JPH0664180B2 - Nuclear fuel pellet loading device - Google Patents

Description

Description: TECHNICAL FIELD OF THE INVENTION The present invention relates to a device for loading a predetermined amount of nuclear fuel pellets into a fuel rod cladding tube.

[Technical background of the invention and its problems]

In general, BWRs are especially important for fuel rods used in nuclear reactors.
For fuel rods for use in fuel cells, the fuel rods are divided into a plurality of regions in the axial direction for the purposes of flattening the axial distribution of in-reactor power, securing a margin for reactor shutdown, and pursuing fuel economy. There is one in which nuclear fuel pellets having different U ₂₃₅ enrichment are loaded into the cladding tube for each region. For the same purpose,
There is also one in which pellets having different concentrations of the combustible absorbent are loaded in each region. On the other hand, regarding PWR fuel rods, there is no axial inhomogeneity in the reactor power that depends on voids like BWR, but similar studies have been made to improve fuel economy. Further, in the FBR, pellets are loaded in the blanket section and the fuel section in the axial direction.

In addition to providing a plurality of regions in one fuel rod as described above, the entire length of the pellet row to be loaded is
For example, looking only at the BWR, the length may be different depending on the reactor type.

From a fuel processing side, for example, BW
Even when producing only R fuel rods, the total length of the pellet row to be loaded varies depending on the reactor type, the axial region design differs depending on the type of fuel rod, and the type of pellets loaded for each region also varies. It will be. Moreover,
As described above, it is necessary to load pellets having almost the same shape without fail in the case where the total length, the region length, and the type of pellets vary depending on the type of fuel rod.
Therefore, there is a problem that the nuclear fuel processing requires a relatively long time and the cost becomes high.

FIG. 17 is a vertical cross-sectional side view of a general nuclear fuel rod. A zirconium alloy or stainless steel cladding tube 1 is loaded with a predetermined number of pellets 2 such as uranium dioxide UO ₂ and the pellets 2 are fixed by a spring 3 from one end. Is pressed, and end plugs 4 and 5 are welded to both ends of the coating tube 1.

Then, in the cladding tube 1 of the nuclear fuel rod, as shown in FIG. 18, two regions are formed: a region A in which pellets 2 are loaded and a plenum B in which pellets are not loaded,
The plenum B is set to a predetermined length to sufficiently store the generated fissile gas, and the pellet 2
The length of the area A in which is loaded is also determined.

By the way, as described above, in order to arrange the nuclear fuel pellets in order in the axial direction to obtain a row of a predetermined length, generally, the length of each of the plurality of nuclear fuel pellets is measured and formed into a predetermined row length by integration. Method, or mark the length to be formed in a row on the alignment tray in advance,
A method is employed in which the marking line is formed into a predetermined row length by a manual operation by a target.

However, in order to measure the length of the nuclear fuel pellets and form the length as described above, the work is troublesome, it takes a long time to form the column length, and the cumulative error becomes large. When using an alignment tray provided with marking lines, various alignment trays for forming the row length are prepared according to the type of fuel rod, and the alignment tray corresponding to the type of fuel rod to be loaded is provided. It is necessary to pick out. Moreover, since it is necessary to manually adjust the total length and the length of each region, a long time is required for the work.

When the inside of the pellet loading area is divided into a plurality of areas according to the type of pellets, the length of each area is generally defined as follows.

That is, if they have been divided into for example five regions as shown in FIG. 19 is, A ₁ region length of _1, A ₁ region and A ₂ region plus the length _2, A ₁ region, A ₂ Length including area and A ₃ area ₃ , A ₁ area, A ₂ area, A ₃
As shown in FIG. 20 and the method for defining the length ₄ including the area and the A ₄ area and the length L ₂ of the plenum B,
The length of each area from A ₁ area to A ₄ area is defined, and only the final A ₅ area is the total length from A ₁ area to A ₅ area, that is, the length of area A where pellets are loaded. There is a method defined by L ₁ . And
The tolerances of the lengths of the respective regions A _{1 to} A _{4 and} the lengths of the regions A are set to be slightly longer than the length of one pellet, and depending on whether one pellet is added in the row or not. The length can be controlled within the tolerance.

By the way, when the pellets are loaded into the fuel rods of the four-region design, conventionally, as shown in FIG. 21, a plurality of types of nuclear fuel pellets 2a, 2b, 2c, and 2d are provided in the transport tray for each type. 6, the transport trays 6 are placed on the loading table 7 in a line corresponding to the loading order. On the other hand, on one side of the loading table 7, there is arranged an array V tray 8 provided with a plurality of dividers a ₁ , a ₂ , ... Corresponding to the fuel design, and pellets of a type to be loaded in each area. Are sequentially arranged on the aligned V tray 8 and then the pellet row is loaded into the cladding tube 1.

However, when the pellet loading operation into the cladding tube is performed manually as described above, the pellets and pellet trays having the same shape should be definitely placed at a predetermined position, and the pellets of each type should be lengthened for each region. While checking, it is necessary to definitely arrange the types of pellets. Then, when checking the length for each area, it is necessary to definitely return the excess pellets of the same shape to the original pellet tray on which the same type of pellets are placed, which is inefficient. Therefore, there is a problem that the work takes a long time.

In addition, even if the number of workers is increased during the loading work that requires a large number of areas, the same type of pellets as described above can be arranged in a predetermined area or returned to the original pellet tray at various locations in the same place. However, there is a problem in that it is difficult to reliably prevent the occurrence of a loading error if only the loading speed is increased.

[Object of the Invention]

The present invention eliminates the above-mentioned drawbacks of the prior art, and secures a predetermined length row of nuclear fuel pellets of a type to be loaded in each region in the fuel rod cladding tube from a pellet transport tray loaded with a predetermined type of pellets. Another object of the present invention is to obtain a nuclear fuel pellet loading device that can be efficiently and efficiently formed to reliably load a predetermined nuclear fuel pellet in a predetermined region.

[Outline of Invention]

The present invention relates to a nuclear fuel pellet loading apparatus for loading one type or multiple types of nuclear fuel pellets per fuel rod in a cladding tube to a predetermined length, respectively. A cladding tube holding device for holding the cladding tube and a number of nuclear fuel pellets corresponding to the number of the cladding tubes are movably held only in the axial direction, and Vs arranged on the same axis as the cladding tube row. Aligned V-tray having grooves and provided with display means for indicating the rear end of the pellet row, stoppers inserted into and removed from the V-grooves for limiting axial movement of the row of nuclear fuel pellets, and nuclear fuel pellets A pellet conveying tray that is arranged and placed for each of the trays, and is selectively moved to the vicinity of the aligned V tray;
A stacker for accommodating the pellet transport tray on which the nuclear fuel pellets are placed and a pellet transport tray on which a predetermined type of pellets are loaded are transported from the stacker to a predetermined position on the same axis as the aligned V tray. And a tray transfer device for controlling the stopper so that the distance between the stopper position for limiting the movement of the pellet in the axial direction and the display means is set to a predetermined pellet area length or column length, and the tray transfer device is It has a control device which controls.

Example of Invention

Embodiments of the present invention will be described below with reference to FIGS. 1 to 16.

FIG. 1 is a plan view of a nuclear fuel pellet loading apparatus according to the present invention. This apparatus sets a cladding tube in a predetermined position or a cladding tube handling section 100 for stacking cladding tubes that have been loaded with nuclear fuel pellets. Forming a row of nuclear fuel pellets,
A pellet handling unit 200 that inserts the fuel pellet row into the cladding tube, a stacker group 300 that stores a pellet transport tray on which nuclear fuel pellets are arrayed, and a tray conveyor that takes out and transports a predetermined pellet transport tray from the stacker group 300. 400, an intermediate storage buffer 500 that can store a plurality of pellet transfer trays, and an empty tray stacker that stores an empty pellet transfer tray that has finished transferring fuel pellets to the pellet handling unit 200.
It is composed of 600.

By the way, the cladding tube handling section 100 is provided with a stack table 12 on which a large number of fuel rod cladding tubes 11 are placed, as shown in FIGS. The stack table 12 is composed of a plurality of support rods 12a tilted in a direction orthogonal to the axis of the cladding tube 11 placed thereon, and below the stack table 12,
A second stack table 14 is provided which is tilted in the direction opposite to the tilt direction of the stack table 12 and on which the cladding tube 13 after nuclear fuel pellet insertion is placed.

A pallet 15 that extends along the edge of the stack table 12 and that can be pitch-fed in a direction orthogonal to the axial direction is provided on the inclined descending end side. That is, the female screw portion 15a provided in the lower portion of the pallet 15 is screwed onto the screw shaft 17 driven by the motor 16, and the rotation of the screw shaft 17 causes the pallet 15 to move in the front-back direction, that is, the stack table 12. The guide member 18 can be moved toward or away from each other, and a plurality of covering tubes 11 can be arranged on the surface of the pallet 15 in parallel with the longitudinal direction of the pallet 15. Are provided with V-shaped grooves 19a, 19b, 19c ...

On the other hand, below the pallet 15, a plurality of operating rods that can be moved up and down and back and forth via a motor 20 and a link 21 are provided.
22 are erected at predetermined intervals in the longitudinal direction of the pallet 15 (FIG. 3). The tip of the operating rod 22 is the pallet 15
Through the opening 15a formed in the above, passing through each support rod 12a of the stack table 12 so as to be able to ascend to a slightly higher position, and further moved forward (in the direction away from the stack table 12). It is designed to descend afterward. An arm 24 that can be vertically swung by a drive mechanism 23 is pivotally attached to the top end of the operating rod 22 (fourth
In the upper position of the arm 24, a V-shaped recess 25 capable of holding the coating tube 11 is formed with the top surface of the operating rod 22.

Further, as shown in FIG. 1 and FIG. 3, a cladding tube pusher 26 that is movable in the longitudinal direction of the pallet 15 is disposed on one end side of the pellet 15. As shown in FIG. 5, the pallet is provided on the pusher 26 for the cladding tube.
A plurality of pads 27 are provided which correspond to the covering tubes 11 arrayed and supported by 15, and which can respectively come into contact with the ends thereof, and the pads 27 are urged by a spring 28 in the protruding direction. Further, when the pad 27 resists the resilience of the spring 28 and retracts, the pad pusher 26 is actuated by the pad 27 to stop the advance of the cladding pusher 26. 29 are provided.

On the other hand, on the other end side of the pallet 15, the pallet 15
A centering fitting (30) capable of inserting and engaging the opening side end of each cladding tube (11) mounted on the machine frame is fixed to the machine frame. That is, the centering metal fitting 30 is provided with a through hole 31 corresponding to the cladding tube 11 and having the same axis as the axis thereof.
A step portion 32 that engages with the opening side end portion of the cladding tube 11 is formed in the middle of the through hole 31, and is further divided into two up and down by a plane including the center line of the through hole 31, and an upper portion 30a thereof can be opened and closed. There is.

Then, by raising each operating rod 22, the V-shaped concave portion formed by the top surface of the operating rod 22 and the arm 24.
If 25 is made to support and hold the coating pipe 11 placed on the edge of the stack table 12, and then the operating rods 22 are moved forward (downward in FIG. 4) and lowered. The covering tube 11 is transferred to the V-shaped groove 19a of the pallet 15 located below. Therefore, 1 for the pallet 15
After moving forward by the pitch, each operating rod 22 is moved up and down again to transfer the next cladding tube 11 to the next V-shaped groove 19b of the pallet 15. In this way palette 1
When the cladding tube 11 is placed in each V-shaped groove on the 5 in sequence,
The cladding tube pusher 26 is operated, each cladding tube 11 is pressed toward the centering fitting 30 side through each pad 27, and the tip end of each cladding tube 11 on the opening side is inserted into the through hole 31 of the centering fitting 30. Pressed to hold each cladding tube 11 in place. In this case, when the covering pipe 11 is pressed by the centering fitting 30 and a load of a predetermined pressure or more is applied to the pad 27, the pad 27 retreats against the spring 28, whereby the limit switch
29 is actuated to stop further movement of the cladding pusher 26.

In this way, in the cladding handling section 100, the cladding 11 to be loaded with fuel pellets can be automatically positioned.

After the nuclear fuel pellets are loaded into the cladding tube, as will be described later, the end plug portion is clamped by a gripper (not shown) attached to the cladding tube pusher 26, and the cladding tube pusher 26 is retracted to remove the tube end portion. Can be pulled out from the centering fitting 30.

By the way, on the same axis as the pallet 15 on which the coating tubes 11 are placed as described above, the aligned V trays 35 are arranged with the centering fitting 30 interposed therebetween.

On the other hand, a plurality of stackers 36a, 36b, 36c, 36d, 36e are arranged in parallel on one side of the above-mentioned aligned V-tray 35, and each stacker is loaded with different types of nuclear fuel pellets. The transport trays are sequentially stored according to their type. That is, for example, a stacker
36a stores the pellet transport tray in which the nuclear fuel pellets to be loaded in the A ₁ area shown in FIG. 19 are stored, and the stacker 36b stores the pellet transport tray in which the nuclear fuel pellets to be loaded in the A ₂ area is loaded. To do.

Further, in front of the row of each stacker 36a, 36b, 36c, 36d, 36e, a tray conveyor 400 that conveys a predetermined pellet transport tray 37 is arranged along the row, and the tray conveyor 400 is provided. On one side of one side of the
An intermediate storage buffer 500 capable of accommodating a plurality of pellet transport trays 37 is arranged between the fuel pellets at the end of 5 and the transfer section 38, and further, the intermediate storage buffer of the fuel pellet transfer section 38. On the other side of 500,
An empty tray stacker 600 for accommodating an empty pellet carrying tray after the nuclear fuel pellets have been transferred to the pellet handling unit 200 is arranged.

By the way, a plurality of V-shaped grooves 40 extending on the same line as the coating tubes 11 on the pallet 15 positioned at a predetermined position are provided on the surface of the aligned V tray 35, as shown in FIG. Above the fuel pellet transfer section 38 shown, extending in the direction orthogonal to each pellet row arranged and stacked in the pellet transport tray transferred to the section, engages with the end surface of each pellet row, and has a predetermined number of rows. A discharge pusher 41 for pushing and transferring the pellet row onto the aligned V-tray 35 is provided, and the discharge pusher 41 is driven by a pellet pusher device 42.

The pellet pusher device 42 releases the interlock when the discharge pusher 41 applies a load more than a predetermined amount to the discharge pusher 41 when transferring the respective pellet rows stacked on the pellet transport tray in the column direction. A slip clutch (not shown) is interposed.

Further, above the aligned V-tray 35, an aligned V-tray is provided.
A stopper device 50 for receiving the row end of each pellet extruded on the 35 is provided. That is, as shown in FIG. 8 and FIG.
With the guide rod 51 and the feed screw 52, the above-mentioned aligned V-tray 35
A stopper position varying member 53 is arranged along the longitudinal direction of the stopper position varying member 53. The stopper position varying member 53 has a top portion that can be moved up and down by an air cylinder 54, and the alignment V
A stopper rod 55 extending in the transverse direction is mounted above the tray 35.

When the stopper rod 55 is moved up and down, the alignment V
A stopper piece 56 is inserted into each groove 40 of the tray 35 so as to be inserted and removed from above, and at its lowered position, the ends of the rows of the nuclear fuel pellets P aligned and held in the groove 40 come into contact with each other. The movement is stopped, and by the contact,
The indicator lamp 45 is turned on.

By the way, an inverted L-shaped swing member 57 corresponding to the stopper piece 56 is pivotally attached to the stopper rod 55.
The lower end of 57 is provided with a detection chip 57a capable of contacting each end of the nuclear fuel pellet P.
A spring 58 biases the detection tip 57 in a direction in which the detection tip 57a projects from the front surface of the stopper piece 56.
Furthermore, when the rocking member 57 is pressed by the nuclear fuel pellet P and rocks against the spring 58, the rocking is confirmed above the stopper 55, and the movement of the pusher 41 in the pellet pusher device 42 is confirmed. A photo sensor 59 for stopping and returning is provided.

On the other hand, as shown in FIG. 10, on the surface of the aligned V tray 35, two marking lines are provided in the vicinity of the fuel pellet transfer section 38.
60a, 60b are provided, and the distance maintained between the stopper device 50 and the marking lines 60a, 60b indicates the length and tolerance of a predetermined fuel region, which can be visually checked. I am doing it. In addition, instead of this marking line,
As shown in FIG. 11, the light-transmissive tolerance member 61 may be embedded in a predetermined position of the aligned V-tray 35 within the tolerance width of the area length.

In addition, above the aligned V tray 35, each V-shaped groove 40 is formed.
A loading pusher 80 is provided which pushes the arrayed pellets in the direction of the coating tube arranged on the pallet 15 and loads the pellets into the coating tube.

As shown in FIG. 12, the loading pusher 80 has a moving member 83 which can be moved along the aligned V tray 35 by the guide rod 81 and the feed screw 82 along the aligned V tray 35, and the moving member thereof. Above the 83, the above-mentioned aligned V-tray 35
Loading pusher retaining member 84 extending transversely above the
However, it is mounted so that it can move up and down.

A plurality of pusher rods 85 respectively corresponding to the V-shaped grooves 40 provided on the aligned V-tray 35 are mounted on the loading pusher holding member 84 so as to be movable back and forth in the longitudinal direction of the grooves 40. Each pusher rod 85 is constantly urged by a spring 86 in the loading direction. Further, on the rear side of the loading pusher holding member 84, there is provided a sensor 87 that detects when all the pusher rods 85 have moved to the retracted position against the spring 86 and stops the movement of the moving member 83. Has been.

By the way, in the stacker group 300, a partition plate 90, as shown in FIG. 13, is provided so that the pellet transport tray on which the nuclear fuel pellets are mounted can be stored for each pellet concentration or for each burnable poison concentration. A plurality of shelves 91 are fixed to the storage section that is provided and is divided by the partition plate 90.

Further, as shown in FIG. 13, the tray conveyor 400 has a moving device 93 that moves on the rails 92a and 92b, and the moving device 93 is provided with a lifter 94 that can be moved up and down along a guide rod. The lifter 94 is screwed onto a drive screw 95a which is rotationally driven by a drive motor 95, and the rotation of the drive screw 95a causes the lifter 94 to move up and down. Further, the lifter 94 is provided with a tray pull-out plate 96 that is horizontally inserted into and removed from the shelf 91 by a drive mechanism (not shown).

On the other hand, the intermediate storage buffer 500 also has a stacker group 3
Similar to 00, a plurality of shelves 91 are provided.

Further, the pellet transfer section 38 is also movable up and down along the guide rod 97, is screwed into a drive screw 98a which is rotationally driven by a drive motor 98, and is vertically moved by the rotation of the drive screw 98a. .

By the way, the position of the stopper device 50, the moving device 9
3, the lifter 94, the drive motor 98 and the like of the pellet transfer unit 38 are controlled by the control device 800, respectively, and a predetermined pellet transfer tray is fed and stored in the intermediate storage buffer 500 in a predetermined order. The pellet transfer tray stored at a predetermined position can be taken out and placed on the pellet transfer section (Fig. 14).

Therefore, in the apparatus as described above, the rows of nuclear fuel pellets are formed and loaded into the cladding tube 11 as follows. That is, when the number of the type of fuel rod to be loaded with nuclear fuel pellets is input to the control unit 800 shown in FIG. 14, the control unit will display a table of pellet type and area length stack length for the stored fuel rod type. A predetermined one is selected from the list, a predetermined pellet type is assigned to the stacker, and this is displayed on the monitor.

Therefore, the worker stores the tray on which the predetermined nuclear fuel pellets are loaded in each of the stackers 36a, 36b, ... Based on the above display. That, A ₁ as example shown in FIG. 19
When the type to each other in five areas A ₅ regions are loaded with different nuclear fuel pellets from the area is the nuclear fuel pellets to be loaded into A ₁ area to the stacker 36a, and the nuclear fuel pellets to be loaded into A ₂ regions in the stacker 36b The predetermined nuclear fuel pellets are sequentially stored in the corresponding stacker.

Therefore, first, in order to form a pellet row in the A ₁ area, in FIG.
The transfer tray 37 accommodated in 36a is pulled out and sent to the intermediate storage buffer 5 by the tray conveyor 4. Then, the transport tray is pulled out to the fuel transfer unit 38 from there. Then, the row of fuel pellets arranged and stacked on the above-mentioned transport tray is pushed out and transferred to the groove 40 of the aligned V-tray 35 by the discharge pusher 41.

Meanwhile, in parallel with this, the stopper piece 56 is moved to a predetermined position corresponding to the column length of the fuel pellets in the A ₁ region by the movement of the stopper position varying member 53 of the stopper member 50, and the stopper piece 56 is aligned. It is inserted into the groove 40 of the V tray 35.

When the nuclear fuel pellet row is pushed out to the aligned V-tray 35 by the pusher 41 operated by the button operation, it hits the stopper piece 56 and the gap between the pellets becomes negligibly small, and the length of each pellet row becomes small. The transfer from the transport tray to the aligned V tray 35 is sequentially performed in parallel with the manual operation until the length exceeds a predetermined tolerance. On the other hand, when there is no more fuel pellets in the transfer tray that has been pulled out to the fuel transfer section 38, the empty transfer tray is sent to the empty tray stacker 600, and a new transfer tray is sent from the intermediate storage buffer 500. , The fuel pellets are transferred to the aligned V tray 35. Therefore, the tip of the longest one pellet row comes into contact with the detection chip 57a of the stopper piece 56, and the swinging member 57 is moved to the spring 5.
When rocking against 8 and all rocking members 57 rock,
This is detected by the photo sensor 59, the movement of the discharge pusher 41 is stopped, and each pellet row is aligned on each groove 40 of the alignment V tray 35. Meanwhile, the discharge pusher
41 returns to the fuel transfer section 38 side. The operator confirms that the pellet row has come into contact with the stopper piece 56 by lighting the indicator lamp provided on each row stopper.

Then, the operator puts each pellet row aligned on each groove 40 of the aligned V-tray 35 within the range of two marking lines at a fixed position indicating the area tolerance provided on the surface of the aligned V-tray 35. The edges of the pellets, that is, cuts, are detected visually or by an optical sensor to cut out so that the rear end of the pellet row is located, and the pellets of a length including the excess predetermined tolerance are grooved 40.
Via the upper part, it is re-stored in the transfer tray on the fuel transfer section 38. At this time, the worker can work in a substantially fixed position and does not require a large number of people easily.

When the row of fuel pellets to be loaded in the A ₁ area is formed in this way, the stopper piece 56 becomes the stopper position variable member.
The movement of 53 sets the fuel pellets to a predetermined position corresponding to the sum of the rows of fuel pellets in the A ₁ area and the A ₂ area, and the fuel pellets loaded in the A ₂ area are transferred from the transfer tray to the aligned V tray in the same manner as described above. Transferred to 35, rows of fuel pellets in the A ₁ and A ₂ areas are formed. The tray conveyor is controlled by the control device by the movement of the stopper position, and the tray conveyor device does not form different types of pellets unless the stopper position is moved. Thereafter, similarly, A ₃ area, A ₄ area, A ₅
When the rows of fuel pellets in the area are sequentially formed, the stopper piece 56 is lifted upward and the loading pusher 80 is
Is moved to the rear end of the fuel pellet row, the tip of each pusher rod 85 is brought into contact with the rear end of each pellet row, and each pellet row is arranged on the pallet 15 by the movement of the loading pusher 80. It is pushed to the side of the covered tube 11 and is inserted and loaded into the covered tube 11.

Then each pellet row is fully inserted and all pusher rods
When the resistance of 85 increases and the pusher rod 85 retracts relative to the spring 86 relative to the load pusher holding member 84, the sensor 87 forms this and the movement of the load pusher 80 in the pellet loading direction is prevented. It is stopped and then retracted to a predetermined position to prevent an excessive load from being applied to the fuel pellets and the like, thereby damaging the fuel pellets and the device.

Further, in forming the pellet row for each area, different kinds of pellets are not handled at the same time, so that different kinds of pellets are prevented from being mixed into a predetermined pellet area.

The loading pusher 80 is a suitable example, but it can be replaced by manually pushing in with a pushing rod (not shown).

By the way, when the loading of nuclear fuel pellets into the cladding tube 11 is completed as described above, after the upper portion 30a of the centering metal fitting 30 is opened, the pallet 15 is moved to the stack table 12 side and supported on it. One of the covered pipes is moved to a position above the operating rod 22, and the covering pipe is lifted above the second stack table 14 by the upward movement of the operating rod 22. Then, the arm 24 is tilted downward so that the cladding tube 11 is moved onto the second stack table 14. After that, the pallet 15 is moved to the stack table 12 side by one pitch, and the next cladding tube is transferred to the second stack table 14 in the same manner. It is placed on the stack table.

Further, in the case of forming the pellet row having the structure as shown in FIG. 20, every time the pellet row in one area is formed, the stopper piece 76 is moved up to the cutting position, and the row is formed by the stopper piece 76. The formed pellet row is the stopper piece
By moving it so that it is closer to the cladding tube than 76,
The length of the pellet row in each region can be set to a predetermined length. Then, only when performing row formation of the last A ₅ region, it may take a method of forming a row of fuel pellets of the entire area of the foregoing.

Further, when the necessity of the processing capacity is not so high, an aligned V tray having one V groove may be used and the processing may be performed for each one. Further, the transport tray may be manually stored in each stage of the intermediate storage buffer.

Further, FIGS. 15 and 16 show, for example, that a 20
FIG. 7 is a view showing a means for feeding a row of pellets arranged in a substantially uniform length and then transferring them to the four grooves 40 of the alignment V-tray 35, wherein the four grooves 40 are on the carrying tray. The pellet rows are arranged so that the axial positions thereof coincide with every four rows. Further, the pusher 41 is configured to discharge only the pellet rows arranged at the positions of the four grooves 40 among the pellet rows on the carrying tray. Therefore, when pellets are placed in all rows on the transport tray as shown in FIG. 15, the leftmost pellet row and every four rows of pellets are first discharged, and then transported as shown in FIG. The positions of the trays are shifted by one pitch, and every four rows of pellets are similarly discharged.

When the pellets are placed on the transport tray, they are stored again in the intermediate buffer, but the control unit (not shown) stores up to which column each intermediate buffer storage tray is used. In the case of using the above, the transport tray is positioned at the discharge position so that the column in which the pellets are present is aligned with the position of the groove 40.

In the above description, four rows of grooves and 20 rows of pellets on the carrying tray have been described, but the grooves 40 may be 20 rows, or the grooves 40 may be only one row. The number of grooves 40 and the number of pellet rows in the carrier tray can be other than the above-described number, by arranging the number of grooves 40 that can be divided by dividing the pellet rows on the carrier tray.

Further, as shown in FIG. 14, the stopper is not movable to an arbitrary position, but a plurality of stoppers may be provided at a fixed predetermined position and selectively used.

〔The invention's effect〕

As described above, according to the present invention, in a nuclear fuel pellet loading device for dividing a cladding tube into a plurality of regions and loading nuclear fuel pellets of a prescribed type for a prescribed length, one cladding tube or parallel cladding tubes is provided. In a state of holding a plurality of cladding tubes, and holding a row of nuclear fuel pellets of a number corresponding to the number of the cladding tubes so as to be movable only in the axial direction, and on the same axis as the cladding tube row. Aligned V trays having V-grooves arranged in a row and provided with a display means for indicating the rear end of the pellet row, and the V-shaped trays along the V-grooves
A stopper that is adjustable in the axial direction of the groove and that is inserted into and removed from each V groove to limit the axial movement of the row of nuclear fuel pellets, and the nuclear fuel pellets are arranged and mounted for each type, and the above-mentioned alignment V A pellet carrying tray that can be moved to the end of the tray, an ejection pusher for transferring the row of nuclear fuel pellets arranged in the pellet carrying tray onto the aligned V tray, and a predetermined amount necessary for loading at least one fuel rod. An intermediate buffer storage for temporarily storing a plurality of the pellet transport trays on which nuclear fuel pellets of different types are arrayed, and a pellet transport tray on which a predetermined type of pellets are loaded from the intermediate buffer storage to the aligned V tray Tray transport device for transporting to a predetermined position on the same axis as the above, and a stopper that limits the movement of the pellet in the axial direction The stopper is controlled so that the distance between the display and the display means is set to a predetermined pellet area length or column length, and the pellet transfer tray on which a plurality of predetermined pallets are arrayed is selected up to the end of the aligned V tray. Since a control device for controlling the intermediate buffer storage and the tray transfer device is provided so as to be moved automatically, predetermined pellets to be loaded into the coating tube are automatically transferred,
It is possible to easily form a pellet row in a predetermined region length, yet to handle the same type of pellets at a substantially fixed position, and to completely prevent mixing of different types of pellets in each region. Therefore, it is possible to reliably prevent the occurrence of a loading error, improve the product accuracy as a fuel rod, and improve the work efficiency.

[Brief description of drawings]

FIG. 1 is a plan view of a nuclear fuel pellet loading apparatus of the present invention, FIG. 2 is a side view taken along line II-II of FIG. 1, FIG. 3 is a perspective view of a cladding tube handling portion, and FIG. 4 is a cladding tube. FIG. 5 is an enlarged side view of the clad tube handling section of the handling section, FIG. 5 is a front view of the clad tube pusher section and the centering metal fitting section, and FIG.
A side view taken along line VI-VI, FIG. 7 is a perspective view of a pellet handling portion, FIG. 8 is a front view of a stopper device, FIG. 9 is a sectional view taken along line IX-IX of FIG. 7, and FIG. 11 and 12 are perspective views of the aligned V-tray unit, FIG. 12 is a perspective view of a loading pusher device, FIG. 13 is a perspective view of a stacker group, and FIG.
The figure is an explanatory view showing the relationship between the control device and the tray conveyor and the stopper device, and FIGS. 15 and 16 are views showing another embodiment of the pusher for transferring the fuel pellets to the aligned V tray, and FIG. Is a cross-sectional view of a general fuel rod, FIG. 18 is an explanatory view of the relationship between the fuel region and the plenum, FIG. 19 and FIG.
FIG. 20 is an explanatory diagram of a method for defining the length of each region when the fuel region is composed of a plurality of regions, and FIG. 21 is a schematic explanatory diagram of a conventional pellet loading device. 100 …… Cladding tube handling part, 200 …… Pellet handling part, 300 …… Stacker group, 400 …… Tray conveyor, 500 …… Intermediate storage buffer, 11 …… Fuel rod cladding tube, 12 …… Stack table, 15… ... palette, 22 ...
… Operation rod, 26 …… Clad tube pusher, 30 …… Center fitting, 35 …… Aligned V tray, 36a, 36b, 36c, 36d, 36e …… Stacker, 38 …… Fuel pellet transfer part, 40 …… V-shaped groove, 41 ... Discharge pusher, 50 ... Stopper device, 55 ...
… Stopper rod, 56 …… Stopper piece, 60a, 60b …… Marking wire, 80 …… Loading pusher, 85 …… Pusher rod, 91 ……
Shelf, 93 ... moving device, 94 ... lifter, 800 ... control device.

Front page continuation (72) Inventor Takashi Sekine 2-3-1, Kawa, Yokosuka, Kanagawa Nihon Clear Fuyuru Co., Ltd. (72) Inventor Tatsushige Yoshida 2-3-1, Kawasuka, Yokosuka, Kanagawa In this Nyuclear Fuel Co., Ltd. (56) Reference JP-A-56-135193 (JP, A) JP-A-61-4999 (JP, A)

Claims (5)

[Claims] 1. A nuclear fuel pellet loading device for dividing a cladding tube into a plurality of regions and loading a prescribed length of nuclear fuel pellets of a prescribed type in one cladding tube or a plurality of claddings in parallel with each other. A clad holding device for holding a tube and a V-groove arranged on the same axis as the clad row, holding a row of nuclear fuel pellets corresponding to the number of the clad tubes so as to be movable only in the axial direction thereof. And an arrayed V-tray having display means for indicating the rear end of the pellet row,
Along with each of the V-grooves, a stopper that can be moved and adjusted in the axial direction of the V-groove and that restricts movement of the row of nuclear fuel pellets in the axial direction by being inserted into and removed from each V-groove and a nuclear fuel pellet is provided for each type. A pellet transport tray that is arranged and mounted on the aligned V tray, and is moved to the end of the aligned V tray; a discharge pusher for transferring a row of nuclear fuel pellets arranged in the pellet transport tray onto the aligned V tray; and at least a fuel rod. An intermediate buffer storage for temporarily accommodating the plurality of pellet transport trays in which a predetermined type of nuclear fuel pellets necessary for loading one is arranged, and a pellet transport tray in which a predetermined type of pellets are loaded. A tray transfer device for transferring from the intermediate buffer storage to a predetermined position on the same axis as the aligned V tray, and in the axial direction of the pellet. The stopper is controlled so that the distance between the stopper position for restricting the movement and the display means is set to a predetermined pellet area length or column length, and the pellet transfer tray on which a plurality of predetermined pallets are arranged and arranged is an aligned V tray. A nuclear fuel pellet loading device having the intermediate buffer storage and a controller for controlling the tray transfer device so that the intermediate buffer storage and the tray transfer device can be selectively moved to the end of the. 2. The nuclear fuel pellet loading apparatus according to claim 1, wherein a plurality of stoppers for restricting axial movement of the nuclear fuel pellet row are provided at predetermined positions. 3. A display means for indicating a rear end of a pellet row provided in the vicinity of the side of the pellet carrying tray on the arrayed V-tray is formed by at least two lines indicating a range of area length tolerance. The nuclear fuel pellet loading apparatus according to claim 1. 4. The discharge pusher is configured so as to be able to simultaneously transfer at least every other plurality of nuclear fuel pellet rows arranged in a pellet carrying tray. Nuclear fuel pellet loading apparatus as described. 5. The nuclear fuel pellets arranged in a pellet carrying tray are transferred simultaneously to all rows to an aligned V-tray, and all the rows are simultaneously inserted into each cladding tube. The nuclear fuel pellet loading apparatus according to item 1.