Devices and techniques related to landfill gas extraction are disclosed. A technique for controlling extraction of landfill gas from a landfill through a gas extraction system is described. The method may include measuring a plurality of values indicating conditions associated with the landfill; computing, based at least in part on the plurality of values and on a model of the landfill, a predicted future state of the landfill; determining, based at least in part on the predicted future state of the landfill, one or more control parameters for one or more respective control devices configured to control operation of the gas extraction system; applying the one or more control parameters to the one or more respective control, and with the one or more control devices, controlling extraction of the landfill gas from the landfill based, at least in part, on the one or more respective control parameters.

A control system for controlling extraction of landfill gas, comprising: at least one sensor configured to measure one or more characteristics of landfill gas; at least one flow control mechanism disposed in well piping and configured to control flow of the landfill gas through the well piping; and at least one processor configured to: obtain a measured concentration of a first gas in landfill gas; determine whether the measured concentration of the first gas is either less than a first threshold concentration or greater than a second threshold concentration; when it is determined that the measured concentration is less than the first threshold concentration, control the at least one flow control mechanism to reduce flow rate of landfill gas; and when it is determined that the concentration is greater than the second threshold concentration, control the at least one flow control mechanism to increase the flow rate of landfill gas.

Described herein are embodiments of a control system that automatically (1) determines whether a gas extraction system is in a state in which landfill gas is being released into the atmosphere, and (2) automatically controls landfill gas flow to mitigate, prevent and/or stop the release of landfill gas. The control system may control a valve to control flow of landfill gas through well piping of the gas extraction system. The pressure of landfill gas in the well piping at a location upstream of the valve may indicate whether there is a risk of landfill gas being released into the atmosphere. The control system may adjust a position of the valve in response to determining that the pressure at the location upstream of the valve indicates that there is a risk of landfill gas being released into the atmosphere.

An underground ventilated system for storing nuclear waste materials. The system includes a storage module having an outer shell defining an internal cavity and an inner shell. A majority of the height of the outer shell may be disposed below grade. The outer shell may include a hermetically sealed bottom. First and second canisters are positioned in lower and upper portions within the cavity respectively in vertically stacked relationship. A centering and spacing ring assembly is interspersed between the first and second canisters to transfer the weight of the upper second canister to the lower first canister. The assembly may include centering lugs which laterally restrain the first and second canisters in case of a seismic event. A natural convection driven ventilated air system cools the canisters to remove residual decay heat to the atmosphere. In one non-limiting embodiment, the shells are made of steel.

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.

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.

A vertical manhole apparatus for use in a waste facility to provide access to one or more leachate collection pipe access points. The vertical manhole is stabilized using stabilizing features extending out from a vertical pipe of the vertical manhole apparatus.

The invention relates to a sewage pit (1, 60) for receiving and discharging waste material, particularly domestic, medical and/or industrial waste comprising liquid and solid constituents, to the sewer (52), the sewage pit comprising: —a housing (2, 3, 4) with a closable receiving space (9), wherein one or more of the walls of the housing is provided with at least one inlet (19) configured to carry the waste material into the receiving space, a flushing liquid feed (10) which is embodied to feed flushing liquid to the receiving space for bringing the waste material into suspension, and at least one outlet (29) which can be connected to the sewer and is configured to discharge the mixture of waste material and flushing liquid from the receiving space and to the sewer, —at least one pump (25, 26) connectable or connected to the one or more outlets which is configured to pump the mixture which has been brought into suspension from the receiving space and to discharge the mixture via the one or more outlets.

A control system for controlling extraction of landfill gas, comprising: at least one sensor configured to measure one or more characteristics of landfill gas; at least one flow control mechanism disposed in well piping and configured to control flow of the landfill gas through the well piping; and at least one processor configured to: obtain a measured concentration of a first gas in landfill gas; determine whether the measured concentration of the first gas is either less than a first threshold concentration or greater than a second threshold concentration; when it is determined that the measured concentration is less than the first threshold concentration, control the at least one flow control mechanism to reduce flow rate of landfill gas; and when it is determined that the concentration is greater than the second threshold concentration, control the at least one flow control mechanism to increase the flow rate of landfill gas.

An apparatus for sampling landfill gas from a landfill flowing through a pipe. The apparatus may comprise: an enclosure configured to receive a section of the pipe; a gas sampling port in the section of the pipe; at least one sensor device disposed in a region of the enclosure, the at least one sensor being coupled to the section of the pipe through the gas sampling port; and thermal insulation positioned to retain heat from the section of the pipe in the region of the enclosure. A method of operating a landfill gas recovery system. The method may comprise: flowing gas from a well riser pipe through a sampling subsystem to a collection system; and heating a portion of the sampling subsystem with the gas flowing from the well riser pipe to the collection system.