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.

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.

One embodiment provides a multi-segment rod that includes a plurality of rod segments. The rod segments are removably mated to each other via mating structures in an axial direction. An irradiation target is disposed within at least one of the rod segments, and at least a portion of at least one mating structure includes one and/or more combinations of neutron absorbing materials.

A nuclear-fuel pin including a linear element made of a metal nuclear-fuel material consisting of uranium and/or plutonium, and cladding including Fe and Cr or an alloy including at least both of said elements, comprises a main shell provided around the linear nuclear-fuel element, said shell including threads or fibers made of SiC. A method for producing a nuclear-fuel pin is also provided.

A nuclear-fuel pin including a linear element made of a metal nuclear-fuel material consisting of uranium and/or plutonium, and cladding including Fe and Cr or an alloy including at least both of said elements, comprises a main shell provided around the linear nuclear-fuel element, said shell including threads or fibers made of SiC. A method for producing a nuclear-fuel pin is also provided.

A nuclear reactor fuel rod is a fuel rod for a light-water reactor. The nuclear reactor fuel rod includes a fuel cladding tube and an end plug, both of which are formed of a silicon carbide material. A bonding portion between the fuel cladding tube and the end plug is formed by brazing with a predetermined metal bonding material interposed, and/or by diffusion bonding. The predetermined metal bonding material has a solidus temperature of 1200° C. or higher. An outer surface of the bonding portion, and a portion of an outer surface of the fuel cladding tube and the end plug, which is adjacent to the outer surface of the bonding portion are covered by bonding-portion coating formed of a predetermined coating metal. The predetermined metal bonding material and the predetermined coating metal have an average linear expansion coefficient which is less than 10 ppm/K.

There is provided a fuel rod assembly comprising a first component of a zirconium-based material. The first component is in contact with or is located adjacent to a second component of a material different from the zirconium-based material, e.g. a nickel-based or iron-based alloy. A coating is disposed on an outer surface of the first component, which is effective to reduce an electrochemical corrosion potential difference between the first component and the second component relative to an electrochemical corrosion potential difference between the first component and the second component without the coating.

There is provided a fuel rod assembly comprising a first component of a zirconium-based material. The first component is in contact with or is located adjacent to a second component of a material different from the zirconium-based material, e.g. a nickel-based or iron-based alloy. A coating is disposed on an outer surface of the first component, which is effective to reduce an electrochemical corrosion potential difference between the first component and the second component relative to an electrochemical corrosion potential difference between the first component and the second component without the coating.

Provided herein is a fuel rod and a fuel assembly for light water reactors in which crack penetration to a fuel cladding tube or an end plug can be prevented even when cracking occurs at the joint between the fuel cladding tube and the end plug for which a ceramic base material is used. A fuel rod 10a for light water reactors includes: a cylindrical cladding tube 11 formed of a ceramic base material; a connection 21 formed of the same or similar material to the cladding tube 11; and an end plug 12a having a concave portion 12f of a continuously curved surface shape adapted to house the connection 21. The end plug 12a is formed of the same or similar material to the cladding tube 11. A slanted surface 11a formed at an end portion of the cladding tube 11, and a slanted surface 12d formed at an end portion of the end plug 12a are joined in contact with each other with a metallic joint material 20. The joint is supported by the connection 21.

Provided herein is a fuel rod and a fuel assembly for light water reactors in which crack penetration to a fuel cladding tube or an end plug can be prevented even when cracking occurs at the joint between the fuel cladding tube and the end plug for which a ceramic base material is used. A fuel rod 10a for light water reactors includes: a cylindrical cladding tube 11 formed of a ceramic base material; a connection 21 formed of the same or similar material to the cladding tube 11; and an end plug 12a having a concave portion 12f of a continuously curved surface shape adapted to house the connection 21. The end plug 12a is formed of the same or similar material to the cladding tube 11. A slanted surface 11a formed at an end portion of the cladding tube 11, and a slanted surface 12d formed at an end portion of the end plug 12a are joined in contact with each other with a metallic joint material 20. The joint is supported by the connection 21.