JPH04194789A - Inspection equipment for nuclear fuel pellet - Google Patents

Abstract

PURPOSE:To attempt the simplification of equipment, space saving and improvement in through-put capability by supplying fuel pellets in a cassette vessel onto an inspection line as sintering plates are left in the vessel for transportation. CONSTITUTION:A determined number of sintering plates 4 loaded with fuel pellets in array are piled and contained in a cassette vessel 3 and are carried in a glove box 1 with an elevator mechanism 5. They are moved to a loader 6, elevated to a determined position and placed at the height of a buffer table 7 in turn from the top plate 4. Then the pellets 19 are pushed out 8 on the table 7 and every pellet is sent to the inspection line 2 to inspect. Pellets judged to be defective are collected in a defective pellet collection vessel 10 and carried out of the box 1 with the elevator mechanism 11. Good ones and semi-good ones are selected 12 and each are sent to collection buffer tables 13 and 14. They are loaded on vacant collection plates piled on an unloader 15 together with a cassette vessel 16 and are carried out of the box 1 with an elevator mechanism 18.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to equipment for inspecting nuclear fuel pellets used in nuclear reactors.

[Conventional technology]

As is well known, the fuel for a nuclear reactor consists of an assembly of fuel rods in which a large number of enriched uranium sintered oxide fuel pellets are inserted into a metal fuel cladding tube such as Zircaloy. It is manufactured by molding and sintering U Oz powder into a cylindrical body with predetermined external dimensions (for example, 5φ x 8 cylinders) using a powder metallurgy method. Specifically, after compression molding the pellets to predetermined external dimensions, a large number of pellets are arranged on a molybdenum sintered dish (a wavy shape with multiple rows of pellet-accommodating grooves formed on the top surface of the dish). This is carried into a sintering furnace and sintered.

In addition, after manufacturing, each fuel pellet has an outer diameter of
Length, dimension 2, weight (molding density), appearance, etc. are inspected, and the products are good, semi-good (external dimensions are slightly larger than the specified dimensions, and can be remade into good products by cutting, grinding, etc.). We are trying to sort out defective products.

Here, the fuel pellet inspection equipment is an inspection line that combines various inspection equipment inside a glove box that serves as a sealed container. A predetermined number of plates are stacked in a stacked manner and stored in a cassette container, and the pellets are transported into a glove box.The pellets are supplied from the sintering plate to an inspection line for inspection and quality selection. Good quality.

We sort and collect substandard and defective products.

Incidentally, fuel pellets are conventionally handled in the inspection equipment as follows. First, a predetermined number of sintered plates taken out from the sintering furnace with pellets loaded thereon are stacked in a stacked manner and housed in a cassette container, and then the cassette container is carried into a glove box. Next, take out the sintered plates one by one from the cassette container and place them in a glove box.

Transfer to the buffer shelf installed in the box. In addition, in a similar manner, pellet collection plates (aluminum plates made in the same shape as the sintered plate) were stacked and stored in a cassette container and transported into the glove box, and then the pellet collection plates were removed from the cassette container. Next, take out the sintered plates and recovery plates one by one from the buffer shelf and transfer them to the 5th position of the pellet supply stage and recovery stage for the inspection line. At this position, pellets are cut out one by one from the sintering plate by operating the puncher mechanism and supplied to the inspection line.

On the other hand, on the inspection line, various inspection devices placed along the conveyance route measure the outer diameter and length of the pellets.

We measure weight, etc. to determine pass/fail, and defective products are discharged from the inspection line and collected in a defective product collection container.
Semi-defective products are sorted separately from the end of the inspection line and transferred to a collection tray. Such a sintered dish.

Handling of collection trays and inspection of pellets are performed in a single wafer manner between the buffer fence and the inspection line, and when the inspection is completed, the buffer shelf is empty, the sintered tray is empty, and the collection tray loaded with inspected pellets is removed. Transfer it to the cassette container again and take it out with the glove ponks.

[Problems to be Solved by the Invention] By the way, in the conventional inspection equipment described above, the layout of various handling devices arranged in the glove box for handling the sintered plate 1 collection plate, and the throughput of the pellet inspection process are particularly difficult to solve. There are problems as follows.

That is, the sintered plates 5 collection plates stored in the cassette container and carried into the glove box are taken out one by one from the cassette container and transferred to the buffer column, and then one plate is placed between the buffer fence and the inspection line. Because we use a single-wafer processing method that transfers each sheet one at a time, a cassette container is carried into the glove box.

In addition to the transport means for carrying out, a dedicated buffer shelf for temporarily storing the sintered plate 1 collection plate, and a plate transfer mechanism for loading and unloading the sintered plate 2 collection plate from and to the buffer shelf are required. Become. For this reason, (1) it is difficult to lay out the various equipment that makes up the inspection equipment with sufficient margin in the limited space inside the glove box whose external dimensions are restricted; As the equipment is arranged densely, maintenance efficiency such as maintenance and inspection becomes worse.

(2) There are many steps required to transport and handle the sintered plate 9 recovery plate inside the glove box, which takes a long time from carrying the pellets into the glove box to taking them out after inspection, which slows down the inspection process. Throughput properties deteriorate.

The present invention has been made in consideration of the above points, and eliminates the need to transfer the sintered plate 1 collection plate stored in a cassette container and carried into the glove box from the cassette container to another buffer column (inside the container). To provide inspection equipment for nuclear fuel pellets, which is capable of supplying and collecting fuel pellets to and from an inspection line while stacked in a stack, thereby simplifying the equipment, saving space, and improving throughput. The purpose is to

[Means to solve the problem]

In order to solve the above problems, the inspection equipment of the present invention includes a transport means for transporting a cassette container carried into a glove box to a predetermined supply position, and a stack of sintering plates on the pellet supply side of the inspection line. A loader loads the pellets loaded on the sintering tray for each school in bulk from the cassette container to the supply buffer table, and the pellets are transferred one by one from the supply buffer table to the inspection line. Equipped with a supply cutting means, on the pellet/two-tray collection side of the inspection line, the non-defective and semi-defective pellets sorted on the inspection line are individually transferred to a stacked collection tray via a collection hoist table. and a transport means for carrying out the cassette container containing the collection tray from the glove box.

In addition, the loader in the inspection equipment includes a lifter that receives the sintered plates housed in the cassette container in a stacked state, pulls them out of the container, and lifts and lowers them, and the sintered plates stacked on the lifter. A positioning mechanism that restrains the uppermost sintering plate in a position aligned with the pass line leading to the supply buffer table during the upward stroke of the lifter, and a positioning mechanism that locks the uppermost sintering plate in a position that aligns with the pass line leading to the supply buffer table, and simultaneously controls the pellets loaded on the sintering plate on the pass line. It is composed of a pusher that transfers the pellets to the supply buffer table, and a tray changing mechanism that separates the empty sintering trays on which the pellets have been transferred from the lifter and holds them in a stacked manner above the lifter. It is.

Effect C] With the above configuration, the sintering tray loaded with uninspected fuel pellets and the collection tray for collecting inspected fuel pellets can be stored in the glove box while stacked in the cassette container for transportation. The fuel pellets are transferred to the collection position in the fuel cell, and at this position, the fuel pellets are supplied to and collected from the inspection line via the supply buffer table and collection buffer table by operating the loader and unloader. Ru. Therefore, there is no need for a buffer fence in the glove box to take out the sintered plates 9 collection plates from the cassette container and transfer them to another location, and a handling device to take the plates in and out from the buffer shelf, allowing the collection to be carried out between the inspection line and the sintered plate. Fuel pellets can be supplied and recovered once, which simplifies the inspection equipment built inside the glove box.

It is possible to save space and improve the throughput of the inspection process.

In addition, the loader, which is placed on the pellet supply side, is designed to line up the pass line that sequentially passes through the supply buffer table starting from the top of the sintered plates stacked together with the cassette containers and loaded onto the lifter. The fuel pellets are aligned and positioned, and at this position, a large number of fuel pellets aligned on the sintering plate are transferred to the supply buffer table at once by operating the pusher mechanism. Therefore, even if the sintered plates undergo thermal deformation due to the history of the sintering process, the amount of thermal deformation will not accumulate in the stacked state of the plates and will not adversely affect the fuel pellet transfer and positioning function. The empty sintering trays on which the pellets have been transferred are temporarily separated from the lifter and held in a stacked manner above the lifter by an interlocking operation between the lifter and the tray changing mechanism. After the fuel pellets have been completely transferred, they are received on the lifter again in a stacked state and housed in the cassette container.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

First, Figure 1 shows a plan layout of the entire pellet inspection equipment. In the figure, 1 is a glove box, 2 is a glove box,
3 is a pellet inspection line installed in a glove box that combines various measuring devices to measure the length, outer diameter, weight, etc. of fuel pellets, and 3 is a predetermined number of stacked sintered plates 4 loaded with pellets to be inspected. 5 is an elevator mechanism for transporting the cassette container 3;
6 is a loader that transfers the cassette table received from the elevator mechanism 5 to the next buffer table, and then transfers the pellets to the buffer table with the sintered plates stacked; 7 is a loader on the inspection line 2; A supply buffer table installed on the supply side, 8 a pusher attached to the loader for transferring pellets from the loader 6 to the buffer table 7, 9
1 is a pusher that cuts out and supplies the inspection line 2 pellets one by one from the buffer dish 7, 10 is a collection container for defective pellets, 11 is an elevator mechanism for carrying out the collection container 10, and 12 is installed on the pellet collection side of the inspection line 2. 13.14 is a buffer table for collecting good pellets, 1 semi-defective pellets, and 15 is a buffer table with the following collection trays stacked on top of each other. An unloader 14 collects the pellets transferred from the cassette container 14, a cassette container 16 that stores collection trays 17 in a stacked manner, and an elevator mechanism 18 for carrying out the cassette container 16.

Here, the sintering plate 4, which is carried into the pellet inspection equipment after the sintering process, is made as a molybdenum type plate, and as shown in FIG. It has a wavy shape with concave grooves 41 formed therein, and engagement grooves 42 into which claws of a plate changing mechanism, which will be described later, fit are provided at the four corners of the lower surface of the plate. The sintered plates 4 are stacked in a predetermined number in a stacked manner as shown in FIG.
It is stored and transported inside. The cassette container 3 is a box-shaped container with an open top, and has a window 31 at the bottom through which a lifter loading table of a loader 6, which will be described later, comes in and out, and an elevator mechanism 5 on the left and right side walls. A support arm 32 for supporting the cassette container 3 is provided on the loader 6 or the like.

Next, the detailed structure of the loader 6 will be explained with reference to FIGS. 3 to 5. That is, the loader 6 includes a movable cart 61 that moves in two wheel directions, front and rear, left and right, on the floor surface inside the glove box 1;
A support stand 6 for the cassette container 3 provided on the upper part of the moving cart 62
2 and a loading table 63 for receiving and mounting the sintering plates 4 in a stacked manner. II! Lifting feed screw 64 for load table 63. A lifter 66 that combines a lifting drive motor 65 (a torque motor that idles with a load torque greater than -window), a positioning mechanism 67 that restrains the sintering plate 4 at the pellet transfer position, and a The sintering tray is composed of a holding mechanism 68 for separating and holding the sintering plates, an idle storage section 69, and the aforementioned pusher 8 for transferring pellets.

Further, as shown in the figure, among the sintered plates 4 stacked on the loading table 63, the positioning mechanism 67 presses the four corners of the upper edge of the topmost sintered plate with claws from above to hold the plate. It is a pawl mechanism that restrains it in that position, and is installed at the same level as the pass line PL leading to the supply side buffer table 7 shown in FIG. On the other hand, the empty sintering plate changing mechanism 68 is a pawl mechanism that holds the plate by inserting a pawl from the side into the cut groove 42 of the sintering plate 4 shown in FIG. The idling storage part 6 is installed above the positioning mechanism 67 with an interval for the entry and exit of the pusher 8.
They are located at the four corners of the upper end of 9.

Next, inspecting the fuel pellets in the inspection equipment with the above configuration,
The handling process will be explained based on the flowchart shown in FIG. First, fuel pellets 19 manufactured through a molding and sintering process are shown in FIG.

As described in FIG. 8, a predetermined number of sintered plates 4 are arranged and loaded in the cassette container 3 in a stacked manner, and then placed on the elevator mechanism 5 and placed in the glove box. will be transported to. The cassette container 3 carried into the glove box is loaded from the elevator mechanism 5 onto the loader 6 and held on its support stand 62, as shown in FIG. Next, after moving the loader 6 to a predetermined supply position where it accesses the supply buffer table 7, the lifter 6 of the loader 6 is moved.
6 is lifted, the sintered plates 4 housed in the cassette container 3 are placed in a stacked state on the loading platform 63, and the lifter is further raised to pull out the sintered plates 4 upward from the cassette container 3. At this time, as shown in FIG.
By protruding the claws 7 into the ascending movement path of the sintered plates 4, the upper edge of the topmost plate among the stacked sintered plates 4 is pressed from above by the claws, and the pass line PL is pressed down. constrained to position. Note that in this restrained state, the drive motor 65 as a torque motor idles. As a result, the first sintering plate 4 is positioned at the pellet transfer position.

Next, the pusher 8 is projected from behind and operated to transfer all the pellets 19 loaded on the first sintering plate 4 waiting on the pass line onto the buffer table 7 at once. Note that the buffer table 7 is made as a wavy plate having the same shape as the sintered plate 4. buffer table 7
The transferred pellets 19 are then cut out one by one from the end and supplied to the inspection line 2 by the operation of the pusher 9.

Further, during the period when the pellets 19 are cut out from the buffer table 7 and supplied to the inspection line 2, the loader 6 performs the following operations. Namely, putushi.

After returning the medium 8 to the standby position, the claws of the positioning mechanism 67 that have been restraining the sintering table 4 are moved back to release the restraint on the plate. As a result, the lifter 66 resumes its upward movement and pushes up the sintered FFs 114 in a stacked state. When the already empty first plate rises to the position of the holding changing mechanism 68, the claw of the holding changing mechanism 68 is protruded and the empty first sintering plate is removed as shown in Fig. 6. 4 cut groove 42
Insert your nails into it to hold the plate. Next, lifter 66
When the is lowered, the -th plate is separated and the empty storage section 6 is moved.
After lowering the remaining sintering plates stacked on the loading table 63 to a level below the pass line PL while leaving them at 9,
Once again, the claws of the positioning mechanism 67 are projected and the lifter 66 is raised in the same manner as above, and this time the second sintering plate 4 is restrained in alignment with the pass line PL.

When all of the first pellets 19 transferred to the buffer table 7 in the previous process are cut and supplied to the inspection line 2, the pellets 19 loaded on the second sintering plate 4 are then pushed through the pusher. 8, the buffer 1 is transferred to the table 7 all at once, and then the empty second sintering plate is held by the holding mechanism 68, stacking it on top of the first empty sintering plate.

Thereafter, the same operation is repeated, and when all the sintering trays 4 are empty, the stacked and held sintering trays 4 are transferred to the transfer table 63 again, and the lifter 66 is lowered to set the cassettes. After being accommodated in the container 3, the receiver is delivered to the elevator mechanism 5 and carried out of the glove box 1.

On the other hand, the length, outer diameter, weight, etc. of the pellets 19 supplied to the inspection line 2 are measured on the way to the conveyance route of the inspection line 2, and the pellets determined to be defective here are The pellets are discharged and collected in a defective pellet collection container 10 shown in FIG. When the collection container 10 is full, the defective pellets are transported out of the glove box 1 by operating the elevator mechanism 11 at an appropriate timing. On the other hand, pellets of good quality or semi-good quality (pellets with an outer diameter slightly larger than the standard size and which can be recycled into good quality by cutting and polishing after inspection) are sorted by the sorting mechanism 12. Each of the recovery buffer tables 13 to 1
Sent on 4th. Then, at an appropriate timing, the sheets are sequentially transferred one by one to the empty collection trays 17 which are stacked together with the cassette containers 16 on the unloader 15, and when all the collection trays 17 are full, the collection trays 17 are transferred to the cassettes. container 1
6 and then loaded onto the elevator mechanism 18 from the unloader 15, and transported out of the glove box 1 via the elevator mechanism 18. The unloader 15 has a structure similar to that of the loader 6 described above, including a moving table, a lifter, and a positioning mechanism.
The inspected pellets are transferred to the collection tray 17 by the bunsha mechanism provided on the fourth side. Thereafter, by repeating the same operations as described above, it is possible to continuously inspect the fuel pellets carried into the glove box 1.

〔Effect of the invention〕

Since the nuclear fuel pellet inspection equipment according to the present invention is configured as described above, it achieves the following effects.

(1) Handling operations for supplying and collecting pellets between the inspection line and the inspection line can be performed while the sintered tray loaded with fuel pellets and the collection tray loaded with inspected pellets are stacked in multiple stages in a cassette container. Therefore, unlike conventional inspection equipment, the glove box does not require a buffer column for taking out and transferring the sintered plates and collection plates one by one from the cassette container, and a handling device for loading and unloading the plates from the buffer shelf. Fuel pellets can be supplied and recovered from the inspection line without any problems, making the inspection equipment built inside the glove box more compact and space-saving, as well as improving the throughput and maintainability of the inspection process. I can figure it out.

(2) In addition, the loader installed on the pellet supply side is installed on the pass line leading to the supply buffer table, starting from the top of the sintered plates loaded on the lifter together with the cassette containers in a stacked state. At this position, a large number of fuel pellets lined up on the sintering plate are transferred to the supply buffer table at once by operation of the puncher mechanism, so the sintering process is Even if thermal deformation occurs in the sintering plates, the amount of thermal deformation will not accumulate when the plates are stacked and have a negative effect on the fuel pellet transfer and positioning function. The reliability of the transfer can be improved.

[BRIEF DESCRIPTION OF THE DRAWINGS] FIG. 1 is a plan layout of inspection equipment according to an embodiment of the present invention, FIG. 2 is a flowchart showing the fuel pellet inspection and handling process in FIG. 1, and FIG. 1, Figure 4 is a side view and front view showing the structure of the loader in Figure 1, Figure 5 is an explanatory diagram of loading the cassette container between the loader and the elevator mechanism, and Figure 6 is the sintering process in the loader. Positioning the plate. An explanatory diagram of the separation operation, Fig. 7 is a perspective external view of the sintered plate, Fig. 8
Figure 0 is a diagram showing how sintering plates are stacked and stored in a cassette container. 1: Niger lobe box, 2: inspection line, 3: cassette container, 4: sintering plate, 6: loader, 7: supply Buffer table, 8.9: Punsha, IO: Defective pellet collection container, 13.14: Collection buffer table, 15: Unloader, 16: Cassette container, 17: Collection tray, PL:
Path line. , +゛- V--J Figure 2 Figure 3 Figure 4 115 Figure 116

Claims (1)

[Claims] 1) An inspection facility that measures the external dimensions, weight, etc. of nuclear fuel pellets manufactured through a molding and sintering process to determine pass/fail, and is a sintering system equipped with a large number of pellets. The plates are stacked in a cassette container and carried into the glove box, and the pellets are supplied from the sintered plate to the inspection line in the glove box for inspection and sorting. In the pellet supply side of the inspection line, which separates and collects semi-defective products and defective products, there is a transport means for transporting the cassette container carried into the glove box to a predetermined supply position, and a stack of sintered plates. A loader that pulls out the pellets as they are from the cassette container and transfers the pellets loaded on the sintering plate one by one to the supply buffer table, and a cutting means that supplies the pellets one by one from the supply buffer table to the inspection line. The pellet collection side of the inspection line houses an unloader that transfers the non-defective and semi-defective pellets sorted on the inspection line to the stacked collection trays via a collection buffer table, and a collection tray. What is claimed is: 1. A nuclear fuel pellet inspection facility comprising: a conveying means for carrying out a cassette container containing cassettes from a glove box; 2) In the inspection equipment according to claim 1, the loader includes a lifter that receives the sintered plates housed in the cassette container in a stacked state, pulls them out of the container, and lifts and lowers them; A positioning mechanism that aligns and restrains the uppermost sintering plate among the mounted sintering plates on the pass line leading to the supply buffer table during the upward stroke of the lifter; a pusher that transfers the pellets in bulk to the supply buffer table, and a tray changing mechanism that separates the empty sintering trays onto which the pellets have been transferred from the lifter and holds them in a stacked manner above the lifter. Nuclear fuel pellet inspection equipment characterized by consisting of a combination of: