Abstract: A nuclear component handling arrangement is disclosed including a storage overpack including an inner envelope, an inner canister including an outer envelope, and a vent and duct system. The inner canister is positionable within the storage overpack. The vent and duct system includes an inlet vent, an outlet vent, and a passageway defined between the inner envelope of the storage overpack and the outer envelope of the inner canister. The passageway extends between the inlet vent and the outlet vent. The inlet vent includes an inlet entrance, an inlet exit, and a curved transition surface extending between the inlet entrance and the inlet exit.

Abstract: A storage device for storing and/or transporting nuclear fuel assemblies. The storage device includes a number N of adjacent recesses. Some of the recesses created by means of notched, intersecting and stacked plates. In at least one transverse plane, at least one of the adjacent recesses has an inner surface which defines the recess. The adjacent recess being formed in part by a first surface of a first notched plate made with boron and a first surface of a second notched plate made without boron.

Abstract: An apparatus is provided for storing hazardous waste material, which includes one or more of spent nuclear fuel, radioactive material, and fissionable material. The apparatus comprises a containment vessel that encloses the hazardous waste material. A fusible alloy material, for example, a eutectic material, resides within the containment vessel and surrounds the hazardous waste material. In the preferred embodiments, it is suggested that the fusible alloy material exhibits liquidus and solidus or melting temperatures that are between about 100 and 300 degrees Fahrenheit for facilities using the apparatus and methods for liquid storage pool loading applications. For facilities using the apparatus and methods for dry loading, the fusible alloy materials may exhibit liquidus and solidus or melting temperatures that are between about 100 and 650 degrees Fahrenheit.

Abstract: A nuclear waste cask with impact protection includes impact limiters comprising deformable energy-absorbing perforated sleeves. An impact amelioration system for nuclear fuel storage components includes impact limiter assemblies at the bottom cask to canister interface including impact limiter plugs frictionally engaging corresponding plug holes formed in the cask closure plate. A nuclear waste fuel storage system includes an unventilated cask including a heavy free-floating radiation shielding lid loosely coupled the top end of the cask in a movable manner via the anchor bosses which provides cask over pressurization protection. A nuclear waste cask includes an axially elongated rectangular cuboid cask body having a cavity for holding nuclear waste materials and cask locking mechanism including first locking protrusions on the lid which are selectively interlockable with mating second locking protrusions on the cask body to lock the lid to the cask body.

Abstract: A fuel rack comprises a base plate and vertically-extending hexagonal tubes. Each tube defines a cell. A top surface of the base plate forms a floor of each cell. Adjustable height pedestals can be connected to a bottom surface of the base plate. Each pedestal includes a tool engagement portion in a top surface of a peg. Rotation of the peg causes pedestal height adjustment. Each peg is aligned with a hole in a cell floor. A tool can extend through the hole to adjust the height of the pedestal. Vertically elongated spacing rods are positioned in gaps between adjacent hexagonal tubes to maintain the gaps. Each spacing rod is plug welded to a corner edge of three adjacent hexagonal tubes at a juncture via holes located in the corner edges of each of the three adjacent hexagonal tubes.

Abstract: A cask liner includes a hollow cylinder comprising a boron-containing composition. The hollow cylinder has no longitudinal joints. The hollow cylinder may be formed as a single unit by isostatic pressing, for example by hot isostatic pressing (HIP) of a blend of a boron-containing powder and an aluminum or aluminum alloy powder which is blended by mechanical alloying. Casked nuclear fuel includes a nuclear fuel rod comprising uranium, which is disposed in or extends through the hollow cylinder of the cask liner.

Abstract: The present application relates to an unloading and temporary storage device. The unloading and temporary storage device includes a stock bin, a stock bin external member, a stock bin internal member, a shielding module and a loading module; the stock bin includes a barrel and a tank body; the stock bin external member includes a cooling water jacket; the stock bin internal member includes a straight bin, an inclined bin and an unloading bin that communicate sequentially; the shielding module includes an external shield and a neutron shield; the loading module includes a loading body; and sphere inlet passages are provided in the loading body. The unloading and temporary storage device can perform the functions of receiving, temporarily storing, atmosphere switching, and unloading of spherical elements, and also has the safety functions of ensuring geometrical integrity of the spherical elements, radiological protection and residual heat removal.

Abstract: A container holds radioactive material. A sub-criticality controller protects the radioactive material from reaching a criticality from contact with the water. The sub-criticality controller includes a metallic composition having at least one metal component and at least one borate component bonded to the at least one metal component. The metallic composition forms borates when the metallic composition contacts the water.

Abstract: A module for storing high level radioactive waste includes an outer shell, having a hermetically closed bottom end, and an inner shell forming a cavity and being positioned inside the outer shell to form a space therebetween. At least one divider extends from the top to the bottom of the inner shell to create a plurality of inlet passageways through the space, each inlet passageway connecting to a bottom portion of the cavity. A plurality of inlet ducts each connect at least one of the inlet passageways and ambient atmosphere, and each includes an inlet duct cover affixed atop a surrounding inlet wall, the inlet wall being peripherally perforated. A removable lid is positioned atop the inner shell and has at least one outlet passageway connecting the cavity and the ambient atmosphere, the lid and the top of the inner shell being configured to form a hermetic seal therebetween.

Abstract: A method of retrofitting a spent nuclear fuel system with a neutron absorbing apparatus. The method includes inserting a neutron absorbing apparatus into a first cell of an array of cells each configured to hold a spent nuclear fuel assembly. The neutron absorbing apparatus includes a first wall and a second wall supported by a corner spine to form a chevron shape and a first locking tab protruding outwardly from the first wall towards a first cell wall of the first cell. The method includes cutting a half-sheared second locking tab in the first cell wall of the first cell adjacent to and above the first locking tab of the neutron absorbing apparatus. Finally, the second locking tab is positioned to locking engage the first locking tab to retain the neutron absorbing apparatus in the first cell during removal of one of the fuel assemblies from the first cell.

Abstract: Proposed is a system for closing a drum unit for storing radioactive waste, the system including: a supporting unit configured to be seated on the ground; a drum unit configured to be seated on a top part of the supporting unit and having a plurality of first fastening holes; a moving unit configured to move to a side of the drum unit; a cover unit provided at the inside of the moving unit or at one side of the drum unit and having a plurality of second fastening holes; tightening units configured to be inserted into the associated second fastening holes; a fastening unit configured to grip the cover unit through a gripping part to move the cover unit to the top part of the drum unit simultaneously, thereby closing a gap between the drum unit and the cover unit; and a controller configured to control the fastening unit.

Abstract: A liquid storage vessel having a base with a bottom and an interior floor; a continuous side extending vertically from the base and having an interior surface, the bottom and continuous side each including an internal layer and an external layer separated by a material barrier, and configured such that the interior layers form an inner containment liner, and the external layers form a continuous exterior structural shell enclosing the inner containment liner. A top is affixed to the continuous side and has an interior ceiling. Access to the tank interior is provided by one or more manways. Mounting and connecting structures enable the tanks to be stacked directly atop one another and then structurally connected. The exterior structural shell is fabricated from high performance fiber reinforced concrete, and the inner containment liner is fabricated from a geopolymer concrete blend.

Abstract: A securing device is installable on an outer circumferential surface of a nuclear reactor core shroud and in contact with an inner circumferential surface of a pressure vessel. The securing device includes a base configured for contacting the outer circumferential surface of the nuclear reactor core shroud. The securing device also includes a radial extender including an actuator, a stationary support section fixed to the base and a movable contact section. The radial extender is configured such that the movable contact section is movable along the stationary support section by the actuator to force the movable contact section radially into the inner circumferential surface of the pressure vessel.

Abstract: A storage apparatus with radiation shielding for spent nuclear fuel includes a fuel basket comprising elongated fuel storage tubes each defining an open cell configured to hold a nuclear fuel assembly. Gamma radiation attenuation inserts are nested inside at least some of the storage tubes. The inserts each comprise elongated open-ended tubular bodies which may have a rectangular cuboid configuration with square cross section. The inserts are composed of a dense metallic material selected for blocking gamma radiation and may have high thermal conductivity for effective heat dissipation from the decaying nuclear fuel. Attenuation inserts can occupy some or all perimeter tubes to provide shielding against gamma radiation emanating in a lateral direction from the fuel basket. The inserts may include upper and lower securement features for detachable fixation to the storage tubes, and air/gas flow cutouts.

Abstract: A modular dry spent fuel canister system in which several different types of inner spent nuclear fuel canisters can be loaded into the same outer cask family. This family typically includes a storage overpack, a transfer cask, a transportation cask and support or auxiliary hardware. The various canisters can be loaded interchangeably into the different types of outer casks. The inner canisters are differentiated not by physical fuel type or dimension, but by the engineering objective or criterion that applies to the spent fuel being stored. One such objective may be for a single canister to store a large number of assemblies economically and safely. A second is a canister designed to greatly reduce the cooling time (or radioactive decay time) that must pass in order to load spent nuclear fuel for off-site storage, so as to meet the decay heat requirements and capabilities of the off-site storage system.

Abstract: Packaging for the transport and/or storage of radioactive materials includes a lateral packaging body around which an outer radiation protection envelope is disposed, which is made from a plurality of individual annular structures stacked on top of each other. Every structure includes an outer annular wall and a radial heat conductive wall, an outer end of which is secured to the wall, and an inner end of which is in contact with the lateral body. Furthermore, two directly consecutive structures delimit an annular cavity housing at least one radiation protection element, the cavity being closed radially towards the outside by the wall of one or both directly consecutive structures, and axially closed by the radial heat-conducting structure of one and the other of the two structures.

Abstract: A separable multi-component cask for spent nuclear fuel transport and storage includes a vertically elongated outer cylinder having a neutron radiation shielding composition and a vertically elongated inner cylinder having a gamma radiation blocking composition. The inner cylinder includes a cavity configured to hold a spent nuclear fuel canister. The inner cylinder is detachably mounted and nested inside a cavity of the outer cylinder and is separable therefrom during spent fuel cask loading operations in a staged manner. An air ventilation annulus formed between the first and second cylinders forms a heat removal passage to remove heat emitted by the radioactive canister when placed inside the second cylinder. A pair of removably coupled mating top flanges on the inner and outer cylinders supports and suspends the inner cylinder in a cantilevered manner, thereby allowing the directly heated inner cylinder to thermally expand to a greater degree than the outer cylinder.

Abstract: The present invention relates to a drying apparatus for drying a canister configured to transport and store spent nuclear fuels, a control method thereof, and a radiation shielding geometry for a radiation dosimeter configured to measure a radiation dose rate. An object of the present invention is to prevent a drying apparatus from being contaminated even in case of a damaged canister loaded with a spent nuclear fuel, by providing a non-contaminated circulation system and a contaminated circulation system, to easily assemble the drying apparatus to have a proper thickness depending upon a radiation dose rate, and to prevent a facility pipeline from being under stress by providing a radiation shielding geometry for a radiation dosimeter for measuring a radiation dose rate.

Abstract: A shipping container comprises a tubular or cylindrical shell having a closed end and an open end, a top end-cap removably secured to the open end of the tubular or cylindrical shell, and at least one fuel assembly compartment defined inside the shell. Each fuel assembly compartment includes elastomeric sidewalls and is sized and shaped to receive an unirradiated nuclear fuel assembly through the open end of the shell. The shipping container may further include a divider component, for example having a cross-shaped cross-section with ends of the cross secured to inner walls of the shell, and the divider component and the inner walls of the shell define the fuel assembly compartments. To load, the shipping container is arranged vertically and an unirradiated nuclear fuel assembly is loaded through the open end of the shell into each compartment, after which the open end is closed off by securing the top end-cap.

Abstract: A method of storing nuclear fuel is described. In some cases, the method includes submerging at least a portion of a nuclear fuel rod in a storage pool containing an aqueous solution including at least one of polyhedral boron hydride anions or carborane anions. In some cases, the method includes adding a salt having a polyhedral boron hydride anion or carborane anion to a storage pool containing water and at least a portion of a nuclear fuel rod submerged in it. The method may include both of these. A storage pool is also described. The storage pool includes an aqueous solution having at least one of polyhedral boron hydride anions or carborane anions with at least a portion of a nuclear fuel rod submerged in the aqueous solution. A method of servicing a nuclear reactor core is also described.

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: A seismic-resistant fuel storage system for a nuclear fuel pool includes a lined fuel pool and a fuel rack comprising tubular nuclear fuel storage cells attached to a common baseplate. Pedestals protrude downwardly from the baseplate supporting the rack on the pool base slab. Spaced embedment plates are fixedly anchored to the base slab to eliminate relative movement between the plates and pool liner. The embedment plates comprise upwardly open recessed receptacles each entrapping one of the rack pedestals therein. The receptacles are configured such that lateral movement of the fuel rack along the base slab in the event of a seismic event is constrained via engagement between receptacle walls and pedestals. Lateral seismic loads are not transferred to the pool liner. In some embodiments, the baseplates in the pool are coplanar and may be abutting engaged to mitigate rack movement during a seismic event.

Abstract: A racking device is provided for storing and/or transporting nuclear fuel assemblies. The racking device includes first stages (Ei?1, Ei+1) for neutron absorption and thermal conductivity, as well as second stages (E2i) for mechanical strength arranged so as to alternate with the first stages. Each first stage (Ei?1, Ei+1) includes first and second assemblies having interlacing notches (6a, 6b) made of aluminium alloy including boron. Each second stage (Ei) includes first and second structures (7a, 7b) stacked in a stacking direction (8) and each is made of one or more materials which are free of neutron-absorbing elements. The first and second structures (7a, 7b) are free of notches on their opposite edges in the stacking direction (8).

Abstract: A nuclear facility includes a fuel element pool which is filled with a cooling liquid. A fuel element rack, which is disposed in the fuel element pool, includes compartments for receiving fuel elements. The fuel elements received in the compartments are in direct contact with the cooling liquid in the fuel element pool. At least one cooling element is disposed in one of the compartments instead of a fuel element. The cooling element acts as a heat exchanger through which a coolant can flow, the cooling element is connected into a cooling circuit and the cooling element is immersed in the cooling liquid.

Abstract: Radiation therapy systems and their components, including secondary radiation shields. At least some versions of the disclosed systems combine a radiation delivery device, a primary radiation shielding device, and a secondary shielding layer into an integrated, modular unit. This is accomplished by using a small direct beam shield capable of blocking a primary beam from a radiation delivery device. In turn, a thinner shielding layer can be used to surround the radiation delivery device and primary shielding device, enabling a single modular unit to be delivered to an installation site. In some embodiments, a bed may be disposed within the secondary shielding layer. In some embodiments, the system is configured to provide up to 4-pi (4?) steradians of radiation coverage to the bed from the radiation delivery device.

Abstract: Radiation therapy systems and their components, including secondary radiation shields. At least some versions of the disclosed systems combine a radiation delivery device, a primary radiation shielding device, and a secondary shielding layer into an integrated, modular unit. This is accomplished by using a small direct beam shield capable of blocking a primary beam from a radiation delivery device. In turn, a thinner shielding layer can be used to surround the radiation delivery device and primary shielding device, enabling a single modular unit to be delivered to an installation site. In some embodiments, a bed may be disposed within the secondary shielding layer. In some embodiments, the system is configured to provide up to 4-pi (4?) steradians of radiation coverage to the bed from the radiation delivery device.

Abstract: A fuel rack for nuclear fuel assemblies includes a base plate and an array of cells for holding fuel assemblies. The array of cells includes: a plurality of first slotted plates slidably interlocked with one another to form a top portion of the array of cells, the plurality of first slotted plates formed of a first material; a plurality of second slotted plates slidably interlocked with one another to form a middle portion of the array of cells, the plurality of second slotted plates formed of a second material, the first and second materials being metallurgically incompatible; and a plurality of third slotted plates slidably interlocked with one another to form a bottom portion of the array of cells, the plurality of third slotted plates formed of the first material and connected to a top surface of the base plate.

Abstract: A neutron absorber member including a tube having a split extending radially completely through a sidewall of said tube throughout the entire axial length thereof such that the absorber member has a C-shaped geometry formed by the split. The sidewall of the tube is resiliently biased radially outwards and comprised of a metal matrix composite that is configured to absorb neutrons emanation from a spent fuel assembly in a sufficient amount to thereby maintain subcriticality of said spent fuel assembly.

Abstract: An entrainment-reducing assembly may include a container configured to hold a liquid. A venting arrangement may extend into an upper portion of the container and be configured to direct condensable and non-condensable gases into the container. A suction structure may extend into a lower portion of the container and be configured to carry out an extraction of excess liquid from the container caused by condensed gases. A deflector may be disposed between the suction structure and the venting arrangement within the container. As a result, an entrainment of uncondensed gases during the extraction of the liquid by the suction structure may be reduced or prevented, thereby protecting the pump from cavitation and failure.

Abstract: A spent nuclear fuel rod canister includes a submersible pressure vessel including a casing that defines an interior cavity, the casing including a corrosion resistant and heat conductive material and a rack enclosed within the interior cavity and configured to support one or more spent nuclear fuel rods. The spent nuclear fuel rod canister includes a heat exchanger attached to the casing of the pressure vessel.

Abstract: A composition for an optical waveguide is cured into a sheet to give a cured product. A difference in light transmittance with respect to light having a wavelength of 450 nm is 15% or less between this cured product and this cured product after retention in atmosphere at 175° C. for 40 hours, the light transmittance being calculated in terms of the cured product at a thickness of 50 ?m.

Abstract: An autonomous facility for storing spent nuclear fuel includes a building forming an enclosed interior space containing a water-filled spent fuel pool. The pool includes fuel racks containing spent fuel assemblies which heat the water via radioactive decay. A passive cooling system includes a submerged heat exchanger in the pool and an air cooled heat exchanger located in ambient air outside the building at a higher elevation than the pool heat exchanger. A heat transfer working fluid circulates in a closed flow loop between the heat exchangers via unpumped natural gravity driven flow to cool the fuel pool. The air cooled heat exchanger may be enclosed in a concrete reinforced silo adjoining the building for impact protection. The building may include a cask pit formed integrally with the pool to allow fuel assembles to be removed from a transport cask and loaded into the fuel rack underwater.

Abstract: A cask transport system includes a support assembly including a plurality of wheels and a support frame coupled to and supported by the wheels. The cask transport system also includes a tower disposed above the support assembly, the tower including a base portion and a tower frame coupled to the base portion, the tower frame movable relative to the base portion. The cask transport system also includes an upper beam assembly coupled to the tower frame, and a bottom block assembly coupled to the upper beam assembly, the bottom block assembly movable relative to the upper beam assembly.

Abstract: A packaging system for radioactive waste is robust, highly functional, and can be used for nearly all radioactive waste streams that require shielded packaging. The packaging system includes a modular container that is configured to receive modular shielding inserts. The packaging system can be used to store, transport, and dispose of radioactive waste.

Abstract: A fuel rack apparatus includes: a base plate having an upper surface and a lower surface; and a plurality of storage tubes coupled to and extending upward from the upper surface of the base plate, the storage tubes arranged in a side-by-side arrangement to form an array of the storage tubes. Each of the storage tubes extend along a longitudinal axis and include: an outer tube having an inner surface defining an inner cavity; and an inner plate-assemblage positioned within the outer tube that divides the inner cavity into a plurality of interior flux trap chambers and a fuel storage cell.

Abstract: A passively-cooled spent nuclear fuel pool system in one embodiment includes a containment vessel comprising a thermally conductive shell and an annular reservoir surrounding the shell that holds a liquid coolant forming a heat sink. A spent fuel pool is disposed inside the containment vessel and includes a body of water in contact with a peripheral sidewall of the fuel pool. At least one spent nuclear fuel rod submerged in the body of water heats the water. The peripheral sidewall of the spent fuel pool is formed by a portion of the shell of the containment vessel adjacent to the fuel pool, thereby defining a shared common heat transfer wall. The heat transfer wall operates to transfer heat from the body of water in the spent fuel pool to the heat sink to cool the body of water. The heat transfer wall comprises metal in one embodiment.

Abstract: A system for storing nuclear fuel, the system including a storage rack and a bearing pad. The storage rack includes an array of cells, each cell configured to receive and store nuclear fuel rods, a base plate configured to support the array of cells, and a support structure configured to support the base plate and to allow cooling fluid to circulate under and up through apertures in the base plate. The bearing pad is coupled to the support structure and is configured to limit lateral movement of the storage rack independent from lateral movement of the bearing pad. The base plate defines a base plate profile in a horizontal plane of the base plate, and the bearing pad defines a bearing pad profile in the horizontal plane of the base plate, wherein the bearing pad profile extends outside of the base plate profile.

Abstract: A transfer cask system for cooling spent nuclear fuel during the transfer from a spent nuclear fuel pool to a storage or transfer cask is disclosed. A canister containing spent nuclear fuel is inserted into a transfer cask. The transfer cask includes spacing components which define an annular region between the transfer cask and the canister. The transfer cask includes air inlets near a bottom end that permit air to flow through the defined annular region and exit at the open top of the transfer cask, thereby cooling the fuel within the canister. The transfer cask further comprises a neutron shield configured to absorb additional heat and shield radiation that may be generated within the canister. The transfer cask includes a transfer door that can open and close and has support rails that can support a spent nuclear fuel canister located in the transfer cask.

Abstract: A nuclear reactor includes a reactor pressure vessel and a nuclear reactor core comprising fissile material disposed in a lower portion of the reactor pressure vessel. The lower portion of the reactor pressure vessel is disposed in a reactor cavity. An annular neutron stop is located at an elevation above the uppermost elevation of the nuclear reactor core. The annular neutron stop comprises neutron absorbing material filling an annular gap between the reactor pressure vessel and the wall of the reactor cavity. The annular neutron stop may comprise an outer neutron stop ring attached to the wall of the reactor cavity, and an inner neutron stop ring attached to the reactor pressure vessel. An excore instrument guide tube penetrates through the annular neutron stop, and a neutron plug comprising neutron absorbing material is disposed in the tube at the penetration through the neutron stop.

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: The present invention concerns a hood for handling and confinement of at least two objects of slender shape, including an external enclosure and internal enclosures inside the external enclosure and at least one motor fixed above an internal enclosure and inside a barrel, the motor(s) being adapted to rotate the screw of the screw-nut mechanism of each internal enclosure and therefore the nut over a stroke A, and first and second mechanical control means, arranged in part above the cover of the external enclosure, respectively for manually guiding the internal enclosures in translation over a stroke A0 and manually pivoting the barrel in order to bring a holding member of one of the internal enclosures opposite the opening in the bottom of the external enclosure. Application to the handling and confinement of nuclear material sample holders.

Abstract: The invention relates to a packaging for transporting and/or storing radioactive materials, comprising a packaging body extending along a longitudinal direction, and further including at least one shock-absorbing cover mounted on one of both longitudinally opposite ends of the packaging body, the absorbing cover comprising attaching portions (44) on said packaging body, each attaching portion defining a clearing hole (58) through which an element (24) screwed in the packaging body passes. According to the invention, the attaching portion (44) has a deformable area (54) which, in the case of an outer bias on the absorbing cover leading to a contact strain between the screwed element (24) and the clearing hole (58), is designed to plastically deform.

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: An integrated storage, transportation and disposal system for used fuel assemblies is provided. The system includes a plurality of sealed canisters and a cask sized to receive the sealed canisters in side by side relationship. The plurality of sealed canisters include an internal basket structure to receive a plurality of used fuel assemblies. The internal basket structure includes a plurality of radiation-absorbing panels and a plurality of hemispherical ribs generally perpendicular to the canister sidewall. The sealed canisters are received within the cask for storage and transportation and are removed from the cask for disposal at a designated repository. The system of the present invention allows the handling of sealed canisters separately or collectively, while allowing storage and transportation of high burnup fuel and damaged fuel to the designated repository.

Abstract: A neutron absorbing apparatus, for insertion into a fuel cell storage system, includes a corner spine, a first all 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: A nuclear fuel assembly having varying spacing between fuel rods is provided. The nuclear fuel assembly includes a bundle of fuel rods. The fuel rods are arranged in a first lattice with a non-uniform pitch between the fuel rods in the lowermost section of the fuel assembly and in a second lattice with a uniform pitch between the fuel rods in the uppermost section of the fuel assembly.

Abstract: An integrated storage, transportation and disposal system for used fuel assemblies is provided. The system includes a plurality of sealed canisters and a cask sized to receive the sealed canisters in side by side relationship. The plurality of sealed canisters include an internal basket structure to receive a plurality of used fuel assemblies. The internal basket structure includes a plurality of radiation-absorbing panels and a plurality of hemispherical ribs generally perpendicular to the canister sidewall. The sealed canisters are received within the cask for storage and transportation and are removed from the cask for disposal at a designated repository. The system of the present invention allows the handling of sealed canisters separately or collectively, while allowing storage and transportation of high burnup fuel and damaged fuel to the designated repository.

Abstract: A heat pipe based passive residual heat removal system for a spent fuel pool (3). Partitions (6) are arranged around an inside of the spent fuel pool. Evaporation-end heat pipes (4) are arranged between the outside of the partitions and an inner wail of the pool. The evaporation-end heat pipes have outlets that extend beyond the pool and are connected to an Inlet of an ascending pipe (10), and have inlets connected to an outlet of a descending pipe (5). Condensation-end heat pipes (7) have inlets connected to an outlet of the ascending pipe, and have outlets connected to an inlet of the descending pipe. The heat pipes cool the spent fuel pool. A heat exchange by phase change of working medium in the heat pipe leads to heat exchange of low temperature difference and high efficiency, relying on density difference for natural circulation drive.

Abstract: An integrated storage, transportation and disposal system for used fuel assemblies is provided. The system includes a plurality of sealed canisters and a cask sized to receive the sealed canisters in side by side relationship. The plurality of sealed canisters include an internal basket structure to receive a plurality of used fuel assemblies. The internal basket structure includes a plurality of radiation-absorbing panels and a plurality of hemispherical ribs generally perpendicular to the canister sidewall. The sealed canisters are received within the cask for storage and transportation and are removed from the cask for disposal at a designated repository. The system of the present invention allows the handling of sealed canisters separately or collectively, while allowing storage and transportation of high burnup fuel and damaged fuel to the designated repository.

Abstract: A spent nuclear fuel rod canister includes a submersible pressure vessel including a casing that defines an interior cavity, the casing including a corrosion resistant and heat conductive material with a thermal conductivity of above about 7.0 watts per meter per kelvin; and a rack enclosed within the interior cavity and configured to support one or more spent nuclear fuel rods.