JP2007333601A - Fuel inspection system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To shorten the time required for the immersion of an ultrasonic inspection device and a fiberscope inspection system into a spent fuel pool and the setting to adapt to fuel assemblies in the inspection of fuel assemblies or fuel rods where radioactivity leakage has occurred. <P>SOLUTION: A fuel inspection system includes the ultrasonic inspection device and the fiberscope inspection system in a single body, such that they are furnished side by side in the vertical direction, the fiberscope inspection system is provided above the ultrasonic inspection device and they share a drive unit for inserting each sensing element into a fuel assembly and pulling it out of the fuel assembly, and a switching unit for driving either of the inspection systems. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a fuel inspection apparatus, and more particularly to a fuel inspection apparatus that can identify a fuel rod in which leakage of radioactivity has occurred and observe the surface of the damaged fuel rod and its surrounding area.

  When radioactivity leakage is observed during the operation of the reactor, after the end of the reactor operation cycle, (1) identify the fuel assembly that has leaked, that is, the broken fuel rods are incorporated, ( 2) Identify the fuel rod in the fuel assembly that is broken (use “damage” as a rule for fuel rods as a result of “braking” of the fuel rods, resulting in “radioactive leakage”), and (3 ) The location of the fuel rod is identified, and the cause of the damage is investigated by observing the damaged location and its surroundings.

  The leaking fuel assembly is identified by a shipping inspection in which each fuel assembly is isolated from the other fuel assemblies and it is individually examined whether or not radioactivity is released. (Non-Patent Document 1) The identification of the fuel rod that has caused the damage is performed by ultrasonic (UT) inspection of each fuel rod of the fuel assembly that is identified as leaking radioactivity. The identification of the damaged part and the observation of the part are made by inspection using a fiberscope.

  The shipping inspection device is permanently installed in the spent fuel pool (hereinafter referred to as “pool” in principle), but the ultrasonic inspection device and the fiberscope inspection device (hereinafter, when there is no need to distinguish between them) The inspection device (also referred to as “inspection device”) is not permanent, and it is submerged in the pool when a need for inspection occurs, and settings (a variety of inspections can be performed on the fuel assembly) To be installed as possible). Note that the shipping inspection is not directly related to the present invention, and thus the description thereof is omitted.

With reference to FIG. 5, a method of identifying a broken fuel rod using ultrasonic waves will be described. FIG. 5 is a diagram showing a state where a broken fuel rod is detected (specified) using ultrasonic waves. In FIG. 5, 131 is a probe on the transmitter side of the ultrasonic inspection apparatus, and 132 is a probe on the receiver side. 310 is a healthy fuel rod, and other healthy fuel rods are indicated by circles. Reference numeral 311 denotes a broken fuel rod, which is indicated by a cross.
The fuel assembly is assembled with fuel rods arranged in a 17 × 17 matrix, for example. As shown in the upper diagram of FIG. 5, 17 fuel rods are arranged (FIG. The probe 131 on the transmitter side of the ultrasonic inspection apparatus is horizontally arranged on one side (upper side in the drawing) of one row (showing a part thereof) and received at the opposite position on the other side (lower side in the drawing). The probe 132 on the child side is arranged, and both probes 131 and 132 are moved in pairs in the direction of the arrow from one end to the other end of the fuel rod row to be inspected, that is, along the row (from left to right in the drawing). The received intensity is checked for each fuel rod position.

If the fuel rod 310 is healthy, the inner surface of the cladding tube made of Zircaloy alloy is in contact with gas (helium), so that the ultrasonic conductivity is good due to reflection at the interface of the ultrasonic wave. When the pair of the probe 131 on the transmitter side and the probe 132 on the receiver side pass through the fuel rod 310, as shown in the example marked with a circle in the lower diagram of FIG. Arise.
Since the broken fuel rod 311 has cooling water infiltrated therein, the reflection of the ultrasonic wave at the interface of the cladding tube is not successful, and the ultrasonic conductivity deteriorates. For this reason, as shown in the example of the mark in the circle in the lower part of FIG. 5, the peak intensity becomes weak, and it can be seen that the peak is broken.
By doing this for all rows of fuel rods, the broken fuel rods are identified.

With reference to FIG. 6, description will be given of how the fuel rod 311 identified as broken is identified as broken and how the broken portion and its surroundings are observed with a fiberscope. FIG. 6 is a diagram illustrating a state in which the inside of the grid is observed with a fiberscope. In FIG. 6, 111 is a fiberscope (fiberscope head), 320 is a support grid for the fuel assembly, 321 is a lateral lattice plate, 322 is a longitudinal lattice plate, and 323 is The dimple part (hard stop and soft stop).
The fiberscope 111 is attached with a glass fiber so that an upper perspective view, a lower perspective view, and a side view can be simultaneously performed. The fiberscope 111 is inserted in the space between the adjacent fuel rods of the damaged fuel rod 311 to be inspected and in the vicinity of the damaged fuel rod 311 and observed between the support grids adjacent to each other in the vertical direction (for each span). To do. Here, the upper perspective view and the lower perspective view are performed because the dimple portion 323 that elastically supports and restrains the fuel rod 311 inside the support grid 320 often breaks the fuel rod. This is because the part can be observed from above or below.

When the observation from one direction of the horizontal cross section of the fuel assembly, for example, the left side of the upper diagram of FIG. 6 is completed, the fiberscope 111 is once pulled out of the fuel assembly, the fuel assembly is rotated 90 degrees, and the fuel assembly again Are observed from different directions, for example, from the upper side of the upper diagram of FIG.
When the observation for one span is completed, the fiberscope 111 is once pulled out of the fuel assembly, the fuel assembly is moved up or down by one span in the spent fuel pool, the fiberscope 111 is inserted again, and the next span Observe in the same way.
By repeating such an operation, the broken fuel rods are observed from the upper and lower sides and four rounds, and the damaged part and its surrounding parts are observed.
Japan Nuclear Safety Research Association Light Water Reactor Fuel Behavior Editorial Committee “Light Water Reactor Fuel Behavior” July 1998, pages 153-154

  However, when the need for inspection occurs, the ultrasonic inspection device and the fiberscope inspection device are submerged in the pool and set correctly according to the fuel assembly stored in the spent fuel rack at the bottom of the pool. The work is an operation that is performed while looking from the top of the pool, and it is necessary to perform it carefully because it is a nuclear device, and it takes time.

In addition, a crane is necessary for setting, but a crane is also necessary for many other operations performed at one time when the reactor is shut down, and time adjustment with these other operations is necessary when using the crane. It will take more time.
For this reason, when inspecting a fuel assembly or fuel rod that has leaked radioactivity, the ultrasonic inspection device and the fiberscope inspection device are submerged into the spent fuel pool and the setting corresponding to the fuel assembly is used. There has been a demand for development of a technique that improves inspection efficiency by reducing the time required.

  The present invention has been made for the purpose of solving the above problems, and is an integration of an ultrasonic inspection apparatus and a fiberscope inspection apparatus. Hereinafter, the invention of each claim will be described.

The invention described in claim 1
A fuel inspection device comprising an ultrasonic inspection device and a fiberscope inspection device integrally.

Since the fuel inspection device of the present invention is integrally provided with an ultrasonic inspection device and a fiberscope inspection device, it is possible to identify and specify the fuel rod in which the fuel assembly that has caused the leakage of radioactivity has been damaged. The ultrasonic inspection device and the fiberscope inspection device are submerged at the same time in order to observe the damaged portion of the fuel rod and the surrounding portion, and the setting corresponding to the fuel assembly is made. For this reason, the time required for them is greatly shortened as compared with the prior art, and the inspection efficiency is greatly improved.
This also facilitates adjustments for other operations and crane use.
Here, “integrated” means not only that the ultrasonic inspection device and the fiberscope inspection device are physically and mechanically one device when used for inspection, but also any one of them. If one is correctly set in the fuel assembly, the other is automatically set correctly.

The invention according to claim 2 is the fuel inspection device, wherein
The ultrasonic inspection apparatus and the fiberscope inspection apparatus are provided side by side in the vertical direction.

In the fuel inspection apparatus according to the present invention, since the fiberscope inspection apparatus and the ultrasonic inspection apparatus are arranged side by side in the vertical direction, the width of the entire inspection apparatus is narrowed, and consequently the inspection apparatus is moved in the lateral direction. Less space for it.
Further, for example, in order to inspect each row and each column of the fuel rods arranged in a 17 × 17 matrix, both the ultrasonic inspection device and the fiberscope inspection device need to be moved laterally at the fuel rod row and column pitches. However, if they are arranged in the vertical direction, the start point and end point of the horizontal movement are the same, and the operation becomes easy.

Invention of Claim 3 is the said fuel inspection apparatus, Comprising:
A fuel inspection device is provided with a fiberscope inspection device above the ultrasonic inspection device.

In the fuel inspection apparatus according to the present invention, the fiberscope inspection apparatus, which is often finely operated to observe the inside of the support grid from above and below, is located above the ultrasonic inspection apparatus. It becomes possible to operate while visually observing. In addition, since the fiberscope inspection device is located above, there is no shadow of illumination, and it is easy to install an underwater lamp for inspection, etc. It becomes easy. On the other hand, since the ultrasonic inspection apparatus does not require illumination for inspection, no major inconvenience occurs.
Further, the amount of lateral movement of the entire integrated inspection apparatus can be reduced.

Invention of Claim 4 is the said fuel inspection apparatus, Comprising:
The ultrasonic inspection apparatus and the fiberscope inspection apparatus have a common drive device for inserting each detection end into the fuel assembly and withdrawing it from the fuel assembly, and has a switching device for selecting which inspection device to drive. This is a fuel inspection device.

The fuel inspection device according to the present invention is a drive device such as a submersible motor (part) or an air cylinder for inserting the detection end of the fiberscope inspection device and the ultrasonic inspection device into the fuel assembly and withdrawing from the fuel assembly. Therefore, the entire inspection apparatus is reduced in weight and costs are reduced.
Note that which of the fiberscope inspection apparatus and the ultrasonic inspection apparatus is driven is adjusted by remotely operating a switching mechanism having a clutch or the like from the pool.

The invention according to claim 5 is the fuel inspection device, wherein
The ultrasonic inspection apparatus includes a first main body, a first installation base, and a first driving unit,
The first main body holds a detection end inserted into the fuel assembly,
The first installation base includes a first moving mechanism that moves the first main body portion in a fuel assembly side direction and an opposite direction, and a first support that holds the posture of the first main body portion while moving. A mechanism,
The first drive unit is fixed to the first installation base and operates the first moving mechanism.
The fiberscope inspection device has a second body part, a second installation base, and a second drive part,
The second main body holds a fiberscope inserted into the fuel assembly,
The second installation base includes a second moving mechanism that moves the second main body portion in the direction of the fuel assembly side and the opposite direction, and a second support that supports the second main body portion while maintaining the posture of the second main body portion during movement. A mechanism,
The second driving unit is fixed to the second installation base and operates the second moving mechanism.
Furthermore, the fuel inspection apparatus is characterized in that the first installation base and the second installation base are fixed to each other.

Both the ultrasonic inspection device and the fiberscope inspection device have an installation base on which a main body part for holding the detection end of the transmitter probe and the receiver probe, or the fiberscope is installed, and both are submerged in the pool. With the installation base set to the fuel assembly, the main body moves in the direction of the fuel assembly with respect to the installation base or moves to the opposite side under the action of the drive unit fixed to the installation base. By doing so, the detection end held by the main body is inserted into the fuel assembly or pulled out from the fuel assembly.
In the present invention, the installation table for the ultrasonic inspection apparatus and the installation table for the fiberscope inspection apparatus are fixed to each other. For this reason, it is not necessary to immerse the two inspection devices individually in the pool and perform setting, and labor and time required for inspection can be greatly saved.
In addition, the equipment for lateral movement used for inspecting the fuel rods in each row and each column arranged in, for example, a 17 × 17 matrix within the fuel assembly is also shared, leading to a reduction in equipment costs. .

  The “first main body” may include a circuit for transmitting and receiving ultrasonic waves and a control unit, and such a component is mainly outside the pool and has some wiring. The main role of the object may be a moving platform for moving the attached detection end.

  In addition, because the “second body part” requires detailed observation by looking inside the support scope from the top and bottom of the support grid, the direction of the fiberscope can be changed or rotated by remote control from outside the pool. It is preferable to incorporate a mechanism for making it move in a vertical direction.

The “first moving mechanism for moving the main body portion in the fuel assembly side direction and the opposite direction” may be any means such as a screw or a V belt as long as the force from the drive portion can be transmitted. From the viewpoints of reliably functioning in the fuel pool and durability, means using a rigid body like a ball screw is preferable. Therefore, the main body portion also has a moving configuration corresponding to the screw, V-belt or ball screw.
Further, “the first support mechanism that supports the main body while maintaining the posture of the main body when moving” means that a part of the main body is fitted, or a part of the main body is fitted, so that the main body is attached to the installation base. This mechanism is slidable without being displaced, and includes, for example, two slide shafts (bars and beams) fixed to the installation table. Therefore, the main body also has a configuration corresponding to the slide shaft or the like (for example, a total of four legs supported at two positions on the front and rear of each shaft).

The first drive unit and the second drive unit include a submersible electric motor, a motor stored in a waterproof chamber, a submersible air cylinder, and the like. The operator (inspector, observer) will be remotely operated.
In addition to the above, remote control of the wavelength and intensity of ultrasonic waves, fine adjustment of the position and direction of the tip (head) of the fiberscope manually using a jig from the top of the pool, and adjustment of moving speed You may be able to do it, and other underwater lights may be blinked.

The invention according to claim 6 is the fuel inspection apparatus,
The ultrasonic inspection apparatus has a drive unit that is shared with the first main body, the first installation base, the first switching device, and the fiberscope inspection apparatus,
The first main body holds a detection end inserted into the fuel assembly,
The first installation base includes a first moving mechanism that moves the first main body portion in a fuel assembly side direction and an opposite direction, and a first support that holds the posture of the first main body portion while moving. A mechanism,
The first switching device performs on / off switching of transmission of driving force between the first moving mechanism and the driving unit,
The drive unit shared with the fiberscope inspection device is fixed to the first installation base, and operates the first moving mechanism via the first switching device.
The fiberscope inspection device has a second main body, a second installation base, a second switching device, and a drive unit shared with the ultrasonic inspection device,
The second main body holds a fiberscope inserted into the fuel assembly,
The second installation base includes a second moving mechanism that moves the second main body portion in the direction of the fuel assembly side and the opposite direction, and a second support that supports the second main body portion while maintaining the posture of the second main body portion during movement. A mechanism,
The second switching device performs on / off switching of transmission of driving force between the second moving mechanism and the driving unit,
The drive unit shared with the ultrasonic inspection apparatus is also fixed to the second installation base, and operates the second moving mechanism via the second switching device,
Furthermore, the first installation base of the ultrasonic inspection apparatus and the second installation base of the fiberscope inspection apparatus are fixed to each other.

In the present invention, since the drive unit is common, the entire apparatus is reduced in weight, setting is easy, and the apparatus is low in cost.
Note that the switching operation of the switching device is performed remotely by an operator from above the pool. In this case, a mechanism for preventing an error in which the switching devices of the two inspection devices are turned on at the same time is incorporated, and the ultrasonic inspection device and the fiberscope inspection device each have an adjustment unit for achieving an optimum moving speed. You may do it.

Further, “the drive unit is also fixed to the second installation table” may be fixed to only one of the two as long as the first installation table and the second installation table are fixed. That is, the fixing of the drive unit to the first installation base and the second installation base may be direct or indirect.
In addition, the positional relationship between the ultrasonic inspection device and the fiberscope inspection device, the fiberscope inspection device requires various complicated movements for observing the inside of the support grid, etc. Since operation and illumination using a jig may be possible, it is preferable to be above the ultrasonic inspection apparatus.

The invention according to claim 7 is the fuel inspection apparatus, wherein
The first body portion of the ultrasonic inspection apparatus has a transmitter-side probe and a receiver-side probe that can be inserted into the fuel assembly with a row of fuel rods sandwiched therebetween and pulled out from the fuel assembly. A fuel inspection apparatus having a detection end of a broken fuel rod made of

  In the invention of this claim, the detection of the broken fuel rod by the ultrasonic wave is only the change in the reception intensity at the time of transmission / reception of the ultrasonic wave with the fuel rod sandwiched therebetween, and therefore, it is arranged in a line. The inspection for the presence or absence of breakage of the fuel rod is only the movement along the row of fuel rods by the first main body. Therefore, setting and inspection of the ultrasonic inspection apparatus are facilitated, and no particular inconvenience occurs even if the ultrasonic inspection apparatus is integrated with the fiberscope inspection apparatus.

In the present invention, since the ultrasonic inspection apparatus and the fiberscope inspection apparatus are integrally provided, the identification of the fuel rod in which the fuel assembly in which the radioactive leakage has occurred is identified, and the damaged portion of the damaged fuel rod In order to observe the surrounding area and the surrounding area, the ultrasonic inspection apparatus and the fiberscope inspection apparatus are simultaneously submerged, and the setting corresponding to the fuel assembly is made. For this reason, as a result of the time required for these operations being significantly shortened compared to the prior art, the inspection efficiency is greatly improved.
This also facilitates time adjustments for other operations and use of the crane.

  Hereinafter, the present invention will be described based on the best mode. In addition, this invention is not limited to the following embodiment. Various modifications can be made to the following embodiments within the same and equivalent scope as the present invention.

(First embodiment)
The present embodiment relates to an inspection apparatus in which a fiberscope inspection apparatus and an ultrasonic inspection apparatus are integrated.

  A fuel inspection apparatus according to an embodiment of the present invention (also referred to as “inspection apparatus” when obvious) will be described with reference to FIGS. 1 to 3. FIG. 1 is a side view showing a state in which the inspection apparatus of the present embodiment is installed in a fuel assembly to be inspected. FIG. 2 is also a view from above. FIG. 3 is a diagram conceptually showing a state in which the fiberscope inspection apparatus is provided above and below the ultrasonic inspection apparatus in this inspection apparatus, that is, the structure of the main part.

  In FIG. 1 to FIG. 3, 100 is a fuel inspection device, 110 is a fiberscope inspection device, 111 is a fiberscope head, 112 is a slide unit, 113 is a ball screw, and 114 is a fiberscope. Is a fiberscope fine adjustment unit for adjusting the rotation angle and the like, 115 is a fiberscope head manual rotation tool attachment, and 116 is a submersible motor unit (the motor is in the chamber). 117 is an installation base for the fiberscope head. Reference numeral 120 denotes an installation table for the fiberscope inspection apparatus.

130 is an ultrasonic inspection apparatus, 131 is a probe on the transmitter side, 132 is a probe on the receiver side, 133 is a slide unit, 134 is a ball screw, and 135 is received on the transmitter side. The child-side ultrasonic probes 131 and 132 are fixed parts, 136 is an underwater motor part, 137 is an installation base for the ultrasonic probe fixing part 135, and 140 is an inspection apparatus installation base.
Reference numeral 160 denotes a storage box for a control system electronic device such as a motor driver or sequencer device, 170 denotes a power line, and 180 denotes a rail for lateral movement.

In addition, although 300 is a fuel assembly, 310 is a fuel rod, 320 is a support grid, 400 is a spent fuel rack, but since these are not directly related to the gist of the present invention, the explanation is omitted. Omitted.
In addition to the above, the inspection device is equipped with a evacuation unit, etc., and an underwater camera etc. is installed nearby, and there are cranes that lift the fuel assembly upward, but these are self-explanatory and the drawings become finer. It is not shown because it is too much.

As shown in FIG. 1, the fuel inspection device 100 is set on the side surface of a specific span (between the upper and lower support grids 320) of the fuel assembly 300 that is lifted from the spent fuel rack by a crane (not shown). Yes. In this state, the fuel assembly 300 can be moved up and down by the crane to change the span to be inspected, or can be rotated by 90 degrees to change the side facing the fuel inspection apparatus 100. Yes.
FIG. 2 is a diagram showing a state in which this state is viewed from above. The fuel inspection apparatus 100 can be moved to the right in the figure by the rail 180 for lateral movement, whereby the row or column of the fuel rod to be inspected can be changed.

  FIG. 3 is a diagram conceptually illustrating a state in which the sensor unit of the fuel inspection apparatus 100 is integrally assembled with the fiberscope fuel inspection apparatus 110 upward and the ultrasonic inspection apparatus 130 downward. The fiberscope inspection apparatus 110 is installed on a dedicated installation table 120, the ultrasonic inspection apparatus 130 is installed directly on the installation table 140 of the inspection apparatus, and the former installation table 120 is fixed to the latter installation table 140. In the fiberscope inspection device 110, the underwater motor unit 116 is rotated forward and reverse by remote operation, so that the ball screw 113 also rotates forward and reverse, and the slide unit 112 is operated by a rack mechanism (not shown). As you approach the fuel assembly, you move away from it. Accordingly, the fiberscope head 111 can be taken in and out of the fuel assembly 300. Similarly, the ultrasonic inspection apparatus 130 can also insert and remove the probe 131 on the transmitter side and the probe 132 on the receiver side.

  FIG. 3 is a conceptual diagram for clearly showing a state in which the fiberscope inspection apparatus 110 and the ultrasonic inspection apparatus 130 are integrally assembled. For this reason, the slide units 112 and 133 of both inspection apparatuses are linear. However, both ends are bent downward and are fixed to the installation bases 120 and 140 in practice. Similarly, the two submersible motor units 116 and 136 are fixed to the corresponding installation bases 120 and 140, respectively.

  Since the fiberscope inspection device 110 is on the upper side, the fiberscope head manual rotation tool attachment 115 is at the top, and is rotated with a jig (not shown) while viewed from above the pool as shown in FIG. be able to. For this reason, it is possible to precisely observe the damaged portion and its periphery with a fiberscope.

(Second Embodiment)
The present embodiment relates to an inspection apparatus in which a drive device (such as an underwater motor unit) of the fiberscope inspection apparatus 110 and the ultrasonic inspection apparatus 130 is shared.
The principle of the switching mechanism of the drive device (submersible motor) of the fuel inspection device of the second embodiment is shown in FIG.

  In FIG. 4, 150 is a combined submersible motor unit, 151 is a rear gear, 152 is a front gear, 153 is an upper gear, 154 is a lower gear, and 155 is an upper clutch control unit. Yes, 156 is a lower clutch control unit, 157 is an upper clutch, and 158 is a lower clutch. Further, 122 is a support arm of the upper clutch control unit 155, 123 is a support unit of the upper gear 153 and the upper clutch 157, 124 is a support unit of the upper clutch 157, and 141 is a frame for a combined submersible motor unit. 142 is a support part of the lower clutch control part 156, 143 is a support part of the lower gear 154 and the lower clutch 158, and 144 is a support part of the lower clutch 158.

  As shown in FIG. 4, the dual-purpose submersible motor unit 150 includes a fiberscope inspection device (a main body portion is not shown) and an ultrasonic inspection device (a main body portion) at the end of the inspection device installation base 140 by the mount 141. (Not shown) is fixed at an intermediate height. A rear gear 151 and a front gear 152 are attached to the shaft. Further, the rear gear 151 can rotate the ball screw 113 of the fiberscope inspection device via the upper gear 153 and the upper clutch 157, and the front gear 152 can be ultrasonically transmitted via the lower gear 154 and the lower clutch 158. It is possible to rotate the ball screw 134 of the inspection device. For this reason, the fiberscope inspection device (the main body portion is not shown) and the ultrasonic inspection device (the main body portion is not shown) are connected to the fuel assembly (the main portion is not shown) with the forward and reverse rotations of the dual-purpose underwater motor unit 150. (Not shown in the figure) or retreat to the opposite side.

  Further, in order to smoothly rotate each part and transmit torque, the upper clutch control unit 155, the lower clutch control unit 156, the support arm 122 of the upper clutch control unit 155, the support unit 123 of the upper gear 153 and the upper clutch 157, the upper clutch The underwater bearing (not shown) is incorporated in the support portion 124 of the lower clutch control portion 157, the support portion 142 of the lower clutch control portion 156, the support portion 143 of the lower gear 154 and the lower clutch 158, and the support portion 144 of the lower clutch 158. ing.

  Further, the upper clutch control unit 155 can move the upper gear 153 and the upper clutch 157 in the direction indicated by the double arrows (left and right in the drawing) in accordance with a signal from a control line (not shown). The device can be connected to and released from the ball screw 113 by remote control. Similarly, the lower clutch control unit 156 can move the lower gear 154 and the lower clutch 158 in a direction indicated by a double arrow by a signal from a control line (not shown), and thereby the ball screw 134 of the ultrasonic inspection apparatus can be moved. It is possible to remotely connect and release.

In the inspection apparatus according to the second embodiment, since the ultrasonic inspection is first performed, the lower clutch 158 is in the engaged state and the upper clutch 157 is in the released state. Next, since observation with a fiberscope is performed, the lower clutch 158 is in a released state, and the upper clutch 157 is in a connected state.
The inspection apparatus according to the present embodiment incorporates a safety device and the like for preventing both the upper and lower clutches 157 and 158 from being simultaneously connected and overloading the submersible motor unit. Since this is a well-known technique, illustration and description are omitted.

It is the figure which looked at a mode that the fuel inspection apparatus of the 1st Embodiment of this invention is set from the side. It is the figure which looked at a mode that the fuel inspection apparatus of the 1st Embodiment of this invention is set from upper direction. It is a figure which shows the structure of the principal part of the fuel inspection apparatus of the 1st Embodiment of this invention. It is a figure which shows the principle of the switching mechanism of the drive device of the fuel inspection apparatus of the 2nd Embodiment of this invention. It is a conceptual diagram which shows the mode of a test | inspection and the detection of the damage by the ultrasonic wave of a fuel rod. It is a figure which shows notionally a mode that the broken location of a fuel rod is observed using a fiberscope.

Explanation of symbols

100 Fuel Inspection Device 110 Fiberscope Inspection Device 111 Fiberscope (Head)
112 Slide unit 113 Ball screw 114 Fiberscope fine adjustment unit 115 Fiberscope head manual rotation tool attachment 116 Submersible motor unit 117 Fiberscope head installation table 120 Fiberscope inspection device installation table 122 Upper clutch control unit support arm 123 Upper gear And upper clutch support portion 124 upper clutch support portion 130 ultrasonic inspection device 131 transmitter-side probe 132 receiver-side probe 133 slide unit 134 ball screw 135 ultrasonic probe fixing portion 136 underwater motor portion 137 ultrasonic probe Mounting base 140 of the inspection unit 141 Mounting base 141 for the inspection device Submount 142 for the underwater motor unit Supporting part 143 for the lower clutch control part Supporting part 144 for the lower gear and the lower clutch 150 Combined submersible motor unit 151 Rear gear 152 Front gear 153 Upper gear 154 Lower gear 155 Upper clutch control unit 156 Lower clutch control unit 157 Upper clutch 158 Lower clutch 160 Storage box 170 Power line 180 Rail 300 for lateral movement Fuel assembly 310 Healthy fuel rod (fuel rod)
311 Damaged fuel rod 320 Support grid 321 Horizontal lattice plate 322 Vertical lattice plate 323 Dimple portion 400 Spent fuel rack

Claims (7)

  A fuel inspection device comprising an ultrasonic inspection device and a fiberscope inspection device integrally.   The fuel inspection apparatus according to claim 1, wherein the ultrasonic inspection apparatus and the fiberscope inspection apparatus are arranged in the vertical direction.   The fuel inspection apparatus according to claim 2, wherein a fiberscope inspection apparatus is provided above the ultrasonic inspection apparatus.   The ultrasonic inspection apparatus and the fiberscope inspection apparatus have a common drive device for inserting each detection end into the fuel assembly and withdrawing it from the fuel assembly, and has a switching device for selecting which inspection device to drive. The fuel inspection device according to claim 1, wherein the fuel inspection device is provided. The ultrasonic inspection apparatus includes a first main body, a first installation base, and a first driving unit,
The first main body holds a detection end inserted into the fuel assembly,
The first installation base includes a first moving mechanism that moves the first main body portion in a fuel assembly side direction and an opposite direction, and a first support that holds the posture of the first main body portion while moving. A mechanism,
The first drive unit is fixed to the first installation base and operates the first moving mechanism.
The fiberscope inspection device has a second body part, a second installation base, and a second drive part,
The second main body holds a fiberscope inserted into the fuel assembly,
The second installation base includes a second moving mechanism that moves the second main body portion in the direction of the fuel assembly side and the opposite direction, and a second support that supports the second main body portion while maintaining the posture of the second main body portion during movement. A mechanism,
The second driving unit is fixed to the second installation base and operates the second moving mechanism.
The fuel inspection apparatus according to any one of claims 1 to 3, wherein the first installation base and the second installation base are fixed to each other. The ultrasonic inspection apparatus has a drive unit that is shared with the first main body, the first installation base, the first switching device, and the fiberscope inspection apparatus,
The first main body holds a detection end inserted into the fuel assembly,
The first installation base includes a first moving mechanism that moves the first main body portion in a fuel assembly side direction and an opposite direction, and a first support that holds the posture of the first main body portion while moving. A mechanism,
The first switching device performs on / off switching of transmission of driving force between the first moving mechanism and the driving unit,
The drive unit shared with the fiberscope inspection device is fixed to the first installation base, and operates the first moving mechanism via the first switching device.
The fiberscope inspection device has a second main body, a second installation base, a second switching device, and a drive unit shared with the ultrasonic inspection device,
The second main body holds a fiberscope inserted into the fuel assembly,
The second installation base includes a second moving mechanism that moves the second main body portion in the direction of the fuel assembly side and the opposite direction, and a second support that supports the second main body portion while maintaining the posture of the second main body portion during movement. A mechanism,
The second switching device performs on / off switching of transmission of driving force between the second moving mechanism and the driving unit,
The drive unit shared with the ultrasonic inspection apparatus is also fixed to the second installation base, and operates the second moving mechanism via the second switching device,
5. The fuel inspection apparatus according to claim 4, wherein the first installation base of the ultrasonic inspection apparatus and the second installation base of the fiberscope inspection apparatus are fixed to each other. The first body portion of the ultrasonic inspection apparatus has a transmitter-side probe and a receiver-side probe that can be inserted into the fuel assembly with a row of fuel rods sandwiched therebetween and pulled out from the fuel assembly. The fuel inspection device according to claim 5 or 6, wherein a detection end of a broken fuel rod made of

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