coil
Coil installation into CSMC facility completedStart of testing in mid June 2008
Upper Terminal
Lower Terminal
NbTi Square Conductor
Precompression System
Intermediate Joint
Coil Design Parameters
PFI
6.3 T
50 kA
2 T/s
49.50 m
Outer Diameter 1.57 m
Inner Diameter 1.39 m
Height 1.40 m
1.40 m
6 t
Height
Weight
Main Winding Envelope
Maximum Field
Maximum Operating Current
Maximum Field Change
Conductor length
[Nunoya et al, presented at ASC 2008][Nunoya et al, presented at ASC 2008][Zanino et al, presented at IAEA 2008][Zanino et al, presented at IAEA 2008]
Cable supplied by RFJacketing and coil manufacture by EU (ASG + Tesla)
Hannu Rajainmäki, Summer School, Kullaa, 17 June 2008 Slide 38
Model 1 Forged Model 2 Cast Weld Qualification
Casting
Forgings
Glass-epoxy
GTAW/SAWClosure Welds
EBW/SAW Fabrication Weld
Main Goals
� Qualify manufacturing techniques
for production of base elements
� Qualify welding processes and NDT
methods
� Provide input to the detailed design
GTAW EB+SAW
TF Coil Case R&D
Hannu Rajainmäki, Summer School, Kullaa, 17 June 2008 Slide 39
Pre-compression Ring Qualification� R&D work in progress at ENEA Frascati to qualify the base material properties (tensile, ultimate, relaxation, creep, thermal contraction, etc.)
� 1/5 scale mock-ups manufactured and tested at RT under similar static load/hoop stress conditions as in the real rings after pre-loading during assembly
R1_Relaxation test_day 6
0
100
200
300
400
500
600
700
800
900
1000
0 3600 7200
Time [s]
Total radial load RL [ton]
Radial stress RS [MPa]
Hoop stress HS [MPa]
First ring (R1) mock-up
Assembly into test machine
Results of relaxation test after 6 days
Hoop stress distribution during testing
Failure of R1 due to damage in one location
Hannu Rajainmäki, Summer School, Kullaa, 17 June 2008 Slide 40
Feeders
• 31 feeders:
– 26 for coils– 3 for structures– 2 for
instrumentation
Required cryogenic power: ~ 64 kW
in-cryostat feeder
cryostat feedthrough
Cold terminal box
safety valves
cubicles
dry box
cryostat wall
TF terminal area
Hannu Rajainmäki, Summer School, Kullaa, 17 June 2008 Slide 41
HTS Current Leads� Application of HTS current leads saves ~ 25 % of the total cryogenic power
needed (18 kW at 4.5 K !)� Large R&D program initiated in EU to develop a 70 kA HTS current lead� Program successfully completed in 2005 by test of a 1:1 prototype
(using Bi-2223 tape stacks) in the TOSKA facility
[R. Heller et al., IEEE Trans. Appl. Supercond. 15, 1496[R. Heller et al., IEEE Trans. Appl. Supercond. 15, 1496--1499 (2005)]1499 (2005)]
� Introduction� ITER Magnet System Design� ITER Magnet System R&D� Main Manufacturing Challenges� Procurement Sharing and Schedule�Summary
Hannu Rajainmäki, Summer School, Kullaa, 17 June 2008 Slide 43
� Heat treatment, insulation and transfer into RP of reacted double pancakes� Tight tolerances / clearances for insertion of radial plate� Maximum allowable deformation of reacted conductor ~0.1%� Permanent elongation after heat treatment ~0.05%
� Manufacture of radial plates and cover welding���� Extruded profiles laser welded together vs. machined plates���� Control of out-of-plane distortion during laser welding of covers
� Vacuum Pressure Impregnation of turn and double pancake insulation
� Insulation Resistance under Irradiation���� Degradation of inter-laminar shear strength���� Gas evolution during machine life
� Case materials and manufacture/assembly of outer intercoil structures
� Manufacture of pre-compression rings with uni-directional glass (S-2 or ECR)-epoxy composite
Main Manufacturing Issues for TF Coil Procurement
Hannu Rajainmäki, Summer School, Kullaa, 17 June 2008 Slide 44
• No prototype for learning & testing of the technology
• Many technological aspects will require additional development compared the model coil
⇓⇓⇓⇓
• Learning to be done directly on final coils (BUT 1 spare coil)
• Very tight schedule
• No full operation cold test of prototype or 1st of series
Main Challenges for TF Coils
Hannu Rajainmäki, Summer School, Kullaa, 17 June 2008 Slide 45
TF coils main manufacturing steps
Wind…React…
Insulated and Transfer
Impregnated of moduleStacking of modules
Welding magnet in case
TFMC manufacturing TFMC manufacturing phasesphases
Hannu Rajainmäki, Summer School, Kullaa, 17 June 2008 Slide 46
Manufacture of radial plates
Machining Method (M)
Laser Welded Method (LW)
• Use of conventional machine.• Use of welding technique to minimize
deformation after welding between segments
• Use of manufacturing technique to minimize deformation and machining time
Courtesy
JA
Radial Plate
Cover Plate
Holes for VPItion
Hannu Rajainmäki, Summer School, Kullaa, 17 June 2008 Slide 47
…compared with the TF model coil…
In the TF model the radial plates were made by machining a single forged plate.
⇓⇓⇓⇓
For TF full size coil, due to the large dimensions, different segments must be welded and machined + groove walls thinner than in TFMC
⇓⇓⇓⇓
Still a lot to explore !Still a lot to explore !
Hannu Rajainmäki, Summer School, Kullaa, 17 June 2008 Slide 48
2) Winding
Winding roll
Sand-blasting machine
Straightening toolWinding machine(trial Fabrication)
Traveling direction
Drum
� Automatic three roll bending machine will be used.
� The conductor should be transferred to RP groove after heat treatment. Therefore,1) High accuracy winding,
and2) Accurate prediction of
conductor elongation /shrinkage (JA think thisis not critical issue now)
are key technologies.
Winding R&D at JAEA
Hannu Rajainmäki, Summer School, Kullaa, 17 June 2008 Slide 49
Heat Treatment
TF coils TFMC
The experience on heat treatment: gained on TFMC is quite relevant to the full size TF coils
Hannu Rajainmäki, Summer School, Kullaa, 17 June 2008 Slide 50
Main issues of length-change
Elongation measurement result of TF coil conductors
-0.02%
+0.03%
Internal tin
SS316LN
-0.2
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
0 100 200 300 400 500 600 700Temperature ( C)
Elo
ngat
ion
(%)
Bronze
-0.02%
+0.03%
-0.02%
+0.03%
-0.02%
+0.03%
Internal tin
SS316LN
-0.2
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
0 100 200 300 400 500 600 700Temperature ( C)
Elo
ngat
ion
(%)
Bronze
Elongation/Shrinkage
Bronze (JASTEC) +0.03%
Internal tin (Mitsubishi) -0.02%
Elongation/Shrinkage
Bronze (JASTEC) +0.03%
Internal tin (Mitsubishi) -0.02%
K. MatsuiITER Superconducting Magnet technology group, JAEA
Progress Meeting between ITER IO, JAPT, and EUPT on the Preparationof the Procurement Specifications for the TF Coil Winding and Structures
27 Sept. 2007Naka, Japan
Hannu Rajainmäki, Summer School, Kullaa, 17 June 2008 Slide 51
Radial plate articulated support
Radial plate(under the support)
Support platform
Heat treatment support
Open TF coil double pancake Umbrella
structure
A possible solution for the Transfer process
Hannu Rajainmäki, Summer School, Kullaa, 17 June 2008 Slide 52
…then the insulation is relatively straightforward…
DP manufacturing. Insulation · The proposed
insulating machine achieves:
· Minimal deformation of the conductor by minimizing the amplitude of the wave.
· Complete insulation of one layer with one roll in one step.
Controlled Strain <0.1%
Hannu Rajainmäki, Summer School, Kullaa, 17 June 2008 Slide 53
…welding of the covers…
Laser welding
Experience on TFMC
Hannu Rajainmäki, Summer School, Kullaa, 17 June 2008 Slide 54
…DP insulation and the impregnation of the DP modules…
…this is relatively straightforward operation…
•Main challenge is to impregnate the turns inside the radial plates
•The resin penetrates through holes in the covers. The distance between holes is determined with preliminary R&D
A section of the TFMC Dummy DP
A fully impregnated TFMC DP
Hannu Rajainmäki, Summer School, Kullaa, 17 June 2008 Slide 55
DP stacking and WP impregnation
8. Winding Pack8. Winding PackStacking of 7 DP
DP surface 2mm shape tolerance 3mm nominal dry glass shimming between DP absorb lack of planarity of DPJoint connection along the stacking process
7mm ground insulation of WP ensures the feasiblity of the requested 3mm shape tolerance
The main issue if the very tight tolerance required on the planarity of the straight length
Hannu Rajainmäki, Summer School, Kullaa, 17 June 2008 Slide 56
� High accuracy required to reduce error fields
� Reduce machining of huge components
� Fitting gaps carry stress penalty
Insertion of Winding into Case
Insertion of WP in the case
Hannu Rajainmäki, Summer School, Kullaa, 17 June 2008 Slide 57
The next phases will be:• Phase I (about 2 years, contract begins early 09)
– Manufacture of a full size dummy (with some sc) DP to:• Verify feasibility of manufacturing full size RPs• Gain experience in Impregnating full size DPs with new resin• Qualify full size tooling & processes
• Phase II– Manufacturing of one full size TF coil in EU and one in JA
• Phase III (completion foreseen in 2014)– Manufacture of the series of remaining 9 coils in EU and 8
for JA.
Future steps for TF Coils
Hannu Rajainmäki, Summer School, Kullaa, 17 June 2008 Slide 58
� Pre-industrial R&D and qualification tests foreseen in the first two years of the contracts (the same for the PF coils) to finalize tooling and manufacturing procedures of double pancakes
� Several sub-scale and full-scale mock-ups of radial plates and welding of conductor cover plates
� Short-beam impregnation tests with the chosen (advanced) resin system
� One full-scale dummy double pancake each with copper cable to validate the winding, insulation, transfer, cover welding and DP impregnation procedures
� One six-turn full-scale coil each with superconducting cable to validate the heat treatment procedure and assess the effect of heat treatment on WP shape and tolerances
� Full-scale conductor and joint samples to be tested in the Sultan facility
� One case mock-up for closure welding qualification and impregnation tests
Qualification Phase for TF Coil Manufacture (EU and JA)
Hannu Rajainmäki, Summer School, Kullaa, 17 June 2008 Slide 59
PF Coil Manufacture on Site
• Large factory needed for the manufacture of PF2 to PF6 coils at Cadarache site
• PF manufacturing building to be available in early 2010
Hannu Rajainmäki, Summer School, Kullaa, 17 June 2008 Slide 60
Wound in Wound in DPsDPs……
Sand blast
Calendering
InsulationTurning table
Hannu Rajainmäki, Summer School, Kullaa, 17 June 2008 Slide 61
Aligning columns
DPsDPs stackingstacking
Hannu Rajainmäki, Summer School, Kullaa, 17 June 2008 Slide 62
� Extensive quality control and quality assurance are foreseen throughout the manufacture of conductors and coils
� Extensive databases for strand and cable properties, winding geometry and all quality control test protocols
� Staged procurement and production-proof samples of the manufactured conductors are required
� A series of leak tests on conductors and coils during different stages of jacketing and winding
� High voltage tests throughout the coil manufacture, also in Paschen-minimum conditions
� Tight control of non-conformities
� Cold testing of all magnets (not yet approved) is proposed down to 4 K to check leak and high voltage integrity and measure joint resistance with moderate current
Quality Assurance Programme
� Introduction� ITER Magnet System Design� ITER Magnet System R&D� Main Manufacturing Challenges� Procurement Sharing and Schedule�Summary
Hannu Rajainmäki, Summer School, Kullaa, 17 June 2008 Slide 64
Magnet Procurement Sharing
TF Coils (including radial plates, not cases)Conductors supplied by CN, EU (~20%), KO, JA, RF, USWindings 10 from EU, 9 from JA
TF StructuresBasic structures from JA (cases, shear keys and bolts)Case-winding pack insertion – 10 EU, 9 JAGravity supports from CNPre-compression rings from EU
CS Coil (includes pre-compression structures and supports)Conductors from JA6 modules from US
PF CoilsConductors from CN, except share between EU and RF for PF1 & PF6Windings PF2-PF6 from EU, PF1 from RF
Correction Coils & Feeders (and CTBs including current leads)CN, including conductors and leads
InstrumentationITER Fund
Hannu Rajainmäki, Summer School, Kullaa, 17 June 2008 Slide 65
ConductorChinaSouth KoreaJapanRussiaUnited StatesEurope
TF CoilJapan
TF coil casesJapan
Europe
TF Coil Sharing
Hannu Rajainmäki, Summer School, Kullaa, 17 June 2008 Slide 66
Magnet Cost SharingRelative Total Contribution of Different Components
Total 802IUA
JA
US
CN
EUKO
RF
Fund 0
50
100
150
200
250
300
350
400
-2 -1 1 2 3 4 5 6 7 8 9 10 11
Yearly Expenditure Plan
Co
st in
IUA
Year relative to January 2009
Total 802 kIUA
Hannu Rajainmäki, Summer School, Kullaa, 17 June 2008 Slide 67
Magnet Construction Schedule
Integrated Project Schedule (IPS): the table below shows the current ITER schedule to meet the deadline of first plasma in 2016 and includes fabrication, not development � Starting time too stringent
A new detailed schedule has been developed and the construction requires 2 years extension of the plasma deadline (2018)
Hannu Rajainmäki, Summer School, Kullaa, 17 June 2008 Slide 68
Superconducting strand contractsSuperconducting strand contracts�� Scope to supply CrScope to supply Cr--coated Nbcoated Nb33Sn strand, if successfully qualified by CPQS Sn strand, if successfully qualified by CPQS
�� Probably more than one supplier for capacity and risk optimisatProbably more than one supplier for capacity and risk optimisationion
�� SomeSome Parties (CN, RF, KO) have only one qualified supplierParties (CN, RF, KO) have only one qualified supplier
Cu strand contractCu strand contract�� Scope to supply CrScope to supply Cr--coated Cu strandcoated Cu strand
�� Relatively simple specification and tender process Relatively simple specification and tender process
�� EU CallEU Call--forfor--Tender launched on 17 March 2008Tender launched on 17 March 2008
Cabling & jacketing contractCabling & jacketing contract�� Scope: Cabling, installation of jacketing line, welding of tubesScope: Cabling, installation of jacketing line, welding of tubes
Procurement of jacket, wrap, spiralProcurement of jacket, wrap, spiralJacketing and compactionJacketing and compaction
� Probably several contracts with specialized laboratories and companies���� sharing/splitting difficult, but enables fast reaction in case of problems
Quality control for strand and conductor testsQuality control for strand and conductor tests
F4E TF ConductorProcurement
Hannu Rajainmäki, Summer School, Kullaa, 17 June 2008 Slide 69
F4E TF Coil Procurement
Raw material for RPs : 5 x10=50 central +
2 x 10 =20 side plates
Radial plate and cover machining: 50 central + 20
side plates
Conductor FROM ITER
Case sections = 4 x 10 = 40 FROM ITER Quality Control
Risk Management
Planning and schedule
Wind 7 x DPs modules
Main tooling (e.g. winding machine, heat treatment oven, etc.)
Assembly 5+2 DP modules to create TF winding pack
(WP)
Heat treat 7 x DPs modules
Transfer and Insulate & Impregnate 7 x DPs modules
X 10 coils
Cold test WP
Assembly in the final case, final impregnation and machining
Packaging and transport
X 10 coils
Manufacturing drawings and procedures
Fabrication of the Full-Size Double-Pancake Prototype
Pre-qualification tests Qualification
phase
Full Production
phase
Transversal activities
Supply may be organized in one single contract or multiple contrSupply may be organized in one single contract or multiple contracts acts �������� Procurement Procurement Arrangement to be signed in June 2008 (?), detailed strategy to Arrangement to be signed in June 2008 (?), detailed strategy to be developedbe developed
� Introduction� ITER Magnet System Design�ITER Magnet System R&D� Main Manufacturing Challenges� Procurement Sharing and Schedule�Summary
Hannu Rajainmäki, Summer School, Kullaa, 17 June 2008 Slide 71
Summary
� The ITER procurement phase started at the end of 2007 with the signature of the first Procurement Arrangements for the TF Conductors
� This is supported by many years of design and R&D work and the production of several Model Coils and Insert Coils
� Several technical issues related to the large size of the coils and lack of experience in some areas - not covered by the Model Coils - are still open and must be tackled in the first stages of the manufacture
� Big challenges are the organization of the in-kind contribution from seven Parties and the management of the procurement contracts
� The foreseen schedule is very tight, especially for the start-up and preparation periods before the full-scale production, and does not take into account learning curves, delays or “force majeure”.
Hannu Rajainmäki, Summer School, Kullaa, 17 June 2008 Slide 72
Acknowledgement
� E. Salpietro, W. Baker (EFDA Garching), A. Portone (F4E)
� N. Mitchell, A. Devred, J. Knaster (ITER IO Cadarache)
� H. Fillunger, R. Maix (ATI Vienna)
� K. Okuno, N. Koizumi and the JADA Team
� All the Colleagues in the EU Associations
� The members of the Magnet Design Review and TF Conductor & Coil Procurement Review Groups
� EU Industrial Partners