Publications Details
Thermal expansion, thermal conductivity, and heat capacity measurements for boreholes UE25 NRG-4, UE25 NRG-5, USW NRG-6, and USW NRG-7/7A
Specimens were tested from four thermal-mechanical units, namely Tiva Canyon (TCw), Paintbrush Tuff (PTn), and two Topopah Spring units (TSw1 and TSw2), and from two lithologies, i.e., welded devitrified (TCw, TSw1, TSw2) and nonwelded vitric tuff (PTn). Thermal conductivities in W(mk){sup {minus}1} averaged over all boreholes, ranged (depending upon temperature and saturation state) from 1.2 to 1.9 for TCw, from 0.4 to 0.9 for PTn, from 1.0 to 1.7 for TSw1, and from 1.5 to 2.3 for TSw2. Mean coefficients of thermal expansion were highly temperature dependent and values, averaged over all boreholes, ranged (depending upon temperature and saturation state) from 6.6 {times} 10{sup {minus}6} to 49 {times} 10{sup {minus}6} C{sup {minus}1} for TCw, from the negative range to 16 {times} 10{sup {minus}6} {center_dot} {degree}C{sup {minus}1} for PTn, from 6.3 {times} 10{sup {minus}6} to 44 {times} 10{sup {minus}6} C{sup {minus}1} for TSw1, and from 6.7 {times} 10{sup {minus}6} to 37 {times} 10{sup {minus}6} {center_dot} {degree}C{sup {minus}1} for TSw2. Mean values of thermal capacitance in J/cm{sup 3}K (averaged overall specimens) ranged from 1.6 J to 2.1 for TSw1 and from 1.8 to 2.5 for TSw2. In general, the lithostratigraphic classifications of rock assigned by the USGS are consistent with the mineralogical data presented in this report.