Abstract: A getter element includes a getter material reactive with a fission product contained within a stream of liquid and/or gas exiting a fuel assembly of a nuclear reactor. At least one transmission pathway passes through the getter element that is sufficiently sized to maintain a flow of the input stream through the getter element at above a selected flow level. At least one transmission pathway includes a reaction surface area sufficient to uptake a pre-identified quantity of the fission product.

Abstract: A nuclear fuel element includes a core comprising a fissile element and an additional element. A protective structure surrounds the core and comprises at least a first material surrounding the nuclear fuel. The first material comprises the fissile element and the additional element and comprises a greater than stoichiometric amount of the additional element. An outer portion of the nuclear fuel element comprises a metal. Related nuclear fuel elements, and related methods are also disclosed.

Abstract: A getter element includes a getter material reactive with a fission product contained within a stream of liquid and/or gas exiting a fuel assembly of a nuclear reactor. At least one transmission pathway passes through the getter element that is sufficiently sized to maintain a flow of the input stream through the getter element at above a selected flow level. At least one transmission pathway includes a reaction surface area sufficient to uptake a pre-identified quantity of the fission product.

Abstract: A Thorium molten salt energy system is disclosed that includes a proton beam source for producing a proton beam, that can vary between a first energy level and a second energy level of, where the generated proton bean can be directed into a main assembly containing both Thorium-containing molten salt and Thorium fuel rods, each containing an inner Beryllium element and an outer solid Thorium element. The generated proton beam can be shaped and directed to impinge upon Lithium within the molten salt to promote the generation of thermal neutrons and the fission of Uranium within the molten salt. The generated proton beam can also be shaped and directed to impinge upon the Beryllium within the Thorium fuel rods to promote the generation of high energy neutrons.

Abstract: A Thorium fuel rod assembly is disclosed that includes first and second support elements and a number of Thorium fuel rods positioned between support elements. Each of the Thorium fuel rod includes an outer fuel element containing a solid Thorium an inner core element containing Beryllium that is positioned within an interior cavity defined by the outer fuel element. In an exemplary disclosure, the inner core element also defines an inner cavity such that a beam of high energy particles may be directed into the inner cavity of the inner core element to impinge upon a Beryllium nucleus within the inner core element to produce a (p, n) reaction resulting in the emission of a neutron, where the emitted neutron may interact with a Thorium nucleus in the outer fuel element to cause the Thorium nucleus to fission.

Abstract: A Thorium fuel rod assembly is disclosed that includes first and second support elements and a number of Thorium fuel rods positioned between support elements. Each of the Thorium fuel rod includes an outer fuel element containing a solid Thorium an inner core element containing Beryllium that is positioned within an interior cavity defined by the outer fuel element. In an exemplary disclosure, the inner core element also defines an inner cavity such that a beam of high energy particles may be directed into the inner cavity of the inner core element to impinge upon a Beryllium nucleus within the inner core element to produce a (p, n) reaction resulting in the emission of a neutron, where the emitted neutron may interact with a Thorium nucleus in the outer fuel element to cause the Thorium nucleus to fission.

Abstract: A Thorium molten salt energy system is disclosed that includes a proton beam source for producing a proton beam, that can vary between a first energy level and a second energy level of, where the generated proton bean can be directed into a main assembly containing both Thorium-containing molten salt and Thorium fuel rods, each containing an inner Beryllium element and an outer solid Thorium element. The generated proton beam can be shaped and directed to impinge upon Lithium within the molten salt to promote the generation of thermal neutrons and the fission of Uranium within the molten salt. The generated proton beam can also be shaped and directed to impinge upon the Beryllium within the Thorium fuel rods to promote the generation of high energy neutrons.

Abstract: A Thorium molten salt energy system is disclosed that includes a proton beam source for producing a proton beam, that can vary between a first energy level and a second energy level of, where the generated proton bean can be directed into a main assembly containing both Thorium-containing molten salt and Thorium fuel rods, each containing an inner Beryllium element and an outer solid Thorium element. The generated proton beam can be shaped and directed to impinge upon Lithium within the molten salt to promote the generation of thermal neutrons and the fission of Uranium within the molten salt. The generated proton beam can also be shaped and directed to impinge upon the Beryllium within the Thorium fuel rods to promote the generation of high energy neutrons.

Abstract: A Thorium fuel rod assembly is disclosed that includes first and second support elements and a number of Thorium fuel rods positioned between support elements. Each of the Thorium fuel rod includes an outer fuel element containing a solid Thorium an inner core element containing Beryllium that is positioned within an interior cavity defined by the outer fuel element. In an exemplary disclosure, the inner core element also defines an inner cavity such that a beam of high energy particles may be directed into the inner cavity of the inner core element to impinge upon a Beryllium nucleus within the inner core element to produce a (p, n) reaction resulting in the emission of a neutron, where the emitted neutron may interact with a Thorium nucleus in the outer fuel element to cause the Thorium nucleus to fission.

Abstract: A getter element includes a getter material reactive with a fission product contained within a stream of liquid and/or gas exiting a fuel assembly of a nuclear reactor. At least one transmission pathway passes through the getter element that is sufficiently sized to maintain a flow of the input stream through the getter element at above a selected flow level. At least one transmission pathway includes a reaction surface area sufficient to uptake a pre-identified quantity of the fission product.

Abstract: The invention relates to nuclear power and can be used in manufacturing of fuel elements for nuclear reactors. A method of sealing nuclear reactor fuel elements is proposed comprising welding one end of a casing with a first plug, loading the fuel element with fuel, and welding a second plug to another end of the casing. The casing is of a high-chromium ferrite-martensite steel and the plugs are of a ferrite steel. Argon arc welding is carried out at a volume ratio of the materials of the casing and the plugs contributing to formation of the metal of the weld seam which allows formation of a ferrite phase in said metal, wherein the ratio is: V1/V2?0.18, where V1 is the volume of ferrite material and V2 is the volume of ferrite-martensite material. Argon arc welding is carried out at a current of 14-20 A, a speed of 12-15 m/h, an arc voltage of 9-10 V and an argon flow rate of 7-8 l/min. This method provides for the desired quality of the welded joins and simplifies the fuel element manufacturing process.

Abstract: Example embodiments relate to a gas-adsorbing material capable of reducing the generation amount of combustible gas without deteriorating gas-adsorbing performance, and a vacuum insulation material including the gas-adsorbing material. The gas-adsorbing material may include a metal selected from at least one of Li, V, Zr, or an alloy including the same, which adsorbs a nitrogen gas and is inactivated by moisture as a nitrogen adsorbing agent, and an additive added to the metal. The metal is attached on the particle surface of the additive. The metal may be an alloy including Li and an alkaline-earth metal, for example, Ba—Li alloy. The additive absorbs moisture, and is selected from at least one of an inorganic oxide, a transition metal, an oxide of a transition metal, an alloy including a transition metal, and a mixture including a transition metal.

Abstract: A system configured to passively filter radioactive materials from a flow may include one or more particulate removal devices; one or more water removal devices; and/or one or more radionuclide removal devices. At least one of the one or more particulate removal devices may mechanically remove particulates of the radioactive materials from the flow. At least one of the one or more water removal devices mechanically may remove water from the flow. At least one of the one or more radionuclide removal devices may remove radioactive aerosols, reactive radioactive gases, or radioactive aerosols and reactive radioactive gases from the flow using engineered filter media. A filter may include a body, including an inlet and an outlet. The body may be configured to store filter media, to contain pressure from gas explosions, and/or to allow the stored filter media to move toward the outlet when pressure at the inlet increases.

Abstract: Use in a nuclear fission reactor of a sacrificial metal in a molten salt fuel containing actinide halides in order to maintain a predefined ratio of actinide trihalide to actinide tetrahalide without reducing actinide trihalide to actinide metal. A method of maintaining oxidation state of a molten salt containing actinide halides. The method comprises contacting the molten salt continuously with a sacrificial metal, the sacrificial metal being selected in order to maintain a predefined ratio of actinide trihalide to actinide tetrahalide without reducing actinide trihalide to actinide metal. A fuel tube containing a sacrificial metal is also described.

Abstract: A nuclear-fuel pin including a linear element made of a metal nuclear-fuel material consisting of uranium and/or plutonium, and cladding including Fe and Cr or an alloy including at least both of said elements, comprises a main shell provided around the linear nuclear-fuel element, said shell including threads or fibers made of SiC. A method for producing a nuclear-fuel pin is also provided.

Abstract: A tritium production element for use in a conventional power reactor, and methods of use and making, are provided, wherein the element experiences reduced tritium permeation during irradiation by incorporating a silicon carbide barrier that encapsulates one or more burnable absorber pellets. The tritium production element includes a tubular cladding that encloses a plurality of burnable absorber pellets, such that individual pellets or groups of pellets are disposed within a silicon carbide barrier layer.

Abstract: UO2 nuclear fuel pellets are fabricated by adding additive powder comprising Mn compound and Al compound into UO2 powder.

Abstract: A nuclear fuel rod plenum spring assembly that has a spacer affixed to the lower end of the ground torsion spring. The spacer has a substantially flat surface on its underside that presses against the upper surface of the upper fuel pellets to spread the load of the spring over the top surface of the upper most fuel pellet.

Abstract: A binary or ternary metallic fuel composition having a metal dopant content of about 1 at. % to 25 at. %. A metal dopant is added to the binary or ternary metallic fuel composition to extend metal fuel burnup. The metal dopant will pin the lanthanides in the fuel phases. For binary U—Zr fuels, the metal dopant is generally palladium or titanium. For ternary U—Pu—Zr fuels, the metal dopant is generally palladium or a mixture of silver and titanium.

Abstract: The present invention relates to a fuel rod of a nuclear fuel assembly having a vase-like compression spring adapted to increase the internal volume thereof wherein when the vase-like compression spring is inserted into a cladding tube, it has a relatively smaller volume occupied inside the fuel rod when compared with the existing coil type compression spring, such that the vase-like compression spring can ensure a sufficient space portion receiving the fission gases generated during the operation of the fuel rod, thereby increasing the burn-up performance of the fuel rod and the mechanical integrity thereof.

Abstract: A neutron absorbing insert for use in a fuel rack and method of manufacturing the same. In ones aspect, the invention is a neutron absorbing apparatus comprising: 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 formed 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 method for installing a locking retainer in a tube to maintain internal components within the tube under compression comprising the steps of: a) providing an elongated retainer spring having large and small diameter sections with the large diameter section of a size for an interference fit with the interior diameter of the tube and the smaller diameter section of a size having a clearance with the interior diameter of the tube; b) inserting a smaller diameter section of an elongated tool into the larger diameter section of the elongated retainer spring; c) engaging a transition between the smaller and larger diameter sections of the tool against a transition between the larger and smaller diameter sections of the elongated retainer spring; d) inserting the combined tool and retainer spring into an open end of the tube containing internal components with an end of the smaller diameter section of the retainer spring entering the tube first; e) advancing the combined tool and retainer spring within the tube to

Abstract: The absorbing rods have a nearly the same shape as the shape of columnar control rods for PWR used in reactivity control of core in a reactor. The absorbing rods can shield neutrons, and are inserted in control rod guide pipes and measuring pipes in fuel assemblies.

Abstract: Method of fabricating a fuel rod, comprising providing an effective amount of a metal oxide in the fuel rod to generate steam and mitigate the tendency for secondary hydriding. Fuel rods fabricated according to the method of the invention are also provided.

Abstract: A new design concept of boiling water reactor fuel rod is disclosed. The new design is characterized by an upward shift in the location of the fuel pellet stack inside the fuel cladding. The resulting axial power shift upward decreases two-phase and total pressure drop and has a stabilizing effect. A device for affecting such fuel pellet displacement is a crushable tube placed under the fuel pellet stack, which also helps to mitigate fuel-clad mechanical interaction and reduces the likelihood of clad failure.

Abstract: A nuclear fuel bundle has differential peak power limits for the edge or peripheral fuel rods and the interior fuel rods. Also, the magnitude of nuclear fuel in the edge or peripheral rods is decreased in comparison with the magnitude of nuclear fuel in the interior rods. The nuclear reactor can thus operate at higher power output by decreasing the margins between the power outputs and peak power limit of the interior rods, as well as by decreasing the margins between the power outputs of the edge or peripheral rods and the increased peak power limit of those rods. The outer or peripheral edge rods can also be enriched for enhanced power output.

Abstract: A fuel assembly for a boiling water reactor where the fuel assembly during operation is arranged vertically in the core of the reactor. The fuel assembly comprises a plurality of vertical fuel rods (22) arranged in one or more fuel bundles, wherein at least the majority of the fuel rods comprise a stack of fuel pellets (7) surrounded by a cladding tube (8b) and a plenum tube (23) which is connected to the upper part of the cladding tube (8b), the plenum tube having a cross-section area which is smaller than the cross-section area of the cladding tube.

Abstract: The reactor shut-down margin and the thermal margin, as well as the output per unit volume of the core is increased. When A is the total cross sectional area of the non-boiling water areas in the channel boxes each surrounding a fuel assembly and non-boiling water areas outside the channel boxes and B is the cross sectional areas of boiling water areas in the channel boxes, the relation of 1>B/(A+B).gtoreq.0.76 is set. A control unit adjusts a rotational speed of a recirculation internal pump which controls the cooling water flow rate per unit area in the core section to 3.0.times.10.sup.3 t/h/m.sup.2 at the beginning of the operation cycle and controls the cooling water flow rate per the unit area in the core cross section to 3.3.times.10.sup.3 t/h/m.sup.2 at the end of an operation cycle.

Abstract: A plenum spring and getter assembly for use in a nuclear fuel rod has a plenum spring design which retains the getter at a desired distance from the fuel column. The plenum spring is a wire having a first wound section of diameter greater than the diameter of the getter installed therein, a second wound section of diameter less than the getter diameter and a third wound section having a diameter which is preferably, but not necessarily, equal to the diameter of the first wound section. The wound sections are connected in series along an axis, with the "necked" second wound section being situated intermediate the first and third wound sections. When the fuel rod in accordance with the invention is installed upright in the reactor, the getter bears against and is supported by the first turn of the necked wound wire section.

Abstract: An agent for trapping the radioactivity of the fission products which appear in a nuclear fuel based on sintered uraniferous oxides in the course of irradiation characterized in that it comprises a stable oxygenated compound, a combination of at least two metallic oxides and at least one oxide of a non-radioactive isotope of the radioactive fission product or products whose radioactivity is to be trapped.

Abstract: A nuclear fuel element comprising sintered pellets based on uraniferous oxide which are surrounded by a metallic sheath and permitting trapping of the fission products which appear in the course of irradiation characterized in that the pellets contain or are coated with or that the sheath is internally coated with an agent for trapping said fission products based on mixed metallic oxide comprising SiO.sub.2 and one at least of the oxides ZrO.sub.2 or CeO.sub.2.

Abstract: A nuclear fuel rod, in which a cladding tube contains fuel pellets therein and two plugs stop end openings of the cladding tube, in which a stopper member stops the fuel pellets from their moving through a spring member arranged between the stopper member and one of the plugs for biasing the stopper member onto the fuel pellets, and a getter tube is also arranged between the stopper member and the one of the plugs, and in which at least one of the spring member, the stopper member and the getter tube is made of a nonmagnetic steel.

Abstract: Fuel element rod for a pressurized water-cooled nuclear reactor having a cylindrical can (2) made from an alloy which is transparent to neutrons and closed at each of its ends by a plug (3, 4), namely an upper plug (3) and a lower plug (4) and having a first portion in which are stacked fuel material pellets (6), which is optionally inserted between two insulating pellets (7, 8), and a second portion or expansion chamber (5) containing a compressed spring (9) bearing at one end on the upper plug (3) and at the other end on the stack of fuel pellets (6) which it maintains in position, characterized in that the spring is made from hafnium.

Abstract: In order to prevent the formation of a hydrogen atmosphere in a free gas ce usually available in the storage containers of radioactive waste, potassium permanganate is dispersed in a suitable carrier within the storage barrel provided for the waste. When the radioactive waste is first encased in cement before being put in a storage barrel, the potassium permanganate is introduced into the cement before it sets by mixing in a solution or crystals. Alternatively the compressed or solidified waste is enveloped in a porous non-reducing aggregate of carrier materials, such as particles of aluminum oxide, on the exposed surfaces of which potassium permanganate is applied or which is mixed with potassium per manganate particles. The waste and the enveloping permanganate-containing carrier material are then securely enclosed in a common container.

Abstract: An improved nuclear fuel element for service in power generating, water cooled nuclear reactors, comprising a fuel cladding container of an alloy of zirconium provided with a barrier lining of unalloyed zirconium metal metallurgically bonded to the container's inner surface, and enclosed therein fissionable nuclear fuel including an additive of aluminum silicate.

Abstract: The scope of the present invention is the provision of a non-evaporable gettering ternary alloy particularly for the sorption of water and water vapor in nuclear reactor fuel elements.

Abstract: A spring retainer is disclosed for use in retaining fuel pellets in a fuel rod both during fabrication and shipment to prevent the fuel pellets from being moved from their design location before installation within a reactor. The cylindrical and solid nuclear pellets containing the reactor fuel are placed within the fuel rods (or cladding) and have an outside diameter slightly less than the inside diameter of the fuel rod. Once the pellets are in place, a two-part spring holder is inserted into the end of the fuel rod. A first compression spring part of the coil spring holder is a conventional coil spring which, acting in compression, bears against the fuel pellets with a preselected force typically forcing the pellets when in the horizontal position into a compacted disposition when the fuel rod is horizontal. This conventional coil spring has a diameter which is less than the inside diameter of the fuel rod.

Abstract: A porous plug is installed in the central region of a fuel rod of annular fuel pellets and prevents relocation of fuel fragments from the inner surface of each fuel pellet while providing a getter for gases produced in the fuel rod during operation of the nuclear reactor.

Abstract: Nuclear fuel elements are provided that are resistant to pellet-clad interaction. The closed end nuclear fuel elements comprise a zirconium or zirconium alloy tube that has a layer of lubricant, preferably graphite, on the inner surface thereof, and enriched uranium dioxide pellets that have a coating on the outer surface thereof of a thickness sufficient to absorb fission products. The coating on the pellets may be a burnable absorber or a material that has a relatively low neutron absorption compared to a burnable absorber. The combination of the layer on the tube and the coating on the pellets reduces both the stress level and the concentration of damaging fission products that would contact and react with the layer of lubricant about the inside surface of the tubular cladding and thus reduces conditions for pellet-clad interaction.

Abstract: An improved cesium getter 28 is provided in a breeder reactor fuel element or pin in the form of an extended surface area, low density element formed in one embodiment as a helically wound foil 30 located with silicon carbide, and located at the upper end of the fertile material upper blanket 20.

Abstract: A non-boron moderator filled rod for a nuclear reactor fuel assembly has a tubular body with a pair of end plugs sealing the opposite ends thereof and defining a chamber within the body. A liquid moderator, such as light water, is contained witin the chamber. One of the end plugs acts as a hydride sink and a hydrogen getter sponge material is disposed adjacent the other end plug.

Abstract: A nuclear reactor fuel rod includes a fuel tube and an improved end plug assembly having a pair of hollow end plugs which seal opposite ends of the fuel tube. Each end plug has an outer body portion with an outside diameter substantially the same as the outside diameter of the fuel tube and an inner body portion of reduced diameter inserted into an end of the tube. Each plug has a cavity defined therein which increases the space within the rod for fission gas expansion. An outer region of the cavity within the outer body portion of the end plug is undercut relative to an inner region of the cavity within the inner body portion of the plug. One of the end plugs also has an insert fitted into its inner body portion which prevents fuel chips from falling into the cavity of the end plug. A slot is formed axially in a side wall of the insert which allows communication of gas from the tube into the cavity of the end plug.

Abstract: A nuclear reactor component such as a fuel rod, burnable absorber rod, or neutron absorber rod, comprising a hermetically sealed metallic tube containing a solid material such as a nuclear fuel, burnable absorber, or neutron absorber, within a helium atmosphere, which solid material will release tritium into the helium atmosphere, has added thereto about 2-3 percent by volume of a gas, selected from oxygen, carbon monoxide and carbon dioxide. The addition of this gas to the helium atmosphere is effective to form an oxide layer on the inner surface of the metallic tube and significantly reduce the permeation of tritium through the metallic tube, such that the tritium is retained within the reactor component.

Abstract: In the event of a breach in the cladding of a rod in an operating liquid metal fast breeder reactor, the rapid release of high-pressure gas from the fission gas plenum may result in a gas blanketing of the breached rod and rods adjacent thereto which impairs the heat transfer to the liquid metal coolant. In order to control the release rate of fission gas in the event of a breached rod, the substantial portion of the conventional fission gas plenum is formed as a gas bottle means which includes a gas pervious means in a small portion thereof. During normal reactor operation, as the fission gas pressure gradually increases, the gas pressure interiorly of and exteriorly of the gas bottle means equalizes.

Abstract: An improved fuel pin cladding, particularly adapted for use in breeder reactors, consisting of composite tubing with austenitic steel on the outer portion of the thickness of the tube wall and with nickel and/or ferritic material on the inner portion of the thickness of the tube wall. The nickel forms a sacrificial barrier as it reacts with certain fission products thereby reducing fission product activity at the austenitic steel interface. The ferritic material forms a preventive barrier for the austenitic steel as it is immune to liquid metal embrittlement. The improved cladding permits the use of high density fuel which in turn leads to a better breeding ratio in breeder reactors, and will increase the threshold at which failure occurs during temperature transients.

Abstract: Apparatus for separating the gaseous hydrogen isotopes protium, deuterium and tritium from a gas stream containing one or a plurality of the hydrogen isotopes. A membrane is provided which is permeable to the hydrogen isotopes and impermeable to the gas stream. The membrane has a side facing away from the gas stream and a side exposed to the gas stream. On the side of the membrane facing away from the gas stream, there is disposed a getter which takes up the hydrogen isotopes by absorption at a predetermined absorption temperature and releases the absorbed hydrogen isotopes again by desorption at a desorption temperature above the absorption temperature. The membrane permeable to the hydrogen isotopes covers a surface of the getter so that the getter, at the absorption temperature, absorbs hydrogen isotopes exclusively through the membrane. The membrane and getter constitute an absorption element and are permanently connected to one another.

Abstract: A method is disclosed for producing a dimensionally stable UO.sub.2 fuel pellet of large grain mole %, and relatively large pore size. A dopant containing an element selected from the group consisting of aluminum, calcium, magnesium, titanium, zirconium, vanadium, niobium, and mixtures thereof is added to a highly sinterable UO.sub.2 powder, which is a UO.sub.2 powder that is sinterable to at least 97% theoretical density at 1600.degree. C. in one hour, and the UO.sub.2 powder can then be formed into fuel pellets. Alternatively, the dopant can be added at a step in the process of producing ammonium diuranate. The ammonium diuranate is collected with about 0.05 to about 1.7 mole%, based on UO.sub.2, of a compound containing said element. That mixture is then calcined to produce UO.sub.2 and the UO.sub.2 is formed into a fuel pellet. The addition of the dopant can also be made at the hydrolysis stage in the manufacture of UO.sub.2 by a dry conversion process.

Abstract: A hydrogen permeation resistant barrier is formed by diffusing aluminum into an iron or nickel alloy and forming an intermetallic aluminide layer.

Abstract: A non-evaporable getter alloy is provided which can be used in a process for the sorption of gas from a closed vessel comprising the step of:introducing into the vessel a non-evaporable ternary gettering alloy whose composition in weight percent when plotted on a ternary composition diagram in weight percent Zr, weight percent V and weight percent Fe lies with a polygon having as its corners the points defined by:(a) 75% Zr-20% V-5% Fe(b) 45% Zr-20% V-35% Fe(c) 45% Zr-50% V-5% Fesuch alloys can sorb water vapor without the release of H.sub.2 between 200.degree.-350.degree. C. and can be used in a wide temperature range for the sorption of other gases. They can also be activated in short times at relatively low temperatures, to be used as a getter at room temperature.

Abstract: A process for the removal of iodine from aqueous solutions, particularly the trapping of radioactive iodine to mitigate damage resulting from accidents or spills associated with nuclear reactors, by exposing the solution to well dispersed silver carbonate which reacts with the iodine and iodides, thereby gettering iodine and iodine compounds from solution. The iodine is not only removed from solution but also from the contiguous vapor.