JP2000065975A - Exchange method for large component and structure in nuclear power station - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an exchange method for large components in a nuclear power station capable of carrying in or out from building without using an airlock as a large structure, maintaining airtightness without providing additional air conditioning device and special seal means and reducing the amount of radioactive waste. SOLUTION: A temporary building 30 provided with chambers 30A and 30B placed on the second floor layer, an outside connection outlet 30Ba provided to a chamber 30B, a boundary connection outlet 30Aa placed at the boundary of the neighboring chambers 30A and 30B and open/close doors 33 and 34 capable of opening and closing the connection outlets 30Aa and Ba in desired restriction state is contacted to the outer wall of the reactor building. The reactor pressure vessel is exchanged via the temporary building by maintaining specific airtightness with the open/close doors 33 and 34.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to large equipment and structures provided in a building of a nuclear power plant, and particularly to those used for preventive maintenance, renewal, decommissioning, etc. of a nuclear power plant. The present invention relates to a method for replacing large equipment and structures in a nuclear power plant, which replaces large equipment and structures with new ones.

[0002]

2. Description of the Related Art For example, in a boiling water nuclear power plant, a primary containment vessel (Primary Container) provided in a reactor building is used.
Reactor Pressure Vessel (ment Vessel)
Vessel). A reactor core loaded with a number of fuel assemblies is provided in the reactor pressure vessel. After the coolant introduced into the reactor building flows into the core from below the core, it is heated and boiled in the core, forming a gas-liquid mixed state containing bubbles, and a steam-water separator and dryer above the core. The steam from which the liquid component has been removed is supplied to the turbine building to generate power.

If such power generation is performed for a long period of time, the equipment in the power plant, especially the reactor pressure vessel, the equipment in the reactor pressure vessel, and the turbine used under severe conditions of high temperature and high pressure, deteriorates. In recent years, in Japan,
Building new nuclear power plants is becoming increasingly difficult, and using existing power plants for as long as possible is of paramount importance. Therefore, it is necessary to replace each degraded device at an appropriate time to extend the life of the entire power plant.

[0004] Here, various methods for replacing each device in a nuclear power plant have already been proposed.
As an example of large equipment, a method of replacing a reactor pressure vessel has been proposed in, for example, Japanese Patent Application Laid-Open No. Hei 6-230188. This means that after an opening is formed in the ceiling of the reactor building, an airlock that can accommodate the reactor pressure vessel is installed on top of this, and the existing (used) reactor pressure vessel is placed inside this airlock. It is stored and transported outside the reactor building.

[0005]

However, the above prior art has the following problems.

(1) Huge structure of airlock In the case of a boiling water type nuclear power plant, even a relatively small reactor pressure vessel has a maximum diameter of about 8 m, a height of about 25 m, and a weight of about 1,000 ton. Also reach. In order to house such a large reactor pressure vessel integrally, for example, a height 2
A huge airlock of 5m or more is required. In addition, at this time, since the inside of the airlock needs to be manufactured with a structure and material that can withstand the negative pressure, it is also necessary to take measures against earthquakes and measures against typhoons, so practical application is difficult in practice. is there.

(2) Maintaining the airtightness of the opening The existing reactor pressure vessel to be replaced needs to be handled as a radioactive substance, and the reactor building where the reactor pressure vessel is installed is a radioactively contaminated area. For this reason, air conditioning is controlled so that the pressure is lower than the atmosphere outside the building. Therefore, in the case where an opening communicating with the outside air is provided in the reactor building, it is necessary to make the size smaller than a size capable of maintaining a negative pressure. To pass a reactor pressure vessel having a diameter of about 8 m, it is necessary to form at least an opening having a diameter of about 10 m in the reactor building. In order to keep the indoor at a negative pressure, the area of the opening to the outside air cannot be set to, for example, 2.5 m ² or more. This 2.5 m ² corresponds to the area of a circle having a diameter of 1.8 m. Therefore, during the opening forming work, it is necessary to devise the opening having a diameter of 10 m to be equal to or less than an opening area equivalent to a circle having a diameter of 1.8 m. No consideration is given. For this reason, the airtightness cannot be maintained only by the existing air conditioning equipment, and a new air conditioning equipment needs to be added. Further, if a gap of 10 cm or more is formed around the reactor pressure vessel while the reactor pressure vessel having a diameter of 8 m passes through the opening, the gap area exceeds 2.5 m ² . Therefore, in such a case, it is necessary to provide a means for reducing the area of the opening having a diameter of 10 m to 8.2 m or less to reduce the gap to 10 cm or less. In a space without pressure difference, it is possible to seal with a simple material such as soft vinyl.
If there is a water column, the load applied to the area of 10m in diameter is 150
Tons, it is necessary to provide a special sealing means separately. As described above, the above prior art does not take into consideration the maintenance of airtightness during the formation of the opening and the passage of the reactor pressure vessel through the opening. This leads to higher costs.

(3) Increasing the amount of radioactive waste Various equipment and facilities used for replacing the reactor pressure vessel are treated as radioactive waste after use, as described in (1) and (2) above. As described above, in the above-described conventional technology, an airlock having a huge structure, an additional air-conditioning facility, and the like are required, so that the amount of waste is enormous.

An object of the present invention is to enable carrying out and carrying in and out of a building without using an airlock as a huge structure, and to maintain airtightness without providing additional air conditioning equipment or special sealing means. Another object of the present invention is to provide a method for replacing large-scale equipment in a nuclear power plant, which can reduce the amount of radioactive waste.

[0010]

Means for Solving the Problems (1) In order to achieve the above-mentioned object, the present invention provides a method for replacing large-sized equipment / structures in a building of a nuclear power plant by replacing large-sized equipment / structures in the building. In the replacement method, a room provided in a plurality of layers, an external communication port with the outside provided in a room of the outermost layer among the rooms of the plurality of layers, and a boundary communication port provided at a boundary of the adjacent room, respectively. And a temporary building provided with an opening / closing means capable of opening and closing the external communication port and the boundary communication port in a desired squeezed state, by bringing the temporary building into close contact with the outer wall of the building, and securing predetermined airtightness with the opening / closing means, Replacement of the large equipment and structures via the temporary building. At the time of replacement of large equipment and structures, the temporary building is brought into close contact with the outer wall of the nuclear power plant building. Since the temporary building has multiple layers of rooms, the innermost room is in contact with the building of the nuclear power plant. Therefore, the boundary connecting port between the room at the innermost layer and the room adjacent to the room may be narrowed to a predetermined opening area or less by the opening / closing means, and the opening forming work may be performed on the exterior wall surface of the building in the room at the innermost layer. In this case, the innermost room communicating with the building through the opening is a radioactively contaminated area (area C),
By narrowing the opening area to the outer layer side by the opening / closing means, the negative pressure in the building can be maintained and airtightness can be secured without providing new air conditioning equipment. After the opening is formed,
Existing large equipment and structures will be transported from the building to the temporary building through this opening, and then to the non-contaminated area (area A) outside the temporary building. First, radiological contamination inspection and measurement of large equipment and structures must be performed in the contamination start area (area B). Therefore,
A large device or structure may be lifted through the opening to penetrate from the innermost layer to the room on the outer layer side, and the inspection or measurement may be performed in that room. At this time, by narrowing each boundary communication port through which large equipment and structures penetrate to a predetermined opening area with opening and closing means, it is possible to maintain negative pressure inside the building without providing special sealing means, The airtightness between the room in the innermost layer, which is the area, and the room for inspection / measurement is maintained, and that room can be used as the contamination start area. In addition, by making the temporary building a multi-layer structure, it is sufficient to provide a two-layer room in the minimum case. Thus, for example, when the height of one layer is set to one floor of an ordinary building, that is, about 3 m, the reactor pressure vessel having a diameter of 8 m and a height of 25 m or more can be obtained only with a small temporary building having a total height of about 6 m. Large devices can be safely replaced.

(2) In the above (1), preferably,
The temporary building is brought into close contact with the outer wall of the building, and the boundary connecting port of the boundary between the innermost room and the room adjacent thereto is closed with the corresponding opening / closing means, and the innermost layer is closed. Inside the room, a part of the outer wall of the building is removed to form an opening, and the large equipment / structure is replaced through the opening.

(3) In the above (1), preferably, the temporary building is brought into close contact with an outer wall of the building, and the large-sized equipment / structure is lifted up to an outer layer side of an innermost layer room among the plurality of rooms. Of the large equipment / structure in the room on the outer layer side in this state by closing each boundary communication port through which the large equipment / structure penetrates with the corresponding opening / closing means. Or perform radioactivity measurement.

(4) In the above (1), preferably, when the replacement of the large-sized equipment / structure is completed, the temporary building is separated from the outer wall of the building to remove the used large-sized equipment / structure. Reuse as part of a temporary building. As a result, the effective use of materials and the amount of waste can be further reduced, and the total cost can be further reduced.

[0014]

An embodiment of the present invention will be described below with reference to the drawings. The present embodiment is an embodiment of a method for replacing a reactor pressure vessel installed in a reactor building of a nuclear power plant.

FIG. 1 is a sectional view showing the entire structure of a reactor building to which the present embodiment is applied. In FIG. 1, a reactor containment vessel 3 is provided in a reactor building 4 and a reactor pressure vessel 1 is housed therein. A reactor internal structure 2 (for example, a steam separator, a drier, an upper grid plate, a fuel assembly, and the like) including equipment forming a reactor core is housed in the reactor pressure vessel 1. A spent fuel pool 19 is provided near the upper part of the reactor building 4, and a reactor well 9 is provided above the reactor containment vessel 3 for filling water when refueling or taking out the reactor internals 2. is there.

FIG. 2 is a sectional view showing the detailed structure of the containment vessel 3 containing the reactor pressure vessel 1. 2, a reactor pressure vessel 1 includes a reactor pressure vessel pedestal 5 serving as a basis for the reactor pressure vessel 1.
Is fixed by a reactor pressure vessel foundation bolt 6.
The reactor pressure vessel 1 includes a main steam nozzle 12, a water supply nozzle 13, a recirculation inlet nozzle 14, and a recirculation outlet nozzle 1.
5 and the like, the main steam pipe 21, the water supply pipe 2
2. It is connected to each system pipe such as the recirculation inlet pipe 23 and the recirculation outlet pipe 25. Further, a reactor pressure vessel heat insulating material 7 and a γ-ray shield (RSW) 8 for shielding radiation are provided on the outer periphery of the reactor pressure vessel 1, and on the upper side of the reactor pressure vessel 1, A refueling bellows 10 and a bulkhead plate 11 for partitioning the reactor well 9 and the containment vessel 3 are provided. Furthermore, a reactor pressure vessel lid (RPV top head) 16 is provided at the top of the reactor pressure vessel 1, and a control rod drive (not shown) is housed at the bottom of the reactor pressure vessel 1. Control rod drive unit housing 17 and neutron flux detector (In Cor
ICM housing 1 for housing e Monitor (not shown)
There are eight.

In this embodiment, a used reactor pressure vessel 1 is carried out by a crawler crane which is a large lifting machine, and then a new one is carried in. Hereinafter, description will be made with reference to FIG. 3 which is a flowchart showing a series of the work procedure.

First, at step 50, the reactor pressure vessel 1
As a preparation stage for replacement, a generator (not shown) in another building is disconnected and the operation of the nuclear power plant is stopped.

Next, at step 51, the reactor opening operation involves removing and opening the reactor pressure vessel lid 16, and then taking out the reactor internals 2 (reactor opening operation).

Then, in step 52, all the fuel assemblies in the reactor core are moved to the spent fuel pool 19 in the reactor building 4 (all fuel removal work).

Next, at step 53, the reactor pressure vessel 1
The reactor pressure vessel 1 is separated from the reactor pressure vessel pedestal 5 by removing the base bolts 6 of the reactor pressure vessel 1 while cutting off the nozzles and pipes (reactor pressure vessel disassembly). At this time, in step 53a, a large lifting machine is set near the reactor building 4 in order to carry out the reactor pressure vessel 1 from the reactor building 4 while performing these operations. FIG. 4 is a diagram showing a state in which a large hoisting machine 29 is installed near the reactor building 4. As shown, the large hoisting machine 29 includes a large hoisting hook 29a and a large hoisting wire 29b. And At this time,
Simultaneously with the setting of the large hoisting machine 29, in step 53b, the two-level temporary building 30 pre-packaged, which is a main part of the present embodiment, is transported to the vicinity of the reactor building 4. FIG. 5 is a sectional view showing the entire structure of the two-level temporary building 30. In FIG. 5, the temporary building 30
It has a two-layer structure including a lowermost one-level room 30A and a uppermost two-level room 30B, and has an entrance / exit 47, a foundation 31 for closely adhering to the roof of the reactor building 4, 2 provided at the upper part of the room 30A of one level
A communication port 30Aa with the room 30B on the second floor, a communication port 30Ba with the outside provided on the upper part of the room 30B on the second floor,
Sliding doors 33 and 34 that can open and close the communication ports 30Aa and 30Ba respectively, door opening and closing devices 33a and 34a that open and close the sliding doors, respectively, and hanging hardware 35 for transporting the temporary building 30 are provided. ing.
FIG. 6 is a plan view showing the opening and closing of the sliding doors 33 and 34, in which the door 33 is open and the door 34 is closed. As shown, the door 3
The bellows 3 and 34 are provided with rubber bellows 33b and 34b for minimizing the gap between the reactor pressure vessel 1 and the outer peripheral surface when the reactor pressure vessel 1 passes. When such a temporary building 30 is transported to the vicinity of the reactor building 4 by the large lifting machine 29, the temporary building 30 is lifted on the roof of the reactor building 4, and the temporary building 30 and the reactor building 4 are brought into close contact with each other. The situation at this time is shown in FIG.

Next, at step 54, the ceiling of the building is opened on the roof of the reactor building 4. At this time, the entrance and exit of workers and the loading and unloading of materials and waste materials are performed at the entrance 47 of the temporary building 30, Alternatively, the construction is performed through the sliding doors 33 and 34, and the construction is performed in the room 30A on the first floor of the temporary building 30. Therefore, by opening and closing the slide-type opening / closing doors 33 and 34 so as to be in a desired throttled state, it is possible to freely reduce the area where the reactor building 4 contacts the outside air. In this way, the opening work is completed, and the opening 36 is opened.
FIG. 8 shows the state provided with.

Thereafter, at step 55, the large lifting machine 29
The suspension hook 29a attached to the tip of the suspension wire 29b is suspended in the reactor building 4. At this time, the door is lowered through the sliding doors 34, 33 of the temporary building 30. For example, when the sliding door 34 is opened, the other door 33 is kept closed or slightly opened.
The negative pressure in the reactor building 4 can be maintained by appropriately adjusting the opening degrees of the reactors 4 and 33. In this way,
FIG. 9 shows a state where the suspension hook 29a of the large-sized hoisting machine 29 is suspended.

Next, at step 56, the reactor pressure vessel 1
The piping connected to the reactor is cut off, a hanging balance 37 is attached to the reactor pressure vessel 1, and the reactor pressure vessel 1 is lifted independently by the hanging hook 29 a of the large hoisting machine 29 that has been lowered. This state is shown in FIG. In addition, it may be lifted integrally with a large block integrated with equipment inside and outside the furnace (for example, the furnace internal structure 2, the control rod driving device housing 17 and the like) (the same applies to the subsequent carrying-out procedure and carrying-in procedure). In this way, the reactor pressure vessel 1 is lifted, and as shown in FIG.
Introduce into 0.

At this time, in step 57, the shield 40 is attached to the reactor pressure vessel 1 before the reactor pressure vessel which has been exposed to a high dose due to long-term use is taken out of the reactor building. Although the structure and mounting method of the shield 40 at this time are not particularly described in detail, for example, JP-A-8-6
It suffices if the mounting is performed by a known method as described in JP-A-2368 or JP-A-9-145882. Step 57 may be performed after step 56 or almost simultaneously with step 56, but is not particularly limited and may be performed at an appropriate time.

Next, at step 58, radioactive contamination inspection and dosimetry for carrying out the reactor pressure vessel 1 with the shield 40 attached to the outside of the reactor building 4 are performed. FIG. 12 shows the implementation status. In FIG. 12, an inspection table 41 is provided in advance on the second floor of the temporary building 30, and the inspector 42 determines the amount of radioactive contamination and the dose on the surface of the reactor pressure vessel 1 that has come out to the room 30B on the second floor. Measure. FIG. 13 shows the open / closed state of the sliding doors 33, 34 at this time.
Shown in The reactor pressure vessel 1 penetrates through the opening / closing door 33, and the bellows 33b closes the door until it almost contacts the reactor pressure vessel 1, so that the negative pressure inside the reactor building is not broken. The hanging wire 29b of the large hoisting machine 29 penetrates the opening / closing door 34, and the opening is adjusted so that the opening area is as small as possible. 2
If one of the three open / close doors 33, 34 is smaller than a specified opening area (for example, smaller than 2.5 m ² ), the negative pressure of the reactor building 4 can be held, but one of the two It is preferable to always adjust the opening of both sheets in preparation for the door being uncontrollable.

Thereafter, in step 59, a portion of the reactor pressure vessel 1 which is determined to be capable of being carried out of the reactor building 4 by radioactive contamination inspection and dose measurement (FIG. 1)
2 and the portion that was in the room 30B on the second floor) is carried out. This state is shown in FIG. In addition, sliding doors 33, 3
FIG. 15 shows the open / closed state of No. 4. At this time, the door 33,
Although the reactor pressure vessel 1 penetrates both of them, since the bellows 33b and 34b control the gap with the reactor pressure vessel 1 to be minimized, the negative pressure of the reactor building is maintained. .

By the way, as shown in FIG.
The part below the part carried out of the reactor building 4 is 2
Since it appears in the room 30B of the hierarchy, the measurement in the above step 58 is performed for this portion. Thereafter, this is sequentially repeated, and finally, all parts of the reactor pressure vessel 1 are measured, and after confirming safety, they are carried out.

The reactor pressure vessel 1 carried out in this manner
Until the final disposal, for example, step 59
In a, it is transported to the storage where it is stored. An example of this transportation situation is shown in FIG. In this case, the large lifting machine 29
The reactor pressure vessel 1 carried out of the reactor building 4 through the temporary building 30 is transported by the large lifting machine 29 to the vertical underground storage 43 provided near the reactor building 4 and stored as it is.

Since the removal of the used reactor pressure vessel 1 has been completed up to the above step 59, next, step 6 is performed.
At 0, a new reactor pressure vessel is loaded. This may be basically the reverse of the above procedure, and a detailed description thereof will be omitted. However, the new reactor pressure vessel is naturally radioactive,
Since there is no high dose, there is no need for a shield, and there is no need to perform various inspections and measurements, and the working steps are shorter than when unloading. However, it is necessary to maintain the negative pressure in the reactor building 4 even when the reactor pressure vessel is carried in. Therefore, the two sliding doors 33 and 34 are opened in accordance with the loading of the reactor pressure vessel from the temporary building 30. Adjust the degree.

Thereafter, in step 61, the suspension hook 29a of the large hoisting machine 29 is carried out from the reactor building 4 while adjusting the opening of the two sliding doors 33, 34.

Next, at step 62, one of the temporary buildings 30
Restoration work is performed to close the opening 36 (see FIG. 8) in the ceiling of the reactor building 4 in the room 30A on the floor.

Since the temporary building 30 becomes unnecessary by closing the opening 36 of the reactor building 4, the temporary building 30 is removed from the roof of the reactor building 4 using the large lifting machine 29 in step 62a.
To remove. FIG. 17 shows the state at this time.

Thereafter, in step 62b, the reactor building 4
The large hoisting machine 29 installed near is removed. Then, in step 63, the reactor pressure vessel 1 is restored in the reactor building 4, and the replacement of the reactor pressure vessel 1 is completed.

As described above, in the present embodiment, when the construction of the opening 36 is performed, the room 30A on the first floor communicating with the reactor building 4 through the opening 36 is connected to the radioactive contamination area (area C). However, by narrowing the opening area to the outer layer side by the opening and closing doors 33 and 34, the negative pressure in the reactor building 4 can be maintained and airtightness can be maintained without providing new air conditioning equipment. it can. After the opening 36 is formed, when the reactor pressure vessel 1 is carried into the temporary building 30 from the reactor building 4 through the opening 36 and dose measurement or the like is performed, the reactor pressure vessel 1 is Is lifted and penetrated into the room 30B of the second floor, and the measurement is performed in the room 30B. At this time, the portion through which the reactor pressure vessel 1 penetrates can be reduced to a predetermined opening area or less by the opening and closing doors 33 and 34. Thereby, the negative pressure in the building is maintained without providing a special sealing means, and the airtightness between the room 30A on the first floor, which is a radioactively contaminated area, and the room 30B on the second floor for inspection and measurement is maintained. be able to. Furthermore, by making the temporary building 30 into a two-story structure, for example, if the height of one layer is made to be one floor of an ordinary building, that is, about 3 m, only the small temporary building having a total height of about 6 m has a diameter of only one. Large equipment such as a reactor pressure vessel with a height of 8 m and a height of 25 m or more can be safely replaced.

As described above, according to the present embodiment, the reactor pressure vessel 1 can be carried out / in from / to the reactor building 4 without using an airlock as a giant structure. And airtightness can be maintained without providing special sealing means. By these means, the cost of the entire construction and the construction period can be significantly reduced, and the amount of radioactive waste generated after use can be significantly reduced.

In Japanese Patent Application Laid-Open No. Hei 6-230188, the replaced reactor pressure vessel is enclosed in an airlock together with the air in the contaminated area, transported outside the power station building, and then the airlock is opened at the location where it was transported. It does not clarify what kind of pollution control is to be performed when doing this. On the other hand, in the present embodiment, the radioactive contamination area (area A)
A temporary building 30 having two levels of rooms 30A and 30B is provided between the inside of the reactor building 4 which is a non-contaminated area (area C) and the outside of the building which is a non-contaminated area (area C). Area), radioactive contamination inspection, dosimetry, and the like can be performed. Therefore, the reactor pressure vessel 1 can be safely and easily replaced with the conventional management standard.

Although the removed temporary building 30 may be disposed of as used radioactive waste, it may be separately reused for other uses. An example of the effective use is shown in FIG. This example is used as a ground building of the vertical underground storage 43 of the used reactor pressure vessel described above with reference to FIG. In FIG. 18, the vertical underground storage 43 is provided with a communication entrance / exit 44 to the storage and a ladder 45 for descending to the bottom of the storage, in which the used reactor pressure vessel 1 is placed. It is standing still. The temporary building 30 is disposed so as to cover the upper part of the storage 43. At this time, the opening / closing function of the slide-type opening / closing door 34 is unnecessary during storage of the reactor pressure vessel, and a cover 46 is provided for the purpose of protecting it.

In the above embodiment, the temporary building 30 has a two-layer structure. However, the present invention is not limited to this, and it goes without saying that the temporary building 30 may have three or more layers. Further, in the above embodiment, the case where the reactor pressure vessel is replaced as an example of the large-sized equipment / structure of the nuclear power plant has been described, but the present invention is not limited to this. For example, it can be applied to other large-scale equipment that needs to remove a part of the wall surface of the building, form an opening, and perform replacement through the opening, such as a feed water heater provided in a turbine building. It is.

[0040]

According to the present invention, it is possible to carry out and carry in from a building without using an airlock as a huge structure, and it is possible to maintain airtightness without providing additional air conditioning equipment or special sealing means. By these means, the cost of the entire construction and the construction period can be significantly reduced, and the amount of radioactive waste generated after use can be significantly reduced.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a reactor building containing a reactor containment vessel and a reactor pressure vessel.

FIG. 2 is a sectional view of a containment vessel containing a reactor pressure vessel.

FIG. 3 is a flowchart showing a procedure of a method of replacing a reactor pressure vessel according to an embodiment of the present invention.

FIG. 4 is a diagram showing a state in which a large lifting machine is set near a reactor building.

FIG. 5 is a sectional view showing a structure of a two-story temporary building.

FIG. 6 is a plan view illustrating opening and closing of a sliding door.

FIG. 7 is a diagram showing a state in which a temporary building is installed on a reactor building roof using a large lifting machine.

FIG. 8 is a diagram showing a state in which an opening for carrying out / in a reactor pressure vessel is provided on a reactor building roof through a temporary building.

FIG. 9 is a view showing a state in which a suspension hook of a large-sized hoist is inserted into a reactor building through a temporary building.

FIG. 10 is a view showing a state in which a reactor pressure vessel is lifted by a lifting hook of a large hoist.

FIG. 11 is a diagram showing a state in which a reactor pressure vessel is lifted and introduced into a temporary building.

FIG. 12 is a diagram showing a state in which a radioactive contamination inspection and a surface dose are measured before the reactor pressure vessel is carried out of the reactor building.

FIG. 13 is a plan view illustrating the opening and closing of a sliding door.

FIG. 14 is a diagram showing a state in which the reactor pressure vessel is sequentially carried out of the reactor building from the part where various inspections have been completed.

FIG. 15 is a plan view showing the opening and closing of the sliding door.

FIG. 16 is a diagram showing a state where the reactor pressure vessel carried out of the reactor building is carried into a vertical underground storage by a large hoist.

FIG. 17 is a diagram showing a state where a temporary building that has been installed on the roof of the reactor building is being removed.

FIG. 18 is a diagram showing a state in which a temporary building is reused as an upper building of a vertical underground storage of a reactor pressure vessel.

[Explanation of symbols]

Reference Signs List 1 reactor pressure vessel 2 reactor internals 3 reactor containment vessel (large equipment / structure) 4 reactor building (building) 30 temporary building (temporary building) 30A one-level room (innermost layer room) 30Aa (Boundary contact) 30B Two-level room (outermost room, room adjacent to innermost room, room on outer layer side than innermost room) 30Ba Contact opening (external communication opening) 33 Sliding door (opening / closing) Means) 33a Opening / closing door opening / closing device (opening / closing means) 34 Sliding opening / closing door (opening / closing means) 34a Opening / closing door opening / closing device (opening / closing means) 36 Opening (opening of building outdoor wall) 41 Inspection table 42 Inspector

Continued on the front page (72) Inventor Masataka Aoki 3-1-1 Sachimachi, Hitachi-City, Ibaraki Pref. Hitachi, Ltd. Hitachi Plant, Ltd. (72) Inventor Seiwa Hosoya 3-1-1 Sachimachi, Hitachi-City, Ibaraki Inside Hitachi, Ltd. Hitachi Plant (72) Inventor Takahiro Adachi 4-3-1, Higashi-Onuma-cho, Hitachi City, Ibaraki Prefecture Inside Icy C Co., Ltd.

Claims (4)

[Claims] In a method for replacing large equipment and structures in a nuclear power plant, the method comprises the steps of: replacing a room provided in a plurality of layers; Of these, the external connection port with the outside provided in the room of the outermost layer, the boundary connection port provided at the boundary of the adjacent room, and the external connection port and the boundary connection port can be opened and closed to a desired throttle state. A temporary building provided with opening / closing means is brought into close contact with the outer wall of the building, and the large-sized equipment / structure is replaced through the temporary building while securing predetermined airtightness with the opening / closing means. How to replace large equipment and structures in a nuclear power plant. 2. The method according to claim 1, wherein the temporary building is brought into close contact with an outer wall of the building, and the innermost room of the plurality of rooms and the innermost room are connected to each other. The boundary communication port at the boundary with the adjacent room is closed with the corresponding opening / closing means, an opening is formed by removing a part of the outer wall of the building inside the innermost room, and through the opening, And replacing the large-sized equipment / structure in the nuclear power plant. 3. The method for replacing large equipment and structures in a nuclear power plant according to claim 1, wherein the temporary building is brought into close contact with an outer wall of the building, and the large equipment and structures are lifted to form the plurality of rooms. Out of which, the innermost room penetrates into the outer room, and the boundary opening through which the large equipment / structure penetrates is closed by the corresponding opening / closing means. In this state, the large equipment is inserted inside the outer room. -A method for replacing large-scale equipment and structures in a nuclear power plant, which performs a radioactive contamination inspection or a radioactivity measurement of the structures. 4. The method for replacing large equipment and structures in a nuclear power plant according to claim 1, wherein when the replacement of the large equipment and structures is completed, the temporary building is moved away from the outer wall of the building and used. A method for replacing large equipment and structures in a nuclear power plant, wherein the large equipment and structures are reused as a part of a temporary building.