JP3388031B2 - Control rod, fuel support bracket - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a boiling water reactor (hereinafter referred to as "boiling water reactor").
(Referred to below as BWR)
(Hereinafter referred to as CR) and fuel support bracket (hereinafter referred to as FS)
Place), remove it, and then lift it out of the reactor
If the CR and FS are to be installed again in the reactor core,
Control rods and fuel support brackets used in
At the same time, grasp CR and FS together and hang them out of the reactor
The present invention relates to a control rod / fuel support bracket grip. 2. Description of the Related Art Generally, a core of a BWR is shown in FIG.
And a cylindrical shape built in the reactor pressure vessel 1.
A plurality of fuel assemblies 3 and CRs in the core shroud 2
(Control rods) 4 are loaded. [0003] The upper part of these fuel assemblies 3 is shown in FIG.
The upper part is supported by an upper lattice plate 5 also shown as 4.
On the other hand, the lower part is connected to the core support via an FS (fuel support bracket) 6.
It is supported by the holding plate 7. [0004] Each FS6 has its cylindrical lower part shown in FIG.
As shown in FIG.
It is supported by a support plate 7 and its substantially prismatic upper surface is shown in FIG.
As shown in FIG. 16, for example, the bottom of four fuel assemblies 3
Fitting holes 6a, 6 for respectively fitting and supporting
b, 6c, 6d and a cross that allows the cross-shaped CR4 to be inserted
And an insertion hole 4a in the shape of a circle. Each of the support fitting holes 6a to 6d is
Each orifice 6e, 6f, 6g, 6h
Through each of the orifices 6e-6h
The coolant flows into each fuel assembly 3 through the holes 6a to 6d.
It is made to make. Also, one corner at the top of FS6
The fixing pin 7b implanted on the core support plate 7 is
FS6 is placed on the core support plate 7 by drilling through holes 6i
It is fixed to. On the other hand, CR 4 is located at the bottom of the reactor pressure vessel 1.
Control rod drive mechanism (hereinafter referred to as C
RD) 8 are detachably connected to each other.
It is moved up and down by each CRD 8 to insert and withdraw into the core.
Will be That is, the CR 4 is connected to the core support plate 7.
The four fuels that pass through the control rod guide tube 9 and are supported by the FS 6
Cross-shaped insertion hole formed between the charge aggregates 3,3,3,3
4a is vertically moved up and down. Further, a conventional connecting machine for CR4 and CRD8.
The structure is of a spud type as shown in FIG.
This spud type coupling 10 is a lower end 4b of CR4.
In the outer circumferential gap of the lock plug 12 inserted into the fitting hole of
, For example, a lock made by making a cut in the circumferential direction
The coupling spud 11 in the form of a nail is not shown in FIG.
Push up with a strong drive piston and insert firmly
As a result, the coupling spud 11 is placed under CR4.
The inner peripheral surface of the end 4b and the outer peripheral surface of the lock plug 12
It is designed to connect CR4 and CRD8 by pinching
You. Further, the lock plug 12 is connected to the unlocking of the CRD 8.
The coupling rod 13 resists the spring force of the spring 4c.
And push it upward to link CR4 and CRD8.
The knot is released and released. By the way, CR4 is required at the time of periodic inspection of BWR.
When removing inside the reactor pressure vessel 1 and hanging it out of the reactor
First, the fuel assembly 3 is pulled out of the reactor core. [0011] However, in the conventional BWR,
The lock plug 12 to the uncouple rod 13
To push the connection between CR4 and CRD8
Because it is a configuration to release, the lock plug 12
Foreign matter such as cladding between the couplings pad 11
If it is, the lock plug 12 will stick and push up.
It becomes difficult to cut the connection between CR4 and CRD8.
May not be released. In recent years, such a problem has been solved.
Example to connect CR4 and CRD8 to erase
For example, bayonet couplings shown in FIGS.
Ring 14 may be employed. The bayonet coupling 14 is a cup.
Lower end 4b of CR4 into which spring pads 11 are inserted
On the inner peripheral surface of the fitting hole 15 of FIG.
Projecting at approximately 90 ° intervals in the directions shown in FIG.
So, the bayonet coupling 14, that is, CR
4 can be rotated approximately 45 ° in the circumferential direction, so that each engagement
The protrusion 16 is moved to the outer peripheral surface side of each coupling spud 11.
By moving, each coupling spud 11 is contracted.
By making the diameter and holding the lock plug 17, the CR
4 and CRD8. Further, as shown in FIG.
Turn CR4 approximately 45 ° or return to the original position
By doing so, each coupling spa
Move the head 11 to increase the diameter in the outer diameter direction.
The connection with RD8 is released. SUMMARY OF THE INVENTION
In the CR4 using the coupling 14, the conventional sputtering is used.
Lock plug 12 and
Entrapment of foreign matter such as cladding between the springs pad 11
Since there is no connection, the connection between CR4 and CRD8 is surely released.
Can be cut off. However, in order to release the connection with CRD8,
The bayonet coupling 14, that is, CR4
Must be rotated approximately 45 ° around its axis
However, CR4 is fixed by the fixing pin 7b of the core support plate 7.
Inserted into the cross-shaped insertion hole 4a of the FS 6
And it can't rotate.
And FS6 may be damaged. The FS 6 is fixed to the fixing pin 7 of the core support plate 7.
After removing from b and free, CR4 and FS6 are simultaneously
When the FS6 is rotated, the upper part of the FS6 is prismatic,
The fuel assembly in the adjacent grid hits
The body 3 may be damaged. That is, FIG. 19A shows the control rod 4
And plan view of the fuel support 6 viewed from above the upper grid plate 5
Indicates a normal state. The communication shown in this figure
The control rods 4 are installed in the same direction as the upper
In addition, the fuel support bracket 6 is provided with a cell formed on the upper grid plate 5.
5 '. Also fuel support bracket
6, a projection 6 'is formed on the core support plate 6'.
Fuel pin is supported by pin 7b provided on 7
The metal fitting 6 is prevented from rotating. Also fuel support
Fuel assembly supporting fitting holes 6a, 6b,
Fuel assemblies having a square cross section are mounted on 6c and 6d, respectively.
Is placed. The four fuel assemblies arranged in this manner are
1 unit, about 100 units of reactor core
Is configured. Now, in the state shown in FIG.
The disposed fuel support 6 and control rod 4 are
Grasp at the same time using a gripper, raise it slightly, then rotate it.
At this time, the protrusion 6 'of the fuel support 6 described above is
It comes into contact with the surrounding fuel assemblies. FIG. 19 (B)
Indicates this state, from the state shown in FIG.
When the fuel support 6 and the control rod 4 are rotated by 45 °,
Is shown. In this state, the protrusion 6 'is shown in the figure.
This part will protrude into the upper cell.
To contact and break the fuel assembly located in the cell
Will be. In order to avoid such a situation
Is the fuel assembly of the cell 5 'as shown in FIG.
In addition to the four bodies, a total of four cells 5 ″
16 fuel assemblies shown in Fig.
To the fuel storage pool located outside the upper part of the reactor pressure vessel
I have to carry it. As described above, the above-described method further includes
Time to transport 16 fuel assemblies out of the reactor pressure vessel
And it takes time. Therefore, the present invention takes into account such circumstances.
The purpose was to clean the reactor pressure vessel.
With a bayonet coupling
Easy, reliable and quick disconnection of the connected CR and CRD
And CR and FS can be atomized.
Can be removed from the furnace pressure vessel and suspended at the same time
An object of the present invention is to provide a control rod / fuel support bracket. The present invention solves the above-mentioned problems.
It is configured as follows. The invention according to claim 1 of the present application is a reactor pressure
Multiple fuels are placed on the core support plate installed in the vessel.
Fuel support for supporting the bottom of the fuel assembly and control rod drive
Removably connected to the mechanism by bayonet coupling
The fuel rod and control rod
From the core support plate and the control rod drive mechanism.
In the rod and fuel support bracket, the reactor pressure vessel
The reactor pressure vessel is provided by an elevating device provided above.
Suspended on the fuel support bracket
And a fuel supply provided at a lower portion of the handle.
Material support bracket gripping mechanism and whether the gripper body can move up and down
And a shaft provided rotatably.
The control rod gripping mechanism provided at the bottom and this shaft
A stopper that does not lower the gripper body from a predetermined value or more,
A rotary drive for rotating this shaft with respect to the grip body.
And a power source. First, a required grid in the reactor pressure vessel Fuel inside
After pulling out the assembly with a refueling machine, etc.,
The control rod and fuel support bracket
Let it. Place the lower part of this grip on the top of the fuel support
After seating, operate the fuel support bracket
Grasp the support bracket. Similarly, control by operating the control rod gripping mechanism
Grab the stick. Thereafter, the lifting drive provided in the main body
Drive the structure, or use the
Drive the strike and lift the entire gripper body via the lifting wire
The fuel support bracket by either means.
Raise to a predetermined height. This predetermined height is the fuel support bracket
Must be above the upper end of the control rod. Thereafter, the control rod gripping mechanism is moved to the gripper body.
Control rod gripping mechanism by operating the rotating drive source
To rotate. Control rod is fixed to control rod gripping mechanism
Therefore, the control rod and the control rod drive mechanism
Couple. During this rotation, the fuel support bracket
Since they are above the upper edge, they do not touch each other.
No. Next, the whole body is suspended.
Raised above the reactor pressure vessel via wire rope
Move to the outside storage pool at
You. Therefore, according to the present invention, the reactor pressure vessel
After grasping both CR and FS inside the reactor, remove
Since it can be hung out of the power container together,
Of CR and FS in the reactor pressure vessel separately
And then remove it from the reactor pressure vessel
Compared to the case where
Significantly improves the efficiency of CR and FS removal and lifting work.
Can be up. As a result, BWR periodic inspection
Workability can be significantly improved. The structure of a further preferred embodiment is as follows.
It has an action and an effect. As a driving means of a CR (control rod) grip portion,
The air cylinder for raising and lowering the CR can determine the lifting height
The pressure can be adjusted according to the pressure. Therefore,
Increasing the supply air pressure from low pressure to high pressure
First, a hook and C held by the hook
Raise the hook to the point where the play between the handle and the handle is eliminated.
And then lift the hook even higher
it can. For this purpose, the CR is lifted at once with a hook.
The shock of the lifting can be alleviated.
Can improve both the soundness and safety of CR at the time of
You. The control rod rotation mechanism holds the CR handle.
A wire is attached to the rotating member that rotates the rotating body that holds the hook.
To the air cylinder for forward / reverse rotation as drive means
Continue to rotate, reducing the burden of the rotational force
be able to. Driven by a control rod gripping air cylinder
While holding the CR with the hook
If the air supply to the
Air cylinder grip for control rod grip by spring force of ring
Operation is retained. Therefore, the CR is grasped by the hook and suspended.
While the air hose is being lifted,
When the supply of air to the control rod gripping air cylinder is interrupted
Even if the hook does not release the CR, it is safe and
A fail-safe effect can be achieved. In case of failure of the control rod gripping air cylinder
If you cannot release the CR more than
The release operation of the CR is forcibly executed by pulling the strip.
Can be made. A pair of plastics is inserted into a pair of existing side holes of the FS.
The FS side is made to protrude and is supported.
There is no need to perform any processing and the FS faces in the radial direction.
Insert a pair of plungers into a pair of side holes
FS is supported and suspended, so FS can be balanced in the radial direction.
These are supported and lifted in a stable state.
Or both lifting reliability and safety
You. When the FS is gripped by the FS grip and lifted
Is locked by the lock mechanism
Therefore, the FS will fall and be damaged by the release operation of the FS.
Can be prevented beforehand, and both reliability and safety can be improved.
Can be Further, an FS grip air series as a driving means is provided.
While grasping the FS by the
Supply of air to the cylinder is due to breakage of the air hose, etc.
Is stopped, the FS is gripped by the spring force of the spring.
The gripping operation of the air cylinder is maintained. Therefore, the FS is held and lifted.
In the meantime, if the air hose breaks,
Even if the supply of air to the cylinder is interrupted,
It is safe because it does not release and has a fail-safe effect
Can be Should the FS gripping air cylinder, etc. fail,
If the FS release operation cannot be performed
Force release of FS by pulling the strip
be able to. When the upper plate is seated on the upper lattice plate,
When the R grip is seated on the control rod handle and when the FS grip
Are seated on the FS, these seats are
Each is detected by the device. Therefore, the presence or absence of these seats is properly determined.
After recognizing, a series of gripping, removing and lifting of CR and FS
Can perform work. As a result, these series
Not only can you increase the reliability of your work,
It can be performed smoothly. The slack of the air hose or cable is the cable
Since these are absorbed constantly by the slack absorption mechanism,
A hose or cable is hooked to other parts by its slack
Reduce the likelihood of any trouble
And reliability can be improved. Embodiments of the present invention will be described below with reference to FIGS.
Will be explained. In addition, in FIG. 1 to FIG.
Are denoted by the same reference numerals. FIG. 1 shows a reactor pressure vessel according to an embodiment of the present invention.
Schematic vertical section showing the overall configuration when suspended in the core of
FIG. 2 and FIG. 2 to FIG. However, CR
(Control rod) 4 is a bayonet coupling shown in FIG.
14 allows it to be detachably connected to a CRD (control rod drive mechanism) 8.
Is tied. Control rod / fuel support fitting of one embodiment of the present invention
The gripper 20 is used for the reactor pressure capacity at the time of periodic inspection of the BWR.
C suspended in the vessel 1 and installed in its core
Remove R4 and FS (fuel support bracket) 6 and pressurize reactor
Hanging it out of the vessel 1 and installing it again in the core
For example, a fuel exchange (not shown).
Attached by hanging ropes such as auxiliary hoist of exchange
An upper plate 30 that moves up and down, and the upper plate 30
The CR grip 40, which is suspended and can move up and down,
FS grip 50 that can be lifted and lowered to the R grip 40
And The upper plate 30 has an upper part as shown in FIGS.
Suspended on the required grid of the grid plate 5, the control rod
Load on the upper support plate 30
It is placed so that it can be loaded to prevent rotation.
There is an upper plate seating detection lever on the bottom of one corner of the upper plate 30
30a is swingably provided. The upper plate seating detection lever 30a is configured such that the upper plate 30
When the user sits on the upper grid plate 5, the upper
The swinging end of the bar 30a swings and the upper plate seating detection limit
The switch 30b is turned on and the upper plate seating detection signal is not shown.
Output to a refueling machine, etc.
You. The upper plate 30 has a rectangular support tube at the center thereof.
31 is fixed by penetrating vertically in the figure.
A square stud 32 is pin 3
2a, swingable upright, long control rod, fuel support
From the horizontal storage state of the bracket 20 to the vertical suspension state
Cannot be easily handled. The square stud 32 has the upper end shown in FIG.
As shown in FIG. 5, a screw hole 32b is formed. This one
An auxiliary hoist of a fuel exchanger (not shown) is
Wire row such as torqueless wire to prevent rotation
Connection with the screw of the bolt attached to the tip of the
Ascend without rotating the entire control rod / fuel holding fixture gripper 20
It is designed to be suspended freely. The support cylinder 31 has a CR grip 40 inside.
The CR grip portion 40 is a cylindrical inner / outer double cylinder 41,4.
2 is concentrically housed in the support cylinder 31 and the outer cylinder 42 is supported.
While fixing to the holding cylinder 31, the inner rotating cylinder 41 is
Bearing 43a and the radial bearing 43b to the outer cylinder 42.
It is mounted so that it can rotate around the axis. The rotating cylinder 41 is, as shown in FIGS. 1 and 4,
Hold the handle 4d of the CR4 at its lower end, or release it
2 and 6, the CR rotating machine shown in FIGS.
By the frame 45, it can be rotated in both forward and reverse directions around the axis.
ing. The CR rotation mechanism 45 is provided in the axial direction of the rotary cylinder 41.
At the side of the intermediate part, the rotating gear 45a is linked with the rotating cylinder 41
A wire provided freely and wound around this rotary gear 45a
Connect both ends of 45b to pulleys 45c and 45d.
After each winding, a pair of left and right air
Upper and lower ends of piston rod 45g of cylinders 45e and 45f
To the piston rod 45g.
The rotating cylinder 41 is moved back and forth around the axis by the backward movement.
It is designed to rotate. The rotary cylinder 41 is a CR lifting air cylinder.
The air is raised and lowered by a
Low-pressure air is supplied to the rising chamber side (lower chamber side) in the cylinder 46.
Is supplied, play the handle 4d of the CR4 with play.
Raise the hook 44 slightly to release the play with the handle 4d.
Raise the hook 44 so that it disappears and adhere to the handle 4d
When the hook 44 is lifted at once.
It is designed to reduce the impact. In addition, for CR lifting
The air cylinder 46 has a low pressure when the supply air is at a high pressure.
Up to a position higher than the lifting height at
It is designed to be raised by millimeters. Then, the rotary cylinder 41 is arranged as shown in FIG.
In addition, a CR gripping mechanism 47 is built in its lower end.
You. This CR gripping mechanism 47 is a hook opening / closing air cylinder.
The piston rod 47b of 47a and the link mechanism 47c
For opening and closing the hook by linking to the swinging end of the hook 44
The supply of air to the air cylinder 47a is performed between the upper chamber side and the lower chamber side.
Side to open the hook 44.
Or close operation to grasp or release the handle 4d of the CR4.
I'm like it. Also, the detection of the opening of the hook 44 is detected.
Hook open detection limit switch 47d and hook 4
Hook detection limit switch 47e for detecting the closing of No. 4
And the seating of the hook 44 on the handle 4d of the CR 4 is detected.
And a CR seating detection limit switch 47f. The rotating cylinder 41 has a guide projection 4 on its bottom surface.
7g is projected. The guide projection 47g is located at the bottom
A guide that fits the cross-shaped central part of the cross-shaped handle 4d
The hook 44 moves down to CR4
As it moves, it gradually fits into this cross-shaped guide groove.
At least, set the hook 44 at the optimal gripping position of the grip 4d.
Inside. Further, a hook opening / closing air cylinder 47a is provided.
In order to respond to such malfunctions,
The air supplied to the damper 47a is
Hold the grabbing motion when interrupted more
A holding switch for urging the piston rod 47b toward the gripping operation side.
Attach the pulling 47i and the piston rod 4
7b is connected to a release operation wire 47h.
-47h against the spring force of the holding spring 47i.
The air cylinder for opening and closing the hook
47a is forcibly released. On the other hand, the FS grip 50 is also shown in FIG.
The lower half of a double cylinder consisting of a rectangular support cylinder 31 and a rotary cylinder 41
Is a rectangular cylinder having a diameter larger than that of the support cylinder 31.
And inserted concentrically into the inside as shown in FIGS. 7 (A) and (B).
The elevating angle cylinder 51 is moved around the axis with respect to the inner support cylinder 31.
It is mounted so that it can be moved up and down with a shift of about 45 ° C. That is, the intermediate portion in the axial direction of the rectangular cylindrical support tube 31
FS lifting air cylinder 52 is fixed to the outer surface of the
And a pin for moving up and down in the FS lifting air cylinder 52.
The elevating and lowering cylinder 51 is hung up and down freely by the stone rod 52a.
I have Further, as shown in FIG.
Inside, outside each corner of the outer surface of the rectangular cylindrical support tube 31
A plurality of guide rollers 53, 53,...
I have. On the other hand, as shown in FIG.
Insert the cross-shaped handle 4d of CR4 through the surface 51a.
While opening the V-shaped insertion hole 51b, as shown in FIG.
The outer surface of each corner of the bottom surface 51a is
The corner pin 54 that comes into contact with the
Each is protruding. Further, as shown in FIG.
The diagonally opposite one of the bottom surfaces 51a of the rectangular cylinder 51
A pair of plate-like guides 55 project from the pair of corners.
And diametrically opposed to the FS6 shown in FIG.
It is inserted into a pair of fuel support fitting holes, for example, 6b and 6d.
Insert the hook 44 into the handle 44d of the CR 44
You will be guided. Then, the elevating and lowering angle cylinder 51 is provided in the lower end thereof.
A pair of left and right FS grip mechanisms 56 and FS grip lock mechanisms 57
And an FS seat detection device 58. FIG.
Now, only one of the pair of left and right FS gripping mechanisms 56 is illustrated.
The other is not shown. Each FS gripping mechanism 56 is provided in the diameter direction of FS6.
In a pair of orifices facing each other, for example, 6f, 6h
A pair of plungers 56 that respectively protrude and hold FS6
a for moving FS through the ring mechanism 56b
The air cylinder 56c and the FS gripping air cylinder 5
FS grip detection device that detects the gripping operation of the FS 6 by the FS 6c
Mitt switch 56d and release operation of FS6 are detected.
FS release detection limit switch 56e. The FS gripping air cylinder 56c is therefore
As a countermeasure in the event of a failure, the FS gripping air cylinder 5
When the FS 6 is grasped by 6c,
Should the air supplied to the air cylinder 56c be
Holds the gripping motion when interrupted due to breakage of
For holding the grip that urges the piston rod 56f in the direction of rotation
It has a built-in spring 56g. The FS gripping air cylinder 56c has
Connect the release operation wire rope 56h
-Spring force of the spring 56g for holding and holding the rope 56h
FS grip air series by pulling up against
The gripping operation of the cylinder 56c is forcibly switched to the releasing operation.
A pair of plungers 56a, 56a are connected to a pair of orifices of FS6.
6f, 6h to retreat inward and force FS
6 is released. The FS grip lock mechanism 57 includes the lifting / lowering rectangular tube 51.
The lock lever 57a is swingably mounted on the bottom surface 51b of the
When the lock lever 57a is
Is always engaged in the engaging hole 56i of the connecting rod 56f of the locking mechanism 56b.
The connecting rod 56f.
And the bottom surface 51a of the elevating cylinder 51 sits on the top surface of the FS6.
When the lock lever 57a swings, the connecting rod 56
f is released from the engagement hole 56i, and the constraint of the connecting rod 56f is released.
And the link mechanism 56b can operate.
You. Therefore, the bottom surface 51a of the vertical cylinder 51 is
When the lock lever 57a moves away from the upper surface of the FS6, the lock lever 57a swings.
To move into the engagement hole 56i of the connecting rod 56f,
By restraining the release action of 56f, gripping of FS6
The operation is locked. The FS seat detection device 58
A seating detection lever 58a is swingably provided on the bottom surface 51a,
The seat detection lever 58a is seated on the upper surface of the FS6.
When the FS seating detection limit switch is
Turn on / off switch 58b and do not output FS seating signal
Then stop. Then, as shown in FIG. 1 and FIG.
An absorption mechanism 59 such as a cable is provided on the upper inner surface of
I have. This corresponds to each of the air cylinders 45e, 45f, 46, 4
Air hoses and cables connected to 7a, 52, 56c
Ropes, operating wires 45h, 47h, 56h, etc.
Class 60 is sucked by the pulleys 59a and 59b and the spring 59c.
The trouble caused by the slack of the cords 60 has not been corrected.
This is to prevent it. Next, the control rod and fuel thus configured
At the time of the periodic inspection of the BWR using the support bracket grip 20,
CR4 and FS6 are placed in a water-filled reactor pressure vessel 1.
The case of pulling up from is described. First, as shown in FIG.
Adjacent four fuel assemblies 3, 3, 3, 3 in the child
CR4 is fully inserted into the core to maintain
The two fuel assemblies that are diagonally opposite to each other
3 and 3 are pulled out of the reactor core using a fuel exchanger or the like. Next, as shown in FIG.
A pair of simulated channels on the trace where the aggregates 3 and 3 were pulled out
61a and 61b are connected diagonally by a handle 61c.
The blade guide (control rod guide device) 61 is inserted. This
After that, as shown in FIG. 9 (C), the remaining two fuel assemblies
The bodies 3 and 3 are pulled out of the core. Next, as shown in FIG.
Guided by the blade guide 61 and the core by CRD8
And pull it all the way out, then
Next, as shown in FIG.
Pull out from inside. Thereafter, the control rod / fuel support of this embodiment is
Inside the screw hole 32b of the square stand 32 of the bracket 20
The wire row of the auxiliary hoist of the refueling machine not shown
Screw the bolt of the pump into the reactor pressure vessel 1
Let go down. Thereafter, as shown in FIG.
The upper plate 30 of the holding device 20 is placed on the upper surface of the upper lattice plate 5.
Almost the entire control rod / fuel support bracket grip 20 is seated.
Is moved from the wire rope to the upper lattice plate 5. As described above, the upper plate 30 is formed on the upper surface of the upper lattice plate 5.
When seated on the upper plate, the upper plate seating detection lever 30a is
It swings by contacting the upper surface of plate 5, and the upper plate seating detection limit
The switch 30b is turned on, and the upper plate seating detection signal is not shown.
Output to a refueling machine through a cable. At this time, the bottom surface 51a of the elevation
Are almost simultaneously on the upper surface of FS6 and the upper surface of handle 4d of CR4.
Since each is seated, CR seating detection limit switch
Both seats from 47f and FS seat limit switch 58b
A signal is output. At this time, the lock lever 57a is
The connecting rod 56f is disengaged from the engaging hole 56i, and the lock mechanism 5
7 is released. Then, the FS gripping air cylinder 56 is
Ring mechanism released when air is supplied to c
A pair of left and right plungers 56a, 56a is formed via 56b.
FS6 projects into a pair of orifices 6f, 6h
Grab 6. At this time, the FS grip detection limit switch 56
A grip signal for detecting the grip state of the FS 6 is output from d.
You. Similarly, an air cylinder for opening and closing the hook
When air is supplied to the grip side of 47a, the hook 44
R4 handle 4d was gripped with some play in the vertical direction
By closing in a state, CR4 is grasped. this
Hook closed from the hook close detection limit switch 47e
A signal is output. Then, the CR lifting air cylinder 46 is next turned on.
When low-pressure air is supplied to the rotary cylinder 41, the rotary cylinder 41 slightly rises
Therefore, the hook 44 contacts the lower surface of the handle 4d of the CR4.
You. That is, the power is supplied to the CR lifting air cylinder 46.
Since the pressure of the supplied air is low, hooks 44 and C
Only the gap (play) between R4 and handle 4a rises,
The hook 44 comes into close contact with the handle 4d. Next, the FS lifting air cylinder 52
When air is supplied to the ascending chamber side (lower chamber side), the elevating angle cylinder 51
Rises. For this purpose, the FS holding mechanism 56
FS6 is lifted slightly upward from core support plate 7.
And the bottom of FS6 is on the handle 4d of CR4
Is raised to a height slightly above the surface, and once that height
Is held. When the raising / lowering angle cylinder 51 is raised, the inner surface thereof
Are provided with a plurality of guide rollers 53, 53.
Since the outer surface of the holding cylinder 31 is rotated, the lifting cylinder 51 and its F
FS6 grasped by the S grasping mechanism 56 moves around the axis.
Rotation can be prevented beforehand. For this reason
FS6 loaded in adjacent grid
Prevent interference such as hitting the body 3
You. Thereafter, the CR gripping mechanism 47 is further added.
To raise CR by several tens of millimeters and rotate CR4,
High pressure air is applied to the lift chamber side (lower chamber side) of the descending air cylinder 46.
A. Thus, the CR4 and CR8 bio networks
Control rod to control the load of the coupling member with the coupling 14
-The load received by the fuel support bracket 20 is the upper part
The grid plate 5 is loaded and supported. [0098] When the CR4 is lifted as described above,
One of the rolling drive air cylinders 45e, 45f, for example,
When air is supplied to the rotary gear 45e, the rotary gear 45a rotates forward.
The rotating cylinder 41 is, for example,
By rotating the CR4 and CRD8 by about 45 °,
Onet coupling 14 can be disconnected
You. In addition, the other CR rotation driving air cylinder 45f
When air is supplied to rotate the rotary cylinder 41 approximately 45 °,
Bayonet coupling between CR4 and CRD8 14
Can be linked. Thus, CR4 is detached from CRD8.
After that, wire rope such as auxiliary hoist of refueling machine
The CR4 and FS6 upwards
And hoist it. Then, these CR4 and FS6 are uppercased.
From the reactor pressure vessel 1 through the
To the other reactor well, and
Underwater into a fuel storage pool that communicates with the
Then, at a predetermined position, CR, CS gripper
Release the CR4 and FS6 by releasing the structures 47 and 56.
And save the work. However, somehow
For these reasons, both gripping mechanisms 47, 56 release
If not, release wires 47h and 56h
By forcibly pulling each, CR4 and FS are forcibly
6 can be released. The CR and FS gripping mechanisms 47 and 56
Once the CR4 and FS6 are grasped, the holding spring
47g, 56g, and the locking operation by the lock mechanism 57
Is held, the CR and FS gripping mechanisms 47 and 56
While moving with grasping CR4 and FS6
Release these CR4 and FS6, causing an unexpected situation
This can be prevented beforehand. According to the present embodiment, CR4 and FS
6 and the control rod / fuel support bracket grip 20 together.
In addition to being able to remove with these CR4 and FS6
From the reactor pressure vessel 1 almost simultaneously to the outside
Can be performed easily, reliably and quickly
Can significantly improve the workability of BWR periodic inspection.
Can be FIG. 10 shows a second embodiment of the present invention.
is there. In the second embodiment, the gripper body 10
0 is a hoist (not shown) via the wire rope 101.
It is driven and suspended in the reactor pressure vessel. Hanger 10
2 is attached to the upper part of the grip
Has the role of attaching the loop 101 to the gripper body 100.
One. At the lower part of the gripper body 100, a fuel support bracket gripper 1 is provided.
No. 03 is provided, and the fuel placed on the core support plate 7 is provided.
The structure is such that the support fitting 6 can be grasped. Also
The gripper body 100 has a control for gripping the head of the control rod 111.
The rod gripper 106 is a shaft 107 and the shaft 1
07 is supported via a support plate 108 that supports
You. The shaft 107 is mounted on a support plate 108 so that it can move up and down.
The shaft 107 is attached near this mounting part.
Control rod rotating unit 109 that is driven to rotate with respect to support plate 108
Is provided. . At the upper end of the shaft 107
The upper part 110 is formed, and the gripper body is raised.
Control rod gripper 106 and shaft 107 are supported
It is prevented from falling off the plate 108. In the figure
The upper lattice plate 5 shown at the top is a fuel assembly (not shown).
It supports the head in the horizontal direction, and the gripper body 100
One installed cell 113 contains a normal reactor operation.
In the rolling state, four fuel assemblies are arranged. Also a grip
The horizontal cross-sectional shape of the body 100 is from the square cell 113
Is also a little small square, and the gripper body 100 or cell
It does not rotate in 113. Like this
The control rod 111 and the control rod 111 are
And taking the fuel support fitting 104 out of the reactor pressure vessel
The method will be described with reference to FIGS. FIG. 11A shows a state before the operation. Core
A fuel support is placed on the control rod guide tube 114 supported by the support plate 7.
A metal fitting 6 is provided. This fuel support 6 is a core
The rotation is prevented by a pin 115 fixed to the support plate 7.
You. The control rod 4 extends through the inside of the fuel
It has a shape with a protruding head. In this state,
Hanging the gripper body 100 from above using the loop 101
Then, it is placed on the fuel support 6. At this point, FIG.
The state shown in is shown. From this state, the fuel holding fixture grip 1
03 is operated to grasp the fuel support fitting 6. Control rod handle
The control rod 111 is grasped by operating the fixture 106. Next, the wire rope B was pulled up.
Therefore, the gripper body 100 is pulled up. At this time fuel support
The metal fitting 6 rises simultaneously with the grip body 100, but the control rod
The grip 106 does not rise when the shaft 107 slides.
No. FIG. 11B shows a state in which the fuel support 6 is raised.
Show. Next, the control rod rotating unit 109 is driven to perform control.
The control rod 4 is rotated by rotating the rod gripper 106 and the control rod 4 by 45 °.
And the control rod drive mechanism are uncoupled. Before rotation
The state is shown in FIG. Next, the control rod 4 and the fuel support fitting 104
Is lifted by the wire rope 101.
Out of the furnace. Before raising the control rod
11D is shown in FIG. Raise the gripper body 100
When the control rod gripper 106 is
The control rod 4 does not slide down with the fuel support
To rise. As described in the above two embodiments, the present invention
Then, from the installation state shown in FIG.
So that the fuel support 6 is not rotated in the horizontal direction,
Uncoupling by rotating only the control rod 4. Accordingly
Control rods without moving surrounding fuel assemblies.
The fuel support and the fuel support can be taken out of the furnace at the same time.
The fuel assembly 116 shown in FIG.
A TV camera installed to monitor all work conditions
The fuel assembly currently being pulled out for installation. This
Of the fuel assembly 116 will be used in the future.
Do not pull out if reliability is confirmed
It is expected to be done. As described above, each of the claims of the present application
According to the invention of the invention, the control rods and fuel support in the reactor pressure vessel
After grasping the metal fittings together, remove it and share it outside the reactor pressure vessel.
To the reactor pressure as before.
Separate grips for the control rod and the fuel support in the container
To remove from the reactor pressure vessel
Controls in the reactor pressure vessel are
The work efficiency of removing and lifting the rod and fuel support
It can be significantly improved. As a result, the BWR
Workability of the periodic inspection work can be significantly improved. How to take out using the conventional simultaneous gripper
According to the method (shown in FIG. 19), 20
It was necessary to remove the fuel assembly of the body.
According to the report, only seven are required, and in the future this will be reduced to four
It is expected. That is, the amount of removal work is significantly reduced
can do. In addition, using the conventional separate gripper
Storage space in the storage pool that was needed when
Can be reduced to １ ／. According to the fifth aspect of the present invention, the control
The rod rotation mechanism is a rotation that suspends a hook that grasps the handle of the control rod.
Rotating member for rotating the body
Since it is connected to the a cylinder and rotated,
The burden can be reduced. According to the sixth aspect of the present invention, the control
Controlled by a hook driven by the first drive source for rod gripping
While grasping the rod, move to the first drive source for grasping the control rod.
Is interrupted, the spring force of the spring
Holding the gripping operation of the first drive source for gripping the control rod
Can be. Accordingly, the control rod is grasped by the hook,
In the event of a break in the motive power line during lifting
The supply of motive power to the first drive source for gripping control rods was interrupted.
The hook does not release the control rod,
Thus, a fail-safe effect can be obtained. Further, according to the seventh aspect of the present invention,
1. Release of control rod due to failure of first drive source for control rod gripping
If you can not move, pull the cable
Can be forcibly executed by releasing the control rod.
Wear. Further, according to the invention of claim 8, the fuel
Insert a pair of plungers into a pair of existing side holes of the support bracket.
It protrudes and supports it.
No processing is required and the radial direction of the fuel support
A pair of plungers in a pair of side holes facing each other
It is inserted, supported and hung.
Support and lift in a stable state balanced in the direction
Therefore, the reliability and safety of these
Can be increased. Further, according to the ninth aspect of the present invention, the fuel
When the fuel support bracket is grasped and lifted by the support bracket
Is locked by the lock mechanism
The fuel support bracket is dropped by the release operation of the fuel support bracket.
Can be prevented from being damaged
And safety can both be improved. Further, according to the tenth aspect of the present invention, the fuel
Fuel support bracket by the first drive source for fuel support bracket
While the fuel is being supplied to the first drive source
Power supply is interrupted due to a break in the supply line
And the first for holding the fuel support bracket by the spring force of the spring.
The gripping operation of the drive source is maintained. Therefore, the fuel support bracket is grasped and suspended.
While the fuel is being supplied,
Supply of motive power to the first drive source for holding the support bracket was interrupted
Even if you do not release the fuel support bracket, it is safe,
A fail-safe effect can be achieved. Further, according to the eleventh aspect of the present invention,
First, the fuel support is lost due to the failure of the first drive source for holding the fuel support bracket.
If it is not possible to release the bracket,
To forcibly release the fuel support bracket by pulling
Can do it.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram showing the entire configuration of a first embodiment of a control rod / fuel support bracket gripper according to the present invention in a state where it is suspended in a core inside a reactor pressure vessel. FIG. FIG. 2 is a detailed view of the upper portion of the embodiment shown in FIG. FIG. 3 is a detailed view of an intermediate portion of the embodiment shown in FIG. FIG. 4 is a detailed view of the lower part of the embodiment shown in FIG. FIG. 5 is a partial sectional view taken along the line VV of FIG. 2; FIG. 6 is a view taken along line VI-VI of FIG. 2; FIG. 7A is a cross-sectional view taken along line VIIA-VIIA in FIG. 3;
(B) is a sectional view taken along the line VIIB-VIIB in FIG. FIG. 8 is a sectional view taken along the line VIII-VIII in FIG. 3; FIGS. 9A to 9E are plan views showing steps of extracting a fuel assembly from within a required lattice. FIG. 10 is a schematic partially cut-away longitudinal sectional view showing the entire configuration of the control rod / fuel support fitting gripper according to the second embodiment of the present invention suspended in a reactor core in a reactor pressure vessel. 11A to 11D are schematic views showing an uncoupling step from the CR side in the embodiment shown in FIG. FIGS. 12A to 12C are plan views showing steps of pulling out a fuel assembly from a required grid. FIG. 13 is a partially cutaway longitudinal sectional view of a core portion of a general BWR. 14 is a partially cutaway perspective view of the upper lattice plate shown in FIG. FIG. 15 is a partially cutaway perspective view of CR, FS, and a core support plate shown in FIG. 13; FIG. 16 is an enlarged perspective view of the FS shown in FIG. 15 and the like. FIG. 17 is a partially enlarged view of a coupling portion between CR and CRD shown in FIG. 13; FIGS. 18A to 18C are schematic cross-sectional views of a bayonet coupling which is a coupling mechanism between a CR and a CRD. 19 (A) to 19 (C) are plan views showing steps of extracting a fuel assembly from a required grid based on a conventional technique. [Description of Signs] 1 Nuclear reactor pressure vessel 2 Core shroud 3 Fuel assembly 4 Control rod 5 Upper grid plate 6 Fuel support bracket 7 Core support plate 8 Control rod drive mechanism 20, 100 Control rod / fuel support bracket grip 30 Upper plate 30a Upper plate seating detection lever 30b Upper plate seating detection limit switch 31 Support tube 32 Square tube studs 40, 106 Control rod grip 41 Rotating tube 42 Outer tube 43a Thrust bearing 43b Radial bearing 44 Hook 45, 109 CR rotation mechanism 45a Rotating gears 45e, 45f Rotating drive air cylinder 45g Piston rod 46 CR lifting / lowering air cylinder 47 CR gripping mechanism 47a Hook opening / closing air cylinder 47b Piston rod 47c Link mechanism 47d Hook open detection limit switch 47e Hook close detection limit switch 47f CR seating detection limit switch 4 i Holding spring 47h Release operation wires 50, 103 FS grip portion 51 Elevating angle cylinder 51a Bottom surface 51b Cross opening 52 FS elevating air cylinder 53 Guide roller 54 Corner pin 55 Guide 56 FS gripping mechanism 56a A pair of plungers 56b Mechanism 56c FS holding air cylinder 56d FS holding detection limit switch 56e FS release detection limit switch 56f Piston rod 56g Holding spring 56h Release operation wire 56i Engagement hole 57 FS lock mechanism 57a Lock lever 58 FS seating detection Device 58a FS seating detection lever 58b FS seating detection limit switch 61 Blade guides 61a, 61b Simulated channel

Claims (1)

(57) [Claims 1] A fuel support fitting mounted on a core support plate installed in a reactor pressure vessel and supporting the bottoms of a plurality of fuel assemblies, and a control rod drive A control rod / fuel support grip for grasping a control rod detachably connected to a mechanism by a bayonet coupling and removing these fuel support brackets and control rods from the core support plate and the control rod drive mechanism. A gripper body suspended from the reactor pressure vessel by a lifting device provided above the reactor pressure vessel so as to be capable of ascending and descending, and provided on a fuel support bracket, and provided at a lower portion of the gripper body. A gripping mechanism for a fuel support fitting, a shaft provided on the gripping body so as to be vertically movable and rotatable, a control rod gripping mechanism provided below the shaft, and Predetermined value from tool body A stopper that does not above downward, the control rod and fuel support fitting pinch device, characterized in that a rotary drive source to rotate relative to the shaft the pinch device body.