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: According to one embodiment, a wafer includes a substrate and a crystal layer. The substrate includes a plurality of SiC regions including SiC and an inter-SiC region including Si provided between the SiC regions. The crystal layer includes a first layer, and a first intermediate layer provided between the substrate and the first layer in a first direction. The first layer includes SiC and nitrogen. The first intermediate layer includes SiC and nitrogen. A second concentration of nitrogen in the first intermediate layer is higher than a first concentration of nitrogen in the first layer.

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: 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 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: In one embodiment, an electrical power storage system using hydrogen includes a power generation unit generating power using hydrogen and oxidant gas and an electrolysis unit electrolyzing steam. The electrical power storage system includes a hydrogen storage unit storing hydrogen generated by the electrolysis and supplying the hydrogen to the power generation unit during power generation, a high-temperature heat storage unit storing high temperature heat generated accompanying the power generation and supplying the heat to the electrolysis unit during the electrolysis, and a low-temperature heat storage unit storing low-temperature heat, which is exchanged in the high-temperature heat storage unit and generating with this heat the steam supplied to the electrolysis unit.

Abstract: A ceramics composite member includes a structure in which a first ceramic member and a second ceramic member are integrated with a joint portion. The joint portion has a texture in which a silicon phase having an average diameter of 0.05 ?m or more and 10 ?m or less is continuously provided in a network form in interstices of silicon carbide particles having an average particle diameter of 0.1 ?m or more and 0.1 mm or less.

Abstract: In one embodiment, an electrical power storage system using hydrogen includes a power generation unit generating power using hydrogen and oxidant gas and an electrolysis unit electrolyzing steam. The electrical power storage system includes a hydrogen storage unit storing hydrogen generated by the electrolysis and supplying the hydrogen to the power generation unit during power generation, a high-temperature heat storage unit storing high temperature heat generated accompanying the power generation and supplying the heat to the electrolysis unit during the electrolysis, and a low-temperature heat storage unit storing low-temperature heat, which is exchanged in the high-temperature heat storage unit and generating with this heat the steam supplied to the electrolysis unit.

Abstract: Silicon carbide matrix composite material (1) comprises silicon carbide matrix (2) as a host The silicon carbide matrix (2) comprises first silicon carbide phase (3) of 0.1 to 10 ?m average crystal grain diameter and second silicon carbide phase (4) of 0.01 to 2 ?m average crystal grain diameter. In interstices of silicon carbide crystal grains constituting the silicon carbide matrix (2), liberated silicon phase (5) amounting to, for example, 5 to 50 mass % based on the composite material (1) is present continuously in network form. This fine structure enables realizing high strength and high toughness of the silicon carbide composite material (1).

Abstract: An optical device has a reflecting mirror using a particle-dispersed silicon material including silicon carbide and silicon. The reflecting mirror includes a plurality of segments joined to each other by reaction sintering. Producing the segments is easy in comparison with that of a reflecting mirror of one piece. Accordingly, it is possible to reduce probability of breakage of the segments and to shorten process time of production of a reflecting mirror.

Abstract: In one embodiment, an electrical power storage system using hydrogen includes a power generation unit generating power using hydrogen and oxidant gas and an electrolysis unit electrolyzing steam. The electrical power storage system includes a hydrogen storage unit storing hydrogen generated by the electrolysis and supplying the hydrogen to the power generation unit during power generation, a high-temperature heat storage unit storing high temperature heat generated accompanying the power generation and supplying the heat to the electrolysis unit during the electrolysis, and a low-temperature heat storage unit storing low-temperature heat, which is exchanged in the high-temperature heat storage unit and generating with this heat the steam supplied to the electrolysis unit.

Abstract: A ceramic heat exchanger includes a heat exchange section that heat-exchanges between two fluids A and B flowing opposite directions to each other. The heat exchange section includes ceramic blocks stacked one on top of another with a seal therebetween. The ceramic blocks have a plurality of parallel lines of flow channels, each line defined by the flow channels through which the same fluid flows, any two adjacent lines being defined by the flow channels through which the different fluids A and B flow respectively. Both ends in the stacking direction of the stack are bound to join and integrate the ceramic blocks with tightening means including end plates and a tie rod. A thermal expansion absorber is disposed on an external surface of the end plates for absorbing thermal expansion in the axial direction of the tie rod.

Abstract: A ceramics composite member includes a structure in which a first ceramic member and a second ceramic member are integrated with a joint portion. The joint portion has a texture in which a silicon phase having an average diameter of 0.05 ?m or more and 10 ?m or less is continuously provided in a network form in interstices of silicon carbide particles having an average particle diameter of 0.1 ?m or more and 0.1 mm or less.

Abstract: In one embodiment, an electrical power storage system using hydrogen includes a power generation unit generating power using hydrogen and oxidant gas and an electrolysis unit electrolyzing steam. The electrical power storage system includes a hydrogen storage unit storing hydrogen generated by the electrolysis and supplying the hydrogen to the power generation unit during power generation, a high-temperature heat storage unit storing high temperature heat generated accompanying the power generation and supplying the heat to the electrolysis unit during the electrolysis, and a low-temperature heat storage unit storing low-temperature heat, which is exchanged in the high-temperature heat storage unit and generating with this heat the steam supplied to the electrolysis unit.

Abstract: An optical device has a reflecting mirror using a particle-dispersed silicon material including silicon carbide and silicon. The reflecting mirror includes a plurality of segments joined to each other by reaction sintering. Producing the segments is easy in comparison with that of a reflecting mirror of one piece. Accordingly, it is possible to reduce probability of breakage of the segments and to shorten process time of production of a reflecting mirror.

Abstract: A sputtering target contains Si and C as its major components and includes a texture in which a Si phase continuously exists in a net shape in gaps among SiC crystal grains. An average diameter of the Si phase is controlled to 1000 nm or less. The sputtering target is sputtered in an oxygen-containing gas, thereby depositing an optical thin film containing Si and O as its major components, and a third element other than the major components, a total amount of the third element being within a range from 10 to 2000 ppm.

Abstract: A ceramic heat exchanger includes a heat exchange section that heat-exchanges between two fluids A and B flowing opposite directions to each other. The heat exchange section includes ceramic blocks stacked one on top of another with a seal therebetween. The ceramic blocks have a plurality of parallel lines of flow channels, each line defined by the flow channels through which the same fluid flows, any two adjacent lines being defined by the flow channels through which the different fluids A and B flow respectively. Both ends in the stacking direction of the stack are bound to join and integrate the ceramic blocks with tightening means including end plates and a tie rod. A thermal expansion absorber is disposed on an external surface of the end plates for absorbing thermal expansion in the axial direction of the tie rod.

Abstract: A ceramics composite member includes a structure in which a first ceramic member and a second ceramic member are integrated with a joint portion. The joint portion has a texture in which a silicon phase having an average diameter of 0.05 ?m or more and 10 ?m or less is continuously provided in a network form in interstices of silicon carbide particles having an average particle diameter of 0.1 ?m or more and 0.1 mm or less.