Apparatus for decommissioning heavy water reactor facilities and method for decommissioning heavy water reactor facilities

Abstract

The present invention relates to a dismantling device for a heavy water reactor facility and a method for dismantling a heavy water reactor facility. The dismantling device for the heavy water reactor facility comprises a vertical transfer unit that is movably installed vertically in a calandria bolt containing calandria, a cutting platform installed inside the calandria bolt and coupled to the vertical transfer unit, and a cutting member coupled to the cutting platform and provided to cut the calandria.

Description

Technology Field

[0001] The present invention relates to a dismantling device for a heavy water reactor facility and a method for dismantling a heavy water reactor facility. Background Technology

[0002] Generally, among nuclear facilities used for nuclear power generation, heavy water reactor facilities include calandria and calandria vaults that house the calandria.

[0003] A calandria is a nuclear fuel injection cylinder for a heavy water nuclear power plant, having a cylindrical pipe structure that injects nuclear fuel and discharges burned fuel bundles during normal operation of the power plant.

[0004] During the decommissioning of heavy water reactor facilities, there are concerns regarding worker exposure and radioactive leakage when dismantling highly radioactive structures, such as guide tubes and toxic substance injection tubes, housed within the calandria. Therefore, the calandria must be dismantled safely and rapidly during the decommissioning of heavy water reactor facilities.

[0005] The conventional method for dismantling heavy water reactor calandria involves installing a large crane on top of the calandria, along with cutting and transfer equipment. Additionally, the top of the calandria bolts is cut to secure a workspace for cutting the calandria.

[0006] However, according to conventional technology, in order to cut the calandria, additional calandria bolts must be cut and additional structures installed for this purpose, which has the disadvantage of increasing the work process and work time, and this may lead to increased radiation exposure. In addition, secondary waste may be generated due to the additional installations for the calandria bolt cutting work. The problem to be solved

[0007] The present invention has been devised to solve the aforementioned problems and achieves at least one of the following objectives.

[0008] The embodiment of the present invention aims to provide a dismantling device for a heavy water reactor facility and a dismantling method for a heavy water reactor facility that eliminates the process of cutting the upper part of a calandria bolt to secure a cutting workspace, thereby eliminating the need for equipment and structures for cutting the upper part of a calandria bolt and shortening the working time.

[0009] The embodiment of the present invention aims to provide a dismantling device for a heavy water reactor facility and a method for dismantling a heavy water reactor facility that minimizes the amount of radioactive materials, dust, and secondary waste generated after the work by utilizing the existing space of the Calandria vault to perform the work.

[0010] The embodiment of the present invention aims to provide a dismantling device for a heavy water reactor facility and a dismantling method for a heavy water reactor facility that perform operations stably by minimizing shaking of the vertical transfer unit. means of solving the problem

[0011] To achieve the above objective, the dismantling device for a heavy water reactor facility according to the present invention comprises a vertical transfer unit that is movably installed vertically in a calandria bolt containing calandria, a cutting platform installed inside the calandria bolt and coupled to the vertical transfer unit, and a cutting member coupled to the cutting platform and provided to cut the calandria.

[0012] The above vertical transfer unit is installed by penetrating a piping hole formed in the calandria bolt to install a piping unit provided in the calandria, and the cutting platform can be inserted downward from the top of the calandria bolt through a deck installation hole formed in the upper part of the calandria bolt and coupled to the vertical transfer unit.

[0013] It may further include a shielding structure that is installed to shield the above-mentioned deck installation hole and is formed in multiple stages.

[0014] It may further include a basket member for loading and transporting the calandria cut by the cutting member.

[0015] It further includes an air purification unit installed to suck in air and foreign substances inside the above-mentioned calandria, and the calandria bolt may have an intake hole formed therein that penetrates the inside and outside and is directly or indirectly connected to the air purification unit.

[0016] The method for dismantling a heavy water reactor facility according to the present invention comprises: a pipe removal step of cutting and removing a piping portion of a calandria installed through a piping hole of a calandria bolt; a vertical transfer unit installation step of installing a vertical transfer unit through the piping hole from which the piping portion has been removed; a cutting platform installation step of inserting a cutting platform through a deck installation hole formed at the upper end of the calandria bolt and connecting it to the vertical transfer unit; and a calandria removal step of cutting and removing the calandria using a cutting member installed at the lower end of the cutting platform.

[0017] The above pipe removal step may include an external cutting step of cutting the portion of the pipe section exposed to the outside of the Calandria bolt from the outside of the Calandria bolt, an equipment insertion step of inserting a pipe cutting device into the pipe section, an internal cutting step of cutting the portion of the pipe section installed inside the Calandria bolt using the pipe cutting device, and a pipe extraction step of extracting the portion of the pipe section cut in the internal cutting step to the outside.

[0018] The above cutting platform installation step may include the step of inserting the cutting platform into the interior of the deck installation hole, the step of combining the cutting platform and the vertical transfer unit inside the Calandria bolt, and the step of installing a shielding structure on the upper part of the cutting platform to shield the deck installation hole.

[0019] The above pipe holes are formed in the above calandria bolts in plurality, and the above vertical transfer units are provided in plurality, each of the plurality of vertical transfer units is installed in each of the plurality of pipe holes, and in the above calandria removal step, each of the plurality of vertical transfer units can be driven individually.

[0020] The above calandria removal step may include an equipment movement step for moving the vertical transfer unit and the cutting platform to a preset position, a container cutting step for cutting the calandria using the cutting member, a basket insertion step for inserting a basket member into the interior of the calandria bolt from the top of the calandria bolt when the container cutting step is completed, a container loading step for loading the cut calandria onto the basket member, and a container removal step for removing the basket member to the outside of the calandria bolt.

[0021] Before the above-mentioned calandria removal step, the method may further include an air purification device installation step in which an air purification unit is installed through an intake hole penetrating the inside and outside of the calandria bolt, and during the above-mentioned calandria removal step, the method may further include a step of operating the air purification unit to suck in gas and dust inside the calandria by operating the air purification device.

[0022] After the above-mentioned calandria removal step, the method may further include an equipment removal step of moving the cutting platform outside the calandria and dismantling the vertical transfer unit. Effects of the invention

[0023] By using the dismantling device and method for dismantling a heavy water reactor facility according to the embodiment of the present invention, the process of cutting the upper part of the Calandria bolt to secure a cutting workspace is omitted, thereby eliminating the need for equipment and structures to cut the upper part of the Calandria bolt and shortening the work time.

[0024] According to an embodiment of the present invention, since work is performed by utilizing the existing space of the Calandria Vault, the amount of radioactive material, dust, and secondary waste generated after work can be minimized.

[0025] According to an embodiment of the present invention, since the transfer operation is performed with the vertical transfer unit installed through the pipe hole formed in the Calandria bolt, the shaking of the vertical transfer unit can be minimized and the operation can be performed stably. Brief explanation of the drawing

[0026] FIG. 1 is a cross-sectional view illustrating a heavy water reactor facility being dismantled by an embodiment of the present invention. Figure 2 is a cross-sectional view of AA of Figure 1. FIG. 3 is a cross-sectional view illustrating the state in which a dismantling device for a heavy water reactor facility according to an embodiment of the present invention is installed in a heavy water reactor facility. Figure 4 is a top view of Figure 3 seen from above. FIG. 5 is a flowchart of a method for dismantling a heavy water reactor facility according to an embodiment of the present invention. Specific details for implementing the invention

[0027] Hereinafter, embodiments of the present invention will be described in detail according to the attached drawings.

[0028] First, the embodiments described below are suitable for illustrating the technical features of the dismantling device and method for dismantling a heavy water reactor facility according to the present invention. However, the present invention is not limited to the embodiments described below, nor are the technical features of the present invention limited by the described embodiments; various modifications are possible within the technical scope of the present invention.

[0029] FIG. 1 is a cross-sectional view illustrating a heavy water reactor facility being dismantled according to an embodiment of the present invention, FIG. 2 is a cross-sectional view AA of FIG. 1, FIG. 3 is a cross-sectional view illustrating a state in which a dismantling device for a heavy water reactor facility according to an embodiment of the present invention is installed in a heavy water reactor facility, FIG. 4 is a top view of FIG. 3 viewed from above, and FIG. 5 is a flowchart of a method for dismantling a heavy water reactor facility according to an embodiment of the present invention.

[0030] Referring to FIGS. 1 to 4, the dismantling device (100) of a heavy water reactor facility according to an embodiment of the present invention further includes a vertical transfer unit (110), a cutting platform (120), and a cutting member (130).

[0031] The vertical transfer unit (110) is installed vertically on the calandria bolt (10) that houses the calandria (1) inside and is movably provided.

[0032] Specifically, the heavy water reactor facility dismantled according to an embodiment of the present invention may be a Calandria (1). A Calandria (1) refers to a sealed reactor vessel in which a fluid conduit or flow channel is installed inside the vessel to separate a high-pressure coolant passing through it from a liquid moderator filled around it. The Calandria (1) may include a vessel section (2) and a piping section (3) connected to the vessel section (2). Additionally, the Calandria (1) may further include a moderator pipe (4) provided on the side and bottom through which the moderator flows, and a guide tube (5) provided on the top.

[0033] A Calandria vault (10) is a structure for housing a Calandria (1) inside. Specifically, the Calandria vault (10) may include a vault body (11) in which a receiving space (12) is formed.

[0034] A piping hole (13) may be formed in the calandria bolt (10) for installing a piping section (3) provided in the calandria (1). Additionally, a deck installation hole (14) may be formed in the calandria bolt (10) for installing a reactivity mechanism deck. The calandria bolt (10) may be opened upward through the deck installation hole (14).

[0035] The vertical transfer unit (110) can be installed by penetrating the pipe hole (13) formed in the calandria bolt (10) to install the pipe section (3) provided in the calandria (1). The vertical transfer unit (110) can be provided to be vertically extended and vertically movable while penetrating the pipe hole (13). The vertical transfer unit (110) can serve to transfer the cutting member (130) to the work position.

[0036] The cutting platform (120) is installed inside the calandria bolt (10) and connected to the vertical transfer unit (110). Here, the cutting platform (120) can be connected to the vertical transfer unit (110) by being inserted downward from the top of the calandria bolt (10) through the deck installation hole (14) formed at the top of the calandria bolt (10).

[0037] Specifically, the cutting platform (120) is a structure for attaching a cutting member (130) and can be installed on the upper part of the calandria (1). The cutting platform (120) can be inserted downward from the upper part of the calandria bolt (10) through the deck installation hole (14). The cutting platform (120) inserted into the calandria bolt (10) can be combined with the vertical transfer unit (110). Subsequently, the cutting platform (120) can move together with the vertical transfer unit (110).

[0038] A cutting member (130) is connected to a cutting platform (120) and is provided to cut the calandria (1).

[0039] Specifically, the cutting member (130) is a member for cutting the calandria (1) inside the calandria bolt (10). The cutting member (130) can be attached to the lower surface of the cutting platform (120). Since the cutting platform (120) is positioned on the upper surface of the calandria (1), the cutting member (130) can be arranged to work between the cutting platform (120) and the upper surface of the calandria (1).

[0040] Additionally, an embodiment of the present invention may further include a gripper member. The gripper member may be installed on the lower surface of the cutting platform (120) and may be installed adjacent to the cutting member (130).

[0041] The gripper member may be provided to grip the calandria (1) or to adsorb or attach to the calandria (1) during the cutting operation of the cutting member (130). By doing so, the cutting operation by the cutting member (130) can be performed smoothly.

[0042] By using such an embodiment of the present invention, the cutting platform (120), cutting member (130), and vertical transfer unit (110), which are equipment for cutting the calandria (1), are inserted into the interior through the piping hole (13) and deck installation hole (14) formed in the existing calandria bolt (10), so the process of cutting the upper part of the calandria bolt (10) to secure a cutting workspace can be omitted.

[0043] Accordingly, according to an embodiment of the present invention, equipment and structures for cutting the upper part of the Calandria bolt (10) are unnecessary, and the working time can be shortened.

[0044] In addition, according to an embodiment of the present invention, work is performed by utilizing the existing space of the Calandria Vault (10), so the amount of radioactive material and dust, and secondary waste generated after work can be minimized.

[0045] In addition, according to an embodiment of the present invention, since the vertical transfer unit (110) is installed through the pipe hole (13) formed in the Calandria bolt (10) and the transfer operation is performed, the shaking of the vertical transfer unit (110) can be minimized and the operation can be performed stably.

[0046] In addition, according to an embodiment of the present invention, the cutting operation is performed inside the Calandria bolt (10), so radiation exposure can be minimized.

[0048] Meanwhile, an embodiment of the present invention may further include a shielding structure (150). The shielding structure (150) may be installed to shield the deck installation hole (14) and may be formed in multiple stages.

[0049] Specifically, the shielding structure (150) is a component for covering the exposed deck installation hole (14) during the cutting operation of the Calandria (1), and is a component for minimizing exposure of workers and others to radioactive materials. For example, the shielding structure (150) may be made of a multi-stage structure capable of shielding the deck installation hole (14) in multiple stages. By doing so, radiation exposure can be minimized during the dismantling operation of the heavy water reactor facility.

[0050] An embodiment of the present invention may further include a basket member (not shown). The basket member may load and transport the calandria (1) cut by the cutting member (130).

[0051] Specifically, the basket member can be vertically inserted into the interior of the calandria bolt (10) through the deck installation hole (14) after the cutting of the calandria (1) is completed and part or all of the shielding structure (150) is removed. All or part of the cut calandria (1) can be loaded into the basket member by the gripper member. The basket member can be removed from the outside of the cut calandria by being pulled out to the outside.

[0052] Here, there are no restrictions on the shape and type of basket member, and various types of baskets can be applied as long as they can transport the cut calandria (1).

[0053] An embodiment of the present invention may further include an air purification unit. The air purification unit may be installed to suck in air and foreign substances inside the calandria (1). Here, known technology may be applied to the type of air purification unit.

[0054] And the Calandria bolt (10) may have an intake hole formed that penetrates the inside and outside and is directly or indirectly connected to the air purification unit.

[0055] In this way, as the air purification unit is installed through the intake hole, contaminated gases and dust generated during cutting operations can be sucked in by the air purification unit.

[0057] Meanwhile, below, a method for dismantling a heavy water reactor facility according to an embodiment of the present invention will be described with reference to FIGS. 1 to 5. FIGS. 1 to 4 are as described above, and FIG. 5 is a flowchart of a method for dismantling a heavy water reactor facility according to an embodiment of the present invention.

[0058] The method for dismantling a heavy water reactor facility according to an embodiment of the present invention relates to a method for dismantling a heavy water reactor facility using the aforementioned dismantling device (100) for the heavy water reactor facility. Therefore, a detailed description of a configuration identical to the aforementioned configuration is omitted below.

[0059] A method for dismantling a heavy water reactor facility according to an embodiment of the present invention includes a pipe removal step (S110), a vertical transfer unit installation step (S120), a cutting platform installation step (S130), and a calandria removal step (S150). Additionally, the present invention further includes an air purification unit installation step (S140) and an equipment dismantling step (S160).

[0060] The pipe removal step (S110) is a step of cutting and removing the pipe portion (3) of the calandria (1) installed through the pipe hole (13) of the calandria bolt (10).

[0061] Specifically, the calandria (1) may largely comprise a container part (2) and a pipe part (3) connected to the container part (2) and penetrating the inside and outside of the calandria bolt (10). The pipe removal step (S110) is a step of cutting and removing the pipe part (3) of the calandria (1), and the pipe part (3) can be cut using cutting equipment and then removed.

[0062] The vertical transfer unit installation step (S120) is a step of installing the vertical transfer unit (110) by passing through the pipe hole (13) from which the pipe section (3) has been removed.

[0063] Specifically, the vertical transfer unit (110) can be extended in a vertical direction and can be installed vertically by passing through the pipe hole (13). The vertical transfer unit (110) is a member that serves to transfer the cutting member (130) to the work position, and can be installed through the pipe hole (13) formed in the calandria bolt (10), rather than being installed in the calandria bolt (10) through a separate installation structure as in the past.

[0064] As a result, work such as cutting the Calandria bolt (10) and installing the installation structure is omitted, and the work time is shortened and the cost can be reduced.

[0065] The cutting platform installation step (S130) is a step of inserting the cutting platform (120) through the deck installation hole (14) formed at the upper end of the Calandria bolt (10) and connecting it to the vertical transfer unit (110).

[0066] Specifically, the cutting platform (120) is a member for attaching the cutting member (130) and the gripper member, and is inserted into the interior of the Calandria bolt (10) in a vertical direction through the deck installation hole (14). It can then be coupled to the lower end of the vertical transfer unit (110) and can subsequently move as a single unit with the vertical transfer unit (110).

[0067] The calandria removal step (S150) is a step of cutting and removing calandria (1) using a cutting member (130) installed at the bottom of the cutting platform (120).

[0068] Specifically, the calandria removal step (S150) is a step of cutting the calandria (1) and transporting it outside. The calandria (1) can be cut using a cutting member (130) and a gripper member installed at the bottom of the cutting platform (120), and the cut calandria (1) can be transported outside using a basket member, etc.

[0070] In this way, by using the method for dismantling a heavy water reactor facility according to an embodiment of the present invention, the cutting platform (120), cutting member (130), and vertical transfer unit (110), which are equipment for cutting the calandria (1), are inserted into the interior through the piping hole (13) and deck installation hole (14) formed in the existing calandria bolt (10), so the process of cutting the upper part of the calandria bolt (10) to secure a cutting work space can be omitted.

[0071] Accordingly, according to an embodiment of the present invention, equipment and structures for cutting the upper part of the Calandria bolt (10) are unnecessary, and the working time can be shortened.

[0072] In addition, according to an embodiment of the present invention, work is performed by utilizing the existing space of the Calandria Vault (10), so the amount of radioactive material and dust, and secondary waste generated after work can be minimized.

[0073] In addition, according to an embodiment of the present invention, since the vertical transfer unit (110) is installed through the pipe hole (13) formed in the Calandria bolt (10) and the transfer operation is performed, the shaking of the vertical transfer unit (110) can be minimized and the operation can be performed stably.

[0074] The pipe removal step (S110) is a step of cutting and pulling out the pipe section (3) as shown in FIGS. 3 and FIGS. 4 while the pipe section (3) is installed as shown in FIGS. 1 and FIGS. 2.

[0075] Specifically, the pipe removal step (S110) may include an external cutting step, an equipment insertion step, an internal cutting step, and a pipe extraction step.

[0076] The external cutting step is a step of cutting the portion of the piping section (3) that is exposed to the outside of the calandria bolt (10) from the outside of the calandria bolt (10). The portion of the piping section (3) exposed to the outside of the calandria bolt (10) can be cut from the outside using a pipe cutting device.

[0077] The equipment insertion step is the step of inserting a pipe cutting device into the pipe section (3). The pipe cutting device can be inserted vertically into the cut pipe section (3). At this time, the pipe cutting device can be inserted up to a position where additional cutting of the pipe section (3) is required.

[0078] The internal cutting step is a step of cutting the part installed inside the Calandria bolt (10) of the pipe section (3) using a pipe cutting device. At this time, the pipe section (3) can be cut while the pipe cutting device is inserted inside the pipe section (3).

[0079] The pipe extraction step is a step of extracting the pipe section (3) that was cut in the internal cutting step to the outside. After the cutting of the pipe section (3) is completed, the pipe cutting device and the cut pipe section (3) can be extracted to the outside.

[0080] By this, the pipe section (3) that was installed in the pipe hole (13) of the Calandria bolt (10) is removed.

[0081] Meanwhile, the cutting platform installation step (S130) may include the step of inserting the cutting platform (120) into the interior of the deck installation hole (14), the step of combining the cutting platform (120) and the vertical transfer unit (110) inside the Calandria bolt (10), and the step of installing a shielding structure (150) on the upper part of the cutting platform (120) to shield the deck installation hole (14).

[0082] Specifically, the cutting platform (120) can be inserted into the interior of the calandria bolt (10) in a vertical direction through the deck installation hole (14) and can be combined with the lower part of the vertical transfer unit (110). In addition, a shielding structure (150) can be installed in the deck installation hole (14) to shield the calandria bolt (10) from the upper part of the cutting platform (120).

[0083] Meanwhile, the pipe holes (13) may be formed in multiple numbers in the Calandria bolt (10). And the vertical transfer units (110) may be provided in multiple numbers, and each of the multiple vertical transfer units (110) may be installed in each of the multiple pipe holes (13).

[0084] In this way, by providing a plurality of vertical transfer units (110), the cutting platform (120) and the cutting member (130) can be stably supported and can be moved without shaking during vertical movement.

[0085] In the Calandria removal step (S150), each of the plurality of vertical moving parts can be driven individually. By being configured so that the vertical moving parts can be driven individually, the cutting platform (120), the cutting member (130) attached thereto, and the gripper member can be accurately moved to the cutting position.

[0086] The calandria removal step (S150) may include an equipment moving step, a container cutting step, a basket insertion step, a container loading step, and a container removal step.

[0087] The equipment movement step is a step of moving the vertical transfer unit (110) and the cutting platform (120) to a preset position. Specifically, the vertical transfer unit (110) can be moved so that the cutting platform (120) moves to a preset height. At this time, since the vertical movement is guided while a plurality of vertical transfer units (110) are inserted into the pipe hole (13), they can move stably.

[0088] The container cutting step is a step of cutting the Calandria (1) using a cutting member (130).

[0089] The basket insertion step is a step of inserting a basket member into the interior of the calandria bolt (10) from the top of the calandria bolt (10) when the container cutting step is completed.

[0090] Specifically, a basket member can be inserted through the deck installation hole (14) on the outer upper part of the Calandria bolt (10). At this time, part or all of the shielding structure (150) can be removed.

[0091] The container loading step is the step of loading the cut Calandria (1) into the basket member. The container removal step is the step of removing the basket member to the outside of the Calandria bolt (10).

[0092] Meanwhile, an embodiment of the present invention may further include an air purification device installation step (S140) in which an air purification unit is installed through an intake hole penetrating the inside and outside of the calandria bolt (10) before the calandria removal step (S150).

[0093] And during the calandria removal step (S150), the air purification unit may be further operated to operate an air purification device to suck in gas and dust inside the calandria (1).

[0094] In this way, by operating the air purification unit during the calandria removal step (S150), contaminated gas and dust generated during the cutting operation can be sucked in by the air purification unit.

[0095] Additionally, an embodiment of the present invention may further include an equipment removal step (S160).

[0096] The equipment removal step (S160) is a step of removing the cutting platform (120) from the Calandria (1) and dismantling the vertical transport unit (110) after the Calandria removal step (S150). The equipment removal step (S160) may include a step of removing the shielding structure before removing the cutting platform (120).

[0097] Once the equipment removal step (S160) is completed, the dismantling of the heavy water facility, Calandria (1), can be completed.

[0098] By using the dismantling device and method for dismantling a heavy water reactor facility according to the embodiment of the present invention, the process of cutting the upper part of the Calandria bolt to secure a cutting workspace is omitted, thereby eliminating the need for equipment and structures to cut the upper part of the Calandria bolt and shortening the work time.

[0099] According to an embodiment of the present invention, since work is performed by utilizing the existing space of the Calandria bolt, the amount of radioactive material, dust, and secondary waste generated after work can be minimized. In addition, according to an embodiment of the present invention, since the transfer work is performed with a vertical transfer unit installed by penetrating the pipe hole formed in the Calandria bolt, shaking of the vertical transfer unit can be minimized and work can be performed stably.

[0100] Although specific embodiments of the present invention have been described above, the spirit and scope of the present invention are not limited to these specific embodiments, and various modifications and variations are possible by those skilled in the art without altering the gist of the invention as described in the claims. Explanation of the symbols

[0101] 1: Calandria 2: Courage Department 3: Piping section 10: Calandria Vault 11: Bolt body 12: Accommodation space 13: Piping hole 14: Deck Installation Hole 100: Decommissioning device for heavy water reactor facilities 110: Vertical transfer unit 120: Cutting Platform 130: Cutting member 150: Shielding structure

Claims

Claim 1 A dismantling device for a heavy water reactor facility comprising: a calandria having a container portion and a piping portion connected to the container portion; a calandria bolt housing the calandria inside; a piping hole formed in the calandria bolt to install the piping portion of the calandria; a deck installation hole formed in the upper portion of the calandria bolt; a vertical transfer portion installed vertically inside the calandria bolt and movably provided through the piping hole; a cutting platform inserted downward from the upper portion of the calandria bolt through the deck installation hole and coupled to the vertical transfer portion inside the calandria bolt to move together with the vertical transfer portion; a cutting member coupled to the cutting platform and provided to cut the calandria inside the calandria bolt; and a shielding structure installed to shield the deck installation hole and formed in multiple stages. Claim 2 delete Claim 3 delete Claim 4 A dismantling device for a heavy water reactor facility according to claim 1, further comprising a basket member for loading and transporting the Calandria cut by the cutting member. Claim 5 delete Claim 6 A method for dismantling a heavy water reactor facility using a dismantling device of claim 1 or 4, comprising: a pipe removal step of cutting and removing the piping portion of the calandria installed through the piping hole of the calandria bolt; a vertical transfer unit installation step of installing a vertical transfer unit through the piping hole from which the piping portion has been removed; a cutting platform installation step of inserting a cutting platform through a deck installation hole formed at the upper end of the calandria bolt and connecting it to the vertical transfer unit; and a calandria removal step of cutting and removing the calandria using a cutting member installed at the lower end of the cutting platform. Claim 7 In claim 6, the pipe removal step comprises: an external cutting step of cutting the portion of the pipe section exposed to the outside of the Calandria bolt from the outside of the Calandria bolt; an equipment insertion step of inserting a pipe cutting device into the pipe section; an internal cutting step of cutting the portion of the pipe section installed inside the Calandria bolt using the pipe cutting device; and a pipe extraction step of extracting the portion of the pipe section cut in the internal cutting step to the outside. Claim 8 In claim 6, the cutting platform installation step comprises: inserting the cutting platform into the interior of the deck installation hole; combining the cutting platform and the vertical transfer unit inside the Calandria bolt; and installing a shielding structure on the upper part of the cutting platform to shield the deck installation hole, thereby dismantling a heavy water reactor facility. Claim 9 A method for dismantling a heavy water reactor facility according to claim 6, wherein the pipe holes are formed in plurality in the Calandria bolts, and the vertical transfer units are provided in plurality, each of the plurality of vertical transfer units is installed in each of the plurality of pipe holes, and in the Calandria removal step, each of the plurality of vertical transfer units is driven individually. Claim 10 In claim 6, the calandria removal step comprises: an equipment movement step for moving the vertical transfer unit and the cutting platform to a preset position; a container cutting step for cutting the calandria using the cutting member; a basket insertion step for inserting a basket member into the interior of the calandria bolt from the upper part of the calandria bolt when the container cutting step is completed; a container loading step for loading the cut calandria onto the basket member; and a container removal step for removing the basket member to the outside of the calandria bolt. Claim 11 delete Claim 12 A method for dismantling a heavy water reactor facility according to claim 6, further comprising, after the above-mentioned calandria removal step, an equipment removal step of moving the cutting platform outside the calandria and dismantling the above-mentioned vertical transfer unit.

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