JP7360990B2 - Steam generator inspection device and steam generator inspection method - Google Patents

Description

The present disclosure relates to a steam generator inspection device and a steam generator inspection method.

For example, in a nuclear power plant that uses a pressurized water reactor (PWR), a steam generator is used to generate steam that drives a turbine connected to a generator. In this type of steam generator, the primary coolant (e.g., light water) supplied from the nuclear reactor flows inside heat transfer tubes housed inside the shell, and the secondary coolant flows outside the heat transfer tubes inside the turbine. Coolant flows. In the heat exchanger tube, the high temperature primary coolant heats the secondary coolant, thereby generating steam to be supplied to the turbine.

One of the inspection items for nuclear power plants is the quality inspection of heat exchanger tubes included in steam generators. For example, Patent Document 1 does not target a steam generator used in a nuclear power plant, but it describes a technique for stabilizing the posture of an inspection device inserted inside a tubular inspection object by fixing it with a balloon. A technique for improving inspection quality is disclosed.

Japanese Patent Application Publication No. 10-239593

One of the inspection items for steam generators is observation and inspection of the outer surfaces of heat exchanger tubes. For example, in the steam generator mentioned above, foreign matter may get mixed into the secondary coolant, and foreign matter may accumulate around the heat exchanger tubes, or foreign matter may collide with the heat exchanger tubes, causing scratches on the outer surface. be. In order to detect such abnormalities, conventionally, an inspection probe (for example, an imaging device capable of capturing an image of the outer surface such as a CCD camera) is used from the outside through a hand hole provided on the side of the body of the steam generator. ) was used to inspect the outer surface of the heat exchanger tube placed inside the body. However, since the inside of the body is partitioned by a plurality of tube support plates for supporting the heat transfer tubes, the range accessible by the inspection probe inserted through the hand hole is limited. In recent years, the quality required for steam generators has improved, and there is a need to efficiently inspect the outer surfaces of heat exchanger tubes over a wider range.

At least one aspect of the present disclosure has been made in view of the above circumstances, and provides a steam generator inspection device capable of efficiently inspecting a wide range of surfaces of heat exchanger tubes included in a steam generator, and a steam generator inspection device. The purpose is to provide a method.

In order to solve the above problems, a steam generator inspection device according to one aspect,
An inspection device for a steam generator having a heat transfer tube inside the body,
a guide tray extending from a first hand hole provided in the body toward the inside of the body;
an inspection cable for inspecting the outer surface of the heat exchanger tube;
The inspection cable is insertable, and the cable is configured such that when the cable is guided from the first hand hole along the guide tray, the portion exposed from the tip of the guide tray can be deformed downward. A containment body;
Equipped with

In order to solve the above problems, a steam generator inspection method according to one aspect includes the following steps:
A method for inspecting a steam generator having a heat transfer tube inside the body, the method comprising:
installing a guide tray so as to extend from a first hand hole provided in the body toward the inside of the body;
inserting a cable housing into the body along the guide tray;
adjusting the insertion amount of the cable accommodating body so that the tip of the cable accommodating body reaches the inspection target position of the heat exchanger tube located below the guide tray;
inserting an inspection cable into the cable housing and inspecting the inspection target position;
Equipped with

According to at least one aspect of the present disclosure, it is possible to provide a steam generator inspection device and a steam generator inspection method that can efficiently inspect the surface of a heat transfer tube included in a steam generator over a wide range.

FIG. 1 is a schematic cross-sectional view schematically showing a steam generator according to an embodiment from the side. FIG. 1 is a perspective view showing the configuration of an inspection device according to an embodiment. 3 is an enlarged view of the vicinity of the tip of the guide tray in FIG. 2. FIG. 3 is a view from A in FIG. 2. FIG. 3 is a view from B in FIG. 2. FIG. FIG. 3 is an enlarged perspective view showing the vicinity of the flow slot in FIG. 2; FIG. 3 is an enlarged perspective view showing the vicinity of the tip of the cable accommodating body in FIG. 2; FIG. 3 is an enlarged view showing the vicinity of the surveillance camera in FIG. 2 from the side. 1 is a flowchart showing each step of a steam generator inspection method according to an embodiment.

Hereinafter, some embodiments of the present disclosure will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of the components described as embodiments or shown in the drawings are not intended to limit the scope of the present disclosure, and are merely illustrative examples. do not have.
For example, expressions expressing relative or absolute positioning such as "in a certain direction,""along a certain direction,""parallel,""orthogonal,""centered,""concentric," or "coaxial" are strictly In addition to representing such an arrangement, it also represents a state in which they are relatively displaced with a tolerance or an angle or distance that allows the same function to be obtained.
For example, expressions such as "same,""equal," and "homogeneous" that indicate that things are in an equal state do not only mean that things are exactly equal, but also have tolerances or differences in the degree to which the same function can be obtained. It also represents the existing state.
For example, expressions expressing shapes such as squares and cylinders do not only refer to shapes such as squares and cylinders in a strict geometric sense, but also include uneven parts and chamfers to the extent that the same effect can be obtained. Shapes including parts, etc. shall also be expressed.
On the other hand, the expressions "comprising,""comprising,""comprising,""containing," or "having" one component are not exclusive expressions that exclude the presence of other components.

(Steam generator configuration)
First, the configuration of the steam generator 1 to be inspected by the inspection apparatus according to at least one embodiment of the present disclosure will be described. FIG. 1 is a schematic sectional view schematically showing a steam generator 1 from the side according to an embodiment.

The steam generator 1 is a heat exchanger having a heat exchanger tube group including a plurality of heat exchanger tubes, and is, for example, a steam generator used in a pressurized water reactor (PWR). A primary coolant (for example, light water) as a reactor coolant and a neutron moderator that flows through the reactor and a secondary coolant that flows through the turbine flow into the steam generator 1 . In the steam generator 1, the primary coolant that has become high temperature and high pressure is exchanged with the secondary coolant to evaporate the secondary coolant and generate steam, and the primary coolant that has become high temperature and high pressure Cool the coolant.

The steam generator 1 has a body 2 that is arranged in the vertical direction and has a sealed hollow cylindrical shape. A heat exchanger tube group 3 is provided within the body 2 . The heat exchanger tube group 3 is composed of a plurality of heat exchanger tubes 5 extending parallel to each other, and includes a circular arc portion 3a having an inverted U shape and a straight line extending in the vertical direction below the circular arc portion 3a. part 3b. Each heat exchanger tube 5 is arranged so that the U-shaped arc portion 3a is convex upward, both ends of the lower side are supported by the tube plate 4, and the straight portion 3b in the middle is arranged so that the U-shaped arc portion 3a is convex upward. It is supported by the body 2 via a support plate 6. A large number of through holes (not shown) are formed in the tube support plate 6, and each heat exchanger tube 5 is inserted into the through holes. In this embodiment, the steam generator 1 includes seven tube support plates 6a, 6b, . . . , 6g arranged at different positions in the vertical direction. These tube support plates 6a, 6b, . . . , 6g are arranged at approximately equal intervals along the vertical direction. These plurality of tube support plates 6 are provided with flow slots 15 through which fluid flowing inside the body 2 passes, as will be described later.

A water chamber 7 is provided at the lower end of the body 2. The interior of the water chamber 7 is partitioned by a partition wall 8 into an entry chamber 71 and an exit chamber 72. The inlet chamber 71 is communicated with one end of each heat exchanger tube 5, and the outlet chamber 72 is communicated with the other end of each heat exchanger tube 5. Further, the entrance chamber 71 is formed with an inlet nozzle 74 that communicates with the outside of the body section 2 , and the outlet chamber 72 is formed with an outlet nozzle 75 that communicates with the outside of the body section 2 . The inlet nozzle 74 is connected to a cooling water pipe (not shown) through which the primary coolant is sent from the pressurized water reactor, and the outlet nozzle 75 is connected to the coolant pipe (not shown) through which the primary coolant is sent from the pressurized water reactor. A cooling water pipe (not shown) that sends to the furnace is connected.

Inside the upper half of the body 2, there is a steam separator 9 that separates the secondary coolant after heat exchange into steam (gas phase) and hot water (liquid phase), and a moisture separator 9 that separates the secondary coolant after heat exchange into steam (gas phase) and hot water (liquid phase). A moisture separator 10 is provided which removes the moisture and brings it into a state close to dry steam. A water supply pipe 11 is inserted between the steam separator 9 and the heat transfer tube group 3 for supplying secondary coolant water into the body 2 from the outside. Furthermore, a steam outlet 12 is formed at the upper end of the body 2. Further, in the lower half of the body 2, the secondary coolant supplied into the body 2 from the water supply pipe 11 is transferred between the body 2 and the tube group outer cylinder 13 provided inside the body 2. The water supply channel 14 is formed so as to flow down between the heat exchanger tubes 4, turn back at the tube plate 4, and rise along the heat exchanger tube group 3.

Note that a cooling water pipe (not shown) that sends steam to the turbine is connected to the steam exhaust port 12, and a cooling water pipe (not shown) is connected to the water supply pipe 11, where the steam used in the turbine is cooled by a condenser (not shown). A cooling water pipe (not shown) for supplying secondary coolant is connected.

In such a steam generator 1, the primary coolant heated in the pressurized water nuclear reactor is sent to the inlet chamber 71, circulates through a large number of heat transfer tubes 5, and reaches the outlet chamber 72. On the other hand, the secondary coolant cooled by the condenser is sent to the water supply pipe 11, passes through the water supply channel 13 in the body 2, and rises along the heat exchanger tube group 3. At this time, heat exchange is performed within the body 2 between the high-pressure, high-temperature primary coolant and the secondary coolant. The cooled primary coolant is then returned to the pressurized water reactor from the outlet chamber 72. On the other hand, the secondary coolant that has undergone heat exchange with the high-pressure, high-temperature primary coolant rises within the body 2 and is separated into steam and hot water by the steam separator 9. Moisture is removed from the separated steam in a moisture separator 10, and the steam is sent to a turbine.

Furthermore, at least one hand hole 20 is provided on the side surface of the body 2. The hand hole 20 is formed to penetrate a wall surface constituting the body 2, and is sealed by a sealing member 22 during normal times (when not inspecting). During non-normal times (during inspection), by removing the sealing member 22 and opening the hand hole 20, the heat transfer tube group 3 is placed inside the body 2 from the outside through the hand hole 20. Configured to be accessible.

The height position of the hand hole 20 provided in the body part 2 can be arbitrarily set within the range where the heat exchanger tube group 3 to be inspected exists. As will be described later, since the inspection range of the inspection device 100 is limited to a predetermined range below the height position of the handhole 20, it is necessary to set the height position of the handhole 20 to obtain an appropriate inspection range. good. For example, from the viewpoint of ensuring a wide inspection range, it is preferable to set the height position of the hand hole 20 at the upper side of the body 2 (at least above the tube support plate 6g disposed at the bottom). ). In FIG. 1, as an example, the height position of the hand hole 20 is set between the tube support plate 6a and the tube support plate 6b, so that a wide range of the straight portion 3b of the heat exchanger tube group 3 is inspected. The case where it is configured to be included is shown.

Further, in this embodiment, the body 2 is provided with a plurality of hand holes 20 (a first hand hole 20a and a second hand hole 20b). The first hand hole 20a and the second hand hole 20b are arranged at positions facing each other (positions at about 180 degrees when viewed from above) in the body 2 having a substantially cylindrical shape. Further, the height positions of the first hand hole 20a and the second hand hole 20b are arranged to be equal to each other.

(Inspection equipment)
Next, the inspection device 100 for the steam generator 1 having the above configuration will be explained. FIG. 2 is a perspective view showing the configuration of the inspection device 100 according to one embodiment. FIG. 3 is an enlarged view of the vicinity of the tip end 102a of the guide tray 102 shown in FIG. FIG. 4 is a view from A in FIG. 2. FIG. 5 is a view from B in FIG. FIG. 6 is an enlarged perspective view showing the vicinity of the flow slot 15 in FIG. 2. As shown in FIG. FIG. 7 is an enlarged perspective view showing the vicinity of the tip of the cable accommodating body 106 in FIG. 2. As shown in FIG. FIG. 8 is an enlarged view showing the vicinity of the surveillance camera 118 in FIG. 2 from the side. In addition, in FIG. 2, a part of the body 2 of the steam generator 1 is omitted in order to clearly show the state in which the inspection device 100 is applied to the steam generator 1.

The inspection device 100 is a device for inspecting the outer surface of each heat exchanger tube 5 that constitutes the heat exchanger tube group 3 housed inside the body 2 of the steam generator 1 . The inspection device 100 includes a guide tray 102, a test cable 104, and a cable accommodating body 106.

The guide tray 102 is a guide member for guiding the cable accommodating body 106 and the trunk section 2 . The guide tray 102 is attached to the first hand hole 20a via a guide tray attachment member 103b (see FIG. 4), and extends toward the inside of the body 2 from the first hand hole 20a. Thereby, the cable accommodating body 106 can be introduced along the guide tray 102 from the outside to the inside of the body 2 through the first hand hole 20a.

The guide tray 102 is configured to be able to guide the cable accommodating body 106 to prevent it from shifting laterally with respect to the insertion direction when the cable accommodating body 106 to be guided is introduced from the outside to the inside of the body 2. be done. For example, the guide tray 102 has a substantially concave cross-sectional shape corresponding to the outer contour of the cable accommodation body 106 in a cross section perpendicular to the extending direction, so that the cable accommodation body 106 is prevented from shifting in the lateral direction with respect to the insertion direction. prevent.

The leading end 102a of the guide tray 102 is open, and the cable accommodating body 106 that reaches the leading end 102a by the guiding tray 102 can be exposed from the leading end 102a. In this embodiment, the guide tray 102 is configured to extend straight from the first hand hole 20a to near the tip 102a, with the tip 102a facing downward. As a result, the portion of the cable accommodating body 106 guided by the guide tray 102 that is exposed from the tip portion 102a is smoothly deformed downward by its own weight.

In this embodiment, as shown in FIG. 3, the distal end portion 102a is curved downward, so that when the cable accommodating body 106 is fed in while being deformed downward at the distal end portion 102a, it is attached to the guide tray 102. Smooth deformation is possible to prevent clogging. Thereby, troubles such as stacking of the cable accommodation body 106 near the tip portion 102a can be effectively avoided.

The guide tray 102 having the above configuration has a variable length from the first hand hole 20a to the tip end 102a (that is, the insertion length into the body 2). For example, as shown in FIG. 4, the guide tray 102 is fixed to the first hand hole 20a via the fixing structure 21, but by configuring the fixing position of the guide tray 102 with respect to the fixing structure 21 to be variable, The length from the first hand hole 20a to the tip end 102a can be changed. In addition, when the fixing structure 21 includes a delivery mechanism (not shown) for adjusting the amount of insertion of the guide tray 102 from the first hand hole 20a, the guide tray 102 is fixed to the first hand hole 20a. The length from the first hand hole 20a to the tip end 102a may be changed by operating the delivery mechanism.

The test cable 104 is a flexible cable body having a test probe 105 at its tip. The inspection probe 105 can be a device for inspecting the outer surface of the heat exchanger tube 5 to be inspected, but in this embodiment, the inspection probe 105 is a CCD camera that can image the outer surface of the heat exchanger tube 5. Such imaging devices are used. The test cable 104 may be a support cable for supporting the test probe 105, a power supply cable for supplying power to the test probe 105, or a cable for transmitting and receiving control signals to and from the test probe 105. It may be a control signal cable for carrying out the test, or it may be a data transmission cable for transmitting the test results of the test probe 105.

The cable accommodation body 106 is configured to be able to be guided into the body 2 along the guide tray 102. Cable housing 106 has an internal space formed along the extending direction of cable housing 106 . This internal space can accommodate cables including the inspection cable 104. The internal space of the cable housing 106 is open at the tip, and as shown in FIG. 7, at least the inspection probe 105 provided at the tip of the inspection cable 104 among the cables inserted inside is exposed to the outside. configured to do so. In this way, the cable housing 106 protects the cables accommodated therein by covering them. Thereby, when these cables are inserted into the interior of the body section 2, damage caused by contact with the surroundings can be effectively prevented.

Further, the cable accommodation body 106 is configured to be allowed to deform in at least one direction so that when guided by the guide tray 102, the portion exposed from the tip portion 102a of the guide tray 102 deforms downward. has. As shown in FIGS. 3 and 6, the cable housing 106 of this embodiment includes a plurality of divided bodies 107 connected to each other along the extending direction of the cable housing 106. The connection angle between adjacent divided bodies 107 is variable, and when the plurality of divided bodies 107 are guided along the guide tray 102, the portion exposed from the tip 102a of the guide tray 102 moves downward due to its own weight. Transform towards the target. Such a cable accommodation body 106 does not twist in the middle when guided along the guide tray 102, and deforms only in one direction so that it can be deformed downward by its own weight from the tip end 102a. is configured so that it is allowed. This prevents the cables accommodated in the cable housing 106 from being twisted, allowing for more reliable testing.

In this case, a separation prevention wire 108 may be accommodated in the internal space of the cable accommodating body 106, as shown in FIG. The separation prevention wire 108 is housed over the entire length of the cable housing 106. As a result, even if the cable housing body 106 separates into a plurality of divided bodies 107 due to some factor (for example, an external impact), the separated divided bodies 107 can be held and the cable housing body 106 can be kept inside the body 2. It can prevent it from falling off.

Note that, as shown in FIGS. 2 and 4, such a cable accommodation body 106 is fed out to the guide tray 102 from a feed device 109 connected to an end of the guide tray 102 on the outside of the body 2. It is now possible. The delivery device 109 includes a reel 111 on which the cable accommodation body 106 is wound in advance. In the delivery device 109, the reel 111 is rotated by operating the handle 109a, and the cable accommodating body 106 wound around the reel 111 is delivered to the guide tray 102 according to the rotation speed. Conversely, when the handle 109a is rotated in the opposite direction, the cable accommodation body 106 is collected on the reel 111. By adjusting the amount of cable accommodating body 106 to be fed out by the feeding device 109 in this way, the position of the tip of the cable accommodating body 106 guided into the interior of the body 2 by the guide tray 102 can be adjusted.

In addition, in the delivery device 109, the reel 111 around which the cable accommodating body 106 is wound is configured to be detachable, so that different cable accommodating bodies 106 can be used depending on the type of inspection.

The cable accommodation body 106 having the above configuration is guided toward the inside of the body 2 from the first hand hole 20a by the guide tray 102. As shown in FIGS. 2 and 3, the cable accommodating body 106 exposed from the tip 102a of the guide tray 102 deforms downward due to its own weight and extends downward.

As shown in FIGS. 2 and 6, the cable accommodation body 106 is configured to be able to pass through the flow slots 15 provided in each of the plurality of tube support plates 6. Each of the plurality of tube support plates 6 is provided with a plurality of flow slots 15 that are opened so that a medium (secondary coolant) flowing inside the body 2 can pass therethrough. Each of the plurality of flow slots 15 is opened in the shape of a long hole in the vicinity of the plurality of heat exchanger tubes 5 supported by the tube support plate 6 along the arrangement direction of the plurality of heat exchanger tubes 5 . Each flow slot 15 is a substantially elliptical long hole defined by a major diameter along the longitudinal direction and a minor diameter along the transverse direction, and is arranged at approximately equal intervals along the arrangement direction.

The cable accommodation body 106 is configured to have a smaller diameter than the flow slot 15 so that it can pass through the flow slot 15. Specifically, the diameter of the cable accommodating body 106 is set smaller than the short diameter of the flow slot 15, which is a long hole. Moreover, each of the plurality of flow slots 15 provided in each tube support plate 6 is formed at a position that overlaps with each other when viewed from above. As a result, the cable accommodating body 106 extending downward from the tip end 102a of the guide tray 102 is guided to the bottom of the body 2 by passing through the plurality of tube support plates 6, as shown in FIG. Is possible.

At the tip of the cable housing 106, as shown in FIG. 7, a test probe 105 provided at the tip of the test cable 104 inserted into the cable housing 106 is exposed. Inspection probe 105 may be configured to be movable based on a control signal. Thereby, by roughly aligning the tip of the cable accommodating body 106 with respect to the inspection target location of the heat exchanger tube 5, the inspection probe 105 can be moved to accurately access the inspection target location. In this case, control signals may be transmitted and received with the inspection probe 105 in a wired manner using the inspection cable 104, or wirelessly by a communication means (not shown).
In addition, when moving the inspection probe 105 after aligning the tip of the cable accommodation body 106 with respect to the inspection target location, for example, by operating the inspection probe 105 so as to insert it between adjacent heat exchanger tubes 5. , the inspection target area can be accessed with high accuracy.

The inspection device 100 also includes a position fixing mechanism 110 for fixing the position of the tip of the cable accommodating body 106 with respect to the heat exchanger tube 5. By fixing the tip position of the cable accommodating body 106 with respect to the heat exchanger tube 5 to be inspected by the position fixing mechanism 110, the attitude of the inspection probe 105 is stabilized, and accurate inspection becomes possible.

Position fixing mechanism 110 includes, for example, an air supply cable 112 and a balloon 114. The air supply cable 112 is inserted into the internal space of the cable housing 106 like other cables, and can supply air from the outside to the balloon 114 provided so as to be exposed from the tip of the cable housing 106. configured. Balloon 114 is inflatable by air supply from air supply cable 112 . The balloon 114 expanded by the air from the air supply cable 112 comes into contact with the heat exchanger tube 5, so that the position of the cable accommodating body 106 can be stably fixed by the reaction force from the surface of the heat exchanger tube 5.

Although FIG. 7 shows an example in which the balloon 114 is expanded at a position where the balloon 114 can come into contact with the surface of the heat exchanger tube 5, for example, the balloon 114 can be expanded inside the flow slot 15 to accommodate the cable. Body 106 may be fixed. In this case, since the gap between the balloon 114 and the flow slot 15 is small, the cable accommodation body 106 can be fixed by bringing the balloon 114 into contact with the inside of the flow slot 15 with a small amount of expansion.

The inspection device 100 further includes a rail frame 116 and a surveillance camera 118 supported by the rail frame 116, as shown in FIG. The rail frame 116 extends toward the inside of the body 2 from at least one of the first hand hole 20a and the second hand hole 20b. In this embodiment, the rail frame 116 is configured to extend toward the inside of the body 2 from both the first hand hole 20a and the second hand hole 20b. In other words, the rail frame 116 has a double-supported structure in which one end is fixed to the first hand hole 20a and the other end is fixed to the second hand hole 20b. Both ends of the rail frame 116 are fixed to the first hand hole 20a and the second hand hole 20b, respectively, via rail frame attachment members 119a, 119b (see FIGS. 2, 4, and 5).

In addition, if there is another configuration for the rail frame 116 between the first hand hole 20a and the second hand hole 20b, the second hand hole 20a may extend toward the inside of the body 2 from the second hand hole 20b. By providing the rail frame 116 with a cantilevered structure, interference with this structure may be avoided. For example, when the height positions of the first hand hole 20a and the second hand hole 20b are the same as the height position of the U-shaped circular arc portion 3a of the heat exchanger tube group 3, the first hand hole 20a The arc portion 3a is interposed between the second hand hole 20b and the second hand hole 20b. Therefore, by providing the rail frame 116 so as to have a cantilever structure from the second hand hole 20b on the opposite side to the first hand hole 20a where the guide tray 102 is provided, it is possible to avoid the arcuate portion 3a. .

Surveillance camera 118 is supported by rail frame 116. In this embodiment, the surveillance camera 118 is suspended and supported from the rail frame 116 via a support wire 122. The support wire 122 is guided along the rail frame 116 from the second hand hole 20b. That is, the support wire 122 is deflected downward by the guide 120 provided at the tip of the rail frame 116. The support wire 122 is supported by the support wire 122 by adjusting the amount of delivery from the second hand hole 20b to the inside of the body 2 by a delivery mechanism (not shown) provided outside the second hand hole 20b. The vertical position of the monitoring camera 118 is variable.

Further, the surveillance camera 118 may be supported with respect to the rail frame 116 via a plurality of cables, as shown in FIG. In this embodiment, the surveillance camera 118 includes an auxiliary wire 124 in addition to the above-mentioned support wire 122 as the plurality of cables. The support wire 122 and the auxiliary wire 124 support the surveillance camera 118 at two points by being connected to different positions of the surveillance camera 118, respectively. This makes it possible to stabilize the posture of the surveillance camera 118 that is suspended and supported, and enables high-quality imaging and monitoring.

The surveillance camera 118 is supported from the second hand hole 20b side of the rail frame 116 and is disposed to face the cable accommodation body 106. This allows the surveillance camera 118 to image the tip of the cable accommodating body 106 from the side opposite to the first hand hole 20a to which the guide tray 102 is fixed.

Further, the surveillance camera 118 is configured to have a smaller diameter than the flow slot 15, similarly to the cable housing 106 described above. Thereby, the surveillance camera 118 can be guided to the bottom of the tube support plate 6 by passing through the flow slot 15, similarly to the cable accommodation body 106.

Note that the surveillance camera 118 may include an illumination device for clearly imaging the inside of the body section 2.

(Inspection method)
Next, a method for inspecting the steam generator 1 using the inspection apparatus 100 having the above configuration will be explained. FIG. 9 is a flowchart showing each step of an inspection method for the steam generator 1 according to an embodiment.

First, in the steam generator 1 under normal conditions, the first hand hole 20a and the second hand hole 20b are opened by removing the sealing member 22 (see FIG. 1) from the first hand hole 20a and the second hand hole 20b. (Step S1).

Next, the rail frame 116 is installed in the opened first hand hole 20a and second hand hole 20b via the rail frame attachment members 119a and 119b (step S2). In this embodiment, as described above with reference to FIG. 2, a case will be described in which the rail frame 116 is installed in a double-sided structure between the first hand hole 20a and the second hand hole 20b.

Note that if there is an inclusion between the first hand hole 20a and the second hand hole 20b as described above, one end of the rail frame 116 may be attached to the second hand hole 20b via the rail frame attachment member 119b. The rail frame 116 having a cantilever structure may be formed by fixing the rail frame 116 with a cantilever structure. At this time, as the hand hole to which the rail frame 116 is attached, the second hand hole 20b located on the opposite side from the first hand hole 20a to which the guide tray 102 is attached is selected as described later.

Subsequently, the surveillance camera 118 connected to the support wire is sent into the body 2 from the second hand hole 20b along the rail frame 116 installed in step S2 (step S3). The surveillance camera 118 may be supported at two points by an auxiliary wire 124 in addition to the support wire 122 (see FIG. 8). By adjusting the feed amount, the surveillance camera 118 sent into the inside of the body 2 is mounted on the tube support plate 6b located directly below the second hand hole 20b (among the tube support plates located below the second hand hole 20b). It is adjusted so that it is suspended and supported above the tube support plate located at the uppermost position.

Subsequently, the guide tray 102 is installed in the opened first hand hole 20a via the guide tray attachment member 103b (step S4). The guide tray 102 is installed corresponding to the position of the heat exchanger tube 5 to be inspected. As described above with reference to FIG. 2, the inspection apparatus 100 performs inspection using the inspection probe 105 guided by the cable accommodating body 106 extending downward from the tip 102a of the guide tray 102. Therefore, the guide tray 102 is installed so that the tip 102a of the guide tray 102 is located above the target position for guiding the inspection probe 105.

Subsequently, the delivery device 109 having the reel 111 around which the cable accommodating body 106 is wound is installed on the guide tray 102 (step S5). A reel 111 around which the cable accommodating body 106 is wound is mounted on the sending device 109 . A plurality of types of reels 111 are prepared in advance, and one selected according to the type of examination is removably mounted on the delivery device 109. This makes it possible to easily replace various cable accommodating bodies 106 depending on the type of inspection, thereby improving work efficiency. Such a delivery device 109 is positioned and installed so that the delivery port of the cable accommodation body 106 and the guide tray 102 are located coaxially.

Subsequently, while monitoring the image captured by the surveillance camera 118 sent into the interior of the body 2 in step S3, the cable housing 106 is sent out from the sending device 109 prepared in step S5 to the guide tray 102 (step S6 ). The cable accommodating body 106 is delivered by rotating the reel 111 by operating a handle 109a included in the delivery device 109. As the amount of cable accommodation body 106 fed out along guide tray 102 increases, the portion exposed from tip 102a of guide tray 102 extends downward due to its own weight.

When the feeding amount further increases, the tip of the cable accommodating body 106 reaches the tube support plate 6b located below the first hand hole 20a. Since the cable accommodation body 106 has a smaller diameter than the flow slot 15 provided in the tube support plate 6b, it can reach below the tube support plate 6b by passing through the flow slot 15. Here, the cable accommodation body 106 is in a state of hanging down from the tip end 102a of the guide tray 102 due to its own weight. Therefore, the tip of the cable accommodating body 106 comes into contact with the periphery of the flow slot 15, which may cause a blockage when the cable accommodating body 106 passes through the flow slot 15. In step S6, when the cable accommodating body 106 is sent out, the tip of the cable accommodating body 106 is monitored by the monitoring camera 118 disposed on the side facing the cable accommodating body 106 to determine whether or not a blockage has occurred. can be monitored. If a blockage occurs, the blockage can be cleared by, for example, operating the delivery device 109 to reapply the approach of the cable accommodation body 106 to the flow slot 15.

Step S6 is continued until the tip of the cable accommodating body 106 reaches the target position by passing the cable accommodating body 106 through the flow slot 15 of at least one tube support plate 6. At this time, as the tip of the cable housing 106 descends, the height position of the surveillance camera 118 is lowered to monitor whether the tip of the cable housing 106 is properly guided inside the body 2. Ru.

Subsequently, when the tip of the cable accommodating body 106 reaches the target position (for example, the position shown in FIG. 2), the position of the cable accommodating body 106 is fixed by operating the position fixing mechanism 110 (step S7). Specifically, as shown in FIG. 2, an air supply cable 112 with a balloon 114 attached to its tip is inserted into the cable housing 106 guided by the guide tray 102 through the first hand hole 20a. . The air supply cable 112 is inserted so that the balloon 114 is exposed from the tip of the cable housing 106. The balloon 114 is then inflated by supplying air from the air supply cable 112 to the balloon 114. As a result, the expanded balloon 114 comes into contact with the surface of the heat exchanger tube 5, and the position of the cable accommodation body 106 is fixed by the reaction force received from the surface of the heat exchanger tube 5.

Subsequently, as shown in FIG. 2, the test cable 104 having the test probe 105 at its tip is sent into the internal space of the cable housing 106 from the first hand hole 20a. Thereby, the inspection probe 105 is made to reach the tip of the cable housing 106 (step S8), and an inspection is performed (step S9). At this time, when the test probe 105 is configured to be movable, the test may be performed while finely adjusting the position of the test probe 105 by operating the test probe 105.

When the inspection in step S9 is completed, it is determined whether there is a next inspection position (step S10). If there is a next inspection position (step S10: YES), the inspection probe 105 is moved to the next inspection position (step S11), and step S9 is repeated.

If the next test position is within the movable range of the test probe 105, the movement of the test probe 105 in step S11 is performed by operating the test probe 105 while maintaining the current state of the guide tray 102 and cable accommodating body 106. It's okay. In this case, there is no need to reset the guide tray 102 or the cable accommodating body 106, so when the next inspection position is close to the inspection probe 105, the inspection probe 105 can be moved efficiently.

Furthermore, the movement of the inspection probe 105 in step S11 is achieved by adjusting the length of the guide tray 102 inside the body section 2 and the delivery amount of the cable accommodation body 106 while the cable accommodation body 106 passes through the flow slot 15. May be done. At this time, the inspection probe 105 is moved with the cable accommodating body 106 fixed in step S107 once released. In this case, the movement range of the inspection probe 105 is limited by the size of the flow slot 15 through which the cable accommodation body 106 passes, but since the work of feeding out the cable accommodation body 106 can be kept to a minimum, it is possible to move the inspection probe 105 to the next inspection position. can effectively reduce the burden of transportation.

Further, the movement of the inspection probe 105 in step S11 is achieved by adjusting the length of the guide tray 102 after the cable accommodation body 106 is collected from the flow slot 15 by the sending device 109, so that the cable accommodation body 106 can be moved to another flow slot 15 by adjusting the length of the guide tray 102. This may be done by re-delivering the body 106. At this time, the inspection probe 105 is moved with the cable accommodating body 106 fixed in step S107 once released. In this case, the movement of the inspection probe 105 is not restricted by the flow slot 15, and therefore can be moved over a wide range.

Further, the movement of the test probe 105 in step S11 may be performed by adjusting or replacing the test probe 105. For example, the inspection probe 105 shown in FIG. 7 has an inverted U-shape suitable for inspecting the lower part of the tube support plate 6; The heat exchanger tube 5 may be deformed and adjusted to have a J-shape suitable for inspecting the heat exchanger tube 5 near the lower part of the tube. Further, the inspection probe 105 having an inverted U-shape shown in FIG. 7 may be replaced with another inspection probe 105 having a J-shape. Such adjustment or replacement of the inspection probe 105 is performed by once releasing the fixation of the cable accommodating body 106 in step S107 and taking the cable accommodating body 106 out of the body 2. Then, the cable housing 106 to which the adjusted or replaced test probe 105 is attached is inserted into the body 2 again, and a similar test is performed.

When the inspection is completed for all inspection positions in this way (step S10: NO), the series of inspection methods ends.

As explained above, in the inspection apparatus 100, the cable accommodating body 106 is inserted into the inside of the body 2 along the guide tray 102 from the first hand hole 20a provided in the body 2 toward the inside. The cable housing body 106 has a portion exposed from the tip end 102a of the guide tray 102 that deforms downward due to its own weight. As a result, cables including the inspection cable 104 inserted into the cable housing 106 can be fed downward through the first hand hole 20a, and the heat exchanger tubes 5 can be inspected over a wider range than in the past. .

In addition, the components in the embodiments described above can be replaced with well-known components as appropriate without departing from the spirit of the present disclosure, and the embodiments described above may be combined as appropriate.

The contents described in each of the above embodiments can be understood as follows, for example.

(1) A steam generator inspection device according to one embodiment includes:
Inspection of a steam generator (for example, the steam generator 1 of the above embodiment) having a heat exchanger tube (for example, the heat exchanger tube 5 of the above embodiment) inside the body (for example, of the above embodiment) that extends along the vertical direction A device (for example, the inspection device 100 of the above embodiment),
a guide tray (for example, the guide tray 102 of the above embodiment) extending toward the inside of the body from a first hand hole (for example, the first hand hole 20a of the above embodiment) provided in the body;
an inspection cable for inspecting the outer surface of the heat exchanger tube (for example, the inspection cable 104 of the above embodiment);
When the inspection cable is insertable and guided along the guide tray from the first hand hole, the tip of the guide tray (for example, the tip 102a in the above embodiment) is inserted inside the trunk. A cable accommodation body (for example, the cable accommodation body 106 of the above embodiment) whose exposed portion is configured to be deformable downward;
Equipped with

According to the above aspect (1), the cable accommodation body is inserted into the interior of the body along the guide tray from the first hand hole provided in the body. The portion of the cable accommodating body exposed from the tip of the guide tray deforms downward under its own weight. As a result, the inspection cable inserted into the cable housing can be sent downward from the first hand hole, and a wider range of heat exchanger tubes can be inspected than in the past.

(2) In another aspect, in the aspect of (1) above,
The guide tray is configured such that a length from the first hand hole to the tip end can be adjusted.

According to the aspect (2) above, by adjusting the length of the guide tray extending from the first hand hole toward the inside of the body, the position of the tip of the guide tray inside the body is changed. can. Thereby, the position of the test cable inserted into the cable accommodating body extending downward from the tip of the guide tray can be changed, so the test position inside the body can be easily adjusted.
The length of the guide tray extending from the first hand hole toward the inside of the body can be adjusted, for example, by changing the mounting position of the guide tray having a predetermined length with respect to the first hand hole. I can do it.

(3) In another aspect, in the aspect (1) or (2) above,
The guide tray is configured such that the leading end thereof faces downward.

According to the above aspect (3), since the tip of the guide tray is configured to face downward, it is possible to guide the cable accommodating body while smoothly deforming it downward from the tip. Thereby, troubles such as stacking of the cable housing near the tip can be avoided, and a highly reliable inspection device can be realized.

(4) In another aspect, in any one of the above (1) to (3),
The heat exchanger tube is connected to the body through a tube support plate (for example, the tube support plate 6 of the above embodiment) provided with a flow slot (for example, the flow slot 15 of the above embodiment) through which a medium flowing inside the body can pass. is supported against the
The cable accommodating body is configured to have a smaller size than the flow slot, so that it can pass through the flow slot.

According to the aspect (4) above, the size of the cable accommodation body is configured to be smaller than the slow slot formed in the tube support plate for supporting the heat exchanger tube inside the body. Thereby, the cable accommodating body extending downward from the tip of the guide tray can reach below the tube support plate by passing through the flow slot, and a wide inspection range can be obtained.

(5) In another aspect, in any one of the above (1) to (4),
The body portion includes a second hand hole (for example, the second hand hole 20b in the above embodiment) provided at a position opposite to the first hand hole,
a rail frame (for example, the rail frame 116 of the above embodiment) extending from at least one of the first hand hole or the second hand hole toward the inside of the body;
a surveillance camera (for example, the surveillance camera 118 of the above embodiment) disposed to face the cable accommodation body and supported by the rail frame via at least one cable;
Equipped with

According to the aspect (5) above, the cable accommodation body is guided by the guide tray by the surveillance camera supported via at least one cable on the rail frame provided from the second hand hole toward the inside of the body. You can observe the situation. This makes it possible to guide the cable accommodating body to the position to be inspected while checking the state of the cable accommodating body inside the body.

(6) In another aspect, in the aspect (5) above,
The at least one cable supports the surveillance camera so as to be movable in the vertical direction with respect to the rail frame.

According to the aspect (6) above, the surveillance camera supported by the rail frame by at least one cable is configured to be movable in the vertical direction inside the body. As a result, by moving the surveillance camera vertically to correspond to the tip of the cable container, which moves up and down depending on the amount of feed from the first hand hole, the situation near the tip of the cable container can be observed at a closer distance. can.

(7) In another aspect, in the aspect (5) or (6) above,
The at least one cable includes a plurality of cables (for example, the support wire 122 and the auxiliary wire 124 in the above embodiment) connected to different positions of the surveillance camera.

According to the aspect (7) above, since the surveillance camera is supported by the plurality of cables at a plurality of positions with respect to the rail frame, the posture of the surveillance camera can be stabilized. Thereby, the state of the cable accommodation body inside the trunk can be well monitored by the surveillance camera.

(8) In another aspect, in any one of the above (5) to (7),
The rail frame is fixed at both ends by the first hand hole and the second hand hole.

According to the aspect (8) above, both ends of the rail frame on which the surveillance camera is supported are fixed to the first hand hole and the second hand hole (that is, the rail frame has a double-end structure), A more structurally stable inspection device can be obtained.

(9) In another aspect, in any one of the above (5) to (7),
One end of the rail frame is fixed to the second hand hole.

According to the aspect (9) above, one end of the rail frame on which the surveillance camera is supported is fixed to the second hand hole (that is, the rail frame has a cantilever structure), so that, for example, the first hand hole Even if another structure exists between the second hand hole and the second hand hole, the rail frame can be arranged in a suitable layout inside the body while avoiding interference with the other structure.

(10) In another aspect, in any one of the above (1) to (9),
A position fixing mechanism (for example, the position fixing mechanism 110 of the above embodiment) is provided for fixing the position of the tip of the cable accommodating body with respect to the heat exchanger tube inside the body.

According to the aspect (10) above, by fixing the tip position of the cable housing with respect to the heat exchanger tube by the position fixing mechanism, inspection using the test cable inserted into the cable housing can be performed in a stable state. It can be performed.

(11) In another aspect, in the aspect (10) above,
The position fixing mechanism is
an air supply cable (for example, the air supply cable 112 of the above embodiment) that is housed in the cable housing together with the inspection cable;
a balloon (for example, the balloon 114 of the above embodiment) that is inflatable by air supplied from the air supply cable and provided at the tip position of the cable housing;
including.

According to the aspect (11) above, by inflating the balloon using air supplied via the air supply cable, the tip position of the cable housing can be fixed with respect to the heat exchanger tube.

(12) In another aspect, in any one of the above (1) to (11),
The cable accommodation body includes a plurality of divided bodies (for example, the divided body 107 of the above embodiment) connected to each other along the extending direction, and together with the inspection cable, a separation prevention wire (for example, the separation prevention wire of the above embodiment) preventive wire 108).

According to the aspect (12) above, the separation prevention wire is accommodated in the cable housing together with the inspection cable. As a result, even if the cable housing is configured with multiple divided bodies and the cable housing separates into multiple divided bodies for some reason, the separated divided bodies will fall out inside the body. can be prevented from happening.

(13) In another aspect, in any one of the above (1) to (12),
A delivery device (for example, the delivery device 109 of the above embodiment) on which a reel (for example, the reel 111 of the above embodiment) on which the cable accommodating body is wound is removably mounted is provided.

According to the aspect (13) above, by handling the cable accommodation body by winding it around a reel, it is possible to easily use different cable accommodation bodies by exchanging the reel for the delivery device.

(14) In another aspect, in any one of the above (1) to (13),
The cable accommodating body is provided with a scale or marker corresponding to a position of the heat exchanger tube to be inspected.

According to the aspect (14) above, the cable housing is provided with a scale or a marker corresponding to the inspection target position of the heat exchanger tube arranged inside the body. During operation, the tip position of the cable accommodating body inside the body can be inspected by adjusting the amount of insertion of the cable accommodating body from the first hand hole while referring to such a scale or marker on the outside of the body. Good positioning can be achieved with respect to the target position.

(15) A steam generator inspection method according to one aspect includes:
A method for inspecting a steam generator (for example, the steam generator 1 of the above embodiment) having a heat exchanger tube (for example, the heat exchanger tube 5 of the above embodiment) inside the body (for example, the body 2 of the above embodiment),
A guide tray (for example, the guide tray 102 of the above embodiment) extends from a first hand hole provided in the body (for example, the first hand hole 20a of the above embodiment) toward the inside of the body. The installation process and
inserting a cable accommodating body (for example, the cable accommodating body 106 of the above embodiment) into the body along the guide tray;
adjusting the insertion amount of the cable accommodating body so that the tip of the cable accommodating body reaches the inspection target position of the heat exchanger tube located below the guide tray;
Inserting a test cable (for example, the test cable 104 of the above embodiment) into the cable housing and testing the test target position;
Equipped with.

According to the aspect (15) above, the cable accommodation body is inserted into the interior of the trunk along the guide tray toward the inside from the first hand hole provided in the trunk. The portion of the cable accommodating body exposed from the tip of the guide tray deforms downward under its own weight. As a result, the inspection cable inserted into the cable housing can be sent downward from the first hand hole, and a wider range of heat exchanger tubes can be inspected than in the past.

(16) In another aspect, in the aspect (15) above,
In the step of adjusting the insertion amount of the cable accommodating body, the insertion amount is adjusted while referring to an image of a surveillance camera (for example, the surveillance camera 118 of the above embodiment) arranged to face the cable accommodating body.

According to the aspect (16) above, the state of the cable accommodation body guided by the guide tray can be observed using a surveillance camera. This makes it possible to guide the cable accommodating body to the position to be inspected while checking the state of the cable accommodating body inside the body.

1 Steam generator 2 Body part 3 Heat exchanger tube group 3a Arc part 3b Straight part 4 Tube plate 5 Heat exchanger tubes 6 Tube support plate 7 Water chamber 8 Partition wall 9 Steam separator 10 Moisture separator 11 Water supply pipe 12 Steam outlet 13 Pipe Outer cylinder 14 Water supply channel 15 Flow slot 20 Hand hole 20a First hand hole 20b Second hand hole 21 Fixed structure 22 Sealing member 71 Entry 72 Outlet 74 Inlet nozzle 75 Outlet nozzle 100 Inspection device 102 Guide tray 102a Tip part 103b Guide tray attachment member 104 Inspection cable 105 Inspection probe 106 Cable housing 107 Divided body 108 Separation prevention wire 109 Delivery device 109a Handle 111 Reel 110 Position fixing mechanism 112 Air supply cable 114 Balloon 116 Rail frame 118 Surveillance camera 119a, 119b Rail Frame mounting member 120 Guide 122 Support wire 124 Auxiliary wire

Claims (20)

An inspection device for a steam generator having a heat transfer tube inside a body extending in the vertical direction,
a guide tray extending from a first hand hole provided in the body toward a second hand hole provided at a position opposite to the first hand hole ;
an inspection cable for inspecting the outer surface of the heat exchanger tube;
The inspection cable is insertable, and when guided from the first hand hole along the guide tray, a portion of the body exposed from the tip of the guide tray is deformed downward. a cable housing configured to allow
A steam generator inspection device equipped with: The steam generator inspection device according to claim 1, wherein the guide tray is configured to have an adjustable length from the first hand hole to the tip end. 3. The steam generator inspection device according to claim 1, wherein the guide tray is configured such that the tip thereof faces downward. The heat exchanger tube is supported with respect to the body via a tube support plate having a flow slot through which a medium flowing inside the body can pass,
The steam generator inspection device according to any one of claims 1 to 3, wherein the cable housing is configured to have a smaller size than the flow slot so that it can pass through the flow slot. a rail frame extending toward the inside of the body from at least one of the first hand hole or the second hand hole;
a surveillance camera disposed to face the cable accommodation body and supported by the rail frame via at least one cable;
The steam generator inspection device according to any one of claims 1 to 4, comprising: The steam generator inspection device according to claim 5, wherein the at least one cable supports the surveillance camera so as to be movable in the vertical direction with respect to the rail frame. The steam generator inspection device according to claim 5 or 6, wherein the at least one cable includes a plurality of cables connected to mutually different positions of the surveillance camera. The steam generator inspection device according to any one of claims 5 to 7, wherein the rail frame is fixed at both ends by the first hand hole and the second hand hole, respectively. The steam generator inspection device according to any one of claims 5 to 7, wherein one end of the rail frame is fixed to the second hand hole. The steam generator inspection device according to any one of claims 1 to 9, further comprising a position fixing mechanism for fixing the position of the tip of the cable housing relative to the heat exchanger tube inside the body. The position fixing mechanism is
an air supply cable accommodated in the cable housing together with the test cable;
a balloon that is inflatable by air supplied from the air supply cable and provided at the tip position of the cable accommodation body;
The steam generator inspection device according to claim 10, comprising: The cable accommodating body includes a plurality of divided bodies connected to each other along an extending direction, and accommodates a separation prevention wire together with the inspection cable. Steam generator inspection equipment. The steam generator inspection device according to any one of claims 1 to 12, comprising a delivery device that removably mounts a reel around which the cable accommodation body is wound. The steam generator inspection device according to any one of claims 1 to 13, wherein the cable housing is provided with a scale or a marker corresponding to a position to be inspected on the heat exchanger tube. A method for inspecting a steam generator having a heat transfer tube inside the body, the method comprising:
a first hand hole provided in the body; and a guide extending from the first hand hole provided in the body to a second hand hole provided at a position opposite to the first hand hole. The process of installing the tray,
inserting a cable housing into the body along the guide tray;
adjusting the insertion amount of the cable accommodating body so that the tip of the cable accommodating body reaches the inspection target position of the heat exchanger tube located below the guide tray;
inserting an inspection cable into the cable housing and inspecting the inspection target position;
A steam generator inspection method comprising: Inspection of the steam generator according to claim 15, wherein in the step of adjusting the insertion amount of the cable housing, the insertion amount is adjusted while referring to an image of a surveillance camera arranged to face the cable housing. Method. An inspection device for a steam generator having a heat transfer tube inside a body extending in the vertical direction,
a guide tray extending from a first hand hole provided in the body toward the inside of the body;
an inspection cable for inspecting the outer surface of the heat exchanger tube;
The inspection cable is insertable, and when guided from the first hand hole along the guide tray, a portion of the body exposed from the tip of the guide tray is deformed downward. a cable housing configured to allow
a second hand hole provided in the body at a position opposite to the first hand hole;
a rail frame extending toward the inside of the body from at least one of the first hand hole or the second hand hole;
a surveillance camera disposed to face the cable accommodation body and supported by the rail frame via at least one cable;
Equipped with
The at least one cable supports the surveillance camera so as to be movable in the vertical direction with respect to the rail frame. An inspection device for a steam generator having a heat transfer tube inside a body extending in the vertical direction,
a guide tray extending from a first hand hole provided in the body toward the inside of the body;
an inspection cable for inspecting the outer surface of the heat exchanger tube;
The inspection cable is insertable, and when guided from the first hand hole along the guide tray, a portion of the body exposed from the tip of the guide tray is deformed downward. a cable housing configured to allow
a second hand hole provided in the body at a position opposite to the first hand hole;
a rail frame extending toward the inside of the body from at least one of the first hand hole or the second hand hole;
a surveillance camera disposed to face the cable accommodation body and supported by the rail frame via at least one cable;
Equipped with
The at least one cable includes a plurality of cables connected to different positions of the surveillance camera. An inspection device for a steam generator having a heat transfer tube inside a body extending in the vertical direction,
a guide tray extending from a first hand hole provided in the body toward the inside of the body;
an inspection cable for inspecting the outer surface of the heat exchanger tube;
The inspection cable is insertable, and when guided from the first hand hole along the guide tray, a portion of the body exposed from the tip of the guide tray is deformed downward. a cable housing configured to allow
An inspection device for a steam generator, comprising a position fixing mechanism for fixing the position of the tip of the cable housing with respect to the heat exchanger tube inside the body. An inspection device for a steam generator having a heat transfer tube inside a body extending in the vertical direction,
a guide tray extending from a first hand hole provided in the body toward the inside of the body;
an inspection cable for inspecting the outer surface of the heat exchanger tube;
The inspection cable is insertable, and when guided from the first hand hole along the guide tray, a portion of the body exposed from the tip of the guide tray is deformed downward. a cable housing configured to allow
Equipped with
In the steam generator inspection device, the cable housing is provided with a scale or marker corresponding to a position to be inspected on the heat exchanger tube.

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