Overview of chemical modeling of nuclear waste glass dissolution

Conference · Fri Feb 01 00:00:00 EST 1991

OSTI ID:138041

Bourcier, W L

Glass dissolution takes place through metal leaching and hydration of the glass surface accompanied by development of alternation layers of varying crystallinity. The reaction which controls the long-term glass dissolution rate appears to be surface layer dissolution. This reaction is reversible because the buildup of dissolved species in solution slows the dissolution rate due to a decreased dissolution affinity. Glass dissolution rates are therefore highly dependent on silica concentrations in solution because silica is the major component of the alteration layer. Chemical modeling of glass dissolution using reaction path computer codes has successfully been applied to short term experimental tests and used to predict long-term repository performance. Current problems and limitations of the models include a poorly defined long-term glass dissolution mechanism, the use of model parameters determined from the same experiments that the model is used to predict, and the lack of sufficient validation of key assumptions in the modeling approach. Work is in progress that addresses these issues. 41 refs., 7 figs., 2 tabs.

• Research Organization: Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
• Sponsoring Organization: USDOE, Washington, DC (USA)
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 138041
• Report Number(s): UCRL-JC-104531; CONF-901105-109; ON: DE91009625
• Resource Relation: Conference: Fall meeting of the Materials Research Society (MRS), Boston, MA (United States), 24 Nov - 1 Dec 1990; Other Information: PBD: Feb 1991
• Country of Publication: United States
• Language: English

Related Subjects

05 NUCLEAR FUELS
40 CHEMISTRY
BOROSILICATE GLASS
DISSOLUTION
HIGH-LEVEL RADIOACTIVE WASTES
UNDERGROUND DISPOSAL
MATHEMATICAL MODELS
KINETICS
LEACHING
HYDRATION
MONTE CARLO METHOD
PH VALUE
SUBSURFACE ENVIRONMENTS
ALPHA-BEARING WASTES
SILICON OXIDES
WATER
SATURATION
BORON
ALUMINIUM
IRON
MANGANESE
CALCIUM
SODIUM
LITHIUM
LEACHATES
CHEMICAL COMPOSITION
YUCCA MOUNTAIN
Yucca Mountain Project