Abstract: 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.

Abstract: Techniques for inspecting a weld of a nuclear waste canister include positioning a gamma ray image detector near a nuclear waste canister that encloses nuclear waste. The nuclear waste canister includes a housing that includes a volume in which the waste is enclosed and a top connected to the housing with at least one weld to seal the nuclear waste in the nuclear waste canister. The techniques further include receiving, at the gamma ray image detector, gamma rays from the nuclear waste that travel through one or more voids in the weld; generating an image of the received gamma rays with the gamma ray image detector; and based on the generated image, determining an integrity of the at least one weld.

Abstract: Techniques for storing hazardous material include moving a storage canister sized to enclose radioactive hazardous material through an entry of a drillhole that extends into a terranean surface and is at least proximate the terranean surface; moving the storage canister from the entry through an angled drillhole portion that is coupled to the entry and deviates from true vertical at an angle; moving the storage canister from the angled drillhole portion to a hazardous material storage drillhole portion coupled to the angled drillhole portion; moving the storage canister into the hazardous material storage drillhole portion; and forming a seal in the drillhole that isolates the hazardous material storage portion of the drillhole from the entry of the drillhole.

Abstract: An apparatus and system for a display screen for use in near-eye display devices. Small light emitting devices are placed behind a plurality of light-directing beads. The light emitting devices and light-directing beads for a display device and system placed in front of a user for near-eye display. This allows a user to experience near-eye display with greater resolution, wider field of view and faster frame rate. Other embodiments are described herein.

Abstract: Techniques for inspecting a weld of a nuclear waste canister include positioning a gamma ray image detector near a nuclear waste canister that encloses nuclear waste. The nuclear waste canister includes a housing that includes a volume in which the waste is enclosed and a top connected to the housing with at least one weld to seal the nuclear waste in the nuclear waste canister. The techniques further include receiving, at the gamma ray image detector, gamma rays from the nuclear waste that travel through one or more voids in the weld; generating an image of the received gamma rays with the gamma ray image detector; and based on the generated image, determining an integrity of the at least one weld.

Abstract: 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.

Abstract: 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.

Abstract: A hazardous material storage repository includes a drillhole extending into the Earth and including an entry. The drillhole includes a vertical drillhole portion, a transition drillhole portion coupled to the vertical drillhole portion, and a hazardous material storage drillhole portion coupled to the transition drillhole portion. The hazardous material storage drillhole portion is located below a self-healing geological formation and is vertically isolated, by the self-healing geological formation, from a zone that comprises mobile water. The repository includes a storage canister positioned in the hazardous material storage drillhole portion and sized to fit from the drillhole entry through the vertical drillhole portion, the transition drillhole portion, and into the hazardous material storage drillhole portion. The storage canister includes an inner cavity sized to enclose hazardous material.

Abstract: A hazardous material storage system includes a drillhole extending into the Earth and including an entry at least proximate a terranean surface. The drillhole includes a substantially vertical portion, a curved portion, and a horizontal portion that includes a hazardous waste repository formed within a first portion of the horizontal portion of the drillhole, the hazardous waste repository vertically isolated, by a rock formation, from a subterranean zone that includes mobile water, and a safety runway formed within a second portion of the horizontal portion exclusive of the hazardous waste repository and adjacent the curved portion, the safety runway defined by a particular length.

Abstract: A hazardous material storage repository includes a drillhole extending into the Earth and including an entry. The drillhole includes a vertical drillhole portion, a transition drillhole portion coupled to the vertical drillhole portion, and a hazardous material storage drillhole portion coupled to the transition drillhole portion. The hazardous material storage drillhole portion is located below a self-healing geological formation and is vertically isolated, by the self-healing geological formation, from a zone that comprises mobile water. The repository includes a storage canister positioned in the hazardous material storage drillhole portion and sized to fit from the drillhole entry through the vertical drillhole portion, the transition drillhole portion, and into the hazardous material storage drillhole portion. The storage canister includes an inner cavity sized to enclose hazardous material.

Abstract: 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.

Abstract: Techniques for inspecting a weld of a nuclear waste canister include positioning a gamma ray image detector near a nuclear waste canister that encloses nuclear waste. The nuclear waste canister includes a housing that includes a volume in which the waste is enclosed and a top connected to the housing with at least one weld to seal the nuclear waste in the nuclear waste canister. The techniques further include receiving, at the gamma ray image detector, gamma rays from the nuclear waste that travel through one or more voids in the weld; generating an image of the received gamma rays with the gamma ray image detector; and based on the generated image, determining an integrity of the at least one weld.

Abstract: A hazardous material storage repository includes a drillhole extending into the Earth and including an entry. The drillhole includes a vertical drillhole portion, a transition drillhole portion coupled to the vertical drillhole portion, and a hazardous material storage drillhole portion coupled to the transition drillhole portion. The hazardous material storage drillhole portion is located below a self-healing geological formation and is vertically isolated, by the self-healing geological formation, from a zone that comprises mobile water. The repository includes a storage canister positioned in the hazardous material storage drillhole portion and sized to fit from the drillhole entry through the vertical drillhole portion, the transition drillhole portion, and into the hazardous material storage drillhole portion. The storage canister includes an inner cavity sized to enclose hazardous material.

Abstract: Techniques for determining the suitability of a subterranean formation as a hazardous waste repository include determining a concentration of at least one noble gas isotope of a plurality of noble gas isotopes in fluid sample from a subterranean formation below a terranean surface; determining a produced amount of the at least one noble gas isotope in the subterranean formation based on a production rate of the at least one noble gas isotope and a minimum residence time; calculating a ratio of the determined concentration of the at least one noble gas isotope in the fluid sample to the determined produced amount of the at least one noble gas isotope; and based on the calculated ratio being at or near a threshold value, determining that the subterranean formation is suitable as a hazardous waste repository.

Abstract: 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.

Abstract: Techniques for storing nuclear waste include placing a plurality of nuclear waste portions into an inner volume of a housing of a nuclear waste canister configured to store the nuclear waste portions in a hazardous waste repository of a directional drillhole formed in a subterranean formation; substantially filling voids within the inner volume and between the plurality of nuclear waste portions with a solid or semi-solid granular material; and sealing the inner volume of the nuclear waste canister to enclose the plurality of nuclear waste portions and the solid or semi-solid granular material.

Abstract: A drillhole plug includes a frame or housing of a corrosion-resistant material and sized to fit within a milled portion of a directional drillhole that includes a hazardous waste repository; and a material that fills at least a portion of the frame or housing. The material exhibits creep such that the material fills one or more voids between the frame or housing and a subterranean formation adjacent the milled portion of the directional drillhole.

Abstract: Techniques for storing nuclear waste hazardous material include identifying a storage area of a directional wellbore formed from a terranean surface and extending into a subterranean formation; circulating a slurry that includes a hardenable material and one or more portions of nuclear waste hazardous material into the storage area; forming a seal in the directional wellbore that isolates the storage area of the directional wellbore from an entry of the directional wellbore; monitoring at least one variable associated with the one or more portions of nuclear waste hazardous material from a sensor positioned proximate the storage area; recording the monitored variable at the terranean surface; and based on the monitored variable exceeding a threshold value, removing the seal from the wellbore and retrieving at least a portion of the slurry from the storage area to the terranean surface.

Abstract: Techniques for inspecting a weld of a nuclear waste canister include positioning a gamma ray image detector near a nuclear waste canister that encloses nuclear waste. The nuclear waste canister includes a housing that includes a volume in which the waste is enclosed and a top connected to the housing with at least one weld to seal the nuclear waste in the nuclear waste canister. The techniques further include receiving, at the gamma ray image detector, gamma rays from the nuclear waste that travel through one or more voids in the weld; generating an image of the received gamma rays with the gamma ray image detector; and based on the generated image, determining an integrity of the at least one weld.

Abstract: Techniques for storing nuclear waste include placing a plurality of nuclear waste portions into an inner volume of a housing of a nuclear waste canister configured to store the nuclear waste portions in a hazardous waste repository of a directional drillhole formed in a subterranean formation; substantially filling voids within the inner volume and between the plurality of nuclear waste portions with a solid or semi-solid granular material; and sealing the inner volume of the nuclear waste canister to enclose the plurality of nuclear waste portions and the solid or semi-solid granular material.