Abstract: An ultrasonic phased array transducer assembly having a single housing in which a plurality of phased array transducer subassemblies are mounted at a skewed angle relative to a leading face of the housing and to each other, with each transducer mounted on composite wedge(s) at different orientations within the housing.

Abstract: An insertable flux thimble interface for use in a bottom nozzle of a fuel assembly in a nuclear reactor (i.e., a bottom nozzle insert) is disclosed herein. In various aspects, the bottom nozzle insert has properties that are different from traditional bottom nozzle flux thimble interfaces. The properties of the bottom nozzle insert may mitigate wear phenomena observed on the flux thimble. For example, the bottom nozzle insert may be constructed from material that is different from the material of the bottom nozzle. In some aspects, the bottom nozzle insert is constructed from material that has a hardness that is less than the hardness the bottom nozzle material. In other aspects, the bottom nozzle insert is constructed from a material that has a hardness that is less than the hardness of the flux thimble material.

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 thermal shield flexure member. The thermal shield flexure member includes a first face portion, a second face portion and a third portion. The first face portion defines openings configured to align with receptacles of a thermal shield. The second face portion defines openings configured to align with openings of a core barrel and openings of an arm portion of a modified thermal shield flexure connected to the core barrel. The third portion is connected to the first face portion and the second face portion, and comprises a radiused portion. The thermal shield flexure member is configured to provide flexibility in an axial direction to accommodate differential axial expansions of the core barrel and the thermal shield, and rigidity in a radial direction to inhibit undesirable shell mode vibrations of the core barrel and/or the thermal shield.

Abstract: Annular nuclear fuel rods are disclosed. The annular nuclear fuel rods include an outer cladding tube made of ceramic composite or cermet composite, an inner cladding tube made of ceramic composite or cermet composite, a nuclear fuel region located between the outer cladding tube and inner cladding tube, and an open channel for liquid coolant to flow.

Abstract: An improved retention and alignment system for nuclear fuel rods includes an upper nozzle plate and a lower nozzle plate, nuclear fuel rods, each having an upper end and a lower end and extending axially between the upper and lower nozzle plates, a first precision magnet incorporated onto the lower end of the fuel rod, and a plurality of second precision magnets incorporated onto the lower nozzle plate in positions confronting the first precision magnets on the fuel rods. Each first precision magnet has at least one of a magnetic north or south polarity and the second precision magnet has at least one of a magnetic south or north polarity opposite the polarity of the confronting first precision magnet to effect magnetic attraction between the confronting first and second precision magnets. Grids between the upper and lower nozzle plates form cells through which the fuel rods pass.

Abstract: A reactor core block is disclosed including a fuel channel, a heat pipe, a primary moderator matrix configured to encompass the fuel channel and the heat pipe, and a secondary moderator channel configured to at least partially surround the fuel channel, the heat pipe, and the primary moderator matrix. The secondary moderator channel is comprised of metal hydride.

Abstract: A temperature measurement sensor for use in a nuclear reactor is described. The sensor includes a first neutron detector member and a second neutron detector member. The first neutron detector includes an outer shield material with an effective neutron capture cross section that is temperature dependent. The first neutron detector member outputs a first current signal and the second neutron detector member outputs a second current signal. An electrical connection between the first and second neutron detector members produces a net current that is the difference in current between the first and second signals. The difference is proportional to changes in temperature.

Abstract: A method for making an improved nuclear fuel cladding tube includes reinforcing a Zr alloy tube by first winding or braiding ceramic yarn directly around the tube to form a ceramic covering, then physically bonding the ceramic covering to the tube by applying a first coating selected from the group consisting of Nb, Nb alloy, Nb oxide, Cr, Cr oxide, Cr alloy, or combinations thereof, by one of a thermal deposition process or a physical deposition process to provide structural support member for the Zr tube, and optionally applying a second coating and optionally applying a third coating by one of a thermal deposition process or a physical deposition process. If the tube softens at 800° C.-1000° C., the structural support tube will reinforce the Zr alloy tube against ballooning and bursting, thereby preventing the release of fission products to the reactor coolant.

Abstract: A replacement thermal sleeve with a flange for a reactor vessel closure head penetration adapter housing. By altering a diameter of the flange, a replacement thermal sleeve can be installed through the narrow diameter of the penetration adapter housing opening from under the reactor vessel head. The flange can be compressible or expandable or the tubular wall of the thermal sleeve can be inserted in longitudinal sections, one at a time, into an opening in the underside of the penetration head adapter and reformed within the opening when fully inserted.

Abstract: A wick assembly for use with a heat pipe is disclosed. The wick assembly includes an end plug including a wick receiving area, a wick, and a crimp. A portion of the wick is positioned about the wick receiving area. The crimp is positioned about the portion of the wick and the wick receiving area. The end plug, the portion of the wick, and the crimp are diffusion bonded.

Abstract: Disclosed is a method for manufacturing free-standing cladding tubes with multi-layer structures. According to the method, a cylindrical mandrel substrate defining a hollow cylindrical inner space is provided. A first cold spray powder metal is selected. The cylindrical mandrel substrate is rotated and the first cold spray powder metal is applied to an outer surface of the cylindrical mandrel substrate to form a first layer. The cylindrical mandrel substrate is removed.

Abstract: An improved retention system for retaining fuel rods in a fuel assembly is disclosed. The retention system includes a plurality of first engagement surfaces on the bottom nozzle of a fuel assembly. There is at least one engagement surface for each fuel rod. A second engagement surface is formed on the bottom end plug of each fuel rod. The first and second engagement surfaces are configured for engagement with each other for axially and laterally retaining each fuel rod within the fuel assembly. Debris deflectors may also be provided to deflect debris from coolant channels surrounding the fuel rods.

Abstract: A method of controlling a nuclear power plant includes obtaining sensor data from one or more sensors of the nuclear power plant, providing the sensor data and a desired plant response to a neural network, wherein the neural network has been previously trained using a simulated nuclear power plant and is structured to determine at least one control system setting to achieve the desired plant response, determining at least one control system setting to achieve the desired plant response with the neural network, and setting or changing at least one control system setting of a control system of the nuclear power plant to the at least one control system setting determined by the neural network.

Abstract: A method of sampling a multi-layered material and a micro-sampling tool are described. The sampling method includes penetrating a top surface of a material in a component of interest with a micro-cutting tool to a predetermined depth sufficient to include each layer of the multi-layered material and a portion of the base, without cutting through the full depth of the base, under-cutting from the depth of penetration through the base to define a micro-sample of the multi-layered material, and removing the micro-sample with each layer of the multi-layered material intact. The micro-sampler includes a cutting tool calibrated to cut to a depth no greater than 2 mm, and in some aspects, no greater than 200 microns into a multi-layered material, the material having a top surface and a metallic or ceramic base and a container for removing and storing a micro-sample cut from the material with each layer of the multi-layered material and a portion of the base intact.

Abstract: A nuclear fuel assembly and a method of manufacture thereof are provided. The method comprises depositing a thermally conductive layer onto at least a portion of at least two nuclear fuel layers to create at least two at least partially coated layers. The method comprises stacking the at least two coated layers and bonding the at least two coated layers to form a nuclear fuel assembly.

Abstract: A method of forming a water resistant boundary on a fissile material for use in a water cooled nuclear reactor is described. The method comprises mixing a powdered fissile material selected from the group consisting of UN and U3Si2 with an additive selected from oxidation resistant materials having a melting or softening point lower than the sintering temperature of the fissile material, pressing the mixed fissile and additive materials into a pellet, sintering the pellet to a temperature greater than the melting point of the additive. Alternatively, if the melting point of the oxidation resistant particles is greater than the sintering temperature of UN or U3Si2, then the oxidation resistant particles can have a particle size distribution less than that of the UN or U3Si2.

Abstract: An apparatus for performing ultrasonic evaluation of a portion of a pipe includes a frame assembly and a plurality of ultrasonic sensors disposed in the frame assembly. The frame assembly includes a frame which is structured to cooperatively engage an outer surface of the pipe. The frame has a curved surface which is curved about an axis which, when the frame is engaged with the pipe, generally coincides with the central longitudinal axis of the pipe. The curved surface is generally defined by a radius which is generally equal to an outer radius of the pipe. The plurality of ultrasonic sensors are disposed in the frame assembly a fixed distance from the curved surface.

Abstract: An apparatus for removing irradiated Co-60 capsules from a plurality of burnable absorber rodlets. The apparatus comprises a solenoid that induces an electromagnetic flux into a Co-60 capsule and locks the Co-60 capsule in parallel with the apparatus. The apparatus is slideable along a longitudinal axis of the burnable absorber rodlet and causes the Co-60 capsule to overcome a plurality of forces exerted on it.

Abstract: Disclosed herein is a method pertaining to a power distribution of a reactor core of a nuclear installation, the method being executed on a general purpose computer. The method comprises: measuring current values from a plurality of vanadium neutron detector assemblies which are disposed in the reactor core of the nuclear installation; determining a measured relative core power distribution based upon the measured current values; producing a measured core power distribution based upon the measured relative core power distribution; and verifying that the reactor is operating within the licensed core operating limits based at least in part upon the measured core power distribution. Also disclosed herein is a vanadium neutron detector assembly.