KR100871290B1 - Pressure device for automation separation spent fuel and rod - Google Patents

Abstract

The present invention relates to an automatic separation extrusion device of spent nuclear fuel and rods, and after the spent nuclear fuel rods are mounted, the pellets and hulls are separated while being transported downward by the extrusion pins. After use, the nuclear fuel rod is mounted on the rotary plate where the discharge hole is formed, and the rotary plate rotates to continuously separate the pellet and the hull. The pellet is separated from the hull while passing through the pellet discharge hole formed in a conical shape is stored in the pellet storage container, the hull is stored separately in the hull storage container provided separately as the brush passes. In this way, pellets and their hulls, which are their cladding pipes, can be automatically collected and collected from the spent nuclear fuel rods, thereby enabling efficient processing, ensuring stability, and enabling automation.

Spent fuel, rod, automatic separation, extrusion equipment, sheath, pellet, hull

Description

Automatic separation and extrusion of spent fuel and rod {PRESSURE DEVICE FOR AUTOMATION SEPARATION SPENT FUEL AND ROD}

1 is a perspective view showing a part of the automatic separation and extrusion of spent nuclear fuel and rod according to the present invention.

Figure 2 is a front view of the automatic separation and extrusion of spent fuel and rods.

Figure 3 is a side view of the separated storage device of spent nuclear fuel rods, showing a state that the second plate is raised.

4 is a side view illustrating a state in which the second plate is lowered.

5 is a partial perspective view for explaining the lowering operation of the extrusion pin of the present invention.

6 is a cross-sectional view illustrating a separation operation of pellets and hulls.

<Explanation of symbols for main parts of the drawings>

10: separate storage unit 11: housing

13, 14, 15: 1st, 2, 3 plate 100: drive unit

110: motor 200: extrusion part

210: extrusion pin 220: load cell

230: disk 300: separation unit

310: rotary plate 320: top plate

321: pellet discharge hole 322: hull discharge hole

400: storage

The present invention relates to an automatic separation extrusion device of spent nuclear fuel and rods, and more particularly, it is possible to automatically separate and collect pellets and their hulls, which are the cladding tubes, from the spent nuclear fuel rods, thereby enabling efficient processing and ensuring stability. The present invention relates to a separate storage device for pellets and hulls of spent fuel rods that can be automated.

Nuclear fuel refers to a material that can be charged into a nuclear reactor and get available energy by chaining nuclear fission, and spent fuel refers to a material remaining after nuclear fission. In general, the material used for nuclear fuel is uranium 235 ²³⁵ U. Uranium 235 ²³⁵ U contains only 0.7% of the natural uranium, so the critical amount is increased as long as natural uranium is used, and the capacity of the reactor is increased because hard water absorbing neutrons cannot be used as a moderator. For this reason, many nuclear reactors use enriched uranium as a fuel for artificially increasing the abundance of uranium 235 ²³⁵ U. In particular, ship propulsion reactors, which require miniaturization, or power generation reactors, which are limited by construction costs per constant power, mostly use enriched uranium.

Nuclear power generates thermal energy by slowly reacting nuclear fuel in a reactor, and generates electricity using the generated energy. Nuclear power uses uranium enriched by about 3 to 5% by using nuclear fuel such as natural uranium. When new fuel is charged into the reactor, it burns for about 3 cycles to generate thermal energy. At one cycle, the reactor is shut down and one-third of the fuel is replaced, where one cycle is about 18 months when nuclear fuel is charged into the reactor to generate energy through nuclear fission. At this time, the turbines, steam generators, generators, valves, pumps, and other equipment that make up the power plant will be repaired, and after the nuclear fuel replacement is completed and maintenance of the equipments is completed, the power plant will be restarted to produce electricity for the next 18 months.

In this case, the nuclear fuel is nuclear fission reaction in the reactor in the form of fuel rod (fuel rod). The nuclear fuel rod is formed with a diameter of about 10 mm and a length of about 4 m, and the cladding tube is made of a Zircalloy alloy having a thickness of about 1 mm, and on both sides of the cladding tube, the capping cap is sealably mounted by resistance welding or the like. .

Nuclear fuel used in nuclear power is loaded with fuel produced in the form of pellets in each fuel rod cladding tube, and then a bundle of tens or hundreds of fuel rods thus produced is used. According to the conventional method, the spent fuel assembly burned in a nuclear power plant is stored and stored in a tank without being processed anymore, but as the period of operation of the nuclear power plant becomes longer, the amount of spent fuel rods gradually accumulates, causing a huge amount of spent fuel rods. It needs storage space. In addition, the necessity and danger of dealing with this accumulated waste continues to be pointed out. In some countries, spent fuel rods are sent to permanent disposal sites for long-term storage, while others are separated from cladding for the purpose of recycling spent fuel.

After the use of the fuel in the reactor for recycling or disposal is completed, the fuel rods are disassembled to separate the fuel and the cladding. Thus, a hull is generated in the process of treating the spent fuel. However, in the present technique, when spent fuel is separated from the cladding, the cladding generated in these processes retains the radioactive products such as uranium or plutonium, fission products, and radioactive products resulting from the radiation of the cladding material. These cladding tubes are classified as high-level radioactive waste. In particular, when the nuclear fuel is separated by a wet process, a special treatment is required because a nuclear material having a high radioactive level such as a fuel dissolving solution is coated on the inner and outer surfaces of the coating tube.

There are roughly two ways to manage spent fuel. One method is to put spent fuel into rocks over 500 meters underground and thoroughly isolate it from the human ecosystem. This is called permanent disposal. Another method is to separate the recycled material from the spent fuel (referred to as "reprocessing") to reuse the fuel material and permanently dispose of the radioactive material.

In particular, spent fuel rods are usually cut to a length of 25 cm, the cut spent fuel rods are moved to a processing space such as a hot cell by a robot and then subjected to a slitting operation of separating pellets and the cladding tube. In this case, in order to separate the cladding pipe and the fuel rods in the form of pellets, a heater capable of supplying high reaction heat is installed inside the vertical reactor. In this case, the heater is configured to have a cylindrical shape surrounding the outside of the reactor. Since the vertical reactor is mounted inside the vertical reactor to separate the cladding tube through a complicated mechanical mechanism, there is a problem in that it takes a long time.

In addition, there is a problem in that the production is complicated and the production cost is increased due to the complex structure, and the work time is long because the complicated structure must be manipulated. In other words, it becomes difficult to introduce an automated process, and thus the work efficiency is lowered because the handles must be manually driven by hand.

In addition, it is difficult to ensure stability due to a complicated driving method and a complicated process, as well as separate sheaths and pellets are stored in the same container, which is a hassle to separate them again.

In addition, when the cladding tube and the pellet are accommodated in the same recovery container, there is a problem in that the amount of waste with strong chemical toxicity or radioactivity is increased.

Accordingly, the present invention is to solve the above-mentioned problems of the present invention, the object of the present invention is a simple structure and easy to manufacture, but the automatic separation and extrusion device of spent nuclear fuel and rods that can efficiently separate the cladding pipe from the pellet To provide.

In addition, another object of the present invention is to provide an automatic separation and extrusion device of spent nuclear fuel and rods that can be easily automated, can shorten the working time to improve the work efficiency and high reliability of the work.

In addition, another object of the present invention is to stably separate the cladding tube and the spent nuclear pellets, the separated cladding tube and pellets can be automatically stored in each other container, no separate work process for separation The present invention provides an automatic separate extrusion device of spent fuel and rods.

In addition, another object of the present invention is to provide an automatic separation and extrusion device for spent nuclear fuel and rods to improve the rapid recovery and safety by devising an automated machine in which the fuel rods are injected and the cladding tube is separated and discharged.

In order to achieve the object of the present invention as described above, the automatic separation of the spent fuel and rod according to the present invention is an apparatus for separating and storing the spent fuel rod for separating and storing the hull and pellets in the spent fuel rod, A driving unit for producing a driving force, an extrusion pin, and an extrusion unit connected to the driving unit and linearly movable, and a rotatable rotary plate having a discharge hole to which the spent nuclear fuel rod is mounted. And a separating part for separating the cladding tube and the pellet, and an accommodating part for storing the separated pellets.

The rotary plate has a plurality of discharge holes are formed, the lower portion of the separation portion is provided with a pellet discharge hole and a hull discharge hole communicating with the container of the accommodating portion, and the discharge hole is the pellet discharge hole in accordance with the rotation of the rotary plate Or optionally side by side with the hull discharge hole.

The pellet discharge hole is formed in a conical shape, the upper portion is smaller than the lower portion, the pellet is passed through the pellet discharge hole and falls to the lower side as the extrusion pin is lowered, the hull is caught in the discharge hole.

The extrusion part includes a plate that is moved up and down by receiving the driving force, the extrusion pin is mounted below the plate. In addition, the extrusion unit further includes a brush formed under the plate. At this time, the hull discharge hole is preferably formed below the brush.

The accommodating part includes a hull storage container installed below the hull discharge hole, and a pellet storage container installed below the pellet discharge hole. The extruder further includes a load cell installed above the extrusion pin, and the load cell preferably receives the driving force to measure the force.

In addition, the automatic separation and extrusion device of spent nuclear fuel and rod of the present invention is a casing, and the inside of the casing, the pellet storage container and the hull storage container separately separated, and constitute the upper side of the casing, hull discharge hole And a top plate having a pellet discharge hole formed thereon, the rotary plate being rotatable on the top plate, an extrusion pin formed to move upward and downward above the rotary plate, and a motor transmitting a driving force to the extrusion pin. Then, the spent nuclear fuel mounted in the discharge hole is pushed out by the extrusion pin to separate the pellets from the hull and to separate and receive the pellet storage container and the hull storage container, respectively.

The guide pillar is vertically erected on the top plate, the plate is installed in the guide column to be movable in the horizontal direction. An elastic member is coupled to the guide pillar to provide a restoring force to the plate.

It further comprises a rotary drive unit for rotating the rotary plate, the rotary drive unit is preferably housed inside the casing. The disc is attached to the lower disk-shaped disk, the extrusion pin is coupled to the lower disk. At this time, the plurality of discharge holes are formed, the discharge hole is preferably formed at intervals of 90 degrees.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings, but the present invention is not limited or limited by the embodiments. In addition, the present invention exemplifies that the spent nuclear fuel is separated into a hull and a pellet of the spent nuclear fuel therein, but is not limited thereto, but the present invention is not limited thereto. Obviously, the present invention can be used in various applications, such as being used for separate storage of a cladding tube.

1 is a perspective view showing a part of the automatic separation and extrusion of spent nuclear fuel and rod according to the present invention, Figure 2 is a front view of the automatic separation and extrusion of spent nuclear fuel and rod. As shown in this, the spent nuclear fuel and rod automatic separation extrusion device 10 includes a drive unit 100, the extrusion unit 200, the separation unit 300 and the receiving unit 400.

The separate storage device 10 includes a housing 11, and inside the housing 11, a storage unit 400 including two storage containers 410 and 420 is mounted. Separation part 300 consisting of an upper plate 320 having a pellet discharge hole and a hull discharge hole (not shown) formed on the upper side of the housing 11 and a rotary plate 310 rotatably mounted on the upper plate 320. ) Is placed. An extruder 200 having an extrusion pin 210 is positioned above the separator 300.

The load cell 220 for measuring the force transmitted to the extrusion pin 210 is mounted on the upper side of the extrusion unit 200. In order to arrange the load cell 220, a disc-shaped disc 230 supports the load cell 220, and the extrusion pin 210 is connected to a lower surface of the disc 230. On the upper side of the load cell 220 is mounted a driving force transfer unit 120 that can move up and down and a motor 110 for generating a driving force. The disk 230 may move up and down with the second plate 14 by receiving a driving force from the driving unit 100 from the driving unit 100, which will be described later.

Four guide pillars 12 are vertically erected on the upper side of the housing 11. The first, second, and third plates 13, 14, and 15 are connected to the guide pillar 12 in a horizontal direction. In FIG. 1, the first, second and third plates 13, 14, and 15 in a plate shape are partially cut and illustrated for convenience of description. The first and third plates 13 and 15 are fixed to the guide pillar 12.

On the other hand, the second plate 14 may move while sliding on the guide pillar 12. The second plate 14 may be formed to extend between the guide pillars 12 to prevent separation, and guide wings 17 may extend to cover the circumference of the guide pillar 12. The guide vane 17 is movable with the second plate 14. In addition, a bearing may be inserted and installed between the second plate 14 and the guide pillar 12. The second plate 14 may receive a driving force of the driving unit 100 and move up and down, details will be described later.

An elastic member 16 is inserted into the guide pillar 12 between the second plate 14 and the third plate 15. The elastic member 16 acts to force the second plate 14 to its original position due to the elastic force. The elastic member 16 may use a coil spring, but is not limited thereto.

The driving unit 100 is mounted on the first plate 13. The driving unit 100 is composed of a motor 110, a driving force transmission unit 120. The motor 110 is a device for converting electrical energy into rotational energy by receiving power, and includes a motor that operates hydraulically in addition to DC and AC motors. The driving force transmission unit 120 may be a bevel gear or a screw worm gear for changing the transmission direction of the driving force. In addition, the driving force transmission unit 120 includes a moving shaft 130, the gear shaft or the screw thread is formed on the moving shaft 130 can be moved up and down by receiving the driving force of the motor.

A brush 240 is mounted below the second plate 14, which is shown in FIG. 2. The brush 240 may move up and down according to the movement of the second plate 14.

3 and 4 illustrate the operation of moving the second plate and the brush up and down. Figure 3 is a side view of the separated storage device of the spent nuclear fuel rod, showing the state that the second plate is raised, Figure 4 shows the state that the second plate is lowered.

As shown in FIG. 3, when the motor 110 does not operate, the elastic member 16 supports the second plate 14 with its restoring force. As described above, the first plate 13 is fixed, but the second plate 14 is movable.

When the motor 110 is operated, a force is transmitted to the load cell 220 while the moving shaft 130 is lowered. The load cell 230 measures the downward pressure and presses the disc 230 downward. The elastic member 16 is compressed while the second plate 14 is lowered together with the disk 230, which is shown in FIG. 4.

As the extrusion pin 210 is coupled to the disk 230 descends, it is lowered to pass through the first discharge hole 311 and the pellet discharge hole 321 formed in the rotary plate 310. The rotary plate 310 having the first discharge hole 311 is rotatable, and the upper plate 320 having the pellet discharge hole 321 is formed as an upper surface of the housing 11 and may be integrally formed with the housing 11. have. The rotary drive unit 330 capable of rotating the rotary plate 310 is mounted in the housing 11, and the rotary drive unit 330 may be a motor. The rotary drive unit 330 rotates the rotary plate 310 so that the first discharge hole 311 or the second discharge hole 312 is positioned below the extrusion pin 210.

5 and 6 are presented to explain the operation of the present invention in more detail. Figure 5 is a partial perspective view for explaining the lowering operation of the extrusion pin of the present invention, Figure 6 is a cross-sectional view showing the separation operation of the pellet and the hull.

As shown in FIG. 5, when the motor 110 operates, the gear parts 111 and 112 composed of worm gears or bevel gears connected to the motor shaft move the moving shaft 130 up and down. When moving downward, a force is transmitted to the load cell 220, and the force is measured as described above. The load cell 220 depresses the disk 230, and the disk 230 also lowers the second plate 14. At this time, the brush 240 and the extrusion pin is attached to the lower portion of the second plate 14 to move together. Three discharge holes 311, 312, and 313 are formed in the rotary plate 310 at intervals of 90 degrees. The rotary drive unit for rotating the rotary plate 310 may be positioned below the extrusion pin or brush 240 by rotating the rotary plate 310. At this time, the pellet discharge hole 321 or the hull discharge hole 322 formed in the upper plate 320 and the discharge hole (311, 312, 313) formed in the rotary plate 310 to be selectively matched.

The discharge holes 311, 312, and 313 formed in the rotary plate 310 have a cylindrical shape having a constant diameter. The pellet discharge hole 321 has a conical shape having an upper portion smaller than the lower portion, and the hull discharge hole 322 has a cylindrical shape having a diameter substantially the same as that of the discharge holes 311, 312, and 313 formed in the rotary plate 310. The pellet discharge hole 321 is formed in the lower portion of the extrusion pin, the hull discharge hole 322 is formed in the lower brush 240. A pellet receiving container 420 in which pellets are stored is disposed below the pellet discharge hole 321, and a hull storing container 410 in which a hull is stored is disposed below the hull discharge hole 322.

The operation is described as follows. In the third discharge hole 313, spent fuel is mounted. At this time, the upper plate 320 formed in the lower portion of the third discharge hole 313 is not formed any hole. The rotary drive unit rotates the rotary plate 310 to rotate to the lower portion formed with the extrusion pin. When the motor 110 is operated, the pellet is stored in the pellet storage container 420 while the extrusion shaft is lowered while the moving shaft 130 is lowered. Only the hull with pellets removed is left in the vent hole. The rotary plate 310 is rotated again to rotate the discharge hole remaining only the hull over the top plate on which the hull discharge hole is formed. As the brush 240 descends again, the hull is dropped into the hull storage container 410.

Figure 6 is shown for illustration of the operation of separating hull and pellets from spent fuel rods. Cut the spent fuel rod to approximately 2 to 5 cm. The cut spent fuel rod is composed of a pellet 520 and the hull 510, which is a covering tube thereof, and is inserted into the discharge hole 311.

Where the spent fuel rod is mounted, no hole is formed in the top plate 320. The rotary plate 310 is rotated so that the pellet discharge hole 321 and the discharge hole 311 equipped with spent fuel are matched. As the extrusion pin 210 descends, the pellet 520 is received into the pellet storage container 420. At this time, since the pellet discharge hole 321 is configured in a conical shape of the lower portion than the lower portion, the hull 510 remains in the discharge hole 311 as it is.

The rotary plate 310 rotates again to convey the discharge hole 311 formed with the hull discharge hole 322. As the brush 240 descends, the hull 510 remaining in the discharge hole 311 is dropped into the hull storage container 410. At this time, since the hull discharge hole 322 is formed with the same diameter as the discharge hole 311, it is dropped on the hull storage container 410 by the brush 240.

This series of operations is continuous. That is, when the spent fuel rod is accommodated in one of the three discharge holes formed in the rotary plate, the pellet is separated from the discharge hole corresponding to the pellet discharge hole due to the lowering of the extrusion pin. In addition, in the discharge hole coincides with the hull discharge hole, the separation of the hull is made due to the lowering of the brush, and the discharge hole is cleaned at the same time. Due to this series of operations, the pellets and hulls are separated efficiently and efficiently, and safety accidents can be prevented in advance, as well as dangerous accidents such as radioactive leakage due to automation. Can be reduced.

Therefore, according to the present invention, the object of the present invention is that the structure is simple and easy to manufacture, and there is an effect that can effectively separate the cladding tube from the pellet.

In addition, it is easy to automate, can shorten the working time can improve the work efficiency and high work reliability, there is an effect that can reduce the risk of safety accidents such as radioactive leakage accidents.

In addition, the cladding tube and the spent nuclear pellets can be stably separated, and the separated cladding tube and pellets can be automatically stored in each other container, so that a separate work process for separation is not required.

In addition, by devising an automated machine in which the fuel rod is inserted and the cover pipe is separated and discharged, there is an effect of improving the rapid recovery rate and safety.

As described above, although described with reference to a preferred embodiment of the present invention, those skilled in the art various modifications and variations of the present invention without departing from the spirit and scope of the invention described in the claims below I can understand that you can.

Claims (20)

In the automatic separation extrusion device of spent fuel and rod for separating and storing hull and pellet from spent fuel rod, A drive unit for producing a driving force; An extrusion unit having an extrusion pin and connected to the driving unit to linearly move; A separator having a rotatable rotary plate having a discharge hole for mounting the spent nuclear fuel rod, wherein the extrusion pin separates the cladding tube and the pellet by pressing the pellet; And An accommodating part accommodating the separated pellets; Automatic separation and extrusion of spent nuclear fuel and rod comprising a. The method of claim 1, The rotary plate is an automatic separation and extrusion device of spent fuel and rods, characterized in that a plurality of discharge holes are formed. The method of claim 1, A lower plate having a pellet discharge hole and a hull discharge hole communicated with the container of the storage part; According to the rotation of the rotary plate, the discharge hole is automatically separated extrusion device of the spent nuclear fuel and rod, characterized in that the pellet discharge hole or the hull discharge hole is selectively arranged side by side. The method of claim 3, The pellet discharge hole is formed in a conical shape of the upper portion is smaller than the lower portion, the pellet is passed through the pellet discharge hole and falls to the lower side as the extrusion pin is lowered, the hull is caught after the use of the discharge hole Automatic separation and extrusion of nuclear fuel and rods. The method of claim 3, wherein The extruding unit includes a plate that is moved up and down by receiving the driving force, the automatic separation and extrusion of spent nuclear fuel and rods, characterized in that the extrusion pin is mounted below the plate. The method of claim 5, The extruder is an automatic separation and extrusion device of spent nuclear fuel and the rod, characterized in that it further comprises a brush formed under the plate. The method of claim 6, The hull discharge hole is an automatic separation and extrusion device of spent nuclear fuel and rods, characterized in that formed below the brush. The method of claim 3, wherein The storage unit is a hull storage container installed below the hull discharge hole; And A pellet storage container installed below the pellet discharge hole; Automatic separation and extrusion of spent nuclear fuel and rods, characterized in that configured to include. The method of claim 1, The extruder further comprises a load cell installed above the extrusion pin, the load cell is automatically separated extrusion device of spent nuclear fuel and rod, characterized in that for receiving the driving force to measure the force. In the automatic separation extrusion device of spent fuel and rod for separating and storing hull and pellet from spent fuel rod, Casing; A pellet storage container and a hull storage container, each contained within the casing and separately separated; An upper plate constituting the upper side of the casing, and having a hull discharge hole and a pellet discharge hole; A rotary plate rotatably formed on the top plate and having a discharge hole formed therein; An extrusion pin installed to be movable upward and downward above the rotary plate; A motor for transmitting a driving force to the extrusion pin; Including, the spent nuclear fuel mounted on the discharge hole by pushing the extrusion pins to separate the pellets from the hull to separate and separately stored in the pellet storage container and hull storage container spent fuel and rods automatic separation extrusion Device. The method of claim 10, The guide column is vertically erected on the upper plate, the automatic separation and extrusion of spent nuclear fuel and rods, characterized in that the guide column is installed to be movable in the horizontal direction. The method of claim 11, The guide pillar is coupled to the elastic member, the automatic separation and extrusion device of spent nuclear fuel and rod, characterized in that to provide a restoring force to the plate. The method of claim 10, And a rotary drive unit capable of rotating the rotary plate, wherein the rotary drive unit is housed inside the casing. The method of claim 11, Disc disk is attached to the lower portion of the plate, the extrusion pin is an automatic separation extrusion device of spent nuclear fuel and rod, characterized in that coupled to the lower disk. The method of claim 10, The discharge hole is an automatic separation and extrusion device of spent nuclear fuel and rods, characterized in that formed a plurality. The method of claim 15, The discharge hole is automatically separated extrusion device of spent fuel and rods, characterized in that formed at intervals of 90 degrees. The method of claim 10, The pellet discharge hole is formed in a conical shape of the upper portion is smaller than the lower portion, the pellet is passed through the pellet discharge hole and falls to the lower side as the extrusion pin is lowered, the hull is caught after the use of the discharge hole Automatic separation and extrusion of nuclear fuel and rods. The method of claim 11, Auto-extruded extrusion device of spent nuclear fuel and rod, characterized in that it further comprises a brush formed under the plate. The method of claim 18, The hull discharge hole is an automatic separation and extrusion device of spent nuclear fuel and rods, characterized in that formed below the brush. The method of claim 10, And a load cell installed above the extrusion pin, wherein the load cell receives the driving force and measures the force.

Images