Abstract: A nuclear reactor fuel bundle assembly including: a fuel bundle including an array of fuel rods and water rods mounted in an upper tie plate and housed in walls of a channel, and a pore type debris shield mounted at least partially in the channel, above or below the upper tie plate, the shield extending to or over the walls of the channel, whereby deflecting and/or capturing falling debris from entering the fuel assembly, wherein the shield is design to be durable, yet flexible, and porous.

Abstract: An isotope production target rod for a power generating nuclear reactor is provided. The isotope production target rod can include at least one rod central body including an outer shell that defines an internal cavity and a plurality of irradiation targets within the internal cavity. The irradiation targets can be positioned in a spatial arrangement utilizing a low nuclear cross-section separating medium to maintain the spatial arrangement.

Abstract: A method and apparatus for repairing and/or reinforcing a Boiling Water Reactor (BWR) jet pump riser pipe. The repair includes attaching two collars to the riser pipe using match drilling to drill holes through the collars and the riser pipe and plugging the holes with expandable plugs. Support columns are attached to the collars. Brace supports are slideably attached to the support columns. Gaps between each brace support and its respective collar are then narrowed as ratchet bolts may apply a force that pulls downward on an upper collar and pulls upward on a lower collar, thereby exerting a compression force on the riser pipe. A clamp assembly may also be located between the two collars that applies a hoop force on the riser pipe.

Abstract: A method and apparatus for repairing and/or preventatively maintaining a jet pump restrainer assembly used in a Boiling Water Reactor (BWR), the repair including attaching a bearing plate or plates to a horizontal surface of a jet pump restrainer assembly bracket, the bearing plate or plates acting to supplement and/or replace an existing contact surface between a mixer wedge and the jet pump restrainer assembly bracket of a jet pump restrainer assembly.

Abstract: Disclosed are various wedges that may be used in a restrainer bracket of a jet pump assembly. The jet pump assembly may include a restrainer bracket having an upper bracket and a lower bracket connected to an inlet mixer. A wedge may be provided between the upper bracket and the lower bracket and a wedge rod may pass through a slotted hole of the wedge. Ends of the wedge rod may be attached to the upper and lower brackets. The restrainer bracket may further include a yolk-like member which surrounds the inlet mixer and is connected to a riser pipe. The wedge may include an inclined surface which is configured to engage with a restrainer bracket pad of the yolk-like member. The wedges may further include inner curved surfaces which contact the wedge rod and the inner curved surfaces may be part of an insert that may be inserted in the wedge.

Abstract: A method and apparatus for physically restraining an inlet mixer of a boiling water reactor (BWR) jet pump assembly. An inlet mixer clamp assembly is attached to the top of a transition piece of the BWR jet pump assembly, to provides a downward clamping force on the top of the inlet mixer. The clamping force restrains the inlet mixer from experiencing vibration and mitigates leakage between the inlet mixer and the transition piece sealing surfaces of the jet pump assembly. The clamping force also restrains the inlet mixer from undesirable rotation, especially during operation of the jet pump assembly. The inlet mixer clamp assembly may be used as an alternative to conventional jet pump beam assemblies. Alternatively, the inlet mixer clamp assembly may be used as a redundant physical restraint in addition to the conventional jet pump beam assemblies.

Abstract: A method and apparatus for a Boiling Water Reactor (BWR) jet pump inlet mixer support that provides rigid support for inlet mixers. The inlet mixer support attaches to a conventional BWR jet pump assembly to pull the inlet mixer away from the centerline of a riser pipe or maintain the existing inlet mixer position. The inlet mixer support may provide redundant support that may otherwise be provided by set screws of a conventional restrainer assembly. The inlet mixer support may, alternatively, be used in lieu of conventional set screws. The inlet mixer support may also counter-act additional side loading that may be applied to inlet mixers to stabilize inlet mixer movement and vibration when the BWR jet pump assembly is in operation. Optionally, the inlet mixer support may also prevent removal of existing restrainer bracket set screws.

Abstract: Example embodiments are directed to tiered tie plates and fuel bundles that use tiered tie plates. Example embodiment tie plates may include upper and lower tiered tie plates. Example embodiment tiered tie plates may have a plurality of bosses divided into groups, or tiers, having differing vertical (axial) displacement. Example embodiment fuel bundles may use tiered tie plates such that fuel rods in example bundles may originate and terminate at different vertical displacements, based upon the vertical displacement of the bosses receiving the fuel rods into the tiered tie plates. Optionally, shanks may be used to further vary fuel rod axial displacement and diameter.

Abstract: An assembly for securing a riser brace to a riser pipe includes brackets configured to engage a yoke of the riser brace and clamp bands that are configured to extend around the riser pipe and connect to the brackets. The assembly also includes a connection that connects the assembly as a unit and is configured to adjust the tightness of the assembly around the riser pipe and riser brace.

Abstract: Disclosed are various torsional restraint systems for torsionally restraining a jet pump assembly, wherein the jet pump assembly includes a riser pipe, a transition assembly on the riser pipe, and a restrainer bracket connecting a first and a second inlet mixer to the riser pipe. The torsional restraint system includes a first contact member operatively attached to a side of the jet pump assembly and a second contact member operatively attached to the side of the jet pump assembly and disposed from the first contact member such that the first and second contact members restrain the riser pipe from rotating about a centerline of the riser pipe.

Abstract: Example embodiments are directed to upper tie plates for debris mitigation and fuel bundles that use the upper tie plates. Example embodiment tie plates may include a plurality of debris capture elements that overlap each other so as to create debris traps for particulate debris that would fall onto the fuel bundle. Example embodiment fuel bundles may use the upper tie plates for debris mitigation.

Abstract: An embodiment of the present invention provides an apparatus and system for repairing and/or maintaining a position of a first component in relation to a second component. The first and second components may be located within a reactor pressure vessel of a nuclear powerplant. The apparatus and system may attach at least one bearing plate to a horizontal surface of the first component. The apparatus and system includes structure to apply a pre-load to the first component. This may assist in maintaining the position of the first component relative to the second component.

Abstract: An embodiment of the present invention takes the form of an apparatus or system that may reduce the level of vibration experienced by an inlet riser or other similar object within a reactor pressure vessel. An embodiment of the present invention may eliminate the need for welding the riser brace to the inlet riser. An embodiment of the present invention provides at least one riser brace clamp that generally clamps the riser brace to the inlet riser. After installation, the riser brace clamp may lower the amplitude of, and/or change the frequency of, the vibration experienced by the inlet riser.

Abstract: A method and apparatus for vertically lifting and supporting a main wedge of a Boiling Water Reactor (BWR) jet pump restrainer assembly, to ensure that the wedge is no longer contacting a restrainer bracket of the restrainer assembly. A main wedge clamp with an upper and lower clamp jaw is used to attach to the upper support of the restrainer assembly, the lower clamp jaw being fashioned with a prong or prongs that fit underneath the crown of the main wedge and provide the vertical lift for the main wedge.

Abstract: Example embodiments are directed to tiered tie plates and fuel bundles that use tiered tie plates. Example embodiment tie plates may include upper and lower tiered tie plates. Example embodiment tiered tie plates may have a plurality of bosses divided into groups, or tiers, having differing vertical (axial) displacement. Example embodiment fuel bundles may use tiered tie plates such that fuel rods in example bundles may originate and terminate at different vertical displacements, based upon the vertical displacement of the bosses receiving the fuel rods into the tiered tie plates. Optionally, shanks may be used to further vary fuel rod axial displacement and diameter.

Abstract: A method and apparatus for repairing and/or reinforcing a Boiling Water Reactor (BWR) jet pump riser pipe. The repair includes attaching two collars to the riser pipe using match drilling to drill holes through the collars and the riser pipe and plugging the holes with expandable plugs. Support columns are attached to the collars. Brace supports are slideably attached to the support columns. Gaps between each brace support and its respective collar are then narrowed as ratchet bolts may apply a force that pulls downward on an upper collar and pulls upward on a lower collar, thereby exerting a compression force on the riser pipe. A clamp assembly may also be located between the two collars that applies a hoop force on the riser pipe.

Abstract: An embodiment of the present invention may reduce the level of vibration experienced by a line, such as, but not limiting of, a pipe, a cable, tubing, or the like, that is connected to at least one separate structure. For example, but not limiting of, the structure includes: a reactor pressure vessel, a sparger pipe, steam generator, a pipe, a pressure vessel, a heat exchanger, a pump, a condenser, a tank, or the like. An embodiment of the present invention may provide support and a preload to the line at a new location or may replace an existing support, such as, but not limiting of, a weld; which may alter the natural frequencies to avoid resonance from occurring when the structure(s) is excited.

Abstract: Example embodiments are directed to tiered tie plates and fuel bundles that use tiered tie plates. Example embodiment tie plates may include upper and lower tiered tie plates. Example embodiment tiered tie plates may have a plurality of bosses divided into groups, or tiers, having differing vertical (axial) displacement. Example embodiment fuel bundles may use tiered tie plates such that fuel rods in example bundles may originate and terminate at different vertical displacements, based upon the vertical displacement of the bosses receiving the fuel rods into the tiered tie plates. Optionally, shanks may be used to further vary fuel rod axial displacement and diameter.

Abstract: Disclosed are various wedges that may be used in a restrainer bracket of a jet pump assembly. The jet pump assembly may include a restrainer bracket having an upper bracket and a lower bracket connected to an inlet mixer. A wedge may be provided between the upper bracket and the lower bracket and a wedge rod may pass through a slotted hole of the wedge. Ends of the wedge rod may be attached to the upper and lower brackets. The restrainer bracket may further include a yolk-like member which surrounds the inlet mixer and is connected to a riser pipe. The wedge may include an inclined surface which is configured to engage with a restrainer bracket pad of the yolk-like member. The wedges may further include inner curved surfaces which contact the wedge rod and the inner curved surfaces may be part of an insert that may be inserted in the wedge.

Abstract: An embodiment of the present invention takes the form of an apparatus or system that may reduce the level of vibration experienced by an inlet riser or other similar object within a reactor pressure vessel. An embodiment of the present invention may eliminate the need for welding the riser brace to the inlet riser. An embodiment of the present invention provides at least one riser brace clamp that generally clamps the riser brace to the inlet riser. After installation, the riser brace clamp may lower the amplitude of, and/or change the frequency of, the vibration experienced by the inlet riser.