Abstract: A thermal insulation coating member includes: a substrate having a surface; a binding layer on the surface, and a thermal insulation layer on the binding layer. The thermal insulation layer includes: a first ceramic layer including a plurality of first flat pores, the plurality of first flat pores being inclined at a first angle with respect to the surface and extending in a first direction; and a second ceramic layer including a plurality of second flat pores, the plurality of second flat pores being inclined at a second angle with respect to the surface and extending in a second direction. The second angle differs from the first angle, the second direction differing from the first direction, or the second angle and the second direction respectively differing from the first angle and the first direction.

Abstract: A thermal insulation coating member comprises: a substrate having a surface; a binding layer on the surface; and a thermal insulation layer on the binding layer. The thermal insulation layer includes: a first ceramic layer having a plurality of first flat pores, the first flat pores being inclined at a first angle with respect to the surface and extending in a first direction; and a second ceramic layer having a plurality of second flat pores, the second flat pores being inclined at a second angle with respect to the surface and extending in a second direction. The second angle differs from the first angle, the second direction differing from the first direction, or the second angle and the second direction respectively differing from the first angle and the first direction.

Abstract: A laser welding head includes a shield gas injection nozzle and welding wire supply nozzle, wherein the shield gas injection nozzle and the welding wire supply nozzle include a main body section and a surface layer section that covers the main body section, and at least part of the surface layer section is formed by at least one of ultra-hard alloy, cermet and ceramics.

Abstract: A laser welding head includes a shield gas injection nozzle and welding wire supply nozzle, wherein the shield gas injection nozzle and the welding wire supply nozzle include a main body section and a surface layer section that covers the main body section, and at least part of the surface layer section is formed by at least one of ultra-hard alloy, cermet and ceramics.

Abstract: A heating laser beam is emitted to a cracked portion to remove moisture from the cracked portion, and subsequently, a welding laser beam is emitted to the cracked portion to heat and melt the cracked portion. The heating laser beam and the welding laser beam are emitted to an entire surface of the cylindrical body inside the reactor such as a stub tube penetrating through and fixed to a reactor bottom portion and a crack of the welded portion between the cylindrical body and the reactor bottom portion to thereby prevent a new crack from occurring and reactor water from leaking.

Abstract: A double-walled tube includes: a plurality of double-walled tube forming members, each having an inner tube and an outer tube, connected by welding at welding portions of axis direction end portions thereof; and each of the welding portions of the double-walled tube forming members including a groove having a length in an axis direction set to be equal to or greater than ½ of a width of a weld bead formed by the welding at the welding portion.

Abstract: A method of sealing a surface crack in a member is provided includes steps of irradiating a region of the member at which the crack is produced with a heating laser beam so as to heat the region to a temperature lower than a melting point of the member, and then irradiating a region of the member at which the crack is produced with a welding laser beam subsequent to irradiation of the heating laser beam so as to heat the region to a temperature higher than or equal to the melting point of the member, thereby sealing an opening of the surface crack of the member.

Abstract: A heating laser beam is emitted to a cracked portion to remove moisture from the cracked portion, and subsequently, a welding laser beam is emitted to the cracked portion to heat and melt the cracked portion. The heating laser beam and the welding laser beam are emitted to an entire surface of the cylindrical body inside the reactor such as a stub tube penetrating through and fixed to a reactor bottom portion and a crack of the welded portion between the cylindrical body and the reactor bottom portion to thereby prevent a new crack from occurring and reactor water from leaking.

Abstract: According to an embodiment, an in-pipe work device is inserted into a pipe and remotely controlled by a control device to perform an operation for an inner surface of the pipe. The in-pipe work device has: a main unit; a main-unit support unit; a rotation arm; a process head; a first distance sensor; and a process head position adjustment mechanism that changes a distance from a rotation center of the rotation arm to the process head. The control device makes the process head position adjustment mechanism expand and contract based upon a result of measurement by the first distance sensor and operation condition information that is input in advance.

Abstract: A method of sealing a surface crack in a member is provided includes steps of irradiating a region of the member at which the crack is produced with a heating laser beam so as to heat the region to a temperature lower than a melting point of the member, and then irradiating a region of the member at which the crack is produced with a welding laser beam subsequent to irradiation of the heating laser beam so as to heat the region to a temperature higher than or equal to the melting point of the member, thereby sealing an opening of the surface crack of the member.

Abstract: An underwater laser processing apparatus includes an optical unit and a nozzle. The optical unit irradiates a condensed laser beam generated by a YAG laser source to a certain point on a underwater workpiece. The nozzle has a gas exit for supplying a gas to the certain point. In the nozzle, an area surrounding the gas exit extends to the surface of the workpiece. This area keeps the supplied gas between the nozzle and the workpiece to improve the underwater laser process.

Abstract: A crushing apparatus (10) includes a supplying section (30) for receiving a solid material (M), a crushing section (50) for crushing the material (M) supplied from the supplying section (30), and a discharging section (100) for discharging the material (M) crushed by the crushing section (50) to the outside. The crushing section (50) is formed by partitioning with a first rotating disk (60) and a second rotating disk (70) respectively connected to a first rotating shaft (110) or a second rotating shaft (111). The first rotating disk (60) and the second rotating disk (70) are arranged with pluralities of blades (63, 73) projected from faces thereof opposed to each other and formed with through holes (61, 71) penetrated in an axial direction at positions proximate to a rotational axis center thereof.

Abstract: A protection plate is welded to a metal structure in water so that the protection plate covers the surface of the structure including a portion to be repaired. The welding is carried out such that the periphery of the protection plate is welded in water by laser welding while inactive gas is supplied to portion to be welded to seal the portion to be repaired by the protection plate. Welding is carried out while the inactive gas is supplied to the portion to be welded coaxially with a laser beam during the laser welding. The plate is provided therein with an opening in advance so as to release vapor produced from water remaining during welding between the protection plate and the structure and the opening is sealed after the periphery of the protection plate is welded to the structure.

Abstract: A crushing apparatus (10) includes a supplying section (30) for receiving a solid material (M), a crushing section (50) for crushing the material (M) supplied from the supplying section (30), and a discharging section (100) for discharging the material (M) crushed by the crushing section (50) to the outside. The crushing section (50) is formed by partitioning with a first rotating disk (60) and a second rotating disk (70) respectively connected to a first rotating shaft (110) or a second rotating shaft (111). The first rotating disk (60) and the second rotating disk (70) are arranged with pluralities of blades (63, 73) projected from faces thereof opposed to each other and formed with through holes (61, 71) penetrated in an axial direction at positions proximate to a rotational axis center thereof.

Abstract: A repair method for a structure having an open flaw in a welding heat affected portion, including, removing at least a part of the open flaw and thereby forming a concave portion in the welding heat affected portion, forming build-up weld layers so as to fill the concave portion, treating a surface of the build-up layers to reduce tensile residual stress by means of at least one of laser peening, shot blasting and water jet machining. Also disclosed is an apparatus suitable for carrying out the repair method.

Abstract: An underwater laser processing apparatus includes an optical unit and a nozzle. The optical unit irradiates a condensed laser beam generated by a YAG laser oscillator to a certain point on a underwater workpiece. The nozzle has a gas exit for supplying a gas to the certain point. In the nozzle, an area surrounding the gas exit extends to the surface of the workpiece. This area keeps the supplied gas between the nozzle and the workpiece to improve the underwater laser process.

Abstract: An underwater laser processing apparatus includes an optical unit and a nozzle. The optical unit irradiates a condensed laser beam generated by a YAG laser source to a certain point on a underwater workpiece. The nozzle has a gas exit for supplying a gas to the certain point. In the nozzle, an area surrounding the gas exit extends to the surface of the workpiece. This area keeps the supplied gas between the nozzle and the workpiece to improve the underwater laser process.

Abstract: A method for manufacturing a control rod of a nuclear reactor, the control rod comprising a blade including neutron absorbers and a sheath, a tie rod for fixing the blade, a handle and a lower blade fixed to the tie rod and the blade. The method comprises a first step for cutting weep holes for water to cool the neutron absorbers in the sheath and cutting a periphery of the sheath, a second step for bending the sheath cut in the first step to a C-shape, a third step for inserting the neutron absorbers in a bent portion of the sheath formed by bending in the second step, a fourth step for successively welding the blade to the tie rod, the blade to the handle and the blade to the lower blade, and a fifth step for finishing portions welded in the fourth step.

Abstract: A method for manufacturing a control rod of a nuclear reactor, the control rod having a blade including neutron absorbers and a sheath, a tie rod for fixing the blade, a handle and a lower-blade fixed to the tie rod and the blade. The method includes a first step for cutting weep holes for water to cool the neutron absorbers in the sheath and cutting a periphery of the sheath, a second step for bending the sheath cut in the first step to a C-shape, a third step for inserting the neutron absorbers in a bent portion of the sheath formed by bending in the second step, a fourth step for successively welding the blade to the tie rod, the blade to the handle and the blade to the lower-blade, and a fifth step for finishing portions welded in the fourth step.

Abstract: A repair method for a structure having an open flaw in a welding heat affected portion, including, removing at least a part of the open flaw and thereby forming a concave portion in the welding heat affected portion, forming build-up weld layers so as to fill the concave portion, treating a surface of the build-up layers to reduce tensile residual stress by means of at least one of laser peening, shot blasting and water jet machining. Also disclosed is an apparatus suitable for carrying out the repair method.