JPH08201587A - Sealing method of sealed vessel using double-lid system - Google Patents

Abstract

PURPOSE: To reduce the cost of preservation and storage of contained matter by exchanging vessel lids with non-double lid in a lid exchange unit after filling and sealing contained matter in a sealed vessel with a vessel lid. CONSTITUTION: After filling contained matter in a sealed vessel 2 and sealing with a vessel lid 7, the lid 7 is exchanged with a non-double system lid 8 in a lid exchanging unit 17 sealed air-tightly. In other words, the upper part of the sealed vessel 2 is fit in the lid exchanging unit 17 and double system lid 7 is exchanged with an ordinary lid (non-double system lid) using a manipulator and the like. Inside of the lid exchanging unit 17 is controlled in negative pressure with an exhaust means 11 and the fitting part of the upper part of the vessel 2 to the lid exchanging unit 17 is sealed with a rubber made packing 18. By this, contamination due to dispersion of powder is prevented. As it is exchanged with non-double system lid 8 of low cost, the preservation and storage cost becomes low and the recovery and reuse of the double system lid 7 result in economical.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sealing method for sealing, storing, storing, etc., a container accommodating a radioactive substance or the like in a sealed environment in the process of manufacturing or reprocessing nuclear fuel.

[0002]

2. Description of the Related Art Conventionally, in processes such as reprocessing of radioactive materials such as nuclear fuel in the nuclear field, uranyl nitrate solution and plutonium nitrate solution are thermally decomposed and denitrated by a reactor such as a fluidized bed apparatus or a roasting furnace to obtain powder. When it is converted into the oxide of the form and is stored / filled in a predetermined container for storage, it is necessary to fill the substance in a sealed container without spreading the contamination to the outside. For that purpose, a so-called double cover type sealed container is used. A double lid type hermetically sealed container is also used for filling and storing radioactive waste that is contaminated with radioactive substances by incineration. In addition, even if it is not a radioactive substance, when handling harmful substances without spreading the pollution to the outside, or when storing substances that dislike external pollution from the external environment and store them in containers, etc. A double lid type hermetically sealed container is used to store and store the product in a container. For such a purpose, the radioactive materials that should be stored in the double lid type sealed container are received in the storage container in an environment that is sealed in a closed space (hereinafter referred to as a cell) that is isolated from the external environment. Work of handing over is carried out, and as means for this, for example, Japanese Patent Publication No. 59-40715, Japanese Patent Publication No. 62-13547, and Japanese Utility Model Publication No. 63-31.
A double lid type connecting device as shown in Japanese Patent Publication No. 039, etc. is adopted.

For example, in a process such as reprocessing of radioactive materials such as nuclear fuel in the field of nuclear power, for example, the separated and purified uranyl nitrate solution is thermally decomposed by heating using a reactor such as a fluidized bed, and an oxide ( Uranium trioxide:
UO ₃ ) converted to powder. This oxide powder is an oxide particle with a particle size distribution of several microns to several hundreds of microns, and is extracted from the upper part (overflow pipe) or the lower part (underflow pipe) of the reaction device and put in a double lid type sealed container. Filled and stored. This double lid type container connecting device will be described with reference to FIG. In general, this connecting device comprises a cell 1 and each opening 1 of the sealed container 2.
a and 2a are connected. That is, the flange 3 is provided around the opening 1a of the cell 1, and the flange 3
A cell lid 4 is provided that closes the opening 1a by fitting the inner lid with the cell lid 4, and the cell lid 4 opens inside the cell 1. Sealed container 2 for storing radioactive materials
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. Incidentally, the flange 5 and the container lid 6
And the container lid 7 is composed of the flange 3 and the cell lid 4
It is assumed that the cell lid 19 is composed of and.

Then, the flange 5 of the hermetically 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 to form a hermetically sealed container. When 2 is relatively rotated about the axis L, both lids 4 and 6 are coupled to each other by a known coupling structure (not shown) provided on the mating surfaces of both 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 in the connected state in the cell 1 are removed, whereby the cell 1
The space inside and the space inside the sealed container 2 communicate with each other. In this state, the contents such as radioactive substances are filled from the cell 1 into the sealed container 2 by remote control. And again after filling,
The opening 1 of the cell 1 and the hermetically sealed container 2 is formed by the 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. In this way, the hermetically-sealed container 2 in which the contents are filled and hermetically sealed is provided on the container lid 7 with an ordinary lid for storage, for example, a screw-type lid,
Alternatively, it is stored in a storage room or the like by attaching a lid or the like for bolting a flange provided at the edge portion between the flange and the sealed container 2.
In this case, the container lid 7 serves as a sealing member. Therefore, the double lid type container lid 7 is stored in a state of being attached to the sealed container 2.

Here, for example, the powder of uranium oxide produced from uranyl nitrate is powder particles having a particle size distribution of about several microns to several hundreds of microns as described above, and this particle powder is transferred to the sealed container 2. In this case, the powder is usually dropped by gravity flow into the container 2 for filling, but in this case, the fine powder of the order of a few microns does not simply drop linearly into the container 2, From the turbulence of the airflow, it scatters around and rises. In order to prevent the spread of contamination to the outside due to the powder rising (that is, to confine radioactive substances and the like in the system), a double lid type hermetically sealed container 2 capable of reliably blocking contact with the outside atmosphere is adopted. It has been done.

[0006]

By the way, in the present situation,
The sealed container 2 filled with powder or the like is stored and stored with the double lid type lid 7 attached thereto as described above. However, compared with a normal lid of a non-double lid type, the double lid has a complicated structure, is laborious to manufacture, and has a high manufacturing cost. On the other hand, the performance characteristic 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 stored is large and the storage period is long, as many lids 7 as the number of the sealed containers 2 are required, and these lids 7 are placed in a state close to the dead store. The storage and storage costs were very 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 do not scatter to the external environment at the time of filling, and to reduce the cost for storing and storing stored items. It is an object of the present invention to provide a method for sealing a hermetically sealed container using the double lid system described above.

[0008]

A method for sealing a hermetically sealed container using a double lid system according to the present invention is a method in which a container lid is attached to an opening of a hermetically sealed container, and the cell is sealed with an opening of a cell sealed by the cell lid. Connect the opening of the container, remove the lid of the container lid together with the lid of the cell lid, fill the contents in the sealed container through the cell, and then seal with the lid of the container lid. In a method for sealing a hermetically sealed container using a double lid method, in which the opening of the container is closed, in a hermetically sealed container, the contents are filled and closed with a lid of a container lid, and then hermetically sealed. In addition, the container lid is replaced with a non-double lid lid in the lid replacement unit.

The replacement of the container lid with the non-double lid type lid is characterized in that it is carried out after the filled contents are 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 exchange unit controlled to a negative pressure. The stored item may be a denitration uranium oxide powder.

[0010]

[Operation] 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 to fill the contents of the sealed container with the surroundings. It can be done reliably without fear of contamination, and because the lid of the non-double lid method is used for storage and storage of the sealed container, the storage and storage cost is low, and the lid of the double lid method is not stored in another sealed container. Effectively usable. By replacing the container lid with a non-double lid type lid after the filling becomes stationary, it is possible to reliably prevent contamination without scattering the stored contents. The recovered container lid is attached to another empty sealed container and is reused for filling the stored items. Since the container lid is replaced with a non-double lid type lid in the lid replacement unit, contamination of the surroundings with filling materials is reliably prevented, and the lid replacement unit is controlled to a negative pressure for filling. Even if an object adheres to the container lid, it is collected under a negative pressure and its contamination is prevented.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to FIGS. 1 to 4, but the same members or parts as those in the above-described conventional art are designated by the same reference numerals and the description thereof will be omitted. 1 to 4 show a process of filling and sealing powder in a hermetic container, FIG. 1 shows a process of replacing the lid of the hermetic container with a double lid type lid, and FIG. 2 shows powder in the hermetic container. FIG. 4 is a diagram showing a process of filling, FIG. 3 is a diagram showing a process of sealing the hermetically sealed container with a double lid type lid, and FIG. 4 is a diagram showing a process of replacing the double lid type lid with a normal lid. FIG. 1 shows the first to third steps. In the first step, in the sealed container 2 before powder filling, for example, a screw-type lid or packing is provided in the opening 2a and the flange thereof. A normal lid (which means a non-double lid lid) 8 such as a lid that is bolted to the sealed container 2 at a part is replaced with a double lid lid 7 (for a container). The sealed container 2 is held on a positioning table 9 which can move up and down and can move back and forth in the traveling direction. The upper portion of the hermetically sealed container 2 is fitted and supported by the lid exchange unit 10 that forms an airtight closed space. An exhaust means 11 for exhausting the internal air is attached to one end of the lid exchange unit 10. In the lid exchange unit 10, the lid 8 of the sealed container 2 is replaced with a double lid lid 7 by a manipulator (not shown) or a manual operation member.

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

Inside the filling unit 12, as shown in the fourth step of FIG. 2, the filling nozzle 1 for powder transfer capable of moving up and down.
5 is arranged, and the tip of the filling nozzle 15 is inserted into the flange 3 when the filling nozzle 15 descends, so that the hermetic container 2
Is connected to the opening 2a. Exhaust means 16 is attached to the filling unit 12. After the filling of the powder p is completed, the double lids 4 and 6 are closed in the sixth step by the above-mentioned operating means. Then, it is the same as the conventional technique until the filling unit 12 is separated from the sealed container 2 in the seventh step.

In the eighth step shown in FIG. 4, a lid exchanging unit 17 similar to the lid exchanging unit 10 in the first step is arranged, and the upper portion of the hermetically sealed container 2 is fitted into the lid exchanging unit 17 to form the double lid type lid 7. 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 lid, such as a lid that is screwed to
In addition, it is designed to be replaced by a manipulator (not shown) or a manually operated member. The lid replacement unit 17 in the eighth step is a hood in consideration of the possibility that the inner surface of the lid 7 for the container attached to the hermetically sealed container 2 in the previous step is contaminated with powder, as described later. You may form 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. Exhaust means 1 so that the pollution due to the scattering of powder is not spread to the outside.
It can be collected from 1.

The present embodiment has the above-mentioned structure. Next, a method of filling the 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, the opening 2a of the hermetically sealed container 2 supported on the positioning base 9 is closed by mounting a normal lid 8 of a screw-in type or the like. 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 or a manual operating means (not shown) to remove the lid 7 of the double lid type.
Is attached to the opening 2a and closed.

Then, by lowering the positioning table 9, the hermetically sealed container 2 is detached from the lid exchange unit 10 and conveyed immediately below the filling unit 12 in the second step. The powder storage tank 14 mounted above the filling unit 12
A powder p such as a radioactive substance is transported to and stored in the. In the next third step, the flange 5 of the lid 7 is moved to the cell 1 of the filling unit 12 by raising the positioning table 9.
To the flange 3 of. Then, the cell lid 4 of the cell lid 19 is connected to the container lid 6 by a known method,
Both lids 4 and 6 are removed from each flange 3 and 5. After that, in the fourth step shown in FIG. 2, the filling nozzle 15 in the filling unit 12 is lowered, and its tip is attached to the flange 3 of the cell 1.
By fitting it inside, it is connected to the opening 2a 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 therein (fifth step). Powder p
Although the fine particles in the powder p are scattered when the powder p falls, the powder p is sealed in the hermetically sealed container 2 because the double lid type lid 7 is used.
The powder can be reliably filled in a sealed state without scattering to the outside of the container and expanding the contamination.

When 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 the double lids including the lids 4 and 6 are fitted to the respective flanges 3 and 5 to open the cell 1 and the sealed container 2. The parts 1a and 2a are closed (sixth step shown in FIG. 3). Then, in the seventh step, the positioning table 9 descends and the sealed container 2 is separated from the filling unit 12. In the conventional filling and sealing method, a normal lid is then mounted on the lid 7 of the hermetically sealed container 2 and then transferred to the storage chamber 20, but in the present embodiment, the hermetically sealed container 2 has a positioning table. The sheet 9 is conveyed to the next eighth step shown in FIG.

Then, in the eighth step, the hermetically sealed container 2 is conveyed immediately below the lid replacement unit 17, and the positioning table 9 is moved up, so that the upper part of the hermetically sealed container 2 is fitted into the lid replacement unit 17. By the time this state is reached, the powder p in the hermetically sealed container 2 has been calmed from the scattered state of the powder at the time of filling and dropping, and the powder p is in a static state in which it is gently accumulated in the hermetically sealed container 2.
Then, as in the first step, the lid 7 is removed using a manipulator, a manual operation means, etc., and the ordinary lid 8 removed in the first step is attached to the opening 2a of the hermetically sealed container 2 to close it. . In addition, the lid 7 of the double lid type to be removed here
Since the atmosphere is the same as that of the powder p filled in the sealed container 2 until the seventh step, the powder p may adhere to the inner surface of the powder p.

However, in this respect, since the inside of the lid replacement unit 17 is controlled to have a negative pressure by the exhaust means 11, even if a small amount of the powder p adheres to the lid 7, it can be recovered via the exhaust means 11. . The hermetically sealed container 2 that has gone through the eighth step is placed from the positioning table 9 on a carrier vehicle or the like (not shown), transported to the storage chamber 20 or the like, and stored and stored. Further, the container lid 7 removed in the eighth step is attached to another empty sealed container 2 in the first step and repeatedly used. In the above-described embodiment, the lid exchange unit 10 of the first step and the lid exchange unit 17 of the eighth step are separately configured, but if both units are made common, the filling and sealing step according to the present embodiment becomes a closed loop. The double lid type container lid 7 removed in the eighth step is replaced with the lid replacement unit 1 in the first step.
It is more preferable because the work of transferring to 0 can be omitted.

As described above, according to this embodiment, the powder p
When filling the sealed container 2 with the stored items such as
The double lid type lid 7 can be used to prevent external contamination by the powder p during filling, etc., and when the sealed container 2 is stored, the lid 7 is replaced with an inexpensive ordinary lid 8 so that the powder p is filled. The storage and storage costs of the sealed container 2 are low,
The double lid type lid 7 is economical because it can be used repeatedly. Moreover, since the double lid type lid 7 is replaced with the normal lid 8 after the powder filling, since the powder p inside the container is in a stationary state, there is no risk of contamination of the surroundings during the replacement.
The possibility of contamination of the inner surface of the container lid 7 is low.

In the above-mentioned embodiment, the contents to be filled in the sealed container 2 are the radioactive oxide powder p, but
Without being limited to this, other substances, for example, toxic substances or the like, or not limited to substances polluting the outside,
It may be a substance or the like that is deteriorated by the entry of external air or the like.

[0022]

As described above, according to the method of sealing a hermetically sealed container using the double lid system according to the present invention, after the contents are filled in the hermetically sealed container and the container is closed by the container lid, the container lid is closed. Since it has been replaced with a non-double lid type lid, when filling powdered items in a sealed container and sealing it, the double lid type lid is used to externally contaminate the item or external contamination. In addition to being able to reliably prevent such problems, when replacing this sealed container with an inexpensive non-double lid type lid, the cost of storing and storing the sealed container filled with stored items is low, and the double lid type lid is Is economical because it can be recovered and used repeatedly. Also, since the replacement of the container lid with the non-double lid type lid is performed after the filled contents are in a stationary state, there is no risk of contamination of the surroundings at the time of this replacement, and the container lid body is replaced. There is little possibility of contamination on the inner surface. Moreover, the lid for the sealed container replaced with the lid of the non-double lid type is economical because it is collected and reused in another empty sealed container. The replacement of the container lid with a non-double lid type lid is performed in an airtightly closed lid exchange unit, and the lid exchange unit is controlled to a negative pressure to collect the deposits and the like on the lid. Therefore, the spread of external pollution and the external pollution can be reliably prevented even at this stage.

[Brief description of drawings]

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

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

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

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 view for explaining a double lid type lid.

[Explanation of symbols]

 2 Sealed container 6 Lid for container 7 Lid for container 8 Normal lid 10,17 Lid replacement unit 19 Lid for cell

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location G21F 9/28 ZAB

Claims (5)

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