Abstract: Methods and systems directed to the separation of tritium from an aqueous stream are described. The separation method is a multistage method that includes a purification stage during which tritium of a tritium-contaminated aqueous stream is adsorbed onto a cooled and wet separation phase, a regeneration stage during which the adsorbed tritium is exchanged with hydrogen in a gaseous stream to regenerate the separation phase and provide a gaseous stream with a high tritium concentration, and a third stage during which the tritium of the gaseous stream is separated from the gaseous stream as a gaseous tritium product.

Abstract: Work area cleanup systems and methods are described for removing tritium from the atmosphere of a work area such as inert gas gloveboxes. Systems utilize a multi-column approach with parallel processing. Tritium of a tritium-contaminated stream is converted into tritiated water and adsorbed onto the separation phase of a first column as a second, parallel column can be simultaneously regenerated. The gaseous stream that exits the column during the regeneration phase can carry a high tritium concentration. The system can also include and a separation stage during which the tritium of the gaseous regeneration stream can be separated from the remainder of the regeneration product.

Abstract: Work area cleanup systems and methods are described for removing tritium from the atmosphere of a work area such as inert gas gloveboxes. Systems utilize a multi-column approach with parallel processing. Tritium of a tritium-contaminated stream is converted into tritiated water and adsorbed onto the separation phase of a first column as a second, parallel column can be simultaneously regenerated. The gaseous stream that exits the column during the regeneration phase can carry a high tritium concentration. The system can also include and a separation stage during which the tritium of the gaseous regeneration stream can be separated from the remainder of the regeneration product.

Abstract: Methods and systems for the separation of isotopes from an aqueous stream are described as can be utilized in one embodiment to remove and recover tritium from contaminated water. Methods include counter-current flow of an aqueous stream on either side of a separation membrane. The separation membrane includes an isotope selective layer (e.g., graphene) and an ion conductive supporting layer (e.g., Nafion®). An electronic driving force encourages passage of isotopes selectively across the membrane to enrich the flow in the isotopes.

Abstract: Methods and systems for the separation of isotopes from an aqueous stream are described as can be utilized in one embodiment to remove and recover tritium from contaminated water. Methods include counter-current flow of an aqueous stream on either side of a separation membrane. The separation membrane includes an isotope selective layer (e.g., graphene) and an ion conductive supporting layer (e.g., Nafion®). An electronic driving force encourages passage of isotopes selectively across the membrane to enrich the flow in the isotopes.

Abstract: A spider for a railroad crossing signal foundation has plastic lined tubular channels extending through it with conical entry sections. In assembling a foundation, upright guide rods are guided into the channels by the entry sections without dislodging the plastic liners. In producing the spider, concrete is poured into a mold about tubular plastic liners so as to form entry sections and channels and to fix the plastic liners in the concrete to line the channels.

Abstract: A railroad crossing signal foundation has upright guide rods (19) to which an upper frame member (14) and a lower frame member (15) are mounted. A concrete reinforcement gridwork (16,17) is supported on the lower frame. After erection in a ground hole, concrete is poured into the hole to a fill plane defined by the upper frame member (14) so as to embed the frame member and gridwork and a portion of the guide rods located below the fill plane.

Abstract: A retaining wall 10 comprises an array of juxtaposed piles 11 and precast panels 12 mounted between adjacent piles. Laterally adjacent panels are mounted to each other and to a common pile 11 by links 38 and 39 pivotably mounted at each end to the panels so as to allow the panels to move with respect to each other and to the pile.

Abstract: A railroad crossing signal foundation 10 comprises a base 11 having a lower concrete slab 15' to which a set of upright guide rods 18 is mounted and upper concrete slabs 15 supported upon the lower slab through which the guide rods extend. A pillar 12 is mounted upon the base that has concrete blocks 16 through which the guide rods extend. The pillar blocks have a support area size substantially less than the support area size of the base slabs such that the pillar may be erected with workers standing upon the base. A concrete crown 13 is mounted upon the pillar through which the guide rods extend. The weight of the foundation components is such that the center of gravity of the foundation is located in the base.

Abstract: A railroad signal foundation assembly 10 comprises a foundation 11 having a concrete base 12, a pillar 13 comprised of tiers of concrete spider blocks 19 mounted upon the base, and a concrete crown 14 mounted upon the pillar. The foundation assembly has a pallet 15 mounted between and extending laterally outward from the crown and base, and mounting bands 16 which secure that pallet aside the pillar. The foundation may be transported as an assembled unit upon the pallet to an erection site, dismounted from the pallet and lowered into a ground hole without a worker being in the hole during its erection.