As is well known, rector components made of zirconium-base alloys oxidise and absorb hydrogen during service. Since both phenomena are potential sources of risk during operation, monitoring of their magnitude is an important issue. Therefore, a project for the non-destructive evaluation of oxide layer thickness on fuel channels, both in-pile and in the decay pools, using the eddy current method, is underway at our laboratory. Oxide layers were grown on zircaloy-4 slabs, in autoclave in 1M LiOH, and their thickness was evaluated by optical microscopy and eddy currents. Good agreement was observed between the results obtained with both methods. The influence of the hydrogen content in the specimens on the eddy current measurements was also considered. It was possible to sort by eddy currents the zircaloy-4 specimens treated in autoclave according to their hydrogen content.Pages: 597-60
