JP2019082490A - Carryout method of nuclear fuel material in nuclear power plant - Google Patents

Abstract

To provide a carryout method of a nuclear fuel material in a nuclear power plant which can carry out a melted nuclear fuel material in a shorter time.SOLUTION: A shied cutting device 123 having a rotating body 124 in which a plurality of cutters 125 for cutting a nuclear fuel material are arranged at a front face, a propulsion part having a plurality of propulsion jacks 127 for progressing the rotating body 124, and a first transfer passage for transferring the nuclear fuel material which is formed and cut in the propulsion part is arranged in an upper part of an RPV 2. The nuclear fuel material existing in a reactor core 4 in the RPV 2 is cut by using the plurality of cutters 125 arranged at the front face of the rotating body 124 while rotating the rotating body 124 by descending the shield cutting device 123 into the RPV 2. The nuclear fuel material is cut in an axial direction of the RPV 2 by progressing the rotating body 124 by driving the propulsion jacks 127 while rotating the rotating body 124. The cut nuclear fuel material is transferred through a first transfer passage 128 and a second transfer passage 139 which is connected to the first transfer passage.SELECTED DRAWING: Figure 58

Description

  The present invention relates to a method of unloading nuclear fuel material in a nuclear power plant, and more particularly to a method of unloading nuclear fuel material in a nuclear power plant suitable for application to a boiling water nuclear power plant and a pressurized water nuclear power plant.

  In nuclear power plants such as boiling water nuclear power plants and pressurized water nuclear power plants, a plurality of fuel assemblies containing nuclear fuel materials are loaded into the core of the nuclear reactor. A fuel assembly which has been loaded into the reactor core and has been operated in a predetermined number of operation cycles is unloaded out of the reactor from the reactor as a spent fuel assembly.

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

JP-A-8-262182

  According to the method for transferring 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 this case, it is a method of unloading the spent fuel assembly from the core. However, if an accident occurs in which the nuclear fuel material contained in the fuel assembly loaded in the core of the reactor melts, as in the case of a nuclear power plant at the Three Mile Nuclear Power Station, the molten nuclear fuel material The task of taking out the reactor from the reactor is extremely difficult and takes a long time to take out the fused and solidified nuclear fuel material.

  An object of the present invention is to provide a method for carrying out nuclear fuel material in a nuclear power plant which can carry out the molten nuclear fuel material in a shorter time.

  A feature of the present invention for achieving the above object is that a plurality of cutter devices for cutting nuclear fuel material are formed in a rotating body provided on the front surface, a propulsion unit having a plurality of propulsion jacks for advancing the rotating body, and a propulsion unit Using a shield cutting device having a transfer passage for transferring the cut nuclear fuel material, cutting of the nuclear fuel material in the nuclear fuel material existing area in the nuclear reactor vessel is performed by a plurality of cutter devices which are pivoted by the rotation of the rotating body. The advancing of the rotating body is performed by a plurality of propulsion jacks, and the cut nuclear fuel material is to be transferred through the transfer passage.

  Cutting of the nuclear fuel material in the nuclear fuel material existing region in the reactor vessel is performed by a plurality of cutter devices which are pivoted by the rotation of the rotating body of the shield cutting device, and the advancing of the rotating body is performed by a plurality of propulsion jacks, Since the cut nuclear fuel material is transferred through the transfer passage, even if the nuclear fuel material in the core melts, the nuclear fuel material can be removed in a shorter time.

  According to the present invention, it is possible to carry out the melted nuclear fuel material in a shorter time.

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-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 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 device shown in FIG. 6, (A) is an enlarged longitudinal sectional view of the cutting device, (B) is an enlarged longitudinal sectional view of the extension pipe. FIG. 7 is an enlarged longitudinal sectional view showing a connection state and a separation state of a cutting device and an extension pipe of the boring device shown in FIG. 6, wherein (A) is an enlarged longitudinal sectional view showing the cutting device and the extension pipe separated; ) Is an enlarged longitudinal sectional view showing the connected cutting device and extension pipe. It is explanatory drawing which shows the state which hold | maintained the extension pipe by the extension pipe movement 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 to a cutting device. It is explanatory drawing which shows the process of the second half of the procedure of connecting an extension pipe to a cutting device. It is explanatory drawing which shows the process of the first half of the procedure of withdrawing the rotating shaft from inside each outer cylinder of the cutting device and extension pipe which are inserted and connected in reactor pressure vessel. It is explanatory drawing which shows the process of the second half of the procedure of withdrawing the rotating shaft from the inside of each outer cylinder of the cutting device and extension pipe which are inserted and connected in reactor pressure vessel. In Example 1, a camera is inserted in the upper end part of a reactor pressure vessel, and it is explanatory drawing which shows the state which opened the hole in the steam dryer and the steam separator using a boring apparatus. In Example 1, it is explanatory drawing which shows the state which inserted the camera between the steam separator and the core through the hole opened to the steam dryer and the steam separator. It is explanatory drawing which shows the state which injected the iron ball and the iron powder in the core. It is explanatory drawing which shows the process of the first half of the procedure of withdrawing each outer cylinder inserted in the reactor pressure vessel and connected from the reactor pressure vessel. It is explanatory drawing which shows the process of the second half of the procedure of withdrawing 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 the turntable on the bottom of the house shown in FIG. FIG. 5 is an explanatory view showing unloading of the upper lid of the reactor containment vessel performed in the first embodiment. It is explanatory drawing which shows the cutting process of the upper lid in the carrying out process of the upper lid of the reactor container 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 reactor container shown in FIG. FIG. 7 is an explanatory view showing unloading of the steam-water separator performed in the first embodiment. It is explanatory drawing which shows cutting | disconnection of the steam separator in the carrying out process of the steam separator shown in FIG. FIG. 7 is an explanatory view showing unloading of the water supply sparger performed in the first embodiment. FIG. 2 is a detailed block diagram of an abrasive water jet apparatus used for cutting components performed in the first embodiment. In Example 1, it is explanatory drawing which shows the state which installed the boring apparatus of another type 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 vertical 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. FIG. 8 is an explanatory view showing unloading of nuclear fuel material present in the core performed in Example 1. FIG. 7 is an explanatory view showing a state of injection of iron powder (shielding powder) to the core performed after unloading nuclear fuel material from the core in Example 1; It is explanatory drawing which shows the boring performed toward a furnace bottom using a boring apparatus in Example 1. FIG. FIG. 7 is an explanatory view showing a state of injection of iron powder onto molten nuclear fuel material dropped to the furnace bottom performed in Example 1. FIG. 40 is an explanatory view showing cutting of a core shroud performed after iron powder injection shown in FIG. 39; FIG. 10 is an explanatory view showing unloading of the nuclear fuel material dropped to the furnace bottom performed in Example 1. FIG. 7 is an explanatory view showing a state of injection of iron powder to the furnace bottom performed after unloading nuclear fuel material from the furnace bottom performed in Example 1. It is explanatory drawing which shows each state of the iron powder injection which is performed below the boring and the reactor pressure vessel which are performed toward the downward direction rather than a reactor pressure vessel using a boring apparatus in Example 1. FIG. FIG. 5 is an explanatory view showing cutting of a core shroud lower shell performed in Example 1; FIG. 8 is an explanatory view showing unloading of nuclear fuel material dropped to the bottom of the reactor containment vessel performed in the first embodiment. FIG. 6 is an explanatory view showing cutting and unloading of the reactor pressure vessel performed in Example 1; FIG. 7 is an explanatory view showing a state after unloading of the reactor pressure vessel in Example 1; FIG. 8 is an explanatory view showing a boring of the reactor pressure vessel by the boring device performed at the time of unloading the nuclear fuel material in the case where the nuclear fuel material and the internal structure in the reactor pressure vessel in the first embodiment are melted. FIG. 10 is an explanatory view showing injection of iron powder onto molten nuclear fuel material at the bottom of the reactor performed at the time of unloading the nuclear fuel material when nuclear fuel material and reactor internals in the reactor pressure vessel are melted in Example 1; . FIG. 8 is an explanatory view showing unloading of the equipment remaining in the reactor pressure vessel performed at the time of unloading of the nuclear fuel material in a case where nuclear fuel materials and reactor internals in the reactor pressure vessel are melted in Example 1; FIG. 8 is an explanatory view showing the delivery of the molten nuclear fuel material present in the reactor bottom performed at the time of unloading the nuclear fuel material in the case where the nuclear fuel material in the reactor pressure vessel and the internal structure in the first embodiment are fused. FIG. 8 is an explanatory view showing the delivery of the molten nuclear fuel material dropped to the bottom of the reactor containment performed at the time of unloading of the nuclear fuel material in the case where the nuclear fuel material and internals in the reactor pressure vessel are melted in Example 1; . 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 other Example of this invention on the opening / closing-type shielding member. In Example 2, a camera is inserted in the upper end part of a reactor pressure vessel, and it is explanatory drawing which shows the state which opened the hole in the steam dryer and the steam separator using a boring apparatus. In Example 2, it is explanatory drawing which shows the state which inserted the camera between a steam separator and a core through the hole opened to a steam dryer and a steam 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 excavation apparatus used for the method of carrying out the nuclear fuel material in the nuclear power plant of Example 3 which is another Example of this invention. In Example 3, it is explanatory drawing which shows cutting of the structure in a reactor pressure vessel using a shield advancing 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 advancing apparatus.

  Examples of the invention are described below.

  A method of carrying out nuclear fuel material in the nuclear power plant of Example 1 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 a method of carrying out nuclear fuel material 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 reactor 1 and a reactor containment vessel (hereinafter referred to as PCV) 9. The PCV 9 is installed in the reactor building 14, and the upper lid 10 is attached and sealed at the upper end. The PCV 9 has a dry well 11 formed therein, and a pressure suppression chamber 12 in which a pressure suppression pool filled with cooling water is formed. One end of a vent passage in communication with the dry well 11 is immersed in the cooling water of the pressure suppression pool in the pressure suppression chamber 12.

  Shield plugs 15, which are a plurality of divided radiation shields, are 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 by attaching 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. And the like. The reactor 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. The lower end of each fuel assembly loaded in the core 4 is supported by the core support plate 5 and the upper end is held by an upper grid plate (not shown). The steam separator 6 is disposed above the upper grid plate located at the upper end of the core 4, and the steam dryer 7 is disposed above the steam separator 6.

  A plurality of control rod guide tubes 8A are disposed below the core 4, and a support cylinder 8 including a plurality of control rod guide tubes 8A is formed. Control rods (not shown) for controlling the reactor power by being inserted into and out of the fuel assemblies in the core 4 are disposed in each control rod guide tube 8A. A plurality of control rod drive housings 39 are attached to the lower mirror of the RPV 2. A control rod drive mechanism (not shown) is installed in each control rod drive mechanism housing 39 and connected with the control rods in the control rod guide tube 8A.

  Steam separator 6 installed in RPV2, steam dryer 7, shroud 87 (described later), upper grid plate, core shroud 116, core support plate 5, support cylinder 8, control rod guide tube 8A, core shroud lower shell 116A is a reactor internal.

  The RPV 2 is mounted on a cylindrical pedestal 37 provided on a concrete mat 38 provided at the bottom of the PCV 9. A cylindrical gamma ray shield 120 is placed 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 sources supplying the current of the boiling water nuclear power plant are temporarily lost and the emergency core cooling is performed. Assume that a condition has occurred where the system did not operate. When all the power is lost, the pumps of the emergency core cooling system, etc. do not operate, and the cooling in each fuel assembly in the core 4 is lost, the nuclear fuel material contained in the fuel assembly melts, Molten nuclear fuel material may fall to the bottom of RPV2.

  If such a fall of the molten nuclear fuel material to the bottom of the RPV 2 occurs, the export of the molten nuclear fuel material to the outside of the RPV 2 and the fall of the molten nuclear fuel material occur for the boiling water nuclear power plant Decommissioning treatment is implemented.

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

  First, when carrying out the nuclear fuel material, the obstacle is removed (step S1). For example, when obstacles for carrying out nuclear fuel material are present on the operating floor of a damaged reactor building, these obstacles are removed using a crawler crane (not shown) or the like. Be removed.

  A traveling crane is installed above the reactor building (step S2). As shown in FIG. 1, a plurality of support members 29A are installed on the outside of one of the opposite side walls of the reactor building 14. Guide rails 31A are installed at the upper ends of these support members 29A. A plurality of support members 29B are installed outside the other side wall of each side wall. Guide rails 31B are installed at the upper ends of these support members 29B. Opposing support members 29A and support members 29B 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, 31B using a crawler crane. The traveling crane 32 includes a traveling carriage 33 moving along the guide rails 31A and 31B, and traversing carriages 34A and 34B provided on the traveling carriage 33 and moving on the traveling carriage 33 in a direction orthogonal to the guide rails 31A and 31B. Have. The traverse carriages 34A, 34B are respectively provided with hooks 35A, 35B which are moved up and down by a wire winding device (not shown).

  The house is installed on the operating floor of the reactor building (step S3). The work house 16A is suspended by 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 to the upper side of the work house 16A, and installed on the work house 16A (see FIG. 1). Seals are provided between the operating floor and the floor of the working house 16A, and between the ceiling of the working house 16A and the floor of the preparation house 16B, respectively, in order to maintain the airtightness between the inner spaces 17A and 17B and the exterior.

  The work house 16A is surrounded by four side walls on four sides, and a floor 22 (see FIG. 2) is attached to lower ends of the side walls, and a ceiling is attached to upper ends of the side walls. Inside the working 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 immediately above the shield plug 15, and an opening (not shown) is formed just above the opening 23 also on the ceiling of the work house 16A. A hydraulic pump / control board 25 is disposed in the interior space 17A and installed on the floor 22. A space 24 in which the discharge container is placed is secured on the floor 22. An overhead crane 18A is installed near the ceiling in the interior space 17A. The overhead crane 18A includes a traveling carriage 19A and a trolley 20A provided on the traveling carriage 19A and movable along the longitudinal direction of the traveling carriage 19A. The 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 an internal space 17A of the work house 16A. A mobile multi-axis robot 26A mounted with a camera for observation is placed on the floor of the work house 16A.

  The preparation house 16B is also surrounded on four sides by four side walls, and a floor is attached to the lower end of these side walls, and a ceiling is attached to the upper end of these side walls. Inside the preparation house 16B, an inner space 17B surrounded by four side walls, a floor and a ceiling is formed. Openings (not shown) are respectively formed just above the openings 23 also in the floor and ceiling of the preparation house 16B. The opening does not have to be disposed directly above the opening 23. Although not shown, a hydraulic pump / control board 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 includes a traveling carriage 19B and a trolley 20B provided on the traveling carriage 19B and movable along the longitudinal direction of the traveling carriage 19B. The 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 provided in an internal space 17B of the preparation house 16B. A mobile multi-axis robot 26B mounted with a camera for observation is placed on the floor of the preparation house 16B.

  After installation of the work houses 16A and 16B, an external power supply is connected to the hydraulic pump / control board 25 in each house. The 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 supplied with electricity from the hydraulic pump / control board 25 in the work house 16A and operate. The 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 supplied with electricity from the hydraulic pump / control board 25 in the work house 16B to operate.

  The hydraulic pump of the hydraulic pump / control board 25 installed respectively in the working houses 16A and 16B is operated by the arm provided on each arm etc. of the movable multi-axis robots 26A and 26B placed in the working houses 16A and 16B. 26 are respectively connected to the cylinders provided in the cutting and disassembling apparatus 88 and the disassembling grapple apparatus 93 shown in FIG. 26, and the hydraulic pressure is controlled to move the movable multi-axis robots 26A and 26B and the cutting and disassembling apparatus 88. And control each operation | movement of the grapple apparatus 93 for disassembly.

  An open / close door 78 is slidably installed on the top of the ceiling of the preparation house 16B, and opens and closes the 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 to open and close an opening formed in the floor. Opening and closing operations of the opening and closing doors 77 and 78 are performed by a motor (not shown).

  The boring device is carried into the work house (step S4). A boring device 43 is suspended on hooks 35A of the traveling crane 32 (see FIG. 3), and through openings formed in the ceiling and floor of the preparation house 16B and the floor of the work house 16A, the interior space of the work house 16A. It is carried into the housing 17A and placed on the opening and closing 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 by the hook 35A of the traveling crane 32, and is carried into the interior space 17A of the work house 16A.

  The structure of the opening and closing shielding member 15A will be described with reference to FIG. The openable and closable 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 movably installed along the rails on rails respectively provided on a pair of beams 30 placed on the operation floor. 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 the hole 42 formed at the joint of the shielding doors 40A and 40B. When the hook 35A is pulled up above the preparation house 16B 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.

  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 board 25 in the working house 16A to the boring device 43 in the working house 16A (see FIG. 5). When unloading the boring device 43 from the work house 16A, the mobile multi-axis robot 26A removes the connector of the power cable 141 from the boring device 43. Description of connection and removal work of such a power supply cable 141 and the boring device 43 (or the boring device 43A described later) will be omitted hereinafter. After the power supply cable 141 is connected to the boring device 43, boring to 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 has 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 of the mast member 51B. The inner blade shaft clamp 52A is disposed above the outer blade shaft clamp 52B. The movable table 53A is attached to the mast member 51B so as to be movable in the vertical direction. The support member 54 is attached to the moving table 53A. Motors 56A and 56B are attached to the upper surface of the support member 54. The drive socket 54A is connected to the rotation shaft of the motor 56A via a gear mechanism (not shown).

  As shown in FIG. 8, the movable table 53B is disposed below the support member 54, and is movably attached to the movable table 53A in the vertical direction. The connector portion 57 in which the rotation shaft 57A is provided is fixed to the moving table 53B. The rotary shaft 57A passes through the upper end of the connector portion 57, and the through portion of the connector portion 57 is sealed in order to maintain air tightness. A cylindrical clamp device 54B is rotatably attached to the moving table 53B through the moving table 53B. A gear 57C rotatably mounted on 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 holds an outer cylinder 45 (described later) of the cutting device 44.

  The cutting device 44 has an outer cylinder (outer blade shaft) 45, an outer blade 46, an inner blade 47, and a rotating shaft (inner blade shaft) 48, as shown in FIG. 9A. The 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 rotating 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 attached to the lower end of the outer cylinder 45. The width of the outer sleeve 46 in the radial direction of the outer sleeve 46 is larger than the thickness of the outer sleeve 45, as shown in FIG. 9A. Two elongated support plates 48A respectively extend from the rotation shaft 48 to the opposite side 180, and each support plate 48A is rotatably mounted on the outer surface of the rotation shaft 48 in the vertical direction. A stopper member (not shown) for blocking the rotation of the support plate 48A above the horizontal is fixed to the rotation shaft 48 just above the mounting position of each support plate 48A with the rotation shaft 48. The ring member 45A 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 1/2 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) attached to the rotating shaft 48 with a weak spring force to support the weight of the support plate 48A. There is. Therefore, when the inner blade 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 blade 47 passes through the inside of the ring member 45A and is more than the ring member 45A. It reaches the lower side, and the tip of the support plate 48A is supported by the upper surface of the ring member 45A. The respective support plates 48A are supported by the ring member 45A because the support plates 48A are not rotated upward from horizontal by the stopper members, and as a result, the rotary shaft 48 is supported by the outer cylinder 45. An annular passage 50 is formed between the rotating shaft 48 and the outer cylinder 45 through which the collected material (for example, cuttings) passes.

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

  The rotating shaft 57A is coupled to the drive socket 54A with the upper end portion thereof inserted into the drive socket 54A as shown in FIG. The upper end portion of the outer cylinder 45 is inserted into the clamp device 54B and gripped by the clamp device 54B. The clamp device 54B is a drive socket that rotates the outer cylinder 45. A gear 57C for rotating the clamp device 54B is connected to the rotation shaft of the motor 56B and meshes with a rotational force transmission mechanism (not shown) provided on the support member 54. The rotational force transmission mechanism can separate the meshing with the gear 57C when moving the moving table 53B along the moving table 53A.

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

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

  The extension pipe supply device 60 has an extension pipe support member 61 and an extension pipe moving device 63. The extension tube support member 61 has an extension tube holder 62 at its upper end (see FIG. 6). A plurality of extension pipe suspending portions 64 are provided in the extension pipe holding portion 62. Each extension pipe suspending portion 64 has chuck holders 64A and 64B as shown in FIG. The chuck holders 64A and 64B are separately movable in the vertical direction. With the extension pipes 66 suspended by the extension pipe holding portion 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, and the outer cylinder of the extension pipe 66 The upper end portion of the blade shaft 66A is gripped by the chuck holder 64B.

  As shown in FIG. 9B, the extension tube 66 is provided with a rotation shaft (inner blade shaft) 48 in an outer cylinder 66A (outer blade shaft). Similarly to the cutting device 44, the extension tube 66 also has the two elongated support plates 48A rotatably mounted on the rotation shaft 48 in the vertical direction. Further, a stopper member (not shown) for blocking the rotation of the support plate 48A above the horizontal is fixed to the rotating shaft 48, and the ring member 66C is an inner surface of the outer cylinder 45 like the ring member 45A. It is fixed to The inner diameter of the ring member 66C is larger than the outer diameter of the inner blade 47. In the extension tube 66 as well, similarly to the cutting device 44, each support plate 48A is pressed against the lower surface of the corresponding spar member by each spring member (not shown) attached to the rotation shaft. Therefore, the rotary shaft 48 of the extension tube 66 is supported by the support plate 48A and the ring member 66C on the outer cylinder 66A, and an annular passage 50A through which the recovered material (for example, cuttings) passes also between the rotary shaft 48 and the outer cylinder 66A. Is formed. In the extension tube 66, the lower end of the rotating shaft 48 is located above the lower end of the outer cylinder 66A by a dimension L, and the upper end of the rotating shaft 48 protrudes above the upper end of the outer cylinder 66A by a dimension L.

  The extension tube moving device 63 has a rotary body 63A, an arm 65C, and a grip portion 65 (see FIG. 7). A rotating shaft 62A is rotatably attached to the extension tube holder 62 and extends downward from the extension tube holder 62. The rotating body 63A is attached to the rotation 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. By the horizontal turning of the rotary body 63A, the arm 65C also turns in the horizontal direction. The gripping portion 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 of the upper lids 10 and 3 will be described. The boring device 43 rests on the shielding door 40B 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 the shielding door 40B in one hole 42 Located directly above. The movable table 53A is lowered to insert the outer blade 46 and the inner blade 47 into the hole 42. When the motor 56A is rotated, the drive socket 54A is rotated, and 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 pivoted. In a state where the inner blade 47 and the outer blade 46 are rotated, the movable 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. The cut pieces (a kind of recovered material) of the shield plug 15 pass through the annular passages 50, 57B, the recovered material discharge port 58 and the transfer duct 59 by the drive of a suction device (not shown) provided in the transfer duct 59. It is collected in the collection container. When the outer cylinder 45 is rotating, the clamp device 52 (specifically, the outer blade shaft clamp 52B) does not grip the outer cylinder 45.

  When cutting of the shield plug 15 is performed by the cutting device 44 which rotates while lowering the moving table 53A and the clamp device 54B is lowered to the position of the clamp device 52 (see FIG. 12A), the lowering of the moving table 53A is stopped The rotation of the motors 56A and 56B is stopped. Then, the upper end portion of the outer cylinder 45 is gripped by 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 disposed around the clamp device 54B without contacting the moving base 53B and the clamp device 54B. . The transfer duct 59 which is flexible and connected to the collected material discharge port 58 also descends as the moving table 53A descends.

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

  The movable table 53A is raised along the mast member 51B such that the clamp device 54B is located above the extension pipe suspending portion 64 provided in the extension pipe holding portion 62. Since the rotation shaft 57A is pulled up by the movement of the moving table 53A, the rotation shaft 57A is separated from the rotation shaft 48. The gripping portion 65 grips one extension pipe 66 suspended from the extension pipe suspending portion 64. At this time, the upper end portion of the rotation shaft 48 of the extension tube 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 rotary shaft 62A is rotated to turn the rotary body 63A. The arm 65C pivots in the horizontal direction to move the extension tube 66 gripped by the arm clamps 65A and 65B to a position just above the cutting device 44 gripped by the clamp device 52 (see FIG. 12D). Then, the movable table 53A is lowered, and the upper end portion of the rotary shaft 48 of the extension tube 66 is connected to the lower end portion of the rotary shaft 57A. After connecting the rotating shaft 48 to the rotating shaft 57A, the arm clamp 65A is separated from the upper end of the rotating shaft 48 of the extension tube 66.

  The moving table 53B is moved downward, the upper end of the outer cylinder 66A of the extension tube 66 is inserted into the clamp device 54B, and the upper end 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 of the rotating shaft 48 of the extension tube 66 is connected to the upper end of the rotating shaft 48 of the cutting device 44 gripped by the inner blade shaft clamp 52A (FIG. 13) (C)). The connection between the lower end portion of the rotary shaft 48 of the extension tube 66 and the upper end portion of the rotary shaft 48 of the cutting device 44 is performed by a known detachable connection structure. After connection of the two rotating shafts 48, the inner blade shaft clamp 52A is separated from the upper end of the rotating 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 gripped by the outer blade shaft clamp 52B. Thereafter, the outer blade shaft clamp 52B is separated from the upper end 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-shaped connecting members 45B are provided at the connecting portion at the upper end of the outer cylinder 45 (see FIG. 10A). The 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 of each connecting member 45B is processed into a hemispherical shape. A plurality of through holes 66D having an inner diameter equal to the outer diameter of the connecting member 45 are formed in the circumferential direction at the connecting portion at the lower end portion of the outer cylinder 66A. The through holes 66D are formed in the circumferential direction of the outer cylinder 66A at the same intervals as the intervals of the connecting member 45B provided in the outer cylinder 45 in the circumferential direction. 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 falling outer cylinder 66A contacts the hemispherical outer surface of the connecting member 45B provided on the upper end portion of the outer cylinder 45, the curved surface along with the falling of the outer cylinder 66A. The connecting member 45 B is pushed toward the inside of the outer cylinder 45, and the connecting member 45 B moves toward the inside of the outer cylinder 45 by overcoming the pressing force to the outside by the spring. When the through hole 66D is lowered to the position of the connecting member 45B, the connecting member 45B which is pressed outward by a 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, while rotating the motors 56A and 56B, the movable table 53A is gradually lowered from the state shown in FIG. 13D, and cutting of the shield plug 15 by the inner cutter 47 and the outer cutter 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 tube 66 shown in FIGS. 12 (A) to 12 (D) and 13 (A) to 13 (D). Is repeated, and the upper lids 10 and 3 are respectively cut by the inner blade 47 and the outer blade 46 to form through holes 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 to retract the boring device (step S6). In step S5, of the cutting device 44 and the extension tube 66 which are connected through the shield plug 15 and the upper lids 10 and 3 by cutting the shield plug 15 and the upper lids 10 and 3, the outer cylinder 45 and 66A is shielded The rotary shaft 48 of the cutting device 44 and the rotary shaft 48 of the extension tube 66 are pulled out leaving the plug 15 and the upper lids 10 and 3 in a penetrating state. The drawing operation of these rotating shafts 48 will be described with reference to FIGS. 14 and 16.

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

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

  The moving table 53A is raised along the mast member 51B until it is positioned above the arm 65C as shown in FIG. 14 (C). The rotation shaft 48 of the extension tube 66 is pulled out of the outer cylinder 66A, and the rotation shaft 48 of the cutting device 44 connected to the rotation shaft 48 is also raised to reach the inside of the outer cylinder 66A from the inner cylinder 45. As described above, the support plate 48A is installed on each rotating shaft 48 so as to be vertically rotatable, and the radial length of the outer cylinder of each stopper member attached to each rotating shaft is For example, the length is 1/4 of the inner diameter of the ring members 45A and 66C. Therefore, when the rotation shaft 48 of the extension pipe 66 located at the highest position in the shield plug 15 is pulled out, if the support plate 45A of the cutting device 44 contacts the ring member 66C of the extension pipe 66 located at the upper side, it moves downward. By rotating, the support plates 45A of the cutting device 44 can easily pass through the ring member 66C, and the stopper members of the cutting device 44 can 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 top in the shield plug 15 is pulled out, Similarly to the support plate 48A of the cutting device 44, each support plate 48A provided on the rotation shaft 48 also rotates downward, and along with each stopper provided on the rotation shaft 48 of the other extension tube 66, upward It can easily pass through the ring member 66C of the extension pipe 66 located.

  Therefore, as described above, the rotary shaft 48 of the extension pipe 66 located uppermost in the shield plug 15 can be pulled out from the outer cylinder 66A, and the rotary shaft 48 of the cutting device 44 can also be pulled out from the outer cylinder 45. . After raising the movable table 53A so as to be positioned above the arm 65C, the cutting device 44 protruding above the upper end of the outer cylinder 66A is the rotating shaft 48 (or a plurality of cutting devices other than the cutting device 44 in step S5). When the extension tube 66 is connected, the upper end portion of the rotation shaft 48 of the other extension tube 66 is gripped by the inner blade shaft clamp 52A (see FIG. 14C).

  The rotation shaft 48 of the extension tube 66 and the rotation shaft 48 of the cutting device 44 (or the rotation shaft 48 of the other extension tube 66) present in the outer sleeve 66A, which are pulled out of the outer cylinder 66A by raising the moving table 53A. Is released (see FIG. 14D). Thereafter, the rotation shaft 62A and the arm 65C are rotated to pivot the arm clamp 65A to the position of the extracted rotation shaft 48, and the arm clamp 65A grips the upper end portion of the rotation shaft 48. The connection state between the rotation shaft 48 of the extension tube 66 and the rotation shaft 48 of the cutting device 44 (or the rotation shaft 48 of the other extension tube 66) present in the outer cylinder 66A, drawn out of the outer cylinder 66A is After being released, the rotation shaft 48 of the cutting device 44 (or the other extension tube 66) present in the outermost cylinder 66A located at the highest position in the shield plug 15 is the most upward by the pair of support plates 48A. The ring member 66C of the outer cylinder 66A located at For this reason, falling of the rotating shaft 48 present in the outer cylinder 66A left in the shield plug 15 or the like is prevented.

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

  The rotation shaft 62A is rotated to pivot the arm 65C toward the extension pipe supply device 60, and the upper end portion of the rotation shaft 48 gripped by the inner blade shaft clamp 52A is extended pipe extension provided in the extension pipe holding portion 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 pipe suspending portion 64 (see FIG. 15 (B)). The inner blade shaft clamp 52A is separated from its rotation axis 48.

  The movable table 53A is lowered, and the lower end portion of the rotation shaft 57A protrudes upward than the upper end of the outer cylinder 66A whose upper end portion is gripped by the outer blade shaft clamp 52B, and is held by the inner blade shaft clamp 52A. It is connected to the upper end portion of the shaft 48 (see FIG. 15C). Then, 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 axes shown in FIGS. 14 (A) to 14 (D) and 15 (A) to 15 (C). The extraction procedure of 48 is repeated until the rotation shaft 48 of the cutting device 44 is gripped by the chuck holder 64A of the extension pipe suspension portion 64.

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

  The inside of the RPV is observed (step S7). The pipe 68A connected to the ventilating air conditioning / water injection system 69 is connected to the upper end of the outer cylinder 66A located uppermost in the shield plug 15, as shown in FIG. The connected outer cylinders 66A and 45 penetrate the shield plug 15 and the upper lids 10 and 3, respectively. The lower end of the lowermost outer cylinder 45 reaches the inside of the RPV 2. After suctioning and treating the gas in the RPV 2 with the ventilation air conditioning / water injection system 69, the camera and dosimeter 68 are inserted into the RPV 2 through the piping 68A and the outer cylinders 66A and 45 (see FIG. 16). Image information obtained by photographing and dose measurement values in the RPV 2 are output. The output image information and dose measurement value are displayed on a display (not shown) installed at a safe place outside the work house 16A.

  The boring object in the RPV is determined (step S8). Since the steam drier 7 appears on the display device, the operator first determines the steam drier 7 and the air-water separator 6 as the objects to be drilled, and performs boring processing using the boring device 43 for these objects. Decide that. Then, the operator inputs a command for carrying out the boring process from the control room provided on the ground to the hydraulic pump / control board 25.

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

  The inner blade is pulled out to retract the boring device (step S10). Similar to step S6, the extraction procedure of the rotating shaft 48 shown in FIGS. 14 (A) to 14 (D) and 15 (A) to 15 (C) is repeated to each rotating shaft 48 and the inner blade. 47 is pulled out of the outer cylinder 66A located at the top in the shield plug 15, and then the boring device 43 is retracted in the working house 16A. The outer cylinder 66A and the outer cylinder 45 connected by pulling out the rotary shafts 48 and the inner blade 47 are from the shield plug 15 to the center of the RPV 2 between the lower end of the steam 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). A camera and a dosimeter 68 are inserted to the lower position of the steam / water separator 6 through the outer cylinder 66A disposed in the steam / water separator 6 and the steam dryer 7 and the like and the outer cylinder 45 (FIG. 17). reference). The camera and the dosimeter 68 capture the condition of the core 4 and measure the dose of the core 4. The image information obtained by the photographing and the measured dose are displayed on the above-mentioned display installed outside the work house 16A. Since the display device shows the molten state of the core 4, the operator decides that it is necessary to carry out the molten nuclear fuel material. The plug 41 is installed by the movable multi-axis robot 26A at the upper end portion of the outer cylinder 66A located at the highest 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 shield in the next step S12 is determined.

  The shield is injected into the core (step S12). The shield supply device 71 is suspended by the hooks 35A of the traveling crane 32, and is carried into the interior space 17B of the preparation house 16B through the opening of the ceiling of the preparation house 16B where the open / close door 78 is opened and released. After the shielding 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 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 by the hook 21B is the opening of the floor of the preparation house 16B and the opening of the ceiling of the working house 16A where the opening / closing door 77 is opened. Is carried into the interior space 17A of the working house 16A. After the shielding 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 place 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 in the outer cylinder 66A disposed on the central axis of the RPV 2. An injection pipe 72 connected to the shield supply device 71 is connected to the upper end of an outer cylinder 66A disposed at the top in the shield plug 15, which is disposed along the central axis of the RPV 2. Two separate areas are formed in the shield supply device 71, and small iron balls 70A, which are granular shields, are filled in one area, and iron powder 70B, which is a powder shield, in other areas. It is filled.

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

  The outer cylinder is recovered and the boring device is carried out (step S13). The pipes 82, 68 are removed using the mobile multi-axis robot 26A. The boring device 43 is disposed on the outer cylinder 66A disposed 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 is Pull up and collect.

  The operation of collecting the outer cylinder 45, 66A will be described with reference to FIGS. In order to make the description easy to understand, the respective outer cylinders 66A located at the uppermost position in the seal plug 15 (in FIG. 18, arranged on the central axis of the RPV 2) are all pulled out in the steps S6 and S10. It is assumed that the upper end of each of the outer cylinder 66A and the other outer cylinder 66A disposed at a position away from the central axis of the RPV 2 is in the state shown in FIG. 19 (A). In this state, the upper blade shaft clamp 52B grips the upper end portion of the outer cylinder 66A located uppermost in the shield plug 15 on the central axis of the RPV 2.

  The movable table 53A is lowered, and the upper end portion of the outer cylinder 66A protruding above 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.

  The movable table 53A is elevated along the mast member 51B until it is positioned above the arm 65C as shown in FIG. 19C. The outer cylinder 66A gripped by the clamp device 54B is pulled out of 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 when the extension pipes 66 are connected to the cutting device 44 in step S10, the outer periphery of the other outer cylinder 66A) There is a blade shaft clamp 52B. The outer blade shaft clamp 52B grips the upper end of the outer cylinder 45 (or another outer cylinder 66A).

  With the outer blade shaft clamp 52B gripping the upper end of the outer cylinder 45 (or the other outer cylinder 66A), the moving table 53A is further raised. The connection between the lower end portion of the outer cylinder 66A gripped by the clamp device 54B and the upper end portion of the outer cylinder 45 (or the other outer sleeve 66A) gripped by the outer blade shaft clamp 52B is released, The outer cylinder 66 thus obtained 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 rotation shaft 62A and the arm 65C are rotated to pivot the arm clamp 65B to the position of the pulled outer cylinder 66A, and the arm clamp 65B grips the upper end portion of the outer cylinder 66A.

  The release of the connection 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 using FIG. explain. A connecting member release clamp 52C is disposed above the outer blade shaft clamp 52B and attached to the outer blade shaft clamp 52B. When the upper end portion of the outer cylinder 45 (or the other outer cylinder 66A) is gripped by the outer blade shaft clamp 52B as shown in FIG. 19C, the connecting member release clamp 52C is opposed to each connecting member 45B. When the outer blade shaft clamp 52B contacts the outer surface of the outer cylinder 45 (or the other outer cylinder 66A), the outer cylinder 66A is held with the hemispherical tip of each connecting member 45B by the connecting member release clamp 52C. Are pushed into the through holes 66D formed in the In this state, as shown in FIG. 19 (D), when the movable table 53A is raised, the tip of each connecting member 45B is hemispherical, so the outer cylinder 66A which is gripped and raised by the clamp device 54B is Each connecting member 45B is moved further inward. Therefore, the tip of each connecting member 45B comes out of each through hole 66D of the outer cylinder 66A, the outer cylinder 66A gripped by the clamp device 54B is moved upward, and eventually the lower end of the outer cylinder 66A is the outer blade shaft clamp It reaches above the upper end of the outer cylinder 45 (or other outer cylinder 66A) gripped by 52B. In this manner, the connection between the outer cylinder 66A gripped by the clamp device 54B and the outer cylinder 45 (or the other outer cylinder 66A) gripped by the outer blade shaft clamp 52B is released.

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

  The rotation shaft 62A is rotated to pivot the arm 65C toward the extension tube supply device 60, and the upper end portion of the outer cylinder 66A gripped by the outer blade shaft clamp 52B is suspended in the extension tube holding portion 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 pipe suspending portion 64 (see FIG. 20 (B)). The movable table 53A is lowered, and the clamp device 54B grips the upper end of the outer cylinder 45 (or other outer cylinder 66A) which is gripped by the outer blade shaft clamp 52B at the upper end and protrudes upward from the shield plug 15 See FIG. 20 (B)). The outer blade shaft clamp 52B is separated from the outer cylinder 45 (or the other outer cylinder 66A). Then, the inner blade shaft clamp 52A is separated from the outer cylinder 66A suspended by the extension pipe suspension portion 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. 19A to 19D and 20A to 20C. The pulling out 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.

  Inserted plugs 79A and 79B (see FIG. 22) having screws formed on the side surfaces are inserted into the through holes formed in each of the upper lids 10 and 3 on the central axis of the RPV 2 Can be attached by The boring device 43 is moved onto the other outer cylinder 66A attached to the shield plug 15, and using the boring device 43, the above-mentioned FIG. 19 (A) to FIG. 19 (D) and FIG. The outer cylinder 66A and the outer cylinder 45 are successively pulled up and collected from the shield plug 15 according to the drawing procedure of the outer cylinder shown in FIG. 20 (C). Thereafter, as described above, the inset plugs 79A and 79B are inserted into the other through holes formed in each of the upper lids 10 and 3 and attached to the upper lids 10 and 3, respectively.

  Thereafter, the open / close door 77 is opened, and the boring device 43 is suspended from the hook 21B of the overhead crane 18B using the movable multi-axis robot 26A, and the winding device (not shown) provided on the trolley 20B is driven. The boring device 43 is raised to the inside of the inner space 17B. The 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 unloading the boring device 43, the open / close door 78 is closed.

  The shield plug is carried out (step S14). The shielding doors 40A and 40B of the opening and closing shielding member 15A are opened. The shield plug 15 is carried out of the work house 16A through the preparation house 16B and out of 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 removal of the shield plug 15 is completed, the shield doors 40A and 40B are closed.

  The upper lid of the PCV is cut and carried out (step S15). Before cutting the top cover 10 of the PCV, as shown in FIG. 21, four additional floors 73 and one turntable 75 are installed. Each additional floor 73 is provided with a 1⁄4 circle guide rail 74 on the top surface, and a 1⁄4 circle arc notch 73 A is formed inside the guide rail 74. As in the case where the shielding body supply device 71 is carried into the work house 16A in step S12, each additional floor 73 and the turntable 75 sequentially use the traveling crane 32 and the overhead crane 18B to sequentially open and close the open / close doors 78 and 77 Then, it passes through the preparation house 16B and is carried into the work house 16A. In the work house 16A, each additional floor 73 is suspended and moved by the overhead crane 20A, and installed on the floor of the work house 16A such 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 connect to form a circle and are arranged concentrically with the opening 23. The turntable 75 moved by the overhead crane 20A is movably installed on the guide rail 74 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 upper lid 10 which has been cut will be specifically described with reference to FIG. 22, FIG. 23 and FIG.

  The storage container 80 (see FIG. 22) storing the cutting device 81 is suspended by the hook 35B of the traveling crane 32, and the opening / closing door 78 is opened and released, 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 by the overhead crane 18B is carried into the working house 16A, as with the shield supply device 71 in step S12. The lid of the storage container 80 is opened using the mobile multi-axis robot 26A, and the cutting device 81 in the storage container 80 is suspended from the overhead crane 18A. The cutting device 81 is withdrawn from inside the storage container 80 by the overhead crane 18A and placed on the turntable 75 in the working 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 disposed on the carriage 82 and extends upward. An axially expandable telescopic tube 84 is attached to the mast member 83 and extends downwardly. 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.

  An electromagnet 87 is suspended from hooks 21A of the two trolleys 20A provided on the overhead crane 18A. The respective hooks 21 A are lowered to cause the electromagnets 87 to be attracted to the upper surface of the upper cover 10 of the PCV 9. With the upper lid 10 attracted to the electromagnets 87 suspended by the hooks 21A, the telescopic tube 84 and the arm 85 are operated to apply the cutter 86 to the cutting position on the upper surface of the upper lid 10 (see FIG. 23). The cutter 86 is pressed to the cutting position, and the turntable 75 carrying the cutting device 81 is moved along the guide rail 74. By the movement of the turntable 75, 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 is moved to the internal space 17A of the working 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 cut-off pieces 10A pulled up are stored in the carry-out container 76 placed on the floor of the working house 16A, and the electromagnets 87 are removed from the cut-off pieces 10A. A lid is attached to the unloading container 76 by the mobile multi-axis robot 26A, and the unloading container 76 is hung on the hook 21A of the overhead crane 18A. The discharge container 76 is moved to the central axis of the RPV 2 and suspended by the hook 21B of the overhead crane 20B. As the hook 21B ascends, the discharge container 76 containing the cut piece 10A is pulled up into the preparation house 16B and placed on the floor of the preparation house 16B. The door 77 is closed and the door 78 is opened. The unloading container 76 accommodating the cutting pieces 10A in the preparation house 16B is suspended by the hooks 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). If the bolt (not shown) attaching the upper lid 3 to the RPV 2 can not be removed, the electromagnet 87 is attracted to the upper surface of the upper lid 3 and the upper lid 3 is removed using the cutting device 81 as in the upper lid 10 in step S15. After cutting, the circular cut piece of the upper lid 3 is accommodated in the carry-out container, and is carried out of the work house 16A through the preparation house 16B and out of the preparation house 16B. Although not shown, after carrying out the cut pieces of the upper lid 3, the cutting device 81 is housed in the storage container 80 using the overhead crane 18A in the working house 16A and 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 carried out of the preparation house 16B.

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

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

  Each structure of the cutting and disassembling device 88 and the disassembling grapple device 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 disposed on one turntable 75 and extends upward. The moving table 90A is attached to the support member 89A so as to be vertically movable 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 apparatus 93 has a support member 89B, a moving table 90B, a main body 91B, an arm 92B, and a grapple 94B. A support member 89B is disposed 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 lowermost position along each of the support members 89A and 89B. The arms 92A and 92B are also extended downward. The steam dryer 7 is cut by the cutter 94A while sandwiching the steam dryer 7 by the grapple 94B. The cutting 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 released from the cut piece 7A, and the grapple 94C is pulled up to move the cut piece 7A into the working house 16A. The cut pieces 7A are moved in the trolley 20A and stored in the carry-out container 76A placed on the floor of the working house 16A (see FIG. 25). As described above, the steam dryer 7 is sequentially cut using the cutter 94A and the grapple 94B, and the cut piece 7A generated by the 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 carrying out the storage container 76 in step S15. It is carried out of the preparation house 16B by 18A, 18B and the traveling crane 32.

  The air-water separator is carried out (step S18). As in the unloading of the steam dryer 7 in step S17, the air-water separator 6 is cut using the cutting and disassembling apparatus 88 and the disassembling grapple apparatus 93, and the cut pieces of the air-water separator 6 are stored in the transport container It is carried out of the preparation house 16B. After the steam-water separator 6 has been taken out, the cutting and disassembling device 88 and the disassembling grapple device 93 are stored in separate storage containers, and are unloaded from the preparation house 16B using the traveling crane 32 and the like.

  The shroud is unloaded (step S19). A shroud 87 having a water supply sparger (not shown) and a core spray header mounted therein is provided at the upper end of the core shroud 116 surrounding the core 4 (see FIG. 27). The cutting device 81A used for cutting the shroud 87 is housed in the housing container 80A, and the housing container 80A, like the housing container 80 housing the cutting device 81 in step S15, the traveling crane 32 and the overhead crane 18B. It is carried into the working house 16A using. The cutting device 81A taken out of 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 thereon similarly to the boring device 43A in step S20. The structure of the support device 106 is the same as that of the support device 106 provided in the boring device 43A shown in FIG. 29 described later.

  The structure of the cutting device 81A will be described with reference to FIG. The cutting device 81A movably attaches the abrasive water jet head 95 to the mast member 83 in the vertical direction. In the abrasive water jet head 95, the support member 96 is provided in the outer cylinder 103A having the outer blade 103B attached to the lower end, and the support plate 101 forming the horizontal hole 101A is attached to the lower end of the support member 96 98 has a head 97 attached. 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 inserted into the horizontal hole 101A and connected to the head 97 by a pin movable along the horizontal hole 101A. The high-pressure water supply hose 102A and the abrasive supply hose 102B disposed in the outer cylinder 103A are connected to the head 97. The inner blade 104 is attached to the support member 96 by a support bar. When the piston in the cylinder 99 moves upward, the pin inserted in the horizontal hole 101A moves along the horizontal hole 101A (moving from left to right in FIG. 28), and the head 97 And the nozzle 98 moves to the right. Conversely, when the piston is pushed down, the pin moves from right to left, and the head 97 and the nozzle 98 also move in the same direction.

  The high-pressure water supplied into the head 97 from the high-pressure water supply hose 102A and the abrasives supplied into the head 97 from the abrasive supply hose 102B are mixed in the head 97, and the high-pressure water containing abrasive is the jet of the nozzle 98. It is injected from The injection port of the nozzle 98 is disposed opposite to the cutting position of the shroud 87. High-pressure water containing abrasive, which is injected from this injection port, is injected toward the shroud 87, and the shroud 87 is cut by the action of the abrasive. Since the turntable provided on the support device 106 pivots, the cutting device 81 moves in the circumferential direction of the shroud 87 while injecting high-pressure water including abrasive from the nozzle 98. Thus, the shroud 87 is cut all around.

  The cut-off shroud 87 is gripped by the respective grapples 94C suspended from the two trolleys 20A provided on the overhead crane 18A, and is raised into the working house 16A. The shroud head 87 is housed in the discharge container 76B in the working house 16A. The unloading container 76B storing the shroud 87 is unloaded from inside the working 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 a part of the plurality of fuel assemblies loaded in the core 4. A boring device 43A is used to transport the nuclear fuel material in the core 4 as described above. The boring device 43A is carried into the working house 16A using the traveling crane 32 and placed on the floor of the working 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 43, the boring device 43A replaces the cutting device 44 with the cutting device 44A (nuclear fuel cutting device), the clamp device 54B with the clamp device 55, the extension tube 66 with the extension tube 66B, and removes the moving base 53B. The separation device 113 and the shield supply device 114 are newly provided. The other configuration of the boring device 43A is substantially the same as 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 clamp device 52 fixed to the lower end of the mast member 51B does not have the inner blade shaft clamp 52A and the outer blade shaft clamp 52B like the boring device 43, and has one clamp. A support member 54 provided with a drive socket 54A is installed on a movable 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. The support member 54 is attached to the moving table 53A. The drive socket 54A is connected to the rotation shaft of the motor 56A via a gear mechanism (not shown). A connector portion 57 in which the rotation shaft 57A is provided is attached to the lower surface of the support member 54. The rotating shaft 57A is coupled to the drive socket 54A.

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

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

  The cutting device 44A has a configuration in which a spiral screw 105 is provided in the cutting device 44 as shown in FIG. The screw 105 is disposed in the outer cylinder 45 and attached to the rotation shaft 48, and is not attached to the outer cylinder 45. The screw 105 is between the lower end of the rotating shaft 48 and the upper end thereof 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 50A through which the collected matter passes is formed between the rotating shaft 48 and the outer cylinder 45. An upper end portion of the rotation shaft 48 is connected to a lower end portion of the rotation shaft 57A in the connector portion 57. The spiral passage 50A is in communication with an annular passage formed in the connector portion 57 and in communication with the collected 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 an extension pipe moving device 63B in the extension pipe supply device 60 of the boring device 43A. The other configuration of the extension tube supply device 60 of the boring device 43A is the same as the configuration of the extension tube supply device 60 of the boring device 43A. The extension tube moving device 63B has a rotary body 63A, an arm 65C and a grip portion 65D (see FIG. 31). The gripping portion 65D does not have the arm clamps 65A and 65B like the gripping portion 65 shown in FIG. 7, but has one clamp. The rotating body 63A is attached to a rotating shaft 62A rotatably attached to the extension tube holding portion 62, the arm 64 is attached to the rotating body 63A, and a gripping portion 65D is provided at the tip of the arm 65C.

  The extension pipes 66B suspended from the extension pipe suspending sections 64 provided in the extension pipe holding section 62 of the extension pipe supply device 60 have a configuration in which the extension pipe 66 is provided with a helical screw 105. The other configuration of the extension tube 66B is the same as the extension tube 66. In the extension tube 66B, the helical screw 105 is disposed in the outer cylinder 66A, is located 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. Mounted on the rotary shaft 48. The helical passage 50A is also formed by the screw 105 in the extension tube 66B.

  A transfer duct 59 which is flexible and is in communication with the recovery outlet 58 is connected to the separating device 113 and a shield supply device 114 is connected to the separating device 113.

  The structure of the supporting device 106 for supporting the boring device 43A in the RPV 2 will be described with reference to FIG. The support device 106 has a turntable 107, a base 108, a cylinder 109 and a pressing member 111. Four cylinders 109 are disposed at an angle of 90 ° in the circumferential direction of the circular base 108 and attached to the side of the base 108 respectively. Each cylinder 109 extends in four directions from the base 108, and a pressing member 111 is attached to the tip of a piston rod 110 connected to a piston (not shown) disposed in the respective cylinder 109. A turntable 107 disposed above the base 108 is pivotably attached to the base 108. The turntable 107 is pivoted by a motor (not shown) provided on the base 108.

  Two guide rails 112 extend in parallel with 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 of the boring device 43A and the extension pipe feeding device 60 are installed on the upper surface of the slide base 51C. The shield supply device 114 is installed on the top 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 and the extension pipe 66B of the boring device 43A are inserted. The through holes 115 extend in the radial direction from the center of the turntable 107. Although not shown, the base 108 is also provided with an elongated through hole, into which the cutting device 44A and the extension tube 66B are inserted, facing the through hole 115 formed in the turntable 107. The elongated through hole formed in the base 108 reaches the center of the base 108.

  The installation operation 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 working house 16A, the working house around the central axis of the RPV 2 with four winches 113A and four pulleys 114A using the mobile multi-axis robot 26A Install on top of the 16A floor. The four winches 113A and the pulleys 114A are disposed at 90 ° intervals in the circumferential direction of the RPV 2. The wire 115A wound around each winch 113A is attached to the suspension ring 107A attached to the base 108 by the mobile multi-axis robot 26A. In the suspension ring 107A, four attachment positions of the wires 115A are provided at 90 ° intervals in the circumferential direction of the suspension ring 107A. The suspension ring 107A surrounds the periphery of the turntable 107, and the suspension ring 107A and the turntable 107 are separated from each other.

  With the four wires 115A attached to the suspension ring 107A and the boring device 43A resting on the supporting device 106, the boring device 43A is suspended to the hook 21A of the overhead crane 18A, and the boring device 43A and the support device 106 are Move to the level of the operating floor just above RPV2. Thereafter, the hooks 21A are removed from the boring device 43A, the respective winches 113A are driven to rewind the wire 115A, and the boring device 43A and the supporting device 106 are lowered in the RPV 2. When the support device 106 reaches near the upper end of the core 4, the descent of the hook 21A is stopped. The hydraulic pressure is applied in the four cylinders 109 to move the pistons in the respective cylinders 109 toward the inner surface of the RPV 2. Therefore, each piston rod 110 is also moved toward the inner surface of the RPV 2 so that the pressing members 111 are in contact with the inner surface of the RPV 2 and the 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 at 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. Thus, the boring device 43A is installed in the RPV 2.

  The nuclear fuel material in the core is unloaded (step S21). The unloading of the nuclear fuel material will be described with reference to FIGS. 29 to 36. 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 44A is inserted into the through hole 115. The radial position of the RPV 2 of the cutting device 44 A is adjusted by moving the slide base 51 C in the radial direction of the RPV 2 along the guide rails 112. When carrying out nuclear fuel material from the periphery of the core 4, the cutting device 44 A is located at the periphery of the core 4. Position on

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

  The scraps of iron powder 70 B, iron balls 70 A, nuclear fuel material cut by outer blade 46 and inner blade 47 and metal members constituting the fuel assembly are spirally formed in outer cylinder 45 in core 4 Go into the passage 50A. The helical screw 105, which rotates with the rotating shaft 48, exerts the function of a screw feeder, and cuts iron powder 70B, iron balls 70A, nuclear fuel material, and metal member cuttings into the helical passage 50A. It is transferred toward the upper end of the spiral passage 50A, and further transferred to the separation device 113 through the annular passage in the connector portion 57, the collected material discharge port 58 and the transfer duct 59. The screw 105 constitutes a transfer device for the cut nuclear fuel material and the like. In the separating device 113, electromagnets are used to separate the iron powder 70B and the iron balls 70A from the cuttings of the nuclear fuel material and the metal member. The iron powder 70B and the iron ball 70A are magnetic materials, and the cutting chips of the nuclear fuel material and the metal member are nonmagnetic materials. Therefore, the iron powder 70B and the iron ball 70A are each cut with the nuclear fuel material and metal member It can be easily separated from the waste. The metal member of the fuel assembly is made of zirconium alloy and is nonmagnetic. The separated iron powder 70B and iron balls 70A are introduced into the shield supply device 114. The nuclear fuel material and metal scraps from which the iron powder 70B and the iron balls 70A are removed are stored in a fuel cask 115A placed on the side of the separating device 113 on the turn table 107. When the fuel cask 115A is full of chips, the chips of nuclear fuel material and metal parts are supplied from the separator 113 into the empty fuel cask 115A placed next to the fuel cask 115A.

  The fuel cask 115A filled with cutting chips is lifted by the hook 21A of the overhead crane 18A and stored in the discharge container 76D in the working house 16A. When the fuel cask 115A transferred from the top of the turn table 107 and filled with cutting chips is stored in the discharge container 76D in a predetermined number, this discharge container 76D is similar to the discharge of the storage container 76 in step S15. , And sealed by a lid and carried out of the preparation house 16B by the overhead cranes 18A and 18B and the traveling crane 32.

  When the clamp 55 holding the outer cylinder 45 is lowered to the vicinity of the clamp 52 due to cutting of nuclear fuel material and fuel assembly metal members in the core 4, the lowering of the moving table 53 and the rotation of the motors 56A, 56B. And, similarly to the connection of the extension pipe 66A to the cutting device 44 of the boring device 43 in step S5, the connection of the extension pipe 66B to the cutting device 44A of the boring device 43A is performed.

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

  When the clamp device 55 is lowered to the vicinity of the clamp device 52 by cutting the nuclear fuel material and the metal member of the fuel assembly with the cutting device 44A which rotates while lowering the movable table 53 (see FIG. 35A), the movable table The lowering of the lever 53 is stopped to stop the rotation of the motors 56A and 56B. The outer cylinder 45 of the cutting device 44A is gripped by the clamp device 52, and the clamp device 55 holding the outer cylinder 45 is released. Thereafter, the movable table 53 is raised to a position above the extension pipe supply device 60 (see FIG. 35 (B)). In a state where one extension pipe 66B suspended by the extension pipe suspending section 64 is gripped by the gripping section 65D of the extension pipe moving device 63B, the rotary body 63A is turned. The arm 65C pivots in the horizontal direction to move the extension tube 66B gripped by the gripping portion 65D to a position just above the cutting device 44 gripped by the clamp device 52 (see FIG. 35C). The movable table 53 is lowered, and the upper end portion of the extension tube 66B gripped by the gripping portion 65D is gripped by the clamp device 55. The gripping portion 65D is released from the extension tube 66B, and the arm 65C is pivoted back to the original position (see FIG. 35D). At this time, the outer cylinder 66A of the extension tube 66B is detachably connected to the connector portion 57, the upper end of the extension tube 66B rotation shaft 48 is connected to the lower end portion of the rotation shaft 57A, and is gripped by the clamp device 55. Specifically, the clamp device 55 grips the upper end of the outer cylinder 66A of the extension tube 66B. Further, the movable table 53 is lowered to connect the lower end of the outer cylinder 66A of the extension tube 66B to the upper end of the outer cylinder 45 gripped by the clamp device 52, and the lower end of the rotation shaft 48 of the extension tube 66B is a cutting device 44A. It connects with the upper end of the rotating shaft 48 of (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 movable table 53 is gradually lowered from the state of FIG. 35 (E), so that the inner cutter 47 and the outer cutter 46 function as nuclear fuel materials and metal members of fuel assemblies in the core 4. Cutting is resumed. When the movable table 53 is lowered 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 collected 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 nuclear fuel material etc., the lowering of the moving table 53 and the rotation of the motors 56A, 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 cutting device 44A ascends to the upper end of the packed bed of iron 70B, slide base 51C is slightly moved in the radial direction of turntable 107, and core 4 is removed using cutting device 44A as described above at a different position from the previous time. The nuclear fuel material and the like in the inside are cut and collected in the fuel cask 115A. Such an operation is repeated to recover all the nuclear fuel materials present in the core 4, housed in the fuel cask 115A, and carried out of the preparation house 16B. Shields such as all the iron balls 70A present in the core 4 are recovered by the shield supply device 114. The iron powder 70B and a part of the iron balls 70A collected by the shield supply device 114 are stored in a shield cask 115B placed on the turntable 107. The shield cask 115B is accommodated in the unloading container 76D in the same manner as the fuel cask 115A and is unloaded out of the preparation house 16B.

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

  The boring device is unloaded (step S23). The 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 RPV 2. In this state, the four winches 113A are driven to wind the wire 115A. Furthermore, the hook 21A is raised. The boring device 43A and the supporting device 106 rise to reach the working house 16A. Similar to the unloading of the boring device 43 in step S13, the boring device 43A is unloaded out of 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 along the entire circumference using the cutting device 81A, similarly to step S19, above the layer of shielding bodies such as the iron powder 70B and the like loaded on the core support plate 5. An upper grid plate is attached to the cut core shroud. After cutting the core shroud 116, the cutting device 81A is carried out of the preparation house 16B. Thereafter, the cut core shroud, to which the upper grid plate is attached, is transferred into the working house 16A and stored in the unloading container in the working house 16A, similarly to the cut shroud 87 in step S19. The unloading container containing the cut core shroud is unloaded from the working 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 carried out (step S25). The boring device 43 is attached to the support device 106, carried into the working house 16A as in step S20, and installed on the inner surface of the RPV 2 using the support device 106. The installation position of the supporting 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.

  As in step S5, the outer blade 46 and the inner blade 47 of the cutting device 44 are pivoted to lower the movable table 53A, and the control rods constituting the core support plate 5 and the support cylinder 8 existing below the core support plate 5 The guide tube 8A is cut (see FIG. 38). When the boring position of the core support plate 5 by the cutting device 44 is located directly above the inner area of the control rod guide tube 8A, the control rod guide tube 8A by the outer blade 46 and the inner blade 47 No cutting takes place. If necessary, an extension pipe 66 is added to the upper end of the cutting device 44 as described above.

  The inner blade is pulled out to retract the boring device (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 tube 66 is used, the outer cylinder 66A is also left). The boring device 43 is retracted near 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 furnace bottom through the core support plate 5 and the outer cylinder 45 etc. left in the RPV 2 (see FIG. 39). With this camera and dosimeter 68, the condition of the furnace bottom in the RPV 2 is photographed, and the dose in the furnace bottom is measured. Based on the image information and the radiation dose obtained by the camera and the dosimeter 68 displayed on the above-mentioned display device, the operator determines the presence or absence of the molten nuclear fuel material dropped to the furnace bottom. Since the display device shows the molten nuclear fuel material present in the furnace bottom, it is necessary to cover the molten nuclear fuel material 13 on the furnace bottom with a shield and then carry out the molten nuclear fuel material.

  A shield is injected into the furnace bottom in the RPV (step S28). The boring device 43 is carried out of 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 working house 16A from the outside. Then, as in step S20, the boring device 43A is installed on the inner surface of the RPV 2 using the support device 106. The shield supply device 114 installed on the turntable 107 of the support device 106 is connected to the outer cylinder 45 (or the outer cylinder 66A) penetrating the core support plate 5. Iron powder, which is a shield in the shield supply device 114, is injected through the outer cylinder 45 (or the outer cylinders 66A and 45) to the furnace bottom in the RPV 2. The injected iron powder falls from the core 4 and is deposited on the molten nuclear fuel material 13 present at the furnace bottom in the RPV 2 to form a shield layer 118 covering the molten nuclear fuel material 13 (FIG. 39) reference).

  The shield on the core support plate is recovered (step S29). A shielding body such as iron powder 70B existing on core support plate 5 is recovered using cutting device 44A of boring device 43A. The motor 56A is rotated to rotate the rotating shaft 48 and the screw 105, and a shield such as iron powder 70B present on the core support plate 5 is guided into the spiral passage 50A. Since the screw 105 becomes a screw feeder, this shield is introduced into the shield cask 115 B via the transfer duct 59 and the separating device 113. At this time, the shielding cask 115 B is connected to the separating device 113. In this way, the shielding body such as iron powder 70B existing on the core support plate 5 is recovered in the shielding cask 115B. As described in step S21, the shield cask 115B is transferred into the work house 16A, stored in the discharge container, and removed out of the preparation house 16B. After the recovery of the shielding body such as the iron powder 70B present 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 unloaded (step S30). The storage container 80B storing the cutting device 81A is carried into the working house 16A using the traveling crane 32 and the overhead crane 18B as in step S19. The cutting device 81A taken out of the storage container 80B is suspended by the overhead crane 16A and lowered in the RPV 2 and installed on the inner surface of the RPV 2 by the supporting device 106 near the upper end of the core shroud 116 remaining in the RPV 2. Be done. The core shroud 116 is used at a position slightly above the core support plate 5 and a position slightly below the core support plate 5, and further below the support cylinder 8, similarly to step S19, using the cutting device 81A. Cut along the entire circumference (see FIG. 40). After cutting the core shroud 116, the cutting device 81A is carried out of the preparation house 16B. After the above cutting, 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 working house 16A in the same manner as the cut shroud 87 in step S19. Ru. In work house 16A, core crane 116 is cut using core crane 18A, core shroud 116 is stored in discharge container 76E, core support plate 5 is stored in discharge container 76F, and support cylinder 8 is stored in discharge container 76G. (See Figure 40). These unloading containers 76E, 76F, 76G are sequentially unloaded out of the preparation house 16B using the overhead cranes 18A, 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 43A is carried into the working house 16A as in step S20, and is further installed on the inner surface of the RPV 2 using the supporting 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 movable table 53 downward while rotating the outer blade 46 and the inner blade 47, and further extending the extension tube The movable table 53 is moved downward while the outer blade 46 and the inner blade 47 are pivoted by connecting 66B to the upper end of the cutting device 44A. Molten nuclear fuel material 13 present at the bottom of the furnace is cut by the pivoting outer blade 46 and inner blade 47 (see FIG. 41). The iron powder of shield layer 118 and the chips of molten nuclear fuel material 13 which have entered spiral passage 50A are transferred in outer cylinder 45 by rotating screw 105, and further through transfer duct 59 to separating device 113. Be transported. In the separating device 113, as described above, cutting chips of the molten nuclear fuel material 13 and iron powder are separated. The separated iron powder is stored in the shield supply device 114. The chips of the molten nuclear fuel material 13 from which the iron powder has been separated are stored in the fuel cask 115A from the separator 113. The fuel cask 115A filled with the chips of the molten nuclear fuel material 13 is transferred into the working house 16A and stored in the discharge container 76D. Similar to the unloading of the storage container 76 in step S15, the container is sealed with a lid, and is unloaded from the preparation house 16B by the overhead cranes 18A and 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 shield 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 iron powder and molten nuclear fuel material present at the furnace bottom in the RPV 2 are removed by the cutting device 44A.

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

  After the injection of the shield in step S32 is completed, the boring device 43A is transferred from the RPV 2 into the working house 16A, and further unloaded from the preparation house 16B.

  Boring to the bottom of the PCV is carried out (step S33). The boring device 43 attached to the supporting device 106 is carried into the RPV 2 as described above and installed on the inner surface of the RPV 2 using the supporting device 106. As in 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 movable table 53A, and the bottom (lower mirror) of the RPV 2 and the control rod drive mechanism housing 39 are cut. (See Figure 43). When the boring position of the bottom of the RPV 2 by the cutting device 44 is located directly above the inner area of the control rod drive mechanism housing 39, the control rod drive mechanism housing 39 by the outer blade 46 and the inner blade 47. Cutting is not performed. If necessary, an extension pipe 66 is added to the upper end of the cutting device 44 as described above.

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

  The bottom of the PCV is observed (step S35). A camera and dosimeter 68 is inserted into the bottom of the PCV 9 through the sleeves 66A, 45 (see FIG. 43). With this camera and dosimeter 68, the situation at the bottom of the PCV 9 is taken and the dose at the bottom of the PCV 9 is measured. Based on the image information and radiation dose obtained by the camera and the dosimeter 68 displayed on the above-mentioned display device, the operator determines the presence or absence of the molten nuclear fuel material dropped to the bottom of the PCV 9. The image on the display unit does not include the image of the molten nuclear fuel material that has dropped to the bottom of PCV 9 and the image of iron powder 121, which is the shielding body that has fallen through the damaged portion of the RPV 2 bottom. Assume the case. The measured dose is also much lower than the dose in the presence of molten nuclear fuel material. For this reason, the operator determines that almost no molten nuclear fuel material is present at the bottom of the PCV 9 and iron powder which is a dropped shield is present. For this reason, it is necessary to recover the iron powder which exists in the bottom of PCV9. If the molten nuclear fuel material dropped to 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 the molten nuclear fuel material and the shielding body dropped to the bottom of the PCV 9 do not exist, each work of steps S36, S37 and S38 described later is performed. Here, the recovery of iron powder present at the bottom of PCV 9 will be described.

  Before recovering the iron powder present at the bottom of the PCV 9, the shield present at the furnace bottom 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 working 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 working house 16A. The boring device 43A 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 (shield) existing at the bottom of the furnace is recovered in the same manner as step S29. The recovered shield is collected in the shield cask 115B. As described in step S21, the shield cask 115B is transferred into the work house 16A, stored in the discharge container, and removed out of the preparation house 16B. Thereafter, the boring device 43A is carried out of the preparation house 16B as described above.

  The bottom portion of the core shroud lower shell and the reactor bottom of the reactor pressure vessel are unloaded (step S37). The unloading 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 of the storage container is suspended by the overhead crane 16A and lowered in the RPV 2 and uses the support device 106 near the upper end of the core shroud lower barrel 116A existing in the RPV 2 as described above. It is installed on the inner surface of RPV2.

  In the vicinity of the weld with the bottom of the RPV 2, the core shroud lower barrel 116A is cut along 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 of the working house 16A. The core shroud lower shell 116A which has been cut is transferred into the working house 16A and stored in the unloading container 76H in the working house 16A, similarly to the cut shroud 87 in step S19.

  The cutting device 81A is again suspended by the overhead crane 16A to lower the interior of the RPV 2 and installed near the furnace bottom on the inner surface of the RPV 2 using the supporting device 106 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 at the inside of the mounting portion of the RPV 2 to the pedestal 37 as in step S19. And let it fall to the bottom of PCV9. A plurality of hearth bottom pieces 2A which are cut and attached with the control rod drive mechanism housing 39 are pulled up into the working house 16A using a grapple or the like attached to the overhead crane 18A, and to the discharge container 76I in the working house 16A. It is stored.

  The delivery container 76H containing the cut-out shroud 87 and the delivery container 76I containing the bottom piece 2A are prepared from inside the working 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 shield at the bottom of the PCV is recovered (step S38). The supporting device 106 in which the separating device 113 is installed on the turntable 107 is carried into the working house 16A in the same manner as the supporting device 106 of the boring device 43A in step S20, and is further lowered in the RPV 2 to perform 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 within the layer of iron powder 121 present at the bottom of the PCV 9.

  The suction pump connected to the separating device 113 is driven, and the iron powder 121 present at the bottom of the PCV 9 is sucked and guided to the separating device 113 through the suction hose 142. In the separation device 113, the iron powder 121 and the other substance are separated, the separated iron powder 121 is stored in the shielding cask 115B, and the other substance is stored in the fuel cask 115A. The shielding cask 115B filled with the iron powder 121 is transferred into the working house 16A and stored in the discharge 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 finished. The fuel cask 115A containing other substances is also transferred into the working house 16A and stored in the unloading container 76D. The delivery container 76J containing the shielding cask 115B and the fuel cask 115A containing the other substance 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 pulled up into the working house 16A, stored in the storage container and transferred, and carried out of the preparation house 16B.

  The RPV is carried out (step S39). The unloading of the RPV 2 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 removed from the storage container is installed on the inner surface of the RPV 2 using the supporting device 106, as described above, below the cutting position at the uppermost position of the RPV 2. Because RPV2 is large, RPV2 is cut at six points in the axial direction to facilitate unloading. In order to reduce the time required to carry out the RPV 2, the support device 106 is disposed below the cutting position of the RPV 2 in each cutting operation.

  By the action of the abrasive contained in the high pressure water jetted from the nozzle 98 of the cutting device 81A supported by the supporting device 106, the cutting position located at the uppermost position of the RPV 2 is cut. Since the turn table 107 turns, the RPV 2 is cut along the entire circumferential direction at the cutting point. With the cutting device 81A disposed in the RPV 2, the cut RPV 2B is transferred into the working house 16A and stored in the discharge container 76L in the working house 16A, similarly to the cut shroud 87 in step S19. . The carry-out container 76L storing the cut-off RPV 2B is carried out of the preparation house 16B in the same manner as the above-described carry-out containers.

  After releasing the pressing of the RPV 2 to the inner surface by the pressing member 11, the cutting device 81A is moved downward by the overhead crane 18A and installed on the inner surface of the RPV 2 by the supporting 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 housed in the carry-out container 76L as described above and carried out of the preparation house 16B. Thus, the RPV 2 is cut at the respective cutting points from the upper side, and carried out of the preparation house 16B. The lowermost cutting point is located slightly above the upper end of the support for mounting the RPV 2 to the pedestal 37. When cutting the RPV 2 in this position, the support device 106 is installed on the inner surface of the pedestal 37.

  After the removal of the RPV 2 is completed, the cutting device 81A is transferred and removed from the preparation house 16B as described above.

  When unloading 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 each operation of the above steps S1 to S39 is completed, the method of 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, in the RPV 2, the core internals such as the steam drier 7 and the steam separator 6 are melted by melting of the nuclear fuel substance of the core 4, and the nuclear fuel substance and the melt 13A of the core internal are It is assumed that it has fallen to the furnace bottom in RPV2. The image displayed on the display device and the measured dose obtained using the camera and dosimeter 68 in step S7 indicate that the inside of the RPV 2 is in the above state (see FIG. 48). There is. The operator who sees the information shown on the display device determines the solidified melt 13A present in the furnace bottom as a boring target (step S8). And each work of steps 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). The boring device 43 is used to lower the cutting device 44 while adding the extension tube 66 as in step S5. When the lower end of the cutting device 44 reaches near the melt 13A at the furnace bottom, the lowering of the cutting device 44 is stopped. After that, using the boring device 43, the respective rotation shafts 48 are pulled out from the extension pipes 66 inserted in the RPV 2 and the cutting device 44 as in step S6. As a result, the outer sleeve 66A and the outer sleeve 45 are left in the RPV 2 in a connected state.

  The injection of the shield (for example, iron powder 121) to the furnace bottom is performed in the same manner as step S12. As shown in FIG. 49, the injection pipe 72 is connected to the shielding body supply device 71 carried in and installed in the work house 16A, and further, among the respective outer cylinders 66A and the outer cylinders 45 connected, the most. It is connected to the upper end of the outer cylinder 66A disposed above. Iron powder 121 is injected from the shield supply device 71 through the outer tubes 66A and 45 disposed in the injection pipe 72 and the RPV 2 into the RPV 2 to cover the top of the melt 13A present in the furnace bottom.

  The outer cylinder is recovered and the boring device is carried out (step S41). Here, similarly to step S13, the outer cylinders 66A and 45 disposed in the RPV 2 are recovered, and the boulin device 43 is carried out of the preparation house 16B.

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

  The remaining equipment in the RPV is carried out (step S42). After the work of step S16 is completed, the cutting device 81A is stored in the storage container and 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 of the storage container is suspended by the overhead crane 16A and lowered in the RPV 2 by the supporting device 106 above the residual equipment (furnace internal structure) 122 remaining in the RPV 2 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 working house 16A. The residual device 122 is accommodated in the unloading container 76M in the working house 16A, and is unloaded from the preparation house 16B to the outside similarly to the above-described unloading containers.

  The molten material is carried out (step S43). The delivery of the melt 13A will be described with reference to FIG. In substantially the same manner as the unloading of the molten fuel material present in the furnace bottom portion in step S31, the unloading of the melt 13A in this step is performed. The boring device 43A is carried into the working house 16A as in step S20, and is further installed on the inner surface of the RPV 2 using the supporting device 106. In the boring device 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 moving the lower blade 46, and the molten nuclear fuel material and the melting furnace The melt 13A including the internal structure is cut. If the length of the cutting device 44A is insufficient, as in step S21, the extension tube 66B is further added to the upper end of the cutting device 44A, and the melt 13A is cut by the cutting device 44A. The cuttings of the melt 13A generated by this cutting and the iron powder 121 enter the outer cylinder 45, are pushed out by the rotating screw 105, and transferred through the transfer duct 59 to the separating device 113.

  The chips of the melt 13A and the iron powder 121 are separated by the separating device 113, and the chips of the separated melt 13A are led to the fuel cask 115A. Also, the separated iron powder 121 is introduced into the shield supply device 114.

  As in step S21, the position of the cutting device 44A in the radial direction of the RPV 2 is changed to cut the melt 13A by the cutting device 44A, and all the melt 13A present in the furnace bottom in the RPV 2 is a plurality of fuel casks Recover in 115A. Each fuel cask 115A filled with cuttings of the melt 13A is transferred to the working house 16A and stored in the discharge container 76D. The delivery container 76D storing the fuel cask 115A is unloaded from the preparation house 16B to the outside.

  After that, each work of the above-mentioned steps S32 to S35 is performed in order. In the operation of step S35, the situation of the bottom of the PCV 9 is photographed by the camera and the dosimeter 68, and the dose of the bottom of the PCV 9 is measured. The information displayed on the display indicates that the melt 13A has dropped to the bottom of the PCV 9. The melt 13A present at the bottom of the PCV 9 is referred to as the melt 13B in order to distinguish it from the melt 13A present at the furnace bottom. The operator looks at the information reported to the display and determines that it is necessary to recover the melt 13B at the bottom of the PCV 9. Thereafter, each work of steps S36 and S37 is performed.

  The molten material at the bottom of the PCV is carried out (step S44). The boring device 43A is carried into the working house 16A as in step S20, and is further installed on the inner surface of the RPV 2 using the supporting device 106 (see FIG. 52). As in the case of carrying out the molten nuclear fuel material 13 at the furnace bottom in step S31, the melt 13B present at the bottom of the PCV 9 is cut using the cutting device 44A, and the cutting chips of the iron powder 121 and the melt 13B rotate. It is transported by 105 and transported through transport duct 59 to the separating device 113. The cuttings of the melt 13B separated by the separation device 113 are stored in the fuel cask 115A. The iron powder 121 separated by the separation device 113 is stored in the shielding cask 115B. The fuel cask 115A filled with the swarf of the melt 13B and the shielding cask 115B filled with the iron powder 121 are respectively transferred to the working house 16A. A plurality of fuel casks 115A are stored in the discharge container 76D, and a plurality of shield casks 115B are stored in the discharge container 76J. The delivery containers 76D and 76J are unloaded from the preparation house 16B to the outside (see FIG. 52).

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

  As described above, each operation of the method for carrying out the nuclear fuel material in the nuclear power plant when the nuclear fuel material of the core and the reactor internals are melted in the RPV 2 is completed.

  In this embodiment, since the cutting of the melted nuclear fuel material present in the RPV 2 and the discharge of the melted nuclear fuel material that has been cut are performed using the cutting device 44A, the time required to carry out the cut molten nuclear fuel material is shortened. Can. In particular, the outer blade 46 provided at the front end of the outer cylinder 45 and the inner blade 47 provided at the front end of the rotary shaft 48 disposed in the outer cylinder 45 are swirled to melt the nuclear fuel material in the reactor 1 And the transfer passage formed between the rotating shaft 48 and the outer cylinder 45 is used to transfer the cut molten nuclear fuel material, so that the time required to carry out the cut molten nuclear fuel material is obtained. It can be shortened. As the screw 105 attached to the rotating shaft 48 is rotated around the rotating shaft 48, the transfer of the cut molten nuclear fuel material can be easily performed. In particular, in the present embodiment, since the screw 105 is provided on the rotating shaft 48 disposed in the outer cylinder 45 in the cutting device 44A, chips and the like of the nuclear fuel material can be more easily transferred by the screw 105. .

  In this embodiment, after boring by the boring device 43 is finished, the outer cylinder 45 of the cutting device 44 and the outer cylinder 66A of the extension tube 66 are left in the reactor 1 and the rotating shaft 48 in these outer cylinders is pulled out. Therefore, granular shields (for example, iron balls 70A) and powder shields (for example, iron powder 70B) can be easily injected into the nuclear reactor 1 using their outer cylinders as injection pipes.

  The cutting device 44 of the boring device 43 has an inner blade 47 attached to the lower end of the rotating shaft 48, and is attached to a lower end of the outer cylinder 45 rotating around the rotating shaft 48 to surround the inner blade 47. In the structure in which the rotating shaft 48 is pulled out from the outer cylinder 45, the holes for inserting the rotating shaft 48 and the outer cylinder 45 are inserted by the inner blade 47 and the outer blade 46 with the shield plug 15, the upper lids 10, 3 It can form in drier 7 grade | etc.,.

  When the outer cylinder 45, 66A is pulled out together with the rotating shaft 48, a shroud head in which the injected granular shield and part of the powder shield are installed in the air-water separator 6 and the steam dryer 7 The particulates accumulate on the upper surface of the cylinder, which hinders the injection of the particulate shield and the powder shield into the core 4, and it takes a long time to inject the predetermined amount of the granular shield and the powder shield. In this embodiment, since the outer cylinder 45, 66A is left in the steam separator 6, and the steam dryer 7, all the injected particulate shields and powder shields pass through the outer cylinder. Can be directly injected into the core 4.

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

  An object to be cut in the reactor is appropriately selected based on information (such as an image in the reactor 1) in the reactor 1 obtained by the camera inserted into the reactor 1 through the outer cylinders and the dosimeter 68. It can be decided. For this reason, it is possible to appropriately determine the work process for cutting the object to be cut. As a result, it is possible to avoid carrying out extra work and to shorten the time required to carry out the molten nuclear fuel material.

  In the present embodiment, since the particulate shield and the powder shield are injected into the core, the radiation emitted from the nuclear fuel material and the molten nuclear fuel material 13 in the core 4 can be injected into the particulate shield and the powder shield filled in the core 4. It can be shielded by the body. For example, when a device used in the present embodiment (for example, the boring device 43A or the like) breaks down in the working house 16A, it is necessary for a worker to enter the working house 16A and check the broken device and check the status of the breakdown. There is. In some cases, the broken equipment must be repaired in the working house 16A. Since the granular shield and the powder shield injected into the above-described core 4 shield the radiation, it is possible to suppress the exposure of the worker who works in the working house 16A.

  In the present embodiment, when cutting the melted nuclear fuel material in the core 4 and the melted nuclear fuel material 13 present in the furnace bottom portion in the RPV 2, the boring device 43A is provided with a pressing device (such as the cylinder 109 and the pressing member 111). In order to install on the inner surface of RPV2 using the support apparatus 106, the boring apparatus 43A can be arrange | positioned above the presence area in RPV2 of nuclear fuel material which is a cutting object in the vicinity of this presence area. For this reason, the number of extension pipes 66 to be added can be reduced. The reduction in the number of extension pipes 66 to be added results in shortening of the time required to add the extension pipes 66 and an increase in pivot torque of the outer blade 46 and the inner blade 47. The reduction of the time required for the addition of the extension pipe 66 directly leads to the reduction of 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 molten nuclear fuel material in the core 4 in the RPV 2, the reactor internals (the steam dryer 7, the steam separator 6, etc.) present in the RPV 2 above the core 4 before the cutting. Since the shroud 87 is cut and carried out of the RPV 2, the boring device 43 A is installed on the inner surface of the RPV 2 using the support device 106 near the core 4 above the core 4 where the nuclear fuel material to be cut exists. can do. In addition, when cutting the molten nuclear fuel material 13 present at the bottom of the reactor in the RPV 2, other reactor internals (core shroud 116, core support plate 5, support cylinder 8, etc.) are cut and carried out of the RPV 2. The boring device 43A can be installed on the inner surface of the RPV 2 using the support device 106 near the furnace bottom where the molten nuclear fuel material 13 to be cut is present.

  In this embodiment, the first rotating device (motor 56A and drive socket 54A) causes the boring device 43 to rotate the rotating shaft 48 of the cutting device 44 and the moving table 53A mounted movably in the vertical direction on the mast member 51B. A second rotating device for rotating the outer cylinder 45 of the cutting device 44 on a moving table 53B mounted on the moving table 53A so as to be vertically movable. The clamp device 54B is a holding device for the outer cylinder. The clamp device 52 having the inner blade shaft clamp 52A and the outer blade shaft clamp 52B is attached to the mast member 51B below the first and second rotating devices, and the extension tube support member 61 and the arm clamps 65A and 65B are provided. As the extension pipe feeding device 60 having the extension pipe moving device 63 is provided, as described above, The long tube 66 can be added to the cutting device 44 to form a deeper hole, and from the outer cylinder 45 left in the reactor 1 of the cutting device 44 and the outer cylinder 66A of the extension tube 66, the extension tube 66 and cutting The rotary shafts 48 of the device 44 can be withdrawn, and further, the outer cylinder 66A of the extension tube 66 left in the reactor 1 and the outer cylinder 45 of the cutting device 44 can be withdrawn.

  In this embodiment, the first rotating device (motor 56A and drive socket 54A) causes the boring device 43A to rotate the rotating shaft 48 of the cutting device 44 and the moving table 53 mounted on the mast member 51B so as to be vertically movable. And a clamp device 55, which is a second rotating device for rotating the outer cylinder 45 of the cutting device 44A, to the support portion 57 attached to the moving table 53, and the first and The clamp device 52 is attached to the mast member 51B below the two-rotation device, and the extension tube supply device 60 having the extension tube support member 61 and the extension tube moving device 63 provided with the grip portion 65D is provided. As described above, the extension pipe 66B can be easily added to the cutting device 44, and the extension pipe 66B and the cutting device 44 can be easily recovered.

  In this embodiment, the working house 16A and the preparation house 16B are installed on the operating floor of the reactor building 14, and the reactor internals (the steam separator 6, the steam dryer 7, the core shroud 166, etc.) in the RPV 2 and the RPV 2 The respective cuttings of the molten nuclear fuel material inside and the shielding body (iron balls 70A and iron powder 70B) injected into RPV 2 are housed in the unloading container, and the outside through the working house 16A and the preparation house 16B. Carried out. For this reason, for example, radioactive materials that enter the air present in the working house 16A from within the RPV 2 are discharged to the external environment as they are transferred from the RPV 2 to the working house 16A from the discharge vessel containing cuttings and shielding bodies. Can be prevented. This is provided on the floor of the preparation house 16B with the opening formed in the ceiling of the work house 16A and the floor of the preparation house 16B, which connects the internal space 17A of the working house 16A and the internal space 17B of the preparation house 16B. The opening can be closed by the opening and closing door 77, and the opening formed in the ceiling of the preparation house 16B for connecting the internal space 17B of the preparation house 16B and the external environment is closed by the opening and closing door 78 provided in the ceiling of the preparation house 16B. This is because ventilation air conditioning systems 36A and 36B for removing radioactive substances are provided in the work house 16A and the preparation house 16B. The air inside each of the working house 16A and the preparation house 16B can be purified by these ventilating air conditioning systems, and radioactive substances contained in the respective air in the internal spaces 17A and 17B can be removed.

  Although iron balls 70A and iron powder 70B are used as shields to be injected into the RPV 2 in this embodiment, tungsten balls and tungsten powder may be used as shields instead of iron balls 70A and iron powders 70B. Since tungsten is not a magnetic substance, when separating scraps such as nuclear fuel material by the separation device 113, the specific gravity of tungsten is lower than that of nuclear fuel material and the scrap of structural members of the fuel assembly, instead of using an electromagnet. Because the difference in specific gravity is so large, it is possible to separate tungsten dust and balls from chips of nuclear fuel material and fuel assembly structural members.

  A method of carrying out nuclear fuel material in a nuclear power plant of Example 2 applied to a boiling water nuclear power plant, which is another embodiment of the present invention, will be described with reference to FIGS. 53 to 56. FIG.

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

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

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

  Boring is performed (step S46). The operation of step S46 is an operation corresponding to step S5 of the first embodiment. The mobile multi-axis robot 26A placed on the operation floor 143 connects the connector of the power cable to the boring device 43 on the operation floor 143. When lowering the boring device 43 from the operation floor 143 to the ground, the mobile multi-axis robot 26A disconnects the connector of the power cable from the boring device 43. Description of connection and removal operations of the power cable and the boring device 43 (or the boring device 43A described later) is omitted in the following. Boring to 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 to retract the boring device (step S47). The work of step S47 is a work corresponding to step S6 of the first embodiment. The rotary shaft 48 of the cutting device 44 and the extension tube 66 of the cutting device 44 and the extension tube 66 disposed through the shield plug 15 and the upper lids 10 and 3 is set on the boring device 43 on the operation floor 143. As in step S6, it is pulled out from the outer cylinders 45 and 66A connected to each other. These outer cylinders 45 and 66A are left penetrating the shield plug 15 and the upper lids 10 and 3. The boring device 43 moves on the operating floor 143 and is retracted to the corner of the operating floor 143.

  The inside of the RPV is observed (step S48). The operation of step S48 is an operation corresponding to step S7 of the first embodiment. 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 top through the shield plug 15 as shown in FIG. 54. . A display (not shown) in which the camera 68 and the camera and dosimeter 68 inserted in the RPV 2 through the outer cylinders 66A and 45 through the pipe 68A and 45 respectively installed the video information in the RPV 2 and the dose measurement in the RPV 2 on the ground on the ground. Output).

  The boring object 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 objects to be drilled. An operator for these targets determines the steam dryer 7 and the air-water separator 6 as boring objects, and decides to carry out boring processing for these.

  Boring to the core is carried out (step S50). The operation of step S50 is an operation corresponding to step S9 of the first embodiment. As in step S9, the boring device 43 lowers the cutting device 44 while adding the extension tube 66, and the inner blade 47 and the outer blade 46 rotate the shield plug 15, the upper lids 10, 3 along the central axis of the RPV 2. Boring is performed on the steam dryer 7 and the steam separator 6 (see FIG. 54).

  The inner blade is pulled out to retract the boring device (step S51). The operation of step S51 is an operation corresponding to step S10 of the first embodiment. The boring device 43 is retracted on the operation floor 143 by pulling out the rotary shafts 48 and the inner blade 47 as in step S6. Each connected outer cylinder 45, 66A is disposed 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 of step S52 is a work corresponding to step S11 of the first embodiment. A camera and a dosimeter 68 (see FIG. 55) inserted in the core 4 through the connected outer cylinders 45 and 66A provide images and dose measurements in the core 4. The operator grasps that the nuclear fuel material in the core 4 is melting based on the image and the dose measurement value.

  The shield is injected into the core (step S53). The operation of step S53 is an operation corresponding to step S12 of the first embodiment. The iron balls 70A and the iron powder 70B are disposed along the central axis of the RPV 2 from the shield supply device 71 installed on the operation floor 143 and are connected to each other in the same manner as step S12. Through the core 4 (see FIG. 56). The iron balls 70A are injected before the iron powder 70B.

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

  After completion of step S54, the operation of step S2 (installation of traveling crane 32) and the operation of step S3 (installation of work house 16A and preparation house 16B) performed in the first embodiment are performed (see FIG. 56). By these operations, the traveling crane 32 is installed across the reactor building 14 as in the first embodiment, 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 then installed on the work house 16A. Thereafter, each operation of steps S14 to S39 performed in the first embodiment is performed.

  The method for carrying out the nuclear fuel material of this embodiment when the internal structures such as the steam separator 6 and the steam dryer 7 are melted in the RPV 2 will be described below.

  The respective operations of steps S45 to S48 are performed, and the image information and dose measurement value in the RPV 2 obtained by the camera and the dosimeter 68 in step S48 are furnaces such as the steam separator 6 and the steam dryer 7 in the RPV 2. It indicates that the internals and nuclear fuel material are melting. For this reason, the operator determines the solidified melt 13A (see FIG. 48) present at the furnace bottom in the RPV 2 as a boring target. Thereafter, steps S40 and S41 implemented in the first embodiment further install the working house 16A and the preparation house 16B on the operation floor 143 of the reactor building 14 without installing the traveling crane 32 above the reactor building 14. It is done without

  In the work of step S40 performed in the present embodiment, the iron powder 121 is injected from the shield supply device 71 installed on the operation floor 143, the injection piping 72, and each outer cylinder 45 connected and disposed in the RPV 2 It is performed by injecting into RPV2 through 66A. The melt 13A present at the bottom of the RPV 2 is covered by the injected iron powder 121. In step S41, after each outer cylinder 45, 66A disposed in the RPV 2 is collected by the boring device 43, the boring device 43 is lowered from the operation floor 143 to the ground by the crane crane.

  After the work of step S41 is completed, the work of step S2 described above (installation of traveling crane 32) and the work of step S3 (installation of work house 16A and 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 above the reactor building 1 and the work house 16A and the preparation house 16B installed on the operation floor 143. , S32 to S37, S44 and S39 are sequentially performed.

  The present embodiment can obtain each effect produced in the first embodiment. Furthermore, in the present embodiment, each operation of steps S45 to S54, S40 and S41 does not install the traveling crane 32 above the reactor building 14, and further the working house 16A and the preparation house 16B on the operation floor 143 of the reactor building 14. As a result, the time required to carry out the nuclear fuel material in the present embodiment can be made shorter than in the first embodiment. This is to carry in the necessary devices to the working houses 16A and 16B performed in the first embodiment in each work of steps S45 to SS48, S50 to S54, S40 and S41 of the present embodiment, and the devices from these houses It is not necessary to carry out the

  A method of carrying out nuclear fuel material in a nuclear power plant of Example 3 applied to a boiling water nuclear power plant which is another embodiment of the present invention will be described with reference to FIGS.

  In the method of carrying out the nuclear fuel material of the present embodiment, the cutting out of the nuclear fuel material in the first and second embodiments is carried out 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 pipe attaching / detaching portion, and a recovery pipe supply device 137.

  The shield cutting device 123 has a cutting portion and a propelling portion. The cutting portion has 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 portion 126 and a plurality of propulsion jacks 127. The propulsion jacks 127 are disposed at predetermined intervals in the circumferential direction of the cylindrical body portion 126 and attached to the cylindrical body portion 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 barrel 126 and is rotated by a first motor (not shown) installed in the cylindrical barrel 126. The recovery pipe 128 is fixed to the housing body 123A. Although not shown, a chip transfer passage is formed in each of the cylindrical body 126 and the housing body 123A, and the chip transfer passage is in communication with the aforementioned recovery pipe 128. A screw feeder (not shown) is installed in the chip transfer passage.

  The recovery pipe attaching / detaching portion has a clamp device 135, a recovery pipe holding member 136, a clamp moving device and a support frame 131. The support frame 131 has two support members 132A and 132B, a connection member 133, and a base member 144 in which an opening 145 is formed. The two support members 132A and 132B are attached to the upper surface of the base member 144, the lower ends of which are disposed above the operating floor 143, and extend upward as they are separated from each other. The upper ends of the support members 132A and 132B are connected by a connecting member 133. The collection pipe holding member 136 is slidably attached to each of the support members 132A and 132B at upper end portions 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 rotation member 134A is disposed along the support member 132A, and the rotation member 134B is disposed along the support member 132B. The lower end of the rotation member 134A is rotatably attached to the base member 144, and the upper end of the rotation member 134A is rotatably attached to the coupling member 133. The lower end of the rotation member 134B is rotatably attached to the base member 144, and the upper end of the rotation member 134B is rotatably attached to the coupling member 133. A second motor for rotating the rotation members 134A and 134B is disposed at the central portion of the connection member 133. A rotation transmission mechanism for transmitting the rotational force from the second motor to the rotation member 134A is attached to the connection member 133, and a rotation transmission mechanism for transmitting the rotation force from the second motor to the rotation member 134B is attached to the connection member 133.

  The clamp device 135 has a clamp mechanism 146 and support portions 147A, 147B. The supports 147A, 147B are attached to the clamp mechanism 146 and face in the opposite direction by 180 °. Each of the support portions 147A and 147B has a screw hole penetrating therethrough. The rotation member 134A penetrates the screw hole of the support portion 147A, and the respective screws of the support portion 147A and the rotation member 134A mesh with each other. The rotation member 134B penetrates the screw hole of the support portion 147B, and the respective screws of the support portion 147B and the rotation member 134B mesh with each other. The clamping device 135 is thus held by the rotating members 134A, 134B.

  The recovery pipe supply device (extension pipe supply device) 137 has a grip (not shown) for gripping the recovery pipe (extension pipe) 139, and is horizontally pivotably attached to the support member 132B.

  The method of carrying out the nuclear fuel material of this embodiment will be described below. The operations of steps S1 to S7 performed in the first embodiment are sequentially performed, and in step S8, it is determined that the boring object (cutting object) in the RPV 2 is the steam dryer 7 and the steam separator 6. In addition, each operation of steps S9 to S14 is performed in order. After the operation 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). The traveling crane 32 is used to transport all the components that make up the shield device 148 onto the operating floor 143. 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 operating floor 143 such that the opening is located directly above the RPV 2. The other members of the shield device 148 are assembled with reference to the base member 144. Lower ends of the support members 132A and 132B are attached to the base member 144, and lower ends of the rotation members 134A and 134B are rotatably attached to the base member 144. The clamp device 135 is attached to the rotation members 134A and 134B, and the recovery pipe holding member 136 is attached to the support members 132A and 132B. 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 of each of the support members 132A and 132B, and the upper end of each of the rotating members 134A and 134B is rotatably attached to the connecting member 133.

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

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

  The connection of the recovery pipe 139 to the recovery pipe 128 is performed as follows. The chuck of the chuck mechanism 146 is spread to rotate the second motor, and the rotating members 134A and 134B are respectively rotated. 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 rotary members 134A and 134B is stopped and the lowering of the clamp device 135 is stopped. The expanding clamp mechanism 146 is narrowed and the recovery tube 128 is gripped by the clamp mechanism 146. Then, the connection between the collection pipe 128 and the collection pipe 129 is released, and the collection pipe holding member 136 is raised to move the collection pipe 129 upward. When the distance between the collection pipe 128 and the collection pipe 129 becomes equal to or more than the length of the collection pipe 139, the elevation of the collection pipe holding member 136 is stopped. The collection pipe supply device 137 holding the collection pipe 139 to be connected pivots to position the collection pipe 139 directly above the collection pipe 128 between the collection pipe 128 and the collection pipe 129. The rotation of the rotating members 134A and 134B raises the clamp device 135 to bring the upper end of the recovery pipe 128 into contact with the lower end of the recovery pipe 139 gripped by the recovery pipe supply device 137. In this state, the recovery pipe 128 and the recovery pipe 139 are connected. The collection pipe holding member 136 is lowered to bring the lower end of the collection pipe 129 into contact with the upper end of the collection pipe 139, and the collection pipe 129 and the collection pipe 139 are connected. At this time, the chuck mechanism 146 is spread to separate the chuck mechanism 146 from the collection tube 128.

  The collection pipe holding member 136 is lowered with the collection pipe 139 connected until the cutter 125 contacts the upper surface of the upper lid 10. If the cutter 125 does not contact the upper surface of the upper lid 10 even if one recovery pipe 139 is connected, the necessary number of the above-mentioned operations are performed until the cutter 125 comes in contact with the upper surface of the upper lid 10. The recovery pipe 139 is further added. When the cutter 125 contacts the upper surface of the upper lid 10, the lowering of the collection pipe holding member 136 is stopped.

  The plurality of propulsion jacks 127 are driven to move the rotating body 124 toward the front 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 plurality of cutters 125 turn and cut the upper lid 10. Each propulsion jack 127 is also a guide member, and the outer surface opposite to the inner surface of the RPV 2 of each propulsion jack 127 contacts the inner surface of the RPV 2 to assist the movement of the cutting portion and the propulsion portion in the RPV 2. The reaction force generated at the time of cutting by the plurality of cutters 125 is received by the collection pipe holding member 136.

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

  By the advancement of the rotary body 124 by the drive of the propulsion jack 127, the upper cover 10 is cut, and the opening 10B penetrating the upper cover 10 is formed (see FIG. 58). The inner diameter of the opening 10B is dimensioned to allow the shield cutting device 123 to pass. When the cutting of the upper cover 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 cover 3 of the RPV 2. Again, the propulsion jacks 127 are driven to rotate the rotary body 124, and the upper lid 3 is cut by the plurality of pivoting cutters 125. The chips of the upper lid 3 are also transferred to the nuclear fuel material recovery building through the debris transfer path in the shield cutting device 123, the connected recovery tubes 128, 139, 129 and the nuclear fuel material transfer tube 130, and are separated by the separating device. It is separated from The separated chips from the upper lid 3 are also collected in the chip storage tank.

  When cutting of the upper lid 3 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 end of the steam dryer 7 in the RPV 2 . The upper lid 3 on which the cutting is performed is also formed with an opening having a size that allows the shield cutting device 123 to pass. During the descent 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 are It is connected to 129 and 139 respectively.

  When the cutter 125 is brought 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 to the lower end by the pivoting cutter 125. When the rotor 124 is moved downward by a predetermined distance by the drive of the propulsion jack 127, the rotor 124 is moved upward by the predetermined distance by the reverse movement of the propulsion jack 127. Thereafter, the collection pipe holding member 136 is moved downward by the distance by the hydraulic cylinder and stopped. Again, the propulsion jack 127 is driven to cut the steam dryer 7 by means of the pivoting cutter 125. The driving of the propulsion jack 127 and the lowering of the recovery pipe holding member 136 are repeated, the steam dryer 7 is cut to the lower end by the cutter 125, and the steam dryer 7 is completely cut. As described above, the chips of the steam dryer 7 are also transferred through the chip transfer passage in the shield cutting device 123, the connected recovery pipes 128, 139, 129 and the nuclear fuel material transfer pipe 130, and the chips are stored. Collected in the tank.

  The drive of the propulsion jack 127 and the lowering of the recovery pipe holding member 136 are repeated, and the addition of the recovery pipe 139 is repeated as necessary, and the air-water separator 6 is cut by the swinging cutter 125 (see FIG. See 58). The cuttings of the air-water separator 6 are also collected in the cuttings 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 addition of the recovery pipe 139 is repeatedly performed as necessary, and the revolving lattice cutter 125 causes nuclear fuel in the upper lattice plate and the core 4 The fuel assemblies containing materials, the core shroud 116, the core support plate 5, the support cylinders 8, the plurality of control rod guide tubes 8A, the molten nuclear fuel material 13 dropped to the bottom of the RPV 2, and the bottom of the RPV 2 are cut in sequence. These chips are also transferred to the nuclear fuel material recovery building through the interiors of the shield cutting device 123, the recovery tubes 128, 139, 129 and the nuclear fuel material transfer tube 130, and are recovered in the debris storage tank. When cutting the bottom of the RPV 2, the control rod drive mechanism housing 39 attached to the bottom of the RPV 2 falls to the bottom of the PCV 9, but drops the shield cutting device 123 near the bottom of the PCV 9. The drive mechanism housing 39 is also cut by the cutter 125.

  Thus, all the operations of the method for transporting nuclear fuel material of the present embodiment are completed. The cuttings collected in the cuttings storage tank are stored in the fuel cask and transferred to the fuel cask storage building as needed.

  When it is determined based on the observation information in RPV 2 in step S 7 that the boring object (cutting object) in RPV 2 is the melt quality 13 A present in the furnace bottom of RPV 2, the shield device 148 in step S 55 described above. Installation on the operation floor 143 of the second embodiment and unloading of the melt 13A containing nuclear fuel material in step S56. In this step S56, cutting of the molten nuclear fuel material 13 present in the furnace bottom portion in the RPV 2 is performed by the shield cutting device 123 of the shield device 148, and cutting debris of the molten nuclear fuel material 13A is recovered in the cutting debris storage tank . The cutter 125 of the shield cutting device 123 cuts the bottom of the RPV 2 and the control rod drive housing 39. However, since the melt 13A contains the melted nuclear fuel material and the reactor internals, cutting of the reactor internals such as the steam dryer 7 and the steam separator 6 by the shield cutting device 123 is not performed.

  The present embodiment can obtain each effect produced in the first embodiment. Furthermore, in the present embodiment, since the internal structure of the RPV 2 and the molten nuclear fuel material are cut and carried out using the shield device 148 having the shield cutting device 123, the nuclear fuel material is carried out in a shorter time than in 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 operation of steps S1 and S45 to S48 of the second embodiment is performed, and it is determined that the boring target (cutting target) in the RPV is the steam dryer 7 and the steam separator 6 in step S49 In each of the steps S50 to S54, S2, S3 and S14, each work of steps S55 and S56 performed in the third embodiment is performed. In addition, when each operation of steps S1 and S45 to S48 of the second embodiment is performed, and it is determined in step S49 that the boring object in the RPV is the molten material 13A present in the furnace bottom portion in the RPV 2 Step S40 and step S41 implemented in the first embodiment do not install the working house 16A and the preparation house 16B on the operation floor 143 of the reactor building 14 without installing the traveling crane 32 above the reactor building 14 Then, the operations of steps S55 and S56 performed in the third embodiment are performed.

  The present embodiment can obtain each effect generated in the first embodiment, and further, since the shield device 148 is used, the time required for carrying out the nuclear fuel material can be shortened more than the second embodiment.

  The embodiments described above can be applied not only to boiling water nuclear power plants but also to pressurized water nuclear power plants.

Other inventive concepts of the present application are described below.
(A1) Before the nuclear fuel material in the nuclear fuel material existing region in the reactor vessel is cut, the powder shielding material is injected into the nuclear reactor container to inject the nuclear fuel material present region. Cover with
Placing a nuclear fuel cutting device in the reactor vessel above the nuclear fuel material presence area covered by said powdery shielding body;
Cutting the nuclear fuel material in the nuclear fuel material presence region by the nuclear fuel cutting device;
The method for carrying out nuclear fuel material in a nuclear power plant for transferring the cut nuclear fuel material.
(A2) Before the nuclear fuel material is cut, a granular shield is injected into the reactor vessel, and after the injection of the granular shield into the reactor vessel is stopped, the nuclear fuel material is cut Prior to the injection of the powder shield into the reactor vessel, the injected powder shield being on the layer of the injected particulate shield covering the nuclear fuel material present area. The nuclear fuel material discharge method in the nuclear power plant according to (A1), which is covered with a body.
(A3) The powder shield is installed after the working house is installed on the operating floor of the reactor building in which the reactor vessel is installed directly above the reactor vessel and the working house is installed on the operating floor The method for carrying out the nuclear fuel material in the nuclear power plant according to (A1), wherein the injection into the reactor vessel is performed.
(A4) A working house is installed directly above the reactor vessel, on the operating floor of a reactor building in which the reactor vessel is installed inside, and after the working house is installed on the operating floor, the granular shielding body The method for carrying out nuclear fuel material in a nuclear power plant according to (A2), wherein injection into the reactor vessel is performed.
(A5) The nuclear fuel in the nuclear power plant according to (A3) or (A4), wherein the nuclear fuel cutting device is lowered from the working house into the reactor vessel, and the nuclear fuel material is cut by the nuclear fuel cutting device. How to carry out the substance.
(A6) As the nuclear fuel cutting device, a nuclear fuel cutting device having a cutting portion for rotating and cutting nuclear fuel material and a transfer passage for transferring the cut nuclear fuel material is used as the nuclear fuel cutting device,
The cutting of the nuclear fuel material in the nuclear fuel material presence region is performed by the cutting portion that rotates and rotates the cutting portion while moving the cutting portion toward the lower end of the nuclear fuel material presence region,
Transfer of the cut nuclear fuel material is performed by transferring the cut nuclear fuel material through the transfer passage. Delivery of nuclear fuel material in the nuclear power plant according to any one of (A1) to (A4) Method.
(A7) The movement of the cutting portion toward the lower end of the nuclear fuel material existing area is performed by adding an extension pipe to the upper end of the transfer passage,
The method of unloading nuclear fuel material in a nuclear power plant according to (A6), wherein the transportation of the cut nuclear fuel material is performed through the transport passage and the extension pipe.
(A8) Before injection of the granular shield, a photographing device is inserted into the reactor vessel, the inside of the reactor vessel is photographed, and the image information in the reactor vessel photographed by the photographing device is displayed The nuclear fuel material discharge method in the nuclear power plant according to (A2) or (A4) as described 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 ... Working 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 Clamps, 52B: outer blade shaft clamps, 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 tube, 81.81 A: Cutting device, 123: Shield cutting device, 124: Rotating body, 125: Cutter, 126: Cylindrical barrel, 127: Propelling Jack 131 ... support frame, 134A, 134B ... rotary member, 135 ... clamping device, 136 ... recovery pipe holding member, 137 ... recovery tube feeder, 146 ... clamping mechanism.

Claims (4)

  A rotating body provided with a plurality of cutter devices for cutting nuclear fuel material on the front surface, a propulsion unit having a plurality of propulsion jacks for advancing the rotating body, and a cutting unit for transporting the cut nuclear fuel material formed in the propulsion unit (1) Using a shield cutting device having a transfer passage, cutting of the nuclear fuel material in a nuclear fuel material existing region in a nuclear reactor vessel is performed by the plurality of cutter devices which are pivoted by the rotation of the rotating body, the rotating body A method of unloading nuclear fuel material in a nuclear power plant, wherein the advanced nuclear fuel material is transferred through the first transfer passage.   The shield cutting device is moved in the reactor vessel from the top of the reactor vessel toward the bottom of the reactor vessel, and at the time of this movement, the shield cutting device is the nuclear fuel material existing region in the nuclear fuel material existing region The method for carrying out the nuclear fuel material in the nuclear power plant according to claim 1, wherein the internal structure of the reactor vessel and the top of the reactor vessel is cut in addition to the substance.   The shield cutting device is extended with an extension pipe in which a second transfer passage is formed and the second transfer passage is in communication with the first transfer passage, and the nuclear fuel cut by the plurality of cutter devices The method of unloading nuclear fuel material in a nuclear power plant according to claim 1 or 2, wherein the material is transferred from the first transfer passage to the second transfer passage.   4. The method of unloading nuclear fuel material in a nuclear power plant according to claim 3, wherein the addition of the extension pipe to the shield cutting device is performed using an extension pipe supply device.

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