Compatibility of tritium permeation barrier coatings in water cooled ceramic breeder blanket

Strict control of tritium migration is an essential requirement for every blanket concept in a fusion reactor. Tritium permeation barriers (TPBs) have been developed in particular for liquid lithium-lead blankets using ceramic coatings; however, recent DEMO reactor design activities initiate an argument that a TPB is necessary also in solid breeder blankets. The previous studies revealed that reduced activation ferritic/martensitic (RAFM) steels and ceramic coatings reacted with solid breeder lithium ceramics under the blanket conditions, indicating the reactivity of solid breeders and its effect on tritium permeation should be taken into consideration. Moreover, not only the RAFM steel but the TPB will be exposed to pressurized water in a case where the TPB is applied to the cooling side. In this study, compatibility tests with pressurized water and lithium ceramic pebbles have been carried out for the investigation of the chemical stability of the TPB coatings and the effect on hydrogen isotope permeation in the Water Cooled Ceramic Breeder blanket.
The 20th International Conference on Fusion Reactor Materials (ICFRM-20)