A power generator system includes one or more heat transfer members configured to contact: a heat source in a hazardous waste repository of a directional drillhole that stores nuclear waste in one or more nuclear waste canisters, and a heat sink in the hazardous waste repository; and one or more thermoelectric generators thermally coupled to the one or more heat transfer members and configured to generate electric power based on a temperature difference between the heat source and the heat sink.

A method for evaluating, selecting, and implementing at existing nuclear surface (or near surface) sites a deeply located high-level nuclear waste (HLW) disposal repository that is located directly vertically below the areal confines of that existing site, within a particular deeply located geologic rock formation. Many of these existing sites are ideal because: they are already legally permitted and/or licensed for using nuclear/radioactive materials, they already have nuclear/radioactive materials onsite that need a long-term safe disposal solution, and many of these existing sites already have onsite useful infrastructure (e.g., roads, buildings, cooling pools, equipment, machinery, personnel, and/or the like). Such existing sites include nuclear power plants (operating or decommissioned), interim spent nuclear fuel rod assemblies (SNF) surface storage sites, and/or near surface SNF storage sites. The deep HLW disposal repository may include a vertical wellbore, a lateral wellbore, and/or a human-made cavern.

This disclosure relates to a method and a system for sequestering carbon-containing materials in underground wells. An example method includes: obtaining a material comprising a carbon-containing liquid; optionally testing the material for compatibility with an underground well; optionally adjusting a property of the material to improve the compatibility; and providing the material for injection into the underground well.

Systems and methods for long-term disposal of high-level nuclear waste in deep geologic formations may include largely intact spent nuclear fuel rod assemblies that may be placed into waste-capsules (e.g., carrier tubes); which may then be placed into various well boreholes. Example embodiments may provide waste-capsules capable of containing and disposing of nuclear waste generated from spent nuclear fuel; including methods for harvesting the nuclear waste from cooling pools and/or surface storage; and operationally processing the waste, fuel assemblies for inclusion in the waste-capsules with various engineered barriers; along with storage in relatively large substantially horizontal well boreholes; which may be drilled into closed deep geologic formations.

Open pit mine (OPM) structures are modified or built new for use in disposing of low-level radioactive/nuclear waste (LLW). A drainage system is added to the OPM to drain water, such as, but not limited to, rain water, out of a volume of the OPM and to a particular geologic zone located far below the OPM that is isolated away from the local water table. Cells are formed within the volume of the OPM that are configured to receive the LLW. Cells are added to the OPM from a bottom towards a top of the OPM. Void spaces around the LLW materials within the cells are filled in with a protective-medium to mitigate against radionuclide migration away from the LLW materials within the cells. The protective-medium may be a blend of carbon nanotubes and a foam cement slurry. The carbon nanotubes may be made from reacting ethylene with vermiculite.

A method of this disclosure directionally drills at least one well extending from ground surface to an interior of an underground mine located below ground, the well being at an oblique angle relative to vertical; blends or mixes together a hazardous material, like lead, zinc, arsenic, and cadmium with cement including a plasticizer; pumps or flows the mixture into the well, wherein the mixture flows toward a lower end of the mine and hardens in place. The method allows for the permanent placement of contaminated mixtures like chat into mines or shafts or depositories, as defined by the United States Environmental Protection Agency, CERCLA and Superfund laws and complies with rules for the permanent closing of these structures with contaminated material and contaminated substances.

A power generator system includes one or more heat transfer members configured to contact: a heat source in a hazardous waste repository of a directional drillhole that stores nuclear waste in one or more nuclear waste canisters, and a heat sink in the hazardous waste repository; and one or more thermoelectric generators thermally coupled to the one or more heat transfer members and configured to generate electric power based on a temperature difference between the heat source and the heat sink.

Techniques for determining the suitability of a subterranean formation as a hazardous waste repository include determining a neutron flux of a first isotope in a subterranean formation; calculating, based at least in part on the determined neutron flux of the first isotope, a predicted production rate of a second isotope in the subterranean formation; calculating a first ratio of the predicted production rate of the second isotope relative to a theoretical production rate of a stable form of the second isotope; measuring respective concentrations of the second isotope and the stable form of the second isotope in a subterranean water sample; calculating a second ratio of the measured concentration of the second isotope relative to the measured concentration of the stable form of the second isotope; and based on a comparison of the first and second ratios, determining that the subterranean formation is suitable as a hazardous waste repository.

A system and method to safely isolate mobile radioactive material during an emergency includes a borehole located in close proximity and at a depth sufficient to safely isolate the material and a man-made vertical-oriented gravity fracture located at the bottom end of the borehole. During an emergency, the mobile radioactive material enters the borehole and then passes from there into the gravity fracture. The mobile radioactive material may have sufficient density to further propagate the fracture vertically downward or a dense slurry or fluid could be mixed with the mobile radioactive material.

Techniques for determining the suitability of a subterranean formation as a hazardous waste repository include determining a neutron flux of a first isotope in a subterranean formation; calculating, based at least in part on the determined neutron flux of the first isotope, a predicted production rate of a second isotope in the subterranean formation; calculating a first ratio of the predicted production rate of the second isotope relative to a theoretical production rate of a stable form of the second isotope; measuring respective concentrations of the second isotope and the stable form of the second isotope in a subterranean water sample; calculating a second ratio of the measured concentration of the second isotope relative to the measured concentration of the stable form of the second isotope; and based on a comparison of the first and second ratios, determining that the subterranean formation is suitable as a hazardous waste repository.