Simulation of ventilation efficiency, and pre-closure temperatures in emplacement drifts at Yucca Mountain, Nevada, using Monte Carlo and composite thermal-pulse methods
January 1, 2004
Predictions of waste canister and repository driftwall temperatures as functions of space and time are important to evaluate pre-closure performance of the proposed repository for spent nuclear fuel and high-level radioactive waste at Yucca Mountain, Nevada. Variations in the lithostratigraphic features in densely welded and crystallized rocks of the 12.8-million-year-old Topopah Spring Tuff, especially the porosity resulting from lithophysal cavities, affect thermal properties. A simulated emplacement drift is based on projecting lithophysal cavity porosity values 50 to 800 m from the Enhanced Characterization of the Repository Block cross drift. Lithophysal cavity porosity varies from 0.00 to 0.05 cm3/cm3 in the middle nonlithophysal zone and from 0.03 to 0.28 cm3/cm3 in the lower lithophysal zone. A ventilation model and computer program titled "Monte Carlo Simulation of Ventilation" (MCSIMVENT), which is based on a composite thermal-pulse calculation, simulates statistical variability and uncertainty of rock-mass thermal properties and ventilation performance along a simulated emplacement drift for a pre-closure period of 50 years. Although ventilation efficiency is relatively insensitive to thermal properties, variations in lithophysal porosity along the drift can result in a range of peak driftwall temperatures can range from 40 to 85??C for the preclosure period. Copyright ?? 2004 by ASME.
Citation Information
Publication Year | 2004 |
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Title | Simulation of ventilation efficiency, and pre-closure temperatures in emplacement drifts at Yucca Mountain, Nevada, using Monte Carlo and composite thermal-pulse methods |
Authors | J.B. Case, D.C. Buesch |
Publication Type | Conference Paper |
Publication Subtype | Conference Paper |
Index ID | 70026229 |
Record Source | USGS Publications Warehouse |
USGS Organization | Geology, Minerals, Energy, and Geophysics Science Center |