TY - GEN
T1 - Obtaining solubility constants to describe the incongruent dissolution of SON68 waste glass by an equilibrium ideal solid solution model approach
AU - Jacques, Diederik
AU - Lemmens, Karel
N1 - Score = 1
PY - 2006
Y1 - 2006
N2 - One of the waste forms resulting from the Belgian programme for nuclear energy is the R7T7 high level waste glass, simulated by the SON68 glass. When exposed to distilled water or synthetic interstitial clay water, SON68 glass dissolves incongruently, releasing some elements (B, Li, Na) faster to the solution than others (Si, Al, Ca). The objective of this study is to describe the composition of the leachate in contact with inactive SON68 glass by assuming congruent glass dissolution followed by the precipitation of a secondary solid phase represented as an ideal solid solution in equilibrium with the leachate. Experimental SON68 dissolution data in distilled water was available at three temperatures. The solubility of the different end members in the solid solution is optimized using the available data for each temperature. The temperature dependence of the different end members was then obtained by Van 't Hoff equation. The calibrated model can describe the composition of the leachate and the altered glass phase during glass dissolution at different temperatures. The model, calibrated for the distilled water system, could successfully describe the composition of the leachate during glass dissolution experiments in a synthetic clay water system.
AB - One of the waste forms resulting from the Belgian programme for nuclear energy is the R7T7 high level waste glass, simulated by the SON68 glass. When exposed to distilled water or synthetic interstitial clay water, SON68 glass dissolves incongruently, releasing some elements (B, Li, Na) faster to the solution than others (Si, Al, Ca). The objective of this study is to describe the composition of the leachate in contact with inactive SON68 glass by assuming congruent glass dissolution followed by the precipitation of a secondary solid phase represented as an ideal solid solution in equilibrium with the leachate. Experimental SON68 dissolution data in distilled water was available at three temperatures. The solubility of the different end members in the solid solution is optimized using the available data for each temperature. The temperature dependence of the different end members was then obtained by Van 't Hoff equation. The calibrated model can describe the composition of the leachate and the altered glass phase during glass dissolution at different temperatures. The model, calibrated for the distilled water system, could successfully describe the composition of the leachate during glass dissolution experiments in a synthetic clay water system.
KW - SON68
KW - Geochemical model
KW - Solid solutions
KW - Glass dissolution
UR - http://ecm.sckcen.be/OTCS/llisapi.dll/open/ezp_30820
U2 - 10.1557/proc-932-90.1
DO - 10.1557/proc-932-90.1
M3 - In-proceedings paper
SN - 1558998896
SN - 9781558998896
T3 - Materials Research Society Symposium Proceedings
SP - 337
EP - 344
BT - 29th International Symposium on the Scientific Basis for Nuclear Waste Management XXIX
PB - MRS - Materials Research Society
CY - Warrendale, United States
T2 - 2005 - MRS
Y2 - 12 September 2005 through 16 September 2005
ER -