Heavy water nuclear power plant pressurizer dismantling device and dismantling method

Abstract

Proposed is a heavy water nuclear power plant pressurizer dismantling device for dismantling a pressurizer disposed inside a heavy water nuclear power plant, wherein the dismantling device includes a posture guiding unit disposed in the vicinity of the pressurizer and connected to the pressurizer to guide movement of the pressurizer, a rail disposed to allow the pressurizer to move toward an exit, and a lifting unit configured to move along the rail and operable to lift the pressurizer.

Description

HEAVY WATER NUCLEAR POWER PLANT PRESSURIZER DISMANTLING DEVICE AND DISMANTLING METHOD CROSS REFERENCE TO RELATED APPLICATION The present application claims priority to Korean Patent Application No. 10-2022- 0128731, filed on October 07, 2022, the entire contents of which are incorporated herein for all purposes by this reference. BACKGROUND OF THE INVENTION 1. Field of the Invention An embodiment of the present disclosure relates to heavy water nuclear power plant pressurizer dismantling device and dismantling method. More specifically, an embodiment of the present disclosure relates to heavy water nuclear power plant pressurizer 15 dismantling device and dismantling method for taking a heavy water reactor type pressurizer out of a containment building. 2. Description of the Background Art To allow safe nuclear fission to be established in a nuclear power plant, a control 20 rod for controlling the number of neutrons, a moderator for reducing the speed of the neutrons, and a coolant for taking the heat out to the outside are essential. The coolant also serves to transfer thermal energy to a steam generator. Depending on types of the moderator used in a nuclear power plant, nuclear reactors are classified into heavy water reactors and light water reactors. 25 Both two types of nuclear power plants, heavy water reactors and light water Date Re9ue / Date Received 2023-08-17 reactors, have been constructed in South Korea. Among 26 nuclear power plants (including Wolsong Unit 1 and Kori Unit 1) constructed in South Korea, Wolsong Units 1 to 4 are the only heavy water reactors. Wolsong Units 1 to 4, which are heavy water reactors developed in Canada, utilize heavy water as the coolant. W olsong Units 1 to 4 5 are also called CANDU reactors. The rest of the 22 Units of nuclear power plants, which are located at sites of the Hanul, Kori, Saeul, Hanbit, and Shin-W olsong, are all light water reactors, wherein the Shin-Wolsong has Units 1 and 2. Unlike the light water nuclear power plant, the heavy water nuclear power plant does not have a polar crane, so it is difficult for large equipment to be handled inside the 1 o containment building. In addition, there is no case that a heavy water nuclear power plant has been decommissioned in the world. Because of being located in a concrete structure by a support, the pressurizer, which is a component of a heavy water nuclear power plant, is more difficult to handle. 15 Such a pressurizer is separated in the containment building, transferred to a comprehensive waste treatment facility, and dismantled inside the treatment facility. However, in the case of heavy water nuclear power plant pressurizer, a polar crane is not available. Therefore, a method is needed to be developed to dismantle the pressurizer from the inner side of the containment building and remove it. 20 The foregoing is intended merely to aid in the understanding of the background of 25 the present disclosure, and is not intended to mean that the present disclosure falls within the purview of the related art that is already known to those skilled in the art. SUMMARY OF THE INVENTION 2 Date Re9ue / Date Received 2023-08-17 Accordingly, the present disclosure has been made keeping in mind the above problems occurring in the related art, and an objective of an embodiment of the present disclosure is to provide a dismantling device and a dismantling method for taking a heavy water nuclear power plant pressurizer out of an inside of a containment building in a 5 nuclear power plant having no polar crane. Problems to be solved by the present disclosure are not limited to the abovementioned problems, and other problems not mentioned herein will be able to be clearly understood by those skilled in the art from the following description. In order to achieve the above objective, according to an embodiment of the present 10 disclosure, there may be provided a heavy water nuclear power plant pressurizer dismantling device, the dismantling device including: a posture guiding unit disposed in the vicinity of the pressurizer and connected to the pressurizer to guide movement of the pressurizer; a rail disposed to allow the pressurizer to move toward an exit; and a lifting unit configured to move along the rail and operable to lift the pressurizer. 15 The posture guiding unit comprises at least four cylinders. The posture guiding unit may include a supporting unit, a first cylinder having a pair of cylinders, and a second cylinder having a pair of cylinders, wherein each of the first cylinder and the second cylinder may have one end part connected to the supporting unit and an opposite end part connected to the pressurizer. 20 The opposite end part of each of the first cylinder and the second cylinder may be disposed to face a center line of the pressurizer. The opposite end part of the second cylinder may be disposed on an upper side of the pressurizer higher than the opposite end part of the first cylinder. When the posture guiding unit guides a posture of the pressurizer, the second 25 cylinder may be operated to be contracted, and the first cylinder may be operated to be 3 Date Re9ue / Date Received 2023-08-17 tensioned. The posture guiding unit may further comprises a third cylinder having a pair of cylinders disposed so as to be symmetrical with the second cylinder In addition, according to another embodiment of the present disclosure, there may 5 be provided a heavy water nuclear power plant pressurizer dismantling method, the dismantling method including: a fixing step of fixing a pressurizer disposed inside a heavy water nuclear power plant using a posture guiding unit; a cutting step of cutting the fixed pressurizer using a cutting device into cut portion; a sealing step of sealing the cut portion of the pressurizer; a taking out step of taking out the sealed portions of the pressurizer using 10 the posture guiding unit; and a transferring step of transferring the taken-out portions of the pressurizer using a rail and a lifting unit. The posture guiding unit may be configured to fix or take out the pressurizer using a plurality of cylinders. The cutting device may be configured to cut the pressurizer using a plurality of 15 circular saws or a plurality oflaser cutting units. 20 25 The cutting device may be configured such that the circular saws may firstly cut the pressurizer, and the laser cutting units may secondly cut a remaining area of the pressunzer. The cutting device may be configured to symmetrically cut the pressurizer. The posture guiding unit may include: a supporting unit; a first cylinder having a pair of cylinders; a second cylinder having a pair of cylinders; and a third cylinder having a pair of cylinders. The posture guiding unit may be configured to fix a position of the pressurizer using the second cylinder and the third cylinder in the fixing step. The posture guiding unit may be configured to take out the pressurizer using the 4 Date Re9ue / Date Received 2023-08-17 first cylinder and the second cylinder in the taking out step. In the taking out step, the posture guide part may be disposed such that the second cylinder may get closer to the pressurizer than the first cylinder, and when the pressurizer is being taken out, it may be configured that the second cylinder may be operated to be 5 contracted, and the first cylinder may be operated to be tensioned. The taking out step may be configured to sequentially take out an upper portion and a lower portion of the pressurizer resulting from the cutting step. When the lower portion of the pressurizer is to be taken out in the taking out step, the posture guiding unit may be configured to be connected with the lower portion by 10 having its position reversed. The sealing step may be configured to insert plates between an upper portion and a lower portion of the pressurizer resulting from the cutting step and seal each of the upper portion and the lower portion of the pressurizer through welding. The transferring step may be configured to transfer an upper portion or a lower 15 portion of the taken-out pressurizer using a crane installed in the lifting unit to a lower side and to transfer each of the upper portion and the lower portion through a transferring unit, which may be connected to an end part of the upper portion or the lower portion to make the upper portion or the lower portion rotated and seated. As described above, according to the embodiment, in the heavy water reactor type 20 where there is no way to handle the pressurizer due to no polar crane available, there is an effect in that it is possible not only to provide a method to separate the pressurizer from a system and to lift and take the pressurizer out but also to reduce operator's exposure and provide an effective dismantling plan for large equipment in heavy water reactors. Various beneficial advantages and effects of the present disclosure are not limited 25 to the above description and will be more easily understood in the process of describing 5 Date Re9ue / Date Received 2023-08-17 specific embodiments of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS 5 The above and other objectives, features, and other advantages of the present disclosure will be more clearly understood from the following detailed description when taken in conjunction with the accompanying drawings, in which: FIG. 1 is a view showing a location of a pressurizer in a heavy water nuclear power plant; FIG. 2 is a view showing a heavy water nuclear power plant pressunzer dismantling device according to an embodiment of the present disclosure; FIG. 3 is a flow chart of a heavy water nuclear power plant pressurizer dismantling method according to another embodiment of the present disclosure; FIGS. 4A to 4C are views showing embodiments of the cutting device used in a 15 cutting step of FIG. 3, respectively; 20 25 FIGS. 5A to 21 are views showing detailed embodiments of an entire process of the heavy water nuclear power plant pressurizer dismantling method shown in FIG. 3; and FIGS. 22 to 27 are views showing an embodiment of a transfer step in the heavy water nuclear power plant pressurizer dismantling method shown in FIG. 3. DETAILED DESCRIPTION OF THE INVENTION Hereinafter, exemplary embodiments according to the present disclosure will be described in detail with reference to the accompanying drawings. However, the technical idea of the present disclosure is not limited to specific 6 Date Re9ue / Date Received 2023-08-17 embodiments that will be described but it may be implemented in various forms. When embodiments are within the scope of the technical idea of the present disclosure, components from different embodiment can be selectively combined or substituted for one another. 5 In addition, unless explicitly defined, terms (including technical and scientific terms) used in the embodiments of the present disclosure may be interpreted as having meanings generally understood by those of ordinary skill in the art to which the present disclosure belongs. Terms commonly used, such as terms defined in a dictionary, may be interpreted to have a meaning in consideration of contextual meanings of related 10 technology. In addition, the terms used in the embodiments of the present disclosure are for describing the embodiments and are not intended to limit the present disclosure. In the present specification, a singular form may also include a plural form unless otherwise specified in a phrase, and when described as "at least one ( or equal to or more 15 than one) of A, B, and C", one or more of all possible combinations of A, B, and C may be included. In addition, terms such as first, second, A, B, (a), (b ), and the like may be used in describing components of the embodiment of the present disclosure. Such terms are only used to distinguish a component from other components, and the nature, turns, orders, or 20 the like of the corresponding components are not limited by the terms. In addition, when a component is described as being "connected", "coupled", or "linked" to another component, it may include not only a case in which the component is directly "connected", "coupled", or "linked" to another component but also a case in which the component is "connected", "coupled", or "linked" to another component due to still 25 another component that is present between the component and another component. 7 Date Re9ue / Date Received 2023-08-17 In addition, when a component is described as being provided or disposed "on (at a top side of) or beneath (at a lower side of)" another component, it may include not only a case in which one component is in direct contact with another component on or beneath another component but also a case in which two components are in contact with each other 5 via one or more other components provided or disposed therebetween. In addition, when expressed as "on (at a top side of) or beneath (at a lower side of)" one component, it may have a meaning of including an upward direction, or a downward direction based on the one component. It should be noted that like reference numerals refer to like parts throughout the 10 various figures and exemplary embodiments. In certain embodiments, a detailed description of functions and configurations well known in the art may be omitted to avoid obscuring appreciation of the disclosure by a person of ordinary skill in the art. For the same reason, some components may be exaggerated, omitted, or schematically illustrated in the accompanying drawings. 15 FIGS. 1 to 27 are drawings schematically showing only the main features for the purpose of clear understanding of the present disclosure conceptually. Therefore, as a result, various modifications of the diagram are expected, and the scope of the present disclosure does not have to be limited by the specific shapes shown in the drawings. FIG. 1 is a view showing a location of a pressurizer 10 in a heavy water nuclear 20 power plant, and FIG. 2 is a view showing a heavy water nuclear power plant pressurizer dismantling device according to an embodiment of the present disclosure. 25 With reference to FIGS. 1 and 2, a dismantling device for a heavy water nuclear power plant pressurizer 10 according to the embodiment of the present disclosure is intended to dismantle the pressurizer 10 disposed inside a heavy water nuclear power plant. It is presumed that is no polar crane inside the containment building inside the 8 Date Re9ue / Date Received 2023-08-17 heavy water nuclear power plant. The heavy water nuclear power plant or the dismantling device according to the present disclosure allows dismantling the pressurizer 10 even without usage of any polar crane inside the containment building inside the heavy water nuclear power plant. In a heavy water nuclear power plant, if a crane is installed in the 5 containment building, typically it is located at a position lower than the pressurizer 10, and the pressurizer 10 is located at an end part of the crane, which makes any usage of the crane inaccessible or unavailable. In addition, the pressurizer 10 is supported and installed by a support inside a concrete structure. Furthermore, unlike a steam generator, the pressurizer 10 does not have 10 a main support, so there exists a difficulty in dismantling. In view of the above, the present disclosure provides a dismantling device and method for heavy water nuclear power plant pressurizer. This enables the dismantling and transportation of the pressurizer 10 from the heavy water nuclear power plant to a comprehensive waste treatment facility even in the absence of a polar crane. 15 With reference to FIG. 2, the heavy water nuclear power plant pressunzer dismantling device according to the embodiment of the present disclosure may include a posture guiding unit 100, a rail 200, and a lifting unit 300. The posture guiding unit 100 is disposed in the vicinity of the pressurizer 10 and may be connected to the pressurizer 10 to guide the movement of the pressurizer 10. In 20 addition, the posture guiding unit 100 may be used to fix the posture of the pressurizer 10 when cutting the pressurizer 10. The posture guiding unit 100 may include at least four cylinders. In one embodiment, the posture guiding unit 100 may include a supporting unit ll O and a first cylinder 120, a second cylinder 130, and a third cylinder 140. Each of the first, second, 25 third, cylinders 110, 120, 130 may be provided as a pair of cylinders. One end of each pair 9 Date Re9ue / Date Received 2023-08-17 may be disposed at the pressurizer 10 while the other end of the pair may be disposed at the pressurizer 10. The supporting unit 110 may be disposed on a concrete structure in the vicinity of the pressurizer 10 and may allow a plurality of cylinders to be connected thereto. In one 5 embodiment, the supporting unit 110 may be provided in a frame structure, thereby supporting the plurality of cylinders, each of which is provided as a pair so as to be disposed on opposite sides of the pressurizer 10. No limit is imposed on the shape of the supporting unit llO, and various structures and shapes for stably supporting the pressurizer 10 may be used. One of the pair of the first cylinder 120, the second cylinder 130, and the third cylinder 140 may be disposed to face the other of the pair of the first cylinder 120, the second cylinder 130 and the third cylinder 140 to stably support the pressurizer 10. No limit is imposed on the structure of such a cylinder, and various known technical configurations of hydraulic or pneumatic may be used. 15 Each of the first cylinder 120, the second cylinder 130, and the third cylinder 140 may have one end part connected to the supporting unit 110 and an opposite end part connected to the pressurizer 10. At this time, the pressurizer 10 may be provided with a fixing device (not shown) for being connected to the cylinder. The fixing device (not shown) provided in the 20 pressurizer 10 may be connected to the cylinder to fix the position of the cylinder. The first cylinder 120, the second cylinder 130, and the third cylinder 140 connected to the pressurizer 10 may be disposed to face a center line of the pressurizer 10 in order to stably support the pressurizer 10. When the pressurizer 10 has a vertically elongated shape, each of the first cylinder 120, the second cylinder 130, and the third 25 cylinder 140 are connected to respective connection positions on the center line of the Date Re9ue / Date Received 2023-08-17 pressurizer 10. The respective connection positions may be located in the middle when viewed from a side of the pressurizer IO.The second cylinder 130 having a pair of cylinders and the third cylinder 140 having a pair of cylinders may perform a function of fixing the position of, i.e., function of securely positioning, the pressurizer 10 during the cutting 5 process of the pressurizer 10. The first cylinder 120 having a pair of cylinders and the second cylinder 130 having a pair of cylinders may perform a function of correcting the posture of the pressurizer 10. In addition, the opposite end part of the second cylinder 130 may be disposed on an upper side of the pressurizer 10 higher than the opposite end part of the first cylinder 10 120. This allows the pressurizer 10 to rotate through the action of contraction of the second cylinder 130 and tension of the first cylinder 120. This rotation of the pressurizer 10 facilitates the adjustment of the posture of the pressurizer 10 during transportation after the cutting process of the pressurizer 10. To look at the operation of such a posture guiding unit 100 in detail, the posture 15 guiding unit 100 is connected to the pressurizer 10 to guide the :fixation and movement of the pressurizer 10. First, the fixing device is connected to the pressurizer 10, and the fixing device is connected to the posture guiding unit 100 after it being connected to the pressurizer 10. According to an embodiment, the supporting unit 110 of the posture guiding unit 20 100 may be fixedly disposed on a concrete structure in the vicinity of the pressurizer 10. The first cylinder 120, a second cylinder 130, and a third cylinder 140, each of which is provided as a pair, are connected to the pressurizer 10. At this time, the second cylinder 130 and the third cylinder 140, which adjust and fix the posture of the pressurizer 10, may be coupled to each other having a symmetrical 25 structure, thereby stably supporting the pressurizer 10, and the first cylinder 120 and the 11 Date Re9ue / Date Received 2023-08-17 second cylinder 130 may operate together in order to move the pressurizer 10. According to an embodiment, the opposite end part of the second cylinder 130 and the opposite end part of the third cylinder 140 may be disposed at a same position on the pressurizer 10. The first cylinder 120, the second cylinder 130, and the third cylinder 140 may be 5 coupled to the pressurizer 10 in a structure that may be installed and separated as needed. In other words, the first cylinder 120, the second cylinder 130, and the third cylinder 140 may be detachably coupled with the pressurizer 10. According to an embodiment, the second cylinder 130 and the third cylinder 140 can be first connected to the pressurizer 10 and serve the purpose of fixing and stabilizing 10 the posture of the pressurizer 10 during the cutting process of the pressurizer 10. After the pressurizer 10 has been cut and the pressurizer 10 is sealed, the first cylinder 120, which is connected to the center of the pressurizer 10, is installed in order to transfer the pressurizer 10. Then the third cylinder 140 may be removed. In this case, the opposite end part of the first cylinder 120 may be disposed on a 15 position lower than a position of the opposite end part of the second cylinder 130. For transferring the pressurizer 10, the second cylinder 130 may be operated to be contracted, and the first cylinder 120 may be operated to be tensioned. In other words, the second cylinder 130 may get shortened while the first cylinder 120 gets lengthened. Through this, the second cylinder 130 may perform an operation of lowering the support region of the 20 pressurizer 10 where the opposite end of the second cylinder 130 is connected, and the first cylinder 120 may raise the support region of the pressurizer 10 where the opposite end of the first cylinder 120 is connected. These operations are combined or performed simultaneously to cause the pressurizer 10 to be rotated while remaining its original position and may be moved toward the rail 200. 25 The rail 200 may move the pressurizer 10 moving through the posture guiding unit 12 Date Re9ue / Date Received 2023-08-17 5 100 toward an exit. One side of the rail 200 may be disposed on a side of the concrete structure where the pressurizer 10 is disposed, and an opposite side of the rail 200 may be disposed toward the exit so that the pressurizer 10 moving along the rail 200 may be discharged from the inside of the nuclear power plant. There is no limitation on the structure of the rail 200, and various structures or configuration can be employed to allow the seated pressurizer 10 to move. In one embodiment, the rail 200 may use a conveyor belt structure. According to an embodiment, the lifting unit 300 may be provided to move along the rail 200. The lifting unit 300 may lift the pressurizer 10. In one embodiment, the 10 lifting unit 300 may include a supporting structure installed on the rail 200 and a crane connected to the supporting structure. The crane means a structure capable of raising and lowering the pressurizer 10. On the other hand, hereinafter, a dismantling method of the heavy water nuclear power plant pressurizer 10 according to another embodiment of the present disclosure will 15 be described with reference to the accompanying drawings. In the description of a dismantling method, duplicated or same description as those described in the dismantling device for the heavy water nuclear power plant pressurizer 10 according to the embodiment of the present disclosure will be omitted. FIG. 3 is a flow chart of a heavy water nuclear power plant pressurizer dismantling 20 method according to another embodiment of the present disclosure, FIGS. 4A to 4C are views from the top of the pressurizer 10, each showing an embodiment of the cutting device used in a cutting step S200 of FIG. 3, and FIGS. 5A to 21 are views showing detailed embodiments of an entire process of the heavy water nuclear power plant pressurizer dismantling method shown in FIG. 3. In the description of FIGS. 3 to 21, the same 25 reference numerals as those of FIGS. 1 to 2 denote the same members, and detailed 13 Date Re9ue / Date Received 2023-08-17 descriptions thereof will be omitted. With reference to FIG. 3, the dismantling method of the heavy water nuclear power plant pressurizer 10 according to another embodiment of the present disclosure may include a fixing step S 100, a cutting step S200, a sealing step S300, a taking out step S400, 5 and a transferring step S500. The fixing step S 100 is a step of fixing the pressurizer 10 disposed inside the heavy water nuclear power plant using the posture guiding unit 100. The posture guiding unit 100 has a plurality of cylinders and uses them to fix and / or take out the pressurizer 10. In one embodiment, the posture guiding unit 100 may 10 include a supporting unit 110, a first cylinder 120, a second cylinder 130, and a third cylinder 140, while each of them is provided as a pair. The second cylinder 130 and the third cylinder 140 each may have one end connected to the supporting unit 110 and an opposite end connected to the pressurizer 10 to fix the position of the pressurizer 10. The second cylinder 130 and the third cylinder 140 15 may be configured to have a symmetrical structure, having the pressurizer 10 in the middle of them. In the fixing step S100, the second cylinder 130 and the third cylinder 140 may be provided to have a three-point support structure to stably fix the pressurizer 10. Each one of the pair of the second cylinder 130 is disposed to face each other with the pressurizer 10 interposed therebetween, so that the pressurizer 10 may be supported more stably. 20 Similarly, each one of the pair of the third cylinder 140 is disposed to face each other with the pressurizer 10 interposed therebetween. One end of both the second cylinder 130 and the third cylinder 140 is coupled to the supporting unit 110. The distance between the two points where the second cylinder 130 and the third cylinder 140 are fixed to the supporting unit 110 may be wider than a diameter of the pressurizer 10. This configuration increases 25 stability. 14 Date Re9ue / Date Received 2023-08-17 In the cutting step S200, the pressurizer 10 fixed by was of the fixing step S 100 may be cut using a cutting device. During dismantling process of a heavy water nuclear power plant, the pressurizer 10 may need to be removed using conventionally existing hatch and airlock, which cannot be modified in size. Consequently the pressurizer 10 in 5 its original size cannot be extracted through the existing openings. Therefore, the pressurizer 10 needs to be cut in order to be safely removed from the facility. FIGS. 4A to 4C are views from the top of the pressurizer 10, each showing an embodiment of the cutting device used in a cutting step of FIG. 3. FIG. 4A shows an embodiment of a cutting device for cutting using a plurality of circular saws 410, FIG. 4B 10 shows an embodiment of a cutting device using a plurality of laser cutting units 420, and FIG. 4C shows an embodiment of a cutting device using the circular saws 410 and the laser cutting units 420 together. With reference to FIGS. 4A to 4C, the cutting device may use the plurality of circular saws 410 or the plurality of laser cutting units 420, or a combination of circular 15 saw(s) 410 and laser cutting unit(s) 420, to cut the pressurizer 10. In the cutting device, the plurality of circular saws 410 or laser cutting units 420 may be disposed at symmetrical positions or disposed to have the same angle in order to reduce operating time for cutting and / or to maintain the balance of the pressurizer 10. In addition, when cutting is performed using the laser cutting units 420, there can 20 be challenges when the material of the pressurizer 10 to be cut is excessively thick. Therefore, a parallel approach can be adopted by utilizing both circular saws 410 and the laser cutting units 420 simultaneously as shown in FIG. 4C. In one embodiment, the cutting device may cut the pressurizer 10 such that 1 / 2 of the initial thickness of the material is cut using the circular saws 410, and the remaining 1 / 2 of the initial thickness of 25 the material is cut using the laser cutting units 420, thereby increasing the cutting 15 Date Re9ue / Date Received 2023-08-17 efficiency. The sealing step S300 is a step of sealing the pressurizer 10 after it has been cut. In the sealing step S300, each of the portions resulting from the cutting of the pressurizer 10 in the cutting step S200 may be sealed individually using plates through 5 welding. Accordingly, diffusion of contaminants inside the cut pressurizer 10 may be prevented. In one embodiment, in the sealing step S300, plates made of metal are inserted between an upper portion and a lower portion of the pressurizer 10 which have been cut. The contact surfaces between the plate and each separated portion of the pressurizer 10 are 10 then welded using a welding machine. This process ensures that each separated upper and lower portions of the pressurizer 10 is properly sealed. The plate used in the sealing step S300 may have various shapes or sizes capable of sealing the opening of each separated upper and lower portions of the pressurizer 10. As the welding method, various known methods for welding metal may be used. 15 The taking out step S400 is a step of using the posture guiding unit 100 to take out the pressurizer 10, which has been sealed in the sealing step S300. In the taking out step S400, the posture guiding unit 100 may take the pressurizer 10 out using the first cylinder 120 and the second cylinder 130. As one embodiment, in the taking out step S400, the posture guiding unit 100 may be disposed such that the second 20 cylinder 130 is getting closer to the pressurizer 10 than the first cylinder 120. When the pressurizer 10 is being taken out, it may be configured such that the second cylinder 130 is operated to be contracted, and the first cylinder 120 is operated to be tensioned so as to be able to make the pressurizer 10 elevated and rotated at the same time. In the taking out step S400, according to an embodiment, the upper portion 10a 25 and the lower portion 10b of the pressurizer 10, which were cut in the cutting step S200, 16 Date Re9ue / Date Received 2023-08-17 may be sequentially taken out. In the taking out step S400, when the upper portion 10a of the pressurizer 10 is to be taken out, a plurality of cylinders is disposed on the top of the support ll0, and when the lower portion 10b of the pressurizer 10 is to be taken out, the position of the posture guiding unit 100 is reversed and the plurality of cylinders is 5 connected to the lower part of (i.e., the bottom of) the supporting unit 110 to lift the lower portion 10b, and then the lower portion 10b may be taken out through the same process as the upper portion 1 0a having been taken out. In the transferring step S500, the pressurizer 10 having been taken out by the taking out step S400 may be transferred to the outside through a hatch and an airlock using 10 the rail 200 and / or the lifting unit 300. At this time, as shown in FIG. 5B, according to an embodiment, a plurality of lifting units 300 (i.e., more than one lifting unit 300) may be provided on the top of the rail, thereby transferring the pressurizer being taken out. A crane may be installed on each of the lifting units 300. Hereinafter, with reference to FIGS. 5A to 21, the dismantling method of heavy 15 water nuclear power plant pressurizer 10 will be further described. FIGS. 5A to 9 are steps of taking out the upper portion 1 0a of the pressurizer 10 that has been cut. During the cutting step S200 in which the pressurizer 10 is being cut, the posture guiding unit 100 is configured to fix the pressurizer 10 using the supporting unit ll 0, the 20 second cylinder 130, and the third cylinder 140. After the cutting step S200 and after removing the cutting device, the first cylinder 120 of the posture guiding unit 100 is installed on the supporting unit 110 as shown in FIGS. 5A and 5B. Then as shown in FIG. 6, the third cylinder of the posture guiding unit 100 is removed, and the sealing step (S300) proceeds. In the sealing step S300, the seal plate is 25 inserted between the upper part 10a and the lower part 10b of the pressurizer 10, and the 17 Date Re9ue / Date Received 2023-08-17 opening of each separated upper and lower part 10a, 10b of the pressurizer 10 is sealed by the seal plates using a sealing method such as welding. Thereafter, as shown in FIG. 7, the posture guiding unit 100 operates the first cylinder 120 and the second cylinder 130 so that the taking out step S400 proceeds. In the 5 taking out step S400, the first cylinder 120 may be tensioned and the second cylinder 130 may be contracted to be able to make the upper part 10a of the pressurizer 10 rotated. Each of the first cylinder 120, second cylinder 130, and the third cylinder 140, at its respective one end, may be rotatably connected to the supporting unit 110. With reference to FIG. 8, the upper part 10a of the pressurizer 10, which is 10 manipulated using the posture guiding unit 100, is adjusted to a horizontal position and is placed onto the rail 200. At this time, the plurality of cranes provided on the lifting unit 300 and a winch device, although not shown in the drawing, installed on the opposite side of the lifting unit 300 may be connected to the upper part 10a of the pressurizer 10. The cylinders 120 and 130 of the posture guiding unit connected to the upper part 10a of 15 pressurizer 10 may be stretched to transfer the upper part 10a of the pressurizer 10 to a side of the lifting unit 300. The crane may be contracted to move the upper part 1 0a of the pressurizer to a side of the lifting unit 300, thereby making the upper part 1 0a of the pressurizer seated on the rail 200. Then, as shown in FIG. 9, the upper part 10a of the pressurizer 10 is seated on the 20 rail 200 and connected to the lifting unit 300 to be transferred along the rail 200. FIGS. 10 to 18 are views showing cases in which the lower portion 10b of the pressurizer 10 is being taken out after the upper portion 10a of the pressurizer 10 has been taken out. After the upper portion 1 0a of the pressurizer 10 has been taken out as shown in 25 FIG. 10, the posture guiding unit 100 is reinstalled. At this time, the position of the 18 Date Re9ue / Date Received 2023-08-17 posture guiding unit 100 is reversed so that the plurality of cylinders is rearranged to face downward. With reference to FIG. 11, the lower portion 10b of the pressurizer 10 fixed by way of the posture guiding unit 100 is lifted upward. Then as shown in FIG. 12, after the lower 5 portion 1 Ob of the pressurizer 10 is fixed, the first cylinder 120 of the posture guiding unit 100 is installed upward on the supporting unit. With reference to FIG. 13, after removing the fixing device, the lower part 10b of the pressurizer 10 is lifted. Then, as shown in FIG. 14, after fixing the lower portion 10b of the pressurizer 10, the second cylinder 130 and the third cylinder 140 of the posture guiding 10 unit 100 are installed, the one end of the each second cylinder 130 and third cylinder 140 onto the supporting unit 110 and the opposing end of the each second cylinder 130 and third cylinder 14 onto the lower portion 1 Ob. Thereafter, as shown in FIG. 15, after removing the fixing device, the lower portion 10b of the pressurizer 10 is lifted above the concrete support 110. And then, as 15 shown in FIGS. 16 to 18, the transferring step S500 of transferring the lower portion 10b of the pressurizer 10 proceeds according to the same process as the upper portion 10a of the pressurizer 10 is being taken out and transferred. With reference to FIGS. 19 to 21, an upper portion or a lower portion of the pressurizer 10, being transferred as the transferring step S500 proceeds, moves along the 20 rail 200, and after the lifting unit 300 moves to the end of the rail 200, the upper portion or the lower portion of the pressurizer 10 moves passing through the hatch along the crane installed on the lifting unit 300. Thereafter, the posture guiding unit 100 is installed on the lower side of the hatch, and the cylinders of the posture guiding unit 100 are connected to the upper portion or the 25 lower portion of the pressurizer 10 to rotate the upper portion or the lower portion of the 19 Date Re9ue / Date Received 2023-08-17 pressurizer 10, and then the upper portion or the lower portion of the pressurizer 10 is taken out through the airlock. FIGS. 22 to 27 are views showing an embodiment of the transferring step in the dismantling method of the heavy water nuclear power plant pressurizer shown in FIG. 3. 5 With reference to FIGS. 22 to 27, the upper portion or the lower portion of the pressurizer 10 transferred through the lifting unit 300 passes through the hatch by way of a crane. At this time, the direction of the upper portion or the lower portion of the pressurizer 10 being transferred through a transferring unit 500 disposed on the floor may be easily changed. The transferring unit 500 may include a transferring unit main body 510, a rotation supporting unit 520, a moving unit 530, and a bogie 540. The transferring unit main body 510 serves to support the entire configuration and may have the rotation supporting unit 520 connected to the upper portion thereof and the moving unit 530 to the lower portion thereof. The shape of the transferring unit main 15 body 510 is not limited and may be modified into various structures such as a tubular structure or a frame structure. The rotation supporting unit 520 may be provided with a groove having a curved surface to support the end part of the curved surface of the upper portion or the lower portion of the pressurizer 10 and have the center rotatably connected to the transferring unit 20 main body 510, thereby supporting the upper portion or the lower portion of the pressurizer 10 lowering via the crane 310. The moving unit 530 is equipped with a plurality of wheels and may move forward and backward according to a moving state of the upper portion or the lower portion of the pressurizer 10. In one embodiment, the moving unit 530 may be provided with a structure 25 that has a skeleton structure provided with a plurality of wheels and may be modified into 20 Date Re9ue / Date Received 2023-08-17 various structures in order for supporting the wheels. The bogie 540 may serve to support the body of the upper portion or the lower portion of the pressurizer 10 when the upper portion or the lower portion of the pressurizer 10 is seated and may be connected with the moving unit 530 to move. In one 5 embodiment, the bogie 540 may be provided with a curved surface to stably support the curved body of the upper portion or the lower portion of the pressurizer 10. With reference again to FIGS. 22 to 27, an end part of the upper portion or the lower portion of the pressurizer 10 passing through the hatch via the crane 310 may be connected to the rotation supporting unit 520 of the transferring unit 500. At this time, the 10 crane 310 is maintaining a supporting force that is coupled with the upper portion or the lower portion of the pressurizer 10, and the upper portion or the lower portion of the pressurizer 10 rotates as the moving unit 530 moves. The rotation supporting unit 520 connected to one side of the upper portion or the lower portion of the pressurizer 10 rotates together along with the movement of the moving unit 530, and the crane 310 moves the 15 rear end of the upper portion or the lower portion of the pressurizer 10 to a lower side. Thereafter, when the rotation supporting unit 520 rotates by a 90 degree angle, the rear end of the upper portion or the lower portion of the pressurizer 10 is seated on the bogie 540. At this time, the entire body of the upper portion or the lower portion of the pressurizer 10 is supported by the rotation supporting unit 520 and the bogie 540, so the 20 coupling between the crane 310 and the upper portion or the lower portion of the pressurizer 10 may be released, and the transferring unit 500 may move, thereby taking out the upper portion or the lower portion of the pressurizer 10. 25 In the above, the embodiments of the present disclosure have been examined in detail with reference to the accompanying drawings. The above description is merely an example of the technical idea of the present 21 Date Re9ue / Date Received 2023-08-17 disclosure, and those skilled in the art will be able to make various modifications, changes, and substitutions for the description without departing from the essential characteristics of the present disclosure. Therefore, the embodiments disclosed in the present disclosure and the accompanying drawings are not intended to limit the technical idea of the present 5 disclosure but to explain, and the scope of the technical idea of the present disclosure is not limited by such embodiments and the accompanying drawings. The protection scope of the present disclosure should be construed according to the following claims, and all technical ideas within the equivalent range thereto should be construed as being included in the scope of the present disclosure. Also, it is noted that any one feature of an embodiment 10 of the present disclosure described in the specification may be applied to another embodiment of the present disclosure. 22 Date Re9ue / Date Received 2023-08-17

Claims

CLAIMS 1. A heavy water nuclear power plant pressurizer dismantling device for dismantling a pressurizer disposed inside a heavy water nuclear power plant, the dismantling device 5 compnsmg: a posture guiding unit disposed in the vicinity of the pressurizer and connected to the pressurizer to guide movement of the pressurizer; a rail disposed to allow the pressurizer to move toward an exit; and a lifting unit configured to move along the rail and operable to lift the pressurizer.

2. The dismantling device of claim 1, wherein the posture guiding unit comprises at least four cylinders.

3. The dismantling device of claim 2, wherein the posture guiding unit comprises a 15 supporting unit, a first cylinder having a pair of cylinders, and a second cylinder having a pair of cylinders, wherein each of the first cylinder and the second cylinder has one end part connected to the supporting unit and an opposite end part connected to the pressurizer. 20 4. The dismantling device of claim 3, wherein the opposite end part of each of the first cylinder and the second cylinder is disposed to face a center line of the pressurizer.

5. The dismantling device of claim 4, wherein the opposite end part of the second cylinder is disposed on an upper side of the pressurizer higher than the opposite end part of 25 the first cylinder. 23 Date Re9ue / Date Received 2023-08-17 5 6. The dismantling device of claim 3, wherein, when the posture guiding unit guides a posture of the pressurizer, the second cylinder is operated to be contracted, and the first cylinder is operated to be tensioned.

7. The dismantling device of claim 3, wherein the posture guiding unit further comprises a third cylinder having a pair of cylinders disposed so as to be symmetrical with the second cylinder. 10 8. A heavy water nuclear power plant pressunzer dismantling method, the dismantling method comprising: a fixing step of fixing a pressurizer disposed inside a heavy water nuclear power plant using a posture guiding unit; a cutting step of cutting the fixed pressurizer using a cutting device into cut portions; 15 a sealing step of sealing the cut portions of the pressurizer; 20 a taking out step of taking out the sealed portion of the pressurizer using the posture guiding unit; and a transferring step of transferring the taken-out portion of the pressurizer using a rail and a lifting unit.

9. The dismantling method of claim 8, wherein the posture guiding unit is configured to fix or take out the pressurizer using a plurality of cylinders.

10. The dismantling method of claim 8, wherein the cutting device is configured to 25 cut the pressurizer using a plurality of circular saws or a plurality oflaser cutting units. 24 Date Re9ue / Date Received 2023-08-17 5 11. The dismantling method of claim 10, wherein, the cutting device is configured such that the circular saws firstly cut the pressurizer, and the laser cutting units secondly cut a remaining area of the pressurizer.

12. The dismantling method of claim 10, wherein the cutting device is configured to symmetrically cut the pressurizer.

13. The dismantling method of claim 9, wherein the posture guiding unit comprises: 1 o a supporting unit; a first cylinder having a pair of cylinders; a second cylinder having a pair of cylinders; and a third cylinder having a pair of cylinders. 15 14. The dismantling method of claim 13, wherein the posture guiding unit is configured to fix a position of the pressurizer using the second cylinder and the third cylinder in the fixing step.

15. The dismantling method of claim 13, wherein the posture guiding unit is 20 configured to take out the pressurizer using the first cylinder and the second cylinder in the taking out step.

16. The dismantling method of claim 13, wherein, in the taking out step, the posture guide part is disposed such that the second cylinder gets closer to the pressurizer than the first 25 cylinder, and 25 Date Re9ue / Date Received 2023-08-17 when the pressurizer is being taken out, it is configured that the second cylinder is operated to be contracted, and the first cylinder is operated to be tensioned.

17. The dismantling method of claim 8, wherein the talcing out step is configured to 5 sequentially take out an upper portion and a lower portion of the pressurizer resulting from the cutting step.

18. The dismantling method of claim 17, wherein, when the lower portion of the pressurizer is to be taken out in the taking out step, the posture guiding unit is configured to 10 be connected with the lower portion by having its position reversed.

19. The dismantling method of claim 8, wherein the sealing step is configured to insert plates between an upper portion and a lower portion of the pressurizer resulting from the cutting step and seal each of the upper portion and the lower portion of the pressurizer 15 through welding.

20. The dismantling method of claim 8, wherein the transferring step is configured to transfer an upper portion or a lower portion of the taken-out pressurizer using a crane installed in the lifting unit to a lower side and to transfer each of the upper portion and the 20 lower portion through a transferring unit, which is connected to an end part of the upper portion or the lower portion to make the upper portion or the lower portion rotated and seated. 26 Date Re9ue / Date Received 2023-08-17