Thermal gradient brine inclusion migration in salt study: gas-liquid inclusions, preliminary model

Technical Report · Mon Oct 01 04:00:00 EDT 1979

OSTI ID:5430360

Olander, D R; Machiels, A J

Natural salt deposits contain small cubical inclusions of brine distributed through the salt. Temperature gradients, resulting from storing heat-generating wastes in the salt, can cause the inclusions to move through the salt. Prediction of the rate and amount of brine-inclusion migration is necessary for the evaluation of bedded or domed salts as possible media for waste repositories. Inclusions filled exclusively with liquid migrate up the temperature gradient towards the heat source. The solubility of salt in the brine inclusion increases with temperature. Consequently, salt dissolves into the inclusion across the hot surface and crystallizes out at the cold surface. Diffusion of salt within the liquid phase from the hot to the cold faces causes the inclusions to move in the opposite direction. In so doing, they change shape and eventually become rectangular parallelipipeds with a width (dimension perpendicular to the thermal gradient) much larger than the thickness (dimension in the direction of the thermal gradient). The inclusions may also contain a gas phase predominantly consisting of water vapor. These entities are termed two-phase or gas-liquid inclusions. The two-phase inclusions usually migrate down the temperature gradient away from the heat source remaining more-or-less cubical. A two-phase inclusion also forms when an all-liquid inclusion reaches the waste package; upon opening up at the salt-package interface, the brine partially evaporates and the inclusion reseals with some insoluble gas trapped inside. These gas-liquid inclusions proceed to move down the temperature gradient, in the opposite sense of the all-liquid inclusions. The gas-liquid inclusions phenomenon provides a pathway by which radionuclides leached from the wasteform by the brine can be transported away from the waste package and thus might have greater access to the biosphere.

• Research Organization: California Univ., Berkeley (USA)
• DOE Contract Number: EY-76-C-06-1830
• OSTI ID: 5430360
• Report Number(s): ONWI-85
• Country of Publication: United States
• Language: English

Related Subjects

052002* -- Nuclear Fuels-- Waste Disposal & Storage
12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES
58 GEOSCIENCES
580100 -- Geology & Hydrology-- (-1989)
BRINES
DATA
DATA FORMS
DISSOLUTION
ENVIRONMENTAL TRANSPORT
FLUIDS
GASES
GEOLOGIC DEPOSITS
GRAPHS
HIGH TEMPERATURE
INCLUSIONS
INFORMATION
LEACHING
LIQUIDS
MANAGEMENT
MASS TRANSFER
MATHEMATICAL MODELS
MEDIUM TEMPERATURE
NUMERICAL DATA
PHYSICAL PROPERTIES
RADIOACTIVE WASTE DISPOSAL
RADIONUCLIDE MIGRATION
SALT DEPOSITS
SEPARATION PROCESSES
SOLUBILITY
TABLES
TEMPERATURE DEPENDENCE
TEMPERATURE GRADIENTS
THEORETICAL DATA
THERMODYNAMIC PROPERTIES
UNDERGROUND DISPOSAL
VELOCITY
WASTE DISPOSAL
WASTE MANAGEMENT