Abstract: A neutron absorbing insert for use in a fuel rack. In one aspect, the insert includes: a plate structure having a first wall and a second wall that is non-coplanar to the first wall; the first and second walls being themed by a single panel of a metal matrix composite having neutron absorbing particulate reinforcement that is bent into the non-coplanar arrangement along a crease; and a plurality of spaced-apart holes formed into the single panel along the crease prior to bending.

Abstract: A system for preparing a container holding radioactive waste for dry storage. In one aspect, the invention can be a system for preparing a container having a cavity loaded with radioactive elements for dry storage, the system comprising: a gas circulation system comprising a condenser module, a desiccant module, and a gas circulator module; the gas circulation system configured to form a hermetically sealed closed-loop path when operably connected to the cavity of the container; and means for adding and removing the desiccant module as part of the hermetically sealed closed-loop path.

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: 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 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: 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 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.

Abstract: A fin and tube assembly for use in a heat exchanger comprising a carbon steel tube, a carbon steel fin, and an external brazing compound comprising a material selected from the group consisting of nickel, chrome, copper, aluminum, zinc, and graphite brazed to the tube and fin is disclosed. A method for making the assembly and a power plant which includes the assembly are also disclosed. The brazing compound functions to prevent corrosion of the carbon steel and also functions to attach the tube and fin together.

Abstract: The present invention provides a method and system for ensuring that cavities used to store radioactive elements are adequately dried without intrusive measuring. In one aspect the invention is a system for drying a cavity loaded with radioactive elements, the loaded cavity having a free volume (VF), a starting vapor pressure (vPS), and a cavity pressure (PC), the system comprising: a non-reactive gas source adapted to supply a non-reactive gas to the system; means to cool a non-reactive gas to a temperature (TC) thereby drying the non-reactive gas; means to flow the dry non-reactive gas to the cavity, the flow means adapted to introduce the dry non-reactive gas to the cavity at a flow rate R for a period of time (t); and means to remove wet non-reactive gas from the cavity; wherein the non-reactive gas source, the cooling means, the flow means, the removal means, and the cavity are fluidly coupled; wherein TC and R are controlled to achieve a desired vapor pressure (vPD) in the cavity in time t.

Abstract: A system and method for transferring a canister of spent nuclear fuel from a transfer cask to a receiving cask. In one aspect, the system comprises a below grade opening adapted for receiving a cask; a platform positioned within the opening, the platform capable of vertical movement; and at least two jacks for vertically moving the platform; wherein the platform is capable of lowering the cask within the opening. In another aspect, the invention is a method of transferring a canister of spent nuclear fuel to a cask comprising the steps of: lowering a receiving cask having a height into a below grade opening so that a portion of the receiving cask's height is below grade level; and transferring the canister to the receiving cask.

Abstract: The present invention provides a method and system for ensuring that cavities used to store radioactive elements are adequately dried without intrusive measuring. In one aspect the invention is a method of drying a cavity loaded with radioactive elements, the loaded cavity having a free volume (VF), a starting vapor pressure (vPS), and a cavity pressure (PC), the method comprising: determining a desired degree of dryness in the cavity in terms of a desired vapor pressure (vPD); cooling a non-reactive gas to a temperature (TC) thereby drying the non-reactive gas; introducing the dry non-reactive gas into the cavity so that the free volume VF of the cavity turns over X times; and removing wet non-reactive gas from the cavity; wherein TC and X are controlled to achieve the desired vapor pressure (vPD) in the cavity. Alternatively, a flow rate (R) can be controlled over time (t) instead of controlling X.

Abstract: An apparatus and method for transferring spent nuclear fuel within a nuclear power plant. In one aspect, the invention is an apparatus for transferring a cask from a first position to a second position comprising: a first beam having a first proximal end and a first distal end, said first proximal end adapted for pivotal connection to a base; a second beam having a second proximal end and a second distal end, said second proximal end adapted for pivotal connection to said base; a member connecting said first distal end and said second distal end, said member comprising a lifting device adapted to raise and lower said cask; wherein said member, said first pivot beam, and said second pivot beam form a unitary structure; and means to rotate said unitary structure about an axis. In another aspect, the invention is a method of using the apparatus to transfer a cask.