JP6473775B2 - Carrying out the reactor internals in a nuclear power plant - Google Patents

Description

  The present invention relates to a method for carrying out an in-furnace structure in a nuclear power plant, and more particularly to a method for carrying out an in-core structure in a nuclear power plant suitable for application to a boiling water nuclear power plant and a pressurized water nuclear power plant.

  In a nuclear power plant such as a boiling water nuclear power plant and a pressurized water nuclear power plant, a plurality of fuel assemblies containing nuclear fuel materials are loaded in a reactor core. A fuel assembly that has experienced operation of the reactor at a predetermined number of operation cycles after being loaded in the core is carried out of the reactor as a spent fuel assembly.

  An example of a method for carrying out spent fuel assemblies from a nuclear reactor in a boiling water nuclear power plant is described in Japanese Patent Application Laid-Open No. 8-262182. The spent fuel assembly is taken out from the reactor using a fuel exchanger movably installed on the operation floor in the reactor building, and is transported to a fuel storage pool formed in the reactor building.

JP-A-8-262182

  In the method of transporting spent fuel assemblies from the reactor described in JP-A-8-262182, the nuclear fuel material in the reactor of the boiling water nuclear power plant is present in a healthy fuel assembly. In some cases, the spent fuel assembly is unloaded from the core. However, in the unlikely event that an accident occurs in which the nuclear fuel material contained in the fuel assembly loaded in the core of the nuclear reactor melts, such as the nuclear plant of the Three Mile Nuclear Power Station, this molten nuclear fuel material It is extremely difficult to carry out the reactor from the nuclear reactor, and it takes a long time to carry out the melted and solidified nuclear fuel material.

  An object of the present invention is to provide a method for carrying out an in-core structure in a nuclear power plant that can prevent radioactive materials from being discharged to the external environment when the in-core structure is transferred from a reactor vessel.

A feature of the present invention that achieves the above-described object is that the first internal space formed in the first work house installed on the operation floor of the reactor building, and the shielding that opens and closes provided in the lower part of the first internal space. using the door, with open the shielding door, step unloading the core internals present in the reactor vessel to the first internal space of the first working house, and in the closed state of the shield door, the An opening / closing door that opens and closes an opening that communicates between the first work house and the second work house is provided in a second work house that is disposed adjacent to the first work house, and exists in the first internal space . Each of the steps of carrying out the in-furnace structure to the second internal space formed in the second work house outside the first work house is carried out, and further, the second internal space is closed with the open / close door closed. The internal furnace structure from the second work house to the outside It is to implement the process of leaving.

The first work house is installed on the operation floor of the reactor building where the reactor vessel is installed directly above the reactor vessel, and the in-reactor structure existing in the reactor vessel with the shielding door open. the process is carried out to the first internal space of the first working houses, and in the closed state of the shielding door opening which communicates the second working houses, which are disposed adjacent to the first working house to the first working House The door for opening and closing the part was opened, each of the steps of carrying out the in-furnace structure existing in the first internal space to the second internal space in the second work house was performed , and the open / close door was closed In this state, since the step of carrying out the reactor internal structure in the second internal space from the second work house to the outside is performed, the reactor vessel is transferred along with the transfer of the cut reactor internal structure from the reactor vessel. Although the radioactive material of the inner enters into the first work in the house, the first work Howe And since the second working house exists, it is possible to prevent the discharge of the external environment of the radioactive substance.

  ADVANTAGE OF THE INVENTION According to this invention, discharge | emission to the external environment of the radioactive substance in a reactor vessel can be prevented with the transfer from the reactor vessel of a reactor internal structure.

It is explanatory drawing which shows the installation state of the house and crane apparatus which are used for the carrying-out method of the nuclear fuel material in the nuclear power plant of Example 1 which is one suitable Example of this invention. It is a top view of the bottom of the house shown in FIG. In Example 1, it is explanatory drawing which shows the state which has arrange | positioned the boring apparatus on the opening-and-closing type shielding member in a house. It is IV-IV sectional drawing of FIG. In Example 1, it is explanatory drawing which shows the state which connected the power supply connector to the boring apparatus and opened the hole in the upper cover of the reactor pressure vessel. It is a detailed block diagram of the boring apparatus shown in FIG. It is a top view of the boring apparatus shown in FIG. It is an enlarged view of the inner blade shaft drive socket vicinity of the boring apparatus shown in FIG. FIG. 7 is an enlarged longitudinal sectional view of a cutting device and an extension pipe used in the boring apparatus shown in FIG. 6, (A) is an enlarged longitudinal sectional view of the cutting apparatus, and (B) is an enlarged longitudinal sectional view of the extension pipe. FIG. 7 is an enlarged longitudinal sectional view showing a connected state and a separated state of the cutting device and the extension pipe of the boring device shown in FIG. 6, and (A) is an enlarged longitudinal sectional view showing the separated cutting device and the extension pipe; ) Is an enlarged longitudinal sectional view showing the connected cutting device and the extension pipe. It is explanatory drawing which shows the state which hold | gripped the extension pipe | tube with the extension pipe | tube moving apparatus of the boring apparatus shown by FIG. It is explanatory drawing which shows the process of the first half of the procedure which connects an extension pipe | tube to a cutting device. It is explanatory drawing which shows the process of the latter half of the procedure which connects an extension pipe | tube to a cutting device. It is explanatory drawing which shows the process of the first half of the procedure which draws out a rotating shaft from the inside of each outer cylinder of the cutting device and extension pipe which are inserted and connected in the reactor pressure vessel. It is explanatory drawing which shows the process of the latter half of the procedure which draws out a rotating shaft from each outer cylinder of the cutting device and extension pipe | tube inserted and connected in the reactor pressure vessel. In Example 1, it is explanatory drawing which shows the state which inserted the camera in the upper end part of the reactor pressure vessel, and opened the hole in the steam dryer and the steam-water separator using the boring apparatus. In Example 1, it is explanatory drawing which shows the state which inserted the camera between the steam-water separator and the core through the hole opened in the steam dryer and the steam-water separator. It is explanatory drawing which shows the state which inject | poured the iron ball and iron powder in the core. It is explanatory drawing which shows the process of the first half of the procedure which pulls out each outer cylinder inserted and connected in the reactor pressure vessel from a reactor pressure vessel. It is explanatory drawing which shows the process of the latter half of the procedure which extracts each outer cylinder inserted in the reactor pressure vessel and connected from the reactor pressure vessel. It is explanatory drawing which shows the state which installed the guide rail and turntable on the bottom of the house shown in FIG. FIG. 3 is an explanatory diagram illustrating the removal of the upper cover of the reactor containment vessel performed in the first embodiment. It is explanatory drawing which shows the cutting process of the upper cover in the carrying-out process of the upper cover of the nuclear reactor containment vessel shown in FIG. It is explanatory drawing which shows the carrying-out process of the upper cover in the carrying-out process of the upper cover of the nuclear reactor containment vessel shown in FIG. It is explanatory drawing which shows carrying out of the steam separator performed in Example 1. FIG. It is explanatory drawing which shows the cutting | disconnection of a steam-water separator in the carrying-out process of the steam-water separator shown in FIG. It is explanatory drawing which shows carrying out of the water supply sparger performed in Example 1. FIG. It is a detailed block diagram of the abrasive water jet apparatus used for the cutting | disconnection of the structural member performed in Example 1. FIG. In Example 1, it is explanatory drawing which shows the state which installed the other type of boring apparatus in the reactor pressure vessel. It is a detailed block diagram of the boring apparatus shown in FIG. It is a top view of the boring apparatus shown in FIG. FIG. 31 is an enlarged longitudinal sectional view of a cutting device used in the boring device shown in FIG. 30. It is a top view of the boring apparatus shown in FIG. It is XX sectional drawing shown in FIG. It is explanatory drawing which shows the process of connecting an extension pipe to the cutting device shown in FIG. It is explanatory drawing which shows carrying out of the nuclear fuel material which exists in the core performed in Example 1. FIG. It is explanatory drawing which shows the injection | pouring state of the iron powder (shielding powder) to the core performed after carrying out of the nuclear fuel material from a core in Example 1. FIG. It is explanatory drawing which shows the boring performed toward a furnace bottom part using a boring apparatus in Example 1. FIG. It is explanatory drawing which shows the injection | pouring state of the iron powder on the molten nucleus fuel material which fell to the furnace bottom part performed in Example 1. FIG. It is explanatory drawing which shows the cutting | disconnection of the core shroud performed after the iron powder injection shown in FIG. It is explanatory drawing which shows carrying out of the nuclear fuel material which fell to the furnace bottom part performed in Example 1. FIG. It is explanatory drawing which shows the injection | pouring state of the iron powder to the furnace bottom part performed after carrying out of the nuclear fuel material from the furnace bottom part performed in Example 1. FIG. In Example 1, it is explanatory drawing which shows each state of the iron powder injection | pouring performed below the boring performed below a reactor pressure vessel and the reactor pressure vessel using a boring apparatus. It is explanatory drawing which shows the cutting | disconnection of the core shroud lower trunk performed in Example 1. FIG. It is explanatory drawing which shows carrying out of the nuclear fuel material which fell to the reactor containment vessel bottom part performed in Example 1. FIG. It is explanatory drawing which shows the cutting | disconnection and carrying out of the reactor pressure vessel performed in Example 1. FIG. FIG. 2 is an explanatory view showing a state after carrying out a reactor pressure vessel in Example 1. It is explanatory drawing which shows the boring of the reactor pressure vessel by the boring apparatus performed at the time of nuclear fuel material carrying-out when the nuclear fuel material and reactor internal structure in a reactor pressure vessel in Example 1 are fuse | melted. It is explanatory drawing which shows the injection | pouring state of the iron powder on the fusion | melting nuclear fuel material of the reactor bottom part performed at the time of nuclear fuel material carrying-out when the nuclear fuel material and reactor internal structure in a reactor pressure vessel in the Example 1 are fuse | melted. . It is explanatory drawing which shows carrying out of the apparatus which remain | survives in the nuclear reactor pressure vessel performed at the time of nuclear fuel material carrying out when the nuclear fuel material and nuclear reactor structure in a nuclear reactor pressure vessel in Example 1 are melted. It is explanatory drawing which shows carrying out of the molten nuclear fuel material which exists in the reactor bottom part performed at the time of nuclear fuel material carrying out when the nuclear fuel material and reactor internal structure in a nuclear reactor pressure vessel in Example 1 are fuse | melted. It is explanatory drawing which shows the removal of the fusion | melting nuclear fuel material which fell to the bottom part of the nuclear reactor containment vessel performed at the time of nuclear fuel material carrying-out at the time of the nuclear fuel material and nuclear reactor structure in a reactor pressure vessel in Example 1 melting. . It is explanatory drawing which shows the state which has arrange | positioned the boring apparatus performed in the carrying-out method of the nuclear fuel material in the nuclear power plant of Example 2 which is another Example of this invention on the opening-and-closing type shielding member. In Example 2, it is explanatory drawing which shows the state which inserted the camera in the upper end part of the reactor pressure vessel, and opened the hole in the steam dryer and the steam-water separator using the boring apparatus. In Example 2, it is explanatory drawing which shows the state which inserted the camera between the steam-water separator and the core through the hole opened in the steam dryer and the steam-water separator. It is explanatory drawing which shows the installation state of the house used in Example 2, and a crane apparatus. It is explanatory drawing which shows the installation state of the shield digging apparatus used for the nuclear fuel material carrying-out method in the nuclear power plant of Example 3 which is another Example of this invention. In Example 3, it is explanatory drawing which shows the cutting of the structure in a reactor pressure vessel using a shield excavation apparatus. In Example 3, it is explanatory drawing which shows the state which cutting of the structure in a reactor pressure vessel was completed using the shield digging apparatus.

  Examples of the present invention will be described below.

  A method for carrying out nuclear fuel material in the nuclear power plant according to the first embodiment applied to a boiling water nuclear power plant, which is a preferred embodiment of the present invention, will be described with reference to FIGS.

  First, a schematic structure of a boiling water nuclear power plant to which the nuclear fuel material carrying-out method in the nuclear power plant of the present embodiment is applied will be described with reference to FIG. The boiling water nuclear power plant includes a nuclear reactor 1 and a reactor containment vessel (hereinafter referred to as PCV) 9. The PCV 9 is installed in the reactor building 14 and is sealed with an upper lid 10 attached to the upper end. The PCV 9 includes a dry well 11 formed inside and a pressure suppression chamber 12 in which a pressure suppression pool filled with cooling water is formed. One end of the vent passage communicated with the dry well 11 is immersed in the cooling water of the pressure suppression pool in the pressure suppression chamber 12.

  A shield plug 15, which is a radiation shield divided into a plurality of parts, is disposed directly above the upper lid 10, and these shield plugs 15 are installed on the operation floor of the reactor building 14.

  A nuclear reactor 1 includes a reactor pressure vessel (hereinafter referred to as RPV) 2 configured with an upper lid 3, a core 4 loaded with a plurality of fuel assemblies including nuclear fuel materials, a steam separator 6, and steam drying. A container 7 is provided. The core 4, the steam separator 6 and the steam dryer 7 are disposed in the RPV 2. A core shroud 116 installed in the RPV 2 surrounds the core 4. Each fuel assembly loaded in the core 4 has a lower end supported by the core support plate 5 and an upper end held by an upper lattice plate (not shown). The steam / water separator 6 is disposed above the upper lattice plate located at the upper end of the core 4, and the steam dryer 7 is disposed above the steam / water separator 6.

  A plurality of control rod guide tubes 8A are arranged below the core 4, and a support cylinder 8 including the plurality of control rod guide tubes 8A is formed. Control rods (not shown) that are put into and out of the fuel assemblies in the core 4 to control the reactor power are disposed in the control rod guide tubes 8A. A plurality of control rod drive mechanism housings 39 are attached to the lower mirror of RPV2. Control rod drive mechanisms (not shown) are installed in the respective control rod drive mechanism housings 39 and connected to the control rods in the control rod guide tube 8A.

  Steam / water separator 6, steam dryer 7, shroud 87 (described later), upper lattice plate, core shroud 116, core support plate 5, support cylinder 8, control rod guide tube 8 </ b> A, core shroud lower body installed in RPV 2 116A is a furnace internal structure.

  The RPV 2 is installed on a cylindrical pedestal 37 provided on a concrete mat 38 provided at the bottom of the PCV 9. A cylindrical γ-ray shield 120 is installed at the upper end of the pedestal 37 and surrounds the RPV 2.

  In such a boiling water nuclear power plant, when the reactor is scrammed and the reactor power is reduced, all the power supply for supplying the current of the boiling water nuclear power plant is temporarily lost and the emergency core cooling Assume that the system did not work. When all the power sources are lost and the pumps of the emergency core cooling system do not operate and the cooling of each fuel assembly in the core 4 is impaired, the nuclear fuel material contained in the fuel assembly is melted, Molten nuclear fuel material can fall to the bottom of the RPV2.

  In the unlikely event that such molten nuclear fuel material falls to the bottom of the RPV2, the boiling water nuclear plant in which the molten nuclear fuel material is carried out of the RPV2 and the molten nuclear fuel material has fallen. Decommissioning treatment is carried out.

  In this embodiment, the nuclear fuel material is melted. For example, the nuclear fuel material in a boiling water nuclear power plant is carried out of the RPV 2. A method for carrying out the nuclear fuel material in the nuclear power plant of this embodiment will be described below.

  First, obstacles are removed when carrying out nuclear fuel material (step S1). For example, if there are obstacles when carrying out nuclear fuel material on the operation floor of a damaged reactor building, these obstacles can be removed using a crawler crane (not shown). It will be removed.

  A traveling crane is installed above the reactor building (step S2). As shown in FIG. 1, a plurality of support members 29 </ b> A are installed on the outer side of one of the opposing side walls of the reactor building 14. A guide rail 31A is installed at the upper end of these support members 29A. A plurality of support members 29B are installed on the outside of the other side walls among the side walls. A guide rail 31B is installed at the upper end of these support members 29B. The opposing support member 29 </ b> A and the support member 29 </ b> B are connected by a beam 30 placed on the operation floor of the reactor building 14. A portal traveling crane 32 is installed on the guide rails 31A and 31B using a crawler crane. The traveling crane 32 includes traveling carriages 33 that move along the guide rails 31 </ b> A and 31 </ b> B, and traversing carriages 34 </ b> A and 34 </ b> B that are provided on the traveling carriage 33 and move on the traveling carriage 33 in a direction perpendicular to the guide rails 31 </ b> A and 31 </ b> B. Have. Each of the traversing carts 34A, 34B is provided with hooks 35A, 35B that move up and down by a wire winding device (not shown).

  A house is installed on the operation floor of the reactor building (step S3). The work house 16A is suspended from the hooks 35A and 35B of the traveling crane 32, moved onto the operation floor, and installed on the operation floor so as to cover the shield plug 15 (see FIG. 1). The preparation house 16B is suspended from the hooks 35A and 35B of the traveling crane 32, moved above the work house 16A, and installed on the work house 16A (see FIG. 1). In order to maintain airtightness between the internal spaces 17A and 17B and the outside, seals are provided between the operation floor and the floor of the work house 16A, and between the ceiling of the work house 16A and the floor of the preparation house 16B.

  The work house 16A is surrounded by four side walls, and a floor 22 (see FIG. 2) is attached to the lower ends of these side walls, and a ceiling is attached to the upper ends of these side walls. Inside the work house 16A, an internal space 17A surrounded by four side walls, a floor, and a ceiling is formed. A large opening 23 is formed in the floor 22 of the work house 16A as shown in FIG. The opening 23 is disposed directly above the shield plug 15, and an opening (not shown) is formed directly above the opening 23 on the ceiling of the work house 16 </ b> A. A hydraulic pump / control panel 25 is disposed in the internal space 17 </ b> A and installed on the floor 22. A space 24 in which the carry-out container is placed is secured on the floor 22. An overhead crane 18A is installed in the vicinity of the ceiling in the internal space 17A. The overhead crane 18A has a trolley 20A that is provided on the traveling carriage 19A and the traveling carriage 19A and is movable along the longitudinal direction of the traveling carriage 19A. A hook 21A is suspended from the trolley 20A. A ventilation air conditioning system 36A is provided in the work house 16A, and a plurality of cameras 27A and a dosimeter 28A are installed in the internal space 17A of the work house 16A. A mobile multi-axis robot 26A equipped with an observation camera is placed on the floor of the work house 16A.

  The preparation house 16B is also surrounded by four side walls, a floor is attached to the lower ends of these side walls, and a ceiling is attached to the upper ends of these side walls. Inside the preparation house 16B, an internal space 17B surrounded by four side walls, a floor, and a ceiling is formed. Openings (not shown) are also formed on the floor and ceiling of the preparation house 16 </ b> B directly above the opening 23. This opening does not need to be arranged directly above the opening 23. Although not shown, a hydraulic pump / control panel 25 is disposed in the internal space 17B and installed on the floor of the preparation house 16B. An overhead crane 18B is installed near the ceiling in the internal space 17B. The overhead crane 18B has a trolley 20B that is provided on the traveling carriage 19B and the traveling carriage 19B and is movable along the longitudinal direction of the traveling carriage 19B. A hook 21B is suspended from the trolley 20B. A ventilation air conditioning system 36B is provided in the preparation house 16B, and a plurality of cameras 27B and a dosimeter 28B are installed in the internal space 17B of the preparation house 16B. A mobile multi-axis robot 26B equipped with an observation camera is placed on the floor of the preparation house 16B.

  After installation of the work houses 16A and 16B, an external power source is connected to the hydraulic pump / control panel 25 in each house. Devices and instruments such as the overhead crane 18A, the ventilation air conditioning system 36A, the camera 27A, and the dosimeter 28A provided in the work house 16A are operated by being supplied with electricity from the hydraulic pump / control panel 25 in the work house 16A. Devices and instruments such as the overhead crane 18B, the ventilation air conditioning system 36B, the camera 27B, and the dosimeter 28B provided in the work house 16B are operated by being supplied with electricity from the hydraulic pump / control panel 25 in the work house 16B.

  The hydraulic pumps of the hydraulic pump / control panel 25 installed in the work houses 16A and 16B are arm operations provided on the arms of the mobile multi-axis robots 26A and 26B placed in the work houses 16A and 16B. 26, and each of the cylinders provided in the cutting and disassembling device 88 and the disassembling grapple device 93 shown in FIG. 26, and controlling the hydraulic pressure to control the mobile multi-axis robots 26A and 26B and the cutting and disassembling device 88. And each operation | movement of the grapple device 93 for dismantling is controlled.

  An open / close door 78 is slidably installed on the upper surface of the ceiling of the preparation house 16B, and opens and closes an opening formed in the ceiling. An open / close door 77 (see FIG. 23) is slidably installed on the upper surface of the floor of the preparation house 16B, and opens and closes an opening formed on the floor. The opening / closing operation of the opening / closing doors 77 and 78 is performed by a motor (not shown).

  The boring device is carried into the work house (step S4). The boring device 43 is suspended from the hook 35A of the traveling crane 32 (see FIG. 3), and the internal space of the work house 16A passes through the openings formed in the ceiling and floor of the preparation house 16B and the floor of the work house 16A. It is carried into 17A and placed on the opening / closing type shielding member 15A (see FIGS. 3 and 4). At this time, the open / close doors 78 and 77 are open. The plug 41 is also suspended from the hook 35A of the traveling crane 32 and carried into the internal space 17A of the work house 16A.

  The structure of the opening / closing type shielding member 15A will be described with reference to FIG. The opening / closing type shielding member 15A is disposed below the opening 23 and above the shield plug 15 and has a pair of shielding doors 40A and 40B made of a radiation shielding material. The shielding doors 40A and 40B are installed on rails provided on a pair of beams 30 placed on the operation floor so as to be movable along the rails. The shielding doors 40A and 40B are opened and closed by a motor. The shielding doors 40A and 40B are closed. The plug 41 is installed in a hole 42 formed at the joint of the shielding doors 40A and 40B. After the boring device 43 and the plug 41 are carried into the work house 16A, the open / close doors 78 and 77 are closed when the hook 35A is pulled up above the preparation house 16B.

  Boring is performed (step S5). The mobile multi-axis robot 26A connects the connector of the power cable 141 connected to the hydraulic pump / control panel 25 in the work house 16A to the boring device 43 in the work house 16A (see FIG. 5). When the boring device 43 is unloaded from the work house 16 </ b> A, the mobile multi-axis robot 26 </ b> A removes the connector of the power cable 141 from the boring device 43. The description of the connection and removal work between the power cable 141 and the boring device 43 (or a boring device 43A described later) will be omitted later. After the power cable 141 is connected to the boring device 43, boring of the upper lid 10 of the PCV 9 and the upper lid 3 of the RPV 2 is performed using the boring device 43.

  Before describing these boring processes, the structure of the boring device 43 will be described with reference to FIGS. 6, 7, 9, 10, and 11.

  The boring device 43 includes a cutting device 44, a support stand 51, clamp devices 52 and 54B, and an extension pipe supply device 60. The support stand 51 includes a base 51A and a mast member 51B attached to the base 51A and extending upward. A clamp device 52 having an inner blade shaft clamp 52A and an outer blade shaft clamp 52B is fixed to the lower end portion of the mast member 51B. The inner blade shaft clamp 52A is disposed above the outer blade shaft clamp 52B. The moving table 53A is attached to the mast member 51B so as to be movable in the vertical direction. A support member 54 is attached to the moving table 53A. Motors 56 </ b> A and 56 </ b> B are attached to the upper surface of the support member 54. The drive socket 54A is connected to the rotating shaft of the motor 56A through a gear mechanism (not shown).

  As shown in FIG. 8, the moving table 53B is disposed below the support member 54 and attached to the moving table 53A so as to be movable in the vertical direction. A connector portion 57 having a rotating shaft 57A provided therein is fixed to the moving table 53B. The rotating shaft 57A passes through the upper end portion of the connector portion 57, and the penetrating portion of the connector portion 57 is sealed to maintain airtightness. A cylindrical clamp device 54B is rotatably attached to the moving table 53B through the moving table 53B. A gear 57C rotatably attached to the moving table 53B meshes with the outer surface of the clamp device 54B. A seal is also provided between the clamp device 54B and the moving table 53B. The cutting device 44 is detachably attached to the clamp device 54B and is gripped by the clamp device 54B. Specifically, the clamp device 54B grips an outer cylinder 45 (described later) of the cutting device 44.

  As shown in FIG. 9A, the cutting device 44 includes an outer cylinder (outer blade shaft) 45, an outer blade 46, an inner blade 47, and a rotating shaft (inner blade shaft) 48. A rotating shaft 48 is disposed in the outer cylinder 45. A plurality of inner blades 47 are annularly arranged and attached to the lower end of the rotation shaft 48. A plurality of outer blades 46 surround a plurality of inner blades 47 attached to the lower end of the rotating shaft 48 and are attached to the lower end portion of the outer cylinder 45. The outer width of the outer cylinder 45 in the radial direction of the outer 46 is larger than the thickness of the outer cylinder 45 as shown in FIG. Two elongated support plates 48A extend from the rotary shaft 48 to the opposite side of the rotary shaft 48, and the respective support plates 48A are attached to the outer surface of the rotary shaft 48 so as to be vertically rotatable. A stopper member (not shown) that prevents the support plate 48A from rotating above the horizontal is fixed to the rotation shaft 48 immediately above the respective attachment position of the support plate 48A with the rotation shaft 48. A ring member 45 </ b> A is fixed to the inner surface of the outer cylinder 45 and protrudes from the inner surface of the outer cylinder 45 toward the rotation shaft 48. The inner diameter of the ring member 45A is larger than the outer diameter of the inner blade 47, and the length of the support plate 48A in the radial direction of the outer cylinder 45 is longer than ½ of the inner diameter of the ring member 45A. . Each support plate 48A is pressed against the lower surface of the corresponding stopper member by each spring member (not shown) having a weak spring force to support the weight of the support plate 48A. Yes. For this reason, when the inner cutter 47 is inserted into the outer cylinder 45 from the upper end of the outer cylinder 45 and the rotary shaft 48 is held by the outer cylinder 45, the inner cutter 47 passes through the ring member 45A and is more than the ring member 45A. It reaches below and the tip of the support plate 48A is supported on the upper surface of the ring member 45A. Since each support plate 48A does not rotate upward from the horizontal by the stopper member, each support plate 48A is supported by the ring member 45A, and as a result, the rotation shaft 48 is supported by the outer cylinder 45. An annular passage 50 through which the collected material (for example, cutting waste) passes is formed between the rotating shaft 48 and the outer cylinder 45.

  The rotating shaft 48 is longer than the outer cylinder 45 by the dimension L, and the upper end portion of the rotating shaft 45 protrudes above the upper end of the outer cylinder 45 by the dimension L.

  As shown in FIG. 8, the rotary shaft 57A is coupled to the drive socket 54A in a state where the upper end portion is inserted into the drive socket 54A. The upper end portion of the outer cylinder 45 is inserted into the clamp device 54B and is gripped by the clamp device 54B. The clamp device 54 </ b> B is a drive socket that rotates the outer cylinder 45. A gear 57C for rotating the clamp device 54B is connected to a rotation shaft of the motor 56B and meshes with a rotational force transmission mechanism (not shown) provided on the support member 54. This rotational force transmission mechanism can disengage the gear 57C when moving the moving table 53B along the moving table 53A.

  When the upper end portion of the outer cylinder 45 is held by the clamp device 54B, the upper end portion of the rotating shaft 48 of the cutting device 44 is connected to the lower end portion of the rotating shaft 57A.

  The recovered material discharge port 58 is provided in the connector portion 57 and communicates with an annular passage 57B formed between the connector portion 57 and the rotating shaft 57A (see FIG. 8). The annular passage 57B communicates with the annular passage 50 in the cutting device 44. A flexible transfer duct 59 connected to the recovered material discharge port 58 is connected to a recovery container (not shown) placed on the base 51A.

  The extension pipe supply device 60 includes an extension pipe support member 61 and an extension pipe moving device 63. The extension pipe support member 61 has an extension pipe holding part 62 at its upper end (see FIG. 6). A plurality of extension tube suspending portions 64 are provided in the extension tube holding portion 62. Each extension pipe suspension part 64 has chuck holders 64A and 64B as shown in FIG. The chuck holders 64A and 64B can be moved in the vertical direction separately. In a state where the plurality of extension pipes 66 are suspended from the extension pipe holding part 62, the upper end portion of the rotation shaft (inner blade shaft) 48 of the extension pipe 66 is gripped by the chuck holder 64A, The upper end portion of the blade shaft 66A is held by the chuck holder 64B.

  As shown in FIG. 9B, the extension tube 66 has a rotating shaft (inner blade shaft) 48 in an outer cylinder 66A (outer blade shaft). Similarly to the cutting device 44, the extension pipe 66 also has two elongated support plates 48 </ b> A attached to the rotary shaft 48 so as to be rotatable in the vertical direction. Further, a stopper member (not shown) for preventing the support plate 48A from rotating above the horizontal is fixed to the rotating shaft 48, and the ring member 66C is similar to the ring member 45A on the inner surface of the outer cylinder 45. It is fixed to. The inner diameter of the ring member 66 </ b> C is larger than the outer diameter of the inner blade 47. Also in the extension pipe 66, as in the cutting device 44, each support plate 48A is pressed against the lower surface of the corresponding stopper member by each spring member (not shown) attached to the rotating shaft. Therefore, the rotating shaft 48 of the extension pipe 66 is supported by the outer cylinder 66A by the support plate 48A and the ring member 66C, and the annular passage 50A through which the collected material (for example, cutting waste) passes between the rotating shaft 48 and the outer cylinder 66A. Is formed. In the extension pipe 66, the lower end of the rotating shaft 48 is positioned above the lower end of the outer cylinder 66A by the dimension L, and the upper end of the rotating shaft 48 protrudes above the upper end of the outer cylinder 66A by the dimension L.

  The extension pipe moving device 63 includes a rotating body 63A, an arm 65C, and a gripping portion 65 (see FIG. 7). The rotation shaft 62A is rotatably attached to the extension tube holding portion 62 and extends downward from the extension tube holding portion 62. A rotating body 63A is attached to the rotating shaft 62A. The arm 65C is attached to the rotating body 63A, and the gripping portion 65 is provided at the tip of the arm 65C. As the rotating body 63A turns in the horizontal direction, the arm 65C also turns in the horizontal direction. The grip 65 has arm clamps 65A and 65B provided at the tip of the arm 65C (see FIG. 11). The arm clamp 65A is located above the arm clamp 65B.

  The boring processing of the upper lids 10 and 3 will be described. The boring device 43 is placed on the shielding door 40B out of the closed shielding doors 40A and 40B, and the outer blade 46 and the inner blade 47 of the cutting device 44 are formed in one hole 42 formed in the shielding door 40B. Located directly above. The moving table 53 </ b> A is lowered and the outer blade 46 and the inner blade 47 are inserted into the holes 42. When the motor 56A rotates, the drive socket 54A is rotated, the rotation shafts 57A and 48 connected to the drive socket 54A are rotated, and the inner blade 47 is rotated. When the motor 56B rotates, the gear 57C and the clamp device 54B which is a drive socket are rotated, the outer cylinder 45 connected to the clamp device 54B is rotated, and the outside 46 is turned. With the inner blade 47 and the outer blade 46 being rotated, the moving table 53A is gradually lowered along the mast member 51B. The shield plug 15 is gradually cut by the rotation of the inner blade 47 and the outer blade 46, and eventually a through hole is formed in the shield plug 15. A cut piece (a kind of collected material) of the shield plug 15 passes through the annular passages 50 and 57B, the collected material discharge port 58 and the transfer duct 59 by driving a suction device (not shown) provided in the transfer duct 59. It is collected in a collection container. When the outer cylinder 45 is rotating, the clamp device 52 (specifically, the outer blade shaft clamp 52B) does not hold the outer cylinder 45.

  When the shield plug 15 is cut by the cutting device 44 rotating while the moving table 53A is lowered, and the clamp device 54B is lowered to the position of the clamp device 52 (see FIG. 12A), the moving table 53A stops being lowered. Then, the rotation of the motors 56A and 56B is stopped. And the upper end part of the outer cylinder 45 is hold | gripped with the outer blade shaft clamp 52B. When the clamp device 54B is lowered to the position of the clamp device 52, the inner blade shaft clamp 52A and the outer blade shaft clamp 52B are arranged around the clamp device 54B without being in contact with the moving base 53B and the clamp device 54B. . The transfer duct 59 having flexibility and connected to the recovered material discharge port 58 also descends as the moving table 53A descends.

  Next, the clamping device 54B holding the outer cylinder 45 is released, and the moving table 53B is directed upward so that the upper end of the rotary shaft 48 of the cutting device 44 is exposed while the position of the moving table 53A is maintained. To move it by a predetermined dimension. The inner blade shaft clamp 52A grips the upper end portion of the rotating shaft 48 that is connected to the rotating shaft 57A and exposed (see FIG. 12B).

  The moving table 53A is raised along the mast member 51B so that the clamp device 54B is located above the extension pipe suspension part 64 provided in the extension pipe holding part 62. Since the rotary table 57A is pulled up by the movement of the moving table 53A, the rotary shaft 57A is separated from the rotary shaft 48. With the gripping part 65, one extension pipe 66 suspended from the extension pipe suspension part 64 is gripped. At this time, the upper end portion of the rotation shaft 48 of the extension pipe 66 is gripped by the arm clamp 65A, and the upper end portion of the outer cylinder 66A is gripped by the arm clamp 65B (see FIG. 12C).

  The rotating shaft 62A is rotated to turn the rotating body 63A. The arm 65C rotates in the horizontal direction, and the extension pipe 66 gripped by the arm clamps 65A and 65B is moved to a position directly above the cutting device 44 gripped by the clamp device 52 (see FIG. 12D). Then, the moving table 53A is lowered, and the upper end portion of the rotating shaft 48 of the extension pipe 66 is connected to the lower end portion of the rotating shaft 57A. After the rotation shaft 48 is connected to the rotation shaft 57A, the arm clamp 65A is separated from the upper end portion of the rotation shaft 48 of the extension pipe 66.

  The moving table 53B is moved downward, the upper end portion of the outer tube 66A of the extension pipe 66 is inserted into the clamp device 54B, and the upper end portion is gripped by the clamp device 54B (see FIG. 13A). At this time, the rotation shaft 48 of the extension pipe 66 is connected to the rotation shaft 57A. After gripping the outer cylinder 66A with the clamp device 54B, the arm clamp 65B is separated from the upper end of the outer cylinder 66A.

  The moving table 53B is moved upward on the moving table 53A without moving the moving table 53A (see FIG. 13B). Thereby, the outer cylinder 66A is lifted upward.

  The moving table 53A is moved downward, and the lower end portion of the rotating shaft 48 of the extension pipe 66 is connected to the upper end portion of the rotating shaft 48 of the cutting device 44 held by the inner blade shaft clamp 52A (FIG. 13). (See (C)). The connection between the lower end portion of the rotating shaft 48 of the extension tube 66 and the upper end portion of the rotating shaft 48 of the cutting device 44 is performed by a known connecting structure that is detachable. After the two rotary shafts 48 are connected, the inner blade shaft clamp 52A is separated from the upper end portion of the rotary shaft 48 of the cutting device 44.

  The moving table 53B is moved downward without moving the moving table 53A, and the lower end of the outer cylinder 66A is connected to the upper end of the outer cylinder 45 held by the outer blade shaft clamp 52B. Thereafter, the outer blade shaft clamp 52B is separated from the upper end portion of the outer cylinder 45 (see FIG. 13D).

  Thus, the connection of the extension pipe 66 to the cutting device 44 is completed.

  The connection between the lower end portion of the outer cylinder 66A and the upper end portion of the outer cylinder 45 will be specifically described with reference to FIG. A plurality of pin-like connecting members 45B are provided at the connecting portion at the upper end of the outer cylinder 45 (see FIG. 10A). These connecting portions 45B are provided at equal intervals in the circumferential direction of the outer cylinder 45. Each connecting member 45B is pressed from the inside to the outside of the outer cylinder 45 by a spring. The surface of the outer end portion of each connecting member 45B is processed into a hemispherical shape. A plurality of through holes 66D having an inner diameter that is the same as the outer diameter of the connecting member 45 are formed in the connecting portion at the lower end portion of the outer cylinder 66A in the circumferential direction. These through holes 66 </ b> D are formed in the circumferential direction of the outer cylinder 66 </ b> A at the same interval as that of the connecting member 45 </ b> B provided in the outer cylinder 45. A curved surface is formed on the inner surface of the lower end portion of the outer cylinder 66A from the lower end of the outer cylinder 66A toward the through hole 66D.

  As the moving base 53B descends, the outer cylinder 66A moves downward, and the upper end of the outer cylinder 45 is inserted into the lower end of the outer cylinder 66A. When the curved surface formed on the inner surface of the lower end portion of the descending outer cylinder 66A comes into contact with the hemispherical outer surface of the connecting member 45B provided on the upper end portion of the outer cylinder 45, the curved surface as the outer cylinder 66A descends. Presses the connecting member 45B toward the inner side of the outer cylinder 45, overcomes the pressing force to the outside by the spring, and the connecting member 45B moves toward the inner side of the outer cylinder 45. When the through hole 66D is lowered to the position of the connecting member 45B, the connecting member 45B pressed outward by the spring is inserted into the through hole 66D. As a result, as shown in FIG. 10B, each connecting member 45B is inserted into each through hole 66D, and the outer cylinder 45 and the outer cylinder 66A are connected.

  Thereafter, the moving table 53A is gradually lowered from the state of FIG. 13D while rotating the motors 56A and 56B, and the cutting of the shield plug 15 by the inner blade 47 and the outer blade 46 is resumed. When the clamp device 54B is lowered again to the position of the inner blade shaft clamp 52A, the additional operation of the extension pipe 66 shown in FIGS. 12 (A) to 12 (D) and FIGS. 13 (A) to 13 (D) is performed. Are repeated, and each of the upper lids 10 and 3 is cut by the inner blade 47 and the outer blade 46 to form a through hole in each of the upper lids 10 and 3 (see FIG. 5). When the through hole is formed in the upper lid 3, the rotation of the motors 56A and 56B and the lowering of the moving table 53A are stopped.

  The inner blade is pulled out and the boring device is retracted (step S6). In step S5, the shield plug 15 and the upper lids 10 and 3 are cut to shield the outer cylinders 45 and 66A out of the cutting device 44 and the extension pipe 66 connected through the shield plug 15 and the upper lids 10 and 3. The rotary shaft 48 of the cutting device 44 and the rotary shaft 48 of the extension pipe 66 are pulled out while leaving the plug 15 and the top lids 10 and 3 penetrating. The pulling operation of these rotating shafts 48 will be described with reference to FIGS.

  When the cutting of the upper lid 3 by the cutting device 44 is completed, it is assumed that the lowered moving table 53A is in the state shown in FIG. In this state, the outer blade shaft clamp 52B grips the upper end portion of the outer tube 66A of the extension tube 66 located at the uppermost position in the shield plug 15.

  The clamp device 54B is moved away from the outer cylinder 66A, and the moving table 53B is moved upward without raising the moving table 53A. By this movement, the clamp device 54B moves upward while being separated from the outer cylinder 66A (see FIG. 14B). At this time, since the rotation shaft 48 of the extension pipe 66 is connected to the rotation shaft 57A, the rotation shaft 48 also moves upward by the amount of the movement base 53B.

  As shown in FIG. 14C, the moving table 53A is raised along the mast member 51B until it is positioned above the arm 65C. The rotating shaft 48 of the extension tube 66 is pulled out from the outer cylinder 66A, and the rotating shaft 48 of the cutting device 44 connected to the rotating shaft 48 is also raised to reach the outer cylinder 66A from the inner cylinder 45. As described above, the support plate 48A is installed on each rotary shaft 48 so as to be able to rotate in the vertical direction, and the length in the radial direction of the outer cylinder of each stopper member attached to each rotary shaft is set. For example, the length is 1/4 of the inner diameter of the ring members 45A and 66C. For this reason, when the rotating shaft 48 of the extension pipe 66 located at the uppermost position in the shield plug 15 is pulled out, the support plate 45A of the cutting device 44 faces downward when it hits the ring member 66C of the extension pipe 66 located at the upper side. By rotating, each support plate 45A of the cutting device 44 can easily pass through the ring member 66C, and each stopper member of the cutting device 44 can also easily pass through the ring member 66C. When a plurality of extension pipes 66 are connected to the cutting device 44 in step S5, when the rotary shaft 48 of the extension pipe 66 located at the uppermost position in the shield plug 15 is pulled out, the other extension pipes 66 located at the lower side are removed. Similarly to the support plate 48A of the cutting device 44, each support plate 48A provided on the rotary shaft 48 also rotates downward, together with each stopper provided on the rotary shaft 48 of the other extension pipe 66, upward. It is possible to easily pass through the ring member 66C of the extension pipe 66 that is positioned.

  Therefore, as described above, the rotation shaft 48 of the extension pipe 66 located in the uppermost position in the shield plug 15 can be pulled out from the outer cylinder 66A, and the rotation shaft 48 of the cutting device 44 can also be pulled out from the outer cylinder 45. . After the moving table 53A is raised until it is positioned above the arm 65C, the cutting device 44 protrudes upward from the upper end of the outer cylinder 66A. When the extension pipe 66 is connected, the upper end portion of the rotation shaft 48) of the other extension pipe 66 is gripped by the inner blade shaft clamp 52A (see FIG. 14C).

  The rotary shaft 48 of the extension pipe 66 that has been lifted and pulled out from the outer cylinder 66A, and the rotary shaft 48 of the cutting device 44 (or the rotary axis 48 of another extension pipe 66) existing in the outer cylinder 66A. Is released (see FIG. 14D). Thereafter, the rotary shaft 62A and the arm 65C are rotated to rotate the arm clamp 65A to the position of the extracted rotary shaft 48, and the upper end portion of the rotary shaft 48 is gripped by the arm clamp 65A. The connection state between the rotation shaft 48 of the extension tube 66 pulled out from the outer tube 66A and the rotation shaft 48 of the cutting device 44 (or the rotation shaft 48 of another extension tube 66) existing in the outer tube 66A is as follows. After the release, the rotary shaft 48 of the cutting device 44 (or other extension pipe 66) existing in the outer cylinder 66A located in the uppermost position in the shield plug 15 is moved upward by the pair of support plates 48A. It is held by the ring member 66C of the outer cylinder 66A located at the position. For this reason, dropping of the rotating shaft 48 existing in the outer cylinder 66A left in the shield plug 15 and the like is prevented.

  The moving table 53A is further raised. As the moving table 53A rises, the rotary shaft 57A rises together with the drive socket 54A, and the connection between the rotary shaft 48 gripped by the arm clamp 65A and the rotary shaft 57A is released (see FIG. 15A).

  The rotary shaft 62A is rotated to pivot the arm 65C toward the extension pipe supply device 60, and the upper end portion of the rotary shaft 48 held by the inner blade shaft clamp 52A is suspended from the extension pipe provided in the extension pipe holding section 62. Move to the position of the lowering portion 64. The upper end portion of the rotating shaft 48 is gripped by the chuck holder 64A of the extension tube suspending portion 64 (see FIG. 15B). The inner blade shaft clamp 52A is separated from the rotating shaft 48.

  The moving table 53A is lowered, and the lower end of the rotation shaft 57A protrudes above the upper end of the outer cylinder 66A whose upper end is gripped by the outer blade shaft clamp 52B and is gripped by the inner blade shaft clamp 52A. It connects with the upper end part of the axis | shaft 48 (refer FIG.15 (C)). The inner blade shaft clamp 52A is separated from the rotating shaft 48.

  When a plurality of extension pipes 66 are sequentially connected to the cutting device 44 in step S5, the rotation shafts shown in FIGS. 14 (A) to 14 (D) and FIGS. 15 (A) to 15 (C). The extraction procedure 48 is repeated until the rotating shaft 48 of the cutting device 44 is gripped by the chuck holder 64A of the extension pipe suspension 64.

  Thus, the extraction of all the rotating shafts 48 from the outer cylinder is completed. Thereafter, the boring device 43 located on the opening / closing type shielding member 15A moves on the floor of the work house 16A and is retracted to the corner of the work house 16A.

  The inside of the RPV is observed (step S7). As shown in FIG. 16, the pipe 68 </ b> A connected to the ventilation / air conditioning / water injection system 69 is connected to the upper end of the outer cylinder 66 </ b> A located at the uppermost position in the shield plug 15. The connected outer cylinders 66A and 45 pass through the shield plug 15 and the upper lids 10 and 3, respectively. The lower end of the outer cylinder 45 located at the lowest position reaches the RPV 2. After the gas in the RPV 2 is sucked and processed by the ventilation air conditioning / water injection system 69, the camera and the dosimeter 68 are inserted into the RPV 2 through the pipe 68A and the outer cylinders 66A and 45 (see FIG. 16), The image information obtained by photographing and the dose measurement value in the RPV 2 are output. The output image information and the measured dose value are displayed on a display device (not shown) installed in a safe place outside the work house 16A.

  An object to be drilled in the RPV is determined (step S8). Since the steam dryer 7 is shown in the display device, the operator first determines the steam dryer 7 and the steam separator 6 as the boring objects, and performs boring processing by the boring device 43 targeting these. Decide that. Then, the operator inputs a command to carry out the boring process to the hydraulic pump / control panel 25 from a control room provided on the ground.

  Boring to the core is performed (step S9). The plug 41 installed in the hole 42 formed at the joint of the shielding doors 40A and 40B is extracted by the mobile multi-axis robot 26A. The boring device is driven until a drive command is output from the hydraulic pump / control panel 25 (particularly, the control panel 25) to the boring device 43 and the inner blade 47 and the outer blade 46 of the boring device 43 are positioned directly above the hole 42. 43 is moved. Similarly to step S5, the motors 56A and 56B are rotated to lower the moving table 53A, and the extension plug 66 is added, and the inner blade 47 and the outer blade 46 are rotated to rotate the shield plug 15 along the central axis of the RPV 2. Boring is performed on the upper lids 10, 3, the steam dryer 7 and the steam / water separator 6 (see FIG. 16). When the inner blade 47 and the outer blade 46 reach below the steam / water separator 6, the rotation of the motors 56A and 56B and the lowering of the moving table 53A are stopped.

  The inner blade is pulled out and the boring device is retracted (step S10). Similarly to step S6, the drawing procedure of the rotating shaft 48 shown in FIGS. 14A to 14D and FIGS. 15A to 15C is repeated, so that each rotating shaft 48 and inner cutter 47 is pulled out from the outer cylinder 66A located at the uppermost position in the shield plug 15, and then the boring device 43 is retracted in the work house 16A. By connecting the rotary shafts 48 and the inner blades 47, the outer cylinders 66A and the outer cylinders 45 connected to each other are connected to the center of the RPV 2 from the shield plug 15 between the lower end of the steam-water separator 6 and the upper end of the core 4. It remains arranged along the axis (see FIG. 16).

The inside of the core is observed (step S11). The camera and dosimeter 68 are inserted to the position below the steam / water separator 6 through the outer cylinders 66A and the outer cylinders 45 disposed in the steam / water separator 6 and the steam dryer 7 (FIG. 17). reference). The state of the core 4 is photographed by the camera and the dosimeter 68, and the dose of the core 4 is measured. The image information obtained by the imaging and the measured dose are displayed on the display device installed outside the work house 16A. Since the display device shows a state in which the core 4 is melted, the operator determines that it is necessary to carry out the molten nuclear fuel material. The plug 41 is installed by the mobile multi-axis robot 26A at the upper end of the outer cylinder 66A positioned at the uppermost position among the outer cylinders 66A arranged on the central axis of the RPV 2, and seals the outer cylinder 66A. Based on the measured dose, the injection amount of the shielding body in the next step S12 is determined.

  The shielding body is injected into the core (step S12). The shield supply device 71 is suspended from the hook 35A of the traveling crane 32, and is carried into the internal space 17B of the preparation house 16B through the opening of the ceiling of the preparation house 16B that is opened and opened. After the shield body supply device 71 is carried into the internal space 17B, the open / close door 78 is closed. The shielding body supply device 71 is suspended from the hook 21B of the overhead crane 18B in the internal space 17B by the mobile multi-axis robot 26B existing in the internal space 17B. Thereafter, the opening / closing door 77 is opened, and the shielding body supply device 7 suspended from the hook 21B is opened at the floor of the preparation house 16B and the opening of the ceiling of the work house 16A. And is carried into the internal space 17A of the work house 16A. After the shield body supply device 71 is carried into the internal space 17B, the open / close door 78 is closed. The shield supply device 71 is suspended by the mobile multi-axis robot 26A on the hook 21A of the overhead crane 18A, transported to a predetermined location on the floor of the work house 16A, and installed there (see FIG. 18). . The mobile multi-axis robot 26A removes the plug 41 installed on the outer cylinder 66A disposed on the central axis of the RPV 2. The injection pipe 72 connected to the shielding body supply device 71 is connected to the upper end of the outer cylinder 66A disposed along the central axis of the RPV 2 and disposed at the uppermost position in the shielding plug 15. Two regions isolated from each other are formed in the shielding body supply device 71. A small iron ball 70A that is a granular shielding body is filled in one region, and iron powder 70B that is a powder shielding body is filled in another region. Filled.

  The iron ball 70A is injected into the core 4 from the shielding body supply device 71 through the injection pipe 72 and the connected outer cylinders 66A and the outer cylinder 45 arranged along the central axis of the RPV 2. The injected iron balls 70 </ b> A are filled between the fuel assemblies remaining in the core 4 and regions where the nuclear fuel material has melted and the fuel assemblies have melted. When a predetermined amount of the iron ball 70A is injected and reaches the upper end of the core 4, the injection of the iron ball 70A is stopped, and the iron powder 70B passes through the outer cylinder 66A and the outer cylinder 45 from the shielding body supply device 71. Then, it is injected onto the packed bed of iron balls 70A formed in the core 4 (see FIG. 18). An amount of iron powder 70B corresponding to an iron plate having a thickness of 500 mm is injected. The injection state of the iron ball 70A and the iron powder 70B is photographed by the camera 78, and the radiation dose at the time of the injection of the iron ball 70A and the iron powder 70B is measured by the dosimeter 68. The injection state of the shielding body can be monitored by an image output from the camera 78, the radiation shielding effect by the injected shielding body is confirmed based on the measured radiation dose, and the core 4 is confirmed based on the radiation shielding effect. Adjust the injection amount of the shielding body. The camera and dosimeter 78 are protected from the injecting shield.

  The outer cylinder is collected and the boring device is carried out (step S13). The pipes 82 and 68 are removed using the mobile multi-axis robot 26A. The boring device 43 is arranged on the outer cylinder 66A arranged on the central axis of the RPV 2, and the outer cylinder 66A is sequentially pulled up using the boring device 43 and collected in the extension pipe supply device 60. Finally, the outer cylinder 45 Pull up and collect.

  The operation | work which collect | recovers the outer cylinders 45 and 66A is demonstrated using FIG.19 and FIG.20. In order to make the explanation easy to understand, the outer cylinders 66A located at the uppermost position in the seal plug 15 (arranged on the central axis of the RPV 2 in FIG. 18), in which the rotary shafts 48 are all pulled out in steps S6 and S10. It is assumed that the upper ends of the outer cylinders 66A and the other outer cylinders 66A arranged at positions away from the central axis of the RPV 2 are in the state shown in FIG. In this state, the outer cutter shaft clamp 52B grips the upper end portion of the outer cylinder 66A located at the uppermost position in the shield plug 15 on the central axis of the RPV 2.

  The moving table 53A is lowered, and the upper end portion of the outer cylinder 66A protruding upward from the shield plug 15 is gripped by the clamp device 54B (see FIG. 19B). The outer blade shaft clamp 52B is separated from the outer cylinder 66A.

  As shown in FIG. 19C, the moving table 53A is raised along the mast member 51B until it is positioned above the arm 65C. The outer cylinder 66A gripped by the clamp device 54B is pulled out from the shield plug 15, and the lower end of the outer cylinder 66A reaches above the outer blade shaft clamp 52B. In this state, the outer cylinder 45 connected to the outer cylinder 66A (or another outer cylinder 66A when a plurality of extension pipes 66 are connected to the cutting device 44 in step S10) is placed around the upper end of the outer cylinder 45A. There is a blade shaft clamp 52B. The outer cutter shaft clamp 52B grips the upper end portion of the outer cylinder 45 (or other outer cylinder 66A).

  With the outer blade shaft clamp 52B gripping the upper end of the outer cylinder 45 (or another outer cylinder 66A), the moving table 53A is further raised. The connection between the lower end of the outer cylinder 66A gripped by the clamp device 54B and the upper end of the outer cylinder 45 (or other outer cylinder 66A) gripped by the outer blade shaft clamp 52B is released, and the grip is held by the clamp device 54B. The outer cylinder 66 is separated from the outer cylinder 45 (or another outer cylinder 66A) gripped by the outer blade shaft clamp 52B (see FIG. 19D). Thereafter, the rotary shaft 62A and the arm 65C are rotated to turn the arm clamp 65B to the position of the extracted outer cylinder 66A, and the upper end portion of the outer cylinder 66A is gripped by the arm clamp 65B.

  The release of the connection state between the outer cylinder 66A gripped by the clamp device 54B and the outer cylinder 45 (or another outer cylinder 66A) gripped by the outer blade shaft clamp 52B is specifically described with reference to FIG. explain. The connecting member release clamp 52C is disposed above the outer blade shaft clamp 52B and attached to the outer blade shaft clamp 52B. As shown in FIG. 19C, when the upper end of the outer cylinder 45 (or another outer cylinder 66A) is gripped by the outer blade shaft clamp 52B, the connecting member release clamp 52C is opposed to each connecting member 45B. When the outer blade shaft clamp 52B comes into contact with the outer surface of the outer cylinder 45 (or another outer cylinder 66A), the outer cylinder 66A in which the hemispherical tip of each connecting member 45B is gripped by the clamping device 54B by the connecting member release clamp 52C. It is pushed into the through hole 66D formed in the above. In this state, when the moving table 53A is lifted as shown in FIG. 19D, the outer cylinder 66A that is gripped and lifted by the clamp device 54B is lifted because the tip of each connecting member 45B is hemispherical. Each connecting member 45B is moved further inward. For this reason, the tip of each connecting member 45B comes out of each through-hole 66D of the outer cylinder 66A, and the outer cylinder 66A gripped by the clamp device 54B is moved upward. It reaches above the upper end of the outer cylinder 45 (or another outer cylinder 66A) gripped by 52B. In this manner, the connection state between the outer cylinder 66A gripped by the clamp device 54B and the outer cylinder 45 (or another outer cylinder 66A) gripped by the outer blade shaft clamp 52B is released.

  The clamp device 54B is moved away from the outer cylinder 66A, and the moving table 53A is further raised. As the moving table 53A rises, the clamp device 54B also rises, and the clamp device 54B reaches above the upper end of the outer cylinder 66A held by the arm clamp 65B (see FIG. 20A).

  The rotary shaft 62A is rotated to turn the arm 65C toward the extension pipe supply device 60, and the upper end of the outer cylinder 66A gripped by the outer blade shaft clamp 52B is suspended from the extension pipe provided in the extension pipe holding section 62. Move to the position of the lowering portion 64. The upper end portion of the outer cylinder 66A is gripped by the chuck holder 64B of the extension tube suspending portion 64 (see FIG. 20B). The moving table 53A is lowered and the upper end of the outer cylinder 45 (or another outer cylinder 66A) protruding upward from the shield plug 15 is grasped by the clamp device 54B by the outer blade shaft clamp 52B (see FIG. (See FIG. 20B). The outer cutter shaft clamp 52B is separated from the outer cylinder 45 (or another outer cylinder 66A). Then, the inner blade shaft clamp 52A is separated from the outer cylinder 66A suspended from the extension pipe suspension 64.

  When a plurality of extension pipes 66 are sequentially connected to the cutting device 44 in step S5, the outer cylinder shown in FIGS. 19 (A) to 19 (D) and FIGS. 20 (A) to 20 (C). The drawing procedure is repeated until the outer cylinder 45 of the cutting device 44 is gripped by the chuck holder 64A of the extension pipe suspending portion 64.

  Insertion plugs 79A and 79B (see FIG. 22) having screws formed on the side surfaces are inserted into through holes formed in the upper lids 10 and 3 on the central axis of the RPV 2, and screws are inserted into the upper lids 10 and 3, respectively. Can be attached by. The boring device 43 is moved onto another outer cylinder 66A attached to the shield plug 15, and the boring device 43 is used to perform the above-described FIGS. 19A to 19D and 20A to 20A. The outer cylinder 66A and the outer cylinder 45 are sequentially pulled up and collected from the shield plug 15 by the procedure for extracting the outer cylinder shown in FIG. Thereafter, as described above, the fitting plugs 79A and 79B are inserted into the other through holes formed in the upper lids 10 and 3, respectively, and attached to the upper lids 10 and 3, respectively.

  Thereafter, the door 77 is opened, the boring device 43 is suspended from the hook 21B of the overhead crane 18B by using the mobile multi-axis robot 26A, and a winding device (not shown) provided on the trolley 20B is driven. The boring device 43 is raised into the internal space 17B. This boring device 43 is placed on the floor of the preparation house 16B. The open / close door 77 is closed and the open / close door 78 is opened, and the boring device 43 in the internal space 17B is suspended from the hook 35A of the traveling crane 32 using the mobile multi-axis robot 26A. The boring device 43 is carried out of the preparation house 16B by raising the hook 35A. After the boring device 43 is unloaded, the open / close door 78 is closed.

  The shield plug is carried out (step S14). The shielding doors 40A and 40B of the openable shielding member 15A are opened. The shield plug 15 is carried out from the work house 16A to the outside of the preparation house 16B through the preparation house 16B using the overhead crane 18B and the traveling crane 32, similarly to the boring device 43 in step S13. After the shield plug 15 is unloaded, the shielding doors 40A and 40B are closed.

  The upper lid of the PCV is cut and carried out (step S15). Before cutting the upper lid 10 of the PCV, four additional floors 73 and one turntable 75 are installed as shown in FIG. Each additional floor 73 is provided with a 1/4 circle guide rail 74 on the upper surface, and a 1/4 circle arc-shaped cutout portion 73 </ b> A is formed inside the guide rail 74. Similarly to the loading of the shielding body supply device 71 into the work house 16A in step S12, each additional floor 73 and turntable 75 sequentially opens and closes the open / close doors 78 and 77 using the traveling crane 32 and the overhead crane 18B. Go through the preparation house 16B and carry it into the work house 16A. In the work house 16A, each additional floor 73 is suspended and moved by the overhead crane 20A, and is installed on the floor of the work house 16A so that the guide rail 74 is located on the opening 23 side. When the installation of the four additional floors 73 is completed, the guide rails 74 of the four additional floors 73 are connected to form one circle and are arranged concentrically with the opening 23. The turntable 75 moved by the overhead crane 20 </ b> A is installed on the guide rail 74 so as to be movable along the guide rail 74.

  The cutting operation of the upper lid 10 of the PCV 9 and the unloading of the cut piece 10A of the cut upper lid 10 will be specifically described with reference to FIGS. 22, 23, and 24. FIG.

  A storage container 80 (see FIG. 22) storing the cutting device 81 is suspended from the hook 35B of the traveling crane 32, and the opening / closing door 78 is opened and released, and the preparation house is opened through the opening formed in the ceiling of the preparation house 16B. It is carried into the internal space 17B of 16B. After the hook 35B is pulled up, the open / close door 78 is closed. Thereafter, the storage container 80 suspended from the overhead crane 18B is carried into the work house 16A in the same manner as the shielding body supply device 71 in step S12. Using the mobile multi-axis robot 26A, the lid of the storage container 80 is opened and the cutting device 81 in the storage container 80 is suspended from the overhead crane 18A. The cutting device 81 is lifted from the storage container 80 by the overhead crane 18A and placed on the turntable 75 in the work house 16A.

  The cutting device 81 includes a carriage 82, a telescopic tube 84, an arm 85, and a cutter 86 (see FIG. 23). A mast member 83 is installed on the carriage 82 and extends upward. An expandable tube 84 that can expand and contract in the axial direction is attached to the mast member 83 and extends downward. A bendable arm 85 is attached to the lower end of the telescopic tube 84, and a cutter 86 is attached to the tip of the arm 85.

  Electromagnets 87 are suspended from the respective hooks 21A of the two trolleys 20A provided on the overhead crane 18A. Each hook 21 </ b> A is lowered to attract each electromagnet 87 to the upper surface of the upper lid 10 of the PCV 9. In a state where the upper lid 10 is attracted to the electromagnets 87 suspended from the hooks 21A, the telescopic tube 84 and the arm 85 are operated to bring the cutter 86 into contact with the cutting position on the upper surface of the upper lid 10 (see FIG. 23). The cutter 86 is pressed against the cutting position, and the turntable 75 on which the cutting device 81 is placed is moved along the guide rail 74. As the turntable 75 moves, the ceiling portion of the upper lid 10 is cut by the cutter 86.

  By driving a winding device (not shown) provided in each trolley 20A and pulling up each hook 21A, the cut circular piece 10A of the upper lid 10 moves to the internal space 17A of the work house 16A. (See FIGS. 22 and 24). An opening 10B is formed in the upper lid 10 from which the cut piece 10A is pulled up. The pulled cut piece 10A is stored in a carry-out container 76 placed on the floor of the work house 16A, and each electromagnet 87 is removed from the cut piece 10A. The mobile multi-axis robot 26A attaches a lid to the carry-out container 76, and the carry-out container 76 is suspended from the hook 21A of the overhead crane 18A. The carry-out container 76 is moved to the central axis of the RPV 2 and is suspended from the hook 21B of the overhead crane 20B. As the hook 21B rises, the carry-out container 76 that stores the cut piece 10A is pulled up into the preparation house 16B and placed on the floor of the preparation house 16B. The opening / closing door 77 is closed and the opening / closing door 78 is opened. The carry-out container 76 storing the cut pieces 10A in the preparation house 16B is suspended from the hook 35A of the traveling crane 32 and carried out of the preparation house 16B (see FIG. 22).

  The upper lid of the RPV is carried out (step S16). When a bolt (not shown) for attaching the upper lid 3 to the RPV 2 cannot be removed, the upper lid 3 is attached to the upper surface of the upper lid 3 using the cutting device 81 by adsorbing the electromagnet 87 in the same manner as the upper lid 10 in step S15. The circular cut piece of the upper lid 3 is housed in a carry-out container and is carried out of the work house 16A, the preparation house 16B, and the preparation house 16B. Although not shown, after the cut piece of the upper lid 3 is carried out, the cutting device 81 is stored in the storage container 80 using the overhead crane 18A in the work house 16A, and is sealed with the lid to store the cutting device 81. The storage container 80 is moved using the overhead crane 18B and the traveling crane 32, and is carried out of the preparation house 16B.

  The steam dryer is carried out (step S17). The carrying out of the steam dryer 7 will be specifically described with reference to FIGS. 25 and 26. Similarly to the loading of the cutting device 81 in step S15, the cutting / disassembling device 88 and the disassembling grapple device 93 are separately stored in the storage container, and each storage container storing the cutting / disassembling device 88 and the disassembling grapple device 93 separately is provided. It is sequentially suspended from the hook 35B and carried into the preparation house 16B, and further suspended from the hook 21B of the overhead crane 18B and carried into the work house 16A.

  The cutting and disassembling device 88 is installed on one turntable 75 that moves on the guide rail 74, and the disassembling grapple device 93 is installed on another turntable 75 that moves on the guide rail 74. The other turntable 75 is also carried into the work house 16A in the same manner as the former turntable 75.

  Each structure of the cutting / disassembling apparatus 88 and the disassembling grapple apparatus 93 will be described with reference to FIG. The cutting and disassembling apparatus 88 includes a support member 89A, a moving table 90A, a main body 91A, an arm 92A, and a cutter 94A. A support member 89A is installed on one turntable 75 and extends upward. The moving table 90A is attached to the support member 89A so as to be movable in the vertical direction along the support member 89A. The main body 91A is installed on the moving table 90A, and the arm 92A is attached to the main body 89A. A cutter 94A is attached to the tip of the arm 91A.

  The disassembling grapple device 93 includes a support member 89B, a moving table 90B, a main body 91B, an arm 92B, and a grapple 94B. The support member 89B is installed on the other turntable 75 and extends upward. The moving table 90B is attached to the support member 89B so as to be movable in the vertical direction along the support member 89B. The main body 91B is installed on the moving table 90B, and the arm 92B is attached to the main body 89B. A cutter 94B is attached to the tip of the arm 91B.

  Each of the moving tables 90A and 90B is lowered to the lowest position along each of the support members 89A and 89B. The arms 92A and 92B are also extended downward. While sandwiching the steam dryer 7 with the grapple 94B, the steam dryer 7 is cut with the cutter 94A. The cut piece 7A of the steam dryer 7 is gripped by a grapple 94C suspended from the trolley 20A of the overhead crane 18A. The grapple 94B is separated from the cut piece 7A, and the grapple 94C is pulled up to move the cut piece 7A into the work house 16A. The cut piece 7A is moved into the carry-out container 76A placed on the floor of the work house 16A by moving the trolley 20A (see FIG. 25). Thus, the steam dryer 7 is sequentially cut using the cutter 94A and the grapple 94B, and the cut piece 7A generated by this cutting is gripped by the grapple 94C and stored in the transport container 76A. After all the cut pieces 7A of the steam dryer 7 are stored in the storage container 76A, the storage container 76A storing the cut pieces 7A is sealed with a lid in the same manner as when the storage container 76 is taken out in step S15, and the overhead crane 18A, 18B and the traveling crane 32 are carried out of the preparation house 16B.

  The steam separator is carried out (step S18). As with the carrying out of the steam dryer 7 in step S17, the steam / water separator 6 is cut using the cutting / disassembling device 88 and the grapple device 93 for disassembling, and the cut pieces of the steam / water separator 6 are stored in the transport container. It is carried out of the preparation house 16B. After the carry-out of the steam / water separator 6 is completed, the cutting / disassembling device 88 and the disassembling grapple device 93 are stored in separate storage containers, and are transferred to the outside from the preparation house 16B using the traveling crane 32 and the like.

  The shroud is carried out (step S19). A shroud 87 in which a water supply sparger (not shown) and a core spray header are attached is provided at the upper end of the core shroud 116 surrounding the core 4 (see FIG. 27). A cutting device 81A used for cutting the shroud 87 is stored in the storage container 80A. The storage container 80A is similar to the storage container 80 storing the cutting device 81 in step S15. And is carried into the work house 16A. The cutting device 81A taken out from the storage container 80A is suspended by the hook 21A of the overhead crane 18A and lowered into the RPV 2. When the cutting device 81A is lowered to the vicinity of the upper end of the shroud 87, the cutting device 81A is fixed to the inner surface of the RPV 2 using the support device 106 provided on the cutting device 81A in the same manner as the boring device 43A in step S20. The structure of the support device 106 has the same structure as the support device 106 provided in a boring device 43A shown in FIG. 29 described later.

  The structure of the cutting device 81A will be described with reference to FIG. In the cutting device 81A, an abrasive water jet head 95 is attached to the mast member 83 so as to be movable in the vertical direction. In the abrasive water jet head 95, a support member 96 is provided in an outer cylinder 103A having an outer blade 103B attached to the lower end portion, and a support plate 101 forming a horizontal hole 101A is attached to the lower end of the support member 96. 98 has a head 97 attached thereto. A cylinder 97 is attached to the support member 96, and one end of the link 100 is connected to a piston rod (not shown) connected to a piston (not shown) disposed in the cylinder 96. The other end of the link 100 is connected to the head 97 by a pin inserted into the horizontal hole 101A and movable along the horizontal hole 101A. A high pressure water supply hose 102 </ b> A and an abrasive supply hose 102 </ b> B disposed in the outer cylinder 103 </ b> A are connected to the head 97. The inner blade 104 is attached to the support member 96 with a support bar. When the piston in the cylinder 99 moves upward, the pin inserted into the horizontal hole 101A moves along the horizontal hole 101A (moves from left to right in FIG. 28), and the head 97 And the nozzle 98 moves toward the right side. Conversely, when the piston is pushed down, the pin moves from right to left, and the head 97 and nozzle 98 move in the same direction.

  The high-pressure water supplied into the head 97 from the high-pressure water supply hose 102 </ b> A and the abrasive supplied from the abrasive supply hose 102 </ b> B into the head 97 are mixed in the head 97, and the high-pressure water containing the abrasive is an injection port of the nozzle 98. Is injected from. The injection port of the nozzle 98 is disposed to face the cutting position of the shroud 87. High-pressure water containing abrasive that is ejected from the ejection port is ejected toward the shroud 87, and the shroud 87 is cut by the action of the abrasive. Since the turntable provided in the support device 106 turns, the cutting device 81 moves in the circumferential direction of the shroud 87 while jetting high-pressure water containing abrasive from the nozzle 98. In this way, the shroud 87 is cut over the entire circumference.

  The cut shroud 87 is gripped by the grapples 94C suspended from the two trolleys 20A provided on the overhead crane 18A and lifted into the work house 16A. The shroud head 87 is accommodated in the carry-out container 76B in the work house 16A. The carry-out container 76B containing the shroud 87 is carried out of the work house 16A through the preparation house 16B and out of the preparation house 16B using the overhead crane 16B and the traveling crane 32.

  A boring device is installed in the RPV (step S20). The nuclear fuel material is melted in some of the plurality of fuel assemblies loaded in the core 4. A boring device 43A is used for transporting the nuclear fuel material in the core 4. The boring device 43A is carried into the work house 16A using the traveling crane 32 and placed on the floor of the work house 16A, similarly to the boring device 43 in step S4.

  The structure of the boring device 43A will be described with reference to FIGS. In the boring device 43A, the cutting device 44 is replaced with a cutting device 44A (nuclear fuel cutting device), the clamping device 54B is replaced with a clamping device 55, the extension tube 66 is replaced with an extension tube 66B, and the moving base 53B is deleted. The separator 113 and the shield supply device 114 are newly provided. The other configuration of the boring device 43A is substantially the same as that of the boring device 43.

  The boring device 43A includes a cutting device 44A, a support stand 51, clamp devices 52 and 55, and an extension pipe supply device 60. The clamping device 52 fixed to the lower end portion of the mast member 51B is not provided with the inner blade shaft clamp 52A and the outer blade shaft clamp 52B unlike the boring device 43, and has one clamp. The support member 54 provided with the drive socket 54A is installed on a moving table 53 attached to the mast member 51B so as to be movable in the vertical direction. A is attached to the mast member 51B so as to be movable in the vertical direction. A support member 54 is attached to the moving table 53A. The drive socket 54A is connected to the rotating shaft of the motor 56A through a gear mechanism (not shown). A connector portion 57 having a rotation shaft 57 </ b> A provided therein is attached to the lower surface of the support member 54. The rotation shaft 57A is connected to the drive socket 54A.

  The boring device 43A is connected to an electrical collective cable 25A and a hydraulic collective cable 25B connected to a hydraulic pump / control panel 25 installed on the floor of the work house 16A.

  Similar to the clamp device 54B, the cylindrical clamp device 55 is rotatably attached to a connector portion 57 that does not rotate, and has a function of a drive socket. Similarly to the clamp device 54B, the clamp device 55 is connected to a rotation shaft of the motor 56B and meshes with a rotational force transmission mechanism (not shown) provided in the support member 54 and the connector portion 57. An outer cylinder 45 (described later) of the cutting device 44 </ b> A is detachably and rotatably connected to the lower end portion of the connector portion 57, and is gripped by the clamp device 55.

  As shown in FIG. 32, the cutting device 44 </ b> A has a configuration in which a spiral screw 105 is provided in the cutting device 44. The screw 105 is disposed in the outer cylinder 45 and attached to the rotating shaft 48, and is not attached to the outer cylinder 45. The screw 105 exists between the lower end and the upper end of the rotating shaft 48 and is attached to the rotating shaft 48 so as to be wound around the outer surface of the rotating shaft 48. A spiral passage 50 </ b> A through which the collected material passes is formed between the rotary shaft 48 and the outer cylinder 45. The upper end portion of the rotating shaft 48 is connected to the lower end portion of the rotating shaft 57 </ b> A in the connector portion 57. The spiral passage 50 </ b> A is formed in the connector portion 57 and communicates with an annular passage communicated with the recovered material discharge port 58.

  The extension pipe supply device 60 of the boring device 43A has a configuration in which the extension pipe moving device 63 is replaced with the extension pipe moving device 63B in the extension pipe supply device 60 of the boring device 43A. The other configuration of the extension pipe supply device 60 of the boring device 43A is the same as the configuration of the extension pipe supply device 60 of the boring device 43A. The extension pipe moving device 63B includes a rotating body 63A, an arm 65C, and a gripping portion 65D (see FIG. 31). The grip portion 65D does not have the arm clamps 65A and 65B like the grip portion 65 shown in FIG. 7, but has one clamp. A rotating body 63A is attached to a rotating shaft 62A that is rotatably attached to the extension tube holding part 62, an arm 64 is attached to the rotating body 63A, and a gripping part 65D is provided at the tip of the arm 65C.

  The extension pipe 66B suspended from each extension pipe suspension section 64 provided in the extension pipe holding section 62 of the extension pipe supply device 60 has a configuration in which a spiral screw 105 is provided on the extension pipe 66. The other structure of the extension pipe 66B is the same as that of the extension pipe 66. In the extension pipe 66B, the spiral screw 105 is disposed in the outer cylinder 66A between the lower end of the rotating shaft 48 and the upper end thereof, and is wound around the outer surface of the rotating shaft 48, like the cutting device 44A. Is attached to the rotary shaft 48. A spiral passage 50 </ b> A is also formed in the extension pipe 66 </ b> B by the screw 105.

  A transfer duct 59 that is flexible and communicates with the recovered material discharge port 58 is connected to the separation device 113, and a shield supply device 114 is connected to the separation device 113.

  The structure of the support device 106 that supports the boring device 43A in the RPV 2 will be described with reference to FIG. The support device 106 includes a turntable 107, a base 108, a cylinder 109, and a pressing member 111. Four cylinders 109 are arranged at 90 ° intervals in the circumferential direction of the circular base 108 and attached to the side surfaces of the base 108. Each cylinder 109 extends from the base 108 in all directions, and a pressing member 111 is attached to the tip of a piston rod 110 connected to a piston (not shown) disposed in each cylinder 109. A turntable 107 disposed above the base 108 is pivotably attached to the base 108. The turntable 107 is turned by a motor (not shown) provided on the base 108.

  Two guide rails 112 are arranged to extend in parallel to each other in the radial direction of the RPV 2 and are installed on the upper surface of the turntable 107. A slide base 51C is movably attached to each guide rail 112. The support stand 51 and the extension pipe supply device 60 of the boring device 43A are installed on the upper surface of the slide base 51C. The shielding body supply device 114 and the separation device 113 are installed on the upper surface of the turntable 107. Between the two guide rails 112, the turntable 107 is formed with an elongated through hole 115 into which the cutting device 44A of the boring device 43A and the extension pipe 66B are inserted. The through hole 115 extends in the radial direction from the center of the turntable 107. Although not shown, the base 108 is also formed with an elongated through hole into which the cutting device 44A and the extension pipe 66B are inserted, facing the through hole 115 formed in the turntable 107. This elongated through hole formed in the base 108 reaches the center of the base 108.

  Installation work of the boring device 43A using the support device 106 in the RPV 2 will be described. When the boring device 43A is placed on the floor of the work house 16A, the mobile multi-axis robot 26A is used to move the four winches 113A and the four pulleys 114A around the central axis of the RPV 2. Install on the top surface of 16A floor. The four winches 113A and the pulleys 114A are arranged every 90 ° in the circumferential direction of the RPV 2. The wire 115A wound around each winch 113A is attached to a suspension ring 107A attached to the base 108 by the mobile multi-axis robot 26A. In the suspension ring 107A, the attachment positions of the wires 115A are provided at four positions every 90 ° in the circumferential direction of the suspension ring 107A. The suspension ring 107A surrounds the turntable 107, and the suspension ring 107A and the turntable 107 are separated from each other.

  In a state where the four wires 115A are attached to the suspension ring 107A and the boring device 43A is placed on the support device 106, the boring device 43A is suspended from the hook 21A of the overhead crane 18A, and the boring device 43A and the support device 106 are connected. Move to the level of the operating floor just above RPV2. Thereafter, the hook 21A is removed from the boring device 43A, each winch 113A is driven to rewind the wire 115A, and the boring device 43A and the support device 106 are lowered in the RPV 2. When the support device 106 reaches the vicinity of the upper end of the core 4, the lowering of the hook 21A is stopped. Hydraulic pressure is applied to the four cylinders 109 to move the pistons in the respective cylinders 109 toward the inner surface of the RPV 2. For this reason, each piston rod 110 is also moved toward the inner surface of the RPV 2, the respective pressing members 111 are brought into contact with the inner surface of the RPV 2, and the respective pressing members 111 are pressed against the inner surface of the RPV 2. When the pressing member 111 is pressed against the inner surface of the RPV 2 with a predetermined pressure, the supply of oil into each cylinder 109 is stopped. Each pressing member 111 is pressed against the inner surface of the RPV 2 in four directions. In this way, the boring device 43A is installed in the RPV 2.

  The nuclear fuel material in the core is carried out (step S21). The removal of the nuclear fuel material will be described with reference to FIGS. A boring device 43A is used to carry out the nuclear fuel material. The support member 54 is lowered along the support stand 51, and the lower end of the cutting device 44 </ b> A is inserted into the through hole 115. The position of the cutting device 44 </ b> A in the radial direction of the RPV 2 is adjusted by moving the slide base 51 </ b> C along the guide rail 112 in the radial direction of the RPV 2. When the nuclear fuel material is carried out from the peripheral part of the core 4, the cutting device 44 </ b> A is positioned in the peripheral part of the core 4. To be located.

  When the lower end portion of the cutting device 44A, that is, the outer blade 46 and the inner blade 47 reach the upper surface of the layer of iron powder 70B filled in the core 4, in the boring device 43A, similarly to the boring device 43 in step S5, The motors 56A and 56B are rotated to rotate the rotating shaft 48 and the outer cylinder 45, respectively. With the outer blade 46 and the inner blade 47 being turned, the support member 54 is further lowered, and the turning outer blade 46 and the inner blade 47 are lowered from the layer of iron powder 70B to the region filled with the nuclear fuel material. Let

  The iron powder 70B, the iron ball 70A, the nuclear fuel material cut by the outer blade 46 and the inner blade 47, and the metal chips constituting the fuel assembly are spirally formed in the outer cylinder 45. Enter the passage 50A. The spiral screw 105 rotating together with the rotary shaft 48 exhibits the function of a screw feeder, and the iron powder 70B, the iron ball 70A, and the nuclear fuel material and the metal member cutting waste that have entered the spiral passage 50A, It moves toward the upper end of the spiral passage 50 </ b> A, and further to the separation device 113 through the annular passage in the connector portion 57, the recovered material discharge port 58 and the transfer duct 59. The screw 105 constitutes a transfer device for the cut nuclear fuel material or the like. In the separation device 113, the iron powder 70B and the iron ball 70A are separated from the nuclear fuel material and each cutting waste of the metal member using an electromagnet. Since the iron powder 70B and the iron ball 70A are magnetic materials, and the cutting scraps of the nuclear fuel material and the metal member are non-magnetic materials, the iron powder 70B and the iron ball 70A are cut into the nuclear fuel material and the metal member using an electromagnet. It can be easily separated from debris. The metal member of the fuel assembly is made of a zirconium alloy and is a nonmagnetic material. The separated iron powder 70 </ b> B and iron ball 70 </ b> A are guided into the shielding body supply device 114. Each of the nuclear fuel material from which the iron powder 70B and the iron ball 70A have been removed and the metal chips are housed in a fuel cask 115A placed on the separation device 113 side on the turntable 107. When the fuel cask 115A is filled with cutting waste, the nuclear fuel material and the metal member cutting waste are supplied from the separation device 113 into the empty fuel cask 115A placed next to the fuel cask 115A.

  The fuel cask 115A filled with cutting waste is lifted by the hook 21A of the overhead crane 18A and stored in the carry-out container 76D in the work house 16A. When the fuel cask 115A transferred from the turntable 107 and filled with the cutting waste is stored in the discharge container 76D in a predetermined number, the discharge container 76D is similar to the discharge of the storage container 76 in step S15. , Sealed with a lid, and carried out of the preparation house 16B by the overhead cranes 18A, 18B and the traveling crane 32.

  When the clamp device 55 holding the outer cylinder 45 is lowered to the vicinity of the clamp device 52 by cutting the nuclear fuel material and the metal member of the fuel assembly in the core 4, the moving table 53 is lowered and the motors 56A and 56B are rotated. The extension tube 66B is connected to the cutting device 44A of the boring device 43A in the same manner as the connection of the extension tube 66A to the cutting device 44 of the boring device 43 in step S5.

  The connecting operation of the extension pipe 66B to the cutting device 44A will be specifically described with reference to FIG.

  When the cutting device 44A that rotates while lowering the moving table 53 cuts the nuclear fuel material and the metal members of the fuel assembly and the clamping device 55 is lowered to the vicinity of the clamping device 52 (see FIG. 35A), the moving table The descent of 53 is stopped and the rotation of the motors 56A and 56B is stopped. The clamping device 52 grips the outer cylinder 45 of the cutting device 44A, and the clamping device 55 that has held the outer cylinder 45 is opened. Thereafter, the moving table 53 is raised to a position above the extension pipe supply device 60 (see FIG. 35B). The rotating body 63A is turned in a state where one extension pipe 66B suspended from the extension pipe suspension section 64 is gripped by the grip section 65D of the extension pipe moving device 63B. The arm 65C rotates in the horizontal direction, and the extension pipe 66B grasped by the grasping portion 65D is moved to a position just above the cutting device 44 grasped by the clamp device 52 (see FIG. 35C). The moving table 53 is lowered, and the upper end portion of the extension pipe 66B grasped by the grasping portion 65D is grasped by the clamp device 55. The grip portion 65D is separated from the extension pipe 66B, and the arm 65C is turned to return to the original position (see FIG. 35D). At this time, the outer tube 66A of the extension tube 66B is detachably connected to the connector portion 57, and the upper end portion of the extension tube 66B rotating shaft 48 is connected to the lower end portion of the rotating shaft 57A and is held by the clamp device 55. Specifically, the clamp device 55 holds the upper end portion of the outer tube 66A of the extension tube 66B. Further, the moving table 53 is lowered to connect the lower end of the outer cylinder 66A of the extension pipe 66B to the upper end of the outer cylinder 45 held by the clamp device 52, and the lower end of the rotating shaft 48 of the extension pipe 66B is connected to the cutting apparatus 44A. It connects with the upper end of the rotating shaft 48 (FIG.35 (E)). The clamp device 52 is released, and the gripping of the outer cylinder 45 by the clamp device 52 is released.

  Thereafter, the motors 56A and 56B are rotated, and the moving table 53 is gradually lowered from the state shown in FIG. 35E, and the nuclear fuel material and the fuel assembly metal members in the core 4 by the inner blade 47 and the outer blade 46 Cutting is resumed. When the moving table 53 descends to the vicinity of the clamp device 52, the additional operation of the extension pipe 66B shown in FIGS. 35 (A) to 35 (E) is repeated, and the nuclear fuel material existing at a deeper position in the core 4 is The fuel can be recovered into the fuel cask 115A while being cut by the cutting device 44A. When the outer blade 46 and the inner blade 47 of the cutting device 44A reach the lower end of the core 4 while cutting the nuclear fuel material or the like, the lowering of the moving table 53 and the rotation of the motors 56A and 56B are stopped.

  Thereafter, while performing the operation from FIG. 35 (E) to FIG. 35 (A), the extension pipes 66B added to the cutting device 44A are separated one by one, and these extension pipes 66B are sequentially inserted into the extension pipe supply device 60. Store in. When the cutting device 44A rises to the upper end of the packed bed of iron content 70B, the slide base 51C is slightly moved in the radial direction of the turntable 107, and at the position different from the previous time, as described above, the core 4 is cut using the cutting device 44A. The nuclear fuel material and the like inside are cut and collected in the fuel cask 115A. By repeating such operations, all nuclear fuel materials existing in the core 4 are collected, stored in the fuel cask 115A, and carried out of the preparation house 16B. All the shielding bodies such as the iron balls 70 </ b> A existing in the core 4 are collected by the shielding body supply apparatus 114. Part of the iron powder 70 </ b> B and the iron ball 70 </ b> A collected by the shielding body supply device 114 is stored in a shielding body cask 115 </ b> B placed on the turntable 107. The shield cask 115B is stored in the carry-out container 76D and carried out of the preparation house 16B in the same manner as the fuel cask 115A.

  A shielding body is injected into the core after removal of the nuclear fuel material (step S22). After the nuclear fuel material in the core 4 is removed by the boring device 43A, a shielding body such as iron powder 70B (which may include the iron ball 70A) is supplied from the shielding body supply device 114 installed on the turntable 107. It inject | pours on the core support plate 5 in the core 4 (refer FIG. 37). When the thickness of the shield such as the injected iron powder 70B reaches a predetermined thickness on the core support plate 5, the injection of the shield such as the iron powder 70B from the shield supply device 114 into the core 4 is stopped. The A shield layer 117 such as iron powder 70B is formed on the core support plate 5.

  The boring device is carried out (step S23). Hydraulic pressure is applied to each cylinder 109 of the support device 106 in the reverse direction. As a result, each piston rod 110 moves toward the center of the turntable 107, and each pressing member 111 is separated from the inner surface of the RPV2. In this state, the four winches 113A are driven to wind the wire 115A. Further, the hook 21A is raised. The boring device 43A and the support device 106 ascend and reach the work house 16A. Similar to the unloading of the boring device 43 in step S13, the boring device 43A is unloaded from the preparation house 16B, and the open / close door 78 is closed.

  The core shroud is unloaded (step S24). The cutting device 81A is installed on the inner surface of the RPV 2 using the support device 106, as in step S19. The core shroud 116 is cut over the entire circumference using the cutting device 81A in the same manner as step S19 above the layer of the shielding body such as the iron powder 70B filled on the core support plate 5. An upper lattice plate is attached to the cut core shroud. After the core shroud 116 is cut, the cutting device 81A is carried out of the preparation house 16B. After that, the cut core shroud to which the upper lattice plate is attached is transferred into the work house 16A and stored in the carry-out container in the work house 16A, similarly to the cut shroud 87 in step S19. The unloading container containing the cut core shroud is unloaded from the work house 16A through the preparation house 16B and out of the preparation house 16B using the overhead crane 16B and the traveling crane 32.

  Boring to the furnace bottom is performed (step S25). The boring device 43 is attached to the support device 106, is carried into the work house 16A, and is installed on the inner surface of the RPV 2 using the support device 106, as in step S20. The installation position of the support device 106 in the axial direction of the RPV 2 is a position slightly above the upper end of the core shroud 116 remaining at this time.

  Similarly to step S5, the outer blade 46 and the inner blade 47 of the cutting device 44 are swung to lower the moving table 53A, and the control rods constituting the core support plate 5 and the support cylinder 8 existing below the core support plate 5 are arranged. The guide tube 8A is cut (see FIG. 38). If the position of the boring processing of the core support plate 5 by the cutting device 44 is located directly above the area inside the control rod guide tube 8A, the control rod guide tube 8A by the outer blade 46 and the inner blade 47 No cutting is performed. If necessary, the extension tube 66 is added to the upper end of the cutting device 44 as described above.

  The inner blade is pulled out and the boring device is retracted (step S26). As in step S6, the rotary shaft 48 and the inner blade 47 are pulled out, and the outer cylinder 45 is left below the core support plate 5 (when the extension pipe 66 is used, the outer cylinder 66A is also left). The boring device 43 is retracted to the vicinity of the inner surface of the RPV 2 by the movement of the slide base 51C.

  The furnace bottom is observed (step S27). A camera and a dosimeter 68 are inserted into the bottom of the furnace through the outer cylinder 45 and the like left in the RPV 2 through the core support plate 5 (see FIG. 39). With this camera and dosimeter 68, the situation of the furnace bottom in the RPV 2 is photographed, and the dose at the furnace bottom is measured. Based on the image information and radiation dose obtained by the camera and the dosimeter 68 displayed on the display device, the operator determines the presence or absence of molten nuclear fuel material that has fallen to the furnace bottom. Since the molten nuclear fuel material existing in the bottom of the furnace is reflected on the display device, it is necessary to cover the molten nuclear fuel material 13 at the bottom of the furnace with a shielding body and then carry out the molten nuclear fuel material.

  The shielding body is injected into the bottom of the furnace in the RPV (step S28). The boring device 43 is carried out from the preparation house 16B to the outside in the same manner as described above, and the boring device 43A attached to the support device 106 is carried into the work house 16A from the outside. And the boring apparatus 43A is installed in the inner surface of RPV2 using the support apparatus 106 similarly to step S20. The shielding body supply device 114 installed on the turntable 107 of the support device 106 is connected to the outer cylinder 45 (or outer cylinder 66A) penetrating the core support plate 5. Iron powder, which is a shielding body in the shielding body supply apparatus 114, is injected into the furnace bottom in the RPV 2 through the outer cylinder 45 (or outer cylinders 66A and 45). The injected iron powder falls from the core 4 and is deposited on the molten nuclear fuel material 13 present at the bottom of the reactor in the RPV 2 to form a shield layer 118 that covers the molten nuclear fuel material 13 (FIG. 39). reference).

  The shielding body on the core support plate is collected (step S29). The shielding body such as the iron powder 70B existing on the core support plate 5 is collected using the cutting device 44A of the boring device 43A. The rotating shaft 48 and the screw 105 are rotated by rotating the motor 56A, and the shielding body such as the iron powder 70B existing on the core support plate 5 is guided into the spiral passage 50A. Since the screw 105 serves as a screw feeder, the shielding body is guided into the shielding body cask 115B via the transfer duct 59 and the separation device 113. At this time, the shielding body cask 115B is connected to the separation device 113. In this way, the shielding body such as the iron powder 70B existing on the core support plate 5 is recovered in the shielding body cask 115B. As described in step S21, the shield cask 115B is transferred into the work house 16A, stored in the carry-out container, and carried out of the preparation house 16B. After the collection of the shielding body such as the iron powder 70B existing on the core support plate 5 is completed, the boring device 43A is carried out of the preparation house 16B as described above.

  The core shroud is carried out (step S30). The storage container 80B storing the cutting device 81A is carried into the work house 16A using the traveling crane 32 and the overhead crane 18B, similarly to step S19. Then, the cutting device 81A taken out from the storage container 80B is suspended by the overhead crane 16A, lowered in the RPV 2, and installed on the inner surface of the RPV 2 by the support device 106 near the upper end of the core shroud 116 remaining in the RPV 2. Is done. The core shroud 116 is used at the position slightly above the core support plate 5, the position slightly below the core support plate 5, and the position below the support cylinder 8 using the cutting device 81 </ b> A as in step S <b> 19. Then, the entire circumference is cut (see FIG. 40). After the core shroud 116 is cut, the cutting device 81A is carried out of the preparation house 16B. After the above cutting, the portion of the core shroud 116 above the core support plate 5, the core support plate 5 and the support cylinder 8 are sequentially transferred into the work house 16A in the same manner as the cut shroud 87 in step S19. The Within the work house 16A, the overhead crane 18A is cut and the core shroud 116 is housed in the carry-out container 76E, the core support plate 5 is housed in the carry-out container 76F, and the support cylinder 8 is housed in the carry-out container 76G. (See FIG. 40). These carry-out containers 76E, 76F, and 76G are sequentially carried out of the preparation house 16B using the overhead cranes 18A and 18B and the traveling crane 32.

  The molten nuclear fuel material present at the bottom of the furnace is carried out (step S31). The boring device 43 </ b> A is carried into the work house 16 </ b> A similarly to step S <b> 20, and further installed on the inner surface of the RPV 2 using the support device 106. In the boring device 43A, as in step S21, the outer cylinder 45 and the rotating shaft 48 of the cutting device 44A are rotated to move the moving table 53 downward while turning the outer blade 46 and the inner blade 47, and further, the extension tube 66B is connected to the upper end of the cutting device 44A, and the moving table 53 is moved downward while turning the outer blade 46 and the inner blade 47. The molten nuclear fuel material 13 present at the bottom of the furnace is cut by the rotating outer blade 46 and inner blade 47 (see FIG. 41). The iron powder of the shield layer 118 and the cutting waste of the molten nuclear fuel material 13 that have entered the spiral passage 50A are transferred through the outer cylinder 45 by the rotating screw 105, and further to the separation device 113 through the transfer duct 59. Be transported. In the separation device 113, the cutting waste and the iron powder of the molten nuclear fuel material 13 are separated as described above. The separated iron powder is stored in the shielding body supply device 114. The cutting waste of the molten nuclear fuel material 13 from which the iron powder has been separated is stored from the separation device 113 into the fuel cask 115A. The fuel cask 115A filled with the cutting waste of the molten nuclear fuel material 13 is transferred into the work house 16A and stored in the carry-out container 76D. In the same manner as the carry-out of the storage container 76 in step S15, it is sealed with a lid and carried out of the preparation house 16B by the overhead cranes 18A, 18B and the traveling crane 32. When the lower end of the cutting device 44A reaches the bottom surface of the RPV 2, the cutting device 44A is pulled up as in step S21. When the lower end of the cutting device 44A reaches the upper end of the shielding body layer 118, the radial position of the RPV 2 of the cutting device 44A is changed, and the cutting device 44A is lowered again to cut the molten nuclear fuel material 13. By repeating the above, all the iron powder and molten nuclear fuel material present at the bottom of the furnace in the RPV 2 are removed by the cutting device 44A.

  A shield is injected into the bottom of the furnace after removal of the nuclear fuel material (step S32). After the nuclear fuel material at the bottom of the furnace is removed by the boring device 43A, iron powder as a shielding body is injected into the core shroud lower shell 116A from the shielding body supply device 114 installed on the turntable 107 at the bottom of the furnace ( (See FIG. 42). When the thickness of the injected iron powder reaches a predetermined thickness on the bottom surface of the RPV 2, the injection of the iron powder from the shield supply device 114 to the furnace bottom is stopped. A shield layer 119 of iron powder is formed on the bottom surface of RPV2.

  After the injection of the shielding body in step S32 is completed, the boring device 43A is transferred from the RPV 2 into the work house 16A and further carried out from the preparation house 16B.

  Boring to the bottom of the PCV is performed (step S33). As described above, the boring device 43 attached to the support device 106 is carried into the RPV 2 and installed on the inner surface of the RPV 2 using the support device 106. Similarly to step S5, the outer blade 46 and the inner blade 47 of the cutting device 44 of the boring device 43 are turned to lower the moving table 53A, and the bottom portion (lower mirror) of the RPV 2 and the control rod drive mechanism housing 39 are cut. (See FIG. 43). When the position of the boring processing of the bottom portion of the RPV 2 by the cutting device 44 is positioned directly above the area inside the control rod drive mechanism housing 39, the control rod drive mechanism housing 39 by the outer blade 46 and the inner blade 47 is used. No cutting is performed. If necessary, the extension tube 66 is added to the upper end of the cutting device 44 as described above.

  The inner blade is pulled out and the boring device is retracted (step S34). Similar to step S6, the rotary shaft 48 and the inner blade 47 are pulled out, leaving the core shroud lower shell 116A and the outer cylinders 66A, 45 connected below the bottom of the RPV 2. The boring device 43 is retracted to the vicinity of the inner surface of the RPV 2 by the movement of the slide base 51C.

  The bottom of the PCV is observed (step S35). The camera and dosimeter 68 are inserted into the bottom of the PCV 9 through the outer cylinders 66A and 45 (see FIG. 43). With this camera and dosimeter 68, the situation at the bottom of the PCV 9 is photographed, and the dose at the bottom of the PCV 9 is measured. Based on the image information and the radiation dose obtained by the camera and the dosimeter 68 displayed on the display device, the operator determines the presence or absence of molten nuclear fuel material that has fallen on the bottom of the PCV 9. The image shown in the display device does not include the image of the molten nuclear fuel material dropped on the bottom of the PCV 9, but includes the image of the iron powder 121 that is the shield that has fallen through the damaged portion of the bottom of the RPV 2 furnace. Assume a case. The measured dose is also much lower than the dose when molten nuclear fuel material is present. For this reason, the operator determines that there is almost no molten nuclear fuel material at the bottom of the PCV 9 and there is iron powder that is a falling shield. For this reason, it is necessary to collect | recover the iron powder which exists in the bottom part of PCV9. If the molten nuclear fuel material dropped on the bottom of the PCV 9 is transferred to the display device, the molten nuclear fuel material must be carried out. In this case, as shown in FIG. 52, the molten nuclear fuel material present at the bottom of the PCV 9 is carried out. Further, when there is no molten nuclear fuel material and shielding body that have fallen on the bottom of the PCV 9, steps S36, S37, and S38 described later are performed. Here, recovery of iron powder present at the bottom of the PCV 9 will be described.

  Before recovering the iron powder present at the bottom of the PCV 9, the shield present at the bottom of the furnace is recovered (step S36). The boring device 43 and the support device 106 used in step S34 are carried out to the outside through the work house 16A and the preparation house 16B. Instead of the boring device 43, the boring device 43A attached to the support device 106 is carried into the RPV 2 through the preparation house 16B and the work house 16A. The boring device 43 </ b> A is installed on the inner surface of the RPV 2 using the support device 106. Using the cutting device 44A of the boring device 43A, the iron powder (shielding body) present at the bottom of the furnace is recovered in the same manner as in step S29. The collected shielding body is collected in the shielding body cask 115B. As described in step S21, the shield cask 115B is transferred into the work house 16A, stored in the carry-out container, and carried out of the preparation house 16B. Thereafter, the boring device 43A is carried out of the preparation house 16B as described above.

  The core shroud lower shell and the reactor bottom of the reactor pressure vessel are carried out (step S37). The removal of the furnace bottom will be described with reference to FIG. The storage container storing the cutting device 81A is carried into the work house 16A using the traveling crane 32 and the overhead crane 18B, as in step S19. The cutting device 81A taken out from the storage container is suspended by the overhead crane 16A and lowered in the RPV 2, and the support device 106 is used in the vicinity of the upper end of the core shroud lower shell 116A existing in the RPV 2 as described above. Installed on the inner surface of the RPV 2.

  In the vicinity of the welded portion with the bottom of the RPV 2, the core shroud lower shell 116A is cut over the entire circumference using the cutting device 81A as in step S19. After cutting the core shroud lower shell 116A, the cutting device 81A is lifted by the overhead crane 18A and placed on the floor surface of the work house 16A. The cut core shroud lower shell 116A is transferred into the work house 16A and stored in the carry-out container 76H in the work house 16A in the same manner as the cut shroud 87 in step S19.

  The cutting device 81A is again suspended from the overhead crane 16A to lower the inside of the RPV 2, and is installed on the inner surface of the RPV 2 using the support device 106 in the vicinity of the bottom of the furnace as described above. With the plurality of control rod drive mechanisms 39 attached, the bottom of the RPV 2 is cut into small blocks using the cutting device 81A in the same manner as in step S19, inside the RPV 2 mounting portion on the pedestal 37. And drop it on the bottom of PCV9. The plurality of furnace bottom pieces 2A, to which the control rod drive mechanism housing 39 is cut and attached, are pulled up into the work house 16A using a grapple or the like attached to the overhead crane 18A. Stored.

  A carry-out container 76H containing the cut shroud 87 and a carry-out container 76I containing the furnace bottom piece 2A are prepared from the work house 16A through the preparation house 16B using the overhead cranes 16A and 16B and the traveling crane 32, respectively. It is carried out of the house 16B.

  The shielding body at the bottom of the PCV is collected (step S38). The support device 106 on which the separation device 113 is installed on the turntable 107 is carried into the work house 16A, similarly to the support device 106 of the boring device 43A in step S20, and is further lowered in the RPV 2 to place the RPV 2 at a predetermined position. (See FIG. 45). A suction hose 142 is connected to the separation device 113. When the support device 106 is installed on the inner surface of the RPV 2, the lower end of the suction hose 142 reaches the layer of the iron powder 121 present at the bottom of the PCV 9.

  The suction pump connected to the separation device 113 is driven, and the iron powder 121 present at the bottom of the PCV 9 is sucked and guided to the separation device 113 through the suction hose 142. In the separation device 113, the iron powder 121 and other substances are separated, the separated iron powder 121 is stored in the shielding body cask 115B, and the other substances are stored in the fuel cask 115A. The shield cask 115B filled with the iron powder 121 is transferred into the work house 16A and stored in the carry-out container 76J. When the substance such as the iron powder 121 disappears at the bottom of the PCV 9, the suction of the substance using the suction hose 142 is completed. The fuel cask 115A in which other substances are stored is also transferred into the work house 16A and stored in the carry-out container 76D. The carry-out container 76J containing the shielding body cask 115B and the fuel cask 115A containing other substances are carried out of the preparation house 16B using the overhead cranes 18A and 18B and the traveling crane 32. After the suction of the iron powder 121 is completed, the support device 106 is also lifted into the work house 16A, stored in a storage container, transferred, and carried out of the preparation house 16B.

  The RPV is carried out (step S39). The carrying out of RPV2 will be described with reference to FIG. The storage container storing the cutting device 81A is carried into the work house 16A using the traveling crane 32 and the overhead crane 18B, as in step S19. The cutting device 81A taken out from the storage container is installed on the inner surface of the RPV 2 using the support device 106, as described above, below the uppermost cutting position of the RPV 2. Since RPV2 is large, RPV2 is cut at six points in the axial direction in order to carry out easily. In order to shorten the time required to carry out the RPV 2, the support device 106 is arranged below the cutting position of the RPV 2 in each cutting operation.

  By the action of the abrasive contained in the high-pressure water sprayed from the nozzle 98 of the cutting device 81A supported by the support device 106, the cutting position located at the top of the RPV 2 is cut. Since the turntable 107 turns, the RPV 2 is cut over the entire circumference in the circumferential direction at the cutting point. In a state where the cutting device 81A is disposed in the RPV 2, the cut RPV 2B is transferred into the work house 16A and stored in the unloading container 76L in the work house 16A in the same manner as the cut shroud 87 in step S19. . The carry-out container 76L storing the cut RPV 2B is carried out of the preparation house 16B in the same manner as the above-described carry-out containers.

  After the pressing of the pressing member 11 to the inner surface of the RPV 2 is released, the cutting device 81A is moved downward by the overhead crane 18A and is installed on the inner surface of the RPV 2 by the support device 106 at a position below the next cutting position. Then, the turntable 107 is turned as described above, and the RPV 2 is cut using the cutting device 81A. The cut RPV 2B is stored in the carry-out container 76L as described above and carried out of the preparation house 16B. Thus, RPV2 is cut | disconnected from each upper part at each cutting location, and is carried out of the preparation house 16B. The lowermost cutting point is a position slightly above the upper end of the support part for mounting the RPV 2 to the pedestal 37. When cutting the RPV 2 at this position, the support device 106 is installed on the inner surface of the pedestal 37.

  After carrying out the RPV 2, the cutting device 81A is transferred and carried out of the preparation house 16B as described above.

  When the carrying out of the RPV 2 and the cutting device 81A is completed, the inside of the reactor building 14 is in the state shown in FIG.

  When the operations in steps S1 to S39 are completed, the method for carrying out the nuclear fuel material in the nuclear power plant of this embodiment is completed.

  It is assumed that the above-described steps S1 to S6 are performed and the observation in the RPV 2 in step S7 is performed. At this time, the state in the RPV 2 is that the nuclear fuel material in the reactor core 4 is melted and the in-furnace structures such as the steam dryer 7 and the steam separator 6 are melted, and the melt 13A of the nuclear fuel material and the in-core structure is Suppose that it is in the state which fell to the furnace bottom part in RPV2. In step S7, the image displayed on the display device and the measured dose obtained using the camera and the dosimeter 68 indicate that the inside of the RPV 2 is in the above state (see FIG. 48). Yes. The operator who sees the information reflected on the display device determines the solid melt 13A present at the bottom of the furnace as the boring object (step S8). And each operation | movement of step S40-41, S14-S16, S42, S43, S32-S37, S44, and S39 shown below is performed in order.

  A shield is injected into the furnace bottom in the RPV (step S40). Using the boring device 43, the cutting device 44 is lowered while the extension pipe 66 is added, as in step S5. When the lower end of the cutting device 44 reaches the vicinity of the melt 13A at the furnace bottom, the lowering of the cutting device 44 is stopped. Thereafter, using the boring device 43, the respective rotation shafts 48 are pulled out from the respective extension pipes 66 inserted into the RPV 2 and the cutting device 44 in the same manner as in step S6. As a result, each outer cylinder 66A and the outer cylinder 45 remain in the RPV 2 in a connected state.

  The shielding body (for example, iron powder 121) is injected into the furnace bottom in the same manner as in step S12. As shown in FIG. 49, the injection pipe 72 is connected to the shielding body supply device 71 that is carried into the work house 16 </ b> A and installed, and the most among the connected outer cylinders 66 </ b> A and outer cylinders 45. It is connected to the upper end of the outer cylinder 66A disposed above. The iron powder 121 is injected into the RPV 2 from the shielding body supply device 71 through the injection pipe 72 and the outer cylinders 66A and 45 disposed in the RPV 2, and covers the melt 13A existing at the bottom of the furnace.

  The outer cylinder is collected and the boring device is carried out (step S41). Here, in the same manner as in step S13, the outer cylinders 66A and 45 arranged in the RPV 2 are collected, and the bowling device 43 is carried out of the preparation house 16B.

  After the operation of step S41 is completed, the operations of steps S14 to S16 described above are performed.

  The residual equipment in the RPV is carried out (step S42). After the work of step S16 is completed, the cutting device 81A is housed in the storage container and is carried into the work house 16A using the traveling crane 32 and the overhead crane 18B as in step S19. Then, the cutting device 81A taken out from the storage container is suspended by the overhead crane 16A, lowered in the RPV 2, and above the residual equipment (in-furnace structure) 122 remaining in the RPV 2 by the support device 106. It is installed on the inner surface of the RPV 2 (see FIG. 50). The residual device 122 is cut using the cutting device 81A, and the cut residual device 122 is carried into the work house 16A. This residual device 122 is housed in the carry-out container 76M in the work house 16A, and is carried out from the preparation house 16B to the outside in the same manner as the carry-out containers described above.

  The melt is carried out (step S43). The carrying out of the melt 13A will be described with reference to FIG. Substantially in the same manner as the molten fuel material present at the furnace bottom in step S31, the molten material 13A is unloaded in this step. The boring device 43 </ b> A is carried into the work house 16 </ b> A similarly to step S <b> 20, and further installed on the inner surface of the RPV 2 using the support device 106. In the boring apparatus 43A, as in step S21, the outer cylinder 45 and the rotating shaft 48 are rotated to move the outer blade 46 and the inner blade 47 downward while turning, and the molten nuclear fuel material and the melting furnace existing at the bottom of the furnace. The melt 13A including the inner structure is cut. When only the length of the cutting device 44A is insufficient, similarly to step S21, the extension pipe 66B is added to the upper end portion of the cutting device 44A, and the melt 13A is cut by the cutting device 44A. The cutting waste of the melt 13 </ b> A generated by this cutting and the iron powder 121 enter the outer cylinder 45, are pushed out by the rotating screw 105, and are transferred to the separation device 113 through the transfer duct 59.

  The cutting waste of the melt 13A and the iron powder 121 are separated by the separation device 113, and the separated cutting waste of the melt 13A is guided to the fuel cask 115A. Further, the separated iron powder 121 is guided into the shielding body supply device 114.

  Similarly to step S21, the position of the cutting device 44A in the radial direction of the RPV 2 is changed, and the cutting of the melt 13A is performed by the cutting device 44A. Collect in 115A. Each fuel cask 115A filled with cutting waste of melt 13A is transferred to work house 16A and stored in carry-out container 76D. The unloading container 76D that stores the fuel cask 115A is unloaded from the preparation house 16B.

  Thereafter, the operations in steps S32 to S35 described above are performed in order. In the operation of step S35, the camera and the dosimeter 68 photograph the situation of the bottom of the PCV 9, and the dose of the bottom of the PCV 9 is measured. The information displayed on the display device indicates that the melt 13A is falling on the bottom of the PCV 9. The melt 13A present at the bottom of the PCV 9 is referred to as a melt 13B in order to distinguish it from the melt 13A present at the bottom of the furnace. The operator looks at the information reported on the display device and determines that the melt 13B at the bottom of the PCV 9 needs to be recovered. Then, each operation | movement of step S36 and S37 is performed.

  The melt at the bottom of the PCV is carried out (step S44). The boring device 43A is carried into the work house 16A as in step S20, and is further installed on the inner surface of the RPV 2 using the support device 106 (see FIG. 52). As with the removal of the molten nuclear fuel material 13 at the bottom of the furnace in step S31, the melt 13B present at the bottom of the PCV 9 is cut using the cutting device 44A, and the iron powder 121 and the cutting waste of the melt 13B are rotated. 105, and transferred to the separation device 113 through the transfer duct 59. The cutting waste of the melt 13B separated by the separation device 113 is stored in the fuel cask 115A. Further, the iron powder 121 separated by the separation device 113 is stored in the shielding body cask 115B. Fuel cask 115A filled with cutting waste of melt 13B and shielding body cask 115B filled with iron powder 121 are respectively transferred to work house 16A. A plurality of fuel casks 115A are stored in the carry-out container 76D, and a plurality of shielding body casks 115B are stored in the carry-out container 76J. The unloading containers 76D and 76J are unloaded from the preparation house 16B (see FIG. 52).

  Thereafter, the RPV 2 is carried out in step S39.

  Thus, each operation of the nuclear fuel material carry-out method in the nuclear power plant when the nuclear fuel material of the core and the reactor internal structure are melted in the RPV 2 is completed.

  In the present embodiment, the cutting device 44A is used to cut the molten nuclear fuel material existing in the RPV 2 and to discharge the cut molten nuclear fuel material, so that the time required to carry out the cut molten nuclear fuel material is shortened. Can do. In particular, the outer blade 46 provided at the distal end portion of the outer cylinder 45 and the inner blade 47 provided at the distal end portion of the rotating shaft 48 disposed in the outer cylinder 45 are swung to melt the nuclear fuel material in the nuclear reactor 1. Since the cut molten nuclear fuel material is transferred using the transfer passage formed between the rotary shaft 48 and the outer cylinder 45, the time required for carrying out the cut molten nuclear fuel material is reduced. It can be shortened. Since the screw 105 which surrounds the rotating shaft 48 and is attached to the rotating shaft 48 is rotated, the cut molten nuclear fuel material can be easily transferred. In particular, in this embodiment, since the screw 105 is provided on the rotary shaft 48 disposed in the outer cylinder 45 in the cutting device 44A, the cutting waste of nuclear fuel material can be more easily transferred by the screw 105. .

  In this embodiment, after the boring process by the boring device 43 is completed, the outer cylinder 45 of the cutting device 44 and the outer cylinder 66A of the extension pipe 66 are left in the nuclear reactor 1 and the rotating shaft 48 in these outer cylinders is pulled out. Therefore, it is possible to easily inject the granular shielding body (for example, iron ball 70A) and the powder shielding body (for example, iron powder 70B) into the nuclear reactor 1 by using the outer cylinder as an injection tube.

  The cutting device 44 of the boring device 43 has an inner blade 47 attached to the lower end portion of the rotating rotating shaft 48, and is attached to the lower end portion of the outer cylinder 45 that surrounds the rotating shaft 48 and surrounds the inner blade 47. 46, the rotary shaft 48 is pulled out from the outer cylinder 45. In the structure in which the rotary shaft 48 and the outer cylinder 45 can be inserted, the shield plug 15, the upper lids 10 and 3 and the steam can be inserted into the holes through which the rotary shaft 48 and the outer cylinder 45 can be inserted. It can be formed in the dryer 7 or the like.

  When the outer cylinders 45 and 66A are pulled out together with the rotary shaft 48, a shroud head in which the injected granular shielding body and part of the powder shielding body are installed in the steam-water separator 6 and the steam dryer 7 are installed. The granular shielding body and the powder shielding body are hindered in the core 4 from being injected, and it takes a long time to inject the predetermined amount of the granular shielding body and the powder shielding body. In this embodiment, since the outer cylinders 45 and 66A are left in the steam separator 6 and the steam dryer 7, all injected granular shielding bodies and powder shielding bodies pass through the outer cylinders. Can be directly injected into the core 4.

  Further, those outer cylinders left in the reactor 1 can be used as a guide tube for inserting a camera and a dosimeter 68 for confirming the situation in the reactor 1 into the reactor 1. The total 68 can be smoothly inserted into the nuclear reactor 1, and the status inside the nuclear reactor 1 can be confirmed in a short time.

  Based on the information in the reactor 1 (images in the reactor 1 etc.) obtained by the camera and the dosimeter 68 inserted into the reactor 1 through those outer cylinders, the object to be cut in the reactor is appropriately selected. Can be determined. For this reason, the work process for cutting a cutting target object can also be determined appropriately. As a result, unnecessary work can be avoided and the time required to carry out the molten nuclear fuel material can be shortened.

  In this embodiment, since the granular shielding body and the powder shielding body are injected into the core, the granular shielding body and the powder shielding filled in the core 4 with the radiation emitted from the nuclear fuel material and the molten nuclear fuel material 13 in the core 4. Can be shielded by the body. For example, when a device (for example, a boring device 43A) used in this embodiment breaks down in the work house 16A, it is necessary for an operator to enter the work house 16A to check the broken device and confirm the state of the failure. There is. In some cases, the failed equipment must be repaired in the work house 16A. Since the granular shielding body and the powder shielding body injected into the core 4 described above shield radiation, it is possible to suppress the exposure of workers working in the work house 16A.

  In this embodiment, when cutting the molten nuclear fuel material in the reactor core 4 and the molten nuclear fuel material 13 present at the bottom of the reactor in the RPV 2, the boring device 43A has a pressing device (cylinder 109, pressing member 111, etc.). Since the support device 106 is used to install the inner surface of the RPV 2, the boring device 43 </ b> A can be disposed near the existence region above the existence region in the RPV 2 of the nuclear fuel material to be cut. For this reason, the number of the extension pipes 66 to be added can be reduced. The reduction in the number of extension pipes 66 to be added leads to a reduction in the time required to add the extension pipe 66 and an increase in the turning torque of the outer blade 46 and the inner blade 47. The reduction in the time required for adding the extension pipe 66 directly leads to a reduction in the time required for the cutting operation of the molten nuclear fuel material. The increase in the turning torque can improve the cutting efficiency of the molten nuclear fuel material by the outer blade 46 and the inner blade 47, and can further shorten the time required for cutting the molten nuclear fuel material.

  In particular, when cutting the molten nuclear fuel material in the core 4 in the RPV 2, the internal structure (steam dryer 7, steam separator 6, etc.) existing in the RPV 2 above the core 4 before the cutting is cut. Since the shroud 87) is cut and carried out of the RPV 2, the boring device 43A is installed on the inner surface of the RPV 2 using the supporting device 106 near the core 4 above the core 4 where the nuclear fuel material to be cut exists. can do. Further, when cutting the molten nuclear fuel material 13 present at the bottom of the reactor inside the RPV 2, other in-core structures (core shroud 116, core support plate 5, support cylinder 8, etc.) are cut out and carried out of the RPV 2. The boring device 43A can be installed on the inner surface of the RPV 2 using the supporting device 106 near the bottom of the furnace where the molten nuclear fuel material 13 to be cut exists.

  In the present embodiment, the boring device 43 is a first rotating device (a motor 56A and a drive socket 54A) that rotates a rotating shaft 48 of the cutting device 44 on a moving table 53A attached to the mast member 51B so as to be movable in the vertical direction. ), And a clamp table 54B, which is a second rotating device that rotates the outer cylinder 45 of the cutting device 44, on a moving table 53B that is attached to the moving table 53A so as to be movable in the vertical direction. A clamp device 52 having an inner blade shaft clamp 52A and an outer blade shaft clamp 52B is attached to the mast member 51B below the first and second rotating devices, and an extension tube support member 61 and arm clamps 65A and 65B are provided. Since the extension pipe supply device 60 having the extension pipe moving device 63 is provided, as described above, A deeper hole can be formed by adding the long tube 66 to the cutting device 44, and the extension tube 66 and the cutting are cut from the outer tube 45 left in the nuclear reactor 1 of the cutting device 44 and the outer tube 66 </ b> A of the extension tube 66. Each rotating shaft 48 of the apparatus 44 can be pulled out, and further, the outer cylinder 66A of the extension pipe 66 and the outer cylinder 45 of the cutting apparatus 44 remaining in the nuclear reactor 1 can be pulled out.

  In this embodiment, the boring device 43A is a first rotating device (a motor 56A and a drive socket 54A) that rotates a rotating shaft 48 of the cutting device 44 on a moving table 53 that is attached to the mast member 51B so as to be movable in the vertical direction. ), And a support device 57 attached to the moving table 53 is provided with a clamp device 55 that is a second rotating device that rotates the outer cylinder 45 of the cutting device 44A and is a gripping device for the outer cylinder. Since the clamp device 52 is attached to the mast member 51B below the two-rotation device, the extension tube support member 61, and the extension tube supply device 60 having the extension tube moving device 63 provided with the grip portion 65D are provided. As described above, it is possible to easily add the extension pipe 66B to the cutting device 44 and to collect the extension pipe 66B and the cutting device 44.

  In this embodiment, the work house 16A and the preparation house 16B are installed on the operation floor of the reactor building 14, and the reactor internal structures (the steam separator 6, the steam dryer 7, the core shroud 166, etc.) in the RPV 2 and the RPV 2 Each of the molten nuclear fuel material in the inside and the shielding body (iron ball 70A and iron powder 70B) injected into the RPV 2 are housed in a carry-out container, and externally passed through the work house 16A and the preparation house 16B. It is carried out to. For this reason, for example, as the unloading container containing the cutting waste and the shielding body is transferred from the RPV 2 to the work house 16A, the radioactive material that is present in the work house 16A from the RPV 2 is discharged to the outside environment. Can be prevented. This is provided in the floor of the preparation house 16B with an opening formed in the ceiling of the work house 16A and the floor of the preparation house 16B that connects the internal space 17A of the work house 16A and the internal space 17B of the preparation house 16B. The opening that can be closed by the open / close door 77 and that is formed on the ceiling of the preparation house 16B and connects the internal space 17B of the preparation house 16B and the external environment is closed by the opening / closing door 78 provided on the ceiling of the preparation house 16B. This is because the ventilation air conditioning systems 36A and 36B for removing radioactive substances are provided in the work house 16A and the preparation house 16B. These ventilation air-conditioning systems can purify the air inside each of the work house 16A and the preparation house 16B, and can remove radioactive substances contained in the air in the internal spaces 17A and 17B.

  In this embodiment, the iron balls 70A and the iron powder 70B are used as the shielding bodies to be injected into the RPV 2. However, tungsten balls and tungsten powder may be used as the shielding bodies instead of the iron balls 70A and the iron powder 70B. Since tungsten is not a magnetic substance, when the cutting waste such as nuclear fuel material is separated by the separation device 113, the specific gravity of tungsten is higher than the cutting waste of the nuclear fuel material and the structural member of the fuel assembly, instead of using an electromagnet. Since it is very large, this specific gravity difference can be used to separate the nuclear fuel material and the cutting scraps of the structural members of the fuel assembly from the tungsten balls and tungsten powder.

  A method for carrying out the nuclear fuel material in the nuclear power plant of the second embodiment applied to a boiling water nuclear power plant as another embodiment of the present invention will be described with reference to FIGS.

  In the case where the in-furnace structures such as the steam separator 6 and the steam dryer 7 in the RPV 2 are not melted, the method for carrying out the nuclear fuel material in the nuclear power plant according to the present embodiment is step S4 performed in the first embodiment. The operations of S13 to S13 are performed in a state where the traveling crane 32 is not installed and the work house 16A and the preparation house 16B are not installed on the operation floor of the reactor building 14, and after the operation of Step S13 is completed, the operation of Step S2 (travel The installation of the crane 32) and the operation of step S3 (installation of the work house 16A and the preparation house 16B) are performed, and thereafter, the operations of steps S13 to S39 performed in the first embodiment are sequentially performed. Further, in the case where the in-reactor structures such as the steam separator 6 and the steam dryer 7 in the RPV 2 are melted, the method for carrying out the nuclear fuel material in the nuclear power plant of the present embodiment is implemented in the first embodiment. The operations of steps S4 to S8, S40 and S41 are performed without installing the traveling crane 32 above the reactor building 14 and without installing the work house 16A and the preparation house 16B on the operation floor of the reactor building 14, After the work in step S41, the work in step S2 (installation of the traveling crane) and the work in step S3 (installation of the work house 16A and the preparation house 16B) are performed, and then steps S14 to S16, S42 performed in the first embodiment. -S43, S32-S37, S44 and S39 are performed in order.

  The obstacle is removed in step S1. Obstacles present on the operation floor of the reactor building are removed using a crawler crane (not shown).

  The boring device is installed on the openable shielding member 15A provided on the operation floor of the reactor building (step S45). The work in step S45 is a work corresponding to step S4 in the first embodiment. The boring device 43 is suspended by a crawler crane installed on the ground and placed on an openable shielding member 15A provided on the operation floor of the reactor building 14 (see FIG. 53).

  Boring is performed (step S46). The work in step S46 is a work corresponding to step S5 in the first embodiment. The mobile multi-axis robot 26 </ b> A placed on the operation floor 143 connects the power cable connector to the boring device 43 on the operation floor 143. When the boring device 43 is lowered from the operation floor 143 to the ground, the mobile multi-axis robot 26A removes the connector of the power cable from the boring device 43. The description of the connection and removal work of the power cable and the boring device 43 (or the boring device 43A described later) will be omitted later. The boring process on the upper lid 10 of the PCV 9 and the upper lid 3 of the RPV 2 is performed using the boring device 43 as in step S5 of the first embodiment.

  The inner blade is pulled out and the boring device is retracted (step S47). The operation in step S47 is an operation corresponding to step S6 in the first embodiment. Of the cutting device 44 and the extension pipe 66 arranged through the shield plug 15 and the upper lids 10 and 3, the respective rotating shafts 48 of the cutting device 44 and the extension pipe 66 are connected to the boring device 43 on the operation floor 143. As in step S6, the outer cylinders 45 and 66A connected to each other are pulled out. These outer cylinders 45 and 66A are left in a state of penetrating the shield plug 15 and the upper lids 10 and 3. The boring device 43 moves on the operation floor 143 and is retracted to the corner of the operation floor 143.

  The inside of the RPV is observed (step S48). The work in step S48 is a work corresponding to step S7 in the first embodiment. As shown in FIG. 54, the pipe 68A connected to the ventilation / air-conditioning / water injection system 69 installed on the operation floor 143 is connected to the upper end of the outer cylinder 66A located at the uppermost position through the shield plug 15. . A camera and a dosimeter 68 inserted into the RPV 2 through the pipe 68A and the outer cylinders 66A and 45 have a display device (not shown) in which the image information in the RPV 2 and the dose measurement values in the RPV 2 are installed in a safe place on the ground. Output).

  An object to be drilled in the RPV is determined (step S49). Since the image displayed on the display device includes the image of the steam dryer, the operator determines the steam dryer 7 and the steam separator 6 as the boring objects. The operator for these objects determines the steam dryer 7 and the steam separator 6 as the boring objects, and decides to perform boring processing for these objects.

  Boring to the core is performed (step S50). The work in step S50 is a work corresponding to step S9 in the first embodiment. As with step S9, the cutting device 44 is lowered by the boring device 43 while adding the extension pipe 66, and the shield plug 15 and the upper lids 10 and 3 are moved along the central axis of the RPV 2 by the rotation of the inner blade 47 and the outer blade 46. Then, a boring process is performed on the steam dryer 7 and the steam separator 6 (see FIG. 54).

  The inner blade is pulled out and the boring device is retracted (step S51). The work in step S51 is a work corresponding to step S10 in the first embodiment. Similarly to step S <b> 6, each rotary shaft 48 and inner blade 47 are pulled out, and the boring device 43 is retracted on the operation floor 143. The connected outer cylinders 45 and 66A are arranged between the lower end of the steam separator 6 and the upper end of the core 4 from the shield plug 15 along the central axis of the RPV 2 (FIG. 55). reference).

  The inside of the core is observed (step S52). The work in step S52 is a work corresponding to step S11 in the first embodiment. Images and dose measurements in the core 4 are obtained by the cameras and dosimeters 68 (see FIG. 55) inserted into the core 4 through the connected outer cylinders 45 and 66A. The operator grasps that the nuclear fuel material in the core 4 is melted based on the image and the dose measurement value.

  The shielding body is injected into the core (step S53). The work in step S53 is a work corresponding to step S12 in the first embodiment. The outer cylinders 45 and 66A are arranged along the central axis of the RPV 2 and connected to each other from the shielding body supply device 71 installed on the operation floor 143 by the iron ball 70A and the iron powder 70B, as in step S12. And injected into the core 4 (see FIG. 56). The iron ball 70A is injected before the iron powder 70B.

  After the injection of the iron ball 70A and the iron powder 70B in step S53 is completed, the outer cylinder is collected and the boring device is removed (step S54). The work in step S54 is a work corresponding to step S13 in the first embodiment. The boring device 43 that has collected the outer cylinders 45 and 66A is removed from the operation floor 143 using a crawler crane and lowered to the ground.

  After step S54, the work of step S2 (installation of the traveling crane 32) and the work of step S3 (installation of the work house 16A and the preparation house 16B) performed in the first embodiment are performed (see FIG. 56). Through these operations, the traveling crane 32 is installed across the reactor building 14 as in Example 1, and the work house 16A is installed on the operation floor 143 of the reactor building 14 so as to cover the shield plug 15, The preparation house 16B is installed on the work house 16A. Then, each operation | work of step S14-S39 implemented in Example 1 is performed.

  A method for carrying out the nuclear fuel material according to the present embodiment when the in-furnace structures such as the steam separator 6 and the steam dryer 7 are melted in the RPV 2 will be described below.

  Steps S45 to S48 are performed, and the image information and the dose measurement values in the RPV 2 obtained by the camera and the dosimeter 68 in the step S48 are stored in the furnace such as the steam separator 6 and the steam dryer 7 in the RPV 2. It shows that the inner structure and nuclear fuel material are melted. For this reason, the operator determines the solidified melt 13A (see FIG. 48) present at the bottom of the furnace in the RPV 2 as a boring object. Thereafter, steps S40 and S41 performed in the first embodiment are further performed on the operation floor 143 of the reactor building 14 without installing the traveling crane 32 above the reactor building 14 and further installing the work house 16A and the preparation house 16B. It is done in a state that does not.

  The work of step S40 performed in the present embodiment includes the iron powder 121 from the shielding body supply device 71 installed on the operation floor 143, the injection pipe 72, and the outer cylinders 45 connected and disposed in the RPV 2. By injecting into RPV2 through 66A. The melt 13A existing at the bottom of the RPV 2 is covered with the injected iron powder 121. In step S41, after the outer cylinders 45 and 66A arranged in the RPV 2 are collected by the boring device 43, the boring device 43 is lowered from the operation floor 143 to the ground by the claw crane.

  After the operation in step S41 is completed, the operation in step S2 (installation of the traveling crane 32) and the operation in step S3 (installation of the work house 16A and the preparation house 16B) are performed. Steps S14 to S16, S42, and S43 are performed in the same manner as in the first embodiment with the traveling crane 32 installed so as to straddle the reactor building 1 and the work house 16A and the preparation house 16B are installed on the operation floor 143. , S32 to S37, S44 and S39 are executed in order.

  In the present embodiment, each effect produced in the first embodiment can be obtained. Further, in this embodiment, the operations of steps S45 to S54, S40 and S41 are not performed by installing the traveling crane 32 above the reactor building 14, and the work house 16A and the preparation house 16B are further placed on the operation floor 143 of the reactor building 14. Therefore, the time required for carrying out the nuclear fuel material in the present embodiment can be reduced as compared with the first embodiment. This is because, in each work of steps S45 to SS48, S50 to S54, S40 and S41 of the present embodiment, the necessary devices are carried into the work houses 16A and 16B performed in the first embodiment, and the devices from these houses. This is because it is not necessary to carry out the operation.

  A method for carrying out the nuclear fuel material in the nuclear power plant of the third embodiment applied to a boiling water nuclear power plant as another embodiment of the present invention will be described with reference to FIGS.

  In the method for carrying out the nuclear fuel material of the present embodiment, the cutting and carrying out of the nuclear fuel material in the first and second embodiments is performed using the shield device 123 instead of the boring device 43A. The structure of the shield device 148 will be described with reference to FIG. The shield device 148 includes a shield cutting device 123, a recovery tube attaching / detaching unit, and a recovery tube supply device 137.

  The shield cutting device 123 has a cutting part and a propulsion part. The cutting unit includes a rotating body 124 and a plurality of cutters 125, and the plurality of cutters 125 are attached to the front surface of the rotating body 124. The propulsion unit has a cylindrical body 126 and a plurality of propulsion jacks 127. The propulsion jack 127 is disposed at a predetermined interval in the circumferential direction of the cylindrical body 126 and is attached to the cylindrical body 126. The cylindrical body portion 126 is attached to the front surface of the housing body portion 123A of the shield cutting device 123. The rotating body 124 is rotatably attached to the front surface of the cylindrical body 126 and is rotated by a first motor (not shown) installed in the cylindrical body 126. A recovery tube 128 is fixed to the housing body 123A. Although not shown, a cutting waste transfer passage is formed in each of the cylindrical body 126 and the case body 123A, and this cutting waste transfer passage is communicated with the recovery pipe 128 described above. A screw feeder (not shown) is installed in the cutting waste transfer passage.

  The collection tube attaching / detaching unit includes a clamp device 135, a collection tube holding member 136, a clamp moving device, and a support frame 131. The support frame 131 includes two support members 132A and 132B, a connecting member 133, and a base member 144 in which a through opening 145 is formed. The two supporting members 132A and 132B are attached to the upper surface of the base member 144 installed on the operation floor 143 at their lower ends, and extend upward while being separated from each other. The upper ends of the support members 132A and 132B are connected by a connecting member 133. The collection tube holding member 136 is slidably attached to the support members 132A and 132B at the upper ends of the support members 132A and 132B.

  The clamp moving device has a pair of rod-shaped rotating members 134A and 134B, a second motor (not shown), and a rotation transmission mechanism (not shown). The rotating members 134A and 134B each have a screw formed on the outer surface. The rotating member 134A is disposed along the support member 132A, and the rotating member 134B is disposed along the support member 132B. The lower end portion of the rotating member 134A is rotatably attached to the base member 144, and the upper end portion of the rotating member 134A is rotatably attached to the connecting member 133. A lower end portion of the rotating member 134B is rotatably attached to the base member 144, and an upper end portion of the rotating member 134B is rotatably attached to the connecting member 133. A second motor that rotates the rotating members 134 </ b> A and 134 </ b> B is installed at the center of the connecting member 133. A rotation transmission mechanism that transmits a rotational force from the second motor to the rotation member 134A is attached to the connection member 133, and a rotation transmission mechanism that transmits the rotation force from the second motor to the rotation member 134B is attached to the connection member 133.

  The clamp device 135 includes a clamp mechanism 146 and support portions 147A and 147B. The support portions 147A and 147B are attached to the clamp mechanism 146 and face the opposite direction of 180 °. Each of the support portions 147A and 147B has a threaded hole therethrough. The rotation member 134A passes through the screw hole of the support portion 147A, and the screws of the support portion 147A and the rotation member 134A mesh with each other. The rotation member 134B passes through the screw hole of the support portion 147B, and the screws of the support portion 147B and the rotation member 134B mesh with each other. In this way, the clamp device 135 is held by the rotating members 134A and 134B.

  The recovery pipe supply device (extension pipe supply device) 137 has a grip portion (not shown) that holds the recovery pipe (extension pipe) 139, and is attached to the support member 132B so as to be pivotable in the horizontal direction.

  The method for carrying out the nuclear fuel material of this embodiment will be described below. Each operation | movement of step S1-S7 implemented in Example 1 is performed in order, and it determines with the boring target object (cutting target object) in RPV2 being the steam dryer 7 and the steam-water separator 6 in step S8. In addition, each operation of steps S9 to S14 is performed in order. After the work of step S14 is completed, the work house 16A and the preparation house 16B installed on the operation floor 143 are removed from the operation floor 143 using the traveling crane 32 (or crawler crane) and transferred to the ground. .

  The shield device is installed (step S55). All the parts constituting the shield device 148 are transported onto the operation floor 143 using the traveling crane 32. Then, the shield device 148 is installed on the operation floor 143 in the following steps. A traveling crane 32 is used to install the shield device 148. The base member 144 is installed on the operation floor 143 so that the opening is positioned directly above the RPV 2. Based on this base member 144, other members of the shield device 148 are assembled. The lower ends of the support members 132A and 132B are attached to the base member 144, and the lower ends of the rotating members 134A and 134B are rotatably attached to the base member 144. The clamp device 135 is attached to the rotating members 134A and 134B, and the recovery tube holding member 136 is attached to the support members 132A and 132B, respectively. The recovery pipe supply device 137 is attached to the support member 132B as described above. A connecting member 133 provided with a motor and a rotation transmission mechanism is attached to the upper end portions of the support members 132A and 132B, and the upper end portions of the rotating members 134A and 134B are rotatably attached to the connecting member 133.

  A recovery pipe 129 to which the nuclear fuel material transfer pipe 130 is connected is connected to the recovery pipe 128. The collection tube holding member 136 holds the collection tube 129. The nuclear fuel material transfer pipe 130 is provided from the operation floor 143 to the nuclear fuel material recovery building (not shown) installed on the ground.

  The nuclear fuel material is carried out (step S56). The recovery pipe holding member 136 is lowered to lower the shield cutting device 123, and the cutter 125 of the shield cutting device 123 is brought closer to the upper lid 10 of the PCV 9. The recovery pipe holding member 136 is lowered by, for example, hydraulic cylinders installed on the holding members 132A and 132B, respectively. The clamp device 135 is also lowered so that the collection tube holding member 136 does not contact the clamp device 135. When the cutter 125 does not come into contact with the upper surface of the upper lid 10 due to the lowering of the recovery pipe holding member 136, the recovery pipe 139 held by the recovery pipe supply device 137 is connected to the recovery pipe 128 fixed to the housing body 123A. To do.

  The recovery pipe 139 is connected to the recovery pipe 128 as follows. The chuck of the chuck mechanism 146 is unfolded and the second motor is rotated to rotate the rotating members 134A and 134B. The clamp device 135 is lowered by the rotation of the rotating members 134A and 134B. When the clamp mechanism 146 is lowered to the position of the recovery pipe 128, the rotation of the rotating members 134A and 134B is stopped, and the lowering of the clamp device 135 is stopped. The spreading clamp mechanism 146 is narrowed and the collection tube 128 is gripped by the clamp mechanism 146. Then, the connection between the collection pipe 128 and the collection pipe 129 is released, the collection pipe holding member 136 is raised, and the collection pipe 129 is moved upward. When the distance between the recovery pipe 128 and the recovery pipe 129 exceeds the length of the recovery pipe 139, the raising of the recovery pipe holding member 136 is stopped. The collection pipe supply device 137 holding the collection pipe 139 to be connected rotates to place the collection pipe 139 between the collection pipe 128 and the collection pipe 129 and directly above the collection pipe 128. The clamp device 135 is raised by the rotation of the rotating members 134A and 134B, and the upper end of the recovery tube 128 is brought into contact with the lower end of the recovery tube 139 held by the recovery tube supply device 137. In this state, the recovery pipe 128 and the recovery pipe 139 are connected. The recovery pipe holding member 136 is lowered to bring the lower end of the recovery pipe 129 into contact with the upper end of the recovery pipe 139, and the recovery pipe 129 and the recovery pipe 139 are connected. At this time, the chuck mechanism 146 is expanded and the chuck mechanism 146 is separated from the recovery pipe 128.

  The recovery tube holding member 136 is lowered with the recovery tube 139 connected until the cutter 125 contacts the upper surface of the upper lid 10. If the cutter 125 does not come into contact with the upper surface of the upper lid 10 even if a single collection tube 139 is connected, the necessary number of pipes can be obtained by the above operation until the cutter 125 comes into contact with the upper surface of the upper lid 10. A collection tube 139 is further added. When the cutter 125 comes into contact with the upper surface of the upper lid 10, the lowering of the collection tube holding member 136 is stopped.

  The plurality of propulsion jacks 127 are driven to move the rotating body 124 toward the front surface in the axial direction of the shield cutting device 123, and the plurality of cutters 125 are pressed against the upper surface of the upper lid 10. The first motor is rotated to rotate the rotating body 124. Thereby, the some cutter 125 turns and cuts the upper cover 10. Each propulsion jack 127 is also a guide member, and the outer surface of each propulsion jack 127 facing the inner surface of the RPV 2 is in contact with the inner surface of the RPV 2, and assists the movement of the cutting portion and the propulsion portion within the RPV 2. Reaction forces generated during cutting by the plurality of cutters 125 are received by the collection tube holding member 136.

  The cutting waste of the upper lid 10 generated by the cutting of the cutter 125 is caused by the rotation of the screw feeder installed in the cutting waste transfer passage, and the cutting waste transfer passage in the shield cutting device 123 and the connected collection pipes 128, 139, 129 and the nuclear fuel material transfer pipe 130 are transferred to the nuclear fuel material recovery building. The transferred cutting waste is recovered in a cutting waste storage tank installed in the nuclear fuel material recovery building. The cutting waste storage tank is surrounded by a radiation shield.

  By the advancement of the rotating body 124 by driving the propulsion jack 127, the upper lid 10 is cut and an opening 10B penetrating the upper lid 10 is formed (see FIG. 58). The inner diameter of the opening 10B is dimensioned to allow the shield cutting device 123 to pass through. When the cutting of the upper lid 10 by the cutter 125 is finished, the driving of the propulsion jack 127 is stopped, and the recovery pipe holding member 136 is lowered by the hydraulic cylinder until the cutter 125 contacts the upper surface of the upper lid 3 of the RPV 2. The propulsion jack 127 is driven again to rotate the rotating body 124, and the upper lid 3 is cut by the plurality of cutters 125 that rotate. The cutting waste of the top lid 3 is also transferred to the nuclear fuel material recovery building through the cutting waste transfer passage in the shield cutting device 123, the connected recovery pipes 128, 139, 129 and the nuclear fuel material transfer pipe 130, and is separated by the separation device. Separated from. The separated cutting waste of the upper lid 3 is also collected in the cutting waste storage tank.

  When the cutting of the upper lid 3 by the cutter 125 is finished, the drive of the propulsion jack 127 is stopped, and the recovery pipe holding member 136 is lowered by the hydraulic cylinder until the cutter 125 contacts the upper end of the steam dryer 7 in the RPV 2. . An opening having a size that allows the shield cutting device 123 to pass through is also formed in the upper lid 3 that has been cut. In the middle of the lowering of the collection pipe holding member 136, a new collection pipe 139 is inserted between the collection pipe 129 and the collection pipe 139 directly connected to the collection pipe 129 as described above, and these collection pipes 129 and 139, respectively.

  When the cutter 125 comes into contact with the upper end of the steam dryer 7, the lowering of the recovery pipe holding member 136 is stopped, the propulsion jack 127 is driven, and the rotating body 124 is also rotated. The steam dryer 7 is cut from the upper end toward the lower end by the rotating cutter 125. When the rotating body 124 is moved downward by a predetermined distance by driving the propulsion jack 127, the rotating body 124 is moved upward by the predetermined distance by moving the propulsion jack 127 in the reverse direction. Thereafter, the recovery pipe holding member 136 is moved downward by that distance by the hydraulic cylinder and stopped. Again, the propulsion jack 127 is driven, and the steam dryer 7 is cut by the rotating cutter 125. The driving of the propulsion jack 127 and the lowering of the recovery pipe holding member 136 are repeatedly performed, the steam dryer 7 is cut to the lower end by the cutter 125, and the steam dryer 7 is entirely cut. As described above, the cutting waste of the steam dryer 7 is also transferred through the cutting waste transfer passage in the shield cutting device 123, the connected recovery pipes 128, 139, and 129 and the nuclear fuel material transfer pipe 130 to store the cutting waste. It is collected in the tank.

  The driving of the propulsion jack 127 and the lowering of the recovery pipe holding member 136 are repeatedly performed, and the recovery pipe 139 is repeatedly added as necessary, and the steam-water separator 6 is cut by the rotating cutter 125 (FIG. 58). The cutting waste of the steam separator 6 is also collected in the cutting waste storage tank.

  Further, the driving of the propulsion jack 127 and the lowering of the recovery pipe holding member 136 are repeatedly performed, and the recovery pipe 139 is repeatedly added as necessary, and the nuclear fuel in the upper lattice plate and the core 4 is rotated by the rotating cutter 125. Each fuel assembly including the material, the core shroud 116, the core support plate 5, the support cylinder 8, the plurality of control rod guide tubes 8A, the molten nuclear fuel material 13 dropped on the bottom of the RPV 2, and the bottom of the RPV 2 are sequentially cut. These cutting wastes are also transferred to the nuclear fuel material recovery building through the shield cutting device 123, the recovery pipes 128, 139, and 129 and the nuclear fuel material transfer pipe 130, and are recovered in the cutting waste storage tank. When cutting the bottom portion of the RPV 2, the control rod drive mechanism housing 39 attached to the bottom portion of the RPV 2 falls to the bottom portion of the PCV 9, but the shield cutting device 123 is lowered to the vicinity of the bottom portion of the PCV 9, so that the dropped control rod The drive mechanism housing 39 is also cut by the cutter 125.

  As described above, all the operations of the nuclear fuel material transfer method of the present embodiment are completed. The cutting waste collected in the cutting waste storage tank is stored in the fuel cask as needed and transferred to the fuel cask storage building.

  Based on the observation information in the RPV 2 in step S7, when it is determined that the boring object (cutting object) in the RPV 2 is the melt 13A present in the furnace bottom of the RPV 2, the shield device 148 in the above-described step S55. Are installed on the operation floor 143, and the melt 13A containing the nuclear fuel material is carried out in step S56. In this step S56, the molten nuclear fuel material 13 existing at the bottom of the furnace in the RPV 2 is cut by the shield cutting device 123 of the shield device 148, and the cutting waste of the molten nuclear fuel material 13A is collected in the cutting waste storage tank. . The furnace 125 of the RPV 2 and the control rod drive device housing 39 are cut by the cutter 125 of the shield cutting device 123. However, since the molten material 13A contains the molten nuclear fuel material and the in-furnace structure, cutting of the in-furnace structure such as the steam dryer 7 and the steam separator 6 by the shield cutting device 123 is not performed.

  In the present embodiment, each effect produced in the first embodiment can be obtained. Further, in this embodiment, the reactor internal structure and the molten nuclear fuel material in the RPV 2 are cut and carried out using the shield device 148 having the shield cutting device 123, so that the nuclear fuel material can be carried out in a shorter time than the first embodiment. It can be performed.

  When the method for carrying out the nuclear fuel material using the shield device 148 having the shield cutting device 123 is applied to the second embodiment, the method for carrying out the nuclear fuel material in the nuclear power plant is as follows. When each work of step S1, S45-S48 of Example 2 is implemented and it is determined in step S49 that the boring object (cutting object) in RPV is the steam dryer 7 and the steam-water separator 6 In step S50 to S54, S2, S3, and S14, the operations in steps S55 and S56 performed in the third embodiment are performed. Further, when the operations of steps S1, S45 to S48 of the second embodiment are performed, and it is determined in step S49 that the object to be drilled in the RPV is the melt 13A existing at the bottom of the furnace in the RPV 2. The steps S40 and S41 performed in the first embodiment do not install the traveling crane 32 above the reactor building 14 and further install the work house 16A and the preparation house 16B on the operation floor 143 of the reactor building 14. After that, steps S55 and S56 performed in the third embodiment are performed.

  In the present embodiment, each effect produced in the first embodiment can be obtained. Further, since the shield device 148 is used, the time required for carrying out the nuclear fuel material can be shortened as compared with the second embodiment.

  Each embodiment described above can be applied not only to a boiling water nuclear plant but also to a pressurized water nuclear plant.

Other inventive concepts of the present application will be described below.
(A1) Prior to cutting the nuclear fuel material in the nuclear fuel material presence region in the nuclear reactor vessel, the powdery shielding body in which the powdery shielding material is injected into the nuclear reactor vessel and the nuclear fuel material existence region is injected Covered with
A nuclear fuel cutting device is disposed above the nuclear fuel material presence region covered with the powder shielding body in the reactor vessel,
Cutting the nuclear fuel material in the nuclear fuel material presence region by the nuclear fuel cutting device;
A nuclear fuel material carrying-out method in a nuclear power plant for transferring the cut nuclear fuel material.
(A2) Before cutting the nuclear fuel material, a granular shielding body is injected into the reactor vessel, and after the injection of the granular shielding body into the nuclear reactor vessel is stopped, the nuclear fuel material is cut. Before the injection of the powdered shielding body into the reactor vessel and over the layer of the injected granular shielding body covering the nuclear fuel material presence region. A method for carrying out nuclear fuel material in a nuclear power plant according to (A1) covered with a body.
(A3) After the work house is installed on the operation floor of the reactor building in which the reactor vessel is installed directly above the reactor vessel, and the work house is installed on the operation floor, the powder shielding body (1) The nuclear fuel material carrying-out method in the nuclear power plant according to (A1).
(A4) The work house is installed on the operation floor of the reactor building in which the reactor vessel is installed directly above the reactor vessel, and after the work house is installed on the operation floor, the granular shield The nuclear fuel material carrying-out method in the nuclear power plant according to (A2), wherein the injection into the reactor vessel is performed.
(A5) Nuclear fuel in the nuclear power plant according to (A3) or (A4), in which the nuclear fuel cutting device is lowered from the work house into the reactor vessel, and the nuclear fuel material is cut by the nuclear fuel cutting device. How to carry out substances.
(A6) As the nuclear fuel cutting device, using a nuclear fuel cutting device having a cutting section that rotates to cut the nuclear fuel material and a transfer passage that transfers the cut nuclear fuel material,
Cutting of the nuclear fuel material in the nuclear fuel material presence region is performed by the rotating cutting unit rotating the cutting unit while moving the cutting part toward the lower end of the nuclear fuel material presence region,
The transport of the cut nuclear fuel material is performed by transporting the cut nuclear fuel material through the transfer passage. (1) The nuclear fuel material is carried out in the nuclear power plant according to any one of (A4). Method.
(A7) The movement of the cutting part toward the lower end of the nuclear fuel material presence region is performed by adding an extension pipe to the upper end of the transfer passage,
The method for carrying out the nuclear fuel material in the nuclear power plant according to (A6), wherein the transferred nuclear fuel material is transferred through the transfer passage and the extension pipe.
(A8) Before injecting the granular shielding body, an imaging device is inserted into the reactor vessel, the inside of the reactor vessel is imaged, and video information in the reactor vessel imaged by the imaging device is obtained. The nuclear fuel material carrying-out method in the nuclear power plant according to (A2) or (A4) displayed on the display device.

  DESCRIPTION OF SYMBOLS 1 ... Reactor, 2 ... Reactor pressure vessel, 4 ... Core, 9 ... Reactor containment vessel, 13 ... Molten nuclear fuel material, 13A, 13B ... Melt, 14 ... Reactor building, 16A ... Work house, 16B ... Preparation House, 18A, 18B ... overhead crane, 43, 43A ... boring device, 44, 44A ... cutting device, 45, 66A ... outer cylinder, 46 ... outer blade, 47 ... inner blade, 48 ... rotating shaft, 52A ... inner blade shaft Clamp, 52B ... outer blade shaft clamp, 53, 53A, 53B ... moving table, 60 ... extension tube supply device, 61 ... extension tube support member, 63, 63B ... extension tube moving device, 65, 65D ... gripping portion, 65A, 65B ... arm clamp, 66, 66B ... extension pipe, 81.81A ... cutting device, 123 ... shield cutting device, 124 ... rotating body, 125 ... cutter, 126 ... cylindrical body, 127 ... thrust Jack 131 ... support frame, 134A, 134B ... rotary member, 135 ... clamping device, 136 ... recovery pipe holding member, 137 ... recovery tube feeder, 146 ... clamping mechanism.

Claims (7)

A method for carrying out reactor internals present in a reactor vessel,
Using the first internal space formed in the first work house installed on the operation floor of the nuclear reactor building and the open / close shield door provided in the lower part of the first internal space, the shield door was opened. while, the step of unloading the core internals present in the reactor vessel to the first internal space of the first working house, and closed the shielding door, adjacent to the first working House The in- furnace structure that is provided in the arranged second work house, opens an open / close door that opens and closes an opening that communicates the first work house and the second work house, and exists in the first internal space Carrying out each of the steps of unloading an object to a second internal space formed in the second work house, which is outside the first work house , and with the open / close door closed, The in-furnace structure existing in the space is Method for carrying out core internals in nuclear power plant which comprises carrying out the process of unloading from the work house to the outside. A lifting means provided in the first work house and a recovery means attached to the lifting means, and lifting and lowering the lifting means to carry out the reactor internal structure from the reactor vessel. Item 2. A method for carrying out a reactor internal in a nuclear power plant according to Item 1. A working means for dismantling the furnace internal structure;
The unloading of the in-reactor structure in the nuclear power plant according to claim 2, wherein the in-reactor structure disassembled by the working means is unloaded from the upper part to the first work house by the recovery means. Method. The method for carrying out an in-core structure in a nuclear power plant according to claim 3, wherein the disassembled in-furnace structure is stored in an unloading container in the first work house and carried out. An in-reactor structure cutting device is lowered from the first work house into the reactor vessel whose upper end is opened, and is disposed above the in-reactor structure existing region in the reactor vessel, The reactor internal structure existing in the internal structure existence region is cut by the reactor internal structure cutting device, and the cut reactor internal structure is transferred from the reactor vessel to the first work house. 5. A method for carrying out a reactor internal in a nuclear power plant according to any one of items 1 to 4. A nuclear fuel cutting device is lowered from the inside of the first work house into the reactor vessel whose upper end is opened, and is disposed above the nuclear fuel material existing region in the reactor vessel, and is present in the nuclear fuel material existing region. 6. The method of carrying out a reactor internal structure in a nuclear power plant according to claim 5, wherein the nuclear fuel material to be cut is cut by the nuclear fuel cutting device, and the cut nuclear fuel material is transferred from the reactor vessel to the first work house. The first ventilation air conditioning system provided in the first work house purifies the air in the first internal space to remove radioactive substances contained in the air, and the second work house is provided with the second work house. The method for carrying out a reactor internal structure in a nuclear power plant according to claim 1, wherein the air in the second internal space is purified by a ventilation air conditioning system to remove radioactive substances contained in the air.

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