JP2002311195A - How to unload the reactor pressure vessel - Google Patents

Abstract

(57) [Problem] To provide a method of unloading a reactor pressure vessel that can replace a reactor pressure vessel including internal and external reactors without removing a gamma shield of a reactor containment vessel. SOLUTION: By lifting a reactor pressure vessel 1, a shaher body 57 different from the γ shield 17 is atomized.
Furnace internal structure 2 in furnace building 31 and CRD housing 23
Into the reactor pressure vessel 1 including the reactor inside the reactor building 31
The reactor pressure at which the shahei body 57 was mounted
The container 1 is carried out of the reactor building 31 .

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 internal and external auxiliary equipment.

[0002]

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

[0003] In one example of the decommissioning technology, JP-A 6 - 230
The method of unloading a reactor pressure vessel described in Japanese Patent No. 188 is a method of 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 a reactor pressure vessel.

On the other hand, a new nuclear power plant must be installed in order to supplement the decommissioned nuclear power plant in terms of power supply and demand.

However, the construction of a new nuclear power plant requires long construction days and enormous costs. 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 satisfies the site conditions and the consent of local residents.

[0006] Therefore, it has become an important issue to extend the service period of an aged nuclear power plant that is currently operating.

In an aging nuclear power plant, repair and replacement of each facility and equipment are performed in a timely manner except for the reactor pressure vessel (hereinafter referred to as RPV) and the internal structure of the reactor internal and external auxiliary equipment. Refreshment of nuclear power plants is being implemented. From the standpoint of operating the plant during the service period, it was not necessary to replace the RPV and the furnace internals.

Further, recently, in an aged plant, a place where preventive maintenance measures are required in the inside and outside of the furnace and in the joint between the RPV and the control rod driving device has been discovered. Preventive maintenance of individual repairs and replacements of these in-core and external equipment requires long-term construction days and enormous costs.Therefore, measures to extend the service period of the nuclear power plant over time and preventive maintenance of in-core and external equipment As a countermeasure, RP that includes auxiliary equipment inside and outside the furnace
It has become necessary to establish a method for replacing V. In this case, it is important to shorten the plant stop period as much as possible.

In performing RPV replacement work, the radiation shield (hereinafter referred to as γ shield) of the containment vessel itself can be continuously used as it is. Since the nozzle has a shape that has entered the γ shield, the RPV nozzle interferes with the γ shield when carrying in and out of the RPV.
The plan was to replace the gamma shield when replacing the V. R including internal and external auxiliary equipment
In PV replacement work, how to shorten the plant outage period,
The challenge is how to do it in a short time.

[0010]

However, the above prior arts have the following problems. Although the method of carrying out RPV was considered,
No method of replacing the RPV, including the introduction of a new RPV, has been considered. 2. In early nuclear power plants, the distance from the center of the RPV to the tip of the nozzle was larger than the inner diameter of the gamma shield, and the RPV nozzle had a shape that entered the gamma shield. During loading and unloading, the RPV nozzle interferes with the existing γ shield. For this reason, when replacing the RPV, the existing γ shield must be removed, and there is a problem that the replacement work requires enormous time and cost.

An object of the present invention is to solve the above-mentioned problems and to provide a method of unloading a reactor pressure vessel that can replace an RPV including internal and external auxiliary equipment without removing a gamma shield of a reactor containment vessel. It is in.

[0012]

(1) In order to achieve the above object, the present invention provides a method for lifting a reactor pressure vessel.
Makes the radiation shield different from the γ shield, for example.
The reactor pressure vessel including internal and external auxiliary equipment in the reactor building
In the reactor building, and the radiation shield
Takes out the attached reactor pressure vessel outside the reactor building
You.

[0013] Thereby, it is arranged around the reactor pressure vessel.
External equipment inside and outside the furnace without removing the gamma shield
The reactor pressure vessel containing the reactor
Reactor building with reactor pressure vessel installed
Can be carried out and new equipment inside and outside the furnace
New reactor pressure vessel, including the gamma shield
New reactor pressure capacity including new internal and external auxiliary equipment
Reactor building in the form as it was installed before unloading
It can be carried indoors. Thereby, the γ shield
No time is required to remove the furnace,
To significantly reduce the time required to replace the reactor pressure vessel.
Can be.

[0014] At this time, for example, equipment inside and outside the furnace is included.
While lifting the reactor pressure vessel integrally, above the gamma shield
Stored in a radiation shield different from the gamma shield set in the section
The reactor building through the opening provided at the top of the reactor building.
Work under high radiation can be slowed if transported outside.
And the time required for removal is reduced and released to the outside environment
The amount of radioactive material used can be reduced.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for replacing a reactor pressure vessel and equipment for replacing a reactor pressure vessel according to one embodiment of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a cross-sectional view of an RPV including internal and external auxiliary equipment.

Among the equipment inside and outside the furnace, each equipment inside the RPV 1 is generally called a furnace internal structure 2. The in-furnace structure 2 includes a steam dryer 3, a shroud head (including a steam-water separator) 4, a core shroud 5, a core support plate 6, an upper lattice plate 7, a shroud support 8, and the like. While accommodating each equipment in the reactor that forms the reactor, it becomes a partition to guide the flow of the reactor coolant entering the core,
The reactor coolant flow path to the reactor core, the flow path for the steam-water mixture, and the necessary flow path for water and steam separated by the built-in steam separator are formed. 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 are provided, and each system pipe is connected to each nozzle point shown above.

At the top of the RPV 1, there is a reactor pressure vessel lid (hereinafter referred to as RPV head) 37. At the bottom of the RPV 1, a control rod drive (hereinafter referred to as CRD) 20 of the inside and outside of the reactor is provided. CRD housing 2 for storing
3 and an ICM housing 24 for accommodating a neutron flux detector (hereinafter referred to as ICM) 21.

FIG. 2 shows a cross section of the reactor containment vessel in which the RPV including the inside and outside auxiliary equipment (furnace internal structure 2, CRD housing 23, etc.) of FIG. 1 is housed.

1 is an 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, the γ shield 17, and the RPV 1
The RPV pedestal 18 which is fixed with the PV foundation bolt 28 and serves as the foundation of the RPV 1, and on the upper part of the PCV 16,
A refueling bellows 15 and a bulkhead plate 19 for partitioning the inside of the PCV 16 are provided with a reactor well 32 for filling water at the time of refueling or taking out the reactor internals.

The RPV pedestal 18 has a CR
D housing 23, C supporting CRD housing 23
An RD housing support beam 22, a CRD housing support block 25, and an ICM housing 24 are provided.

Gamma shield 17 and RPV pedestal 1
The connection 8 is supported by a γ shield foundation bolt 29.

Above the γ shield 17, a support PCV stabilizer 30 for earthquake resistance of the PCV 16 and a support RPV stabilizer 30a for earthquake resistance of the RPV are provided.

FIG. 3 shows a cross section of a 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 of replacing the reactor pressure vessel according to one embodiment of the present invention, the inside and outside of the reactor (reactor internal structure 2, CRD housing 23, etc.)
Into a large block integrated with RPV (Modularization)
The details of the unloading method and its equipment will be described.

FIG. 4 shows a flowchart of a series of unloading operations by making a large block (modularization) in which the furnace internal structure 2, the CRD housing 23 and the like are integrated with the RPV 1.

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

The reactor opening operation is a critical operation necessary for handling fuel in the reactor core, and mainly includes an RPV head removing operation for removing the RPV head 37, a steam dryer removing operation for removing the steam dryer 3, and a shroud. Head 4
A shroud head removal operation of removing the shroud head is performed.

Next, the entire fuel removal operation in the core is performed (38). The 100% fuel removal operation is an operation of moving all the fuel loaded in the reactor core to the spent fuel rack 56 of the spent fuel pool 33.

FIG. 5 shows an unloading procedure during the operation of removing all the fuel in the core.

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

When carrying out the RPV 1 and the reactor internals 2, since the fuel itself is the radiation source, it is necessary to transport the RPV 1 and the reactor internals 2 out of the reactor building 31 with the fuel loaded. In the meantime, there is a risk of radioactive contamination in the atmosphere and a 100% refueling operation is performed to reduce the RPV1 surface dose.

When all the fuel has been removed, the RPV 1
Then, the furnace water contained therein is drained, and then the furnace internal structure 2, the CRD housing 23, and the like are integrated with the RPV 1 to carry out a large block (module) carrying out operation.

It should be noted that the reactor water may be filled in the RPV 1 without performing the above-described operation of draining the reactor water. In this case, the reactor water has a shielding effect when the RPV 1, the reactor internals 2, the CRD housing 23, and the like are carried out of the reactor building.

However, in the case where the above operation is performed in a state where the reactor water is contained, it is necessary to insert a nozzle plug in each of the nozzles 9 to 13 in order to prevent water leakage from each of the nozzles 9 to 13 provided in the RPV 1. is there.

FIG. 6 is a carry-out procedure diagram showing the bulkhead plate, the pipe removal section, and the disassembly position in the pedestal. The broken line indicates the area to be removed.

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

In step 39, the disassembly operation of the RPV 1 is first performed.

The disassembly of the RPV 1 is performed according to the following procedure.

1. The cutting operation of the bulkhead plate 19 is performed (40).

2. A 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 work of carrying out the cut nozzle and the pipe is performed (43).

5. Loosen the RPV base bolt 28 and remove the RPV
Separate the pedestal 18 from the RPV 1 (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 performed in step 45 in the following procedure.

1. CRD housing support block 2
5 is removed (46).

2. The cable is disconnected from the CRD 20 and the ICM 21 (47).

3. The CRD 20 is removed 48.

4. The CRD insertion / extraction pipe 20a is cut (49).

5. The work of removing the housing support beam 22 is performed (50).

Here, an example of cutting the RPV nozzles 9 to 13 will be described with reference to FIG.

FIG. 7 shows details of the vicinity of the RPV nozzle 13 in the portion A in FIG. The positional relationship between the RPV nozzle 13 and the γ shield 17 is shown.
A nozzle opening 90 is formed at the position of the V nozzle 13 and R
The PV 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 welding wire 67a of 3b enters the γ shield 17 by the dimension of 68a. An RPV heat insulating material 92 is mounted on the outer periphery of the RPV 1, and a nozzle heat insulating material 92 a is mounted on the RPV nozzle 13. Also, connection pipe 13c
Is provided with a pipe heat insulating material 92b. 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 siled plug 64 is removed, the pipe heat insulator 92b attached to the outer periphery of the connection pipe 13c is removed, and the nozzle heat insulator 92a attached to the RPV nozzle 13 is removed. The nozzle safe end 13b and the connection pipe 13c
Is cut at the cutting position 67b, and then the connection pipe 13c is cut at the cutting position 67c, and the connection 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 shield cut off from the γ shield 17 when the RPV 1 is carried out.
The gap between the cutting position 67 of the RPV nozzle 13 and the γ shield 17 is set at the RPV1 body side from the inner wall position of the γ shield 17 so that the nozzle height does not interfere with the V nozzle 13.
Is the γ shield 17 when carrying out the RPV1 (lifting movement).
And a gap ensuring a margin for preventing the cut RPV nozzles 13 from interfering with each other.

As another method of removing the pipe, the pipe 13
A method in which the cutting position 67b of c is set to the same position as the nozzle cutting position 67 and the pipe is removed 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 opening to seal the nozzle.

After the RPV disassembly operation and the disassembly operation in the RPV pedestal described above are completed, next, the furnace internal structure 2, the CRD housing 23, and the like are lifted by a large block integrated with the RPV 1. A shield attaching operation is performed (51).

FIG. 8 is an unloading procedure diagram showing a state before the RPV is lifted. 57a is an upper shielding (hereinafter, referred to as “shahei”) body of the RPV 1 installed above the γ shield 17;
Reference numeral 7b denotes a core shaving body of the RPV 1 temporarily placed above the γ shield 17.

FIG. 9 is an unloading procedure diagram showing a state in which the RPV 1 is lifted.
This shows a state where the core shaher 57b is set in the core.

FIG. 10 shows the RPV 1 in the suspended state.
It is an unloading point figure showing the state where lower shaher body 57c was attached.

FIG. 11 shows the CRD when the RPV 1 is lifted.
It is a carry-out point figure showing the state where cover 57d was attached to housing 23 part.

In carrying out the unloading operation by integrating the reactor internals 2 and the CRD housing 23 and the like with the RPV 1 into a large block, the radiation dose of the RPV 1 and the internal reactors 2 is extremely large. Before being carried out, the work of attaching the cylindrical shaher bodies 57a to 57d is performed (51).

In order to prevent the scattering of radioactive dust attached to the surface of the RPV 1 when transported outside,
It is necessary to seal RPV1 with cylindrical shaher bodies 57a-57d.

FIGS. 8 to 11 show the shaher bodies 57a to 57d.
The work of attaching the will be described.

The upper shaher 57 a of the RPV 1 is set above the γ shield 17. Next, the reactor core shaher 57b of RPV1 is temporarily placed on the upper part of the γ shield 17,
The RPV core shaher 57b is set on the outer surface of the RPV core while a large block in which the furnace internal structure 2 and the CRD housing 23 are integrated with the RPV 1 is lifted above the γ shield 17.

Next, in a state where a large block in which the furnace internal structure 2, the CRD housing 23 and the like are integrated with the RPV 1 is lifted, the RPV lower shaher 57c divided into several parts is attached, and then the CRD housing 23 portion and the large block A shaher body 57d is attached to the bottom, and a large block in which the furnace internals 2, the CRD housing 23, and the like are integrated with the RPV 1 is stored in the shaher bodies 57a to 57d and is sealed.

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

In the unloading work in step 52 by forming a large block in which the reactor internal structure 2 and the CRD housing 23 and the like are integrated with the RPV 1, a temporary opening 58 is installed on the ceiling of the reactor building 31 (54). ), A large hoist 60 is installed near the reactor building 31 (55), and the large hoist 6
At 0, it is lifted (53) and carried out of the reactor building 31 through the temporary opening 58. At this time, the temporary opening 5 of the reactor building 31
From 8, a shutter 59 that can be opened and closed is installed in the temporary opening 58 so that air containing radioactive materials in the reactor building 31 is not released out of the reactor building 31.

FIG. 13 shows the details of the intake / exhaust equipment of the part B in FIG. With reference to FIG. 13, a description will be given of a measure for preventing the air containing radioactive material in the reactor building 31 from being released from the reactor building temporary opening 58 to the outside of the reactor building 31.

A lid or shutter 59 is provided at the temporary opening 58 provided at the upper part of the reactor building 31, for example, at the ceiling, so that radioactivity does not leak outside. At this time, in order to prevent the contaminated air in 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 maintained at a negative pressure to maintain airtightness. If the methods are used together, the effect of the measures will be greatly increased.

In this method, a duct 62 having a suction port is provided near the temporary opening 58, and a device for exhausting air from the stack 66 to the outside through the exhaust duct 65 by the filter 63 and the exhaust fan 64 is provided. It is possible to maintain airtightness by keeping the reactor building at negative pressure.

Next, a method of maintaining a hermetic state by installing a clean room above the reactor building will be described.

FIG. 14 shows that a clean room is installed in the upper part of the reactor building, and a large lifting machine is used.
It is a carry-out point figure which shows the state which lifted the large block which integrated D housing 23 with RPV1.

As shown in FIG. 14, when carrying out the reactor outside the reactor building 31, a clean room 61 adjacent to the ceiling of the reactor building 31 is provided, in which the reactor internal structure 2 and the CRD are provided.
After moving the 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 hoist 60 lays jars on the ground to withstand its own weight and the weight when the large block in which the furnace internals 2 and the CRD housing 23 and the like are integrated with the RPV 1 is lifted, and is laid on the ground. After laying iron plates to take measures to strengthen the ground, the furnace internal structure 2 and C
The large block in which the RD housing 23 and the like are integrated with the RPV 1 is carried out.

The storage of the large-size block in which the reactor internals 2 and the CRD housing 23 and the like carried out of the reactor building 31 are integrated with the RPV 1 is inserted into a waste storage provided near the reactor building 31. There is a method of transporting and storing the waste using a large trailer to a waste storage provided on the site of the nuclear power plant, and in each case, the surface dose is reduced to such an extent that the environment is not affected by shielding or decontamination. And can be stored in a waste storage.

Thus, the unloading work by forming the furnace internal structure 2, the CRD housing 23 and the like into a large block integrally with the RPV 1 is completed.

Next, a detailed description will be given of a carrying-in method using a large block in which the furnace internal structure 2, the CRD housing 23 and the like are integrated with the RPV 1, and equipment therefor.

FIG. 15 shows the RPV nozzle 13 of the part A in FIG.
Example 1 of the improvement of the shape of a newly loaded RPV nozzle is shown in the enlarged detail of FIG.

Referring to FIG. 15, the shape of the RPV nozzle before the improvement and the shape after the improvement will be compared.

13 is an old RPV nozzle before replacement, 13
a is the nozzle of the newly loaded RPV according to the 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 nozzle nozzle of the PV and the RPV cylinder, D2 is the diameter of the welding line between the nozzle nozzle of the new RPV and the RPV cylinder, L
a indicates the height of the old RPV nozzle nozzle, and Lb indicates the height of the new RPV nozzle nozzle.

If the height of the old RPV nozzle 13 is kept at La, the height of the nozzle is high and the old RPV nozzle 13 enters the γ shield 17, and the furnace internal structure 2, the CRD housing 23 and the like are integrated with the RPV 1 in a large size. When the block is carried in, the nozzle of the RPV 1 and the γ shield 17 interfere.
RPV1 without interference between RPV nozzle and γ shield 17
In order to be able to carry the RP, the nozzle height of the RPV nozzle 13 is reduced, and the RP
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 made the same as that of the old RPV nozzle 13, a height for satisfying the reinforcement and the shape specification is required due to the standard requirement for the reinforcing design of the nozzle nozzle portion. The height of the nozzle 13 is γ
It cannot be lowered until it does not interfere with the shield 17.

For the newly introduced RPV 1, it is necessary to reduce the height of the nozzle so that the interference with the γ shield 17 does not occur in the structure of the nozzle portion, the welding position, and the like.

The reduction of the nozzle height can be achieved by modifying the nozzle structure as follows and changing it from the conventional one.

When determining the shape and size of the nozzle base, the old RPV nozzle 13 was reinforced by the nozzle base itself without changing the plate thickness on the RPV body side, so that the nozzle base was thick. And the height La of the nozzle was high.

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

As a result, the height of the RPV nozzle 13a can be brought closer to the RPV 1 body side than the inner wall of the γ shield 17, and the RPV nozzle 13a is suspended while the RPV 1 is suspended.
A gap 69 where the tip a does not interfere with the γ shield 17 can be secured.

FIG. 16 shows the RPV nozzle 13 of the part A in FIG.
2 shows an embodiment 2 in which the shape of an RPV nozzle newly introduced is improved.

Referring to FIG. 16, description will be made while comparing the shape of the RPV nozzle before the improvement with the shape after the improvement of the first embodiment.

13 is the old RPV nozzle, La is the height of the old RPV nozzle, 13d is the improved new RPV nozzle, L
b indicates the height of the new RPV nozzle. The improved new RPV nozzle 13d has a nozzle nozzle projecting to the inside of the RPV cylinder to provide extra reinforcement for this portion, and by inclining the outer shape of the nozzle nozzle on the outer surface side of the RPV cylinder, the pipe is improved. The height of the table is reduced like Lb. This allows
Raise the height of the RPV nozzle 13 d from the inner wall of the γ shield 17
The gap 69 can be secured to the body of the PV1 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
The gap 69 between the inner walls of the RPV 1 and the gamma shield 17 can be a gap having a sufficient margin to prevent interference between the RPV nozzle and the γ shield 17 when the RPV 1 is carried in (suspended movement). RPV1 without
Can be brought in.

Next, referring to FIG. 17 to FIG.
In the method of replacing the reactor pressure vessel according to one embodiment, a detailed description will be given of a method of carrying in a large block (modularization) in which the reactor internal structure 2 and the CRD housing 23 are integrated with the RPV and the equipment thereof. .

FIG. 17 shows a flowchart of a series of loading operations by a large block (modularization) in which the furnace internals 2, the CRD housing 23 and the like are integrated with the RPV 1. First, the R that has been made into a large block in step 72 is
Carry in the work of loading the PV.

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

At the factory or on-site, in carrying out the work of loading the large-sized block in which the RPV 1, the reactor internals 2, the CRD housing 23 and the like are integrated, at step 71, as in the case of unloading the RPV 1, The lifter 60 is lifted by a large lifting machine 60 installed in the vicinity of the reactor 31, and the shutter 59 of the temporary opening 58 provided in the reactor building 31 used at the time of carrying out the RPV 1 is opened (70).
Carry in 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 flowing out of the temporary opening 58 to the outside is the same as that for the RPV1 unloading. An exhaust system is provided near the temporary opening 58 of the building 31 to take measures against a method of maintaining the reactor building 31 at a negative pressure and maintaining airtightness.

Next, a new RPV 1, a reactor internal structure 2, a CRD housing 23 and the like are integrated and carried into the PCV 16 in the reactor building 31, and 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 where 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, and the pipe 13c, and the work location in the pedestal.

FIG. 21 shows where the bulkhead plate 19 is attached.

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

1. The work of tightening the foundation bolt 28 of the RPV is performed (75).

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

3. The welding work of the nozzles of the RPV nozzle portions 9 to 12 and 13a and the nozzle safe end 13b is performed (7).
7).

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

5. The welding operation of the bulkhead plate 19 is performed (79).

On the other hand, after integrally carrying in the RPV 1, the furnace internals 2, the CRD housing 23, etc., the RPV pedestal 1
The setting work in 8 is performed, but is performed in the following procedure.

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

[0113] 2. The CRD insertion / extraction piping connection work is performed (82).

3. Perform CRD20 mounting work (8
3).

4. A cable is attached between the CRD 20 and the ICM 21 (84).

5. CRD housing support block 2
5 is carried out (85).

According to the above, RPV1, furnace internal structure 2, CR
A series of carrying-in work by forming a large block integrating the D housing 23 and the like is completed.

Thereafter, the operation shifts to the main work of the regular periodic inspection. At step 86, the CRD is inspected. Next, all fuel loading and fuel shuffling work are performed (87).
Next, a core confirmation operation is performed (88). Next, reactor restoration work was performed (89), and RPV leak tests, PCV equipment restoration work, PCV leak tests, system configuration tests for all nuclear power plant systems, and pre-startup tests were performed. Regular inspections of nuclear power plants are completed.

As described above, in the above-described embodiment, the replacement by the large block (modularization) in which the RPV 1, the furnace internal structure 2, the CRD housing 23 and the like are integrated without moving the existing γ shield is shown. By way of example, RPV
Needless to say, the above-described method can be used to carry out the loading / unloading of the structures of the furnace interior 2, the CRD housing 23, respectively.

Next, a method for replacing a reactor pressure vessel according to 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 loading the PV.

FIG. 22 shows an example of the RP in the unloading method explained in FIG.
FIG. 6 is an overall view of the γ shield 17 after V is carried out. RP
A nozzle opening 90 is provided in the γ shield 17 of the V nozzle portion. The nozzle opening 90 of the γ shield 17
In this state, when the new RPV1 is loaded, the RPV nozzle interferes and the RPV1 cannot be loaded.

FIG. 23 is an overall view of the γ shield 17 from which the nozzle interference portion of the RPV 1 has been cut off in order to carry out a method of replacing a 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 which cut out the inner wall of the shield is shown.

After carrying out the RPV 1 and before carrying in the new RPV 1, the inner wall portion 91 of the γ shield from the top of the γ shield 17 to the nozzle opening 90 which interferes with the new RPV nozzle is cut from the upper end of the γ shield 17 to the nozzle opening 90. I do.

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

In this state, the new RPV 1 is loaded,
1 is fixed to the RPV pedestal 18 with the RPV base bolts, and after the installation is completed, the iron plate of the inner portion 91 of the cut γ shield 17 is attached, and the inside of the γ shield 17 is filled with concrete or lead as a shielding material. Let it recover. The setting work of the RPV 1 and the setting work in the pedestal are performed in the same manner as the work described with reference to 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.

Thereafter, the process shifts to the main work of the regular periodic inspection, and the process of terminating the periodic inspection of the nuclear power plant after various tests is the same as the process described with reference to FIG.

According to this method, the interference between the nozzles of the new RPV 1 and the γ shield 17 when the new RPV 1 is carried in is avoided, and the existing γ shield 17 is not moved. 23 can be replaced by a large block (module) integrating the components.

According to each of the above-described embodiments, the reactor internal structure 2, the CRD housing 23, and the like are assembled to the RPV 1 body in a factory or a power plant premises, and the existing γ shield 17 is not removed, but is integrally formed. Take it out of the reactor building 31,
Since it is carried into the reactor building 31 and installed,
The replacement time of the PV 1, the furnace internals 2, the CRD housing 23, and the like is reduced, and the plant shutdown period during the nuclear power plant life extension work can be shortened.

[0130]

According to the present invention, the time for carrying out the RPV body and the equipment inside and outside the furnace (furnace internal structure, CRD housing, etc.) from the installation location, the time for loading into the installation location, and the installation time are reduced. It is possible to shorten the plant outage period during the nuclear power plant life extension work.

[Brief description of the drawings]

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

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

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

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

FIG. 5 is a schematic view of an unloading procedure during the operation of removing all the fuel in the core.

FIG. 6 is an unloading outline diagram showing a bulkhead plate, a pipe removal section, and a disassembly position in a pedestal.

FIG. 7 is a detailed view of the vicinity of the RPV nozzle 13 in a portion A of FIG. 2;

FIG. 8 is a carry-out procedure diagram showing a state before the RPV is lifted.

FIG. 9 is an unloading procedure diagram showing a state in which the RPV core shaher is set with the RPV suspended.

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

FIG. 11 is a carry-out procedure diagram showing a state in which the CRD housing unit shaher is attached in the RPV suspended state.

FIG. 12 is a carry-out procedure diagram showing a state in which the RPV is lifted by a large-sized hoist.

FIG. 13 is a detailed view of an air intake / exhaust facility of a portion B in FIG.

FIG. 14 is an unloading procedure diagram showing a state where a clean room is installed above the reactor building and the RPV is lifted by a large lifting machine.

FIG. 15 is an enlarged detail view of Embodiment 1 of the nozzle shape improvement of the RPV nozzle 13 in the A section of FIG. 2;

FIG. 16 is an enlarged detailed view of a second embodiment of the nozzle shape improvement of the RPV nozzle 13 in the part A in FIG. 2;

FIG. 17 is a flowchart of a series of loading operations by a large block in which the in-furnace structure 2, the CRD housing 23, and the like according to the position embodiment of the present invention are integrated with the RPV 1.

FIG. 18 is a loading procedure diagram of a new RPV that has been made into a large block.

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

FIG. 20 is a recovery procedure diagram showing connections between RPV nozzles and pipes and work locations in the pedestal.

FIG. 21 is a cross-sectional view of the inside of the PCV after the RPV replacement operation has been completed.

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

FIG. 23 is an overall view of a γ shield in which a nozzle interference portion of an RPV according to another embodiment of the present invention is cut off.

[Explanation of symbols]

1 ... reactor pressure vessel (RPV), 2 ... reactor internals, 3 ...
Steam dryer, 4 shroud head (including steam-water separator), 5 core shroud, 6 core support plate, 7 upper grid 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 Refueling bellows, 16 Reactor containment vessel (PC
V), 17: γ shield, 18: RPV pedestal, 1
9: Bulkhead plate, 20: Control rod drive (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 base bolt, 29 gamma shield base 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: upper RPV shading body, 57b: RPV core shading body, 57c: RPV
Lower shading body, 57d: CRD housing shading body, 58: Temporary opening, 59: Shutter, 60: Large lifting machine, 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 ... Gap between nozzle cutting position and 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 gamma shield, 90 ... nozzle opening, 91 ... the inside cutout, D1 ... the diameter of the weld line between the old RPV nozzle nozzle and the RPV cylinder, D2 ... the new RPV nozzle nozzle and RPV Diameter of welding line with body, La ... old RPV
Nozzle nozzle height, Lb ... height of new RPV nozzle nozzle,
92: RPV heat insulating material, 92a: Nozzle heat insulating material, 92b:
Pipe insulation

────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] April 17, 2002 (2002.4.1.
7)

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] Full text

[Correction method] Change

[Correction contents]

[Document Name] Statement

[Title of the Invention] Method of unloading reactor pressure vessel

[Claims]

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 internal and external auxiliary equipment.

[0002]

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

One example of the above decommissioning technology is disclosed in Japanese Patent Laid-Open No. 6-230.
The method of unloading a reactor pressure vessel described in Japanese Patent No. 188 is a method of 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 a reactor pressure vessel.

On the other hand, a new nuclear power plant must be installed in order to supplement the decommissioned nuclear power plant in terms of power supply and demand.

However, the construction of a new nuclear power plant requires long construction days and enormous costs. 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 satisfies the site conditions and the consent of local residents.

[0006] Therefore, it has become an important issue to extend the service period of an aged nuclear power plant that is currently operating.

In an aging nuclear power plant, repair and replacement of each facility and equipment are performed in a timely manner except for the reactor pressure vessel (hereinafter referred to as RPV) and the internal structure of the reactor internal and external auxiliary equipment. Refreshment of nuclear power plants is being implemented. From the standpoint of operating the plant during the service period, it was not necessary to replace the RPV and the furnace internals.

Further, recently, in an aged plant, a place where preventive maintenance measures are required in the inside and outside of the furnace and in the joint between the RPV and the control rod driving device has been discovered. Preventive maintenance of individual repairs and replacements of these in-core and external equipment requires long-term construction days and enormous costs.Therefore, measures to extend the service period of the nuclear power plant over time and preventive maintenance of in-core and external equipment As a countermeasure, RP that includes auxiliary equipment inside and outside the furnace
It has become necessary to establish a method for replacing V. In this case, it is important to shorten the plant stop period as much as possible.

In performing RPV replacement work, the radiation shield (hereinafter referred to as γ shield) of the containment vessel itself can be continuously used as it is. Since the nozzle has a shape that has entered the γ shield, the RPV nozzle interferes with the γ shield when carrying in and out of the RPV.
The plan was to replace the gamma shield when replacing the V. R including internal and external auxiliary equipment
In PV replacement work, how to shorten the plant outage period,
The challenge is how to do it in a short time.

[0010]

However, the above prior arts include: Although a method for carrying out RPV was considered, a new RP
A method of replacing the RPV including the introduction of the V was not considered. 2. In early nuclear power plants, the distance from the RPV center to the tip of the nozzle was larger than the gamma shield inner diameter,
Since the RPV nozzle has a shape in which it enters the γ shield, the RPV nozzle interferes with the existing γ shield when loading / unloading the RPV when replacing the RPV. For this reason, when replacing the RPV, the existing γ shield must be removed, and there is a problem that the replacement work requires enormous time and cost.

An object of the present invention is to solve the above-mentioned problems and to provide a method of unloading a reactor pressure vessel capable of replacing an RPV including internal and external equipment without removing a gamma shield of a reactor containment vessel. It is in.

[0012]

Means for Solving the Problems (1) In order to achieve the above object, the present invention raises a reactor pressure vessel so that a radiation shield different from, for example, a γ shield is installed inside and outside the reactor inside a reactor building. The reactor pressure vessel including the ancillary equipment is attached inside the reactor building, and the reactor pressure vessel to which the radiation shield is attached is carried out outside the reactor building.

[0013] Thus, without removing the gamma shield disposed around the reactor pressure vessel, the reactor pressure vessel including the inside / outside ancillary equipment and the reactor pressure vessel including the inside / outside ancillary equipment can be installed. A new reactor pressure vessel that can be carried out of the reactor building outside as it is, including new internal and external auxiliary equipment, including new internal and external auxiliary equipment without removing the gamma shield The new reactor pressure vessel can be carried into the reactor building as it was installed before unloading. As a result, the time for removing the γ shield becomes unnecessary, and the replacement time of the reactor pressure vessel including the internal and external auxiliary equipment can be significantly reduced.

At this time, for example, while the reactor pressure vessel including the inside and outside of the reactor is integrally lifted, the reactor pressure vessel is housed in a radiation shield different from the γ shield set at the upper part of the γ shield, and is provided above the reactor building. If it is carried out outside the reactor building through the open part, work under high radiation is eased, the time required for carrying out is shortened, and the amount of radioactive material released to the external environment can be reduced. .

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for replacing a reactor pressure vessel and equipment for replacing a reactor pressure vessel according to one embodiment of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a cross-sectional view of an RPV including internal and external auxiliary equipment.

Among the equipment inside and outside the furnace, each equipment inside the RPV 1 is generally called a furnace internal structure 2. The in-furnace structure 2 includes a steam dryer 3, a shroud head (including a steam-water separator) 4, a core shroud 5, a core support plate 6, an upper lattice plate 7, a shroud support 8, and the like. While accommodating each equipment in the reactor that forms the reactor, it becomes a partition to guide the flow of the reactor coolant entering the core,
The reactor coolant flow path to the reactor core, the flow path for the steam-water mixture, and the necessary flow path for water and steam separated by the built-in steam separator are formed. 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 are provided, and each system pipe is connected to each nozzle point shown above.

At the top of the RPV 1, there is a reactor pressure vessel lid (hereinafter referred to as RPV head) 37. At the bottom of the RPV 1, a control rod drive (hereinafter referred to as CRD) 20 of the inside and outside of the reactor is provided. CRD housing 2 for storing
3 and an ICM housing 24 for accommodating a neutron flux detector (hereinafter referred to as ICM) 21.

FIG. 2 shows a cross section of the reactor containment vessel in which the RPV including the inside and outside auxiliary equipment (furnace internal structure 2, CRD housing 23, etc.) of FIG. 1 is housed.

1 is an 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, the γ shield 17, and the RPV 1
The RPV pedestal 18 which is fixed with the PV foundation bolt 28 and serves as the foundation of the RPV 1, and on the upper part of the PCV 16,
A refueling bellows 15 and a bulkhead plate 19 for partitioning the inside of the PCV 16 are provided with a reactor well 32 for filling water at the time of refueling or taking out the reactor internals.

The RPV pedestal 18 has a CR
D housing 23, C supporting CRD housing 23
An RD housing support beam 22, a CRD housing support block 25, and an ICM housing 24 are provided.

Gamma shield 17 and RPV pedestal 1
The connection 8 is supported by a γ shield foundation bolt 29.

Above the γ shield 17, a support PCV stabilizer 30 for earthquake resistance of the PCV 16 and a support RPV stabilizer 30a for earthquake resistance of the RPV are provided.

FIG. 3 shows a cross section of a 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 of replacing the reactor pressure vessel according to one embodiment of the present invention, the inside and outside of the reactor (reactor internal structure 2, CRD housing 23, etc.)
Into a large block integrated with RPV (Modularization)
The details of the unloading method and its equipment will be described.

FIG. 4 shows a flowchart of a series of unloading operations by making a large block (modularization) in which the furnace internal structure 2, the CRD housing 23 and the like are integrated with the RPV 1.

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

The reactor opening operation is a critical operation necessary for handling fuel in the reactor core, and mainly includes an RPV head removing operation for removing the RPV head 37, a steam dryer removing operation for removing the steam dryer 3, and a shroud. Head 4
A shroud head removal operation of removing the shroud head is performed.

Next, the entire fuel removal operation in the core is performed (38). The 100% fuel removal operation is an operation of moving all the fuel loaded in the reactor core to the spent fuel rack 56 of the spent fuel pool 33.

FIG. 5 shows an unloading procedure during the operation of removing all the fuel in the core.

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

When carrying out the RPV 1 and the reactor internals 2, since the fuel itself is the radiation source, it is necessary to transport the RPV 1 and the reactor internals 2 out of the reactor building 31 with the fuel loaded. In the meantime, there is a risk of radioactive contamination in the atmosphere and a 100% refueling operation is performed to reduce the RPV1 surface dose.

When all the fuel has been removed, the RPV 1
Then, the furnace water contained therein is drained, and then the furnace internal structure 2, the CRD housing 23, and the like are integrated with the RPV 1 to carry out a large block (module) carrying out operation.

It should be noted that the reactor water may be filled in the RPV 1 without performing the above-described operation of draining the reactor water. In this case, the reactor water has a shielding effect when the RPV 1, the reactor internals 2, the CRD housing 23, and the like are carried out of the reactor building.

However, in the case where the above operation is performed in a state where the reactor water is contained, it is necessary to insert a nozzle plug in each of the nozzles 9 to 13 in order to prevent water leakage from each of the nozzles 9 to 13 provided in the RPV 1. is there.

FIG. 6 is a carry-out procedure diagram showing the bulkhead plate, the pipe removal section, and the disassembly position in the pedestal. The broken line indicates the area to be removed.

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

In step 39, the disassembly operation of the RPV 1 is first performed.

The disassembly of the RPV 1 is performed according to the following procedure.

1. The cutting operation of the bulkhead plate 19 is performed (40).

2. A 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 work of carrying out the cut nozzle and the pipe is performed (43).

5. Loosen the RPV base bolt 28 and remove the RPV
Separate the pedestal 18 from the RPV 1 (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 performed in step 45 in the following procedure.

1. CRD housing support block 2
5 is removed (46).

2. The cable is disconnected from the CRD 20 and the ICM 21 (47).

3. The CRD 20 is removed 48.

4. The CRD insertion / extraction pipe 20a is cut (49).

5. The work of removing the housing support beam 22 is performed (50).

Here, an example of cutting the RPV nozzles 9 to 13 will be described with reference to FIG.

FIG. 7 shows details of the vicinity of the RPV nozzle 13 in the portion A in FIG. The positional relationship between the RPV nozzle 13 and the γ shield 17 is shown.
A nozzle opening 90 is formed at the position of the V nozzle 13 and R
The PV 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 welding wire 67a of 3b enters the γ shield 17 by the dimension of 68a. An RPV heat insulating material 92 is mounted on the outer periphery of the RPV 1, and a nozzle heat insulating material 92 a is mounted on the RPV nozzle 13. Also, connection pipe 13c
Is provided with a pipe heat insulating material 92b. 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 siled plug 64 is removed, the pipe heat insulator 92b attached to the outer periphery of the connection pipe 13c is removed, and the nozzle heat insulator 92a attached to the RPV nozzle 13 is removed. The nozzle safe end 13b and the connection pipe 13c
Is cut at the cutting position 67b, and then the connection pipe 13c is cut at the cutting position 67c, and the connection 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 shield cut off from the γ shield 17 when the RPV 1 is carried out.
The VPV nozzle 13 is located at the RPV1 body side from the inner wall position of the γ shield 17 so that the nozzle height does not interfere with the gap 68 between the cutting position 67 of the RPV nozzle 13 and the γ shield 17
Is the γ shield 17 when carrying out the RPV1 (lifting movement).
And a gap ensuring a margin for preventing the cut RPV nozzles 13 from interfering with each other.

As another method of removing the pipe, the pipe 13
A method in which the cutting position 67b of c is set to the same position as the nozzle cutting position 67 and the pipe is removed 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 opening to seal the nozzle.

After the RPV disassembly operation and the disassembly operation in the RPV pedestal described above are completed, next, the furnace internal structure 2, the CRD housing 23, and the like are lifted by a large block integrated with the RPV 1. A shield attaching operation is performed (51).

FIG. 8 is an unloading procedure diagram showing a state before the RPV is lifted. 57a is an upper shielding (hereinafter, referred to as “shahei”) body of the RPV 1 installed above the γ shield 17;
Reference numeral 7b denotes a core shaving body of the RPV 1 temporarily placed above the γ shield 17.

FIG. 9 is an unloading procedure diagram showing a state in which the RPV 1 is lifted.
This shows a state where the core shaher 57b is set in the core.

FIG. 10 shows the RPV 1 in the suspended state.
It is an unloading point figure showing the state where lower shaher body 57c was attached.

FIG. 11 shows the CRD when the RPV 1 is lifted.
It is a carry-out point figure showing the state where cover 57d was attached to housing 23 part.

In carrying out the unloading operation by integrating the reactor internals 2 and the CRD housing 23 and the like with the RPV 1 into a large block, the radiation dose of the RPV 1 and the internal reactors 2 is extremely large. Before being carried out, the work of attaching the cylindrical shaher bodies 57a to 57d is performed (51).

In order to prevent the scattering of radioactive dust attached to the surface of the RPV 1 when transported outside,
It is necessary to seal RPV1 with cylindrical shaher bodies 57a-57d.

FIGS. 8 to 11 show the shaher bodies 57a to 57d.
The work of attaching the will be described.

The upper shaher 57 a of the RPV 1 is set above the γ shield 17. Next, the reactor core shaher 57b of RPV1 is temporarily placed on the upper part of the γ shield 17,
The RPV core shaher 57b is set on the outer surface of the RPV core while a large block in which the furnace internal structure 2 and the CRD housing 23 are integrated with the RPV 1 is lifted above the γ shield 17.

Next, in a state where a large block in which the furnace internal structure 2, the CRD housing 23 and the like are integrated with the RPV 1 is lifted, the RPV lower shaher 57c divided into several parts is attached, and then the CRD housing 23 portion and the large block A shaher body 57d is attached to the bottom, and a large block in which the furnace internals 2, the CRD housing 23, and the like are integrated with the RPV 1 is stored in the shaher bodies 57a to 57d and is sealed.

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

In the unloading work in step 52 by forming a large block in which the reactor internal structure 2 and the CRD housing 23 and the like are integrated with the RPV 1, a temporary opening 58 is installed on the ceiling of the reactor building 31 (54). ), A large hoist 60 is installed near the reactor building 31 (55), and the large hoist 6
At 0, it is lifted (53) and carried out of the reactor building 31 through the temporary opening 58. At this time, the temporary opening 5 of the reactor building 31
From 8, a shutter 59 that can be opened and closed is installed in the temporary opening 58 so that air containing radioactive materials in the reactor building 31 is not released out of the reactor building 31.

FIG. 13 shows the details of the intake / exhaust equipment of the part B in FIG. With reference to FIG. 13, a description will be given of a measure for preventing the air containing radioactive material in the reactor building 31 from being released from the reactor building temporary opening 58 to the outside of the reactor building 31.

A lid or shutter 59 is provided at the temporary opening 58 provided at the upper part of the reactor building 31, for example, at the ceiling, so that radioactivity does not leak outside. At this time, in order to prevent the contaminated air in 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 maintained at a negative pressure to maintain airtightness. If the methods are used together, the effect of the measures will be greatly increased.

In this method, a duct 62 having a suction port is provided near the temporary opening 58, and a device for exhausting air from the stack 66 to the outside through the exhaust duct 65 by the filter 63 and the exhaust fan 64 is provided. It is possible to maintain airtightness by keeping the reactor building at negative pressure.

Next, a method of maintaining a hermetic state by installing a clean room above the reactor building will be described.

FIG. 14 shows that a clean room is installed in the upper part of the reactor building, and a large lifting machine is used.
It is a carry-out point figure which shows the state which lifted the large block which integrated D housing 23 with RPV1.

As shown in FIG. 14, when carrying out the reactor outside the reactor building 31, a clean room 61 adjacent to the ceiling of the reactor building 31 is provided, in which the reactor internal structure 2 and the CRD are provided.
After moving the 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 hoist 60 lays jars on the ground to withstand its own weight and the weight when the large block in which the furnace internals 2 and the CRD housing 23 and the like are integrated with the RPV 1 is lifted, and is laid on the ground. After laying iron plates to take measures to strengthen the ground, the furnace internal structure 2 and C
The large block in which the RD housing 23 and the like are integrated with the RPV 1 is carried out.

The storage of the large-size block in which the reactor internals 2 and the CRD housing 23 and the like carried out of the reactor building 31 are integrated with the RPV 1 is inserted into a waste storage provided near the reactor building 31. There is a method of transporting and storing the waste using a large trailer to a waste storage provided on the site of the nuclear power plant, and in each case, the surface dose is reduced to such an extent that the environment is not affected by shielding or decontamination. And can be stored in a waste storage.

Thus, the unloading work by forming the furnace internal structure 2, the CRD housing 23 and the like into a large block integrally with the RPV 1 is completed.

Next, a detailed description will be given of a carrying-in method using a large block in which the furnace internal structure 2, the CRD housing 23 and the like are integrated with the RPV 1, and equipment therefor.

FIG. 15 shows the RPV nozzle 13 of the part A in FIG.
Example 1 of the improvement of the shape of a newly loaded RPV nozzle is shown in the enlarged detail of FIG.

Referring to FIG. 15, the shape of the RPV nozzle before the improvement and the shape after the improvement will be compared.

13 is an old RPV nozzle before replacement, 13
a is the nozzle of the newly loaded RPV according to the 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 nozzle nozzle of the PV and the RPV cylinder, D2 is the diameter of the welding line between the nozzle nozzle of the new RPV and the RPV cylinder, L
a indicates the height of the old RPV nozzle nozzle, and Lb indicates the height of the new RPV nozzle nozzle.

If the height of the old RPV nozzle 13 is kept at La, the height of the nozzle is high and the old RPV nozzle 13 enters the γ shield 17, and the furnace internal structure 2, the CRD housing 23 and the like are integrated with the RPV 1 in a large size. When the block is carried in, the nozzle of the RPV 1 and the γ shield 17 interfere.
RPV1 without interference between RPV nozzle and γ shield 17
In order to be able to carry the RP, the nozzle height of the RPV nozzle 13 is reduced, and the RP
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 made the same as that of the old RPV nozzle 13, a height for satisfying the reinforcement and the shape specification is required due to the standard requirement for the reinforcing design of the nozzle nozzle portion. The height of the nozzle 13 is γ
It cannot be lowered until it does not interfere with the shield 17.

For the newly introduced RPV 1, it is necessary to reduce the height of the nozzle so that the interference with the γ shield 17 does not occur in the structure of the nozzle portion, the welding position, and the like.

The reduction of the nozzle height can be achieved by modifying the nozzle structure as follows and changing it from the conventional one.

When determining the shape and size of the nozzle base, the old RPV nozzle 13 was reinforced by the nozzle base itself without changing the plate thickness on the RPV body side, so that the nozzle base was thick. And the height La of the nozzle was high.

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

As a result, the height of the RPV nozzle 13a can be brought closer to the RPV 1 body side than the inner wall of the γ shield 17, and the RPV nozzle 13a is suspended while the RPV 1 is suspended.
A gap 69 where the tip a does not interfere with the γ shield 17 can be secured.

FIG. 16 shows the RPV nozzle 13 of the part A in FIG.
2 shows an embodiment 2 in which the shape of an RPV nozzle newly introduced is improved.

Referring to FIG. 16, description will be made while comparing the shape of the RPV nozzle before the improvement with the shape after the improvement of the first embodiment.

13 is the old RPV nozzle, La is the height of the old RPV nozzle, 13d is the improved new RPV nozzle, L
b indicates the height of the new RPV nozzle. The improved new RPV nozzle 13d has a nozzle nozzle projecting to the inside of the RPV cylinder to provide extra reinforcement for this portion, and by inclining the outer shape of the nozzle nozzle on the outer surface side of the RPV cylinder, the pipe is improved. The height of the table is reduced like Lb. This allows
Raise the height of the RPV nozzle 13 d from the inner wall of the γ shield 17
The gap 69 can be secured to the body of the PV1 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
The gap 69 between the inner walls of the RPV 1 and the gamma shield 17 can be a gap having a sufficient margin to prevent interference between the RPV nozzle and the γ shield 17 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 a reactor pressure vessel according to one embodiment of the present invention, a large-scale structure in which the reactor internal structure 2, the CRD housing 23 and the like are integrated with the RPV will be described. A detailed description will be given of a loading method and its equipment by block (modularization).

FIG. 17 shows a flowchart of a series of loading operations by a large block (modularization) in which the furnace internals 2, the CRD housing 23 and the like are integrated with the RPV 1. First, the R that has been made into a large block in step 72 is
Carry in the work of loading the PV.

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

At the factory or on-site, in carrying out the work of loading the large-sized block in which the RPV 1, the reactor internals 2, the CRD housing 23 and the like are integrated, at step 71, as in the case of unloading the RPV 1, The lifter 60 is lifted by a large lifting machine 60 installed in the vicinity of the reactor 31, and the shutter 59 of the temporary opening 58 provided in the reactor building 31 used at the time of carrying out the RPV 1 is opened (70).
Carry in 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 flowing out of the temporary opening 58 to the outside is the same as that for the RPV1 unloading. An exhaust system is provided near the temporary opening 58 of the building 31 to take measures against a method of maintaining the reactor building 31 at a negative pressure and maintaining airtightness.

Next, a new RPV 1, a reactor internal structure 2, a CRD housing 23 and the like are integrated and carried into the PCV 16 in the reactor building 31, and 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 where 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, and the pipe 13c, and the work location in the pedestal.

FIG. 21 shows where the bulkhead plate 19 is attached.

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

1. The work of tightening the foundation bolt 28 of the RPV is performed (75).

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

3. The welding work of the nozzles of the RPV nozzle portions 9 to 12 and 13a and the nozzle safe end 13b is performed (7).
7).

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

5. The welding operation of the bulkhead plate 19 is performed (79).

On the other hand, after integrally carrying in the RPV 1, the furnace internals 2, the CRD housing 23, etc., the RPV pedestal 1
The setting work in 8 is performed, but is performed in the following procedure.

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

[0113] 2. The CRD insertion / extraction piping connection work is performed (82).

3. Perform CRD20 mounting work (8
3).

4. A cable is attached between the CRD 20 and the ICM 21 (84).

5. CRD housing support block 2
5 is carried out (85).

According to the above, RPV1, furnace internal structure 2, CR
A series of carrying-in work by forming a large block integrating the D housing 23 and the like is completed.

Thereafter, the operation shifts to the main work of the regular periodic inspection. At step 86, the CRD is inspected. Next, all fuel loading and fuel shuffling work are performed (87).
Next, a core confirmation operation is performed (88). Next, reactor restoration work was performed (89), and RPV leak tests, PCV equipment restoration work, PCV leak tests, system configuration tests for all nuclear power plant systems, and pre-startup tests were performed. Regular inspections of nuclear power plants are completed.

As described above, in the above-described embodiment, the replacement by the large block (modularization) in which the RPV 1, the furnace internal structure 2, the CRD housing 23 and the like are integrated without moving the existing γ shield is shown. By way of example, RPV
Needless to say, the above-described method can be used to carry out the loading / unloading of the structures of the furnace interior 2, the CRD housing 23, respectively.

Next, a method for replacing a reactor pressure vessel according to 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 loading the PV.

FIG. 22 shows an example of the RP in the unloading method explained in FIG.
FIG. 6 is an overall view of the γ shield 17 after V is carried out. RP
A nozzle opening 90 is provided in the γ shield 17 of the V nozzle portion. The nozzle opening 90 of the γ shield 17
In this state, when the new RPV1 is loaded, the RPV nozzle interferes and the RPV1 cannot be loaded.

FIG. 23 is an overall view of the γ shield 17 from which the nozzle interference portion of the RPV 1 has been cut off in order to carry out a method of replacing a 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 which cut out the inner wall of the shield 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 to the nozzle opening 90 which interferes with the new RPV nozzle is cut from the upper end of the γ shield 17 to the nozzle opening 90. I do.

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

In this state, the new RPV 1 is loaded,
1 is fixed to the RPV pedestal 18 with the RPV base bolts, and after the installation is completed, the iron plate of the inner portion 91 of the cut γ shield 17 is attached, and the inside of the γ shield 17 is filled with concrete or lead as a shielding material. Let it recover. The setting work of the RPV 1 and the setting work in the pedestal are performed in the same manner as the work described with reference to 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.

Thereafter, the process shifts to the main work of the regular periodic inspection, and the process of terminating the periodic inspection of the nuclear power plant after various tests is the same as the process described with reference to FIG.

According to this method, the interference between the nozzles of the new RPV 1 and the γ shield 17 when the new RPV 1 is carried in is avoided, and the existing γ shield 17 is not moved. 23 can be replaced by a large block (module) integrating the components.

According to each of the above-described embodiments, the reactor internal structure 2, the CRD housing 23, and the like are assembled to the RPV 1 body in a factory or a power plant premises, and the existing γ shield 17 is not removed, but is integrally formed. Take it out of the reactor building 31,
Since it is carried into the reactor building 31 and installed,
The replacement time of the PV 1, the furnace internals 2, the CRD housing 23, and the like is reduced, and the plant shutdown period during the nuclear power plant life extension work can be shortened.

[0130]

According to the present invention, the time for carrying out the RPV body and the equipment inside and outside the furnace (furnace internal structure, CRD housing, etc.) from the installation location, the time for loading into the installation location, and the installation time are reduced. It is possible to shorten the plant outage period during the nuclear power plant life extension work.

[Brief description of the drawings]

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

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

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

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

FIG. 5 is a schematic view of an unloading procedure during the operation of removing all the fuel in the core.

FIG. 6 is an unloading outline diagram showing a bulkhead plate, a pipe removal section, and a disassembly position in a pedestal.

FIG. 7 is a detailed view of the vicinity of the RPV nozzle 13 in a portion A of FIG. 2;

FIG. 8 is a carry-out procedure diagram showing a state before the RPV is lifted.

FIG. 9 is an unloading procedure diagram showing a state in which the RPV core shaher is set with the RPV suspended.

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

FIG. 11 is a carry-out procedure diagram showing a state in which the CRD housing unit shaher is attached in the RPV suspended state.

FIG. 12 is a carry-out procedure diagram showing a state in which the RPV is lifted by a large-sized hoist.

FIG. 13 is a detailed view of an air intake / exhaust facility of a portion B in FIG.

FIG. 14 is an unloading procedure diagram showing a state where a clean room is installed above the reactor building and the RPV is lifted by a large lifting machine.

FIG. 15 is an enlarged detail view of Embodiment 1 of the nozzle shape improvement of the RPV nozzle 13 in the A section of FIG. 2;

FIG. 16 is an enlarged detailed view of a second embodiment of the nozzle shape improvement of the RPV nozzle 13 in the part A in FIG. 2;

FIG. 17 is a flowchart of a series of loading operations by a large block in which the in-furnace structure 2, the CRD housing 23, and the like according to the position embodiment of the present invention are integrated with the RPV 1.

FIG. 18 is a loading procedure diagram of a new RPV that has been made into a large block.

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

FIG. 20 is a recovery procedure diagram showing connections between RPV nozzles and pipes and work locations in the pedestal.

FIG. 21 is a cross-sectional view of the inside of the PCV after the RPV replacement operation has been completed.

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

FIG. 23 is an overall view of a γ shield in which a nozzle interference portion of an RPV according to another embodiment of the present invention is cut off.

[Description of Signs] 1 ... Reactor pressure vessel (RPV), 2 ... Reactor internal structure, 3 ...
Steam dryer, 4 shroud head (including steam-water separator), 5 core shroud, 6 core support plate, 7 upper grid 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 Refueling bellows, 16 Reactor containment vessel (PC
V), 17: γ shield, 18: RPV pedestal, 1
9: Bulkhead plate, 20: Control rod drive (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 base bolt, 29 gamma shield base 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: upper RPV shading body, 57b: RPV core shading body, 57c: RPV
Lower shading body, 57d: CRD housing shading body, 58: Temporary opening, 59: Shutter, 60: Large lifting machine, 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 ... Gap between nozzle cutting position and 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 gamma shield, 90 ... nozzle opening, 91 ... the inside cutout, D1 ... the diameter of the weld line between the old RPV nozzle nozzle and the RPV cylinder, D2 ... the new RPV nozzle nozzle and RPV Diameter of welding line with body, La ... old RPV
Nozzle nozzle height, Lb ... height of new RPV nozzle nozzle,
92: RPV heat insulating material, 92a: Nozzle heat insulating material, 92b:
Pipe insulation

Continued on the front page (72) Inventor Takeo Neya 3-1-1 Sachimachi, Hitachi-shi, Ibaraki Pref. Hitachi, Ltd. Hitachi Plant (72) Inventor Hideo Yonemura 3-1-1 Sachimachi, Hitachi-shi, Ibaraki No. within Hitachi, Ltd.Hitachi Plant (72) Inventor Wataru Sagawa 3-1-1, Sachimachi, Hitachi, Hitachi, Ibaraki Prefecture Within Hitachi, Ltd.Hitachi Plant (72) Inventor, Kiyokazu Hosoya No. 1-1, Hitachi, Ltd. Hitachi, Ltd. Hitachi Plant (72) Inventor Masao Kubo 6-9, Takaracho, Kure City, Hiroshima Prefecture Babcock Hitachi, Ltd. Kure Plant

Claims (1)

[Claims] 1. Lifting a reactor pressure vessel,
Before the radiation shield including the external and internal equipment inside the reactor building
Attached to the reactor pressure vessel inside the reactor building, the reactor pressure vessel to which the radiation shield was attached,
Reactor pressure vessel characterized by being transported outside the reactor building
How to remove the container.