JP3937083B2 - How to replace the reactor pressure vessel - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for replacing a reactor pressure vessel, and in particular, carries out a reactor pressure vessel and a reactor shielding wall from a reactor building, and carries in and installs a new reactor pressure vessel and a reactor shielding wall. The present invention relates to a method for replacing a reactor shielding wall at the time.
[0002]
[Prior art]
Nuclear power plants are designed with a predetermined useful life, and will be destroyed (decommissioned) in principle when the useful life has elapsed. When a nuclear power plant reaches the end of its useful life, the nuclear power plant must be dismantled and decommissioned, so to supplement the power generation capacity of the nuclear power plant that was decommissioned and to meet the increasing demand for power It is necessary to construct a new nuclear power plant.
[0003]
However, the construction of a new nuclear power plant takes a long construction period and enormous costs. In addition, various issues such as selection of candidate locations satisfying conditions and obtaining consent from neighboring residents must be cleared. Therefore, extending the useful life of currently operating nuclear power plants has become an important issue.
[0004]
The actual nuclear power plant is designed and built with a sufficient margin for the determined service life, so that it is possible to extend the life by replacing only the equipment and parts that have reached the end of their lives. The reactor pressure vessel (RPV) is the most important equipment of a nuclear power plant, and generally the useful life of the nuclear power plant also depends on the design life of the reactor pressure vessel and the equipment in the reactor. At nuclear power plants, each facility and equipment is repaired and replaced in a timely manner, and countermeasures against aging are taken.
[0005]
However, aging deterioration within the service life also occurs, and for example, there is an example in which an important core shroud is replaced in an in-furnace structure. Thus, even in-furnace equipment for which replacement measures have not been taken so far, the possibility of aging deterioration within the useful life remains.
[0006]
For these reasons, it has become necessary to replace the reactor pressure vessel and the reactor internal structure at once. In such a case, there are problems such as shielding of highly-radiated facilities and equipment, shortening of the plant shutdown period, and cost reduction.
[0007]
Regarding the method of replacing the reactor pressure vessel, JP-A-8-62368 and JP-A-8-62369 disclose that the reactor internals and the control rod drive mechanism housing ( The method of carrying out and carrying in the reactor pressure vessel integrally with the reactor shielding wall (RSW) with the CRD housing) attached is shown. Similarly, Japanese Patent Application Laid-Open No. 9-145882 uses a large lifting machine to carry out unloading without removing the reactor shielding wall and attaching the reactor internal structure and the control rod drive mechanism housing to the reactor pressure vessel. Shows how to do.
[0008]
Japanese Laid-Open Patent Publication No. 10-39077 discloses a method of cutting a reactor shielding wall into an upper part and a lower part, and simultaneously carrying out and carrying in the reactor pressure vessel and the upper part of the reactor shielding wall. The cutting position in this example is the lower side position of the lower nozzle opening. The upper part of the new shield wall to be carried in is formed up to the upper side of the lower nozzle opening, and a temporary support material is provided on the lower part of the reactor shield wall left in the reactor containment vessel (PCV). After positioning the upper part of the reactor shielding wall and aligning it, a connecting wall connecting the upper part of the reactor shielding wall and the lower part of the reactor shielding wall is installed on site to construct a new reactor shielding wall.
[0009]
Furthermore, Japanese Patent Laid-Open No. 8-285991 carries out an existing reactor pressure vessel, divides the reactor shielding wall into two parts, an upper part and a lower part, carries out the upper part of the existing reactor shielding wall, and has a vertical cutting plane in advance. In addition, the upper part of the new reactor shielding wall, which is divided into multiple parts so as to face in the radial direction, is carried into the reactor containment vessel, and a plurality of new reactor pressure vessels are placed inside the reactor containment vessel so as not to obstruct the inside. Temporarily placed the new reactor shielding wall upper part, loaded and installed a new reactor pressure vessel, and placed a plurality of temporarily placed new reactor shielding wall upper parts on the remaining shielding wall lower part, A plurality of new reactor shielding wall upper portions are welded to each other, and a method of welding these reactor shielding wall upper portions and shielding wall lower portions is disclosed.
[0010]
[Problems to be solved by the invention]
The method for replacing a reactor shielding wall in the above-mentioned JP-A-10-39077 has the following problems.
1. There is no description about the connection of the old and new parts of the column, which is the strength member of the reactor shielding wall.
2. It is unclear how much manufacturing and installation errors can be absorbed when the old and new reactor shielding walls are overlapped.
3. The assembly of the opening of the lower nozzle is a so-called on-site alignment operation, which is a complicated operation.
[0011]
The method for replacing the reactor shielding wall disclosed in Japanese Patent Laid-Open No. 8-2855991 has the following problems.
1. First, since the existing reactor pressure vessel is carried out alone, it is necessary to take additional radiation shielding measures.
2. The upper part of the new reactor shielding wall divided into multiple parts is carried into the reactor containment vessel, and the upper part of the new reactor shielding wall is installed at a position that does not hinder the introduction of the new reactor pressure vessel inside the containment vessel. However, it is difficult to secure a space for temporary placement in the reactor containment vessel.
3. After loading the reactor pressure vessel, the upper part of the reactor shielding wall and the lower part of the shielding wall divided into a plurality of positions are aligned, making it difficult to obtain the required installation accuracy.
4). After carrying in the reactor pressure vessel, the upper parts of the new reactor shielding walls divided into multiple parts will be welded together, and the upper part of these reactor shielding walls and the lower part of the shielding wall will be welded. The amount is enormous and work efficiency is extremely poor.
[0012]
An object of the present invention is to provide a method of replacing a reactor pressure vessel that can shorten the construction period and can reduce the cost while sufficiently securing the strength of the reactor shielding wall.
[0013]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a reactor pressure vessel replacement method in which an existing reactor shield wall is cut at a predetermined height in a circumferential direction and the reactor shield wall and the reactor pressure vessel are replaced. , The reactor pressure vessel and the reactor shielding wall are carried out as a unit, and a connecting lid for connecting the columns of the reactor shielding wall is mounted on the reactor shielding wall left as the base, and the atoms remaining as the base Reactor shielding wall column, inner steel plate, outer steel plate and connecting lid are welded, and mortar is filled between the reactor shielding wall and connecting lid left as the base, and the new reactor shielding wall and new reactor pressure The vessel is carried in, the column at the lower end of the new reactor shielding wall and the connection lid are welded, the inner steel plate and outer steel plate of the new reactor shielding wall are welded to the connection lid, and the lower part of the new reactor shielding wall is welded. Reactor pressure vessel filling with mortar We propose a method instead.
[0014]
In this way, since the reactor pressure vessel and the reactor shielding wall are carried out as a unit, it is not necessary to take a separate radiation shielding measure. Moreover, since a cylindrical new reactor shielding wall is carried in, a temporary storage space is not required. In addition, it is easy to align the cylindrical new reactor shielding wall with the remaining reactor shielding wall as the base, ensuring the column strength of the old and new reactor shielding walls, while accurately aligning the old and new reactor shielding wall columns. Will be able to connect to.
[0015]
The present invention also provides a reactor pressure vessel replacement method in which an existing reactor shield wall is cut at a predetermined height in a circumferential direction and the reactor shield wall and the reactor pressure vessel are replaced. The reactor shielding wall is unloaded and the connecting lid connecting the reactor shielding wall columns is mounted on the reactor shielding wall left as the base, and the reactor shielding wall column left as the base, The inner and outer steel plates and the connection lid are welded, and the mortar is filled between the reactor shield wall and the connection lid left as the base, and the new reactor shield wall is carried in front of the new reactor pressure vessel. Weld the column and connecting lid at the lower end of the new reactor shielding wall, weld the inner and outer steel plates of the new reactor shielding wall, and the connecting lid, and fill the bottom of the new reactor shielding wall with mortar. To replace the reactor pressure vessel To.
[0016]
In this case, the new reactor shielding wall is carried in front of the new reactor pressure vessel, the column at the lower end of the new reactor shielding wall and the connection lid are welded, and the outer steel plate of the new reactor shielding wall is attached. Since the new inner steel plate and the new outer steel plate can be welded to the connection lid, in addition to the advantages of the above solution, a wider work space can be obtained and the work in the reactor containment vessel can be facilitated.
[0017]
The predetermined height at which the existing reactor shielding wall is cut is lower than the lower nozzle opening of the reactor pressure vessel and is located in a higher range than the radial beam in the existing reactor shielding wall. This is desirable from the viewpoint of reducing the amount of construction.
[0018]
If the new nozzle shielding wall up to the lower nozzle opening is prefabricated at the factory or site as an integrated structure, the amount of work in the reactor containment vessel where various pipes and supports are complicated can be greatly reduced. .
[0019]
In any case, the inner diameter of the ring formed by the connection lid is smaller than the inner diameter of the ring formed by the column of the reactor shielding wall, and the outer diameter of the ring formed by the connection lid is smaller than that of the reactor shielding wall. If the diameter is larger than the outer diameter of the ring formed by the column, the column can be easily aligned.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Next, an embodiment of a reactor pressure vessel replacement method according to the present invention will be described with reference to FIGS.
[0021]
FIG. 1 is a flowchart showing an embodiment of a work procedure for carrying out / loading a reactor pressure vessel and a reactor shielding wall in the method for replacing a reactor pressure vessel according to the present invention.
Step A: Remove existing fuel.
Step B: Cut the pipe connected to the existing reactor pressure vessel.
Step C: Cut existing reactor shielding walls.
Step D: Unload existing reactor pressure vessel and existing reactor shielding wall.
Step E: Hang the upper surface of the reactor shielding wall left as the base.
Step F: Install the connection lid on the reactor shielding wall left as the base.
Step G: Weld the column of the reactor shielding wall, the inner steel plate, the outer steel plate, and the connection lid that are left as the base.
Step H: Fill mortar between the reactor shielding wall left as the base and the connecting lid.
Step I: Bring in the new reactor shielding wall and reactor pressure vessel.
Step J: Weld the column of the new reactor shielding wall and the connecting lid.
Step K: Weld the inner and outer steel plates of the new reactor shielding wall and the connecting lid.
Step L: Fill the bottom of the new reactor shielding wall with mortar.
Step M: Weld the piping connected to the new reactor pressure vessel.
Step N: Install fuel or the like.
[0022]
FIG. 2 is a longitudinal sectional view showing an example of the arrangement of the reactor pressure vessel and the reactor shielding wall to be carried in / out of the reactor building. In Step A, the existing fuel is taken out. The step of taking out fuel, etc., in step A is a critical work necessary for taking out all the fuel from the reactor core, which is not different from the work that is usually carried out in the periodic inspection. The removal operation of the fuel and the like in Step A mainly includes an operation of removing the reactor containment vessel lid, that is, the reactor containment vessel head 4, an operation of removing the reactor pressure vessel lid, that is, the reactor pressure vessel head 5, and a steam dryer. That is, an operation of removing the dryer 6, an operation of removing the steam separator, that is, the separator 7, and an operation of removing all the fuel loaded in the core from the core and moving it to the spent fuel rack 9 of the spent fuel pool 8. Consists of.
[0023]
When the reactor pressure vessel head 5, the dryer 6, and the separator 7 are reused, they remain removed, but when the reactor pressure vessel head 5, the dryer 6, and the separator 7 are all replaced together with the reactor pressure vessel 2 main body. Reattach to the reactor pressure vessel 2 body.
[0024]
At this stage, if there is something to be reused for in-reactor equipment such as control rod (CR), CR guide tube, support fitting, neutron flux measurement guide tube (ICM), control rod drive mechanism (CRD), etc. Or may be carried out in parallel with Step B (cutting operation of the existing reactor pressure vessel connection pipe) and Step C (cutting operation of the existing reactor shielding wall) described later. .
[0025]
FIG. 3 is a longitudinal sectional view showing the positional relationship between the reactor shielding wall, the reactor pressure vessel, the nozzle, and the connection pipe in the reactor containment vessel. The reactor pressure vessel 2 is provided with a main steam nozzle 11, a feed water nozzle 12, a core spray nozzle 13, a recirculation water inlet nozzle 14, a recirculation water outlet nozzle 15, various instrumentation nozzles, and a drain / vent nozzle. The main steam pipe 16, the feed water pipe 17, the core spray pipe 18, the recirculation water inlet pipe 19, the recirculation water outlet pipe 20, various instrumentation pipes, and the drain / vent pipe are connected.
[0026]
In Step B, the various pipes connected to the existing reactor pressure vessel are cut. At that time, the bulkhead plate 21 that separates the reactor well and the inside of the containment vessel 10 is cut and removed, and the reactor containment vessel stabilizer 22 of the earthquake-resistant support that connects the containment vessel 10 and the reactor shielding wall 2. And the fuel exchange bellows 23 and the like are cut and removed, and an outlet to the upper part in the reactor containment vessel 10 is secured.
[0027]
Moreover, although there exists the operation | work which removes the foundation bolt 24 of the reactor pressure vessel 2, you may implement this removal operation | work after the cutting operation | work of the reactor shielding wall of the following step C.
[0028]
4 is a perspective view showing the entire structure of the reactor shielding wall, FIG. 5 is a developed view showing the reactor shielding wall of FIG. 4 cut in the vertical direction, and FIG. It is a plane sectional view which meets an -A line. The reactor shielding wall 3 is formed by filling concrete between the reactor shielding wall inner steel plate 24 and the reactor shielding wall outer steel plate 25, and a column 27 is installed every about 30 degrees. The column 27 is welded to the reactor shielding wall inner steel plate 24 and the reactor shielding wall outer steel plate 25.
[0029]
In Step C, the existing reactor shielding wall is cut. At that time, if the column 27 is cut, there is a problem that the longitudinal load transmission function of the reactor shielding wall is lost and the column strength is lowered. Therefore, it is necessary to reliably restore the longitudinal load transfer function between the column of the reactor shielding wall left as the base and the column of the new reactor shielding wall placed thereon.
[0030]
As shown in FIG. 5, the reactor shielding wall 3 is provided with nozzle openings 28 and 29 of various nozzles. The core region in the reactor pressure vessel 2 is located above the lower nozzle opening 29. Therefore, when the reactor pressure vessel 2 is replaced, when the reactor pressure vessel and the reactor shielding wall are carried out as a unit, the reactor is cut at the lower position of the lower nozzle opening 29 and the reactor above the lower nozzle opening 29. Since the core region in the reactor pressure vessel 2 can be shielded by carrying it out integrally with the shielding wall, a shielding effect can be sufficiently expected. On the other hand, a radial beam 37 is disposed below the reactor shielding wall 3. If the radial beam 37 is also removed and restored again, the work in the reactor containment vessel increases. Therefore, as shown in FIG. 5, the cutting is performed at any position within a desired cutting position range 30 from the upper side of the radial beam 37 to the lower side of the lower nozzle opening 29.
[0031]
In parallel with the above cutting operation, various supports connected to the reactor pressure vessel 2 and the reactor shielding wall 3 are cut, and the next step D is prepared for carrying out the reactor pressure vessel and the reactor shielding wall. .
[0032]
FIG. 7 is a longitudinal sectional view showing a state in which an existing reactor pressure vessel and a reactor shielding wall are integrally carried out to the outside of the reactor building. In Step D, the existing reactor pressure vessel and the existing reactor shielding wall are carried out. Using the large lifting machine 31, the reactor shielding wall 3 and the reactor pressure vessel 2 on the upper side of the lower nozzle opening after cutting are integrally carried out from the reactor building opening 32 to the outside of the reactor building 33.
[0033]
FIG. 8 is a perspective view for explaining the lifting operation on the upper surface of the reactor shielding wall left as the base. In Step E, the upper surface of the reactor shielding wall left as the base is sandwiched.
[0034]
FIG. 9 is a view showing a state in which a plurality of connection lids are welded to the upper surface of the reactor shielding wall after hanging. In Step F, a connection lid is attached on the reactor shielding wall left as a base. That is, as shown in FIG. 9, a plurality of connection lids 35 that form two segments as one segment on the reactor shielding wall 34 having a flat cut surface left in the reactor containment vessel 10. Install. The connection lid 35 is an iron plate. The inner diameter of the connecting lid is smaller than the inner diameter of the reactor shielding wall, and the outer diameter of the connecting lid is larger than the outer diameter of the reactor shielding wall. The side surface of the connection lid 35 may be any shape that can connect the column upper surface and the side surface of the connection lid by welding.
[0035]
In Step G, the column of the reactor shielding wall, the inner steel plate, the outer steel plate, and the connection lid that are left as the base are welded. The plurality of connection lids 35 and the column 27 of the reactor shielding wall 34 left as the base are welded. Further, the plurality of connection lids 35 and the reactor shielding wall inner steel plate 24 and the reactor shielding wall outer steel plate 25 of the reactor shielding wall 34 left as the base are welded.
[0036]
FIG. 10 is a longitudinal sectional view for explaining the mortar filling operation into the lower space of the connection lid. In Step H, mortar is filled between the reactor shielding wall left as the base and the connection lid. Since the cut surface of the upper surface of the reactor shielding wall left as the base is uneven, the mortar is filled from the hole 38 formed in the connection lid 35, and the lower space of the connection lid 35 is filled and flattened.
[0037]
In Step I, a new reactor shielding wall and a reactor pressure vessel are carried in. The new reactor shielding wall 3 and the new reactor pressure vessel 2 formed up to the lower nozzle opening 29 are integrally carried into the reactor containment vessel 10. The new reactor shielding wall is formed in advance in the factory or on site up to the lower nozzle opening 29 and formed as an integral structure. That is, there is a portion that is not filled with concrete at the lowermost part of the new reactor shielding wall so that the column and connecting lid of the new reactor shielding wall can be welded in Step J.
[0038]
In Step I, it is assumed that the new reactor shielding wall and the reactor pressure vessel are carried together, but after the new reactor shielding wall is carried in and fixed on the remaining reactor shielding wall as the base. A new reactor pressure vessel may be carried in.
[0039]
FIG. 11 (A) is a longitudinal sectional view of the inner steel plate, outer steel plate, and concrete portion of the connected old and new reactor shielding walls, and FIG. 11 (B) is the column portion of the connected old and new reactor shielding walls. It is a longitudinal cross-sectional view. In Step J, the column of the new reactor shielding wall and the connection lid are welded. The new reactor shielding wall 36 is placed on the existing reactor shielding wall 34 to which the plurality of connection lids 35 are welded, and the plurality of connection lids 35 and the column 27 of the new reactor shielding wall 36 are welded.
[0040]
Further, the plurality of connection lids 35 and the reactor shielding wall inner steel plate 24 and the reactor shielding wall outer steel plate 25 of the new reactor shielding wall 36 are welded. In this embodiment, the outer steel plate 25 at the lower end of the column of the new reactor shielding wall is attached after the welding between the connecting lid and the column is completed, and only this portion is filled with mortar.
[0041]
In Step K, the outer steel plate of the new reactor shielding wall is attached. After welding the connection lid 35 and the column of the new reactor shielding wall 36, the reactor shielding wall outer steel plate 25 at the lower end of the new reactor shielding wall is attached.
[0042]
In Step L, mortar is filled in the lower part of the new reactor shielding wall.
[0043]
In the conventional construction method of the new reactor shielding wall 36, after the outer steel plate 25 and the inner steel plate 24 are connected to the existing reactor shielding wall 34, the concrete 26 is caused to flow in the steel plates in the reactor containment vessel. I was working. In this conventional construction method, the concrete for the entire length of the reactor shielding wall is poured into the reactor containment vessel, and the work in the reactor containment vessel becomes complicated and large-scale, and the concrete filling work requires days. In addition, the work in the reactor containment vessel 10 is prolonged, such as the inability to weld the structure to the reactor shielding wall for about two weeks until the concrete hardens. It was a pass.
[0044]
Therefore, in the present invention, a new reactor shielding wall 36 that has been solidified by pouring concrete in advance at a factory or the like is manufactured, loaded as an integral structure, installed on a connection lid, adjusted in position, and installed in the new reactor shielding wall. Since the connecting lid, column, inner steel plate, and outer steel plate are welded only at the lower end, and only this part is filled with mortar, it can be efficiently constructed.
[0045]
FIG. 12 is a perspective view showing the structure of the entire reactor shielding wall after welding and connecting the new reactor shielding wall to the reactor shielding wall left as the base. Here, the illustration of the reactor pressure vessel 2 is omitted.
[0046]
In Step M, various pipes connected to the new reactor pressure vessel are welded. Each nozzle of the reactor pressure vessel and each system pipe are welded and connected to restore.
[0047]
In Step N, fuel or the like is attached. This operation is a reverse procedure of the operation of taking out fuel and the like in step A, and is an operation for returning the total number of fuels into the core as is performed in the periodic inspection. After all the fuel is returned to the reactor core, the separator 7 is attached, the dryer 6 is attached, the reactor pressure vessel head 5 is attached, and the reactor containment vessel head 4 is attached.
[0048]
With the above operation procedure, the replacement work of the reactor pressure vessel and the reactor shielding wall was completed.
[0049]
According to the present embodiment, it is easy to align the new reactor shielding wall with the reactor shielding wall left as the base while ensuring the column strength of the reactor shielding wall, shortening the construction period and reducing the cost. Can be reduced.
[0050]
【The invention's effect】
According to the present invention, since the reactor pressure vessel and the reactor shielding wall are carried out integrally, there is no need to take a radiation shielding measure. Moreover, since a cylindrical new reactor shielding wall is carried in, a temporary storage space is not required. In addition, it is easy to align the cylindrical new reactor shielding wall with the remaining reactor shielding wall as the base, ensuring the column strength of the old and new reactor shielding walls, and the new and old reactor shielding wall columns. Can connect.
[0051]
In addition, when the new reactor shielding wall is carried separately from the new reactor pressure vessel, the new reactor shielding wall is carried before the new reactor pressure vessel, and the column at the lower end of the new reactor shielding wall is In addition to the advantages of the above solution, a wider working space can be obtained in the reactor containment vessel because the connection lid can be welded and the inner steel plate and outer steel plate of the new reactor shielding wall can be welded to the connection lid. Work becomes easier.
[0052]
The predetermined height at which the existing reactor shielding wall is cut is lower than the lower nozzle opening of the reactor pressure vessel and is located in a higher range than the radial beam in the existing reactor shielding wall. This is desirable from the viewpoint of reducing the amount of construction.
[0053]
If the new nozzle shielding wall up to the lower nozzle opening is prefabricated at the factory or site as an integrated structure, the amount of work in the reactor containment vessel where various pipes and supports are complicated can be greatly reduced. .
[0054]
In any case, the inner diameter of the ring formed by the connection lid is smaller than the inner diameter of the ring formed by the column of the reactor shielding wall, and the outer diameter of the ring formed by the connection lid is smaller than that of the reactor shielding wall. If the diameter is larger than the outer diameter of the ring formed by the column, the column can be easily aligned.
[0055]
As a result, while ensuring the column strength of the reactor shielding wall, the construction period can be shortened and the cost can be reduced.
[Brief description of the drawings]
FIG. 1 is a flowchart showing one embodiment of a work procedure for carrying out / in a reactor pressure vessel and a reactor shielding wall in a method for replacing a reactor pressure vessel according to the present invention.
FIG. 2 is a longitudinal sectional view showing an example of an arrangement of a reactor pressure vessel and a reactor shielding wall to be carried in / out of the reactor building.
FIG. 3 is a longitudinal sectional view showing a positional relationship among a reactor shielding wall and a reactor pressure vessel, a nozzle and a connection pipe in a reactor containment vessel.
FIG. 4 is a perspective view showing an overall structure of a reactor shielding wall.
FIG. 5 is a development view showing the reactor shielding wall of FIG. 4 cut in the vertical direction.
6 is a cross-sectional plan view taken along the line AA in FIG.
FIG. 7 is a longitudinal sectional view showing a state in which an existing reactor pressure vessel and a reactor shielding wall are integrally carried out of the reactor building.
FIG. 8 is a perspective view for explaining a lifting operation on the upper surface of the reactor shielding wall left as a base.
FIG. 9 is a view showing a state in which a plurality of connection lids are welded to the upper surface of the reactor shielding wall after suspension.
FIG. 10 is a longitudinal sectional view for explaining a mortar filling operation into a connecting lid lower space.
11A is a longitudinal cross-sectional view of the inner steel plate, outer steel plate, and concrete portion of the connected old and new reactor shielding walls, and FIG. 11B is the column view of the connected old and new reactor shielding walls. It is a longitudinal cross-sectional view.
FIG. 12 is a perspective view showing the structure of the entire reactor shielding wall after welding and connecting the new reactor shielding wall to the reactor shielding wall left as the base.
[Explanation of symbols]
A Fuel removal process B Reactor pressure vessel connection piping cutting process C Reactor shielding wall cutting process D Reactor shielding wall and reactor pressure vessel unloading process E Existing reactor shielding wall upper surface is suspended process F Existing reactor Connection lid installation process on shielding wall G Connection lid and column welding process H Existing reactor shielding wall mortar filling process I New reactor shielding wall and reactor pressure vessel loading process J New reactor shielding wall column and connection lid Welding process K Inner steel plate and outer steel plate of new reactor shielding wall Connection and lid welding process L New reactor shielding wall lower mortar filling process M Reactor pressure vessel connection piping welding process N Fuel installation process 2 Reactor Pressure vessel 3 Reactor shielding wall 4 Reactor containment head 5 Reactor pressure vessel head 6 Steam dryer 7 Steam separator 8 Used fuel pool 9 Used fuel rack 10 Containment vessel 1 Main steam nozzle 12 Water supply nozzle 13 Core spray nozzle 14 Recirculation water inlet nozzle 15 Recirculation water outlet nozzle 16 Main steam pipe 17 Water supply pipe 18 Core spray pipe 19 Recirculation water inlet pipe 20 Recirculation water outlet pipe 21 Bulkhead plate 22 Containment vessel stabilizer 23 Refueling bellows 24 Reactor shielding wall inner steel plate 25 Reactor shielding wall outer steel plate 26 Concrete 27 Column 28 Nozzle opening 29 Lower nozzle opening 30 Desired cutting position range 31 Large lifting machine 32 Reactor building Opening 33 Reactor building 34 Existing reactor shielding wall 35 Connection lid 36 New reactor shielding wall 37 Radial beam 38 Hole

Claims (5)

In the method of replacing the reactor pressure vessel, the existing reactor shield wall is cut at a predetermined height in the circumferential direction to replace the cut reactor shield wall and the reactor pressure vessel.
Unloading the reactor pressure vessel and the reactor shielding wall together,
Attach a connection lid to connect the columns of the reactor shielding wall on the reactor shielding wall left as the base,
Weld the column of the reactor shielding wall left as the base, the inner steel plate, the outer steel plate and the connection lid,
Fill the mortar between the reactor shielding wall left as the base and the connecting lid,
Carry in the cylindrical new reactor shielding wall and the new reactor pressure vessel,
Welding the column at the lower end of the new reactor shielding wall and the connecting lid;
Welding the inner steel plate and outer steel plate of the new reactor shielding wall and the connection lid;
A method for replacing a reactor pressure vessel, characterized in that mortar is filled under a new reactor shielding wall. In the method of replacing the reactor pressure vessel, the existing reactor shield wall is cut at a predetermined height in the circumferential direction and the cut reactor reactor wall and the reactor pressure vessel are replaced.
Unloading the reactor pressure vessel and the reactor shielding wall together,
Attach a connection lid to connect the columns of the reactor shielding wall on the reactor shielding wall left as the base,
Weld the column of the reactor shielding wall left as the base, the inner steel plate, the outer steel plate and the connection lid,
Fill the mortar between the reactor shielding wall left as the base and the connecting lid,
Bring the cylindrical new reactor shielding wall in front of the new reactor pressure vessel,
Welding the column at the lower end of the new reactor shielding wall and the connecting lid;
Welding the inner steel plate and outer steel plate of the new reactor shielding wall and the connection lid;
A method for replacing a reactor pressure vessel, characterized in that mortar is filled under a new reactor shielding wall. The method for replacing a reactor pressure vessel according to claim 1 or 2,
The predetermined height at which the existing reactor shielding wall is cut is lower than the lower nozzle opening of the reactor pressure vessel and higher than the radial beam in the existing reactor shielding wall. Reactor pressure vessel replacement method characterized. The method of replacing a reactor pressure vessel according to claim 3,
A method for replacing a reactor pressure vessel, wherein a part up to a lower nozzle opening of the new reactor shielding wall is manufactured in advance as an integrated structure in a factory or field. In the method for replacing a reactor pressure vessel according to any one of claims 1 to 4,
The inner diameter of the ring formed by the connection lid is smaller than the inner diameter of the ring formed by the column of the reactor shielding wall,
A method for replacing a reactor pressure vessel, wherein an outer diameter of a ring formed by the connection lid is larger than an outer diameter of a ring formed by a column of the reactor shielding wall.

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