Abstract: A detection apparatus includes a resonant electrical circuit supported within an interior of a nuclear fuel rod generates a response pulse in response to an excitation pure and transmits the response pulse through a cladding of the fuel rod to another location within a reactor in which the fuel rod is housed and without any breach in the cladding. A characteristic of the response pulse is indicative of a condition of the fuel rod. The detection apparatus also includes a transmitter positioned outside the cladding, in the reactor, in the vicinity of the fuel rod and configured to generate the excitation pulse and transmit the excitation pulse through the cladding to the resonant electrical circuit. A receiver is supported within the reactor outside of the cladding and, in response to the response pulse, communicates a signal to an electronic processing apparatus outside of the reactor.

Abstract: A detection apparatus includes a resonant electrical circuit supported within an interior of a nuclear fuel rod generates a response pulse in response to an excitation pulse and transmits the response pulse through a cladding of the fuel rod to another location within a reactor in which the fuel rod is housed and without any breach in the cladding. A characteristic of the response pulse is indicative of a condition of the fuel rod. The detection apparatus also includes a transmitter positioned outside the cladding, in the reactor, in the vicinity of the fuel rod and configured to generate the excitation pulse and transmit the excitation pulse through the cladding to the resonant electrical circuit. A receiver is supported within the reactor outside of the cladding and, in response to the response pulse, communicates a signal to an electronic processing apparatus outside of the reactor.

Abstract: The invention relates to a multi-component cladding for a nuclear fuel rod that includes a combination of ceramic and metal components. More particularly, the invention is directed to a cladding that includes a ceramic composite having a zirconium composition deposited thereon to form a zirconium coated ceramic composite. The ceramic composite includes a ceramic matrix and a plurality of ceramic fibers. The cladding is effective to protect the contents of the cladding structure from exposure to high temperature environments during various load conditions of a nuclear reactor.

Abstract: A block style heat exchanger for a heat pipe reactor having a plurality of heat pipes extending from a reactor core. The heat exchanger includes a plurality of primary channels, each for receiving heat transferred from the core via one of the heat pipes. The primary channels extending within a block of one or more materials. The heat exchanger also includes a plurality of secondary channels defined within the block for transmitting a flow of the secondary heat transfer medium through the heat exchanger from an inlet to an outlet. The block is formed from one or both of: a plurality of plates bonded together, with each plate defining at least a portion of one or more of the plurality of primary channels and/or the plurality of secondary channels, and/or a unitary piece of material formed from an additive manufacturing process.

Abstract: An apparatus and method for pressurizing SiC clad rods of a nuclear core component. A lower end of the rod is sealed with a lower end plug and an upper end of the rod is sealed between the cladding and an external piece of an upper end plug that has a through opening through which a separate internal piece of the upper end plug extends. The internal piece of the upper end plug is initially moveable within the through opening between an upper position that forms a gas tight seal and a lower position that forms a gaseous path through the through opening. The rod is placed in a pressure chamber pressurized to a desired pressure. When the pressure is reduced within the pressure chamber the internal pressure in the rod biases the internal piece of the upper end plug in the upper sealed position.

Abstract: A portable real-time system monitoring device is advantageously capable of autonomously learning the normal behavior of any system and of alerting the user or taking other action when the system becomes unpredictable or otherwise undesirable. No prior knowledge about the system is needed by the device. This is because the device uses a combination of machine learning and statistical process control to autonomously develop its own model of the monitored system and then autonomously monitor the system for unexpected behavior. Therefore, without any prior analysis or model creation, it can be deployed on any system, and it can be reused on any other system after it has been reset. The advantageous device of the disclosed and claimed concept performs this function in either real time or near real-time.

Abstract: A method is described for forming duplex layers including an interlayer and a corrosion resistant boundary layer on a nuclear fuel rod cladding tube for use in a water cooled nuclear reactor. The method includes forming, by thermal deposition or physical vapor deposition, on the exterior of a substrate, an inner interlayer with Mo, Ta, W or Nb or other particles, and forming, by thermal deposition or physical vapor deposition, on the interlayer, an outer corrosion resistant layer with particles selected from the group consisting of Cr, a Cr alloy, and combinations thereof. The interlayer prevents eutectic formation between the corrosion resistant layer and the substrate.

Abstract: A system for use in shutting down a nuclear reactor includes a housing that defines a region therein sealed from an ambient environment and a gate member disposed within the region in a manner such that the gate member segregates the region into a first compartment and a second compartment isolated from the first compartment. The gate member is formed from a material having a predetermined melting point. The system further includes a neutron absorbing material disposed within the first compartment and a dispersion mechanism disposed within the region. The dispersion mechanism structured to encourage the neutron absorbing material from the first compartment into the second compartment.

Abstract: A fuel assembly inspection system that utilizes a pressure transducer mounted to a utility's spent fuel handling tool to detect a relative change in depth of a fuel assembly during fuel inspections. The system then wirelessly transmits the signal to a fuel inspection recording system, which converts the signal to a relative height along the fuel assembly being viewed by a camera, and displays the relative height along with the applicable fuel assembly feature being viewed by the camera (e.g., nozzle, grid, span) via a text overlay on the video image of the inspection.

Abstract: A method is described that includes the steps of making a thin walled Zr alloy tube, loading nuclear fuel pellets into the tube, compressing the tube onto the fuel pellets to substantially reduce free space around the fuel pellets, positioning end plugs at each of two ends of the tube, filling the tube with a heat transferring gas, and coating the compressed tube with a corrosion resistant material using a thermal deposition process, such as cold spray, before inserting the tube into a pre-formed SiC composite cover having at least one closed end.

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 runner assembly for mounting to, and rotating with, a pump shaft of a pump includes a support member to be fixed to the pump shaft; a seal face ring positioned on, and mounted to the support member by a support shroud coupled to the support member; and an outer O-ring positioned in an upward and radially outward facing notch defined in a top portion of the support member. The outer O-ring forms a static sealed joint between the top of the support member and the bottom of the seal face ring.

Abstract: Described herein is a clamp for repairing a site of at least one damaged nozzle on a pipe for carrying liquid, such as a sparger nozzle in a header pipe in a boiling water reactor of a nuclear power plant. The clamp in general includes a housing configured for mounting over the site on a surface the pipe, wherein the housing has a front, sides, top, and back. The housing may include an opening, or the clamp may include an orifice plate having an opening and being positioned on the front side of the housing such that liquid exiting the pipe flows through one or both the opening in the housing and opening in the orifice plate. The clamp also includes a bottom surface which, together with the housing and orifice plate, when included, defines an interior chamber. The bottom plate has an opening for alignment, upon installation, with the site, and at least one member, for example, wedges for securing one of the damaged nozzle or support rings for stabilizing a replacement nozzle in position within the housing.

Abstract: The present invention relates to a control rod drive mechanism assembly for a nuclear reactor having a nuclear reactor vessel, a nuclear reactor core, a reactor vessel head, a latch housing nozzle, a latch housing, a rod travel housing, a latch assembly, a drive rod assembly and a rod control cluster assembly. The latch housing is integrated with the latch housing nozzle, the rod travel housing is welded to the latch housing, and the latch assembly is connected to the rod travel housing. The latch assembly includes the drive rod assembly and the rod control cluster assembly which is attached to the drive rod assembly.

Abstract: A system that measures the temperature distribution of the reactor coolant flowing through the hot leg or cold leg pipes by measuring the speed of sound time delay. This concept uses radiation hardened and temperature tolerant ultrasonic signal drivers based on vacuum micro-electronic technology. The system employs ultrasonic signals propagated through water, and relies on the characteristic that the speed of sound changes as the density and temperature of the water changes. Thus, a measured difference in the speed of sound in water may be directly correlated to a temperature change of the water.

Abstract: A zirconium alloy nuclear reactor cylindrical cladding has an inner Zr substrate surface, an outer volume of protective material, and an integrated middle volume of zirconium oxide, zirconium and protective material, where the protective material is applied by impaction at a velocity greater than 340 meters/second to provide the integrated middle volume resulting in structural integrity for the cladding.

Abstract: A spacer grid specifically designed for accident tolerant fuel utilizing fuel rods with SiC cladding for implementation in pressurized water reactors. The spacer grid tubular generally square design allows for ease of SiC fuel rod insertion during the fuel assembly fabrication process by providing a smooth contact geometry. The co-planar vertically oriented support allows the fuel rods to be rotated axially more freely at the grid location than a conventional six-point contact geometry used in existing fuel assembly designs. Since the SiC fuel rod has higher stiffness than a metallic fuel rod, the six-point contact geometry, which consists of two spring and four dimples, can potentially damage the fuel rod in the event of fuel rod deflection induced by a seismic event or a bowed fuel assembly. The fuel rod support cells are attached at their corners which are shared between adjacent support cells.

Abstract: An igniter apparatus which generates a high speed buoyancy induced vortex to funnel hydrogen and air from the surrounding onto the “igniter core” where an “igniter core” heats up to the auto ignition temperature by the exothermic catalytic oxidation of hydrogen on its surface. Water (vapor) is formed as the product, which inhibits the oxidation reaction, if not stripped away from the catalyst surface. The high velocity of the vortex ensures the stripping of the boundary layer of steam that is formed by the reaction, thus ensuring more active sites are available for hydrogen oxidation. The vortex is formed by channeling an upward draft into a vortex by guided fins. The upward draft is formed by a plate, which is also coated with a hydrogen recombination catalyst. The plate becomes hot by the same catalytic oxidation reaction in the presence of air containing hydrogen.

Abstract: A detection apparatus is a flow and temperature measuring device in the form of a tube having a channel positioned parallel to a coolant flow stream and contains a drogue that is firmly attached to a mount within the channel. The mount has a load detection apparatus firmly imbedded near the flow inlet to the tube. The drogue has at least neutral buoyancy in the fluid at the minimum fluid temperature of interest. A change in the buoyancy of the drogue as a function of temperature and a corresponding change in the strain detection apparatus output in the fluid is determined by a combination of simple physics and calibration measurements. The relationship between changes in strain detection apparatus signal output and flow-rate-induced forces applied to the drogue surface are also determined using a combination of simple physics and calibration measurements. A system and method are also described.

Abstract: A method whereby signals that are output by replacement SPNDs are converted into equivalent signals that would have been detected by legacy SPNDs for input to the legacy software. The replacement SPNDs have a different geometry than the legacy SPNDs and also have a different neutron sensitivity than the legacy SPNDs. The replacement SPNDs are subjected to a neutron flux in a core of a reactor and responsively output a set of signals. The set of signals and the geometry of the replacement SPNDs are employed to create a characterization of the neutron flux in the form of a curve that represents flux as a function of location along the core of the reactor. The legacy geometry of the legacy SPNDs is then employed to find the values on the curve that correspond with the positions where the legacy SPNDs had been located to create inputs for the legacy software.