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 nuclear reactor is disclosed including a reactor core and a reflector assembly surrounding the reactor core. The reflector assembly includes a stationary reflector component including a graphite support structure comprising a plurality of channels defined therein and a plurality of beryllium-oxide pins positioned in the channels.

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 reactor core mechanical support bracket is disclosed. The support bracket includes a housing, a spring disposed internally within the housing, a shaft slidingly disposed within the housing, a shaft travel pin, and a flange. The shaft is configured to engage the spring to compress and decompress the spring as the shaft travels in and out of the housing. The shaft travel pin controls the travel of the shaft. The flange is configured to mount the nuclear reactor core mechanical support bracket to a canister of a nuclear reactor. The shaft includes an inset configured to interface with a nuclear reactor core component.

Abstract: A nuclear reactor core mechanical support bracket is disclosed. The support bracket includes a housing, a spring disposed internally within the housing, a shaft slidingly disposed within the housing, a shaft travel pin, and a flange. The shaft is configured to engage the spring to compress and decompress the spring as the shaft travels in and out of the housing. The shaft travel pin controls the travel of the shaft. The flange is configured to mount the nuclear reactor core mechanical support bracket to a canister of a nuclear reactor. The shaft includes an inset configured to interface with a nuclear reactor core component.

Abstract: A nuclear reactor core mechanical support bracket is disclosed. The support bracket includes a housing, a spring disposed internally within the housing, a shaft slidingly disposed within the housing, a shaft travel pin, and a flange. The shaft is configured to engage the spring to compress and decompress the spring as the shaft travels in and out of the housing. The shaft travel pin controls the travel of the shaft. The flange is configured to mount the nuclear reactor core mechanical support bracket to a canister of a nuclear reactor. The shaft includes an inset configured to interface with a nuclear reactor core component.

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 reactor core mechanical support bracket is disclosed. The support bracket includes a housing, a spring disposed internally within the housing, a shaft slidingly disposed within the housing and to engage the spring to compress and decompress the spring as the shaft travels in and out of the housing, a shaft travel pin to control the travel of the shaft, and a flange to mount the support bracket to a canister of a nuclear reactor. The shaft includes an inset configured to interface with a nuclear reactor core component.

Abstract: A debris filtering skirt configured for use with a flow plate of a bottom nozzle of a nuclear reactor is disclosed herein. The debris filtering skirt includes a base portion defining an opening between a bottom edge and a reactor vessel lower core plate, and the opening includes a dimension configured to position the bottom nozzle a predetermined distance away from the reactor vessel lower core plate. The debris filtering skirt also includes a plurality of holes, and at least one hole of the plurality of holes includes a dimension determined based, at least in part, on a predetermined size of debris capable of traversing through the inlet and the outlet. The dimension of the opening and the dimension of the at least one hole are determined based, at least in part, on a predetermined loss coefficient of the bottom nozzle.

Abstract: A configurable unit cell of a core of a nuclear reactor is disclosed herein. The configurable unit cell includes a core block material and a plurality of interchangeable components configured to affect a performance parameter of the core of the nuclear reactor. The configurable unit cell further includes a plurality of channels defined within the core block material. Each channel of the plurality of channels is configured to engage an interchangeable component of the plurality of interchangeable components in an operating configuration. Each channel of the plurality of channels is separated from an adjacent channel of the plurality of channels by a predetermined pitch.

Abstract: An adjustable core assembly for a nuclear reactor is disclosed herein. The adjustable core can include a plurality of reactivity control cells configured to accommodate a reactivity control rod, and a plurality of unit cells. The plurality of unit cells defines a radial dimension corresponding to an initial power output of the core. Each unit cell of the plurality of unit cells is configured to accommodate fuel configured to generate energy and a heat pipe configured to transfer thermal energy away from the core. Each unit cell of the plurality unit cells can be coupled to an adjacent unit cell in a radial direction, thereby altering the radial dimension, wherein the altered radial dimension corresponds to an adjusted power output of the core, and wherein the adjusted power output of the core is different than the initial power output of the core.

Abstract: A nuclear reactor is disclosed including a reactor core and a reflector assembly surrounding the reactor core. The reflector assembly includes a stationary reflector component including a graphite support structure comprising a plurality of channels defined therein and a plurality of beryllium-oxide pins positioned in the channels.

Abstract: Methods of installing an external dashpot tube around a control rod guide tube in a nuclear reactor fuel assembly are disclosed herein. The nuclear reactor fuel assembly may include a top nozzle, a bottom nozzle, and a plurality of grids. The various methods may comprise inserting a guide tube into a skeleton of the nuclear reactor fuel assembly to a lower middle grid, the lower middle grid being second closest grid to the bottom nozzle of the plurality of grids. The various methods may also include installing an external dashpot tube over the guide tube after it has been inserted to the lower middle grid; inserting the guide tube with the installed external dashpot tube to the bottom nozzle; attaching the guide tube to the skeleton; and bulging the guide tube onto the external dashpot tube.

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: 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 filtering arrangement for use in a bottom nozzle of a fuel assembly in a nuclear reactor includes a top surface, a bottom surface, a plurality of vertical wall portions arranged in a generally squared grid-like pattern which extend between the bottom surface and the top surface and define a plurality of non-circular passages extending between the bottom surface and the top surface through the arrangement, and a plurality of first debris filters which are each positioned between the top surface and the bottom surface to generally span across a respective one of the plurality of passages.

Abstract: A spring apparatus in accordance with the disclosed and claimed concept is usable in a nuclear installation. In one embodiment, the spring apparatus includes a plurality of springs that are in a compressed state and that are compressively engaged with an upper core plate of a nuclear reactor when the reactor is in a cold condition. However, when the reactor is in a hot condition, a spring of the plurality of springs is in a free state wherein a free end of the spring is in an uncompressed state and is disengaged from the upper core plate. In another embodiment, the spring apparatus employs a support apparatus that is also in accordance with the disclosed and claimed concept and that includes one or more bumpers that engage the springs of a spring pack from the underside.

Abstract: A nuclear fuel assembly comprising a plurality of control rod guide assemblies. At least one of the control rod guide assemblies includes a guide tube having an axial dimension, the guide tube being supported by the plurality of grids and extending axially between the top nozzle and the bottom nozzle, the guide tube having an upper portion having a first radius and a lower portion having a second radius less than the first radius, and an external dashpot tube disposed around a portion of the lower portion in an area beginning at the bottom grid and extending toward the top nozzle.

Abstract: A nuclear fuel assembly comprising a plurality of control rod guide assemblies. At least one of the control rod guide assemblies includes a guide tube having an axial dimension, the guide tube being supported by the plurality of grids and extending axially between the top nozzle and the bottom nozzle, the guide tube having an upper portion having a first radius and a lower portion having a second radius less than the first radius, and an external dashpot tube disposed around a portion of the lower portion in an area beginning at the bottom grid and extending toward the top nozzle.

Abstract: A nuclear fuel assembly comprising a plurality of control rod guide assemblies. At least one of the control rod guide assemblies includes a guide tube having an axial dimension, the guide tube being supported by the plurality of grids and extending axially between the top nozzle and the bottom nozzle, the guide tube having an upper portion having a first radius and a lower portion having a second radius less than the first radius, and an external dashpot tube disposed around a portion of the lower portion in an area beginning at the bottom grid and extending toward the top nozzle.