Mass transfer in a salt repository

Technical Report · Wed May 01 04:00:00 EDT 1985

DOI:https://doi.org/10.2172/6381376· OSTI ID:6381376

Pigford, T H; Chambre, P L

To meet regulatory requirements for radioactive waste in a salt repository it is necessary to predict the rates of corrosion of the waste container, the release rates of radionuclides from the waste package, and the cumulative release of radionuclides into the accessible environment. The mechanisms that may control these rates and an approach to predicting these rates from mass-transfer theory are described. This new mechanistic approach is suggested by three premises: (a) a brine inclusion originally in a salt crystal moves along grain boundaries after thermal-induced migration out of the crystal, (b) brine moves along a grain boundary under the influence of a pressure gradient, and (c) salt surrounding a heat-generating waste package will soon creep and consolidate as a monolithic medium surrounding and in contact with the waste package. After consolidation there may be very little migration of intergranular and intragranular brine to the waste package. The corrosion rate of the waste container may then be limited by the rate at which brine reaches the container and may be calculable from mass-transfer theory, and the rate at which dissolved radionuclides leave the waste package may be limited by molecular diffusion in intragranular brine and may be calculable from mass-transfer theory. If porous nonsalt interbeds intersect the waste-package borehole, the release rate of dissolved radionuclides to interbed brine may also be calculable from mass-transfer theory. The logic of these conclusions is described, as an aid in formulating the calculations that are to be made.

• Research Organization: Lawrence Berkeley Lab., CA (USA)
• DOE Contract Number: AC03-76SF00098
• OSTI ID: 6381376
• Report Number(s): LBL-19918; UCB-NE-4058; ON: DE86006384
• Country of Publication: United States
• Language: English

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& Rock Mechanics-- (-1989)
BRINES
CHEMICAL REACTIONS
CONTAINERS
CORROSION
CREEP
CRYSTAL STRUCTURE
GEOLOGIC DEPOSITS
GRAIN BOUNDARIES
INCLUSIONS
MASS TRANSFER
MECHANICAL PROPERTIES
MICROSTRUCTURE
SALT DEPOSITS
TIME DEPENDENCE