JPS62151792A - Full automatic type control-rod abrasion inspection system - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a fully automatic control rod wear inspection system that is applied to wear detection and remaining life diagnosis of control rods in, for example, a PWR nuclear reactor.

[Conventional technology]

Generally, in a nuclear reactor, control rods are used to control nuclear reactions and neutron flux distribution, but it is known that these control rods wear out with long-term use. However, in conventional inspections, confirmation of the integrity of control rods relies on visual inspection using underwater television, and all inspection processes are performed manually by inspection personnel. (The control rods used in nuclear reactors are radioactive and are handled in shielding water.

) [Problems to be Solved by the Invention] Therefore, since conventional visual inspection is performed using an underwater television, there are the following problems.

(1) The total amount of wear from the start of use of the control rod, the amount of progress of wear over a specific period of use, and the shape of these wear (rod cross section and rod axis length direction) can only be grasped qualitatively.

(2) The control rods have a cluster-type structure, with a total of 16~
It consists of 24 rods, but inspection is difficult because the center is a blind spot for the outer control rods.

(3) All inspections are performed manually, and when a suspicious subject appears, the inspection is repeated many times, which takes a long time.

(4) Inspection records consist only of videotapes and sketches by inspectors, making it impossible to record and store quantitative data, which poses problems in terms of quality control.

1” (5) Since quantitative wear data cannot be obtained, it is impossible to estimate the remaining life.

In addition, commercially available differential transformer type displacement meters and commercially available strain gauge type displacement meters can only perform partial calibration of the outermost rod of the control rod cluster assembly, and it is impossible to perform a full inspection of the central rod. .

The present invention was made to solve the above-mentioned problems, and its purpose is to qualitatively and quantitatively measure the amount of wear and wear shape of control rods with high accuracy, fully automatically, and to It is an object of the present invention to provide a highly reliable fully automatic control rod wear inspection system capable of continuously performing inspections in a short period of time, determining the health of control rods, and diagnosing their lifespan.

[Means for solving problems]

In order to achieve the above object, the present invention inspects a control rod assembly in which a plurality of elongated control rods are assembled in a cluster via a cross member, and in which the control rods are individually inserted at the same time. A plurality of cross-sectional deformation detection sensors are arranged to measure the wear condition of the control rod, an amplifier amplifies the individual signals from each cross-sectional deformation detection sensor, and converts the output signal from the amplifier into a digital signal. an arithmetic device comprising an interface section, a computer that performs predetermined wear measurement processing on signals from the interface section, and a CRT that displays the processing results of this computer, and the detection sensor is characterized in that a differential transformer type sensor is disposed within a cylindrical body and a movable magnetic core is operated via a leaf spring type contact plate.

[Effect]

In the fully automatic control rod wear inspection system configured as described above, wear conditions are surveyed over the entire control rod using multiple cross-sectional deformation detection sensors, and each sensor signal is amplified by an amplifier and then converted to a digital signal by an interface. The computer of the arithmetic unit performs software processing, and the results are displayed on the CRT.

〔Example〕

An embodiment of the present invention shown in the drawings will be described below.

FIG. 1 shows an example of the configuration of a fully automatic control rod wear inspection system according to the present invention. In other words, the fully automatic control rod wear inspection system of this embodiment includes a plurality of small differential transformer type sensors 1 arranged around the control rod and individual signals from each of the small differential transformer type sensors 1. It has a built-in amplifier unit (amplifier) 2 to amplify, a strain gauge type sensor 3 placed around the control rod, a scanner, a converter, and an interface to capture the output signal from the amplifier unit 2 and convert it into a digital signal. A personal computer 50 that performs a predetermined wear measurement process on the casing 4 and the signals from the casing 4. (A floppy disk 60 for storing the processing results of the personal computer 50, M/4-sonal computer 50
The system is comprised of an arithmetic unit comprising a CRT 70° for displaying the processing results at the personal computer 5o and a printer 8o for recording the processing results at the personal computer 5o, and a lifting device 9° for raising and lowering the control rod. .

In a fully automatic control rod wear inspection system with such a configuration, the amount of wear is surveyed over the entire length of the control rod using a plurality of small differential transformer type sensors 1 arranged around the control rod, and each small differential transformer Individual signals from the type sensor 1 are amplified by an amplifier unit 2, then converted into digital signals by a converter taken in by a scanner, and subjected to software processing by a motherboard computer 50 via an interface. The data processed by the personal computer 50t'(7) is stored on the floppy disk 60, the amount of wear in the axial direction is displayed on the CRT 70, and the state of wear is drawn on the printer 80.

In addition, if a more detailed cross-sectional wear inspection is required, the inspection area is automatically selected and the inspection area is commanded to the control rod cluster lifting device 90. After automatic positioning is performed, the control rod The detailed cross-sectional wear shape of the control rod is measured by rotating one strain gauge type sensor 3 installed around the control rod. Then, it is converted into a digital signal by the converter in the housing 4, and then sent through the interface to the 2
- After software processing is performed on the personal computer 50, it is stored on the floppy disk 60 and transferred to the CRT 70.
The detailed cross-sectional wear shape of the K control rod is displayed, and the printer 8
0 shows the cross-sectional wear shape of the control rod.

Next, the details of each of the above-mentioned components will be explained.

(,) Small differential transformer type sensor 1 The small differential transformer type sensor 1 has a contact hole 6 as shown in Fig. 2.
, a movable magnetic core, a sensor 8 , a spring base 9 , and a sensor guide 10 . That is, the plurality of ultra-small contact springs 6 installed around the control rod are constantly brought into contact with the control rod by the spring force of the main body.

The movable magnetic core 7 is fixed to the contact spring 6 at its end, and if the control rod is worn, the contact spring 6 and the movable magnetic core 7 simultaneously move in the left-right direction. Since a voltage is applied to the sensor 8 in advance to form a magnetic field, the movable magnetic core 7
It outputs a voltage that changes by moving from side to side. Furthermore, the contact spring 6 and the sensor 8 are fixed by spring pads, and a sensor guide 10 is provided to protect the contact spring 6 from the control rod.

(b) Differential) lance type sensor unit As shown in Figure 3, the sensor unit has a contact pin 6 and a movable magnetic core 7.
, a sensor 8 , a spring pace 9 , a sensor guide 10 , and a tube guide 11 . That is, the tube guide 11 is made of a soft material to prevent damage to the control rod when it is moved up and down. Further, the spring base 9 has a plurality of contact springs 6, movable magnetic cores 7, and sensors 8 fixed around the control rod. moreover,
The sensor guides 10 are installed above and below to protect the contact springs 6.

(c) Strain dart type sensor 3 As shown in FIG. 4, the strain gauge type sensor 3 includes a strain sensor 3, a stepping motor 12, and a first gear 13.
, a second gear 14, a shell 1-5, a cylinder body 16, and a cylinder piston 17.

In other words, the strain sensor 3 installed around the control rod is constantly brought into contact with the control rod by the spring force of the main body, and even if the control rod is worn, the strain sensor 3 is constantly in contact with the surface of the control rod. I'm letting you do it. Further, the rotation of the strain sensor 3 is achieved by transmitting the rotational driving force of the stepping motor 12 to the shell 15 via the first gear 13 and the second gear 14. Rotate at the same time to go around the control rod surface.

On the other hand, in order to fix the control rod when measuring the amount of wear on the control rod surface, a cylinder body 16 is installed at two locations on the top and bottom of the control rod.
The control rod is fixed by moving the cylinder piston 17 using water pressure (pneumatic pressure, oil pressure, etc. can also be used).

(d) Sensor drive mechanism As shown in FIG. 5, the strain gauge type sensor drive section includes a cylinder main body 16, a cylinder screw 717, a stepping motor 18 for vertically moving the sensor, a lifting screw 19, and a female screw 20. , a guide rod 21, a strain sensor 3, a stepping motor 12 for rotating the sensor, and a first gear 1.
3, a shell 15, a second gear 14, and an external box 22. In other words, after setting the control rod to an arbitrary height, in order to fix the control rod when measuring the amount of wear on the control right surface, a cylinder body 16 is installed at two locations above and below the control rod, and water pressure (pneumatic pressure, The control rod is fixed by moving the cylinder piston 17 using force (also possible with hydraulic pressure, etc.).

Further, after the control rod is fixed, the strain sensor 3 can be raised and lowered independently so that the amount of wear near the top and bottom of the strain sensor 3 can be measured in detail.

The strain sensor 3 is raised and lowered by rotating the raising and lowering screw 19 by a stepping motor 18 for moving the sensor up and down, which is received by a fixed female screw 20 to raise and lower the strain sensor 3. Note that the guide rod 21 is used to assist the strain sensor 3 so that it becomes vertical when going up and down.

Further, the rotation of the strain sensor 3 is achieved by transmitting the rotational driving force of the stepping motor 12 for sensor rotation to the shell 15 via the first gear 13 and the second gear 14, and the strain sensor fixed to the shell 15. - Rotate at the same time as 3 to go around the surface of the control rod. In addition, when measuring multiple control rods at the same time, the first gear 13 and the @2 gear 14
It is also possible to rotate other sensors at the same time. Furthermore, these components are housed in an external box 2 and an inner circle 2, and can be used underwater.

(,) Functional integrated storage container As shown in FIG. 6, the functional integrated storage container includes a lifting aid 23, a pace plate 24, a guide frame 25, a guide hole 26, and a differential transformer type measurement Bo.
x 27, signal cable 28, and air tube 29
, strain sensor type measurement box 30, and signal cable 3
1 and an air hose 32. That is,
The functionally integrated storage container is moved by a lifting device (not shown) using lifting eye bolts 23, and the pace plate 24 is placed on a rack in an existing spent fuel pit. Further, the control rod cluster is lifted and lowered and positioned using an existing handling device, and when installed on the functional integrated storage container, it is guided by a guide frame 25 and final positioning is performed by a guide hole 26.

On the other hand, a survey inspection of the general wear status of the control rod cluster is performed using a differential transformer type measurement box, and the measurement is transmitted to the CPU via the signal cable 28 for signal processing. Further, in order to prevent water from entering the differential transformer type measurement box 27, internal pressure can be applied using the air tube 29 as necessary.

If a more detailed inspection of the cross-sectional wear shape is required, detailed measurement is performed using the strain sensor type measurement box 30, and the signal is transmitted to the CPU via the signal cable 31 for signal processing. Additionally, an air hose 32 is installed as a power source for fixing the upper and lower parts of the subject during measurement.

(f) Sensor output signal processing circuit As shown in FIG. 7, the sensor output signal processing circuit includes a differential transformer deafness sensor unit 39 and an amplifier unit 2.
, the cable 51, the scanner 41, the converter 42, the two-axis signal 43, the interface 44, and the! - sonal computer 5, floppy disk 6, CR
T7(!:, It is specifically composed of a printer 8, an XY plotter 45, a strain gauge sensor unit 46, a cable 47, an N1 converter 48, and an interface 49.

That is, the sensor unit 39 is an ultra-small differential transformer type sensor, and detects voltage changes in the degree of magnetic coupling from changes in the positions of the primary coil, secondary coil, and movable magnetic core. A plurality of sensors (24 in the illustrated example) are installed around the specimen, and signals are detected simultaneously from each sensor.

The sensor units 39 can be installed in accordance with the number of specimens having multiple tubes (four sensor units in the example shown in FIG. 7). Further, the amplifier unit 2 amplifies the output voltage signal output from the sensor unit 39 and transmits the output voltage signal through the cable 51 to the scanner 4.
After the output signals are arranged in step 1, they are converted into digital signals by an A/l) converter 42 and input to an interface 44. Further, a signal indicating the height position of the specimen is also input to the interface 44 at the same time, and then processed by the personal computer 5 and stored on the floppy disk 6. The data organized through signal processing is displayed in an arbitrary format on the CRT 7, and necessary data is recorded on the printer 8. In addition, figures and the like are drawn and recorded using the X-Y roller 45.

On the other hand, the strain dart sensor unit 46 is a small strain gauge type sensor, and a Wheatstone bridge circuit is built into the sensor body, and a change in resistance value caused by strain in the sensor is detected as a voltage change. One sensor is installed around the control rod, and the sensor is rotated to measure the cross-sectional wear shape. It is also possible to install multiple sensor units 46 according to the number of control rods (seventh sensor unit 46).
In the example shown, there are 4 sensor units).

Further, the output voltage signal output from the sensor unit 46 is transmitted via a cable 47, converted into a digital signal by an N1 converter 48, and inputted to an interface 49.
A personal computer 5 processes the signals and records them on a floppy disk 6. The data organized through signal processing is displayed in an arbitrary format on the CRT 7, and necessary data is recorded on the printer 8. Also, the figures are X-Y
Let f-lotter 45 draw and record.

(g) Functional logic of the fully automatic system The functional logic of the fully automatic system, as shown in FIG. It consists of a comparison 37 with the progress prediction program and a lifespan display 38 of the subject.

In other words, in the wear inspection of the control rod cluster, a survey inspection 33 of the general wear condition of the rod to be inspected is performed using a differential transformer type sensor, and if a more detailed inspection of the cross-sectional wear shape is required, a detailed inspection part command is sent. Then, the control rod cluster lifting device performs automatic positioning 34 to the inspection site.

In the detailed inspection 35, a detailed cross-sectional wear shape is inspected using a strain gauge type sensor. In addition to this, automatic positioning and detailed inspection are performed in sequence according to the instructions of the inspection part each time, as necessary for the detailed inspection 35. On the other hand, the inspection data is instantaneously processed and the survey inspection results of the general wear status of the rod to be inspected as well as the detailed inspection results of any part are displayed on the CRT.
It is possible to display and plot on a plotter. In addition, when the wear inspection is completed, the life progress prediction program is instantly compared with the measured data37, and the life of the test object is displayed38.As mentioned above, in the fully automatic control rod wear inspection system configured in this embodiment, The following effects can be obtained.

(1) The total length of all the rods that make up the control rod cluster assembly, as well as the amount of wear and wear shape at any cross section, can be determined remotely and fully automatically underwater under high radiation conditions, allowing for quantitative determination of wear. This allows for highly accurate measurement and shortening of inspection time.

(2) By processing the results of general survey inspections using software within a computer, it is possible to automatically select the areas that require detailed inspections and then conduct detailed inspections continuously. , detailed data for rod health determination can be automatically collected.

(3) It is possible to instantly determine the health of the object and diagnose its lifespan.

The present invention can be similarly applied to an apparatus for inspecting external surface wear and pre-life diagnosis for small-diameter pipes and round bars, or an apparatus for inspecting inner surface wear and thinning of pipes and diagnosing pre-life for medium-sized pipes. be.

〔Effect of the invention〕

As explained above, according to the present invention, in an apparatus for inspecting a control rod assembly in which a plurality of elongated control rods are assembled in a cluster via a spider member, the control rods can be inserted simultaneously separately. a plurality of cross-sectional deformation detection sensors arranged in the control rod to measure the wear state of the control rods, an amplifier that amplifies the individual signals from each cross-sectional deformation detection sensor, and an interface section that converts the output signal from the amplifier into a digital signal. , a computer that performs predetermined wear measurement processing on the signal from this interface section, and a C that displays the processing results of this computer.
and an arithmetic unit equipped with an RT, and the detection sensor has a configuration in which a differential/auxiliary transformer type sensor is arranged in a cylindrical body and a movable magnetic core is operated via a leaf spring type contact plate. Therefore, in addition to qualitatively and quantitatively measuring the wear amount and wear shape of control rods with high precision in a fully automatic manner, □゛ Detailed inspections are performed continuously and in a short period of time to determine the health of control rods. A highly reliable fully automatic control rod wear inspection system capable of diagnosing life can be provided.

[Brief explanation of drawings]

FIG. 1 is an overall configuration diagram showing one embodiment of the present invention, FIG. 2 is a configuration diagram showing details of a differential transformer type sensor in the same embodiment, and FIG. 3 is a differential transformer type sensor unit in the same embodiment. Fig. 4 shows the strain r in the same example.
- A configuration diagram showing the details of the di-type sensor, FIG. 5 is a diagram showing the sensor drive mechanism in the same embodiment, FIG. 6 is a configuration diagram showing the functional integrated storage container in the same embodiment, and FIG. 7 is a diagram showing the same implementation. FIG. 8 is a diagram showing the specific configuration of the sensor output signal processing circuit in the example, and is a functional logic diagram showing the processing contents in the example. l... Small differential transformer type sensor, 2... Amplifier unit, 3... Distortion dirge type sensor, 4... Housing, 50... Personal computer, 60... Floppy disk, 70... ...CRT, 80...Printer, 90...Elevating device. Applicant Sub-Agent Patent Attorney Takehiko Suzue Figure 4 Figure 6

Claims (1)

[Claims] When inspecting a control rod assembly in which a plurality of elongated control rods are assembled in a cluster via a spider member, the control rods are arranged so that they are individually inserted at the same time, and the wear state of the control rods is measured. a plurality of cross-sectional deformation detection sensors, an amplifier that amplifies the individual signals from each cross-sectional deformation detection sensor, an interface unit that converts the output signal from the amplifier into a digital signal, and a a computer that performs a predetermined wear measurement process, and an arithmetic unit equipped with a CRT that displays the processing results of this computer, and the detection sensor is a differential transformer type sensor inside the cylindrical body. A fully automatic control rod wear inspection system characterized by a configuration in which a movable magnetic core is operated via a leaf spring type contact plate.