JPS6256999B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a control rod drive replacement device, and more particularly to a control rod drive replacement device equipped with a cleaning device.

The control rod drive device (hereinafter referred to as CRD), which is installed at the bottom of the reactor vessel, is installed in the reactor pressure vessel when the boiling water reactor is shut down.
It is removed from inside the CRD housing and maintenance inspection is performed. The area below the reactor pressure vessel is an area with extremely high radioactivity levels, and replacing the CRD is not an easy task. In order to reduce the radiation exposure of workers, a CRD replacement device described in Japanese Patent Application Laid-open No. 140793/1983 has been developed. This CRD
In the replacement device, a drench tube is provided on the outside, and after the cooling water that leaks from inside the CRD housing when the CRD is removed is received in the drain sleeve, it is guided to the space inside the pedestal through the drench tube.

Since the drain sleeve is located above the removable head of the CRD exchanger, it is contaminated by high radioactivity level cooling water leaking from above the removable head and within the CRD housing. Therefore, maintenance and inspection of the removable head is difficult.

SUMMARY OF THE INVENTION An object of the present invention is to provide a CRD replacement device that eliminates the above-mentioned drawbacks of the prior art and allows easy maintenance and inspection.

The present invention is characterized by a rotating truck and a control rod drive that moves on the rotating truck and pulls out the control rod driving device from inside the reactor vessel and inserts the control rod driving device into the reactor vessel. and a cleaning means for spraying a cleaning liquid into a space inside the attachment/detachment device body provided in the attachment/detachment head of the control rod drive device operation portion, and a coolant scattering prevention provided in the attachment/detachment head portion. The reason is that the equipment has been installed.

Other features of the present invention include a rotating carriage, a control rod driving device attaching/detaching means that moves on the rotating carriage and detaches and attaches the control rod driving device between the inside of the reactor vessel, and the control rod driving unit. a coolant discharge passage attached to the device attachment/detachment means and for collecting and flowing coolant leaking when the control rod drive device is removed from the reactor vessel; and a cleaning device attached to the control rod drive device attachment/detachment means; Accordingly, a cleaning means having at least an upwardly directed cleaning liquid spout for cleaning the inside of the control rod drive device housing formed at the lower part of the reactor vessel is provided.

A CRD exchanging device which is a preferred embodiment of the present invention will be explained based on FIG.

A reactor pressure vessel 1 is installed on a pedestal 2 located within a containment vessel (not shown). A CRD housing 3 and a neutron flux measuring instrument housing 4 are provided in a protruding manner at the bottom of the reactor pressure vessel 1 . The CRD housing 3 and the neutron flux measuring instrument housing 4 also form part of the reactor pressure vessel 1 . The CRD 5 is housed within the CRD housing 3. A space 6 is formed below the reactor pressure vessel 1 within the pedestal 2 . The loading/unloading entrance 9 for loading and unloading the CRD 5 into and out of the space 6 is located at the pedestal 2.
established in Within the space 6, a bracket 7 is provided projecting from the side wall of the pedestal 2. An annular rail 8 is mounted on the upper part of the bracket 7. The turning movement device 11 moves on the rails 8.

The CRD exchange device 10 includes a turning movement device 11,
It is composed of a CRD attachment/detachment device 16 and a CRD handling device 76. The turning movement device 11 includes a traveling cart 17 of a CRD attachment/detachment device 16 and a CRD handling device 7.
Two sets of rails are provided on which six running carts 77 run independently.

The structure of the CRD attachment/detachment device 16 will be explained based on FIG. 2. The CRD attachment/detachment device 16 is connected to the traveling bogie 1
Contains 7. Wheels 18 disposed on rails 13 provided on a linear frame 12 provided in the turning movement device 11 are attached to a shaft (not shown) of a traveling trolley 17. A pair of opposing frames 19 are fixed by a connecting plate 20. frame 1
9 is detachably attached to the traveling carriage 17. A motor 21 is attached to the upper end of the connecting plate 20. The motor 21 is connected to a rotating shaft 22 attached to the frame 19 via a speed reducer (not shown).
Pinions (not shown) that mesh with racks 15 provided at the bottom of the frame 12 are attached to both ends of the rotating shaft 22.

The attachment/detachment device main body 23 is attached to the connecting plate 20 by the clip 6.
9 and 71 are removably attached.
The detailed structure of the attachment/detachment device main body 23 will be explained based on FIGS. 3, 4, and 5.

The detachable device main body 23 is composed of a detachable head 24 and a detachable head holding member. First, the structure of the detachable head 24 will be described. A connecting bolt handling device 29 and a cooling water splash prevention device 35 are provided in the upper part of the housing 25, and an uncoupling device 48 is provided in the housing 25. An elevating column 57 is attached to the lower end of the housing 25. Furthermore, a cleaning device 60 is provided.

The housing 25 is composed of a plurality of housings, which will be described later. A housing 26 located at the bottom of the housing 25 is attached to the upper end of the lifting column 57. Housing 27, 28 and 29
are sequentially arranged above the housing 26, and each housing is fixed to each other. The annular passage 43 is
It is formed between the housing 29 and the adapter 54. An annular passageway 44 is formed within the housing 28 and between the piston 50 and the piston 50 described below. Passage 4 formed between housing 27 and housing 28
6 is connected to the annular passage 44 by an opening 45 provided in the housing 28. A passageway 47 is formed between housing 26 and housing 28.

The connecting bolt handling device 29 includes an air motor 30 and a bolt wrench 33. air motor 30
There are eight sets, the same number as the number of bolts (hereinafter referred to as CRD connection bolts) 59 that fix the CRD housing 3 and CRD 5. The bolt wrench 33 is attached to a rotating shaft 32 connected to the rotating shaft 31 of the air motor 30. Rotating shaft 32 and bolt wrench 3
3 is installed in a bolt house 34 attached to the upper part of the housing 29.

The cooling water scattering prevention device 35 is composed of a drain sleeve 36 which is composed of an inner drain sleeve 37 and an outer sleeve 38 and surrounds the bolt house 34, a drain sleeve operating means 39, and a drain passage 41. The upper end of the drain sleeve operating means 39 passes through the lower end of the outer drain sleeve 38 and is attached to the lower end of the inner drain sleeve 37 . The seal ring 40 is attached to the inner drain sleeve 3
7 and the upper end of the outer drain sleeve 38. The drain passage 41 includes a space 42 in the bolt house 29, annular passages 43 and 44, an opening 45, passages 46 and 47, and a lifting column 5.
7 and a hole 58 therein.

An uncoupling spring device 48 installed in the housing 25 connects a cylinder 49 and a piston 5.
Starting from 0. A cylinder 49 is inserted into the housing 28, the lower end of which is sealed. A piston 50 having an adapter 54 at the top is inserted into the cylinder 49 . A tube 52 having a detector 51 and a piston portion 53 is arranged within the piston 50.

The cleaning device 60 includes an annular header 63 formed between a cylindrical member 61 provided on the inner wall surface of the bolt house 34 and the bolt house 34 , a large number of spout ports 62 formed downward in the cylindrical member 61 , and the bolt house 34 It consists of a passage 64 that passes through the annular header 63 and is connected to the annular header 63, and a pipe 65 that is connected to the passage 64. The pipe 65 descends between the air motors 30,
It passes through the housing 26 and is inserted into the hole 58 of the lifting column 57. The piping 65 is connected to the lifting column 5
7 is connected to a flexible high pressure hose (not shown) at the lower end. Although not shown, this high-pressure hose is guided to the outside through the carry-in/out port 9 and connected to a wash water supply pump.

Next, the detachable head holding member 66 will be explained below. The detachable head holding member 66 includes a casing 6
7 is included. A lifting device 68 and clips 69 and 71 are attached to the casing 67. A lifting column 57 is inserted into the casing 67.
A lifting device 68 including an air motor 68a is engaged with a rack provided on the lifting column 57.

A clip 69 is provided on the support sleeve 70 surrounding the upper part of the casing 67.
It is attached to the connecting plate 20. A clip 71 provided on a support sleeve 72 surrounding the lower portion of the casing 67 is attached to the connecting plate 20.
Detachable head rotation device 7 attached to the connecting plate 20
The third gear 74 meshes with a gear 75 provided around the casing 67.

The CRD handling device 76 will be explained based on FIG. The CRD handling device 76 includes a traveling truck 77, wheels 78 attached to the traveling truck 77, and wheels 78 attached to the traveling truck 77.
A mast 79 is rotatably attached to the mast 79, a mast overturning device 80 is provided on the traveling truck 77, and a cart truck 81 is detachably attached to the mast 79.
Consisting of

The operation for removing the CRD 5 from inside the CRD housing 3 will be described. Rotate the rotation movement device 11,
Furthermore, the traveling cart 21 is moved and the detachable head 24 is moved.
Below the CRD5 that should be removed, that is, A in Figure 1.
position at a point. The elevating column 57 is raised by driving the air motor 69, and the attachment/detachment head 87 is raised. The detachable head 24 is rotated by operating the detachable head rotation device 97, and the bolt wrench 33 and CRD are rotated.
After the positioning with the connecting bolt 59 is completed, the elevating column 57 is raised again, and when the lower part of the CRD 5 contacts the upper part of the bolt house 34, the driving of the air motor 69 is stopped. The bolt wrench 33 engages with the head of the CRD connecting bolt 59.

Compressed air is introduced into the space 55 and the piston 50
to move the piston tube 82 of the CRD 5 upward. When the CRD 5 is operated in this state and the index tube (not shown) of the CRD 5 is lowered, the CRD 5 and the control rods attached to the CRD 5 inside the reactor pressure vessel 1 are completely separated. By supplying compressed air to the space 56, a detector 61 is inserted into the piston tube 82 to detect their separation.

After the control rod and CRD 5 are separated, the drain sleeve operating means 39 is operated to close the drain sleeve 36.
to rise. Eventually, the outer drain sleeve 38
The lower end of is in contact with the stepped part of the bolt house 34,
The outer drain sleeve 38 stops rising, and the inner drain sleeve 37 rises further to compress the seal ring 40. This allows effective sealing between the CRD housing 3 and the drain sleeve 36.

Rotate the bolt wrench 33 and remove the CRD connection bolt 59. Then, lower the attachment/detachment head a little. Cooling water with a high radioactivity level inside the CRD housing 3 leaks and collects in the space 42. The drain sleeve 36 prevents this outflowing cooling water (drain water) from scattering around. Drain water is drained to the bottom of the space 6 through the drain passage 41. At this time, cleaning water is supplied into the annular header 63 through the pipe 65, and the cleaning water is jetted out from the spout 62 into the space 42. Thereby, it is possible to prevent the clay mixed with the drain water from adhering to the inside of the drain passage 41. In particular, the amount of drain water is small, and sludge-like crud occurs.
When the cleaning water flows out from inside the CRD housing 3, by jetting the cleaning water into the space 42, it is possible to prevent sludge-like crud from adhering inside the drain passage 41. Even after drain water has been drained,
Cleaning water is supplied into the space 42 for a while to clean the drain passage 41. In this manner, since the drain passage 41 is cleaned, maintenance and inspection of the attachment/detachment device main body 23 can be easily performed.

When cleaning of the drain passage 41 is completed, the drain sleeve 36, piston 50 and tube 52 are lowered.

The lowering of the detachable head 24 is resumed, and when half of the CRD 5 is pulled out from the CRD housing 3, the lowering of the detachable head 24 is stopped. Thereafter, the CRD handling device 76 is moved to engage the CRD attachment/detachment device 16. When the detachable head 24 is lowered,
The CRD 5 is moved into the cart trolley 81. When the attachment/detachment head 24 is lowered to the lowest position, the CRD attachment/detachment device 16 is moved to point B in FIG. The CRD 5 is lowered by operating a lifting device (not shown) provided on the cart cart 81, and the CRD 5 is completely pulled out from the inside of the CRD housing 3. The CRD gripping device 83 grips the upper part of the CRD 5 on the traveling trolley 7
7 and the rotating moving trolley 11, and move the CRD5.
Move to a position where it can be rolled over.

By operating the mast rolling device 80, the sector gear 85 rotates about the support shaft 86. sector gear 8
5, the mast 79 is attached to the arrow 8 in FIG.
It is rolled over in the direction of 4. When the axis of the CRD 5 is oriented horizontally, the cart 81 carrying the CRD 5 is pulled out from the mast 79. Cart trolley 81
is carried out of the containment vessel through the carry-in/out port 9.

For CRD5 that has undergone maintenance and inspection, reverse the procedure.
It is installed inside the CRD housing 3. The CRD attachment/detachment device 16 and the CRD device 76 connect the CRD 5 to the CRD housing 3, that is, the reactor pressure vessel 1.
insertion and CRD5 from inside reactor pressure vessel 1
This is the CRD operation unit that pulls out the CRD.

As described in Japanese Patent Application No. 53-119340, the attachment/detachment device main body 23 has the clips 69 and 71 removed from the connecting plate 20 by the CRD handling device 76, and is placed on the CRD handling device 76. It is rolled over and transported to the vicinity of the carry-in/out entrance 9, and then taken out from the carry-in/out entrance 9 by the cart truck 81, where maintenance and inspection are performed. Since the drain passage 41 has been cleaned as described above, the degree of radioactive contamination of the attachment/detachment device main body 23 is low, and its maintenance and inspection can be easily performed.

Furthermore, according to this embodiment, since the crud does not remain attached to the outer surface of the piston 50, the crud bites into the sliding surface between the cylinder 49 and the piston 50 as the piston 50 descends, and the crud is attached to the outer surface of the piston 50. There is no risk of hindrance to movement.

Another embodiment of the invention is shown in FIGS. 10 and 11. FIG. 10 shows the structure of the upper end of a detachable head 90 constituting the CRD attaching and detaching device of the CRD exchange device. Components that are the same as those of the detachable head 24 of the previously described embodiment are designated by the same reference numerals, and only different parts will be described below. Header 91 is bolt house 3
4 is placed near the inner wall of the bolt house 34. The upper wall of the header 91 is the bolt house 34
an upper lid 9 having an upwardly directed spout 92;
Consisting of 3. The side wall 94 of the header 91 facing the space 42 is part of the bolt house 34. A downwardly directed spout 95 is provided in the side wall 94. The headers 91 are arranged at four locations in the bolt house 34 between the bolt wrenches 33. Four passages 96 communicating with each header 91 are provided in the bolt house 34. A pipe 97 is connected to each passage 96, and each pipe 97 is inserted into the lifting column 57 in the same way as the pipe 65 in the above-described embodiment.

The drain sleeve 36 is CRD as shown in Figure 10.
When drain water surrounds the housing 3 and is discharged from the inside of the CRD housing 3, cleaning water is supplied into the header 91 through the piping 97, similarly to the embodiment described above. Washing water is ejected from the ejection ports 92 and 95 and supplied into the drain passage 41.

In this embodiment as well, effects similar to those of the above-mentioned embodiments can be obtained. Furthermore, in this embodiment, the following new effects can be obtained.
Cart trolley 81 removed from CRD handling device 76
While unloading CRD5 by
CRD attachment/detachment device traveling trolley and attachment/detachment head 90
Raise the removable head 90 and attach it to the CRD5.
Move it to just below the CRD housing 3 that you pulled out. The drain sleeve 36 is raised to near the top of the flange of the CRD housing 3. header 9
Cleaning water is supplied into the interior of the cleaning device 1, and the cleaning water is spouted from the spout ports 92 and 95. The cleaning water spouted from the spout 92 is delivered to the CRD housing 3 shown in FIG.
The inner CRD 5 is inserted into the hole 99. A thermal sleeve 98 is provided within the hole 99. The cleaning water jetted from the spout 92 washes off the highly radioactive crud adhering to the inner surface of the thermal sleeve 98. Further, although not shown, cleaning water jetted from spout ports with different inclination angles provided in the upper lid 93 cleans the lower surface of the flange of the CRD housing 3. These wash waters are discharged to the bottom of the space 6 through the drain passage 41.

The conventional cleaning work of CRD housing 3 involves a worker pulling the hose into the cleaning hose space 6 from the loading/unloading port 9 and pulling the hose to the CRD housing 3 to be cleaned in a highly radioactive atmosphere. As a result, the work was carried out in a highly radioactive atmosphere.
This method requires a short amount of time for workers to work, is inefficient, and requires a large number of replacement workers. However, in this embodiment, the CRD housing 3 can be cleaned simply and without the risk of exposure by using the CRD exchange device without using any special equipment. By cleaning the inner surface of the CRD housing 3 and its flange surface, the risk of radiation exposure to workers is reduced.
Maintenance and inspection work for the CRD housing 3 becomes easier. Since the crud attached to the bottom surface of the flange of CRD housing 3 can be removed, the flange of CRD housing 3 when CRD5 is installed can be removed.
O-rings can reliably seal between the flanges of CRD5.

FIG. 13 shows a downward spout 99 and an upward spout 10 instead of the cylindrical member 61 shown in FIG.
A cylindrical member 98 provided with 0 is provided. The cleaning water spouted from the spout 100 causes the 10th
Similar to the embodiment shown in the figure, the CRD housing 3 can be cleaned.

FIG. 14 shows the structure of the upper end of the detachable head 101 applied to another embodiment of the present invention. In this embodiment, the pipe 102 that supplies cleaning water
A nozzle 102 connected to the bolt house 34 is provided in the bolt house 34. In FIG. 14, nozzle 102
oriented upwards, but sideways and downwardly directed nozzles are also provided. This embodiment also provides the same effects as those of the above-mentioned embodiments.

Furthermore, as another embodiment of the present invention, a flexible hose for supplying cleaning water and a jetting nozzle at the tip of the hose are attached to the traveling trolley 17 of the CRD attaching/detaching device 16 or the traveling trolley 77 of the CRD handling device 76. Good too. As a result, there is no need for the worker to carry a hose to the vicinity of the CRD housing 3 to be cleaned as described above, and the risk of exposure of the worker to radiation is reduced accordingly. When cleaning the CRD housing 3, use the CRD attachment/detachment device 16 or
A worker moves the CRD handling device 76 below a predetermined CRD housing 3, removes the hose and the jet nozzle from the traveling cart, and removes the jet nozzle.
CRD housing 3 toward the inside of CRD housing 3
Clean the area. Although the risk of radiation exposure to workers is greater than in the previously described embodiments, the risk is less than in the conventional method. In this case, there is a risk that the outer surfaces of the CRD attachment/detachment device 16 and the CRD handling device 76 will be contaminated by splashing of the cleaning water containing highly radioactive crud. However, the hose and jet nozzle described above can be used to clean the outer surfaces of the CRD attachment/detachment device 16 and the CRD handling device 76. This facilitates maintenance and inspection of the CRD operating section.

According to the first aspect of the present invention, maintenance of a CRD replacement device can be performed easily and safely. Further, according to the second aspect of the present invention, the inside of the CRD housing can be easily cleaned without using any special equipment and without the risk of exposure to radiation by using the CRD exchange device.

[Brief explanation of the drawing]

Figure 1 shows a CRD that is a preferred embodiment of the present invention.
Side view of the exchange device, Figure 2 shows the CRD shown in Figure 1.
A detailed side view of the attachment/detachment device, FIG. 3 is a vertical sectional view of the upper part of the attachment/detachment device main body shown in FIG. 2, FIG. 4 is an enlarged view of a portion of FIG. 3, and FIG. FIG. 6 is a cross-sectional view of the lower part of FIG. 3, FIG. 7 is a cross-sectional view of FIG. 3, FIG. 8 is a side view of the CRD handling device shown in FIG. 1, and FIG. teeth
An explanatory diagram of a state in which the CRD is rolled over; FIG. 10 is a vertical sectional view of the upper end of the detachable head applied to another embodiment of the present invention; FIG. 11 is an enlarged view of section XI in FIG. 10;
Figure 12 is a vertical sectional view of the CRD housing, Figure 13
This figure is a longitudinal sectional view of another embodiment of the cleaning water spouting part corresponding to the part shown in FIG. 3, and FIG. 14 is a longitudinal sectional view of the upper end of the detachable head applied to another embodiment of the present invention. 1... Reactor pressure vessel, 3... CRD housing, 5... CRD, 10... CRD exchange device, 11
...Rotating movement device, 16...CRD attachment/detaching device, 1
7, 77...Traveling trolley, 23...Detachable device main body,
24,90,101...Detachable head, 29...Connection bolt handling device, 33...Bolt house, 35
. . . Cooling water scattering prevention device, 36 . ... Annular header, 64, 96 ... Passage, 65, 97 ... Piping, 76 ... CRD handling device, 81 ... Cart trolley, 91 ... Header, 102 ... Nozzle.

Claims (1)

[Scope of Claims] 1. A rotating truck, and a control rod that moves on the rotating truck and pulls out the control rod driving device from inside the reactor vessel and inserts the control rod driving device into the reactor vessel. A cleaning means for spraying a cleaning liquid into a space inside the attachment/detachment device body provided in the attachment/detachment head of the control rod drive device operation portion, and a coolant scattering prevention device provided in the attachment/detachment head. 1. A control rod drive device exchange device comprising: 2. a rotating carriage, a control rod drive unit attachment/detachment means that moves on the rotating carriage and detaches and attaches the control rod drive unit between the reactor vessel and the interior of the reactor vessel; a coolant discharge passage that collects and flows coolant that leaks when the control rod drive device is removed from the reactor vessel; and a cleaning means attached to the control rod drive device attachment/detachment means, the cleaning means being attached to the lower part of the reactor vessel. 1. A control rod drive device replacement device comprising: a cleaning means having at least an upwardly directed cleaning liquid spout for cleaning the inside of the formed control rod drive device housing.