Abstract: A channel box has a hollow elongated portion and accommodates a plurality of nuclear reactor fuel rods inside the hollow elongated portion, wherein the hollow elongated portion is constituted by a plurality types of silicon carbide composite materials. The channel box has a shape that can be achieved by applying the silicon carbide composite material and can increase earthquake resistance and improve functions and performance as a fuel assembly.

Abstract: An eddy current flaw detection device according to an embodiment includes: a first exciter/detector that is supplied with alternating current and can induce eddy current in a tested object by generating a magnetic field change in the tested object; a second exciter/detector disposed opposite side of the first exciter/detector sandwiching the tested object therebetween. The second exciter/detector can detect a change in a reactive magnetic field generated by the eddy current. The first and second exciter/detectors each may have a coil including a helical coil wire, and the coil wire of the first exciter/detector may be thicker than the coil wire of the second exciter/detector.

Abstract: A channel box has a hollow cylindrical portion and accommodates a plurality of nuclear reactor fuel rods inside the hollow cylindrical portion, wherein the hollow cylindrical portion is constituted by a plurality types of silicon carbide composite materials. The channel box has a shape that can be achieved by applying the silicon carbide composite material and can increase earthquake resistance and improve functions and performance as a fuel assembly.

Abstract: An eddy current flaw detection device according to an embodiment includes: a first exciter/detector that is supplied with alternating current and can induce eddy current in a tested object by generating a magnetic field change in the tested object; a second exciter/detector disposed opposite side of the first exciter/detector sandwiching the tested object therebetween. The second exciter/detector can detect a change in a reactive magnetic field generated by the eddy current. The first and second exciter/detectors each may have a coil including a helical coil wire, and the coil wire of the first exciter/detector may be thicker than the coil wire of the second exciter/detector.

Abstract: A channel box in an embodiment includes a tubular portion. The tubular portion includes a first tubular layer, a second tubular layer, and an intermediate tubular layer. The first tubular layer contains silicon carbide as a major component. The second tubular layer is in parallel to and surrounds or is surrounded by the first tubular layer and contains silicon carbide fibers and silicon carbide complexed with the silicon carbide fibers. The intermediate tubular layer is disposed between the first tubular layer and the second tubular layer and contains a solid lubricant.

Abstract: A container comprising: a container body that includes a wall portion separating inside and outside and is formed of a long-fiber-reinforced silicon-carbide composite material obtained by combining monofilaments of silicon carbide with a silicon carbide matrix, the wall portion having a thickness equal to a specific dimension; and a lid configured to close an opening of the container body, formed of a material containing at least silicon carbide, and equipped with such a wall portion separating inside and outside that thickness is within a range of 1 to 3 times the specific dimension.

Abstract: There are provided a continuous fiber-reinforced silicon carbide member and the like which allow sufficient improvement in a mechanical property and environmental resistance. The continuous fiber-reinforced silicon carbide member of an embodiment is a tubular shape and has a first composite material layer and a second composite material layer. In the first composite material layer, continuous fibers of silicon carbide are combined with a matrix of silicon carbide. In the second composite material layer, continuous fibers of carbon are combined with a matrix of silicon carbide. Then, the first composite material layer and the second composite material layer are stacked.

Abstract: A nuclear reactor control rod with SiC fiber reinforced structure comprises wing sections and a central joint section. Each of the wing sections is a flat plate spreading axially and radially, and includes storage tubes and a wing surface structural member. The storage tubes are arranged in parallel in a flat plane and contain a neutron absorbing member containing the neutron absorbing material. The wing surface structural member is formed by molding of SiC/SiC composite material as to cover surfaces of the storage tubes and formed to have an outward shape of a flat plate. The central joint section and storage tubes are made of SiC/SiC composite material. The central joint section bundles the wing sections together at center. The storage tubes are bundled together with fibers made of SiC or a textile made of SiC.

Abstract: A channel box in an embodiment includes a tubular portion. The tubular portion includes a first tubular layer, a second tubular layer, and an intermediate tubular layer. The first tubular layer contains silicon carbide as a major component. The second tubular layer is in parallel to and surrounds or is surrounded by the first tubular layer and contains silicon carbide fibers and silicon carbide complexed with the silicon carbide fibers. The intermediate tubular layer is disposed between the first tubular layer and the second tubular layer and contains a solid lubricant.

Abstract: A reactor control rod for nuclear reactor according to an embodiment has: a plurality of wing sections arranged radially around an axis extending in vertical direction in such a way as to be spaced out each other in a circumferential direction; and a central joint section bundling the plurality of wing sections together at center, wherein at least part of the central joint section and wing surface structural member is made of SiC-fiber-reinforced SiC composite material. The wing surface structural member of side of the central joint section may be sealed with the SiC-fiber-reinforced SiC composite material. Orientation directions of SiC fibers in the SiC-fiber-reinforced SiC composite material may be such that arithmetic mean of cos2? for all SiC fibers may be ½ or greater, where ? is an angle formed of each fiber with the longitudinal direction of the wing section.

Abstract: A retainer provided at lower portion of a pump beam of a jet pump for circulating cooling water to a reactor core or a bolt for fastening the retainer is cut through an underwater-remote control to remove the bolt and the retainer is removed through the underwater-remote control.

Abstract: A retainer provided at lower portion of a pump beam of a jet pump for circulating cooling water to a reactor core or a bolt for fastening the retainer is cut through an underwater-remote control to remove the bolt and the retainer is removed through the underwater-remote control.

Abstract: A retainer provided at lower portion of a pump beam of a jet pump for circulating cooling water to a reactor core or a bolt for fastening the retainer is cut through an underwater-remote control to remove the bolt and the retainer is removed through the underwater-remote control.

Abstract: A fuel inlet mechanism to introduce a coolant into a fuel assembly configured to be charged in a light water nuclear reactor, includes, a filter catching a foreign substance included in the coolant on an upstream side of the fuel assembly, the filter having a plurality of through holes to pass the coolant, and the through holes having an inlet portion, an outlet portion and at least one bent portion to a degree by which the outlet portion cannot be seen through from the inlet portion by a straight line.

Abstract: A retainer provided at lower portion of a pump beam of a jet pump for circulating cooling water to a reactor core or a bolt for fastening the retainer is cut through an underwater-remote control to remove the bolt and the retainer is removed through the underwater-remote control.

Abstract: A fuel inlet mechanism to introduce a coolant into a fuel assembly configured to be charged in a light water nuclear reactor, includes, a filter catching a foreign substance included in the coolant on an upstream side of the fuel assembly, the filter having a plurality of through holes to pass the coolant, and the through holes having an inlet portion, an outlet portion and at least one bent portion to a degree by which the outlet portion cannot be seen through from the inlet portion by a straight line.

Abstract: A core inlet structure for coolant disposed in a reactor pressure vessel of a boiling water reactor includes a core support plate provided with a plurality of fuel support holes, a reinforcing beam supporting the core support plate, a plurality of control rod guide pipes standing perpendicularly and having upper end portions fitted to the fuel support holes, and a fuel support member inserted into upper end portions of the control rod guide pipes and supported by the core support plate so as to support lower end portions of fuel assemblies. An inlet orifice is formed to the fuel support member so as to adjust flow rate of a coolant flowing in the fuel assemblies, and a vortex control structure is provided for the inlet orifice or provided at a portion on a coolant upstream side of the inlet orifice.

Abstract: A fuel inlet mechanism to introduce a coolant into a fuel assembly configured to be charged in a light water nuclear reactor, includes, a filter catching a foreign substance included in the coolant on an upstream side of the fuel assembly, the filter having a plurality of through holes to pass the coolant, and the through holes having an inlet portion, an outlet portion and at least one bent portion to a degree by which the outlet portion cannot be seen through from the inlet portion by a straight line.

Abstract: A gap between adjoining fuel rods arranged in a fuel assembly is measured by setting a measuring device into a fluid such as cooling water or a specific gas such as CF filling a container, placing a fuel assembly to be inspected to a predetermined portion the container, measuring a distribution of the fluid distributed in the fuel assembly by utilizing a nuclear magnetic resonance imaging system, and measuring the gap in accordance with the fluid distribution as an image. The measuring device includes a magnet unit and a coil unit for generating magnetic fields, and the coil unit includes a coil assembly for generating gradient magnetic fields and a coil assembly for generating a high-frequency magnetic field and detecting a nuclear magnetic resonance signal.

Abstract: A foreign matter recovering apparatus includes a body for approaching a fuel assembly, a body fixing section for fixing the body to the fuel assembly for positioning, a moving mechanism section movable relative to the body, a recovering working unit adapted to be moved by the moving mechanism section to gain access to clearance of the fuel assembly to allow foreign matter to be recovered thereby, and a remote control section for remotely controlling the working unit on the basis of an image representing a working state of the working unit to operate it properly.