JP2005308628A - Reactor pressure vessel replacement method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To propose a method for replacing a nuclear reactor pressure vessel enabling full safety in carrying in/out operations of the nuclear reactor pressure vessel when the nuclear reactor pressure vessel installed inside a reactor building is replaced. <P>SOLUTION: This method for replacing a nuclear reactor pressure vessel includes a process for carrying out the nuclear reactor pressure vessel from a nuclear reactor storage vessel, a process for fixing an additional shielding plate 56 on the remaining inner surface of a nuclear reactor shielding wall 5 inside the nuclear reactor storage vessel, and a process for carrying in a new nuclear reactor pressure vessel into the nuclear reactor storage vessel. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for replacing a reactor pressure vessel installed in a reactor building.

The nuclear power plant can extend the life of the nuclear power plant by extending the reactor pressure vessel. With regard to carrying out the reactor pressure vessel from the reactor building and carrying it into the reactor building, a method has been proposed in which an opening is provided on the roof of the reactor building and the reactor pressure vessel is carried out and carried in through this opening. (See Patent Document 1).
Also, the reactor pressure vessel placed outside the reactor building is lifted and transported in a lying state, and the reverse of the method of raising the pressure vessel above the opening of the reactor containment vessel and carrying it into the reactor containment vessel. There has been proposed a method for carrying out the reactor pressure vessel to the outside of the reactor building according to the procedure (see Patent Document 2).
JP 2003-215294 A JP-A-57-151892

However, in the former technique, since a vertically long reactor pressure vessel is carried in and out while standing, it is necessary to provide a huge gate-type support structure that straddles the reactor building. In addition, it is necessary to take measures in the building so that it does not fall to the spent fuel pool side when the reactor pressure vessel is suspended. There is a problem.
On the other hand, in the latter technique, the procedure for lifting and loading the reactor pressure vessel in a lying state is shown, but for the specific reactor equipment configuration required to carry out the reactor pressure vessel, Not proposed. In other words, when carrying out the reactor pressure vessel, it is necessary to prevent the radioactive material from being scattered outside, so it is sufficient to simply remove the reactor pressure vessel in the reverse order of the loading method. There are problems such as being unable to secure. In particular, various problems that occur when only the reactor pressure vessel is carried out and carried in (the reactor shielding wall is not carried out or carried in) are unsolved.

  The present invention has been made in view of the above-described circumstances, and when replacing the reactor pressure vessel installed in the reactor building, sufficiently ensure the safety of carrying out and carrying in the reactor pressure vessel. The purpose of this is to propose a reactor pressure vessel replacement method.

The reactor pressure vessel replacement method according to the present invention employs the following means in order to solve the above problems.
The present invention relates to a reactor pressure vessel replacement method, a step of unloading the reactor pressure vessel from the reactor containment vessel, and a step of attaching an additional shielding plate to the inner surface of the reactor shielding wall left in the reactor containment vessel. And a step of carrying a new reactor pressure vessel into the reactor containment vessel. According to this invention, the reactor shielding wall left in the reactor containment vessel can be reused while avoiding exposure of the reactor shielding wall from the core region.

  In addition, the step of attaching the additional shielding plate to the inner surface so that the attaching step of the additional shielding plate does not interfere with the metal heat insulating support material provided on the inner surface, the step of removing the metal heat insulating support material, and the metal heat insulating support With the step of attaching an additional shielding plate to the inner surface from which the material has been removed, the metal heat insulating support material can be removed while avoiding exposure of the reactor shielding wall from the core region.

In addition, the step of attaching the additional shielding plate includes a step of suspending the temporary shielding material from above the reactor shielding wall and avoiding the metal heat insulating support material provided on the inner surface, and placing it on the inner surface.
The temporary shielding plate can be easily attached to the reactor shielding wall.
Further, when the temporary shielding material is removed after carrying in a new reactor pressure vessel and installing the metal heat insulating material, the subsequent operation of the reactor can be performed safely and reliably.

According to the present invention, the following effects can be obtained.
The present invention relates to a reactor pressure vessel replacement method, a step of unloading the reactor pressure vessel from the reactor containment vessel, and a step of attaching an additional shielding plate to the inner surface of the reactor shielding wall left in the reactor containment vessel. And a step of carrying a new reactor pressure vessel into the reactor containment vessel.
As a result, the reactor shielding wall remaining in the reactor containment vessel can be reused while avoiding exposure of the reactor shielding wall from the core region, so that the safety of workers can be ensured. In addition, the cost for replacing the reactor pressure vessel can be reduced.

Hereinafter, an embodiment of a reactor pressure vessel replacement method of the present invention will be described with reference to the drawings.
FIG. 1 is a longitudinal sectional view showing a configuration of a nuclear reactor facility 1 which is a part of a boiling water nuclear power plant (BWR plant). FIG. 2 is a longitudinal sectional view showing a detailed configuration of the reactor pressure vessel 4.
The nuclear reactor facility 1 includes a nuclear reactor building 2, an attached building 20, and a crossing passage 30 that connects the nuclear reactor building 2 and the attached building 20.

The reactor building 2 is erected on the ground and includes a reactor containment vessel 3 (Primary Containment Vessel) inside.
The reactor containment vessel 3 is a building important for safety of the reactor, and houses the reactor pressure vessel 4 and structures such as cooling system equipment. Generally, it is made of light bulb-shaped or bell-shaped steel or reinforced concrete, and has an airtight and pressure-resistant structure, and radioactive materials are released to the outside in the event of an accident such as a reactor accident or damage to the reactor cooling system. It serves to prevent. In addition, in this embodiment, it forms in a bell shape.
The reactor pressure vessel 4 (Reactor Pressure Vessel) is a vertical cylindrical shape with a hemispherical top and bottom, and includes a reactor pressure vessel upper lid (RPV upper lid 53) and a reactor pressure vessel body 4b. The reactor pressure vessel 4 is installed on the pedestal 9 and is fixed by a foundation bolt and is self-supporting. Note that the pedestal 9 is a structure of concrete and a steel plate frame or a reinforcing bar because it serves as the foundation of the reactor pressure vessel 4.
A reactor shielding wall 5 for shielding radiation from the reactor is provided outside the reactor pressure vessel 4. The reactor shielding wall 5 is an iron plate frame concrete structure having a thickness of 600 to 700 mm.
The RPV upper lid 53, which is the upper lid of the reactor pressure vessel 4, is fixed to the flange 4c of the reactor pressure vessel body 4b by bolts. In addition, a nozzle such as a main steam outlet nozzle 80 is attached to the reactor pressure vessel 4 and is connected to piping outside the reactor pressure vessel 4.

  At the top of the reactor containment vessel 3, when the structure in the fuel assembly 10 or the reactor pressure vessel 4 is exchanged or taken out, the reactor well 6 is filled with shielding water that shields radiation from the fuel assembly 10 or the like. Is provided. When exchanging the reactor pressure vessel 4, the reactor pressure vessel 4 is unloaded from the reactor well 6 and loaded.

FIG. 3 is a plan layout view of the operation floor 11 of the reactor building 2.
The operation floor 11 in the reactor building 2 includes a spent fuel pool 7 for storing the spent fuel assembly 10 and an equipment pool 8 for storing the reactor internal structure taken out from the reactor. Are arranged symmetrically with respect to the reactor well 6. The spent fuel pool 7 is filled with water to shield radiation from the spent fuel assembly.

A traveling rail 12 is laid on the operation floor 11 so as to straddle the reactor well 6, the spent fuel pool 7, and the equipment pool 8. A portal crane 13 that suspends and conveys the reactor pressure vessel 4 is placed on the traveling rail 12.
The portal crane 13 is provided with an auxiliary hoist 13a. Note that the traveling rail (hoist rail) of the auxiliary hoist 13a does not interfere with the reactor pressure vessel 4 temporarily placed on the cradle 18 during the replacement operation of the reactor pressure vessel 4 to be described later. The pressure vessel 4 is attached to a height at which it can travel.
A first opening 41 through which the portal crane 13 can pass is provided on the side wall 2a on the equipment pool 8 side of the reactor building 2, and a first hermetic door 42 is further provided in the first opening 41. . Thereby, it is prevented that a radioactive substance is discharged | emitted from the reactor building 2 outside at the time other than passage of the portal crane 13. FIG.

Returning to FIG. 1, the attached building 20 is connected to the reactor building 2 through the transfer passage 30. The attached building 20 is a facility used to carry out and carry in the reactor pressure vessel 4, and is erected at substantially the same height as the reactor building 2, and its inside is hollow.
The traveling rails 12 are also laid in the attached building 20 and the crossing passage 30. Therefore, the portal crane 13 can reciprocate through the passage 30 between the reactor building 2 and the attached building 20.
In addition, a second opening 43 through which a heavy goods transporting vehicle 22 (see FIG. 10) loaded with the reactor pressure vessel 4 can pass is provided on the ground floor 21 of the annex building 20, and this second opening is further provided. A second hermetic door 44 is provided at 43. The second hermetic door 44 is interlocked so as not to be opened simultaneously with the first hermetic door 42. Thereby, when the reactor pressure vessel 4 is carried out, the inside of the reactor building 2 can be maintained at a negative pressure, and the radioactive substance is prevented from being released to the outside.

In the space between the reactor building 2 and the accessory building 20, in other words, in the space between the reactor building 2 and the accessory building 20, the reactor well 6 A device storage area 60 is provided to store the device 50 to be removed from the inside or the reactor pressure vessel 4, for example, the PCV top head 51, the RPV upper lid heat insulating material 52, the RPV upper lid 53 and the like. Normally, these devices 50 are temporarily placed on the operation floor 11 of the reactor building 2, but there are not a few cases where these devices 50 get in the way when the reactor pressure vessel 4 is carried out. For this reason, the safety | security of carrying out work may be impaired. Therefore, by storing these devices 50 in the device storage area 60, the safety of the unloading work is ensured.
The device storage area 60 includes a plurality of levels 61. The floor surface 62 of each floor 61 is configured to be openable and closable. That is, by closing the floor surface 62 of each level 61, a plurality of devices 50 removed from the reactor well 6 or the reactor pressure vessel 4 can be accommodated so as to be stacked.

Next, replacement work of the reactor pressure vessel 4 will be described with reference to FIGS.
This step is a step of carrying out and carrying in only the reactor pressure vessel 4 (the reactor shielding wall 5 is not carried out).
Specifically, disassembly process, unloading preparation process, reactor pressure vessel unloading process, reactor shield wall inner surface cleaning process, new reactor pressure vessel loading process, reactor pressure vessel peripheral recovery process, fuel reloading process, It consists of an entry process.

First, in the disconnection process, the reactor well cover 14 is removed, and then the PCV top head 51, the RPV upper lid heat insulating material 52, the RPV upper lid 53, etc. are removed from the reactor well 6.
As shown in FIG. 4, these devices are accommodated from the lower floor of the device accommodating region 60 in the order of removal from the reactor well 6 or the reactor pressure vessel 4. Specifically, the floor surface 62 other than the lowest floor in the device accommodation area 60 is opened, and the PCV top head 51 is accommodated in the lowest hierarchy 61. Next, the floor surface 62 immediately above the lowest floor 61 is closed to accommodate the RPV upper lid heat insulating material 52. Similarly, the RPV upper lid 53 and the like are accommodated so as to be stacked on the uppermost layer 61.
Subsequently, the reactor well 6 and the equipment pool 8 are filled with water, and the in-furnace structures such as the shroud head 83 integrated with the steam dryer 81 and the steam separator 82 are removed from the inside of the furnace, and the equipment pool 8 Transport to. Next, the pool gate 15 of the spent fuel pool 7 is opened, and the fuel assembly 10 is taken out from the furnace and transferred to the spent fuel pool 7.

Next, in the unloading preparation process, all the in-furnace structures such as the control rod guide tube 86 and the control rod drive mechanism 87 are removed.
And it confirms that the water level of the reactor well 6 has fallen from the flange 4c of the reactor pressure vessel 4, drains the equipment pool 8, and removes the pool gate 16. FIG. Here, although not essential, since it is effective in reducing the exposure to workers, it is desirable to carry out chemical decontamination of the reactor pressure vessel 4 and the connection piping.
Next, before draining the water in the reactor pressure vessel 4, an internal shield 78 is attached to the top of the core shroud 84 (see FIG. 5).
Then, the piping connected to the reactor pressure vessel 4 and the supporting structure thereof are removed in a necessary minimum range.
A shielding lid 70 is attached to the flange 4 c of the reactor pressure vessel 4. Since the reactor pressure vessel 4 and the reactor containment vessel 3 are connected via the bulkhead 76 and the like, the part that interferes when the reactor pressure vessel 4 is carried out is removed from the bulkhead 76 and the like.
Next, the stabilizer 77 is removed, and the reactor pressure vessel 4 is separated from the reactor shielding wall 5.
Further, as shown in FIG. 5, mortar 94 is filled in the gap between the reactor pressure vessel 4 and the metal heat insulating material 93. In the mortar 94, the high-dose portion in the core region has a high density, and the portion away from the core region has a low density. Specifically, a low-density mortar 94 is filled at the bottom of the reactor pressure vessel. On the other hand, a high-density mortar 94 is filled in the gap between the reactor pressure vessel body 4 b and the metal heat insulating material 93. This avoids weight gain due to excessive shielding. And the opening part, such as an existing nozzle, is also closed with the metal heat insulating material 93 or an iron plate, and the mortar 94 is inject | poured.
The metal heat insulating material 93 is supported by a support material 96 provided on the stabilizer bracket 4d of the reactor pressure vessel 4.
And the fixed part edge cutting of the metal heat insulating material 93 attached to the inner wall of the reactor shielding wall 5 is performed.

Next, in the reactor pressure vessel unloading process, first, the portal crane 13 is moved from the attached building 20 to the upper portion of the reactor well 6.
Then, after cutting the pipes connected to the four main steam outlet nozzles 80 of the reactor pressure vessel 4, the suspension pins 71 are fitted into each of the main steam outlet nozzles 80 and fixed by welding. The suspension pin 71 is attached in a direction substantially perpendicular to the traveling direction of the portal crane 13. If the orientation of the main steam outlet nozzle 80 is not appropriate, a hole may be provided in the reactor pressure vessel body 4b and the suspension pin 71 may be attached. Moreover, the method of attaching two suspension metal fittings in the opposite direction perpendicular | vertical to the running direction of the portal crane 13 using the implantation bolt hole of the flange 4c may be sufficient.
When the four suspension pins 71 are located at substantially the same height, when the reactor pressure vessel 4 is placed in a horizontal (horizontal) state, the wire 73 that is hung on the lower suspension pin 71 is suspended on the upper side. It will interfere with the pin 71. Therefore, the protruding length of the hanging pin 71 on the lower side is made longer than that of the hanging pin 71 on the upper side.
Then, the wire 73 is hung on the four suspension pins 71 to separate the reactor pressure vessel 4 from the pedestal 9.

When the reactor pressure vessel 4 is lifted and the lower end of the reactor pressure vessel 4 moves to above the top of the reactor shielding wall 5, the lifting operation is temporarily stopped. Then, as shown in FIG. 6, a cradle 18 is placed on the top of the reactor shielding wall 5, and the reactor pressure vessel 4 is temporarily placed on the cradle 18.
Further, since the metal heat insulating material 93 of the reactor pressure vessel 4 is radially arranged in a cylindrical shape, the outer surface shielding material 95 is provided on the outer surface of the metal heat insulating material 93 using the auxiliary hoist 13a provided in the portal crane 13. Is attached (see FIG. 7). The outer surface shielding member 95 is fixed by using a predetermined fixing tool so that the reactor pressure vessel 4 does not move even when the reactor pressure vessel 4 is in a horizontal (horizontal) state.
Next, the suspension pins 72 are attached to two existing nozzles (recirculation inlet nozzle is optimal) located below the center of gravity of the entire reactor pressure vessel 4 to be carried out and on the spent fuel pool 7 side. The attachment method of the suspension pin 72 is the same as that of the suspension pin 71. Further, the suspension pin 72 is also attached in a direction substantially perpendicular to the traveling direction of the portal crane 13. When the direction of the nozzle is not appropriate, a hole is made in the reactor pressure vessel body 4b and the suspension pin 72 is attached.
And the suspension position of the wire 73 of the portal crane 13 is changed. Specifically, the wire 73 is detached from the two suspension pins 71 on the spent fuel pool 7 side among the four suspension pins 71 and the wires 73 are hung on the two suspension pins 72.
Then, the lifting of the reactor pressure vessel 4 is resumed, and the reactor pressure vessel 4 becomes an interference (opening of the bulkhead 76, the wall surface of the reactor well 6 on the spent fuel pool 7 side, the portal crane 13 main body, the atom The reactor pressure vessel 4 is gradually tilted toward the equipment pool 8 side while moving the portal crane 13 so as not to interfere with the ceiling truss of the reactor building 2 (see FIG. 8).
Then, when the reactor pressure vessel 4 becomes substantially horizontal (horizontal) with respect to the operation floor 11, the reactor is covered with an unloading sheet or the like, and after measuring surface contamination and surface dose rate, the portal crane 13 is attached to the attached building 20. (See FIG. 9).
Next, the first airtight door 42 of the first opening 41 is opened, and the portal crane 13 is passed through and moved to the crossing passage 30. The first hermetic door 42 is closed immediately after passing through the portal crane 13 to prevent the radioactive material from diffusing out of the reactor building 2.
Then, after the reactor pressure vessel 4 is moved to the annex building 20, the wire is extended again, and the reactor pressure vessel 4 is hung down to the ground floor 21 while lying down (see FIG. 10). At this time, on the ground floor 21 of the annex building 20, the heavy material transporting vehicle 22 is put on standby and the suspended reactor pressure vessel 4 is mounted.
Then, the wires are removed from the suspension pins 71, 72, and the heavy goods transporting vehicle 22 loaded with the reactor pressure vessel 4 is moved out of the attached building 20 from the second opening 43.

In the reactor shielding wall inner surface care process, it is necessary to remove the metal heat insulating support material 5b for the inner surface maintenance of the reactor shielding wall 5.
Since the inner surface of the reactor shielding wall 5 is activated by radiation from the reactor and the radiation is emitted from all directions, it is necessary to consider all directions for shielding the operator. . Therefore, as shown in FIG. 11B, an additional shielding plate 56 that has a shape that can be shouldered on the top of the reactor shielding wall 5 and that is vertically divided so as not to interfere with the metal heat insulating support material 5b is provided for the reactor shielding. It is attached to the inner surface side of the wall 5, and the atmospheric dose rate in the inner surface side space of the reactor shielding wall 5 is reduced to a workable value. Then, a work scaffold (not shown) and the like are assembled.
Next, the portions other than the shoulder portions of the additional shielding plate 56 are welded and fixed to the reactor shielding wall 5. Around that time, the metal heat insulating support material 5b is removed.
Subsequently, as shown in FIG. 11C, an additional shielding plate 56 is further attached to the portion where the metal heat insulating support material 5b has been removed, and as shown in FIG. The entire inner surface of the region is covered with an additional shielding wall 56. Since the stabilizer 77 is attached to the top of the reactor shielding wall 5, the shoulder portion of the additional shielding material 56 is removed. Then, the work scaffold (not shown) and the like are dismantled.
Further, as shown in FIG. 12B, a temporary shielding material 55 such as a lead-hair sheet having a hanging curtain shape is hung on the top of the reactor shielding wall 5 so as not to interfere with the metal heat insulating support member 5b. A method of reducing the atmospheric dose rate in the inner surface side space of the shielding wall 5 to a workable value may be used. This method is applicable when the atmospheric dose is not so high. Then, a work scaffold (not shown) and the like are assembled.
Subsequently, the inner surface of the additional shielding plate 56 is painted. However, when the temporary shielding material 55 in the form of a hanging curtain is entirely removed, the atmospheric dose increases, so it is necessary to paint while temporarily removing the temporary shielding material 55 partially. . During the period until the coating dries, the portion of the temporary shielding material 55 cannot be restored. Therefore, it takes time to move to the next painting operation, but the shape of the reactor shielding wall 5 can be maintained as it is. There are advantages. Then, the work scaffold (not shown) and the like are disassembled, and the temporary shielding material 55 is also removed.

In the new reactor pressure vessel carrying-in process, first, the new reactor pressure vessel 4 is carried into the annex building 20 by the heavy goods transporting vehicle 22.
Then, the portal crane 13 lifts four points of the reactor pressure vessel 4 and the reactor shielding wall 5 in a horizontal (horizontal) state, and carries them into the operation floor 11. The reactor pressure vessel 4 may be the main body alone, but it is preferable to carry in the reactor after installing the reactor internals such as the jet pump 88, the core shroud 84, and the control rod drive mechanism housing 89 at the factory.
The existing nozzles (the main steam outlet nozzle 80 and the recirculation inlet nozzle 85) may be used for the four-point suspension position, as in the case of carrying out. In addition, a dedicated suspension pin may be attached near an existing nozzle in advance at the factory.
Subsequently, the reactor pressure vessel 4 is erected above the reactor well 6 and suspended in the reactor containment vessel 3.
Then, when the lower end of the reactor pressure vessel 4 moves to above the top of the reactor shielding wall 5, the suspension operation is temporarily stopped. Then, a cradle 18 is placed on the top of the reactor shielding wall 5, and the reactor pressure vessel 4 is temporarily placed on the cradle 18.
Next, the two wires below the center of gravity of the reactor pressure vessel 4 are removed, and the wire 73 is re-hanged on the dedicated suspension pin attached at or near the main steam outlet nozzle 80. Two suspension fittings may be attached using the stud bolt holes of the flange 4c of the reactor pressure vessel 4 and used.
When the wiring is completed, the reactor pressure vessel 4 is slightly lifted, the cradle 18 placed on the top of the reactor shielding wall 5 is removed, and the reactor pressure vessel 4 is suspended to the pedestal 9.
Then, the reactor pressure vessel 4 is installed at a predetermined position and fixed with a foundation bolt. Further, the wire 73 and the like are removed, and the portal crane 13 is moved to the attached building 20.

In the reactor pressure vessel periphery restoration process, a metal heat insulating material (not shown) and a stabilizer 77 are attached between the reactor pressure vessel 4 and the reactor shielding wall 5. Further, the bulkhead 76 that connects the reactor pressure vessel 4 and the reactor containment vessel 3 is restored. Furthermore, piping is connected to the existing nozzle of the reactor pressure vessel 4 to restore the piping structure.
Moreover, the pool gate 16 of the equipment pool 8 is attached, and the equipment pool 8 is filled with water. Then, the steam dryer 81 and the shroud head 83 are returned to the equipment pool 8.
Furnace structures such as the control rod guide tube 86 and the control rod drive mechanism 87 are attached. Coordination adjustment with the reactor pressure vessel 4 of the shroud head 83 and the steam dryer 81 is also performed.
The RPV upper lid 53 is attached and the pressure resistance test is performed to confirm the soundness of the reactor pressure boundary before use. Also, the RPV upper lid 53 is removed to prepare for fuel loading.

In the fuel reloading process, the reactor well 6 is filled with water, the pool gate 15 of the spent fuel pool 7 is opened, and the fuel assembly 10 is loaded into the reactor pressure vessel 4.
Subsequently, the pool gate 16 of the equipment pool 8 is removed, and the in-furnace structures such as the shroud head 83 and the steam dryer 81 are restored.
After the reactor is restored, the RPV upper lid 53 is attached and the reactor pressure boundary leakage test is performed. Subsequently, the RPV upper lid heat insulating material 52 and the PCV top head 51 are mounted and the opening of the reactor containment vessel 3 such as the equipment hatch is closed, and then the entire leakage rate test of the reactor containment vessel boundary is performed.
Then, the reactor well cover 14 is attached, and the restoration work of the operation floor 11 is completed.

In the merging process, various tests and system configuration of the reactor building 2 necessary for restarting the startup are performed, the startup is started, the power generation is restarted, and the startup is performed.
When disassembling the attached building 20 or the crossing passage 30, the portal crane 13 is suspended, and it is carried out after confirming that there is no contamination. In addition, the attached building 20 and the like are decontaminated and disassembled. The first opening 41 is sealed.
Through the above steps, the replacement operation of the reactor pressure vessel 4 is completed.

  As described above, according to the present invention, in the method for replacing the reactor pressure vessel 4, the step of unloading the reactor pressure vessel 4 from the reactor containment vessel 3 and the atoms remaining in the reactor containment vessel 3 are performed. A step of attaching the additional shielding plate 56 or the temporary shielding member 55 to the inner surface of the reactor shielding wall 5 and a step of carrying a new reactor pressure vessel 4 into the reactor containment vessel 3 are provided. Thereby, while avoiding exposure of the reactor shielding wall 5 from the core region, the inner surface of the reactor shielding wall 5 can be restored and the reactor shielding wall 5 can be reused. Safety can be ensured and the cost for replacement of the reactor pressure vessel 4 can be reduced.

  It should be noted that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the present invention.

Longitudinal sectional view showing the configuration of nuclear reactor facility 1 Longitudinal sectional view showing the detailed configuration of the reactor pressure vessel 4 Plan view of the operation floor 11 of the reactor building 2 The figure explaining the exchange work of the reactor pressure vessel 4 Replacement work diagram following FIG. Replacement work diagram following FIG. Replacement work diagram following FIG. Replacement work diagram following FIG. Replacement work diagram following FIG. Replacement work diagram following FIG. Replacement work diagram following FIG. Replacement work diagram instead of FIG.

Explanation of symbols

3 Reactor containment vessel 4 Reactor pressure vessel 5 Reactor shielding wall 5b Metal insulation support material 55 Temporary shielding material 56 Additional shielding plate

Claims (4)

Carrying out the reactor pressure vessel from the reactor containment vessel;
Attaching an additional shielding plate to the inner surface of the reactor shielding wall left in the reactor containment vessel;
Carrying a new reactor pressure vessel into the reactor containment vessel;
A reactor pressure vessel replacement method characterized by comprising: The step of attaching the additional shielding plate includes:
Attaching an additional shielding plate vertically divided so as not to interfere with the metal heat insulating support provided on the inner surface to the inner surface;
Removing the metal thermal insulation support;
A step of further attaching an additional shielding plate to the inner surface from which the metal heat insulating support material has been removed,
The reactor pressure vessel replacement method according to claim 1, wherein: The step of attaching the additional shielding plate includes:
2. The nuclear reactor according to claim 1, further comprising a step of suspending a temporary shielding material from above the reactor shielding wall and disposing the temporary shielding material on the inner surface while avoiding a metal heat insulating support material provided on the inner surface. Pressure vessel replacement method. The method of claim 3, wherein the temporary shielding material is removed after the new reactor pressure vessel is carried in and a metal heat insulating material is installed.

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