JPS6330796A - Rotating drive for continuous melting treater - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a rotational drive device and a rotational positioning device for a continuous melting and processing device for spent nuclear fuel, and in particular to a fuel piece loading operation required by its operating method. , relates to a device suitable for accurately performing operations such as removing and relocating a fuel loading basket.

[Conventional technology]

The conventional device consists of a motor drive device external to the tank that cooperates with a wheel having integral toothing with a revolution support device, and a device in which a movable member engages a cam fixed to the drive pinion to ensure positioning. ing. However, in order to protect the motor from radiation, it is necessary to take measures such as increasing the distance between the motor and the melting section and installing a shielding wall between them, making the device also very fragile. Also,
In the case of a motor and a drive device, the revolution support device is simply driven by a motor, and no consideration has been given to moving the revolution support device one station at a time in a certain unit operation. In devices for ensuring positioning, consideration has been given to a specific structure for mitigating the impact received by the cam and the movable member.

[Problem that the invention seeks to solve]

Nuclear fuel that releases energy through a nuclear fission reaction in a nuclear reactor, consumes fissile material, and is no longer suitable for use is generally referred to as spent nuclear fuel. Process 7 is a process for recovering and reusing fissile materials and nuclear raw materials contained in this spent nuclear fuel.

The reprocessing process further consists of a wide variety of unit processes. In the Vinylex process, in the first step, the fuel rods are sheared into small pieces, and the nuclear fuel material inside is then dissolved in nitric acid, which is used as a dissolution solution. Since the covering material of this fuel piece is generally a zirconium alloy or stainless steel, it does not dissolve in nitric acid and can be separated after the nuclear fuel material has finished melting.

There are two methods for melting nuclear fuel: the so-called batch method, which adds the necessary amount of nitric acid to a corrosion-resistant container loaded with nuclear fuel, completes the fuel melting, and then takes out the dissolved liquid, and the other method, which melts while loading nuclear fuel and nitric acid into the container. Continuous method for extracting liquid,
There is also a semi-continuous system which is a compromise between the two.

In general, continuous systems are more efficient than batch systems, but there is a problem in removing undissolved materials such as coating materials.As a solution to this problem, devices have been devised to continuously process the processed materials.

However, since this device has a vertical structure, it is disadvantageous in terms of earthquake resistance, and the complicated structure causes clogging of the passage by the covering material. Moreover, it is impossible to confirm this visually from the outside. In order to avoid clogging caused by the covering material, multiple fuel loading baskets loaded with fuel pieces are immersed in the dissolving treatment solution in a circular dissolving vessel held horizontally, and the fuel loading baskets are moved along the circumference. Research and development is progressing on a continuous melting treatment device that moves in the following directions.

FIG. 4 is a schematic diagram of the dissolution processing container section of the continuous dissolution processing apparatus. The circumferential motion of the fuel basket is moved counterclockwise by 30 degrees of central angle, one station per hour. This movement itself is carried out in a short period of time, and the loading of fuel pieces and the dumping of covering material are all completed within the remaining stationary time. The time required from the start of loading fuel chips to the removal of the fuel loading basket is 9 hours.

Operations such as dumping the cladding material are performed using various manipulators, so it is necessary to accurately determine the position of the fuel loading basket. It is also important to skillfully control the rotation of the annular frame that suspends the fuel loading basket so as not to place any strain on the equipment during positioning. The above-mentioned continuous melting processing equipment is also equipped with a rotary drive device using an electric motor and a device that performs positioning by engaging a movable member with a cam fixed to the drive pinion. This results in a large-scale installation that requires a distance from the processing section and a shield. Furthermore, there is no measure to reduce the impact applied to the cam and movable members, which poses a problem in terms of strength.

An object of the present invention is to provide a rotary drive device and a positioning device that are radiation-resistant, corrosion-resistant, compact, and have good impact protection.

[Means for solving problems]

The present invention provides an annular frame rotation drive device in a continuous melting treatment device for spent nuclear fuel, and a fuel receiving container that can be used for operations such as inserting a fuel loading basket, lifting a fuel loading basket, and relocating the fuel loading basket into a melting treatment container. This relates to a positioning device provided for reliable implementation.

The rotation and drive device is characterized by the ability to freely change the rotation speed by injecting compressed air.In particular, by using a rotary actuator and cam clutch, it has improved radiation resistance and enables accurate rotation at a fixed angle. did. The positioning device is characterized by inserting the shaft into a dimple provided on the upper surface of the annular frame to determine its resting position, and in particular, shaft insertion using the elastic force of a spring, and shaft insertion by cooperation with the rotation drive device. This made it possible to alleviate the impact of time. Furthermore, by separating the driving part from the corrosive atmosphere with a bellows, we prevented a decrease in reliability due to corrosion.

[Function] When the annular frame is rotated by the rotary drive device and the next resting position approaches, a dimple provided on the upper surface of the annular frame is attached to the front part in the direction of movement. Force is applied, and at the same time, the devices cooperate to gradually reduce the rotational speed of the rotary wheel Psh device. This makes the operation of inserting the shaft into the dimple smoother and reduces the burden on the dimple and shaft. Therefore, it is possible to reduce malfunctions due to shaft deformation or the like.

Even when the shaft is pulled out from the dimple, the rotational drive device is driven after the shaft is completely pulled out, and the devices cooperate to gradually increase the rotational speed.

〔Example〕

The present invention will be explained in detail below.

FIG. 1 is a longitudinal sectional view showing the configuration of a rotary drive device according to an embodiment.

The device is basically a rotary actuator with 1° gear and 6
It consists of gear 7, gear 8, and cam clutch 9. Drive part and case 2. It consists of a support part consisting of a holder 4.

The device whose structure is shown in FIG. 1 is a rotary actuator 1.
It is driven by supplying compressed air to and transmits its rotation via a gear 8 to a gear (not shown) of an annular frame 21 suspending a fuel load 25.

A sufficient amount of compressed air is supplied to the rotary actuator 1 to rotate the gear 6 by a certain angle. This rotation is directly transmitted to gear 8 via gear 7 and cam clutch 9, and rotates annular frame 21. Gear 6 at this time,
The dimensions of gear 7 and gear 8 are such that gear 8 rotates once with one supply of compressed air, and one rotation of gear 8 corresponds to 2 times when fuel is loaded.
5 to correspond to moving one station.

Next, when the supply of compressed air is cut off, gears 6 and 7 rotate in the opposite direction and return to their original positions, but due to the action of cam clutch 9, gear 8
remains as it is without returning to its original state.

By repeating the above process, the annular frame 21 is rotated intermittently at a constant angle, and when the shaft 18 is inserted into the dimple 23 in the positioning device whose structure is shown in FIG. When pulling out from the dimple 23, the flow rate of compressed air supplied to the rotary actuator 1 per unit time is changed to control the rotational speed so as to prevent a large impact from being applied to the shaft 18 and the dimple 23.

FIG. 2 is a longitudinal sectional view showing the configuration of a positioning device according to an embodiment.

The device basically consists of an air cylinder 10, a knuckle joint 11. Bin 12, shaft 18. and a driving part consisting of a spring 16, and a supporting part consisting of a holder 15, a cap 14, a plate 19, and a rond 20 for fixing to the upper lid 22 of the dissolution tank main body. By making a long hole in the upper part of the shaft 18, it gives freedom in the vertical direction,
It is connected to the knuckle joint 11 via the pin 12.

This device makes it possible to move the synakkle joint 11 up and down by driving the air cylinder 10. Dimples 23 for positioning are provided on the upper surface of the annular frame 21 which suspends and rotates the fuel loading cylinder 25, as many as are necessary for the melting process. 21
fix the position.

FIG. 3 sequentially shows the principle of operation of this device.

The annular frame 21 remains stationary most of the time, except when new fuel pieces are to be introduced into the fuel loading tank 25 during the melting process (FIG. 3(a)). At this time, the knuckle joint 11 is in a lowered state, and the shaft 18 is inserted into the dimple 23 by the elastic force of the spring 16. A long hole is made in the upper part of the shaft 18 to ensure the degree of freedom of the bottle 12, and the mechanism is such that the shaft 18 is pressed downward only by the elastic force of the spring 16, so that no more force than necessary is applied.

When trying to rotate the annular frame 21, the air cylinder 10 is driven to rotate the knuckle joint 11 and the shaft 1.
8 to release the fixation (Fig. 3(b)). When the drawing is completed, the annular frame 21 is gradually rotated by the rotation drive device (see FIG. 1) (FIG. 3(C)). The shaft 18 remains pulled out until the next resting position approaches, but when the resting position approaches, the shaft 18f! : Plan the timing to push,
At the same time, in preparation for the shaft 18 being inserted into the dimple 23, the rotational speed of the annular frame 21 is reduced (see Fig. 3).
d)).

The shaft 18 is inserted into the dimple 23 corresponding to the next resting position while keeping the shape of the shaft rubbed against the surface of the annular arm 21, and is fixed again (FIG. 3(a)).

By repeating the above operations, condylar positioning is performed.

In addition to the above-mentioned advantages, the present invention makes it easy to take measures against the problem of small particles adhering to the driving part and interfering with the operation. Furthermore, as shown in FIG. 2, a bellows 17 is provided, making it suitable for use in an atmosphere where nuclear fuel is dissolved. Additionally, these devices are designed to facilitate remote maintenance.

〔Effect of the invention〕

The effects of the present invention include: (1) Can withstand use in high radiation and nitric acid atmospheres.

(2) It is possible to position the annular frame smoothly and accurately.

(3) The structure is relatively simple, compact, and structurally stable.

(4) Measures against adhesion of small particles to moving parts can be easily taken.

(5) It can be installed and removed from the main body of the melting treatment device by remote control, and maintenance is also easy.

[Brief explanation of drawings]

FIG. 1 is a vertical cross-sectional view showing the basic configuration of an annular frame rotation drive device according to an embodiment of the present invention, and FIG. 2 is a vertical cross-sectional view showing the basic configuration of an annular frame positioning device according to an embodiment of the present invention. 3 is a longitudinal cross-sectional view showing the operating principle of the positioning device shown in FIG. 2, and FIG. 4 is a perspective view schematically showing the melting processing container section of the continuous nuclear fuel melting processing apparatus. 1...Rotary actuator, 2...Case, 3
...Punto, 4...Holder, 5...Bunto,
9...Cam clutch, 10...Air cylinder, 11
... Knuckle joint, 21 ... Annular frame, 22
... Upper lid of the melting treatment equipment main body, 23... Dimples, 24... Outer wall, 25... Fuel loading, 26...
・Partition wall, 27...Dissolving treatment liquid, 28...Roller, 2
9... Rotation drive device, 30... Rotation positioning device.

Claims (1)

[Claims] 1. A plurality of corrosion-resistant fuel loading baskets are arranged in a horizontal annular container that holds a dissolution treatment liquid, and while the lower part of the fuel loading basket is immersed in the dissolution treatment liquid, the nuclear fuel is melted by sequentially rotating and moving in one direction. Transmits accurate rotation at a fixed pitch in one direction in the rotary drive device of continuous melting processing equipment, which moves the fuel loading basket by rotating the annular frame on which the fuel loading basket is suspended. A rotary drive device for a continuous melting treatment device, characterized in that the rotation speed can be controlled.