1. KIT – University of the State of Baden-Württemberg and National Research Center of the Helmholtz Association Institute for Technical Physics – Tritium Laboratory Karlsruhe www.kit.edu Tritium coupled phenomena in solid breeder blanket concepts: state of the art and rationale for future work plan David DEMANGE

2. 2 Institute for Technical Physics Tritium Laboratory Karlsruhe 10/09/11 D. Demange, 16th CBBI KIT – University of the State of Baden-Württemberg and National Research Center of the Helmholtz Association Content Introduction to TBM CA and Predictive Tools Group Coupled phenomena: material & environmental parameters Proposal for experiments in ITER TBM State of the art on simulations State of the art on experiments Future R&D

3. 3 Institute for Technical Physics Tritium Laboratory Karlsruhe 10/09/11 D. Demange, 16th CBBI KIT – University of the State of Baden-Württemberg and National Research Center of the Helmholtz Association EU TBM – Consortium of Associates

4. 4 Institute for Technical Physics Tritium Laboratory Karlsruhe 10/09/11 D. Demange, 16th CBBI KIT – University of the State of Baden-Württemberg and National Research Center of the Helmholtz Association EU TBM – Predictive tools group Objective: Develop “DEMO relevant” experimental program & simulation capacity Topics (for HCPB): Electromagnetic Pebble bed mechanics Thermo hydraulic Tritium transfer cycle N: neutronics Others…(coupling) Methodology: 1) Expression of the needs (what kind of experiments we want to perform) 2) State of the art and rationale of R&D programme 3) Write and propose the programme to F4E

5. 5 Institute for Technical Physics Tritium Laboratory Karlsruhe 10/09/11 D. Demange, 16th CBBI KIT – University of the State of Baden-Württemberg and National Research Center of the Helmholtz Association Coupled phenomena in HCPB …rather vague, not well defined …intrinsically difficult and challenging for both experiments and model point of view …elucidate T behaviour (migration and release) in ceramic breeder and beryllium multiplier under operation as it will be in the machine …Need collaboration and cooperation of many experts

6. 6 Institute for Technical Physics Tritium Laboratory Karlsruhe 10/09/11 D. Demange, 16th CBBI KIT – University of the State of Baden-Württemberg and National Research Center of the Helmholtz Association Coupled phenomena – organisation

7. 7 Institute for Technical Physics Tritium Laboratory Karlsruhe 10/09/11 D. Demange, 16th CBBI KIT – University of the State of Baden-Württemberg and National Research Center of the Helmholtz Association Objective and methodology 1)Propose a list of experiments/tests to be performed in ITER with the aim to achieve a reliable TBMs testing programme 2)Compare the proposed tests/experiments requirements with the present state-of-the-art and assess maturity level 3)Propose an action list for future work plan aiming at covering the gap Important remarks ITER operation implies constraints and could globally restrict the possibilities (availability, invasiveness, accuracy…) time schedule for tritium in TBM is rather late (not before 2026) “satellites” experiments could be favoured when possible, recommended for fundamental aspects of coupled phenomena

8. 8 Institute for Technical Physics Tritium Laboratory Karlsruhe 10/09/11 D. Demange, 16th CBBI KIT – University of the State of Baden-Württemberg and National Research Center of the Helmholtz Association Content Introduction to TBM CA and Predictive Tools Group Coupled phenomena: material & environmental parameters Proposal for experiments in ITER TBM State of the art on simulations State of the art on experiments Future R&D

9. 9 Institute for Technical Physics Tritium Laboratory Karlsruhe 10/09/11 D. Demange, 16th CBBI KIT – University of the State of Baden-Württemberg and National Research Center of the Helmholtz Association Coupled phenomena – parameters Intrinsic parameters Chemical composition Pebble diameter Porosity (open/closed) Texture (grain size) Surface chemistry Post treatment Defaults / voids Environmental parameters  Which operation parameter can influence which material parameter?  What consequence on tritium release after (very) long operation time? “AGEING EFFECT” Burn-up Temperature (cycles) Purge gas chemistry Neutron flux Magnetic field Tritium release parameter Macroscopic - Microscopic Damage To be detailed (list extension, ranking, clarification…)

10. 10 Institute for Technical Physics Tritium Laboratory Karlsruhe 10/09/11 D. Demange, 16th CBBI KIT – University of the State of Baden-Württemberg and National Research Center of the Helmholtz Association Matrix view of ageing effect Operating conditions Material parameters TimeNeutron Magnetic field Temperat ure cycles Purge gas Bulk chemistry Yes Yes (burn-up) NoNo (?) Yes (reductive) Surface chemistry Yes?No Yes (drying) Yes (reductive) Pebbles diameter Yes?No? Open / close porosity Yes No? Grain sizeYes?NoMaybeNo Defaults, voids Yes Yes (burn-up) Yes?No

11. 11 Institute for Technical Physics Tritium Laboratory Karlsruhe 10/09/11 D. Demange, 16th CBBI KIT – University of the State of Baden-Württemberg and National Research Center of the Helmholtz Association Content Introduction to TBM CA and Predictive Tools Group Coupled phenomena: material & environmental parameters Proposal for experiments in ITER TBM State of the art on simulations State of the art on experiments Future R&D

12. 12 Institute for Technical Physics Tritium Laboratory Karlsruhe 10/09/11 D. Demange, 16th CBBI KIT – University of the State of Baden-Württemberg and National Research Center of the Helmholtz Association Coupled phenomena – ITER TBM IN ITER, all effects act at the same time (discrimination impossible)  Experiments can only validate the technology (but not the science)

13. 13 Institute for Technical Physics Tritium Laboratory Karlsruhe 10/09/11 D. Demange, 16th CBBI KIT – University of the State of Baden-Württemberg and National Research Center of the Helmholtz Association Experiments in ITER TBM Repeat frequently the same experiment (during DT phase) Tritium release rate HT/HTO ratio Mains issues to tackle When do changes happen? What are the consequences on tritium release? What are the material properties modifications? Measurements necessary Operational conditions (temperature, neutron fluxes,…) Tritium measurements (on line) Post Irradiation Examinations (tritium inventory + mechanical properties + microstructure….)

14. 14 Institute for Technical Physics Tritium Laboratory Karlsruhe 10/09/11 D. Demange, 16th CBBI KIT – University of the State of Baden-Württemberg and National Research Center of the Helmholtz Association Content Introduction to TBM CA and Predictive Tools Group Coupled phenomena: material & environmental parameters Proposal for experiments in ITER TBM State of the art on simulations State of the art on experiments Future R&D

15. 15 Institute for Technical Physics Tritium Laboratory Karlsruhe 10/09/11 D. Demange, 16th CBBI KIT – University of the State of Baden-Württemberg and National Research Center of the Helmholtz Association … all what follows is “only” compilation from recent peer reviewed literature to get a clear picture on state of the art for tritium coupled phenomena Ceramic breederNeutron multiplier Experiments In pile Out of pile SimulationsUS and JAEU

16. 16 Institute for Technical Physics Tritium Laboratory Karlsruhe 10/09/11 D. Demange, 16th CBBI KIT – University of the State of Baden-Württemberg and National Research Center of the Helmholtz Association “Simple” simulation from US (UCLA) Detailed microstructure Surface coverage Benchmarked with in-pile experiments (limited) A. Badawi et al., J. Nucl. Mater. 273 (1999) 79 M.A. Abdou et al., Fusion Technol. 18 (1990) 165

17. 17 Institute for Technical Physics Tritium Laboratory Karlsruhe 10/09/11 D. Demange, 16th CBBI KIT – University of the State of Baden-Württemberg and National Research Center of the Helmholtz Association “Fine” simulation from JA (Kyushu) Water layer at the grain surface Isotopic exchanges - gas/gas, - water/water + water formation Benchmark with out of pile experiments (satisfactory) T. Kinjyo et al., Fusion Eng. Des. 83 (2008) 580

18. 18 Institute for Technical Physics Tritium Laboratory Karlsruhe 10/09/11 D. Demange, 16th CBBI KIT – University of the State of Baden-Württemberg and National Research Center of the Helmholtz Association Content Introduction to TBM CA and Predictive Tools Group Coupled phenomena: material & environmental parameters Proposal for experiments in ITER TBM State of the art on simulations State of the art on experiments Future R&D

19. 19 Institute for Technical Physics Tritium Laboratory Karlsruhe 10/09/11 D. Demange, 16th CBBI KIT – University of the State of Baden-Württemberg and National Research Center of the Helmholtz Association In pile T release (at HFR Petten) J. Van der Laan et al., Fusion Eng. Des. 39–40 (1998) 751 M.M.W. Peeters et al., Fusion Eng. Des. 82 (2007) 2318 Huge differences for different grades of same material

20. 20 Institute for Technical Physics Tritium Laboratory Karlsruhe 10/09/11 D. Demange, 16th CBBI KIT – University of the State of Baden-Württemberg and National Research Center of the Helmholtz Association In pile T release (WWRK & YAYOI) Y. Chikhray et al., J. Nucl. Mater. 367-370 (2007) 1028 K. Tsuchiya et al., Fusion Eng. Des. 51–52 (2000) 887 On line and real time tritium monitoring (without or with HTO/HT discrimination)

21. 21 Institute for Technical Physics Tritium Laboratory Karlsruhe 10/09/11 D. Demange, 16th CBBI KIT – University of the State of Baden-Württemberg and National Research Center of the Helmholtz Association Out of pile T release T. Kinjyo et al., Fusion Eng. Des. 82 (2007) 2147 T. Kinjyo et al., Fusion Eng. Des. 81 (2006) 573 Very good agreement between experiments and model especially when H2O in purge gas

22. 22 Institute for Technical Physics Tritium Laboratory Karlsruhe 10/09/11 D. Demange, 16th CBBI KIT – University of the State of Baden-Württemberg and National Research Center of the Helmholtz Association Purge gas and surface reactions M. Nishikawa et al., J. Nucl. Mater. 335 (2004) 70 Effect of purge gas and temperature well understood

23. 23 Institute for Technical Physics Tritium Laboratory Karlsruhe 10/09/11 D. Demange, 16th CBBI KIT – University of the State of Baden-Württemberg and National Research Center of the Helmholtz Association Diffusion or surface limited regime M. Nishikawa et al., Fusion Eng. Des. 39-40 (1998) 615 T. Kawagoe et al., J. Nucl. Mater. 297 (2001) 27 If grain size change over long time operation…

24. 24 Institute for Technical Physics Tritium Laboratory Karlsruhe 10/09/11 D. Demange, 16th CBBI KIT – University of the State of Baden-Württemberg and National Research Center of the Helmholtz Association High burn up effect Facilitated T release with high burn up only sensitive at low temperatures J. van der Laan et al., J. Nucl. Mater. 233- 237 (1996) 1446

25. 25 Institute for Technical Physics Tritium Laboratory Karlsruhe 10/09/11 D. Demange, 16th CBBI KIT – University of the State of Baden-Württemberg and National Research Center of the Helmholtz Association Post irradiation experiments G. Piazza et al., J. Nucl. Mater. 329–333 (2004) 1260 T release for high burn up (11%) occurs at lower temperature capsule 8-13 from EXOTIC-8 with 11% Li-burn-up

26. 26 Institute for Technical Physics Tritium Laboratory Karlsruhe 10/09/11 D. Demange, 16th CBBI KIT – University of the State of Baden-Württemberg and National Research Center of the Helmholtz Association Long term annealing Microstructure, composition changed,… G. Piazza et al., J. Nucl. Mater. 329–333 (2004) 1260 After 96 days at 970°C with He + 0.1% H2

27. 27 Institute for Technical Physics Tritium Laboratory Karlsruhe 10/09/11 D. Demange, 16th CBBI KIT – University of the State of Baden-Württemberg and National Research Center of the Helmholtz Association Effect of porosity M.M.W. Peeters et al., Fusion Eng. Des. 82 (2007) 2318 Open porosity facilitate T release, closed porosity has no effect

28. 28 Institute for Technical Physics Tritium Laboratory Karlsruhe 10/09/11 D. Demange, 16th CBBI KIT – University of the State of Baden-Württemberg and National Research Center of the Helmholtz Association Effect of magnetic field G. Kizane et al., Fusion Eng. Des. 75- 79 (2005) 897 J. Tiliks et al., J. Nucl. Mater. 386– 388 (2009) 874 Magnetic field and electron radiation seem both to facilitate T release

29. 29 Institute for Technical Physics Tritium Laboratory Karlsruhe 10/09/11 D. Demange, 16th CBBI KIT – University of the State of Baden-Württemberg and National Research Center of the Helmholtz Association Conclusions For tritium in functional materials huge amount of experimental results produced on tritium behaviour understanding of fundamental phenomena is well advanced On coupled phenomena the system is much more difficult to apprehend insufficient results have been produced dedicated modelling inexistent, ageing effect not included Accordingly it is difficult to ensure over the overall life-time of a solid blanket self sufficiency and reasonable tritium inventory, tritium behaviour not dramatically affected …But ageing effect and coupled phenomena seem to facilitate tritium release

30. 30 Institute for Technical Physics Tritium Laboratory Karlsruhe 10/09/11 D. Demange, 16th CBBI KIT – University of the State of Baden-Württemberg and National Research Center of the Helmholtz Association Content Introduction to TBM CA and Predictive Tools Group Coupled phenomena: material & environmental parameters Proposal for experiments in ITER TBM State of the art on simulations State of the art on experiments Future R&D

31. 31 Institute for Technical Physics Tritium Laboratory Karlsruhe 10/09/11 D. Demange, 16th CBBI KIT – University of the State of Baden-Württemberg and National Research Center of the Helmholtz Association Rationale for future R&D fabrication of wide range of materials is recommended (silicate and titanate, with wide range of porosity, grain size) using the latest production routes [2010-2015] irradiation campaign up to high burn-up and tritium measurement (in- and out-of-pile) systematically associated with post irradiation examinations of all these materials (mechanical, optical, tritium residual inventory…) [2013-2018] development of model and simulation tools for tritium release phenomena at the pebble scale, including ageing effects, with input from experimental data on tritium release and correlation between possible coupled phenomena [2013-2018] development and demonstration of alternative tritium measurement techniques such as advanced spectroscopic analytical techniques with the possibility to discriminate between chemical species [2013-2018]

32. 32 Institute for Technical Physics Tritium Laboratory Karlsruhe 10/09/11 D. Demange, 16th CBBI KIT – University of the State of Baden-Württemberg and National Research Center of the Helmholtz Association Acknowledgements to… Experts that participated to the work - L. Magielsen, J. Van der Laan (NRG) - F. Gabriel, N. Ghirelli, (CEA) - E. Magnani, A. Klix(KIT) - L. Sedano (CIEMAT) Major support and funding - Fusion Program from KIT - Fusion for Energy - EU TBM Consortium …Thank you for your attention

33. 33 Institute for Technical Physics Tritium Laboratory Karlsruhe 10/09/11 D. Demange, 16th CBBI KIT – University of the State of Baden-Württemberg and National Research Center of the Helmholtz Association State of the art - conclusion “Despite increasing research activity and remarkable progress in understanding tritium transport mechanisms in ceramic breeders during the past decade, a full understanding on this subject is still far from being reached. Tritium release from ceramic breeder materials is a complex process which cannot be predicted accurately using a simple model. Purely diffusion or desorption models have been applicable over a small range of experimental conditions but have failed under slightly different conditions. Parameters such as temperature, purge gas compositions, and microstructure characteristics (i.e., grain size, pore size, BET surface area) have been found to strongly affect each tritium transport step of the release sequence and ultimately the overall release rate and inventory.” G. Federici et al., J. Nucl. Mater. 187 (1992) 1