JP2020076576A - Checking device of nuclear reactor pressure vessel and checking method thereof - Google Patents

Abstract

To provide a checking device and checking method of a nuclear reactor pressure vessel in which a non-destructive inspection of inspection object parts such as parts in the vicinity of a feedwater nozzle and the like can be conducted in a short time, and repair works can be efficiently conducted.SOLUTION: A checking device 10 of a nuclear reactor pressure vessel 1 has: a flaw detection probe 11 that conducts a non-destructive inspection of an inspection object part of the nuclear reactor pressure vessel; a linear arm 12; a drive unit 13 that makes the arm move back and forth, or rotate to drive; a base plate 14 that is provided in the drive unit; and pinchingly holding fixation parts 15a and b that are provided in the base plate, and pinchingly hold core spray plumbing 4 arranged in the vicinity of the inspection object part, in which a tip of the arm and the flaw detection probe are connected by a curved arm with a prescribed curvature rate, and the arm is demountably mounted to the drive unit.SELECTED DRAWING: Figure 2

Description

  Embodiments of the present invention relate to an inspection device and an inspection method for a reactor pressure vessel.

  Generally, in an aged nuclear power plant, in order to evaluate the soundness of the reactor internals such as the nozzle corners in the reactor pressure vessel, surface inspection and volume inspection are performed using inspection equipment. Etc. non-destructive inspection is carried out.

  For example, as shown in FIG. 4, when inspecting the vicinity of the water supply nozzle 2 formed above the core 5 of the reactor pressure vessel 1, from the operating floor, The inspection device 10 is hung inside with an overhead crane or the like (not shown), and then the inspection device 10 is moved to the vicinity of the water supply nozzle 2, and then the water supply sparger 3 in the reactor pressure vessel 1 or immediately below it. By fixing the inspection device 10 by utilizing the internal structure of the core spray (CS) pipe 4 or the like arranged, or by adsorbing and fixing the inspection device 10 to a desired position by suction means (not shown), A non-destructive inspection of the corners of the water supply nozzle 2 is performed.

  However, when inspecting a narrow portion such as a corner portion of the water supply nozzle 2, the thermal sleeve 18 and the water supply sparger 3 arranged in the water supply nozzle 2 are present in the vicinity of the water supply nozzle 2, so that the inspection device 10 is installed. It is difficult to access the inspection target part.

  Therefore, in order to perform a nondestructive inspection on a narrow portion such as a corner portion of the water supply nozzle 2 which is difficult to access, an inspection device having a plurality of driving parts and an inspection device having an inspection arm such as an offset arm have been proposed.

JP, 2005-102527, A

  In the inspection device having the conventional offset arm described above, the flaw detection probe provided at the tip of the inspection device is placed close to a narrow corner part while avoiding the water supply sparger 3 provided on the inner peripheral surface of the reactor pressure vessel 1. To do so, two offset arms, specifically, a single offset arm and a double offset arm are used to perform flaw detection inspection over the entire circumference of the nozzle corner portion.

  However, when performing the flaw detection inspection over the entire circumference of the corner portion of the water supply nozzle 2, it is necessary to replace the two offset arms, which causes a problem that the time required for the nondestructive inspection becomes long.

  Further, when it is necessary to repair the inspection target portion after the non-destructive inspection, it is necessary to use a repair device to which a polishing tool or the like is attached instead of the inspection device 10, and it takes time to perform the replacement work, There is a problem that the inspection and repair work is further prolonged because it is necessary to reposition the device on the inspection target part.

  The embodiment of the present invention is made in order to solve the above problems, and can perform a nondestructive inspection of a narrow portion such as the vicinity of the water supply nozzle portion in a short time, and also when repair work is required, It is an object of the present invention to provide an inspection device and inspection method for a reactor pressure vessel that can efficiently perform repair work at a corresponding place.

  In order to solve the above problems, the inspection device for a reactor pressure vessel according to the present embodiment, a flaw detection probe for performing a nondestructive inspection of an inspection target portion of the reactor pressure vessel, a linear arm, the front and rear arms Reactor pressure having a drive unit for moving or rotating the drive, a base plate provided for the drive unit, and a grip fixing unit that is provided on the base plate and that grips the core spray pipe arranged near the inspection target unit. In the container inspection device, the distal end portion of the arm and the flaw detection probe are connected by a bending arm having a predetermined bending degree, and the arm is detachably attached to the drive unit.

  In addition, the inspection method of the reactor pressure vessel according to the present embodiment uses the inspection device according to the present embodiment, and is gripped and fixed to the core spray pipe arranged in the reactor pressure vessel by the gripping and fixing portion of the inspection device. It is characterized by performing the inspection work of the corner of the water supply nozzle of the reactor pressure vessel.

  According to the embodiment of the present invention, a non-destructive inspection of a narrow area such as the vicinity of the water supply nozzle of the reactor pressure vessel can be efficiently performed in a short time, and even when repair work is required, the corresponding place The repair work can be efficiently performed.

The block diagram of the inspection apparatus which concerns on 1st Embodiment. The block diagram when the inspection apparatus which concerns on 1st Embodiment is installed in the water supply nozzle part. The block diagram of the inspection apparatus which concerns on 2nd Embodiment. Schematic diagram of a reactor pressure vessel.

  Embodiments of a reactor pressure vessel inspection device and inspection method according to the present invention will be described below with reference to the drawings.

[First Embodiment]
An inspection device for a reactor pressure vessel according to the first embodiment will be described with reference to FIGS. 1, 2 and 4.
In addition, in the present embodiment, an example of performing a flaw detection inspection of a narrow portion near the corner 2a of the water supply nozzle 2 as an inspection target portion will be described, but it is needless to say that the present invention can be applied to other internal reactor structures.

(overall structure)
FIG. 4 is a configuration diagram of the reactor pressure vessel 1 including the water supply nozzle 2 to be inspected, which is arranged on the reactor core 5 and the inner circumference of the reactor pressure vessel 1 and connected to the water supply nozzle 2 via a thermal sleeve 18. A reactor internal structure including a water supply sparger 3, a CS pipe (core spray pipe) 4 and the like, and an inspection device 10 are illustrated.
During the inspection work, the reactor pressure vessel 1 is filled with water, and the steam dryer, steam separator, and the like provided on the upper part of the core 5 are removed.

  When performing the inspection work of the water supply nozzle 2, the inspection device 10 is located near the water supply nozzle 2 inside the reactor pressure vessel 1 from the operating floor above the reactor pressure vessel 1 by a remote control device including an overhead crane. Suspended and moved (not shown).

(Inspection device)
As shown in FIG. 1, the inspection device 10 includes a linear arm 12, a drive unit 13 that moves the arm 12 back and forth or rotates by, for example, electromagnetic force, and a surface of an inspection target portion by ultrasonic waves, eddy currents, and the like. The flaw detection probe 11 for inspecting the presence or absence of a defect, the bending arm 12a connected to the tip of the arm 12 and the flaw detection probe 11 and having a predetermined bending degree, the base plate 14 attached to the drive unit 13, and the base plate 14 It is composed of a pair of attached gripping fixing portions 15a and 15b.
The grip fixing portions 15a and 15b have a pair of grip portions 16a and 16b that are opened and closed by an electric motor or the like, respectively.

  The arm 12 is removably attached to the drive unit 13, and is configured to be replaceable with an arm equipped with another inspection tool or an arm equipped with a repair tool described later. When the arm is replaced with another arm, the replacement operation is performed by a remote operation device (not shown) while the inspection device 10 is suspended in the reactor pressure vessel 1.

Further, as the front-back movement and rotation driving means of the arm 12, in addition to the driving means using electromagnetic force, a driving means using an electric motor, hydraulic pressure, or the like, or a driving means using a telescopic telescope or the like that can be expanded and contracted is used. ..
Further, the flaw detection probe 11 may be provided with a sensor for measuring a distance from the inspection flaw detection surface, and the position state of the flaw detection probe 11 may be confirmed.

(Action)
When non-destructively inspecting the narrow portion where the thermal sleeve 18 is arranged in the vicinity of the corner portion 2a of the water supply nozzle 2 by using the inspection device 10 of the present embodiment, first, the reactor is operated by a remote control device (not shown). The inspection device 10 suspended and held in water in the pressure vessel 1 is brought close to the water supply nozzle 2.
Next, the inspection device 10 is positioned so that the flaw detection probe 11 attached to the tip of the curved arm 12a is located at the corner 2a of the water supply nozzle 2.

  At that time, as shown in FIG. 1, the grip portions 16a and 16b of the gripping and fixing portions 15a and 15b approach the CS pipe 4 arranged below the water supply sparger 3 in the open state, and then, as shown in FIG. As shown, the grip portions 16a and 16b are closed to grip the CS pipe 4. As a result, the inspection device 10 is firmly fixed to the CS pipe 4.

Next, the arm 12 is moved back and forth in the axial direction by the drive unit 13, and the flaw detection probe 11 is set in the narrow portion of the corner portion 2 a of the water supply nozzle 2.
Then, when the arm 12 is rotated by the drive unit 13 in this state, the flaw detection probe 11 turns, and the non-destructive inspection of the peripheral surface of the narrow portion near the corner 2a is performed.

  At that time, since the flaw detection probe 11 is connected to the arm 12 by a bending arm 12a having a predetermined bending degree so that the flaw detection probe 11 can rotate and move along the peripheral surface of the narrow portion, the arm 12 is rotationally driven. As a result, the flaw detection probe 11 can be moved along the peripheral surface of the narrow portion of the corner 2a, whereby the flaw inspection of the narrow portion can be performed in a short time.

(effect)
According to the present embodiment, by providing the bending arm 12a having a predetermined bending degree at the tip of the arm 12, it is possible to move the arm 12 back and forth or rotationally drive it to narrow the vicinity of the corner 2a of the water supply nozzle 2. Non-destructive inspection around the entire circumference of the section can be performed in a short time.

  Further, since the arm 12 and the drive unit 13 are detachable, it is possible to replace only the arm 12 in a state in which the grip fixing portions 15a and 15b are gripped and fixed to the CS pipe 4. It can be easily replaced with an arm 12 having a different flaw detection probe 11.

[Second Embodiment]
An inspection device 20 for a reactor pressure vessel according to the second embodiment will be described with reference to FIG.
In the second embodiment, as shown in FIG. 3, in the inspection device 20, two curved arms 12a and 12b to which flaw detection probes 11a and 11b are attached respectively face the arm 12 by approximately 180 degrees. Is provided.

  Since the arm 12 is detachably attached to the drive unit 13, when the arm 12 having the single curved arm 12a is attached to the drive unit 13, the arm 12 is detached from the drive unit 13 and the second main arm is attached. The arm 12 having the two flaw detection probes 11a and 11b of the above embodiment is mounted on the drive unit 13. The attachment / detachment work of the arm 12 is performed by a remote device (not shown).

Further, the two bending arms 12a and 12b may be independently operable by the drive unit 13 by using an appropriate drive mechanism.
According to the present embodiment, by using the two curved arms 12a and 12b to which the flaw detection probes 11a and 11b are attached, the flaw detection inspection time can be shortened and the efficiency can be improved.

  Further, since the arm 12 and the drive unit 13 are configured to be detachable, by exchanging with the arm 12 having a flaw detection probe of a different type or shape depending on the installation location and shape of the flaw detection target, flaw detection work can be performed. It is possible to shorten and improve efficiency.

  The flaw detection probe 11 may be attached to one of the two curved arms 12a and 12b, and the repair tool described later may be attached to the other. As a result, flaw detection and repair work can be performed simultaneously.

[Third Embodiment]
When a repair work such as polishing is required as a result of the flaw detection inspection, the arm 13 for repair work, which has a repair tool such as a brush attached to the tip thereof, can be attached to the drive unit 13.

Thus, once the inspection device 10 is once installed at a predetermined position in the reactor pressure vessel 1, it is not necessary to repeat the positioning work by simply replacing the inspection and repair work arms 12 as appropriate. Since repair work can be performed, the inspection and repair work can be shortened and efficiency can be improved.
Although some embodiments of the present invention have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention.

  For example, in the above embodiment, an example of performing flaw detection on a narrow portion in the vicinity of the water supply nozzle in the reactor pressure vessel has been described, but it is not necessarily limited to the narrow portion, and the inner peripheral surface of the reactor pressure vessel and the piping in the reactor are described. It can be applied to the outer peripheral surface and the like, and can also be applied to nondestructive inspection of structures in other technical fields.

  Further, these novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and the scope equivalent thereto.

  DESCRIPTION OF SYMBOLS 1 ... Reactor pressure vessel, 2 ... Water supply nozzle, 2a ... Corner part, 3 ... Water supply sparger, 4 ... CS piping (core spray piping), 5 ... Reactor core 10, 20 ... Inspection device, 11, 11a, 11b ... Flaw detection probe, 12 ... Arm, 12a, 12b ... Curved arm, 13 ... Drive part, 14 ... Base plate, 15, 15a, 15b ... Grip fixing part, 16a, 16b ... Grip part, 18 ... Thermal sleeve

Claims (6)

A flaw detection probe for performing nondestructive inspection of an inspection target portion of a reactor pressure vessel, a linear arm, a drive unit for moving the arm back and forth or rotating, a base plate provided on the drive unit, and the base plate. In a device for inspecting a reactor pressure vessel, which is provided, and has a grip fixing portion that grips the core spray pipe arranged in the vicinity of the inspection target portion,
An inspection apparatus for a reactor pressure vessel, wherein a tip portion of the arm and the flaw detection probe are connected by a bending arm having a predetermined bending degree, and the arm is detachably attached to the drive unit.   The inspection device for a reactor pressure vessel according to claim 1, wherein the inspection target portion is a water supply nozzle of the reactor pressure vessel.   The inspection device for a reactor pressure vessel according to claim 1 or 2, wherein a plurality of the curved arms are provided at the distal end portions of the arms so as to be spaced apart from each other.   The inspection device for a reactor pressure vessel according to claim 3, wherein a flaw detection probe is attached to one of the plurality of curved arms, and a repair tool is attached to the other curved arm.   The reactor pressure vessel inspection device according to any one of claims 1 to 3, wherein an arm provided with a repair tool is attached to the drive unit instead of the arm provided with the flaw detection probe.   Using the inspection device according to any one of claims 1 to 5, the water supply nozzle corner of the reactor pressure vessel is gripped and fixed to the core spray pipe arranged in the reactor pressure vessel by the gripping and fixing portion of the inspection device. A method for inspecting a reactor pressure vessel, which comprises inspecting the internal parts.

Images