JP2018066625A - Device and method for cleaning radioactive contaminated material storage tank - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cleaning device capable of reliably cleaning the inside of a horizontally long radioactive contamination storage tank. SOLUTION: A boom 30 is rotatably connected to a tip of a long-distance operating paddle 2 of a radioactive contamination storage tank cleaning device 1. Cleaning nozzles 41 and 42 are provided at the tip of the boom 30. The remote rotation operation means 50 makes the boom 30 rotatable with respect to the long-distance operation paddle 2. The boom 30 is inserted into the tank 90 from the manhole 93 at the upper part of the radioactive contamination storage tank 90. [Selection diagram] FIG. 11

Description

  The present invention relates to an apparatus and a method for cleaning the inside of a tank that stores radioactive contaminants, and more particularly, to a cleaning apparatus and a cleaning method suitable for a horizontally long radioactive contaminant storage tank.

  At the Fukushima nuclear power plant, since the previous accident, many storage tanks have been set up on the premises to store high doses of radioactive contaminants. The radioactive contaminant storage tank has a horizontally long cylindrical shape and takes up space, while its capacity is relatively small. Therefore, a plan to remove the current horizontally long tank and install a new large capacity tank is underway. Some of the horizontal tanks are moved to another location for temporary storage of radioactive contaminants, but they must be cleaned before being removed or moved to another location. On the other hand, because of the high dose, a person cannot enter the tank directly for cleaning.

JP, 2006-003976, A

  A manhole is provided above the radioactive contaminant storage tank. The manhole is arranged so as to be biased to one side with respect to the central portion in the longitudinal direction of the tank. Specifically, the distance from the manhole to the short distance side end of the tank is 4 meters. The distance from the manhole to the long end of the tank is 9 meters. Ring-shaped inner peripheral ribs are provided at three locations in the longitudinal direction of the inner peripheral surface of the tank.

The inventors have studied that a cleaning jig provided with a cleaning nozzle at the tip is inserted into a tank from a manhole and cleaned remotely. However, even if the cleaning jig can reach the short distance side end, it is necessary not only to be a long distance but also to get over one or two inner peripheral ribs to the long distance side end. is there.
An object of this invention is to provide the washing | cleaning apparatus and method which can wash | clean the inside of a horizontally long radioactive contaminant storage tank reliably in view of the said situation.

In order to solve the above problems, the apparatus of the present invention is a radioactive contaminant storage tank cleaning device for cleaning the inside of a horizontally long radioactive contaminant storage tank,
An operation rod,
A boom that is rotatably connected to the tip of the operating rod and extends from the operating rod;
A cleaning nozzle provided at the tip of the boom;
Remote rotation operation means capable of remotely rotating the boom with respect to the operation rod;
It can be inserted into the radioactive contaminant storage tank from the manhole at the top of the radioactive contaminant storage tank.
According to the radioactive contaminant storage tank cleaning apparatus according to the present invention, the inside of the horizontally long radioactive contaminant storage tank can be cleaned to the end on the long distance side. Even if there are ring-shaped inner ribs and other obstacles on the inner peripheral surface of the radioactive contaminant storage tank, you can get over obstacles such as inner ribs by rotating the boom. It is possible to clean the inside of the radioactive contaminant storage tank longer than the obstacle.

It is preferable that the remote rotation operation means includes an operation wire extending along the operation rod and the boom, and a distal end portion of the operation wire is connected to a distal end portion of the boom.
The boom can be remotely rotated by pulling or loosening the operation wire on the hand side of the operation rod.

The method of the present invention is a radioactive contaminant storage tank method for cleaning the inside of a horizontally long radioactive contaminant storage tank,
A suction step of sucking and sending out radioactive contaminants in the radioactive contaminant storage tank by means of an ejector device inserted from a manhole at the top of the radioactive contaminant storage tank;
A short-distance washing step of washing a short-distance washing range centering on a manhole in the radioactive contaminant storage tank by a short-distance washing device provided with a short-distance washing nozzle at the tip of the operation rod;
A long-distance washing step of washing a long-distance washing range farther than the short-distance washing range as seen from the manhole in the radioactive contamination storage tank by the radioactive contamination storage tank washing device (long-distance washing device);
It is provided with.
First, a part to most of the radioactive contaminants in the radioactive contaminant storage tank are sucked out by the suction step. Next, the inner wall of the radioactive contaminant storage tank is cleaned by a short distance cleaning process and a long distance cleaning process.

In the long-distance cleaning process, a pedestal is inserted into the radioactive contaminant storage tank from the manhole, and the radioactive contamination is straddled across the inner peripheral rib formed in the intermediate portion in the longitudinal direction of the radioactive contaminant storage tank. It is preferable to place the radioactive contaminant storage tank cleaning device on the gantry and perform the cleaning of the long-distance cleaning range.
Thereby, the said radioactive contaminant storage tank washing | cleaning apparatus can wash | clean the long distance washing | cleaning range, without being caught by an inner peripheral rib.

  According to the present invention, the inside of the horizontally long radioactive contaminant storage tank can be reliably cleaned.

FIG. 1 is a side sectional view showing a radioactive contaminant storage tank to be cleaned in an embodiment of the present invention. FIG. 2A is a plan view of the long-distance cleaning device (radiopollutant storage tank cleaning device) in the embodiment. FIG. 2B is a side view of the long-distance cleaning apparatus. FIG. 3 is a perspective view of the long-distance cleaning apparatus. Fig.4 (a) is a top view of the mount frame in the said embodiment. FIG. 4B is a side view of the gantry. FIG. 5 is a cross-sectional view of the tip portion of the ejector device in the embodiment. FIG. 6A is a plan view of the short distance cleaning apparatus in the embodiment. FIG. 6B is a side view of the short distance cleaning apparatus. Fig.7 (a) is side surface sectional drawing of the radioactive contaminant storage tank in the sucking-out process of the radioactive contaminant by an ejector apparatus. FIG.7 (b) is side surface sectional drawing of the radioactive contaminant storage tank in the short distance cleaning process by a short distance cleaning apparatus. FIG.7 (c) is side surface sectional drawing of the radioactive contaminant storage tank in the first half part of the long distance cleaning process by a long distance cleaning apparatus. FIG. 8 is a plan view of the manhole of the radioactive contaminant storage tank taken along line VIII-VIII in FIG. FIG. 9A to FIG. 9E are side cross-sectional views of a part of the radioactive contaminant storage tank, which sequentially shows the installation process of the gantry to the tank bottom. FIG. 10A is a side cross-sectional view of the radioactive contaminant storage tank in a state in which the gantry is installed at the bottom of the tank. FIG.10 (b) is side surface sectional drawing which expands and shows the circular part Xb of the same figure (a). 10 (c) and 10 (d) are side cross-sectional views of the radioactive contaminant storage tank showing the latter half of the long-distance cleaning process by the long-distance cleaning apparatus in order. Fig.11 (a) is side surface sectional drawing of a radioactive contaminant storage tank which shows the latter half part of the long distance cleaning process after FIG.10 (b) by a long distance cleaning apparatus. FIG. 11B is an enlarged side view showing the long-distance cleaning jig in FIG. FIG. 12 is a side cross-sectional view of the radioactive contaminant storage tank showing the final stage of the long-distance cleaning process by the long-distance cleaning apparatus.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
As shown in FIG. 1, the radioactive contaminant storage tank 90 to be cleaned has a horizontally long cylindrical shape. A radioactive contaminant 9 is stored in the radioactive contaminant storage tank 90. The radioactive contaminant 9 includes a slurry 9b and a supernatant 9a. A manhole 93 is provided in the upper part of the radioactive contaminant storage tank 90. The manhole 93 is arranged to be biased to one side with respect to the central portion in the longitudinal direction of the radioactive contaminant storage tank 90. Specifically, the distance from the manhole 93 to the short distance side end 90d of the radioactive contaminant storage tank 90 is 4 meters. The distance from the manhole 93 to the long distance side end portion 90e of the radioactive contaminant storage tank 90 is 9 meters. Ring-shaped inner peripheral ribs 92 are provided at three locations in the longitudinal direction of the inner peripheral surface of the radioactive contaminant storage tank 90.

As shown in FIGS. 2 to 6, the cleaning system for the radioactive contaminant storage tank 90 includes a long-distance cleaning device 1 (a radioactive contaminant storage tank cleaning device), a gantry 6, an ejector device 7, and a short distance. A cleaning device 8 is included. As will be described later, the apparatuses 1, 7, and 8 are selectively used according to the cleaning stage.
As shown in FIGS. 2 and 3, the long-distance cleaning apparatus 1 includes a long-distance operation rod 2 and a long-distance cleaning jig 3. As shown in FIG. 3, the long-distance operation rod 2 extends like a bow. The long distance operation rod 2 may be linear.

  As shown in FIGS. 2 and 3, the long distance cleaning jig 3 is connected to the tip of the long distance operation rod 2. The long-distance cleaning jig 3 can be inserted into the radioactive contaminant storage tank 90 from the manhole 93 at the top of the radioactive contaminant storage tank 90. The long-distance cleaning jig 3 includes a base 10, a boom 30, and a cleaning nozzle manifold 40.

  The base plate 10 has a substantially rectangular plate shape. The base 10 is provided with a rotation connecting portion 11, a counterweight 12, and wheels 21, 22, and 25. The rotary connecting portion 11 has a pair of connecting plates 11a. The connecting plates 11 a are erected on the upper surface of the base 10 and are opposed to each other in the width direction of the base 10. A distal end portion of the long-distance operation rod 2 is rotatably connected to the connecting plate 11a. The rotating shaft 11 c is directed in the width direction of the base 10. The long-distance cleaning jig 3 is rotatable so as to be lifted around the rotation axis 11c with respect to the long-distance operation rod 2 (FIG. 11).

A counterweight 12 is provided behind the rotary connecting portion 11 on the upper surface of the base 10.
Rear wheels 21 and 22 are disposed on the left and right sides of the front portion of the bottom surface of the base plate 10. The first rear wheel 21 and the second rear wheel 22 are arranged close to each other in the front-rear direction.
Auxiliary rear wheels 25 are disposed on the left and right sides of the rear portion of the base plate 10. The auxiliary rear wheel 25 is disposed at a higher position than the rear wheels 21 and 22 in the height direction orthogonal to the base plate 10. An arrangement space for the counterweight 12 is secured between the left and right auxiliary rear wheels 25.

  The base end portion of the boom 30 is fixed to the base plate 10. The boom 30 extends linearly forward from the base plate 10. As a result, the boom 30 is rotatably connected to the distal end portion of the long-distance operation rod 2 via the platform 10 and extends from the long-distance operation rod 2.

  A cleaning nozzle manifold 40 is provided at the tip of the boom 30. The cleaning nozzle manifold 40 includes a plurality of cleaning nozzles 41 and 42. The front washing nozzle 41 is directed obliquely downward. The rear cleaning nozzle 42 is directed obliquely downward to the rear. The number of cleaning nozzles 41 and 42 can be set as appropriate, and is not limited to that shown in the drawing. The rear washing nozzle 42 may be omitted, and the washing nozzle manifold 40 may be configured with only the front washing nozzle 41.

  A cleaning liquid tube 44 extends from the high-pressure cleaning liquid supply source 49 (FIG. 2A). Although simplified in the figure, the cleaning liquid tube 44 extends along the long-distance operation rod 2 and the boom 30. The cleaning liquid tube 44 in the long-distance operation rod 2 is piped on the outer surface of the long-distance operation rod 2, but the cleaning liquid tube 44 may be passed through the long-distance operation rod 2. The boom 30 is provided with an inverted U-shaped tube locking portion 34 at an interval in the longitudinal direction. A cleaning liquid tube 44 is passed through the tube locking portion 34. The tip of the cleaning liquid tube 44 is connected to the cleaning nozzle manifold 40.

  A front wheel support portion 33 is provided in front of the cleaning nozzle manifold 40. The front wheel support portion 33 is supported by the boom 30 via the connecting rod 32. A front wheel 23 is rotatably provided on the front wheel support portion 33.

  A pair of guide bars 35 are provided on both sides of the boom 30 in parallel. A tip guide portion 35 a is provided at the tip portion of the guide bar 35. The tip guide portion 35a is formed in an arc shape. The distal end guide portion 35 a is disposed on the left and right sides of the cleaning nozzle manifold 40, and an intermediate portion thereof protrudes downward from the nozzles 41 and 42. The distal end portion of the distal end guide portion 35 a is disposed on the side near the front wheel 23.

As shown in FIG. 3, the long-distance cleaning apparatus 1 further includes a remote rotation operation unit 50 (an uplifting unit). The remote rotation operation means 50 includes an operation wire 51 and a pulley 52. A pulley 52 is provided at an intermediate portion of the long-distance operation rod 2. The operation wire 51 extends along the long-distance operation rod 2 and the boom 30. An intermediate portion of the operation wire 51 is wound around the pulley 52. The distal end portion of the operation wire 51 is connected to the distal end portion of the boom 30.
By pulling or loosening the operation wire 51 on the proximal side of the long-distance operation rod 2 (right side in FIG. 2), the long-distance cleaning jig 3 and the boom 30 are remotely rotated with respect to the long-distance operation rod 2. It is possible to operate.

  As shown in FIG. 4, the gantry 6 includes a short distance side base plate 61 and a long distance side base plate 62. These base plates 61 and 62 are rotatably connected via a hinge 66. A short-distance end inclined portion 63 having a U-shaped frame shape extends obliquely upward from an end portion of the short-distance side base plate 61. A plate-like long-distance end inclined portion 64 extends obliquely downward from the end of the long-distance side base plate 62. Wheels 65 are provided at various locations on the bottom of the gantry 6.

As shown in FIG. 5, the ejector device 7 includes an eject pipe 70, one or a plurality of (only one is shown in the figure) cleaning nozzles 71, and an eject nozzle 72. The distal end portion (lower end portion in FIG. 5) of the eject tube 70 is expanded. The eject tube 70 may be a straight tube having the same diameter as that of the tip portion except for the tip portion. A cleaning nozzle 71 is provided on the outer surface of the opening at the tip of the eject tube 70. A high pressure cleaning liquid supply source 79 is connected to the supply port of the cleaning nozzle 71.
A plurality of cleaning nozzles 71 may be provided at intervals in the circumferential direction of the eject pipe 70. The injection direction of the cleaning nozzle 71 may be parallel to the axis of the tip of the eject pipe 70 or may be oblique.

  An eject nozzle 72 is provided at a position shifted in the circumferential direction from the cleaning nozzle 71 at the tip of the eject pipe 70. A compressed air supply source 78 is connected to the supply port of the eject nozzle 72. The tip of the eject nozzle 72 faces the inside of the tip opening of the eject pipe 70.

As shown in FIG. 6, the short distance cleaning device 8 includes a short distance operation rod 82 and a short distance cleaning jig 83. A short-distance cleaning jig 83 is rotatably connected to the tip of the short-distance operation rod 82. The short distance cleaning jig 83 has a rectangular plate shape. Wheels 85 are provided at the four corners of the bottom surface of the short distance cleaning jig 83. A short-distance cleaning nozzle 84 is provided at the center of the bottom surface of the short-distance cleaning jig 83. As shown in FIG. 6B, a high-pressure cleaning liquid supply source 89 is connected to the supply port of the short-distance cleaning nozzle 84. The tip of the short-distance cleaning nozzle 84 is directed obliquely downward.
The high-pressure cleaning liquid supply sources 49, 79, and 89 may be configured by a common high-pressure cleaning liquid supply source.

The radioactive contaminant storage tank 90 is cleaned as follows.
<Suction process>
As shown in FIG. 7A, the manhole 93 is opened. Then, the ejector device 7 is inserted from the manhole 93 into the radioactive contaminant storage tank 90. Compressed air from the compressed air supply source 78 is jetted from the eject nozzle 72 into the eject pipe 70.
The compressed air flows to the back side (upper side in FIG. 5) of the eject pipe 70. As a result, a decompression chamber 70e is formed inside the tip of the eject pipe 70, and the supernatant 9a and the slurry 9b are sucked into the eject pipe 70 by the ejector effect.
A high-pressure cleaning liquid (water) from a high-pressure cleaning liquid supply source 79 is sprayed from the cleaning nozzle 71 to the highly viscous or hard slurry 9b. The slurry 9b is broken or crushed by the high-pressure washing liquid to improve the fluidity. Thereby, a highly viscous or hard slurry 9b can be sucked out. Preferably, most of the radioactive contaminants 9 (supernatant 9a and slurry 9b) in the radioactive contaminant storage tank 90 are sucked out.
By using the ejector device 7 instead of the vacuum pump as the suction means, clogging or the like in the tube can be reduced.
In addition, the sucked radioactive contaminant 9 (supernatant 9a and slurry 9b) is temporarily stored in a tank in another place. After the large-capacity tank is completed, it will be transferred to it.

<Short distance cleaning process>
Next, as shown in FIG. 7B, the short distance cleaning jig 83 of the short distance cleaning device 8 is inserted into the tank 90 from the manhole 93. The high-pressure cleaning liquid (water) from the high-pressure cleaning liquid supply source 89 is jetted from the short-distance cleaning nozzle 84. As a result, the short-range cleaning range around the manhole 93 in the tank 90 is cleaned. In particular, the tank bottom 90b directly under and around the manhole 93 is cleaned. The washed liquid containing the radioactive contaminant 9 is sent out from the delivery pipe 96 and processed.

<First half of long distance cleaning process (medium distance cleaning process)>
Next, as shown in FIG. 7C, the long distance cleaning jig 3 of the long distance cleaning apparatus 1 is inserted into the tank 90 from the manhole 93.
As shown in FIG. 8, the heel guide 4 is installed in the manhole 93. The scissors guide 4 includes, for example, two guide members 4a and a pair of base portions 4b. The two guide members 4a have a parallel bar shape. The end portions on the same side of the guide members 4a are connected by an arcuate base portion 4b. Base portion 4 b is attached to the edge of manhole 93. The long-distance operation rod 2 is guided by passing the long-distance operation rod 2 between the two guide members 4a and 4a. (Note that the heel guide 4 can also be used as a guide for the short-distance operation rod 82 of the short-distance cleaning device 8).
As shown in FIG. 7C, the cleaning range in the tank 90 is expanded by injecting cleaning liquid such as water from the cleaning nozzles 41 and 42. That is, the long-distance cleaning range far from the short-distance cleaning range as viewed from the manhole 93 in the tank 90 is cleaned.
The tank bottom 90b and the like in front of the boom 30 can be cleaned with the cleaning liquid from the front cleaning nozzle 41.
The tank bottom 90b and the like behind the boom 30 can be cleaned with the cleaning liquid from the rear cleaning nozzle 42. In particular, the corner portion formed by the inner peripheral rib 92 and the tank bottom portion 90b on the longer distance side (left side in FIG. 7C) can be cleaned.

Preferably, until this stage, the entire portion from the short-distance side end portion 90d to the middle portion in the longitudinal direction of the radioactive contaminant storage tank 90 is cleaned. More preferably, the cleaning is performed between the inner peripheral rib 92B at the center of the radioactive contaminant storage tank 90 and the inner peripheral rib 92C on the long distance side (left side in FIG. 7C).
In other words, the long-distance cleaning device 1 inserted from the manhole 93 reaches the short-distance side end 90d (two-dot chain line in FIG. 7C) and reaches between the inner peripheral ribs 92B and 92C. (The solid line in FIG. 7C), the length of the long-distance cleaning device 1 is set.

<Stage installation process>
Next, as shown in FIG. 9A, the gantry 6 is suspended by a crane or the like (not shown) and inserted into the radioactive contaminant storage tank 90 from the manhole 93. At this time, the end of the gantry 6 on the short distance side is directed downward. Thereby, first, the wheel 65A at the end of the short-distance end inclined portion 63 is landed on the tank bottom 90b.
As shown in FIG. 9 (b), when the gantry 6 is further lowered, the base plates 61 and 62 are bent around the hinge 66, and the short-distance end inclined portion 63 is on the short-distance side (in FIG. 9B). Slide to the right).
Almost at the same time when the wheel 65A and the short-distance end inclined portion 63 hits the inner rib 92A on the short-distance side (right side in the figure), the connecting portion between the short-distance side base plate 61 and the short-distance end inclined portion 63 The wheels 65B land on the tank bottom 90b.
As shown in FIG. 9C, when the gantry 6 is further lowered, the short-distance side base plate 61 gradually lies with the wheel 65B as the rotation center, so that the short-distance end inclined portion 63 is inclined upward. Is done. Thus, the wheel 65A can get over the inner peripheral rib 92A.
As shown in FIG. 9D, when the gantry 6 is further lowered, the short distance side base plate 61 is slid to the short distance side (right side in the figure). Eventually, the wheel 65B hits the inner peripheral rib 92A. At almost the same time, the wheel 65C on the hinge 66 side of the short distance side base plate 61 is landed on the tank bottom portion 90b, and the short distance side base plate 61 is horizontally placed on the tank bottom portion 90b.
Next, as shown in FIG. 9E, the long distance side base plate 62 is rotated around the hinge 66 toward the long distance side (left side in the figure).
As a result, as shown in FIG. 10A, the gantry 6 is placed on the tank bottom 90b. As shown in FIG. 10B, the end of the long distance side plate 62 straddles the upper part of the inner peripheral rib 92B at the center (intermediate portion in the longitudinal direction) of the tank 90, and the long distance end inclined portion 64 is inside. It is arranged on the long distance side (left side in the figure) from the peripheral rib 92B.

<Latter half of long-distance cleaning process>
Next, as shown in FIG. 10C, the long distance cleaning jig 3 is placed on the gantry 6. Further, the distal end portion of the long distance cleaning jig 3 is extended to the longer distance side (left side in FIG. 10C) than the gantry 6. Thereby, the inside of the tank 90 (long distance cleaning range) longer than the middle between the two inner peripheral ribs 92B and 92C can be cleaned without the long distance cleaning jig 3 being caught by the inner peripheral rib 92B. it can.

As shown in FIG. 10D, when the cleaning is advanced to the long distance side (left side in FIG. 10), the front wheel 23 at the tip of the long distance cleaning jig 3 eventually comes into contact with the inner peripheral rib 92C.
Here, as shown by the solid lines in FIG. 11A and FIG. 11B, the long distance cleaning jig 3 is rotated by the remote rotation operating means 50. Specifically, the operation wire 51 is pulled on the hand side of the long-distance operation rod 2 outside the radioactive contaminant storage tank 90. By this pulling force, the long distance cleaning jig 3 is rotated with respect to the long distance operation rod 2 with the second rear wheel 22 as a fulcrum, and the tip of the boom 30 is raised. As a result, the front wheel 23 and thus the tip of the boom 30 can get over the inner peripheral rib 92C.

As indicated by a two-dot chain line in FIG. 11B, depending on the angle of the long-distance cleaning jig 3, the tip guide portion 35a is rubbed against the upper end portion of the inner peripheral rib 92C. At this time, it is possible to prevent the nozzles 41, 42 and the like from being caught on the inner peripheral rib 92C by the tip guide portion 35a. Therefore, the tip of the boom 30 can smoothly get over the inner peripheral rib 92C.
Further, by providing the counterweight 12 at the rear part of the base plate 10, the boom 30 can be rotated upward with a lighter force.
As shown by a three-dot chain line in FIG. 11B, when the long-distance cleaning jig 3 is tilted to the maximum extent, the auxiliary rear wheel 25 is landed on the tank bottom 90b. Therefore, it is possible to prevent the rear portion of the base 10 from directly hitting the tank bottom portion 90b.

As shown in FIG. 12, the inside of the radioactive contaminant storage tank 90 on the longer distance side (left side in FIG. 12) than the inner peripheral rib 92C can be cleaned by the tip of the boom 30 getting over the inner peripheral rib 92C. Further, the tip of the boom 30 can reach the long distance side end 90e of the tank 90, and the long distance side end 90e can be cleaned.
Thereby, the entire region of the radioactive contaminant storage tank 90 can be reliably cleaned. That is, it is possible to clean not only the short-range cleaning range immediately below and around the manhole 93 in the radioactive contaminant storage tank 90 but also the long-range cleaning range farther than the short-range cleaning range as viewed from the manhole 93. Even if there are ribs 93 or other obstacles on the inner wall of the tank 90, the obstacles can be overcome and cleaning beyond the obstacles can be performed.

The present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.
For example, the washing procedure can be modified as appropriate.
The remote rotation operation means 50 may be configured to rotationally drive the boom 30 with electric power or the like.

  The present invention can be applied as a cleaning system in a tank storing radioactive contaminants.

1 Long-distance cleaning device (radiopollutant storage tank cleaning device)
2 Long-distance operation 棹 (operation 棹)
3 Long distance cleaning jig 6 Base 9 Radioactive contaminant 11c Rotating shaft 30 Boom 40 Cleaning nozzle manifold 41 Front cleaning nozzle (cleaning nozzle)
42 Back washing nozzle (washing nozzle)
50 Remote rotation operation means 51 Operation wire 7 Ejector device 70 Eject pipe 70e Decompression chamber 72 Eject nozzle 8 Short distance cleaning device 82 Short distance operation rod 83 Short distance cleaning jig 84 Short distance cleaning nozzle 90 Radioactive contaminant storage tank 90b Tank bottom 90d Short distance side end portion 90e Long distance side end portion 92 Inner peripheral rib 92B Inner peripheral rib 93 in the middle portion in the longitudinal direction Manhole

Claims (4)

An apparatus for cleaning the inside of a horizontally long radioactive contaminant storage tank,
An operation rod,
A boom that is rotatably connected to the tip of the operating rod and extends from the operating rod;
A cleaning nozzle provided at the tip of the boom;
Remote rotation operation means capable of remotely rotating the boom with respect to the operation rod;
The radioactive contaminant storage tank cleaning device is characterized in that it can be inserted into the radioactive contaminant storage tank from a manhole at the top of the radioactive contaminant storage tank.   The remote rotation operation means includes an operation wire extending along the operation rod and the boom, and a distal end portion of the operation wire is connected to a distal end portion of the boom. The radioactive contaminant storage tank cleaning device as described. A method for cleaning the inside of a horizontally long radioactive contaminant storage tank,
A suction step of sucking and sending out radioactive contaminants in the radioactive contaminant storage tank by means of an ejector device inserted from a manhole at the top of the radioactive contaminant storage tank;
A short-distance washing step of washing a short-distance washing range centering on a manhole in the radioactive contaminant storage tank by a short-distance washing device provided with a short-distance washing nozzle at the tip of the operation rod;
A long-distance washing step of washing a long-distance washing range farther than the short-distance washing range as viewed from the manhole in the radioactive contamination storage tank by the radioactive-contamination storage tank washing device according to claim 1 or 2; ,
A method for cleaning a radioactive pollutant storage tank.   In the long-distance cleaning step, a gantry is inserted into the radioactive contaminant storage tank from the manhole, and the radioactive contamination is straddled across an inner peripheral rib formed in the middle portion of the radioactive contaminant storage tank in the longitudinal direction. 4. The radioactive contamination according to claim 3, wherein the radioactive contamination storage tank is placed on the bottom of the waste storage tank, and then the radioactive contamination storage tank cleaning device is mounted on the mount for cleaning the long-distance cleaning range. Waste storage tank cleaning method.

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