Abstract: Disclosed herein are zirconium-based alloys and methods of fabricating nuclear reactor components, particularly fuel cladding tubes, from such alloys that exhibit improved corrosion resistance in aggressive coolant compositions. The fabrication steps include a late-stage ?-treatment on the outer region of the tubes. The zirconium-based alloys will include between about 1.30 and 1.60 wt % tin; between about 0.06 and 0.15 wt % chromium; between about 0.16 and 0.24 wt % iron, and between 0.05 and 0.08 wt % nickel, with the total content of the iron, chromium and nickel comprising above about 0.31 wt % of the alloy and will be characterized by second phase precipitates having an average size typically less than about 40 nm. The final finished cladding will have a surface roughness of less than about 0.50 ?m Ra and preferably less then about 0.10 ?m Ra.

Abstract: A system and method for assessing failure of fuel rods are disclosed. The method may include monitoring fuel rod operational conditions, comparing the fuel rod parameters to parameters limits, calculating the fuel rod performance parameters to determine the likelihood of failure of individual fuel rods, and updating plant operating parameters based on the calculated fuel rod parameters. The system may input the calculated fuel rod parameters into a fuel failure model to assess the probability of failure, and predict the probability of failure of individual fuel rods based on fuel rod parameters in the fuel failure model.

Abstract: An apparatus generating a graphical image of a core of a boiling water reactor (BWR) using at least one data set of channel deformation data including: a computer system including a display device for presenting the graphical image and a processor generating the graphical image using the at least one data set; the graphical image of the core includes symbolic representations of control blades arranged in the core, indicia identify each control blade, and indicia regarding deformation of channels adjacent each control blade, and a viewer software tool executed by the processor which accesses the at least one data set and determines a location in the core of the control blades and channels, and correlates the deformation data with the channels for display on the graphical image.

Abstract: Disclosed herein are zirconium-based alloys that may be fabricated to form nuclear reactor components, particularly fuel cladding tubes, that exhibit sufficient corrosion resistance and hydrogen absorption characteristics, without requiring a late stage ?+? or ?-quenching processes. The zirconium-base alloys will include between about 1.30-1.60 wt % tin; 0.0975-0.15 wt % chromium; 0.16-0.24 wt % iron; and up to about 0.08 wt % nickel, with the total content of the iron, chromium and nickel comprising at least about 0.3175 wt % of the alloy. The resulting components will exhibit a surface region having a mean precipitate sizing of between about 50 and 100 nm and a Sigma A of less than about 2×10?19 hour with the workpiece processing generally being limited to temperatures below 680° C. for extrusion and below 625° C. for all other operations, thereby simplifying the fabrication of the nuclear reactor components while providing corrosion resistance comparable with conventional alloys.

Abstract: A method for treating a Zr-alloy fuel bundle material in a nuclear reactor includes treating a surface of the Zr-alloy fuel bundle material with a laser beam generated by a solid-state laser, and a nuclear reactor including a treated Zr-alloy fuel bundle material. This may reduce the generation of shadow corrosion and/or reduce the propensity for interference between control blade and fuel channel during operation of the nuclear reactor.

Abstract: An apparatus generating a graphical image of a core of a boiling water reactor (BWR) using at least one data set of channel deformation data including: a computer system including a display device for presenting the graphical image and a processor generating the graphical image using the at least one data set; the graphical image of the core includes symbolic representations of control blades arranged in the core, indicia identify each control blade, and indicia regarding deformation of channels adjacent each control blade, and a viewer software tool executed by the processor which accesses the at least one data set and determines a location in the core of the control blades and channels, and correlates the deformation data with the channels for display on the graphical image.

Abstract: In a method of determining a cell friction metric for a control cell of a nuclear reactor, a channel face fast fluence and/or a channel face controlled operation parameter is determined for all channels. A total bow value is calculated for each channel based on the channel face fast fluence and/or channel face control parameters. For each channel, a channel wall pressure drop parameter is determined, and a total bulge value is calculated for each channel using the channel face fast fluence and channel wall pressure drop parameters. Total deformation at specified channel axial elevations for the cell is determined based on the total bow and bulge values. A control blade axial friction force value is calculated at each axial elevation based on the total deformation, along with channel stiffness and channel-control blade friction coefficient values. A maximum friction value is selected as the cell friction metric for the cell.

Abstract: A zirconium alloy suitable for forming reactor components that exhibit reduced irradiation growth and improved corrosion resistance during operation of a light water reactor (LWR), for example, a boiling water reactor (BWR). During operation of the reactor, the reactor components will be exposed to a strong, and frequently asymmetrical, radiation fields sufficient to induce or accelerate corrosion of the irradiated alloy surfaces within the reactor core. Reactor components fabricated from the disclosed zirconium alloy will also tend to exhibit an improved tolerance for cold-working during fabrication of the component, thereby simplifying the fabrication of such components by reducing or eliminating subsequent thermal processing, for example, anneals, without unduly degrading the performance of the finished component.

Abstract: Method and system for determining immanence of catastrophic failure for a selected tire among a plurality of tires that are concurrently in operation, the method comprising the steps of: selecting a tire from the plurality of tires; monitoring vibration amplitude versus time signals for the selected tire; using signal averaging to minimize signal noise in the selected tire's vibration signals; at selected intervals, fast Fourier transforming the averaged vibration signals to create a harmonic spectrum for the selected tire; cleaning the selected tire's harmonic spectrum by applying coherence function and averaging calculations to it for minimizing contributions to the selected tire's harmonic spectrum from all other vibration sources including the remaining one(s) of the plurality of tires; comparing the most recent cleaned spectrum with stored values of previous cleaned spectra of the selected tire to track changes in higher order harmonic magnitudes; and determining whether catastrophic failure of the selec

Abstract: A system and method for assessing failure of fuel rods are disclosed. The method may include monitoring fuel rod operational conditions, comparing the fuel rod parameters to parameters limits, calculating the fuel rod performance parameters to determine the likelihood of failure of individual fuel rods, and updating plant operating parameters based on the calculated fuel rod parameters. The system may input the calculated fuel rod parameters into a fuel failure model to assess the probability of failure, and predict the probability of failure of individual fuel rods based on fuel rod parameters in the fuel failure model.

Abstract: Disclosed herein are zirconium-based alloys and methods of fabricating nuclear reactor components, particularly fuel cladding tubes, from such alloys that exhibit improved corrosion resistance in aggressive coolant compositions. The fabrication steps include a late-stage ?-treatment on the outer region of the tubes. The zirconium-based alloys will include between about 1.30 and 1.60 wt % tin; between about 0.06 and 0.15 wt % chromium; between about 0.16 and 0.24 wt % iron, and between 0.05 and 0.08 wt % nickel, with the total content of the iron, chromium and nickel comprising above about .31 wt % of the alloy and will be characterized by second phase precipitates having an average size typically less than about 40 nm. The final finished cladding will have a surface roughness of less than about 0.50 ?m Ra and preferably less then about 0.10 ?m Ra.

Abstract: Disclosed herein are zirconium-based alloys that may be fabricated to form nuclear reactor components, particularly fuel cladding tubes, that exhibit sufficient corrosion resistance and hydrogen absorption characteristics, without requiring a late stage ?+? or ?-quenching processes. The zirconium-base alloys will include between about 1.30-1.60 wt % tin; 0.0975-0.15 wt % chromium; 0.16-0.24 wt % iron; and up to about 0.08 wt % nickel, with the total content of the iron, chromium and nickel comprising at least about 0.3175 wt % of the alloy. The resulting components will exhibt a surface region having a mean precipitate sizing of between about 50 and 100 nm and a Sigma A of less than about 2×10?19 hour with the workpiece processing generally being limited to temperatures below 680° C. for extrusion and below 625° C. for all other operations, thereby simplifying the fabrication of the nuclear reactor components while providing corrosion resistance comparable with conventional alloys.

Abstract: In a zirconium-alloy fuel element cladding, a method for generating regions of coarse and fine intermetallic precipitates across the cladding wall is provided. The method includes steps of specific heat treatments and anneals that coarsen precipitates in the bulk of the cladding. The method also includes at least one step in which an outer region (exterior) of the cladding is heated to the beta or alpha plus beta phase, while an inner region (interior) is maintained at a temperature at which little or no metallurgical change occurs. This method produces a composite cladding in which the outer region comprises fine precipitates and the inner region comprises coarse precipitates.

Abstract: A Zircaloy cladding having an outer region comprising fine precipitates and inner region comprising coarse precipitates is provided. The outer region comprises about 10% and the inner region comprises about 90% of the cladding wall thickness. Such Zircaloy tubing is resistant to propagation of cracks and at the same time resistant to corrosion in boiling water reactors (BWR). Resistance to damage caused by the pellet-cladding-interaction can be achieved by standard application of a zirconium or zirconium-alloy liner on the tubing inside surface.

Abstract: In a zirconium-alloy fuel element cladding, a method for generating regions of coarse and fine intermetallic precipitates across the cladding wall is provided. The method includes steps of specific heat treatments and anneals that coarsen precipitates in the bulk of the cladding. The method also includes at least one step in which an outer region (exterior) of the cladding is heated to the beta or alpha plus beta phase, while an inner region (interior) is maintained at a temperature at which little or no metallurgical change occurs. This method produces a composite cladding in which the outer region comprises fine precipitates and the inner region comprises coarse precipitates.