JP2015190773A - Operation house for exporting fuel debris, in-reactor apparatuses and the like, and operator access air lock apparatus used therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an operation house for exporting fuel debris, in-reactor apparatuses and the like, and an operator access air lock apparatus used therefor, by which maintenance and the like can be performed by an operator by approaching apparatuses arranged inside an operation house while preventing exposure to radiation.SOLUTION: An operation house is provided with an air lock on a side wall thereof, and the air lock is provided with an air-tight door on the inner part side of the operation house. On the outside or the inside of the air-tight door, an extendable duct is provided, into which an operator can enter from the inside of the air lock and which extends toward the inner part side of the operation house and air-tightly isolates the inside of the air lock from the inner part side of the operation house. There is also provided means at a tip end part of the extendable duct, for performing maintenance operation of apparatuses arranged inside the operation house while observing the apparatuses.

Description

  The present invention relates to a work house for carrying out fuel debris or in-reactor equipment in a boiling water nuclear power plant, and an airlock device for approaching a worker used therefor.

  In the boiling water nuclear power plant, multiple emergency cooling facilities are provided so that the core in the reactor pressure vessel is always cooled, and measures are taken to prevent a core melting accident. However, although the probability is very low, it can be assumed that the function of the emergency cooling facility is lost and the core is melted. Studies have been made on a method for extracting nuclear fuel material when such core melting occurs.

Patent Document 1 describes a method of carrying out fuel debris from a reactor pressure vessel in an air environment. In this Patent Document 1, a first house (work house) is provided on a reactor building, and a second house (preparation house) is further provided on the reactor building, and a top cover (top head) of a reactor containment vessel and a reactor pressure vessel is provided. ) Bores using a boring device, and further drills the steam dryer and steam separator and drills to the core, and injects the shield from the bored holes into the reactor containment vessel. After confirming the radiation shielding effect by the injected shielding body, the method of opening the top head of the reactor containment vessel and the reactor pressure vessel, then carrying out the steam dryer etc. and carrying out the fuel debris is described. Has been.
By using the work house, it is possible to carry out the fuel debris and in-furnace equipment while suppressing the scattering of radioactive materials. Note that the work house is airtight and nitrogen environment is required to suppress scattering of radioactive materials.

JP 2013-19875 A

  In the work house, work is performed by a fully remote automatic device arranged in the work house in order to prevent exposure of workers. However, in the unlikely event that a trouble occurs in a fully remote automatic device or the like disposed in the work house, it may be necessary for the worker to approach the work house and perform maintenance or the like of the device. In other words, there is a limit to finely handling maintenance and inspection with a remote automatic device.

  Since the work house is a polluted environment and a nitrogen environment, there are restrictions on the entry and exit of workers. Therefore, when carrying out maintenance and inspection for various devices in the work house, it is necessary to devise an approach that prevents the worker from being exposed and allows the worker to access the various devices in the work house as much as possible.

  However, in the prior art including Patent Document 1, it is sufficiently considered that a worker approaches various devices in a work house and performs maintenance etc. when a trouble occurs in a fully remote automatic device. Not.

  The purpose of the present invention is to prevent the worker from being exposed in the event that a trouble or the like occurs in the device arranged in the work house, and to perform maintenance of the device by approaching the device arranged in the work house by the worker. An object of the present invention is to provide a work house for carrying out fuel debris or in-furnace equipment and the like and an air lock device for approaching a worker used therefor.

  In the present invention, an air lock is disposed on the side wall of the work house, and an operator can enter from the inside of the air lock to the outside or inside of the hermetic door disposed on the inside of the work house of the air lock. A telescopic duct that extends toward the work house and isolates the inside of the airlock airtightly from the inside of the work house is provided, and maintenance work is performed on the equipment placed in the work house while an operator observes the tip of the telescopic duct. Means for performing is provided.

  According to the present invention, in the unlikely event that a trouble occurs in the device arranged in the work house, the worker is prevented from being exposed and the worker approaches the device arranged in the work house to perform maintenance of the device. Can be done.

  Problems, configurations, and effects other than those described above will be clarified by the following description of embodiments.

It is a schematic block diagram of a boiling water nuclear power plant. The figure explaining the work house for carrying out the fuel debris of one Example of this invention, or equipment in a furnace. The figure explaining the structure of the airlock apparatus for worker approach of one Example of this invention. The figure explaining an example of the maintenance work tool provided in the front-end | tip of the airlock apparatus for worker approach of one Example of this invention. The figure explaining other examples of the maintenance work tool provided in the front-end | tip of the airlock apparatus for worker approach of one Example of this invention. The figure (step 1) explaining the step which a worker approaches to the maintenance work position in a work house using the air lock device for worker approach of one example of the present invention. The figure explaining the step which a worker approaches to the maintenance work position in a work house using the air lock device for worker approach of one example of the present invention (Step 2). The figure explaining the step which a worker approaches to the maintenance work position in a work house using the air lock device for worker approach of one example of the present invention (Step 3). The figure explaining the step which a worker approaches to the maintenance work position in a work house using the air lock device for worker approach of one example of the present invention (Step 4). The figure explaining the step which a worker approaches to the maintenance work position in a work house using the air lock device for worker approach of one example of the present invention (Step 5). The figure explaining a mode that the maintenance operation | work of a cutting device is performed using the airlock apparatus for worker approach of one Example of this invention. The figure explaining a mode that the maintenance operation | work of a cutting device is performed using the airlock apparatus for worker approach of one Example of this invention. The figure explaining the structure of the airlock apparatus for worker approach of the other Example of this invention. The figure explaining the structure of the airlock apparatus for worker approach of the other Example of this invention (at the time of extension of an expansion-contraction duct). The figure explaining the structure of the airlock apparatus for worker approach of the other Example of this invention (at the time of replacement | exchange of an expansion duct).

  Embodiments of the present invention will be described below with reference to the drawings.

First, a schematic configuration of a boiling water nuclear plant to which the present invention is applied will be described with reference to FIG.
The boiling water nuclear power plant 1 includes a nuclear reactor 2 and a reactor containment vessel 3 (hereinafter abbreviated as PCV 3). The PCV 3 is installed in the reactor building 4, and a reactor containment vessel upper lid 5 (hereinafter, abbreviated as PCV upper lid 5) is attached to the upper end portion of the PCV 3 and sealed. The PCV 3 includes a dry well 6 formed inside, and a pressure suppression chamber 7 in which a pressure suppression pool filled with cooling water is formed. One end of the vent passage 8 connected to the dry well 6 is immersed in the cooling water of the pressure suppression pool in the pressure suppression chamber 7. A shield plug 9, which is a radiation shield divided into a plurality of parts, is disposed directly above the PCV upper lid 5, and these shield plugs 9 are installed on the operation floor 29 of the reactor building 4.
At the top of the PCV 3, when the reactor is shut down, the lid of the reactor pressure vessel 11 (hereinafter abbreviated as RPV 11) is opened to take out the fuel assembly 16, and to the adjacent spent fuel storage pool 28 (hereinafter abbreviated as SFP 28). It is a pool through which it is transferred, and is provided with a reactor well 26 for filling water for shielding radiation or the like. Further, a dryer / separator pool 27 (hereinafter abbreviated as DSP 27) and an SFP 28 for temporarily storing used fuel are provided so as to sandwich the reactor well 26. The DSP 27 is used as a place for temporarily placing in-furnace equipment such as the steam dryer 14 and the steam separator 13 during periodic inspection.
The nuclear reactor 2 includes a reactor pressure vessel 11 (hereinafter abbreviated as RPV 11) configured by attaching a reactor pressure vessel upper lid 10 (hereinafter abbreviated as RPV upper lid 10), and a plurality of fuel assemblies 16 including nuclear fuel materials. Is loaded with a core 12, a steam dryer 14, a steam-water separator 13 and the like. The core 12, the steam dryer 14 and the steam separator 13 are disposed in the RPV 11. A core shroud 15 installed in the RPV 11 surrounds the core 12. Each fuel assembly 16 loaded in the core 12 has a lower end supported by the core support plate 17 and an upper end held by the upper lattice plate 18. The steam / water separator 13 is disposed above the upper lattice plate 18 located at the upper end of the core 12, and the steam dryer 14 is disposed above the steam / water separator 13. The fuel assembly 16 has a fuel rod in which, for example, a plurality of pellets of MOX fuel are filled in a stainless steel cladding tube in the axial direction. A fuel assembly 16 is formed by arranging a plurality of fuel rods in a square lattice shape in a channel box having a quadrangular cross section.
A plurality of control rod guide tubes 19 are arranged below the core 12, and a support cylinder including the plurality of control rod guide tubes 19 is formed. Control rods 20 that are taken in and out between the fuel assemblies 16 in the core 12 and control the reactor power are disposed in the control rod guide tubes 19. A plurality of control rod drive mechanism housings 21 are attached to the lower mirror 22 of the RPV 11. A control rod drive mechanism (not shown) is installed in each control rod drive mechanism housing 21 and connected to the control rod 20 in the control rod guide tube 19. The steam dryer 14, the steam separator 13, the core shroud 15, the upper lattice plate 18, the core support plate 17, the support cylinder, the control rod guide tube 19, and the core shroud lower shell installed in the RPV 11 are in-core structures. Is.

  The RPV 11 is installed on a cylindrical pedestal 24 provided on a concrete mat 23 provided at the bottom of the PCV 3. A cylindrical γ-ray shield 25 is installed at the upper end of the pedestal 24 and surrounds the RPV 11.

  An outline of the form of fuel debris when core melting occurs in such a boiling water nuclear power plant 1 will be described. When the function of the emergency cooling facility is lost and the cooling water is not injected into the RPV 11, it is considered that the fuel pellets and the cladding tube in the fuel assembly are melted by the decay heat of the nuclear fuel material. The molten nuclear fuel material is originally located on the position where the nuclear fuel, that is, the fuel rod, the vicinity of the lower mirror 21 and the control rod guide tube 19 which is the bottom of the RPV 11 or the concrete mat 23 which is the bottom of the PCV 3. Is estimated to exist. In some cases, the fuel rod is hardly left at the position where the fuel rod originally existed, and is near the lower mirror 22 and the control rod guide tube 19 that are the bottom of the RPV 11 or on the concrete mat 23 that is the bottom of the PCV 3. It is estimated that a considerable number exists in

Such fuel debris and in-furnace equipment are carried out by, for example, the technique described in Patent Document 1. And when carrying out fuel debris, in-furnace equipment, etc., as a preparatory work, for example, a work house is installed above operation floor 29 using a technique as indicated in patent documents 1. The work house is used when carrying out in-furnace equipment and fuel debris such as the steam dryer 14 and the steam separator 13 from the boiling water nuclear plant 1 as described above. The number and arrangement of the work houses are not limited to those of Patent Document 1, and for example, a plurality of work houses may be installed in the horizontal direction above the operation floor 29 in some cases. In the following embodiment, a case where a plurality of work houses are arranged in the horizontal direction will be described as an example.
Note that the operation of carrying out the in-reactor equipment in a severe environment with a high dose is not limited to the boiling water nuclear plant 1 in such a state. For example, work such as decommissioning is also assumed, and therefore the work house of the present invention is also applicable to such a case.

  FIG. 2 shows a situation where a work house according to an embodiment of the present invention is installed above the operation floor 29. As shown in FIG. 2, in the present embodiment, the first work house 40 and the second work house 50 are provided on the beam 100 positioned above the operation floor 29. As shown in Patent Document 1, the beam 100 is installed outside the opposing side walls of the reactor building and supports a guide rail (not shown) of a traveling crane (not shown) for installing a work house (not shown). (Not shown) and is placed on the operation floor 29.

The first work house 40 is installed above the shield plug 9 shown in FIG. The first work house 40 is surrounded by four first work house side walls 44 on four sides, a ceiling surface is attached to the upper end portion of the side wall, and a floor surface is attached to the lower end portion of the side wall. , A closed space is formed by the ceiling surface and the floor surface. However, an opening provided with an electric door (not shown) is formed on the floor surface of the first work house 40, and the first work house 40 is positioned so that the opening is directly above the shield plug 9. Is positioned.
Here, the size of the opening formed in the floor surface of the first work house 40 is larger than at least the circular cross-sectional opening of the RPV 11 located directly below the floor surface, and preferably, the crossing of the PCV 3 is performed. It is larger than the opening of the surface circular shape. As a result, as will be described later, it is possible to access the in-furnace equipment housed in the RPV 11 and, for example, it is suitable for the dismantling work of the PCV 3 during the decommissioning work. In addition, the shape of the opening formed in the floor surface of the first work house 40 is not necessarily similar to the circular shape of the cross-sectional openings of the RPV 11 and the PCV 3, and may be, for example, rectangular.

  A rail 41 in the first work house is laid on the upper part of the inner walls of two opposing first work house side walls 44 of the first work house 40. A traveling carriage 42 is provided so as to travel along the longitudinal direction of the rail 41 in the first work house. On the traveling carriage 42, a traversing carriage 43 is provided so as to travel along the longitudinal direction of the traveling carriage 42. The traversing cart 43 is provided with a hook 49. A crane device (hereinafter referred to as a first work house crane device (first unloading device)) is constituted by the rail 41 in the first work house, the traveling carriage 42, the traversing carriage 43 and the hook 49.

The second work house 50 is installed above the DSP 27. Similarly to the first work house 40, the second work house 50 forms a closed space with the four second work house side walls 54, the ceiling surface, and the floor surface. Similarly to the first work house 40, an opening having an electric door is formed on the floor surface of the second work house 50, and the second work house is positioned so that the opening is located directly above the DSP 27. A work house 50 is positioned. The size of the opening formed in the floor surface of the second work house 50 is at least larger than the upper opening surface of the DSP 27 located directly below, and the shape is, for example, rectangular.
Similarly to the first work house 40, a crane device (hereinafter, second work house crane device) is also provided in the second work house 50 by a rail 51 in the second work house, a traveling carriage 52, a transverse carriage 53, and a hook 59. (Referred to as “second carry-out device”).

  In addition, although illustration is abbreviate | omitted in the 1st work house 40 and the 2nd work house 50, the nitrogen injection apparatus which inject | pours nitrogen gas into a work house, the holding | grip mechanism in a front-end | tip part, although not shown in figure An articulated manipulator that is movable in any direction in a three-dimensional space, a shielding water tank that contains shielding water poured into the first bag-like shield 32 and the second bag-like shielding 34 described later, and shielding water Various equipment such as a pump for feeding water, a plurality of cameras for photographing the interior space of the work house, and a dosimeter are installed. Moreover, the cutting device 300 which can move a floor surface is installed in the 2nd work house. The flat area of the second bag-shaped shield 34 that is installed on the operation floor 29 and above the first bag-shaped shield 32 and the RPV 11 is from an opening formed on the floor surface of the first work house 40. Big enough. Similarly, the plane area of the second bag-shaped shield 34 installed above the DSP 27 is sufficiently larger than the opening formed on the floor surface of the second work house 50.

  After installing the first work house 40 and the second work house 50, an external power source is connected to the hydraulic pump / control panel in each house. Devices and instruments such as crane devices, ventilation air-conditioning systems, electric doors, and cameras provided in the first work house and the second work house operate by being supplied with electricity from a hydraulic pump / control panel in the work house. In addition, a remote operation panel (not shown) is provided separately for operating devices and instruments in the work house remotely from the outside of the boiling water nuclear power plant 1, and the remote operation panels are provided in the first work house 40 and the second work house. A control panel installed in the work house 50 is connected wirelessly or by wire, and the operations of the various devices and instruments are remotely controlled via the control panel.

  The first work house side wall 44 and the second work house side wall 54 are provided with electric open / close doors (not shown) in order to carry out in-furnace equipment. The first work house side wall 44 and the second work house side wall 54 are provided with air lock devices 400 and 500 for approaching workers. Details of the worker approaching air lock device will be described later.

The situation below the first work house 40 and the second work house 50 will be described for reference. FIG. 2 shows a state where the steam dryer 14 is carried out to the DSP 27.
The front ends of the four wires suspended from the first work house crane device are connected to the upper surface of the suspension balance 45 via a hook. A wire and a hook for lifting the in-furnace equipment are attached to the lower surface of the suspension balance 45. Between the first work house crane apparatus and the suspension balance 45, there is provided a first bag-like shield 32 that is provided on the gantry 33 and into which shielding water can be injected. The first bag-like shield 32 is constituted by joining a plurality of compartmentalized water storage bags, and four wires suspended from the first work house crane apparatus without leaking the shield water injected therein. It has a through-hole that allows it to penetrate. The gantry 33 similarly has a through hole so as to communicate with the through hole of the first bag-shaped shield 32. In addition, the bottom surface of each water bag which comprises the 1st bag-shaped shielding body 32 is equipped with the injection | pouring port which inject | pours shielding water inside, and the drainage port for discharging | emitting the shielding water stored inside.

  Further, on the floor surface of the DSP 27, a carriage having an extendable cargo bed made up of a cutting frame 38 and a moving rail 39 is installed, and an expandable shielding water storage tank 36 is provided in a state of being folded so as to surround the cutting frame 38. FIG. 2 shows a state where the steam dryer 14 is carried out to the DSP 27 and the telescopic shielding water storage tank 36 is extended. In addition, an open / close type DSP shield 35 is installed at the height of the operation floor 29 above the DSP 27, and the DSP shield 35 is configured to be slidable on the rail by a cylinder (not shown) or the like. .

  The RPV shield 31 is installed immediately above the steam dryer 14, and is configured to be able to open and close by sliding on the rail by a cylinder (not shown). FIG. 2 shows a state in which the DSP shield 35 and the RPV shield 31 are opened. The area of the DSP shield 35 is larger than the area of the DSP 27, and the area of the RPV shield 31 is larger than the opening of the RPV 11. Therefore, the RPV shield 31 is opened when the in-furnace equipment is carried out of the RPV 11, and the RPV shield 31 is closed after the in-furnace equipment is carried out, thereby shielding the radiation from inside the RPV 11 and from the inside of the RPV 11. The diffusion of contaminants can be prevented.

  On the upper part of the DSP shield 35, a second bag-like shield 34 that is configured to be stretchable from the left and right and that can be filled with shielding water such as water or boric acid water is installed. That is, the second bag-shaped shield 34 is formed by joining a plurality of partitioned water storage bags. Each of the water storage bags having one end fixed to each of the left and right sides is provided with a shielding water injection port and a discharge port (not shown) on the bottom surface thereof. The second bag-shaped shield 34 that can be shielded by radiation by sequentially extending from the left and right side walls of the DSP 27 toward the center by injecting the shielding water and intimately contacting the end opposite to the fixed end. It becomes a state. Moreover, the 2nd bag-shaped shielding body 34 each drains shielding water below from the water storage bag divided by the center part side via a drainage port. Here, by draining into the DSP 27, the water bag is sequentially folded from the water storage bag disposed on the center side and contracts horizontally to the fixed end side. Thereby, an opening part is formed in the center part of the 2nd bag-shaped shielding body 34, and an opening part is expanded in a horizontal direction. In FIG. 2, the second bag-shaped shield 34 shows a state in which an opening before stretching is formed. As shielding water, in addition to the above water and boric acid water, for example, it has fluidity at room temperature, and the specific gravity is at least a specific gravity of concrete (2.15 g / cm 3) or more in order to ensure sufficient radiation shielding properties. You may use the barium sulfate aqueous solution which disperse | distributed barium sulfate which is material to the solution. The aqueous barium sulfate solution is used as a medical material and is not harmful to the human body, is liquid at room temperature, has a specific gravity of about 4.5 g / cm 3, and is suitable as shielding water. The second bag-shaped shield 34 is also installed above the RPV 11 and at the height of the operation floor 29 as shown in FIG.

A sheet 46, a sheet cutting device 47, and a sheet operating device 48 for operating the sheet are installed on the upper part of the second bag-shaped shield 34. The sheet 46 is used for packing a cut piece of in-furnace equipment. Thereby, scattering of the radioactive dust adhering to a cut piece can be prevented. Moreover, the sheet | seat 46 provided in the upper part of the 2nd bag-shaped shielding body 34 above RPV11 has a role of the curing sheet which isolates a work house side from a furnace inner side, when carrying out an in-furnace apparatus and fuel debris.
In FIG. 2, when the steam dryer 14 is carried out to the DSP 27, the steam / water separation plug 30 on the DSP 27 side is carried out, and the shielded DSP gate 37 is opened and closed.

Next, details of a configuration example of the air lock device for approaching a worker will be described with reference to FIG. Although the worker approaching air lock device 500 will be described as an example in FIG. 3, other worker approaching air lock devices 400 and 600 have the same configuration.
As described above, in the work house, work is performed by a fully remote automatic device arranged in the work house in order to prevent exposure of workers. However, in the unlikely event that a trouble occurs in a fully remote automatic device installed in the work house, there are limits to how detailed maintenance and inspection can be handled with the remote automatic device, so that workers can work. It may be necessary to approach the house and perform maintenance on the device. However, even if various shielding means are provided in the work house, since the work house is in a polluted environment and a nitrogen environment, entry and exit of workers should be suppressed.
Therefore, in this embodiment, an air lock 500 device for approaching the worker is provided in advance in the second work house 50, and in the unlikely event that trouble occurs in the device disposed in the work house, the exposure of the worker is prevented. A worker can approach the device arranged in the work house and perform fine maintenance of the device.

The worker approaching air lock device 500 is attached so as to penetrate the second work house side wall 54 which is a work house boundary. The worker approaching air lock device 500 includes an air lock 501, an extendable duct 502, and a maintenance work tool (FIGS. 4 and 5).
The air lock 501 includes a main body 510 formed in a cylindrical shape, a first hatch 512 and a second hatch 513 which are airtight doors. The second hatch 513 is provided on the partition wall 511 that partitions the inside of the air lock 501. The main body 510, the partition wall 511, the first hatch 512, and the second hatch 513 are formed of stainless steel or the like. The main body 510 is installed so as to penetrate the second work house side wall 54, so that the air tightness in the work house is maintained between the periphery of the main body 510 and the inner wall of the through hole of the second work house side wall 54. It is connected to the. A work floor 514 is provided at a lower portion of the airlock main body 510.

  An air supply line 516 and an exhaust line 517 are provided in the replacement area 515 of the air lock 501 so that the air in the replacement area 515 can be cleaned. That is, in the unlikely event that leakage occurs in the expansion duct 502 described later, the worker cleans the air in the replacement area 515 when the worker returns from the work area 518 to the replacement area 515, and then the worker cleans the first hatch 512. I try to keep out of the clean area. An air supply pump 519 is provided in the air supply line 516, and an exhaust pump 520 and a filter 521 for removing dust are provided in the exhaust line 517.

  An air supply line 522 and an exhaust line 523 are provided in the work area 518 of the air lock 501 so that the air in the work area 518 can be purified. An air supply pump 524 is provided in the air supply line 522, and an exhaust pump 525 and a filter 526 for removing dust are provided in the exhaust line 523. While the worker is working in the work area 518, the internal pressure in the work area 518 is set to be higher than the internal pressure in the first work house 50. As a result, even if a later-described telescopic duct 502 is perforated, the contaminated air in the second work house 50 is prevented from entering the work area 518, thereby minimizing the entry of the contaminated air. be able to. Further, by making the internal pressure in the work area 518 higher than the internal pressure in the second work house 50, the extension duct 502 described later can be easily extended. That is, pressurizing the inside of the work area 518 is an assist when the telescopic duct 502 is pushed out in the extending direction, and the expansion of the telescopic duct 502 is facilitated.

  A telescopic duct 502 is provided at the tip of the air lock 501 on the second work house 50 side (the tip of the work area 518 outside the second hatch 513). One end of the telescopic duct 502 is attached to the tip of the air lock 501, and a separator 527 is attached to the other end. The work area 518 side of the air lock 501 is airtightly isolated from the inside of the second work house 50 by the telescopic duct 502. For this reason, the telescopic duct 502, the tip of the air lock 501 and the separator 527 are connected so as to be kept airtight. An operator can enter the telescopic duct 502 from the work area 518 side of the air lock 501. The telescopic duct 502 extends toward the inside of the second work house 50 when pressed by an operator. Further, as described above, the internal pressure in the work area 518 assists the extension of the telescopic duct 502. The telescopic duct 502 is made of, for example, reinforced with aramid fibers based on a resin sheet such as polyurethane. For example, an aramid fiber sheet is disposed between two polyurethane resin sheets to form a material for the stretch duct. The telescopic duct constructed using the material formed in this way is resistant to radiation and can maintain the necessary strength by the reinforcing material. Further, if necessary, two aramid fiber sheets may be provided, and a stainless fiber sheet may be disposed between the aramid fibers. In this case, there is an advantage that breakage is suppressed even if it contacts a structure or the like. When the stainless steel fiber sheet is not disposed, the weight of the expansion duct 502 is reduced, and the expansion work of the expansion duct becomes easy.

  The separator 527 attached to the tip of the telescopic duct 502 is made of a lightweight metal such as glass fiber reinforced plastic (GFRP), carbon fiber reinforced plastic (CFRP), or aluminum in order to reduce the weight and facilitate the work of workers. It is configured. The separator 527 is provided with a work window 528 so that the inside of the work house can be observed from the work area side. The work window 528 is made of radiation shielding glass.

In addition, the front end of the air lock, that is, the separator 527 is attached to the front end of the air lock so that the operator can perform maintenance work on the device disposed in the second work house 50 while observing the front end of the telescopic duct 502. A maintenance work tool for performing maintenance work as shown in FIG.
FIG. 4 shows an example in which a work manipulator 529 is installed on the separator 527 (the tip of the air lock). The work manipulator 529 may be either mechanical or electric. An operator operates the master arm 530 while directly observing the inside of the work house from the work window 528, drives the slave arm 531, and performs maintenance work.
FIG. 5 shows an example in which a work glove 532 is installed on the separator 527 (the tip of the air lock). A worker puts his hand into the work glove 532 and performs maintenance work by fine manual work while directly observing the inside of the work house from the work window 528.

Next, with reference to FIG. 6 to FIG. 10, steps in which the worker approaches the maintenance work position in the work house using the worker approaching air lock device of this embodiment will be described. 6 to 10, the maintenance work tool, the air supply line, and the exhaust line are not shown.
(Step 1)
FIG. 6 shows a state before the worker enters the worker approaching air lock device 500. Both the first hatch 512 and the second hatch 513 are closed (closed). The telescopic duct 502 is in a contracted (folded) state.
(Step 2)
FIG. 7 shows a state where the first hatch 512 is opened and an operator enters the replacement area 515 of the air lock 501. At this time, the second hatch 513 is closed, and the telescopic duct 502 is also contracted.
(Step 3)
FIG. 8 shows a state in which the first hatch 512 is closed, the second hatch 513 is opened, and an operator is going into and out of the work area 518 of the air lock 501. The contraction duct 502 is in a contracted state.
(Step 4)
In FIG. 9, the worker enters and exits the work area 518 and closes the second hatch 513. Even at this stage, the contraction duct 502 is contracted.
(Step 5)
In FIG. 10, clean air is supplied from the air supply line 522 to the work area 518 of the air lock 501 to pressurize the work area 518 so that the pressure in the work area 518 is higher than the pressure in the second work house 50. . An operator pushes the separator 527 at the tip of the telescopic duct 502 while extending the telescopic duct 502 with the assistance of this pressurization. Thereby, the environment which can approach through a telescopic duct to the maintenance work position in the 2nd work house 50 is provided. And an operator can perform maintenance work using the maintenance work tool shown in FIG. 4 and FIG.

Next, an example of maintenance work will be described with reference to FIGS. 11 and 12 are diagrams for explaining maintenance work of the cutting tool 301 of the cutting apparatus 300. FIG. FIG. 11 shows a state before the start of maintenance work.
As shown in FIG. 12, an environment in which the telescopic duct 502 of the worker approaching air lock device 500 is extended so that the worker can approach through the telescopic duct to the vicinity of the cutting device that is the maintenance work target in the second work house 50. Make. Then, the telescopic tube 302 of the cutting device 300 is pulled up and bent, and the cutting tool 301 is moved to the side surface side of the DSP 27. In this state, maintenance work (inspection, tool replacement, etc.) of the cutting tool 301 is performed through the telescopic duct.

  According to the present embodiment, it is possible to prevent the worker from being exposed and to perform maintenance of the cutting tool and the like by approaching the cutting device arranged in the second work house 50 by the worker.

Another embodiment of the worker approaching air lock device will be described with reference to FIGS. In this embodiment, the worker approaching air lock device 500 will be described as an example, but the other worker approaching air lock devices 400 and 600 have the same configuration.
In this embodiment, in consideration of the fact that the expansion duct is contaminated, the expansion duct can be replaced. The description of the same parts as those in the above embodiment is omitted.

  As shown in FIG. 13, in this embodiment, the telescopic duct 502 is housed inside the second hatch 513 (inside the air lock 501). One end (left end) of the telescopic duct 502 is similar to the piston of the cylinder, and the outer periphery thereof is slidably in contact with the inner peripheral wall surface of the main body 510 of the air lock 501 via the annular seal structure 533. The telescopic duct 502 is configured to be removable from the seal structure 533 and the separator 527.

  The extension state of the telescopic duct 502 will be described with reference to FIG. In this embodiment, the second hatch 513 is opened to the outside, and the telescopic duct 502 is pushed out to the outside of the second hatch 513. At this time, clean air is supplied from the air supply line 516 to the replacement area 515 to pressurize the replacement area 515 so that the pressure in the replacement area 515 is higher than the pressure in the second work house 50. An operator pushes the separator 527 at the tip of the telescopic duct 502 while extending the telescopic duct 502 with the assistance of this pressurization. Thereby, also in the present embodiment, an environment is provided in which the maintenance work position in the second work house 50 can be approached through the telescopic duct. And an operator can perform maintenance work using the maintenance work tool shown in FIG. 4 and FIG.

  In this embodiment, since the expansion duct 502 is provided inside the second hatch 513, the expansion duct 502 can be replaced relatively easily when the expansion duct is contaminated or damaged. That is, as shown in FIG. 15, in a state where the second hatch 513 is closed, the telescopic duct 503 is detached from the separator 527 in the replacement area 515, folded, and stored in the carry-out container 534. Thereafter, the first hatch 512 is opened, the carry-out container 534 is carried out of the air lock device 500 for approaching the worker, and the telescopic duct 502 is discarded. Then, a new telescopic duct is attached to the separator 527, and the replacement operation of the telescopic duct is completed.

  In the present embodiment, in addition to the effects of the above-described embodiments, the expansion duct can be replaced relatively easily even if the expansion duct is contaminated or damaged.

  In addition, this invention is not limited to an above-described Example, Various modifications are included. For example, the above-described embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described. Further, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. Moreover, it is possible to add, delete, and replace other configurations for a part of the configuration of each embodiment.

DESCRIPTION OF SYMBOLS 1 ... Boiling water type nuclear power plant, 2 ... Reactor, 3 ... Reactor containment vessel (PCV), 4 ... Reactor building, 5 ... Reactor containment vessel top cover (PCV top cover) , 6 ... Dry well, 7 ... Pressure suppression chamber, 8 ... Vent passage, 9 ... Shield plug, 10 ... Reactor power vessel top cover (RPV top cover), 11 ... Reactor Pressure vessel (RPV), 12 ... core, 13 ... steam separator, 14 ... steam dryer, 15 ... core shroud, 16 ... fuel assembly, 17 ... core support Plate, 18 ... upper lattice plate, 19 ... control rod guide tube, 20 ... control rod, 21 ... control rod drive mechanism housing, 22 ... lower mirror, 23 ... concrete mat, 24 ... Pedestal, 25 ... γ-ray shield, 26 ... Reactor well, 27 ... Dora Separator pool (DSP), 28 ... spent fuel storage pool (SFP), 29 ... operation floor, 30 ... air / water separation plug, 31 ... RPV shield, 32 ... first One bag-like shield, 33 ... frame, 34 ... second bag-like shield, 35 ... DSP shield, 36 ... telescopic shielding water reservoir, 37 ... shielded DSP gate, 38 ... cutting frame, 39 ... moving rail, 40 ... first work house, 41 ... rail in the first work house, 42, 52 ... traveling carriage, 43, 53 ... traversing Carriage, 44 ... first work house side wall, 45 ... suspension balance, 46 ... sheet, 47 ... sheet cutting device, 48 ... sheet operation device, 49, 59 ... hook, 50 ... Second work house, 51 ... Rail in second work house, 54 ... Second Side wall of work house, 55... In-furnace equipment cut piece storage container, 100... Beam, 300 .. In-furnace equipment cutting device, 301 ... Cutting tool, 302 ... Telescopic tube, 400, 500, 600 ... Air lock device for approaching a worker, 501 ... Air lock, 502 ... telescopic duct, 510 ... main body, 511 ... partition wall, 512 ... first hatch, 513 ... Second hatch, 514 ... work floor, 515 ... replacement area, 516, 522 ... air supply line, 517, 523 ... exhaust line, 518 ... work area, 519, 524 ... Air supply pump, 520, 525 ... exhaust pump, 521, 526 ... filter, 527 ... separator, 528 ... work window, 529 ... work manipulator, 530 ... master arm, 531 ... the slave arm, 532 ... work glove, 533 ... seal structure, 534 ... carry-out container.

Claims (12)

A work house for carrying out fuel debris or in-reactor equipment, which is installed above the operation floor in the reactor building and used for carrying out fuel debris or in-reactor equipment,
An air lock provided on a side wall of the work house; provided on the outside or inside of an airtight door disposed on the inside of the work house of the air lock; an operator can enter from the inside of the air lock; and An extension duct that extends toward the inside of the work house and isolates the inside of the airlock in an airtight manner with respect to the inside of the work house, and is provided at a distal end of the extension duct, and the work house is observed while an operator observes A work house for carrying out fuel debris or in-furnace equipment or the like, characterized by comprising means for performing maintenance work on the apparatus disposed inside. In the work house for carrying out fuel debris or in-furnace equipment according to claim 1,
The telescopic duct is provided outside the hermetic door on the inside of the work house,
The inside of the air lock is divided into a replacement area outside the work house and a work area inside the work house by the hermetic door inside the work house, and supplies clean air into the replacement area. A work house for carrying out fuel debris or in-furnace equipment or the like, characterized in that an air supply line and an exhaust line for discharging air in the replacement area are provided. In the work house for carrying out fuel debris or in-furnace equipment according to claim 1 or 2,
The telescopic duct is provided outside the hermetic door on the inside of the work house,
The inside of the air lock is divided into a replacement area outside the work house and a work area inside the work house by the airtight door inside the work house, and supplies clean air into the work area. An air supply line and an exhaust line for exhausting the air in the replacement area are provided, and when an operator works in the work area, the internal pressure of the work area is made higher than the internal pressure of the work house. A work house for carrying out fuel debris or in-furnace equipment. In the work house for carrying out fuel debris or in-furnace equipment according to any one of claims 1 to 3,
A fuel debris characterized in that a separator is provided at an end portion of the telescopic duct located on the work house side, and a work window for an operator to observe the inside of the work house is provided on the separator. Or a work house for carrying out equipment in the furnace. In the work house for carrying out fuel debris or in-furnace equipment according to claim 4,
Means for carrying out the maintenance work is provided on the separator plate. A work house for carrying out fuel debris or in-furnace equipment or the like. In the work house for carrying out fuel debris or in-furnace equipment according to claim 5,
The work house for carrying out fuel debris or in-furnace equipment or the like, characterized in that the means for performing the maintenance work is a work manipulator driven by a master arm located inside the telescopic duct. In the work house for carrying out fuel debris or in-furnace equipment according to claim 5,
The work house for carrying out fuel debris or in-furnace equipment or the like, wherein the means for performing the maintenance work on the separator is a work glove. In the work house for carrying out fuel debris or in-furnace equipment according to claim 1,
The telescopic duct is provided inside the airtight door on the inside of the work house,
For carrying out fuel debris or in-furnace equipment or the like having an annular seal structure slidably in contact with the inner peripheral wall surface of the air lock on the outer periphery of the inner end of the air lock of the telescopic duct Working house. In the work house for carrying out fuel debris or in-furnace equipment according to claim 8,
A work house for carrying out fuel debris or in-furnace equipment or the like, characterized in that an air supply line for supplying clean air into the air lock and an exhaust line for discharging the air in the air lock are provided. In the work house for carrying out fuel debris or in-furnace equipment according to claim 9,
A work house for carrying out fuel debris or in-furnace equipment or the like, wherein an internal pressure of the air lock is set to be higher than an internal pressure of the work house when an operator works in the air lock. In the work house for carrying out fuel debris or in-furnace equipment according to any one of claims 8 to 10,
A separator is provided at a tip of the extension duct on the work house side, and the extension duct is configured to be removable from the seal structure and the separator. Unloading work house. An air lock for approaching workers installed on the side wall of a work house for carrying out fuel debris or in-reactor equipment installed above the operation floor in the reactor building and used for carrying out fuel debris or in-reactor equipment A device,
An air lock provided on the side wall, and provided on the outside or inside of the airtight door disposed on the inside of the work house of the air lock, allowing an operator to enter from the inside of the air lock, and the inside of the work house An expansion duct that extends toward the work chamber and hermetically isolates the inside of the air lock from the inside of the work house, and is provided at the tip of the telescopic duct, and is disposed in the work house while being observed by an operator. An air lock device for approaching a worker used in a work house for carrying out fuel debris or in-furnace equipment or the like, characterized in that it comprises means for performing maintenance work on the device.

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