Nozzle stub working system for reactor vessel

Patent metadata

Field	Value
Publication number	US-9524803-B2
Application number	US-201013263938-A
Country	US
Kind code	B2
Filing date	May 26, 2010
Priority date	Jul 10, 2009
Publication date	Dec 20, 2016
Grant date	Dec 20, 2016

Abstract

A reactor vessel that performs work inside a nozzle stub of the reactor vessel, including a platform unit that is provided at an upper portion inside the reactor vessel 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 an access window moving device that opens and closes the access window; a working device; and a control device that is provided at the outside of the reactor vessel and controls the access window moving device and the working device, 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.

First claim

The invention claimed is:

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; and
a 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, and
a 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, and
wherein 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, and
a 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; and
a 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, and
a constructing unit that performs an inner surface construction at the inner surface of the nozzle stub, and

wherein 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, and
wherein 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, and
wherein 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, and
wherein 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 devic

Assignees

• Sugiura Atsushi
• Hori Takumi
• Nishikawa Kenji
• Onishi Ken
• Shimonabe Noriaki
• Tsuzuki Satoshi
• Wakamoto Ikuo
• Mitsubishi Heavy Ind Ltd

Inventors

• Sugiura Atsushi
• Hori Takumi
• Nishikawa Kenji
• Onishi Ken
• Shimonabe Noriaki
• Tsuzuki Satoshi
• Wakamoto Ikuo

Classifications

• G21C19/207

  Assembling, maintenance or repair of reactor components (G21C3/334 takes precedence) · CPC title

• G21C17/01

  Inspection of the inner surfaces of vessels · CPC title

• G21C17/017 Primary

  Inspection or maintenance of pipe-lines or tubes in nuclear installations · CPC title

• G21C17/003

  Remote inspection of vessels, e.g. pressure vessels · CPC title

• G21C19/14

  characterised by their adaptation for use with horizontal channels in the reactor core · CPC title