PERMEATION STUDY OF BREAKDOWN AND REPAIR OF BARRIER OXIDE AT ALLOY OXIDE INTERFACES

We are investigating the effectiveness of surface oxides as barriers t o the absorption of deuterium by Zr-2.5Nb and 403 SS (stainless steel) . In our equipment, breakdown of such barriers is signalled by permeat ion of D, detected by a mass spectrometer. First results indicate that permeation through Zr-2.5Nb can easily be prevented by continued expo sure to a low partial pressure of oxygen. For 403 SS, oxygen also prod uces a barrier to D2, though it is less effective for 403 SS than for Zr-2.5Nb.