JP3519074B2 - Removal method of reactor pressure vessel - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for unloading a reactor pressure vessel including equipment inside and outside the reactor.

[0002]

2. Description of the Related Art A reactor pressure vessel is the most important equipment of a nuclear power plant, and the service life of the nuclear power plant is generally R
It depends on the service life of PV and auxiliary equipment inside and outside the furnace. Further, when the nuclear power plant is out of service, the nuclear power plant must be dismantled and the RPV must be decommissioned.

An example of the above decommissioning technology is disclosed in Japanese Patent Laid-Open No. 6-230.
The method for unloading a reactor pressure vessel described in Japanese Patent No. 188 is a method for unloading a reactor pressure vessel that does not emit radiation into the atmosphere, and includes loading a new reactor pressure vessel. It is not a method of replacing the reactor pressure vessel.

On the other hand, in order to supply power demand, it is necessary to install a new nuclear power plant in order to supplement the nuclear power plant that has been decommissioned.

However, construction of a new nuclear power plant requires long working days and enormous cost. In addition, in order to construct a new nuclear power plant, it is necessary to clear various issues such as a candidate site plan that meets the location conditions and the consent of local residents.

Therefore, it is becoming an important issue to extend the service period of the aged nuclear power plant which is currently operating.

At the aged nuclear power plant, each facility / equipment is repaired or replaced in a timely manner except for the reactor pressure vessel (hereinafter referred to as RPV) and the reactor internal structure of the reactor internal / external auxiliary equipment, Nuclear power plant is being refreshed. From the standpoint of operating the plant within the service period, it was not necessary to replace the RPV and internal reactor components.

Further, recently, in an aged plant, locations where preventive maintenance measures are required have been found in the auxiliary equipment inside and outside the furnace, the joint between the RPV and the control rod drive device, and the like. Performing preventive maintenance such as repair and replacement of these equipment inside and outside the reactor would require long construction days and enormous cost.Therefore, measures to extend the service life of aged nuclear power plant and preventive maintenance of equipment inside and outside the reactor As a countermeasure, RP including auxiliary equipment inside and outside the furnace
It has become necessary to establish a V replacement method. In this case, it is important to shorten the plant shutdown period as much as possible.

In the replacement work of the RPV, the radiation shield (hereinafter, referred to as a γ shield) of the reactor containment vessel itself can be continuously used as it is. Since the nozzle has a shape that goes inside the γ shield, when considering the loading and unloading of the RPV, the RPV nozzle interferes with the γ shield.
It was planned to remove the γ shield in order to replace the V. R including equipment inside and outside the furnace
In PV replacement work, how to shorten the plant downtime,
The challenge is how to do it in a short period of time.

[0010]

However, the above-mentioned conventional techniques have the following problems. The method of carrying out the RPV was considered, but the new RP
No method of replacing the RPV including the delivery of V has been considered. 2. In the early nuclear power plants, the distance from the center of the RPV to the tip of the nozzle was larger than the γ shield inner diameter dimension,
Since the RPV nozzle has a shape that fits inside the γ shield, when considering replacement of the RPV, the RPV nozzle interferes with the existing γ shield when the RPV is carried in and out. Therefore, when replacing the RPV, the existing γ shield must also be removed, and there has been a problem that the replacement work requires an enormous amount of time and cost.

An object of the present invention is to solve the above problems and provide a method for unloading a reactor pressure vessel in which the RPV including the equipment inside and outside the reactor can be replaced without removing the γ shield of the reactor containment vessel. Especially.

[0012]

Means for Solving the Problems] (1) To achieve the above object, the present invention, gamma shield set on a different radiation shield gamma shield and the reactor internal and external accessory devices reactor building Suspend the reactor pressure vessel including the above on the γ shield.
Stored in the radiation shield while raising Ri, the reactor pressure vessel in a state of being stored in the radiation shield, said original
It is carried out to the outside of the reactor building through an opening provided in the upper part of the sub reactor building . (2) In order to achieve the above object, the present invention provides
A radiation shield different from the shield is set on the gamma shield
However, the reactor pressure volume including the equipment inside and outside the reactor building
While holding the vessel above the gamma shield,
Stored in a shield, and in the state of lifting it, another shield is attached to the bottom.
Attach the body and store it in the radiation shield
The reactor pressure vessel with the shield attached is
From the opening in the upper part of the sub reactor building to the outside of the reactor building
Carry out.

[0013] By these, without detaching the γ shield disposed around the reactor pressure vessel, a reactor pressure vessel containing a reactor internal and external accessory device, installation is a reactor pressure vessel containing a reactor internal and external accessory device The new reactor pressure vessel, including new reactor internal and external auxiliary equipment, can be carried out to the outside of the reactor building as it is, and new internal and external auxiliary equipment can be installed without removing the γ shield. A new reactor pressure vessel including the new reactor pressure vessel can be loaded into the reactor building as it was installed before delivery. As a result, the time for removing the γ shield is not necessary, and the time required for replacing the reactor pressure vessel including the equipment inside and outside the reactor can be significantly reduced.

At this time, as in the above (1) and (2), the reactor pressure vessel including the equipment inside and outside the reactor is lifted up integrally and stored in a radiation shield different from the γ shield set above the γ shield. By carrying out from the opening provided in the upper part of the reactor building to the outside of the reactor building, the work under high radiation is alleviated, the time required for carrying out is shortened, and the amount of radioactive materials released to the external environment is reduced. The amount can be reduced.

(3) In the above (1) or (2) , preferably, the reactor pressure vessel is carried out after cutting the nozzle portion.

(4) In the above item ( 3 ), more preferably, the nozzle portion is cut at a nozzle height that does not interfere with the inner wall of the γ shield.

[0017] (5) above (1) In any one of to (4), and preferably, before Symbol reactor pressure vessel wherein
Provided in the vicinity of the opening so that the contaminated air in the reactor building does not flow out to the outside of the reactor building from the opening formed in the roof of the reactor building when being carried out to the outside of the reactor building. Intake of the polluted air by the intake and exhaust equipment provided,
After cleaning, exhaust to the outside of the reactor building.

This makes it possible to maintain a negative pressure inside the reactor building to maintain airtightness, and prevent radioactive materials from being released to the external environment.

( 6 ) In the above ( 5 ), more preferably, the intake and exhaust equipment cleans the contaminated air, and a suction duct having a suction port near the opening for sucking the contaminated air. It has a filter, an exhaust fan for exhausting the cleaned air, and an exhaust duct for exhausting the air to the outside of the reactor building.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a method for replacing a reactor pressure vessel and equipment for replacing the reactor pressure vessel according to an embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows a cross section of an RPV including auxiliary equipment inside and outside the furnace.

Among the auxiliary equipment inside and outside the furnace, each equipment inside the RPV 1 is generally called a reactor internal structure 2. The in-core structure 2 is composed of a steam dryer 3, a shroud head (including a steam separator) 4, a core shroud 5, a core support plate 6, an upper lattice plate 7, a shroud support 8 and the like, and the core part While accommodating each equipment in the reactor forming the, it becomes a partition for guiding the flow of the reactor coolant entering the core,
The reactor coolant flow path to the core, the flow path with the steam-water mixture, and the necessary flow path for the water and steam separated by the built-in steam-water separator are formed, and thereby the reactor cooling It provides a water circulation circuit.

The RPV 1 includes a main steam nozzle 9, a water supply nozzle 10, a core spray nozzle 11, and a recirculation inlet nozzle 1.
2, Recirculation outlet nozzle (hereinafter referred to as RPV nozzle) 1
3 and the like are provided, and each system pipe is connected to each nozzle tip shown above.

A reactor pressure vessel lid (hereinafter referred to as an RPV head) 37 is provided on the top of the RPV 1, and a control rod drive device (hereinafter referred to as a CRD) 20 among reactor auxiliary equipment is provided at the bottom of the RPV 1. CRD housing 2 for housing
3 and a neutron flux detector (hereinafter referred to as ICM) 21. There is an ICM housing 24.

FIG. 2 shows a cross section of the reactor containment vessel in which the RPV including the reactor internal / external auxiliary equipment (reactor internal structure 2, CRD housing 23, etc.) is accommodated.

Reference numeral 1 is RPV, 16 is a reactor containment vessel (hereinafter referred to as PCV), 31 is a reactor building, 17 is a γ shield, and 9 to 13 are RPV nozzles.

In the PCV 16, the RPV heat insulating material 92 provided on the outer periphery of the RPV 1, the γ shield 17, and the RPV 1 are R
RPV pedestal 18, which is fixed by PV foundation bolt 28 and serves as the foundation of RPV 1, and PCV 16 upper part,
A reactor well 32 and a fuel exchange bellows 15 for partitioning the inside of the PCV 16 for filling water at the time of refueling or taking out reactor internals are provided.

In the RPV pedestal 18, CR
C that supports the D housing 23 and the CRD housing 23
An RD housing support beam 22, a CRD housing support block 25, and an ICM housing 24 are provided.

Γ shield 17 and RPV pedestal 1
The connection of 8 is supported by a gamma shield foundation bolt 29.

On the upper part of the γ shield 17, a seismic support PCV stabilizer 30 for the PCV 16 and an seismic support RPV stabilizer 30a for the RPV are provided.

FIG. 3 shows a cross section of the reactor building 31 in which the PCV 16 of FIG. 2 is housed.

A spent fuel pool 33 is provided in the reactor building 31, a rack 56 for storing spent fuel is provided in the spent fuel pool, and a reactor well 32 is provided above the PCV 16.

Next, referring to FIGS. 4 to 16, in the method for replacing the reactor pressure vessel according to the embodiment of the present invention, the auxiliary equipment inside and outside the reactor (reactor internal structure 2, CRD housing 23, etc.).
Large block with RPV integrated (modularized)
A detailed explanation of the carry-out method and its equipment will be given.

FIG. 4 shows a flow chart of a series of unloading operations by forming the reactor internal structure 2, the CRD housing 23, etc., into a large block (modularization) integrated with the RPV 1.

First, in step 35, the generator is disconnected, the periodical inspection of the nuclear power plant is started, and then the reactor opening work is performed (36).

The nuclear reactor opening work is a critical work required to handle the fuel in the core, and mainly includes the RPV head removing work for removing the RPV head 37, the steam dryer removing work for removing the steam dryer 3, and the shroud. Head 4
Shroud head removal work is performed.

Next, the operation for extracting all the fuel in the core is performed (38). The total fuel removal operation is an operation of moving all the fuel loaded in the core to the spent fuel rack 56 of the spent fuel pool 33.

FIG. 5 shows a procedure for carrying out the fuel during the operation for taking out all the fuel in the core.

1 is RPV, 2 is a furnace internal structure, and 23 is CR
D housing, 27 is fuel, and 19 is a bulkhead plate that partitions the reactor well 32 and the PCV 16.

When carrying out the RPV 1 and the in-core structure 2, since the fuel itself is a radiation source, it is necessary to carry out the RPV 1 and the in-core structure 2 outside the reactor building 31 with the fuel loaded. , There is a risk of radioactive contamination in the atmosphere and 100% fuel removal work is carried out to reduce the surface dose of RPV1.

When all the fuel has been taken out, RPV1
Draining of the reactor water contained therein is carried out, and then the carrying-out work is carried out by making the reactor internal structure 2 and the CRD housing 23 and the like integrated with the RPV 1 into a large block (modularization).

The reactor water may be contained in the RPV 1 without performing the reactor water draining operation described above. In that case, the reactor water has a shielding effect when the RPV 1, the reactor internal structure 2, the CRD housing 23, and the like are carried out to the outside of the reactor building.

However, in the case where the above-mentioned reactor water is contained, it is necessary to provide nozzle plugs to the nozzles 9 to 13 in order to prevent water leakage from the nozzles 9 to 13 provided in the RPV 1. is there.

FIG. 6 is a unloading procedure diagram showing the bulkhead plate, the pipe removing portion, and the dismantling position in the pedestal. The broken line shows the range to be removed.

Reference numeral 19 is a bulkhead plate partitioning the reactor well 32 from the PCV 16, 30 is a seismic support PCV stabilizer connecting the PCV and the γ shield 17,
Reference numeral 34 is a pipe connected to each nozzle of the RPV 1, and 14 is a nozzle plug for preventing leakage of reactor water when the pipe is cut.

In step 39, the dismantling work of RPV1 is first carried out.

The dismantling work of RPV1 is performed in the following procedure.

1. The bulkhead plate 19 is cut (40).

2. The cutting operation of the PCV stabilizer 30 is performed (41).

3. The RPV nozzles 9 to 13 and the pipe 34 attached to the nozzles are cut (42).

4. The unloading work of the cut nozzle and piping is performed (43).

5. Loosen RPV foundation bolt 28 to RPV
Separate the pedestal 18 and RPV1 (4
4).

On the other hand, in parallel with the dismantling work of the RPV 1, the dismantling work in the RPV pedestal 18 is carried out in the following procedure at step 45.

1. CRD housing support block 2
Perform removal work of 5 (46).

2. Cable removal work of CRD20 and ICM21 is performed (47).

3. The CRD 20 is removed 48.

4. CRD insertion and withdrawal piping 20a is cut (49).

5. The housing support beam 22 is removed (50).

An example of cutting the RPV nozzles 9 to 13 described above will now be described with reference to the representative nozzle 13 with reference to FIG.

FIG. 7 shows details around the RPV nozzle 13 in the A section of FIG. RPV and shows the positional relationship between the nozzle 13 and γ shield 17, the γ shield 17, the nozzle opening 90 is formed at a position of the RPV nozzle 13, RPV
The nozzle 13 is connected to the connection pipe 13c by welding with the nozzle safe end 13b.

RPV nozzle 13 and nozzle safe end 1
The weld line 67a of 3b is inserted into the gamma shield 17 by the size of 68a. An RPV heat insulating material 92 is attached to the outer periphery of the RPV 1, and a nozzle heat insulating material 92a is attached to the RPV nozzle 13. Also, the connection pipe 13c
A pipe heat insulating material 92b is attached to the. The outside of the nozzle heat insulating material 92 a in the opening of the γ shield 17 is closed by a shield plug 64.

In the case of cutting the connection pipe 13c, first, the shield plug 64 is removed, the pipe heat insulating material 92b attached to the outer periphery of the connection pipe 13c is removed, and the nozzle heat insulating material 92a attached to the RPV nozzle 13 is removed. After that, the nozzle safe end 13b and the connection pipe 13c
Is cut at the cutting position 67b, then the connecting pipe 13c is cut at the cutting position 67c, and the connecting pipe 13c is removed.

Next, the nozzle is cut at the cutting position 67 of the RPV nozzle 13. Cutting position 67 of RPV nozzle 13
Is the RP that was disconnected from the γ shield 17 when carrying out the RPV1.
The VPV nozzle 13 is located on the RPV1 body side from the inner wall position of the γ shield 17 so that the nozzle height does not interfere, and the cutting position 67 of the RPV nozzle 13 and the gap 68 between the γ shield 17 are arranged.
Is the γ shield 17 when the RPV1 is carried out (lifted and moved).
And the RPV nozzle 13 that has been cut is a gap that secures a margin so as not to interfere.

As another method for removing the pipe, the pipe 13
A method of removing the pipe by setting the cutting position 67b of c to the same position as the nozzle cutting position 67 may be adopted. Since the radiation inside the RPV 1 comes out from the RPV nozzle 13 after cutting, a temporary shielding plate is attached to the nozzle cutting port to seal it.

After the dismantling work of the RPV and the dismantling work in the RPV pedestal described above are completed, next, while the furnace internal structure 2 and the CRD housing 23 and the like are lifted by a large block integrated with the RPV 1. Shielding work is performed (51).

FIG. 8 is a unloading procedure diagram showing a state before lifting the RPV. 57 a is an upper shield (hereinafter referred to as “shahey”) body of RPV 1 installed on the γ shield 17.
Reference numeral 7b denotes a core core shay body of RPV1 temporarily placed on the upper part of the γ shield 17.

FIG. 9 is a carrying-out procedure diagram showing a state in which the RPV 1 is lifted up, and the RPV temporarily placed on the upper part of the γ shield 17.
It shows a state in which the reactor core portion shay body 57b is set in the reactor core portion.

FIG. 10 shows the RPV with the RPV 1 being suspended.
It is a carrying-out point diagram which shows the state which attached the lower shay body 57c.

FIG. 11 shows the CRD with the RPV1 being lifted.
It is a carrying-out point diagram which shows the state which attached the cover 57d to the housing 23 part.

In carrying out the integrated unloading work by forming the reactor internal structure 2 and the CRD housing 23 and the like into a large block by integrating them with the RPV 1, since the radiation doses of the RPV 1 and the reactor internal structure 2 are extremely large, the reactor building 31 Before carrying out, the work of attaching the cylindrical shay bodies 57a to 57d is performed (51).

Further, in order to prevent the scattering of radioactive dust attached to the surface of RPV1 when it is carried out outdoors,
It is necessary to seal the RPV 1 with the cylindrical shay bodies 57a to 57d.

The shay bodies 57a to 57d shown in FIGS.
The work of attaching the is explained.

The upper shay body 57a of the RPV 1 is set above the γ shield 17. Next, the core portion shay body 57b of the RPV 1 is temporarily placed on the upper portion of the γ shield 17,
While suspending a large block in which the reactor internal structure 2, the CRD housing 23 and the like are integrated with the RPV 1 from above the γ shield 17, the RPV core portion shay body 57b is set on the outer surface of the RPV core portion.

Next, with the large block in which the reactor internal structure 2 and the CRD housing 23, etc. are integrated with the RPV 1, is lifted, the RPV lower shay body 57c divided into several pieces is attached, and then the CRD housing 23 part and the large block. The shay body 57d is attached to the bottom portion, and a large block in which the reactor internal structure 2, the CRD housing 23, and the like are integrated with the RPV 1 is stored in the shay bodies 57a to 57d to be in a sealed state.

FIG. 12 is a unloading procedure diagram showing a state in which the RPV 1 is lifted by a large-sized lifting machine.

In the integrated carry-out work in step 52 by forming the reactor internal structure 2, the CRD housing 23 and the like into a large block by integrating them with the RPV 1, a temporary opening 58 is installed in the ceiling of the reactor building 31 (54 ), A large lifting machine 60 is installed near the reactor building 31 (55), and a large lifting machine 6 is installed.
It is hoisted at 0 (53) and is carried out from the temporary opening 58 to the outside of the reactor building 31. At this time, the temporary opening 5 of the reactor building 31
In order to prevent the air containing the radioactive material in the reactor building 31 from being discharged to the outside of the reactor building 31, the temporary opening 58 is provided with a shutter 59 that can be opened and closed.

FIG. 13 shows the details of the intake / exhaust equipment of the part B in FIG. A measure for preventing the air containing the radioactive material in the reactor building 31 from being discharged to the outside of the reactor building 31 through the temporary opening 58 of the reactor building will be described with reference to FIG.

A lid or a shutter 59 is provided on the temporary opening 58 provided on the upper part of the reactor building 31, for example, on the ceiling so that radioactivity does not leak outside. At this time, in order to prevent the contaminated air of the reactor building 31 from flowing out from the temporary opening 58 to the outside, an intake / exhaust facility is provided near the opening, and the reactor building 31 is kept at a negative pressure to maintain airtightness. If the methods are used together, the effect of the measures will be greatly improved.

According to this method, a duct 62 with a suction port is provided near the temporary opening 58, and a facility for exhausting air from the stack 66 through the exhaust duct 65 by the filter 63 and the exhaust fan 64 is installed. It is possible to keep the reactor building under negative pressure and maintain airtightness.

Next, a method of installing a clean room above the reactor building to maintain airtightness will be described.

In FIG. 14, a clean room is installed in the upper part of the reactor building, and a large lifting machine is used for the reactor internal structure 2 and CR.
It is a carrying-out procedure diagram showing a state in which a large block in which the D housing 23 and the like are integrated with the RPV 1 is lifted.

As shown in FIG. 14, when carrying out of the reactor building 31, a clean room 61 adjacent to the ceiling of the reactor building 31 is provided, in which the reactor internals 2 and the CRD are installed.
After moving a large block in which the housing 23 and the like are integrated with the RPV 1 and closing the shutter 59 of the reactor building 31,
There is also a method of carrying it out of the reactor building 31.

The large lifting machine 60 lays a jari on the ground so as to withstand its own weight and a large block in which the reactor internal structure 2, the CRD housing 23 and the like are integrated with the RPV 1 and the weight at the time of lifting. After taking measures to strengthen the ground by laying an iron plate, the internal structures 2 and C
A large block in which the RD housing 23 and the like are integrated with the RPV 1 is carried out.

The storage of a large block that has been carried out from the reactor building 31 and in which the reactor internal structure 2 and the CRD housing 23 and the like are integrated with the RPV 1 is inserted into the waste storage provided near the reactor building 31. There is a method to store and to store it, and a method to transport it to a waste storage warehouse on the premises of the nuclear power plant with a large trailer and store it.In either case, the surface dose does not affect the environment due to shielding or decontamination. It can be stored in the waste storage after reducing the amount.

As described above, the carrying-out work by forming the reactor internal structure 2, the CRD housing 23 and the like into a large block by integrating them with the RPV 1 is completed.

Next, a detailed description will be given of the carrying-in method and its equipment by making the reactor internal structure 2, the CRD housing 23 and the like into a large block by integrating them with the RPV 1.

FIG. 15 shows the RPV nozzle 13 of part A in FIG.
FIG. 4 shows Example 1 of the improvement of the shape of the newly introduced RPV nozzle in the enlarged detail of FIG.

The shape of the RPV nozzle before improvement and the shape after improvement will be described with reference to FIG.

13 is the old RPV nozzle before replacement, 13
a is a newly introduced RPV nozzle according to the present invention, 13
b is the nozzle safe end welded to the nozzle, D1 is the old R
The diameter of the welding line between the PV nozzle nozzle stub and the RPV cylinder, D2 is the diameter of the welding line between the new RPV nozzle nozzle stub and the RPV cylinder, L
a indicates the height of the old RPV nozzle nozzle base, and Lb indicates the height of the new RPV nozzle nozzle base.

When the height R of the old RPV nozzle 13 remains the same, the height of the nozzle is high and the old RPV nozzle 13 enters the γ shield 17, and the reactor internal structure 2 and the CRD housing 23 and the like are integrated with the RPV 1 in a large size. The nozzle of the RPV 1 interferes with the γ shield 17 when the block is loaded.
RPV1 without interference between RPV nozzle and γ shield 17
In order to be able to carry in the RP, the nozzle height of the RPV nozzle 13 is made lower and the RP from the inner wall of the γ shield 17 is reduced.
It is necessary to make the shape and size of the RPV nozzle 13a so as to bring it to the body side of V1.

When the nozzle shape of the RPV 1 is the same as that of the old RPV nozzle 13, the height required to satisfy the reinforcement and the shape regulation is required due to the standard requirement for the reinforcement design of the nozzle nozzle base portion. Γ the height of the nozzle 13
It cannot be lowered without interfering with the shield 17.

For this reason, for the newly loaded RPV 1, it is necessary to reduce the height of the nozzle so as not to interfere with the γ shield 17 with respect to the structure of the nozzle portion, the welding position, and the like.

The reduction of the nozzle height is achieved by devising the nozzle structure shape as follows and changing it from the conventional one.

In the old RPV nozzle 13, when determining the shape and size of the nozzle stub, since the nozzle stub was reinforced by the nozzle stub itself without changing the plate thickness on the RPV barrel side, the nozzle stub was thick-walled. And the height La of the nozzle was high.

In the improved new RPV nozzle 13a, the height of the nozzle stub was lowered by devising a design method for reinforcing the nozzle nozzle stub while satisfying the requirements of the standard. That is, in determining the structural shape of the nozzle stub, the thickness of the nozzle stub on the RPV barrel side is increased, and the diameter D2 of the welding line between the nozzle nozzle stub and the RPV barrel is set larger than the conventional diameter D1. By providing a surplus for reinforcement in the portion, the surplus required for the reinforcement is made small in the nozzle part protruding to the outside of the RPV cylinder, and the height of the nozzle is lowered like Lb. .

As a result, the height of the RPV nozzle 13a can be brought closer to the body of the RPV1 than the inner wall of the γ shield 17, and the RPV nozzle 13 can be suspended with the RPV1 suspended.
It is possible to secure a gap 69 where the tip of a and the γ shield 17 do not interfere with each other.

FIG. 16 shows the RPV nozzle 13 of part A of FIG.
2 shows the second embodiment of the improvement of the newly introduced RPV nozzle shape in the enlarged detail of FIG.

In FIG. 16, the shape of the RPV nozzle before improvement and the shape after improvement in Example 1 will be described in comparison.

13 is the old RPV nozzle, La is the height of the old RPV nozzle, 13d is the improved new RPV nozzle, L
b shows the height of the new RPV nozzle. In the improved new RPV nozzle 13d, the nozzle nozzle base is extended to the inside of the RPV cylinder to provide a surplus of reinforcement in this portion, and the outer surface shape of the nozzle surface on the outer surface side of the RPV cylinder is tilted. The height of the table is as low as Lb. This allows
Set the height of the RPV nozzle 13d to R from the inner wall of the γ shield 17.
It can be brought to the PV1 barrel side, and a gap 69 can be secured so that the tip of the RPV nozzle 13d and the γ shield 17 do not interfere with each other while the RPV1 is suspended.

By improving the height of the RPV nozzle as described above, the nozzle and the γ shield 17 are improved.
The gap 69 on the inner wall of the RPV can be a gap that secures a margin so that the RPV nozzle and the γ shield 17 do not interfere with each other when the RPV 1 is carried in (suspended movement). RPV1 without
Can be brought in.

Next, referring to FIGS. 17 to 23, in the method of replacing the reactor pressure vessel according to the embodiment of the present invention, the reactor internal structure 2, the CRD housing 23 and the like are integrated into the RPV in a large size. A detailed explanation of the method of carrying in by using blocks (modularization) and its equipment is given.

FIG. 17 shows a flow chart of a series of carrying-in work by making the reactor internal structure 2, the CRD housing 23 and the like into a large block (modularization) integrated with the RPV 1. First, R that was made into a large block in step 72
PV loading work is performed.

FIG. 18 shows a new RPV made into a large block.
FIG. As shown in FIG. 18, the new RP
V1, the furnace internal structure 2, the CRD housing 23, etc. are made into a large block and carried in (73).

At the factory or on-site, when carrying in the work of forming a large block in which the RPV 1, the internal structure 2, the CRD housing 23, etc. are made into an integrated structure, the same as when carrying out the RPV 1, the reactor building is carried out in step 71. 31. A large lifting machine 60 installed near 31 is used to open the shutter 59 of the temporary opening 58 provided in the reactor building 31 used when unloading the RPV 1 (70), and from there, the reactor building 3
Bring it to 1.

When the shutter 59 of the temporary opening 58 of the reactor building 31 is opened, the method of preventing the contaminated air of the reactor building 31 from being washed away from the temporary opening 58 to the outside is the same as when the RPV 1 is carried out. Exhaust equipment is provided near the temporary opening 58 of the building 31 to take measures against the method of keeping the reactor building 31 at a negative pressure and maintaining airtightness.

Next, the new RPV 1, the reactor internal structure 2, the CRD housing 23, etc. are integrated and carried into the PCV 16 in the reactor building 31, the RPV 1 is installed on the RPV pedestal 18, and then the RPV setting operation is performed ( 74).

FIG. 19 is a recovery procedure diagram showing a state in which the new RPV 1 is set on the RPV pedestal 18.

FIG. 20 is a recovery procedure diagram showing the connection of the RPV nozzle 13a, the nozzle safe end 13b, the pipe 13c, and the work place in the pedestal.

FIG. 21 shows the mounting location of the bulkhead plate 19.

The setting operation of the new RPV 1 is as follows, but the procedure does not necessarily have to be in the following order.

1. Tighten the RPV foundation bolt 28 (75).

2. The setting operation of the RPV stabilizer 30a is performed (76).

3. Weld the nozzles of the RPV nozzles 9 to 12 and 13a and the nozzle safe end 13b (7
7).

4. Nozzle safe end 13b and piping 13
The welding work of c is performed (78).

5. The bulkhead plate 19 is welded (79).

On the other hand, after the integrated carrying-in work of the RPV 1, the internal structure 2, the CRD housing 23, etc., in parallel with the work inside the PCV 16, at step 80, the RPV pedestal 1 is carried out.
Although the setting work in 8 is performed, it is carried out by the following procedure.

1. The mounting work of the housing support beam 22 is performed (81).

2. CRD insertion and withdrawal piping connection work is performed (82).

3. Install the CRD20 (8
3).

4. The cable installation work of CRD20 and ICM21 is performed (84).

5. CRD housing support block 2
5 is attached (85).

As described above, RPV1, internal structure 2, CR
A series of carrying-in operations by integrating the D housing 23 and the like into a large block is completed.

After that, the main work of normal regular inspection is started. In step 86, CRD inspection work is performed. Next, all fuel loading and fuel shuffling operations are performed (87).
Next, the core confirmation work is performed (88). Next, the nuclear reactor recovery work is performed (89), the RPV leakage test, the PCV equipment restoration work, the PCV leakage test, the system configuration test for the entire nuclear power plant system, and the pre-startup test are performed. Regular inspection of nuclear power plant is completed.

As described above, the above-described embodiment is a replacement in which the existing γ-shield is not moved and the RPV 1, the in-core structure 2, the CRD housing 23 and the like are integrated into a large block (modularization). For example, RPV
It goes without saying that the above-described method can be used to replace the structures 1, 1, the internal structure 2, and the CRD housing 23 in and out, respectively.

Next, a method of replacing the reactor pressure vessel of another embodiment of the present invention will be described.

In another embodiment, the inner wall of the γ shield 17 at the opening of the RPV nozzle portion provided in the γ shield 17 is partially cut off without improving the nozzle of the RPV 1.
This is a method of restoring the deleted inner wall after carrying in the PV.

FIG. 22 shows the RP by the carry-out method explained in FIG.
FIG. 7 is an overall view of the γ shield 17 after carrying out V. RP
A nozzle opening 90 is provided in the γ shield 17 of the V nozzle portion. The nozzle opening 90 of this γ shield 17
As it is, the RPV nozzle cannot interfere with the loading of the new RPV1 and the RPV1 cannot be loaded.

FIG. 23 is an overall view of the γ shield 17 in which the nozzle interference portion of the RPV 1 is cut out in order to carry out the method of replacing the reactor pressure vessel according to another embodiment of the present invention. 9
1 is the γ from the top of the γ shield 17 to the nozzle opening 90
The part where the inner wall of the shield is cut off is shown.

After carrying out the RPV1 and before carrying in the new RPV1, the inner wall portion 91 of the γ shield from the top of the γ shield 17 which interferes with the new RPV nozzle to the nozzle opening 90 is cut from the upper end of the γ shield 17 to the nozzle opening 90. To do.

The inner wall portion 91 of the γ shield 17 is cut off by a method such as a cutter method using a cutter with a rotary blade or a wire saw method using a wire in which artificial diamond powder is welded with a metal. The frame iron plate and the built-in concrete are cut at the same time and removed.

In this state, the new RPV1 is carried in and the new RPV is
1 is fixed to the RPV pedestal 18 by the RPV foundation bolt, and after the installation is completed, the iron plate of the cut inner portion 91 of the γ shield 17 is attached, and the γ shield 17 is filled with concrete or lead as a shielding material. Restore. The setting work of the RPV1 and the setting work in the pedestal are performed in the same manner as the work explained in FIG.
A series of carrying-in work in which the furnace internal structure 2, the CRD housing 23 and the like are integrated is completed.

After that, the process of shifting to the main work of the normal periodic inspection, completing the periodic inspection of the nuclear power plant through various tests, is the same as the process described in FIG.

Also by this method, 17 interference between each nozzle of the new RPV1 and the γ shield when the new RPV1 is carried in is avoided, and the existing γ shield 17 is not moved, and the RPV1, the in-core structure 2, and the CRD housing are not moved. It is possible to replace by integrating 23 and the like into a large block (modularization).

According to each of the above-mentioned embodiments, the RPV 1 main body, the reactor internal structure 2, the CRD housing 23, etc. are assembled in the factory or the power plant premises, and the existing γ shield 17 is not removed but integrated. Transported out of the reactor building 31,
Since it will be carried in and installed in the reactor building 31, R
The replacement time of the PV 1, the in-core structure 2, the CRD housing 23, etc. can be reduced, and the plant suspension period at the time of the nuclear power plant life extension construction can be shortened.

[0135]

According to the present invention, the unloading time of the RPV main body and the auxiliary equipment inside and outside the furnace (reactor internal structure, CRD housing, etc.) from the installation place, the installation time to the installation place, and the installation time are reduced, It is possible to shorten the plant shutdown period during the nuclear power plant life extension work.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a reactor pressure vessel including internal and external auxiliary equipment.

FIG. 2 is a cross-sectional view of a reactor containment vessel in which the reactor pressure vessel of FIG. 1 is housed.

FIG. 3 is a cross-sectional view of a reactor building in which the containment vessel of FIG. 2 is housed.

FIG. 4 is a reactor internal structure and CRD according to an embodiment of the present invention.
It is a flowchart figure of a series of unloading work by making a housing etc. into a large block by integrating with RPV.

FIG. 5 is a unloading procedure diagram during an operation of taking out all the fuel in the core.

FIG. 6 is a unloading procedure diagram showing a bulkhead plate, a pipe removing portion, and a dismantling position in a pedestal.

FIG. 7 is a detailed view around the RPV nozzle 13 of part A in FIG.

FIG. 8 is a unloading procedure diagram showing a state before lifting the RPV.

FIG. 9 is a unloading procedure diagram showing a state in which the RPV core portion shay body is set with the RPV being lifted.

FIG. 10 is a unloading procedure diagram showing a state in which the RPV lower shady body is attached in the RPV suspended state.

FIG. 11 is a unloading procedure diagram showing a state in which the CRD housing portion shay body is attached in the RPV suspended state.

FIG. 12 is a unloading procedure diagram showing a state where the RPV is lifted by a large-sized lifting machine.

FIG. 13 is a detailed view of the intake / exhaust equipment of section B of FIG.

FIG. 14 is a unloading procedure diagram showing a state in which a clean room is installed in the upper part of the reactor building and the RPV is lifted by a large lifting machine.

FIG. 15 is an enlarged detailed view of the first embodiment of improving the nozzle shape of the RPV nozzle 13 in the A section of FIG.

16 is an enlarged detailed view of a second embodiment of the nozzle shape improvement of the RPV nozzle 13 in the A section of FIG.

FIG. 17 is a reactor internal structure 2 and C according to an embodiment of the present invention.
It is a flowchart figure of a series of carrying-in operation by large-sized block which integrated RD housing 23 grade | etc., With RPV1.

FIG. 18 is a diagram showing how to carry in a new RPV in a large block.

FIG. 19 is a recovery point diagram showing a state in which the new RPV is set on the RPV pedestal.

FIG. 20 is a recovery point diagram showing the connection between the RPV nozzle and the pipe, and the work place in the pedestal.

FIG. 21 is a cross-sectional view of the inside of the PCV in which the RPV replacement work has been completed.

FIG. 22 is an overall view of the γ shield after carrying out the RPV.

FIG. 23 is an overall view of a γ shield with the nozzle interference portion of the RPV of another embodiment of the present invention removed.

[Explanation of symbols]

1 ... Reactor pressure vessel (RPV), 2 ... Reactor internal structure, 3 ...
Steam dryer, 4 ... Shroud head (including steam separator), 5 ... Core shroud, 6 ... Core support plate, 7 ... Upper lattice plate, 8 ... Shroud support, 9 ... Main steam nozzle,
10 ... Water supply nozzle, 11 ... Core spray nozzle, 12 ...
Recirculation inlet nozzle, 13 ... Recirculation outlet nozzle (RPV nozzle), 13a ... New RPV nozzle, 13b ... Nozzle safe end, 13c ... Connection pipe, 14 ... Noise plug, 1
5 ... Fuel exchange bellows, 16 ... Reactor containment vessel (PC
V), 17 ... γ shield, 18 ... RPV pedestal, 1
9 ... Bulkhead plate, 20 ... Control rod drive device (C
RD), 21 ... Neutron flux detector (ICM), 22 ... CR
D housing support beam, 23 ... CRD housing, 24 ... ICM housing, 25 ... CRD housing support block, 27 ... Fuel, 28 ... RPV foundation bolt, 29 ... γ shield foundation bolt, 30 ... PCV stabilizer, 30a ... RPV stabilizer, 31 … Reactor building, 32… Reactor well, 33… Spent fuel pool, 3
4 ... Piping, 37 ... Reactor pressure vessel lid (RPV head),
56 ... spent fuel rack, 57a ... RPV upper shay body, 57b ... RPV core portion shay body, 57c ... RPV
Lower shay body, 57d ... CRD housing section shay body, 58 ... Temporary opening, 59 ... Shutter, 60 ... Large hoist, 61 ... Clean room, 62 ... Suction duct, 6
3 ... Filter, 64 ... Exhaust fan, 65 ... Exhaust duct,
66 ... Stack, 67 ... Nozzle cutting position, 67a ... Nozzle and nozzle safe end welding position, 67b ... Nozzle safe end and piping cutting position, 67c ... Pipe cutting position, 68 ... Nozzle cutting position and gap between gamma shield inner wall , 6
8a ... Distance between the tip of the nozzle and the inner wall of the gamma shield, 69 ...
The gap between the new RPV nozzle and the inner wall of the γ shield, 90 ... Nozzle opening, 91 ... Inner cut portion, D1 ... Diameter of welding line between old RPV nozzle base and RPV barrel, D2 ... New RPV nozzle base and RPV Diameter of welding line with body, La ... Old RPV
Nozzle nozzle base height, Lb ... new RPV nozzle base height,
92 ... RPV heat insulating material, 92a ... Nozzle heat insulating material, 92b ...
Pipe insulation

─────────────────────────────────────────────────── ─── Continuation of front page (72) Hideo Yonemura 3-1-1, Saiwaicho, Hitachi-shi, Ibaraki Hitachi Ltd. Hitachi factory (72) Inventor Wataru Sagawa 3--1, Saiwaicho, Hitachi, Ibaraki No. 1 Hitachi Ltd., Hitachi factory (72) Inventor Kiyokazu Hosoya 3-1-1, Saiwaicho, Hitachi City, Ibaraki Hitachi Ltd. Hitachi factory (72) Masao Kubo 6-9 Takaracho, Kure-shi, Hiroshima No. Babcock Hiritsu Co., Ltd. Kure Works (56) Reference JP-A-9-145882 (JP, A) JP-A-6-230188 (JP, A) JP-A-7-218696 (JP, A) JP-A 62-285100 (JP, A) JP-A-2-296197 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G21F 3/00 G21F 9/30 G21C 13/00 G21C 19 / 02

Claims (6)

(57) [Claims] 1. A γ shield set on a different radiation shield γ shield the reactor pressure vessel containing a reactor internal and external accessory devices reactor building
The above-mentioned gamma shield while suspending
A reactor characterized in that the reactor pressure vessel stored in the shielding body and stored in the radiation shielding body is carried out to the outside of the reactor building through an opening provided in an upper portion of the reactor building. How to carry out the pressure vessel. 2. A radiation shield different from the γ shield is set on the γ shield, and the reactor pressure vessel including the reactor internal and external auxiliary equipment in the reactor building is lifted on the γ shield while being provided on the radiation shield. Storing and hanging it another shield at the bottom
Attached to the radiation shield and attached to the other shield
The reactor pressure vessel in the
The method for unloading a reactor pressure vessel is characterized in that the reactor pressure vessel is unloaded to the outside of the reactor building through an opening provided in . 3. A method for carrying out a nuclear reactor pressure vessel according to claim 1 or 2, wherein said reactor pressure vessel, a reactor pressure vessel method of the unloading, characterized in that it is carried out after cutting the nozzle portion. 4. The method for unloading a reactor pressure vessel according to claim 3 , wherein the nozzle portion is cut at a nozzle height that does not interfere with the inner wall of the γ shield. 5. The method for unloading a reactor pressure vessel according to claim 1, wherein when the reactor pressure vessel is carried out to the outside of the reactor building, the inside of the reactor building is In order to prevent contaminated air from flowing out of the opening formed in the roof of the reactor building to the outside of the reactor building, the intake and exhaust equipment provided in the vicinity of the opening sucks in and cleans the contaminated air. A method of unloading a reactor pressure vessel, characterized by exhausting air to the outside of the reactor building. 6. The method for unloading a reactor pressure vessel according to claim 5, wherein the intake and exhaust equipment has a suction duct having a suction port near the opening for sucking the contaminated air, and the contaminated air. And a filter for cleaning the air, an exhaust fan for exhausting the cleaned air, and an exhaust duct for exhausting the air to the outside of the reactor building.