JP2002082194A - Building shielding unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a building shielding unit, capable of shielding a building of a facility from the side to the upper surfaces by remote control, in the case of accident generation in a nuclear material treatment facilities, such as a fast breeder reactor and preventing discharge of radioactive materials, radiation, etc., from the nuclear material treatment facility. SOLUTION: The building shielder surrounds the side of the nuclear material treatment facility with water, to change fast neutron discharge from the nuclear material treatment facility into thermal neutron and forms a pyrolant layer on a pylorant holding member placed to cover the nuclear material treatment facility. By making it react, it is changed into a strong reaction product capable of forming a block to be a protective member.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a building shut-off device, and more particularly, to an accident or the like occurring in a nuclear material-using facility such as a fast breeder reactor. When released outside the building,
The present invention relates to a building shut-off device for preventing the radioactive material, radiation, and the like from being diffused to an external environment.

[0002]

2. Description of the Related Art In a nuclear power plant equipped with a fast breeder reactor or a light water reactor, safety measures are taken to prevent accidents from occurring, and even if an accident occurs, the damage is prevented from spreading. It is necessary to take measures. First of all, to prevent the spread of damage, radioactive materials in nuclear power plant facilities must be absolutely prevented from being released to the external environment.

In a nuclear power plant, four barriers are provided between a nuclear fuel containing a radioactive substance and the external environment so that the radioactive substance is not released to the external environment. That is, the first barrier is a fuel pellet, the second barrier is a cladding tube, the third barrier is a reactor pressure vessel, and the fourth barrier is a reactor containment vessel.

That is, in a nuclear power plant, most of the radioactive material in nuclear fuel is held in fuel pellets, and hardly leaks out of the fuel pellets. Since the fuel pellets are contained in the leak cladding tube, the radioactive material leaking from the fuel pellets is retained in the cladding tube and is not released outside the cladding tube, and even when the fuel pellet ruptures. The debris is retained in the cladding and is not released outside the cladding. In addition, since the cladding tube is housed in the reactor pressure vessel, pinholes or cracks may occur in the cladding tube, or the cladding tube may be damaged, and radioactive materials contained in nuclear fuel in the cladding tube may be damaged. Leakage outside the cladding tube will not be released outside the reactor pressure vessel. Furthermore, since the reactor pressure vessel is housed in the reactor containment vessel, even if an accident that destroys the reactor pressure vessel occurs, the radioactive material in the reactor pressure vessel can be kept in the reactor containment vessel. Will not be released to the outside.

[0005] It is generally believed that these four barriers can prevent radioactive material in the reactor from being released to the external environment.

However, since the nuclear power generated in a nuclear reactor is very powerful, it is not sufficient that the containment vessel is destroyed depending on the type and situation of the abnormal situation in the nuclear reactor. Can be considered. When an accident occurs such that the containment vessel is destroyed, radioactive materials are released to the external environment, and the external environment is radioactively contaminated, causing a catastrophic disaster. In the case of Chernobyl, the misery is clear. Such a situation must be prevented at all.

[0007] In the event of an accident or the like in which the containment vessel is destroyed, the building of the nuclear power plant must be isolated from the external environment to prevent the release of radioactive materials and the like to the external environment. Must.

However, in order to shield the building of the nuclear power plant with concrete or the like after the occurrence of such an accident, the worker approaches the accident site in a situation where radioactivity and radiation are being emitted. It is difficult and time consuming, during which time radioactive materials are scattered and the spread of damage cannot be prevented. In addition, there is a high risk that workers who perform the work will be exposed.

Therefore, it is desirable to equip the nuclear power plant with equipment capable of immediately shielding the building of the nuclear power plant by remote control when an accident occurs. Even if an accident that destroys the containment vessel and releases radioactive material does not actually occur, considering the misery when the accident occurred, equipment that was carefully considered It is preferable to provide In addition, by providing such equipment, it is possible to give a sense of security to nearby residents and the like, and to bring peace of life.

[0010] However, no such device or equipment currently exists.

[0011]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems, that is, when an accident occurs in a nuclear material-using facility such as a fast breeder reactor, the building of the facility is shielded by remote control, An object of the present invention is to provide a building shut-off device capable of preventing a radioactive substance, radiation, and the like from being released from the nuclear material use facility.

[0012]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a defense wall which is installed so as to surround a nuclear material use facility, and has a greater height than the nuclear material use facility; Water storage means for storing a sufficient amount of water for submerging the nuclear material use facility in an internal space surrounded by walls, and water for supplying the water stored in the water storage means to the internal space A supply means, a pyrolant holding member provided to cover the upper part of the nuclear material use facility and capable of holding a pyrolant, a pyrolant storage container storing the pyrolant, and a pyrolant in the pyrolant storage container in the internal space. And a pyrolant igniting means for igniting the pyrolant on the pyrolant holding member. In a preferred embodiment of the building shut-off device, the pyrolant includes 30 to 80% of metal particles and 5 to 40% of carbon single particles, and the metal particles include W, Or, it is Zr, and the metal particles and the carbon simple particles have a particle diameter of 1 to 100.
μm, and the pyrolant contains boron.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a building shut-off device 1, which is a specific example of a building shut-off device according to the present invention. FIG.
1 is a schematic cross-sectional view when crossing the building shut-off device 1 in a vertical direction.

The building shut-off device 1 is a fast breeder reactor building 2
, A water storage container 5 containing water 29, and a water supply unit 6 for supplying the water 29 in the water storage container 5 into an internal space 4 surrounded by the defense wall 3.
And a pyrolant storage means 7 for storing the pyrolant 28, and a pyrolant 282 in the pyrolant storage means 7
Pyrolyte supply means 8 for supplying 8 into the internal space 4
And a pyrolant holding member 9 provided so as to cover the upper part of the building 2, and pyrolant ignition means 17 mounted on the pyrolant holding member 9.

The defense wall 3 surrounds the building 2 on all sides without any gap, prevents radioactive substances and the like emitted from the building 2 in the lateral direction from being emitted to the outside environment, and furthermore, the water storage container 5. Has a function of retaining water supplied into the internal space 4 from the inside.

The planar shape of the space surrounded by the defense wall 3 is not particularly limited as long as it can surround the building 2.
Can be appropriately determined according to the shape and the like, for example, a square, a rectangle, a circle, and the like.

The area in the horizontal direction of the space surrounded by the protective wall 3 is not particularly limited as long as it can surround the building 2, but if it is too large, the internal space 4 becomes large. The amount of water to be supplied to the container becomes enormous, and the capacity of the water storage container 5 for storing the water also becomes enormous,
On the other hand, if it is too small, the distance between the building 2 and the defense wall 3 becomes short, so that the distance that the radiation emitted from the inside of the building 2 passes through the water stored in the internal space 4 becomes short, and the neutrons Problems such as insufficient deceleration and absorption occur.
Therefore, as the area, the amount of water supplied into the internal space 4 does not become enormous, and the radiation passage distance that can sufficiently reduce the neutrons and absorb the neutrons can be secured. Preferably, it is a size.

The height of the defense wall 3 is not particularly limited as long as it is larger than the height of the building 2, but the amount of water supplied into the internal space 4 does not become enormous for the same reason as the above-mentioned area. Further, it is preferable that the size is large enough to secure a radiation passage distance that can sufficiently slow down or absorb neutrons. The reason why the height of the defense wall 3 is required to be larger than the height of the building 2 is that the whole of the building 2 can be completely submerged by the water stored in the internal space 4. Further, as described later, this is because a layer of the pyrolant can be formed above the building 2.

The material of the defense wall 3 is not particularly limited as long as it can absorb the radiation emitted from inside the building 2 and can withstand the pressure of the water stored in the internal space 4. Without, for example, concrete, iron, lead,
And tungsten, etc., and in particular, concrete is preferable in terms of mechanical strength, price, and ease of implementation.In addition, iron, lead,
And concrete containing barium and the like, and concrete containing boron for absorbing neutrons are particularly preferable.

The thickness of the defense wall 3 is not particularly limited as long as it can absorb the radiation emitted from inside the building 2 and can withstand the pressure of the water stored in the internal space 4. Determined from the relationship with the material.

At the lower end of the defense wall 3, an explosive 20 and a detonator (not shown) connected thereto are provided. These are activated when the water supply means 6 described later malfunctions and the water 29 in the water storage container 5 is injected into the internal space 4, destroying a part of the defense wall 3 and being destroyed. The part has a function of discharging the injected water to the outside of the internal space 4.

The water storage container 5 is a container that is injected into the internal space 4 and stores a sufficient amount of water for submerging the building 2 when a radioactive substance release accident occurs in the building 2. . Further, in the building shut-off device 1, the water surrounds the entire building 2, thereby cooling the building 2, absorbing radioactive substances emitted from the building 2, α-rays and β-rays, and building. It has the function of decelerating the fast neutrons emitted from 2 and converting them into thermal neutrons to facilitate absorption by the defense wall 3 and the like. In FIG. 1, the water storage container 5 is held at a predetermined height by a construction material 30. In the building shutoff device 1, the water storage container 5 serves as a water storage means of the building shielding prevention device according to the present invention.

The capacity of the water storage container 5 needs to be equal to or more than the above-mentioned amount of water, and is therefore determined by the size of the internal space 4, the size of the building 2, and the like.

The number of the water storage containers 5 is not limited to one, but can be determined as needed. Therefore, when a plurality of water storage containers 5 are used, the sum of their capacities only needs to be equal to or greater than the amount of water shown above.

Although the shape of the water storage container 5 is shown in a circular cross section in FIG. 1, it is not limited to this shape and is not particularly limited as long as the object of the present invention can be achieved.

The material of the water storage container 5 is not particularly limited as long as it can withstand the pressure of the water 29 contained therein and can be destroyed by the action of the explosive 10 described later. , For example, metal.

The water storage container 5 is installed above the top of the building 2. By doing so, the water reservoir 5
The internal water 29 can be supplied into the internal space 4 by gravity without using power, and the building 2 can be submerged. Therefore, even when the power cannot be used due to an accident in the fast breeder reactor facility, the water 29 in the water storage container 5 can be supplied to the internal space 4.

[0028] The water storage means of the building shut-off device according to the present invention can supply water into the internal space.
It is not limited to a container such as the water storage container 5, and may be, for example, a reservoir or a pool.

The water supply means 6 includes a water pipe 12 for connecting the water storage container 5 and the defense wall 3, an explosive 10, an explosive 11, and a closing plate 13 provided in the water pipe 12, an explosive 10 and an explosive 11. And an initiating device (not shown) for initiating the device.

The water supply pipe 12 is a pipe that forms a flowing water channel when the water 29 in the water storage container 5 is supplied to the internal space 4. One end of the water pipe 12 is in contact with the outer wall surface of the water storage container 5, and the other end penetrates the upper end of the defense wall 3, reaches the inner wall surface of the defense wall 3, and forms an opening 14. . The position where the water pipe 12 is joined in the water storage container 5
This is near the bottom of the water storage container 5 so that all the water 29 in the inside can be supplied to the internal space 4 through the water supply pipe 12. Inside the water pipe 12, as described later, the explosive 1
0 and the explosive 11 are exploded, and the water reservoir 5 and the closing plate 1 are exploded.
Since the operation of destroying 3 is performed, the water pipe 12 is made of a material having such a strength that it is not destroyed even if such an explosion occurs, and has such a wall thickness.

A portion of the water pipe 12 adjacent to the outer wall surface of the water storage container 5 is provided with an explosive 10.
In the middle part of the water pipe 12 in the longitudinal direction, the water pipe 1
A closing plate 13 that closes the water channel in 2 is attached, and an explosive 11 is provided adjacent to the closing plate 13.

The explosive 10 is released from the water reservoir 5 by the explosion.
Has a function of breaking a portion surrounded by the peripheral edge of the water supply pipe 12 and guiding the water 29 in the water storage container 5 into the water supply pipe 12. The type of the explosive 10 is a water reservoir 5
Is not particularly limited as long as it satisfies the conditions such as being able to blast as described above, and examples thereof include dynamite, nitrite explosive, TNT, RDX, and PETN.

The closing plate 13 causes the explosive 10 to explode accidentally,
When the water storage container 5 is destroyed and the water 29 in the water storage container 5 flows down in the water supply channel 12, it has a function of preventing the water from flowing into the internal space 4. Therefore, the closing plate 13 is formed of a material having a strength capable of withstanding the pressure of the water 29 in the water storage container 5 flowing down in the water supply passage 12 and has such a thickness.

The explosive 11 destroys the obstruction plate 13 due to the explosion, penetrates the water passage in the water supply space 12, and allows the water flowing down from the water storage container 5 through the water supply pipe 12 to flow into the internal space 4. Has functions. Therefore, an accident occurs in the facility of the fast breeder reactor, and the water reservoir 5
When supplying the water 29 in the inside, the explosive 10 and the explosive 11
Are exploded at the same time to destroy the above-mentioned portion of the water storage container 5 and the closing plate 13, and the inside of the water storage container 5 and the internal space 4 are communicated. The type of the explosive 11 is the same as that of the explosive 10.

As described above, in the building shut-off device 1, the flow path of water is formed by the action of explosive, and then the water 29 in the water storage container 5 is supplied to the internal space 4 by its own weight. Therefore, a power source such as electric power is not required for the water supply, and the water supply means 6 can be started even when electric power or the like becomes unavailable due to an accident in the facility of the fast breeder reactor. Has advantages.

An explosive device (not shown) is connected to each of the explosives 10 and 11. When an accident occurs in the facility of the fast breeder reactor and the water 29 in the water storage container 5 is supplied to the internal space 4, the detonator is operated to explode the explosive 10 and the explosive 11. The method for initiating the explosion is not particularly limited as long as the explosive 10 and the explosive 11 can be exploded, and examples thereof include an electric explosion method and a method using a fuse.

A plurality of water pipes 12 can be installed in one water storage container 5 as needed. in this case,
An explosive 10, an explosive 11, and a closing plate 13 are attached to each water pipe 12.

The water supply means of the building shut-off device according to the present invention is not limited to the water supply means 6 as long as the water contained in the water storage means can be supplied into the internal space. Instead, for example, a pump or the like may be used. If a pump is used as the water supply means, the water storage means can be installed at a position lower than the internal space.

The pyrolant is composed of a mixture of a metal and an oxidizing agent, simple carbon or nitrogen, and is usually a granular material, which generates an exothermic reaction by adding electric or thermal energy to cause agglomeration. Is a substance that becomes a lump. As described later, when an accident occurs in the building 2, the pyrolant functions as a protection member against radioactive substances and radiation by being stacked on the pyrolant holding member 9 and then being formed into a lump by the reaction.

The mass of the pyrolant has a high mechanical strength, and has a sufficient resistance to a mechanical shock or the like even if an explosion or the like occurs in the building 2.

The metal is not particularly limited as long as it can constitute a pyrolant, but a metal having a higher density is preferable in that it has a superior property of absorbing γ-rays. , Zr, Ti,
Examples include W, Cu, Pb, Ni, Mn, and Mo. Of these, W and Zr are particularly preferred.

Examples of the oxidizing agent include ammonium perchlorate, ammonium nitrate, and nitrite.

However, since the pyrolant containing the oxidizing agent generates gas when reacted, the pyrolant used for the building shut-off device 1 is a metal and carbon simple substance that does not generate gas by the reaction. Alternatively, a pyrolant containing nitrogen is suitable.

The pyrolant containing metal and simple carbon can be produced by mixing metal particles and simple carbon particles. As for the compounding ratio in this pyrorant, 30 to 80% of metal particles and 5% of carbon single particles were used.
Preferably it is で 40%. When the mixing ratio is within the above range, there is an advantage that gas is not generated. The pyrolant containing metal and nitrogen can be manufactured by mixing a substance that generates nitrogen with metal particles.

The particle diameter of the metal particles and the carbon single particles contained in the pyrorant is preferably 1 to 100 μm. When the particle size is within this range,
There is an advantage that the packing density of the pyrolant can be made relatively large.

It is preferable to further mix boron, cadmium, or the like with the pyrolante, since the lump obtained from these pyrolantes can absorb neutron rays.

The pyrolant storage means 7 is a container for storing the pyrolant 28 to be supplied into the internal space 4 when an accident occurs in the building 2. In the building shutoff device 1, the pyrolant storage means 7 is held at a predetermined height by a construction material (not shown), like the water reservoir 5.

The pyrolant storing means 7 has a capacity capable of storing an amount of pyrolant necessary to be supplied onto a pyrolant holding member 9 described later. Therefore, the capacity of the pyrolant storage container is appropriately determined according to the horizontal size of the internal space 4 and the like.

The number of the pyrolant storage means 7 is not limited to one, but can be appropriately determined as needed. Therefore, when a plurality of the pyrolant storage means 7 are used, the sum of their capacities may be equal to or greater than the amount of the pyrolant described above.

The shape of the pyrolant storage means 7 is as follows.
Although FIG. 1 shows a circular cross section, the shape is not limited to this shape, and there is no particular limitation as long as the object of the present invention can be achieved.

The material of the pyrolant storage means 7 can withstand the pressure of the pyrolant 28 stored therein, and can be destroyed by the action of the explosive 15 described later, and can be manufactured. There is no particular limitation as long as the conditions are satisfied, and examples thereof include metals.

The pyrolant storage means 7 is provided above the pyrolant holding member 9. By doing so, the pyrolant 2 in the pyrolant storage means 7 is
8 can be supplied onto the pyrolant holding member 9 by gravity without using power. Therefore,
In the building shut-off device 1, even when the power cannot be used due to an accident in the fast breeder reactor facility, the pyrorant 28 in the pyrorant storage means 7 can be supplied onto the pyrorant holding member 9.

The pyrolant supply means 8 is means for supplying the pyrolant 28 in the pyrolant accommodating means 7 onto the pyrolant holding member 9.
, An explosive 15 provided in the communication tube 16, and a detonator (not shown) for detonating the explosive 15.

The transmission pipe 16 is a pipe that forms a passage when the pyrolante 28 in the pyrolante housing means 7 is supplied onto the pyrolante holding member 9. Transmission pipe 16
Has one end abutting against the outer wall surface of the pyrolant storage means 7 and the other end exceeding the upper end of the defense wall 3 so that the opening 2
4 extends toward the pyrolant holding member 9. The position at which the transmission pipe 16 is joined in the pyrolant storage means 7 is determined by the pyrolant 28 in the pyrolant storage means 7.
Is located near the lowermost portion of the pyrolant receiving means 7 so that all of the liquid can be supplied into the internal space 4 through the communication pipe 16. As described later, the explosive 15 is exploded inside the transmission pipe 16 to destroy the pyrolant storage means 7, so that the transmission pipe 16 is not destroyed even if such an explosion occurs. It is made of a strong material and has such a thickness.

The pyrolant storage means 7 in the transmission pipe 16
The explosive 15 is provided in a portion adjacent to the outer wall surface of the gun. The explosive 15 has a function of destroying a portion of the pyrolant storage means 7 surrounded by the peripheral end of the transmission pipe 16 due to the explosion, and guiding the pyrorant 28 in the pyrolant storage means 7 into the transmission pipe 16. Gunpowder 1
The five types can be the same as in the case of the explosive 10.

An explosive device (not shown) is connected to the explosive 15. The detonator connected to the explosive 15 is the explosive 10
And a detonator connected to the explosive 11.

As described above, in the building shut-off device 1, the passage of the pyrolant is formed by the action of the explosive, and thereafter, the pyrolant 28 in the pyrolant storage means 7 is supplied to the internal space 4 by its own weight. Therefore, a power source such as electric power is not required for the supply of the pyrolant, and the pyrolant supply means 8 can be activated even when the electric power becomes unusable due to an accident in the facility of the fast breeder reactor. Have.

The pyrolant supply means of the building shielding prevention device according to the present invention is limited to a means such as the pyrolant supply means 8 as long as the pyrolant contained in the pyrolant storage means can be supplied into the internal space. For example, a pump or the like may be used. If a pump is used as the pyrolant supply means, the pyrolant storage means can be installed at a position lower than the internal space.

The pyrolant holding member 9 has a function of holding the pyrolant 28 supplied from the pyrolant storage means 7 and forming a layer of pyrolite above the building 2.

The pyrolant holding member 9 is a plate-like net, and is installed in the internal space 4 so as to cover the entire horizontal plane. The mesh size of the pyrolant holding member 9 is such that the pyrolant 28 supplied from the pyrolant holding means 7 does not pass through the pyrolant holding means 9 and is, for example, 1 to 10 mm. Further, the position where the pyrolant holding member 9 is installed is a position where when water is supplied from the water storage container 5 into the internal space 4, the water covers directly above the surface of the water stored in the internal space 4. It is lower than the opening 14 of the water pipe 12.

In the building shut-off device 1, since the pyrolant holding means 9 is a net, the opening 14
Can be transferred to the lower part of the internal space 4 through the pyrolant holding means 9 and stored in the internal space 4. Further, since the size of the mesh is the above-described size, the pyrolant 28 supplied from the pyrolant storage means 7 is held on the pyrolant holding member 9 and can cover the upper part of the building 2.
Further, since the installation position of the pyrolant holding member 9 is as described above, the pyrolant 28 supplied on the pyrolant holding member 9 is not immersed in water, and the mass of the pyrolant is placed on the pyrolant holding member 9. When the body is formed, no extra space is created between the mass and the surface of the water stored in the internal space 4.

The material of the pyrolant holding means 9 is as follows.
There is no particular limitation as long as it satisfies conditions such as having a strength that can withstand the weight of the pyrorant supplied thereon, and examples thereof include metals.

The thickness of the pyrolant holding means 9 is as follows.
There is no particular limitation as long as conditions such as the above-mentioned strength can be ensured, and it can be appropriately determined according to the purpose.

The pyrolant holding member in the building shut-off device according to the present invention is not limited to a mesh as long as it can hold the pyrolant.
A member formed by providing a large number of small holes or slits in a plate-like body may be used. Further, the pyrolant holding member in the building shut-off device according to the present invention does not need to be constituted by one member, and may be constituted by a plurality of members. There is no necessity, and for example, it may be a sheet shape or a blind shape.

The pyrolant holding member in the building shut-off device according to the present invention does not need to be always provided on the defense wall, and is usually evacuated to prevent accidents that require the operation of the building shut-off device. Only when it occurs, it may be installed at the above-mentioned predetermined position. For example, as shown in FIG. 2 and FIG. 3, the pyrolant holding member 21 is formed into a sheet-like member and a cord-like member, and is usually retracted to a position along the inner wall surface of the defense wall 22 (FIG. 2). A rail 23 is provided on the defense wall 22 at a position where the pyrolant holding member 21 is installed, and when an accident occurs, the pyrolant holding member 21 is moved from its end along the rail 23 (FIG. 3), and It can be installed at a location.

The pyrolant igniting means 17 is means for igniting the pyrolant 28 on the pyrolant holding member 9 to start the reaction of the pyrolant, and the igniter 18 mounted on the upper surface of the pyrolant holding member 9 and the It has a lead wire 19 to be connected and an energy loading device (not shown) for loading energy to the lead wire 19.

The pyrolant loading means in the building shut-off device according to the present invention may be of any type as long as the pyrolant can be ignited to form a mass of pyrolant. For example, a method of causing ignition may be used.

Next, the operation of the building shut-off device 1 will be described with reference to FIGS.
This will be described with reference to FIG.

When an accident in which radioactive substances and radiation are released from the building 2 occurs in the fast breeder reactor, first, the explosives 10 and 11 provided in the water supply channel 12 are activated, and the detonators connected to the explosives 11 are operated. Gunpowder 1
Explode 1 A predetermined portion of the water reservoir 5 is destroyed by the explosion of the explosive 10, and the closing plate 13 is exploded by the explosion of the explosive 11.
Is destroyed. Thereby, the inside of the water storage container 5 and the internal space 4 communicate with each other via the internal space of the water pipe 12.

Since the water storage container 5 is higher than the opening 14 of the water supply pipe 12, the water stored in the water storage container 5 flows down through the water supply pipe 12 by gravity and is supplied to the internal space 4. Since the pyrolant holding member 9 installed in the internal space 4 is a net, the water supplied to the internal space 4 passes through the pyrolant holding member, reaches the lower part of the internal space 4, and accumulates in the internal space 4. And stored water 26 (FIG. 4). The amount of water contained in the water storage container 5 depends on the internal space 4.
Is sufficient to submerge the building 2 in the inside, so that when the water 29 in the water storage container 5 is completely transferred to the internal space 4, the surface of the stored water 26 in the internal space 4 becomes
Are located higher than the uppermost part of the (FIG. 5).

After all the water 29 in the water storage container 5 has moved into the internal space 4, the explosive device connected to the explosive 15 provided in the transmission pipe 16 is activated to explode the explosive 15. The explosion of the explosive 15 destroys a predetermined portion of the pyrolant container 7. As a result, the interior of the pyrolant storage means 7 and the internal space 4 communicate with each other via the internal space of the communication pipe 16.

Since the pyrolant storage means 7 is higher than the opening 24 of the transmission pipe 16, the pyrolant storage means 7
The pyrolant 28 flows down through the communication pipe 16 and is supplied onto the pyrolant holding member 9 in the internal space 4.
Since the size of the mesh of the pyrolant holding member 9 is such that the particles of the pyrolant do not pass, the pyrolant 28 supplied on the pyrolant holding member 9 does not migrate below the pyrolant holding member 9, and Substantially all is held on the pyrolant holding member 9 (FIG. 6). Further, since the pyrolant holding member 9 is installed above the surface of the stored water 26 in the internal space 4, the pyrolant 28 supplied on the pyrolant holding member 9 is stored in the stored water 26 in the internal space 4. Do not soak.

Further, since the pyrolant 28 is a granular material, the pyrolant 28 continuously supplied from the pyrolant storage means 7 to the pyrolant holding member 9 through the transmission pipe 16 is located far from the sequentially supplied place. And spread over the entire surface of the pyrolant holding member 9 (FIG. 6).

The pyrolant 2 of the pyrolant storage means 7
8 are all supplied onto the pyrolant holding member 9, and the layer 25 of the pyrolant 28 is formed on the pyrolant holding member 9 (FIG. 7). The thickness of the layer 25 does not necessarily have to be uniform as long as it is a certain value or more.

As described above, the pyrolant 28 spreads on the pyrolant holding member 9 over the entire surface of the pyrolant holding member 9, so that a part thereof always comes into contact with the igniter 17 installed on the pyrolant holding member 9. After the layer 25 is formed, energy is loaded on the igniter 17 by an igniter connected to the igniter 17 through the lead wire 19 to ignite the igniter 17. Due to the ignition, the pyrolant in contact with the igniter 17 reacts to generate heat, and receives the heat. The pyrolant that has generated heat reacts with the adjacent pyrolant to generate heat. Repeat this process,
The reaction of the pyrolant extends concentrically from the portion adjacent to the igniter 17 to the entire layer 25. By this reaction, the constituent particles of the pyrolant are fused and integrated with each other, and when the reaction is completed in the whole of the pyrolant constituting the layer 25, the layer 25 becomes one lump 27 (FIG. 7).
become.

Since all of the above operations can be remotely controlled, even if radioactive substances and radiation are emitted from the building 2, operations can be performed smoothly and quickly.

In this manner, as shown in FIG. 7, the building 2 is surrounded by the stored water 26 in the side and top directions, further surrounded by the defense wall 3 in the horizontal direction, and holds the pyrolant above. Member 9 and lump 2
7 is covered. That is, the building 2 is in a state where the outside environment is isolated by the stored water 26, the defense wall 3, the block 27, and the like.

Therefore, the radioactive substance released from the building 2 is not blocked by the storage water 26, the defense wall 3, the block 27, and the like, and is not released to the outside environment.

The radiation emitted from the building 2 is as follows. Α-rays and β-rays having low permeability cannot pass through the storage water 26, the defense wall 3, the block 27, and the like, and are not emitted to the external environment. The γ-rays penetrate the stored water 26, but the defense wall 3 and the block 2 are made to contain a high-density metal in the defense wall 3 and the pyrolant 28 forming the block 2.
So it is not released to the external environment.
The neutron beam contains boron, cadmium, and the like in the defense wall 3 and the pyrolant 28 forming the massive body 2, so that the storage water 26 surrounding the building 2 and the pyrolant 28 contain carbon. In such a case, after being decelerated by the carbon to become thermal neutrons, the neutrons are absorbed by the defense wall 3 and the lump 2 and are not released to the external environment.

By operating as described above, the building shut-off device 1 can release radioactive materials and radiation to the external environment even if an accident occurs in which radioactive materials and radiation are released from the building 2. Can be prevented.

In the above description of the building shut-off device 1, the installation object of the building shut-off device 1 is a fast breeder reactor facility. It can be installed in the use facility in the same manner as described above, and at that time, it operates similarly to the above.

[0082]

According to the present invention, there is provided a building shut-off device for isolating a nuclear material using facility from an external environment in a short time when a radioactive substance and a radiation accident occur in the nuclear material using facility. It is possible to prevent radioactive materials and radiation from being released from the nuclear material use facility to the external environment.

Since the pyrorant is a granular material, it is possible to easily form a layer of the pyrorant by pouring the pyrorant onto the pyrorant holding member provided above the nuclear material using facility when an accident occurs.
In addition, since the pyrolant becomes a strong lump by the reaction, the pyrolant constituting the layer is reacted to form a lump, whereby a defense wall can be constructed above the nuclear material use facility. Thereby, in the building shut-off device according to the present invention, the defense wall can be provided not only in the side surface direction of the nuclear material use facility but also in the upper surface direction thereof.

Although it is difficult to construct a strong defense wall above the facility after the occurrence of the radioactive material and radiation emission accident by the conventional technology, the building shut-off device according to the present invention is as described above. Easy.

In the building shut-off device according to the present invention, the above operation can be performed by remote control.
In this operation, there is no possibility that the worker is exposed.

[0086] In the building shut-off device according to the present invention, since the facility using nuclear material is surrounded by water, fast neutrons emitted from the facility using nuclear material can be decelerated into thermal neutrons that can be easily absorbed. .

The pyrolant can contain boron or the like, so that the thermal neutrons can be absorbed by the defense wall constructed above the nuclear material use facility.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view when crossing a building shut-off device 1 in a vertical direction.

FIG. 2 is a perspective view showing a configuration in which the pyrolant holding member 21 is attached to the defense wall 2;
It is explanatory drawing which shows the state retracted to the position along the inner wall surface of No. 2.

FIG. 3 is a diagram showing a configuration in which the pyrolant holding member 21 is mounted on the rail 2;
It is explanatory drawing which shows the state which moved along 3.

FIG. 4 is an explanatory diagram illustrating a situation in which water 29 in a water storage container 5 is supplied into an internal space 4.

FIG. 5 is an explanatory diagram showing a state when all of the water 29 in the water storage container 5 has moved to the internal space 4.

FIG. 6 is an explanatory diagram showing a situation in which the pyrorant 28 in the pyrorant storage means 7 is supplied onto the pyrorant holding member 9;

FIG. 7 is an explanatory view showing a state in which a layer 25 of a pyrorant is formed on the pyrolant holding member 9 or a state in which a lump 27 is formed on the pyrolant holding member 9;

[Explanation of symbols]

1. Building shut-off device 2. Building 3. Defense wall 4.
..Internal space, 5 ... Water storage container, 6 ... Water supply means, 7
..Pyrorant storage means, 8..Pyrorant supply means, 9.Pyrorant holding members, 10.Explosives, 11
..Explosives, 12..water pipes, 13..obstruction plates, 14 ...
Opening, 15 ... explosive, 16 ... conduit, 17 ... pyrolant ignition means 17, 18 ... igniter 18, 19 ... lead wire, 20 ... explosive, 21 ... pyrolant holding means, 22 ... Defense wall, 23, rail, 24, opening,
25 ・ ・ layer, 26 ・ ・ reserved water, 27 ・ ・ mass, 28 ・
・ Pyrorant, 29 ・ ・ Water, 30 ・ ・ Construction materials

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hidefumi Shibamoto 1847 Sugao, Akirano-shi, Tokyo Hosoya Fireworks Co., Ltd. (72) Inventor Fumio Hosoya 1847, Sugao, Akiruno-shi Tokyo

Claims (5)

[Claims] 1. A defense wall installed so as to surround a nuclear material use facility, and having a height greater than the nuclear material use facility, and a nuclear material use facility in an internal space surrounded by the defense wall. Water storage means for storing a sufficient amount of water to submerge the water, water supply means for supplying the water stored in the water storage means into the internal space, and so as to cover above the nuclear material use facility A pyrolant holding member that is provided and can hold a pyrolant, a pyrolant storage container that stores the pyrolant, a pyrolant supply unit that supplies the pyrolant in the pyrolant storage container into the internal space, and on the pyrolant holding member. A building shut-off device comprising: a pyrolant ignition means for igniting a pyrolant. 2. The method according to claim 1, wherein the pyrolant comprises metal particles 30 to 8;
The building shut-off device according to claim 1, comprising 0% and 5 to 40% of carbon single particles. 3. The building shut-off device according to claim 2, wherein the metal particles are W or Zr. 4. The building shut-off device according to claim 2, wherein the metal particles and the carbon single particles have a particle size of 1 to 100 μm. 5. The building shut-off device according to claim 1, wherein the pyrolant contains boron.