Sample collecting device of tubular structure

Abstract

A sample collecting device of a tubular structure comprises a main transfer unit, a fixed clamp, a cutting unit, and a machining tool transfer unit. The main transfer unit includes a central shaft which is inserted into a pressure tube and moves in the longitudinal direction of the pressure tube. The fixed clamp includes a plurality of supports which come into close contact with the inner wall of the pressure tube when unfolded. The cutting unit includes a machining tool having a cutting blade, a motor which rotates the machining tool, and a right-angle hollow reducer coupled to the motor and the machining tool. The machining tool transfer unit includes a fixing part coupled to an end of the central shaft and a moving part which supports the cutting unit and adjusts the height of the machining tool. The machining tool drills a hole in the pressure tube, and then drills a hole in a calandria tube surrounding the pressure tube, thereby sequentially generating machining chips from the pressure tube and the calandria tube, and the machining chips are collected in a collection box.

Description

Sampling device of a tubular structure

[0001] The present invention relates to a sample collection device for tubular structures, and more specifically, to a device for directly collecting samples from pressure tubes and reactor tubes before decommissioning a heavy water reactor of a nuclear power plant.

[0002] When a nuclear power plant is operated for a long period, a phenomenon called radioactivity occurs in which structures such as the reactor emit radiation due to neutrons generated in the core and radionuclides produced by capture reactions. When decommissioning a nuclear power plant, the inventory of radionuclides resulting from radioactivity must be calculated. Although various evaluation methods exist for this purpose, accuracy can be significantly improved by directly collecting and analyzing samples from the radioactive structures.

[0003] Inside the calandria vessel of a heavy water reactor, there are reactor tubes and pressure tubes. The reactor tubes and pressure tubes consist of narrow, long tubes with an inner diameter of approximately 100 mm to 130 mm stacked in a double layer. Due to the structural characteristics of the reactor tubes and pressure tubes, it is very difficult to collect samples directly, and currently, the radionuclide inventory is calculated relying on computer simulations.

[0004] The present invention relates to a sample collection device of a tubular structure capable of accurately calculating the radionuclide inventory of a pressure tube and a reactor tube by directly collecting samples of the pressure tube and the reactor tube from inside the pressure tube.

[0005] A sample collection device for a tubular structure according to one embodiment includes a main transfer unit, a fixed clamp, a cutting unit, and a processing tool transfer unit. The main transfer unit includes a central axis parallel to the longitudinal direction of the tubular structure and a first driving unit that pushes and moves the central axis. The fixed clamp is coupled to the central axis and includes a plurality of support members that are spaced apart from the inner wall of the tubular structure in a folded state and are in close contact with the inner wall of the tubular structure in an unfolded state. The cutting unit includes a processing tool having a cutting edge, a motor that provides rotational power to the processing tool, and a reduction gear coupled to the processing tool and the motor. The processing tool transfer unit includes a fixed part coupled to the end of the central axis, a moving part that supports the cutting unit and moves along the radial direction of the tubular structure relative to the fixed part, and a second driving unit that provides power to the moving part.

[0006] Multiple supports may be positioned at a distance from each other along the circumferential direction of the tubular structure, and each of the multiple supports may be formed in a curved shape corresponding to the inner wall of the tubular structure.

[0007] The central axis may include an inner axis and an outer axis that can slide along the axial direction relative to the inner axis. Each of the plurality of supports may be connected to the inner axis and the outer axis by an X-shaped connecting link.

[0008] The connecting link may include a first link member and a second link member rotatably connected at the center. Both ends of the first link member may be rotatably connected to the end of the inner shaft and the inner surface of the support. Both ends of the second link member may be rotatably connected to the end of the outer shaft and the inner surface of the support.

[0009] The machining tool can be cup-shaped. The reduction gear can be a hollow reduction gear having a hollow rotating shaft that communicates with the internal space of the machining tool. The internal space of the motor can communicate with the internal space of the reduction gear. The reduction gear is configured as a right-angle hollow reduction gear, so that the rotating shaft of the motor and the hollow rotating shaft can be orthogonal.

[0010] The sample collection device of the tubular structure may further include a processing chip recovery unit for recovering processing chips generated during the operation of a processing tool. The processing chip recovery unit may include a discharge pipe connected to a motor, a vacuum ejector connected to the discharge pipe, an air compressor that supplies compressed air to the vacuum ejector, and a recovery container connected to the outlet of the vacuum ejector. The vacuum ejector, the air compressor, and the recovery container may be located outside the tubular structure.

[0011] The sample collection device of the tubular structure may further include a housing surrounding the central axis, the cutting portion, and the processing tool transfer portion. The housing may have a plurality of first openings corresponding to a plurality of supports and a second opening corresponding to a processing tool.

[0012] A sample collection device of a tubular structure according to another embodiment includes a main transfer unit, a fixed clamp, a cutting unit, a processing tool transfer unit, and a processing chip recovery unit. The main transfer unit includes a central axis that is inserted into the interior of a pressure tube installed in a heavy water reactor and moves along the longitudinal direction of the pressure tube. The fixed clamp is coupled to the central axis and includes a plurality of supports that are in close contact with the inner wall of the pressure tube in an unfolded state. The cutting unit includes a cup-shaped processing tool equipped with a cutting edge, a motor that rotates the processing tool, and a right-angle hollow reduction gear coupled to the motor and the processing tool. The processing tool transfer unit includes a fixed part coupled to the end of the central axis and a moving part that supports the cutting unit and moves along the radial direction of the pressure tube relative to the fixed part to adjust the height of the processing tool. The processing chip recovery unit includes a discharge pipe connected to the motor, a vacuum ejector connected to the discharge pipe and supplied with compressed air, and a recovery container connected to the outlet of the vacuum ejector. After drilling a hole in the pressure tube, the machining tool drills a hole in the reactor tube surrounding the pressure tube, sequentially generating machining chips from the pressure tube and the reactor tube, and the machining chips are collected in a recovery container.

[0013] According to the present invention, a sample can be directly collected from a pressure tube and a reactor tube by inserting and operating a processing tool into the pressure tube and reactor tube, which are in the form of a double-layered, narrow, and long tube, and the collected sample can be automatically collected in a recovery container. By analyzing the collected sample, the amount of radionuclides in the reactor tube and pressure tube can be accurately calculated before the decommissioning of a heavy water reactor.

[0014] FIGS. 1 and FIGS. 2 are configuration diagrams of a sample collection device according to one embodiment.

[0015] FIGS. 3 and FIGS. 4 are configuration diagrams showing one example of a fixed clamp among the sample collection devices illustrated in FIG. 1.

[0016] Figure 5 is a configuration diagram of the cutting section of the sample collection device shown in Figure 1.

[0017] Figure 6 is a configuration diagram of the processing chip recovery unit of the sample collection device shown in Figure 1.

[0018] Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings so that those skilled in the art can easily implement the present invention. The present invention may be embodied in various different forms and is not limited to the embodiments described herein.

[0019] FIG. 1 is a configuration diagram of a sample collection device of a tubular structure according to one embodiment (hereinafter referred to as the "sample collection device" for convenience). FIG. 2 is a configuration diagram showing the sample collection process of the sample collection device illustrated in FIG. 1.

[0020] Referring to FIGS. 1 and 2, the tubular structure (200) for which a sample is required is a radioactive structure of a heavy water reactor, and may be a reactor tube (210) and a pressure tube (220) of the heavy water reactor. The heavy water reactor uses natural uranium as nuclear fuel and heavy water as a coolant and moderator. The heavy water reactor includes a calandria vessel with approximately 380 fuel channels installed horizontally.

[0021] Each fuel channel consists of a calandria tube, a pressure tube, an end fitting, an annulus spacer, and an end closure.

[0022] The reactor tube (210) may be a zirconium alloy tube with an inner diameter of about 130 mm and a thickness of about 1.4 mm. The pressure tube (220) may be a zirconium-niobium alloy tube with an inner diameter of about 103 mm, a thickness of about 4 mm, and a length of about 6 m. The pressure tube (220) is located inside the reactor tube (210), and annular spacers are installed at regular intervals between the reactor tube (210) and the pressure tube (220) to prevent the two tubes from coming into contact.

[0023] It is difficult to directly collect samples from the pressure tube (220) and the reactor tube (210) due to the form of a double-layered, narrow, and long tube. The sample collection device (100) of this embodiment is inserted into the interior of the pressure tube (220) before the decommissioning of the heavy water reactor, and can directly collect samples from the pressure tube (220) and the reactor tube (210). By analyzing the samples collected in this way, the amount of radionuclides in the pressure tube (220) and the reactor tube (210) can be accurately calculated.

[0024] The sample collection device (100) of the present embodiment may include a main transfer unit (120) comprising a central axis (121) and a first drive unit (125), a fixed clamp (130) comprising a plurality of support members (131) coupled to the central axis (121), a cutting unit (140) comprising a processing tool (141), a hollow reduction gear (142), and a motor (143), a processing tool transfer unit (150) connecting the main transfer unit (120) and the cutting unit (140) and adjusting the height of the processing tool (141), and a processing chip recovery unit (160) connected to the motor (143).

[0025] The main transfer unit (120) functions to transfer the cutting processing unit (140) and the processing tool transfer unit (150) to a specific location (sample collection location) inside the pressure tube (220). The central axis (121) has a long rod shape parallel to the longitudinal direction of the pressure tube (220) and has an outer diameter smaller than the inner diameter of the pressure tube (220) so as not to come into contact with the inner wall of the pressure tube (220).

[0026] The first drive unit (125) can be coupled to the end of the central axis (121) and can move the central axis (121) by pushing it along the longitudinal direction of the pressure tube (220). The first drive unit (125) may be composed of a hydraulic device, a pneumatic device, or an electric motor and gear assembly, etc. After the sample collection is completed, the first drive unit (125) can pull the central axis (121) to return the central axis (121) to its initial position.

[0027] When the cutting processing unit (140) and the processing tool transfer unit (150) reach a specific location (sample collection location) inside the pressure tube (220), the fixing clamp (130) operates to fix the central axis (121) inside the pressure tube (220). The fixing clamp (130) includes a plurality of support members (131) that are spaced apart from the inner wall of the pressure tube (220) in the folded state and are in close contact with the inner wall of the pressure tube (220) in the unfolded state.

[0028] Multiple support members (131) are spaced apart from the inner wall of the pressure tube (220) in the folded state to facilitate the movement of the central axis (121). The fixing clamp (130) may be referred to as an internal pipe clamp, and any configuration capable of switching between the folded state and the unfolded state of the multiple support members (131) can be applied.

[0029] FIGS. 3 and FIGS. 4 are configuration diagrams showing one example of a fixed clamp among the sample collection devices illustrated in FIG. 1.

[0030] Referring to FIGS. 1 to 4, a plurality of support members (131) may have a curved shape that is bent along the circumferential direction of the pressure tube (220) in correspondence with the shape of the inner wall of the pressure tube (220), and may be positioned at a distance from each other along the circumferential direction of the pressure tube (220). The central axis (121) may be formed as a double structure of an inner axis (122) and an outer axis (123). The outer axis (123) is a hollow tubular shape that surrounds the inner axis (122), and the inner axis (122) is capable of moving forward and backward relative to the outer axis (123).

[0031] Each of the plurality of support members (131) may be connected to an inner axis (122) and an outer axis (123) by an X-shaped connecting link (135). The connecting link (135) may include a first link member (136) and a second link member (137) that are rotatably connected at the center. Both ends of the first link member (136) may be rotatably connected to the end of the inner axis (122) and the inner surface of the support member (131). Both ends of the second link member (137) may be rotatably connected to the end of the outer axis (123) and the inner surface of the support member (131).

[0032] As shown in FIGS. 1 and 3, when the outer axis (123) moves from the inner axis (122) toward the right side of the drawing, the connecting link (135) becomes a flat X-shape, and the plurality of supports (131) are positioned close to the central axis (121). That is, the plurality of supports (131) are in a folded state and are positioned at a distance from the inner wall of the pressure tube (220).

[0033] Conversely, as shown in FIGS. 2 and 4, when the outer axis (123) moves from the inner axis (122) toward the left side of the drawing, the connecting link (135) becomes an upright X shape, and the plurality of supports (133) move away from the central axis (121). That is, the plurality of supports (131) become unfolded and are fixed to the pressure tube (220) by adhering to the inner wall of the pressure tube (220). The fixing clamp (130) is not limited to the illustrated example and can be modified in various ways.

[0034] Referring again to FIGS. 1 and FIGS. 2, the cutting machine (140) includes a machining tool (141) that sequentially drills through the pressure tube (220) and the reactor tube (210) to produce machining chips, a motor (143) that provides rotational power to the machining tool (141), and a hollow reduction gear (142) that reduces the rotational power of the motor (143) and transmits it to the machining tool (141).

[0035] Figure 5 is a configuration diagram of the cutting section of the sample collection device shown in Figure 1.

[0036] Referring to FIGS. 1, 2, and 5, the rotation axis of the motor (143) may be parallel to the longitudinal direction of the pressure tube (220), and the hollow rotation axis (142a) of the hollow reduction gear (142) may be perpendicular to the rotation axis of the motor (143). That is, the hollow reduction gear (142) may be a right-angle hollow reduction gear having a reduction rotation axis perpendicular to the rotation axis of the motor (143). The hollow rotation axis (142a) of the hollow reduction gear (142) is parallel to the radial direction of the pressure tube (220). A cutting machined part (140) equipped with a right-angle hollow reduction gear is advantageous for saving space and can be miniaturized.

[0037] The machining tool (141) is formed in the shape of a hollow cup, and a sharp cutting edge is positioned along the circular edge. The machining tool (141) can rotate while in close contact with the inner wall of the pressure tube (220) to pierce the pressure tube (220). The internal space of the machining tool (141) is connected to the internal space of the hollow rotating shaft (142a), and the internal space of the hollow rotating shaft (142a) is connected to the internal space of the motor (143). The hollow reduction gear (142) can be located inside the gear housing (144), and the motor (143) can be coupled to the side of the gear housing (144).

[0038] Referring to FIGS. 1 and 2, the processing tool transfer unit (150) is coupled to the central axis (121) and the cutting processing unit (140), respectively, and connects the central axis (121) and the cutting processing unit (140), and functions to adjust the height of the processing tool (141). The processing tool transfer unit (150) may include a fixed part (151) coupled to the end of the central axis (121) (e.g., the end of the inner axis (122)), a moving part (152) capable of moving up and down along the radial direction of the pressure tube (220) relative to the fixed part (151), and a second driving part (153) that provides power to the moving part (152).

[0039] The processing tool transfer unit (150) may be composed of a linear motion guide (LM guide) equipped with an electric motor, a hydraulic cylinder, a pneumatic cylinder, or an electric motor and a rack-pinion gear assembly, and any configuration capable of linear movement of the moving unit (152) other than these configurations may be applied.

[0040] The cutting machine part (140) is coupled to the moving part (152) and can move up or down along the moving part (152). When the moving part (152) moves down, the machining tool (141) is positioned at a distance from the inner wall of the pressure tube (220). When the moving part (152) moves up, the machining tool (141) comes into close contact with the inner wall of the pressure tube (220). The machining chips produced by the machining tool (141) can be recovered by the machining chip recovery part (160).

[0041] Figure 6 is a configuration diagram of the processing chip recovery unit of the sample collection device shown in Figure 1.

[0042] Referring to FIGS. 1 and FIGS. 6, the processing chip recovery unit (160) may include a discharge pipe (161) connected to a motor (143), a vacuum ejector (162) connected to the discharge pipe (161), an air compressor (163) providing compressed air to the vacuum ejector (162), and a recovery box (164) connected to the outlet of the vacuum ejector (162). The remaining components, excluding the discharge pipe (161), may be located outside the pressure pipe (220).

[0043] When compressed air is supplied to the vacuum ejector (162) during the operation of the processing tool (141), the air (air containing a number of processing chips) in the discharge pipe (161) is sucked into the vacuum ejector (162), and the compressed air and the air in the discharge pipe (161) are discharged together into the recovery unit (164). The processing chip recovery unit (160) is not limited to the configuration described above and can be made of a combination of various mechanical elements.

[0044] The sample collection device (100) of the present embodiment may further include a housing (170). The housing (170) may include a cylindrical tubular part (171) surrounding a central axis (121), a cutting part (140), and a processing tool transfer part (150), and a disc-shaped plate part (172) fixed to the end of the tubular part (171).

[0045] In the tubular section (171), a plurality of first openings (173) corresponding to a plurality of support members (131) and a second opening (174) corresponding to a processing tool (141) are located. The plurality of support members (131) can be extended through the plurality of first openings (173) and adhere to the inner wall of the pressure tube (220). The processing tool (141) can be raised through the second opening (174) and adhere to the inner wall of the pressure tube (220). The housing (170) can enclose the cutting section (140) inside to prevent processing chips from flying throughout the pressure tube (220) during the sample collection process.

[0046] Next, the sample collection process using the sample collection device of the aforementioned configuration is described.

[0047] Referring to FIGS. 1, 2, and 6, the main conveying unit (120) can be inserted into the pressure tube (220) while the plurality of support members (131) are folded, and the central axis (121) can be advanced by the operation of the first driving unit (125). When the central axis (121) advances and reaches a specific position (sample collection position), the operation of the first driving unit (125) is stopped.

[0048] Subsequently, a plurality of support members (131) can be extended from the central axis (121) and adhere to the inner wall of the pressure tube (220). The sample collection device (100) can be firmly fixed inside the pressure tube (220) by the operation of the fixing clamp (130).

[0049] Next, the second drive unit (153) of the processing tool transfer unit (150) operates to raise the moving unit (152) relative to the fixed unit (151). Then, the cutting unit (140) rises so that the processing tool (141) can be in close contact with the inner wall of the pressure tube (220). Next, the motor (143) of the cutting unit (140) operates to rotate the processing tool (141), thereby making a hole in the pressure tube (220).

[0050] During the process of the processing tool (141) drilling a hole in the pressure tube (220), a number of processing chips are generated from the pressure tube (220), and compressed air can be injected into the vacuum ejector (162). The processing chips generated from the pressure tube (220) can be collected in the recovery container (164) via the hollow reduction gear (142), motor (143), discharge tube (161), and vacuum ejector (162).

[0051] When the processing tool (141) makes a hole in the pressure tube (220), the second driving unit (153) can be operated to further raise the moving unit (152), and the processing tool (141) can pass through the hole in the pressure tube (220) and be in close contact with the inner wall of the reactor tube (210). Then, the motor (143) of the cutting processing unit (140) operates to rotate the processing tool (141), thereby making a hole in the reactor tube (210).

[0052] During the process of the processing tool (141) drilling a hole in the reactor tube (210), a number of processing chips are generated from the reactor tube (210), and compressed air can be injected into the vacuum ejector (162). The processing chips generated from the reactor tube (210) can be collected in the recovery container (164) via the hollow reduction gear (142), motor (143), discharge pipe (161), and vacuum ejector (162).

[0053] When sample collection from the pressure tube (220) and the reactor tube (210) is completed, the motor (143) stops operating, and the second drive unit (153) operates to lower the moving unit (152) and return the processing tool (141) to its initial position. Subsequently, the plurality of support members (131) can be switched to a folded state, and the central axis (121) can be moved backward by the operation of the first drive unit (125) to return to its initial position.

[0054] Samples directly collected from the pressure tube (220) and the reactor tube (210) are collected in the recovery container (164) of the processing chip recovery unit (160), and the collected samples can be analyzed to accurately calculate the amount of radionuclides in the pressure tube (220) and the reactor tube (210).

[0055] Although preferred embodiments of the present invention have been described above, the present invention is not limited thereto and can be implemented with various modifications within the scope of the claims, the detailed description of the invention, and the attached drawings, and it is obvious that such modifications also fall within the scope of the present invention.

Claims

1. A main transfer unit comprising a central axis parallel to the longitudinal direction of a tubular structure and a first driving unit for pushing and moving the central axis; A fixing clamp comprising a plurality of support members coupled to the central axis, spaced apart from the inner wall of the tubular structure in a folded state, and in close contact with the inner wall of the tubular structure in an unfolded state; A cutting machine part comprising a machining tool having a cutting edge, a motor providing rotational power to the machining tool, and a reduction gear coupled to the machining tool and the motor; and A machining tool transfer unit comprising a fixed part coupled to the end of the central axis, a moving part that supports the cutting part and moves along the radial direction of the tubular structure relative to the fixed part, and a second driving part that provides power to the moving part. A sample collection device of a tubular structure including 2. In Paragraph 1, A sample collection device for a tubular structure, wherein the plurality of support members are positioned at a distance from each other along the circumferential direction of the tubular structure, and each of the plurality of support members is formed in a curved shape corresponding to the inner wall of the tubular structure.

3. In Paragraph 1, A sample collection device of a tubular structure, wherein the central axis comprises an inner axis and an outer axis capable of sliding along the axial direction with respect to the inner axis, and each of the plurality of supports is coupled to the inner axis and the outer axis by an X-shaped coupling link.

4. In Paragraph 3, The above-mentioned connecting link includes a first link member and a second link member rotatably connected at the center, and A sample collection device of a tubular structure in which both ends of the first link member are rotatably coupled to the end of the inner shaft and the inner surface of the support, and both ends of the second link member are rotatably coupled to the end of the outer shaft and the inner surface of the support.

5. In Paragraph 1, The above processing tool is formed in a cup shape, and the reduction gear is formed as a hollow reduction gear having a hollow rotating shaft communicating with the internal space of the processing tool, and the internal space of the motor is a tubular structure sample collection device communicating with the internal space of the reduction gear.

6. In Paragraph 5, The above reduction gear is configured as a right-angle hollow reduction gear, and the sample collection device is a tubular structure in which the rotational shaft of the motor and the hollow rotational shaft are orthogonal.

7. In Paragraph 5, A sample collection device of a tubular structure that is connected to the motor and further includes a processing chip recovery unit for recovering processing chips generated when the processing tool is operated.

8. In Paragraph 7, The above-mentioned processing chip recovery unit includes a discharge pipe connected to the motor, a vacuum ejector connected to the discharge pipe, an air compressor that supplies compressed air to the vacuum ejector, and a recovery box connected to the outlet of the vacuum ejector. The above vacuum ejector, the above air compressor, and the above recovery box are a sample collection device of a tubular structure located outside the tubular structure.

9. In any one of paragraphs 1 through 8, It further includes a housing surrounding the central axis, the cutting portion, and the processing tool feed portion, and A sample collection device of a tubular structure in which a plurality of first openings corresponding to the plurality of supports and a second opening corresponding to the processing tool are located in the housing.

10. A main conveying unit comprising a central axis that is inserted into the interior of a pressure pipe installed in a heavy water reactor and moves along the longitudinal direction of the pressure pipe; A fixing clamp comprising a plurality of supports coupled to the central axis and adhering to the inner wall of the pressure tube in an unfolded state; A cutting processing unit comprising a cup-shaped processing tool equipped with a cutting edge, a motor for rotating the processing tool, and a right-angle hollow reduction gear coupled to the motor and the processing tool; A machining tool transfer unit comprising a fixed part coupled to the end of the central axis and a moving part that supports the cutting part and moves along the radial direction of the pressure tube relative to the fixed part to adjust the height of the machining tool; and A processing chip recovery unit comprising a discharge pipe connected to the motor, a vacuum ejector connected to the discharge pipe and receiving compressed air, and a recovery box connected to the outlet of the vacuum ejector, A sample collection device of a tubular structure in which the processing tool drills a hole in the pressure tube and then drills a hole in the reactor tube surrounding the pressure tube to sequentially generate processing chips from the pressure tube and the reactor tube, and the processing chips are collected in the recovery container.

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