In the Coralus project, for nuclear waste glass the results from laboratory tests and the corresponding modelling are compared to results obtained from in situ corrosion tests. The present report discusses the modeling of SIMS profiles, obtained form the Coralus in situ test.
Two models are used: the Fit_sims model and the Boksay model. Despite different basic assumptions, both lead (for the boron profiles) to similar values (roughly equal within a factor two) for the thickness of the gel and the thickness of the diffusion layer. For the diffusion coefficient in the gel, the difference is larger (up to a factor ten).
The thickest layers are measured at 90°C for glass dissolution next to clay (Fit Sims: gel ≈9×10-6 m, diffusion layer ≈5×10-6 m). In contact with Ca-Bentonite, the gel/diffusion layer is thinner than for glass in contact with Boom Clay (at 30°C and 90°C).
Similar to SEM measurements, the thickness measured by SIMS varies from one site to another site on the same glass sample. For SIMS, differences up to a factor five are measured. Comparing SIMS profiles with leach data and mass loss data, indicates congruent dissolution.
|Number of pages
|Published - Aug 2009
|Studiecentrum voor Kernenergie