JP2020180803A - Fire-resistant structure of fire protecting target cable, underfloor structure of nuclear facility, and method for constructing underfloor structure of nuclear facility - Google Patents

Abstract

To prevent a fire in a cable of one system from propagating to a cable of another system.SOLUTION: A fire-resistant structure 26 of a fire protecting target cable 28 includes a fire-resistant object 32 covering a fire protecting target cable 28 located between a first floor 20 and a second floor 22 above the first floor 20 of a nuclear facility 1, the fire-resistant object separating the fire protecting target cable 28 from fire protecting target cables 28 in other systems.SELECTED DRAWING: Figure 1

Description

The present invention relates to a fireproof structure of a cable subject to fire protection, an underfloor structure of a nuclear facility, and a method of constructing an underfloor structure of a nuclear facility.

The safety system equipment of nuclear equipment has a multiplexed configuration so that the function is maintained even if a single failure is assumed. The multiplexed equipment is designed to be divided into systems and each system is arranged separately. In addition, cables connected to devices are also arranged separately for each system. For example, as shown in Patent Document 1, such a cable of a nuclear facility may be provided under the floor of the nuclear facility.

Japanese Unexamined Patent Publication No. 2005-979929

Here, in the unlikely event that a fire breaks out in the nuclear power equipment, if the fire spreads to all the cables of the system, there is a risk that the entire function will be lost. Therefore, it is required to prevent a fire in one system of cables from spreading to cables of another system.

The present invention solves the above-mentioned problems, and has a fire-resistant structure of a cable subject to fire protection capable of suppressing a fire in a cable of one system from extending to a cable of another system, and under the floor of a nuclear facility. It is an object of the present invention to provide a construction method of a structure and an underfloor structure of a nuclear facility.

In order to solve the above-mentioned problems and achieve the object, the fire-resistant structure of the cable subject to fire protection according to the present disclosure is provided between the first floor of the nuclear facility and the second floor provided above the first floor. It includes a refractory material that covers the provided fire protection target cable and separates the fire protection target cable from another system of fire protection target cable.

According to the fire protection structure of the fire protection target cable, the fire protection target cables are covered and the fire protection target cables having different systems are separated from each other. Therefore, a fire in one system of the fire protection target cable is fire protection of another system. It can be appropriately suppressed to reach the target cable.

It is preferable that the refractory material covers the storage portion, including a storage portion that separates the fire protection target cable from the fire protection target cable of another system. By providing the storage portion, it is possible to improve the fire protection performance of the cable subject to fire protection and to improve the seismic resistance of the fire resistant structure.

The refractory is preferably composed of a member having a specific gravity smaller than that of the first floor. According to this fireproof structure, the layout of the fire protection target cable 28 can be preferably changed.

The refractory material preferably includes a first refractory material in which a space for arranging the fire protection target cable is formed, and a second refractory material covering the space. According to this fireproof structure, it is possible to easily arrange the cables subject to fire protection.

It is preferable that at least one of a fire detector and a fire extinguishing system is provided in the space inside the refractory where the cable subject to fire protection is installed. By providing at least one of the fire detector and the fire extinguishing equipment in this way, even if a fire occurs, it is possible to detect and extinguish the fire, and it is possible to suppress the spread of damage.

In order to solve the above-mentioned problems and achieve the object, the underfloor structure of the nuclear equipment according to the present disclosure includes a first floor of the nuclear equipment, a second floor provided above the first floor, and the first floor. A fire resistance that covers a plurality of systems of fire protection target cables and the fire protection target cable provided between the floor and the second floor, and separates the fire protection target cable from the fire protection target cable of another system. Includes fireproof structures, including objects.

Further, it is preferable that a plurality of pillar members are provided so as to be scattered between the first floor and the second floor at predetermined intervals to support the second floor. By providing the pillar members in this way, it is possible to maintain the strength of the second floor.

In order to solve the above-mentioned problems and achieve the object, the method of constructing the underfloor structure of the nuclear equipment according to the present disclosure includes a first floor of the nuclear equipment and a second floor provided above the first floor. It is a construction method of the underfloor structure of the nuclear power equipment including the cable installation step of installing a plurality of systems of fire protection target cables between the first floor and the second floor, and the fire protection target cable is a fire resistant material. Includes a fireproof installation step that separates the fire protected cable from the fire protected cable of another system by covering with.

According to the present invention, it is possible to prevent a fire in one system of cables from spreading to cables of another system.

FIG. 1 is a schematic view of the underfloor structure of the nuclear power facility according to the first embodiment. FIG. 2 is a schematic view of the underfloor structure of the nuclear power facility according to the first embodiment. FIG. 3 is a schematic view illustrating an example of a construction method of the underfloor structure according to the first embodiment. FIG. 4 is a schematic view of the underfloor structure of the nuclear power facility according to the second embodiment. FIG. 5 is a schematic view of the first refractory according to the second embodiment. FIG. 6 is a schematic view illustrating an example of a construction method of the underfloor structure according to the second embodiment.

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be noted that the present invention is not limited to this embodiment, and when there are a plurality of embodiments, the present invention also includes a combination of the respective embodiments.

(First Embodiment)
First, the first embodiment will be described. FIG. 1 is a schematic view of the underfloor structure of the nuclear power facility according to the first embodiment. As shown in FIG. 1, the nuclear power facility 1 according to the first embodiment is a nuclear power plant and includes a central control room 10. The central control room 10 is a room for controlling the nuclear power facility 1, and the control system 12 is provided on the underfloor structure 14. The control system 12 includes, for example, a control panel for controlling the nuclear facility 1, an instrument panel showing the state of the nuclear facility 1, and the like. The underfloor structure 14 according to the present embodiment is not limited to the underfloor structure of the central control room 10, and may be the underfloor structure of any equipment provided in the nuclear facility 1.

The underfloor structure 14 includes a first floor 20, a second floor 22, a pillar member 24, a fireproof structure 26, and a fire protection target cable 28. The first floor 20 is the floor of the nuclear power facility 1, here the central control room 10. The first floor 20 is made of a member having fire resistance, and is made of concrete in this embodiment. However, the material of the first floor 20 is not limited to concrete. Hereinafter, one direction parallel to the surface of the first floor 20 is referred to as a direction X, and one direction parallel to the surface of the first floor 20 and intersecting the direction X is referred to as a direction Y. In this embodiment, the direction Y is a direction orthogonal to the direction X. Further, the direction orthogonal to the surface of the first floor 20, that is, the direction orthogonal to the direction X and the direction Y is defined as the direction Z. That is, the direction Z is the vertical direction. Further, hereinafter, the upper side in the direction Z refers to the upward side in the vertical direction, that is, the direction away from the ground surface, and the lower side in the direction Z refers to the downward side in the vertical direction, that is, the direction approaching the ground surface.

The second floor 22 is provided on the upper side in the direction Z of the first floor 20. The second floor 22 is provided so as to overlap the entire area of the first floor 20, that is, to cover the first floor 20, when viewed from the upper side in the direction Z. The second floor 22 is the floor of the nuclear facility 1, here the central control room 10. The control system 12 is provided on the upper surface 22A in the direction Z of the second floor 22. That is, the equipment operated by the operator such as the control system 12 is provided on the second floor 22. The second floor 22 is made of a member having fire resistance, and is made of calcium silicate in the present embodiment. However, the material of the first floor 20 is not limited to calcium silicate.

Further, the second floor 22 is not in contact with the first floor 20 in the direction Z, and is provided apart from the first floor 20. Therefore, a space S0 is formed between the first floor 20 and the second floor 22.

The pillar member 24 is provided in the space S0 between the first floor 20 and the second floor 22. The pillar member 24 is a columnar member whose length in the direction Z is longer than the length in the directions X and Y. The column member 24 has a lower end in the direction Z connected to the surface 20A of the first floor 20 and an upper end in the direction Z connected to the lower surface 22B of the second floor 22. , Supports the second floor 22. The pillar member 24 is made of a member having fire resistance, and is made of concrete in this embodiment. However, the material of the column member 24 is not limited to concrete.

FIG. 2 is a schematic view of the underfloor structure of the nuclear power facility according to the first embodiment. FIG. 2 is a view when the underfloor structure 14 is viewed from the upper side in the direction Z in a state where the first floor 20 is not provided. As shown in FIGS. 1 and 2, a plurality of pillar members 24 are provided. The pillar members 24 are provided so as to be scattered at predetermined intervals in the directions X and Y. Further, the cable 28 subject to fire protection is actually provided in the storage portion 30 and the refractory 32 described later, but in FIG. 2, for convenience of explanation, the cable subject to fire protection in the storage portion 30 and the refractory 32 is provided. 28 is shown in the figure.

As described above, the underfloor structure 14 has a double floor structure of the first floor 20 and the second floor 22, and the second floor 22 is supported by the pillar member 24. Further, in the underfloor structure 14, a fire protection target cable 28 is provided in the space S0 between the first floor 20 and the second floor 22. The fire protection target cable 28 is a cable connected to the equipment (for example, safety system equipment) of the nuclear facility 1, for example, a cable connected to the control system 12. In the present embodiment, the equipment of the nuclear facility 1 (for example, the control system 12) has a plurality of equipment having the same functions, and each equipment is individually controlled by a system different from each other. In addition, a fire protection target cable 28 (wiring) is individually connected to each device. Therefore, it can be said that the fire protection target cable 28 provided in the space S0 is provided for each system.

Here, in the unlikely event that a fire breaks out in the nuclear power equipment, if the fire spreads to the fire protection target cables 28 of all the systems, there is a risk that the entire function will be lost. Therefore, it is required to prevent the fire in the fire protection target cable 28 of one system from extending to the fire protection target cable 28 of the other system. Therefore, for example, as stipulated in the "Examination Standards for Fire Protection of Practical Power Reactors and Their Ancillary Facilities", cables for safety equipment between different systems have a fire resistance capacity of 1 hour between each system. It is necessary to satisfy that it is separated by a partition wall, etc., and that a fire detection equipment and an automatic fire extinguishing equipment are provided, or that it is separated from other fire areas by a fireproof wall having a fire resistance capacity of 3 hours in the fire area. It is desired. In the underfloor structure 14 according to the present embodiment, the fire protection target cable 28 is separated from the fire protection target cable 28 of another system by providing the fire protection structure 26 as a partition wall or a fire resistance wall, and the fire protection target cable 28 is provided. It suppresses the fire in the designated area from reaching the area where the fire protection target cable 28 of another system is provided. Hereinafter, the fireproof structure 26 will be described.

As shown in FIG. 1, the fireproof structure 26 is arranged in the space S0 between the first floor 20 and the second floor 22. The refractory structure 26 includes a storage portion 30 and a refractory object 32. The storage unit 30 is a container (tray) for storing the fire protection target cable 28 inside. The storage portion 30 includes a main body portion 40 and a lid portion 42. The main body 40 is a hollow container, and the upper surface in the direction Z is open. The lid portion 42 is a lid of the main body portion 40 and covers an open area on the upper side in the direction Z of the main body portion 40. The lid portion 42 is configured to be openable / closable with respect to the main body portion 40 or removable from the main body portion 40, and covers a state of covering the upper open region in the direction Z of the main body portion 40 and releases the region. The state can be switched. The lid 42 of the storage unit 30 is closed with the fire protection target cable 28 housed in the main body 40, and the fire protection target cable 28 in the main body 40 is isolated from the outside of the main body 40.

The storage unit 30 is provided for each cable 28 subject to fire protection. That is, the fire protection target cables 28 of different systems are stored in different storage portions 30. In other words, the storage unit 30 separates the fire protection target cables 28 of different systems. The storage unit 30 is made of iron, for example, but the material of the storage unit 30 is not limited to iron and may be arbitrary.

In the examples of FIGS. 1 and 2, the storage unit 30 and the fire protection target cable 28 in the storage unit 30 extend along the direction Y, and the plurality of storage units 30 and the fire protection target cable 28 have directions. Lined up in X. The storage section 30 is preferably provided so that the cables 28 subject to fire protection are arranged in a direction along the surface of the first floor 20, but the storage section 30 and the cables 28 subject to fire protection in the storage section 30 are provided. The extending direction and the direction in which the lines are aligned may be arbitrary.

Further, as shown in FIG. 1, a fire detector 50 and a fire extinguishing equipment 52 are provided in the storage unit 30. The fire detector 50 and the fire extinguishing equipment 52 are provided in the respective storage portions 30. The fire detector 50 is a sensor that detects that a fire has occurred in the storage unit 30, and may be, for example, a temperature sensor that detects the ambient temperature. The fire extinguishing equipment 52 is a fire extinguishing device. For example, when the fire detector 50 detects that a fire has occurred in the storage unit 30, it releases a medium for extinguishing a fire or the like to extinguish the fire. In the example of FIG. 1, the fire detector 50 and the fire extinguishing equipment 52 are attached to the lid portion 42, but are not limited to being attached to the lid portion 42. Further, since the storage portion 30 is provided in the space S of the refractory material 32 as described later, it can be said that the fire detector 50 and the fire extinguishing equipment 52 are provided in the space S of each refractory material 32. .. Further, the fire detector 50 and the fire extinguishing equipment 52 may be provided in the space S0 between the first floor 20 and the second floor 22 outside the storage portion 30 (space S). Further, the fire detector 50 and the fire extinguishing equipment 52 are not indispensable and may not be provided, but at least one of the fire detector 50 and the fire extinguishing equipment 52 is in the storage portion 30 (space S). It is preferable that it is provided in.

The refractory 32 is provided so as to cover the storage portion 30. Specifically, the storage portion 30 may be provided on the outer peripheral surface in contact with any one of the first floor 20, the second floor 22, and the pillar member 24. In this case, the refractory 32 may be provided so as to cover an area on the outer peripheral surface of the storage portion 30 that does not come into contact with any of the first floor 20, the second floor 22, and the pillar member 24. That is, in the example of FIG. 1, the lower surface of the storage portion 30 in the direction Z is in contact with the second floor 22. Therefore, the refractory 32 covers an area other than the lower surface of the storage portion 30 on the outer peripheral surface of the storage portion 30. However, the refractory 32 may cover an area on the outer peripheral surface of the storage portion 30 that does not come into contact with any of the first floor 20, the second floor 22, and the pillar member 24. For example, in the example of FIG. 1, the refractory 32 also covers a region in contact with the pillar member 24 on the outer peripheral surface of the storage portion 30. Further, the refractory 32 may cover the entire outer peripheral surface of the storage portion 30.

The refractory 32 covers each of the storage portions 30. Therefore, it can be said that the adjacent storage portions 30 are not in contact with each other and are separated from each other, and the refractory 32 is provided between the adjacent storage portions 30. In other words, the refractory 32 has a space S for arranging the storage portion 30 (fire protection target cable 28) inside, and the storage portion 30 (fire protection target cable) has a space S of the refractory 32. It is provided inside. The space S is closed by being covered with at least one of the refractory 32, the first floor 20, the second floor 22, and the pillar member 24. The spaces S are separated from each other without communicating with each other.

The refractory 32 is made of a member having fire resistance. In the present embodiment, the refractory material 32 is made of a material different from that of the first floor 20, and further, is made of a material having a lighter specific gravity than that of the first floor 20. The material of the refractory 32 is, for example, calcium silicate, but the material is not limited to calcium silicate as long as it has fire resistance.

In the examples of FIGS. 1 and 2, the refractory material 32 is provided for each storage unit 30, that is, for each cable 28 subject to fire protection. However, one refractory object 32 may be provided for each of the plurality of storage portions 30 (fire protection target cables 28). In this case, the refractory 32 has a plurality of spaces S for storing the storage portion 30, and the spaces S do not communicate with each other and are separated from each other. Further, in the example of FIG. 1, the upper surface of the refractory 32 in the direction Z is not in contact with the lower surface of the second floor 22 in the direction Z, and is between the refractory 32 and the second floor 22. Although a space is formed in the above, the upper surface of the refractory 32 and the lower surface of the second floor 22 may be in contact with each other.

The fireproof structure 26 has the above configuration. In the present embodiment, the storage unit 30 and the refractory 32 cover all the fire protection target cables 28 arranged in the space S0, but are not limited to covering all the fire protection target cables 28. It is preferable that the storage portion 30 and the refractory 32 cover all the fire protection target cables 28 except one of the plurality of fire protection target cables 28 (of different systems) provided in the space S0. For example, when four fire protection target cables 28 are provided, it is preferable that the three fire protection target cables 28 are covered with a storage portion 30 and a refractory object 32. By covering all the fire protection target cables 28 except one in this way, the fire protection target cable 28 can be separated from the fire protection target cable 28 of another system. Further, in the examples of FIGS. 1 and 2, a fireproof structure 26 is provided so as to arrange four fire protection target cables 28, that is, four systems of fire protection target cables 28 between adjacent pillar members 24. .. However, the number of systems provided between the adjacent pillar members 24 is arbitrary, and may be one or a plurality of two or more.

Further, in the present embodiment, the fire protection target cable 28 is stored in the storage portion 30, but the fire protection target cable 28 is not limited to being provided in the storage portion 30. For example, the refractory 32 may directly cover the fire protection target cable 28 without providing the storage portion 30. Even in this case, since the fire protection target cable 28 is covered with the refractory material 32, the fire protection target cable 28 can be separated from the fire protection target cable 28 of another system.

Next, the construction method of the underfloor structure 14 will be described. FIG. 3 is a schematic view illustrating an example of a construction method of the underfloor structure according to the first embodiment. As shown in FIG. 3, when the underfloor structure 14 is constructed, the storage portion 30 is provided in the space S between the first floor 20 and the second floor 22 (step S10). In this case, the storage portion 30 is provided in the space S with the upper side of the main body portion 40 in the direction Z open. Then, the fire protection target cable 28 is installed in the storage unit 30 from the upper side in the direction Z of the main body unit 40 (step S12; cable installation step), and the fire detector 50 and the fire extinguishing equipment are installed in the storage unit 30. 52 and is installed. After installing the fire protection target cable 28, the fire detector 50, and the fire extinguishing equipment 52, the lid portion 42 is closed to make the inside of the storage portion 30 a closed space. Then, the periphery of the storage portion 30 is covered with the refractory 32 (step S14; the refractory installation step) to separate the fire protection target cable 28 from the fire protection target cable 28 of another system. As a result, the fireproof structure 26 is installed in the space S between the first floor 20 and the second floor 22, and the construction of the underfloor structure 14 is completed.

The construction method of the underfloor structure 14 is not limited to the one shown in the example of FIG. For example, the second floor 22 may be installed after performing steps S10, S12, and S14 before installing the second floor 22 and constructing the fireproof structure 26 in step S14. Further, in steps S10 and S12, the storage unit 30 is first provided in the space S, and then the fire protection target cable 28 and the like are stored in the storage unit 30, but the fire protection target cable 28 and the like are stored. The unit 30 may be installed in the space S. Further, in step S14, after the fire protection target cable 28 and the storage portion 30 are installed in the space S, the storage portion 30 is covered with the refractory 32, but the storage in the state where the fire protection target cable 28 is stored first. The portion 30 may be covered with the refractory material 32 and then installed in the space S. Further, when the storage portion 30 is not provided, the cable 28 subject to fire protection may be installed in the space S, and then the cable 28 subject to fire protection may be covered with the refractory 32, or the cable 28 may be covered with the refractory 32. The fire protection target cable 28 may be installed in the space S.

As described above, the fireproof structure 26 according to the present embodiment covers the fire protection target cable 28 provided between the first floor 20 and the second floor 22, and the fire protection target cable 28 is of another system. Includes a refractory 32 that separates from the fire protection cable 28. Since the fireproof structure 26 covers the fire protection target cables 28 and separates the fire protection target cables 28 having different systems from each other, a fire in one system of the fire protection target cables 28 causes a fire protection target cable 28 of another system. Can be appropriately suppressed.

Further, the fireproof structure 26 includes a storage portion 30 that separates the fire protection target cable 28 from the fire protection target cable 28 of another system. The refractory 32 covers the storage portion 30. By providing the storage portion 30 in this way, it is possible to improve the fire prevention performance of the cable 28 subject to fire protection and to improve the seismic resistance of the fire resistant structure 26.

Further, the refractory 32 is composed of a member having a specific gravity smaller than that of the first floor 20. When the refractory material covering the fire protection target cable 28 is made of the same member as the first floor 20, such as concrete, it is difficult to change the layout of the fire protection target cable 28 in the space S0 because the weight becomes heavy. It becomes. On the other hand, by forming the refractory 32 with a member having a specific gravity smaller than that of the first floor 20, for example, when the layout of the fire protection target cable 28 is changed, the refractory 32 has a shape conforming to the changed layout. It can be easily replaced with the refractory material 32 of. Therefore, according to the fireproof structure 26, the layout of the fire protection target cable 28 can be preferably changed.

Further, at least one of the fire detector 50 and the fire extinguishing equipment 52 is provided in the space S in which the fire protection target cable 28 is installed inside the refractory 32. By providing at least one of the fire detector 50 and the fire extinguishing equipment 52 in this way, even if a fire occurs, it is possible to detect and extinguish the fire, and it is possible to suppress the spread of damage. ..

Further, the underfloor structure 14 according to the present embodiment is located between the first floor 20 of the nuclear facility 1, the second floor 22 provided above the first floor 20, and the first floor 20 and the second floor 22. It is provided with a plurality of systems of cables 28 subject to fire protection and a fireproof structure 26. The fireproof structure 26 includes a refractory 32 that covers the fire protection target cable 28 and separates the fire protection target cable 28 from the fire protection target cable 28 of another system. The underfloor structure 14 according to the present embodiment is provided with the fireproof structure 26 to appropriately prevent the fire in the fire protection target cable 28 of one system from extending to the fire protection target cable 28 of the other system. Can be done.

Further, the underfloor structure 14 is provided so as to be scattered between the first floor 20 and the second floor 22 at a predetermined interval, and includes a plurality of pillar members 24 that support the second floor 22. By providing the pillar member 24 in this way, it is possible to maintain the strength of the second floor 22. Further, by interspersing the column members 24, it is possible to support the second floor 22 without providing a beam-shaped member formed long along the surface of the first floor 20, and the weight can be increased. It can be suppressed.

Further, the construction method of the underfloor structure 14 according to the present embodiment is a construction method of the underfloor structure 14 of the nuclear equipment 1 including the first floor 20 and the second floor 22, and the first floor 20 and the second floor 22 are constructed. By covering the cable installation step of providing the fire protection target cables 28 of a plurality of systems and the fire protection target cable 28 with the refractory 32, the fire protection target cable 28 can be separated from the fire protection target cable 28 of another system. Includes a refractory installation step to separate. According to the law behind the present embodiment, by covering the fire protection target cable 28 with the refractory material 32, the fire in the fire protection target cable 28 of one system extends to the fire protection target cable 28 of the other system. , Can be suppressed appropriately.

(Second Embodiment)
Next, the second embodiment will be described. The second embodiment is different from the first embodiment in that the refractory 32a has the first refractory 60 and the second refractory 62. In the second embodiment, the description of the parts having the same configuration as that of the first embodiment will be omitted.

FIG. 4 is a schematic view of the underfloor structure of the nuclear power facility according to the second embodiment. As shown in FIG. 4, the refractory structure 26a of the underfloor structure 14a according to the second embodiment includes a storage portion 30 and a refractory 32a. The refractory 32a has a first refractory 60 and a second refractory 62. In the first refractory 60, a space Sa for arranging the fire protection target cable 28 is formed. In the first refractory 60, the space Sa is not a closed space and is open to the upper side in the direction Z. That is, the space Sa is formed in a groove shape in the first refractory 60. The space Sa is provided with a fire protection target cable 28, a fire detector 50, fire extinguishing equipment 52, and a storage unit 30 housed in the space Sa. The second refractory 62 is a lid of the first refractory 60 and is arranged on the upper surface 60A in the direction Z of the first refractory 60. By arranging the second refractory material 62 on the surface 60A of the first refractory material 60, the second refractory material 62 covers the open area on the upper side in the direction Z of the space Sa, and makes the space Sa a closed space. That is, by arranging the second refractory 62 on the first refractory 60, the spaces Sa are separated from each other without communicating with each other.

FIG. 5 is a schematic view of the first refractory according to the second embodiment. In the first embodiment, for example, by bending the refractory 32 and winding it around the storage portion 30, a space S having a shape matching the shape of the storage portion 30 and the fire protection target cable 28 is formed. On the other hand, the first refractory 60 according to the second embodiment is formed in a modular shape, and the shape of the space Sa is preset. Then, a plurality of first refractories 60 having different shapes of the space Sa are prepared, and when the underfloor structure 14a is constructed, the first refractory 60 in which the space Sa matching the layout of the cable 28 subject to fire protection is formed is selected. To use. In FIG. 5, a combination of a first refractory 60S in which the space Sa is formed along the direction Y and a first refractory 60T in which the spaces Sa on both ends in the direction X are formed so as to face the direction X from the middle. An example of connecting spaces Sa to each other is given. By combining the first refractories 60 having different shapes of the spaces Sa and connecting the spaces Sa to each other, it is possible to form the space Sa that matches the layout of the cable 28 subject to fire protection. However, the first refractories 60S and 60T in FIG. 5 and the shape of the space Sa formed are examples.

In this way, by preparing a plurality of first refractories 60 having different shapes of the space Sa, the fire protection target cable 28 can be installed by selecting the first refractory 60 as the fire protection target cable 28. This eliminates the need to bend or process the refractory to match the shape of the fire protection target cable 28.

In addition, in FIGS. 4 and 5, a plurality of (four in this case) spaces Sa are formed in one first refractory 60, and a storage portion 30 is provided in each space Sa, the first refractory. The number of spaces Sa formed in 60 is arbitrary. For example, the first refractories 60 in which one space Sa is formed may be arranged side by side, and the storage portion 30 may be provided in the space Sa of each of the first refractories 60. Further, in the example of FIG. 4, the upper surface of the second refractory 62 in the direction Z is in contact with the lower surface of the second floor 22 in the direction Z, but is in contact with the upper surface of the second refractory 62. A space may be formed between the second refractory 62 and the second floor 22 without being in contact with the lower surface of the second floor 22.

Next, the construction method of the underfloor structure 14a will be described. FIG. 6 is a schematic view illustrating an example of a construction method of the underfloor structure according to the second embodiment. As shown in FIG. 6, when the underfloor structure 14a is constructed, the first refractory material 60 is provided in the space S between the first floor 20 and the second floor 22 (step S20). As the first refractory 60, a space Sa that matches the layout of the fire protection target cable 28 is selected and arranged in the space S. Then, the main body 40 of the storage portion 30 is installed in the space Sa of the first refractory 60 from the upper side in the direction Z of the first refractory 60 (step S22). Then, the cable 28 subject to fire protection, the fire detector 50, and the fire extinguishing equipment 52 are installed in the main body 40 (step S24; cable installation step). After installing the fire protection target cable 28, the fire detector 50, and the fire extinguishing equipment 52, the lid portion 42 is closed to make the inside of the storage portion 30 a closed space. Next, the second refractory material 62 is installed on the surface 60A of the first refractory material 60 to form the refractory material 32a, and the first refractory material 60 and the second refractory material 62, that is, the refractory material 32a. The storage portion 30 (fire protection target cable 28) is covered with the space Sa as a closed space (step S26; refractory installation step). As a result, the fire protection target cable 28 is separated from the fire protection target cable 28 of another system.

The construction method of the underfloor structure 14a is not limited to the one shown in the example of FIG. For example, the second floor 22 may be installed after performing steps S20, S22, S24, and S26 before installing the second floor 22 and constructing the fireproof structure 26 in step S26. Further, in step S22, the storage unit 30 is first provided in the space Sa, and then the fire protection target cable 28 and the like are stored in the storage unit 30, but the storage unit 30 in a state where the fire protection target cable 28 and the like are stored. May be installed in the space Sa. If the storage unit 30 is not provided, the cable 28 subject to fire protection, the fire detector 50, and the fire extinguishing equipment 52 are installed in the space Sa of the first refractory 60, and then on the surface 60A of the first refractory 60. A second refractory material 62 is installed in.

As described above, the refractory 32a according to the second embodiment includes the first refractory 60 in which the space Sa for arranging the fire protection target cable 28 is formed, and the second refractory 62 covering the space Sa. ,including. According to the refractory material 32a according to the second embodiment, the fire protection target cable 28 can be covered by arranging the fire protection target cable 28 in the space Sa and covering the space Sa with the second fire protection material 62. For example, work such as bending a refractory to cover the fire protection target cable 28 becomes unnecessary, and the fire protection target cable 28 can be easily arranged. Further, by preparing a modular first refractory material 60 having a different shape of the space Sa, a plurality of the first refractory materials 60 having a different shape of the space Sa can be combined to match the layout of the cable 28 subject to fire protection. The space Sa can be formed, and the fire protection target cable 28 can be easily arranged.

Although the embodiments of the present invention have been described above, the embodiments are not limited by the contents of the embodiments. Further, the above-mentioned components include those that can be easily assumed by those skilled in the art, those that are substantially the same, that is, those having a so-called equal range. Furthermore, the components described above can be combined as appropriate. Further, various omissions, replacements or changes of components can be made without departing from the gist of the above-described embodiment.

1 Nuclear equipment 10 Central control room 12 Control system 14 Underfloor structure 20 1st floor 22 2nd floor 24 Pillar members 26 Fireproof structure 28 Fire protection target cable 30 Storage unit 32 Refractory

Claims (8)

Cover the fire protection target cable provided between the first floor of the nuclear facility and the second floor provided above the first floor.
A refractory material that separates the fire protection cable from another system of fire protection cable.
Fireproof structure of cables subject to fire protection. Includes a storage compartment that separates the fire protection cable from another system of fire protection cable.
The refractory structure of the cable subject to fire protection according to claim 1, wherein the refractory material covers the storage portion. The fireproof structure of the cable subject to fire protection according to claim 1 or 2, wherein the refractory is composed of a member having a specific gravity smaller than that of the first floor. The refractory material includes any one of claims 1 to 3, including a first refractory material in which a space for arranging the fire protection target cable is formed, and a second refractory material covering the space. The fireproof structure of the cable subject to fire protection described in the section. The invention according to any one of claims 1 to 4, wherein at least one of a fire detector and a fire extinguishing system is provided in a space inside the refractory where the cable subject to fire protection is installed. Fireproof structure of cables subject to fire protection. The first floor of nuclear equipment and
The second floor provided above the first floor and
A plurality of systems of fire protection target cables provided between the first floor and the second floor, and
A fireproof structure containing a refractory material that covers the fire protection target cable and separates the fire protection target cable from the fire protection target cable of another system.
Underfloor structure of nuclear equipment, including. The sixth aspect of claim 6, further comprising a plurality of pillar members provided so as to be scattered between the first floor and the second floor at predetermined intervals to support the second floor. Underfloor structure of nuclear equipment. A method of constructing an underfloor structure of a nuclear facility including a first floor of the nuclear facility and a second floor provided above the first floor.
A cable installation step for installing a plurality of systems of fire protection target cables between the first floor and the second floor, and
A refractory installation step of separating the fire protection cable from the fire protection cable of another system by covering the fire protection cable with a refractory material.
Construction method of underfloor structure of nuclear equipment including.

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