JP2006138717A - Radioactive waste container - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a radioactive waste container capable of utilizing thermal energy emitted from radioactive waste emitting heat, such as glass-solidified matter by efficiently converting the thermal energy into electrical energy. <P>SOLUTION: The radioactive waste container 10 comprises a container body 11 for accommodating the radioactive waste emitting heat, a coated heat-insulation section 12 formed and coated on the exterior side of the container body to block dispersion through the exterior surface of the container body of the heat emitted from the radioactive waste and a thermoelectric element 13, penetrating the heat insulation section from the front face to the rear face and generating electricity due to the difference in the temperature at between one end positioned at the container body side and the other end exposed to the outside. The heat, emitted from the radioactive waste, is confined to be within the interior by the heat insulation effect of the coated heat insulation section to increase the temperature difference between the exterior surface of the container body and the exterior surface of the coated heat-insulating section. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radioactive waste storage container for storing and storing or disposing of radioactive waste that generates heat, and more particularly, a radioactive waste storage container having a function of converting thermal energy generated from the radioactive waste into electrical energy. About.

  Some of the radioactive waste generated during the operation of the nuclear reactor or the reprocessing of spent fuel emits radiation and generates heat. In particular, a vitrified body obtained by solidifying a high-level radioactive waste liquid generated by reprocessing spent fuel with borosilicate glass radiates heat of about 1 to 3 kW per bottle. The amount of such heat generation gradually decreases with time as the radioactive material in the vitrified body collapses and the energy decreases, but some of the radioactive materials have a considerably long life. Since it is contained, heat generation continues for a considerably long period of time.

For this reason, in the current geological disposal plan, the vitrified material is stored while being cooled for several decades after its production, and after the calorific value has sufficiently decreased, the thickness of the carbon steel, generally called an overpack, is generally reduced. It is supposed to be hermetically sealed in a meat cylindrical container and buried in the disposal hole (geological disposal) in the disposal hole drilled deep underground several hundred meters deep.
On the other hand, effective use of thermal energy generated by heat generation of the vitrified body during the above-mentioned decades of storage period has also been studied. For example, a thermoelectric element is placed in the vicinity of the vitrified glass being stored in the storage to vitrify the glass. It has been proposed to generate power using the temperature difference between the body surface temperature and the surroundings (normal temperature) (see, for example, Patent Document 1).
Japanese Patent Laid-Open No. 5-150099

  By the way, even after the geological disposal, the vitrified body still generates heat while its calorific value is considerably reduced. For this reason, there is a concern that when the temperature around the disposal hole rises due to the effect of heat generation after disposal, the corrosion of the overpack is accelerated due to the high temperature, and the through hole becomes empty. Then, groundwater enters into the overpack from this through hole, and the vitrified material inside the overpack dissolves little by little in the groundwater together with the radioactive material contained in the vitrified material, and the radioactive material leaks to the outside. The possibility of doing it cannot be denied.

  Further, since the heat generated from the vitrified body or the like is energy that can be used effectively, it is needless to say that it is desirable to take it out and use it after disposal. However, it has been considered in conventional research that it is difficult to remove and effectively use such heat, especially after disposal. The reason for this is that the vitrified waste is buried in the deep underground several hundred meters or more, and the tunnels used for the buried disposal are backfilled after disposal and cannot be directly accessed by people. This is because cooling by means of this is unrealistic.

  In addition, as in the invention described in Patent Document 1, a method of arranging a thermoelectric element around a vitrified body and converting the heat energy to electric energy to remove the heat is also effective for the disposed vitrified body. I can't say that. This is because, for the following three reasons, the amount of electricity generated per thermoelectric element is extremely small, and the use of the electric energy becomes impractical. First, at the time of disposal, the calorific value of the vitrified body itself is considerably reduced. Second, the thermoelectric element cannot be brought into direct contact with the vitrified body, and the amount of heat per unit surface area on the thermoelectric element contact surface is considerably reduced. As described above, during disposal, the vitrified body is hermetically stored in a thick cylindrical container called an overpack, and the entire overpack is buried and disposed. Therefore, the thermoelectric element is not brought into direct contact with the vitrified body. The plan would be to contact the outer surface of the overpack having a thickness of about 20 cm. Since the outer surface area of the overpack is naturally larger than that of the vitrified body (about 45 cm in diameter), the thermal energy per unit surface area (that is, the unit area that the thermoelectric element contacts) dissipated from the outer surface of the overpack is reduced. It will decrease. Third, as described above, the temperature of the entire disposal site increases due to the heat generation of the vitrified body (about 80 ° C. in the current plan), and the temperature difference from the outer surface of the overpack (100 ° C. or less in the current plan) This is because the conversion efficiency of the thermoelectric element from heat energy to electric energy is extremely reduced.

  In view of the above circumstances, in the present invention, there is provided a radioactive waste storage container that can efficiently convert thermal energy generated from radioactive waste that generates heat, such as vitrified glass, into electrical energy. For the purpose.

  In order to achieve the above object, according to a first aspect of the present invention, there is provided a container main body for storing the radioactive waste that generates heat, and the container for the heat generated from the radioactive waste provided to cover the outside of the container main body. A temperature difference between a coated heat insulating part that blocks diffusion from the outer surface of the main body, one end positioned on the container main body side and the other end exposed to the outside, disposed through the front and back of the coated heat insulating part The heat generated from the radioactive waste is confined inside by the heat insulating effect of the covering heat insulating part, and the temperature difference between the outer surface of the container body and the outer surface of the covering heat insulating part is increased. A radioactive waste container is provided.

The radioactive waste that generates heat may be a glass solid (Claim 2), and the container body may be an overpack made of carbon steel (Claim 3).
The material of the covering heat insulating portion may be zirconia ceramics (Claim 4).

  In invention of Claim 1, the container main body which stores the radioactive waste which heat | fever-generates, such as a glass solidified body, is covered with the coating heat insulation part which interrupts | blocks heat, and the front and back of a coating heat insulation part are penetrated in a part of this coating heat insulation part. A thermoelectric element was fitted, and one end of the thermoelectric element was in contact with the outer surface of the container body, and the other end was exposed to the outside. The effect of this configuration is that a sufficient amount of heat can be efficiently obtained with a small number of thermoelectric elements even if the calorific value of radioactive waste such as vitrified substances is not in direct contact with the vitrified substances etc. where the thermoelectric elements generate heat. It is. That is, heat dissipation from the outer surface of the container main body is blocked by the heat insulating effect of the covering heat insulating portion, and heat generated from radioactive waste such as a glass solidified body is confined and accumulated in the storage container. The temperature rises and the temperature difference with the outside increases. In addition, since most of the heat dissipated from the storage container is concentrated only on the contact surface of the thermoelectric element without the heat insulating material, the amount of heat per unit area increases. Due to these two effects, the energy efficiency of the thermoelectric element can be increased, and sufficient power can be obtained efficiently with a small number of thermoelectric elements.

  If the radioactive waste is a vitrified material, the calorific value is relatively large compared to other radioactive wastes, so that the thermal energy can be more effectively used (Claim 2). By making the carbon steel overpack assumed in the current disposal plan, it can be an appropriate disposal container in the current vitrified disposal plan and have a certain amount of radiation shielding effect. (Claim 3).

  Moreover, by using zirconia ceramics as the material for the coated heat insulating portion, it is possible to obtain a coated heat insulating portion that is stable for a long period of time, has excellent water resistance, and has a high heat insulating effect.

Embodiments of the present invention will be described with reference to the drawings.
The storage container 10 which is the 1st Example of this invention shown in FIG. 1 is a disposal container for storing the vitrified body (radioactive waste) G and carrying out geological disposal. The shape of the vitrified body is about 45 cm in diameter and about 1.5 m in height. The storage container 10 includes an overpack (container body) 11 made of carbon steel for storing the vitrified body G, and a heat insulating portion that covers the periphery of the overpack (container body) 11 and blocks the heat generated from the vitrified body to prevent the diffusion to the outside (Covered heat insulating part) 12 and a thermoelectric element 13 or the like that is fitted into a hole 12e formed in the heat insulating part 12 and converts heat energy into electric energy.

The overpack 11 includes an overpack body 11a that is a bottomed thick cylindrical body and a thick disk-shaped lid portion 11b that closes an open end 11d at the top of the overpack body 11a. The shape and size of the space portion 11c inside the overpack body 11a is set to such a size that only the vitrified body G can be accommodated.
The material of the overpack 11 is not particularly limited, but carbon steel that is relatively excellent in corrosion resistance in a geological disposal environment and does not cause pitting corrosion due to uniform corrosion can be suitably used. Further, the thickness of the overpack 11 is not particularly limited, but when the material is carbon steel, the thickness required for geological disposal, specifically, the pressure resistance that can withstand the pressure from the surrounding rock mass, As the thickness set by the gamma ray shielding performance for preventing radiolysis of the surrounding groundwater and the like, it is considered that all of the lid, side surface, and bottom portion should be about 20 cm.

The heat insulating portion 12 includes a bottomed cylindrical heat insulating portion main body 12a and a thick disk-shaped lid portion 12b that closes the open end 12d on the upper portion of the heat insulating portion main body 12a. The shape and size of the space portion 12c inside the heat insulating portion main body 12a is set to such a size that only one overpack 11 can be accommodated.
The heat insulating portion 12 has a function of blocking heat dissipated from the outer surface of the overpack 11 and confining it inside. For example, a plurality of holes 12e penetrating from the front side to the back side are formed in the heat insulating part 12, and a thermoelectric element 13 described later has one end surface (high temperature surface) 13a outside the overpack 11 in the hole part 12e. It is fitted so that it contacts the surface and the other end surface is exposed to the outside to form a heat radiating surface 13b. In addition, on the upper surface of the heat insulating portion 12, a lid portion 12b that closes the open end 12d of the upper portion of the heat insulating portion 12 after the overpack 11 is stored is installed between the heat insulating portion main body 12a and the lid portion 12b. It has a structure that can be fixed by fitting without generating a gap.

  The material of the heat insulating part 12 is not particularly limited as long as it is a material excellent in heat insulation, heat resistance, strength, long-term stability and water resistance. For example, urethane is used as an organic material, and tetragonal crystal is used as an inorganic material. And zirconia ceramics composed of monoclinic crystals can be suitably used. Moreover, about the thickness, the emitted-heat amount from a vitrified body, the outer surface temperature of the heat insulation part 12 (it restrict | limits to 100 degrees C or less from a viewpoint of protection of the bentonite layers B and C mentioned later), and the thermal conductivity of the heat insulation part 12 In consideration of the above, the balance between the two is taken into consideration so that the heat insulating portion 12 becomes too thick and the diameter and height of the entire storage container 10 become too large, resulting in an increase in the drilling amount of the disposal hole. To set.

  Since the thermoelectric element 13 is a well-known one, a detailed description thereof is omitted. However, one end (high temperature surface) 13a of the thermoelectric element 13 is in contact with the high temperature side heat source and the other end forms a heat radiation surface 13b. The thermal energy and the electrical energy are directly converted using the thermoelectromotive force due to the temperature difference between the high temperature surface 13a and the heat radiating surface 13b. As a result, simple power generation without moving parts, that is, power generation with a small size and a long life can be achieved. At this time, the heat radiating surface 13b is formed on the same surface as the outer surface of the heat insulating portion 12, and the storage container 10 is installed in the disposal hole H, which will be described later, together with the bentonite layers B and C, The bentonite layers B and C are brought into contact with each other.

  Regarding the number and arrangement of the thermoelectric elements 13, the temperature distribution inside the storage container 10 due to heat generation from the vitrified body is taken into consideration, and the calorific value of the vitrified body as a whole of the storage container 10 is as efficient as possible to electric energy. It is set so that the number of thermoelectric elements can be reduced as much as possible. 1 and 2, the electrical output terminal of the thermoelectric element 13 is not shown, but the high temperature surface 13a and the heat radiating surface 13b also function as positive (+) and negative (-) electrical output terminals, respectively. Alternatively, each may be pulled out by an electric wire.

  The method for storing the vitrified body in the storage container 10 is performed as follows. First, in a cell (not shown) having a shielding function, the vitrified body G is stored in the space portion 11c in the overpack body 11a by remote control. Thereafter, a lid portion 11b is installed at the open end 11d of the overpack body 11, and the lid portion 11b is remotely welded to the overpack body 11a to seal the space portion 11c. Next, the overpack 11 is accommodated in the space 12c of the heat insulating body 12a by remote control, and the lid 12b is fixed to the open end 12d of the heat insulating body 12a by fitting.

Next, a disposal method of the storage container 10 will be described with reference to FIG.
FIG. 2 shows a state in which the disposal container 10 containing the glass solid G is buried in the underground disposal hole H. A bottomed cylindrical disposal hole H is drilled in the bedrock at a depth of several hundred meters or more underground, and a kind of clay-bottomed cylindrical bottomed container called bentonite (hereinafter “bentonite container B”) Is provided). The bentonite container B functions to delay the time when the groundwater enters from the surrounding rock and the corrosion of the overpack 11 of the storage container 10 starts.

A space S for accommodating the storage container 10 in close contact is formed at the center of the bentonite container B. The storage container 10 is stored in the space S, and a bentonite lid C is provided above the storage container 10. Further, the tunnel (not shown) leading to the disposal hole H is backfilled with rock, soil, sand, etc. of the same material as the bentonite or the bedrock, and the disposal is completed.
Next, the operation of the storage container 10 will be described.

  The heat generated from the vitrified body G is not dissipated from the storage container 10 to the outside due to the heat insulating effect of the heat insulating portion 12, but is accumulated in the vitrified body G and the overpack 11. For this reason, the temperature inside the overpack 11 rises, and the temperature difference between the outer surface of the overpack 11 and the outside where the heat of the vitrified body G is not transmitted becomes large. Further, since almost all the heat dissipated from the storage container 10 is concentrated on the high temperature surface 13a of the thermoelectric element 13, the amount of heat per unit area, that is, the thermal energy density is increased. For this reason, the temperature difference between the high temperature surface 13a and the heat radiating surface 13b of the thermoelectric element 13 is large, and the thermal energy density concentrated on the thermoelectric element 13 is also large. The amount of power generation per element 13 and the conversion efficiency can be improved.

  Further, after the geological disposal, most of the heat energy generated from the vitrified body G is efficiently converted into electric energy by the above action of the storage container 10 and bentonite container B or lid C outside the storage container 10 (hereinafter, both are combined). To “bentonite layers B and C”). That is, the heat generated by the vitrified body is electrically converted, so that the temperature of the surrounding bentonite layer and the outer rock is not increased while the vitrified body is appropriately removed. For this reason, the bentonite layer and the bedrock are not exposed to high temperatures and their properties and functions are not altered.

  As described above, there are various methods for using the electric energy generated by converting from the heat energy. For example, as shown in FIG. 3, one end 13c of the output terminal of the thermoelectric element 13 is brought into contact with the overpack 11. The other output terminal 13d may be brought into contact with the bentonite layers B and C to create a potential difference between the overpack 11 and the bentonite layers B and C. The electrical output terminals 13c and 13d in FIG. 3 are made to coincide with the high temperature surface 13a and the heat radiating surface 13b of the thermoelectric element 13, respectively, and the both ends are in contact with the overpack 11 and the bentonite layers B and C to generate heat. In addition to sending and receiving, it is also designed to send and receive electrical energy. The electromotive force generated by the temperature difference is adjusted by adjusting the number and arrangement of the thermoelectric elements, and the potential difference is adjusted to be in an appropriate range. Then, the outer surface of the overpack 11 remains in a metallic state, or an oxide film (passive state) is formed to become a stable state, and a state in which corrosion does not proceed in any state can be formed. If the outer surface of the overpack 11 is passive from the beginning, it is sufficient to keep the electric potential at which the overpack 11 does not melt.

  This will be described in more detail below. In the underground environment under the geological disposal conditions, the pH value is 7 to 8, and the overpack 11 side potential is about 0 to -0.5 V with respect to the bentonite layers B and C. As shown in FIG. 4 ("Introduction to Environmental Materials Science" (Edited by the Corrosion and Corrosion Protection Association), page 19), the condition of carbon steel is in the corrosive region under the conditions where pH is 7 and potential difference Eh is 0 (near P). Corrosion will proceed at a slow rate. When the overpack 11 side potential is lowered, for example, by about 0.15 V to 0.2 V, and the state is shifted so that the potential becomes −0.65 V to −0.7 V, a metal region indicated by Q in FIG. Although the state shifts to (metal state region), since carbon steel exists stably in the metal state in that state, corrosion does not proceed. On the other hand, for example, when the voltage is increased by about 0.5 V to 1.5 V, the state shifts to a region indicated by R in FIG. 4, and in this state, the carbon steel forms an oxide film on the surface and further corrosion does not proceed (unless Working).

  As described above, when a through-hole is generated in the overpack 11 due to corrosion, the groundwater penetrates into the overpack and comes into contact with the vitrified body, so that the radioactive substance contained in the vitrified body is gradually dissolved and discharged. Risk of leakage. Therefore, it is important to prevent the overpack 11 from being corroded. Usually, however, the corrosion is set by considering the corrosion rate and the service life. However, it goes without saying that it is more preferable if the corrosion of the overpack 11 can be prevented by the electrochemical means as described above. Although it is difficult to supply electric power for such an electrochemical reaction from the outside to the overpack 11 disposed in the formation several hundred meters below ground, depending on the storage container 10, the power is generated by the storage container itself. Since it can supply, corrosion prevention by such an electrochemical reaction is attained.

Although the description of the storage container 10 according to the first embodiment is finished as described above, it is needless to say that there are various other modes in this embodiment. The example of another aspect concerning this is shown below.
In the first embodiment, the overpack 11 is made of carbon steel. However, the material is not limited as long as it is a material that does not easily corrode in a geological disposal environment. For example, carbon steel coated with titanium or copper Etc. can also be used suitably.

In the first embodiment, a plurality of thermoelectric elements are used, but one thermoelectric element may be used if the heat energy generated from the vitrified body can be appropriately converted into electric energy.
In the first embodiment, the generated electricity is used for the electrochemical anticorrosion reaction to prevent corrosion of the overpack. For example, as shown in FIG. May be connected to a heat dissipating element 14 such as nichrome to return the electric energy back to heat energy and dissipate heat. It is possible to prevent the temperature near the disposal hole H from rising and the corrosion reaction of the overpack 11 from being promoted.

In the first embodiment, the vitrified body is stored in the storage container and disposed of in the geological formation. However, for example, the spent fuel can be stored in the storage container and disposed directly.
By the way, although the above-mentioned 1st Example is an Example at the time of using the container for storage of this invention as a geological disposal container, the storage container of this invention is several dozens before performing geological disposal of a glass solidification body. It can also be used as a storage container for years of storage.

  When storing a vitrified body in a conventional storage container, the vitrified body is usually cooled by air-cooling the outside of the storage container. In such a case, for example, in a natural air cooling system, sufficient cooling cannot be performed unless a large number of cooling fins are installed on the surface of the storage container. Alternatively, in the case of forced air cooling or water cooling, equipment such as a blower and a cooling water circulation pump and extra energy for operating the equipment are required, leading to an increase in storage cost. In addition, the heat generated from the radioactive waste is wasted in the atmosphere.

When the storage container of the present invention is used as a storage container, most of the heat generated from the vitrified body can be converted into electric energy and taken out, so that the cooling fins, blowers, cooling water circulation pumps, etc. Therefore, it is possible to obtain an excellent effect that the equipment for the operation is not required, and the extra energy for operating them is also unnecessary.
Hereinafter, an embodiment in which the present invention is applied to a vitrified storage container will be described as a second embodiment with reference to FIG.

  The basic configuration of the storage container 20 according to the second embodiment is substantially the same as that of the first embodiment, but (1) installed on the ground, and (2) stores a plurality of glass solidified bodies in the container body. (However, if the validity can be confirmed by cost evaluation, it may be integrated.) (3) The container body is composed of a metal with a bottom having a thin cylindrical shape and a thin disc-shaped lid. (4) The coating heat insulating portion is different from the first embodiment in that it is thick concrete that also serves as a shield. These storage containers are used for storage and not disposal, and in order to reduce costs, as many glass solids as possible are stored in one storage container 20, and the constituent materials of the storage container 20 are inexpensive. It is a difference that arises for the purpose of making it.

  The storage container 20 includes, for example, canisters (container main bodies) 21 that store the vitrified bodies G in three stages and 21 in seven stages, and a canister storage section that covers the entire surface of the canister 21 and blocks heat dissipated from the canister 21. One end (high temperature surface) 23a contacts the canister 21 in the (cover insulation part) 22 and a plurality of through holes 22c drilled in the canister storage part 22, and the other end (heat radiating surface) 23b passes through the through hole 22c to the outside. It includes a thermoelectric element 23 and the like inserted so that heat can be dissipated.

  The canister 21 includes a canister body 21a, which is a bottomed thin cylindrical metal container, and a lid portion 21b that closes an open end 21d at the top of the body 21a. Inside, there are three shelves (not shown) and a fixed frame of the glass solid G, and seven glass solids G can be stored in three stages, and 21 can be stored in three stages. In addition, the glass solid body G is horizontally arrange | positioned as follows. That is, an integrated vitrified body is placed on the central axis of the canister 21 main body 21a, and a total of six bodies, ie, a total of one per stage, are located at each vertex of the hexagon that coincides with the central axis. Seven vitrified bodies are placed. In addition, in FIG. 6, since there exists the glass solidified body G which mutually overlaps, some glass solidified bodies G are not described.

The lid 21b is welded or bolted to the open end 21d at the top of the canister, and has a structure that can seal the canister main body 21a containing the glass solidified body G.
The material of the canister 21 is not particularly limited, but is required to be a material having excellent thermal conductivity, cost, strength, and resistance to a load applied under a high temperature for a long time, that is, a material excellent in creep characteristics. Austenitic stainless steel such as can be suitably used.

  The canister storage unit 22 corresponds to the heat insulating unit 12 described in the first embodiment, has a bottomed cylindrical shape, and has a canister storage unit main body 22a for storing the canister 21 and canister storage after the canister 21 is stored. A lid portion 22b that closes the open end 22d of the upper portion main body 22a is provided. The canister housing portion 22 includes a plurality of through holes 22 c that penetrate the canister housing portion 22 from the front to the back in order to fit the thermoelectric element 23.

The thickness of the canister housing 22 is determined in consideration of its heat insulating performance, the total amount of heat generated from the 21 vitrified bodies G, the allowable temperature of the outer surface of the canister housing 22 and the required radiation shielding performance. To do. The material is not particularly limited, but concrete can be preferably used in consideration of heat insulation, workability, shielding performance, cost, and the like.
As in the first embodiment, a thermoelectric element 23 that converts thermal energy into electrical energy using a temperature difference between the outer surface of the canister 21 and the outside of the canister housing 22 is fitted into the through hole 22c. The high-temperature surface 23a of the thermoelectric element 23 is in contact with the outer surface of the canister 21, and heat is dissipated to the outside from the heat radiation surface 23b at the other end through the through hole 22c. The thermoelectric elements 23, their number and arrangement, electrical output terminals (not shown), and the like are the same as those in the first embodiment, and thus description thereof is omitted.

The usage method of this storage container 20 is demonstrated below.
That is, in the remote cell having a shielding function, the glass solid body G21 is stored and fixed inside the canister body 21a of the storage container 20, and then the lid portion 21b is fixed by welding or bolting. Then, the canister 21 is housed in the canister housing main body 22a. At this time, the high temperature surface 23 a of the thermoelectric element 23 contacts the canister 21. Further, the open end 22d of the canister housing main body 22a is closed by the lid portion 22b. Thereafter, the storage container 20 is carried out to a storage area (not shown) and fixed for storage. At this time, an electrical output terminal (not shown) of each thermoelectric element 23 is connected to a battery (not shown) in the storage area to store one end of electricity generated by the thermoelectric element 23, for radiation measurement equipment, lighting, facility operation / management Used as a power source for computers and the like.

  The operation of the storage container 20 is to accumulate heat generated from the vitrified body G by the heat insulating effect of the canister storage unit 22, increase the outer surface temperature of the canister 21, and increase the temperature difference from the outside. It is the same as in the first embodiment in improving the power generation efficiency of the plurality of thermoelectric elements 23 that are in contact with the outer surface of 21 and efficiently converting the heat of the vitrified body into electrical energy. As a result of the efficient conversion of thermal energy into electrical energy, it is possible to eliminate the need for complicatedly shaped cooling fins for improving the cooling function, which is necessary for ordinary natural air-cooled storage containers. Further, there is no need for equipment for forcibly circulating air or cooling water required for the forced air cooling method or the water cooling method, or extra energy for operating it.

In this embodiment, the object to be stored is a vitrified body, but the spent fuel can be stored in the storage container.
In addition, embodiment described here is an example, Comprising: This invention is not limited only to this, It cannot be overemphasized that a change can be added in the range of the summary of this invention.

It is a schematic sectional drawing which shows the structure of the storage container used for the geological disposal of the vitrified body which is the 1st Example of this invention. It is explanatory drawing which shows the state which carried out the geological disposal of the storage container of FIG. It is explanatory drawing which shows the outline of the system for preventing the corrosion of an overpack using the electricity which generate | occur | produces with the storage container of FIG. 1 for an electrochemical reaction. It is a pH-Eh diagram of iron showing that corrosion can be prevented by an electrochemical reaction. FIG. 2 is a schematic explanatory diagram of a heat removal system in which electricity generated by the storage container of FIG. 1 is returned to heat at a place away from the temperature so that the temperature in the vicinity of the disposal hole storing the storage container does not rise. It is a schematic sectional drawing which shows the structure of the storage container used for storage of the vitrified body which is the 2nd Example of this invention.

Explanation of symbols

10,20 Storage container 11 Overpack (container body)
12 Heat insulation part (Coating heat insulation part)
13,23 Thermoelectric element 13a, 23a High temperature surface 13b, 23b Heat radiation surface 21 Canister (container body)
22 Canister storage (coating insulation)

Claims (4)

A container body for storing radioactive waste that generates heat;
A covering heat insulating portion provided to cover the outside of the container main body and blocking the dissipation of heat generated from the radioactive waste from the outer surface of the container main body;
A thermoelectric element that is disposed through the front and back of the covering heat insulating part, and that generates electricity by a temperature difference between one end positioned on the container body side and the other end exposed to the outside;
The heat generated from the radioactive waste is confined inside by the heat insulating effect of the covering heat insulating portion, and the temperature difference between the outer surface of the container main body and the outer surface of the covering heat insulating portion is increased. Storage container.   The radioactive waste storage container according to claim 1, wherein the radioactive waste that generates heat is a glass solid.   The radioactive waste storage container according to claim 1, wherein the container main body is an overpack made of carbon steel.   The radioactive waste storage container according to claim 1, wherein a material of the covering heat insulating portion is zirconia ceramics.

Images