JPH0672055U - Inspection device for reactor pressure vessel - Google Patents

Abstract

(57) [Summary] [Purpose] To improve the reliability of flaw detection inspection by making it possible to continuously measure the installation dimensions of the running track along the longitudinal direction of the track. According to the inspection device 10 of the present invention, a base plate 6 is movably supported on a running track 4 installed along the circumferential welding line 2a of the reactor pressure vessel 1 on the inner circumference of a metal heat insulating material 3. The probe modules 8a, 8b for extending the base plate 6 in a direction orthogonal to the running track 4 to support the flaw detection arm 7 so that the flaw detection arm 7 can reciprocate, and for performing flaw detection inspection of the welded portion 2a at the upper and lower ends of the flaw detection arm 7. Is provided. Particularly, in the present invention, the probe modules 8a and 8b are replaced with the measurement sensor modules 11a and 11b and run along the running track 4, so that the space between the pressure vessel 1 and the track 4 can be obtained before the flaw inspection. L can be measured.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an inspection device for a reactor pressure vessel (RPV: Reactor Pressure Vessel).

[0002]

[Prior art]

 Generally, in an in-service inspection (ISI: In-service Inspection) of a reactor pressure vessel (hereinafter referred to as “RPV”), an inspection device 5 is installed on the outer periphery of the RPV 1 as shown in FIG. The inspection device 5 is inspected for defects such as "scratches" and "cracks" in the welded portions 2a and 2b while running along the welding line.

FIG. 3 and FIG. 4 show an example of an inspection device used for such in-service inspection (hereinafter referred to as “ISI”). The inspection device 5 for ISI is for performing a flaw inspection on the circumferential welded portion 2a of the RPV trunk device 1a, and is guided by a running track 4 installed along the circumferential direction on the outer peripheral side of the trunk device 1a in advance. To do. That is, a running track 4 is provided along the circumferential direction on the inner peripheral side of the metal heat insulating material 3 surrounding the body device 1a, and a base plate 6 is movably supported on the running track 4. The base plate 6 supports a flaw detection arm 7 that extends in a direction orthogonal to the traveling track 4 (hence, in a direction orthogonal to the welding line). The welded portion 2a is ultrasonically flaw-detected at both upper and lower ends of the flaw detection arm 7. The probe modules 8a and 8b for carrying out are mounted.

The probe modules 8a and 8b emit ultrasonic waves (pulse waves) at a predetermined incident angle θ within the wall thickness of the body device 1a, and in the unlikely event of a "flaw" or a "crack" in the welded portion 2a. Receives reflected echoes from equal defects.

Therefore, according to the inspection device 5, the flaw detection arm 7 is moved up and down while the base plate 6 is traveling along the traveling track 4, so that the circumferential welding portion 2a of the body device 1a is connected to the module 8a. It is possible to scan in the longitudinal direction and the depth direction (thickness direction) by ultrasonic waves from 8b, and it is possible to inspect for a defect in the welded portion 2a over a predetermined inspection volume range (oblique angle flaw detection).

[0006]

[Problems to be solved by the device]

 By the way, if a defect is detected in the flaw detection inspection as described above, the location of the defect must be specified from the position of the probe modules 8a and 8b at that time. In this case, if the traveling track 4 supporting the inspection device 5 is not installed to the trunk device 1a according to the design value, the positions of the probe modules 8a and 8b, and by extension, the detection position of the defective portion are detected. Will result in an error.

In order to eliminate such an error, conventionally, the distance between the body device 1a and the track 4 and the inclination angle of the track 4 are measured at the time of construction using a tape measure or the like. In the measurement by, the reliability of the measurement data is inferior, which causes the reliability of the flaw detection inspection result to be reduced. In addition, the installation dimension measurement of the running track 4 as described above cannot be performed over the entire track because it can be measured only in a place where humans can access, and in this respect also, the reliability of flaw inspection is still improved. There was room for.

An object of the present invention is to provide an inspection device for a reactor pressure vessel capable of continuously and automatically measuring the installation dimension of a running track along the longitudinal direction of the track and thereby improving the reliability of flaw detection inspection. To do.

[0009]

[Means for Solving the Problems]

 In order to achieve the above object, the inspection apparatus according to the present invention supports a base plate movably supported on a running track installed along the welding line on the outer peripheral side of the reactor pressure vessel, and the base plate supports the running track and the running track. The flaw detection arm is supported by extending in the orthogonal direction, and the flaw detection arm is provided with a probe module for flaw detection inspection of the welded part of the pressure vessel and a measurement sensor module for measuring the distance between the pressure vessel and the orbit. It is provided so that it can be replaced.

[0010]

[Action]

 According to the above configuration, by replacing the existing probe module with the measurement sensor module, it is possible to measure the track installation dimension by the measurement sensor module before the flaw inspection by the probe module. In other words, if the base plate is run along the running track with the measurement sensor module mounted on the flaw detection arm, the distance from the outer circumference of the pressure vessel to the running track is continuously and automatically measured along the longitudinal direction of the track. Can be measured at.

[0011]

【Example】

 Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

In FIG. 1, reference numeral 1a denotes a body device of a reactor pressure vessel (RPV) 1, and a cylindrical metal heat insulating material 3 is erected on the outer peripheral side of the body device 1a at a predetermined interval. There is. On the inner peripheral side of the metal heat insulating material 3, a ring-shaped running track 4 is installed along the circumferential welding portion 2a of the body device 1a. The running track 4 is used for flaw inspection of the welding portion 2a. The inspection device 10 is supported.

This inspection apparatus 10 has a base plate 6 capable of traveling along a traveling track 4 as in the conventional case, and a flaw detection arm 7 extending in a direction orthogonal to the traveling track 4, that is, a vertical direction is supported on the base plate 6. Has been done. The flaw detection arm 7 is supported by the base plate 6 so as to be capable of reciprocating in the upward and downward directions.

In the inspection apparatus 10 of the present embodiment, existing probe modules 8a and 8b (see FIG. 3) are provided on both upper and lower ends of the flaw detection arm 7 for flaw detection of the welded portion 2a of the body device 1a. , RPV 1 and measurement sensor modules 11a and 11b for measuring the distance L between the tracks 4 are exchangeably mounted.

As shown in FIG. 2, each of the measurement sensor modules 11a and 11b has a substantially bottomed cylindrical casing 12, in which a measurement plate 13 is reciprocally incorporated. A pair of brackets 14, 14 extending through the opening 12a of the casing 12 is formed on the front side of the measuring plate 13 so as to project therefrom, and a roller 15 is rotatably supported between the brackets 14, 14. . Guide rollers 16 are supported on the outer peripheral edge of the measuring plate 13 at intervals in the circumferential direction, and the guide rollers 16 enable the measuring plate 13 to smoothly reciprocate in the casing 12.

On the back side of the measurement plate 13, a measurement ultrasonic probe 17 for detecting the amount of movement of the plate 13 is further incorporated. The ultrasonic probe 17 for measurement is inserted and supported substantially at the center of a probe support plate 18 fitted in the casing 12, and the distance to the back surface of the measurement plate 13 can be detected.

A substantially cylindrical expandable bellows 19 is stretched between the probe support plate 18 and the measurement plate 13. The expandable bellows 19 is provided concentrically with the support plate 18 and the plate 13, and defines a water chamber 20 on the inner peripheral side. Water injected into the casing 12 from the water supply port 21 is further supplied to the water chamber 20 through the communication hole 18a of the probe support plate 18. Further, the water that cannot be completely contained in the water chamber 20 is discharged to the outside of the casing 12 through the drain port 22.

In FIG. 1, reference numerals 23, 24, and 25 denote an ultrasonic flaw detector, a controller, and a pen chart recorder, which are attached to the inspection apparatus 10, respectively. .

Next, the operation of this embodiment will be described.

When the RPV 1 and the metal heat insulating material 3 are constructed during the construction of the nuclear power plant, the running track 4 is installed on the inner peripheral side of the metal heat insulating material 3, and the inspection device 10 is set on the running track 4. Measure the installation dimensions of track 4. At this time, the measurement sensor modules 11a and 11b are mounted on the flaw detection arm 7 of the inspection apparatus 10, and the modules 11a and 11b are connected to hoses (not shown) to inject water. As shown in FIG. 2, the water injected into the measurement sensor modules 11a and 11b passes through the communication hole 18a of the flaw detector support plate 18 and enters the telescopic bellows 19, which causes the measurement ultrasonic probe. 17 is immersed in water. When the water pressure in the expandable bellows 19 increases, the measuring plate 13 advances forward and the roller 15 comes into contact with the outer peripheral surface of the body device 1a.

When such work is completed, the inspection device 10 is caused to travel along the running track 4 by the operation of the controller 24. Then, the change in the distance between the body device 1a and the track 4 is detected by the measurement sensor modules 11a and 11b at any time. That is, in each of the measurement sensor modules 11a and 11b, the measurement plate 13 reciprocates according to the change in the distance between the body device 1a and the track 4, and the path length of the ultrasonic wave from the measurement ultrasonic probe 17 is changed. Change. Here, the ultrasonic probe for measurement 17 transmits ultrasonic waves toward the measurement plate 13 at predetermined time intervals and receives the reflection echo from the back surface of the measurement plate 13, and at any time, the echo height is increased. Besides, the distance to the outer peripheral surface of the body device 1a can be detected.

The detection data from the measurement sensor modules 11a and 11b are taken into the pen chart recorder 25 via the corresponding ultrasonic flaw detectors 23 and 23 as shown in FIG. The pen chart recorder 25 also receives the position data from the controller 24, and the above detection data is plotted on the recording paper together with the position data. That is, on the recording paper of the pen chart recorder 25, the intervals between the outer circumference of the body device 1a and the flaw detection arm 7 at two positions above and below the circumferential welding portion 2a are continuous along the circumferential direction of the body device 1a. By reading the waveform on this recording paper, it is possible to know the distance L between the RPV 1 and the running track 4 as well as the installation dimensions such as the inclination angle (tilt angle) of the running track 4 and thus the amount of twist. You can

As described above, according to the present embodiment, the measurement sensor modules 11a and 11b are attached in place of the existing probe modules 8a and 8b, so that the RPV 1 and the track 4 are connected before the flaw inspection. It is possible to automatically and continuously measure the installation dimensions such as the distance between and the inclination angle of the track 4. Normally, when constructing a nuclear power plant, the running track 4 is installed independently of the RPV 1. Therefore, it is very difficult to install the running track 4 accurately, and some installation error occurs. In this respect, the conventional manual measurement of the installation dimension was inferior in reliability of the measurement data because the measurement points were limited. However, in this embodiment, since the installation dimensions of the traveling track 4 can be continuously and automatically measured, the positions of the probe modules 8a and 8b can be accurately determined by considering the data measured in advance in the flaw inspection. It is possible to grasp and to know the defect occurrence site with high accuracy in case of defect detection.

Further, according to the present embodiment, the installation dimension of the traveling track 4 can be measured only by replacing the existing flaw detection modules 8a and 8b with the measurement sensor modules 11a and 11b. Is extremely easy. Moreover, since it is possible to confirm that the inspection device 10 can travel simultaneously with the measurement of the installation dimension of the traveling track 4, it is possible to smoothly carry out the flaw detection inspection thereafter.

Further, according to the present embodiment, the measurement plate 13 is displaced according to the change in the distance between the RPV 1 and the track 4, and the displacement amount of the measurement plate 13 is immersed in water. Since it is detected by No. 17, the measurement can be performed in the same manner as the vertical flaw detection of the normal water immersion method. For this reason, it is possible to perform measurement using an existing device (ultrasonic flaw detector 23 or the like) without newly equipping an additional device dedicated to the measurement sensor modules 11a and 11b.

In the above embodiment, the inspection device 10 of the type in which the pair of flaw detection modules 8a and 8a are mounted on the flaw detection arm 7 has been described, but a single flaw detection module can be reciprocated in the flaw detection arm 7. You may apply to what is mounted on. In this case, a single measurement sensor module is mounted, but by moving this measurement sensor module up and down while moving the outer circumference of the RPV 1 in the circumferential direction, the installation dimension of the traveling track 4 can be measured in the same manner as described above. . Further, although the inspection device 10 for the circumferential welding portion 2a of the RPV 1 has been described, it may be applied to the inspection device for the longitudinal welding portion 2b shown in FIG.

[0027]

[Effect of device]

 In short, according to the present invention, since the installation dimension of the running track can be measured prior to the flaw detection inspection, the reliability of the flaw detection inspection can be improved.

[Brief description of drawings]

FIG. 1 is a schematic view showing an embodiment of an inspection apparatus for a reactor pressure vessel according to the present invention.

FIG. 2 is a cross-sectional view showing a schematic configuration of a measurement sensor module applied to a reactor pressure vessel inspection device.

FIG. 3 is a schematic diagram showing an example of a conventional reactor pressure vessel inspection device.

FIG. 4 is a view on arrow AA of FIG.

FIG. 5 is a diagram showing a usage state of a reactor pressure vessel inspection device.

[Explanation of symbols]

 1 Reactor Pressure Vessel 1a Body Device 2a Circumferential Weld Section 4 Trajectory 6 Base Plate 7 Flaw Detection Arms 8a, 8b Probe Module 10 Inspection Device 11a, 11b Measurement Sensor Module 12 Casing 13 Measurement Plate 17 Ultrasonic Probe for Measurement 18 Probe Support Plate 19 Telescopic Bellows 20 Water Chamber

Claims (2)

[Scope of utility model registration request] 1. A base plate is movably supported on a traveling orbit installed along the welding line on the outer peripheral side of a reactor pressure vessel, and the flaw detection arm is extended to the base plate in a direction orthogonal to the traveling orbit. Inspection of a reactor pressure vessel, which is supported, and in which the probe arm for performing flaw inspection of the welded portion of the pressure vessel and the measurement sensor module for measuring the distance between the pressure vessel and the orbit are exchangeably provided on the flaw detection arm. apparatus. 2. The measurement sensor module comprises a casing having a substantially bottomed cylindrical shape, a measurement plate that reciprocates in the casing according to the distance between the pressure vessel and the orbit, and a measurement plate on the back side of the measurement plate. The reactor pressure vessel inspection device according to claim 1, further comprising: an ultrasonic probe that is provided in a submerged state to detect the amount of movement of the plate.