JPH0527081A - Channel box loading confirming device for fuel assembly - Google Patents

Abstract

PURPOSE:To obtain a loading confirming device for a channel box in a fuel assembly used in a nuclear power plant. CONSTITUTION:A channel box loading confirming device for a fuel assembly is equipped with a shaft body 21 having a hooked part 22 for a suspending hook of an upper part tie plate in the lower part and having a contact part 23 with an upper surface of the upper part tie plate in the bottom part, contactor 24 installed on the shaft body 21 so as to be shiftable in the axial direction and freely turnable for the hooked part 22, and a position detector for detecting the relative position in the axial direction of the contactor 24 for the contact part 23. The loading of the channel biox is confirm from the position detection values of the detection part in the cases where the contactor 24 contacts the upper surface of the channel box and the upper surface of a fixing tool, in the state where the contact part 23 contacts the upper surface of the upper part tie plate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for confirming the attachment of a channel box in a fuel assembly used in a nuclear power plant.

[0002]

2. Description of the Related Art A nuclear fuel in a nuclear power plant is formed by packing pellets of a nuclear fuel material in an elongated cladding tube to form a fuel rod. Configure a bundle. The fuel bundle configured as described above is covered with a rectangular tube-shaped channel box around the periphery and is loaded into the core as a fuel assembly. After being used for a predetermined period, it is taken out of the core again and replaced with a new one as appropriate. In addition, the fuel bundles are visually inspected periodically as needed. The visual inspection is conducted by placing the fuel assembly in water such as the fuel pool, but usually before the fuel assembly is loaded into the core and when it is loaded and used and then transferred from the core to the fuel pool. To be done. The visual inspection of the fuel bundle was performed remotely by a TV camera etc. with the channel box covering the fuel assembly removed, and if it was confirmed that there was no abnormality, the channel box was attached again to the core. Is loaded.

FIG. 1 shows a state where a fuel assembly is arranged in the water of a fuel pool. A channel attachment / detachment machine 3 is installed on the inner side wall 2 of the fuel pool 1, and a fuel assembly 4 is attached to the channel attachment / detachment machine 3. The channel box 5 of the fuel assembly 4 is attached / detached by the channel attaching / detaching machine 3. FIG. 2 shows the details of the fuel assembly 4. A large number of fuel rods 6 are assembled into a rectangular shape to form a fuel bundle 7, and an upper tie plate 8 and a lower tie plate 9 are attached to the upper and lower ends thereof. And the upper tie plate 8
A lifting hook 1 for lifting the fuel assembly 4
0 is provided on the upper surface thereof. Channel box 5
Are attached to the upper tie plate 8 and the lower tie plate 9 so as to cover the periphery of the fuel bundle 7, respectively.

FIG. 3 is an enlarged view showing a state in which the upper end of the channel box 5 is attached to the upper tie plate 8. Upper tie plate 8 mounted on top of fuel bundle 7
The lifting hook 10 is provided so as to cross the upper surface diagonally, and bar-shaped projections 11 are provided at the four corners. And this rod-shaped protrusion 11
At least one of these has an internal thread engraved. In addition,
The upper tie plate 8 is provided with a large number of holes 12 corresponding to the positions of the fuel rods. A pair of fixing flanges 13 are provided at diagonal corners of the upper end of the channel box 5, that is, at positions corresponding to the rod-shaped projections 11. Then, a hole 14 is formed in the fixing flange 13 corresponding to the rod-shaped projection 11 on which the inner screw is engraved.
The cap screw 16 of No. 5 is inserted into this hole 14 and the channel box 5 is attached to the upper tie plate 8.
Although the mounting of the channel box 5 on the upper tie plate 8 must be done securely, this confirmation is usually made carefully by a method such as carefully monitoring the tightening torque of the fixture.

[0005]

However, since such a conventional confirmation method requires a great deal of work, a further improved and efficient method has been demanded.
Therefore, an object of the present invention is to improve such a conventional method and to provide a channel box mounting confirmation device having a high certainty and capable of more efficient confirmation work.

[0006]

In order to solve the above-mentioned problems, a mounting confirmation device of the present invention is provided with a fuel bundle which is mounted on a channel attaching / detaching device and placed underwater, a lifting hook and a rod-shaped projection for fixing the channel. And an upper tie plate attached to the upper end of the fuel bundle, and a channel box in which a fixing flange provided on the upper end is removably attached to the rod-like protrusion by a fixture. Is a device for confirming the attachment of the channel box in the fuel assembly. Further, a shaft body having a hooking portion for the lifting hook at a lower portion and a contacting portion for the upper tie plate at a bottom portion is provided on the shaft body so as to be axially movable and rotatable with respect to the hooking portion. And a position detector that detects the relative position of the probe in the axial direction with respect to the contact portion. Then, in the state where the contact portion is in contact with the upper surface of the upper tie plate, the channel box is determined from the respective position detection values of the detection portion when the probe is in contact with the upper surface of the channel box and the upper surface of the fixture. It is characterized in that it is configured to confirm the attachment of the.

[0007]

The apparatus for confirming the attachment of the channel box of the present invention uses the upper surface of the upper tie plate as a reference to confirm the attached state of the attached channel box by measuring the position of the upper surface of the channel box, and further confirms the upper surface of the upper tie plate. Using the standard as a reference, check the fixed state of the fixture on which the channel box is mounted by measuring the position of the fixture top surface. That is, the reference position is established by abutting the abutment portion provided on the bottom of the shaft on the upper surface of the upper tie plate, and detecting when the probe abuts on the channel box upper surface and the fixture upper surface, respectively. The mounting state of the channel box is confirmed by determining whether the position detection value obtained by the unit is within the allowable range with respect to the set value.

[0008]

Embodiments of the present invention will now be described with reference to the drawings. FIG. 4 is a perspective view showing an example of a channel box mounting confirmation device of the present invention. The mounting confirmation device 20 is the shaft 2
1, a hooking portion 22 rotatably provided on the lower portion of the shaft body 21, and an abutting portion 23 provided on the bottom portion of the shaft body 21,
The shaft body 2 can be freely moved and rotated in the axial direction with respect to the hook portion 22.
1 and the probe 24 provided in the first embodiment. Further shaft 2
A measuring device main body 25 is provided on the upper part of 1. When confirming the channel mounting of the fuel assembly 4 mounted on the channel attaching / detaching device 3 shown in FIG. 1, the shaft body 21 has a measuring device main body 25 provided on the upper part thereof located in a space above the water surface. It is supposed to be

The shaft 21 is a double pipe, and a measuring rod (not shown) is inserted into the hollow portion of the outer frame pipe 26 so as to be movable in the axial direction. The hook portion 22 is rotatably provided at the lower portion of the frame pipe 26, and the contact portion 23 is fixed to the bottom portion. The tip of the abutting portion 23 is formed in a conical shape so as to be aligned with the hole 12 of the upper tie plate 8 shown in FIG. The hook 22 is the lifting hook 10 of the upper tie plate 8 shown in FIG.
On the other hand, it has a rectangular box body 27 whose bottom is opened and which is enlarged in a taper shape so that it can be lowered from above and easily hooked. A mounting ring 29 is coupled to one side surface of the box body 27 via a pair of brackets 28, and the mounting ring 29 is rotatably coupled to the frame pipe 26.

A slit 30 is provided in the mounting ring 29 in the circumferential direction thereof, and a projection 31 projecting from the outer periphery of the frame pipe 26 is inserted into the slit 30, whereby the frame pipe of the hooking portion 22 is inserted. The movement of 26 in the axial direction is restricted to a predetermined angle. Further, as shown in FIG. 5, a channel guide 32 is attached to a side surface of a box body 27 of the hook portion 22. As will be described later, the channel guide 32 guides the hooking portion 22 to the outside of the corner of the channel box when the box 27 is hooked to the hanging hook, thereby facilitating the hooking operation. Is. In addition, the shaft 21
Has a function of supporting more stably.

The probe 24 has a rectangular shape with a wedge shape on the lower side, and is attached to the lower portion of the measuring rod provided in the hollow portion of the frame pipe 26. Then, a detection piece constituting a detection section (49 in FIG. 8) is attached to the upper part of the measurement rod in the measuring device main body 25 as described later. The case 33 of the measuring device main body 25 has a mounting pipe 34 that vertically penetrates the case 33.
Is fixed, and a handle 35 and a hook 36 for lifting are provided on the upper part thereof. The upper portion of the frame pipe 26 is inserted into the hollow portion of the mounting pipe 34.

A rack (not shown) is provided at the upper end of the measuring rod, and the rack is screwed with a pinion (not shown) provided on the shaft 38 of the measuring rod up / down lever 37. Therefore, the measurement rod can be moved in the vertical direction by rotating the measurement rod up / down lever 37 up / down. The detection unit housed in the measuring device body 25 is
The vertical movement of the detection rod is detected or measured digitally or in an analog manner, but such measuring means is usually used in this field and its detailed description is omitted. An optical measuring device using a laser beam is preferable as such a detecting unit. In this type of optical measuring device, a laser oscillator and an optical sensor for receiving the laser light are arranged opposite to each other, and the optical sensor is detected by the amount of shielding of the laser light by a detection piece (light shielding piece) which is inserted between the two. Is configured to change the output signal of the.

When such an optical measuring device is applied to the present invention, a detection piece serving as a light shielding piece is attached to the upper part of the detection rod and, for example, the position of the detection rod is taken out from the optical sensor as an analog electric signal. .. The reference surface (the contact portion 23 that contacts the upper surface of the upper tie plate 8)
Position), the electric signal corresponding to the distance of the probe 24 from a normal position signal set by a presetting device is compared. Output an alarm signal. In this case, the deviation is allowed to have a predetermined value in order to consider a manufacturing error of a channel or the like. The power switch 39 for the measuring circuit and "OK" and "NO" indicating normal / abnormal mounting of the channel are displayed on the upper front surface of the measuring device body 25 in FIG.
The two indicator lights 40 are provided. The above-mentioned detection piece is usually constructed so that its vertical position can be adjusted for adjusting the zero point or the like.

In the present invention, in addition to the method of displaying the presence / absence of normality / abnormality as described above, as shown in FIG. 4, a connector 41 provided with an analog electric signal of an optical sensor from the measuring instrument main body 25 is provided on the upper portion thereof. Thus, the cable 42 can be taken out to the outside, and the dimension display 43 can display the dimension corresponding to the distance of the probe 24 from the reference plane. In addition, in order to confirm the vertical position of the measuring device main body 25, a water bubble type level gauge 44 is provided above the measuring device main body 25.

FIG. 6 shows a calibration block for the detector of the verification device of the present invention. The calibrating block 45 has a cylindrical shape. The lower portion of the frame pipe 21 shown in FIG. 4 is inserted into the hollow portion of the calibrating block 45, and the hole 46 provided at the center of the bottom portion has a conical shape at the tip of the abutting portion 23. The part of can be abutted. Further, three step surfaces are formed on the upper surface of the cylindrical body, and the step surfaces 47 and 48 are arranged so as to be offset from each other by 90 degrees.
Are at the rectification positions corresponding to the upper surface of the channel box 8 shown in FIG. 3 and the upper surface of the fixture 15 with the channel box 8 fixed thereto, respectively. The reason why the hole 46 is provided in the cylindrical body is that the conical portion at the tip of the abutting portion 23 of the frame pipe 21 comes into contact with the hole 12 provided in the upper surface of the upper tie plate serving as the reference surface. This is because it is adapted to it.

In order to calibrate the detecting portion using the calibrating block 45, first, the lower portion of the frame pipe 21 of the apparatus is inserted into the cylindrical body of the calibrating block 45, and the tip portion of the abutting portion 23 thereof has a conical shape. The portion abuts the hole 46. At that time, the level gauge 44 of the measuring device main body 25 confirms that the device is vertical. Next, the measuring rod up / down lever 37
Is rotated downward to lower the measuring rod, and the lower portion of the probe 24 is brought into contact with the step surface 47. The output signal value of the optical sensor of the detection unit at that time, the upper and lower positions of the detection piece in the detection unit, so as to match the preset setting value corresponding to the position of the upper surface of the normally mounted channel box. adjust.

Next, the measurement rod up / down lever 37 is once rotated upward to raise the measurement rod, and the measurement rod up / down lever 37 is horizontally rotated to move the frame pipe 21 to 90 °.
After rotating once, the measuring rod is lowered again to bring the lower portion of the probe 24 into contact with the step surface 48. The output signal value of the optical sensor of the detection unit at that time is regarded as a value corresponding to the normal position of the upper surface of the fixture 15 of the channel box, and the set values of the setting unit are matched. This completes the calibration of the detection unit.

FIG. 7 is a plan view showing the confirmation of the mounting of the channel box by the confirmation device shown in FIG. 4, and FIGS. 8 and 9 are sectional views taken along line AA and BB of FIG. 7, respectively. It is a figure. 7 to 9, the lower portion of the probe 24 is brought into contact with the upper surface of the channel box 5, and the position thereof is measured. Probe 2 provided under the measuring rod
A vertical slit 50 is provided in the lower part of the frame pipe for vertically moving 4. On the other hand, a detecting piece 51 of the detecting portion 49 is provided on the upper part of the measuring rod, and a similar slit 52 is provided for vertical movement of the detecting piece 51. The laser oscillator 53 and the optical sensor 54 are arranged so as to sandwich the detection piece 51.

10 to 12 show a state in which the lower portion of the probe 24 is in contact with the upper surface of the cap screw 16 of the fixture 15 for fixing the channel box 5 and the position thereof is measured. The configuration is the same as in FIGS. However, the measuring rod is rotated 90 degrees with respect to the previous figure. Next, the operation of the confirmation device of the above-described embodiment will be described. As shown in FIG. 1, the confirmation device is hung from above the fuel assembly attached to the channel attachment / detachment device by an appropriate hang device, and the contact portion 2 at the bottom of the shaft body 21 is hung.
The tip portion of 3 is brought into contact with the hole 12 of the upper tie plate 8 and the hooking portion 22 is hooked on the lifting hook 10.
This suspension is performed by using the hook 36 of the confirmation device shown in FIG. At that time, the level gauge 44 confirms the verticality of the shaft body 21.

Next, the measuring rod up / down lever 3 of the confirmation device
7 is rotated downward to lower the measuring rod, and the lower portion of the probe 24 is brought into contact with the upper surface of the channel box 5 as shown in FIGS. 7 to 9 to check the mounting state of the channel box 5. If the mounting state is in the abnormal range, the "NO" indicator light 40 is turned on, so the measurement work is interrupted and the channel box is mounted again. If the mounted state is within the normal range, the "OK" indicator light 40 is turned on, and the next measurement operation starts.

Next, the measurement rod up / down lever 37 is once rotated upward to raise the measurement rod, and then the shaft body 21 is rotated 90 degrees by the measurement rod up / down lever 37 to descend again to move the probe 24 downward. The lower part is brought into contact with the upper surface of the cap screw 16 of the fixture 15 for fixing the channel box 5, and the fixed state of the fixture 15 is confirmed. If it is in the normal range, the "OK" indicator light 40 is turned on, but if it is in the abnormal range, the "NO" indicator light 40 is turned on. Therefore, the fixture 15 should be fixed again and the measurement should be performed again. To do.

[0022]

Since the channel box mounting confirmation device of the present invention is constructed as described above, the channel box mounting confirmation can be surely and quickly performed.

[Brief description of drawings]

FIG. 1 is a side view showing a state where a fuel assembly is arranged in water of a fuel pool.

FIG. 2 is a partially cutaway perspective view showing details of a fuel assembly 4 of FIG.

3 is a partially enlarged perspective view showing a state in which an upper end portion of a channel box 5 is attached to an upper tie plate 8 in the fuel assembly 4 of FIG.

FIG. 4 is a perspective view showing an example of a channel box mounting confirmation device of the present invention.

5 is an enlarged perspective view of a hooking portion 22 in FIG.

FIG. 6 is a perspective view showing a calibration block for a detection unit of the verification device of the present invention.

7 is a plan view showing the confirmation of the mounting of the channel box by the confirmation device shown in FIG.

8 is a cross-sectional view taken along the line AA of FIG.

9 is a sectional view taken along the line BB of FIG.

10 is a plan view showing the confirmation of the mounting of the channel box by the confirmation device shown in FIG.

11 is a cross-sectional view taken along the line AA of FIG.

12 is a sectional view taken along the line BB of FIG.

[Explanation of symbols]

 1 Fuel Pool 2 Inner Wall 3 Channel Attachment / Detachment 4 Fuel Assembly 5 Channel Box 6 Fuel Rod 7 Fuel Bundle 8 Upper Tie Plate 9 Lower Tie Plate 10 Lifting Hook 11 Circulation Piping 12 Hole 13 Fixing Flange 14 Hole 15 Fixing Tool 16 Cap Screw 20 Installation confirmation device 21 Shaft body 22 Hooking portion 23 Abutment portion 24 Probe 25 Measuring instrument body 26 Frame pipe 27 Box body 28 Bracket 29 Mounting ring 30 Slit 31 Protrusion portion 32 Channel guide 33 Case 34 Mounting pipe 35 Handle 36 Hook 37 Measuring Rod Vertical Lever 38 Axis 39 Power Switch 40 Indicator Light 41 Connector 42 Cable 43 Dimension Indicator 44 Level Gauge 45 Calibration Block 46 Hole 47 Stepped Surface 48 Stepped Surface 49 Detection Section 50 Slit 51 Detection piece 52 Slit 53 Laser oscillator 54 Optical sensor

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yutaka Hirose 8 Shinsita, Isogo-ku, Yokohama City, Kanagawa Prefecture Isogo Engineering Center, Toshiba Yokohama Works, Ltd. (72) Isao Akimoto 6606 Fukaya, Ayase City, Kanagawa Prefecture Oyama Co., Ltd. Inside the office

Claims (1)

Claims: 1. A fuel bundle (4) mounted on a channel attaching / detaching machine (2) and placed underwater, and a lifting hook (1).
0) and a rod-shaped protrusion (11) for fixing the channel on the upper surface, and an upper tie plate (8) attached to the upper end of the fuel bundle (4), and a fixing flange (13) provided on the upper end. ) To the rod-shaped projection (11).
5) A device for confirming the attachment of the channel box (5) in a fuel assembly comprising a channel box (5) detachably attached by means of (5), wherein a hooking portion (22) to the lifting hook (10) is provided at a lower portion. ) And a shaft body (21) having a bottom portion provided with a contact portion (23) for contacting the upper tie plate (8), and the shaft body capable of axial movement and rotation with respect to the hooking portion (22). A probe (24) provided on (21) and a position detector (4) for detecting the axial relative position of the probe (24) to the contact portion (23).
9) and the probe (24) with the contact portion (23) in contact with the upper surface of the upper tie plate (8).
To confirm the attachment of the channel box (5) from the respective position detection values of the detection unit (49) when the upper surface of the channel box (5) and the upper surface of the fixture (15) are contacted with each other. A device for confirming the attachment of a channel box of a fuel assembly, which is characterized in that: