Systems and/or methods of waste disposal use human-made caverns that are constructed within deep geological formations. A given human-made cavern may be constructed by first drilling out a vertical wellbore to a deep geological formation. Then a bottom portion of the vertical wellbore is jet drilled using an abrasive jetting fluid to form a launch chamber of void volume, that is sized to fit a reaming tool in its deployed open configuration. A reaming tool, in a closed configuration, is then inserted into the vertical wellbore for landing in the launch chamber. The reaming tool is then deployed into its open configuration while in the launch chamber. Reaming operations then occur from the launch chamber directed downwards within the deep geological formation, forming a given human-made cavern. The newly formed human-made cavern may be conditioned and/or configured for receiving amounts of the waste for long-term disposal and/or storage.

Systems and/or methods of waste disposal use human-made caverns that are constructed within deep geological formations. A given human-made cavern may be constructed by first drilling out a vertical wellbore to a deep geological formation. Then a bottom portion of the vertical wellbore is jet drilled using an abrasive jetting fluid to form a launch chamber of void volume, that is sized to fit a reaming tool in its deployed open configuration. A reaming tool, in a closed configuration, is then inserted into the vertical wellbore for landing in the launch chamber. The reaming tool is then deployed into its open configuration while in the launch chamber. Reaming operations then occur from the launch chamber directed downwards within the deep geological formation, forming a given human-made cavern. The newly formed human-made cavern may be conditioned and/or configured for receiving amounts of the waste for long-term disposal and/or storage.

A hazardous material repository includes a drillhole formed from a terranean surface into a subterranean zone that includes a geologic formation, where the drillhole includes a vertical portion and a non-vertical portion coupled to the vertical portion by a transition portion, the non-vertical portion includes a storage volume for hazardous waste; a casing installed between the geologic formation and the drillhole, the casing including one or more metallic tubular sections; at least one canister positioned in the storage volume of the non-vertical portion of the drillhole, the at least one canister sized to enclose a portion of hazardous material and including an outer housing formed from a non-corrosive metallic material; and a backfill material inserted into the non-vertical portion of the drillhole to fill at least a portion of the storage volume between the at least one canister and the casing.

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 disposal device comprises a raw material conveyor, a raw material mixer, a liquid waste conveying pipeline, an additive tank, a powder waste conveyor, an output pump, a liquid supply pump, a liquid supply manifold, an output manifold, a mixed liquid conveying pipeline, a high-pressure injection pump, a high-pressure pipeline, and a wellhead sealing device. A method of employing the device includes: drilling a well; forming a fracture in the granite stratum; preparing a raw material; and injecting, by using the disposal device, a sand-carrying feed liquid from a high-pressure injection pump into the fracture of the underground granite stratum, so as to perform solidification.

A disposal device comprises a raw material conveyor, a raw material mixer, a liquid waste conveying pipeline, an additive tank, a powder waste conveyor, an output pump, a liquid supply pump, a liquid supply manifold, an output manifold, a mixed liquid conveying pipeline, a high-pressure injection pump, a high-pressure pipeline, and a wellhead sealing device. A method of employing the device includes: drilling a well; forming a fracture in the granite stratum; preparing a raw material; and injecting, by using the disposal device, a sand-carrying feed liquid from a high-pressure injection pump into the fracture of the underground granite stratum, so as to perform solidification.

A waste material depositing system for depositing waste material into a sub-seabed sediment of an ocean floor. There is a penetrator including a first disposal stage and a second disposal stage. The first disposal stage having an outer shell disposed about a cavity, the cavity being shaped and sized to receive a waste disposal canister. The second disposal stage being removably coupled to a top end of the first disposal stage by an automatic disengagement device, and having: an outer cylinder, a plurality of second disposal fins disposed along a length of the outer cylinder, and an arrestor system coupled to a top portion of the outer cylinder.

A waste material depositing system for depositing waste material into a sub-seabed sediment of an ocean floor. There is a penetrator including a first disposal stage and a second disposal stage. The first disposal stage having an outer shell disposed about a cavity, the cavity being shaped and sized to receive a waste disposal canister. The second disposal stage being removably coupled to a top end of the first disposal stage by an automatic disengagement device, and having: an outer cylinder, a plurality of second disposal fins disposed along a length of the outer cylinder, and an arrestor system coupled to a top portion of the outer cylinder.

A container holds radioactive material. A sub-criticality controller protects the radioactive material from reaching a criticality from contact with the water. The sub-criticality controller includes a metallic composition having at least one metal component and at least one borate component bonded to the at least one metal component. The metallic composition forms borates when the metallic composition contacts the water.

A container holds radioactive material. A sub-criticality controller protects the radioactive material from reaching a criticality from contact with the water. The sub-criticality controller includes a metallic composition having at least one metal component and at least one borate component bonded to the at least one metal component. The metallic composition forms borates when the metallic composition contacts the water.