Apparatuses and methods for repairing a defect in a nuclear reactor are provided. The apparatus includes a body for insertion in a tubular structure, the body includes: an end effector having a weld torch operable to deposit weld material by forming molten weld droplets and depositing the weld droplets the tubular structure. A drive unit includes a brace for selectively anchoring against said tubular structure; at least one linear actuator for moving the apparatus relative to the brace; and a rotational actuator coupled to rotate the weld torch. The method includes inserting a repair apparatus into tubular structure of the nuclear reactor; moving the repair apparatus to a defect location; depositing a protective weld layer over the defect by sequentially depositing weld droplets atop a weld pool on the tubular structure, wherein the protective weld layer bonds to the tubular structure surrounding the defect.

In one embodiment, a laser peening apparatus includes an output unit (41) configured to output laser light (6); a light-guide unit (31) configured to guide the outputted laser light (6); a condenser lens (42) configured to condense the guided laser light (6); an irradiation nozzle (32) configured to radiate the condensed laser light (6); a focus-change unit (50) configured to change a focal position of the laser light (6) based on distance from an irradiation target (4, 5) of the laser light (6) to the irradiation nozzle (32); and a control unit (66) configured to apply laser peening by radiating the laser light (6) toward the irradiation target (4, 5) which is in contact with water.

A method for restraining a sleeve lining a tube passing through a nuclear reactor pressure vessel is provided. The method includes attaching in situ a radial protrusion on an external surface of the sleeve; and attaching a collar to an end of the tube and coupling the radial protrusion with the collar to retain the thermal sleeve in position.

A method for restraining a sleeve lining a tube passing through a nuclear reactor pressure vessel is provided. The method includes attaching in situ a radial protrusion on an external surface of the sleeve; and attaching a collar to an end of the tube and coupling the radial protrusion with the collar to retain the thermal sleeve in position.

A modular kinematic and telemetry system for an irrigation system includes a condition-based monitoring (CBM) system and a plurality of sets of modular foot assemblies. The CBM system has a housing and supports a plurality of kinematic and telemetry components. The plurality of sets of modular foot assemblies includes a first set and a second set that secure to the housing of the CBM system. The first set is configured to secure the CBM system to a first end gun configuration and the second set is configured to secure the CBM system to a second end gun configuration that is different from the first end gun configuration.

A modular kinematic and telemetry system for an irrigation system includes a condition-based monitoring (CBM) system and a plurality of sets of modular foot assemblies. The CBM system has a housing and supports a plurality of kinematic and telemetry components. The plurality of sets of modular foot assemblies includes a first set and a second set that secure to the housing of the CBM system. The first set is configured to secure the CBM system to a first end gun configuration and the second set is configured to secure the CBM system to a second end gun configuration that is different from the first end gun configuration.

There is provided an inspection device for inspecting an inner surface of a nozzle provided in a reactor vessel. The inspection device includes: a device frame, an inspection unit provided on the device frame, an inspection unit push-out moving mechanism for pushing out and moving the inspection unit to the inner surface of the nozzle, a rotation moving mechanism for rotating and moving the inspection unit, a calibration test unit arranged on the device frame for calibrating the inspection unit; and a calibration test unit forward/backward moving mechanism for moving the calibration test unit forward or backward in the direction along the central axis with regard to a track where the inspection unit makes push-out movement.

An assembly for acting on the outer surface of a tube, and corresponding method are provided. The assembly includes a carrier; at least one inspection or maintenance tool; the carrier includes at least one rolling body; an actuator. The carrier further includes a device for connecting the carrier to the tube, arranged so that the tube absorbs at least 50% of the weight of the carrier and the tool.

An assembly for acting on the outer surface of a tube, and corresponding method are provided. The assembly includes a carrier; at least one inspection or maintenance tool; the carrier includes at least one rolling body; an actuator. The carrier further includes a device for connecting the carrier to the tube, arranged so that the tube absorbs at least 50% of the weight of the carrier and the tool.

A method of extending a life expectancy of a high-temperature piping, includes removing a heat insulation material which covers the piping having a high creep rupture risk, and lowering an outer surface temperature of piping, wherein a width of an exposed portion obtained is twice or more a distance from a peeled-off end portion of the exposed portion to a portion where a compressive stress is asymptotical to 0 after a change in stress between a tensile stress and the compressive stress occurring in the piping due to the removal of the heat insulation material is made from the tensile stress to the compressive stress, and the distance is calculated based on the following formulae, βx=5, $\beta =\sqrt[4]{\frac{3\left(1-v^2\right)}{a^2{h}^2}}$
here, ν is a Poisson's ratio, a is an average radius of the piping, and h is a plate thickness of the piping.