Abstract: A jet pump measuring pipe repair method that repairs a ruptured part of a measuring pipe horizontally installed to a lower portion of a jet pump provided in reactor water inside a reactor pressure vessel. The repair method includes: fixing a support member to the jet pump near the measuring pipe left remained; mounting, after the support member fixing, a measuring pipe connector provided with a pipe-repairing pipe having both ends over which connecting pipes are fitted, respectively, to the support member; connecting, after the connector mounting, the remaining measuring pipe and connecting pipe using the measuring pipe connector.

Abstract: A diffuser extension sleeve 40 includes: a fixer 41 fixed to an upper portion of a diffuser in which an edge of an inlet mixer 25 is inserted, the inlet mixer 25 guiding circulating water, which is transported from a recirculating pump by pressure, downward along an inner surface of a reactor pressure vessel; a spacer 42 having a lower portion inserted in a gap defined by an outer surface 25a of the inlet mixer and an inner surface 26a of the diffuser; and a support 43 supporting the spacer 42 from the fixer 41 side and guiding movement of the spacer 42 in a longitudinal direction of the inlet mixer 25.

Abstract: A reactor measurement-pipe maintenance clamp apparatus includes a first clamp mechanism and a second clamp mechanism. The first clamp mechanism includes clamps to fix the measurement pipe between the clamps, first clamp operation bolts that are allowed to be turned by remote control from above a reactor core, and wedge mechanisms to convert the turning of the clamp operation bolts to displacement of the clamps in a radial direction of the diffuser to generate clamping forces for securing the measurement pipe. The second clamp mechanism includes a support clamp to hold the support, a second clamp operation bolt that is allowed to be turned by remote control from above the reactor core, and a wedge mechanism to convert the turning of the second clamp operation bolt to displacement of the support clamp in a tangential direction of the diffuser to generate clamping force for fixing the support.

Abstract: An ultrasonic flaw detector including an ultrasonic probe for emitting an ultrasonic wave on an object to be inspected and receiving a reflected ultrasonic wave from the object, a drive element control unit for controlling a plurality of ultrasonic elements to emit an ultrasonic wave from the ultrasonic probe and to control a reflected ultrasonic wave from the object, and a calculation unit for obtaining, by using a refraction angle of the ultrasonic wave at a time of the ultrasonic wave entering the object, an incident position of the ultrasonic wave on a surface of the object, and a surface shape of a surface of the object at the incident position, the incident angle of the ultrasonic wave entering the incident position, and obtaining a plurality of ultrasonic elements to be driven, based on the incident position and the incident angle.

Abstract: In a jet pump measurement pipe repair method according to the present embodiment, a breakage part of a measurement pipe horizontally fixed to a lower part of a jet pump provided in reactor water in a reactor pressure vessel is repaired. The method has: a step of cutting and removing the measurement pipe including the breakage part; a step of retaining a connection pipe for connecting the remaining measurement pipe on the jet pump by means of a clamp; and a step of connecting ends of the remaining measurement pipe by means of the connection pipe.

Abstract: A jet pump measuring pipe repair method that repairs a ruptured part of a measuring pipe horizontally installed to a lower portion of a jet pump provided in reactor water inside a reactor pressure vessel. The repair method includes: fixing a support member to the jet pump near the measuring pipe left remained; mounting, after the support member fixing, a measuring pipe connector provided with a pipe-repairing pipe having both ends over which connecting pipes are fitted, respectively, to the support member; connecting, after the connector mounting, the remaining measuring pipe and connecting pipe using the measuring pipe connector.

Abstract: A reactor measurement-pipe maintenance clamp apparatus includes a first clamp mechanism and a second clamp mechanism. The first clamp mechanism includes clamps to fix the measurement pipe between the clamps, first clamp operation bolts that are allowed to be turned by remote control from above a reactor core, and wedge mechanisms to convert the turning of the clamp operation bolts to displacement of the clamps in a radial direction of the diffuser to generate clamping forces for securing the measurement pipe. The second clamp mechanism includes a support clamp to hold the support, a second clamp operation bolt that is allowed to be turned by remote control from above the reactor core, and a wedge mechanism to convert the turning of the second clamp operation bolt to displacement of the support clamp in a tangential direction of the diffuser to generate clamping force for fixing the support.

Abstract: According to an embodiment, an ultrasonic flaw detection device is provided with: an ultrasonic probe, which applies ultrasonic waves, by driving a plurality of ultrasonic elements, to a test object to be inspected, and which receives reflected ultrasonic waves from the test object; and an analysis unit, which analyzes the signals of the reflected ultrasonic waves received by the ultrasonic probe, and which calculates the flaw detection results. The analysis unit calculates the flaw detection results using an ultrasonic wave propagation path obtained on the basis of the surface information of the test object having the ultrasonic waves applied thereto, thereby obtaining highly accurate detection results even the surface of the test object is formed in complex shape.

Abstract: An ultrasonic flaw detector including an ultrasonic probe for emitting an ultrasonic wave on an object to be inspected and receiving a reflected ultrasonic wave from the object, a drive element control unit for controlling a plurality of ultrasonic elements to emit an ultrasonic wave on the ultrasonic probe and to control a reflected ultrasonic wave from the ultrasonic probe, and a calculation unit for obtaining, by using a refraction angle of the ultrasonic wave at a time of the ultrasonic wave entering the object, an incident position of the ultrasonic wave on a surface of the object, and a surface shape of a surface of the object at the incident position, the incident angle of the ultrasonic wave entering the incident position, and obtaining a plurality of ultrasonic elements to be driven, based on the incident position and the incident angle.

Abstract: In a jet pump measurement pipe repair method according to the present embodiment, a breakage part of a measurement pipe horizontally fixed to a lower part of a jet pump provided in reactor water in a reactor pressure vessel is repaired. The method has: a step of cutting and removing the measurement pipe including the breakage part; a step of retaining a connection pipe for connecting the remaining measurement pipe on the jet pump by means of a clamp; and a step of connecting ends of the remaining measurement pipe by means of the connection pipe.