JP6728971B2 - Radioactive waste storage facility - Google Patents

Description

The present invention relates to a shielding lid member and a radioactive waste storage facility.

In nuclear power plants, etc., radioactive waste is generated by the operation and dismantling of facilities. Such radioactive waste is classified into high-level radioactive waste containing spent fuel and the like and low-level radioactive waste other than high-level radioactive waste. Among these, the high-level radioactive waste is mixed with, for example, glass and cooled as a vitrified body in a radioactive waste storage facility as disclosed in Patent Document 1 for a certain period.

Such high-level radioactive waste has a high calorific value. Therefore, the surface temperature of the vitrified body containing the high level radioactive waste becomes a high temperature of 200° C. or higher. Therefore, in the radioactive waste storage facility disclosed in Patent Document 1, due to the draft effect utilizing the heat quantity of the vitrified body, the flow of cooling air is provided inside the storage area of the vitrified body without using a power source. The vitrified body is formed and cooled by the flow of the cooling air.

JP-A-11-295492

However, although not shown in Patent Document 1, in an actual storage facility, in order to prevent the radiation emitted from the vitrified body from leaking to the outside, a large louver or a louver is provided in the middle of the flow path of the cooling air. A maze board is installed. As a result, the center of gravity of the building becomes high, and in order to meet the required seismic performance, the number of foundation piles and other measures for improving seismic strength will increase.

The present invention has been made in view of the above problems, and an object thereof is to make it possible to eliminate or reduce louvers and labyrinth plates installed in the cooling air flow passage in a radioactive waste storage facility.

The present invention adopts the following configurations as means for solving the above problems.

A first aspect of the present invention is a shield lid member, and employs a configuration including a canister having a grip portion formed on an upper portion thereof, and a shield portion which is housed inside the canister and shields radiation.

A second aspect of the invention adopts the configuration of the first aspect of the invention, which has a weight housed inside the canister.

A third aspect of the invention adopts the configuration of the first or second aspect of the invention, in which the canister has a recess formed in a bottom portion.

A fourth invention is a radioactive waste storage facility for storing a vitrified body or a container containing high-level radioactive waste, and a storage pipe for accommodating a plurality of vitrified bodies or a container in a stacked state, A configuration is provided in which the shielding lid member according to any one of the first to third aspects of the present invention is disposed on the above-mentioned vitrified body or container at the uppermost stage.

In a fifth aspect based on the fourth aspect, the shielding lid member has the same outer shape as the vitrified body or the containing body and is housed in the housing pipe.

The shielding lid member of the present invention includes a canister having a grip portion formed on the upper portion thereof, like the vitrified body or the containing body. Therefore, it can be transported in the storage facility in the same manner as a vitrified body or a container, and can be easily placed on a plurality of laminated vitrified bodies or a container. By placing such a shielding lid member on the vitrified body or the container, the radiation emitted from the vitrified body or the container can be shielded by the shielding portion of the shielding lid member. As a result, the amount of radiation radiated to the flow path of the cooling air can be reduced, and it becomes possible to reduce or reduce the conventionally installed louvers and maze plates.

It is sectional drawing which shows schematic structure of the radioactive waste storage facility in one Embodiment of this invention. It is an expansion schematic diagram including a part of storage area with which the radioactive waste storage equipment in one embodiment of the present invention is provided. It is a longitudinal cross-sectional view which shows typically the schematic structure of the storage pipe arrange|positioned at the vitrified substance storage area with which the radioactive waste storage facility in one Embodiment of this invention is equipped. It is a fragmentary sectional view showing typically a vitrification object stored by radioactive waste storage equipment in one embodiment of the present invention. It is a fragmentary sectional view showing typically the shielding lid member with which the radioactive waste storage equipment in one embodiment of the present invention is provided.

An embodiment of a shielding lid member and a radioactive waste storage facility according to the present invention will be described below with reference to the drawings. In the drawings below, the scale of each member is appropriately changed in order to make each member recognizable.

FIG. 1 is a sectional view showing a schematic configuration of a radioactive waste storage facility 1 of this embodiment. In addition, FIG. 2 is an enlarged schematic diagram including a part of a storage area included in the radioactive waste storage facility 1 of the present embodiment. As shown in FIG. 1 or FIG. 2, the radioactive waste storage facility 1 of the present embodiment includes a building 2, a lower plenum forming plate 3, an upper plenum forming plate 4, a plurality of ventilation pipes 5, and a plurality of housings. The pipe 6, the plug 7, the storage pipe lid 8, the shielding lid member 9, the upper shielding plate 10, the heat insulating material 11, and the floor traveling crane 12 are provided.

The radioactive waste storage facility 1 of the present embodiment is a facility for storing the vitrified body while cooling it for a long period of time. In addition, as will be described later with reference to the drawings, in the present embodiment, the vitrified body is a solidified glass containing radioactive waste (high-level radioactive waste or low-level radioactive waste) and the solidified glass. It includes a canister for housing. It should be noted that a container having solid waste containing or consisting of radioactive waste and a canister for storing this solid waste can be stored in the radioactive waste storage facility 1 of the present embodiment.

The building 2 is a concrete structure having a storage area R1. The building 2 is constructed such that the lower part is buried in the ground, and has a floor 2a installed at substantially the same height as the surrounding ground. In the building 2, the space below the floor 2a is the storage area R1 described above, and the space above the floor 2a is the transfer chamber R2. The storage area R1 is a space for storing the vitrified body. Further, the transfer chamber R2 is a space in which the floor traveling crane 12 is disposed and the vitrified body is carried in from a vitrified body receiving building (not shown) adjacent to the building 2.

Further, the building 2 has a building bottom portion 2b and a storage area side wall 2c. As shown in FIG. 1, a storage area R1 is formed by being surrounded by a floor 2a, a building bottom 2b, and a storage area side wall 2c. Further, the building 2 has an introduction opening 2d opened at an upper portion of a side wall of the building 2 and a discharge opening 2f formed at a tip portion of a chimney portion 2e protruding upward from the ceiling. The introduction opening 2d is an opening for introducing the outside air Y (cooling air) supplied to the storage area R1 into the building 2. The discharge opening 2f is an opening for discharging the outside air Y discharged from the storage area R1 to the outside of the building 2. Furthermore, the building 2 has an inlet shaft R3 connected from the introduction opening 2d to the lower part of the storage area R1 and an outlet shaft R4 extending from the upper part of the storage area R1 to the discharge opening 2f. As shown in FIG. 1, the inlet shaft R3 and the outlet shaft R4 are arranged on opposite sides of the storage area R1.

The lower plenum forming plate 3 is a plate member arranged in the storage area R1 and is fixed to the storage area side wall 2c so that the front and back surfaces thereof are oriented in the vertical direction. The lower plenum forming plate 3 is arranged with a certain gap with respect to the building bottom 2b, and forms a lower plenum R5 with the building bottom 2b. The lower plenum R5 is a space provided in the lowest layer of the storage area R1 and is connected to the inlet shaft R3. Such a lower plenum R5 is a space to which the outside air Y is supplied from the inlet shaft R3, and distributes the supplied outside air Y to each ventilation pipe 5.

The upper plenum forming plate 4 is a plate member arranged above the lower plenum forming plate 3 in the storage area R1, and is fixed to the storage area side wall 2c with the front and back surfaces thereof facing upward and downward. The upper plenum forming plate 4 is arranged with a constant gap with respect to the floor 2a, and forms an upper plenum R6 with the floor 2a. The upper plenum R6 is a space provided in the uppermost layer of the storage area R1 and is connected to the outlet shaft R4. Such an upper plenum R6 is a space where the outside air Y is discharged from the plurality of ventilation pipes 5, and the outside air Y discharged from the plurality of ventilation pipes 5 is collectively guided to the outlet shaft R4.

The ventilation pipe 5 is a straight pipe member that communicates from the lower plenum R5 to the upper plenum R6, and is arranged such that the pipe axis is oriented in the vertical direction. The ventilation pipe 5 penetrates the lower plenum forming plate 3 and the upper plenum forming plate 4 so that the lower end opening is arranged in the lower plenum R5 and the upper end opening is arranged in the upper plenum R6, and the lower plenum forming plate 3 and It is supported by the upper plenum forming plate 4. The same number of ventilation tubes 5 as the storage tubes 6 are provided. These ventilation pipes 5 guide the outside air Y supplied to the lower plenum R5 to the upper plenum R6. That is, the outside air Y flows through the inside of the ventilation pipe 5 from the lower plenum R5 to the upper plenum R6.

The storage pipe 6 is a straight pipe member whose upper end penetrates the floor 2 a of the building 2 and is suspended and supported by the floor 2 a so as to be inserted into the ventilation pipe 5. The storage pipe 6 has a bottomed shape in which the upper end is opened and the lower end is closed, and the lower end position has a length substantially the same as the lower end position of the ventilation pipe 5. Further, the storage tube 6 has a smaller diameter than the ventilation tube 5 so that a space is formed between the accommodation tube 6 and the inner wall surface of the ventilation tube 5. Such a storage tube 6 stores therein the vitrified body in a laminated state.

FIG. 3 is a vertical cross-sectional view schematically showing the schematic configuration of the storage tube 6. As shown in this figure, the plug 7 is fitted to the upper end of the storage tube 6 and seals the area of the storage tube 6 in which the vitrified body is stored. The storage tube lid 8 is arranged further above the plug 7, and is attached to the storage tube 6 so as to close the open end of the storage tube 6.

The shielding lid member 9 is housed in the housing pipe 6 as shown in FIG. The shielding lid member 9 is placed on the uppermost stage of the plurality of vitrified bodies X that are stacked and stored in the storage tube 6. Here, the configuration of the shielding lid member 9 will be described with reference to FIGS. 4 and 5. FIG. 4 is a partial cross-sectional view schematically showing the vitrified body X. Further, FIG. 5 is a partial cross-sectional view schematically showing the shielding lid member 9. As shown in FIG. 4, the vitrified body X has a canister X1 which is a metal container and a solidified glass X2 which is housed inside the canister X1. The canister X1 has a hollow and substantially cylindrical shape, and a grip portion X11 is formed on an upper portion thereof. The grip portion X11 is a portion gripped by the floor traveling crane 12, for example. At the bottom of the canister X1, there is formed a recess X12 capable of accommodating the grip X11. In such a recess X12, when the vitrified body X is stacked, the grip portion X11 of the vitrified body X arranged below is accommodated. The solidified glass X2 contains a radioactive substance.

As shown in FIG. 5, the shielding lid member 9 has a metal canister 9a, a lid portion 9b (shielding portion), and a weight 9c housed inside the canister 9a. The canister 9a has a hollow cylindrical shape having the same outer shape as the canister X1 of the vitrified body X. That is, the canister 9a has the grip portion 9a1 formed on the upper portion. The grip portion 9a1 is a portion gripped by the floor traveling crane 12, for example. At the bottom of the canister 9a, there is formed a recess 9a2 capable of accommodating the grip 9a1. When the shielding lid member 9 is placed on the vitrified body X, the grip portion X11 of the lower vitrified body X is accommodated in the recess 9a2. The shielding lid member 9 having such a canister 9a has the same outer shape as the vitrified body X.

The lid portion 9b is a portion having a high radiation shielding effect by containing lead or iron, and is arranged inside the canister 9a and above the internal space. Such a lid portion 9b shields the radiation emitted upward from the high-level radioactive vitrified body arranged below the shielding lid member 9. The position and shape of the lid 9b are not limited to those shown in FIG. For example, the lid 9b may be formed so as to cover the entire inner side surface of the canister 9a. The lid 9b may be formed integrally with a part of the canister 9a instead of being formed separately from the canister 9a. That is, for example, the canister 9a may be locally formed to have a large thickness in the vicinity of the grip portion 9a1, and the thick portion may function as the lid 9b.

The weight 9c is arranged inside the canister X1 and below the internal space. The weight of the weight 9c is set such that the weight of the shielding lid member 9 is the same as the weight of the vitrified body X. That is, the weight 9c adjusts the weight of the shielding lid member 9 so that the weight of the shielding lid member 9 becomes equal to the weight of the vitrified body X.

The upper shield plate 10 is a plate member that is placed on the upper plenum forming plate 4 and that shields radiation by containing lead and iron. Such an upper shield plate 10 shields the radiation that is about to enter the upper plenum R6 through the spaces between the storage tubes 6. The heat insulating material 11 is attached to the inner wall surface of the building 2 forming the upper plenum R6 and the outlet shaft R4. The heat insulating material 11 suppresses the building 2 from being heated by the radiant heat emitted from the vitrified body X.

As shown in FIG. 1, the floor traveling crane 12 is installed on the floor portion 2a of the building 2 so as to be arranged in the transfer chamber R2. The floor traveling crane 12 is capable of traveling vertically and horizontally along the floor 2a, and is further configured to be capable of moving up and down the vitrified body X. Such a floor traveling crane 12 receives the vitrified body X from a glass vitrified body receiving building (not shown), conveys the received vitrified body X to the upper side of the storage pipe 6, and then stores the vitrified body in the storage pipe 6. Store X. Further, in the radioactive waste storage facility 1 of the present embodiment, the floor traveling crane 12 also conveys the shielding lid member 9 and stores the shielding lid member 9 in the storage pipe 6.

In the radioactive waste storage facility 1 of this embodiment having such a configuration, the vitrified body X is stored for a long period of time in a state in which the vitrified body X is stacked in the storage pipe 6. At this time, the air in the storage area R1 warmed by the amount of heat of the vitrified body X becomes lighter and is discharged to the outside from the discharge opening 2f through the outlet shaft R4. Further, as the warmed air is discharged from the discharge opening 2f, the outside air Y flows into the inlet shaft R3 from the introduction opening 2d. The outside air Y flowing into the inlet shaft R3 as described above flows into the respective ventilation pipes 5 from the lower plenum R5, rises in the ventilation pipes 5 and is guided to the upper plenum R6. In this way, the outside air Y flows from the lower side to the upper side in the ventilation tube 5 so that the vitrified body X stored in the storage tube 6 is cooled by heat exchange. The outside air Y flowing into the upper plenum R6 from the ventilation pipe 5 is discharged to the outside of the building 2 from the discharge opening 2f through the outlet shaft R4.

Further, a high level of radiation is emitted from the vitrified body X. Such high-level radiation is prevented from entering the upper plenum R6 by the shielding lid member 9 and the upper shielding plate 10 arranged above the vitrified body X. In the conventional radioactive waste storage facility, a maze plate or a louver is installed inside the exit shaft R4 in order to prevent the radiation from reflecting and traveling inside the exit shaft R4. On the other hand, in the radioactive waste storage facility 1 of the present embodiment, since the radiation that enters the upper plenum R6 is small, the labyrinth plate and the louver are not installed inside the exit shaft R4 that has been installed conventionally. Further, the radiant heat radiated from the vitrified body X is suppressed from being absorbed by the heat insulating material 11 and reaching the building 2.

The shielding lid member 9 included in the radioactive waste storage facility 1 of the present embodiment described above includes the canister 9a having the grip portion 9a1 formed on the upper portion thereof, like the vitrified body X. The shielding lid member 9 can be transported inside the radioactive waste storage facility 1 in the same manner as the vitrified body X, and can be easily placed on the plurality of laminated vitrified bodies X. it can. By placing such a shielding lid member 9 on the vitrified body X, the radiation emitted from the vitrified body X can be shielded by the lid portion 9b of the shielding lid member 9. As a result, the amount of radiation emitted to the upper plenum R6 and the exit shaft R4 can be reduced, and the louvers and labyrinth plates that have been conventionally installed can be reduced or reduced. Therefore, the center of gravity of the building 2 can be lowered and the seismic resistance of the radioactive waste storage facility 1 can be improved, as compared with the case where the maze plate or the louver is installed inside the exit shaft R4 or the like. Become.

Further, in the radioactive waste storage facility 1 of the present embodiment, the shielding lid member 9 has the same outer shape as the vitrified body X. Therefore, the shielding lid member 9 can be handled by the floor traveling crane 12 like the vitrified body X. Therefore, the shielding lid member 9 can be easily installed. Further, the shielding lid member 9 is adjusted to have the same weight as the vitrified body X by the weight 9c. Therefore, it becomes possible to handle the shielding lid member 9 more similarly to the vitrified body X.

Further, in the radioactive waste storage facility 1 of the present embodiment, since the concave portion 9a2 is formed at the bottom of the shielding lid member 9, the concave portion 9a2 is formed on the vitrified body X without coming into contact with the grip X11 of the vitrified body X. The shielding lid member 9 can be stacked. Therefore, the shielding lid member 9 can be mounted on the vitrified body X more stably.

The preferred embodiments of the present invention have been described above with reference to the drawings, but the present invention is not limited to the above embodiments. The shapes, combinations, and the like of the constituent members shown in the above-described embodiments are merely examples, and various modifications can be made based on design requirements and the like without departing from the spirit of the present invention.

For example, in the above embodiment, the weight 9c is arranged in the lower portion inside the canister 9a. However, the present invention is not limited to this, and weights 9c having different specific gravities may be arranged so as to fully fill the inside of the canister 9a.

Moreover, in the said embodiment, the structure which arrange|positions the shielding lid member 9 on the uppermost vitrification body X of the vitrification bodies X laminated|stacked and arranged is adopted. However, the present invention is not limited to this, and it is also possible to employ a configuration in which the shielding lid member 9 is arranged below the lowermost vitrified body X of the vitrified bodies X to be laminated and arranged. ..

Further, in the above embodiment, the shield lid member 9 has the same outer shape as the vitrified body X. However, the present invention is not limited to this, and the shielding lid member 9 may not have the same outer shape as the vitrified body X, for example, the recess 9a2 may have a shape capable of accommodating the gripping portion 9a1. For example, it may have a shape excluding the curved portion.

1 radioactive waste storage facility 2 building 2a floor 2b building bottom 2c storage area side wall 2d introduction opening 2e chimney 2f discharge opening 3 lower plenum forming plate 4 upper plenum forming plate 5 ventilation pipe 6 storage pipe 7 plug 8 storage pipe lid 9 Shielding lid member 9a Canister 9a1 Grip portion 9a2 Recessed portion 9b Lid portion (shielding portion)
9c Weight 10 Upper shielding plate 11 Heat insulating material 12 Floor traveling crane R1 Storage area R2 Transfer chamber R3 Entrance shaft R4 Exit shaft R5 Lower plenum R6 Upper plenum X Vitrified body X1 Canister X11 Grip X12 Recess X2 Solidified glass Y Outside air

Claims (3)

A radioactive waste storage facility for storing vitrified or containing bodies containing high-level radioactive waste,
A storage tube that stores a plurality of vitrified bodies or storage bodies in a stacked state,
A shielding lid member which is disposed on the uppermost vitrified body or container and does not contain the high level radioactive waste;
Equipped with
The shielding lid member,
A canister with a grip formed on the top,
A shielding portion which is housed inside the canister and shields radiation.
Have
The radioactive waste storage facility , wherein the shielding lid member has the same outer shape as the vitrified body or the container and is housed in the housing pipe . The radioactive waste storage facility according to claim 1 , wherein the shielding lid member has a weight housed inside the canister. The radioactive waste storage facility according to claim 1 or 2, wherein the canister has a recess formed at the bottom.

Images