Jenks, G. H.
Senior Chemist, Oak Ridge National Laboratory,
Pages: 17 Published: Jan 1964
A correlation and analysis of many of the data obtained at Oak Ridge National Laboratory (ORNL) for the in-pile corrosion of Zircaloy-2 in oxygenated uranyl sulfate solutions is described. These data were obtained in a program of in-pile loop and autoclave experiments in which a variety of solution compositions, solution velocities, fission power densities, and temperatures were tested. The experiments had the objective of obtaining information which would enable the prediction and control of corrosion in homogeneous reactors. The correlations were based on the following equation for the relationship between corrosion rate, R (mil per year), and fission power density in solution, P(w per ml), 1/R = K1/KPα + 1/K, where α is a factor by which the effective power density at a corroding surface is greater than that in solution, owing to uranium sorption on the surface; K1 and K are other factors evaluated from the data. A semi-empirical model for the radiation effects on the corrosion which leads to this equation is described. A brief review of experimental methods and results is also given. Considerations of the experimental corrosion data at 280 C and of probable relative and absolute values of α led to the conclusions that a relationship of the above form was obeyed up to the highest power density tested (110 w per ml), and that the values of K and K1/K were essentially independent of changes in solution composition. On the bases of the reasonable assumptions that the general relationship, with K and K1/K independent of solution composition, was obeyed at other temperatures, and that the values of α in certain experiments did not change appreciably with change in temperature, it was concluded that over the temperature range investigated (225 to 330 C) the data obtained in all experiments were reasonably well represented by the equation:
Paper ID: STP47072S