Technical note: water migration induced by thermal loading of a granitic rock mass
Water inflow into instrumentation and heater boreholes was monitored for nearly 2 years during two thermomechanical experiments in a granitic rock mass in Stripa, Sweden. Flow of water into the boreholes increased rapidly when heater power was switched on or when heater power was increased. Water inflow in most boreholes began to decline within 30-50 days past the turn on of power to the heaters. When heater power was switched off, water inflow suddenly decreased, then gradually increased with time. Thus the inflow records indicate the presence of two flow components; a relatively steady inflow from the normal hydrologic regime, and a transient flow component attributed to the closing, and with power turn off to the heaters, the opening of fractures and cracks by thermally induced stress changes. The water volumes for individual boreholes ascribed to crack closure while the heaters were operating are in the range of 1-10 liters, and are comparable to a reduction of .001 in the pore space of a .5 m radius of rock surrounding a borehole. An anomalous inflow record was noted for one borehole. As heater power was increased in one of the thermomechanical experiments, flow into the hole increased greatly, and remained high until heater power was turned off, suggesting the added thermal load may have opened a conductive fracture.
- OSTI ID:
- 6896418
- Journal Information:
- Int. J. Rock Mech. Min. Sci.; (United States), Journal Name: Int. J. Rock Mech. Min. Sci.; (United States); ISSN IJRMA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES
BOREHOLES
CAVITIES
ENVIRONMENTAL TRANSPORT
EUROPE
FABRICATION
GRANITES
HEAT TREATMENTS
HEATING
IGNEOUS ROCKS
MANAGEMENT
MASS TRANSFER
MATERIALS WORKING
PLUTONIC ROCKS
RADIOACTIVE WASTE STORAGE
ROCKS
SCANDINAVIA
STORAGE
SWEDEN
TEMPERATURE DEPENDENCE
THERMOMECHANICAL TREATMENTS
VARIATIONS
WASTE MANAGEMENT
WASTE STORAGE
WATER INFLUX
WESTERN EUROPE