Earth Sciences Division (ESD) Department of Energy (DOE) Lawrence Berkeley National Laboratory (LBNL)

The Yucca Mountain Project: Heater Testing

Schematic of ESF Thermal Test Facility Berkeley Lab is a leader in investigating the complex coupled effects of thermal, hydrological and chemical processes driven by the heat generated from radioactive waste decay. In collaboration with other national laboratories, Berkeley Lab conducted in situ thermal tests at the Yucca Mountain Exploratory Studies Facility (ESF). Such field tests evaluate the effects of waste-generated heat on the flow system. They provide data to test models used in the repository design, achieving the optimal waste-heat load. This program again exemplifies the approach of iterative field testing and modeling for test design, test evaluation, and model refinement.

The overall objective of the underground heater tests in ESF Alcove 5 to acquire a more in-depth understanding of the coupled thermal, hydrological, mechanical, and chemical processes (THMC) at Yucca Mountain, by implementing a close integration of modeling and measurements. THMC measurements included passive monitoring data on temperature, mechanical displacement, microseismic events, and relative humidity gathered by sensors installed in instrumented boreholes; periodic active testing by geophysical methods (electrical resistivity tomography, crosshole radar tomography, borehole neutron logging) and air injection tests to monitor the redistribution of moisture; and water and gas sampling. Model predictions were performed prior to heating. As the tests progressed, data were being continuously compared to model predictions, to shed light on model conceptualization of processes, and to reevaluate the accuracy of the numerical model.

Drifts and Boreholes of the Drift-Scale Test The Underground Thermal Test Program consisted of the Single Heater Test (SHT) and the Drift Scale Test (SDT). The Single Heater Test, with a heating period of 9 months, involved a 5 m long and 4 kW line heater during 1996 and 1997. The Drift Scale Test had 9 canister heaters in the Heated Drift, and 50 wing heaters. Heating was initiated at 187 kW in December 1997, and the test was conducted over a period of 8 years.

The following links provide information on specific tests conducted under the heater testing program:

For more information, please contact:

Jens Birkholzer
Earth Sciences Division
Phone: 510-486-7134