The Interaction Between Nuclear Waste Glass and Ordinary Portland Cement

The interaction between simulated reference waste glasses SON68 and SM539, and cement has been studied in suspensions of ordinary Portland cement and synthetic cement water with pH 13.5 at 30 degrees C. The cement appears to trigger glass dissolution by consumption of glass matrix components. This leads to fast glass dissolution at a constant rate with formation of a porous gel layer on the glass. A glass dissolution model has been proposed considering that the silicon coming from the glass reacts with portlandite to form C-S-H phases. The transformation of C-S-H into C-A-S-H phases is a second parallel driving force especially for the Al-rich SM539 glass. After consumption of the portlandite, the glass alteration rate is expected to decrease.