Proof-of-principle tests of the REKA method for in situ thermophysical property measurement
- Univ. of Nevada, Reno (United States)
It would be advantageous to measure rock thermophysical properties at Yucca Mountain around the exploratory drifts at some 500-1000 points in standard rockbolt holes. The in situ values, being primary site characteristics, would be applicable to (1) validate highly speculative empirical models for rockmass effects, (2) analyze the variability of rock properties at low cost, (3) identify initial convective effects, (4) monitor rock dryout due to ventilation, and (5) support hydrothermal site characterization. A scaled version of the thermal probe method, called REKA (Rapid Evaluation of K and Alpha) has been tested in the Mackay School of Mines Thermophysical Laboratory under different, controlled conditions in order to evaluate its application potential for field measurements when rockmass effects are present. The REKA method involves a single borehole probe with a heater and temperature measurement section. An elliptical temperature field is generated by the heater, and the temperature distribution along the length of the probe is recorded at several locations and at given time intervals for a period of 24 hours. The scaled REKA probe requires an approximately 0.9 m-deep (3 ft) hole which is 0.013 m (1/2 in) in diameter. The full-size probe version that has been used in underground mines requires approximately 1.8 m-deep (6 ft) hole with (0.045 m 1 3/4 in) diameter. Other probe sizes can also be selected in order to apply the method to the standard drillholes that are used for rockbolt installations. Three laboratory test series were conducted using different, controlled conditions in two host test beds to determine the response of the REKA probe to conditions that may be present during actual in situ measurements.
- OSTI ID:
- 130788
- Report Number(s):
- CONF-9504179-; TRN: 95:006995-0024
- Resource Relation:
- Conference: 6. annual international conference on high level radioactive waste management, Las Vegas, NV (United States), 30 Apr - 5 May 1995; Other Information: PBD: 1995; Related Information: Is Part Of High level radioactive waste management: Proceedings; PB: 811 p.
- Country of Publication:
- United States
- Language:
- English
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