Abstract: A system and method for drying cavities containing spent nuclear fuel is devised. The invention utilizes a non-intrusive procedure that is based on monitoring the dew point temperature of a non-reactive gas that is circulated through the cavity. In one aspect, the invention is a system for drying a cavity loaded with spent nuclear fuel comprising: a canister forming the cavity, the cavity having an inlet and an outlet; a source of non-reactive gas; means for flowing the non-reactive gas from the source of non-reactive gas through the cavity; and means for repetitively measuring the dew point temperature of the non-reactive gas exiting the cavity.

Abstract: A neutron absorbing apparatus, for insertion into a fuel cell storage system, includes a corner spine, a first wall and a second wall, each wall being affixed to the corner spine to form a chevron shape. Each wall includes an absorption sheet affixed to the corner spine, each absorption sheet being formed of a metal matrix composite having neutron absorbing particulate reinforcement, and a guide sheet affixed to and covering a fractional upper portion of the absorption sheet and extending over a top of the absorption sheet. The absorption sheet extends along the corner spine a greater length than the guide sheet.

Abstract: Described herein are compositions for use in the brazing of metal substrates, methods of making and using these compositions are also described herein. Heat exchangers often have a distributor tube whose external surface is provided with cooling fins. The distributor tube is typically a steel tube coated with a metal having good heat conduction, such as aluminum. The cooling fins themselves also generally comprise aluminum because of its good heat conductivity and low weight.

Abstract: A ventilated apparatus for storing and/or transporting high level radioactive waste. In one aspect, the invention is a ventilated apparatus comprising: an overpack body having an inner surface forming a cavity about a longitudinal axis. A bottom portion of the overpack body is formed by a plurality of segments. Each of the segments extends from a first end wall having a projection to a second end wall having a channel. The segments circumferentially surround a longitudinal axis and are arranged in an intermeshing and spaced-apart configuration such that the projections of the first end walls of the segments project into the channels of the second end walls of adjacent ones of the segments, thereby forming inlet ducts between adjacent ones of the segments. The inlet ducts form air inlet passageways from the external atmosphere to a bottom portion of the cavity.

Abstract: An autonomous self-powered system for cooling radioactive materials comprising: a pool of liquid; a closed-loop fluid circuit comprising a working fluid having a boiling temperature that is less than a boiling temperature of the liquid of the pool, the closed-loop fluid circuit comprising, in operable fluid coupling, an evaporative heat exchanger at least partially immersed in the liquid of the pool, a turbogenerator, and a condenser; one or more forced flow units operably coupled to the closed-loop fluid circuit to induce flow of the working fluid through the closed-loop fluid circuit; and the closed-loop fluid circuit converting thermal energy extracted from the liquid of the pool into electrical energy in accordance with the Rankine Cycle, the electrical energy powering the one or more forced flow units.

Abstract: An apparatus, system and method for storing high level radioactive waste. In one aspect, the invention is a specially designed ring structure for providing neutron and gamma radiation shielding for high level radioactive materials that produce residual heat. A plurality of the ring structures may be arranged in a stacked assembly that completely surrounds an internal containment boundary. Collars may be provided at the ring-to-ring interfaces. The ring structures may have voids which are configured for receiving neutron absorbing material that completely surrounds the containment boundary.

Abstract: A container system, for radioactive waste and method for using the same is provided. The system includes a canister configured for holding radioactive waste and a lid system. In one embodiment, the lid system comprises a two-part lid assembly including a confinement lid and a shielded lifting lid. The confinement lid is detachably mounted to the confinement lid. In use, the lifting lid supports die confinement lid for lifting and placement on the canister. The lifting lid further shields operators while the confinement lid is mounted to the canister. Thereafter, the lifting lid is removed and may be reused for confinement lid mountings on other canisters. In one embodiment, the confinement lid is bolted to the canister. The canister may be disposed in a protective overpack for transport and storage.

Abstract: A system and method for storing high level radioactive waste, such as spent nuclear fuel. In one embodiment, the invention is a method of storing high level radioactive waste comprising: a) positioning a metal canister containing high level radioactive waste having a heat generation rate in a storage cavity of a ventilated system comprising a cask body, a cask lid positioned atop the cask body, at least one outlet duct extending from a top of the storage cavity to an ambient atmosphere, and a plurality of inlet ducts, each of the inlet ducts extending from a first opening in the outer surface of the cask body to a second opening in the inner surface of the cask, body; and b) sealing selected ones of the plurality of inlet ducts over time as a function of a decay of the heat generation rate to maintain more a predetermined percentage of a vertical height of the metal canister above a predetermined threshold temperature.

Abstract: A system and method for drying cavities containing spent nuclear fuel is devised.

Abstract: A system and method for storing multiple canisters containing high level waste below grade that afford adequate ventilation of the spent fuel storage cavity. In one aspect, the invention is a ventilated system for storing high level waste emitting heat, the system comprising: an air-intake shell forming an air-intake cavity; a plurality of storage shells, each storage shell forming a storage cavity; a lid positioned atop each of the storage shells; an outlet vent forming a passageway between an ambient environment and a top portion of each of the storage cavities; and a network of pipes forming hermetically sealed passageways between a bottom portion of the air-intake cavity and at least two different openings at a bottom portion of each of the storage cavities such that blockage of a first one of the openings does not prohibit air from flowing from the air-intake cavity into the storage cavity via a second one of the openings.

Abstract: A system and method for storing radioactive waste, such as spent nuclear fuel, in one embodiment, the invention is a method of controlling temperature of a portion of a storage system comprising a container loaded with radioactive waste and a ventilated module in which the container is positioned, the ventilated module configured so that heat generated by the radioactive waste causes a natural convective flow of air through, a ventilation passageway of the ventilated module, the method comprising; throttling the natural convective flow of the air through the ventilated module to alter a heat rejection rate of the storage system to compensate for a decreasing heat generation rate of the radioactive waste to maintain the portion of the storage system within a predetermined temperature range.

Abstract: A ventilated system for storing high level radioactive waste, such as used nuclear fuel, in a below-grade environment, in one embodiment, the invention is a ventilated system comprising an air-intake shell and a plurality of storage shells that are interconnected by a network of pipes configured to achieve double redundancy and/or improved air delivery. In another embodiment, the invention is a ventilated system that utilizes a mass of low level radioactive waste contained in a hermetically sealed enclosure cavity, the low level radioactive waste providing radiation shielding for high level radioactive waste stored in a storage cavity of said ventilated system.

Abstract: A container and system for handling damaged nuclear fuel, and a method of making the same. In one embodiment, the invention is a damaged fuel container having a specially designed top cap that can be detachably coupled to the elongated tubular wall by simply translating the top cap into proper position within, the elongated tubular wall, wherein biased locking elements automatically lock the top cap to the elongated tubular wall. In another embodiment, the vent screens of the damaged fuel container are integrally formed rather than being separate components. In still other embodiments, the lower vent screens are arranged on an upstanding portion of the damaged fuel container. In an even further embodiment, the elongated tubular wall is formed by an extrusion process.

Abstract: Systems and methods for storing spent nuclear fuel below grade that afford adequate ventilation of the spent fuel storage cavity. In one aspect, the invention is a system comprising: a shell forming a cavity for receiving a canister of spent nuclear fuel, at least a portion of the shell positioned below grade; and at least one inlet ventilation duct extending from an above grade inlet to a below grade outlet at or near a bottom of the cavity; the inlet ventilation duct connected to the shell so that the cavity is hermetically sealed to ingress of below grade fluids.

Abstract: A system for receiving and storing high level radioactive waste comprising: an enclosure comprising walls having inlet ventilation ducts, a roof comprising an array of holes, and a floor; an array of metal shells located in an internal space of the enclosure, the array of metal shells being co-axial with the array of holes in the roof so that containers holding high level radioactive waste can be lowered through the array of holes in the roof and into the array of metal shells; the array of metal shells acting as load bearing columns for the roof; and each of the metal shells comprising (i) an expansion joint for accommodating thermal expansion and/or contraction of the metal shells; and (ii) one or more holes at a bottom portion of the metal shell.

Abstract: A system for removing thermal energy generated by radioactive materials is provided. The system comprises an air-cooled shell-and- tube heat exchanger, comprising a shell and plurality of heat exchange tubes arranged in a substantially vertical orientation within the shell, the heat exchange tubes comprising interior cavities that collectively form a tube-side fluid path, the shell forming a shell-side fluid path that extends from an air inlet of the shell to an air outlet of the shell, the air inlet at a lower elevation than the air outlet; a heat rejection closed-loop fluid circuit comprising the tube-side fluid path, a coolant fluid flowing through the heat rejection closed-loop fluid circuit, the heat rejection closed-loop fluid circuit thermally coupled to the radioactive materials; and the air-cooled shell-and-tube heat exchanger transferring thermal energy from the coolant fluid flowing through the tube-side fluid path to air flowing through the shell-side fluid path.

Abstract: An apparatus for supporting radioactive fuel assemblies, such as spent nuclear fuel. In one aspect, the invention is an apparatus, which can be in the form of a fuel basket, fuel rack, or the like, in which polygonal storage tubes are used not only for their internal cells but are also strategically patterned to create resultant cells with their outside surfaces.

Abstract: A method for preparing a cavity loaded with wet radioactive elements for dry storage, the method including: connecting a condensing module, a vacuum module, and a gas circulator module to the cavity so as to form a hermetically sealed closed-loop path that includes the cavity; filling the closed-loop path with a non-reactive gas; circulating the non-reactive gas through the closed-loop path until the condensing module is no longer removing substantial amounts of water from the circulating non-reactive gas, wherein the vacuum module is sealed off from the closed-loop path during the circulating; discontinuing the circulation of the non-reactive gas through the closed-loop path; fluidly coupling the vacuum module to the cavity and fluidly isolating the cavity and the vacuum module; and applying a vacuum pressure to the cavity via the vacuum module so as to create a sub-atmospheric pressure within the cavity.

Abstract: A canister apparatus, basket apparatus and combinations thereof for transporting and/or storing high level radioactive waste, such as spent nuclear fuel. The canister apparatus comprises a cavity for receiving the spent nuclear fuel that is surrounded by two independent gas-tight containment boundaries. The structures that form the two independent gas-tight containment boundaries are in substantially continuous surface contact with one another, thereby facilitating sufficient heat removal from the cavity. In another aspect, the invention is a basket apparatus having a plurality of disk-like grates arranged in a stacked and spaced arrangement so that the cells of the disk-like grates are aligned. In still another aspect, the invention can be a basket apparatus having a disk-like grate having a ring-like structure encompassing a gridwork of beams specially arranged to achieve a unique cell configuration.

Abstract: A transfer cask for maximizing the radiation shielding for spent nuclear fuel during cask transfer procedures has a cylindrical inner shell forming a cavity within which a spent nuclear fuel canister can be placed; a cylindrical outer shell concentric with and surrounding the inner shell to form an annulus with the inner shell, the annulus adapted for receiving gamma absorbing material; a jacket shell concentric with and surrounding the second shell to form a jacket for holding a neutron absorbing liquid; the jacket shell having filling and drainage systems; and a removable bottom lid so that a canister can be lowered from the cavity into a transport cask or permanent storage cask.