LAUSR

Abstract Tritium permeation through and corrosion of structural materials are critical issues in fusion reactor liquid lithium-lead blanket concepts from the viewpoints of an efficient fuel cycle, higher operation rates, and radiological safety. In this study, lithium-lead compatibility of ceramic coatings has been investigated for the development of tritium permeation barriers with corrosion protection. Erbium oxide, yttrium oxide and zirconium oxide coatings were fabricated by a metal organic decomposition method on reduced activation ferritic/martensitic steel F82H substrates. Corrosion and delamination of the coatings were accelerated under a higher oxygen concentration. Under a lower oxygen concentration, zirconium oxide coatings had the best lithium-lead compatibility among three coating materials from surface and cross-sectional observations. However, the zirconium oxide coating after lithium-lead immersion at 550 °C for 500 h showed higher deuterium permeability in comparison to the sample without immersion. Formation of a chromium oxide layer on the surface of the substrate before fabricating the coatings drastically improved the lithium-lead compatibility of erbium oxide and yttrium oxide coatings. Degradation of the coatings was mainly caused by corrosion and delamination depending on immersion temperature, test duration, and impurity concentration.