JP4186539B2 - Canister visual inspection device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a canister visual inspection apparatus for inspecting the soundness of a canister stored in a cask.
[0002]
[Prior art]
At present, as an intermediate storage method for spent fuel generated in nuclear power plants and the like, it is housed and stored in a device having a high radiation shielding capability called a metal storage cask in Japan.
[0003]
In the US and the like, there is an increasing record of storing a combination of a concrete cask and a sealed container called a metal canister instead of a metal storage cask because of its low cost.
[0004]
An example of a concrete cask will be described with reference to FIGS. 9 and 10.
[0005]
9 is a front sectional view of the concrete cask, and FIG. 10 is a sectional view taken along line XX of FIG.
[0006]
As shown in the figure, the concrete cask 20 includes a cylindrical body 21 made of reinforced concrete and an upper lid 22. A canister 30 indicated by a broken line is accommodated inside the cylindrical body 21, and then the upper lid 22 is fixed to the cylindrical body 21 by bolt fastening or the like, and the canister 30 is stored in the cask 20.
[0007]
The thickness W of the cylindrical body 20 is set to a thickness sufficient to block radiation emitted from the canister 30.
[0008]
Air inlets 23 for introducing air for cooling the stored canister 30 from the outside are provided at four locations in the circumferential direction at the lower side of the cylindrical body 21, and at four locations in the circumferential direction at the upper side of the cylindrical body 21. An exhaust port 25 for discharging the air introduced into the cask 20 from the intake port 23 to the outside is provided.
[0009]
The air introduced into the cask 20 from the air inlet 23 flows between the cask 20 and the canister 30 and takes away the decay heat generated in the canister 30. Thereafter, the air becomes an updraft and is discharged from the exhaust port 25 to the outside.
[0010]
The inner wall of the concrete cask 20 is provided with a plurality (eight in the drawing) of guide rails 26 extending in the longitudinal direction (vertical direction) in order to ensure the air flow rate of the cooling air.
[0011]
By the way, after accommodating the canister 30 in the concrete cask 20, it is planned to store it for about 40 to 50 years. During the storage period, the soundness of the canister 30 is periodically (eg every several years). Inspection / inspection is required. Specifically, it is necessary to observe the outer surface of the canister 30 to confirm the presence or absence of abnormal corrosion or defects.
[0012]
In the United States and the like, a soundness inspection of the canister 30 stored in the concrete cask 20 has already been performed. The surface is observed from a remote location.
[0013]
[Problems to be solved by the invention]
Here, as described above, the soundness inspection checks for the presence or absence of abnormal corrosion or defects on the outer surface of the canister 30, but the weld seam portion of the canister 30 is also most likely to be abnormal, and the inspection is performed. It is a necessary part.
[0014]
However, it has been a very difficult task to position the distal end portion (observation portion) of the flexible fiberscope 27 in accordance with the target site such as the weld seam of the canister 30. For this reason, skill is required for the inspection work, leading to a prolonged work period and an increase in cost.
[0015]
Further, since the fiberscope 27 swings in the cask 20, the distance between the canister 30 and the fiberscope 27 is not constant, and it is difficult to focus on the surface of the canister 30.
[0016]
Furthermore, since the concrete cask 20 is dark, a lighting device is provided at the tip of the fiberscope 27. However, if the fiberscope 27 swings too close to the surface of the canister 30, light reflection is strong and white and nothing is visible. There was also a problem that there was no such thing.
[0017]
Accordingly, an object of the present invention is to provide a canister appearance inspection device that solves the above-described problems and can easily and appropriately inspect the appearance of a canister stored in a cask.
[0018]
[Means for Solving the Problems]
To accomplish the above object, key catcher scan in order to test the integrity of the stored canister into click, the appearance of the canister by introducing flexible viewing equipment such as fiber scope in key catcher scan click in the canister appearance inspection apparatus for inspecting the inner wall of the cask, along the storage surface of the canister provided with a guide means for guiding the viewing device, the upper surface of the canister stored in the key catcher scan click along further comprising a top guide means for guiding the viewing equipment, the top guide means, mounted rotatably on introducing hole formed at a substantially central portion of the lid of the key catcher scan click the key catcher scan click A pipe body extending along the lower surface of the lid, and a slit-like inspection window formed on the canister side of the pipe body are provided.
[0019]
Here, it is preferable that a shielding lid is attached to the upper end opening of the pipe body when visual inspection is not performed .
[0024]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.
[0025]
FIG. 1 is a front sectional view of a canister appearance inspection apparatus showing a reference example that is not an embodiment of the present invention , and FIG. 2 is a sectional view taken along line II-II in FIG. FIG. 3 is an enlarged front sectional view of the canister visual inspection apparatus. FIG. 4 is an enlarged perspective view of the lower end portion of the guide means.
[0026]
Since the concrete cask 20 for storing the canister 30 is the same as that shown in FIG. 9, the same elements are denoted by the same reference numerals and the description thereof is omitted.
[0027]
The canister appearance inspection apparatus according to the present embodiment introduces a long and flexible visual recognition device 1 (hereinafter, referred to as a fiberscope) such as a fiberscope into a concrete cask 20 and observes the appearance of the canister 30 stored therein. However, it is characterized in that it is provided with guide means 2 for guiding the visual recognition device 1 along the surface of the canister 30.
[0028]
The guide means 2 has an opening formed on the pipe body 3 through which the fiberscope 1 is inserted to restrict the moving direction thereof, and on the side of the pipe body 3 facing the canister 30 (that is, on the inner side of the concrete cask 20). The slit-shaped inspection window 5 is provided (see FIG. 4). Accordingly, the guide means 2 and the pipe body 3 are the same in the drawing.
[0029]
The pipe body 3 includes an introduction portion 6 attached in the exhaust port 25 of the concrete cask 20, a longitudinal seam inspection portion 7 extending in the vertical direction (vertical direction) along the guide rail 26 on the inner wall of the cask 20, It has a transverse seam inspection part 8 that is formed continuously at substantially the lowest part and the middle part of the seam inspection part 7 and extends along the inner wall of the concrete cask 20 along the lateral direction (circumferential direction).
[0030]
The longitudinal seam inspection unit 7 and the lateral seam inspection unit 8 of the pipe body 3 are arranged so that the distance from the canister 30 accommodated in the concrete cask 20 is the same at all positions. In other words, the distances from the inner wall of the cask 20 of the longitudinal seam inspection unit 7 and the horizontal seam inspection unit 8 are equal at all positions.
[0031]
Further, the longitudinal seam inspection unit 7 and the lateral seam inspection unit 8 are arranged so that the distance between the fiberscope 1 and the canister 30 is appropriately maintained when the fiberscope 1 is inserted therein. That is, if the fiberscope 1 is too close to the surface of the canister 30, the reflected light of the illumination of the fiberscope 1 becomes too strong, so that the distance between the fiberscope 1 and the canister 30 is appropriately secured to prevent this.
[0032]
In the present embodiment, the side seam inspection unit 8 is arranged in accordance with the height of the weld seam (weld line) extending in the lateral direction (circumferential direction) on the side surface of the canister 30 stored in the concrete cask 20. In other words, as shown in the figure, the transverse seam inspection portion 8 is provided at the lowermost portion and the middle portion of the inner wall of the cask 20. However, in the present invention, there is no restriction on the position and number of the transverse seam inspection units 8, and they may be appropriately provided according to the part of the canister 30 to be inspected.
[0033]
As shown in FIG. 2, one guide means 2 of the present embodiment is provided between each guide rail 26 provided on the inner wall of the concrete cask 20. That is, in the present embodiment, a total of eight guide means 2 are provided. The transverse joint inspection portion 8 of each guide means 2 is formed over almost the entire area between the guide rails 26. Therefore, as can be seen from the figure, when the transverse seam inspection portions 8 of all the guide means 2 are combined, they are formed over almost the entire circumference of the inner wall of the concrete cask 20.
[0034]
It should be noted that all the transverse seam inspection portions 8 of each guide means 2 may be provided at the same height or at different heights.
[0035]
As shown in FIG. 4, the inspection window 5 is continuously formed so as to extend along the longitudinal direction of the longitudinal seam inspection portion 7 and the lateral seam inspection portion 8 of the pipe body 3. Further, as described above, the inspection window 5 is formed in a portion of the pipe body 3 that faces the surface of the canister 30. The width H of the inspection window 5 is appropriately set according to the size of the distal end portion (observation portion) 1 a of the fiber scope 1. That is, the fiberscope 1 inserted into the pipe body 3 is formed in a size that allows the surface of the canister 30 to be sufficiently observed from the inspection window 5. The inspection window 5 may be provided over the entire length of the longitudinal seam inspection unit 7 and the horizontal seam inspection unit 8 or may be partially provided. The distal end portion of the transverse seam inspection portion 8, that is, the distal end portion of the pipe body 3 is closed by the lid 9.
[0036]
Now, a canister appearance inspection method using the canister appearance inspection apparatus will be described.
[0037]
First, each guide means 2 is attached to the concrete cask 20 in advance. Next, the canister 30 transported from a nuclear power plant or the like is accommodated in the concrete cask 20. At this time, the weld seam extending in the longitudinal direction on the side surface of the canister 30 is used as the longitudinal seam of any guide means 2. It accommodates according to the position of the inspection unit 7.
[0038]
Then, as shown in FIG. 3, the fiberscope 1 provided with illumination means (not shown) such as a lamp is inserted into the pipe body 3 of the guide means 2 from the introduction portion 6. If it is determined that the fiberscope 1 has been inserted a predetermined distance and the observation part 1a has reached the longitudinal seam inspection part 7, the fiberscope 1 is rotated and the observation part 1a is moved to the inspection window 5 side of the pipe body 3. That is, it is positioned so as to face the canister 30 side stored in the cask 20.
[0039]
Here, when the observation part 1 a of the fiberscope 1 faces the part other than the inspection window 5, the observation part 1 a faces the inner surface of the pipe body 3. Since the distance between the inner surface of the pipe body 3 and the observation part 1a of the fiberscope 1 is very close, in that case, a white image is observed by the reflected light of the illumination.
[0040]
On the other hand, when the observation part 1a of the fiberscope 1 faces the inspection window 5, the observation part 1a faces the surface of the canister 30 through the inspection window 5 at an appropriate distance, so that the surface of the canister 30 is in focus. The observed image is observed. Therefore, the operator can execute the facing of the fiberscope 1 relatively easily and accurately.
[0041]
Further, the surface of the canister 30 observed when the observation part 1a of the fiberscope 1 faces the inspection window 5 side becomes an inspection target part such as a weld seam extending in the vertical direction through the canister 30. That is, the operator does not need to find the welding seam (inspection site) while confirming the image obtained with the fiberscope 1, and is simply guided into the welding seam simply by inserting the fiberscope 1 into the guide means 2. It is.
[0042]
Next, the fiberscope 1 is further inserted in this state. As a result, the observation unit 1a of the fiberscope 1 moves downward along the longitudinal seam inspection unit 7 in a state where movement in the lateral direction is restricted to some extent by the guide means 2.
[0043]
The fiberscope 1 is always kept at a constant distance from the surface of the canister 30 by the guide means 2, so that the focus is not deviated and a good image can always be obtained. Moreover, since the observation part 1a moves downward along the weld seam of the canister 30, the longitudinal weld seam of the canister 30 can be inspected sequentially from top to bottom.
[0044]
When the observation unit 1a of the fiberscope 1 reaches the lowermost end of the longitudinal seam inspection unit 7, the observation unit 1a moves into the transverse seam inspection unit 8. At this time, the surface of the canister 30 observed from the inspection window 5 becomes an inspection site such as a weld seam extending in the circumferential direction of the canister 30. The fiberscope 1 is sequentially inserted, and the weld seam in the lateral direction of the canister 30 is observed. Also at this time, since the distance between the observation unit 1a of the fiberscope 1 and the surface of the canister 30 is always kept constant, a good image can be obtained without always performing the focusing operation. Moreover, since the observation part 1a of the fiberscope 1 is guided along the weld seam extending through the canister 30 in the lateral direction, the weld seam can be inspected sequentially. If the observation part 1a of the fiberscope 1 has moved to the tip of the transverse joint inspection part 8, the fiberscope 1 is removed from the guide means 2 and inserted into the pipe body 3 of another guide means 2 to perform the same inspection. .
[0045]
When the inspection by all the guide means 2 is completed, the inspection is ended. When an abnormality is observed on the surface of the canister 30, the abnormality occurrence position can be specified from the insertion amount of the fiberscope 1.
[0046]
Here, an image obtained by the fiberscope 1 may be recorded on a VTR or the like. If the inspection image is recorded, the surface state of the canister 30 can be compared for each inspection.
[0047]
Thus, according to the canister appearance inspection apparatus of the present embodiment, the observation unit 1a is guided to the target inspection position simply by inserting the fiberscope 1 into the guide means 2. In addition, since the distance between the fiberscope 1 and the canister 30 is always kept constant, good observation can be performed. Therefore, it is possible to perform inspection in a short period without requiring skill in the inspection work.
[0048]
Further, since the fiberscope 1 is accommodated in the guide means 2, if a material having high radiation shielding performance is selected as the material of the guide means 2, the deterioration of the fiberscope 1 due to the radiation from the canister 30 can be reduced.
[0049]
Next, another arrangement example of the guide unit 2 will be described with reference to FIGS. 5 and 6.
[0050]
This embodiment is applied to a structure in which guide rails 26 are arranged on both sides of each exhaust port 25 of the cask 20. Two guide means 2 are respectively arranged between the guide rails 26 located on both sides of the exhaust port 25. Further, slits are formed in the lowermost part and the middle part of the guide rail 26, and the transverse joint inspection parts 8 of some guide means 2 extend in the lateral direction beyond the guide rail 26 by passing through the slits. . Thus, the guide means 2 of the present invention is appropriately arranged in consideration of the positional relationship between the guide rail 26 and the exhaust port 25, the number of the guide rails 26, and the like.
[0051]
FIG. 7 is a diagram showing an embodiment of the present invention. The present embodiment further includes upper surface guide means for inspecting the upper surface of the canister 30 stored in the concrete cask 20.
[0052]
The upper surface guide means will be described with reference to FIG.
[0053]
As shown in the figure, an introduction hole 10 penetrating in the vertical direction is formed in a substantially central portion of the upper lid 22 forming the upper surface of the concrete cask 20, and the upper surface guide means 11 is rotatably attached to the introduction hole 10.
[0054]
The upper surface guide means 11 is formed laterally along the upper surface 13 of the inner wall of the cask 20 (the lower surface of the upper lid 22) formed continuously from the introduction portion 12 extending through the introduction hole 10 of the concrete cask 20 and the lower end portion of the introduction portion 12. It has a pipe body 16 having an upper surface inspection portion 15 extending in the (diameter direction), and a slit-shaped inspection window 17 formed on the canister 30 side of the upper surface inspection portion 15, that is, on the lower side. The upper surface inspection unit 15 extends to almost the outer edge of the canister 30.
[0055]
A flange portion 18 is provided at the upper end portion of the introduction portion 12 to prevent the pipe body 16 from falling into the canister 20 and to be used when the pipe body 16 is rotated. Naturally, the flange portion 18 is formed larger than the introduction hole 10.
[0056]
A visual inspection of the upper surface of the canister 30 can be performed by inserting the visual recognition device 1 such as a fiberscope into the pipe body 16 of the upper surface guide means 11 and aligning the direction of the observation unit 1 a with the inspection window 17.
[0057]
Further, if the upper surface guide means 11 is rotated in a state where the observation part 1a of the fiberscope 1 is aligned with the position of the weld seam 30a extending in the circumferential direction on the upper surface of the canister 30, the weld seam on the upper surface of the canister 30 is made all around. Can be tested across.
[0058]
In FIG. 7, the inspection window 17 is formed only in a portion facing the weld seam 30 a of the canister 30, but it may be formed over almost the entire longitudinal direction of the upper surface inspection portion 15.
[0059]
Here, when visual inspection of the upper surface of the canister 30 is not performed, it is preferable to close the upper end opening of the pipe body 16 by screwing a shielding lid 19 made of metal or the like as shown in FIG. .
[0060]
Heretofore, a fiber scope has been described as the visual recognition device 1, but the present invention is not limited in this respect, and other means such as a CCD camera attached to the tip of a flexible cable may be used.
[0061]
The concrete cask to which the canister appearance inspection apparatus of the present invention is applied is not limited to the illustrated one.
[0062]
Moreover, the pipe body 3 is not limited to a cylindrical shape, and may have other shapes such as a square shape as long as the visual recognition device 1 can be inserted.
[0063]
【The invention's effect】
In short, according to the present invention, the excellent effect that the appearance inspection of the canister stored in the cask can be executed easily and appropriately is exhibited.
[Brief description of the drawings]
1 is a front sectional view of the canister appearance inspection apparatus according to the reference example is not a implementation form of the present invention.
FIG. 2 is a cross-sectional view taken along the line II-II in FIG.
FIG. 3 is an enlarged front sectional view of the canister visual inspection apparatus.
FIG. 4 is an enlarged perspective view of a lower end portion of the guide means.
5 is a front sectional view of the canister appearance inspection apparatus according to the reference example is not a implementation form of the present invention.
6 is a cross-sectional view taken along line VI-VI in FIG.
FIG. 7 is a front sectional view of the upper surface guide means of the canister visual inspection apparatus according to the embodiment of the present invention .
FIG. 8 is a front sectional view showing a state in which the pipe body of the upper surface guide means is closed.
FIG. 9 is a front sectional view showing a conventional canister appearance inspection apparatus.
10 is a cross-sectional view taken along line XX in FIG.
[Explanation of symbols]
1 Visual equipment (fiberscope)
2 Guide means 3 Pipe body 5 Inspection window 20 Cask 30 Canister

Claims (2)

· The order to test the integrity of the canister stored in the catcher scan click, the canister appearance inspection apparatus for inspecting the appearance of the canister by introducing flexible viewing equipment such as fiber scope in key catcher scan click,
Upper surface on the inner wall of the cask, along the storage surface of the canister provided with a guide means for guiding the viewing device, for guiding the viewing device along an upper surface of the canister stored in the key catcher scan click further comprising a guide means, the upper surface guide means, the pipe extending along the lower surface of the key catcher scan click of the introduction hole formed at a substantially central portion of the lid is provided rotatably in the key catcher scan click lid And a canister appearance inspection device comprising a slit-shaped inspection window formed on the canister side of the pipe body.   The canister appearance inspection apparatus according to claim 1, wherein a shielding lid is attached to the upper end opening of the pipe body when visual inspection is not performed.

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