JPH07325183A - Dimension and shape measuring device for housing mounting part of control rod drive mechanism - Google Patents

Abstract

PURPOSE:To easily and exactly measure the inner diameter of bevel part by providing a measuring means in the groove part, detecting whether or not a device body is horizontally put on a stub tube, measuring the groove part inner diameter and monitoring and recording the measured value. CONSTITUTION:An inner diameter measuring device 10 is hung down with a hang down part 11 together with a cable 21 from a reactor pressure vessel 1 and the device 10 is gradually lowered to place at the top of a stub tube 9. At this moment, a guide for insertion 13 is inserted in the opening of tube 9, positioned and centered. When the bottom surface 14 of the device 10 touches the tube 9 top, a measuring probe 16 is positioned in J groove 9a. Simultaneously, if or not the device 10 is horizontally placed is detected with a plurality of limit switches 15 the signal is sent to monitoring/recording device 22 to monitor the placing state of the device 10. Then, the measured value of the probe 16 is processed in an operator to obtain the inner diameter data of the J groove 9a and record in the device 22.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a size and shape measuring device for a control rod drive mechanism housing installation portion in a nuclear reactor, and particularly to a control rod drive mechanism housing penetrating portion of a reactor pressure vessel and a stub attached to this penetrating portion. The present invention relates to a device for measuring the size and shape of a tube.

[0002]

2. Description of the Related Art A boiling water reactor as a light water reactor (hereinafter referred to as
It is called BWR. ), A control rod drive mechanism housing (hereinafter, referred to as CRD housing) is installed in a suspended state under the reactor pressure vessel, and the start / stop of the reactor and the reactor output are controlled in this CRD housing. A control rod drive mechanism (CRD) is provided. The CRD housing is installed on the lower mirror part of the reactor pressure vessel via a stub tube.

To install the CRD housing, a groove for attaching a stub tube is formed on the penetrating portion of the CRD housing of the reactor pressure vessel by overlay welding and subsequent forming.
The stub tube is fixed to the groove for mounting the stub tube by welding. A J-groove is formed on the top of the stub tube, and the CRD housing is inserted into the J-groove of the stub tube from below and fixed by welding to be installed.

The stub tube mounting groove formed in the penetrating portion of the CRD housing of the reactor pressure vessel is formed along the inclined surface of the lower mirror portion of the reactor pressure vessel. Although the groove on the reactor pressure vessel (lower) side of the stub tube is molded to match this groove for mounting the stub tube, the groove on the lower side of the stub tube is the actual groove for mounting the stub tube. Since it is formed in conformity with the designed stub tube attachment groove, a gap may occur at the groove alignment portion and a mismatch may occur.

On the other hand, a J groove is formed at the top of the stub tube, and a CRD housing is welded to this J groove (J welding).
Although it is installed in the CRD housing J
In welding, the J-groove size of the stub tube and the size and shape after welding were measured and confirmed by a gauge.

[0006]

As described above, the stub tube is welded to the CRD housing penetrating portion of the reactor pressure vessel, and when the CRD housing is inserted from below into the J groove of this stub tube, welding is performed. , It is necessary for welding to measure the J-groove dimension of the stub tube. Since this dimension measurement allows workers to access the site before the reactor operation,
It is easy to measure with a gauge such as a caliper or a micrometer, but after the operation, the reactor water is stored in the reactor pressure vessel and the radiation dose in the reactor is high, so it is not possible for workers to approach. It is possible and cannot be measured.

Therefore, it is necessary to measure the size and shape of the groove for mounting the stub tube formed on the penetrating portion of the CRD housing of the reactor pressure vessel and the inclined surface of the lower mirror portion, and the size and shape of the J groove at the top of the stub tube. Need to be done remotely.

The present invention has been made in consideration of the above circumstances, and remotely measures the inner diameter dimension and the inner surface welding shape of the penetration portion of the control rod drive mechanism housing of the reactor pressure vessel and the stub tube attached to this penetration portion. An object of the present invention is to provide a size / shape measuring device for a control rod drive mechanism housing installation part that can perform work.

[0009]

In order to solve the above-mentioned problems, according to claim 1 of the present invention, the control rod drive mechanism housing is welded and fixed by being suspended from the upper portion of the reactor pressure vessel by a suspending member. The measuring device main body is positioned on the stub tube, and the measuring device main body is formed on the top part of the stub tube and a detecting means for detecting whether the device main body is horizontally mounted on the stub tube. It is characterized in that it is provided with a measuring means for measuring the inner diameter of the groove portion and a monitoring / recording means for monitoring / recording the measurement value of the measuring means.

According to a second aspect of the present invention, instead of the suspending member for suspending the measuring apparatus main body from the upper portion of the reactor pressure vessel according to the first aspect, the measuring apparatus main body is inserted from below the penetrating portion of the reactor pressure vessel. It is characterized by attaching the support shaft of.

A third aspect of the present invention is characterized in that the measuring means according to the first or second aspect includes a plurality of measuring rollers and a spring for urging the rollers in the outer diameter direction.

A fourth aspect of the invention is characterized in that the detecting means and the measuring means according to the first or second aspect are constructed in a watertight structure.

According to a fifth aspect of the present invention, the measuring means is inserted into the through portion of the reactor pressure vessel from below to measure the inner diameter of the reactor pressure vessel, the observing means for observing the measurement site of the through portion by the measuring means, and the measuring means. The display means for displaying the measurement result from, the operating shaft for operating the vertical movement and rotation of the measuring means, and the vertical position and the circumferential position of the measuring means are fixed based on the scale engraved on the operating shaft. Fixing means for

According to a sixth aspect of the present invention, the stub tube is inserted into the stub tube for welding and fixing the control rod drive mechanism housing through the penetrating portion of the reactor pressure vessel, and the measuring means for measuring the inner diameter dimension and shape thereof, and the stub tube by the measuring means. An observation means for observing a measurement site inside, a vertical drive means for vertically moving the measurement means, a rotation drive means for rotationally driving the measurement means, and a recording means for recording a measurement result by the measurement means. It is characterized by

[0015]

According to the first aspect of the present invention, the measuring device main body is suspended from the upper portion of the reactor pressure vessel by the suspending member, and when the measuring device body comes into contact with the top of the stub tube, the measuring means is positioned in the groove. The detection means detects whether or not the device body is horizontally placed on the stub tube, the inner diameter of the groove is measured by the measurement means, and the measurement value of the measurement means is monitored by the recording means. By recording, it is possible to easily and accurately measure the inner diameter of the groove at the top of the stub tube even if reactor water is stored in the reactor pressure vessel. The quantity is reduced.

According to a second aspect of the present invention, instead of the suspending member for suspending the measuring apparatus body from the upper portion of the reactor pressure vessel according to the first aspect, the measuring apparatus body is inserted from below the penetrating portion of the reactor pressure vessel. By attaching the support shaft for this, the operability can be improved as compared with the first aspect.

In a third aspect of the present invention, the measuring means of the first or second aspect has a plurality of measuring rollers and a spring for urging the rollers in the outer diameter direction, so that the measuring means contacts the surface to be measured. In doing so, the force is absorbed by the elastic force of the spring, so that no unreasonable force acts on the tip of the measuring means.

In the fourth aspect, since the detecting means and the measuring means of the first or second aspect are constructed in a watertight structure, it is possible to perform remote measurement in water.

In the fifth aspect, while observing the measurement portion of the penetrating portion by the observation means, the measurement position is confirmed,
The vertical position and the circumferential position of the measuring means are fixed by the fixing means based on the scale engraved on the operating shaft for operating the measuring means. To measure the inner diameter,
It is possible to accurately measure the inner diameter of the penetrating portion.

In the sixth aspect, the measuring means is inserted from below the penetrating portion of the reactor pressure vessel, and while observing the inside of the stub tube by the observing means, the shape and inner diameter of the stub tube are measured by the measuring means. Simple and accurate measurement can be performed. Further, by rotating the measuring means by the rotation driving means and moving it up and down by the vertical driving means, it is possible to extremely accurately measure the shape and size at each position in the circumferential direction and the vertical direction within the stub tube.

[0021]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 4 is a block diagram showing the lower structure of a boiling water reactor. As shown in FIG. 4, the BWR comprises a reactor pressure vessel 1, which is supported on its support pedestal 2 via a support skirt 3. In the lower part (lower mirror) of the reactor pressure vessel 1, a large number of control rod drive mechanisms (CRD) 4 for inserting and pulling out control rods from the core of the BWR are vertically installed.

CRD housing 5 of control rod drive mechanism 4
Is welded to the lower mirror of the reactor pressure vessel 1 and stainless steel is used for the CRD housing 5. Further, in order to display the output of the reactor and evaluate the burnup, the neutron flux generated in the core of the reactor is detected and monitored by the neutron flux detector 6.

FIG. 1 is a sectional view showing a first embodiment of a size / shape measuring device for a control rod drive mechanism housing installation portion according to the present invention. In this first embodiment, the J on the top of the stub tube is used.
1 shows an example of a groove inner diameter dimension measuring device.

In FIG. 1, a build-up portion 7 is formed by welding on the lower mirror portion of the reactor pressure vessel 1 and is mirror-finished. CRD housing penetration part 1 of reactor pressure vessel 1
The stub tube 9 is welded to the inclined portion of a by the welding portion 8. At the top of the stub tube 9, there is a J groove 9a.
The CRD housing 5 is inserted into the J groove 9a of the stub tube 9 from below and fixed by welding.

The inner diameter dimension of the J groove 9a on the top of the stub tube 9 is measured by an inner diameter dimension measuring device 10 as a measuring device body. A receiving metal fitting 12 to which the lowering member 11 is connected, an insertion guide 13 formed in a substantially inverted conical shape with a diameter reduced toward a lower end, a flange 14 formed to project in a radial direction, and a circumference of the flange 14. A plurality of limit switches 15 are arranged at predetermined intervals in the direction and detect whether or not the measuring device 10 is horizontally placed on the top of the stub tube 9, and the inner diameter of the J groove 9a. Stylus 1 as measuring means for measuring
6 and. In addition, when the inner diameter dimension measuring apparatus 10 is used in water, the limit switch 15 needs to have a watertight structure.

As shown in FIG. 2, the tracing stylus 16 has two to four measuring rollers 17 provided at a predetermined interval in the circumferential direction, and a spring 18 for urging the measuring rollers 17 in the outer diameter direction. A measuring device 19 for measuring the amount of displacement of the moving stroke of the measuring roller 17, and a seal member 20 for making the measuring device 19 a watertight structure.

When the bottom surface of the flange 14 of the inner diameter dimension measuring device 10 is brought into horizontal contact with the top of the stub tube 9, the probe 1
The positional relationship between the limit switch 15 and the probe 16 is set so that the probe 6 is positioned in the J groove 9a, and the measurement value of the probe 16 is passed through the cable 21 which is an underwater specification with good insulation. The monitoring / recording device 22 installed on the operation floor (not shown) can monitor or record. Also, the inner diameter measurement device 1
In the vicinity of 0, the measuring work light 23 and the measuring device 1
A monitor camera 24 for observing 0 is arranged, and when the light 23 and the monitor camera 24 are used underwater, it is necessary to have a watertight structure.

Next, the operation of this embodiment will be described.

When the reactor water 1b is contained in the reactor pressure vessel 1, the CRD housing penetrating portion 1a of the reactor pressure vessel 1 is surrounded by a cylindrical seal pipe 25, and the lower end of the seal pipe 25 is By sealing the bottom of the reactor pressure vessel 1 with the seal packing 26, the stub tube 9 is replaced with a partial space (in the air) formed in the reactor pressure vessel 1. Here, as a backup of the seal pipe 25, a closure plug 27 may be fitted from below to the CRD housing penetrating portion 1a of the reactor pressure vessel 1 as shown in FIG.

To replace the stub tube 9,
It is necessary to measure the inner diameter dimension of the J groove 9a at the top of the stub tube 9. In this case, the inner diameter dimension measuring device 10 is suspended from the upper portion of the reactor pressure vessel 1 together with the cable 21 by the suspending member 11, and gradually the inner diameter dimension measuring device 1 is suspended.
0 is dropped and installed on the top of the stub tube 9. Here, the inner diameter dimension measuring device 10 is provided on the top of the stub tube 9.
When installing, the insertion guide 13 is inserted into the opening of the stub tube 9 for positioning and centering, and when the bottom surface of the flange 14 of the inner diameter dimension measuring device 10 abuts on the top of the stub tube 9. , The probe 16 is J
It is positioned in the groove 9a.

At the same time, a plurality of limit switches 15 detect whether or not the inner diameter measuring device 10 is horizontally mounted, and the detection signal is sent to the monitoring / recording device 22 installed on the operation floor. The monitoring / recording device 22 monitors the installation state of the measuring device 10. The inner diameter dimension measuring device 10 is observed by the monitor camera 24.
Then, the moving stroke displacement amount of the measuring roller 17 is detected by the measuring device 19 of the tracing stylus 16, and the detection signal is processed through a cable 21 by an arithmetic unit (not shown) such as a computer installed on the operation floor. The J groove 9a at the top of the stub tube 9
The inner diameter dimension data of is obtained. This inner diameter dimension data is monitored and recorded by the monitoring / recording device 22 installed on the operation floor.
Will be recorded at.

As described above, according to this embodiment, the inside diameter measuring apparatus 10 is suspended from the upper portion of the reactor pressure vessel 1 by the suspending member 11, and when contacted with the top of the stub tube 9, the probe 16 Is positioned in the J groove 9a, and the limit switch 15 detects whether or not the measuring device 10 is horizontally placed on the stub tube 9, and the inner diameter dimension of the J groove 9a is measured by the probe 16. This probe 16
By monitoring / recording the measured value of 2 by the monitoring / recording device 22, the inner diameter of the J groove 9a at the top of the stub tube 9 can be simply and accurately measured even if the reactor water 1b is stored in the reactor pressure vessel 1. In addition, because of the remote measurement, the radiation dose of the worker is reduced.

Further, since the limit switch 15 and the probe 16 have a watertight structure and the cable 21 has an underwater specification, remote measurement in water is possible.

Further, the tracing stylus 16 is provided with 2 to 4 measuring rollers 17 at predetermined intervals in the circumferential direction of the flange 14, and the measuring rollers 17 are urged by a spring 18 in the outer diameter direction. Therefore, when the tracing stylus 16 comes into contact with the surface to be measured, the force is absorbed by the elastic force of the spring 18, so that an unreasonable force does not act on the tip of the tracing stylus 16.

FIG. 3 is a cross-sectional view showing a modification of the first embodiment of the control rod drive mechanism housing installation portion size / shape measuring device according to the present invention. The same or corresponding portions as those of the first embodiment will be described using the same reference numerals. The same applies to the following examples.

In this modified example, the inner diameter measuring device 10a is inserted from below the stub tube 9 and the stub tube 9 is inserted.
The inner diameter of the J groove 9a at the top is measured. That is, in this inner diameter dimension measuring device 10a, a supporting shaft 28 is attached to the flange 14 instead of the hanging member 11 and the receiving metal fitting 12 of the first embodiment, and by raising the supporting shaft 28, The flange 14 abuts on the J groove 9a of the stub tube 9, and the tracing stylus 16 is positioned in the J groove 9a.

A plurality of limit switches 15 detect whether or not the inner diameter measuring device 10a is positioned horizontally, and monitor / install on the operation floor.
After confirming with the recording device 22, the measuring device 19 of the tracing stylus 16
The inner diameter dimension of the J groove 9a at the top of the stub tube 9 is grasped by.

According to this modification, the inner diameter dimension measuring device 1
0a is inserted from below the stub tube 9 to measure the inner diameter dimension of the J groove 9a at the top of the stub tube 9, so that the operability can be improved as compared with the first embodiment.
The rest of the configuration and operation are similar to those of the first embodiment, so description thereof will be omitted.

FIG. 5 is a sectional view showing a second embodiment of a size / shape measuring device for a control rod drive mechanism housing installation portion according to the present invention. In this second embodiment, the C of the reactor pressure vessel 1 is
1 shows an example of an inner diameter dimension measuring device for measuring an inner diameter dimension of an RD housing penetrating portion 1a.

As shown in FIG. 5, the inner diameter dimension measuring device 30
Is a face-matching jig 31 fixed to the lower surfaces of a plurality of CRD housings 5, and an operating shaft which is inserted through the face-matching jig 31 and has scale marks engraved for aligning the vertical position and the circumferential position. 32 and this operation shaft 3
2 is attached to the upper part of the reactor pressure vessel 1
Observation for observing the measuring part of the CRD housing penetrating part 1a, which is inserted from below into the penetrating part 1a of the CRD housing as a measuring means for measuring the inner diameter dimension thereof and is installed above the measuring part 33. A camera 34 with a light as means, a fixed plate 35 for positioning the operation shaft 32 in the vertical direction, and a set screw 36 for fixing the operation shaft 32 to the fixed plate 35 so as not to rotate.
And a counter 37 as display means for displaying the measurement result from the measuring tool 33. Then, the fixing plate 35
The set screw 36 has a function as a fixing means for fixing the vertical position and the circumferential position of the measuring tool 33.

In the measuring tool 33, as shown in FIG. 6, an electric 3-point micrometer is used as the measuring element 38,
CRD of the measuring tool 33 manually via the operation shaft 32
When the housing penetrating portion 1a is rotated once, a radial displacement amount of the stylus 38 in the radial direction due to the rotation is detected, and the detection signal is processed by an arithmetic device (not shown) such as a computer. Thus, the inner diameter dimension data of the CRD housing penetrating portion 1a is obtained, and this inner diameter dimension data is displayed on the counter 37.

Next, the operation of this embodiment will be described.

The measuring tool 33 is inserted from below the CRD housing penetrating portion 1a of the reactor pressure vessel 1, the face-to-face jigs 31 are fixed to the lower surfaces of the plurality of CRD housings 5, and then the camera 34 with a light penetrates. While observing the measurement portion of the portion 1a, the range L that is the reference dimension of the penetrating portion 1a
So that the measuring tool 33 is arranged on the operating shaft 32, the vertical position of the measuring tool 33 is positioned by the fixing plate 35 based on the scale scale engraved on the operation shaft 32, and the set screw 36
Fixed by.

Then, at that position, the measuring tool 33 is manually rotated once around the CRD housing penetrating portion 1a, and the radial displacement amount of the probe 38 in the radial direction due to the rotation is detected. By performing signal processing with an arithmetic device (not shown) such as a computer, inner diameter dimension data of the CRD housing penetrating portion 1a is obtained, and this inner diameter dimension data is displayed on the counter 37.

As described above, according to this embodiment, the measuring tool 33 is inserted from below the CRD housing penetrating portion 1a, and the CR
After fixing the face-to-face jig 31 to the lower surface of the D housing 5, while observing the measurement site of the CRD housing penetrating portion 1a with the camera with light 34, the measurement position is confirmed, and the vertical direction of the measuring tool 33. The position and the circumferential position are fixed by a fixing plate 35 based on a scale scale engraved on the operation shaft 32 for operating the measuring tool 33, and the position in the vertical direction and the circumferential direction by a probe 38 of an electric 3-point micrometer. Since the inner diameter is measured while corresponding to
It is possible to accurately measure the inner diameter of the D housing penetrating portion 1a. The rest of the configuration and operation are similar to those of the first embodiment, so description thereof will be omitted.

FIG. 7 is a sectional view showing a third embodiment of a size / shape measuring apparatus for a control rod drive mechanism housing installation portion according to the present invention. In the third embodiment, the C of the reactor pressure vessel 1 is
The measuring device provides measurement data to the grinder side in order to smooth the surface of the welded portion after welding the stub tube 9 to the RD housing penetrating portion 1a.
The measurement items by this measuring device are the shape measurement of the inner diameter and the inner surface of the stub tube 9.

As shown in FIG. 7, the measuring device 40 includes a support plate 4 attached to the lower surfaces of a plurality of CRD housings 5.
1, a long operating shaft 42 which is erected at a substantially central portion of the support plate 41 and has a high straightness, and the operating shaft 4
2, a centering mechanism 43 that is attached to the upper part of the operation shaft 42 to prevent the CRD housing penetrating portion 1a of the operation shaft 42 from being displaced with respect to the axis, and a measurement that measures the inner diameter and inner surface shape of the stub tube 9 that is installed at the upper end of the operation shaft 42. A digital dial gauge 44 as a means, and a camera with light 45 as an observing means installed above the dial gauge 44 and observing a measurement site such as the weld 8 on the inner surface of the stub tube 9 are provided.

A turntable 46 with a ratchet is provided on the lower surface of the support plate 41 of the measuring device 40. The turntable 46 positions the dial gauge 44 in the rotational direction via the operation shaft 42. The operation shaft 42 is rotated by driving a rotation motor 47 as a rotation driving means, and its rotational position is detected by the rotation direction position detection encoder 48, while the vertical movement of the operation shaft 42 is performed as a vertical driving means. By driving the vertical drive motor 49 of
The vertical position is detected by the vertical position detection encoder 50. These rotation and vertical movements are operated by operation signals sent from the control panel 51.

Further, the shape of the dial gauge 44
The measurement result of the dimension is led to the control computer 53 and the recorder 54 as a recording means through the converter 52. The position measured by the dial gauge 44 is observed by the camera 45 with a light, and this image is displayed on the monitor television 55 so that it can be monitored, and a video is taken if necessary.

Next, the operation of this embodiment will be described.

The measuring device 40 is inserted from below the CRD housing penetrating portion 1a of the reactor pressure vessel 1, and the supporting plate 41 is attached to the lower surface of the plurality of CRD housings 5. Then, the centering mechanism 43 is arranged in the CRD housing penetrating portion 1a, and the deviation of the operation shaft 42 from the axis is prevented. Then, while observing the welded portion 8 of the stub tube 9 with the camera with light 45, the uneven shape of the surface of the welded portion 8 is measured with the dial gauge 44.

In this case, the turntable 4 with a ratchet
6, the dial gauge 44 is positioned in the rotational direction via the operation shaft 42, and an operation signal is sent from the control panel 51 to drive the vertical drive motor 49 and measure the vertical shape of the surface of the welded portion 8. To do. Then, the rotation motor 47 is driven to rotate the operation shaft 42 about 10 degrees in the circumferential direction, and the vertical shape is measured by the dial gauge 44 while driving the vertical driving motor 49 in the same manner as described above.
On the other hand, when measuring the inner diameter of the stub tube 9, the operation shaft 42 is rotated in the circumferential direction, and the inner diameter dimension is measured by the dial gauge 44. The measurement signals of these shapes and inner diameters are guided to the control computer 53 and the recorder 54 through the converter 52, and the operator can confirm the inner surface shape and the inner diameter of the stub tube 9 by the recorder 54.

As described above, according to the present embodiment, the measuring device 40 is inserted from below the CRD housing penetrating portion 1a of the reactor pressure vessel 1, the supporting plate 41 is attached to the lower surfaces of the plurality of CRD housings 5, and the centering is performed. The mechanism 43 prevents the axial center of the operation shaft 42 from shifting, and the camera 45 with a light
By observing the surface of the welded portion 8 of the stub tube 9 and measuring the shape and inner diameter of the surface of the welded portion 8 with the dial gauge 44, a simple and accurate measurement can be performed.

Further, according to this embodiment, the operating shaft 42 of the measuring device 40 is rotated by the rotating motor 47, and its rotational position is detected by the rotational direction position detecting encoder 48, so that the operating shaft 42 is moved up and down. By vertically moving by 49 and detecting the vertical position by the vertical position detection encoder 50, the shape and size at each position in the circumferential direction and the vertical direction in the stub tube 9 can be measured extremely accurately. The rest of the configuration and operation are similar to those of the first embodiment, so description thereof will be omitted.

[0056]

As described above, according to the first aspect of the present invention.
According to the above, the measuring device main body is suspended from the upper part of the reactor pressure vessel by the suspending member, and when the measuring device is brought into contact with the top part of the stub tube, the measuring means is positioned in the groove part, and the device main body is horizontally placed on the stub tube. By detecting whether or not it has been placed by the detecting means, measuring the inner diameter of the groove portion by the measuring means, and monitoring and recording the measured value of this measuring means by the monitoring / recording means, the reactor pressure vessel Even if the reactor water is stored in the stub tube, the inner diameter of the groove at the top of the stub tube can be easily and accurately measured, and the radiation dose to the worker is reduced because of remote measurement.

According to claim 2, instead of the suspending member for suspending the measuring device main body from the upper portion of the reactor pressure container according to claim 1, the measuring device main body is inserted from below the penetrating portion of the reactor pressure container. By attaching the support shaft for this, the operability can be improved as compared with the first aspect.

According to claim 3, the measuring means of claim 1 or 2 has a plurality of measuring rollers and a spring for urging the rollers in the outer diameter direction. When the contact is made, the force is absorbed by the elastic force of the spring, so that an unreasonable force does not act on the tip of the measuring means and the durability can be improved.

According to the fourth aspect, since the detecting means and the measuring means according to the first or second aspect are constructed in a watertight structure, remote measurement in water becomes possible and versatility is enhanced.

According to the fifth aspect, while observing the measurement portion of the penetrating portion with the observation means, the measurement position is confirmed, and the vertical position and the circumferential position of the measurement means are set on the operation shaft for operating the measurement means. The inner diameter of the penetrating portion is fixed by the fixing means based on the engraved scale, and the inner diameter of the penetrating portion is measured by the measuring means in correspondence with the position in the vertical direction and the circumferential direction. Can be measured accurately.

According to the sixth aspect, the measuring means is inserted from below the penetrating portion of the reactor pressure vessel, and while observing the inside of the stub tube by the observing means, its shape and inner diameter can be measured by the measuring means. In addition to the effect of claim 1,
Simple and accurate measurement can be performed. Further, by rotating the measuring means by the rotation driving means and moving it up and down by the vertical driving means, it is possible to extremely accurately measure the shape and size at each position in the circumferential direction and the vertical direction within the stub tube.

[Brief description of drawings]

FIG. 1 is a sectional view showing a first embodiment of a size / shape measuring device for a control rod drive mechanism housing installation part according to the present invention.

FIG. 2 is a cross-sectional view of an essential part showing the internal structure of the probe shown in FIG.

FIG. 3 is a cross-sectional view showing a modified example of the first embodiment of the dimension / shape measuring apparatus for the control rod drive mechanism housing installation section according to the present invention.

FIG. 4 is a configuration diagram showing a lower structure of a boiling water reactor.

FIG. 5 is a cross-sectional view showing a second embodiment of a size / shape measuring device for a control rod drive mechanism housing installation part according to the present invention.

6 is a plan view showing the measuring tool of FIG. 5. FIG.

FIG. 7 is a sectional view showing a third embodiment of a size / shape measuring device for a control rod drive mechanism housing installation part according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Reactor pressure vessel 1a CRD housing penetration part 4 Control rod drive mechanism (CRD) 5 CRD housing 8 Welding part 9 Stub tube 9a J groove 10 Internal diameter measurement device (measurement device main body) 11 Suspension member 13 Insertion guide 14 Flange 15 Limit switch (detecting means) 16 Measuring element (measuring means) 17 Measuring roller 18 Spring 19 Measuring instrument 22 Monitoring / recording device (monitoring / recording device) 28 Support shaft 30 Inner diameter dimension measuring device 32 Operation shaft 33 Measuring tool ( Measuring means 34 Camera with light (observation means) 35 Fixing plate (fixing means) 36 Set screw (fixing means) 37 Counter (display means) 40 Measuring device 42 Operation shaft 43 Centering mechanism 44 Dial gauge 45 Camera with light (observation) Means) 47 Rotation Motor 47 (Rotation Driving Means ) 48 rotation direction position detection encoder 49 vertical drive motor (vertical drive means) 50 vertical position detection encoder 51 control panel 54 recorder (recording means) 55 monitor TV

Claims (6)

[Claims] 1. A measuring device main body, which is suspended from an upper portion of a reactor pressure vessel by a suspending member and is positioned on a stub tube for welding and fixing a control rod drive mechanism housing. Detecting means for detecting whether the device body is horizontally placed on the stub tube, measuring means for measuring the inner diameter of the groove formed on the top of the stub tube, and the measured value of this measuring means. A dimension / shape measuring device for a control rod drive mechanism housing installation part, which is provided with a monitoring / recording means for monitoring / recording. 2. A support shaft for inserting the measuring device main body from below the penetrating portion of the reactor pressure container is attached instead of the suspending member for suspending the measuring device main body from the upper portion of the reactor pressure container. The size and shape measuring device for a control rod drive mechanism housing installation portion according to claim 1. 3. The control rod drive mechanism housing installation portion according to claim 1 or 2, wherein the measuring means has a plurality of measuring rollers and a spring for urging the rollers in an outer diameter direction. Dimension / shape measuring device. 4. The size / shape measuring device for a control rod drive mechanism housing installation part according to claim 1 or 2, wherein the detecting means and the measuring means are constructed in a watertight structure. 5. A measuring means which is inserted from below into a penetrating portion of a reactor pressure vessel to measure an inner diameter dimension thereof, an observing means for observing a measurement site of the penetrating portion by the measuring means, and a measurement from the measuring means. Display means for displaying the result, operating shaft for operating the vertical movement and rotation of the measuring means, and fixing means for fixing the vertical position and circumferential position of the measuring means based on the scale engraved on the operating shaft. A control rod drive mechanism housing installation portion size / shape measuring device characterized by including. 6. A measuring means inserted into a stub tube for welding and fixing a control rod drive mechanism housing through a penetrating portion of a reactor pressure vessel, and measuring means for measuring an inner diameter dimension and shape of the stub tube, and measurement in the stub tube by the measuring means. Observing means for observing the part, vertical drive means for moving the measuring means up and down, rotation drive means for rotationally driving the measuring means,
A control rod drive mechanism housing installation portion size / shape measuring device comprising: recording means for recording a measurement result by the measuring means.