Site selection and investigation for subsurface disposal of radioactive wastes in hydraulically induced fractures
Injection into a thick shale formation of intermediate-level radioactive wastes (specific activity of less than 6 x 10/sup 3/ ..mu..Ci/ml consisting mainly of radionuclides such as strontium and cesium with half-lives of less than 50 years) mixed with cement is a promising and feasible disposal method. Hydraulic fracturing provides openings in the shale to accommodate the wastes. Ion exchange and radionuclide adsorption materials can be added to the grout during mixing to further increase the radionuclide retaining capacity of the grout. After solidification of the grout, the injected wastes become an integral part of the shale formation and thus the wastes will remain at depth and in place as long as the injection zone is not subjected to erosion or dissolution. Problems concerning safety of the disposal method are: (1) potential of inducing vertical fractures; (2) phase separation during and after injections; (3) reliability of methods for determining orientation of induced fractures; (4) possibility of triggering earthquakes; and (5) radionuclides leaching and transporting by ground water. Waste injections are made in multiple-layer injection stages in an injection well. After the first series of injections are made at the greatest depth, the well is plugged by cement at the injection depth. The depth of the second series of injections is located at a suitable distance above the first injection depth. The repeated use of the injection well distributes the cost of construction of injection and monitoring wells over many injections, thereby making hydraulic fracturing and grout injection economically attractive as a method for disposal of radioactive wastes. Theoretical considerations of inducing nearly horizontal bedding-plane fractures in shale and field procedures for site selection, safety, monitoring and operation of radioactive waste disposal are discussed. Case histories are used as examples to demonstrate the theoretical applications and field operations.
- Research Organization:
- Geological Survey, Reston, VA (USA)
- OSTI ID:
- 5490984
- Report Number(s):
- USGS-OFR-80-450; ON: DE82010967
- Country of Publication:
- United States
- Language:
- English
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Selection and investigation of sites for the disposal of radioactive wastes in hydraulically induced subsurface fractures
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Related Subjects
12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES
BUILDING MATERIALS
CEMENTS
COMMINUTION
DATA
EXPERIMENTAL DATA
FRACTURING
GEOLOGIC DEPOSITS
HYDRAULIC FRACTURING
INFORMATION
INTERMEDIATE-LEVEL RADIOACTIVE WASTES
MANAGEMENT
MATERIALS
MONITORING
NUMERICAL DATA
RADIOACTIVE MATERIALS
RADIOACTIVE WASTE DISPOSAL
RADIOACTIVE WASTES
ROCKS
SAFETY
SEDIMENTARY ROCKS
SHALES
SITE SELECTION
STRESSES
UNDERGROUND DISPOSAL
WASTE DISPOSAL
WASTE MANAGEMENT
WASTES