JP2000230999A - Method for forming solidified glass and carriage dolly using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make uniformly coolable molten glass by uniformly charging mixture of molten glass and radioactive waste in a canister and pilling molten glass on the side wall for improving the cooling efficiency. SOLUTION: In this forming method, a motor 55 of a rotation maintaining mechanism 50 is driven at the injection position of a canister 20 loaded on a carriage dolly 30 immediately blow a glass melting furnace to rotate the canister 20 at a specific revolution speed and simultaneously the mixture of molten glass and radioactive waste are made to flow down from the glass melting furnace to be injected into the canister 20.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a vitrified material for forming a vitrified material for storing radioactive waste by injecting a mixture of molten glass and radioactive waste from a glass melting furnace into a canister. The present invention relates to a transport vehicle used at that time.

[0002]

2. Description of the Related Art Highly radioactive wastes such as fission products separated by reprocessing of spent nuclear fuel are mixed with glass to generate radiation and heat, and filled and sealed in a container called a canister. It is solidified, cooled and stored in a dedicated radioactive waste management facility until the temperature falls below a predetermined temperature, and then subjected to final geological disposal.

[0003] The vitrified material is prepared, for example, by putting radioactive waste into a glass melting furnace together with a glass raw material, heating and melting it by an electric current, mixing the mixed waste, and a nozzle provided at a lower portion through a canister disposed below the nozzle. Formed by pouring into

The operation of injecting the mixture of the molten glass and the radioactive waste into the canister is performed in a compartment separated from the outside by a shielding wall, and the transfer of the canister in the compartment is provided in the compartment. It is performed by a dedicated cart. That is, in the compartment, a rail is laid between the canister carry-in / out position and the pouring position below the glass melting furnace, and a bogie that moves along the rail is provided. The carriage is transported between the loading / unloading position and the injection position.

[0005]

The mixture of molten glass and radioactive waste injected into the canister from the glass melting furnace rises to the center in the canister due to its high viscosity and is cooled when it comes into contact with the side wall of the canister. To solidify in a short time. For this reason, there is a possibility that a gap may be formed inside and uneven density may occur depending on a portion.

[0006] If the density of the filled solid is nonuniform, individual differences in weight and eccentricity of the center of gravity affect the handling, and unbalance in heat generation is undesirable.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and has been made in consideration of the above circumstances. An object of the present invention is to provide a method for forming a vitrified body that can be raised and uniformly cooled, and to provide a transport trolley using the same.

[0008]

According to the present invention, there is provided a method for forming a vitrified body, wherein the mixture of molten glass and radioactive waste is injected into a canister to form a vitrified body. The mixture of the molten glass and the radioactive waste is injected from a glass melting furnace while rotating the canister at a predetermined speed about its axis.

[0009] Further, a canister is mounted as a carrier truck using the carrier, and is transported from a glass melting furnace to a pouring position and carried out from the pouring position after pouring the molten glass, wherein the canister is supported vertically. The canister supporting portion is rotatably provided around the center axis of the canister held by the canister supporting portion, and is provided with rotation driving means for driving the canister supporting portion to rotate.

[0010]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a conceptual view showing a state in which a mixture of molten glass and radioactive waste is injected into a canister mounted on a carrier by applying the method for forming a vitrified body according to the present invention, and FIG. FIG. 3 is a vertical sectional view of the carrier, and FIG. 3 is a sectional view taken along the line AA of FIG.

The glass melting furnace 10 is formed of a ceramic refractory brick, has a rectangular shape in a plane, and has a nozzle 1 at the center of the bottom of a melting chamber 11 having a bottom surface inclined downward toward the center.
2 is provided.

Electrodes 13 are provided on a pair of opposed side walls of the melting chamber 11.
The bottom electrode 14 is provided at the bottom, and the high-level waste liquid and the glass material, which are radioactive wastes, supplied into the melting chamber 11 via the supply paths 15 and 16, respectively. Heat is melted and mixed by energization between the main electrodes 13 and between the main electrode 13 and the bottom electrode 14, flows down from the nozzle 12, and is injected into the canister 20 disposed below the nozzle 12. The discharge / stop from the nozzle 12 is performed by adjusting the temperature of the nozzle 12, and this temperature control is performed in a separate control room (not shown).

The canister 20 is mounted on a transport trolley 30 and transported from the loading position to an injection position immediately below the glass melting furnace 10, and the molten glass and the radioactive waste are discharged from the glass melting furnace 10 while being mounted on the transport trolley 30. Mixture 1 with
And then transported to the unloading position.

The transport vehicle 30 is provided with a traveling drive mechanism 40 and a rotation holding mechanism 5 on a flat and rectangular chassis 31.
0.

The traveling drive mechanism 40 includes a traveling motor 41 disposed on the upper surface of the chassis 31 and one axle 42A of wheels (drive wheels 42 and driven wheels 43) disposed at four corners on the lower surface of the chassis 31. The wheels (drive wheels 42) are rotationally driven by driving of the traveling motor 41. This allows
The transport vehicle 30 is driven to move by the rotation of the traveling motor 41, and moves along a predetermined rail along a rail (not shown).

The rotation holding mechanism 50 is supported by a turntable 53 in which a support inner cylinder 54 is rotated and driven by a rotation motor 55 inside a cylindrical outer cylinder 51 having a predetermined height provided on the upper surface of the chassis 31. And are concentrically housed.

Guide rollers 51A are provided at four locations on the inner peripheral surface near the upper end and the lower end of the outer cylinder 51 in the circumferential direction, respectively. The guide roller 51A is rotatable about a vertical axis on the inner peripheral surface of the outer cylinder 51, and its outer peripheral surface is
The guide roller 51A functions so as to hold the support inner cylinder 54 so that it can rotate stably in a vertical state.

The turntable 53 is arranged on the upper surface of the chassis 31 via a bearing 52 so as to be rotatable around a vertical rotation axis coinciding with the center axis of the outer cylinder 51. A sprocket 53A formed on the outer periphery thereof, and a sprocket 55 fixed to the output shaft of a rotary motor 55 disposed on the chassis 31 outside the outer cylinder 51 with its output shaft being vertical.
A is linked with a chain 56, and the turntable 53 is driven to rotate at a predetermined rotation speed by a rotation motor 55.

The support inner cylinder 54 has a cylindrical shape with a bottom having a predetermined height and an inside diameter in which the canister 20 can be accommodated with a predetermined fitting tolerance. It is fixed to the upper surface. The upper end opening is tapered at a predetermined gradient, and canister 2
0 is easily accommodated.

In the rotation holding mechanism 50 configured as described above, by inserting the canister 20 into the support inner cylinder 54, the canister 20 is held vertically and the turntable 5 is driven by the rotation motor 55.
3 and the support inner cylinder 54 rotate, and the canister 20 supported by the support inner cylinder 54 can be rotated around the central axis.

The carriage 30 constructed as described above is
The canister 20 is held by the support inner cylinder 54 of the rotation holding mechanism 50, and the canister 20 travels by driving the traveling motor 41 of the traveling drive mechanism 40, and rotates the canister 20 held by driving the rotation motor 55 of the rotation holding mechanism 50. can do.

Here, the movement drive control of the transport trolley 30 by the travel drive mechanism 40 (travel motor 41) and the rotation drive control of the turntable 53 (held canister 20) by the rotation holding mechanism 50 (rotation motor 55) are as follows.
This is to be performed in an isolated control room like the glass melting furnace 10 described above.

The carriage 30 having the above configuration is driven and controlled as follows.

That is, when transporting between the loading / unloading position where the canister 20 is mounted and the pouring position from the glass melting furnace 10, the traveling motor 41 of the traveling drive mechanism 40
Drive and drive.

At the pouring position where the held canister 20 is located directly below the glass melting furnace 10, the rotation holding mechanism 50
While rotating the canister 20 at a predetermined number of revolutions by driving the rotary motor 55, the mixture 1 of the molten glass and the radioactive waste from the glass melting furnace 10 flows down and is injected into the canister 20.

As described above, when the mixture 1 of the molten glass and the radioactive waste is injected from the glass melting furnace 10, the canister 20 is rotated, so that the injected mixture 1 of the molten glass and the radioactive waste is converted into the canister. 2
As shown in FIG. 2, the centrifugal force generated by the zero rotation causes the peripheral wall surface to be pressed, and as a result, uniform filling without formation of voids becomes possible.

The configuration of the drive system for the traveling drive and the rotational drive of the transport trolley 30 is not limited to the above configuration example, but can be changed as appropriate.

For example, as shown in a conceptual vertical sectional view of FIG. 4, the driving for driving and the rotating driving of the canister 20 may be performed by one motor 60. still,
In the figure, portions having the same functions as those in the above configuration example are denoted by the same reference numerals, and description thereof will be omitted.

The illustrated carriage 30 'connects a motor 60 to a gear box 70 capable of outputting to two shafts 71 and 72,
The respective output shafts 71 and 72 are connected to the drive wheels 42 and the turntable 53 of the rotation holding mechanism 50 via gear trains 81 and 82.
It is linked to.

The output shafts 71 and 72 can be switched by a clutch (not shown) interposed between the input and output. Further, the gear box 70 may be constituted by a planetary gear, and a brake may be provided on each output shaft, and the rotation of the output shaft may be controlled by the brake to distribute the torque.

In other words, from the viewpoint of the control structure that the movement driving of the transport carriage 30 and the rotation driving of the canister 20 are performed independently and are not performed simultaneously, it is possible to use a structure in which one motor 60 is also used. According to this configuration, it can be configured at low cost.

[0033]

As described above, according to the method for forming a vitrified body according to the present invention, when a mixture of molten glass and radioactive waste is injected into a canister to form a vitrified body, By injecting a mixture of molten glass and radioactive waste from a glass melting furnace while rotating the canister at a predetermined speed about its axis, the mixture of injected molten glass and radioactive waste is caused by rotation of the canister. The canister is pressed against the peripheral wall surface of the canister by centrifugal force, and as a result, uniform filling without forming voids becomes possible.

Further, as a carrier using the method for forming a vitrified body according to the present invention, a canister supporting portion for vertically supporting a canister is provided rotatably around a center axis of the canister held by the canister, and When the mixture of the molten glass and the radioactive waste is injected into the canister from the glass melting furnace, the canister supporting unit is rotationally driven by the rotary driving unit. The canister to be held can be rotated around the central axis, and the mixture of the molten glass and the radioactive waste to be injected is pressed against the peripheral wall of the canister by centrifugal force due to the rotation of the canister to form a void. It is possible to prevent and uniformly fill.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing a state in which a mixture of molten glass and radioactive waste is injected into a canister mounted on a carrier by applying a method for forming a vitrified body according to the present invention.

FIG. 2 is a vertical cross-sectional view of the transport vehicle.

FIG. 3 is a sectional view taken along line AA of FIG. 2;

FIG. 4 is a longitudinal sectional view of another configuration example of the transport vehicle.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Mixture of molten glass and radioactive waste 10 Glass melting furnace 20 Canister 30 Transporting trolley 50 Rotation holding mechanism 54 Support inner cylinder (canister support) 55 Rotation motor (rotation drive means)

Claims (2)

[Claims] 1. A method for injecting a mixture of molten glass and radioactive waste into a canister to form a vitrified body, wherein the canister is rotated from a glass melting furnace at a predetermined speed about its axis. A method for forming a vitrified material, comprising injecting a mixture of molten glass and radioactive waste. 2. A trolley having a canister mounted thereon and transported from a glass melting furnace to an injection position and carried out of the injection position after the molten glass is injected, wherein the canister supporting portion vertically supporting the canister holds the canister. The method for forming a vitrified body according to claim 1, further comprising: a rotatable driving unit that is rotatably provided around a central axis of the canister and that rotatably drives the canister support. The transport trolley used.