EU considerations on Design and Qualification of Plasma Facing Components for ITER

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1 EU considerations on Design and Qualification of Plasma Facing Components for ITER Patrick Lorenzetto, F4E Barcelona with inputs from B. Riccardi (F4E), V. Barabash and M. Merola (ITER IO) on Readiness to Proceed from Near Term Fusion Systems to Power Plants UCSD, La Jolla, CA December 10-12,

2 Content ITER In-Vessel component materials ITER Divertor - Divertor design -Divertor R&D - Divertor qualification phase ITER First Wall - First Wall design -First Wall R&D - First Wall qualification phase Conclusion 2

3 Content ITER In-Vessel component materials ITER Divertor - Divertor design -Divertor R&D - Divertor qualification phase ITER First Wall - First Wall design -First Wall R&D - First Wall qualification phase Conclusion 3

4 ITER In-Vessel component materials Strategy for the material selection The material choice for ITER was performed based on industrially available materials while taking into account their physical and mechanical properties, maintainability, reliability, corrosion performance and safety requirements at the ITER operational conditions. Experience from current tokamaks has been taken into account, (plasma facing, diagnostics materials, etc.). Knowledge from fission neutron irradiation programs was used. 4

5 ITER In-Vessel component materials The ITER in-vessel materials categories: Standard materials with established manufacturing technologies, directly applicable to ITER, (e.g. steels 316L(N), Ni based alloy type 718, Ti alloys, W). First Wall and Blanket Divertor 5

6 ITER In-Vessel component materials The ITER in-vessel materials categories: Standard materials, which require some modifications, such as more stringent limits on the alloying elements, appropriate fabrication routes etc (e.g. CuCrZr alloys). First Wall and Blanket Be CuCrZr 316L(N) SS Divertor CFC or W 6

7 ITER In-Vessel component materials The ITER in-vessel materials categories: Materials requiring new developments (e.g. CFC) or new joining techniques (e.g. Be, CFC, W with CuCrZr alloy by Hot Isostatic Pressing, Hot Radial Pressing, brazing). First Wall and Blanket Be CuCrZr 316L(N) SS Divertor CFC or W 7

8 ITER In-Vessel component materials Armour materials Compromise: Plasma Performance Materials Lifetime T retention ~ 680m 2 Be first wall low Z compatibility with wide operating range and low T retention Large experience from JET operation ~ 50 m 2 CFC Divertor Target (before Tritium phase) Good resistance under transients (ELMs and Disruptions) Low Z compatibility with wide range of plasma regimes (T e,div ~ ev) Large T retention (co-deposition) ~ 100m 2 Tungsten Baffle/Dome Low Erosion, long Lifetime and low T retention Less experience 8

9 ITER In-Vessel component materials Conceptual Design Phase Preliminary selection of materials Preliminary design assessment and identification of the missing data Engineering Design Phase Extensive R&D programs on materials characterization and optimization Development of materials database and justifications Finalization of materials grades selection Pre-construction and Construction Phase Finalisation of material data base for licensing authorities Procurement of the materials in accordance with specifications Control during manufacturing of the components Operation Phase Monitoring properties, material sampling to complete required data base. 9

10 Content ITER In-Vessel component materials ITER Divertor - Divertor design -Divertor R&D - Divertor qualification phase ITER First Wall - First Wall design -First Wall R&D - First Wall qualification phase Conclusion 10

11 ITER Divertor Divertor design 54 Cassettes each 8.3 tons Armour heat sink options Monoblock (Preferred option) flat-tile 11 Main VT design parameters Total power 180 MW (Design Scenario) Surface heat flux (MW/m 2 ) Steady state (400s, 3000 cycles, CFC/W: 10/ 5 MW/m 2 Transient (10 s, 300 cycles) : 20 MW/m 2 N-volumetric heating : max 10 MW/m 3 N-damage: dpa Disruptions: <100 MJ/m 2 x 1-10ms x 300 cycles ELMs heat loads: <10 MJ/m 2, 1 Hz

12 Vertical Target full and medium-scale mock-ups CFC-W monoblocks (by HIPping) ITER Divertor Divertor R&D CFC monoblocks W monoblocks 10 MW/m 2 x 1000 cycles 10 MW/m 2 x 1000 cycles 20 MW/m 2 x 1000 cycles 23 MW/m 2 x 1000 cycles CFC-W monoblocks (by HRP) 3000 cycles at 10 MW/m 2 on CFC and W 2000 cycles at 20 MW/m 2 on CFC and 15 MW/m 2 on W experimental critical heat flux: 35 MW/m 2 on the CFC 12

13 ITER Divertor Divertor R&D Vertical Target medium-scale mock-ups W monoblocks (by brazing) Tested in FE200 facility 5 MW/m 2 x 100 cycles 10 MW/m 2 x 1000 cycles 20 MW/m 2 x 1000 cycles W flat tile / CuCrZr hypervapotron / SS backplate HIPping + explosion bonding (PLANSEE) Brazing + explosion bonding (ANSALDO) Tested in FE200 facility (AREVA - F) 5 MW/m 2 x 100 cycles 10 MW/m 2 x 1000 cycles 20 MW/m 2 x 766 cycles 13

14 ITER Divertor Divertor R&D High heat flux performance of neutron irradiated CFC and Tungsten Mock-Ups CFC monoblock geometry Irradiated 200 C, 1 dpa in CFC Successfully tested up to 15 MW/m 2, 1000 cycles with no failure (Test limited by the high surface temperature due to reduced K) W monoblock geometry Unirradiated cycles x 20 MW/m 2 no failure Irradiated 200 C, 0.1 and 0.5 dpa in W - Successfully tested up to 18 MW/m cycles W flat tile geometry Unirradiated cycles x 14 MW/m 2 no failure Irradiated 200 C, 0.1 and 0.5 dpa in W - Failure limit: 10 MW/m 2 Monoblock geometry more robust Performances after irradiation above the ITER requirements 14

15 ITER Divertor Divertor R&D Qualification of different CFC grades Future HHF test campaign: Screening test at 5 MW/m cycles at 10 MW/m 2 + screening test at 5 MW/m cycles at 20 MW/m 2 + screening test at 5 MW/m 2 15

16 ITER Divertor Divertor R&D Repair technique The aim of the activity is the development of repair methods for defected monoblocks in order to reduce the scrape rate during series production of the divertor plasma facing units and therefore to reduce the fabrication cost. Repair methods have been demonstrated at Plansee for both CFC and W monoblocks. An R&D programme is in preparation to increase the data base. W monoblocks 16 CFC monoblocks

17 Development of Acceptance Test Criteria ITER Divertor Divertor R&D Scope of the activity - To provide analytical and experimental basis for the definition of acceptance criteria for the divertor PFCs - To correlate defects with non-destructive testing result (US and IR thermography) and performance Work program (1) UT examination before HHF at FE200 (2) SATIR IR thermography (3) HHF (4) SATIR (5) UT (6) Destructive examinations. Mock-ups with artificial defects 112 samples split in 2 batches : - 56 HIPing Plansee - 56Hot Radial Pressing Ansaldo Ricerche Each batch of 56 samples includes : - 28 CFC monoblocks (26 short, 2 high - 14 W monoblocks and 14 W flat tiles W W flat tile (Plansee) W monoblock (Ansaldo) CFC monoblock (Plansee) CFC monoblock (Ansaldo) 17

18 Full scale dummy prototype manufacturing and testing ITER Divertor Divertor R&D Objectives Address key manufacturing issues, Perform hydraulic tests, Establish a procedure for draining and drying the divertor components. Perform assembly and integration tests on a full-scale prototype with realistic tolerances, dimensions, weight and accessibility. 18

19 ITER Divertor Divertor R&D Simulation of Remote Integration of Divertor system 19

20 ITER Divertor Divertor Qualification Phase Qualification process Each DA shall supply at least two partial full scale Qualification Prototypes (QPs) Each DA can supply more than two QPs (maximum four) with different technologies and/or manufactured by different companies The DA is considered qualified if: At least two of the delivered QPs meet all the prescribed acceptance criteria At least one of the delivered QPs withstands the high heat flux qualification tests HHF qualification tests CFC armoured part of QP (absorbed heat flux): Thermal Mapping at 5 MW/m cycles at 10 MW/m 2 Thermal Mapping at 5 MW/m cycles at 20 MW/m 2 Final Thermal Mapping at 5 MW/m 2 W armoured part of QP (absorbed heat flux): Thermal Mapping at 1 MW/m cycles at 3 MW/m 2 Thermal Mapping at 1 MW/m cycles at 5 MW/m 2 Final Thermal Mapping at 1 MW/m 2 20

21 ITER Divertor Divertor Qualification Phase Three Inner Vertical Target qualification prototypes delivered by the EU DA The companies involved are: Plansee SE (A) and Ansaldo Ricerche (I) The selected prototype versions are : full monoblock and mono-flat tile CFC material: SNECMA NB41 Mono-flat tile version Full monoblock version ANSALDO 21

22 Tentative EU IVT and CB procurement schedules ITER Divertor Divertor Qualification Phase Manufacturing of Qualification Prototypes (QP): July 2008 Completion of QP-HHF testing: February 2009 Signature of IVT Procurement Arrangement: February 2009? Completion of IVT prototype manufacturing: July 2011 IVT manufacturing Batch 1 (15%): (October 2012) IVT manufacturing Batch 2 (35%): (October 2014) IVT manufacturing Batch 3 (50%): (August 2016) Signature of CB Procurement Arrangement: July 2009? Completion of CB prototype manufacturing: December 2011 CB manufacturing and PFC+diagnostic assembly Batch 1: (January 2014) CB manufacturing and PFC+diagnostic assembly Batch 2: (June 2015) CB manufacturing and PFC+diagnostic assembly Batch 3: (January 2017) 22

23 Content ITER In-Vessel component materials ITER Divertor - Divertor design -Divertor R&D - Divertor qualification phase ITER First Wall - First Wall design -First Wall R&D - First Wall qualification phase Conclusion 23

24 First Wall design Present main design parameters 440 blanket modules FW surface: 680 m 2 Surface heat flux (MW/m 2 ) Steady state, av./max: 0.25/0.5 Transients for 10 s up to 1.4 Neutron wall load (MW/m 2 ) av./max: 0.55/0.78 Neutron fluence (MWa/m 2 ) av./target max: 0.3/0.5 Nominal number of cycles 30,000 Typical dimensions: 1 x x 0.5 m 3 Max weight: 4.5 tons 2006 design Option A 10-mm thick Beryllium armor Present draft design Option 20-mm thick CuCrZr alloy heat sink layer 316L(N)-IG stainless steel cooling tubes 2006 design Option B 24

25 First Wall R&D First Wall panel fabrication routes Solid HIP fabrication route 316L(N) Stainless Steel backing plate and Cu alloy plates with embedded 316L(N) Stainless Steel tubes joined by solid HIPping Powder HIP fabrication route 316L(N) Stainless Steel Powder and 316L(N) Stainless Steel tube gallery joined by HIPping CuCrZr alloy powder joined by HIPping Be tiles joined by HIPping Be tiles joined by Inductive Brazing (CuCrZr) Be tiles joined by HIPping Be tiles joined by Inductive Brazing (CuCrZr) 25

26 First Wall R&D HIPped fabrication route recommended by the EU DA for the manufacture of FW panels 316L SS / CuCrZr joining 1040 C, 140 MPa, 2 hrs Post HIP Solution Annealing HT with fast cooling 316L Stainless Steel / CuCrZr alloy HIP joining CuCrZr / Beryllium joining 580 C, 140 MPa, 2 hrs CuCrZr alloy / Beryllium HIP joining One full scale FW panel prototype with brazed Be tiles completed Three full scale FW panel prototypes with HIPped Be tiles completed One full scale FW panel prototype with HIPped Be tiles in progress Full scale FW panel prototypes 26

27 First Wall R&D Major achievements and test plans HHF tests of CuCrZr/316L SS mock-ups performed up to 7 MW/m 2 No degradation of the thermal fatigue performance observed on Be/CuAl25 joints after neutron irradiation up to 0.6 dpa. 3x2 FW mock-ups will be thermal fatigue tested at 0.5 MW/m 2 parallel to neutron irradiation up to resp. 0.6 and 1 dpa HHF tests of FW mock-ups performed up to 3 MW/m 2 HHF testing of full scale FW panels 27 Thermal fatigue tests of FW mock-ups performed at MW/m 2 for 30,000 cycles. Post fatigue HHF tests in JUDITH2 R&D continues e.g. on material joining to further improve the performances and increase engineering margins, and to define acceptance criteria

28 First Wall Qualification Phase Extract from the Common Understanding on the Design and Procurement of the ITER Blanket First Wall elements presented at the IO-DA meeting of 10 th January Well in advance of the assumed start of the procurement, each DA should first demonstrate, through a qualification program its technical capability to carry out the procurement with the required quality, and in an efficient and timely manner. The First Wall Qualification (FWQ) programme has been split into two stages: - Stage I for the fabrication and testing of FW mock-ups, - Stage II for the fabrication and testing of partial full scale FW panel prototypes. Two test facilities have been selected for Stage I. Each DA shall manufacture three FWQ mock-ups: one mock-up shall be tested in each test facility, one spare mock-up in case one fails. To qualify the DA, two mock-ups at least over the three shall pass the acceptance tests. E-beam type test facility Sandia N.L. (USA) 28 Radiative type test facility NRI Rěz (Czech Rep.)

29 First Wall Qualification Phase Preliminary results of the first stage of the FWQ Programme The first of the two EU FWQ mock-ups has successfully been tested at the Sandia N.L. (USA) for 12,000 cycles of 1.6 minute at 0.88 MW/m 2 and subsequent 1000 cycles of 40 sec at 1.4 MW/m 2. It has further been tested up to 2.2 MW/m 2 (limit to keep the Be temperature below about 650 C and avoid Be vaporisation) for 100 cycles without any sign of failure. It will be sent back to EU for subsequent ultrasonic testing. The second EU FWQ mock-up has successfully been tested at the NRI (Czech Republic) for 12,000 cycles of 5 minutes at 0.63 MW/m 2. Ultrasonic test did not reveal any indication of failure. It will be sent to FZJ Juelich (D) for subsequent 1000 cycles of 20 sec at 1.7 MW/m 2. Courtesy NRI EU FWQ mock-up after thermal fatigue test at NRI 240 mm (L) x 80 mm (w) x 81 mm (H) 29

30 Conclusion A successful R&D programme has been carried out in Europe over more than 15 years to develop reference fabrication routes for the Divertor and FW components, investigate and develop alternative fabrication methods to enhance competition, reduce technical risk and fabrication cost. R&D continues to further improve the performances and increase engineering margins, develop acceptance tests and criteria for the series production, develop repair techniques. Qualification programmes for the procurement of ITER In-Vessel components have started. Close collaboration between the main partners, IO, DAs including Industry and Laboratories is essential for the success of the Project. 30