Kinetic evaluation of aqueous dissolution of P0798 simulated HLW glass as a function of dissolved silica concentration by using micro-channel flow-through test method

Inagaki, Yaohiro*; Sakatani, Keiichi*; Mitsui, Seiichiro  ; Idemitsu, Kazuya*; Arima, Tatsumi*; Noshita, Kenji*

Modeling long-term dissolution of HLW glass in geological disposal needs a consistent evaluation of glass dissolution kinetics under conditions of near silica-saturation. The evaluation of the kinetics also needs reliable and precise data obtained under well-constrained experimental conditions for multiple parameters such as pH, solution concentrations of elements and reactive glass surface area. In the present study, therefore, aqueous dissolution tests were performed for a Japanese type of simulated HLW glass, P0798, by using "Micro-channel flow-through test method" as a function of dissolved silica concentration at several constant pHs. The test results showed that the glass matrix dissolution proceeds at certain rates even under conditions of near silica-saturation, and behavior of aluminum can play an important role in the glass dissolution as well as ion-exchange of alkaline elements.