JP6424437B2 - Reactor removal method - Google Patents

Description

  The present invention relates to a removal method of a nuclear reactor.

  In nuclear reactor facilities such as nuclear power plants, decommissioning will be taken once the operation mission is completed. Therefore, it is urgently needed to establish a safe and reasonable dismantling and removal method for reactor pressure vessels accompanying the decommissioning of reactors. In order to dismantle and remove the reactor pressure vessel, it is considered realistic that the reactor pressure vessel is subdivided, sequentially removed, and disposed of. Patent Document 1 discloses a method for removing a reactor pressure vessel from a reactor building of a boiling water reactor type nuclear power plant facility.

  As described in Patent Document 1, this decommissioning is performed in the order of system decontamination, safe storage, and dismantling and removal. In safe storage, the equipment is stored until the radiation level of the equipment decreases to a predetermined value (about 5 to 10 years), and then dismantling piping and equipment and dismantling heavy reactor pressure vessels. Dismantling and removal work is carried out to subdivide this and remove it from the reactor building. In the removal work of the dismantling material, the dismantling material is stored in the radiation shielding container in the reactor building, transferred to a storage facility such as a turbine building or a radiation control building, and temporarily stored. Thereafter, the radiation shielding container is transported to a predetermined place by a ship and buried in the ground.

  In Patent Document 1, in order to efficiently transfer dismantling products disassembled in the reactor building from the reactor building to the storage facility, a tunnel connecting the reactor building and the turbine building directly connected to the nuclear power plant facilities A reactor removal method that uses (main steam tunnel) as a passage for unloading reactor pressure vessels stored in the reactor building and transfers the dismantled material to the turbine building via the tunnel for storage. It is disclosed.

Patent No. 4898567

In the above-mentioned prior art, the turbine building must be dismantled in advance in order to secure a space for storing dismantling materials in the turbine building. It is not possible to secure a flow line (main steam tunnel) for carrying out the dismantling material.
Therefore, in order to dismantle the reactor building without waiting for the dismantling of the turbine building, the torus chamber in which the suppression chamber, which communicates with the reactor containment vessel and the vent pipe, is accommodated in advance is disassembled, and the torus It is conceivable to access the ground using the appendage of the existing equipment attached to the room and to secure another flow line in which the reactor building and the turbine building are not directly connected.

  In the case of dismantling the torus room in advance, dismantling work of the structure in the torus room, shredding work of dismantling objects, storing work of shredded dismantling objects in the container, storage work of the stored container is required. The required work space is required. In addition, although the stored container stored is taken out via the said flow line, it must be stored in a torus chamber until the final disposal site of the dismantling thing is decided. In such a case, when the structure in the torus chamber is completely dismantled, the floor space in the torus chamber is compressed by the dismantling material. In this case, the working space and the flow line space can not be secured, and there is a problem that it becomes difficult to secure the previous disassembly and the flow line in the torus room.

  This invention is made in view of the said problem, and aims at provision of the removal method of the reactor which can reduce the pressure of the floor surface space in a torus room by a demolition thing.

In order to solve the above-mentioned problems, the present invention is a removal method of a nuclear reactor having a torus chamber in which a suppression chamber in communication with a reactor containment vessel and a vent pipe is accommodated, the method comprising the suppression chamber A first step of partially disassembling the structure in the torus chamber, and a space surrounded by a space or a casing surrounded by the casing of the suppression chamber in the torus chamber, and a dissembled product produced by the dissection And a second step of storing using at least a part of
By adopting this method, according to the present invention, the structure in the torus chamber including the suppression chamber is partially disassembled instead of being disassembled collectively, thereby reducing the amount of disassembly products resulting from the disassembly. Reduce pressure on floor space. Further, in the present invention, by storing the dismantled material in the space surrounded by the space surrounded by the housing of the suppression chamber which is the largest structure in the torus chamber or the case, the filling of the dismantled materials in the torus chamber Increase the rate and reduce the pressure on the floor space in the torus room.

Further, in the present invention, the suppression chamber is self-supporting in the torus chamber via the support leg, and the first step includes the step of partially disassembling the lower portion of the suppression chamber, the second step The process adopts a method of storing the dismantled material in a space below the suppression chamber which becomes roof-like by the dismantling via the support legs and is self-supporting.
By adopting this method, in the present invention, the lower part of the suppression chamber is disassembled while maintaining the self-supporting function by the support legs, and the fragments are stored in the space below the roof-shaped suppression chamber. Thus, in the present invention, while the amount of dismantling material is reduced without dismantling the upper portion of the suppression chamber, the filling rate of dismantling material in the torus chamber is increased, and the pressure on the floor space in the torus chamber is reduced.

Further, in the present invention, the support legs are provided in a pair so as to face each other in the width direction of the suppression chamber, and in the first step, the support legs are provided in the pair. The method of dismantling at least any one part partially and increasing the distance between the support legs in the width direction is adopted.
By adopting this method, in the present invention, the pair of support legs supporting the suppression chamber is partially disassembled, and the distance between the support legs is increased, whereby the lower portion of the roof-shaped suppression chamber is formed. Make space easy to use. For example, by increasing the distance between the support legs, a forklift or the like can be easily made to enter, and the efficiency of the filling work of the dismantled material in the space below the roof-shaped suppression chamber is improved.

Further, in the present invention, the suppression chamber holds pool water in a space surrounded by the housing, and the second step is a step of storing the dismantled material submerged in the pool water. Adopt a method that
By adopting this method, in the present invention, the debris is submerged in the pool water of the suppression chamber, and the debris is stored in the space surrounded by the casing of the suppression chamber, thereby filling the debris in the torus chamber. Increase the rate and reduce the pressure on the floor space in the torus room.

Further, in the present invention, the first step is a step of partially dismantling the upper portion of the suppression chamber for holding the pool water, and partially dismantling the upper portion of the suppression chamber by the weight of the pool water. And a step of reinforcing the case so as not to be buckled.
By adopting this method, in the present invention, the upper part of the suppression chamber is disassembled while leaving the lower part of the suppression chamber and maintaining the retention function of the pool water. In addition, disassembling the upper portion of the suppression chamber may reduce the structural strength, so the case is reinforced so as not to buckle. Thus, according to the present invention, dismantling materials are reduced without dismantling the lower part of the suppression chamber to reduce the pressure on the floor space in the torus chamber, and since the pool water retention function is provided, the pool water is discarded. Pre-treatment can be performed in parallel with disassembly of the structure in the torus chamber.

Further, in the present invention, the suppression chamber is self-supporting in the torus chamber via a support leg, and the first step includes a step of partially disassembling the upper portion of the suppression chamber, the second step The process employs a method of storing the dismantled material on the suppression chamber which is self-supporting in a bowl shape by the dismantling via the support leg.
By adopting this method, in the present invention, the upper part of the suppression chamber is disassembled while maintaining the self-supporting function by the support legs, and the fragments are stored above the bowl-shaped suppression chamber. Thus, according to the present invention, while the amount of dismantling material is reduced without dismantling the lower part of the suppression chamber, the filling rate of dismantling material in the torus chamber is increased, and the pressure on the floor space in the torus chamber is reduced.

Further, in the present invention, the torus chamber has an annular area for accommodating the suppression chamber, and the first step includes the step of disassembling the structure of a part of the annular area. The second step includes a step of temporarily placing the scrap in the partial area in another area, and a step of providing a scrap yard for storing the scrap in the partial area. Adopt the method of including.
By adopting this method, in the present invention, the structure in a part of the annular area of the torus chamber is disassembled, the disassembled object is temporarily placed in another area, and a scrap yard is provided in the disassembled area. By providing the scrap yard, the storage operation for storing the dismantled material in the container is advanced, and then the unloading operation for discharging the dismantled material and the just-in-time operation are performed. This reduces the number of stored debris in the torus room and reduces the pressure on the floor space in the torus room.

  According to the present invention, it is possible to reduce the pressure on the floor surface space in the torus room by the dismantling material, and to reliably perform the prior disassembly and the flow line in the torus room.

BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing which shows schematic structure of the nuclear reactor in 1st Embodiment of this invention. It is an arrow AA figure in FIG. It is a figure for demonstrating the carrying out of the demolished thing using an appendage of the removal method of the reactor in 1st Embodiment of this invention. It is a figure which shows the work flow of the incomplete dismantling method in 1st Embodiment of this invention. It is a schematic diagram for demonstrating the working process of the incomplete dismantling construction method in 1st Embodiment of this invention. It is a schematic diagram for demonstrating the working process of the incomplete dismantling construction method in 1st Embodiment of this invention. It is a figure which shows the operation flow of the incomplete dismantling method in 2nd Embodiment of this invention. It is a schematic diagram for demonstrating the operation process of the incomplete dismantling construction method in 2nd Embodiment of this invention. It is a schematic diagram for demonstrating the operation process of the incomplete dismantling construction method in 2nd Embodiment of this invention. It is a figure which shows the operation flow of the incomplete dismantling method in 3rd Embodiment of this invention. It is a schematic diagram for demonstrating the working process of the incomplete dismantling construction method in 3rd Embodiment of this invention. It is a schematic diagram for demonstrating the working process of the incomplete dismantling construction method in 3rd Embodiment of this invention. It is a schematic diagram for demonstrating the working process of the incomplete dismantling construction method in 3rd Embodiment of this invention. It is a schematic diagram for demonstrating the working process of the incomplete dismantling construction method in 3rd Embodiment of this invention. It is a schematic diagram for demonstrating the working process of the incomplete dismantling construction method in 3rd Embodiment of this invention. It is a schematic diagram for demonstrating the working process of the incomplete dismantling construction method in 3rd Embodiment of this invention. It is a schematic diagram for demonstrating the working process of the incomplete dismantling construction method in 3rd Embodiment of this invention. It is a schematic diagram for demonstrating the working process of the incomplete dismantling construction method in 3rd Embodiment of this invention. It is a schematic diagram for demonstrating the working process of the incomplete dismantling construction method in 3rd Embodiment of this invention. It is a schematic diagram for demonstrating the working process of the incomplete dismantling construction method in 3rd Embodiment of this invention. It is a schematic diagram for demonstrating the working process of the incomplete dismantling construction method in 3rd Embodiment of this invention. It is a figure for comparing the work flow of the incomplete dismantling method and conventional construction method in a 3rd embodiment of the present invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

First Embodiment
FIG. 1 is a cross-sectional view showing a schematic configuration of a nuclear reactor in a first embodiment of the present invention. FIG. 2 is a view on arrow AA in FIG.
The nuclear reactor of this embodiment relates to a boiling water nuclear power plant, and a turbine building (not shown) is provided around the reactor.

  As shown in FIG. 1, the nuclear reactor includes a reactor pressure vessel 1 (RPV) and a steel nuclear reactor containment vessel 2 (PCV) provided surrounding the reactor pressure vessel 1. The reactor containment vessel 2 primarily accommodates the reactor pressure vessel 1 and forms a pressure barrier and a barrier to the release of radioactive materials upon loss of coolant and the like. The reactor containment vessel 2 is a steel self-contained containment vessel whose base is supported by the reactor building foundation.

  The reactor containment vessel 2 is provided in a concrete reactor building 3 (R / B) as a radiation shield. The periphery of the reactor containment vessel 2 is thickly covered with a living body shielding wall 3a which forms a part of the reactor building 3. The living body shielding wall 3a isolates a radioactive contamination area and a clean area. The reactor containment vessel 2 includes a pressure suppression system including a dry well 4 (D / W), a suppression chamber 5 (S / C), and a vent pipe 6.

As shown in FIG. 2, the suppression chamber 5 is formed of a steel pipe annularly disposed around the reactor containment vessel 2. The suppression chamber 5 is in communication with the dry well 4 of the reactor containment vessel 2 via a plurality of vent pipes 6 (not shown in FIG. 2, see FIG. 1).
The vent pipe 6 is made of a large diameter steel pipe having an inner diameter of about 2 m. The vent pipe 6 connects the space of the dry well 4 and the water of the suppression chamber 5.

  The vent pipe 6 has a vent header 7 and a downcomer 8. The vent header 7 is annularly provided in the suppression chamber 5 and connected to the plurality of vent pipes 6. The downcomer 8 is branched from the vent header 7 and opened in the pool water P of the suppression chamber 5. A plurality of downcomers 8 are provided between adjacent vent pipes 6.

  An internal corridor 13 is provided in the suppression chamber 5. The internal corridor 13 is provided above the pool water P so as to be able to circulate inside the suppression chamber 5. On the other hand, an external corridor 14 is provided outside the suppression chamber 5. The outer corridor 14 is provided above the suppression chamber 5 so as to be able to go around the outside of the suppression chamber 5. The suppression chamber 5 is self-supporting in the torus chamber 9 via the support legs 19.

  A torus chamber 9 which is located around the lower part of the reactor containment vessel 2 and in which a suppression chamber 5 is accommodated is provided in a ring shape in the basement in the reactor building 3. The torus chamber 9 has a space cross-sectional area of, for example, about 8 m in height × about 8 m in width, and forms a torus-shaped space of 30 m to 40 m in diameter around the reactor containment vessel 2. The torus chamber 9 is formed as an underground structure which forms a part of a concrete reactor building 3 as a radiation shield.

  The reactor building 3 is provided with an appendage 10 (attached chamber) which is attached to the side of the torus chamber 9 and which communicates with the ground outside the reactor building 3. The appendage 10 is an underground structure attached to the outside of the torus chamber 9 so as to protrude therefrom. The appendage 10 is a core spray pump chamber for housing a core spray pump 11 that constitutes a part of an emergency core cooling system (ECCS).

  In the appendage 10, in addition to the core spray pump 11, a heat exchanger, a drain tank, a drain pump, etc. (all not shown) that similarly constitute an emergency core cooling system are accommodated. The appendage 10 has an underground upper floor 10a and an underground lower floor 10b, and can be returned and received by a ladder (not shown). The core spray pump 11 is arrange | positioned at the underground lower floor 10b.

  A communication port 16 communicating with the torus chamber 9 is formed on the side of the underground upper floor 10a. Further, a hatch 17a that can communicate with the ground outside the reactor building 3 is provided at the top of the underground upper floor 10a. The hatch 17a can be opened to a size that can transfer the core spray pump 11 or the like, for example, a size of about 2 m × 2 m. As shown in FIG. 2, two appendages 10 are provided beside the torus chamber 9. Further, the torus chamber 9 is provided with a communication port 18 communicating with a main steam tunnel (not shown) connected to the turbine building.

Then, the removal method of the reactor of the said structure is demonstrated.
FIG. 3 is a view for explaining the carrying-out of the disassembled object X using the appendage 10 of the removal method of the nuclear reactor in the first embodiment of the present invention.
In the present method, first, in-furnace decontamination, systematic decontamination, and water treatment in the suppression chamber 5 are performed, and then, as shown in FIG. 3, the suppression chamber 5 is disassembled in advance. When the suppression chamber 5 is disassembled in advance, the vent pipe 6, the torus chamber 9, and the appendage 10 can be communicated. Thus, it is possible to secure a flow line 20 for transfer from / into the reactor containment vessel 2 to the ground outside the reactor building 3.

  The flow line 20 is formed using the existing structure, the vent pipe 6, the torus chamber 9, and the appendage 10. In addition, in order to secure the space cross-sectional area in the flow line 20, it is preferable that the vent header 7 and the downcomer 8 be removed along with the disassembly of the suppression chamber 5 and removed. Further, the communication port 16 between the torus chamber 9 and the appendage 10 may be enlarged if necessary. The appendage 10 is a core spray pump chamber, is provided with a large hatch 17a serving as an outlet, and is suitable for use as a flow line.

Thus, dismantling of the reactor building 3 without waiting for dismantling of the turbine building by securing another flow line in which the reactor building 3 and the turbine building are not directly connected using the existing structure. Work can be done. For this reason, it becomes possible to perform disassembly work in parallel with the turbine building side.
When dismantling the reactor pressure vessel 1, radioactive floats produced during dismantling leak from the inside of the reactor building 3 to the ground through the flow line 20. Therefore, in the present method, the hatch 17a is enclosed before dismantling. The garage 21 will be set up temporarily. The garage 21 is for the transport vehicle T that transports the disassembled object X to the outside, and is provided on the ground so as to communicate with the appendage 10. A shutter 22 is provided in the garage 21 and is closed when the transport vehicle T receives a load.

  The dismantling product X of the reactor pressure vessel 1 subdivided in the reactor containment vessel 2 is carried out by providing a lifting machine 24 at an appropriate position of the flow line 20. Specifically, a lifting machine 24 is installed on a rail 25 constructed so as to pass the vent pipe 6 between the reactor containment vessel 2 and the torus chamber 9, and the dismantled object X is carried out to the torus chamber 9. Further, a lifting machine 24 is installed on a rail 26 erected so as to pass the communication port 16 between the torus chamber 9 and the appendage 10, and the container storing the object X is taken out to the appendage 10 in the torus chamber 9. Then, the hoisting machine 24 is installed on the rail 27 erected in the garage 21, and the to-be-removed object X is pulled up to the ground and placed on the loading platform of the transport vehicle T to carry it out.

  Thus, in the present method, the inside of the torus chamber 9 is disassembled in advance, and another independent flow line 20 in which the reactor building 3 and the turbine building are not directly connected is secured without waiting for the dismantling of the turbine building. The dismantling work in the reactor building 3 can be performed. In addition, since the large space of the torus chamber 9 can be used, waste materials can be treated even before the final disposal site is determined, and the scrapped material X treated with waste materials is stored in the reactor building 3 be able to.

  By the way, the structures in the torus chamber 9 include structures that are not effective for securing work space and flow line space. Such a structure is, for example, a high part in the torus chamber 9 or the like which does not press the floor space in that state, or a valve or the like, which must be disassembled into a large number of members. There is a part etc which can not secure the ratio. Disassembling such a structure squeezes the floor space in the torus chamber 9 and can not secure a work space and a flow line space, and the prior disassembly of the torus chamber and the flow line 20 It becomes difficult to secure.

So, in this method, the incomplete dismantling method of dismantling the structure in the torus chamber 9 partially is employ | adopted. The incomplete dismantling method described below with reference to FIGS. 4 to 6 is the one after the pool water P of the suppression chamber 5 has been transferred.
FIG. 4 is a diagram showing a work flow of the incomplete dismantling method in the first embodiment of the present invention. FIG.5 and FIG.6 is a schematic diagram for demonstrating the working process of the incomplete dismantling method in 1st Embodiment of this invention.

  In this method, first, maintenance of the work space in the torus room 9 and loading of dismantling equipment are performed (step S1). The delivery of dismantling equipment can be performed via the appendage 10. The dismantling equipment includes the rail 30 and the lifting machine 31 shown in FIG. 5A, which are installed inside the upper portion 5 a of the suppression chamber 5. The rails 30 extend in the longitudinal direction (ring circumferential direction) of the suppression chamber 5. The lifting machine 31 is movable along the rail in the longitudinal direction of the suppression chamber 5 (in the direction perpendicular to the sheet of FIG. 5A) and the suspension point is in the width direction of the suppression chamber 5 (in FIG. 5A). Movable in the left and right direction).

  Next, the support legs 19 of the suppression chamber 5 are made slim and the steps on the floor of the torus chamber 9 are removed (step S2: first step). This step S2 enables the forklift and the like to travel in a later step. In the present embodiment, as shown in FIG. 5B, the support legs 19 are provided in a pair so as to face each other in the width direction of the suppression chamber 5. In this step S2, at least one of the pair of support legs 19 (both in the present embodiment) is partially disassembled to increase the distance between the support legs 19 in the width direction. This makes it easy to utilize the space below the suppression chamber 5.

  Next, reinforcement of the part to be disassembled is performed (step S3). This step S3 is to reinforce the structure as necessary in order to maintain the function of supporting the dead weight of the suppression chamber 5 in a later step. For example, a support is applied to the outside of the slimmed support leg 19 to reinforce the support leg 19. Further, for example, a support is applied to the vent pipe 6, the vent header 7 and the like as needed, and the support is reinforced.

  Next, dismantling of the lower portion 5b of the suppression chamber 5 and cutting of the downcomer 8 and the like are performed (step S4: first step). This step S3 is for partially disassembling the structure in the torus chamber 9 including the suppression chamber 5. When the lower portion 5b of the suppression chamber 5 is disassembled, as shown in FIG. 6A, the upper portion 5a of the suppression chamber 5 remains, and the suppression chamber 5 supported by the support legs 19 becomes a roof and becomes independent. As a result, the space s1 enclosed by the casing (shell) of the suppression chamber 5 is opened, and a large space is formed below the roof-shaped suppression chamber 5.

  Next, the interfering substance in the container loading and unloading is removed (step S5). This step S5 is for removing a structure that interferes with the loading and unloading of the container from the ceiling of the torus chamber 9 and the appendage 10. This container accommodates the dismantling object X produced in step S2, step S4, and the like.

  Finally, the space under the roof-shaped suppression chamber 5 is maintained as a temporary storage space, and the dismantling object X accommodated in the container is stored (step S6: second process). In this step S6, as shown in FIG. 6B, the to-be-discarded article X is stored using at least a part of the space s1 enclosed by the casing of the suppression chamber 5 in the torus chamber 9. The dismantling object X accommodated in the container is stored in multi-tiered stacking using a lifting machine 31, a forklift and the like in the space below the roof-shaped suppression chamber 5. The containers stacked in multiple stages can be used as a scaffold and can be used for full-scale dismantling such as dismantling of the upper portion 5a of the suppression chamber 5 in the post process.

  As described above, according to this incomplete dismantling method, the structure in the torus chamber 9 including the suppression chamber 5 is not dismantled together but dismantled partially, so that the dismantling object X produced by dismantling is The pressure on the floor space in the torus chamber 9 can be reduced. In addition, by storing the disassembly X in the space s1 surrounded by the casing of the suppression chamber 5, which is the largest structure in the torus chamber 9, the filling rate of the disassembly X in the torus chamber 9 is increased, The pressure on the floor space in the torus chamber 9 can be reduced.

  Specifically, as shown in FIG. 6 (b), the lower part 5b of the suppression chamber 5 is disassembled while maintaining the self-supporting function by the support legs 19, and the disassembly is carried out in the space below the roof-shaped suppression chamber 5. Store X As a result, while the dismantling object X is reduced without dismantling the upper portion 5a of the suppression chamber 5 which is not effective for securing the work space and flow line space, the filling rate of the dismantling object X in the torus chamber 9 is increased, The pressure on the floor space in 9 can be reduced.

  Furthermore, in this incomplete dismantling method, the pair of support legs 19 supporting the suppression chamber 5 is partially disassembled, and the distance between the support legs 19 is increased, so that the lower part of the roof-shaped suppression chamber 5 is formed. Make it easy to use the As shown in FIG. 6A, by increasing the distance between the support legs 19, it becomes easy for a forklift or the like to enter, and the efficiency of the filling operation of the object X in the space below the roof-shaped suppression chamber 5 Can be implemented.

As described above, according to the above-described embodiment, a removal method of a reactor having a torus chamber 9 in which the suppression chamber 5 communicated with the reactor containment vessel 2 and the vent pipe 6 is accommodated, which is a suppression chamber The first step of partially disassembling the structure in the torus chamber 9 including 5 and at least the space s1 enclosed in the torus chamber 9 by the casing of the suppression chamber 5 in the torus chamber 9 By adopting the method of having the second step of storing using a part, the scrap X generated by the demolition is reduced, the filling rate of the scrap X in the torus chamber 9 is increased, and the torus chamber 9 The pressure on the floor space inside can be reduced.
For this reason, according to the present embodiment, it is possible to reduce the pressure of the floor space in the torus chamber 9 by the dismantling object X, and to reliably perform the prior disassembly and the flow line 20 in the torus chamber 9.

Second Embodiment
Next, a second embodiment of the present invention will be described. In the following description, the same or equivalent components as or to those of the embodiment described above are designated by the same reference numerals, any explanation of which will be simplified or omitted.

FIG. 7 is a diagram showing a work flow of the incomplete dismantling method according to the second embodiment of the present invention. FIG.8 and FIG.9 is a schematic diagram for demonstrating the working process of the incomplete dismantling method in 2nd Embodiment of this invention. FIG. 9 (b) is a side view of the torus chamber 9 shown in FIG. 9 (a).
In the incomplete dismantling method of the second embodiment, the pool water P of the suppression chamber 5 is not transferred. Also in this method, first, as in the above-described embodiment, maintenance of the work space in the torus chamber 9 and loading of dismantling equipment are performed (step S11). By this step S11, the inside of the torus chamber 9 is maintained as shown in FIG. 8 (a).

  Next, in the present method, the downcomer 8 and the vent header 7 are partially disassembled (step S12). This step S12 is for partially disassembling the structure in the torus chamber 9 (first step), and the disassembled object X produced by the disassembly is surrounded by the casing of the suppression chamber 5 in the torus chamber 9 Is stored using at least a part of the space s2 (second step). As shown in FIG. 8 (b), the suppression chamber 5 holds the pool water P in the space s2 surrounded by the housing, and the partially disassembled disassembly X is submerged in the pool water P. Temporary storage.

  Next, reinforcement of the portion to be cut of the suppression chamber 5 is reinforced (step S13). In this step S13, the structural strength may be reduced if the upper portion 5a of the suppression chamber 5 is disassembled in a later step, so the case is reinforced if necessary so as not to be buckled by the weight of the pool water P. is there. For example, as shown in FIG. 9A, the reinforcing member 32a is assembled in a truss shape so as to support the inner side of the suppression chamber 5, and is reinforced. Further, as shown in FIG. 9 (b), a reinforcing member 32b is stretched in a wire shape and reinforced on the ceiling of the torus chamber 9 so as to open the opening of the suppression chamber 5.

  Next, partial cutting of the upper portion 5a of the suppression chamber 5 and temporary placement of the cut piece on the floor or the like are performed (step S14). When the upper portion 5a of the suppression chamber 5 is disassembled, as shown in FIG. 9A, the lower portion 5b of the suppression chamber 5 remains, and the suppression chamber 5 supported by the support legs 19 becomes bowl-like and becomes independent. Thus, by leaving the lower part 5b of the suppression chamber 5, disassembly can be performed while maintaining the function of holding the pool water P. In addition, as shown to Fig.9 (a), the disassembly thing X which is a cutting piece is temporarily placed under the lower part 5b of the suppression chamber 5. As shown in FIG.

  Next, the floor plate 33 is installed on the removed portion of the suppression chamber 5, and the floor surface is reinforced (step S15). In this step S15, as shown in FIG. 9 (b), a water treatment facility for treating pool water P, a floor board for forming equipment temporary storage space R for temporarily placing a deionizing ion exchange resin etc. 33 will be installed. The weight of the floor plate 33 and the floor load of the equipment installed on the floor surface support the column from the floor surface of the torus chamber 9 as needed.

  Finally, the guide 34 or the like is installed as a breakwater when the pool water P waves up, and is maintained as a temporary storage place, and materials and the like are stored (step S16). Although it is necessary to discard the pool water P for disassembling the suppression chamber 5, the pool water P contains a rust inhibitor such as hexavalent chromium, and it is necessary to render it harmless to the environmental standard level. In this step S16, the place where the equipment for the water treatment is installed is maintained, and the pool water P is circulated to perform the detoxification treatment.

  As described above, according to this incomplete dismantling method, the structure in the torus chamber 9 including the suppression chamber 5 is not dismantled together but dismantled partially, so that the dismantling object X produced by dismantling is The pressure on the floor space in the torus chamber 9 can be reduced. In addition, by storing the disassembly X in the space s2 surrounded by the casing of the suppression chamber 5, which is the largest structure in the torus chamber 9, the filling rate of the disassembly X in the torus chamber 9 is increased, and the torus The pressure on the floor space in the chamber 9 can be reduced.

  Specifically, as shown in FIG. 8 (b), the scrap water X is submerged in the pool water P of the suppression chamber 5, and the scrap water X is stored in the space surrounded by the housing of the suppression chamber 5. The filling rate of the to-be-discarded object X in the torus chamber 9 can be increased, and the pressure on the floor space in the torus chamber 9 can be reduced.

  Moreover, in this incomplete dismantling method, the upper part 5a of the suppression chamber 5 is dismantled while maintaining the pool water P holding function while leaving the lower part 5b of the suppression chamber 5. Since disassembling the upper portion 5a of the suppression chamber 5 may reduce the structural strength, as shown in FIG. 9, the housing is reinforced so as not to be buckled. As a result, the disassembly X is reduced without dismantling the lower portion 5b of the suppression chamber 5 to reduce the pressure on the floor space in the torus chamber 9, and the pool water P is retained. Pretreatment for disposal can be performed in parallel with disassembly of the structures in the torus chamber 9.

Third Embodiment
Next, a third embodiment of the present invention will be described. In the following description, the same or equivalent components as or to those of the embodiment described above are designated by the same reference numerals, any explanation of which will be simplified or omitted.

FIG. 10 is a diagram showing a work flow of the incomplete dismantling method in the third embodiment of the present invention. FIG. 11 to FIG. 21 are schematic views for explaining the working process of the incomplete dismantling method according to the third embodiment of the present invention.
The third embodiment is different from the above-described embodiment, and is a process incomplete dismantling method, and adopts a scrap yard method for storing the dismantling object X generated by dismantling without storing it in a container.

  In the present method, first, the upper portion 5a of the suppression chamber 5, the vent pipe 6, the vent header 7 and the like are disassembled and temporarily placed (step S21). As shown in FIG. 11, the torus chamber 9 has an annular area K that accommodates the suppression chamber 5, and the step S 21 includes the scrap X generated in the area (a part of the area) indicated by the symbol K 2. It is temporarily placed in the area (another area) indicated by reference numeral K1. As shown in FIG. 12 (a), a rail 40 and a lifting machine 41 are provided in the area indicated by the reference symbol K1, and not only the dismantled material X generated in the area but also the area indicated by the reference symbol K2 The dismantling object X is also stored (temporarily placed) on the suppression chamber 5. As a result, as shown in FIG. 12 (b), the area indicated by the reference symbol K2 is not compressed by the disassembled object X, and a space is secured.

  Next, the lower part 5b of the suppression chamber 5 is disassembled and temporarily placed (step S22). In step S22, as shown in FIG. 13, the dismantled object X produced in the area (a part of the area) indicated by the code K4 is temporarily placed in the area (the other area) indicated by the code K3. Dismantling of the lower portion 5b of the suppression chamber 5 is performed in the area indicated by reference numeral K4. In the area indicated by the reference sign K3, as shown in FIG. 14A, the dismantled object X produced in the area indicated by the reference sign K4 is stored (temporarily placed) on the suppression chamber 5. Thereby, as shown in FIG. 14B, in the area indicated by reference numeral K4, the upper portion 5a and the lower portion 5b of the suppression chamber 5 are disassembled to secure a space.

  Next, the dividing wall Y1 on one side of the scrap yard Y is installed (step S23). In step S23, as shown in FIG. 15, an area indicated by reference numeral K4 in which the upper part 5a and the lower part 5b of the suppression chamber 5 are disassembled and an area indicated by reference numeral K1 in which the lower part 5b of the suppression chamber 5 and the object X remains. The partition Y1 on one side of the scrap yard Y is installed at the boundary (side of the communication port 18 communicating with the main steam tunnel). In the partition Y1 of the scrap yard Y, as shown in FIG. 16, while supporting both sides of the plate member 50 by the support member 51, at least the suppression chamber 5 is provided to increase the filling ratio to the plate member 50 by a predetermined height. Height) to build up.

  Next, movement and shredding of the disassembly X of the lower part 5b of the suppression chamber 5 to the scrap yard Y is performed (step S24). In step S24, as shown in FIG. 17, the scrap X generated in the area (a part of the area) indicated by the code K3 and the demolished goods X stored are indicated by the sign K6 via the area indicated by the sign K5. It moves to the area (other area). An area indicated by reference sign K5 is an area for shredding the object X. In this area, after shredding and moving the dismantling object X stored in the area indicated by the code K3, the work of dismantling and shredding the lower portion 5b of the suppression chamber 5 remaining as shown in FIG. To be done. The area indicated by the reference symbol K6 is an area for storing the dismantled objects X generated in the area indicated by the reference symbol K5 and other areas as shown in FIG. 18 (b). To go.

  Next, dismantling of the lower portion 5b of the suppression chamber 5 and temporary placement in the scrap yard Y are sequentially performed (step S25). In step S25, as shown in FIG. 19, the bulkhead Y2 on the other side of the scrap yard Y is installed, and the disassembly X is moved to the area indicated by the code K6 surrounded by the bulkhead Y1 and the bulkhead Y2; Disassembly of the lower part 5b of the suppression chamber 5 is sequentially advanced. First, the object X stored on the lower portion 5b of the suppression chamber 5 is moved from the area indicated by the symbol K1 (see FIG. 20A). Next, the lower portion 5b of the suppression chamber 5 is disassembled in the area indicated by the reference sign K7, and the object X is moved to the area indicated by the reference sign K5 (see FIG. 20 (b)). The to-be-discarded object X is shredded in the area shown by code K5, and is accommodated in the area shown by code K6.

  Finally, the loading of the container and the storage and unloading of the object X are performed (step S26). In step S26, as shown in FIG. 21, one batch of container is carried into the area indicated by symbol K8, the scrap X of the scrap yard Y is stored in the container, and the scrap X stored in the container is unloaded. It is a thing. The loading, storage, and unloading are batch processes, and are sequentially repeated. Loading of the container and unloading of the dismantled object X stored in the container can be performed from the appendage 10 through the communication port 16 or from the main steam tunnel through the communication port 18.

As described above, according to this incomplete dismantling method, the structure in a part of the annular area K of the torus chamber 9 is dismantled, and the dismantling object X is temporarily placed in another area and dismantled in the dismantled area A scrap yard Y is provided, and the storage operation for storing the disassembled object X in the container is advanced, and thereafter, the unloading operation for discharging the disassembled object X and the just-in-time operation are performed. As a result, the number of stored items of dismantling material X in the torus chamber 9 (the number of stored containers) can be reduced, and the pressure on the floor space in the torus chamber 9 can be reduced.
Further, in this incomplete dismantling method, the upper part 5a of the suppression chamber 5 is dismantled while maintaining the self-supporting function by the support legs 19, and the dismantling object X is stored on the wedge-shaped suppression chamber 5. Thereby, while reducing the dismantling object X without dismantling the lower part 5b of the suppression chamber 5, the filling rate of the dismantling object X in the torus chamber 9 is increased, and the pressure on the floor space in the torus chamber 9 is reduced. be able to.

FIG. 22 is a diagram for comparing the work flow of the incomplete dismantling method and the conventional method according to the third embodiment of the present invention. Fig. 22 (a) shows the incomplete dismantling method of the third embodiment, and Fig. 22 (b) shows the conventional method.
As shown in FIG. 22 (b), in the conventional construction method, the inside of the torus chamber 9 is roughly disassembled, the disassembled object X is shredded, and the shredded disassembled object X is stored in a container and temporarily stored. Then, this cycle is repeated, and when the final disposal site of the dismantling object X is determined, the container temporarily stored is unloaded. Therefore, when the time to take out the dismantling object X is delayed, the floor space of the torus chamber 9 may be compressed by the container.

  On the other hand, as shown in FIG. 22 (a), in the present method (scrap yard method), the inside of the torus chamber 9 is roughly disassembled, the demolished article X is shredded, and the shredded demolished article X is put into a scrap yard Y. Temporary storage. Then, when the final disposal site of the dismantling object X is determined, the dismantling object X that has been temporarily stored is stored in a container and carried out. As described above, in the present method, by providing the scrap yard Y, the work of storing the dismantling object X in the container can be made just-in-time for the work of unloading the dismantling object X. (The number of stored containers) can be reduced to secure space. Therefore, even if the time to take out the dismantling object X is delayed, the floor space in the torus chamber 9 is not compressed.

  Further, according to this method, by providing the scrap yard Y, it becomes easy to secure an empty space in the torus chamber 9 as described above. Therefore, the work space can be easily divided into disassembly and container storage, and the work can be closed in the torus chamber 9. Further, by providing the scrap yard Y, since the dismantling objects X can be sorted and stored, it is possible to reduce empty containers and their storage places. Further, in the storage operation of the dismantling object X, the handling rate of the container can be increased because the dismantling object X which has already been shredded can be handled, and the storage according to the degree of contamination of the dismantling object X becomes easy . In addition, it is possible to eliminate the use of custom-made containers for multi-stage stacking.

  As mentioned above, although the suitable embodiment of the present invention was described referring to drawings, the present invention is not limited to the above-mentioned embodiment. The shapes, combinations, and the like of the constituent members shown in the above-described embodiment are merely examples, and various changes can be made based on design requirements and the like without departing from the spirit of the present invention.

  DESCRIPTION OF SYMBOLS 2 ... Reactor containment vessel, 5 ... Suppression chamber, 5a ... Upper part, 5b ... Lower part 6 ... Vent pipe, 9 ... Torus room, 10 ... Appendage, 19 ... Supporting leg, 20 ... Flow line, 32a ... Reinforcement material, 32b ... Reinforcement, K ... Annular area, P ... Pool water, s 1 ... Space, s 2 ... Space, X ... Demolition, Y ... Scrap yard

Claims (8)

A removal method of a reactor having a torus chamber in which a suppression chamber communicating with a reactor containment vessel and a vent pipe is accommodated,
A first step of partially disassembling at least the suppression chamber among the structures in the torus chamber;
And d) storing the dismantling products produced by the dismantling using at least a part of the space surrounded by the housing of the suppression chamber or the space surrounded by the housing in the torus chamber. ,
The housing is self-supporting through the support legs in the torus chamber,
The first step includes the step of partially disassembling the lower portion of the housing,
The second step includes the step of storing the dismantled material in a space below the casing which becomes self-supporting in a roof shape by the dismantling via the support legs. Construction method. The support legs are provided in pairs so as to face each other in the width direction of the housing,
The first step includes a step of partially disassembling at least one of the pair of support legs to increase a distance between the support legs in the width direction. The removal method of the reactor according to claim 1. A removal method of a reactor having a torus chamber in which a suppression chamber communicating with a reactor containment vessel and a vent pipe is accommodated,
A first step of partially disassembling at least the suppression chamber among the structures in the torus chamber;
And d) storing the dismantling products produced by the dismantling using at least a part of the space surrounded by the housing of the suppression chamber or the space surrounded by the housing in the torus chamber. ,
The suppression chamber holds pool water in a space enclosed by the housing,
The removal method of a nuclear reactor, wherein the second step includes a step of storing the dismantled material submerged in the pool water for storage. The first step is
Partially dismantling the upper part of the case holding the pool water;
4. The nuclear reactor removing method according to claim 3 , further comprising the step of reinforcing the housing so as not to be buckled by the weight of the pool water by partial dismantling of the upper part of the housing. . The housing is self-supporting through the support legs in the torus chamber,
The first step includes the step of partially disassembling the upper portion of the housing,
5. The method according to claim 3, wherein the second step includes the step of storing the dismantled material on the casing which is self-supporting in a bowl shape by the dismantling via the support leg. Reactor removal method as described. A removal method of a reactor having a torus chamber in which a suppression chamber communicating with a reactor containment vessel and a vent pipe is accommodated,
A first step of partially disassembling at least the suppression chamber among the structures in the torus chamber;
And d) storing the dismantling products produced by the dismantling using at least a part of the space surrounded by the housing of the suppression chamber or the space surrounded by the housing in the torus chamber. ,
The housing is self-supporting through the support legs in the torus chamber,
The first step includes the step of partially disassembling the upper portion of the housing,
The removal method of a nuclear reactor, wherein the second step includes a step of storing the dismantled product on the casing which is self-supporting in a bowl shape by the dismantling through the support leg. The torus chamber has an annular area for receiving the suppression chamber;
The first step includes disassembling the structure in a part of the annular area,
The second step is
Temporarily placing the scraps of the part of the area in another area;
The process of providing a scrap yard for storing the said demolition thing in the said one part area, The removal method of the reactor as described in any one of Claims 1-6 characterized by the above-mentioned. A removal method of a reactor having a torus chamber in which a suppression chamber communicating with a reactor containment vessel and a vent pipe is accommodated,
A first step of partially disassembling at least the suppression chamber among the structures in the torus chamber;
And d) storing the dismantling products produced by the dismantling using at least a part of the space surrounded by the housing of the suppression chamber or the space surrounded by the housing in the torus chamber. ,
The torus chamber has an annular area for receiving the suppression chamber;
The first step includes disassembling the structure in a part of the annular area,
The second step is
Temporarily placing the scraps of the part of the area in another area;
And a step of providing a scrap yard for storing the dismantled material in the part of the area.

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