Abstract: A test lead assembly is provided for an electrical connector assembly, such as a terminal board. The terminal board includes a generally planar member and a number of fasteners, such as terminal screws, which are structured to fasten and electrically connect electrical conductors to the generally planar member. The test lead assembly includes an extension member having first and second opposing ends, and an intermediate portion extending therebetween. The first end is fastened to the enlarged head of a corresponding one of the terminal screws. A connection element is disposed at or about the second end of the extension member. In one embodiment the connection element is a thumb screw that electrically connects a test element to the extension member. The test lead assembly enables the terminal board to be tested, without loosening or otherwise disturbing the electrical connections of the terminal board. An associated method is also disclosed.

Abstract: The present invention relates generally to a process and chemical composition for the removal of adherent niobium-rich second-phase particles (SPPs) from pickled niobium-containing zirconium alloys which includes applying to the alloy surface a chemical composition comprising alkaline hydrogen peroxide; an alkali metal meta-silicate; and a magnesium salt.

Abstract: The present invention provides a two-step process for producing nuclear grade, active uranium dioxide (UO2) powder in which the first step comprises reacting uranium hexafluoride (UF6) with steam in a flame reactor to yield uranyl fluoride (UO2F2); and the second step comprises removing fluoride and reducing UO2F2 to uranium dioxide (UO2) in a kiln under a steam/hydrogen atmosphere. The two-step process, each step separated by a positive sealed valve means to prevent gas, particularly H2 flow back, tightly controls the exothermicity of the reaction, which allows for a very tight temperature control which controls the growth of the particles and results in UO2 powder that is active and of consistent morphology.

Abstract: A debris filter bottom nozzle for a nuclear fuel assembly having a support skirt and a top plate. The top nozzle plate has defined therethrough a plurality of flow holes. The axial bore through each flow hole is contoured as a venture. Preferably, the venturi is formed with a double chamfered inlet.

Abstract: A method for applying a burnable poison onto the cladding of a nuclear fuel rod (2) which comprises, providing a nuclear fuel rod (2) and at least one application device (8), rotating the nuclear fuel rod, optionally removing one or more oxides and/or surface deposits on the outer surface of the nuclear fuel rod (2) by spraying an abrasive material onto the nuclear fuel rod via the application device (8) while adjusting the position of the application device in relation to the nuclear fuel rod (2), and applying burnable poison particles (33) onto the outer surface (6) of the nuclear fuel rod (2) by spraying the burnable poison onto the nuclear fuel rod via the application device while adjusting the position of the application device (8) in relation to the nuclear fuel rod, where the burnable poison particles are applied at a velocity sufficient to cause adhesion to the outer surface (6) of the cladding.

Abstract: A permanent cavity seal ring that replaces the function of the temporary cavity seal ring typically used in narrow thermal expansion gap pressurized water reactors, to seal the gap between the reactor cavity well and the reactor during refueling. The permanent seal ring uses a C-shaped flexure that is shielded by a rigid cantilevered support arm from any accidentally dropped equipment from above in the refueling canal. The construction accommodates the thermal expansion of the reactor vessel while permitting the reactor cavity cooling air to exit the annulus between the vessel and the reactor cavity wall during plant operation, without a significant increase in pressure drop.

Abstract: An online data driven computerized procedures system that guides an operator through a complex process facility's operating procedures. The system monitors plant data, processes the data and then, based upon this processing, presents the status of the current procedure step and/or substep to the operator. The system supports multiple users and a single procedure definition supports several interface formats that can be tailored to the individual user. Layered security controls access privileges and revisions are version controlled. The procedures run on a server that is platform independent of the user workstations that the server interfaces with and the user interface supports diverse procedural views.

Abstract: A pipe clamp for reinforcing a welded joint between two pipes, having a plurality of circumferential clamp segments that are bolted together around the joint. One axial end of the clamp has circumferentially extended ridges that project inward and seat in corresponding circumferential grooves in a pipe on one side of the joint. The other axial end of the clamp has circumferentially spaced fingers that extend inward and fit into corresponding pockets on the other side of the weld joint. Either or both the ridges or the fingers have a taper whose cross-section reduces in an inward direction and fits in complimentary grooves or pockets on either side of the joint. The taper forces the opposite sides of the weld joint toward each other as the clamp segments are tightened together.

Abstract: A grading system for a pressurized water reactor steam generator secondary side performance that provides a cumulative assessment of tube bundle deposit inventory and characteristics, i.e., scale density and distribution, hard scale collar formation, thermal performance, loose parts management, and steam generator secondary side chemistry performance. Results are summarized in a cumulative quality point average with individual parameter ratings available so that specific performance improvement may be achieved.

Abstract: A method of synthesizing nondestructive examination data of a component that combines data sets acquired at least two different frequencies. At least one of the data sets is interpolated or extrapolated to the equivalent of data acquired at one of the other frequencies employing a third, reference set of eddy current inspection data that is acquired at each of the inspection frequencies being combined.

Abstract: A nuclear fuel assembly having an instrumentation tube having an insert that centers the in-core instrumentation while permitting bugling or welding of the instrumentation tube wall to a grid strap to obtain a rigid connection there between at any elevation along the instrumentation tube.

Abstract: A method is provided for removing radioactive internals structural members in the core of a reactor pressure vessel in a containment vessel. The method includes placing a first cask in a first internals assembly, detaching radioactive first internals structural members from second internals structural members in the first internals assembly, placing the detached first internals structural members in the first cask, placing the first internals assembly in a second cask, and removing the second cask containing the first internals assembly and containing the casked detached radioactive first internals members from the containment vessel. The first internal members may be radioactive baffle plates, and the second internals members may be former plates bolted to the radioactive baffle plates. Novel tooling, framework and fixtures facilitate disassembling, moving and storing the radioactive baffle plates.

Abstract: A nuclear fuel assembly having a tube-in-tube control rod guide tube design that incorporates an end plug that extends axially upward to an elevation above the lower most grid where it is sealed at its upper end to the lower end of the control rod guide tube. The guide tube lower end plug has a threaded recess in its upper surface that mates with a corresponding dashpot end plug threaded extension that is formed as an insert in the lower end of the guide tube. A hole formed through the outer wall of the guide tube end plug at the elevation of the lower portion of the recess provides a positive inspection port for assuring the proper seating of the dashpot. A method of manufacture of such a fuel assembly is also disclosed.

Abstract: A method of examining a steam generator heat exchange tube from the outside surface employing ultrasonic nondestructive inspection techniques. An ultrasonic transducer contacts the outside surface of the tube and transmits a pseudo helical Lamb wave into the wall of the tube chosen to have a mode that does not significantly interact with water in the tube. The reflected waves are then analyzed for changes in modes to identify defects in the wall of the tube.

Abstract: A bi-alloy spacer grid (BASG) is provided with grid straps and springs made using different zirconium alloys. The grid straps are made from a relatively low growth zirconium alloy, and the springs are made from a relatively high growth zirconium alloy. The springs are coupled to the grid straps by welding, mechanical interference, or secondary forming in place. When subjected to irradiation, the springs grow relative to the grid straps thereby maintaining contact with the fuel rod cladding, while the grid straps resist growth to maintain structural stability of the entire fuel assembly. The optimized balance of the high growth springs and low growth grid straps mitigates the formation of gaps between the fuel rods and grid support structures). The growth properties of the grid straps and springs may be further controlled through optional different fabrication processes.

Abstract: An alignment system that employs jacking block assemblies and alignment posts around the periphery of the top plate of a nuclear reactor lower internals core shroud to align an upper core plate with the lower internals and the core shroud with the core barrel. The distal ends of the alignment posts are chamfered and are closely received within notches machined in the upper core plate at spaced locations around the outer circumference of the upper core plate. The jacking block assemblies are used to center the core shroud in the core barrel and the alignment posts assure the proper orientation of the upper core plate. The alignment posts may alternately be formed in the upper core plate and the notches may be formed in top plate.

Abstract: The invention relates generally to a method for the calculation of radiation field distributions employing a new parallel 3-D radiation transport code and, a multi-processor computer architecture. The code solves algorithms using a domain decomposition approach. For example, angular and spatial domains can be partitioned into subsets and, the subsets can be independently allocated and processed.

Abstract: A method is provided for recovering operating margin in a nuclear reactor. The reactor includes a steam generator, a Reactor Coolant System (RCS) having a hot leg with a temperature, Thot, and a cold leg with a temperature, Tcold, a Reactor Trip System (RTS) having an Over Temperature Delta Temperature (OTDT) trip function and an Over Power Delta Temperature (OPDT) trip function, and a control system. The method improves the RTS by filtering only the hot leg temperature signal of the RCS. Thus, the needs for separate Tavg and Delta-T filters, and for filtering of temperature signals in both the hot leg and cold leg are eliminated. A reactor system is also disclosed.

Abstract: The present invention relates generally to a process and chemical composition for the removal of adherent niobium-rich second-phase particles (SPPs) from pickled niobium-containing zirconium alloys which includes applying to the alloy surface a chemical composition comprising alkaline hydrogen peroxide; an alkali metal meta-silicate; and a magnesium salt.

Abstract: A spacer grid having tunable mixing vanes for optimizing coolant flow is provided for a nuclear fuel assembly. The mixing vanes include an upper piece and a lower piece, which are coupled to a middle ligament that is coupled to the top or downstream portion of one or more of the grid straps forming the spacer grid. The upper piece, lower piece, and middle ligament are bent, rotated, and/or twisted into various positions to more effectively mix the coolant and affect the coolant's flow as it moves upwards through the fuel assembly. For example, in one embodiment, the mixing vane has an “S” shape wherein the middle ligament is positioned parallel to the longitudinal axes of the fuel rods of the fuel assembly, the upper piece bends towards one of the fuel rods, and the lower piece bends away from the fuel rod. In this manner, optimized even and sustained mixing of the coolant is provided.