Basaltic glass corrosion in the GRAAL model

Whole title Contribution of basaltic glass to the validation of the GRAAL model over geological time scale

Subject GRAAL model was developed to calculate the corrosion rate of R7T7-type nuclear glass as a function of time and environmental conditions (temperature, nature and renewal rate of the groundwater, presence of nearfield materials) (Frugier et al., J. Nucl.Mater. 2008). A recent study attempts to extend the model to the whole R7T7 domain (pHD thesis by Fleury, 2013).

Because internal parameters of the model are semi-empirical (composition, solubility and water diffusion through the passivating layer, initial dissolution rate), the parameterization of the model requires specific experiments on the glass of interest.

The validation of the GRAAL model, especially over geological time scale could be envisioned thanks an application to basaltic glass samples from Iceland and Sicily altered in the field from few thousands year until few millions year. This goal is made possible because both types of glasses, i.e. basaltic and nuclear, display similar corrosion mechanisms, already captured in GRAAL.

The present dissertation aims to parameterize GRAAL for basaltic glass compositions following a similar experimental approach than that of the R7T7 glass (experiments on simplified glasses altered at various T and pHs).

More information ...

Expected profile Master of Science (already obtained or currently in progress), great skills in geochemistry and if possible in glass science. The candidate must be motivated both by experimentation and modeling.

Location Marcoule (Gard), France

Contact Dr Stéphane Gin