Shroud marking device

Abstract

Easily place marks at any location on the wall surface of the shroud. [Solution] The shroud marking device 10 comprises a mounting portion 11 attached to the shroud 124 of the nuclear reactor, a long frame portion 12 held by the mounting portion 11, a marking portion 13 for marking the wall surface 124a of the shroud 124, a guide portion 14 for movably holding the marking portion 13 along the longitudinal direction of the frame portion 12, and a lifting drive portion 15 for moving the guide portion 14 along the longitudinal direction of the frame portion 12.

Description

Technical Field

[0004] , , , ,

[0005] , , , ,

[0001] The present invention relates to a shroud marking device.

Background Art

[0002] Conventionally, when decommissioning a nuclear reactor, the nuclear reactor equipment is disassembled using, for example, the cutting and disassembling device described in Patent Document 1. When disassembling the nuclear reactor equipment, in order to study the aging degradation status of the material used for the shroud of the nuclear reactor, a research member (sampling material) is obtained from the disassembled shroud. However, when the shroud is disassembled, the location where the sampling material is obtained may become unclear. Therefore, before disassembling the shroud, with the shroud installed in the nuclear reactor pressure vessel, an operator manually operates an instrument to apply a mark (indicator) to the location where the sampling material is to be obtained to clarify the location. At that time, the operator measures the position of the location where the sampling material is to be obtained with a measuring instrument or the like and records the measurement results on a paper medium, a computer, or the like.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, the locations where the sampling materials are to be obtained are underwater and often there are multiple locations. Therefore, the measurement work and the mark application work for the locations are difficult to execute and impose a great burden on the operator. Therefore, there is a desire to provide a device that can easily apply a mark to an arbitrary position on the wall surface of the shroud (specifically, the position where the sampling material is to be obtained).

[0005] The present invention was made to solve the aforementioned problems, and its main objective is to provide a shroud marking device that allows for easy application of marks to any position on the wall surface of a shroud. [Means for solving the problem]

[0006] To achieve the above objective, the present invention provides a shroud marking device comprising: a mounting portion attached to the shroud of a nuclear reactor; an elongated frame portion held by the mounting portion; a marking portion for applying a mark to the wall surface of the shroud; a guide portion for movably holding the marking portion along the longitudinal direction of the frame portion; and a lifting drive portion for moving the guide portion along the longitudinal direction of the frame portion. Other methods will be described later. [Effects of the Invention]

[0007] According to the present invention, marks can be easily applied to any position on the wall surface of the shroud. [Brief explanation of the drawing]

[0008] [Figure 1] This is an explanatory diagram of a nuclear power plant in which the shroud marking device according to the embodiment is used. [Figure 2] This is an external view of the reactor well and the surrounding structures. [Figure 3] This is a schematic diagram of a shroud marking device according to an embodiment. [Figure 4] This is a front view of a shroud marking device according to an embodiment of the device. [Figure 5A] This is a side view of a shroud marking device according to an embodiment of the device. [Figure 5B] This is an internal configuration diagram of a shroud marking device according to an embodiment. [Figure 5C] This is an internal configuration diagram of a shroud marking device according to an embodiment. [Figure 6] This is an explanatory diagram of the cutting guide that regulates the cutting depth of a rotary saw. [Figure 7A] This is a diagram (1) illustrating the placement of marks on the wall surface of the shroud. [Figure 7B] This is diagram (2) illustrating the mark placement locations on the wall surface of the shroud. [Figure 8] This is a flowchart showing the operation of the shroud marking device when marking is applied. [Modes for carrying out the invention]

[0009] Hereinafter, embodiments of the present invention (hereinafter referred to as "these embodiments") will be described in detail with reference to the drawings. Note that each figure is merely a schematic representation to the extent necessary for a thorough understanding of the present invention. Therefore, the present invention is not limited to the illustrated examples. Furthermore, in each figure, common or similar components are denoted by the same reference numerals, and their redundant descriptions are omitted.

[0010] <Configuration of nuclear power plants that use shroud marking equipment> The shroud marking device 10 according to this embodiment is a device that marks (in particular the inner wall surface) of a shroud installed in a nuclear power plant. The configuration of the nuclear power plant 120 in which the shroud marking device 10 according to this embodiment is used will be described below with reference to Figures 1 and 2. Figure 1 is an explanatory diagram of the nuclear power plant 120. Figure 2 is an external view of the reactor well 131 and the surrounding structures.

[0011] As shown in Figure 1, in the nuclear power plant 120, a reactor pressure vessel 122 containing the reactor core 121 is located inside the building 123. A cylindrical shroud 124 is installed inside the reactor pressure vessel 122 to hold the reactor core 121. Multiple fuel assemblies (not shown) are loaded into the reactor core 121.

[0012] Above the reactor pressure vessel 122, a reactor well 131 is provided. The reactor well 131 is a space used to transfer a spent or fuel assembly (not shown) for changing the loading position, etc. into the fuel pool 132 underwater. The reactor well 131 is filled with water during the refueling operation and drained before restart after refueling.

[0013] As shown in FIGS. 1 and 2, around the reactor well 131, a fuel pool 132, a DS pool 133, etc. are provided. The fuel pool 132 is a pool for storing spent fuel rods, etc. The DS pool 133 is a pool for temporarily storing devices such as a steam dryer (not shown) and a moisture separator (not shown).

[0014] As shown in FIG. 1, above the reactor well 131, the fuel pool 132, and the DS pool 133, a carriage 70 that moves on the pool is arranged. The carriage 70 is a device for transporting (mounting and moving) the shroud marking device 10 and the camera 60 according to this embodiment. The camera 60 is a device for taking a moving image of the shroud marking device 10 (particularly the marking unit 13 provided in the shroud marking device 10 (FIG. 3)). An opening is formed in the ceiling plate, and the carriage 70 suspends the shroud marking device 10 and the camera 60 into the fuel pool 13 through the opening.

[0015] The carriage 70 is electrically connected to the control device 80 via a connection cable 90c. The connection cable 90c is a cable bundling the connection cable 90a and the connection cable 90b. The control device 80 is a device for controlling the operations of the shroud marking device 10 and the camera 60. The control device 80 is electrically connected to the shroud marking device 10 via the connection cable 90a. Also, the control device 80 is electrically connected to the camera 60 via the connection cable 90b. Hereinafter, the connection cables 90a, 90b, and 90c may be collectively referred to as the "connection cable 90". Here, the operation of the carriage 70 will be described as being controlled by another control device not shown.

[0016] When decommissioning a nuclear reactor, an operator disassembles nuclear reactor equipment using a cutting and disassembling device (not shown). When disassembling the nuclear reactor equipment, the operator sets the positions and types for marking (performing marking) on the wall surface of the shroud 124 in the control device 80. Then, the control device 80 outputs a travel instruction for the carriage 70 to another control device (not shown), and in response, the other control device (not shown) travels the carriage 70 to an arbitrary location above the shroud 124 (for example, a location suitable for the marking operation). Then, the control device 80 suspends the shroud marking device 10 and the camera 60 from the carriage 70. However, the other control device (not shown) may travel the carriage 70 or suspend the shroud marking device 10 and the camera 60 in response to a travel instruction for the carriage 70 input by the operator. The operator attaches it to the upper ring 124b (FIG. 3) provided on the upper part of the shroud marking device 10. The camera 60 captures a moving image of the attachment operation of the shroud marking device 10 to the shroud 124.

[0017] <Configuration of Shroud Marking Device> Hereinafter, referring to FIGS. 3 to 6, the configuration of the shroud marking device 10 according to the present embodiment will be described. FIG. 3 is a schematic configuration diagram of the shroud marking device 10. FIG. 4 is a front view of the shroud marking device 10. FIG. 5A is a side view of the shroud marking device 10. FIG. 5B is an internal configuration diagram of the shroud marking device 10. FIG. 5C is an internal configuration diagram of the shroud marking device 10. FIG. 6 is an explanatory diagram of a cutting guide 13b that regulates the cutting depth of the rotary saw 13a.

[0018] Figure 3 shows a schematic configuration of the shroud marking device 10. As shown in Figure 3, the shroud 124 has a configuration in which the upper part is wider than the lower part. The shroud marking device 10 is suspended from the trolley 70 (Figure 1) near the upper ring 124b located on the upper part of the shroud 124. The worker attaches the shroud marking device 10 to the upper ring 124b of the shroud 124. The overall dimensions of the shroud marking device 10 are approximately 1560 mm in length, 1600 mm in width, and 6000 mm in height.

[0019] The shroud marking device 10 comprises a mounting section 11, a frame section 12, a marking section 13, a guide section 14, and a lifting drive section 15. The mounting portion 11 is a component that is attached to the reactor shroud 124. The frame portion 12 is an elongated component held by the mounting portion 11. The marking section 13 is a component that marks the wall surface 124a of the shroud 124. The guide section 14 is a component that holds the marking section 13 so that it can move along the longitudinal direction of the frame section 12. The lifting drive unit 15 is a component that moves the guide unit 14 along the longitudinal direction of the frame unit 12.

[0020] The frame section 12, marking section 13, guide section 14, and lifting drive section 15 are located on the inside of the shroud 124. Water is stored inside the shroud 124. The shroud marking device 10 is electrically connected to the control device 80 via a connecting cable 90a, and its operation is controlled by the control device 80. The shroud marking device 10 can place marks at any position on the wall surface 124a of the shroud 124. The marks represent the locations where the sampled material was acquired, and consist of code information or symbol information arbitrarily set to represent the acquisition locations. The marks are formed by cutting marks to make them resistant to fading.

[0021] Figures 4 and 5A to 5C show the specific configuration of the shroud marking device 10. Figure 4 shows the configuration of the shroud marking device 10 as viewed from the front (from the outside to the inside of the shroud 124). Figures 5A to 5C show the configuration of the shroud marking device 10 as viewed from the side. Figure 5A shows the external configuration of the shroud marking device 10. Figures 5B and 5C show the configuration of the shroud marking device 10 with the inside of the frame portion 12 transparent. Figure 5B shows that the frame portion 12 rotates along arrow A11, and that the marking portion 13 moves along arrow A12 together with the guide portion 14. Figure 5C shows that the rotary saw 13a of the marking portion 13 moves along arrow A13.

[0022] As shown in Figure 4 and Figures 5A to 5C, the mounting portion 11 of the shroud marking device 10 has a shaft portion 11b. Also, as shown in Figures 5A to 5C, the mounting portion 11 of the shroud marking device 10 has a main body portion 11a, a fixing jig portion 11c, an engaging portion 11d, and an engaging drive portion 11e. The shaft portion 11b is the part that holds the frame portion 12 so that it can rotate. The main body portion 11a is the part that constitutes the main body of the mounting portion 11. The fixing jig portion 11c is a part that is attached to the main body portion 11a in order to fix the mounting portion 11 to the upper ring 124b (Figure 3) of the shroud 124. The engaging portion 11d is the part that engages with the mounting portion 11. The engaging portion 11d is composed of multiple pairs of claw-shaped parts arranged opposite each other, and it clamps onto the upper ring 124b (Figure 3) of the shroud 124. The engagement drive unit 11e is a mechanism that drives the engagement unit 11d to clamp the upper ring 124b (Figure 3) of the shroud 124. In this embodiment, the engagement drive unit 11e is described as being composed of a hydraulic cylinder. In the example shown in Figures 5A to 5C, the engagement drive unit 11e is provided on the fixing jig unit 11c, but it may also be provided on the main body unit 11a.

[0023] Furthermore, as shown in Figure 4 and Figures 5A to 5C, the frame portion 12 of the shroud marking device 10 has a main body portion 12a, a holding portion 12b, and an extension portion 12c. The main body portion 12a is the part that constitutes the main body of the frame portion 12. As shown in Figure 4, in this embodiment, it is assumed that two main body portions 12a are rotatably attached to the shaft portion 11b of the mounting portion 11. The retaining portion 12b is the part that holds the guide portion 14. As shown in Figure 4, in this embodiment, the two retaining portions 12b are arranged inside the two main body portions 12a. The extension portion 12c is a part that extends above the main body portion 12a. In this embodiment, it is described that two extension portions 12c are rotatably attached to the shaft portion 11b of the mounting portion 11.

[0024] The upper end of the extension portion 12c of the frame portion 12 is connected to the main body portion 11a of the mounting portion 11 via a rotation drive unit 16. The rotation drive unit 16 is a mechanism that rotates the frame portion 12 around the shaft portion 11b by extending and retracting. In this embodiment, the rotation drive unit 16 is described as being composed of a hydraulic cylinder.

[0025] The arrangement of the main body 12a (and holding part 12b) and the extension part 12c is fixed. In the illustrated example, as shown in Figures 5A to 5C, in a side view, the extension part 12c is fixedly positioned in a direction that extends straight upwards from the main body 12a. Also, as shown in Figure 4, in a front view, the extension part 12c is positioned outside the main body 12a.

[0026] Furthermore, as shown in Figures 4 and 5A to 5C, the marking section 13 of the shroud marking device 10 has a rotary saw 13a (disc saw). The rotary saw 13a is a component that applies (forms) cutting marks as marks on the wall surface 124a of the shroud 124.

[0027] Furthermore, as shown in Figures 4 and 5A to 5C, the guide section 14 of the shroud marking device 10 has a moving-to-moving drive section 17. The moving-to-moving drive section 17 is a mechanism that moves the rotary saw 13a of the marking section 13 in the moving-to-moving direction (the direction of separation and the direction of approach) relative to the wall surface 124a of the shroud 124.

[0028] Furthermore, as shown in Figures 4 and 5A to 5C, the lifting drive unit 15 of the shroud marking device 10 includes a rotary motor 15a, a ball screw 15b, and a ball screw rotation holding unit 15c. The rotary motor 15a is a drive unit that rotates the ball screw 15b. The ball screw rotation holding unit 15c is a component that holds the ball screw 15b so that it can rotate freely.

[0029] Furthermore, as shown in Figures 4 and 5A to 5C, the shroud marking device 10 has a first position detection unit 18 in the lifting drive unit 15. The first position detection unit 18 is a component that detects the position of the marking unit 13 (particularly the rotary saw 13a) in the longitudinal direction of the frame unit 12.

[0030] Furthermore, as shown in Figures 4 and 5A to 5C, the shroud marking device 10 has a second position detection unit 19 in the guide unit 14. The second position detection unit 19 is a component that detects the position of the marking unit 13 (particularly the rotary saw 13a) in the moving-away direction.

[0031] As shown in Figure 6, the marking section 13 may also have a cutting guide 13b. The cutting guide 13b is a component that regulates the cutting depth of the rotary saw 13a of the marking section 13 against the wall surface 124a of the shroud 124. In this embodiment, the cutting guide 13b is described as being arranged around the rotating rotary saw 13a as a non-rotating member.

[0032] <Mark placement location on the Shroud's wall> The mark placement positions on the wall surface 124a of the shroud 124 will be explained below with reference to Figures 7A and 7B. Figures 7A and 7B are explanatory diagrams of the mark placement positions on the wall surface 124a of the shroud 124, respectively. The shroud 124 has a pre-set reference position P0 for mark placement. Figure 7A shows that marks are placed on the wall surface 124a of the shroud 124 within a range of 52° ± 20° from the reference position P0. Figure 7B shows that marks are placed on the wall surface 124a of the shroud 124 within a range of 78° ± 20° from the reference position P0. The positions at 52° and 78° from the reference position P0 are positions where the degradation of the sampling material is expected to be severe based on past data, and the ±20° range is the acceptable range for acquiring the sampling material. The ±20° range may be narrowed according to the operation, such as a range of ±10° or a range of ±5°. The marking position can be set by changing the type of fixing jig 11c attached to the main body 11a of the mounting part 11 (specifically, the jig for 52° setting or the jig for 78° setting). This point will be explained in more detail below.

[0033] As shown in Figures 5A to 5C, a fixing jig 11c is attached to the mounting portion 11. The fixing jig 11c has multiple pairs (two pairs in the example shown in Figures 7A and 7B) of engaging portions 11d arranged opposite each other. Each engaging portion 11d is claw-shaped and engages with the upper ring 124b of the shroud 124. The fixing jig 11c also has a hydraulic cylinder as an engagement drive unit 11e (Figures 5A to 5C) that changes the spacing between each pair of engaging portions 11d. The worker operates the engagement drive unit 11e to narrow the spacing between each pair of engaging portions 11d, thereby causing the upper ring 124b of the shroud 124 to be clamped between each pair of engaging portions 11d. In this way, the worker temporarily fixes the mounting portion 11 to the upper ring 124b of the shroud 124. Next, the worker fixes the mounting part 11 to the upper ring 124b of the shroud 124 using the head bolt brackets 125, 127 (Figure 5B) and guide bolts (not shown). At this time, the worker can set the marking position by changing the type of fixing jig part 11c to either the 52° setting jig part or the 78° setting jig part and attaching the fixing jig part 11c to the main body part 11a of the mounting part 11. The shape of the 52° setting jig part is suitable for mounting at a position 52° from the setting reference position P0 on the upper ring 124b of the shroud 124. The shape of the 78° setting jig part is suitable for mounting at a position 78° from the setting reference position P0 on the upper ring 124b of the shroud 124. Preferably, the shroud marking device 10 applies different types of marks to the wall surface 124a of the shroud 124, depending on the type of fixing jig portion 11c attached to the main body portion 11a of the mounting portion 11.

[0034] <Operation of the shroud marking device> The operation of the shroud marking device 10 will be explained below with reference to Figure 8. Figure 8 is a flowchart showing the operation of the shroud marking device 10 when marking. Here, it is assumed that the position and type of marks to be applied to the wall surface 124a of the shroud 124 are pre-set in the control device 80 (Figure 1). Also, it is assumed that the shroud marking device 10 and the camera 60 are pre-suspended by the trolley 70 near the upper ring 124b of the shroud marking device 10. Furthermore, here, it is assumed that marks are first applied to the wall surface 124a of the shroud 124 within a range of 52°±20° from the set reference position P0, and then marks are applied within a range of 78°±20° from the set reference position P0.

[0035] As shown in Figure 8, for example, when dismantling reactor equipment during the decommissioning of a nuclear reactor, the worker removes the upper grid plate (not shown) located above the shroud 124 (step S105). Here, we will explain assuming that marks are placed at the locations where sampling material will be taken during the dismantling of the reactor equipment. However, marks can be placed on the wall surface 124a of the shroud 124 at any time, not limited to the dismantling of the reactor equipment.

[0036] Next, the worker installs the shroud marking device 10 so that the rotary saw 13a is positioned within a range of 52° ± 20° from the set reference position P0 (step S110). At this time, the worker attaches the fixing jig part 11c for 52° setting to the main body part 11a of the mounting part 11 and positions the mounting part 11 on the upper ring 124b of the shroud 124.

[0037] Next, the operator instructs the shroud marking device 10 to begin the marking process. The shroud marking device 10 then rotates the frame section 12 in the direction of arrow A11 in Figure 5B using the rotation drive unit 16 (hydraulic cylinder). At this time, the shroud marking device 10 calculates the rotation angle of the frame section 12 based on the engagement position of the engagement portion 11d of the mounting portion 11 to the shroud 124 and the mounting position of the head bolt bracket 125. The shroud marking device 10 then rotates the frame section 12 at the calculated rotation angle. As a result, the shroud marking device 10 presses the lower end of the frame section 12 against the wall surface 124a of the shroud 124, thereby fixing the frame section 12 (step S115).

[0038] Next, the shroud marking device 10 moves the guide section 14 along the longitudinal direction of the frame section 12 in the direction of arrow A12 in Figure 5B using the lifting drive unit 15. This positions the rotary saw 13a at the starting height for marking (step S120).

[0039] Next, the shroud marking device 10 rotates the rotary saw 13a using the marking unit 13, moving the rotary saw 13a in the direction of the wall (in the direction of arrow A13 in Figure 5C). As a result, the shroud marking device 10 cuts into the wall surface 124a of the shroud 124 with the rotary saw 13a and begins to apply the mark (step S125).

[0040] Next, the shroud marking device 10 moves the guide section 14 along the longitudinal direction of the frame section 12 using the lifting drive unit 15. This allows the shroud marking device 10 to mark the wall surface 124a of the shroud 124 with a mark of any length (step S130).

[0041] Next, the shroud marking device 10 moves the rotary saw 13a in the direction of separation (opposite direction to arrow A13 in Figure 5C) using the marking unit 13, and stops the rotation of the rotary saw 13a. With this, the shroud marking device 10 completes the marking process (step S135).

[0042] Next, the shroud marking device 10 rotates the frame portion 12 in the opposite direction to arrow A11 in Figure 5B using the rotation drive unit 16 (hydraulic cylinder). This causes the shroud marking device 10 to separate the lower end of the frame portion 12 from the wall surface 124a of the shroud 124, thereby releasing the frame portion 12 from its fixed position (step S140).

[0043] Next, the worker removes the shroud marking device 10 from the shroud 124 (step S145).

[0044] Next, the worker installs the shroud marking device 10 so that the rotary saw 13a is positioned within a range of 78° ± 20° from the set reference position P0 (step S150). At this time, the worker attaches the fixing jig part 11c for 78° setting to the main body part 11a of the mounting part 11 and positions the mounting part 11 on the upper ring 124b of the shroud 124.

[0045] After this, the processes from step S155 to step S180 are carried out in the same manner as the processes from step S115 to step S140.

[0046] Then, after the processing in step S180, the worker removes the shroud marking device 10 from the shroud 124 and stores the shroud marking device 10 in a desired location (for example, the DS pool 133) (step S185). At this time, for example, the worker has the shroud marking device 10 and camera 60 lifted onto the trolley 70 and moves the trolley 70 onto the DS pool 133. Then, the worker has the shroud marking device 10 and camera 60 lowered onto the trolley 70. In this way, the worker stores the shroud marking device 10 and camera 60 in the DS pool 133.

[0047] <Main features of the shroud marking device> (1) As shown in Figure 3, the shroud marking device 10 according to this embodiment comprises a mounting portion 11, a frame portion 12, a marking portion 13, a guide portion 14, and a lifting drive portion 15. The mounting portion 11 is a component that is attached to the shroud 124 of the nuclear reactor. The frame portion 12 is a long, rectangular component held by the mounting portion 11. The marking portion 13 is a component that marks the wall surface 124a of the shroud 124. The guide portion 14 is a component that holds the marking portion 13 so as to be movable along the longitudinal direction of the frame portion 12. The lifting drive portion 15 is a component that moves the guide portion 14 along the longitudinal direction of the frame portion 12.

[0048] The shroud marking device 10 according to this embodiment can easily apply marks to any position on the wall surface 124a of the shroud 124.

[0049] (2) As shown in Figure 4 and Figures 5A to 5C, in the shroud marking device 10 of item (1) above, the marking section 13 has a rotary saw 13a.

[0050] The shroud marking device 10 according to this embodiment can make the mark difficult to erase by forming the mark with cutting marks. Furthermore, the shroud marking device 10 can apply a mark to the wall surface 124a of the shroud 124 underwater.

[0051] (3) As shown in Figure 6, in the shroud marking device 10 of item (2) above, the marking unit 13 may be configured to have a cutting guide 13b that restricts the cutting depth of the rotary saw 13a. As shown in Figures 7A and 7B, in the shroud marking device 10 of item (2) above, the marking unit 13 marks the wall surface 124a of the shroud 124 in either or both of the ranges of 52°±20° and 78°±20° from an arbitrarily determined set reference position P0.

[0052] The shroud marking device 10 according to this embodiment can keep the cutting depth of the rotary saw 13a (i.e., the depth of the mark formed on the wall surface 124a of the shroud 124) constant using the cutting guide 13b. The positions in the ranges of 52°±20° and 78°±20° from the set reference position P0 are positions where, based on past data, the deterioration of the sample material is expected to be severe. By applying marks at these positions, the shroud marking device 10 according to this embodiment can easily study the aging deterioration status of the material used in the shroud 124. Note that the positions in the ranges of 52°±20° and 78°±20° overlap. However, by changing the type of mark applied to the wall surface 124a of the shroud 124 according to the type of fixing jig part 11c attached to the main body part 11a of the mounting part 11, it is possible to determine which range the sample material belongs to.

[0053] (4) As shown in Figure 4 and Figures 5A to 5C, in the shroud marking device 10 of item (1) above, the lifting drive unit 15 is fixed to the frame unit 12.

[0054] In this embodiment, the shroud marking device 10 moves the guide section 14 using a lifting drive unit 15 fixed to the frame section 12. This allows the shroud marking device 10 to stably move the guide section 14 (i.e., the marking section 13).

[0055] (5) As shown in Figures 5B and 5C, and Figures 7A and 7B, in the shroud marking device 10 of item (1) above, the mounting portion 11 has a plurality of engaging portions 11d. The mounting portion 11 is held at multiple points by the plurality of engaging portions 11d to the upper ring 124b provided on the upper part of the shroud 124, which has a circular shape when viewed from above. Also, as shown in Figures 5B and 5C, in the shroud marking device 10 of item (1) above, the mounting portion 11 is fixed to the head bolt brackets 125 and 127 provided on the shroud 124 with guide bolts (not shown). Furthermore, as shown in Figure 4, and Figures 5A to 5C, in the shroud marking device 10 of item (1) above, the mounting portion 11 has a shaft portion 11b that rotatably holds the frame portion 12.

[0056] The shroud marking device 10 according to this embodiment can be firmly attached to the upper ring 124b, which has a circular shape when viewed from above, so as not to shift position. Furthermore, the mounting portion 11 of the shroud marking device 10, which is temporarily fixed to the shroud 124 by the engaging portion 11d, can be firmly permanently fixed by guide bolts (not shown) and head bolt brackets 125, 127. In addition, the shroud marking device 10 can rotate the frame portion 12 against the wall surface 124a (inner wall surface) of the shroud 124, which has a configuration in which the upper portion is wider than the lower portion, and press the lower end of the frame portion 12 against it. In this way, the shroud marking device 10 can fix the frame portion 12.

[0057] (6) As shown in Figures 5A to 5C, the shroud marking device 10 described in item (5) above is equipped with a rotation drive unit 16 that rotates the frame portion 12 around the shaft portion 11b.

[0058] In this embodiment, the shroud marking device 10 can rotate the frame portion 12 around the shaft portion 11b using the rotation drive unit 16. This allows the shroud marking device 10 to press the lower end of the frame portion 12 against the wall surface 124a (inner wall surface) of the shroud 124, thereby fixing the frame portion 12 in place.

[0059] (7) As shown in Figure 4 and Figures 5A to 5C, the shroud marking device 10 of item (1) above is provided with a first position detection unit 18 that detects the position of the marking portion 13 in the longitudinal direction of the frame portion 12.

[0060] In this embodiment, the shroud marking device 10 can detect the position of the marking portion 13 in the longitudinal direction of the frame portion 12 using the first position detection unit 18. This allows the shroud marking device 10 to manage the starting and ending height positions for mark application and to suitably apply marks to the wall surface 124a of the shroud 124.

[0061] (8) As shown in Figure 4 and Figures 5A to 5C, the shroud marking device 10 described in item (7) above includes a moving-away drive unit 17 and a second position detection unit 19. The moving-away drive unit 17 is a component that moves the marking unit 13 (rotary saw 13a) in the moving-away direction relative to the wall surface 124a of the shroud 124. The second position detection unit 19 is a component that detects the position of the marking unit 13 in the moving-away direction.

[0062] The shroud marking device 10 according to this embodiment can manage whether or not a mark has been suitably applied to the wall surface 124a of the shroud 124 by detecting the position of the marking portion 13 in the moving-away direction with the second position detection unit 19.

[0063] As described above, the shroud marking device 10 according to this embodiment makes it possible to easily apply a mark to any position on the wall surface 124a of the shroud 124 placed in water.

[0064] The present invention is not limited to the embodiments described above, and includes various modifications. For example, the embodiments described above are described in detail for the purpose of clearly illustrating the present invention, and are not necessarily limited to those having all the configurations described. Furthermore, it is possible to replace some of the configurations of the embodiments with other configurations, and it is also possible to add other configurations to the configurations of the embodiments. In addition, it is possible to add, delete, or replace some of the configurations of each configuration with other configurations. [Explanation of Symbols]

[0065] 10 Shroud marking device 11 Mounting part 11a Main body 11b Shaft 11c Fixing jig section 11d Engagement part 11e Engagement drive unit (hydraulic cylinder) 12 Frame section 12a Main body 12b Holding part 12c extension 13 Marking section 13a Rotary saw (disc saw) 13b Cutting Guide 14 Guide section 15 Lifting drive unit 15a Rotary motor 15b Ball screw 15c Ball screw rotation retaining part 16. Rotary drive unit (hydraulic cylinder) 17. Disconnection drive unit 18. First position detection unit 19. Second position detection unit 60 Cameras 70 bogies 80 Control device 90, 90a, 90b, 90c connection cables 120 Nuclear Power Plants 121 reactor core 122 Reactor pressure vessel 123 Building 124 Shroud 124a Wall surface (interior wall surface) 124b Upper ring 125,127 Head bolt bracket 131 Reactor well 132 Fuel Pools 133 DS Pool P0 Setting reference position

Claims

1. A mounting part that is attached to the reactor shroud, A long frame portion held by the aforementioned mounting portion, A marking section for applying a mark to the wall surface of the aforementioned shroud, A guide portion that holds the marking portion movably along the longitudinal direction of the frame portion, The system includes a lifting drive unit that moves the guide portion along the longitudinal direction of the frame portion, A shroud marking device characterized by the following features.

2. In the shroud marking apparatus according to claim 1, The marking section has a rotary saw. A shroud marking device characterized by the following features.

3. In the shroud marking apparatus according to claim 2, The marking section has a cutting guide that regulates the cutting depth of the rotary saw, and marks are made on the wall surface of the shroud within either or both of the ranges of 52°±20° and 78°±20° from an arbitrarily determined set reference position. A shroud marking device characterized by the following features.

4. In the shroud marking apparatus according to claim 1, The lifting drive unit is fixed to the frame portion. A shroud marking device characterized by the following features.

5. In the shroud marking apparatus according to claim 1, The mounting portion has multiple engaging portions, which hold it at multiple points on the upper ring provided on the upper part of the shroud, which has a circular shape when viewed from above, and is fixed to the head bolt bracket provided on the shroud by guide bolts, and further has a shaft portion that holds the frame portion rotatably. A shroud marking device characterized by the following features.

6. In the shroud marking apparatus according to claim 5, It includes a rotation drive unit that rotates the frame portion around the shaft portion, A shroud marking device characterized by the following features.

7. In the shroud marking apparatus according to claim 1, The frame portion is equipped with a first position detection unit that detects the position of the marking portion in the longitudinal direction of the frame portion. A shroud marking device characterized by the following features.

8. In the shroud marking apparatus according to claim 7, A moving drive unit moves the marking portion in the moving-away direction relative to the wall surface of the shroud, It includes a second position detection unit that detects the position of the marking portion in the aforementioned moving-away direction, A shroud marking device characterized by the following features.

Images