Fluid flow through very low permeability materials: A concern in the geological isolation of waste

Conference · Thu Dec 31 04:00:00 EST 1992

OSTI ID:10106879

Deal, D E

The geological isolation of waste usually involves the selection of sites where very low permeability materials exist, but there are few earth materials that are truly impermeable. Regulatory concerns for the containment of radioactive material extend for geologic periods of time (i.e., 10,000 years or more), and it becomes nearly impossible to ``assure`` the behavior of the site for such long periods of time. Experience at the Waste Isolation Pilot Plant (WIPP) shows that very slow movements of fluid can take place through materials that may, in fact, have no intrinsic permeability in their undisturbed condition. Conventional hydrologic models may not be appropriate to describe flow, may provide modeling results that could be in significant variance with reality, and may not be easy to defend during the compliance process. Additionally, the very small volumes of fluid and very slow flow rates involved are difficult to observe, measure, and quantify. The WIPP disposal horizon is excavated 655 m below the surface in bedded salt of Permian age. Salt has some unique properties, but similar hydrologic problems can be expected in site investigations were other relatively impermeable beds occur, and especially in deep sites where significant overburden and confining pressures may be encountered. Innovative techniques developed during the investigations at the WIPP may find utility when investigating other disposal sites. Ongoing work at the WIPP is expected to continue to advance understanding of flow through very low permeability materials. The study of flow under these conditions will become increasingly important as additional waste disposal sites are designed that require assurance of their safety for geological periods of time.

• Research Organization: International Technology Corp., Albuquerque, NM (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: AC04-86AL31950
• OSTI ID: 10106879
• Report Number(s): DOE/WIPP--91-047C; CONF-920307--101; ON: DE94003900
• Country of Publication: United States
• Language: English

Related Subjects

052002
053001
11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS
12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES
BRINES
FLUID FLOW
PERMEABILITY
PERMIAN PERIOD
RADIOACTIVE WASTE DISPOSAL
SALT DEPOSITS
SITE SELECTION
SITING
WASTE DISPOSAL AND STORAGE
WIPP