JPH11311693A - Taking-out method of nuclear reactor pressurized vessel and opening and closing device therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the discharge of radioactive substances from a building by using an air conditioner in an existing building by a comparatively simple facility, even in the case where RPV is integrally taken out from a reactor building, by providing a temporary opening part for taking-out and an openable door in the ceiling of the reactor building. SOLUTION: A temporary opening part for taking-out and an openable door are provided in the ceiling of a reactor building 4. Next, a shielding body 28 which shields radiation around a reactor pressure vessel 11 is provided. A reactor pressure vessel 1 is hung up directly under the door in a state in which the door is in opened size in which a hang wire 29b can pass therethrough. The door is opened up to the size, through which the reactor pressure vessel 1 can pass, and the reactor pressure vessel 1 directly under the door is taken out to the outside. The immediately after the reactor pressure vessel 1 is taken out to the outside of the door, it is closed. RPV can be integrally taken out, while negative pressure is maintained in the reactor building by the air conditioner in the existing building by the use of a comparatively simple facility by minimizing a gap between RPV and the temporary opening part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an unloading method and an unloading opening / closing device for unloading large equipment such as a reactor pressure vessel housed in a reactor building of a nuclear power plant outside a building.

[0002]

2. Description of the Related Art Reactor pressure vessels (hereinafter referred to as RPVs) are the most important components of a nuclear power plant, and the service period of a nuclear power plant generally depends on the service periods of RPV and auxiliary equipment inside and outside the reactor. ing. In recent years, it has become an important issue to extend the life of a nuclear plant and extend the service period of an aged nuclear power plant that is currently operating. In order to extend the service period of an aging nuclear power plant, it has become necessary to replace the RPV including auxiliary equipment inside and outside the reactor.

[0003] RP from reactor building accompanying RPV replacement
The V carrying-out method includes a first method in which the RPV is shredded in the reactor building, stored in a storage container, and carried out, and a second method in which the RPV is carried out of the reactor building as a unit. In order not to increase the capacity of the storage facility, the second method is advantageous.

[0004] As a conventional technique for carrying out an RPV integrally, for example, in Japanese Patent Application Laid-Open No. 8-262190, a gantry is provided across a reactor building, and a storage facility equipped with an air lock and a crane is provided on the gantry. Describes a technique of moving an RPV from a building into this storage facility and carrying it out. The publication also states that the release of radioactive materials from the reactor building can be prevented by carrying out the RPV using this device.

[0005]

However, for example, in a 780 MWe-scale reactor, the RPV has a diameter of about 6 mm.
m, the length is about 22 m, and the weight is about 530 tons. Therefore, in the above-mentioned conventional technology, the storage facility for storing the RPV and its mount are quite large. This also increases costs.

[0006] An object of the present invention is to provide an RPV capable of preventing the release of radioactive substances from a building using an existing building air-conditioning system with relatively simple equipment even when the RPV is integrally carried out of the reactor building. An object of the present invention is to provide a carry-out method and a carry-out opening / closing device.

[0007]

According to a first aspect of the present invention, there is provided a reactor pressure vessel housed in a reactor building of a nuclear power plant, which is integrally carried out of the reactor building. In the method for unloading a reactor pressure vessel, there is provided a temporary opening for unloading and a door that can be opened and closed on a ceiling of a reactor building.
Step, a second step of providing a shield for shielding radiation around the reactor pressure vessel, lifting the reactor pressure vessel to just below the door with the door open to a size that allows the hanging wire to pass through A third step of opening the door to a size that allows the reactor pressure vessel to pass through and a fourth step of carrying out the reactor pressure vessel immediately below the door to the outside, and placing the reactor pressure vessel outside the door; A fifth step of closing the door immediately after being carried out.

According to a second aspect of the present invention, there is provided a method for unloading a reactor pressure vessel housed in a reactor building of a nuclear power plant, wherein the reactor pressure vessel is integrally unloaded outside the reactor building.
A first step of providing a temporary opening for opening and a door that can be opened and closed on the ceiling of the reactor building; a second step of providing a shield for shielding radiation around the reactor pressure vessel; A third step of providing a seal curtain for accommodating a reactor pressure vessel, a fourth step of opening the door and carrying out the reactor pressure vessel to the outside after accommodating the reactor pressure vessel in the seal curtain, And a fifth step of closing the door after unloading the reactor pressure vessel to the outside of the door.

According to a third aspect of the present invention, there is provided a method for unloading a reactor pressure vessel housed in a reactor building of a nuclear power plant out of a reactor building.
A first step of providing a temporary opening for opening and a door that can be opened and closed on the ceiling of the reactor building; a second step of providing a shield for shielding radiation around the reactor pressure vessel; below the temporary opening A third step of forming an air curtain for separating the temporary opening from the interior of the reactor building, a fourth step of opening the door and carrying out the reactor pressure vessel to the outside, and the reactor pressure vessel A fifth step of closing the door after carrying it out of the door.

According to a fourth aspect of the present invention, there is provided an unloading opening / closing device for integrally unloading a reactor pressure vessel from a reactor building of a nuclear power plant, wherein the opening and closing device is formed on a ceiling of the reactor building and shields radiation therearound. A temporary opening for passing a reactor pressure vessel provided with a shield for performing, and a door provided on an upper part of the temporary opening, wherein the door is provided with respect to a central axis of the temporary opening. It has a double structure consisting of an upper door and a lower door slidable in opposite directions, and each of the upper door and the lower door has a notch with a semicircular cross section on the center axis side of the temporary opening. Each of the cutouts is provided with a seal member.

According to a fifth aspect of the present invention, there is provided an opening / closing device for unloading a reactor pressure vessel from a reactor building of a nuclear power plant, wherein the opening / closing device is formed on a ceiling of the reactor building and shields radiation therearound. Opening for letting through a reactor pressure vessel provided with a shielding body for opening and closing, an openable / closable door provided above the temporary opening, and the shielding body provided inside the temporary opening And a seal curtain for accommodating a reactor pressure vessel provided with the inside thereof.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of a method for carrying out a reactor pressure vessel (RPV) to the outside of a reactor building according to the present invention will be described below with reference to FIGS. FIG. 1 is a flowchart showing the unloading procedure of the first embodiment, FIG. 2 is a schematic longitudinal sectional view of a reactor building to which the unloading method of this embodiment is applied, and FIG. 3 is a reactor containment vessel (hereinafter, PCV) of FIG. 4 to 16 are schematic longitudinal sectional views showing a state around the PCV in main working steps in FIG. The present embodiment shows a procedure from carrying out the RPV integrally from the reactor building to transporting it to the temporary storage facility.

As shown in FIG. 2, P
There is CV3 and RPV1 is stored. The in-furnace structure 2 is housed in the RPV 1. In the upper region of the reactor building 4, a reactor well 9 is provided above the PCV 3, and a spent fuel pool 19 is provided adjacent to the reactor well 9. Reactor well 9 contains refueling and reactor internals 2
Is filled with water at the time of removal.

As shown in FIG. 3, the RPV 1 is fixed to a base RPV pedestal 5 with RPV base bolts 6. An RPV heat insulating material 7 and a γ-ray shield (hereinafter, referred to as RSW) 8 for shielding radiation are provided on the outer periphery of the RPV 1. At the top of PCV3, reactor well 9 and PCV3
A fuel exchange bellows 10 and a bulkhead plate 11 for partitioning the inside are provided.

The RPV 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, a main steam pipe 22, a water supply pipe 2
3, connected to each system pipe such as a recirculation inlet pipe 24 and a recirculation outlet pipe 25. A reactor pressure vessel lid (hereinafter, referred to as an RPV top head) 16 is provided above the RPV 1.
At the bottom of the RPV 1, a CRD housing 17 for accommodating a control rod drive (hereinafter, referred to as CRD) or an ICM housing 1 for accommodating a neutron flux detector (hereinafter, referred to as ICM).
8 are provided.

First, in step S1 of FIG. 1, the generator is disconnected and the operation of the nuclear power plant is stopped. Step S2
Then, the RPV top head 16 is opened and the reactor opening operation is performed. In the reactor opening work, the RPV top head 1
6 and an operation for removing a part of the furnace internal structure 2 are performed. In step S3, all the fuel is taken out of the reactor core and moved to the spent fuel pool 19 in the reactor building 4.

FIG. 4 shows a state around the PCV during the fuel removal operation in step S3. When unloading the RPV 1 and the in-furnace structure 2, the fuel 20 is a radiation source.
If the RPV 1 and the reactor internals 2 are carried out of the reactor building while the RPV is loaded, there is a possibility of radioactive contamination in the atmosphere. Therefore, in order to reduce the surface dose of the RPV 1, an operation of removing all the fuel 20 from the core is performed.

Next, in step S4, an operation of cutting each nozzle and pipe of the RPV 1 and an operation of removing the RPV base bolt 6 and separating the RPV 1 from the RPV pedestal 5 are performed to disassemble the RPV. FIG. 5 shows the bulkhead plate 11, PCV stabilizer 21, and RPV1 of the PCV3.
The positions where the pipes and the like connected to each nozzle are removed are indicated by broken lines. In FIG. 5, the PCV stabilizer 21 is a PC
Seismic support connecting V3 and RSW8, 26 is piping 2
It is a plug for preventing reactor water from leaking when cutting 2 to 25.

In this step, first, the bulkhead plate 11 is cut and removed, and then the PCV stabilizer 21 is cut and removed to secure a space for carrying out the removed material in the PCV3. Next, the plug 26 is attached to the RPV nozzles 12 to 15, the RPV nozzles 12 to 15 and the pipes 22 to 25 are cut and removed, and the disassembly around the RPV is completed.

At this time, in step S5, in parallel with the operation of step S4, a large hoisting machine 29 used to carry out the RPV 1 from the reactor building 4 is installed near the reactor building 4. FIG. 6 is a diagram showing a state where the large hoisting machine 29 is installed near the reactor building 4. Next, in step S6, a temporary opening and a door for carrying out the RPV are provided on the ceiling of the reactor building 4. FIG. 7 shows a state where a temporary opening 31 for carrying out RPV is provided on the ceiling of the reactor building 4 and a door 32 which can be opened and closed is provided on the roof. The door 32 includes an upper door 32a and a lower door 32b slidable (openable and closable) in directions opposite to each other with respect to the central axis of the temporary opening 31 having a circular cross section. In FIG.
The state where the suspension hook 29a of the large-sized hoisting machine 29 was positioned just above the door 32 is shown.

Next, in step S7, the upper door 32 of the temporary opening portion 31 is opened by a space capable of carrying the hanging hook 29a of the large hoisting machine 29. In step S8, the hanging hook 29a of the large hoist is carried in. FIG. 9 shows the door 32
3 shows a state in which a part of is opened to carry the suspension hook 29a of the large hoisting machine 29 into the reactor building.

Hereinafter, the manner in which the upper door 32a and the lower door 32b have a double structure of upper and lower doors will be described with reference to FIG. When the door 32 is in the closed state, as shown in FIG. 10A, the upper door 32a and the lower door 32b completely overlap. The door 32 has a structure in which the upper door 32a and the lower door 32b slide (open and close) in opposite directions to each other and simultaneously with respect to the central axis of the temporary opening 31. FIG. 10B shows a state where a part of the door 32 is opened. Upper door 32a and lower door 32b
Has a notch with a semicircular cross section on the center axis side of the temporary opening 31. A seal member 32c such as rubber or a sheet is attached to the cutout portions of the upper door 32a and the lower door 32b. The fully opened state of the door 32 is shown in FIG.

Here, a guide of the opening area of the temporary opening 31 will be described. In order to manage negative pressure inside the building with the existing ventilation (air conditioning) equipment installed inside the reactor building,
It is necessary to compare the amount of air flowing out from the temporary opening 31 of the reactor building 4 with the capacity of the existing ventilation equipment to determine the opening area of the temporary opening 31 that is allowed when the RPV is carried out.

Ventilation power P ₁ (kgf / m ² ) by wind outside the building
Is generally given by:

[0025]

[Number 1] _{P 1 = C · γ · v} 1 2 / 2g ... ( Equation 1) where, C is the wind pressure coefficient, γ (kgf / m ³⁾ is outside air specific weight, v ₁ (m / s) is Wind speed over the building, g = 9.8 (m /
s ² ) is the acceleration of gravity. On the roof of the building, C = -0.
9 Here, the negative wind pressure coefficient means a suction force from indoors to outdoors.

On the other hand, the outflow amount P ₀ (kgf / m ² ) of the building air per unit opening area due to the generated differential pressure is generally given by the following equation.

[0027]

[Number 2] _{P 0 = γ · ζ 0 ·} v 0 2 / 2g ... ( Equation 2) where, zeta ₀ outflow loss factor of the opening, v ₀ (m / s) in the outgoing air flow rate of the opening is there.

Now, let us estimate ζ ₀ . For simplicity, consider a model in which the air in the pipe flows out to the atmosphere from an orifice provided at the outlet of the pipe. In this case, there is a relationship as shown in FIG. 22 between the ratio d ₀ / d of the pipe inner diameter d and the orifice diameter d ₀ and the outflow loss coefficient ζ ₀ when air exits the orifice. Thus, for example, an average inner diameter of the reactor building corresponding to inner tube diameter d 40 m, the inner diameter of the temporary openings corresponding to orifice diameter d ₀ and 10 m, zeta from d ₀ / d = 0.25, and the 23 ₀ = 2.7. The smaller amount than the inner diameter of the provisional opening 10 m, zeta Figures 23 ₀ =
It can be seen that 2.7 is maintained.

On the other hand, the following equation is obtained from Equation 2.

[0030]

Equation 3] _{v 0 = (2g · P 0} / (γ · ζ 0)) 0.5 ... ( Equation 3) Now, P ₁ (ventilation force by building outside the wind) and P ₀ (air outflow by generating differential pressure ) Is balanced (P ₁ = P ₀ ), the following equation is obtained from Equations 1 and 3.

[0031]

V ₀ = v ₁ (C / ζ ₀ ) ^0.5 (Equation 4) Air outflow amount Q ₀ (m ³ / h) per unit area from the opening
/ M is between ²⁾ and v _0, since Q ₀ = relation 3600V ₀ holds, the number 4 the following equation is obtained.

[0032]

Q ₀ = 3600 v ₁ (C / ζ ₀ ) ^0.5 (Equation 5) Normally, large hoists are used under outdoor wind speeds of 10 m / s or less. Thus, taking necessary air volume to Q ₁ to the indoor needed to maintain the reactor building under conditions of outdoor wind speed 10 m / s in the negative pressure, consisting of several 5 as follows.

[0033]

Q ₁ = 3600 × 10 × (0.9 / 2.7) ^0.5 = 20785 (m ³ / h / m ² ) (Equation 6) By the way, a reactor building in a nuclear power plant with an output of 780 MWe Air flow Q on the operating floor
₂ is about 51000 (m ³ / h). Therefore, the permissible opening area S (m ² ) permissible in the temporary opening under this condition.
Is given by the following equation.

[0034]

S = Q ₂ / Q ₁ = 51000/20785 = 2.5 (Equation 7) In other words, in order to prevent air containing radioactive substances inside the reactor building from flowing out of the building, the RPV must be unloaded. At this time, the opening area of the temporary opening may be set to 2.5 m ² or less.

The opening area of the temporary opening when carrying out the RPV is 2.
If the volume cannot be reduced to 5 m ² or less, it is necessary to increase the amount of air taken into the reactor building by providing temporary intake and exhaust equipment.

For the above reasons, in this embodiment, when the RPV passes through the temporary opening 31, the opening area of the gap between the shielding body (described later in detail) covering the RPV and the temporary opening 31 is 2.5.
The provisional opening 31 is configured to be m ² or less. For example, when the outer diameter of the shield covering the RPV is about 10 m, the inner diameter of the temporary opening 31 may be about 10.16 m or less.
In addition, since the above estimation is performed under the condition of the outdoor wind speed of 10 m / s, when the RPV is carried out under the condition that the outdoor wind speed is weaker, the opening area of the gap may be larger than 2.5 m ^2. Is done.

As described above, the opening area of the gap between the shield covering the RPV and the temporary opening portion 31 is set to 2.5 m ² or less, and further, as shown in FIG. By providing the sealing member 32c in the notch of the lower door 32b and the lower door 32b, the gap between the shield covering the RPV and the upper door 32a and the lower door 32b can be sufficiently reduced when the RPV is carried out from the temporary opening 31. In addition, the air-conditioning system in the existing reactor building can maintain the negative pressure in the building. Thereby, it is possible to prevent the air containing radioactive material in the reactor building from flowing out of the building.

Next, in step S9, the RP having high radioactivity is used.
Attach the shield to V1. In this step, first, as shown in FIG.
Temporarily put on the upper side of RSW8, attach the suspension balance 33 to the RPV1, and attach the suspension hook 29a of the large lifting machine 29 to the suspension balance 33.
Attach to Thereafter, the RPV 1 is lifted together with the hanging balance 33, and the shield 27 is attached to the lower end of the hanging balance 33. Thus, the RPV 1 can be moved in a state where the shield 27 is provided on the entire circumference of the RPV 1.

Next, in step S10, the large lifting machine 29
Raise RPV1 using. FIG. 12 shows a state where the RPV 1 is lifted. In the figure, the RPV 1 and the shield 27 are suspended by a suspension hook 29 a via a suspension balance 33. In step S11, the shield 2 is further placed on the CRD housing and the ICM housing below the RPV1.
8 is provided. FIG. 13 shows a state in which the shield 28 is provided and the RPV 1 is lifted to near the ceiling of the reactor building 4. In this state, the upper door 32a and the lower door 3 of the reactor building 4
Reference numeral 2b is open as much as the hanging wire 29b of the large lifting machine 29 can pass. In this way, air containing radioactive materials inside the reactor building is prevented from flowing out of the building.

Next, in step S12, the RPV1 is carried out of the reactor building while the door 32 is gradually opened in accordance with the lifting of the RPV1. That is, in this step, the RPV
1 is lifted, and when the upper end approaches the door 32, the door 3
2, the temporary opening 31 and the door 32 are passed through the RPV 1, and the door 32 is closed immediately after the passage is completed. Thus, the carrying out of the RPV is completed. FIG. 14 shows a state in which the RPV 1 has passed through the temporary opening 31, and FIG. 15 shows a state in which the RPV 1 has been carried out of the reactor building.

[0041] As described above, in this embodiment, the opening area of the gap between the shield 27 and the temporary opening 31 during RPV out shown in Figure 14 is set to be 2.5 m ² or less, RPV 1 The upper door 32 immediately after the
By closing the lower door 32a and the lower door 32b, the inside of the reactor building 4 is maintained at a negative pressure, and the air containing radioactive substances in the reactor building 4 is prevented from flowing out.

Next, in step S13, the RPV1 is loaded on a large trailer previously arranged near the reactor building 4 and transported to the temporary storage facility. FIG. 16 shows a state before the RPV 1 carried out of the reactor building 4 is laid down by the RPV transport skid 34 installed on the large trailer 35 from the state of being lifted by the large hoisting machine 29 and transported to the temporary storage facility. Is shown.

As described above, according to the present embodiment,
By simply installing a door with a simple structure above the temporary opening, use the existing reactor building air-conditioning system to maintain a negative pressure inside the reactor building when unloading the RPV from the reactor building. Can be. Therefore, it is possible to prevent air containing radioactive substances in the reactor building from flowing out to the outside with relatively simple equipment. Accordingly, construction costs can be reduced. In addition, since large-scale intake and exhaust equipment other than the existing air conditioning equipment is not required, this also contributes to cost reduction. Furthermore, RP
Since the V can be unified, the process of RPV replacement work can be greatly reduced. In the present embodiment, the example in which the shields 27 and 28 are provided and moved on the RPV 1 has been described. Or simplify
It is also possible to move without attaching a shield. In this case, the unloading operation of the RPV can be unmanned or remotely monitored, and the cost can be further reduced.

In this embodiment, an example in which the method of carrying out the RPV according to the present invention is applied to the replacement work of the RPV has been described. It goes without saying that the present invention can be applied to the operation of carrying out and dismantling large equipment such as RPV using a door.

Next, a second embodiment of the method of unloading the RPV according to the present invention will be described with reference to FIGS. FIG.
FIG. 18 is a flowchart showing an unloading procedure according to the second embodiment.
20 to 20 are schematic longitudinal sectional views showing the state around the RPV in the main operation steps of FIG. In this embodiment, the RP
This is an example in which a seal curtain is used when carrying out V. Steps T1 to T11 in FIG. 17 correspond to step S in the first embodiment.
Since they are the same as 1 to S11, the description is omitted here. This embodiment is different from the first embodiment in step T12 and subsequent steps.

In step T12 of FIG.
A cylindrical seal curtain 36a for accommodating the RPV 1 is mounted inside the inside. The seal curtain 36a is installed on the inner surface of the temporary opening 31, and the installation portion is firmly laid to prevent air in the reactor building from entering the seal curtain 36a from this installation portion. As the seal curtain, a flameproof sheet for construction or a material similar thereto, which is difficult to pass air can be used. In Step T13, the RPV1 is lifted to a position where the RPV1 enters the seal curtain 36a. FIG. 18 shows a state after the end of step T13.

Next, at step T14, the bottom of the seal curtain 36a is closed so that the RPV 1 is stored inside the seal curtain 36a. FIG. 19 shows a state after the end of step T14. In the figure, the bottom of the seal curtain is indicated by 36b. By configuring the seal curtain in this way, the air inside the reactor building and the air inside the seal curtain are shut off.

Next, at step T15, the RPV 1 is carried out. In this step, first, the upper door 32 of the temporary opening 31
a and the lower door 32b are opened. Even if the door 32 of the temporary opening portion 31 is fully opened in this way, it is possible to prevent the air in the reactor building from flowing out of the building due to the blocking action of the seal curtain. After the door 32 is fully opened, the RPV 1 is carried out of the reactor building 4. FIG. 20 shows a state in which the RPV 1 is being carried out. After the carrying out of the RPV 1 is completed, the upper door 32a and the lower door 32b of the temporary opening 31 are closed, and the carrying out of the RPV is completed. Next, in step T16, step S13 in FIG.
The transport operation of the RPV 1 is performed in the same manner as described above.

Also in this embodiment, by simply providing a door and a seal curtain having a simple structure at the temporary opening, the reactor building can be maintained at a negative pressure and airtight can be maintained by using the existing reactor building air conditioning equipment. . Therefore, it is possible to prevent the air in the reactor building containing radioactive substances from flowing out to the outside with relatively simple equipment. Accordingly, construction costs can be reduced. In addition, since large-scale intake and exhaust equipment other than the existing air conditioning equipment is not required, this also contributes to cost reduction. Further, since the RPV can be integrally carried out, the RPV replacement work process can be greatly reduced.

Next, the RP according to the present invention will be described with reference to FIG.
A third embodiment of the method of unloading V will be described. The present embodiment is an example in which an RPV is carried out while maintaining a negative pressure in the reactor building by providing an air curtain at the temporary opening.
FIG. 21 is a schematic configuration diagram of equipment in a reactor building for carrying out the carrying out method of the present embodiment.

In FIG. 21, 37 is an intake fan, 38 is a discharge filter, 39 is a discharge duct, 40 is a discharge nozzle, 41
Is an exhaust fan, 42 is a suction filter, 43 is a suction duct, and 44 is a suction nozzle. The distal end of the discharge duct 39 and the distal end of the suction duct 43 facing each other below the temporary opening 31 have an annular cross section. A discharge nozzle 40 is provided at the tip of a discharge duct 39 whose section is annular, and a suction duct 43 whose section is annular.
An air curtain corresponding to the shape of the opening is provided below the temporary opening 31 having a circular cross section by providing the suction nozzles 44 at the front end of the opening so as to face each other.

In this embodiment, the upper door 32a of the temporary opening 31
Before opening the lower door 32b, the air in the reactor building 4 sucked by the intake fan 37 is discharged in the horizontal direction from the discharge nozzle 40 through the discharge filter 38 and the discharge duct 39, and the exhaust fan 41 sucks the suction nozzle. The air is sucked from the exhaust pipe 44 and exhausted from the exhaust fan 41 into the reactor building 4 through the intake duct 43 and the intake filter 42. Thus, an air curtain is formed below the door 32 of the temporary opening 31. FIG.
In FIG. 1, the flow of air from the discharge nozzle 40 to the suction nozzle 44 is indicated by an arrow.

In this embodiment, the temporary opening 3
In a state where an air curtain is formed below the first door 32,
The same shields 27 and 28 as in the first embodiment
And then unload the RPV1. In this case, equipment for forming an air curtain is required as compared with the first and second embodiments. However, compared to the related art, it is relatively simple equipment, and the existing air-conditioning equipment in the reactor building is used. As a result, the inside of the reactor building 4 can be maintained at a negative pressure, and the air containing radioactive materials inside the reactor building can be prevented from being released outside the building.
Accordingly, construction costs can be reduced. Further, since the RPV can be carried out integrally, the process of RPV replacement work can be greatly reduced.

As described above, in the first embodiment, the RP
By making the gap between V and the temporary opening extremely small,
In the second embodiment, a seal curtain is used, and in the third embodiment, an air curtain is used. By using relatively simple equipment, the air-conditioning equipment in the existing reactor building is used to load the reactor building. It is possible to carry out the RPV integrally while maintaining the pressure. Although the example of carrying out the RPV has been described in the above embodiment, the present invention can be applied to the carrying out of large-sized equipment inside the reactor building other than the RPV.

[0055]

According to the present invention, when large-sized equipment such as RPVs are integrally carried out of a reactor building, relatively simple equipment can be used by using the existing air-conditioning equipment in the reactor building. Can be maintained at a negative pressure, and air containing radioactive materials in the reactor building can be prevented from flowing out. Accordingly, construction costs can be reduced. In addition, since large equipment can be unified, the process of RPV replacement work and decommissioning work can be greatly reduced.

[Brief description of the drawings]

FIG. 1 is a flowchart showing a first embodiment of an RPV unloading method according to the present invention.

FIG. 2 is a schematic longitudinal sectional view of a reactor building to which the carrying-out method of the present invention is applied.

FIG. 3 is a schematic longitudinal sectional view around the PCV of FIG. 2;

FIG. 4 is a diagram showing a state during the operation of step S3 in FIG. 1;

FIG. 5 is a diagram showing an application target position of the work in step S4 of FIG. 1;

FIG. 6 is a diagram showing a state at the end of the work in step S5 in FIG. 1;

FIG. 7 is a view showing a state at the end of the work in step S6 in FIG. 1;

FIG. 8 is a diagram showing a state at the end of the work in step S6 in FIG. 1;

FIG. 9 is a diagram showing a state during the operation of step S8 in FIG. 1;

FIGS. 10A and 10B are explanatory diagrams of an open / closed state of a door of a temporary opening, and FIG.
Shows a state where the door is closed, (b) shows a state where a part of the door is open, and (c) shows a state where the door is fully opened.

FIG. 11 is a diagram showing a state during the operation of step S9 in FIG. 1;

FIG. 12 is a diagram showing a state during the operation of step S10 in FIG. 1;

FIG. 13 is a diagram showing a state at the end of the work in step S11 of FIG. 1;

FIG. 14 is a diagram showing a state during the operation of step S12 in FIG. 1;

FIG. 15 is a diagram showing a state at the end of the work in step S12 in FIG. 1;

FIG. 16 is a diagram showing a state during the operation of step S13 in FIG. 1;

FIG. 17 is a flowchart showing a second embodiment of an RPV unloading method according to the present invention.

FIG. 18 is a diagram showing a state at the end of the work in step T13 in FIG. 17;

FIG. 19 is a diagram showing a state at the end of the operation in step T14 in FIG. 17;

FIG. 20 is a diagram showing a state during the operation of step T15 in FIG. 17;

FIG. 21 is a schematic configuration diagram of equipment in a reactor building for carrying out a third embodiment of the method for unloading RPV according to the present invention.

FIG. 22 is a diagram showing a relationship between an outflow loss coefficient of air and an orifice diameter.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... RPV, 2 ... reactor internal structure, 3 ... PCV, 4 ... reactor building, 8 ... RSW, 9 ... reactor well, 17 ... CRD housing, 18 ... ICM housing, 19 ... spent fuel pool, 20 ... Fuel, 26 plug, 27, 28 shield, 29 large hoist, 29a hanging hook, 29b
Suspension wire, 31: Temporary opening, 32: Door, 32a: Upper door, 32b: Lower door, 33: Hanging balance, 34: Transport skid, 35: Large trailer, 36a, 36b: Seal curtain, 37: Intake fan , 38 ... discharge filter, 39
... discharge duct, 40 ... discharge nozzle, 41 ... exhaust fan,
42: suction filter, 43: suction duct, 44: suction nozzle.

Claims (8)

[Claims] In a method for unloading a reactor pressure vessel housed in a reactor building of a nuclear power plant, the reactor pressure vessel is integrally carried out of the reactor building. A first step of providing a temporary opening and a door that can be opened and closed, a second step of providing a shielding body for shielding radiation around the reactor pressure vessel, and the door is opened to a size that allows a hanging wire to pass therethrough. A third step of lifting the reactor pressure vessel to just below the door, a fourth step of opening the door to a size that allows the reactor pressure vessel to pass through, and carrying out the reactor pressure vessel immediately below the door to the outside; And a fifth step of closing the door immediately after unloading the reactor pressure vessel to the outside of the door. 2. The reactor according to claim 1, wherein said door has a double structure comprising an upper door and a lower door slidable in directions opposite to each other with respect to a center axis of said temporary opening. How to unload the pressure vessel. 3. The door according to claim 2, wherein the upper door and the lower door each have a notch having a semicircular cross section on the center axis side of the temporary opening, and a seal member is provided at each notch. A method for unloading a reactor pressure vessel, characterized in that: 4. The reactor according to claim 1, wherein the clearance between the shield of the reactor pressure vessel and the temporary opening is 2.5 m when the reactor pressure vessel is carried out. ^A method for unloading a reactor pressure vessel, wherein the number is ² or less. 5. A method for unloading a reactor pressure vessel housed in a reactor building of a nuclear power plant, wherein the reactor pressure vessel is unified to the outside of the reactor building. A first step of providing a temporary opening and a door which can be opened and closed, a second step of providing a shield for shielding radiation around the reactor pressure vessel, and for storing the reactor pressure vessel inside the temporary opening A third step of providing a seal curtain, a fourth step of opening the door and carrying out the reactor pressure vessel to the outside after storing the reactor pressure vessel in the seal curtain, and A fifth step of closing the door after being carried out of the door, and carrying out the reactor pressure vessel. 6. A method for unloading a reactor pressure vessel housed in a reactor building of a nuclear power plant, wherein the reactor pressure vessel is integrally transported to the outside of the reactor building. A first step of providing a temporary opening and an openable door, a second step of providing a shielding body for shielding radiation around the reactor pressure vessel, and the temporary opening and the atom below the temporary opening. A third step of forming an air curtain for separating the inside of the reactor building, a fourth step of opening the door and carrying out the reactor pressure vessel outside, and after carrying out the reactor pressure vessel outside the door A method for carrying out a reactor pressure vessel, comprising a fifth step of closing the door. 7. An opening / closing device for unloading a reactor pressure vessel from a reactor building of a nuclear power plant, wherein the switching device is formed on a ceiling of the reactor building and shields radiation therearound. A temporary opening for allowing the reactor pressure vessel provided with the body to pass therethrough, and a door provided above the temporary opening, wherein the doors are arranged in opposite directions with respect to a central axis of the temporary opening. It has a double structure consisting of a slidable upper door and a lower door, and the upper door and the lower door each have a notch with a semicircular cross section on the center axis side of the temporary opening. An opening / closing device for carrying out, wherein a sealing member is provided in a portion. 8. An opening / closing device for unloading a reactor pressure vessel from a reactor building of a nuclear power plant, wherein the opening and closing device is formed on a ceiling of the reactor building and shields radiation therearound. A temporary opening for allowing the reactor pressure vessel provided with the body to pass therethrough, an openable / closable door provided above the temporary opening, and the shielding body provided inside the temporary opening. A carry-out opening / closing device, comprising: a seal curtain for accommodating a reactor pressure vessel therein.