Joint seismic, hydrogeological, and geomechanical investigations of a fracture zone in the Grimsel Rock Laboratory, Switzerland

Technical Report · Fri Jun 01 00:00:00 EDT 1990

DOI:https://doi.org/10.2172/6290417· OSTI ID:6290417

Majer, E L; Myer, L R; Peterson, Jr, J E; Karasaki, K; Long, J C.S.; Martel, S J ^[1]; Bluemling, P; Vomvoris, S ^[2]

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1. Lawrence Berkeley Lab., CA (USA)
2. Swiss National Cooperative for the Storage of Nuclear Waste, Baden (Switzerland)

This report is one of a series documenting the results of the Nagra-DOE Cooperative (NDC-I) research program in which the cooperating scientists explore the geological, geophysical, hydrological, geochemical, and structural effects anticipated from the use of a rock mass as a geologic repository for nuclear waste. From 1987 to 1989 the United States Department of Energy (DOE) and the Swiss Cooperative for the Storage of Nuclear Waste (Nagra) participated in an agreement to carryout experiments for understanding the effect of fractures in the storage and disposal of nuclear waste. As part of this joint work field and laboratory experiments were conducted at a controlled site in the Nagra underground Grimsel test site in Switzerland. The primary goal of these experiments in this fractured granite was to determine the fundamental nature of the propagation of seismic waves in fractured media, and to relate the seismological parameters to the hydrological parameters. The work is ultimately aimed at the characterization and monitoring of subsurface sites for the storage of nuclear waste. The seismic experiments utilizes high frequency (1000 to 10,000 Hertz) signals in a cross-hole configuration at scales of several tens of meters. Two-, three-, and four-sided tomographic images of the fractures and geologic structure were produced from over 60,000 raypaths through a 10 by 21 meter region bounded by two nearly horizontal boreholes and two tunnels. Intersecting this region was a dominant fracture zone which was the target of the investigations. In addition to these controlled seismic imaging experiments, laboratory work using core from this region were studied for the relation between fracture content, saturation, and seismic velocity and attenuation. In-situ geomechanical and hydrologic tests were carried out to determine the mechanical stiffness and conductivity of the fractures. 20 refs., 90 figs., 6 tabs.

• Research Organization: Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Nationale Genossenschaft fuer die Lagerung Radioaktiver Abfaelle (NAGRA), Baden (Switzerland)
• Sponsoring Organization: DOE/ER
• DOE Contract Number: AC03-76SF00098
• OSTI ID: 6290417
• Report Number(s): LBL-27913; NDC-14; ON: DE91004657; TRN: 91-002954
• Country of Publication: United States
• Language: English

Related Subjects

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES
58 GEOSCIENCES
GEOLOGIC FRACTURES
SEISMIC WAVES
RADIOACTIVE WASTES
UNDERGROUND DISPOSAL
ANISOTROPY
BOREHOLES
GEOLOGIC SURVEYS
GRANITES
HYDROLOGY
LEAKS
MAPPING
RADIOACTIVE WASTE DISPOSAL
RADIOACTIVE WASTE FACILITIES
SEISMIC SURVEYS
SWITZERLAND
TOMOGRAPHY
UNDERGROUND FACILITIES
WELL LOGGING
CAVITIES
DIAGNOSTIC TECHNIQUES
EUROPE
GEOLOGIC STRUCTURES
GEOPHYSICAL SURVEYS
IGNEOUS ROCKS
MANAGEMENT
MATERIALS
NUCLEAR FACILITIES
PLUTONIC ROCKS
RADIOACTIVE MATERIALS
ROCKS
SURVEYS
WASTE DISPOSAL
WASTE MANAGEMENT
WASTES
WESTERN EUROPE
052002* - Nuclear Fuels- Waste Disposal & Storage
580000 - Geosciences