Measurement of the glass dissolution rate in the presence of alteration phases

The dissolution rate of LD6-5412 glass was measured at 90{circ}C in the presence of its alteration phases with the Product Consistency Test (PCT) Method B, the Vapor Hydration Test (VHT), and the Accelerated Dissolution Test (ADT). Alteration phases formed during the PCTs and VHTs, but variations in the time required for their nucleation resulted in large uncertainties in the measured rates. The alteration phases are generated separately for use in the SDTs, so the measured rates are not affected by the kinetics of alteration phase nucleation. The rates measured in the PCTs, VHTs, and ADTs were 0.4 g/(m{sup 2}{sm_bullet}d) (a lower bound), 2 g/(m{sup 2}{sm_bullet}d) (extrapolated from the results of tests run at high temperatures), and 1.4 g/(m{sup 2}{sm_bullet}d), respectively. The solution pHs were about 12 in all the tests