Methods for dismantling nuclear reactor equipment

Abstract

This invention provides a method for dismantling nuclear reactor equipment that improves the efficiency of sorting and managing metal powder generated during dismantling and tools used in dismantling, while also preventing sorting errors. [Solution] The method for dismantling a nuclear reactor facility includes the steps of: preparing a plurality of types of containers separated according to the radiation level of the contents; cutting an object to be cut located inside the containment vessel to generate cutting pieces; placing the cutting pieces into containers selected from the plurality of types of containers according to the radiation level of each cutting piece; and placing at least one of the metal powder generated when the cutting pieces were produced and the tools used to produce the cutting pieces into a container capable of accommodating the cutting piece with the highest radiation level.

Description

Technical Field

[0001] The present disclosure relates to a method for disassembling reactor facilities.

Background Art

[0002] Patent Document 1 describes a method for disassembling nuclear power plant facilities by cutting. In this disassembling method, by cutting and disassembling from the upper surface of the reactor, the recovery operation of the cut pieces is facilitated, and the entire disassembling operation can be remotely controlled.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, reactor facilities have a large number of members with different levels of radiation dose (dose). When disassembling and disposing of such reactor facilities, it is necessary to dispose of them at an appropriate management level according to the dose level. Here, when cutting and disassembling reactor facilities, a large amount of metal powder (for example, cutting powder) and tools used for disassembling are also generated as waste. It is not easy to set the classification in disposal for metal powder and tools used for disassembling in the same way as for members. Therefore, it is required to improve the workability regarding the sorting management of the disposal classification of metal powder and to prevent sorting failures.

[0005] The present disclosure has been made to solve the above problems, and an object thereof is to provide a method for disassembling reactor facilities that can improve the workability regarding the sorting management of metal powder generated by disassembling and tools used for disassembling, and can prevent sorting failures.

Means for Solving the Problems

[0006] To solve the above problems, the method for dismantling a nuclear reactor facility according to this disclosure includes the steps of: preparing a plurality of types of containers separated according to the radiation level of the contents; cutting an object to be cut provided in a containment vessel to generate cut pieces; placing the cut pieces in a container selected from the plurality of types of containers according to the radiation level of each cut piece; and placing at least one of the metal powder generated when the cut pieces were produced and the tools used to produce the cut pieces into the container capable of accommodating the cut piece with the highest radiation level. Furthermore, at least one of the multiple containers contains the cutting piece with the highest radiation level and the metal powder with different radiation levels generated when the cutting pieces with different radiation levels were produced. [Effects of the Invention]

[0007] According to the reactor equipment dismantling method of this disclosure, it is possible to improve the work efficiency related to the sorting and management of metal powder generated by dismantling and tools used for dismantling, and to prevent sorting defects. [Brief explanation of the drawing]

[0008] [Figure 1] This is a schematic diagram showing the general outline of the reactor equipment according to this embodiment. [Figure 2] This is a longitudinal cross-sectional view showing a pressurized water reactor according to the embodiment. [Figure 3] This is a flowchart illustrating a method for dismantling a nuclear reactor facility according to an embodiment. [Figure 4] This is a conceptual diagram showing an outline of the disposal procedure for the reactor equipment according to the embodiment. [Modes for carrying out the invention]

[0009] The following describes an embodiment for implementing the method for dismantling reactor equipment 1 according to this disclosure, with reference to the drawings. However, this disclosure is not limited to this embodiment.

[0010] <Embodiment> (Nuclear reactor equipment) Figure 1 shows a schematic diagram of the reactor equipment 1 to be dismantled according to this embodiment. The reactor equipment 1 comprises a reactor containment vessel 15, a reactor 10, a pressurizer 11, a steam generator 12, and a primary coolant loop 13. The reactor 10, pressurizer 11, steam generator 12, and primary coolant loop 13 are located inside the reactor containment vessel 15.

[0011] The reactor 10 in this embodiment is a pressurized water reactor (PWR) that sends high-temperature, high-pressure water that does not boil to a steam generator 12. The configuration of the reactor 10 will be described later. The primary coolant loop 13 forms a flow path for circulating primary coolant between the reactor 10 and the steam generator 12. The primary coolant loop 13 has a primary coolant pump 14 for circulating the primary coolant. The pressurizer 11 pressurizes the inside of the primary coolant loop 13 so that the primary coolant does not boil. The steam generator 12 heats the secondary coolant by exchanging heat between the secondary coolant flowing through a turbine system (not shown) and the primary coolant circulating through the primary coolant loop 13, thereby generating steam. In the turbine system, the thermal energy of the steam supplied from the steam generator 12 is converted into rotational energy.

[0012] (nuclear reactor) Figure 2 is a longitudinal cross-sectional view showing a pressurized water reactor, which is a reactor 10 according to this embodiment. In this embodiment, the reactor 10 uses light water as a reactor coolant and neutron moderator, creating high-temperature, high-pressure water that does not boil throughout the entire core. This high-temperature, high-pressure water is sent to a steam generator 12 to generate steam through heat exchange, and this steam is sent to a turbine to generate electricity. In this embodiment, the reactor 10 comprises a reactor vessel 2, a control rod drive unit 3, an upper core structure 5, and a lower core structure 6.

[0013] The reactor vessel 2 has a reactor vessel body 21 and a reactor vessel lid 22 (upper mirror) so that internal reactor structures can be inserted inside. The top of the reactor vessel body 21 can be opened by removing the reactor vessel lid 22. The lower part of the reactor vessel body 21 has a cylindrical shape that is closed off by a hemispherical lower mirror. An inlet nozzle (inlet nozzle holder) for supplying light water (coolant) as primary cooling water (water) and an outlet nozzle (outlet nozzle holder) for discharging light water are formed at the top of the reactor vessel body 21. The reactor vessel lid 22 is attached to the top of the reactor vessel body 21.

[0014] The upper core structure 5 is located inside the reactor vessel 2. The upper core structure 5 can be removed from the reactor vessel body 21 by moving it upward in the vertical direction Dv relative to the reactor vessel body 21. The upper core structure 5 in this embodiment includes an upper core plate 51, an upper core support plate 52, and an upper core support column 53.

[0015] The upper core plate 51 and the upper core support plate 52 are formed in a horizontally expanding disc shape. Furthermore, the upper core plate 51 and the upper core support plate 52 are formed to allow the insertion of guide tubes, water level gauge support pipes, etc. The upper core plate 51 is positioned vertically below the upper core support plate 52 in a direction Dv. Multiple upper core support columns 53 are arranged to connect the upper core plate 51 and the upper core support plate 52.

[0016] The lower core structure 6 is located inside the reactor vessel 2. Many of the components of the lower core structure 6 are positioned vertically Dv below the upper core structure 5. The lower core structure 6 can be removed from the reactor vessel body 21 by moving it vertically Dv above the reactor vessel body 21. The lower core structure 6 is separable from the upper core structure 5 inside the reactor vessel body 21. The lower core structure 6 includes a core tank 61, a lower core plate 62, and a lower core support plate 63.

[0017] The core barrel 61 is formed in a cylindrical shape extending downward from the upper core support plate 52. The upper part of the core barrel 61 is connected to the upper core support plate 52. The lower core plate 62 is connected to the lower part of the core barrel 61. The core is formed by the upper core support plate 52, the core barrel 61, and the lower core plate 62. A large number of fuel assemblies are arranged inside the core. The fuel assembly is composed of a large number of fuel rods. The lower core support plate 63 is arranged at a distance below the lower core plate 62 in the vertical direction Dv. The lower core support plate 63 is located near the lower reflector and fixed to the reactor vessel main body 21. The lower core support plate 63 has a disk shape.

[0018] (Method for Dismantling Nuclear Reactor Equipment) Hereinafter, a method for dismantling the nuclear reactor equipment 1 according to an embodiment of the present disclosure will be described. FIG. 3 is a flowchart showing the method for dismantling the nuclear reactor equipment 1 according to an embodiment of the present disclosure. FIG. 4 is a conceptual diagram showing an outline of the procedure of the nuclear reactor equipment 1 according to the embodiment. Hereinafter, the case where the nuclear reactor 10 and the steam generator 12 are cut as objects to be cut will be taken as an example for explanation.

[0019] In the method for dismantling the nuclear reactor equipment 1 shown in FIG. 3, first, a step (step S1) of preparing a container 70 capable of accommodating an object (content) having a predetermined dose is carried out. In the present embodiment, in this step, a plurality of types of containers 70 are prepared. The plurality of types of containers 70 are classified according to the radiation level of the content. Specifically, the plurality of types of containers 70 are classified according to the high or low radiation level of the content.

[0020] As shown in FIG. 4, in step S1 of the present embodiment, a total of six containers 70 are prepared. The six containers 70 are storage containers corresponding to two different radiation levels. The plurality of containers 70 includes a high-dose container group 70A which is a set of containers 70 capable of storing high-dose contents, and a low-dose container group 70B which is a set of containers 70 capable of storing relatively low-dose contents. The high-dose container group 70A is a set of containers 70 that store the contents related to the disassembly of the high-dose nuclear reactor 10. The low-dose container group 70B is a set of containers 70 that store the contents related to the disassembly of the steam generator 12 which has a lower radiation dose than the nuclear reactor 10. The high-dose container group 70A and the low-dose container group 70B each have three containers 70. Here, each of the containers 70 in the high-dose container group 70A is conveniently referred to as a first high-dose container 71, a second high-dose container 72, and a third high-dose container 73. Also, each of the containers 70 in the low-dose container group 70B is conveniently referred to as a first low-dose container 75, a second low-dose container 76, and a third low-dose container 77.

[0021] As shown in FIG. 3, after preparing the plurality of containers 70, a process (step S2) of cutting the object to be cut to generate cut pieces 80 is carried out. In this process, as shown in FIG. 4, the object to be cut provided in the reactor containment vessel 15 is cut to generate cut pieces 80. As described above, in the present embodiment, an example of cutting the nuclear reactor 10 and the steam generator 12 as the objects to be cut will be described.

[0022] In this process, the cut pieces 80, metal powder 90, and tools 95 related to the disassembly of the nuclear reactor 10 and the steam generator 12 are distinguishable. That is, in this process, the disassembly of the nuclear reactor 10 and the disassembly of the steam generator 12 are carried out in a state where the cut pieces 80, metal powder 90, and tools 95 related to each are distinguishable. In other words, in this process, the cut pieces 80, metal powder 90, and tools 95 with different radiation levels are carried out in a state where they are not mixed as much as possible.

[0023] As shown in Figure 4, the cutting of each object in this process generates cutting pieces 80 and metal powder 90. In addition, tools 95 used to cut each object are generated. The cutting pieces 80, metal powder 90, and tools 95 related to the cutting of the reactor 10 are conveniently referred to as high-dose cutting pieces 80A, high-dose metal powder 90A, and high-dose tools 95A. The cutting pieces 80, metal powder 90, and tools 95 related to the cutting of the steam generator 12 are conveniently referred to as low-dose cutting pieces 80B, low-dose metal powder 90B, and low-dose tools 95B.

[0024] Here, "cuttings" refers to chunks of a predetermined size that are generated when an object to be cut is cut. In other words, "cuttings" refers to what remains after removing chips and other randomly generated fragments that occur when cutting an object.

[0025] Furthermore, "metal powder" refers to the chips and other debris generated when cutting an object. In other words, "metal powder" is a general term for anything smaller than the cut pieces. Specific examples of "metal powder" include chips, dross, slag, spatter, and other metal particles. Fragments that are randomly generated when cutting an object are also treated as "metal powder."

[0026] Furthermore, this embodiment describes an example of cutting an object using a disc saw. In other words, this embodiment includes a disc saw as the tool 95 used to generate the cut pieces 80. The disc saw comes into contact with the object being cut, which has a radiation dose. Therefore, the used disc saw (replacement blade) must be treated as an object with a radiation dose, similar to the cut pieces. The broken fragments of the disc saw generated by cutting are treated as "metal powder".

[0027] As shown in Figure 3, after cutting the object to be cut to generate cutting pieces 80, a step (step S3) is performed in which the cutting pieces 80 are placed in a container 70. In this step, as shown in Figure 4, the cutting pieces 80 generated in step S2 are placed in the container 70 prepared in step S1. In this step, the cutting pieces 80 are placed in a container 70 selected from a plurality of types of containers 70 according to the radiation level of each cutting piece 80. In other words, in this embodiment, high-dose cutting pieces 80A are placed in at least a portion of the high-dose container group 70A, and low-dose cutting pieces 80B are placed in at least a portion of the low-dose container group 70B. Specifically, in this step, high-dose cutting pieces 80A are placed in the first high-dose container 71 and the second high-dose container 72. Also in this step, low-dose cutting pieces 80B are placed in the first low-dose container 75 and the second low-dose container 76.

[0028] As shown in Figure 3, after the cut pieces 80 are placed in the container 70, a step (step S4) is performed in which the metal powder 90 and the tool 95 are placed in the container 70. In this step, at least one of the metal powder 90 and the tool 95 is placed in the container 70 capable of accommodating the cut piece 80 with the highest radiation level. In other words, at least one of the metal powder 90 and the tool 95 is placed in the container 70 corresponding to the highest radiation level among the cut pieces 80 of the object to be cut. In this step according to this embodiment, at least one of the metal powder 90 and the tool 95 is placed in the container 70 corresponding to the same radiation level as the container 70 that accommodates the corresponding cut piece 80. As a specific example, the metal powder 90 (high-dose metal powder 90A) and the tool 95 (high-dose tool 95A) related to the cutting of the reactor 10 are placed in the same container 70 (one of the high-dose container group 70A) as the cut piece 80 (high-dose cut piece 80A) generated by cutting the reactor 10.

[0029] In this embodiment, as shown in Figure 4, the metal powder 90 and the tool 95 are placed in the container 70. In this process, the high-dose metal powder 90A is placed in the first high-dose container 71, the second high-dose container 72, and the third high-dose container 73. In other words, the high-dose metal powder 90A is placed in all the containers 70 of the high-dose container group 70A. The high-dose tool 95A is placed in the second high-dose container 72 and the third high-dose container 73. When the high-dose metal powder 90A and the high-dose tool 95A are placed in the container, the first high-dose container 71 contains the high-dose cutting piece 80A and the high-dose metal powder 90A. The second high-dose container 72 contains the high-dose cutting piece 80A, the high-dose metal powder 90A, and the high-dose tool 95A. The third high-dose container 73 contains the high-dose metal powder 90A and the high-dose tool 95A. In other words, at least one of the high-dose containers 70A does not contain high-dose cuttings 80A, but rather high-dose metal powder 90A. Also, at least one of the high-dose containers 70A contains both high-dose cuttings 80A and high-dose metal powder 90A. The first high-dose container 71, the second high-dose container 72, and the third high-dose container 73 are disposed of after being treated appropriately.

[0030] Furthermore, in this process, the low-dose metal powder 90B is contained in the second low-dose container 76 and the third low-dose container 77. The low-dose tool 95B is contained in the first low-dose container 75. When the high-dose metal powder 90A and the low-dose tool 95B are contained, the first low-dose container 75 contains the low-dose cuttings 80B and the low-dose tool 95B. The second low-dose container 76 contains the low-dose cuttings 80B and the low-dose metal powder 90B. The third low-dose container 77 contains only the low-dose metal powder 90B. In other words, at least one of the multiple low-dose container groups 70B contains the low-dose metal powder 90B and not the low-dose cuttings 80B. Also, at least one of the low-dose container groups 70B contains only the low-dose metal powder 90B. Furthermore, at least one of the high-dose containers 70A contains high-dose cuttings 80A and high-dose metal powder 90A. The first low-dose container 75, the second low-dose container 76, and the third low-dose container 77 are disposed of after being treated appropriately.

[0031] (Effects and Benefits) In the dismantling method for the reactor equipment 1 according to this embodiment, first, a container 70 capable of containing an object having a predetermined dose is prepared. After preparing the container 70, the object to be cut is cut to generate cut pieces 80. After generating the cut pieces 80, the cut pieces 80 are placed in the container 70. After placing the cut pieces 80 in the container 70, at least one of the metal powder 90 and the tool 95 is placed in the container 70 capable of containing the cut piece 80 with the highest radiation level. With this dismantling method, the metal powder 90 and the tool 95 related to a certain object to be cut are placed in the container 70 corresponding to the highest radiation level among the cut pieces 80 generated from that object. In other words, the metal powder 90 and the tool 95 related to a certain object to be cut are treated as having the highest radioactivity level among the cut pieces 80 generated from that object. The metal powder 90 and the tool 95 related to a certain object to be cut have the same radioactivity level as or lower than the cut pieces 80 generated from that object, and will never have a higher radioactivity level than the corresponding cut piece 80. Therefore, this process allows the metal powder 90 and the tool 95 to be treated at an appropriate radiation level.

[0032] Furthermore, it is difficult to appropriately evaluate the radioactivity levels of the metal powder 90 and tools 95 used in cutting the object to be cut. According to the dismantling method of this embodiment, the processing of the metal powder 90 and tools 95 can be automatically determined according to the radioactivity level of the corresponding cut piece 80. This makes it easy to determine the processing category of the metal powder 90 and tools 95, improving work efficiency. Improved work efficiency also shortens working time and reduces the effects of radiation. Therefore, according to the dismantling method of the reactor equipment 1 of this embodiment, work efficiency in sorting and managing the metal powder 90 generated by dismantling and the tools 95 used in dismantling can be improved, and sorting defects can be prevented.

[0033] Furthermore, in this embodiment, at least one of the multiple containers 70 does not contain the cut pieces 80, but rather contains metal powder 90. Specific examples in this embodiment include the third high-dose container 73 and the third low-dose container 77. By providing such containers 70, the metal powder 90 can be contained and disposed of more easily. In addition, by processing the metal powder 90 during the cutting of the object to be cut, it is possible to prevent it from interfering with the work and improve the work efficiency related to cutting.

[0034] Furthermore, at least one of the multiple containers 70 in this embodiment contains the cut pieces 80 and the metal powder 90. Specific examples in the embodiment include the first high-dose container 71, the second high-dose container 72, and the second low-dose container 76. By containing the cut pieces 80 and the metal powder 90 in the same container 70, the metal powder 90 can be contained in the space created by the cut pieces 80 inside the container 70. In other words, since the cut pieces 80 have a certain size, if only the cut pieces 80 are contained in the container 70, it may not be possible to contain up to the weight limit due to space limitations, even though it is possible to contain them by weight. In such cases, the container 70 can be effectively utilized by containing the metal powder 90 in the space where the cut pieces 80 cannot be contained. In particular, containers 70 containing highly radioactive materials are expensive, so by effectively utilizing the dead space in the container 70, the total number of containers 70 required can be reduced. That is, the cost of disposing of the cut pieces 80 and the metal powder 90 can be reduced, and the overall cost of dismantling the reactor equipment 1 can be reduced.

[0035] Furthermore, since the cut pieces 80 and metal powder 90 are housed inside a single container 70, a large portion of the cut pieces 80 will be shielded by the metal powder 90. As described above, the radiation level of the metal powder 90 is lower than or equal to the radiation level of the corresponding cut pieces 80, so by housing the cut pieces 80 and metal powder 90 together, the dose from the cut pieces 80 can be reduced by the metal powder 90. This reduces the dose on the surface (outside) of the container 70. Therefore, the effects of radiation can be reduced, and workers can work more safely.

[0036] <Modified examples of embodiments> Furthermore, the following configuration may be used as a modified example of the embodiment. In the modified method for dismantling the reactor equipment 1, at least one of the multiple containers 70 contains the cutting piece 80 with the highest radiation level and metal powder 90 with different radiation levels that were generated when the cutting pieces 80 with different radiation levels were produced. In other words, in the modified method for dismantling the reactor equipment 1, the metal powder 90 generated when the cutting pieces 80 with different radiation levels were produced are both contained in the same container 70 (capable of containing the cutting piece 80 with the highest radiation level). A specific example of the modified example is a configuration in which the first high-dose container 71 of the embodiment contains low-dose metal powder 90B. In this case, the first high-dose container 71 contains the high-dose cutting piece 80A, the high-dose metal powder 90A, and the low-dose metal powder 90B.

[0037] In this modified configuration, the high-dose cuttings 80A contained in the first high-dose container 71 are shielded by a mixture of high-dose metal powder 90A and low-dose metal powder 90B. Therefore, the dose from the high-dose cuttings 80A can be further reduced. This also allows for a further reduction in the dose on the surface (outside) of the first high-dose container 71. Consequently, the effects of radiation can be further reduced, and workers can work more safely.

[0038] Furthermore, by housing the low-dose metal powder 90B in the first high-dose container 71 in this manner, even when high-dose metal powder 90A and low-dose metal powder 90B cannot be distinguished, work efficiency can be improved while preventing sorting errors. Therefore, even in environments where high-dose metal powder 90A and low-dose metal powder 90B are mixed, work efficiency can be improved while preventing sorting errors. In other words, by housing the metal powder 90 in a container 70 capable of accommodating the cutting piece 80 with the highest radiation level, work efficiency can be improved while preventing sorting errors related to the processing of the metal powder 90. In other words, according to the modified method for dismantling the reactor equipment 1, the container 70 to which the metal powder 90 will be housed can be determined more easily, thereby improving work efficiency.

[0039] In addition, in the modified method for dismantling reactor equipment 1, the high-dose metal powder 90A and low-dose metal powder 90B may be placed in the first high-dose container 71 in a state where they are separated, or the metal powder 90 in a state where the high-dose metal powder 90A and low-dose metal powder 90B are mixed may be placed in the first high-dose container 71.

[0040] (Other embodiments) Although embodiments of this disclosure have been described in detail above with reference to the drawings, the specific configuration is not limited to these embodiments and may include design changes and the like that do not depart from the gist of this disclosure.

[0041] It should be noted that the reactor 10 to be dismantled is not limited to pressurized water reactors. For example, reactor 10 may be a boiling water reactor.

[0042] Furthermore, although the reactor 10 and steam generator 12 are exemplified as the targets for dismantling in this embodiment, the targets for dismantling are not limited to these. This embodiment may be applied to components not exemplified in Figure 1 as well.

[0043] Furthermore, in the embodiment, an example was given in which the reactor 10, as high-radiation equipment, and the steam generator 12, as relatively low-radiation equipment, were dismantled. In particular, the assumed radiation levels of the reactor 10 can be subdivided. For example, the upper core structure 5 has a lower radiation level compared to the lower core structure 6, which is closer to the core. Therefore, the dismantling method according to this embodiment can be applied by dividing the structure into the upper core structure 5 and the lower core structure 6. This prevents the upper core structure 5 from being treated as an object with an unnecessarily high radiation level. In other words, the disposal cost of the upper core structure 5 can be reduced, and the overall cost of dismantling the reactor equipment 1 can be reduced.

[0044] Furthermore, the method of containing the metal powder 90 in the container 70 is not limited to the embodiment. Depending on the method of recovering the metal powder 90, the method of containing the metal powder 90 in the container 70 may be applied as appropriate. For example, the metal powder 90 may be contained in the container 70 together with a filter for recovering the metal powder 90.

[0045] Furthermore, the locations (containers 70) for housing the cutting pieces 80, metal powder 90, and tools 95 for the reactor 10 and steam generator 12, respectively, in the embodiments are examples illustrating this disclosure. The selection of locations for housing the cutting pieces 80, metal powder 90, and tools 95 may be appropriately chosen without departing from the gist of this disclosure. As a specific example, there may be a container 70 in the high-dose container group 70A that houses only high-dose metal powder 90A. In other words, the combinations selected from the cutting pieces 80, metal powder 90, and tools 95 to be housed inside the container 70 are not limited by the level of radiation. Furthermore, although not illustrated in the embodiments, a container 70 may house only tools 95.

[0046] Furthermore, in this embodiment, it is not limited to the case that at least one of the multiple containers 70 contains metal powder 90 and not cut pieces 80. In other words, it is possible that all of the prepared containers 70 contain cut pieces 80.

[0047] Furthermore, in this embodiment, any metal chips or other debris adhering to the cut piece 80 when it is placed in the container 70 are not treated as "metal powder." In other words, the placement of metal chips or other debris adhering to the cut piece 80 in the container 70 is not treated as "the cut piece 80 and metal powder 90 being placed in the container 70." The same applies to metal chips or other debris adhering to the tool 95.

[0048] Furthermore, in this embodiment, for the sake of explanation, the timing of dismantling the reactor 10 and the steam generator 12 is not defined. The timing of dismantling the reactor 10 and the steam generator 12 is not limited as long as the cut pieces 80, metal powder 90, and tools 95 related to each can be distinguished. As a specific example, if the reactor 10 and the steam generator 12 are located far enough apart that the cut pieces 80, metal powder 90, and tools 95 related to each can be distinguished, the dismantling may be carried out simultaneously. On the other hand, if the cut pieces 80, metal powder 90, and tools 95 related to the reactor 10 and the steam generator 12 become mixed when dismantled simultaneously, it is necessary to take appropriate measures, such as staggering the timing of the dismantling.

[0049] Furthermore, in the embodiment, step S1 is not limited to being performed before step S2. The container 70 only needs to be prepared at the stage of receiving the cut pieces 80, and the order of steps S1 and S2 in the embodiment may be as described. Moreover, in the embodiment, step S3 is not limited to being performed before step S4. In other words, the order in which the cut pieces 80, metal powder 90, and tool 95 are received does not matter. As a specific example, metal powder 90 may be received in a container 70 that will only receive metal powder 90, before the cut pieces 80 are received in other containers 70.

[0050] <Note> The method for dismantling the reactor equipment 1 described in the embodiment and the modified embodiment can be understood, for example, as follows.

[0051] (1) A method for dismantling a reactor facility 1 according to the first embodiment includes the steps of: preparing a plurality of types of containers 70 separated according to the radiation levels of the contents; cutting an object to be cut provided in the reactor containment vessel 15 to generate cut pieces 80; placing the cut pieces 80 in a container 70 selected from the plurality of types of containers 70 according to the radiation level of each cut piece 80; and placing at least one of the metal powder 90 and the tool 95 used for the cutting in the container 70 corresponding to the cut piece 80 of the object to be cut that has the highest radiation level.

[0052] With this configuration, the metal powder 90 and tools 95 used for cutting the object to be cut are housed in a container 70 corresponding to the highest anticipated radiation level. Therefore, the metal powder 90 and tools 95 are processed at an appropriate radiation level. In addition, the processing classification of the metal powder 90 and tools 95 can be easily determined, improving work efficiency. Thus, this method for dismantling the reactor equipment 1 improves work efficiency in sorting and managing the metal powder 90 generated by the dismantling and the tools 95 used for dismantling, and prevents sorting errors.

[0053] (2) A method for dismantling the reactor equipment 1 according to the second embodiment is the method for dismantling the reactor equipment 1 according to (1), wherein at least one of the plurality of containers 70 contains the cut pieces 80 and the metal powder 90.

[0054] With this configuration, the metal powder 90 can be contained in the space created by the cut pieces 80 inside the container 70. Therefore, the space that cannot be filled by the cut pieces 80 alone can be contained with the metal powder 90, making effective use of the container 70. Consequently, work efficiency can be improved and the cost of dismantling the reactor equipment 1 can be reduced.

[0055] (3) A method for dismantling the reactor equipment 1 according to the third embodiment is the method for dismantling the reactor equipment 1 according to (1) or (2), wherein at least one of the plurality of containers 70 contains the cutting piece 80 with the highest radiation level and the metal powder 90 with different radiation levels that were generated when the cutting pieces 80 with different radiation levels were produced.

[0056] With this configuration, the container 70 for containing the metal powder 90 can be determined more easily. Therefore, the work efficiency related to sorting and management can be improved. In addition, the metal powder 90 shields the cut pieces 80, reducing the radiation dose on the surface of the container 70.

[0057] (4) The fourth method for dismantling the reactor equipment 1 is the method for dismantling the reactor equipment 1 according to (1) to (3), wherein at least one of the plurality of containers 70 does not contain the cut pieces 80 but contains the metal powder 90.

[0058] With this configuration, the metal powder 90 can be more easily contained and disposed of. In other words, work efficiency can be improved. [Explanation of symbols]

[0059] 1 Nuclear reactor equipment 10 nuclear reactor 11 Pressurizer 12 Steam generator 13 Primary coolant loop 14. Primary coolant pump 15. Reactor containment vessel 2 Reactor vessel 21. Reactor vessel body 22 Reactor vessel lid 3. Control rod drive mechanism 5. Upper core structure 51 Upper core plate 52 Upper core support plate 53 Upper core support column 6. Lower core structure 61 Core tank 62 Lower core plate 63 Lower core support plate 70 containers 70A High-Dose Vessel Group 71. First high-dose container 72. Second high-dose container 73 Third High-Dose Container 70B Low dose container group 75. First Low-Dose Vessel 76 Second Low-Dose Vessel 77 Third Low-Dose Container 80 Cut piece 80A High-Dose Cut Piece 80B Low-dose section 90 Metal powder 90A High-dose metal powder 90B Low-dose metal powder 95 Tools 95A High-Dose Tools 95B Low-dose tools Dv Vertical direction

Claims

1. The process involves preparing multiple types of containers, each categorized according to the radiation level of the contents, A process of cutting an object to be cut located inside a storage container to generate cut pieces, A step of placing the cut pieces into a container selected from a plurality of types of containers according to the radiation level of each cut piece, A step of placing at least one of the metal powder generated when the cut piece was produced and the tool used to produce the cut piece into the container capable of containing the cut piece with the highest radiation level, Includes, At least one of the multiple containers contains the cutting piece with the highest radiation level and the metal powder with different radiation levels generated when the cutting pieces with different radiation levels were produced. Methods for dismantling nuclear reactor equipment.

2. At least one of the plurality of containers contains the cut pieces and the metal powder. The method for dismantling a nuclear reactor facility as described in claim 1.

3. At least one of the multiple containers contains the metal powder but not the cut pieces. A method for dismantling a nuclear reactor facility according to claim 1 or 2.

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