Association Euratom-Cea IEA Tritium and Safety Issues in LL Breeders, June 2007, Idaho Falls J-F. Salavy 1 IEA Implementing Agreement on Nuclear Technology for Fusion Reactors Liquid Breeder Blankets Subtask Coordinating Meeting on R&D for Tritium and Safety Issues in Lead-Lithium Breeders June 2007, Idaho Falls, ID, USA Permeation coating development J-F. Salavy 1, A. Aiello 2, A. Ciampichetti 2, F. Gabriel 1, O. Gastaldi 1, L. Giancarli 1, J. Konys 3, Y. Poitevin 4, I. Ricapito 2, M. Zmitko 4 ( 1 CEA, 2 ENEA, 3 FZK, 4 EFDA)

Association Euratom-Cea IEA Tritium and Safety Issues in LL Breeders, June 2007, Idaho Falls J-F. Salavy 2 Outline Basic features of the HCLL concept Recall of the EU R&D on anti permeation coatings Overview from M. Zmitko (EFDA): done this morning Overview of the permeation results for coatings on PbLi side Overview from A. Aiello (ENEA) Overview of the results on oxides coatings on He side Coatings needs from a HCLL Project point of view Summary

Association Euratom-Cea IEA Tritium and Safety Issues in LL Breeders, June 2007, Idaho Falls J-F. Salavy 3 The HCLL (He-PbLi) DEMO blanket Stiffening grid Module box (container & surface heat extraction) Breeder cooling unit (heat extraction from PbLi) He collector system (back plates) DEMO HCLL Main features 2m x 2m modules RAFM steel (EUROFER) He (8 MPa, °C) Liquid Pb-15.6Li (eutectic) as breeder and multiplier PbLi slowly re- circulating ( 10/50 rec/day) 90% 6 Li in PbLi TBR = 1.15 with 550mm Breeder radial depth Lifetime 7.5 MWy/m 2

Association Euratom-Cea IEA Tritium and Safety Issues in LL Breeders, June 2007, Idaho Falls J-F. Salavy 4 The HCLL TBMs to be tested in ITER TBMs have to be DEMO-relevant  TBMs proposal are derived from DEMO programs First TBMs have to be installed since the first day of the H-H operation (to check interfaces & main operations, compatibility with ITER operations and to support to licensing & safety) TBM design (mainly Breeder Units) will be specifically optimized for each ITER phase (at least 4 different TBMs could be tested in ITER) Each party (7) intends to test TBMs in ITER. 3 ports are allocated for TBM testing. Half- port TBM (vertical or horizontal) are considered up to now Top cover Stiffening grid BUs PbLi distribution box FW/SW Stiffening rod BUs back plates BUs He collectors PbLi feeding pipe BP1 BP2 BP3 BP4 He inlet pipe He outlet pipe PbLi outlet pipe PbLi inlet pipe Vertical shear key-way Horizontal shear key-way Back collector PbLi inlet Horizontal stiffening plate Breeding zone cell Breeding zone column LiPb distrib. box LiPb outlet PbLi flow path

Association Euratom-Cea IEA Tritium and Safety Issues in LL Breeders, June 2007, Idaho Falls J-F. Salavy 5 Recall of the EU R&D on anti permeation coatings Overview from M. Zmitko (EFDA) See presentation from M. Zmitko at this workshop: « Recent and on-going tritium-related activities in Europe for HCLL blanket »

Association Euratom-Cea IEA Tritium and Safety Issues in LL Breeders, June 2007, Idaho Falls J-F. Salavy 6 Overview of the permeation results for coatings on PbLi side - Overview from A. Aiello, ENEA Brasimone

Association Euratom-Cea IEA Tritium and Safety Issues in LL Breeders, June 2007, Idaho Falls J-F. Salavy 7 Overview of the results for oxides coatings on He side (1/2) from I. Ricapito, A. Aiello, ENEA Brasimone on-line oxidation: the oxidation part of PERI II can be seen like the device shown above where the oxidation section is represented by the high pressure side of the apparatus. In this case the water content of the Ar gas was measured by means of a hygrometer. During the test humidity was added to high purity gas flowing Argon in a water partially filled bottle. the performances of the on-line oxidation, and therefore the effectiveness of the self healing, have been tested using one oxidation time, 60 min, at 550 °C with different gas mixtures On-line oxidation and test procedure on Eurofer 97

Association Euratom-Cea IEA Tritium and Safety Issues in LL Breeders, June 2007, Idaho Falls J-F. Salavy 8 Overview of the results for oxides coatings on He side (2/2) Summary of the main results Samples of Eurofer 97 were tested in a wide range of gas mixtures, with variable water content, maintaining a constant temperature of 550°C. The variation in the specimen permeability was evaluated using a quadrupole technique while flowing the oxidant mixture in the high pressure side. The results of the permeation tests gave a PRF in the range 1 – 30 with a Gaussian shape of the PRF curve, centred on the H 2 /H 2 O molar ratio of 70/3. The micrographs confirmed the permeation results, at least in terms of oxide thickness and density. Results seems to be independent on the water partial pressure or gas mass flow rate.

Association Euratom-Cea IEA Tritium and Safety Issues in LL Breeders, June 2007, Idaho Falls J-F. Salavy 9 Coatings needs from a HCLL Project point of view (1/3) Do we need anti-permeation coatings for HCLL TBM operation in ITER? –No (low amount of Tritium, no safety concern) Do we want to test anti-permeation coatings in HCLL TBM testing campaign in ITER? –Yes (because they will be probably needed for DEMO operation and ITER will be an unique opportunity to investigate their behaviour in representative conditions) –But: Will we be able to investigate during tests their effects on permeation? What kind of PIEs can give useful information? Will we be able to produce in time?

Association Euratom-Cea IEA Tritium and Safety Issues in LL Breeders, June 2007, Idaho Falls J-F. Salavy 10 Coatings needs from a HCLL Project point of view (2/3) Will we be able to investigate their effects on permeation during ITER testing? –Difficult to answer today. Will depend on progresses of R&D on sensors and modelling tools. –Will need to be measured with and without barriers in same precise conditions: probably feasible for oxides on He side but very difficult for coatings on PbLi side What kind of PIEs can give useful information? –Remaining thickness, presence of cracks, microstructure. –Need of a dedicated PIE programme (to be developed) integrating developments of RH preparation tools to be installed in ITER hot cell.

Association Euratom-Cea IEA Tritium and Safety Issues in LL Breeders, June 2007, Idaho Falls J-F. Salavy 11 Coatings needs from a HCLL Project point of view (3/3) Will we be able to produce in time? (Note: they are not needed for the first years of operations) –Probably yes for oxides coatings, depending on He control possibilities in the Coolant Purification System for HCLL TBM He coolant circuit and on future developments onto the characterization under thermal cycle and for more relevant specimens geometries –Probably not for coatings on PbLi side if a significant increase of the R&D effort in that field is not done very quickly.

Association Euratom-Cea IEA Tritium and Safety Issues in LL Breeders, June 2007, Idaho Falls J-F. Salavy 12 Summary Coatings needs for HCLL TBM: –Not needed to operate the TBM in ITER. –Unique possibility to test in representative conditions before DEMO. Al based coatings on PbLi side: –Several techniques investigated at laboratory scale. –Huge difficulties to obtain stable coatings, even with simple geometries. –Discrepancy between anti-permeation coating efficiency data. –Efficiency difficult (impossible?) to be quantified in TBM. –Strong development effort needed to be in time for ITER testing. –need in DEMO HCLL blanket not yet fully established (depends on many parameters such as PbLi/T data, PbLi thermal hydraulic condition, efficiency of the coatings on the He-side, general T-system management, etc..). Oxide coatings on He side: –On going promising activities. –PRF ~10 to 30 obtained (ENEA). Optimisation still needed. –Possible testing in TBM for ITER operation (schedule and technical). –Characterization and qualification effort (cycling, relevant geometry) needed.