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Summary of heat management concepts for an unsaturated tuff repository

Journal Article · · Transactions of the American Nuclear Society
OSTI ID:89021

Yucca Mountain, Nevada, is being evaluated as a potential repository site for high-level nuclear waste and spent reactor fuel. Vitrified reprocessing waste will generate significant heat for hundreds of years, whereas spent reactor fuel will do so for up to a hundred thousand years. Thermal loads evaluated for repository conceptual design have been in the range of 20 to 120 kW/acre at emplacement, compared with a flux resulting from the geothermal gradient of 0.2 kW/acre. This heat could have significant consequences for repository performance. The repository horizon is an unsaturated tuff with {approximately}15% porosity. About two-thirds of the rock-pore-volume contains liquid water. The remaining third contains air near 100% relative humidity. At these saturation levels at an ambient temperature of 25{degrees}C, water does not flow into openings except along occasional fractures. However, heat from emplaced waste mobilizes water in the rock and might cause increased flow of liquid water into the openings.

OSTI ID:
89021
Report Number(s):
CONF-941102--
Journal Information:
Transactions of the American Nuclear Society, Journal Name: Transactions of the American Nuclear Society Vol. 71; ISSN 0003-018X; ISSN TANSAO
Country of Publication:
United States
Language:
English