In-situ measurement of corrosion rate of Zircaloy-4 was tested by applying AC-impedance method in 300degC water in a static autoclave. Impedance data of surface oxide layer of sample were obtained by the Frequency Response Analysis Method and converted into the corrosion rate, and were compared with a theoretical prediction. The results led to the conclusion that the present method permits in-situ measurement of the corrosion rate. It was also found that degradation of water quality affects the data to a considerable extent, and that the impedance data indicate the property change of the double-layer structure of oxide. (author).
Suzuki, Motoe 
- Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment