1. Mario Merola EU R&D on Divertor Components Presented by Mario Merola EFDA Close Support Unit, Garching, Germany

2. Mario Merola Talk Overview Divertor Acceptance Criteria Assembly and hydraulic tests Irradiation tests Other activities Present and future plans

3. Mario Merola Talk Overview Divertor Acceptance Criteria Assembly and hydraulic tests Irradiation tests Other activities Present and future plans

4. Mario Merola Scope of the activity To provide an analytical and experimental basis for the definition of acceptance criteria for the divertor PFCs To correlate this defect with the non- destructive testing evidence Main focus on CFC armour

5. Mario Merola Transient Thermography Inspection element to be tested reference element tested element reference Flow direction of heating medium Source: CEA/Plansee

6. Mario Merola - = T min,Ref (t) temperature evolution of the reference tile T min (t) temperature evolution of the tile to be tested  T min,Ref (t) maximum temperature difference Error criterion:  T min,Ref = max [  T min,Ref (t)]> 3 K (SATIR) Source: CEA/Plansee Transient Thermography Inspection See A. Durocher et al., poster F 146

7. Mario Merola Possible PFC geometries MonoblockFlat tile

8. Mario Merola M M FT

9. Mario Merola Failure of a flat tile

10. Mario Merola Failure of a flat tile

11. Mario Merola Failure of a flat tile

12. Mario Merola Failure of a monoblock

13. Mario Merola Failure of a monoblock

14. Mario Merola Failure of a monoblock

15. Mario Merola Thermography Acceptance Criteria Statistical approach In order to screen out defects that might lead to a CHF event or too high erosion the following tentative infrared acceptance values are proposed for discussion: Less than 50% of the CFC monoblocks can have a DT > 4.0  C Less than 5% of the CFC monoblocks can have a DT > 8.0  C No CFC monoblocks shall be accepted with a DT > 10.0  C See E. D‘Agata, R. Tivey, poster F 92

16. Mario Merola W monoblocks: 10 MW/m 2 x 1000 cycles CFC monoblock 10 MW/m 2 x 1000 cycles 20 MW/m 2 x 1000 cycles 23 MW/m 2 x 1000 cycles See M. Missirlian et al., poster F 100 Vertical Target Full-Scale Prototype

17. Mario Merola Vertical Target Full-Scale Prototype 108 CFC monoblocks 107 CFC monoblocks met the tentative acceptance criteria 99.1 % acceptance rate !

18. Mario Merola Following activities Manufacturing of more than 100 mock-ups with artificial defects High heat flux test of mock-ups with artificial defects Final definition of the divertor acceptance criteria Non-destructive and destructive examinations of mock-ups

19. Mario Merola Talk Overview Divertor Acceptance Criteria Assembly and hydraulic tests Irradiation tests Other activities Present and future plans

20. Mario Merola Talk Overview Divertor Acceptance Criteria Assembly and hydraulic tests Irradiation tests Other activities Present and future plans

21. Mario Merola Background and Justification Due to the extremely high heat loads expected onto the PFCs, the hydraulic design of the divertor is particularly critical. Another important issue is the definition of a proper procedure to drain and dry the divertor components. The assembly and integration procedures need to be demonstrated on a full-scale prototype with realistic tolerances, dimensions, weight and accessibility.

22. Mario Merola Time Schedule Preparatory activities for the integration and hydraulic tests –Completed Manufacturing of the full-scale divertor prototypes –Prototypes completion expected by mid-2005 Execution of the tests –Start foreseen mid-2005 –Completion expected mid-2006

23. Mario Merola Inlet temperature: 100 °C Inlet water pressure: 4.3 MPa Total pressure drop:< 1.4 MPa CHF margin:> 1.4 Total flow rate: < 1000 kg/s Divertor coolant design parameters

24. Mario Merola The overall ITER Divertor geometrical model

25. Mario Merola The results of overall ITER Divertor steady state hydraulic characterization The  p(G) function

26. Mario Merola Inlet temperature: 100 °C Inlet water pressure: 4.3 MPa Total pressure drop:< 1.4 MPa CHF margin:> 1.4 Total flow rate: < 1000 kg/s Divertor coolant design parameters

27. Mario Merola Inlet temperature: 100 °C Inlet water pressure: 4.3 MPa Total pressure drop:1.21< 1.4 MPa CHF margin:1.57> 1.4 Total flow rate: 934< 1000 kg/s Divertor coolant design parameters See G. Dell‘Orco et al., poster F 66

28. Mario Merola Talk Overview Divertor Acceptance Criteria Assembly and hydraulic tests Irradiation tests Other activities Present and future plans

29. Mario Merola Talk Overview Divertor Acceptance Criteria Assembly and hydraulic tests Irradiation tests Other activities Present and future plans

30. Mario Merola Neutron-Irradiation Experiments PARIDE 1 - 4 PARIDE 1: · temperature: 350°C · target fluence: 0.5 dpa PARIDE 2: · temperature: 700°C · target fluence: 0.5 dpa High Flux Reactor Petten, Netherlands PARIDE 3: · temperature: 200°C · target fluence: 0.2 dpa PARIDE 4: · temperature: 200°C · target fluence: 1 dpa

31. Mario Merola Testing of Tungsten Macrobrush Mock-Ups 200°C, PARIDE 3 (0.1 dpa in tungsten) - 1000 cycles x 10 MW/m 2 – overheating, loss of tiles Unrirradiated - 1000 cycles x 8 MW/m 2 – no failure - 1000 cycles x 14 MW/m 2 – no failure 200°C, PARIDE 4 (0.5 dpa in tungsten) - 1000 cycles x 10 MW/m 2 – overheating - 1000 cycles x 14 MW/m 2 – loss of tiles

32. Mario Merola Testing of W monoblock Mock-Ups unrirradiated - 1000 cycles x 10-14 MW/m 2 – no failure - 1000 cycles x 18 MW/m 2 – no failure, different technologies - 1000 cycles x 20 MW/m 2 – no failure 200°C, 0.1 dpa (in W) - 1000 cycles x 10 MW/m 2 – no failure - 1000 cycles x 14 MW/m 2 – no failure - 1000 cycles x 18 MW/m 2 – no failure 200°C, 0.5 dpa (in W) - 1000 cycles x 10 MW/m 2 – no failure - 1000 cycles x 14 MW/m 2 – no failure - 1000 cycles x 18 MW/m 2 – no failure

33. Mario Merola Irradiation of W armoured mock-ups The irradiated pure Cu interlayer leads to a reduction of the high heat flux performances in a flat tile geometry. The monoblock solution seems not to be affected by this problem.

34. Mario Merola Talk Overview Divertor Acceptance Criteria Assembly and hydraulic tests Irradiation tests Other activities Present and future plans

35. Mario Merola Talk Overview Divertor Acceptance Criteria Assembly and hydraulic tests Irradiation tests Other activities Present and future plans

36. Mario Merola Other activities High heat flux testing Design of the CB to VV locking system Experimental test on the PFC multilink attachments Brazing of twisted tapes into the VT See I. Bobin Vastra et al., poster F 265 And P. Majerus et al., poster F 239

37. Mario Merola Talk Overview Divertor Acceptance Criteria Assembly and hydraulic tests Irradiation tests Other activities Present and future plans

38. Mario Merola Talk Overview Divertor Acceptance Criteria Assembly and hydraulic tests Irradiation tests Other activities Present and future plans

39. Mario Merola Present and future plans in the divertor area Completion of the on-going activities Optimisation of the existing HHF technologies and CFC materials Promoting competitions among industries Development of repairing methods Design supporting analysis Study of the effects of ELMs Diagnostic integration NDT methods during ITER procurement