Determination of in-Situ Thermal Properties of Stripa Granite from Temperature Measurements in the Full-Scale Heater Experiments: Method and Preliminary Results. Technical Information Report No. 24

摘要

The in-situ thermal conductivity and thermal diffusivity of a granite rock mass at the Stripa mine, Sweden, have been extracted from the first 70 days of temperature data for the 5 kW full-scale heater experiment by means of least-squares fit to a finite-line source solution. Thermal conductivity and thermal diffusivity have been determined to be 3.69 W/(m- exp 0 C) and 1.84 x 10 exp -6 m exp 2 /s, respectively, at an average rock temperature of 23 exp 0 C (the average value of the actual temperature data used). These values are only slightly higher than the corresponding laboratory values, i.e., there is no significant size effect in the thermal properties of this rock mass. Since the size and shape of the heater canister used are similar to those considered for nuclear waste canisters and a substantial volume of rock is heated, the thermal properties obtained in this study are representative of in-situ rock mass properties under actual nuclear repository operating conditions. (ERA citation 05:021896)