An extraction device for extracting a nuclear fuel rod or a cluster rod comprises an attachment portion configured to be inserted into a sleeve of the rod through an end without an end plug, and a grip portion, the attachment portion comprising an elongated body along a longitudinal axis and at least one tooth projecting from the body, the or each tooth being configured to allow the attachment portion to be forcibly inserted into the sleeve axially, and to engage with the inner surface of the sleeve so as to prevent the attachment portion from being extracted from the sleeve.

An extraction device for extracting a nuclear fuel rod or a cluster rod comprises an attachment portion configured to be inserted into a sleeve of the rod through an end without an end plug, and a grip portion, the attachment portion comprising an elongated body along a longitudinal axis and at least one tooth projecting from the body, the or each tooth being configured to allow the attachment portion to be forcibly inserted into the sleeve axially, and to engage with the inner surface of the sleeve so as to prevent the attachment portion from being extracted from the sleeve.

A nuclear fuel assembly is constructed with fuel assembly components that are wire wrapped and positioned in hexagonal rings within a fuel assembly duct. The fuel assembly components positioned in an outermost ring of the fuel assembly are wire wrapped with a pitch that is shorter than fuel assembly components positioned at an interior ring of the fuel assembly. The shorter pitch at the outer ring of the fuel assembly increases pressure drop of a coolant fluid at the edge and corner subchannels and thereby reduces the temperature gradient across the fuel assembly, which provides a higher output temperature of the nuclear reactor without substantially increasing peak temperature of the fuel cladding.

A fuel assembly for a boiling water reactor having fuel rods, two or three water rods, a tie plate, spacers, a handle, and a joint arrangement. The joint arrangement is configured to transfer a vertical lifting force from the handle to the water rods. The joint arrangement includes a balancing element arranged between the water rods and the handle. The joint arrangement includes a first joint arranged between the balancing element and the handle and a set of second joints arranged between a respective one of said water rods and said balancing element. The first joint and the set of second joints are configured to allow a rotational movement of said balancing element in relation to said handle as well as in relation to said water rods in order to balance lifting forces in the water rods.

A fuel assembly for a boiling water reactor having fuel rods, two or three water rods, a tie plate, spacers, a handle, and a joint arrangement. The joint arrangement is configured to transfer a vertical lifting force from the handle to the water rods. The joint arrangement includes a balancing element arranged between the water rods and the handle. The joint arrangement includes a first joint arranged between the balancing element and the handle and a set of second joints arranged between a respective one of said water rods and said balancing element. The first joint and the set of second joints are configured to allow a rotational movement of said balancing element in relation to said handle as well as in relation to said water rods in order to balance lifting forces in the water rods.

A mitigation assembly for a nuclear reactor including a box with an upper portion forming the head of the assembly housing an upper neutron shielding device, including a head including removable lock and a slug installed free to move in translation relative over a given travel distance, the lock being configured such that locking/unlocking between the head and the box can be made by displacement of the slug with an extraction grab with its pawls attached in the slug. The lower part of the upper neutron shielding device includes a cone-shaped sealing block with the tip of the cone oriented downwards, cooperating with a cone-shaped internal surface of the box, a sealing device being formed between the two, the assembly created forming a removable sealing plug.

A mitigation assembly for a nuclear reactor including a box with an upper portion forming the head of the assembly housing an upper neutron shielding device, including a head including removable lock and a slug installed free to move in translation relative over a given travel distance, the lock being configured such that locking/unlocking between the head and the box can be made by displacement of the slug with an extraction grab with its pawls attached in the slug. The lower part of the upper neutron shielding device includes a cone-shaped sealing block with the tip of the cone oriented downwards, cooperating with a cone-shaped internal surface of the box, a sealing device being formed between the two, the assembly created forming a removable sealing plug.

Provided is mobile equipment for measuring structural deformation of a nuclear fuel assembly, the mobile equipment including: a container; a power means and a loading table disposed inside the container; a pedestal disposed on one side of the loading table of the container, the pedestal being provided with a hinge means and a fixing means configured to fix the nuclear fuel assembly upright; a column seated on the loading table and provided at one end part thereof with a rotating shaft detachably installed to the hinge means, and configured to be erected upright on the fixing means of the pedestal by power of the power means; and a scanner configured to move upward and downward in a longitudinal direction of the column and to measure the structural deformation of the nuclear fuel assembly.

A repair device for underwater repair of a hole in a nuclear reactor part includes a holder (32), a cutting tool (22) held by the holder (32) and having at least one cutting tooth (70) for remachining an inner surface of the hole. The cutting tool (22) has a suction channel (44) extending into the cutting tool (22) between at least one inlet opening (46) and at least one outlet opening (48), a drive shaft (34) for rotating the cutting tool (22), the drive shaft (34) being held by the holder (32), and a suction tube (36) connected to the holder (32) and fluidly connected to the outlet opening (48) of the suction channel (44).

A repair device for underwater repair of a hole in a nuclear reactor part includes a holder (32), a cutting tool (22) held by the holder (32) and having at least one cutting tooth (70) for remachining an inner surface of the hole. The cutting tool (22) has a suction channel (44) extending into the cutting tool (22) between at least one inlet opening (46) and at least one outlet opening (48), a drive shaft (34) for rotating the cutting tool (22), the drive shaft (34) being held by the holder (32), and a suction tube (36) connected to the holder (32) and fluidly connected to the outlet opening (48) of the suction channel (44).