Liquid metal compatibility issues for test blanket modules

Liquid metal compatibility issues are being investigated for two different test blanket modules involving either Li or Pb–17 at.%Li. A solution to the magnetohydrodynamic (MHD) problem for the V–Li concept may be attainable using multi-layer coatings or a flow channel insert with vanadium in contact with the flowing Li instead of a ceramic insulating layer. These strategies rely on the expected excellent compatibility of vanadium alloys which is being further investigated. For systems using Pb–17Li, capsule testing of SiC and various alloys is being conducted. Monolithic SiC specimens exposed for 1000 h in Pb–Li at 800 and 1100 °C showed no mass change after cleaning and no detectable increase in the Si content of the Pb–Li after the test. In order to investigate the behavior of corrosion resistant aluminide coatings, initial capsule testing at 700 °C has been used to establish baseline dissolution rates for 316 stainless steel, FeCrAl, Fe3Al and NiAl. The samples containing Al showed significantly less mass loss than 316 stainless steel, suggesting that aluminide coatings will be beneficial in this temperature range.