JPS5939274B2 - position measuring device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a position measuring device for nuclear fuel rods placed 10 to 20 meters below the water surface in a nuclear reactor or fuel storage pool in a nuclear power plant.

At nuclear power plants, fuel replacement work is performed about once a year.

In this fuel exchange work, fuel is brought in using a crane called a fuel exchange platform and taken out and put in at a predetermined location.In recent years, automatic fuel exchange equipment has been introduced for the purpose of improving work efficiency and reducing obscurity. This automatic fuel exchange device is a device that operates remotely and automatically, and the positions of the fuel rods to be handled are precisely measured in advance and stored in the electronic computer that controls platform operation or in the storage device of the control device. Before describing the conventional method for measuring the position of fuel rods, an overview of the refueling floor and refueling equipment of a nuclear power plant will first be explained.

In FIG. 1, 1 is a fuel pool, 2 is a nuclear reactor communicating with this fuel pool 1, and a position at a predetermined depth from the water surface of these fuel pool 1 and nuclear reactor 2, that is, approximately below the water surface in the reactor. The fuel assembly, which will be described later, is placed approximately 10 meters below the water surface in the fuel pool. Further, 3 is a bridge that runs on a rail 6 laid on the floor of the fuel pool 1 and the reactor 2, 4 is a trolley that runs on a rail □ laid on the bridge 3 in a direction perpendicular to the rail 6, Reference numeral 5 denotes a telescopic mast-like hoist fixed to the trolley 4 so as to hang down inside the pool or furnace. By operating the bridge 3, trolley 4, and hoist 5 in three directions, the position of the fuel gripper attached to the tip of the hoist 5 is three-dimensionally controlled. During this operation, fuel pool 1 is usually
Both reactors 2 are filled with water to just below the floor surface. FIGS. 2a and 2b schematically show the inside of the nuclear reactor 2 and the fuel pool 1, as well as some details thereof.

That is, as shown in FIG. 2a, a grid plate 16 is assembled inside the nuclear reactor 2 as shown, and a rack 17 is assembled inside the fuel pool 1 as shown. As shown in FIG. 2B, a fuel assembly 15 having a fuel handle 14 attached to its tip end is housed in each plotter assembled using the grid plate 16 and the rack 17. A fuel handle center mark 18 is attached to the fuel handles 14 of these fuel assemblies 15. On the other hand, as shown in FIG.
It is meant to be grabbed, moved and stored.

Therefore, in order to measure the position of the fuel rods on the fuel exchange floor and fuel exchange equipment of such a nuclear power plant, it is necessary to move the hoist 5 as shown in Fig. 3b before loading the fuel rods for the first time. Instead of attaching the fuel grip 10 to the tip, a jig 13 for measuring the position of the fuel assembly 15 is attached to the center of the fuel handle 14 or, if there is no fuel assembly 15, to the grid plate 16 inside the reactor 2. At the top, a panel with scale marks is placed on the upper end of the rack 17 in the fuel pool 1.

Then, manually operate the bridge 3, trolley 4, and hoist 5 so that the needle at the tip of the measuring jig 13 coincides with the center of the fuel handle 14 on this panel. , the position of the trolley 4 is set on the bridge 3 with reference to the position measurement origin 8 set on the floor in advance.
, the values indicated by the shaft encoder attached to the trolley 4 are read as X and Y coordinate values. However, in the above-mentioned fuel rod position measurement method, in a nuclear power plant before fuel is loaded, a person measuring the position can easily get down on the grid plate or fuel rack inside the reactor before filling the reactor and fuel pool with water. Precise position measurement is possible, but in a nuclear power plant that has started operation, the above-mentioned measurement is impossible and position measurement cannot be easily performed.

The present invention was made in view of the above-mentioned circumstances, and its purpose is to provide a nuclear power plant located at a predetermined depth below the water surface in the reactor or fuel storage pool of a nuclear power plant, where it is difficult to directly measure the position. It is an object of the present invention to provide a position measuring device that can accurately measure the position of a fuel assembly regardless of whether or not a nuclear power plant is already in operation.

An embodiment of the present invention will be described below with reference to the drawings. Fourth
The figure shows an example of a system configuration of a nuclear fuel rod position measuring device according to the present invention.

That is, in FIG. 4, reference numeral 12 indicates a camera head and an image pickup tube, and the camera head and image pickup tube 12, as shown in FIG. Instead of the tool 13, it is attached to the tip of the hoist 5 via a camera head support 11, and converts optical information obtained through a lens into an electrical signal. The outputs of the camera head and image pickup tube 12 are applied to a video monitor control device 22 through an amplifier 21, and the outputs of this control device 22 are applied to a video monitor 19 and to a position detector 23 for an optical receiver. When the light pen 20 is directed to a predetermined location on the image displayed on the video monitor 19, the optical receiver position detector 23 converts the signal from the light pen 20 into an X, Y orthogonal detector with the center of the video monitor 19 as the origin. This signal is converted into a coordinate axis voltage output signal, and this signal is applied to the video monitor arithmetic processing unit 24 through the A/D converter 25. On the other hand, 28 is the fuel handle 1
4 is an operator console for detecting the position of the tip in the depth direction; 29 is a bridge shaft encoder; 30 is an encoder for measuring the trolley position; both encoders 29
, 30 to output distance signals from each position measurement origin 8. Reference numeral 31 denotes a hoist shaft encoder, and this hoist shaft encoder 31 determines the Z-direction position of the tip of the lens in the camera head (for example, by selecting the indicated value of the hoist shaft encoder 31 when the mast is completely retracted as a reference value). It is used to detect the The output signals of the operator console 28, the bridge shaft encoder 29, the trolley position measurement encoder 30, and the hoist shaft encoder 31 are transmitted to the computer input/output control device 3.
2 to the computer central processing control unit 33, respectively. Further, the output of the hoist shaft encoder 31 is applied to the arithmetic processing device 24 mentioned above. This arithmetic processing device 24 outputs a digital signal added from the above-mentioned A/D converter 25 as a distance deviation signal based on the output signal of the hoist shaft encoder 31, and this signal is sent to the electronic computer through the input/output control device 32. It is added to the central processing control unit 33. This electronic computer central processing control unit 33 performs arithmetic processing on the basis of each of the above-mentioned signals, and adds the results of the calculation to the storage device 34 of the electronic computer. Next, the operation of the position measuring device configured as described above will be described. First, the camera head and image pickup tube 12 attached to the tip of the hoist 5 via the camera head support 11 are lowered to a predetermined depth according to the indicated value of the hoist shaft encoder 31. Here, the optical information of the fuel handle 14 obtained through the lens is converted into an electrical signal by the image pickup tube 12, and this signal is sent to the video monitor 1 through the amplifier 21.
It will be reproduced on 9th Saturday. In this state, the distance from the absolute origin 8 for position measurement of the center (origin) of the video monitor 19 is adjusted in advance so that it can be obtained by the output signals from the bridge shaft encoder 29 and the trolley shaft encoder 30. It is something that can be kept. As shown in FIG. 5, when the light pen 20 is used to indicate the center of the handle 14 of the fuel assembly displayed on the screen of the video monitor 19, the position detection device 23 uses the signal from the light pen 20 to point the center of the video monitor as the origin. This signal is converted into an X, Y orthogonal coordinate axis voltage output signal, which is further converted into a digital signal through an A/D converter 25, and the video monitor arithmetic processing unit 24 converts the digital signal into a distance deviation signal using the output signal of the hoist encoder 31. Output as . The above arithmetic processing device 2
The conversion coefficient for converting into a distance signal in step 4 is calculated by calculating the Z direction position of the lens tip in the camera head given by the output signal of the hoist shaft encoder 31 and the depth direction position of the handle tip given from the operator console 28. It can be determined by feeding it to the processing device 24 and performing arithmetic processing. A distance deviation signal from the video monitor origin of the target position (the center of the fuel assembly handle 14) obtained as a result of the above calculation, and a bridge shaft encoder 29 and a trolley shaft encoder 30 that indicate the position of the video monitor origin. Further, the distance signals from each of the measurement origins 8 are sent through the input/output device 32 of the electronic computer to the electronic computer arithmetic control device 33 for calculation processing, and the absolute distance signals from the measurement origins 8 of the target position are converted into digital signals. At the same time, the bridge 3 and trolley 4 are
Outputs the operation signal that drives the. The positioning output can be obtained, for example, as shown in FIG. 6 as follows. The camera head target position (company target) is X, the Yl measurement target position (fine adjustment target) is X+εX, Y+εY, and the measurement target relative to the origin on the video monitor is X, y. Here, as mentioned above, X, Y are encoder instruction values and distance signals (digital signals) from the measurement origin, εX, εy are distance deviations between the measurement target position and X, Y, and X, y are This is a voltage deviation signal between the video monitor and the measurement target position. The relationship between the voltage deviation signals X, y and the distance deviation signal is given by a function of the vertical distance (1) from the camera lens surface to the upper end level H of the handle 14 of the fuel assembly 15 when focused. , generally expressed as the formula. Although εy′ is obtained as an analog quantity, it is possible to further A/D convert these to obtain digital distance deviation signals εX, εy expressed in ABCD codes, and therefore the measurement target position X+εX, Y+εy can be obtained.

In the above equation, the function f(l) is obtained, for example, from the relationship when L is the distance between the center of the camera lens and the screen inside the camera.

The coarse adjustment target positions X and Y obtained as described above are input to the storage device 34 of the computer.

That is, after inputting the rough adjustment target positions X and Y into the storage device 34 of the computer using the operator console 28 or other computer peripheral device, the operator console 2
When an instruction to start position measurement is given to the electronic computer from 8, the output of the electronic computer drives the automatic fuel exchange platform, finally positions to the fine adjustment target, and the measurement results are stored in the storage device 34. . This control operation will be explained below with reference to the control block diagram of FIG.

T1 is the rough target position X, Y, which is stored in advance in the storage device 41 and retrieved by the control element D4O. The current position signal M of the platform, which is the controlled object 39, is read as a feedback signal L via the control element A35, and this feedback signal L is compared with the rough target position T1 to obtain a deviation signal S. This deviation signal S is applied as a drive signal N to the controlled object 39 via the control element B36, and drives the position of the controlled object 39 to the rough target position. When the coarse target positions X, Y and the current position of the controlled object 39 match, the deviation signal S=o, and at this time the drive output signal of the control element B36 becomes N-0, and the adjustment switching mechanism SW is switched from the coarse adjustment circuit to the fine adjustment circuit. Switched to regulation circuit. This switching operation is performed by the control element B36 that can determine N-0.
Alternatively, this can be done by the control element D reading the current position of the controlled object 36. T2 is the fine adjustment target position X, y on the video monitor, and the control element C37 receives the target position signal T indicated by the sensor 38 (corresponding to a light receiving device such as a light pen).
It is obtained by converting 2'. That is, the deviation signal S at this point is the X, Y target position TlX at T1.
, Tly and X, Y target positions T2X, T2y at T2
Then, TlX-T2X-εTly-T2y-εy, the control element A36 generates a driving signal N for the controlled object 39, and a positioning operation is performed. The current position signal P of the controlled object 39 when the positioning to the fine adjustment target position is completed and becomes S-0 is stored in the storage device 41 of the control element D4O as a position measurement result, and the control element D4O performs the following The coarse target position T1 of the measurement target is taken out, the adjustment switching mechanism SW is switched to the coarse adjustment circuit, and the above measurement operation is repeated. With a measuring device configured like this, it is possible to easily measure the position inside the reactor core and pool when introducing a new automatic fuel exchange device into an existing nuclear power plant, and it is possible to easily measure the position inside the reactor core and pool. Even if the previously measured position of the fuel rods becomes misaligned due to deformation of the reactor grate plate or fuel rack for some reason after the plant has started operating, it is possible to easily remeasure the position of the fuel rods.

In addition, using the computer installed for the automatic fuel exchange platform or for this device, the measurer can automatically do everything except indicate the position on the video monitor with an optical receiver or light pen. This enables labor-saving measurement work even in newly constructed plants.
This has a great effect on reducing radiation exposure and increasing efficiency. In the above embodiment, it is necessary for the measurer to specify the measurement point on the video monitor soil, but as shown in FIG. The position is specially processed so that it shows particularly high brightness under external lighting, and a control element F such as an X-Y analyzer is introduced instead of the video monitor mentioned in the previous embodiment, and the Inside the Y analyzer control device 44, the brightest point position (target position reflected light 43) is automatically detected at the center of the handle, which is the target position, and the X and y at that time are output as the final target position. In this case, it becomes possible to further simplify the operation of the measurer.

In addition, the present invention can be implemented with various modifications without changing the gist thereof. As described above, according to the present invention, the measurer can obtain measurement results one by one by simply indicating the target position that is continuously displayed on the video monitor, so it is possible to obtain measurement results in a place that is difficult for humans to approach. It is possible to provide a position measuring device that can easily measure a position and can extremely reduce the labor required for the measurement.

[Brief explanation of drawings]

Figure 1 is an overall configuration diagram showing an outline of the fuel exchange floor and fuel exchange equipment of a nuclear power plant, Figures 2 a and b are the reactor,
A diagram schematically showing the inside of the fuel pool and a part thereof in detail,
Figures 3a to 3d show the tip of the hoist, where a shows the case where the grip is attached, b shows the case where the position measurement jig is attached, and c and d show the camera head and image pickup tube applied in the present invention. 4 is a system configuration diagram showing an embodiment of the present invention, and FIG. 5 is an explanatory diagram of the video monitor and target position indicating operation in the same embodiment.
FIG. 6 is an explanatory diagram of the measuring method in the same embodiment, FIG. 7 is a control block diagram of the same embodiment, and FIG. 8 is a control block diagram of another embodiment of the present invention. 1...fuel pool, 2...nuclear reactor, 3
・・・・・・Bridge, 4...Trolley 1, 5・
...Hoist, 8 ...Position measurement origin, 1
0...Fuel grip, 12...Camera head and imaging tube, 14...Fuel handle, 15...
... Fuel assembly, 18 ... Fuel handle center mark, 19 ... Video monitor, 20.
-... Light pen, 22... Control device for video monitor, 23... Position detector for optical receiver, 24... Arithmetic processing device, 25... ...A
/D converter, 28...Console for measurer, 2
9... Encoder for bridge position measurement, 30.
...Trolley position measurement encoder, 31...
... Hoist position measurement enaider, 32...
- Computer input/output control device, 33... Computer central processing control device, 34... Computer storage device, 35-37... Control element, 38...
...Sensor, 39...Controlled object, 40...
...Control element, 41...Storage device, 42...
... Control element, 43 ... Target position reflected light,
44... Control element.

Claims (1)

[Claims] 1 A movable transporter that can be operated in three directions on a plane with a reference position as its origin and in a direction perpendicular to the plane by a drive device, a sensor that generates a movement distance signal of this movable transporter from the reference position, and the target A movable transport device comprising a gripping device that clamps an object to be transported, a television camera attached to the gripping device, and a display that displays the position of the object when the television camera is brought close to the object. An input device that generates a relative position signal on the display according to the position of the transported object when the position of the transported object on the display is indicated, and a reference position of the transporter body obtained by the sensor. a distance signal arithmetic processing device for arithmetic processing a distance signal; and a distance signal arithmetic processing device that calculates and processes a distance signal from the reference position of the object to be transported using the arithmetic processing signal, and drives the movable transporter based on the measured position. A position measuring device comprising: a control device that gives control commands to the device.