JP5722385B2 - Precast concrete containment - Google Patents

Description

  The present invention relates to a precast concrete containment for storing radioactive contaminants.

  In Japan, which owns a nuclear power plant, a nuclear power plant accident may occur for some reason, such as an earthquake or tsunami, and a serious problem may occur where radioactive contamination occurs in the surrounding area. At that time, a method for storing contaminated waste is a major issue. In particular, there is a problem in the storage method of contaminated soil and other pollutants (hereinafter referred to as radioactive pollutants) containing radioactive substances generated when debris treatment and soil decontamination are performed. Here, as a container for storing various radioactive pollutants, there is a storage container having a container body made of concrete and having a storage space inside, and a lid that can cover the storage space. Widely known (see, for example, Patent Document 1). Such a storage container is often developed as a container for temporary storage in a temporary storage place for a storage period of about 3 years.

  However, since the storage period of radioactive pollutants is not clear, the provisional container for storing radioactive pollutants is the provisional container described above so that the residents around the storage facilities can live safely and safely. Not only a storage site and an intermediate storage facility for a certain period of time but also a final disposal site for permanent storage is required. For that purpose, it is necessary to prevent the radioactive pollutant from flowing out of the container permanently in consideration of unexpected situations. As an unforeseen situation, the bag containing the radioactive pollutant inside is damaged by some reason, and the radioactive material flows into the container from the inside of the bag. In that state, the container deteriorates over time due to long-term storage. It is conceivable that the radioactive substance further flows out of the container from the damaged part due to the occurrence of damage such as cracks due to some factors such as. As a means for preventing the outflow of such a radioactive substance, it has been conventionally considered to provide a waterproof layer formed of a resin or the like on the inner surface of the container body, but the waterproof layer itself is aged when stored for a long time. It may break due to deterioration, and it may still occur that the radioactive substance flows out of the container from the damaged portion. Therefore, there is a need for a concrete container that can more reliably prevent leakage of radioactive substances.

JP 2012-46190 A

  The present invention focuses on the above points, and an object thereof is to realize a concrete containment vessel that can prevent or suppress the outflow of radioactive substances to the outside.

In order to solve the above problems, the precast concrete storage container according to the present invention has the following configuration. That is, the precast concrete storage container according to the present invention is a precast concrete storage container including a container body having a storage space therein and a lid for closing the storage space, and faces the storage space. A radioactive substance adsorbing layer containing zeolite capable of ion exchange with a radioactive substance arranged in a containment space, wherein the radioactive substance adsorbing layer contains a zeolite filled between the object to be stored and the container body It is formed by the liquid substance which has this.

  If this is the case, radioactive materials such as cesium contained in the containment are adsorbed on the zeolite by ion exchange with the zeolite contained in the radioactive material adsorption layer. Leakage can be prevented or suppressed more reliably.

  As a configuration of a container main body for easily realizing such a precast concrete containment vessel, a bottom plate and a side plate rising from an outer peripheral portion of the bottom plate are provided, and the radioactive substance is provided on the inner surface side of the bottom plate and the side plate. The thing which provided the adsorption layer is mentioned.

  As a configuration for more reliably preventing or suppressing leakage of radioactive material stored in such a storage container, it is formed using an adhesive having an extension ability between the upper surface of the container body and the lower surface of the lid. The thing provided with the attached adhesion part is mentioned.

  ADVANTAGE OF THE INVENTION According to this invention, the concrete storage container which can prevent or suppress the outflow of a radioactive substance to the exterior, and the panel used for such a concrete storage container are realizable.

The whole perspective view which shows the containment container made from precast concrete relevant to this invention. The front view which shows the storage container made from the same precast concrete . The top view which shows the container main body of the storage container made from the precast concrete . AA sectional drawing in FIG. Sectional drawing which shows the storage container made from precast concrete of one Embodiment of this invention. Schematic which shows one use aspect of the zeolite panel relevant to this invention.

An embodiment of the present invention will be described below with reference to the drawings .

Figures 1-4 precast concrete containment vessel 1 shown in includes a container body 2 having a storage space S inside, a lid 3 for closing the storage space S, the upper surface and the lid 3 of the container body 2 The adhesive part 4 formed using the adhesive agent which has an elongation capability between the lower surfaces of these . And it has the zeolite panel 5 which is the radioactive substance adsorption layer containing the zeolite which can exchange the radioactive substance and the radioactive substance arranged in this storage space S facing the said storage space S.

  The container body 2 includes a bottom plate 6 and a side plate 7 rising from the outer peripheral portion of the bottom plate 6. Further, the space defined by the bottom plate 6 and the side plate 7 is the storage space S in which an object to be stored containing a radioactive substance can be stored. A projection 71 projecting upward is formed in a portion of the upper surface of the side plate 7 near the storage space S. Insert nuts 72 are embedded in the corners of the projections 71 for screwing bolts B inserted from the lid 3 side. Further, a seal material 73 is provided at a position spaced apart from the protrusion 71 by a predetermined distance so as to prevent an adhesive for forming the adhesive portion 4 described later from flowing away. Furthermore, the inner surface of the bottom plate 6 and the side plate 7, that is, the surface facing the storage space S, is provided with recesses 6a and 7a for arranging the zeolite panel 5 therein. And in the state which the to-be-contained object containing a radioactive substance was distribute | arranged to the said storage space S, the said cover body 3 is distribute | arranged above this container main body 2, and the said storage space S is obstruct | occluded.

  The lid 3 has the same shape as the container body 2 when viewed in plan. On the lower surface of the lid 3, a recess 3 a is provided in which the protrusion 71 of the container body 2 can be accommodated. Further, bolt insertion holes 3b for inserting bolts B for fastening the lid 3 to the container body 2 by screwing the insert nuts 72 of the container body 2 to the four corners of the lid body are provided. Provided. A counterbore for accommodating the head of the bolt B is provided at the upper portion of the bolt insertion hole 3b. Then, in a state where the projection 71 of the container body 2 is housed in the recess 3a, an adhesive portion 4 is disposed between the lid body 3 and the container body 2 so as to seal the storage space S. ing.

  The bonding portion 4 is disposed in a region defined by the outer surface of the projection 71 of the bottom plate 6, the upper surface of the bottom plate 6, the inner surface of the sealing material 73, and the lower surface of the lid 3, as described above. It is formed using an adhesive having an elongation ability.

Thus the zeolite panel 5 is formed on the inner surface of the bottom plate 6 and the side plate 7. More specifically, the radioactive substance adsorbing layer is disposed in recesses 6 a and 7 a provided on the inner surfaces of the bottom plate 6 and the side plate 7. Moreover, it said zeolite panel 5, a resin or metal grid frame such FRP, are formed by filling the granular zeolite. That is, the zeolite panel 5 is formed in a porous shape in which the surface of the granular zeolite is exposed to the outside in order to increase the specific surface area and enhance the adsorption effect. The lattice frame forms the outer surface of the zeolite panel 5 and functions as a frame material for maintaining a state in which the zeolite is filled therein.

  This precast concrete storage container 1 is used in the following manner. That is, in a state in which the bag body W which is a storage object in which radioactive contaminants, in other words, waste such as soil containing radioactive substances is stored, is disposed in the storage space S, the recess 3a on the lower surface of the lid 3 The protrusion 71 of the container body 2 is housed therein, and the container body 2 and the lid body 3 are bonded via the bonding portion 4, and then the fixing bolt B is inserted from the lid body 3 side to insert the nut of the container body 2. The fixing bolt B is screwed to 72 and the lid 3 and the container body 2 are fastened.

That is, according to the configuration shown in FIGS. 1 to 4, when a radioactive substance such as cesium leaks from the inside of the bag body W, the radioactive substance comes into contact with the zeolite panel 5 disposed on the inner surface of the container body 2. . At that time, the radioactive substance is ion-exchanged with the zeolite inside the zeolite panel 5 and adsorbed in the zeolite. And even if the container body 2 is damaged due to aging or the like, the radioactive material is in the state adsorbed in the zeolite panel 5, so the leakage of the radioactive material to the outside of the container is compared with the conventional concrete container. It is prevented or suppressed more reliably.

  Further, the container body 2 includes a bottom plate 6 and a side plate 7 rising from the outer peripheral portion of the bottom plate 6, and the zeolite panel 5 is provided on the inner surface side of the bottom plate 6 and the side plate 7. This kind of concrete container provided with the container body 2 can be easily realized.

  Further, since the zeolite panel 5 is provided as a radioactive substance adsorbing layer, prior to the operation of storing the contents to be stored in the container, for example, before the storage container 1 is carried into the decontamination site, The zeolite panel 5 can be arranged on the inner surface side of the bottom plate 6 and the side plate 7, and labor can be reduced.

  And since it has the adhesion part 4 formed using the adhesive agent which has an elongation capability between the upper surface of the said container main body 2, and the lower surface of the said cover body 3, it is a cover in the state which the fixing bolt B corroded Even when the body 3 is subjected to an action that moves relative to the container body 2, the adhesive layer is stretched, the lid 3 is in close contact with the container body 2, and the storage space S is kept sealed. Therefore, the leakage of the radioactive substance stored in the storage container 1 can be prevented or suppressed more reliably.

In addition, the structure of the panel 5 is not restricted to the form described above.

For example, in the above-described form , the radioactive substance adsorbing layer is a panel containing zeolite, but this panel may be formed as follows. That is, a zeolite panel formed by mixing granular zeolite, fiber and cement paste into a plate shape may be used. In this case, the fiber and the cement paste have a function as a bonding member for bonding the zeolites in the claims. Further, a zeolite panel may be formed by mixing granular zeolite and cement paste to form a plate, and further applying a sol-like substance obtained by mixing powdered zeolite and water. In this case, the cement paste has a function as a binding member for binding the zeolites in the claims.

  Even in such a case, when radioactive material such as cesium leaks from the inside of the bag, which is a containment containing radioactive material, this radioactive material comes into contact with the zeolite panel arranged on the inner surface of the container body, At this time, the radioactive substance is ion-exchanged with the zeolite inside the zeolite panel and is adsorbed in the zeolite. Therefore, leakage of radioactive material to the outside of the container is more reliably prevented or suppressed as compared with a conventional concrete container.

In addition, in the above-described embodiment , the panel that is the radioactive substance adsorbing layer is formed in a porous shape so as to increase the specific surface area and enhance the adsorption effect, but a panel that is not porous may be employed.

  Such a panel containing zeolite can also be provided on the inner surface of a pipe rod formed of an existing or new concrete structure. That is, as shown in FIG. 6, in a pipe formed by laying a plurality of box culverts X1 which are concrete structures, a panel containing such zeolite on the inner surface of the bottom plate X6 and the side plate X7 of the box culvert X1. X5 can also be arranged. When the panel X5 containing zeolite is arranged on the inner surface of the tube tub formed by laying a plurality of box culverts X1 in this way, radioactive substances mixed in the water flowing in the tube jar are ion-exchanged with the zeolite in the panel X5. A radioactive substance can be adsorbed on the zeolite in the panel X5. Therefore, such a panel X5 is provided on the inner surface of a concrete structure constituting a pipe for draining water from a temporary storage facility or final treatment facility for radioactive pollutants, or a pipe for forming a water channel near the decontamination site. It is possible to prevent or suppress the diffusion of radioactive substances mixed in the wastewater from the temporary storage facility, the final treatment facility or the decontamination site. In addition, although the culvert formed by burying the box culvert X1 in the basement is shown in FIG. 6, the concrete structure that constitutes the culvert formed by laying a plurality of concrete structures opened upward is shown. Of course, such a panel X5 may be arranged on the inner surface. In addition to the box culvert, such a panel may be arranged on the inner surface of another concrete structure capable of forming a pipe rod such as a fume pipe.

Furthermore, you may comprise the said radioactive substance adsorption layer with the liquid substance which has the fluidity | liquidity containing the zeolite filled between the to-be-contained object and the said container main body. That is, you may comprise as follows using the storage container A1 shown in FIG. In other words, a powdery zeolite and water are kneaded to create a liquid material having fluidity, and this liquid material is stored in the storage space S in which the bag body W that is a containment containing the radioactive material is stored in the storage space S. Alternatively, the radioactive substance adsorbing layer A5 may be formed by filling between the article to be stored W and the container main body A2. Here, the storage container A1 has substantially the same configuration as the storage container 1 in the above-described embodiment. That is, the storage container A1 extends between a container body A2 having a storage space S therein, a lid A3 that closes the storage space S, and an upper surface of the container body A2 and a lower surface of the lid A3. And an adhesive portion (not shown) formed using an adhesive having a capability. Further, the container main body A2 includes a bottom plate A6 and a side plate A7 that stands up from the outer periphery of the bottom plate A6. A space defined by the bottom plate A6 and the side plate A7 is the storage space S. According to this embodiment, even if the radioactive substance leaks to the outside of the bag body, the radioactive substance contacts the radioactive substance adsorption layer before reaching the container body, and the zeolite and the radioactive substance in the radioactive substance adsorption layer are ionized. Since the exchange is performed, the radioactive substance is adsorbed on the radioactive substance adsorption layer. Therefore, even with such a configuration, leakage of the radioactive substance to the outside can be prevented or suppressed.

  And in embodiment mentioned above, although the container main body has comprised the rectangular parallelepiped shape or the cube shape, you may set the shape of a container main body arbitrarily, such as cylindrical shape, hexagonal column shape, spherical shape, hemispherical shape, etc. .

  In addition, various changes may be made without departing from the spirit of the present invention.

A1 ... containment vessel
A2 ... Container body
A3 ... Lid
A5 ... Radioactive material adsorption layer S ... Storage space

Claims (3)

A precast concrete storage container provided with a container body having a storage space inside and a lid for closing the storage space, the ion exchange with a radioactive substance facing the storage space and disposed in the storage space Equipped with a radioactive material adsorption layer containing possible zeolite,
A precast concrete storage container in which the radioactive substance adsorbing layer is formed of a fluid material having fluidity including zeolite filled between the object to be stored and the container body . 2. The precast concrete storage container according to claim 1, wherein the container body includes a bottom plate and a side plate rising from an outer peripheral portion of the bottom plate, and the radioactive substance adsorbing layer is provided on an inner surface side of the bottom plate and the side plate. The precast concrete storage container according to claim 1 or 2, further comprising an adhesive portion formed by using an adhesive having an extension ability between the upper surface of the container body and the lower surface of the lid.

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