Westinghouse Electric Company LLC

Yuriy Aleshin

Alexander W Harkness

James A Sparrow

Joonhyung Choi

Stuart T Kellner

Michael O Bausch

Alex Levinsky

Carter Eliot Lunde

Brian Millare

Garry C Crabtree

Matthew R Heisel

Hemant H Shah

Thanh H Do

Andrew Atwood

Keith J Drudy

David B Mitchell

Stephen H Green

Aleksey Slyeptsov

Hemant Shah

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.

Devices, systems, and methods for adjusting the output of a reactor core

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.

Zirconium-coated silicon carbide fuel cladding for accident tolerant fuel application

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.

Enhanced graphite neutron reflector with beryllium oxide inclusions

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.

Bottom nozzle with protective insert

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.

Micro-reactor core mechanical support

Nuclear reactor core support system providing radial and axial support

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.

Method of installing an external dashpot tube around a control rod guide tube in a nuclear fuel assembly

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.

Spring apparatus and support apparatus usable in nuclear installation

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.

Fuel assembly with an external dashpot disposed around a guide tube portion

A method of detecting defects in nuclear fuel within a fuel rod that first heats the fuel rod to a temperature substantially above the ambient temperature. The surface temperature of the fuel rod cladding is then monitored as the fuel rod is allowed to cool. Variations in the temperature measured over the surface is then noted as an indication of defects.

Nuclear fuel rod pellet stack inspection

A nuclear fuel rod plenum spring assembly that has a spacer affixed to the lower end of the ground torsion spring. The spacer has a substantially flat surface on its underside that presses against the upper surface of the upper fuel pellets to spread the load of the spring over the top surface of the upper most fuel pellet.

Nuclear fuel rod plenum spring assembly

The present invention provides novel fuel assemblies for use with PWR nuclear reactors and power plants, and in particular, VVER nuclear reactors. The fuel assemblies offer enhanced structural stability, skeletal rigidity, and distortion (bow and twist) resistance to support high burn-up fuel management. Each fuel assembly may include a plurality of fuel rods, a plurality of control rods and guide thimbles, at least one instrumentation tube, and a plurality of grids. At least one fuel rod is replaced with a structural support replacement rod made from zirconium (Zr) alloy, stainless steel, or any other suitable material. The structural support replacement rod may be hollow or solid. The structural support replacement rods are preferably disposed at or about the periphery, and in some cases, the corners of the geometric array, which is preferably a hexagon or square.

Nuclear fuel assemblies with structural support replacement rods

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.

Tube-in-tube threaded dashpot end plug

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 tipper 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.

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Columbia, SC, United States of America

Yuriy Aleshin