JP3173960B2 - Sealing method of sealed container using double lid method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for hermetically sealing a container containing a radioactive substance and the like in a closed environment in a process of manufacturing and reprocessing nuclear fuel, and for storing and storing the same.

[0002]

2. Description of the Related Art Conventionally, in processes such as reprocessing of radioactive materials such as nuclear fuel in the field of nuclear power, a uranyl nitrate solution or a plutonium nitrate solution is thermally decomposed and denitrated by a reactor such as a fluidized bed apparatus or a roasting furnace. In the case where the oxide is converted into an oxide and stored in a predetermined container to be stored, it is necessary to fill the substance into a sealed container without spreading contamination to the outside. For that purpose, a so-called double lid (double cover) type sealed container is used. Similarly, when storing and storing radioactive waste that has been incinerated with radioactive material, a double-lid type sealed container is used. Even if it is not a radioactive substance, when handling harmful substances without spreading the contamination to the outside, or when protecting substances that dislike contamination from the outside from the external environment and storing them in containers, etc. In order to store and store in a container, a sealed container of a double lid system is used. For such a purpose, radioactive materials to be stored in a double-lid type sealed container are received in a closed container (hereinafter, referred to as a cell) in a closed container isolated from the external environment. For example, Japanese Patent Publication No. 59-40715, Japanese Patent Publication No. 62-13547, and Japanese Utility Model Publication No. 63-31
No. 039, for example, employs a double lid type connection device.

For example, in the process of reprocessing radioactive materials such as nuclear fuel in the field of nuclear power, for example, a separated and purified uranyl nitrate solution is thermally decomposed by heating using a reactor such as a fluidized bed, and the oxide ( Uranium trioxide:
UO ₃ ) Converted to powder. This oxide powder is oxide particles having a particle size distribution of about several microns to several hundreds of microns, and is extracted from the upper part (overflow pipe) or the lower part (underflow pipe) of the reactor, and is sealed in a double lid type sealed container. Filled and stored. The connection device for the double lid type storage container will be described with reference to FIG. In general, this connection device is used for each opening 1 of the cell 1 and the sealed container 2.
a and 2a are connected. That is, a flange 3 is provided on the periphery of the opening 1a of the cell 1, and this flange 3
A cell lid 4 that seals the opening 1a by being fitted to the inner peripheral surface of the cell 1 is provided, and the cell lid 4 opens inside the cell 1. Sealed container 2 for storing radioactive materials, etc.
A flange 5 is also provided on the periphery of the opening 2a, and a container lid 6 that opens to the outside of the sealed container 2 is provided so as to seal the opening 2a. The flange 5 and the container lid 6
Constitutes the container lid 7, the flange 3 and the cell lid 4
It is assumed that the cell lid 19 is constituted by the above.

Then, the flange 5 of the sealed container 2 whose opening 2a is closed by the container lid 6 is brought into close contact with the flange 3 of the cell 1 whose opening 1a is closed by the cell lid 4. When the base 2 is relatively rotated about the axis L, the lids 4 and 6 are connected to each other by a known connection structure (not shown) provided on the mating surface of the lids 4 and 6. In this state, the flanges 3 and 5 are connected and fixed to each other, and the lids 4 and 6 connected in the cell 1 are removed.
And the space in the sealed container 2 communicates with each other. In this state, a container such as a radioactive substance is filled into the sealed container 2 from the cell 1 by remote control. And again after filling
Opening 1 of cell 1 and sealed container 2 by both lids 4 and 6
The cells 1 and 2a are closed in an airtight state so that the cell 1 and the sealed container 2 are separated from each other. In this way, the sealed container 2 filled and sealed with the stored contents is further covered with a normal lid for storage from above the container lid 7, for example, a screw-in lid,
Alternatively, a lid or the like for bolting a flange provided on the edge portion to the sealed container 2 is attached, and stored in a storage room or the like.
In this case, the container lid 7 functions as a sealing member. For this reason, the container lid 7 of the double lid type is stored while being attached to the sealed container 2.

The uranium oxide powder produced from, for example, uranyl nitrate is powder particles having a particle size distribution of several microns to several hundred microns as described above. In this case, the powder is usually dropped into the container 2 by gravity flow and filled. In this case, the fine powder of the order of several microns out of the powder does not simply fall into the container 2 but linearly. The air turbulence scatters and soars around. In order to prevent the spread of contamination to the outside due to the soaring of the powder (that is, to confine radioactive materials and the like in the system), a sealed container 2 of a double lid system capable of reliably shutting off contact with an external atmosphere is employed. It is being done.

[0006]

By the way, at present,
The sealed container 2 filled with the powder or the like is stored and stored with the double-lid type lid 7 attached as described above. However, as compared with a normal lid of the non-double lid type, the double lid has a complicated structure, requires much time for production, and has a high production cost. On the other hand, the characteristic of the performance of the double lid is required only when the container such as powder is filled in the sealed container 2. Therefore, when the number of the sealed containers 2 to be stored is large and the storage period is long, the double lid type lids 7 are required as many as the number of the sealed containers 2, and these lids 7 are placed in a state close to dead storage, so There were drawbacks in that the storage and storage costs were extremely high and the economy was poor.

In view of such circumstances, the present invention makes it possible to effectively use a double-lid type lid so that stored items are not scattered to the external environment during filling, and to reduce costs for storage and storage of stored items. It is an object of the present invention to provide a method for sealing a sealed container using a double lid system.

[0008]

According to the present invention, there is provided a method for sealing a hermetically sealed container using a double lid system, wherein a lid for a container is attached to an opening of a sealed container, and an opening of a cell sealed with a lid for a cell is sealed. Connect the opening of the container, remove the lid of the container lid together with the lid of the cell lid, fill the contents into the sealed container via the cell, and then seal with the lid of the container lid In the method for sealing a sealed container using a double lid system, in which the opening of the container is closed, after the contents are filled in the sealed container and closed by the lid of the container lid, the container is hermetically sealed. Wherein the container lid is replaced with a non-double lid type lid in the lid replacement unit.

[0009] It is characterized in that the replacement of the container lid with the non-double lid type lid is carried out after the filled storage is in a stationary state. The container lid replaced with the non-double lid type lid is collected, attached to another empty sealed container, and reused. The replacement of the container lid with a non-double lid type lid is performed in a lid replacement unit controlled to a negative pressure. The storage material may be an oxide powder of denitrated uranium.

[0010]

After the contents are filled in the sealed container and closed by the container lid, the container lid is replaced with a non-double lid type lid so that the contents of the sealed container can be filled around the container. Non-double lid type lids are used for storage and storage of sealed containers because of the risk of contamination.The storage and storage costs are low, and double lid type lids can be stored in separate sealed containers without being dead. Can be used effectively. By replacing the container lid with a non-double lid type lid after the filling is in a stationary state, contamination can be reliably prevented without scattering of the stored items. The recovered container lid is attached to another empty sealed container and reused for filling the stored items. The replacement of the container lid with a non-double lid type lid is performed in the lid replacement unit, so that contamination etc. due to the surrounding packing material is reliably prevented, and the lid replacement unit is controlled to a negative pressure to fill the container. Even if an object adheres to the container lid, it is collected under a negative pressure, thereby preventing contamination.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 1 to 4. The same reference numerals are used for members or parts similar to those in the above-mentioned prior art, and the description is omitted. 1 to 4 show a process of filling and sealing a powder in a sealed container. FIG. 1 is a diagram showing a process of replacing a lid of the sealed container with a double lid type lid. FIG. FIG. 3 is a view showing a step of filling, FIG. 3 is a view showing a step of sealing a sealed container with a double-lid type lid, and FIG. 4 is a view showing a step of replacing a double-lid type lid with a normal lid. FIG. 1 shows the first to third steps. In the first step, for example, a screw-type lid or packing is provided at an opening 2a in a sealed container 2 before filling with powder, and a flange thereof is provided. The normal lid (refers to a lid of a non-double lid type) 8 such as a lid of a type that is bolted to the sealed container 2 at the part is replaced with a double lid type (for container) lid 7. The sealed container 2 is held on a positioning table 9 that can move up and down and move back and forth in the direction of travel. The upper portion of the sealed container 2 is fitted and supported by a lid replacement unit 10 forming an airtight closed space. At one end of the lid exchange unit 10, an exhaust means 11 for exhausting the internal air is attached. In the lid replacement unit 10, the lid 8 of the sealed container 2 is replaced with a double lid type lid 7 by a manipulator or a manual operation member (not shown).

In the second step of FIG. 1, a filling unit 12 having a cell 1 connected to the lid 7 of the sealed container 2 is disposed above the sealed container 2 conveyed from the first step. . A powder storage tank 14 for feeding an oxide powder p generated from, for example, uranyl nitrate is provided above the filling unit 12. The powder storage tank 14 includes a feeder 13.
Is connected to the cell 1 of the filling unit 12.
Then, in the third step, the flange 5 of the sealed container 2 is connected to the flange 3 of the cell 1 in the same manner as in the above-described conventional technique, and the container lid 6 is connected to the cell lid 4 by operating means (not shown).
It is connected and removed.

As shown in a fourth step of FIG. 2, the filling unit 12 has a filling nozzle 1 capable of moving powder up and down.
When the filling nozzle 15 descends, its tip is inserted into the flange 3 and the sealed container 2
Is connected to the opening 2a. The filling unit 12 is provided with exhaust means 16. After the filling of the powder p is completed, the double lids 4 and 6 are closed in the sixth step by the operation means described above. Until the filling unit 12 is separated from the sealed container 2 in the seventh step, it is the same as the conventional technique.

In an eighth step shown in FIG. 4, a lid replacement unit 17 similar to the lid replacement unit 10 in the first step is arranged, and the upper portion of the sealed container 2 is fitted to the lid replacement unit 17, whereby the double lid type lid 7 is formed. From the normal lid 8 (eg screw-in lid,
Alternatively, it has a packing and its flange portion is a sealed container 2.
Non-double lid type lids such as lids screwed to
In addition, it is designed to be replaced by a manipulator or a manual operation member (not shown). The lid replacement unit 17 in the eighth step, as described later, takes into account the possibility that the inner surface of the container lid 7 attached to the sealed container 2 in the previous step may be contaminated with powder, and It may be formed in a shape. In addition to this, the inside of the lid replacement unit 17 is controlled and controlled to a negative pressure by the exhaust means 11, and the fitting portion between the lid replacement unit 17 and the upper portion of the sealed container 2 is sealed with a rubber packing 18 or the like. In order to prevent contamination due to scattering of powder from spreading outside, the exhaust means 1
1 and can be collected.

This embodiment has the above-mentioned structure. Next, a method for filling the hermetically sealed container 2 with the powder p and sealing it will be described with reference to the first to eighth steps shown in FIGS. . In the first step shown in FIG. 1, a normal lid 8 such as a screw-in type is attached to the opening 2a of the sealed container 2 supported on the positioning table 9 and is closed. Then, by moving the positioning table 9 at a predetermined position upward,
The sealed container 2 is fitted into the lower opening of the lid replacement unit 10. In this state, the lid 8 is removed by operating a manipulator (not shown) or a manual operation means, etc.
Is attached to the opening 2a and closed.

Then, by lowering the positioning table 9, the sealed container 2 is detached from the lid changing unit 10, and is conveyed immediately below the filling unit 12 in the second step. The powder storage tank 14 attached above the filling unit 12
, A powder p such as a radioactive substance is conveyed and stored. In the next third step, the positioning table 9 is raised so that the flange 5 of the lid 7 is connected to the cell 1 of the filling unit 12.
To the flange 3. Then, the cell lid 4 of the cell lid 19 is connected to the container lid 6 by a known method,
The lids 4, 6 are removed from the flanges 3, 5. Thereafter, in a fourth step shown in FIG. 2, the filling nozzle 15 in the filling unit 12 is lowered, and the tip thereof is connected to the flange 3 of the cell 1.
By being fitted inside, it is connected with the opening 2 a of the sealed container 2. In this state, the powder p in the powder storage tank 14 is transferred from the filling nozzle 15 into the sealed container 2 via the feeder 13 and filled (fifth step). Powder p
When the powder p falls, the fine particles in the powder p are scattered. However, since the double lid type lid 7 is used, the powder p
The powder can be reliably filled in a sealed state without spreading outside to spread the contamination.

After the filling of the powder p into the sealed container 2 is completed,
When the feeder 13 is stopped, the filling nozzle 15 rises and is separated from the flange 3, and then a double lid composed of lids 4, 6 is fitted to each flange 3, 5 to open the cell 1 and the sealed container 2. The portions 1a and 2a are closed (sixth step shown in FIG. 3). Thereafter, the positioning table 9 is lowered in the seventh step, and the sealed container 2 is separated from the filling unit 12. In the conventional filling and sealing method, a normal lid is attached from above on the lid 7 of the sealed container 2 and then transferred to the storage room 20. In the present embodiment, the sealed container 2 is By 9 the wafer is conveyed to the next eighth step shown in FIG.

Then, in the eighth step, the sealed container 2 is transported directly below the lid replacement unit 17 and the positioning table 9 is raised, so that the upper portion of the sealed container 2 is fitted to the lid replacement unit 17. By this time, the powder p in the sealed container 2 is in a calming state in which the powder is scattered when filled and dropped, and the powder p is quietly deposited in the sealed container 2.
Then, similarly to the first step, the lid 7 is removed using a manipulator, manual operation means, or the like, and the normal lid 8 removed in the first step is attached to the opening 2a of the sealed container 2 and closed. . The lid 7 of the double lid type removed here
Since the atmosphere is the same as that of the filled powder p attached to the sealed container 2 until the seventh step, it is not impossible that the powder p adheres to the inner surface.

However, in this regard, since the inside of the lid replacement unit 17 is controlled to a negative pressure by the exhaust means 11, even if the powder p slightly adheres to the lid 7, it can be recovered through the exhaust means 11. . The sealed container 2 that has passed through the eighth step is placed on a carrier (not shown) or the like from the positioning table 9 and transported to the storage room 20 or the like for storage and storage. The container lid 7 removed in the eighth step is attached to another empty sealed container 2 in the first step, and is used repeatedly. In the above-described embodiment, the lid replacement unit 10 in the first step and the lid replacement unit 17 in the eighth step are separately configured. However, if both units are common, the filling and sealing step according to the present embodiment becomes a closed loop. The lid 7 for the double lid type container removed in the eighth step is replaced with the lid replacement unit 1 in the first step.
This is more preferable because the operation of transporting to zero can be omitted.

As described above, according to this embodiment, the powder p
When filling the sealed container 2 with the storage items such as
By using the lid 7 of the double lid type, external contamination due to the powder p at the time of filling or the like can be prevented, and when the sealed container 2 is stored, it is replaced with a low-cost ordinary lid 8, so that the powder p is filled. Storage and storage costs of the sealed container 2
The double lid type lid 7 is economical because it can be used repeatedly. Moreover, the replacement of the lid 7 of the double lid system with the ordinary lid 8 after filling the powder is performed in a state where the powder p inside the container is stationary, so that there is no risk of the surroundings being contaminated at the time of the replacement.
The possibility of contamination of the inner surface of the container lid 7 is also small.

In the above-described embodiment, the container filled in the sealed container 2 is the radioactive oxide powder p.
Without being limited to this, other substances, for example, toxic substances, etc., or not only substances that pollute the outside,
It may be a substance that is degraded by the intrusion of external air or the like.

[0022]

As described above, in the method for sealing a sealed container using the double lid system according to the present invention, the container is filled after the sealed container is filled with the contents and closed by the container lid. Was replaced with a non-double lid type lid, so when filling a sealed container with powdered material or the like, and using a double lid type lid, external contamination or external contamination by the stored material was used. Can be reliably prevented, and when storing this sealed container, replace it with a low-cost non-double lid type lid, and the cost of storing and storing the sealed container filled with the storage items is reduced, and the double lid type lid is stored. Is economical because it can be recovered and used repeatedly. In addition, since the replacement of the container lid with the non-double lid type lid is performed after the filled storage is in a stationary state, there is no risk of surroundings being contaminated at the time of the replacement, and the container lid is replaced. There is little possibility of contamination of the inner surface. Further, the lid for the sealed container replaced with the lid of the non-double lid type is recovered and reused in another empty sealed container, which is economical. The replacement of the container lid with a non-double lid type lid is performed in an airtightly sealed lid exchange unit, and the lid exchange unit is controlled to a negative pressure so that deposits on the lid can be collected. Therefore, the spread of contamination to the outside and the contamination from outside are surely prevented even at this stage.

[Brief description of the drawings]

FIG. 1 is a view showing a filling method of a sealed container according to an embodiment of the present invention, showing first to third steps of exchanging a lid of a sealed container with a double lid type.

FIG. 2 is a view showing fourth and fifth steps of filling the powder into a sealed container after the step shown in FIG. 1;

FIG. 3 is a view showing sixth and seventh steps of sealing the sealed container with a double-lid type lid after receiving the step shown in FIG. 2;

FIG. 4 is a view showing an eighth step of replacing the double lid type lid with a normal lid after the step shown in FIG. 3;

FIG. 5 is a schematic diagram for explaining a double lid type lid.

[Explanation of symbols]

 2 Sealed container 6 Container lid 7 Container lid 8 Normal lid 10, 17 Lid replacement unit 19 Cell lid

────────────────────────────────────────────────── ─── Continued on the front page (51) Int.Cl. ⁷ Identification code FI G21F 9/36 511 G21F 5/00 G (56) References JP-A-60-349100 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G21C 21/02 G21F 5/00 G21F 9/36

Claims (5)

(57) [Claims] 1. A container lid is attached to an opening of a sealed container, and an opening of the sealed container is connected to an opening of a cell sealed with a cell lid, and a lid of the container lid is used for a cell. Removed together with the lid of the lid, filled the contents into the sealed container via the cell, and then closed the opening of the sealed container with the lid of the container lid, sealing using a double lid system In the method for sealing a container, after the contents are filled in the sealed container and closed by a lid of the container lid, the container lid is closed in a hermetically sealed lid replacement unit by a non-double lid type lid. A method for sealing a hermetically sealed container using a double lid system, characterized in that the container is replaced. 2. The hermetic seal according to claim 1, wherein the replacement of the container lid with a non-double lid type lid is performed after the filled contents are in a stationary state. Container sealing method. 3. The container lid replaced with the non-dual lid type lid is recovered, attached to another empty sealed container, and reused. 3. The method for sealing a sealed container according to 1. 4. The method according to claim 1, wherein the replacement of the container lid with a non-double lid type lid is performed in the lid replacement unit controlled to a negative pressure. How to seal a sealed container. 5. The method for sealing a sealed container according to claim 1, wherein the storage is an oxide powder of denitrated uranium.