Patent Number: 
Section: claims

1. A nozzle stub working system for a reactor vessel that performs work inside a nozzle stub protruding outward from a side surface of the reactor vessel and allowing the inside and the outside of the reactor vessel to communicate with each other, the nozzle stub working system for the reactor vessel comprising:a platform unit that is provided at an upper portion inside the reactor vessel, of which the upper portion is opened by separating an upper structure and an inner structure therefrom, and includes a substantially cylindrical side wall portion and a bottom portion blocking the lower end of the side wall portion;an access window that is provided at the side wall portion of the platform unit to allow the inside of the platform unit to communicate with the nozzle stub;an access window moving device that opens and closes the access window;a working device that advances from the inside of the platform unit to the inside of the nozzle stub to perform work inside the nozzle stub;a working floor that is provided above the reactor vessel;an elevating device that elevates the working device from the working floor into the platform unit;a moving device that is provided inside the platform unit, configured to send and receive the working device between the moving device and the elevating device inside the platform unit, configured to separably attach the working device thereto, and configured to move the working device attached to the moving device between predetermined positions of the nozzle stub and the inside of the platform unit; anda control device that is provided at the outside of the reactor vessel and controls the access window moving device and the working device, the elevating device, and the moving device,wherein the moving device includes:a first moving unit that separably attaches the working device to the front end thereof and moves the attached working device to be rotatable about a horizontal axis and two axes perpendicular thereto, anda second moving unit that includes a support plate on which the working device is placed and moves the working device placed on the support plate to slide the support plate,wherein the control device drives the access window moving device to open the access window, drives the working device to perform work inside the nozzle stub, and then drives the access window moving device to close the access window after the performance of the work,wherein the first moving unit is provided with a lower plate and a plurality of upper plates having a first upper plate and a second upper plate, the first upper plate being arranged on the lower plate, the second upper plate being arranged on the first upper plate, and the first moving unit adjusts a position of the working device relative to the nozzle stub by sliding the first upper plates with respect to the lower plate and sliding the second upper plate with respect to the first upper plate,wherein the control device drives the elevating device to drop the working device into the platform unit, andwherein the control device drives the moving device. 2. The nozzle stub working system for the reactor vessel according to claim 1,wherein the moving device is configured to be rotatable about the central axis of the platform unit. 3. The nozzle stub working system for the reactor vessel according to claim 1 or 2,wherein the working device includes:a first working unit that is separably attached to the front end of the first moving unit and is driven while being attached thereto, anda second working unit that is placed on the support plate of the second moving unit and includes a fixing unit fixed to an inner surface of the nozzle stub inside the nozzle stub. 4. The nozzle stub working system for the reactor vessel according to claim 1 or 2, further comprising:a storage device that receives a plurality of working devices,wherein the elevating device elevates the storage device receiving the plurality of working devices. 5. The nozzle stub working system for the reactor vessel according to claim 4, further comprising:a plurality of types of the working devices; anda plurality of the storage devices that correspond to the types of the working devices, each type of the working device being received in each storage device,wherein the control device drives the elevating device to selectively elevate the storage device in accordance with the type of work. 6. The nozzle stub working system for the reactor vessel according to claim 1, further comprising:a nozzle stub blocking device that blocks the nozzle stub inside the nozzle stub,wherein the control device drives the nozzle stub blocking device to block the nozzle stub at a position on the inner side of a work position when seen from the reactor vessel inside the nozzle stub before the work inside the nozzle stub using the working device. 7. The nozzle stub working system for the reactor vessel according to claim 1, further comprising:a gap closing device that closes a gap between the access window and the nozzle stub,wherein the control device drives the gap closing device to close a gap between the access window and the nozzle stub before or immediately after driving the access window moving device to open the access window. 8. The nozzle stub working system for the reactor vessel according to claim 1,wherein the working device includes:an inspecting unit that inspects the inner surface of the nozzle stub, anda constructing unit that performs an inner surface construction at the inner surface of the nozzle stub, andwherein the control device allows the inspecting unit to inspect the inner surface of the nozzle stub and allows the constructing unit to perform the inner surface construction at the inner surface of the nozzle stub on the basis of the inspection result of the inspecting unit. 9. The nozzle stub working system for the reactor vessel according to claim 8,wherein the constructing unit includes a cutting unit that cuts the inner surface of the nozzle stub, andwherein the control device drives the cutting unit to cut the inner surface of the nozzle stub in an area that is determined as a defective position on the basis of the inspection result using the inspecting unit. 10. The nozzle stub working system for the reactor vessel according to claim 9,wherein the control device allows the inspecting unit to inspect the area cut by the cutting unit after the cutting is performed by the cutting unit, and drives the cutting unit again to perform cutting when a defective position is found on the basis of the inspection result using the inspecting unit. 11. The nozzle stub working system for the reactor vessel according to claim 9,wherein the constructing unit further includes a welding unit that welds the inner surface of the nozzle stub, andwherein the control device drives the welding unit to perform welding on the area cut by the cutting unit. 12. The nozzle stub working system for the reactor vessel according to claim 11,wherein the constructing unit further includes a finish processing unit that performs finish processing on the inner surface of the nozzle stub, andwherein the control device drives the finish processing unit to perform finish processing on the area welded by the welding unit. 13. The nozzle stub working system for the reactor vessel according to claim 11,wherein the control device allows the inspecting unit to inspect the area welded by the welding unit, and retreats the working device inside the platform unit to close the access window using the access window moving device when a construction is determined to be satisfactory in all areas on the basis of the inspection result using the inspecting unit. 14. The nozzle stub working system for the reactor vessel according to claim 13,wherein the control device drives the cutting unit again to perform cutting on the area determined as a defective construction. 15. A nozzle stub working system for a reactor vessel that performs work inside a nozzle stub protruding outward from a side surface of the reactor vessel and allowing the inside and the outside of the reactor vessel to communicate with each other, the nozzle stub working system for the reactor vessel comprising:a platform unit that is provided at an upper portion inside the reactor vessel, of which the upper portion is opened by separating an upper structure and an inner structure therefrom, and includes a substantially cylindrical side wall portion and a bottom portion blocking the lower end of the side wall portion;an access window that is provided at the side wall portion of the platform unit to allow the inside of the platform unit to communicate with the nozzle stub;an access window moving device that opens and closes the access window;a working device that advances from the inside of the platform unit to the inside of the nozzle stub to perform work inside the nozzle stub;a control device that is provided at the outside of the reactor vessel, after driving the access window moving device to open the access window, drives the working device to perform work inside the nozzle stub, and then drives the access window moving device to open and to close the access window after the performance of the work,a working floor that is provided above the reactor vessel;an elevating device that elevates the working device from the working floor into the platform unit; anda moving device that is provided inside the platform unit, separably attaches the working device thereto, and moves the working device attached thereto,wherein the moving device includes:a first moving unit that separably attaches the working device to the front end thereof and moves the attached working device to be rotatable about a horizontal axis and two axes perpendicular thereto, anda second moving unit that includes a support plate on which the working device is placed and moves the working device placed on the support plate to slide the support plate,wherein the first moving unit is provided with a lower plate and a plurality of upper plates having a first upper plate and a second upper plate, the first upper plate being arranged on the lower plate, the second upper plate being arranged on the first upper plate, and the first moving unit adjusts a position of the working device relative to the nozzle stub by sliding the first upper plates with respect to the lower plate and sliding the second upper plate with respect to the first upper plate,wherein the control device drives the elevating device to drop the working device into the platform unit, andwherein the elevating device includes:a support table configured to travel on the working floor;a frame that is provided on the support table to be rotatable about the perpendicular axis;a pair of a first rail and a second rail that is respectively disposed at the frame and the inner peripheral surface of the platform unit to be substantially perpendicular thereto;a body configured to travel up and down on the first rail and the second rail; anda pair of grip portions configured to be movable close to or away from the body. 16. The nozzle stub working system for the reactor vessel according to claim 15, further comprising:wherein the control device drives the moving device to send and receive the working device between the moving device and the elevating device inside the platform unit, and moves the working device attached to the moving device between predetermined positions inside the platform unit and the nozzle stub. 17. The nozzle stub working system for the reactor vessel according to claim 1,wherein the moving device is configured to be rotatable about the central axis of the platform unit,wherein the first moving unit includes a guide rail that is formed in a circular-are shape at an outer periphery on the bottom portion of the platform unit and a unit body that is movable about the central axis of the platform unit in a circumferential direction along the guide rail, andwherein the second moving unit is provided near an inner periphery of the guide rail of the first moving unit on the bottom portion of the platform unit to be rotatable about the central axis of the platform unit. 18. The nozzle stub working system for the reactor vessel according to claim 1 or 2, further comprising:a storage device that receives a plurality of working devices,wherein the elevating device elevates the storage device receiving the plurality of working devices,wherein the storage device includes a leg portion that is capable of being disposed inside the platform unit and a body having a substantially cylindrical shape that is supported by the leg portion, and a plurality of receiving concave portions is provided at the body in a circumferential direction to receive a target working device. 19. A nozzle stub working system for a reactor vessel that performs work inside a nozzle stub protruding outward from a side surface of the reactor vessel and allowing the inside and the outside of the reactor vessel to communicate with each other, the nozzle stub working system for the reactor vessel comprising:a platform unit that is provided at an upper portion inside the reactor vessel, of which the upper portion is opened by separating an upper structure and an inner structure therefrom, and includes a substantially cylindrical side wall portion and a bottom portion blocking the lower end of the side wall portion;an access window that is provided at the side wall portion of the platform unit to allow the inside of the platform unit to communicate with the nozzle stub;an access window moving device that opens and closes the access window;a working device that advances from the inside of the platform unit to the inside of the nozzle stub to perform work inside the nozzle stub; anda working floor that is provided above the reactor vessel; andan elevating device that elevates the working device from the working floor into the platform unit,a moving device that is provided inside the platform unit, configured to send and receive the working device between the moving device and the elevating device inside the platform unit, configured to separably attach the working device, and configured to moves the working device attached to the moving device between predetermined positions of the nozzle stub and the inside of the platform unit; anda control device that is provided at the outside of the reactor vessel and controls the access window moving device and the working device, the elevating device, and the moving device,wherein the moving device includes:a first moving unit that is provided with a lower plate and a plurality of upper plates having a first upper plate and a second upper plate, the first upper plate being arranged on the lower plate, the second upper plate being arranged on the first upper plate, anda second moving unit that includes a support plate on which the working device is placed and moves the working device placed on the support plate to be slid, and whereinthe control device is configured to:(a) drive the elevating device to drop the working device into the platform unit;(b) after (a), drive the access window moving device to open the access window;(c) after (b), drive the first moving unit to adjust a position of the working device relative to nozzle stub by separably attaching the working device to the front end of the first moving unit and rotating the attached working device about a horizontal axis and two axes, and by sliding the first upper plate with respect to the lower plate and sliding the second upper plate with respect to the first upper plate;(d) after (c), drive the working device to perform work inside the nozzle stub; and(e) after (d), drive the access window moving device to close the access window. 20. The nozzle stub working system for the reactor vessel according to claim 19, wherein the moving device is rotatable about the central axis of the platform unit,wherein the first moving unit includes a guide rail that is formed in a circular-arc shape at an outer periphery on the bottom portion of the platform unit and a unit body that is movable about the central axis of the platform unit in a circumferential direction along the guide rail,wherein the second moving unit is provided near an inner periphery of the guide rail of the first moving unit on the bottom portion of the platform unit to be rotatable about the central axis of the platform unit. 21. The nozzle stub working system for the reactor vessel according to claim 19, further comprising:a storage device that receives the plurality of working devices,wherein the elevating device elevates the storage devices receiving a plurality of working devices,wherein the storage device includes a leg portion that may be disposed inside the platform unit and a body having a substantially cylindrical shape that is supported by the leg portion, and a plurality of receiving concave portions is provided at the body in a circumferential direction to receive a target working device.