ITER Vacuum Vessel Status and Procurement

Transcription

1 ITER Vacuum Vessel Status and Procurement IBF, Nice 11 December 2007 Presented by K. Ioki Tokamak Department, ITER Organization 1

2 VV design Design Review Activities VV Procurement Contents Main Vessel Ports 2

3 Vacuum Vessel Design and Activities Importance of the Vacuum vessel - First safety barrier (SIC: Safety Class Component) - Magnet and VV are the critical path in the ITER construction schedule. Vacuum vessel design - Basic structure is unchanged. - Double wall all-welded structure - Detail CAD models are being prepared (well advanced). - Definition of interfaces is critical. Vacuum vessel Analysis - Analysis report will be updated in preparation for assessment by Accepted Notified Body (ANB) Vacuum vessel Code & standards - RCC-MR 2007 Version - PED/ESPN - IO will be manufacturer - Selection of ANB Intermodular key Blanket flexible support housing Upper segment of Main Vessel (w/o outer shell) Vacuum vessel CAD model (2007) 3

4 Vacuum Vessel Port Design Blanket cooling pipes Additional shielding Connecting duct Port stub Upper Port Structure 4

5 Function - Neutron shielding. - Ripple mitigation In-wall shielding of the Vacuum Vessel - Progressing- Structure and Materials - Multi-plates mechanically assembled. - Borated steel and Ferritic steel (SS 430) - Eddy currents are minimized in this design. Ferromagnetic steel plates - EM forces calculated. - Support design progressing. Corrosion test is starting - SCC/Crevice corrosion - Work-hardened stainless steel - Galvanic corrosion (mixed materials) Optimization for Ripple minimization - Detail calculation on-going. 5

6 Ripple Requirement from Plasma Physics Updated In the 2005 design, the maximum ripple is ~1% (localized) which was accepted at the previous stage. Recent proposal is the maximum ripple should be as small as possible (<0.2 % proposed). Z(m) Optimization of Ferromagnetic Insert Design The maximum ripple can be reduced to ~0.3 % in the current design. Further reduction is to be studied C E1-2.0 Toroidal field ripple without additional ferromagnetic insets (Full TF current) Regular equatorial port region Additional Ferromagnetic Inserts NB port opening NB equatorial port region R ip p le % Filling factor FullTF current -2.0 H alf TF current

7 Vacuum vessel sector Leak Testing (Proposed) Helium enclosure, could also be flexible oven filled to 1 bar For the VV system 1 x 10-7 Pam 3 /s Calibrated leak LPT on UHV surface He RGA Leak rate <10-9 Pam 3 /s is a target value to be achieved. This is challenging for a large complicate component. Measurement of outgassing rate (JA) Outgassing rate seems to be acceptable based on the test result. - Low impurity liquid penetrant (Dye) should be selected. - Careful cleaning after LPT is required. 7

8 Liquid Penetrant Outgassing Test for UHV use 200 C Measurement of outgassing rate (JA) 8

9 Design Development of NB Port liners (On-going) - Fabrication technology - Mitigate high peak stresses. - RH compatible structure NB ports Inside view of HNB port HNB liner structure High heat flux element the HNB liner structure 9

10 Port Flange Design Double metallic gasket seals Exploded view of option A (Stiffeners of the strip plate are not shown) removable flat strip VV outer lip Port plug compliant plate part of the gasket flange - Gasket - M52 standard bolts or superbolts Port plug M52 Bolts (under vacuum) - Lip seal- plug inner lip 0.05 MPa tracer gas Vacuum / He feeding pipe for local and continuous leak checking 10

11 Design of this part is the same and frozen. This Flange design allows shift from Gasket (Hydrogen Phase) to lip weld sealing (D-T T Phase) Flat strip TIG welding of a 2mm flat strip Double TIG welding of inner and outer U shape lip One of the Two Designs can be selected depending on further design efforts, cost estimation and R&D / Qualification tests results : 11

12 R&D: Full scale Equatorial flange mock-up Simplified mock-up Qualification of sealing EP : 2090 x 2542 Mock-up Manufacture (k ) Test campaign* (k ) Total cost (k ) Equatorial flange Upper flange (*) Includes the baking and insulation equipment 12

13 Partial Full-scale VV Sector Fabrication Partial VV Sector Fabrication was completed. - Dimensional accuracy is mostly within the required (or target) tolerances. - Fabrication methods to be further optimized. - EB welding was used for welding between the inner shell and keys and flexible support housings Partial VV Sector Mock-up: PS2 (Curved Section) Fabrication Welding joint connection between PS1 (straight section) and PS2 (Inboard upper curved section) Partial Full-scale VV Sector Fabrication (EU) Automatic NG TIG welding on the outer shell of the PS1-PS2 joint 13

14 Partial Full-scale VV Sector Fabrication - Observed 4-5 mm relative vertical movement of PS2 component respect to the PS1 component. - Heavy and dirty work was required for dismantling the jigs. (To be included) Completion of PS1 and PS2 joint Partial Full-scale VV Sector Fabrication (EU) Cutting fixtures 14

15 Partial Full-scale VV Sector Fabrication Summary: Fabrication tolerance - Poloidal movements of the PS2 respect to the PS1 was observed (~0.2 PS1 / PS2 deflection) - All Outer Shell surface is within the acceptance fabrication tolerances (±10 mm) - Some of the Inner Shell Housing positions (radial ~+6mm) are out of the target fabrication tolerances: (radial ±5 mm, poloidal ±3 mm). This can be improved in the future. - All Inner Shell surface is within the target fabrication tolerances (±10 mm) Result of Partial Full-scale VV Sector Fabrication (EU) A poloidal movement (X-Z plane) of the PS2 was observed respect to the PS1, due to the jig dismantling (Laser Tracker measurement). The red line (see Left) shows this PS2 movement (amplified 10 times). 15

16 VV Mock-up Fabrication Upper section Welding of Flexible support housing After welding ribs and alignment of housings (Additional ribs to avoid distortion) Lower section Welding of intermodular key (With protection plate) Welding of centering key Welding of center rib EB welding on Full-scale partial mock-up (2007 JA report) 16

17 VV Mock-up Fabrication Full-scale partial mock-up (Left: Plasma side, Right: Outer shell side) (2007 JA report) 17

18 ITER VV Field Joint Welding R&D After fabrication, sectors A and B were welded together at the field joint on the center of the ports. This involved welding splice plates using the automatic NG-TIG process and inspecting the joint by the UT method. Outer Shell Welding Machine Outer Shell Welding Head Full Scale Sector Model (JA) 18

19 ITER VV Field Joint Welding R&D Inner Shell Splice Plate Inner Shell Welding Machine Full Scale Sector Model (JA) 19

20 Study of Increased Vertical and Horizontal Loads The lower port stub region (especially vertical gussets) is to be reinforced. 20

21 Study of Increased Vertical and Horizontal Loads The VV horizontal displacement during VDE is increased. 10 mm 15 mm The gaps between VV/VVTS and VVTS/TFC is marginally acceptable. To be studied further. 21

22 VV Supporting System High vertical load will be acceptable when it is transient. Damper shall have a function of the actuator to position the VV horizontally with accuracy of 1mm. 22

23 VV Supporting System Toroidal support (for VV center positioning) (1) Adequate flexibility (spring constant) in the toroidal direction is required to mitigate the reaction force (2) Active position control mechanism is under consideration. 23

24 Triangular Support Design Improvement To improve the plasma vertical stability - Wider copper cladding area - To Minimize cut-outs - To increase the copper coating thickness and achieve better material quality 24

25 Vessels and Interfaces Activities - by Design Review WGs WG1 Physics WG2 Safety WG5 Vessels - ELM control coil proposal - Plasma vertical stability improvement - Ripple minimization - Tritium inventory, Dust removal - VV ESPN categorization - VV ISI requirement - Blanket manifold - RH 3 requirement - VV support improvement - Blanket flexible support improvement - Dome shape cryostat / Independent support structure WG6 Heating - Enlargement of the DNB port opening 25

26 Interface with Heating System NB Port Opening Update DNB Port Opening enlarged 2004 Design [On-going job] Reasons: - Beam blocking - Tilted angle from the perpendicular direction New proposed Design 26

27 NB Port Opening Update (VV Port #4) Design update of the VV structure in the DNB port area 27

28 Interfaces with Blanket Attachments 4 Interfaces remain the same - Hydraulic connection - Current straps - Keys - Flexible supports Current strap Hydraulic Connection No Change!! Intermodular key Flexible support 28

29 ELM s Mitigation Wall Mounted Coil Concept This option was studied but dropped considering cost and schedule impacts 29

30 ELM s Mitigation Port Coil Concept mid+top port coils This option is to be further studied. 30

31 ELM s Mitigation Coil Concept Located Between VV Inner and Outer Shells Coils located between the VV inner and outer shells This option was proposed in a recent STAC meeting for study. There is a concern on the VV procurement schedule. 31

32 VV Procurement Schedule It is clear that the critical path activities for the project are the procurements of the VV, the TF coils, and the buildings. The VV Procurement Arrangement (PA) is scheduled to be issued mid To meet this schedule the following dates must be met. VV Design Frozen Sept 2007 Design options should be eliminated (for the VV) Blanket Attachment Blanket Manifolds Lower Ports (new proposal for blanket piping) Divertor Support (Updated design) ELM Control Coils (new proposal) NB Port (Size, angle, location) VV Port Flange Design Triangular Support Modifications VV Gravity Supports VV Interfaces Frozen Nov 2007 Blanket Cooling system Diagnostics NB - Safety Building - Plasma Cryostat - TS 32

33 VV Procurement Schedule Structures for lifting 1.5 Vacuum Vessel Date Design Frozen Sept-07 Divertor support rail Triangular support VV gravity support Interfaces Frozen Code Selection: RCC-MR 2007 PA* Complete PA* Signed 3D Models Complete Call for Tender Contract Awarded Nov-07 Dec-07 Apr-08 June-08 July-08 July 08 KO Sept 08 EU Dec 08 KO June 09 EU PA*: Procurement Arrangement between IO and Das - Design and interface freeze dates are critical to allow the VV P33P 33rocurement to proceed on schedule. - These dates may drive blanket and divertor design activities. 33

34 Vacuum Vessel Manufacturing Scheme (w/o Consortium) Contract Manufacturer IO IO Subcontractor Subcontractor Control Control of of fabrication fabrication Notified Body: Check design, Manufacture, and issue the statement of conformity Design/ESR: - Strength, - Seismic, - hazard - Etc. Main Main VV VV 80%-EU 80%-EU FJ FJ Welding Welding IO IO Main Main VV VV 20%-KO 20%-KO Fabrication: - Welding - Materials - NDT - Test (pressure) - Etc. Equatorial Equatorial and and Lower Lower Ports Ports KO KO Upper Upper Ports Ports RF RF VV VV IW IW Shield Shield IN IN (non structural) (non structural) Global Conformity Dossier Manufacturer (IO): Declaration of Conformity 34

35 VV Sector Fabrication Schedule (Delivery to the ITER Site) Contract Award First sector delivery Last sector delivery IPS Case A Rev 0 (12/2008) (6/2009) (35 months from 12/2008) (29 months from 6/2009) 11/2011 (47 months from 12/2008) (41 months from 6/2009) 11/2012 KO plan 12/ months 52 months 4/2012 4/2013 Procurement sharing of the VV components Procurement DA Main Vessel Ports Others EU 7 VV sectors KO 2 VV sectors Equatorial ports VV supports Lower ports NB liners RF Upper ports IN In-wall shielding 35

36 Materials for the VV fabrication Main Vessel (316 L(N) IG) In-wall shielding (1% and 2% Borated steel and 430) Additional shielding Water Main vessel total Ports (316 L(N) IG, 304 L) Main vessel and ports Grand total Weight (ton)

37 Summary 1. VV/ports detail design, analysis and R&D are progressing towards the Procurement Arrangement (PA) and call-for-tender. 2. The VV procurement schedule is very critical. (VV design freeze - Sept 2007, interface freeze - Nov 2007, PA signed - June 08) 3. New proposals and design improvements have been discussed and concluded in Design Review Meetings. Results of the Design Review Meetings are being incorporated into the 2007 ITER baseline design. 37