Measurement and modeling of flow through unsaturated heterogeneous rock in the context of geologic disposal of nuclear waste
- Center for Nuclear Waste Regulatory Analyses, San Antonio, TX (United States)
Deep geologic disposal of high-level and transuranic waste is currently being pursued vigorously. Assessing long-term performance of such repositories involves laboratory and field measurements, and numerical modeling. There exist two primary characteristics, associated with assessing repository performance, that define problems of modeling and measurement of non-isothermal flow through geologic media exposed to variable boundary conditions (e.g., climatic changes). These are: (1) the large time scale (tens of thousands of years) and highly variable space scale (from one meter to 10{sup 5} meters); and (2) the hierarchy of heterogeneities and discontinuities characterizing the medium. This paper provides an overview of recent work, conducted at the Center for Nuclear Waste Regulatory Analyses (CNWRA), related to laboratory experiments, consideration of similitude, and numerical modeling of flow through heterogeneous media under non-homogeneous boundary conditions. As discussed, there exist neither good methods of measuring flows at these scales nor are there adequate similitude analyses that would allow reasonable scaling up of laboratory-scale experiments. Reliable assessment of long-term geologic repositories will require sophisticated geostatistical models capable of addressing variables scales of heterogeneities conditioned with observed results from adequately sized field-scale experiments conducted for sufficiently long durations.
- Sponsoring Organization:
- Nuclear Regulatory Commission, Washington, DC (United States)
- OSTI ID:
- 435771
- Report Number(s):
- CONF-951135--; ISBN 0-7918-1755-5
- Country of Publication:
- United States
- Language:
- English
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