Pb-Li compatibility issues for DEMO

The current dual coolant fusion blanket concept is limited to a ∼475 C (748 K) wall temperature due to dissolution/redeposition of the FeCr steel in Pb-Li. Higher wall temperatures could be achieved if compatibility issues can be controlled. Isothermal capsule experiments have demonstrated that thin (<50 μm) Al-rich coatings on Gr.92 steel can reduce mass loss in Pb-Li for up to 5000 h at 700 C (973 K) and that similar coating performance was obtained for coated oxide dispersion strengthened FeCr steels at 700 C (973 K). Dissimilar material experiments at 700 C (973 K) suggested a possible reaction between Fe and SiC in Pb-Li that needs to be further studied as it could limit the blanket temperatures.