JPH09318302A - Shape measurement device for reactor internal structure in nuclear reactor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely and safely measure shape and size of a reactor internal structure in a nuclear reactor by providing an elongated frame clamped to a sample member with a length measurement device, a waviness measurement device and a with measurement device, for allowing remote control. SOLUTION: At a bottom part of a main body frame 20, a contact member 25 for clamping is provided, and a buffle board contact confirming sensor 27 is provided on its upper surface, and two clamp cylinders 29 are provided on further upper part. A magne-scale 31 is so provided as to be interlocked with the cylinder 29, and, in corporation with a clamp mechanism and the sensor 27, a measurement device is constituted. When a moving carriage 45 is moved vertically by a lifting motor 41, a magne-scale 51 moves in accordance with the surface of a core waffle board 5, and if there is a rough which constitutes waviness, its height is measured corresponding to a position in vertical direction due to a moving amount detector 47. Then, two range sensor detects a range by detecting a reflection ultrasonic wave, and when there is a difference between measured ranges, change in width is measured.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for remotely measuring the shape and size of a mechanical structure, and more particularly to the length of an internal structure such as a core baffle plate of a pressurized water reactor,
The present invention relates to a shape measuring device suitable for measuring waviness and width of a surface.

[0002]

2. Description of the Related Art A fuel assembly loaded in a reactor vessel is generally a vertically long structure having a rectangular cross section. The outer peripheral flat cross section of a core formed by arranging a plurality of these fuel cells adjacent to each other has a stepped shape. These are surrounded by an in-core structure including a plate-shaped member called a core baffle plate. An example of a pressurized water reactor will be described with reference to FIGS. 3 and 4. Below a lower reactor core plate 1 and a lower reactor core support plate 3 are provided below a reactor core 1 which is hung and supported in a reactor vessel (not shown). Are installed in a lateral direction. A plurality of fuel assemblies 4 are loaded on the lower core plate 2 to form a core, and a core baffle plate 5 facing and surrounding the outer peripheral surface of the core baffle plate 5 is provided on the inner surface of the core tank 1 via a horizontal mounting plate 6. It is fixed. FIG. 4 shows only the assembly of the core baffle plate 5 and the mounting plate 6, but as can be seen, the core baffle plate 5 is constructed by combining a plurality of flat plates as shown in the drawing, and the whole circle of the core is formed. It has a structure that surrounds the circumference.

[0003]

Since the core baffle plate as described above is close to the fuel assembly of the core which is a heat generating source, it is affected by heat and further receives radiation emitted from the core. For this reason, the core baffle plate is easily deformed, but if it is deformed too much, the dimension between the core baffle plate and the core changes, which may cause various problems. Therefore, it is required to accurately measure the change in the shape and size of the core baffle plate. However, the in-core structure including this kind of core baffle plate is radioactive after the start of the operation of the reactor, and therefore the inspector cannot directly approach and inspect it. As described above, an apparatus for remotely measuring the shape and size of a core structure such as a core baffle plate has been conventionally demanded, but the present invention measures the shape of a reactor internal structure corresponding to such needs. It is an object to provide a device.

[0004]

In order to solve such a problem, according to the present invention, a shape measuring device for the internal structure of a nuclear reactor is provided in a vertically long frame having a suspender at its upper portion and the frame. The length measuring device comprises a length measuring device, a waviness measuring device and a width measuring device, and the length measuring device is a clamp cylinder provided on the frame so as to extend and contract in the longitudinal direction, a first magnescale interlocking with the clamp cylinder and the It has a contact sensor provided at the tip of the frame,
The waviness measuring device is a carriage that moves in the longitudinal direction along the frame, a second magnescale that is provided on the front surface of the carriage and is pressed against a portion to be measured, and a movement amount that is fixed and fixed to the carriage and moves together. And the width detector has a plurality of pairs of ultrasonic sensors vertically arranged along both sides of the frame.

[0005]

Embodiments of the present invention will be described below with reference to the accompanying drawings. In FIG. 1, a vertically long main body frame 20 has a substantially U-shaped flat cross section, and a suspender 23 is erected on a top plate 21 thereof. This suspending tool 23 is used when suspended by a crane or the like for performing measurement. A clamp pad 25 is provided so as to project from the lower end of the main body frame 20, a baffle plate contact confirmation sensor 27 is provided on the upper surface thereof, and two clamp cylinders 29 are provided on the upper portion. The clamp cylinder 29 and the abutting member 25 are used for fixing the main body frame 20 to the core baffle plate 5 indicated by the chain double-dashed line at the time of measurement, but also have the function of both-end rulers for length measurement. A magnet scale 31, which is a measuring instrument, is provided so as to interlock with the clamp cylinder 29, and this cooperates with the above-mentioned clamp mechanism and sensor 27 to form a length measuring device. That is, it is confirmed from the output of the sensor 27 that the contact member 25 is in contact with the lower end surface of the core baffle plate 5, and the reading of the magnescale 31 interlocked with the clamp cylinder 29 that contacts the upper end surface of the main body frame 20 is performed remotely. The vertical length of the core baffle plate 5 can be measured by obtaining the core baffle plate 5. A backing plate 33 is disposed on the upper and lower portions of the front surface of the main body frame 20, and is abutted against the core side surface of the core baffle plate 5 during the above-mentioned mounting, so that the main body frame 20
To ensure the correct measurement posture.

An elevating motor 41 is attached to the lower surface of the top plate 21, and a carriage or a moving carriage 45 is attached to an elevating chain 43 wound around a sprocket of its output shaft. 2 on the inner surface of the body frame 20 on the opposite side.
The guide rails 35 are provided so as to extend in the vertical direction, and the guides at both ends of the moving carriage 45 are slidably fitted. That is, when the elevating motor 41 drives the elevating chain 43 to move in the vertical direction, the moving carriage 45 is guided by the guide rails 35 and moves up and down in a correct posture. Mobile trolley 4
The movement amount detector 47 fixed to the rear surface side of 5 meshes with the rack 37 provided on the main body frame 20, and the movement amount of the moving carriage 45 is detected from the number of rotations thereof. Mobile trolley 45
3 on the front side of the
One Magnescale 51 is provided, and this Magnescale 51 is pressed against the core side surface of the core baffle plate 5 during measurement. Therefore, as described above, when the moving carriage 45 is moved in the vertical direction by the lifting motor 41, the magnet scale 51 moves following the surface of the core baffle plate 5, and if there is unevenness that constitutes undulations, its height moves. It is measured corresponding to the vertical position by the quantity detector 47. That is, the waviness in the longitudinal direction is measured, and the above-mentioned members cooperate to configure the waviness measuring device 40.

Further, ultrasonic sensors 61 (only one position is shown) are arranged at six positions on the side surface of the main body frame 20 to form a width detector 60. This ultrasonic sensor 61 is
As shown in FIG. 2, it is composed of two distance sensors 63 and 65, which are connected to a distance measuring device (not shown) via cables 67 and 69. These distance sensors 6
Numerals 3 and 65 transmit ultrasonic waves as shown by the broken line, detect reflected ultrasonic waves to detect the distance, and if there is a difference in the measured distances between them, it is determined that there is a side edge of the core baffle plate, and the width Is measured. A thermometer 71 is attached at an appropriate position above and below the body frame 20 in order to measure the temperature when the above-described series of measurement work is performed.

[0008]

As described above, according to the present invention,
The length-measuring device clamped to the member to be measured is equipped with a remotely operable length measuring device, waviness measuring device, and width measuring device, so the shape and dimensions of the activated nuclear reactor internal structure can be measured safely and reliably. can do.

[Brief description of drawings]

FIG. 1 is a partially cutaway perspective view showing the entire structure of an embodiment of the present invention.

FIG. 2 is a partial plan view showing a part of the embodiment in an enlarged manner.

FIG. 3 is a partially cutaway perspective view showing an example of a reactor internal structure which is an example of an object to be measured by the shape measuring apparatus of the present invention.

FIG. 4 is a perspective view showing a part of FIG. 3 extracted.

[Explanation of symbols]

 5 Core Baffle Plate 20 Body Frame 21 Top Plate 23 Lifting Tool 25 Touching Member 27 Sensor 29 Clamp Cylinder 31 Magnescale 33 Touching Plate 35 Guide Rail 37 Rack 40 Waviness Measuring Device 41 Lifting Motor 43 Lifting Chain 45 Moving Cart 47 Moving Distance Detector 49 Spring Return Type Cylinder 51 Magnescale 60 Width Detector 61 Ultrasonic Sensor 63,65 Distance Sensor 67,69 Cable 71 Thermometer

Claims (1)

[Claims] 1. A vertically long frame having a suspender on an upper portion thereof, and a length measuring device, a waviness measuring device, and a width measuring device provided on the frame, wherein the length measuring device is extendable and contractible in a longitudinal direction. A clamp cylinder, a first magnescale interlocking with the clamp cylinder, and a contact sensor provided at the tip of the frame, wherein the waviness measuring device moves in the longitudinal direction along the frame. The carriage has a second magnescale mounted on the front surface of the carriage to be pressed against the measured portion and a movement amount detector which is fixed to the carriage and moves in conjunction with the carriage. The width detector is provided along both sides of the frame. A shape measuring apparatus for a reactor internal structure, comprising a plurality of pairs of ultrasonic sensors arranged in the vertical direction.