Development of a leach model for a commercial nuclear waste glass
A leach model is presented for a commonly studied commercial nuclear waste glass, PNL 76-68. Boron release is taken to be a monitor of the reaction rate of the glass, while the actual releases of many other glass constituents into solution during static tests are evidently controlled by solubilities. The reaction rate determined in this way passes from linear to parabolic kinetics over the duration of the experiments analyzed, and boron concentrations in solution are found to be a function of the product of time and surface area-to-solution volume ratio. This behavior is found to be explained well by assuming the reaction is impeded by resorption of reaction products onto the reacting surface. Two model parameters are found as functions of temperature by fitting the model to published data. It is conluded that the accumulation of silica near the glass surface in a waste package in a repository could limit the rate of reaction of the glass, but not that the reaction would cease as silica reaches its solubility limit in solution.
- Research Organization:
- Pacific Northwest Laboratory, P.O. Box 999, Richland, Washington 99352
- DOE Contract Number:
- AC06-65RL01830
- OSTI ID:
- 5231064
- Journal Information:
- Nucl. Technol.; (United States), Vol. 63:1
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS
BOROSILICATE GLASS
LEACHING
HIGH-LEVEL RADIOACTIVE WASTES
BORON
CHEMICAL REACTION KINETICS
SILICA
SOLUBILITY
SOLUTIONS
CHALCOGENIDES
DISPERSIONS
DISSOLUTION
ELEMENTS
GLASS
KINETICS
MATERIALS
MINERALS
MIXTURES
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
RADIOACTIVE MATERIALS
RADIOACTIVE WASTES
REACTION KINETICS
SEMIMETALS
SEPARATION PROCESSES
SILICON COMPOUNDS
SILICON OXIDES
WASTES
052002* - Nuclear Fuels- Waste Disposal & Storage
054000 - Nuclear Fuels- Health & Safety