JP2013002924A - Bridge type crane and method of disassembling nuclear power plant - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bridge type crane which can be installed by occupying a little land in a nuclear power plant, and with which work such as lifting a heavy object can be performed efficiently without taking into account a lifting load/lifting margin based of a work radius in the case of lifting, and an exposed dose of a worker can be reduced, or a method of disassembling a nuclear power plant.SOLUTION: A bridge type crane 10 is provided which is disposed over a work area including a reactor building 102. The bridge type crane 10 comprises an internal space which is formed in a length direction within a horizontal beam 12 of the bridge type crane 10, lifting means (movable winch 22) which is disposed in the internal space, is movable in the length direction of the beam 12 and can lift a heavy object through an opening 18 which is opened along with the length direction of the beam 12 in a lower end of the beam 12, and a movable drivers cab 28 which is disposed in the lifting means and in which a worker is accommodated and a control means for controlling the lifting means through operation of the worker is disposed.

Description

  The present invention relates to a bridge crane and a method for dismantling a nuclear power plant, and more particularly, to a technique for improving work efficiency and suppressing worker exposure.

  Nuclear power plants are dismantled and removed when their useful lives have been exceeded, or due to social circumstances or accidents. The procedure for dismantling and removing a nuclear power plant is usually as follows. First, the operating nuclear reactor is stopped, and spent fuel and unused fuel are transported to a reprocessing plant or storage facility. And the radioactive material adhering to the piping and container arranged in the nuclear power plant is decontaminated (system decontamination). In this state, the nuclear power plant is safely stored under appropriate management for about 5 to 10 years. After that, the pipes and containers inside the building are dismantled, the radioactive material inside the building is removed, and finally the building is dismantled.

  When performing such demolition work, usually use overhead cranes and other permanent equipment in the building to lift up the structures in the building, etc., but if these facilities cannot be used for some reason, It is possible to introduce a crawler crane. However, in the crawler crane, the working radius for lifting the structure is limited to a certain range. Furthermore, if the structure is shredded in order to reduce the lifting load and widen the working radius, the exposure and the number of work processes are inevitable. In addition, since it is necessary to consider the interference between the crane arm and the building, it is necessary to frequently move the installation position of the crane, which inevitably increases the number of work processes. This is the same problem when constructing a nuclear power plant. Moreover, there is a problem that the amount of exposure of workers increases when the dismantling work is prolonged.

  On the other hand, Patent Document 1 discloses a technology in which an overhead crane that can be shared between a nuclear building and a turbine building is arranged, and a structure to be arranged in each building is lifted and carried by the overhead crane. Also, in Patent Document 2, an overhead crane that can be shared between the turbine building and the waste treatment building is arranged, and the structure is lifted by the overhead crane to temporarily inspect the structure inside the turbine building, and temporarily installed in the waste treatment building. The technology to put is disclosed. Therefore, it is thought that the working efficiency can be improved by applying the techniques disclosed in Patent Document 1 and Patent Document 2 and lifting structures and the like using an overhead crane even when the nuclear power plant is dismantled. .

JP 2002-140744 A Japanese Patent No. 3996153

However, the movable range of such overhead cranes is limited to the building interior, so it is unsuitable for dismantling work and construction work involving the transportation of heavy objects inside and outside the building, especially in the dismantling work of nuclear power plants. Since the amount of radioactive material in the building is overwhelmingly larger than during construction and inspection, exposure of workers becomes a problem.
In the unlikely event that a malfunction occurs in a permanent facility in the building due to an accident or the like, there is a possibility that a large obstacle will be caused in the transportation of heavy objects.

  Accordingly, the present invention pays attention to the above-mentioned problems, and efficiently carries in / out heavy objects to / from a building such as a reactor building, and in particular, a bridge capable of suppressing the exposure of workers when dismantling the reactor building. The purpose is to provide a method for dismantling the crane and nuclear power plant.

  In order to achieve the above object, a bridge crane according to the present invention is firstly a bridge crane arranged across a work area including a reactor building, wherein the horizontal beam of the bridge crane is provided. An inner space formed in the longitudinal direction of the inner space, and an opening disposed in the inner space and movable in the longitudinal direction of the beam, and opened at the lower end of the beam along the longitudinal direction of the beam. A lifting means capable of lifting a heavy object, and a mobile cab arranged in the lifting means and accommodating a worker, and a control means for controlling the lifting means by operation of the worker. It is characterized by that.

  With the above configuration, the portion of the bridge crane that occupies the ground is only the support column, so that the arrangement space can be reduced. Further, since the beam is arranged so as to straddle the reactor building, it is possible to lift a heavy object without considering the interference between the beam and the reactor building. In addition, since the mobile cab that accommodates the workers moves with the lifting means, the workers can see the state of the lift, and the mobile cab is located in the beam so that the radiation is emitted from the reactor building. The exposure amount of the worker can be reduced.

Second, the internal space is divided into a work space through which the lifting means passes and a multipurpose space spatially separated from the work space.
With the above configuration, various devices can be arranged in the multipurpose space without interfering with the lifting means.

Third, in the multipurpose space, an air conditioner with a high performance filter that removes radioactive pollutants is disposed, and a door is disposed in a partition that partitions the work space and the multipurpose space. Features.
With the above configuration, an operator in the mobile cab can retreat to the multipurpose space when the radiation dose emitted from the reactor building increases.

Fourth, the camera has a camera arranged in the mobile cab and capable of photographing the lower part through the opening, and a monitor arranged in the multipurpose space and displaying an image taken by the camera. And a remote control unit arranged in a space and capable of remotely operating the control means.
With the above configuration, the operator can operate the lifting means without entering the mobile cab.

Fifth, a radiation shielding member is disposed on at least a wall surface of the multipurpose space and the mobile cab facing the reactor building.
With the above configuration, the radiation emitted from the reactor building can be shielded by the radiation shielding member, and the exposure dose of the worker can be suppressed.

Sixth, a jib crane movable in the longitudinal direction of the beam is disposed on the upper part of the beam.
With the above configuration, for example, relatively light materials other than the structure in the reactor building can be lifted and transported independently without using lifting means.

Seventh, a plurality of the reactor buildings are arranged in a row, and a pair of girders are arranged in a direction parallel to the arrangement direction of the reactor buildings so that the reactor buildings are sandwiched between the reactor buildings. And is movable along the girder.
With the above configuration, one bridge crane can be arranged on all the reactor buildings, so that the cost can be suppressed.

  Eighth, the girder is arranged so that the length of the reactor building is within a quadrangle that is longer than the length between both ends in the arrangement direction of the reactor building and whose apex is the end in the longitudinal direction of the girder. It is characterized by that.

  With the above configuration, the site outside the both ends of the reactor building in the arrangement direction is used as materials to be carried into the reactor building using a bridge crane, temporary storage for structures carried out from the reactor building, etc. Can be improved.

Ninthly, a pile supporting the girder is driven into the ground on which the girder is arranged.
With the above configuration, the bridge crane can be stably moved by reducing the bending due to the load of the bridge crane of the girder without interfering with a structure such as a trench disposed in the ground.

  On the other hand, the method for dismantling a nuclear power plant according to the present invention firstly includes a beam and a movable object disposed in the beam and movable in the longitudinal direction of the beam, and capable of lifting heavy objects in a reactor building. A bridge crane having lifting means is disposed so as to straddle the reactor building and the turbine building adjacent to the reactor building, and after removing heavy objects in the turbine building from the turbine building, the lifting crane A part of a heavy object in the reactor building is lifted by means and carried into the turbine building.

  With the above method, a part of the heavy object in the reactor building can be temporarily placed in the turbine building. As a result, it is possible to secure a space necessary for the dismantling of heavy objects in the reactor building, thereby improving work efficiency. In addition, since any heavy object is placed in the reactor building or the turbine building, the leakage of radioactive materials accompanying the work can be reduced by each building.

Second, the reactor building is covered with a lid that covers an upper portion of the reactor building and has an open / close door that can take out heavy objects in the reactor building.
By the above method, leakage of radioactive materials can be reduced during the work of carrying heavy objects or when storing safely.

  According to the dismantling method of the bridge crane and the nuclear power plant according to the present invention, the nuclear power plant can be installed with a small amount of land, and the lifting load and the lifting allowance depending on the working radius at the time of lifting are taken into consideration. Thus, it is possible to efficiently perform work such as lifting heavy objects without reducing the amount of exposure of workers.

It is a bridge type crane of this embodiment, and a bird's-eye view of a nuclear power station. It is a front view of the bridge type crane and nuclear power plant of this embodiment, and the side view of the bridge type crane of this embodiment. It is the sectional view on the AA line of FIG. 2, and is an arrangement | positioning figure of the component in the beam which comprises the bridge type crane of this embodiment. It is a schematic diagram (the 1 and a front view and a side view) of the foundation structure of the bridge type crane of this embodiment. It is a schematic diagram (the 2) of the basic structure of the bridge crane of this embodiment. It is a schematic diagram (the 3) of the basic structure of the bridge crane of this embodiment. It is a schematic diagram of the nuclear reactor building used as the application object of the bridge crane of this embodiment. It is a schematic diagram which shows the dismantling process (process of installing a bridge crane) of the nuclear power plant of this embodiment. It is a schematic diagram which shows the dismantling process (process of transferring and storing a part of structure in a reactor building to a turbine building) of the nuclear power plant of this embodiment. It is a schematic diagram which shows the dismantling process (process which installs a cover in a reactor building) of the nuclear power plant of this embodiment. It is a schematic diagram which shows the dismantling process (process to carry out nuclear reactor fuel) of the nuclear power plant of this embodiment. It is a schematic diagram which shows the dismantling process (process which dismantles and carries out a nuclear reactor) of the nuclear power station of this embodiment.

  Hereinafter, the present invention will be described in detail with reference to embodiments shown in the drawings. However, the components, types, combinations, shapes, relative arrangements, and the like described in this embodiment are merely illustrative examples and not intended to limit the scope of the present invention only unless otherwise specified. .

  FIG. 1 shows a bird's-eye view of the bridge-type crane 10 of this embodiment and the nuclear power plant 100, and FIG. 2 shows a front view of the bridge-type crane 10 and the nuclear power plant 100 of this embodiment and the bridge-type of this embodiment. A side view of the crane 10 is shown.

  As shown in FIG. 1, a nuclear power plant 100 to which the bridge crane 10 of the present embodiment is applied is mainly configured by a reactor building 102, a turbine building 120, and a main exhaust tower 122 (FIG. 2). . A plurality of reactor buildings 102 (four in this embodiment) are arranged and arranged in a row. A turbine building 120 is disposed adjacent to the reactor building 102. The turbine building 120 (four buildings in this embodiment) is arranged with its longitudinal direction oriented in a direction parallel to the arrangement direction of the reactor buildings 102. Between the reactor building 102 and the turbine building 120, a pipe for supplying steam for turbine power generation (not shown), a pipe for sending condensate (not shown), a pipe for air conditioning (not shown), and the like are arranged. Further, a cable (not shown) and the like are arranged.

  As shown in FIG. 1, girder 38 is arranged in parallel with each other so as to sandwich the reactor building 102 and the turbine building 120. The girder 38 is designed so that its longitudinal direction is longer than the arrangement length of the reactor building 102, and at least the reactor building 102 is in a square (in a plane) having apexes at both ends in the longitudinal direction of the girder 38. And the turbine building 120 is arranged to be accommodated.

  As shown in FIG. 2, the bridge crane 10 is arranged so as to straddle the reactor building 102 and the turbine building 120, and the beam 12 arranged horizontally on the reactor building 102 and the turbine building 120, and the beam 12. It has the support | pillar 30 arrange | positioned on the girder 38 while supporting the both ends of the longitudinal direction of this. The beam 12 is formed by connecting a plurality of steel plates, for example, and is arranged in a direction perpendicular to the arrangement direction of the reactor buildings 102. A traveling wheel 32 and a drive means (not shown) for driving the traveling wheel 32 are disposed below the support column 30, and the support column 30 can move along the longitudinal direction of the girder 38. Therefore, the bridge crane 10 can move along the longitudinal direction of the girder 38 to translate the beam 12 in a direction perpendicular to the longitudinal direction of the beam 12.

  Therefore, as shown in FIG. 1, the position further ahead of both ends in the longitudinal direction of the girder 38 can be set as the preparation area 124, and after the bridge crane 10 is moved to the preparation area 124, this preparation area The goods carried to 124, the parts assembled in this preparation area 124, etc. can be lifted, moved to the reactor building 102 and the turbine building 120, and the lifted goods and parts can be suspended. Conversely, a structure (heavy object) suspended from the reactor building 102 or the turbine building 120 can be suspended from the preparation area 124 and temporarily placed. A region including the reactor building 102 sandwiched between the two preparation areas 124 is a work area of the bridge crane 10.

  Thus, in the bridge type crane 10 of this embodiment, since only one reactor building 102 and the turbine building 120 can be accessed, the number of lifting machines such as mobile cranes and crawler cranes can be reduced, and the arrangement space can be reduced. Can be reduced and the land can be used effectively. Further, since the number of lifting machines to be used is reduced, it is possible to reduce the work load of the decontamination work after use and the waste generated by the work. In FIG. 1, one bridge crane 10 is disposed, but two or more bridge cranes 10 may be disposed.

  FIG. 3 is a cross-sectional view taken along the line AA in FIG. 2, and shows an arrangement diagram of components in the beam 12 constituting the bridge crane 10 of the present embodiment. As shown in FIG. 3, the beam 12 has a hollow inside and is partitioned into a lower working space 14 and an upper multipurpose space 16. Therefore, the work space 14 occupies the space below the internal space of the beam 12 and from one end to the other end in the longitudinal direction of the beam 12. The multipurpose space 16 occupies the space from one end to the other end in the longitudinal direction of the beam 12 above the internal space of the beam 12.

  At the center of the lower wall surface of the work space 14, there is an opening 18 opened along the longitudinal direction of the beam 12, and at a position adjacent to the opening 18 on the wall surface forming the lower part of the work space 14, A first rail 20 parallel to the longitudinal direction of the beam 12 is arranged so as to sandwich the opening 18.

  A mobile hoist 22 serving as a lifting means is disposed in the work space 14. The mobile hoist 22 is disposed on the first rail 20 and can travel on the first rail 20 by a driving means (not shown). The mobile hoist 22 is disposed at a position where the wire 24 is suspended from the opening 18. A hook 26 is provided at the tip of the wire 24.

  Here, the mobile hoist 22 has a main winding that lifts a heavy weight at a low speed and an auxiliary winding that lifts a small weight at a high speed, both of which are in the longitudinal direction of the first rail 20. FIG. 3 shows only the main volume.

  A mobile cab 28 is disposed in the mobile hoist 22. The mobile cab 28 is disposed at a position facing the opening 18 of the mobile hoist 22, driving means (not shown) for driving the mobile hoist 22 on the rail, and driving of the main winding. Means (not shown) and control means (not shown) for controlling auxiliary winding driving means (not shown) are arranged. Then, an operator enters the mobile cab 28 and operates a control means (not shown) to move the mobile hoist 22 and to roll up and lower the main and auxiliary windings. it can. The mobile cab 28 is covered with the beam 12 except for the opening 18, and a radiation shielding member is disposed on the floor surface as will be described later, so that it is received from the reactor building 102 or the like. The amount of radiation can be reduced to reduce the exposure amount of workers. An air conditioner (not shown) is arranged in the mobile cab 28, and an air supply port (not shown) and an exhaust port connected to the air conditioner (not shown) are formed on the wall surface forming the mobile cab 28. (Not shown) is arranged, and a high-performance filter for shielding radioactive pollutants such as a high efficiency particulate air (HEPA) filter (not shown) is arranged at the air supply port (not shown). It is assumed that clean air can be supplied into 28.

  Various components are arranged in the multipurpose space 16. An air conditioner (not shown) is arranged in the multipurpose space 16, and an air supply port (not shown) and an exhaust port (not shown) connected to the air conditioner are arranged on the wall surface forming the multipurpose space 16. The air supply port (not shown) is disposed, for example, on one end side in the longitudinal direction of the beam 12 and sucks outside air by an air supply fan (not shown) through a HEPA filter (not shown). Further, the exhaust port (not shown) is disposed, for example, on the other end side opposite to the one end side in the longitudinal direction of the beam 12, and is disposed in the multipurpose space 16 by an exhaust fan (not shown) disposed at the exhaust port (not shown). Exhaust the air outside. On the lower surface of the multipurpose space 16 (partition from the work space 14), one door (not shown) through which workers in the work space 14 can enter and exit is arranged, or a plurality of doors arranged in the longitudinal direction of the beam 12. Has been. The multipurpose space 16 may be partitioned into a plurality of parts in the longitudinal direction, and an air conditioner (intake port, exhaust port) or door (not shown) may be provided for each partitioned space.

  In the multipurpose space 16, a wireless cab (not shown) having a monitor (not shown) and a remote control unit (not shown) is arranged, and a camera (not shown) is arranged in the mobile cab 28. The The camera (not shown) is arranged with the optical axis in the direction through which the hook 26 at the tip of the wire 24 of the winder enters the field of view through the opening 18, and wirelessly (or wired) may be used to monitor moving image data of the subject. (Not shown). A remote control unit (not shown) can output a signal for operating a control means (not shown) disposed in the mobile cab 28 wirelessly (may be wired). Therefore, the worker can operate the mobile hoist 22 from the radio operator cab (not shown) without entering the mobile operator cab 28.

  Further, the multipurpose space 16 is provided with a fuel exchanger operating room and a spare room for operating a fuel exchanger for exchanging the fuel of the reactor by radio. In addition, a driving means (not shown) for driving the traveling wheel 32, an emergency power source for the moving hoist, and an operation room such as an underwater cutting machine for cutting the reactor pressure vessel 104 can be arranged.

  As shown in FIG. 2, an elevator 33 and a staircase (not shown) are arranged on the column 30 of the bridge crane 10 so that workers can enter the multipurpose space 16 and the mobile cab 28 from the column 30. It has become.

  In addition, radiation shielding members (not shown) such as lead are arranged on the wall surfaces (wall surfaces facing the reactor building 102 and the turbine building 120) that form at least the lower surface of the multipurpose space 16, the work space 14, and the mobile cab 28. It is preferable to do. Thereby, the exposure amount of a worker can be reduced. Of course, the radiation shielding member (not shown) may be disposed not only on the lower surface but also on the side surface and the upper surface.

  As shown in FIG. 2, a jib crane 34 is disposed on the beam 12. The jib crane 34 is movable in the longitudinal direction of the beam 12 and is used to lift a relatively light material that does not need to be lifted by the mobile hoist 22. A wheel for moving the jib crane 34 is disposed below the jib crane 34, and a second rail 36 on which the wheel of the jib crane 34 is placed along the longitudinal direction of the beam 12 is disposed on the beam 12 as shown in FIG. 3. ing. By arranging the jib crane 34 on the beam 12 in this manner, the mobile hoist 22 and another crane can be introduced without the need to secure a new crane installation location. Note that a plurality of jib cranes 34 may be arranged on the beam 12 as shown in FIG.

  As shown in FIG. 2, the main exhaust tower 122 is arranged in the nuclear power plant 100, but when the main exhaust tower 122 interferes with the beam 12 of the bridge crane 10, the part that interferes with the beam 12. It is necessary to cut and dismantle the upper part. In this case, the demolished material is lowered to the ground by the mobile hoist 22, the jib crane 34, or the above-described crawler crane.

  FIG. 4 is a schematic diagram (No. 1, front view and side view) of the basic structure of the bridge crane 10 of the present embodiment, and FIG. 5 is a schematic diagram of the basic structure of the bridge crane 10 of the present embodiment (No. 1). 2) is shown, and FIG. 6 shows a schematic diagram (part 3) of the basic structure of the bridge crane 10 of the present embodiment. As shown in FIG. 4, the girder 38 is made of, for example, steel and has a certain rigidity against the load of the bridge crane 10. On the girder 38, a third rail 40 on which the traveling wheel 32 is placed is disposed along the longitudinal direction of the girder 38.

  On the other hand, at the position where the girder 38 is disposed on the ground, the pile 42 is driven at a predetermined interval along the longitudinal direction of the girder 38, and the girder 38 is disposed on the pile 42. Thereby, the sinking of the girder 38 into the ground due to the load of the bridge crane 10 can be avoided, and the stability of the bridge crane 10 can be ensured. Furthermore, as shown in FIG. 5, the pile 42 can be driven across equipment such as pipes and trenches 126 buried in the ground, so that the stability of the bridge crane 10 is avoided while avoiding interference with these equipment. Can be secured. Furthermore, since the reinforcement of the girder 38 is limited by performing the reinforcement of the girder 38 only by the pile 42, the process and cost for it can be suppressed. When the ground on which the girder 38 is placed is solid, as shown in FIG. 6, the concrete girder 38 is arranged without driving the pile 42, and the third girder for the traveling wheel 32 is placed on the girder 38. The rail 40 may be disposed.

  In FIG. 7, the schematic diagram of the reactor building 102 used as the application object of the bridge crane 10 of this embodiment is shown. As shown in FIG. 7, the reactor building 102 includes a reactor pressure vessel 104 (RPV: Reactor Pressure Vessel) mainly containing reactor fuel, and a reactor containment vessel 108 (PCV) containing the reactor pressure vessel 104. : Primary Containment Vessel). Further, the reactor containment vessel 108 is covered with a concrete protective wall 112 on its side surface and with an upper part of the reactor well cover 114 made of concrete. In addition, a spent fuel pool 116 for cooling the spent reactor fuel with circulating cooling water is disposed at the upper part of the reactor. An overhead crane 118 is disposed on the upper part of the reactor building 102, and a fuel exchanger (not shown) is disposed at a position adjacent to the spent fuel pool 116. The upper portion of the reactor pressure vessel 104 is sealed by the RPV head 106, and the upper portion of the reactor containment vessel 108 is sealed by the PCV head 110. Further, a shroud (not shown) and a steam dryer (not shown) are arranged inside the reactor containment vessel 108, and a γ-ray shield (not shown) is arranged around the reactor containment vessel 108. In addition to these, devices (not shown) attached to the reactor pressure vessel 104 and the reactor containment vessel 108 are arranged in the reactor building 102. On the other hand, in the turbine building 120, a turbine body (not shown), a generator (not shown), a condenser (not shown), a heat exchanger (not shown), and an overhead crane (not shown) are arranged.

  As will be described later, these building components are cut to an appropriate size as needed and then carried out by the bridge crane 10. In particular, the reactor pressure vessel 104 is cut into small pieces and then carried out in a state of being accommodated in a transport cask 48 (heavy object). Further, when the spent fuel and the reactor fuel are carried out, they are carried out in a state of being accommodated in the fuel cask 46. Further, when the structure in the reactor building 102 is safely stored or when the reactor pressure vessel 104 is dismantled, the reactor building 102 is covered in order to reduce leakage of radioactivity to the outside. A lid 44 (cover) made of a steel plate having an openable / closable door from which a structure in the reactor building 102 can be taken out is put on the reactor building 102. Of course, an opening 18 (not shown) is provided at a position facing the open / close door of the reactor building 102. The open / close door is opened / closed by lifting the free end of the open / close door (not shown) with the jib crane 34 or the like.

  8 to 12 show the dismantling process of the nuclear power plant 100 of this embodiment, FIG. 8 shows the process of installing the bridge crane 10, and FIG. 9 shows a part of the structure in the reactor building 102 in the turbine building 120. FIG. 10 shows a step of installing a cover on the reactor building 102, FIG. 11 shows a step of carrying out the reactor fuel, and FIG. 12 shows a step of dismantling and carrying out the reactor. Here, it is assumed that the reactor pressure vessel 104 and the spent fuel pool 116 are already in a cold shutdown state.

  First, as shown in FIG. 8, first, the bridge crane 10 that straddles the reactor building 102 and the turbine building 120 is arranged. First, the girder 38 on which the bridge crane 10 is placed is disposed as shown in FIG. 1 and the like (first step). And the support | pillar 30 is stood up using the crawler crane etc. in the edge part of the longitudinal direction of the girder 38, the beam 12 formed by joining the steel plate is lifted with the crawler crane, and is connected to the support | pillar 30. Further, the jib crane 34 is lifted by a crawler crane and mounted on the beam 12. Further, when the main exhaust tower 122 interferes with the beam 12, the part of the main exhaust tower 122 beyond the part that interferes with the beam 12 is disassembled and removed. For this dismantling and removal, a crawler crane or a bridge crane 10 (mobile hoist 22 (not shown), jib crane 34) may be used.

  Second, as shown in FIG. 9, a structure (turbine body, generator) in the turbine building 120 having a relatively low radiation level using a mobile hoist 22 (not shown in FIGS. 9 to 12). Etc.), a part (equipment) of the structure (heavy object) in the reactor building 102 is transferred to the turbine building 120 (second step). At this time, the ceiling of the turbine building 120 is provided with an opening enough to carry in and out the structure, and when stable storage or the like is performed, the opening is covered with a steel plate material or the like. As a result, a space necessary for dismantling the reactor pressure vessel 104 and the reactor containment vessel 108 in the reactor building 102 can be secured, and work efficiency can be improved. Moreover, since any structure arranged in the reactor building 102 is placed in the reactor building 102 or the turbine building 120, the leakage of radioactive materials accompanying the work can be reduced by each building. Of the equipment carried out from the reactor building 102, those with a large radiation dose are carried out from the reactor building 102 and transferred to the turbine building 120 in a state of being stored in a high radiation object storage cask.

  Third, as shown in FIG. 10, a lid 44 is placed on the upper part of the reactor building 102 and stably stored for a long period of time (third step). Here, the lid body 44 may be lifted by the mobile hoisting machine 22 after being assembled, or the steel plates constituting the lid body 44 are lifted one by one by the mobile hoisting machine 22, and are successively placed in the reactor building 102. And the lid body 44 may be formed. After the above operation, the remaining part of the main exhaust tower 122 is dismantled. After stable storage, the structure derived from the reactor building 102 arranged in the turbine building 120 is carried out by the mobile hoist 22 and the turbine building 120 is disassembled.

  Fourth, as shown in FIG. 11, the spent fuel in the reactor building 102 and the fuel in the reactor pressure vessel 104 are carried out (fourth step). First, the fuel cask 46 (heavy object) is introduced into the reactor building 102 through the open / close door using the mobile hoist 22, and the spent fuel in the spent fuel pool 116 is replaced with a fuel exchanger (mobile hoist). And may be accommodated together with water in the pool. Further, the reactor well cover 114 (FIG. 7), the PCV head 110 (FIG. 7), the RPV head 106 (FIG. 7), etc. are removed from the reactor building 102, and these are lifted by the mobile hoist 22 to form the turbine building 120. The reactor fuel in the reactor pressure vessel 104 is moved and temporarily placed, and is introduced into the spent fuel pool 116 by using a fuel exchanger (or the mobile hoist 22), and is then stored in the fuel cask 46 in the pool. Contain with water. Accordingly, new water is supplied to the spent fuel pool 116 in accordance with the progress of work by the amount of water carried out by the fuel cask 46 (same for the transport cask 48).

  Then, the fuel cask 46 is lifted by the mobile hoist 22, the bridge crane 10 is moved along the girder 38 in the lifted state, and is transported waiting in the preparation area 124 (may be other place). The operation of hanging on the vehicle 128 and loading the fuel cask 46 on the transporting vehicle 128 is repeated until the spent fuel and the reactor fuel are exhausted.

  Fifth, as shown in FIG. 12, the structure in the reactor building 102 is dismantled and carried out (fifth step). First, the transporting cask 48 (heavy material) is introduced into the spent fuel pool 116 by the mobile hoist 22, and structures other than the reactor pressure vessel 104 in the reactor building 102 are cut in water. Then, cut pieces (heavy objects) generated by cutting are introduced into the spent fuel pool 116 and accommodated in the transport cask 48, and the transport cask 48 is loaded on the transport vehicle 128 by the mobile hoist 22 in the same manner as described above. Repeat until all pieces are gone. Finally, an underwater cutting device is introduced by the mobile hoist 22 to cut the reactor pressure vessel 104. Then, the cut pieces are introduced into the spent fuel pool 116 and accommodated in the transport cask 48. The transport cask 48 is loaded on the transport vehicle 128 by the mobile hoist 22 in the same manner as described above, and the process is repeated until all the cut pieces are removed.

  Through the above steps, the structure containing a high concentration of radioactive material is removed, and then the reactor building 102 is dismantled. Of course, the bridge crane 10 of this embodiment can also be used for this dismantling work. Since there are a plurality of reactor buildings 102 to which the bridge crane 10 of the present embodiment is applied, for example, the previous steps (second step to fourth step) are performed one by one in each reactor building 102. After the previous process is completed in all the reactor buildings 102, the next process (third process to fifth process) is performed one by one in each reactor building 102. It will be.

  In conventional mobile cranes / crawler cranes, there are limitations on lifting load and allowance depending on the working radius. In addition, it is necessary to always pay attention to the interference between the crane arm and the building. However, the bridge crane 10 of the present embodiment does not have them, and the crane 10 is always lifted from the vertical direction, debris, building demolition, heavy object movement, Since the fuel can be moved easily and safely, the workability can be improved and the process can be shortened. For example, the removal of fuel and equipment from the nuclear reactor and spent fuel pool 116 can be handled in the same manner as the overhead crane 118 (FIG. 7) disposed in the nuclear reactor building 102 and the fuel exchanger. Further, unlike the overhead crane 118 (FIG. 7), a heavy object (structure) can be transported between the inside and outside of the building, so that the work efficiency is higher than when the overhead crane 118 (FIG. 7) is used. improves.

  Further, in the case of a large crawler crane, ground curing in the operating range becomes large, but in the bridge type crane 10 of the present embodiment, only the foundation portion of the girder 38 is strengthened (strengthening using the pile 42). be able to. In particular, when the girder 38 is laid on a road laid in parallel in the arrangement direction of the reactor building 102, the foundation (pile 42) is small, and work efficiency and cost can be suppressed. Furthermore, when there are a plurality of reactor buildings 102 and turbine buildings 120, it is necessary to move the installation position in the case of a crawler crane. However, in the bridge crane 10 of this embodiment, all the reactor buildings are within the movable range. 102, because the turbine building 120 enters, it is possible to improve work efficiency and shorten the work period.

  At a nuclear power plant, it can be installed with a small amount of land, and it can efficiently lift heavy objects without considering the lifting load and lifting allowance due to the working radius during lifting. It can be used as a dismantling method for bridge cranes or nuclear power plants that can reduce the exposure of workers.

10 ......... bridge crane, 12 ......... beam, 14 ... work space, 16 ... multipurpose space, 18 ... opening, 20 ... first rail, 22 ... movable Hoisting machine, 24 ......... Wire, 26 ......... Hook, 28 ......... Mobile operator's cab, 30 ......... Pole, 32 ......... Running wheel, 33 ......... Elevator, 34 ......... Jib crane, 36 ......... Second rail, 38 ......... Girder, 40 ......... Third rail, 42 ......... Pile, 44 ......... Cover, 46 ......... Fuel cask, 48 ......... Transport cask , 100 ......... Nuclear power plant, 102 ......... Reactor building, 104 ... ... Reactor pressure vessel, 106 ... ... RPV head, 108 ... ... Reactor containment vessel, 110 ... ... PCV head, 112 ……… Protection wall, 114 ……… Reactor well cover, 116 ……… Use See fuel pool, 118 ......... overhead crane, 120 ......... turbine building, 122 ......... main exhaust tower, 124 ......... preparation area, 126 ......... pipe trench, 128 ......... carrier vehicle.

Claims (11)

A bridge crane arranged across a work area including the reactor building,
An internal space formed over the longitudinal direction in the horizontal beam of the bridge crane;
A lifting means disposed in the internal space and movable in the longitudinal direction of the beam, and capable of lifting a heavy object through an opening opened along the longitudinal direction of the beam at the lower end of the beam;
A mobile cab in which a control means is arranged which is disposed in the lifting means and accommodates a worker and which controls the lifting means by operation of the worker;
A bridge-type crane characterized by comprising:   The bridge crane according to claim 1, wherein the internal space is partitioned into a work space through which the lifting means passes and a multipurpose space spatially separated from the work space.   An air conditioner with a high-performance filter that shields radioactive pollutants is disposed in the multi-purpose space, and a door is disposed in a partition that partitions the work space and the multi-purpose space. Item 3. The bridge crane according to item 2. A camera arranged in the mobile cab and capable of photographing the lower part through the opening;
A monitor arranged in the multipurpose space and displaying an image taken by the camera;
4. The bridge crane according to claim 2, further comprising a remote control unit arranged in the multipurpose space and capable of remotely operating the control unit. 5.   The bridge crane according to any one of claims 2 to 4, wherein a radiation shielding member is disposed on at least a wall surface of the multi-purpose space and the mobile cab facing the reactor building.   The bridge crane according to any one of claims 1 to 5, wherein a jib crane that is movable in a longitudinal direction of the beam is disposed on the upper portion of the beam. A plurality of the reactor buildings are arranged in a row, and a pair of girders are arranged so as to sandwich the reactor building in a direction parallel to the arrangement direction of the reactor buildings,
The bridge crane according to any one of claims 1 to 6, wherein the support column is disposed on a girder and is movable along the girder.   The girder is longer than the length between both ends in the arrangement direction of the reactor building, and the girder is arranged so that the reactor building fits in a quadrangle having the longitudinal end of the girder as a vertex. The bridge crane according to claim 7.   The bridge crane according to claim 7 or 8, wherein a pile supporting the girder is driven into a ground on which the girder is arranged. A bridge-type crane including a beam and lifting means disposed on the beam and movable in a longitudinal direction of the beam and capable of lifting a heavy object in the reactor building, the reactor building and the reactor Arranged so as to straddle the turbine building adjacent to the building,
A nuclear power plant characterized in that after removing heavy objects in the turbine building from the turbine building, a part of the heavy objects in the reactor building is lifted by the lifting means and carried into the turbine building. Dismantling method.   11. The nuclear power plant dismantling according to claim 10, wherein a cover body that covers an upper part of the reactor building and has an open / close door capable of taking out a heavy object in the reactor building is placed on the reactor building. Method.