Status of evaluation of tuff in southern Nevada for geologic disposal of high-level nuclear wastes
Technical Report
·
OSTI ID:59380
One rock type presently being evaluated as a possible disposal medium for nuclear wastes is silicic tuff, a fragmented volcanic rock similar to granite in composition. The purposes of this paper are to discuss the geologic setting of tuff, which locally occurs in great thicknesses in southern Nevada, and to provide a brief overview of some aspects of efforts to evaluate the potential of tuff as a medium for safe geologic disposal of high level radioactive wastes. Emphasis is placed on those factors that might affect site characterization and on preliminary geochemical and material properties data. Siliceous tuff in southern Nevada occurs in a complex and locally active geological environment. Regional thrust faulting, Basin and Range faulting, and present-day seismicity complicate exploration and site characterization activities. The inherent variability of tuff and the complexity of caldera complexes also complicate siting efforts, but may serve to enhance long-term containment. Time-space trends of silicic volcanism are moderately well-established, while those of recent basaltic volcanism are not. At present, the final consequences for repository siting of the geologic complexities described in this paper are not known. Evidence from laboratory cation exchange (K/sub D/) measurements indicate that tuff and tuffaceous alluvium can serve as effective natural barriers to migration of radionuclides. This fact, coupled with multiple hydrologic barriers and long flow paths, as in the vicinity of the Nevada Test Site, might well result in tuff being a suitable medium for the safe long-term geologic disposal of nuclear wastes. Preliminary thermal modeling indicates the strong influence of varying assumptions regarding in situ fluid pressures and geothermal heat flux on acceptable initial areal power loadings.
- Research Organization:
- Sandia National Labs., Albuquerque, NM (United States); Los Alamos National Lab., NM (United States)
- DOE Contract Number:
- AC04-76DP00789
- OSTI ID:
- 59380
- Report Number(s):
- DOE/NBM--2011302; ON: DE82011302
- Country of Publication:
- United States
- Language:
- English
Similar Records
Status of evaluation of tuff in southern Nevada for geologic disposal of high level nuclear wastes
Geology of the Nevada Test Site and nearby areas, southern Nevada
Preliminary survey of tuff distribution in Esmeralda, Nye, and Lincoln Counties, Nevada
Conference
·
Sun Dec 30 23:00:00 EST 1979
·
OSTI ID:59392
Geology of the Nevada Test Site and nearby areas, southern Nevada
Technical Report
·
Fri Oct 01 00:00:00 EDT 1982
·
OSTI ID:59476
Preliminary survey of tuff distribution in Esmeralda, Nye, and Lincoln Counties, Nevada
Technical Report
·
Sat Jan 31 23:00:00 EST 1981
·
OSTI ID:59425