JP5859344B2 - Thermal sleeve repair method - Google Patents

Description

  The present invention relates to a method for repairing a thermal sleeve of a steam generator feed water inner pipe.

  There are various methods for repairing the steam generator feed pipe. For example, a water pressure nozzle for a reactor pressure vessel employs a technique of directly welding a new safe end integrated with a thermal sleeve on site.

  Patent Document 1 describes a method for replacing a safe end portion of a water supply nozzle of a reactor pressure vessel as a method for preventing cracking due to a heat affected zone when different materials are welded. In the method described in Patent Document 1, after welding a new thermal sleeve made of carbon steel to a new safe-end thermal sleeve mounting portion, the welded portion is subjected to heat treatment after welding. Therefore, post-weld heat treatment with the welded portion is simultaneously performed. It is possible to perform heat treatment once after welding.

Japanese Patent No. 3767077

  Some steam generators have a thermal sleeve structure having a discontinuous shape at the joint between the water supply inlet nozzle and the water supply inner pipe. If the material of the thermal sleeve of the steam generator feed water pipe is carbon steel, etc., the thermal sleeve structure of the feed water inner pipe has a discontinuous shape, so the thermal sleeve of the feed water inner pipe is reduced by erosion and corrosion. There is a risk of meat. For this purpose, it is necessary to establish a repair method in the case where thinning occurs in the thermal sleeve of the steam generator water supply pipe.

  This invention is made | formed in view of the above, Comprising: It aims at providing the thermal sleeve repair method which can repair easily the thermal sleeve which the water supply inlet nozzle of a steam generator has.

  In order to solve the above-described problems and achieve the object, the thermal sleeve repair method according to the present invention is a method of connecting a thermal sleeve of a water supply inner pipe disposed inside a water supply inlet nozzle of a steam generator and the thermal sleeve. The procedure for separating a part of the supplied water supply pipe, the procedure for removing a part of the water supply inner pipe from the water supply inner pipe, the procedure for removing the thermal sleeve from the water supply inlet nozzle, and a new thermal And a step of attaching a sleeve and a step of attaching a part of the inner pipe of the feed water removed from the inside of the steam generator.

  With the above configuration, the thermal sleeve repairing method according to the present invention can easily replace the thermal sleeve disposed in the steam generator only by removing a part of the water supply inner pipe connected to the thermal sleeve. .

  As a preferred aspect of the present invention, it is desirable that a part of the water supply inner pipe to be removed first includes a T joint of the water supply inner pipe connected to the thermal sleeve and a reducer connected to the T joint.

  With the above configuration, the thermal sleeve repair method according to the present invention can simplify the work process by removing a part of the water supply inner pipe rather than removing each part of the water supply inner pipe to which the thermal sleeve is attached.

  As a preferred embodiment of the present invention, it is desirable to include a procedure for dividing the new thermal sleeve before attaching the new thermal sleeve from the inside of the steam generator.

  With the above configuration, the thermal sleeve repair method according to the present invention divides a new thermal sleeve before conveying the new thermal sleeve into the steam generator, thereby conveying the new thermal sleeve into the steam generator. Easy to do.

  As a preferred embodiment of the present invention, it is desirable that the new thermal sleeve includes a procedure of being divided and then carried into the steam generator through a secondary manhole disposed in the steam generator.

  With the above configuration, the thermal sleeve repair method according to the present invention allows the new thermal sleeve to be easily moved into the steam generator without removing the components in the steam generator when the new thermal sleeve is transported into the steam generator. Can be conveyed.

  As a preferable aspect of the present invention, it is desirable that the new thermal sleeve includes a procedure of attaching the inside of the water supply inlet nozzle through the opening after the main water supply pipe of the steam generator is cut after being divided.

  With the above configuration, the thermal sleeve repair method according to the present invention can easily attach a new thermal sleeve from the water supply inlet nozzle. Moreover, the work process which replace | exchanges a thermal sleeve can be shortened by attaching a new thermal sleeve from a feed water inlet nozzle.

  As a preferable aspect of the present invention, it is desirable that the new thermal sleeve includes a procedure for attaching the water supply inlet nozzle to the inside through the opening formed by cutting the water supply inlet nozzle of the steam generator.

  With the above configuration, the thermal sleeve repair method according to the present invention can attach a new thermal sleeve directly through the cutting opening of the water supply inlet nozzle without dividing the new thermal sleeve attached to the water supply inlet nozzle. Therefore, the work process of dividing a new thermal sleeve can be omitted.

  The present invention has an effect that it is possible to easily repair a thermal sleeve damaged inside the feed water inlet nozzle in the steam generator.

FIG. 1 is an explanatory diagram schematically illustrating the entire steam generator according to the first embodiment. FIG. 2 is an explanatory view schematically showing the entire area of the water supply inner pipe of the first embodiment. FIG. 3 is an explanatory view schematically showing the inner side of the water supply inlet nozzle according to the first embodiment. FIG. 4 is a flowchart of the thermal sleeve repair method according to the first embodiment. FIG. 5 is an explanatory diagram schematically illustrating a state in which a part of the water supply inner pipe and the thermal sleeve of Embodiment 1 are cut. FIG. 6 is an explanatory diagram showing a state where a part of the water supply inner pipe of the first embodiment is removed. FIG. 7 is an explanatory view showing a state in which the thermal sleeve of Embodiment 1 is removed. FIG. 8 is an explanatory view showing a state in which the new thermal sleeve of Embodiment 1 is attached. FIG. 9 is an explanatory diagram illustrating a state in which a part of the water supply inner pipe of Embodiment 1 is attached. FIG. 10 is a flowchart of the thermal sleeve repair method according to the second embodiment. FIG. 11 is an explanatory diagram schematically illustrating a state in which the main water supply pipe of the second embodiment is cut. FIG. 12 is an explanatory view schematically illustrating a state in which a part of the water supply inner pipe and the thermal sleeve according to the second embodiment are cut. FIG. 13 is an explanatory diagram illustrating a state where a part of the water supply inner pipe of the second embodiment is removed. FIG. 14 is an explanatory view showing a state in which the thermal sleeve of the second embodiment is removed. FIG. 15 is an explanatory view schematically showing a state in which the new thermal sleeve of the second embodiment is carried in from the water supply inlet nozzle. FIG. 16 is an explanatory view schematically showing a state in which the new thermal sleeve of Embodiment 2 is attached to the inside of the water supply inlet nozzle. FIG. 17 is an explanatory diagram showing a state in which a part of the water supply inner pipe of Embodiment 2 is attached. FIG. 18 is an explanatory view schematically showing a state in which the main water supply pipe of Embodiment 2 is attached. FIG. 19 is a flowchart of the thermal sleeve repair method according to the third embodiment. FIG. 20 is an explanatory diagram schematically illustrating a state in which the main water supply pipe of the third embodiment is cut. FIG. 21 is an explanatory diagram schematically illustrating a state where the water supply inlet nozzle according to the third embodiment is cut. FIG. 22 is an explanatory view schematically showing a state where a part of the water supply inner pipe and the thermal sleeve of the third embodiment are cut. FIG. 23 is an explanatory diagram illustrating a state where a part of the water supply inner pipe of the third embodiment is removed. FIG. 24 is an explanatory view showing a state in which the thermal sleeve of the third embodiment is removed. FIG. 25 is an explanatory view schematically showing a state where the new thermal sleeve of the third embodiment is carried in from the water supply inlet nozzle. FIG. 26 is an explanatory view schematically showing a state in which the new thermal sleeve of the third embodiment is attached to the inside of the water supply inlet nozzle. FIG. 27 is an explanatory view schematically showing a state in which a part of the water supply inner pipe of the third embodiment is attached. FIG. 28 is an explanatory diagram schematically illustrating a state in which the new water supply inlet nozzle according to the third embodiment is attached. FIG. 29 is an explanatory view schematically showing a state in which the main water supply pipe of Embodiment 3 is attached.

  Hereinafter, the present invention will be described in detail with reference to the drawings. The present invention is not limited to the following description. In addition, constituent elements in the following description include those that can be easily assumed by those skilled in the art, those that are substantially the same, and those in a so-called equivalent range.

(Embodiment 1)
FIG. 1 is an explanatory diagram schematically illustrating the entire steam generator according to the first embodiment. Below, the steam generator 1 of Embodiment 1 is demonstrated. The steam generator 1 includes a body portion 2, a tube group outer tube 3, a heat transfer tube 4, a water supply inner tube 5, a tube plate 6, a steam / water separator 7, a moisture separator 8, and a steam outlet. It includes a nozzle 9, a primary coolant inlet nozzle 9a, and a primary coolant outlet nozzle 9b.

  The steam generator 1 is used, for example, in a pressurized water reactor. The steam generator 1 has a hollow cylindrical shape extending in the vertical direction and sealed. The body 2 is an outer shell member of the steam generator 1. The lower half of the tube group outer tube 3 is disposed with a gap between the tube plate 6 and the tube plate 6. The heat transfer tube 4 is a part of the heat transfer tube group disposed in the tube group outer cylinder 3.

  The water supply inner pipe 5 supplies secondary cooling water from the outside of the steam generator 1 into the body 2. The water supply inner pipe 5 is provided between the steam separator 7 and the tube group outer cylinder 3. The tube plate 6 supports the end of the heat transfer tube 4.

  The steam separator 7 separates water vapor into steam and hot water. Moreover, the moisture separator 8 removes the moisture of the steam separated by the steam separator 7 and brings it into a state close to dry steam. Both the steam separator 7 and the humidity separator 8 are provided in the upper half of the body 2. A main steam pipe that sends steam to the turbine is connected to the steam outlet nozzle 9.

  For example, a cooling water pipe to which primary cooling water is sent from a pressurized water reactor is connected to the primary coolant inlet nozzle 9a. The primary coolant outlet nozzle 9b is connected to, for example, a cooling water pipe for sending the primary cooling water after heat exchange in the steam generator 1 to the pressurized water reactor.

  FIG. 2 is an explanatory view schematically showing the entire area of the water supply inner pipe of the first embodiment. The body 2 has a water supply inlet nozzle 16. The water supply inlet nozzle 16 has a protruding portion 37 a that protrudes outward in the radial direction of the body portion 2.

  FIG. 3 is an explanatory view schematically showing the inner side of the water supply inlet nozzle according to the first embodiment. The water supply inner pipe 5 of the first embodiment will be described below. The water supply inner pipe 5 of the first embodiment includes a water supply inlet nozzle 16, a part 10 of the water supply inner pipe, a main water supply pipe 11, and a thermal sleeve 15.

  The water supply inlet nozzle 16 is an inlet for introducing secondary cooling water into the steam generator 1. In addition, the water supply inlet nozzle 16 is also a place connecting the thermal sleeve 15 and the main water supply pipe 11. The thermal sleeve 15 is inserted into the water supply inlet nozzle 16. The main water supply pipe 11 is a pipe that conveys secondary cooling water from the water supply inlet nozzle 16 into the steam generator 1.

  Part 10 of the water supply inner pipe includes a reducer 12, a J tube 13, and a water supply inner pipe T-joint 14. The reducer 12 connects the water supply inner pipe 5 and the water supply inner pipe T joint 14. The J tube 13 is an outflow pipe through which secondary cooling water passing through the feed water inner pipe 5 flows out into the steam generator 1. Moreover, it can suppress that a vapor | steam flows in in the feed water inner pipe 5. FIG.

  The water supply inner pipe T-joint 14 connects the reducer 12 and the thermal sleeve 15. The thermal sleeve 15 is disposed in the water supply inlet nozzle 16 and connects the main water supply pipe 11 and the water supply pipe T joint 14.

  FIG. 4 is a flowchart of the thermal sleeve repair method according to the first embodiment. Moreover, FIG. 5 is explanatory drawing which shows typically a mode that a part of water supply inner pipe and Embodiment 1 of Embodiment 1 were cut | disconnected. When performing the thermal sleeve repair method of this embodiment, in step S101, the part 10 of the water supply inner pipe of the steam generator 1 and the thermal sleeve 15 are separated.

  The location where the water supply inner pipe 5 is separated is, for example, the boundary between the thermal sleeve 15 of the water supply inner pipe 5 and the water supply inner pipe T joint 14 connected to the thermal sleeve 15. The location where the water supply inner pipe 5 is separated is not limited to the location of the first embodiment.

  FIG. 6 is an explanatory diagram showing a state where a part of the water supply inner pipe of the first embodiment is removed. In step S102, a part 10 of the feed water inner pipe is removed from the feed water inner pipe 5 of the steam generator 1. In step S102, not only the J tube 13 which is a part 10 of the water supply inner pipe but also the J tube 13 disposed on the thermal sleeve 15 is removed. Further, the reducer 12, which is a part 10 of the water supply inner pipe, the J tube 13, and the water supply inner pipe T-joint 14 can be removed together from the water supply inner pipe 5 of the steam generator 1, so that the steam generator The unnecessary work in 1 can be reduced.

  FIG. 7 is an explanatory view showing a state in which the thermal sleeve of Embodiment 1 is removed. In step S <b> 103, the thermal sleeve 15 is removed from the feed water inlet nozzle 16 of the steam generator 1. In step S102, since part 10 of the feed water inner pipe is removed from the feed water inner pipe 5 of the steam generator 1, the thermal sleeve 15 can be easily removed from the feed water inlet nozzle 16 of the steam generator 1.

  FIG. 8 is an explanatory view showing a state in which the new thermal sleeve of Embodiment 1 is attached. In the first embodiment, for example, in order to attach a new thermal sleeve 15 a to the feed water inlet nozzle 16 from within the steam generator 1, a new thermal sleeve 15 a is inserted from the secondary manhole 17 disposed in the steam generator 1. Transport. Further, the method of transporting from the steam generator 1 to the new thermal sleeve 15 a is not limited to the method according to the first embodiment, that is, the method of transporting from the secondary side manhole 17.

  In the first embodiment, the new thermal sleeve 15a is divided before the new thermal sleeve 15a is conveyed from the secondary manhole 17 disposed in the steam generator 1. For example, the new thermal sleeve 15a is divided into three parts with the central axis in the longitudinal direction as the center of division. That is, a new cylindrical thermal sleeve 15a is divided into three parts in the circumferential direction. By dividing the new thermal sleeve 15a, the new thermal sleeve 15a can be easily conveyed to the secondary manhole 17 disposed in the steam generator 1. The number of divisions of the new thermal sleeve 15a is not limited to three.

  The divided new thermal sleeve 15a is transported to the secondary manhole 17 arranged in the steam generator 1, and then joined by welding or the like in the steam generator 1 to be assembled as a cylindrical member. Then, it progresses to step S104 and the new thermal sleeve 15a is attached to the feed water inlet nozzle 16 from the inside of the steam generator 1. FIG. When a new thermal sleeve 15a is attached from the steam generator 1 to the feed water inlet nozzle 16, the J tube 13 disposed on the thermal sleeve 15 removed in step S102 is also attached to the new thermal sleeve 15a.

  FIG. 9 is an explanatory diagram illustrating a state in which a part of the water supply inner pipe of Embodiment 1 is attached. In step S <b> 105, a part 10 of the water supply inner pipe is attached in the water supply inner pipe 5. A part 10 of the water supply inner pipe attached in the water supply inner pipe 5 is a part 10 of the water supply inner pipe of the steam generator 1 removed in step S102.

  First, the water supply inner pipe T-joint 14 is attached to a new thermal sleeve 15 a attached in the steam generator 1. Thereafter, the reducer 12 is attached to the water supply inner pipe T-joint 14. In addition, the J tube 13 is provided with water supply after the water supply inner pipe T-joint 14 is attached to a new thermal sleeve 15 a attached to the steam generator 1 or after the reducer 12 is attached to the water supply inner pipe T-joint 14. It is attached to the inner pipe T joint 14.

  In addition, the order which attaches the water supply inner pipe T joint 14, the reducer 12, and the J tube 13 which are a part 10 of the water supply inner pipe in the steam generator 1 is not limited to the order described in the first embodiment. Absent. For example, a water supply inner pipe T-joint 14, a reducer 12, and a J tube, which are a part 10 of the water supply inner pipe, are welded in the steam generator 1, and are connected to the water supply inlet nozzle 16 in the steam generator 1. You may attach to the new thermal sleeve 15a attached.

  As described above, the thermal sleeve repair method according to the present embodiment can easily replace the thermal sleeve disposed in the steam generator by only removing a part of the water supply inner pipe to which the thermal sleeve is connected.

(Embodiment 2)
FIG. 10 is a flowchart of the thermal sleeve repair method according to the second embodiment. The steam generator 1 of the second embodiment is the same as that of the first embodiment, and includes a water supply inlet nozzle 26, a part 20 of a water supply inner pipe, a main water supply pipe 21, and a thermal sleeve 25.

  FIG. 11 is an explanatory diagram schematically illustrating a state in which the main water supply pipe of the second embodiment is cut. In executing the thermal sleeve repair method according to the present embodiment, first, the main water supply pipe 21 of the steam generator 1 is cut in step S201. For example, cutting is performed at the joint between the water supply inlet nozzle 26 of the steam generator 1 and the main water supply pipe 21. In addition, the cutting location of the main water supply pipe 21 of the steam generator 1 is not limited to the location in the second embodiment.

  FIG. 12 is an explanatory view schematically illustrating a state in which a part of the water supply inner pipe and the thermal sleeve according to the second embodiment are cut. Similarly to the first embodiment, in step S202, the part 20 of the water supply inner pipe of the steam generator 1 and the thermal sleeve 25 are separated. The place which isolate | separates the water supply inner pipe 5 is a boundary of the thermal sleeve 25 of a water supply inner pipe, and the water supply inner pipe T joint 24 which contacts the thermal sleeve 25, for example. Moreover, the location which isolate | separates the water supply inner pipe 5 is not limited to the location mentioned above.

  FIG. 13 is an explanatory diagram illustrating a state where a part of the water supply inner pipe of the second embodiment is removed. Similarly to the first embodiment, in step S203, a part 20 of the water supply inner pipe is removed from the water supply inner pipe 5 of the steam generator 1. In step S203, not only the J tube 23 which is a part 20 of the water supply inner pipe but also the J tube 23 disposed on the thermal sleeve 25 is removed.

  FIG. 14 is an explanatory view showing a state in which the thermal sleeve of the second embodiment is removed. Similarly to the first embodiment, in step S204, the thermal sleeve 25 is removed from the feed water inlet nozzle 26 of the steam generator 1.

  FIG. 15 is an explanatory view schematically showing a state in which the new thermal sleeve of the second embodiment is carried in from the water supply inlet nozzle. In the second embodiment, for example, a new thermal sleeve 25 a is attached to the steam generator 1 from the feed water inlet nozzle 26. In the second embodiment, as in the first embodiment, a new thermal sleeve 25a is divided. For example, the new thermal sleeve 25a is divided into three parts around the central axis in the longitudinal direction of the new thermal sleeve 25a. Thereafter, a new thermal sleeve 25 a is conveyed from the feed water inlet nozzle 26 of the steam generator 1 into the steam generator 1.

  FIG. 16 is an explanatory view schematically showing a state in which the new thermal sleeve of Embodiment 2 is attached to the inside of the water supply inlet nozzle. In the thermal sleeve repair method according to the present embodiment, a new thermal sleeve 25a is attached to the feed water inlet nozzle 26 from within the steam generator 1 in step S205. In the second embodiment, as in the first embodiment, before the new thermal sleeve 25 a is attached to the feed water inlet nozzle 26, the new thermal sleeve 25 a divided and transported into the steam generator 1 is replaced with the steam generator 1. Welded inside.

  FIG. 17 is an explanatory diagram showing a state in which a part of the water supply inner pipe of Embodiment 2 is attached. In step S <b> 206, a part 20 of the water supply inner pipe is attached in the steam generator 1. The part 20 of the feed water inner pipe attached to the steam generator 1 is the part 20 of the feed water inner pipe of the steam generator 1 removed in step S206.

  FIG. 18 is an explanatory view schematically showing a state in which the main water supply pipe of Embodiment 2 is attached. As in step S207, the main water supply pipe 21 of the steam generator 1 cut in step S201 is welded. For example, welding is performed at the joint between the water supply inlet nozzle 26 of the steam generator 1 and the main water supply pipe 21. In addition, the welding location of the main water supply pipe 21 of the steam generator 1 is not limited to the location mentioned above.

  As described above, the thermal sleeve repair method according to the present embodiment can easily replace the thermal sleeve disposed in the steam generator by only removing a part of the water supply inner pipe to which the thermal sleeve is connected.

(Embodiment 3)
FIG. 19 is a flowchart of the thermal sleeve repair method according to the third embodiment. Similarly to the second embodiment, the steam generator 1 of the third embodiment includes a water supply inlet nozzle 36, a part 30 of the water supply inner pipe, a main water supply pipe 31, and a thermal sleeve 35.

  FIG. 20 is an explanatory diagram schematically illustrating a state in which the main water supply pipe of the third embodiment is cut. Similar to the second embodiment, first, in step S301, the main water supply pipe 31 of the steam generator 1 is cut. For example, cutting is performed at the joint between the water supply inlet nozzle 36 and the main water supply pipe 31 of the steam generator 1. In addition, the cutting | disconnection location of the main feed pipe 31 of the steam generator 1 is not limited to the location mentioned above.

  FIG. 21 is an explanatory diagram schematically illustrating a state where the water supply inlet nozzle according to the third embodiment is cut. In step S <b> 302, the water supply inlet nozzle 36 in the steam generator 1 is cut in order to transport the thermal sleeve 35 into the steam generator 1.

  In the third embodiment, for example, the water supply inlet nozzle 36 is cut at the position of the cutting portion 37. The cutting part 37 is preferably located at a position closer to the water supply inner pipe 5 than the protruding part 37 a of the water supply inlet nozzle 36. Since the new thermal sleeve 35a is inserted in the position where the protrusion 37a of the water supply inlet nozzle 36 is formed, the water supply inlet nozzle 36 is cut at a position closer to the water supply inner pipe 5 than the protrusion 37a. .

  FIG. 22 is an explanatory view schematically showing a state where a part of the water supply inner pipe and the thermal sleeve of the third embodiment are cut. Similarly to the first and second embodiments, in step S303, the part 30 of the water supply inner pipe and the thermal sleeve 35 are cut.

  FIG. 23 is an explanatory diagram illustrating a state where a part of the water supply inner pipe of the third embodiment is removed. Similar to the first and second embodiments, in step S304, a part 30 of the water supply inner pipe is removed from the water supply inner pipe 5. In step S305, not only the J tube 33 which is a part 30 of the water supply inner pipe but also the J tube 33 disposed in the thermal sleeve 35 is removed.

  FIG. 24 is an explanatory view showing a state in which the thermal sleeve of the third embodiment is removed. Similar to the first and second embodiments, the thermal sleeve 35 is removed from the feed water inlet nozzle 36 in step S305. In this case, the thermal sleeve 35 may be removed inside the steam generator 1, or the thermal sleeve 35 may be removed outside the steam generator 1. The latter is more preferable because the operation of taking out the thermal sleeve 35 from the inside of the steam generator 1 becomes unnecessary.

  FIG. 25 is an explanatory view schematically showing a state where the new thermal sleeve of the third embodiment is carried in from the water supply inlet nozzle. In step S306, a new thermal sleeve 35a is conveyed from the feed water inlet nozzle 36 of the steam generator 1. In the third embodiment, the new thermal sleeve 35a is attached to the feed water inlet nozzle 36 by inserting it into the steam generator 1 from the feed water inlet nozzle 36 without dividing the new thermal sleeve 35a.

  That is, in the thermal sleeve repairing method according to the present embodiment, the water supply inlet nozzle 36 is cut at a position closer to the water supply inner pipe 5 than the protrusion 37a of the water supply inlet nozzle 6, so that a new thermal sleeve 35 a is attached. It attaches to the water supply inlet nozzle 36 without dividing | segmenting. For this reason, the procedure for dividing the new thermal sleeve 35a can be omitted, and the work can be shortened.

  FIG. 26 is an explanatory view schematically showing a state in which the new thermal sleeve of the third embodiment is attached to the inside of the water supply inlet nozzle.

  FIG. 27 is an explanatory view schematically showing a state in which a part of the water supply inner pipe of the third embodiment is attached. As in the first and second embodiments, a part 30 of the water supply inner pipe is attached from the steam generator 1.

  FIG. 28 is an explanatory diagram schematically illustrating a state in which the new water supply inlet nozzle according to the third embodiment is attached. In step S308, the water supply inlet nozzle 36 cut in step S302 is welded.

  FIG. 29 is an explanatory view schematically showing a state in which the main water supply pipe of Embodiment 3 is attached. As in the second embodiment, in step S309, the main water supply pipe 31 of the steam generator 1 cut in step S301 is welded. For example, welding is performed at the joint between the water supply inlet nozzle 36 of the steam generator 1 and the main water supply pipe 31. In addition, the welding location of the main water supply pipe 31 of the steam generator 1 is not limited to this part.

  As described above, the thermal sleeve repair method according to the present embodiment can attach a new thermal sleeve directly from the water supply inlet nozzle without dividing the new thermal sleeve attached to the water supply inlet nozzle. Therefore, the work process of dividing a new thermal sleeve can be omitted.

DESCRIPTION OF SYMBOLS 1 Steam generator 2 Body part 3 Tube group outer cylinder 4 Heat transfer pipe 5 Water supply inner pipe 6 Tube plate 7 Air-water separator 8 Moisture separator 9 Steam outlet nozzle 9a Primary coolant inlet nozzle 9b Primary coolant outlet pipe Base 10, 20, 30 Part of water supply inner pipe 11, 21, 31 Main water supply pipe 12, 22, 32 Reducer 13, 23, 33 J tube 14, 24, 34 Water supply inner pipe T joint 15, 25, 35 Thermal sleeve 15a, 25a, 35a New thermal sleeve 16, 26, 36 Water supply inlet nozzle 17 Secondary side manhole 37 Cutting part 37a Protruding part

Claims (6)

Separating the thermal sleeve of the feed water inner pipe disposed inside the feed water inlet nozzle of the steam generator and a part of the feed water inner pipe connected to the thermal sleeve;
A procedure for removing a portion of the water supply pipe from the water supply pipe;
The procedure to remove the thermal sleeve from the water supply inlet nozzle,
To install a new thermal sleeve from inside the steam generator,
Attaching a part of the water supply inner pipe removed in the procedure for removing a part of the water supply inner pipe from the water supply inner pipe to the water supply inner pipe from the inside of the steam generator ;
A thermal sleeve repairing method comprising: The part of the water supply inner pipe to be removed in the procedure of removing a part of the water supply inner pipe from the water supply inner pipe includes a T joint of the water supply inner pipe connected to the thermal sleeve and a reducer connected to the T joint. The thermal sleeve repair method according to claim 1, wherein the thermal sleeve is repaired.   The thermal sleeve repairing method according to claim 2, further comprising a step of dividing the new thermal sleeve before attaching the new thermal sleeve from the inside of the steam generator.   4. The thermal sleeve repair method according to claim 3, further comprising a step of bringing the new thermal sleeve into the steam generator through a secondary manhole disposed in the steam generator after being divided.   4. The thermal sleeve repairing method according to claim 3, wherein the new thermal sleeve includes a step of attaching to the inside of the water supply inlet nozzle through the opening after the main water supply pipe of the steam generator is cut after being divided. .   The thermal sleeve repairing method according to claim 2, further comprising a step of attaching the new thermal sleeve to the inside of the water supply inlet nozzle through an opening formed by cutting the water supply inlet nozzle of the steam generator.

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