Corrosion of radioactive aluminophosphate glasses under repository conditions

The surface corrosion of aluminophosphate glass is controlled by its interaction with underground water. The mathematical model for corrosion involves the hydrolytic dissolution of glass, generation and growth of the surface corrosion layer, diffusion through it and chemical reaction in solution. The corrosion layer growth rate and the leaching rate have been approximated. It is assumed that stratal water saturated with phosphate ions can dissolve the glass. At an early stage the dissolution is diffusion-like, i.e. proportional to the square root of time. Later, it is linear with time. This paper shows the growth of a stable front of a glass corrosion layer. The mathematical model was used to process experimental data. There are some recommendations for future work. (author)