JP2000284093A - Treatment method of reactor pressure vessel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a treatment method of reactor pressure vessel. capable of making the reactor pressure vessel in one piece with the reactor outside structures to be a large module, reducing repulse force added to a protect cover itself, the attaching mechanism of a protect cover and the reactor pressure vessel when turning the large module in the state the reactor outside structures with the protect cover and reducing the strength necessary for them for reducing the cost. SOLUTION: In a treatment method of a reactor pressure vessel attaching a protect cover 101 so as to cover the reactor outside structures 7 and 8 in the state of a large module 100 which the reactor pressure vessel 1 is made one body with the reactor outside structures 7 and 8 and reversing the posture between a vertically hung posture and a horizontally put posture on the large module 100 of the attached state, a reversing shaft 26 is provided to the reversal ring 15 of the protect cover 101 and reversing is made at the posture reversal around the reversing shaft 26.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reactor pressure vessel provided in a building of a nuclear power plant, and more particularly to a reactor pressure vessel for nuclear power plant construction, preventive maintenance, renewal, or decommissioning. Take the pressure vessel into the building
The present invention relates to a method of handling a reactor pressure vessel which is turned over to be carried in.

[0002]

2. Description of the Related Art For example, in a boiling water nuclear power plant, a primary containment vessel (Primary Container) provided in a reactor building is used.
Reactor Pressure Vessel (ment Vessel)
Vessel, hereinafter abbreviated as RPV as appropriate).
A reactor core loaded with a number of fuel assemblies is provided in the reactor pressure vessel. After the coolant introduced into the reactor building flows into the core from below the core, it is heated and boiled in the core, forming a gas-liquid mixed state containing bubbles, and a steam-water separator and dryer above the core. The steam from which the liquid component has been removed is supplied to the turbine building to generate power.

[0003] As such an operation is performed, each facility and equipment deteriorates. Therefore, in an existing nuclear power plant, repair and replacement of each facility and equipment are usually performed in a timely manner, and the refreshment is performed. Is being implemented.

However, at this time, the reactor pressure vessel and the internal structure inside the reactor (for example, the steam separator, the dryer, the shroud, the upper grid plate, the jet pump, the core support plate, the control rod, and Control rod guide tube, etc.), out-of-reactor structures outside the reactor pressure vessel (e.g., control rod drive mechanism, in-core monitor housing, etc.), are relatively easily detachable structures. Only the thing, its repair
A replacement had been made. Conventionally, repair and replacement were not required for the reactor pressure vessel and reactor internals by adopting a structure corresponding to the plant operation during the normal service period in advance.

[0005] In recent years, in Japan, it has become very difficult to construct a new nuclear power plant, and the most important task is to use an existing power plant for as long as possible. Therefore, it is necessary to replace the deteriorated facilities and equipment, including the reactor pressure vessel and the reactor internals, which had not been replaced conventionally, at an appropriate time to extend the life of the entire power plant.

[0006] By the way, the reactor pressure vessel, which is the largest facility, has conventionally been carried into a building alone at the time of construction while being separated from the external structure, and installed on a pedestal in the reactor building. After that, for example, about 180
The control rod drive mechanism housing and about 40 in-core monitor housings were mounted on a reactor pressure vessel already installed in the pedestal. Also, while transported to the vicinity of the building before loading, the reactor pressure vessel newly manufactured at the factory is placed horizontally and transported to the vicinity of the reactor building by trailer, and then a large lift installed near the building is installed. It was lifted by heavy equipment, lifted from horizontal to vertical, turned upside down, and transported above the building in this state.

Here, when replacing the reactor pressure vessel,
Unlike the loading of the reactor pressure vessel during the above construction,
In order to temporarily shut down the operating nuclear power plant, we need to take out the activated reactor pressure vessel in a short time and bring in a new reactor pressure vessel in a short time.
It is important to minimize the plant outage period. That is, in the construction of a nuclear power plant, since the entire process is as long as about 3 to 4 years, even if the time for installation of the control rod drive mechanism housing and the in-core monitor housing is secured with sufficient time, the entire process is not completed. Did not affect the length. Therefore, there is no need to carry the control rod drive mechanism housing and the in-core monitor housing in a state where they are previously attached to the reactor pressure vessel.

On the other hand, when replacing the reactor pressure vessel, from the viewpoint of shortening the plant shutdown period as described above, in-reactor structures and out-of-furnace structures (control rod drive mechanism housing, in-core monitor housing, etc.) ) Is integrated with the reactor pressure vessel to form a large module and carry it out of the reactor building. For the reactor pressure vessel to be newly brought in, the above-mentioned external structure is attached to the reactor pressure vessel at a factory or the like in advance. A method of bringing the reactor into the reactor building in a state of being considered has been considered.

In these cases, the control rod drive mechanism housing and the in-core monitor are used even when the reactor pressure vessel is changed from vertical suspension to horizontal placement (or vice versa) when loading / unloading the reactor pressure vessel. A structure is required in which the housing can be inverted with the shape attached to the reactor pressure vessel. At this time, the control rod drive mechanism housing and the in-core monitor housing protrude from the bottom of the reactor pressure vessel.Because these are precision important devices, they work safely and securely so as not to collide with obstacles during reversal. Must.

As a prior art in consideration of such a point,
For example, as described in JP-A-55-2134,
When installing a new reactor pressure vessel, a protective cover (skirt) is attached to the bottom of the reactor pressure vessel in the manufacturing plant so as to cover the control rod drive mechanism housing and the in-core monitor housing, and the reactor pressure vessel and the protective cover are attached. A method has been proposed in which a large module is integrated and transported and turned around near the reactor building in this state. In this conventional technique, the head of the reactor pressure vessel is gradually lifted with a crane while the bottom of the protective cover is rotatably supported by a support structure, so that the state of the large module can be maintained in a horizontal position. Inverting operation to vertical suspension is enabled.

[0011]

However, the above prior art has the following problems. That is, in the above-described conventional technology, the reversal is performed in a state of a large module in which the reactor pressure vessel and the protective cover are integrated. At this time, this large module has a height of about 25 m, a diameter of 6 m, and a weight of 10 m.
It will be 00 tons. When this heavy structure is rotated around the rotation axis of the bottom of the protective cover and inverted, the reactor pressure at the upper edge of the protective cover is changed from the rotation center at the bottom of the protective cover during the inversion. Since there is a large distance between the connecting portion and the bottom of the container, an extremely large reaction force (bending force) of several hundred tons is applied to the connecting portion and other portions of the protective cover by this distance. Therefore, it is necessary to manufacture the protective cover itself and the mounting structure between the protective cover and the reactor pressure vessel so as to obtain an extremely strong strength capable of withstanding the reaction force, which leads to an increase in cost.

In the case where the above-mentioned prior art method is applied to unloading of a reactor pressure vessel when it is replaced, the used reactor pressure in a large block state including high-activity internal structures is included. Around the container, a shield for shielding radiation is required, and the weight of the shield is about 400 tons. Therefore, the reaction force at the time of the reversal acts more greatly.

An object of the present invention is to provide a large module by integrating a reactor pressure vessel with a structure outside the reactor, and furthermore, when the large module is turned over while the structure outside the reactor is covered with a protective cover, protection is required. To provide a method of handling a reactor pressure vessel that can reduce the reaction force applied to the cover itself or the protective cover and the mounting structure between the reactor pressure vessel and the strength required for them to reduce costs. is there.

[0014]

(1) In order to achieve the above object, the present invention provides a reactor pressure vessel in a state of a large module in which a reactor pressure vessel is integrated with at least an external structure. A protective cover is attached to the bottom of the vessel so as to cover the outer structure, and the large module with the protective cover attached is provided with a vertical posture in which the longitudinal direction of the reactor pressure vessel is substantially vertical and In a method of handling a reactor pressure vessel that performs a position reversal between horizontal postures in which the longitudinal direction of the reactor pressure vessel is substantially horizontal, in the connection portion between the reactor pressure vessel and the protective cover,
A rotation axis for reversing the posture is provided, and when the posture of the large module is reversed between the vertical posture and the horizontal posture, the reversal is performed about the rotation shaft as a rotation center.

By providing a rotation axis, which is a rotation center for reversing, at a connection portion of the protective cover with the reactor pressure vessel, a large bending force due to a large distance from the rotation center as in the conventional structure. Does not occur, and when reversing,
The force applied to the connection portion and other portions of the protective cover can be significantly reduced. Therefore, the strength of the protective cover itself and the structure for mounting the protective cover and the reactor pressure vessel can be reduced, so that the cost can be reduced. In particular, for most of the protective cover other than the connection portion, it is sufficient to simply have a function of covering the external structure, so that the required strength can be extremely reduced.

(2) In the above (1), preferably,
The protective cover has a closed bottomed container shape, and a connection portion of the protective cover is provided at an upper edge of the container shape.

(3) In the above (1) or (2), preferably, the protective cover includes a ring member detachably attached to the reactor pressure vessel as a connection portion with the reactor pressure vessel. The rotation shaft is provided on the ring member.

(4) In any one of the above (1) to (3), preferably, the connecting portion of the protective cover is configured to be detachable from a skirt flange of the reactor pressure vessel. .

(5) In order to achieve the above object, the present invention also provides a reactor pressure vessel in a state of a large module in which the reactor pressure vessel is integrated with at least an out-of-pile structure. It is carried out to the outside of the reactor building in a vertical posture in a substantially vertical direction, and a protective cover is attached to the large module that has been carried out so as to cover the outer structure at the bottom of the reactor pressure vessel. The mounted large module is inverted from the vertical position to a horizontal position in which the longitudinal direction of the reactor pressure vessel is substantially horizontal, and the large module in the horizontal position is loaded on the transport means. In the method for handling a reactor pressure vessel to be transported, a rotation axis for reversing the attitude is provided at a connection portion of the protective cover with the reactor pressure vessel, and the vertical attitude is changed from the horizontal attitude to the horizontal attitude. When energized inversion to perform the inversion as the pivot center of the pivot shaft.

(6) In order to achieve the above object, the present invention relates to a reactor pressure vessel integrated with at least an external structure to form a large module. Along with loading the transport means in a lateral posture in which the longitudinal direction is substantially horizontal, a protective cover is attached to the bottom of the reactor pressure vessel so as to cover the outer structure, and a large module with the protective cover is attached to the reactor. The large module transported to the vicinity of the reactor building is inverted from the horizontal position to a vertical position in which the longitudinal direction of the reactor pressure vessel is substantially vertical. In the method for handling a reactor pressure vessel for loading a module into the reactor building, the connection of the protective cover with the reactor pressure vessel may include the posture inversion. It provided the rotation axis of the eye, when the posture inverted from the horizontal posture to the vertical posture, causes the reversal as the pivot center of the pivot shaft.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a method for handling a reactor pressure vessel according to one embodiment of the present invention will be described in detail with reference to the drawings. This embodiment is an embodiment in which a used reactor pressure vessel is carried out when a used reactor pressure vessel is replaced in order to further extend an operation period in an aged power plant.

FIG. 2 is a cross-sectional view showing the structure in the reactor containment vessel in which the reactor pressure vessel of the nuclear power plant to which the present embodiment is applied is stored.

In FIG. 2, a reactor containment vessel 3 is provided in a reactor building 4, and a reactor pressure vessel 1 is housed therein. Inside the reactor pressure vessel 1, a reactor internal structure 2 (e.g., a steam separator, a dryer, a shroud, an upper grid plate, a jet pump, a core support plate, a control rod, a control rod guide, etc.) Pipe etc.) are stored. A reactor well 35 is provided at the upper part of the containment vessel 3 for filling water when refueling or removing the reactor internals 2.

The reactor pressure vessel 1 includes a reactor pressure vessel pedestal 6 serving as a basis for the reactor pressure vessel 1.
Is installed via a ring girder 36. FIG. 3 is an enlarged view of a portion A in FIG. 2 showing the installation structure.

In FIG. 3, a ring girder 36 is fixed to the reactor pressure vessel pedestal 6 via a ring girder embedding base bolt 37, and an upper flange portion 36a of the ring girder 36 is attached to the reactor pressure vessel 36a. The flange portion 1b of the skirt 1a is fixed. The reactor pressure vessel skirt flange portion 1b is a strength member having a thickness of, for example, about 100 to 120 mm. At this time, the reactor pressure vessel base bolt 5 is inserted through the through-hole 36aa of the ring girder upper flange 36a and the through-hole 1ba of the reactor pressure vessel skirt flange 1b. The reactor pressure vessel 1 is positioned and fixed on the reactor pressure vessel pedestal 6.

Returning to FIG. 2, this reactor pressure vessel 1 includes:
A main steam nozzle 38, a water supply nozzle 39, a recirculation inlet nozzle 40, a recirculation outlet nozzle 41, and the like are provided. Each of a main steam pipe 42, a water supply pipe 43, a recirculation inlet pipe 44, a recirculation outlet pipe 45, and the like is provided. Connected to system piping. A reactor pressure vessel heat insulator 46 and a reactor pressure vessel shield (RSW) 9 for shielding radiation (γ-rays or the like) are provided on the outer periphery of the reactor pressure vessel 1. A fuel exchange bellows 46 and a bulkhead plate 47 for partitioning the reactor well 35 and the containment vessel 3 from the upper side are provided. Further, the reactor pressure vessel 1
At the top of the reactor pressure vessel lid (RPV top head)
There are 48. In addition, a control rod drive (Control Rod Drive,
A control rod drive housing 7 for accommodating the
An ICM housing 1 containing a neutron flux detector (In Core Monitor, not shown) is arranged.

In this embodiment, a used reactor pressure vessel 1 is carried out by a crawler crane which is a large-sized hoist. Hereinafter, description will be given with reference to FIG. 4 which is a flowchart showing a series of the work procedure.

First, in step 10 of FIG. 4, the reactor pressure vessel 1 is integrated with the reactor pressure vessel shield 9, the reactor internals 2, the control rod drive mechanism housing 7, and the in-core monitor housing 8. The structure (large module) 100 is carried out of the reactor building 4 in the state of the structure 100.
The unloading procedure at this time may be performed by a known method. For example, as shown in FIG. 5, a temporary opening 12 of the reactor building and a shutter 13 for reducing the emission of radioactive materials in the reactor building 4 are previously installed on the roof of the reactor building 4. Thereafter, while opening the shutter 13, the large module 100 is lifted by the large lifting machine 15 arranged near the reactor building 4 in a vertically suspended posture such that the longitudinal direction of the reactor pressure vessel 1 is substantially vertical. Take it out of building 4. When the carrying out is completed, the shutter 13 of the reactor building 4 is closed.

Next, the process proceeds to step 20, in which the large module 100 is reversed from a vertically suspended position by the large lifting machine 15 to a horizontal position (described later) for loading on the trailer 28.

More specifically, first, in step 21, a reversing bearing 29 (details will be described later) for reversing the reactor pressure vessel 1 is provided on the trailer 28, and the reversing bearing 29 is provided on the reversing bearing. Is provided with a protective cover 101 (same as above) for protecting structures outside the furnace. This procedure is shown in FIG.
This will be described with reference to (a), FIG. 6 (b), and FIG. 6 (c).
FIG. 6A is a perspective view showing this state, and FIG.
FIG. 6B is a side view as viewed from a direction B in FIG.
FIG. 6C is a front view seen from the direction C in FIG. 6A.

6 (a) to 6 (c), the trailer 28 has a large module 100 placed horizontally (described later).
It is intended to be loaded and transported to a storage facility in a state where the vehicle is in a state where the vehicle is operated. A gantry 33 is provided on the trailer 28, and the large module 100 is placed on the gantry 33 in a horizontal state (a state in which the longitudinal direction of the reactor pressure vessel 1 is substantially horizontal). Reactor pressure vessel cradle 30 for placing and fixing
And a bracket 31 for fixing the large module 100 mounted on the reactor pressure vessel pedestal 30 with wires 34 and the like, and a pedestal for securing the reactor pressure vessel pedestal 30 and the bracket 31 32 are provided in advance.

The reversing bearing 29 is installed on the base 33 of the trailer 28. The reversing bearing 29 includes a groove 29c for rotatably supporting a reversing shaft 26 (same) of a reversing ring 25 (described later), and two support legs 29d installed so as to sandwich the reversing ring 25; Supports 29a and 29b for reinforcing support legs 29d so as not to fall down
And

Thereafter, a protective cover 101 for covering the out-of-furnace structures 7 and 8 of the large module 100 is installed on the reversing bearing 29. FIG. 7 is a perspective view showing a detailed structure of the protective cover 101. As shown in FIG. In FIG. 7, the protective cover 101 has a substantially cylindrical container shape with no bottomed lid.
An inversion ring portion 25 located at the upper edge thereof and serving as a connection portion with the reactor pressure vessel 1, and a control rod drive mechanism housing 7 fixed below the inversion ring portion 25 and serving as an external structure And a substantially thin cylindrical housing cover 27 for protecting the in-core monitor housing 8.

The reversing ring portion 25 is provided with the same number of through holes 25a as the through holes 36aa of the ring girder upper flange portion 36a described above. A bolt (which may be a bolt) is penetrated and fastened so that it can be attached to and detached from the through hole 1ba of the reactor pressure vessel skirt flange portion 1b. Further, a reversing shaft 26 serving as a rotation center axis at the time of reversing is fixed to the reversing ring portion 25. The reversing shaft 26 is inserted into the groove 2 of the reversing bearing support leg 29d.
9c, the protective cover 101
Is rotatably installed on the reversing bearing 29. At this time, as shown in FIGS. 6A to 6C, the protective cover 101
Is set such that the reversal ring 25 is at the top.

After the protective cover 101 is installed in this manner, a substantially flange-shaped stopper portion 26a is provided at the tip of the reversing shaft 26 so that the reversing shaft 26 does not come off the groove 29c. Further, in FIG. 5 described above, this step 21 is completed and the reversing bearing 29 and the protective cover 1
Also, the trailer 28 in a state where 01 is installed is shown.

When step 21g is completed as described above, the process proceeds to step 22, where the large module 100 in the vertically suspended state is gradually lowered by the large lifting machine 15 as shown in FIG. Further, as shown in FIG. 9, after the external structures 7, 8 projecting from the bottom of the reactor pressure vessel 1 penetrate into the housing cover 27 of the protective cover 101, the reversal ring 25 and the reactor The pressure vessel skirt flange portion 1b is fixed by the above-mentioned bolt (schematically indicated by reference numeral 49 in FIG. 9). As a result, the out-of-furnace structures 7 and 8 of the large-sized module 100 are housed in the housing cover 27 and covered around the same, and are protected from interference with surrounding structures.

Thereafter, the process proceeds to step 23, and as shown in FIG. 1, while the large module 100 is suspended by the large hoist 15 more slowly, the trailer 28 is suspended.
Is slowly moved in a direction (in this case, leftward in FIG. 1) according to the direction in which the large module 100 is to be inverted (in this case, clockwise in FIG. 1). Thereby, the protective cover 101 rotates about the reversing shaft 26 as a rotation center,
The large module 100 is gradually inverted from the vertically suspended state. At this time, the moving distance and speed of the trailer 28 and the distance and speed at which the large module 100 is suspended are mutually set so that the load applied to the reversing shaft 26 of the reversing ring 25 becomes, for example, about half of the total weight of the large module 100. Adjust or control as appropriate. In this way, the large module 100 is gradually placed laterally toward the reactor pressure vessel cradle 30 on the trailer 28 while preventing excessive load and moment from being applied to the reversing shaft 26 and the reversing bearing 29. .

Then, in step 24, FIG. 10 (a) and FIG.
As shown in (b), the large module 100 is placed horizontally on the reactor pressure vessel cradle 30 on the trailer 28,
It is fixed with a wire 34 or the like.

As described above, the inversion procedure in step 20 is completed.

Thereafter, the process proceeds to step 40, where the large module 100 loaded on the trailer 28 as described above is loaded.
Is transported to a storage (not shown) of the reactor pressure vessel 1 installed in, for example, the premises of a nuclear power plant while being in the loaded state.

As described above, a structure (large module) 100 in which the reactor pressure vessel 1 is integrated with the reactor pressure vessel shield 9, the reactor internal structure 2, the control rod drive mechanism housing 7, and the in-core monitor housing 8 Is completed.

In the above description, the reversal ring 25
Constitutes a ring member provided as a connection portion with the reactor pressure vessel and detachable from the reactor pressure vessel.
Constitute a rotation axis for reversing the posture. In addition, the vertically suspended state of the large module 101 by the large lifting machine 15 is as follows.
The horizontal orientation on the trailer 28 corresponds to a vertical orientation in which the longitudinal direction of the reactor pressure vessel is substantially vertical, and the horizontal orientation in which the longitudinal direction of the reactor pressure vessel is substantially horizontal. Further, the trailer 28 constitutes a transporting means for loading and transporting the large module in the horizontal posture.

According to the present embodiment, the protective cover 101 provided with the reversing shaft 26 is attached to the reactor pressure vessel skirt flange 1b, which is a strength member, and the large module 100 is hung on the reversing bearing 29 provided on the trailer 28. , Large module 1 while moving trailer 28
By tilting 00 from the vertical suspension to the horizontal position,
In order to prevent collisions with obstacles such as the control rod drive mechanism housing 7 and the in-core monitor housing 8 which are the structures outside the furnace and to ensure their safety, they are easily inverted in a state where they are integrated, Reversal can be completed in time.

At this time, a reversing shaft 26 serving as a rotation center for reversing is provided on a reversing ring portion 25 of the protective cover 101, which is a connection portion with the reactor pressure vessel 1. As a result, a large bending force is not generated due to a large distance from the center of rotation as in the conventional structure described in Japanese Patent Application Laid-Open No. 55-2134, and the protective cover 101 is turned over when it is turned over.
Can be significantly reduced. Therefore, the strength of the protective cover 101 itself and the structure for attaching the protective cover 101 to the reactor pressure vessel 1 (for example, the reversal ring 25 and fastening bolts) can be reduced.
Cost can be reduced. In particular, protective cover 1
Of the parts 01, the housing cover 27 which is not the connection part with the reactor pressure vessel 1 only needs to have a function of simply covering the out-of-pile structures 7, 8, so that the required strength can be extremely reduced.

In the above-described embodiment, the reactor pressure vessel shield 9 which has been disposed and used around the reactor pressure vessel 1 in the reactor building 4 is replaced with the used reactor pressure vessel 1. Although unified and carried out in the form included in the large-sized module 100, it is not restricted to this. In other words, the used reactor pressure vessel shield 9 is not carried out, and instead a new reactor pressure vessel shield for carrying out is separately manufactured and attached to the reactor pressure vessel 1. It may be carried out while being incorporated in the large module 100. Further, in the above, in addition to the out-of-furnace structures 7 and 8, the in-furnace structure 2 was also carried out in a form included in the large-sized module 100, but is not limited to this, and excluding them, the out-of-furnace structures 7 and 8 are excluded. Only 8 may be carried out as a large module 100 together with the reactor pressure vessel 1. In these cases, a similar effect is obtained.

Further, in the above embodiment, the case where the reactor pressure vessel 1 is carried out of the reactor building 4 has been described as an example. However, as described above, the main part of the present invention is that when the large module 100 is turned over. It is needless to say that the method can be applied to the loading of the reactor pressure vessel 1 into the reactor building 4 by applying the method. The steps in this case are:
Basically, the procedure is the reverse of the above-described unloading operation. That is, for example, in a manufacturing plant, the reactor pressure vessel 1 is integrated with at least
0, the large module 100 is placed horizontally on the trailer 28, and at this time, a protective cover 101 is attached to the bottom of the reactor pressure vessel 1 so as to cover the outer structures 7, 8; It is transported to the vicinity of the reactor building 4. Then, the transported large module 100 is lifted by the large lifting machine 15 and the trailer 28 is moved in the direction corresponding to the reversing direction. State. Thereafter, the large module 100 in the vertically suspended state may be carried into the reactor building 4. However,
The attachment of the protective cover 101 to the reactor pressure vessel 1
It is also possible to carry out at a factory or the like before loading the trailer on the 28.

The same effect as in the above embodiment can be obtained also in the case of carrying in as described above.

Further, the present embodiment replaces the present invention with a reactor pressure vessel 1 used in an aged power plant,
Although the embodiment is for the case of further extending the operation period, the present invention is not limited to this. That is, when constructing a new power plant, the reactor pressure vessel 1 in the form of a large module 100 including the out-of-reactor structures 7, 8 and the like for some reason.
It can also be applied to the transport of refuse, and when the decommissioning of the aging power plant is to be carried out at the end of the initial operation period without extending the operation period, the external structures 7, 8 etc. The present invention can also be applied to the case where the reactor pressure vessel 1 is carried out in the form of a large module 100 including In these cases, a similar effect is obtained.

[0049]

According to the present invention, when a reactor pressure vessel is integrated with a structure outside the reactor to form a large module, and when the large module is turned over while the structure outside the reactor is covered with a protective cover, In addition, the reaction force applied to the protective cover itself or the mounting structure between the protective cover and the reactor pressure vessel can be reduced, and the strength required for them can be reduced to reduce costs.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a state in which a large module is gradually tilted and inverted from a vertically suspended state by a method for handling a reactor pressure vessel according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view illustrating a structure inside a reactor containment vessel in which a reactor pressure vessel of a nuclear power plant to which an embodiment of the present invention is applied is stored.

FIG. 3 is an enlarged view of a portion A in FIG. 2;

FIG. 4 is a flowchart showing a series of operation procedures for unloading a used reactor pressure vessel.

FIG. 5 is a diagram illustrating a state in which a large module is carried out of a reactor building.

FIG. 6 is a perspective view showing a state in which a reversing bearing and a protective cover are provided on a trailer, a side view seen from a B direction, and a front view seen from a C direction.

FIG. 7 is a perspective view illustrating a detailed structure of a protective cover.

FIG. 8 is a diagram illustrating a state where a large module carried out of a reactor building is gradually suspended.

FIG. 9 is a diagram illustrating a state in which the external structure is penetrated into a housing cover portion of a protective cover and fixed.

FIG. 10 is a side view showing a state in which the inverted large module is placed horizontally on the trailer, and is a view seen from an arrow D direction.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Reactor pressure vessel 1a Reactor pressure vessel skirt 1b Skirt flange 2 In-furnace structure 7 Control rod drive mechanism housing (out-of-furnace structure) 8 In-core monitor housing (out-of-furnace structure) 25 Inversion ring part (ring member, vessel) Upper edge, connecting portion) 26 reversing shaft (rotating shaft) 27 housing cover 28 trailer (transportation means) 29 reversing bearing 100 large module 101 protective cover

Claims (6)

[Claims] 1. A protection cover is attached to a bottom portion of the reactor pressure vessel so as to cover the outer structure while maintaining a state of a large module in which the reactor pressure vessel is integrated with at least the outer structure. The large module with the protective cover attached is positioned between a vertical position in which the longitudinal direction of the reactor pressure vessel is substantially vertical and a horizontal position in which the longitudinal direction of the reactor pressure vessel is substantially horizontal. In the method for handling a reactor pressure vessel that performs reversal, a rotation axis for reversing the attitude is provided at a connection portion of the protective cover with the reactor pressure vessel, and a space between the vertical attitude and the horizontal attitude is provided. Wherein when the attitude of the large module is reversed, the reversal is performed about the rotation axis as a rotation center. 2. The method for handling a reactor pressure vessel according to claim 1, wherein said protective cover has a closed bottomed container shape, and a connection portion of said protective cover is provided on said container shape. A method for handling a reactor pressure vessel provided at an edge. 3. The method for handling a reactor pressure vessel according to claim 1, wherein the protective cover includes a ring member detachable from the reactor pressure vessel as a connection portion with the reactor pressure vessel. Wherein the rotating shaft is provided on the ring member. 4. The method for handling a reactor pressure vessel according to claim 1, wherein the connection portion of the protective cover is configured to be detachable from a skirt flange of the reactor pressure vessel. A method for handling a reactor pressure vessel, characterized in that: 5. The reactor pressure vessel is unloaded outside the reactor building in a vertical position with the longitudinal direction of the reactor pressure vessel being substantially vertical while the reactor pressure vessel is in the state of a large module integrated with at least the external structure. Then, for the large module taken out,
A protective cover is attached to the bottom of the reactor pressure vessel so as to cover the outer structure, and the large module with the protective cover is attached, from the vertical position, the longitudinal direction of the reactor pressure vessel is defined as a substantially horizontal direction. In a method of handling a reactor pressure vessel in which a large-sized module in the lateral attitude is loaded on a transporting means and transported, the connection between the protective cover and the reactor pressure vessel is performed. A rotating shaft for reversing the posture, wherein when the posture is reversed from the vertical posture to the horizontal posture, the reversal is performed about the rotation shaft as a rotation center, How to handle. 6. The reactor pressure vessel is integrated with at least a structure outside the reactor to form a large module state, and the large module is placed in a horizontal posture in which the longitudinal direction of the reactor pressure vessel is substantially horizontal, and the transportation means Along with loading, a protective cover is attached to the bottom of the reactor pressure vessel so as to cover the outer structure, the large module with the protective cover is transported to the vicinity of the reactor building, and the transported large module is A reactor pressure vessel for reversing the attitude from the horizontal attitude to a vertical attitude in which the longitudinal direction of the reactor pressure vessel is substantially vertical, and carrying the large module in this vertical attitude into the reactor building. In the handling method, a rotation axis for reversing the attitude is provided at a connection portion of the protective cover with the reactor pressure vessel, and the vertical attitude is changed from the horizontal attitude to the vertical attitude. During posture inverted, the reactor pressure vessel handling method, characterized in that to perform the inversion as the pivot center of the pivot shaft.