JP3028277B2 - Method and apparatus for transferring sintered fuel pellets - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a process for producing fuel pellets to be used in a cladding tube of a fuel rod, wherein the pellets are sintered on a molybdenum sintering tray. And other methods for transferring the sintered fuel pellets from the sintering tray to a transfer tray made of stainless steel, etc. for temporary storage or temporary storage, etc., and a transfer that can be used to carry out the method. To a replacement device.

[0002]

_2. Description of the Related Art The sintering of fuel pellets is performed using UO ₂
The powder is compression molded into a cylindrical shape, which is 400 to 500
With only about one piece placed on the sintering tray,
It will be heated above 750 ° C. For this reason, even if a sintering tray made of Montbden is used repeatedly for the sintering process, it will be deformed such as warping or bending, and the sintering bottom plate surface of the sintering tray will have a rough surface. It becomes a slippery state.

On the other hand, when the conventional means for transferring sintered fuel pellets is used, a transfer tray b made of stainless steel or the like is placed on a tray table a as shown in FIG.
And a sintering tray c on which a large number of sintered fuel pellets P having undergone the sintering process are placed in a forest.
Are arranged adjacently by a robot (not shown), and then a transfer pusher d provided on the tray table a is operated. By pushing the sintered fuel pellets P in the direction of arrow A in this manner, the sintered fuel pellets P are slid on the sintering bottom plate surface c ₁ of the sintering tray c, and the sintered fuel pellets P are moved to the sintering bottom plate surface c. so that shifts over ₁ and transferring a bottom plate surface b ₁ of a transfer tray b as flush state.

[0004]

When according 0006] the conventional sintered nuclear fuel pellets sorting means, sintering trays c repeated use as sintering processing former opinion is, or are deformed, the sintering for the bottom plate surface c ₁ Because the surface is rough, the bottom surface of the sintered fuel pellets P is caught by the rough surface and falls down when pushed by the pusher d, and in addition, the bottom edge of the bottom surface or the bottom surface is chipped. Occurs, resulting in a defective product. In addition, since the above-mentioned overturning does not cause a volume shrinkage in the fuel pellet material compression-molded by the sintering process, a gap is formed between the sintered fuel pellets P, so that the frequency of occurrence is considerably high. It has become.

[0005] The present invention is intended to solve the above-mentioned conventional deficiencies, and when the method for transferring sintered fuel pellets according to claim 1 is used, the sintered fuel pellets on the sintering tray are pushed and slid. The tray holder on which a large number of the sintered fuel pellets are held in a sandwiched state by a movable holding plate of a separately provided holding mechanism, and a sintering tray or a transfer tray is placed in this state. In addition to raising and lowering itself, the fuel pellets are appropriately moved in the front-rear direction, which is the transfer direction of the sintered fuel pellets. Thus, the transfer of the sintered fuel pellets can be realized without sliding between the bottom surface of the sintered fuel pellets and the sintering tray or the transfer tray. Its purpose is to suppress the occurrence.

[0006] Further, in the same manner as in the first aspect of the present invention, in the second aspect, in addition to the step of the first aspect, the sintering of the fuel pellets by the movable pressing plate is performed only once. After the clamping, the clamp is released once, and the clamping process is performed again so that the clamping is performed again, so that the sintered fuel pellets in the clamping state are not unintentionally dropped. Then, if the reliability is to be further improved, and under the first re-clamping step, and the sintered fuel pellets slip down, the re-clamping step is performed. Furthermore, by repeating the required number of times,
The object set forth in claim 1 is to be realized with higher reliability.

Next, a third aspect of the present invention relates to an apparatus for transferring sintered fuel pellets which is suitable for carrying out the transfer method according to the first and second aspects, which is controlled by an electric controller. A base that is driven in the front-rear direction by the front-rear drive mechanism, a holding mechanism that is provided adjacent to the base, and a tray table that can be moved up and down by a lifting-direction drive mechanism provided on the base. And a sintering tray and a transfer tray which can be arranged side by side on the tray table. And, the movable presser plate which can hold the sintered fuel pellets on the sintering tray freely,
To be activated by the operation of the presser mechanism,
Accordingly, it is an object of the present invention to enable the transfer method according to the first and second aspects to be performed with high reliability.

[0008]

In order to achieve the above object, according to the present invention, there is provided a sintering tray in which a large number of sintered fuel pellets are placed in a forest on a sintering bottom plate surface. And a transfer tray for transferring the sintered fuel pellets onto the transfer bottom plate surface, are arranged side by side in the front-rear direction on the tray table, and by operating a separately prepared holding mechanism, By closing and moving the pair of movable holding plates mounted side by side in the front-rear direction, a large number of sintered fuel pellets in the sintering tray are clamped from the front and rear sides, and then the tray table is lowered for sintering. The sintering bottom plate surface of the tray is separated from the bottom surface of the sintered fuel pellets by a required length, and furthermore, the tray mounting table is moved in the front-rear direction, thereby clamping the transfer bottom plate surface of the transfer tray. Has been sintered After placing the bottom plate surface of the transfer tray of the transfer tray on the bottom surface of the sintered fuel pellet, the pair of movable holding plates are removed. By opening and moving forward and backward,
Releasing the sintered fuel pellets from said pinching,
A method of transferring sintered fuel pellets, characterized in that the tray for sintering and the transfer tray are returned to their original positions by lowering the tray table and moving it back and forth. And

Further, in the transfer method according to claim 2, according to claim 1, the sintering bottom plate surface of the sintering tray is lowered by lowering the tray mounting table from the bottom surface of the sintered fuel pellets. When it is confirmed that there is no slippage of the sandwiched sintered fuel pellets when separated by the required length, raise the above tray mounting base and place the sintering bottom plate surface of the sintering tray on the bottom surface of the sintered fuel pellets. After the contact, the sandwiching of the sintered fuel pellets by the movable presser plate is released, and furthermore, the movable presser plate is closed and moved in the front-rear direction. , From the front and rear sides, and then the tray mounting table is lowered again to perform a clamping step again to separate the sintering bottom plate surface of the sintering tray from the bottom surface of the sintered fuel pellets. After or without application, when slippage is confirmed in the sintered fuel pellets, the above-described re-clamping step is repeated a required number of times until no slippage occurs. The content of the process is that the process is performed.

According to a third aspect of the present invention, which is a device capable of performing the above-mentioned transfer method, a front-rear drive mechanism operated by an electric controller and a required length in the front-rear direction by the front-rear drive mechanism are provided. a base which is reciprocable, a lifting direction drive mechanism both provided in the pressing mechanism and the base itself of adjacently provided on a base that is to be operated by the electrical controller of the lifting direction The drive mechanism is capable of reciprocating up and down by a required length in the vertical direction, and a large number of sintering fuel pellets are used for transferring a sintering tray placed in a forest on the sintering bottom plate surface and the sintering fuel pellets. A transfer tray for transfer on the bottom plate surface, and a tray table that can be arranged so as to be able to be arranged side by side in the front-rear direction, and the press mechanism mechanism has the sintering It is equipped with a pair of movable holding plates that can close or open a large number of sintered fuel pellets placed on the forest on the sintering bottom plate surface from the front and rear sides to clamp or release the clamping, respectively. To provide an apparatus for transferring sintered fuel pellets.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention aims at achieving the above object. First, a transfer apparatus according to claim 3 which can be used for carrying out the transfer method according to claims 1 and 2 is described.
As will be described in detail below with reference to FIGS. 1 and 2, the device includes an electric controller 1 and a base 3 driven in a front-rear direction indicated by an arrow X by a front-rear drive mechanism 2 operated by the electric controller 1. The pressing mechanism 4 provided adjacent to the base 3 to be operated by the electric controller 1 and the elevating drive mechanism 5 provided on the base 3 itself, and the operation of the elevating drive mechanism 5 causes the arrow Y to move. And a tray table 6 driven vertically.

Further, a transfer tray 7 is placed on one side in the front-rear direction on the tray mounting table 6 in a horizontal state, and a large number of sintered fuel pellets P are placed on the other side in a forest. Thus, the sintering tray 8 carried by a robot or the like can be arranged in an adjacent state. The transfer tray 7 and the sintering tray 8 are respectively provided with upright side plates 7a and 8a having a flat U-shape from their peripheral edges. Without
Moreover, the transfer bottom plate surface 7b of the transfer tray 7 and the sintering bottom plate surface 8b of the sintering tray 8 are arranged and held with their opening edges 7c, 8c abutting on each other so as to be flush with each other. You.

Next, as an example of the above-mentioned front-back direction driving mechanism 2, as shown in FIG. 2, a motor 2a driven by an electric controller 1 and a driving screw shaft 2b rotated by the motor 2a are provided. The drive screw shaft 2b is mounted on the base 3
A traverse mechanism is formed by screwing through a bearing 2c fixed to the base 3, and the base 3 is reciprocally movable in the arrow X direction by the operation of the motor 2a.

Further, the pressing mechanism 4 illustrated in the drawing is an example in which a pair of legs 4a and 4b erected from an erected table 4A adjacent to the base 3 is driven by an air cylinder or the like. Parts 4c and 4d are fixedly provided, and when these parts are operated by the electric controller 1, the movable holding plates 4e and 4e extending from the pair of driving parts 4c and 4d are provided.
By f, the sintering fuel pellets P of the forest stand arrangement can be held on the sintering bottom plate surface 8b of the sintering tray 8 from the front-back direction indicated by the arrow X.

For this reason, an adjusting arm rod 4g which can extend in the front-rear direction by a required length from the opposing surfaces of the driving units 4c and 4d and can rotate toward the tray table 6 from the standing state. , 4h are bent in a substantially L-shape. At the free ends of the adjusting arm rods 4g, 4h, the movable holding plates 4e, 4f are perpendicular to the front-rear direction indicated by the arrow X.
Are attached so as to be parallel to each other. Therefore, by appropriately adjusting the operation of the press mechanism 4, the adjusting arm rods 4g and 4h in the upright state are rotated until they become horizontal as shown in FIGS. 1 and 2, and the movable press plates 4e and 4f are moved. After being mounted on the sintering bottom plate surface 8b of the sintering tray 8, the adjusting arm rods 4g and 4h are closed and moved in the front-rear direction, thereby clamping the sintered fuel pellets P on the sintering bottom plate surface 8b. can do.

The movable holding plates 4e and 4f illustrated in FIG. 1 have escape prevention curved ends 4i and 4j formed at both ends thereof and bent inward, thereby being movable. When the holding operation is performed by the holding plates 4e and 4f, the sintered fuel pellets P are prevented from unintentionally falling out in the left-right direction indicated by an arrow Z perpendicular to the front-rear direction. The elevating and lowering direction driving mechanism 5 is an elevating motor 5b attached to an attachment board 5a attached to the upper surface of the base 3.
By the operation of, the vertically movable cylinder 5c is fixed to the center of the lower surface of the tray table 6 so that the tray table 6 can be vertically moved by a desired height.

Therefore, in order to carry out the transfer method of claim 1 using the transfer device for the sintered fuel pellets P, first, as shown in FIG. The transfer tray 7 and the sintering tray 8 on which the sintered fuel pellets P are erected in the forest are arranged side by side in the front-rear direction by using a robot. And the transfer bottom plate surface 7b and the sintering bottom plate surface 8b are flush with each other.

At this time, in the pressing mechanism 4, the adjusting arm rods 4g, 4h extending from the driving parts 4c, 4d are provided.
Since the movable holding plates 4e and 4f fixed to are in an upright state as shown in FIG. 3A, the pressing mechanism 4 is operated by the electric controller 1 to be shown in FIG. By rotating the adjusting arm rods 4g and 4h by approximately 90 degrees as described above, the movable holding plates 4e and 4f are brought into a horizontal state, whereby the movable holding plate 4e is placed on the sintering bottom plate surface 8b of the sintering tray 8. , 4f approaching or in contact with each other, and the sintered fuel pellets P are interposed between the two movable holding plates 4e, 4f.

Next, as clearly shown in FIG.
By moving the adjusting arm rods 4g and 4h by driving c and 4d, the movable holding plates 4e and 4f are closed and moved so as to approach in the front-rear direction (arrow X) as illustrated in FIGS. As a result, the above-mentioned sintered fuel pellets P are held between the movable holding plates 4e and 4f. As a subsequent step, in claim 1, as shown in FIG. 3 (D), the lifting / lowering direction driving mechanism 5 described above with reference to FIGS. By lowering here in the up-down direction (arrow Y), the sintering bottom plate surface 8b of the sintering tray 8 is separated from the bottom surface P 'of the sintered fuel pellets P.

In claim 1, following FIG. 3 (D), FIG.
As clearly shown in FIG. 1 (I), the base 3 is moved in the front-rear direction by the front-rear drive mechanism 2 as shown by the arrow X, as shown by FIGS. The transfer bottom plate surface 7b of the transfer tray 7 on the tray mounting table 6 is disposed immediately below the sandwiched sintered fuel pellets P, and the tray mounting table 6 is operated by the lifting / lowering driving mechanism 5. As a result, the transfer bottom plate surface 7b of the transfer tray 7 is brought into contact with the bottom surface P 'of the sintered fuel pellets P, and the state shown in FIG.

Further, according to the first aspect, the pair of movable holding plates 4e, 4f held therebetween are opened and moved in the front-rear direction by the driving units 4c, 4d of the holding mechanism unit 4.
As shown in FIG. 3 (K), the sintered fuel pellets P are released from the sandwiched state, and from this state, the tray table 6 is lowered again by the same operation as before, and then moved in the front-rear direction to form the sintering tray 8. By returning the transfer tray 7 to the initial position, the entire process is completed.

Therefore, in the above process, the sintered fuel pellets P are held by the movable holding plates 4e and 4f in a timely manner, and the sintering tray 8 and the transfer tray 7 are moved up and down in a timely manner. The sintered fuel pellets P are transferred from the sintering tray 8 to the transfer tray 7 without any sliding contact between the bottom surface P 'of the fuel pellets P, the sintering bottom plate surface 8b, and the transfer bottom plate surface 7b. It becomes possible to change.

Here, in order to return the transfer tray 7 and the sintering tray 8 to their original positions from the state (K) in FIG. 3, the holding mechanism is clearly shown in FIG. Part 4
By driving the drive units 4c and 4d of the trays, the movable holding plates 4e and 4f are turned by 90 ° to bring the first upright state, and then the tray base 6 is moved by moving the base 3 in the front-rear direction.
Is returned to the original position, thereby returning to the state of FIG.

Next, the transfer method of claim 2 will be described. As shown in FIG. 3 of claim 1, (A) to (D) and (I) to (M) are performed in the same step. However, when the sintering bottom plate surface 8b of the sintering tray 8 is separated from the step (D), that is, the bottom surface P 'of the sintering fuel pellet P, the sandwiched sintering fuel pellet P slips off. Will check if
In practice, this confirmation is based on the above separation distance of about 1
This is determined by whether or not the sintered fuel pellets P that have slipped and fallen down and are in contact with the sintering bottom plate surface 8b.

According to the second aspect of the present invention,
If it does not slip down, the process may proceed to the step (I), but even in such a case, the lowered sintering tray 8 is moved by the operation of the elevation driving mechanism 5. The sintering fuel pellet P is moved upward to be placed on the sintering bottom plate surface 8b to the state shown in FIG. 3E, and the movable holding plate 4 is driven by the driving units 4c and 4d of the holding mechanism unit 4.
e, 4f are opened and moved in the above-mentioned direction, and the sandwiching of the sintered fuel pellets P by the movable holding plates 4e, 4f is released as shown in the same figure (F), and the movable holding plates 4e, 4f are immediately closed and moved. By performing the clamping state again and the clamping step again as shown in FIG. 3 (G), a clamping state without slippage can be realized more reliably. Then, while maintaining the sandwiching state, the tray placing table 6 is lowered again to lower the sintering tray 8 and the transfer tray 7 as shown in FIG. 3 (H). The drop in (D) was about 3 times as large as 2 to 3 mm, and when the re-clamping step thus performed was completed, as shown in FIGS. 3 (I) to (M), The same steps as in claim 1 will be continued.

Further, in claim 2, as described above, FIG.
In the step (D), if slippage of the sintered fuel pellets P is confirmed, as described above, (E) and (F)
(G) In order to compensate for the uncertainty of the sandwiching of the sintered fuel pellets P due to the occurrence of slippage, in addition to the re-clamping step shown in (H), the re-clamping described in the above (E) to (H) is performed. After repeating the process at least once, the process shifts to the same processes (I) to (M) as in claim 1, but the re-clamping process is repeated a required number of times until there is no slippage. . Thus, claim 2
As compared with the method according to the first aspect, it is possible to reliably prevent the burned-out fuel pellets P from falling off due to insufficient pinching of the burned-out fuel pellets P, and to thereby cause the occurrence of damage and danger. .

[0027]

Since the present invention is embodied or constituted as described above, according to the transfer method of the first aspect, the sintered fuel pellets are properly held and transferred to the sintering tray. The fuel tray is also moved up and down and moved back and forth as needed, so that the sintered fuel pellets are not transferred by being slid on the deformed or damaged sintering tray, and the sintered fuel pellets are not moved. There is no danger of scratches or defects occurring. In addition, overturning of the burned fuel pellets during sliding can be eliminated, accidental damage due to the overturn can be avoided, and work for returning the overturned burned fuel pellets can be released.

Further, in accordance with the transfer direction of the second aspect, in addition to the method of the first aspect, the sandwiching step for the sintered fuel pellets is repeatedly performed as appropriate, so that the sandwiched sintered fuel pellets are It is possible to avoid with high reliability that the device falls unintentionally in the sandwiched state.

In the case of using the transfer device according to the third aspect, the method according to the first and second aspects is performed by using an electric controller, a front-back direction driving mechanism, a base, a holding mechanism, a lifting-lowering direction driving mechanism, Based on the proper configuration of the tray mounting table, the transfer tray mounted thereon, and the sintering tray, the operation of each of the components by the electric controller can be performed more efficiently and with high reliability. it can.

[Brief description of the drawings]

FIG. 1 is an explanatory perspective view of one embodiment showing a device for transferring sintered fuel pellets according to the present invention.

FIG. 2 is a schematic front view of the transfer device.

3 (A) to 3 (M) are process schematic diagrams illustrating a transfer method according to claims 1 and 2 of the present application.

FIG. 4 is an explanatory longitudinal side view in an embodiment showing a conventional method for transferring sintered fuel pellets.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electric controller 2 Front-back direction drive mechanism 3 Base 4 Holding mechanism part 4e Movable holding plate 4f Movable holding plate 5 Elevating direction drive mechanism 6 Tray mounting table 7 Transfer tray 7b Transfer bottom plate surface 8 Sintering tray 8b Sintering Bottom plate surface P Sintered fuel pellet P 'Bottom surface of sintered fuel pellet

Claims (3)

(57) [Claims] 1. A sintering tray in which a large number of sintered fuel pellets are erected on a sintering bottom plate surface, and a transfer tray for transferring the sintering fuel pellets on a transfer bottom plate surface. Are arranged side by side in the front and rear direction on the tray table, and by operating a separately prepared holding mechanism, the pair of movable holding plates mounted together are closed and moved in the front and rear direction,
After sandwiching a large number of the fuel pellets in the sintering tray from the front and rear sides, the tray mounting table is lowered to separate the sintering bottom plate surface of the sintering tray from the bottom surface of the sintered fuel pellets by a required length. Then, by moving the tray table in the front-rear direction, the transfer bottom plate surface of the transfer tray is disposed immediately below the sandwiched fuel pellets that are sandwiched, and then the tray table is moved. After being raised, the transfer bottom plate surface of the transfer tray is brought into contact with the bottom surface of the sintered fuel pellets, the pair of movable holding plates are opened and moved in the front-rear direction, so that the sintered fuel pellets are moved. The sintering is released from the above-mentioned holding, and further, after lowering the tray table, the sintering tray and the transfer tray are moved back and forth to return to the original position. fuel Sorting method of the toilet. 2. A sintering tray in which a large number of sintered fuel pellets are erected on a sintering bottom plate surface, and a transfer tray for transferring the sintering fuel pellets to a transfer bottom plate surface. Are arranged side by side in the front and rear direction on the tray table, and by operating a separately prepared holding mechanism, the pair of movable holding plates mounted together are closed and moved in the front and rear direction,
After sandwiching a large number of the fuel pellets in the sintering tray from the front and rear sides, the tray mounting table is lowered to separate the sintering bottom plate surface of the sintering tray from the bottom surface of the sintered fuel pellets by a required length. Then, when it is confirmed that the sandwiched sintered fuel pellets do not slip down, after raising the tray mounting table and contacting the sintering bottom plate surface of the sintering tray with the bottom surface of the sintered fuel pellets, Release of the sandwiching of the sintered fuel pellets by the movable presser plate, and further closing and moving the movable presser plate in the front-rear direction, again sandwiching a large number of the sintered fuel pellets in the sintering tray from the front and rear sides. Thereafter, the tray mounting table was lowered again, and a sintering step was performed in which the sintering bottom plate surface of the sintering tray was separated from the bottom surface of the sintered fuel pellets. When the above-mentioned sintering fuel pellets were found to have slipped off, the above-described pinching step was repeated a required number of times until no slip-off occurred. By moving the transfer tray in the direction, the transfer bottom plate surface of the transfer tray is disposed immediately below the sandwiched sintered fuel pellets, and then the tray table is raised to move the transfer tray. After the transfer bottom plate surface abuts against the bottom surface of the sintered fuel pellets, the pair of movable holding plates are opened and moved in the front-rear direction to release the sintered fuel pellets from the clamping, and After lowering the tray table,
A method for transferring sintered fuel pellets, wherein the method moves the sintering tray and the transfer tray back to the original position by moving the sintering tray back and forth. 3. A front-rear drive mechanism operated by an electric controller, and a base reciprocally movable by a required length in the front-rear direction by the front-rear drive mechanism, are both operated by the electric controller. a lifting direction drive mechanism provided on the pressing mechanism and the base itself of adjacently provided on a base which will be a freely predetermined length by reciprocating the vertical direction by the elevating direction drive mechanism, and a large number of sintered A sintering tray in which the spent fuel pellets are placed in a forest on the sintering bottom plate surface, and a transfer tray for transferring the sintered fuel pellets on the transfer bottom plate surface are arranged side by side in the front-rear direction. A tray placement table that can be freely arranged as much as possible, and the press mechanism mechanism is provided with a large number of sintered fuel pellets which are placed in a forest on the sintering bottom plate surface of the sintering tray by the operation thereof. An apparatus for transferring sintered fuel pellets, comprising a pair of movable pressing plates which can be closed or opened from the front and rear sides so as to be able to clamp or release the clamping, respectively.