Cable recycling method and cable recycling system

Abstract

To produce a recyclable material which is easy to recycle, for recycling a waste cable in a nuclear power facility.SOLUTION: A cable recycling method for recycling a waste cable in a nuclear power facility includes: a measurement step of measuring a radiation dose of the waste cable; a cable bore classification step of classifying at least one of a power cable and a power supply cable, out of the waste cables having a radiation dose lower than a predetermined reference value, according to a size of bores; a stripped copper wire extraction step of peeling a covering material from the cables having bores of a predetermined size or larger, out of the cables classified in the classification step, to obtain a stripped copper wire; and a copper nugget generation step of crushing the cables having bores smaller than the predetermined size, out of the cables classified in the classification step, and separating crushed materials into coating materials and copper nuggets to obtain the copper nuggets. A series of the above steps is conducted on the premises of a nuclear power facility.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a cable recycling method and a cable recycling system for recycling waste cables from nuclear facilities. [Background technology]

[0002] Various waste materials are generated during the operation and dismantling of nuclear facilities. Among these waste materials, waste that is not contaminated by radioactive materials (called "non-radioactive waste (NR)")) can be taken out of the nuclear facility as industrial waste and reused or disposed of. Typical examples of non-radioactive waste include metal and concrete materials and tools. Considering the location of the waste cables installed in the clean area of ​​a nuclear facility, it is clear that they are not contaminated by radioactive materials, so there is a high possibility that they can be treated as non-radioactive waste.

[0003] In addition, for those waste materials with low radioactive concentrations and that pose little impact on human health, a clearance system has been established that allows them to be taken outside the nuclear facility as normal waste and reused or disposed of, rather than being treated as radioactive waste.

[0004] The radioactivity concentration that serves as the standard value for the aforementioned clearance system is called the clearance level, and specifically, it is defined as the radioactivity concentration that results in a radiation dose of 0.01 millisieverts (10 microsieverts) received over a one-year period.

[0005] However, in Japan, this clearance system has not yet taken root in society. Therefore, even if the waste material clears the above-mentioned standard value of the clearance system, the electric power utility voluntarily limits the destination of the waste material so that it does not circulate on the market. Therefore, the waste material generated from the nuclear facility is stored inside the nuclear facility until the destination of the waste material is decided.

[0006] The waste generated from nuclear facilities includes a large amount of cables, which are bulky and require a large amount of storage space.

[0007] Regarding cable recycling, there are the following prior patent documents 1 to 9. The scrap wire recovery method disclosed in Patent Document 1 is an improvement of the method of recovering scrap wire by separating used electric wires into metal and coating. Specifically, it discloses that used electric wires are crushed in a crusher, and then the crushed electric wire scraps are rolled in a rolling mill to separate them into copper wire and plastic coating, and finally, a wind-powered separator separates them into coating powder and copper powder.

[0008] The method of separating and recovering steel from waste electric wires disclosed in Patent Document 2 involves separating aluminum material from waste electric wires that contain aluminum material in part, and then separating and recovering copper wire material. This method includes the following first to third steps. First, in the first step, the waste electric wires are crushed and individually separated into copper wire material, aluminum material, and insulating material containing plastic. Next, in the second step, the mixture of copper wire material, aluminum material, and insulating material individually separated in the first step is passed through a first wet or dry specific gravity separator to separate the copper wire material and the aluminum material from the insulating material. Then, in the third step, the copper wire material and aluminum material separated in the second step are further passed through a second wet or dry specific gravity separator to separate the copper wire material and the aluminum material.

[0009] The method and system for recovering metals from metal electric wires disclosed in Patent Document 3 recovers the core material, which is the metal content, from metal electric wires, similarly to Patent Documents 1 and 2. The invention of Patent Document 3 is said to have the advantage that it is not necessary to introduce a dehydration / drying / wet process when separating the peeled insulation, and no chemicals are used.

[0010] The method for processing coated copper wire scraps disclosed in Patent Document 4 includes a copper nugget sorting step of processing coated copper wire scraps into nuggets to obtain copper nuggets and coating resin, and feeding the coating resin into a fluidized bed gasification and melting furnace to pyrolyze the coating resin and obtain a solid recovered material containing copper. The copper nugget sorting step includes a step (S1) of cutting coated copper wire scraps, a step (S2) of primary crushing and magnetic separation, a step (S3) of secondary crushing and magnetic separation, and a step (S4) of separating and recovering copper nuggets and resin materials from non-magnetic materials.

[0011] The method and device for treating contaminated cables disclosed in Patent Document 5 involves peeling the coating from the core wire of the cable, rolling the contaminated coating into a sheet using a heated roll, winding it up using a treated sheath winder, measuring the level of contamination using a dosimeter, and collecting it in a drum while collecting the uncontaminated core wire.

[0012] In the method of decontaminating wires and the like disclosed in Patent Document 6, the removed cables are first sorted into small and large diameter items. The small diameter items are cut into chips using a cutting machine, then frozen and hardened. They are then powdered by impact and separated into coating powder and conductor pieces. On the other hand, the large diameter items are frozen, struck with an air hammer drill or the like to crush the coating, and the conductor parts are wound up using a winding machine. The coating powder is then liquefied in a heating and melting device, solidified by cooling into a shape that is easy to store, and stored. On the other hand, the conductor pieces and the wound conductor are reused after undergoing an acid washing process and a decontamination process.

[0013] Patent Document 7 discloses a method and device for cutting a cable coating layer, which reduces the amount of sealed container used and the storage space required when cutting and separating the coating layer from a radiation-contaminated cable and sealing and storing only the separated coating layer in a sealed container.

[0014] Patent Document 8 discloses an apparatus for peeling a coating film from cables and the like, which peels off the coating layer from cables and the like that have been coated with a synthetic resin film to prevent contamination of long objects such as cables brought into radioisotope facilities such as nuclear power plants when the cables and the like are carried out of a controlled area.

[0015] Prior art document 9 discloses a method of removing a cable in which, before removing a cable that has been laid in a radiation controlled area to an uncontrolled area, the covering layer of the cable is peeled off within the radiation controlled area and only the core is removed to the uncontrolled area. [Prior art documents] [Patent documents]

[0016] [Patent Document 1] JP 1979-156187 A [Patent Document 2] JP 2001-184959 A [Patent Document 3] Patent Publication No. 2017-176995 [Patent Document 4] Patent Publication No. 2021-159794 [Patent Document 5] JP 1987-138796 A [Patent Document 6] Japanese Patent Publication No. 62-269097 [Patent Document 7] Patent Publication No. 2004-237423 [Patent Document 8] Japanese Patent Publication No. 62-189905 [Patent Document 9] Patent Publication No. 2002-048896 Summary of the Invention [Problem to be solved by the invention]

[0017] As shown in the above Patent Documents 1 to 9, there are various processing devices and methods for recycling waste cables.

[0018] However, the radiation dose of discarded cables varies depending on the location in the nuclear facility where they were installed. Also, there are various types of discarded cables, each with different diameters, structures, compositions, etc.

[0019] If such waste cables are recycled together in one processing method, for example if a waste cable with a high level of radiation is mixed in, the radiation level of the entire recycled material (referring to recycled material obtained from waste cables, such as shiny copper wire, copper nuggets, miscellaneous nuggets, etc.; the same applies below) may be higher than expected, and even cables with low levels of radiation that are reusable may not be able to be reused. In addition, if waste cables with various compositions are recycled together, the quality of the composition of the recycled material may decrease, which may result in a lower selling price for the recycled material or limited reuse destinations.

[0020] Therefore, an object of the present invention is to produce a recycled material that is easy to reuse when recycling waste cables from nuclear facilities. [Means for solving the problem]

[0021] The present invention, which has solved the above problems, is as follows.

[0022] (First aspect) A cable recycling method for recycling waste cables from a nuclear facility, comprising the steps of: A measuring step of measuring a radiation dose of the waste cable; a cable diameter classification step of classifying at least one of a power cable and a power source cable among the discarded cables having a radiation dose less than a predetermined reference value according to the size of the diameter; a shiny copper wire extracting step of removing the coating from the cables having a diameter equal to or larger than a predetermined size among the cables classified in the classification step to obtain a shiny copper wire; a copper nugget producing step of pulverizing the cables having a diameter smaller than a predetermined size among the cables classified in the classification step, and separating the pulverized material into a coating material and copper nuggets to obtain copper nuggets, A cable recycling method characterized in that each of the above steps is carried out within the premises of a nuclear facility.

[0023] (Action and effect) In this embodiment, the radiation dose of the waste cable is measured in the measuring step, and the waste cable with a high radiation dose is not transferred to the subsequent Pika copper wire extraction step or the copper nugget production step. Therefore, the Pika copper wire obtained in the Pika copper wire extraction step and the copper nugget obtained in the copper nugget production step have low radiation doses, and it is possible to prevent the occurrence of a situation in which the Pika copper wire and the copper nugget obtained have high radiation doses and cannot be reused.

[0024] Furthermore, in this embodiment, at least one of the power cable and the power cable is extracted from the waste cable. By subjecting the power cable and the power cable to the subsequent copper nugget production process, while not subjecting the control cable and the data cable to the subsequent copper nugget production process, the copper nugget obtained by the copper nugget production process contains almost no impurities such as plated nuggets. In other words, when the control cable and the data cable are made into a nugget, the nugget contains some impurities such as plated nuggets, but by not subjecting the control cable and the data cable to the copper nugget production process, the quality of the copper nugget obtained by the copper nugget production process can be maintained.

[0025] Furthermore, in this embodiment, after extracting at least one of the power cable and the power cable, the extracted cables are further sorted according to the diameter and are assigned to either the Pika copper wire extraction process or the copper nugget production process according to the diameter. If an attempt is made to extract the Pika copper wire from a cable whose diameter is less than a predetermined size, it is troublesome because of the small diameter, but by limiting the objects from which the Pika copper wire is to be extracted to cables whose diameter is equal to or larger than a predetermined size, it is possible to reduce the occurrence of such trouble.

[0026] In the future, when the significance of the clearance system becomes understood and established in society, and it becomes possible to sell discarded cables to outside parties, it will be possible to sell them at a higher price by making them into shiny copper wire or copper nuggets rather than selling miscellaneous discarded cables in their original state.

[0027] In addition, by processing the waste cables into shiny copper wires or copper nuggets in advance, they can be immediately reused as copper resources, making them easy to reuse. In other words, if the waste cables are stored as they are, when trying to reuse the copper contained in the waste cables, it is necessary to start with the work of processing the waste cables into shiny copper wires or copper nuggets, which requires a lot of time and effort, but by storing the waste cables after completing these steps in advance, there is an advantage that when trying to reuse the copper contained in the waste cables, the copper resources contained in the waste cables can be immediately used.

[0028] In addition, in this embodiment, the series of steps described above are carried out within the premises of a nuclear facility, so that the following effects can be obtained.

[0029] In other words, because the waste cables are separated into copper (pika copper wire and copper nuggets) and coating material within the nuclear facility premises, the space required for storage can be reduced compared to storing miscellaneous waste cables as is. In particular, when the waste cables are made into copper nuggets, the space required for storage can be significantly reduced.

[0030] In the future, when the significance of the clearance system is understood and established in society, and it becomes possible to sell waste cables to outside parties, it is expected that the following procedure will be followed. That is, first, the operator of the nuclear facility will store the waste cables on the premises of the facility, and sell them to a successful bidder through competitive bidding. The successful bidder will transport the waste cables from the premises of the nuclear facility to the outside, transport them to a temporary storage location for waste cables, and temporarily store them in the temporary storage location. The successful bidder will then sell the waste cables to a recycler, who will transport them to the storage location of the recycler. The recycler will then extract the shiny copper wire and nugget copper from the waste cables, and sell them to other businesses. If the above procedure is followed in the process of reusing waste cables, there is a problem that the waste cables will be transported many times, resulting in a large amount of CO2 emissions associated with the transportation.

[0031] According to this aspect, the operator of the nuclear facility can extract the Pika copper wire and the nugget copper from the waste cable on the premises of the facility and sell the Pika copper wire and the nugget copper to the business that needs them. As a result, the aforementioned successful bidder and the recycler do not get involved, and the number of transportation times can be reduced, so that the amount of CO2 emissions associated with transportation can be reduced, which can contribute to the SDGs and carbon neutrality.

[0032] (Second aspect) A cable recycling method for recycling waste cables from a nuclear facility, comprising the steps of: A measuring step of measuring a radiation dose of the waste cable; and a miscellaneous nugget producing step of pulverizing at least one of a control cable and a data cable among the waste cables having a radiation dose less than a predetermined reference value, and separating the pulverized material into a coating material and a miscellaneous nugget to obtain the miscellaneous nugget, A cable recycling method characterized in that each of the above steps is carried out within the premises of a nuclear facility.

[0033] (Action and effect) In this embodiment, the radiation dose of the waste cable is measured in the measurement step, and waste cables with high radiation doses are not transferred to the subsequent miscellaneous nugget production step. Therefore, the miscellaneous nuggets obtained in the miscellaneous nugget production step have a low radiation dose, and it is possible to prevent the occurrence of a situation in which the miscellaneous nuggets obtained have a high radiation dose and cannot be reused.

[0034] Furthermore, in this embodiment, at least one of the control cable and the data cable is extracted from the waste cable. Generally, the selling price of the miscellaneous nuggets obtained from the control cable or the data cable tends to be lower than the price of the copper nuggets and the copper nuggets, but there is an advantage in that the control cable or the data cable can be sold at a higher price by making the miscellaneous nuggets than by selling them as they are.

[0035] In addition, by processing the waste cables into miscellaneous nuggets in advance, they can be immediately reused as resources, which is an advantage in that they can be easily reused.

[0036] In this embodiment, the above steps are carried out within the premises of a nuclear facility. Therefore, the same effects as those described in the section on effects of the first embodiment can be obtained. This point is omitted here to avoid duplication.

[0037] (Third aspect) After the measuring step, A temporary shiny copper wire extraction process for obtaining a temporary shiny copper wire by stripping a coating material from at least one of a power cable and a power cable among the waste cables having a radiation dose equal to or higher than a predetermined reference value; A temporary copper wire measuring step of measuring the radiation dose of the temporary copper wire, As a result of the provisional shiny copper wire remeasurement process, when the radiation dose of the provisional shiny copper wire is less than a predetermined reference value, the provisional shiny copper wire is judged to be able to be distributed as a shiny copper wire, The cable recycling method according to the first or second aspect, wherein the series of steps are carried out within the premises of a nuclear facility.

[0038] (Action and effect) Even if the radiation level of a power cable or a power cable is equal to or higher than a predetermined standard, when the insulation of the cable is stripped off, the radiation level of the shiny copper wire obtained by stripping off the insulation is often below the predetermined standard value. This is because radioactive materials are generally only attached to the outer surface of the insulation, and the shiny copper wire inside is not contaminated.

[0039] However, if the cable is installed in an environment where it is exposed to a large amount of radiation from the outside, the shiny copper wire inside the insulation may become radioactive and the shiny copper wire itself may begin to emit radiation. Of course, it is difficult to reuse such shiny copper wire.

[0040] Therefore, in this embodiment, even if the radiation level of the power cable or the power supply cable is equal to or higher than a predetermined standard value, the cable is not immediately classified as radioactive waste, but is instead reused as much as possible.

[0041] That is, first, the coating is stripped from the power cables or power cables whose radiation dose is equal to or exceeds a predetermined standard value. Here, the Pika copper wire obtained by stripping the coating is called a provisional Pika copper wire because it is not known whether it can be reused as a resource.

[0042] The radiation level of the temporary shiny copper wire is then measured again. If the radiation level of the temporary shiny copper wire is below a predetermined standard value, it can be reused and is therefore judged to be suitable for distribution as a shiny copper wire (can be sold to the outside as a shiny copper wire). On the other hand, if the radiation level of the temporary shiny copper wire is below a predetermined standard value, it is judged to be radioactive and is disposed of as radioactive waste.

[0043] As described above, by reusing as much as possible power cables and power cables with radiation levels above a predetermined standard, the amount of radioactive waste can be reduced. In addition, it becomes possible to extract shiny copper wire that can be sold to the outside from power cables and power cables with radiation levels above a predetermined standard, which allows for the effective use of limited global resources. In addition, it is possible to reduce the amount of new shiny copper wire-like resources (shiny copper wire that is not derived from recycling) produced by other businesses, which reduces the amount of carbon dioxide and other emissions that occur when producing new shiny copper wire-like resources. Furthermore, it becomes possible to sell part of the temporary shiny copper wire extracted from power cables and power cables with radiation levels above a predetermined standard as shiny copper wire, which can provide financial benefits.

[0044] (Fourth aspect) After the measuring step, a step of removing an outer covering material from at least one of a control cable and a data cable among the waste cables having a radiation dose equal to or higher than a predetermined reference value to obtain a temporary miscellaneous nugget material; a measurement step of measuring a radiation dose of the temporary miscellaneous nugget material; A temporary miscellaneous nugget material-derived miscellaneous nugget producing process includes crushing the temporary miscellaneous nugget material having a radiation dose less than a predetermined reference value as a result of the temporary miscellaneous nugget material measuring process to obtain a miscellaneous nugget, The cable recycling method according to the first or second aspect, wherein the series of steps are carried out within the premises of a nuclear facility.

[0045] (Action and effect) Even if the radiation dose of the control cable and data cable is equal to or higher than the predetermined standard value, when the coating material of the cable is stripped off, the radiation dose of the miscellaneous nugget material obtained by stripping off the coating material is often less than the predetermined standard value because the radioactive material is generally only attached to the outer surface of the coating material, and the miscellaneous nugget material inside is not contaminated.

[0046] However, if the cable is installed in an environment where it is exposed to a large amount of radiation from the outside, the miscellaneous nugget material inside the insulation may become radioactive and may itself emit radiation. Of course, it is difficult to reuse such miscellaneous nugget material.

[0047] Therefore, in this embodiment, even if the radiation dose of the control cable and the data cable is equal to or exceeds a predetermined reference value, they are not immediately classified as radioactive waste, but are reused as much as possible.

[0048] That is, first, the outer coating material is stripped from the control cables and data cables whose radiation dose is equal to or exceeds a predetermined standard value. Here, the miscellaneous nugget material obtained by stripping the coating material is called a provisional miscellaneous nugget material because it is not known whether it can be reused as a resource.

[0049] The radiation dose of this temporary miscellaneous nugget material is then measured again. If the radiation dose of the temporary miscellaneous nugget material is below a predetermined reference value, it is determined to be a miscellaneous nugget material since it can be reused. This miscellaneous nugget material is then crushed to obtain a miscellaneous nugget. On the other hand, if the radiation dose of the temporary miscellaneous nugget material is below a predetermined reference value, it is determined that the temporary miscellaneous nugget material is activated and is disposed of as radioactive waste.

[0050] As described above, the amount of radioactive waste can be reduced by reusing as much as possible the control cables and data cables whose radiation levels are equal to or higher than the predetermined standard value. In addition, it becomes possible to obtain miscellaneous nuggets that can be sold to the outside from the control cables and data cables whose radiation levels are equal to or higher than the predetermined standard value, and this makes it possible to effectively utilize the earth's limited resources. In addition, it becomes possible to reduce the amount of resources similar to miscellaneous nuggets (those not derived from recycling) produced by other businesses, and therefore it is possible to reduce the amount of carbon dioxide and other emissions that occur when the above resources are newly produced. In addition, it becomes possible to obtain and sell miscellaneous nuggets from the control cables and data cables whose radiation levels are equal to or higher than the predetermined standard value, and therefore it is possible to obtain monetary profits.

[0051] (Fifth aspect) A cable recycling system for recycling waste cables at a nuclear facility, the system being installed on the premises of the nuclear facility, comprising: The cable recycling system comprises: A coating material stripper that strips a coating material from the waste cable; A peeling machine exhaust hood provided in a working area of ​​the coating material peeling machine; an exhaust purification device provided downstream of the peeling machine exhaust hood and including a metallic exhaust purification filter for removing radioactive dust from exhaust gas containing the radioactive dust generated in a working area of ​​the coating material peeling machine; a residual dust removal device provided downstream of the exhaust purification device and configured to remove the radioactive dust remaining in the purified exhaust gas discharged from the exhaust purification device; The residual dust removal device has a residual dust removal filter having a particle collection rate of 99.97% or more for dust particles having a particle size of 0.3 μm remaining in the purified exhaust gas, The waste cable to be supplied to the coating material stripper is Power cables with radiation levels exceeding predetermined standards; Power cables with radiation levels exceeding predetermined standards; Control cables with radiation levels exceeding predetermined standards; Data cables with radiation levels exceeding a predetermined standard value; A power cable whose radiation dose is less than a predetermined standard value and whose diameter is equal to or larger than a predetermined size; and A power cable whose radiation level is less than a predetermined standard value and whose diameter is equal to or larger than a predetermined size; At least one cable selected from the group consisting of A cable recycling system comprising:

[0052] (Action and effect) According to the cable recycling system of this embodiment, a coating stripper can be used to strip the coating from a power cable or a power cable with a radiation dose equal to or higher than a predetermined reference value, to obtain a temporary shiny copper wire. Then, for example, the radiation dose of this temporary shiny copper wire is measured again, and if the radiation dose of the temporary shiny copper wire is less than the predetermined reference value, the temporary shiny copper wire can be determined to be eligible for distribution as a shiny copper wire and can be distributed in the market. As a result, the same effects as those of the third embodiment can be obtained.

[0053] According to the cable recycling system of this embodiment, the coating material can be stripped from a control cable or data cable having a radiation dose equal to or greater than a predetermined reference value using a coating material stripper to obtain a temporary miscellaneous nugget material. Then, for example, the radiation dose of this temporary miscellaneous nugget material can be measured again, and if the radiation dose of the temporary miscellaneous nugget material is less than the predetermined reference value, the temporary miscellaneous nugget material can be used to generate miscellaneous nuggets, and the generated miscellaneous nuggets can be distributed in the market. As a result, the same effects as those of the fourth embodiment can be obtained.

[0054] In addition, according to the cable recycling system of this embodiment, it is possible to obtain Pika copper wire from a power cable or a power cable whose radiation dose is less than a predetermined standard value and whose diameter is equal to or larger than a predetermined size. As a result, it is possible to obtain the same effect as the first embodiment.

[0055] Furthermore, by installing this cable recycling system on the premises of a nuclear facility, it is possible to obtain effects similar to those described in the action and effects column of the first embodiment (effects obtained by carrying out each series of steps on the premises of a nuclear facility).

[0056] In addition, if radioactive materials are attached to the outer surfaces of the power cables, power cables, control cables, and data cables to be processed in the cable recycling system of this embodiment, there is a risk that the attached radioactive materials will spread when the coating material is stripped off by the coating material stripper, causing a deterioration in the working environment. Therefore, by providing a coating material stripper exhaust hood as in this embodiment, it is possible to prevent the spread of radioactive materials, prevent the working environment from becoming worse, and ensure the safety of the operator of the coating material stripper, etc.

[0057] The cable recycling system of the fifth aspect can be suitably used in the cable recycling methods of the first, third and fourth aspects.

[0058] (Sixth aspect) A cable recycling system for recycling waste cables at a nuclear facility, the system being installed on the premises of the nuclear facility, comprising: The cable recycling system comprises: A miniaturization device for miniaturizing the waste cable; a wet specific gravity separator that separates the small objects reduced in size by the miniaturization device into coating materials and nuggets using a liquid; A dehydrator for dehydrating the separated nuggets; a dryer for drying the dehydrated nuggets; an exhaust purification device including a metallic exhaust purification filter for removing the radioactive dust from exhaust gas containing the radioactive dust exhausted from at least one selected from the group consisting of the miniaturization device, the wet specific gravity separator, the dehydrator, and the dryer; a residual dust removal device provided downstream of the exhaust purification device and configured to remove the radioactive dust remaining in the purified exhaust gas discharged from the exhaust purification device; The residual dust removal device has a residual dust removal filter having a particle collection rate of 99.97% or more for dust particles having a particle size of 0.3 μm remaining in the purified exhaust gas, The waste cable to be supplied to the miniaturization device is A power cable having a radiation dose less than a predetermined standard value and a diameter less than a predetermined size; A power cable having a radiation amount less than a predetermined standard value and a diameter less than a predetermined size; A control cable having a radiation dose below a predetermined reference value; and A data cable whose radiation level is below a predetermined standard value; At least one cable selected from the group consisting of A cable recycling system comprising:

[0059] (Action and effect) According to the cable recycling system of this embodiment, a nugget can be produced from at least one cable selected from the group of power cables or power cables whose radiation dose is less than a predetermined standard value and whose diameter is less than a predetermined size, and control cables or data cables whose radiation dose is less than a predetermined standard value.

[0060] By installing this cable recycling system on the premises of a nuclear facility, it is possible to obtain effects similar to those described in the action and effect column of the first embodiment (effects obtained by carrying out each series of processes on the premises of a nuclear facility).

[0061] In addition, if radioactive materials are attached to the outer surface of each of the cables (power cable, power cable, control cable, data cable) to be treated in the cable recycling system of this embodiment, there is a risk that the attached radioactive materials will spread and deteriorate the working environment due to the operations of the downsizing device, wet specific gravity separator, dehydrator, and dryer. Therefore, by purifying the exhaust gas of at least one selected from the group consisting of the downsizing device, wet specific gravity separator, dehydrator, and dryer as in this embodiment, it is possible to prevent the spread of radioactive materials, prevent deterioration of the working environment, and ensure the safety of the operators of each machine.

[0062] From the viewpoint of preventing the spread of radioactive materials, it is preferable to purify the exhaust from as many of the miniaturization equipment, wet specific gravity separator, dehydrator, and dryer as possible, and it is most preferable to purify the exhaust from all of these machines. Considering the structure of each machine, it is preferable to focus on purifying the exhaust from the miniaturization equipment, dehydrator, and dryer, since there is a high possibility of radioactive materials leaking from these machines.

[0063] The type of miniaturization device is not particularly limited, but for example, a miniaturization device having a crusher that is supplied with waste cables and crushes the supplied waste cables, a crusher that crushes the crushed material crushed by the crusher, and a moving path for the crushed material connecting the crusher and the crusher can be exemplified. Other examples include a miniaturization device that does not have the moving path and has only the crusher and the crusher. As described above, the miniaturization device may be one that can reduce the waste cables to the size of a nugget, and the structure of the machine is not particularly limited.

[0064] The cable recycling system of the sixth aspect can be suitably used in the cable recycling methods of the first, second and fourth aspects.

[0065] (Seventh aspect) A cable recycling system for recycling waste cables at a nuclear facility, the system being installed on the premises of the nuclear facility, comprising: The cable recycling system comprises: A miniaturization device for miniaturizing the waste cable; a dry specific gravity separator for separating the small objects reduced in size by the reduction device into coating materials and nuggets; an exhaust purification device including a metallic exhaust purification filter for removing radioactive dust from exhaust gas containing the radioactive dust exhausted from at least one of the miniaturization device and the dry specific gravity separator; a residual dust removal device provided downstream of the exhaust purification device and configured to remove the radioactive dust remaining in the purified exhaust gas discharged from the exhaust purification device; The residual dust removal device has a residual dust removal filter having a particle collection rate of 99.97% or more for dust particles having a particle size of 0.3 μm remaining in the purified exhaust gas, The waste cable to be supplied to the miniaturization device is A power cable having a radiation dose less than a predetermined standard value and a diameter less than a predetermined size; A power cable having a radiation amount less than a predetermined standard value and a diameter less than a predetermined size; A control cable having a radiation dose below a predetermined reference value; and A data cable whose radiation level is below a predetermined standard value; At least one cable selected from the group consisting of A cable recycling system comprising:

[0066] (Action and effect) In this embodiment, a dry specific gravity sorter is used. When a dry specific gravity sorter is used as the sorter instead of a wet specific gravity sorter, radioactive materials are likely to leak, so it is preferable to purify the exhaust from the dry specific gravity sorter as well. Therefore, by adopting a configuration like this embodiment, it is possible to obtain the same effects as the sixth embodiment.

[0067] The cable recycling system of the seventh aspect can also be suitably used in the cable recycling methods of the first, second and fourth aspects.

[0068] (Eighth aspect) A cable recycling system for recycling waste cables at a nuclear facility, the system being installed on the premises of the nuclear facility, comprising: The cable recycling system comprises: A crusher to which the waste cable is supplied and which crushes the supplied waste cable; A crusher for crushing the crushed material crushed by the crusher; A path for moving the crushed material between the crushers; a wet specific gravity separator that separates the pulverized material pulverized by the pulverizer into a coating material and nuggets using a liquid; A dehydrator for dehydrating the separated nuggets; a dryer for drying the dehydrated nuggets; an exhaust purification device including a metallic exhaust purification filter for removing the radioactive dust from exhaust containing the radioactive dust exhausted from at least one selected from the group consisting of the crusher, the pulverizer, and the wet specific gravity separator; a residual dust removal device provided downstream of the exhaust purification device and configured to remove the radioactive dust remaining in the purified exhaust gas discharged from the exhaust purification device; The residual dust removal device has a residual dust removal filter having a particle collection rate of 99.97% or more for dust particles having a particle size of 0.3 μm remaining in the purified exhaust gas, The waste cable to be supplied to the crusher is A power cable having a radiation dose less than a predetermined standard value and a diameter less than a predetermined size; A power cable having a radiation amount less than a predetermined standard value and a diameter less than a predetermined size; A control cable having a radiation dose below a predetermined reference value; and A data cable whose radiation level is below a predetermined standard value; At least one cable selected from the group consisting of The exhaust gas containing radioactive dust exhausted from at least one selected from the group consisting of the moving path, the dehydrator, and the dryer is guided to the residual dust removal device without passing through the exhaust gas purification device, and the radioactive dust contained in the exhaust gas is removed by the residual dust removal device. A cable recycling system comprising:

[0069] (Action and effect) For example, if the moving path is a type that moves crushed materials while leaving them stationary, such as a belt conveyor, radioactive dust particles and dust are unlikely to be generated. Therefore, even if the exhaust gas generated from the moving path is supplied to the residual dust removal device without passing through the exhaust gas purification device, the residual dust removal filter is unlikely to become clogged. Furthermore, by supplying the exhaust gas generated from the moving path to the residual dust removal device without passing through the exhaust gas purification device and purifying it in the residual dust removal device, there is an advantage in that the capacity of the exhaust gas purification device can be reduced.

[0070] In addition, since the dehydrator and the dryer are devices located at the rear of the cable recycling system, even if radioactive dust is attached to the outside of the waste cable supplied to the crusher or dust is mixed into the waste cable, it is highly likely that the radioactive dust and dust are removed before reaching the dehydrator and the dryer. Therefore, the amount of radioactive dust and dust contained in the exhaust from the dehydrator and the dryer generally tends to be extremely small. Therefore, even if the exhaust generated from the dehydrator and the dryer is supplied to the residual dust removal device without passing through the exhaust purification device, the residual dust removal filter is unlikely to become clogged. Furthermore, there is an advantage in that the capacity of the exhaust purification device can be reduced by supplying the exhaust generated from the dehydrator and the dryer to the residual dust removal device without passing through the exhaust purification device and purifying it in the residual dust removal device. The effect can be obtained.

[0071] The cable recycling system of the eighth aspect can also be suitably used in the cable recycling methods of the first, second and fourth aspects.

[0072] (Ninth aspect) The wet specific gravity separator includes: A liquid circulation path is connected to circulate the liquid used in the wet specific gravity separator and supply it to the wet specific gravity separator again, The liquid circulation path includes: a purification device is provided for purifying the used liquid passing through the liquid circulation path; The purification device is a contaminated liquid spraying unit that sprays contaminated liquid, which is a used liquid passing through the liquid circulation path; A freezing coil that freezes a portion of the contaminated liquid sprayed from the liquid spraying unit that does not contain radioactive dust and adheres it to an outer surface; an impure liquid outlet for discharging the remainder of the contaminated liquid sprayed from the liquid spraying unit, the remainder including radioactive dust; a dissolution promoting liquid spraying unit that sprays a dissolution promoting liquid that dissolves the frozen material formed on the outer surface of the freezing coil after the liquid spraying unit stops spraying the liquid; a non-impurity liquid outlet for discharging a liquid not containing radioactive dust dissolved by the dissolution promoting liquid sprayed from the dissolution promoting liquid spraying section; The cable recycling system of the sixth or eighth aspect, wherein the liquid not containing radioactive dust discharged from the non-impure liquid discharge port is used in the wet specific gravity separator.

[0073] (Action and effect) When using a wet specific gravity separator as a separator in a cable recycling system, a liquid (e.g., water) is required for the separator. In this embodiment, the liquid is circulated and used, so that the liquid can be effectively utilized.

[0074] As the liquid is circulated, there is a risk that the concentration of radioactive materials in the liquid will gradually increase. To address this issue, a purification device is installed in the liquid circulation path to remove radioactive materials from the circulated liquid. A method that uses a filter can be considered as a method for removing radioactive materials from the liquid. This method of using a filter generates a large amount of cake containing radioactive materials, which creates the problem of the need to secure a place to dispose of the cake (radioactive waste).

[0075] Therefore, in the cable recycling system of this embodiment, the radioactive material is concentrated using a freezing coil and the concentrated radioactive material is disposed of. This system has the advantage that the amount of radioactive waste discharged can be reduced because a large amount of cake as described above is not generated. Effect of the Invention

[0076] According to the present invention, when recycling waste cables from nuclear facilities, recycled materials that are easy to reuse can be produced. [Brief description of the drawings]

[0077] [Figure 1] FIG. 1 is a flow diagram of a cable recycling method according to a first embodiment of the present invention. [Diagram 2] FIG. 4 is a flow diagram of a cable recycling method according to a second embodiment of the present invention. [Diagram 3] FIG. 1 is a schematic diagram of a cable recycling system including a coating material stripper. [Figure 4] 1 is a schematic diagram showing a coating material before and after a stripping process using a coating material stripper. FIG. [Diagram 5] An enlarged view of the exhaust purification filter of the radioactive dust removal system, showing the state during filtration. [Figure 6] An enlarged view of the exhaust purification filter of the radioactive dust removal system, showing the state during cleaning. [Figure 7] 6 is a cross-sectional view taken along line AA in FIG. 5. [Figure 8] 8 is an enlarged view of a portion X of the exhaust purification filter in FIG. 7. [Figure 9] FIG. 1 is an image diagram showing an example of a main filter made of a plurality of metal fibers having gaps between the metal fibers. [Figure 10] FIG. 2 is a cross-sectional view showing an example of lamination of a metal fiber sheet and a metal mesh sheet. [Figure 11] FIG. 11 is a cross-sectional view showing another example of lamination of a metal fiber sheet and a metal mesh sheet. [Figure 12] 4 is a side view of the exhaust purification device, showing a state in which small spaces are formed by partition walls. FIG. [Figure 13] 13 is a cross-sectional view of FIG. 12 taken along line B-B. [Figure 14]FIG. 1 is a schematic diagram of a cable recycling system for a cable nugget plant, which uses a wet specific gravity separator. [Figure 15] FIG. 1 is a schematic diagram of a system for purifying liquid for use in a wet density separator. [Figure 16] FIG. 1 is a schematic diagram of a cable recycling system for a cable nugget plant, which uses a dry specific gravity separator. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0078] Hereinafter, a preferred embodiment of the present invention will be described. Note that the following description and drawings merely show one embodiment of the present invention, and the contents of the present invention should not be interpreted as being limited to this embodiment.

[0079] (Cable recycling method) FIG. 1 shows a flow diagram of a cable recycling method according to a first embodiment. When a nuclear facility is dismantled or when part of the nuclear facility is remodeled, waste cables 33 are generated from the cables used within the nuclear facility. In the cable recycling method, valuable resources such as Pika copper wire, copper nuggets, and miscellaneous nuggets are recovered from the waste cables 33.

[0080] The procedure of the cable recycling method is as follows: First, the radiation dose of the waste cable 33 is measured using a radiation measuring device.

[0081] (When radiation levels are below the standard value) If the radiation dose is below the standard value, the waste cable 33 can be reused without stripping off the coating material, and so the process proceeds to the cable type classification process on the left side of Fig. 1. The standard value for the radiation dose is the clearance level (radiation dose received in one year is 0.01 mSv) set by the clearance system. Of course, a value lower than the clearance level may be used as the standard value.

[0082] (Cable type classification process) In this cable type classification process, the cables are classified by type. Specifically, they are classified into power cables, power cables, control cables, and data cables. As shown in Figure 1, "power cables and power cables" have the same subsequent flow, so they may be classified together. For the same reason, "control cables and data cables" may also be classified together.

[0083] (Power cable, power cable) The power cables and power cables classified by the cable type classification process are further classified by cable diameter classification process. Specifically, among power cables and power cables, cables whose diameter (meaning "outer diameter of cable"; the same applies below) is equal to or larger than a predetermined value are transferred to a Pika copper wire extraction process. In the Pika copper wire extraction process, the coating material of the power cable or power cable is stripped to obtain a Pika copper wire. On the other hand, among power cables and power cables, cables whose diameter is less than a predetermined value are transferred to a copper nugget production process. In the copper nugget production process, the power cable or power cable is cut and then the coating material is separated from the copper nugget to obtain a copper nugget.

[0084] In the cable diameter classification step, the standard diameter for classifying cables can be determined arbitrarily. For example, when a coating stripper is used in the Pika copper wire removal step, the diameter recommended for this coating stripper may be used as the basis for the predetermined value. Specifically, when the diameter of the cable that can be processed by the coating stripper used in the Pika copper wire removal step is 10 mm to 40 mm, it is preferable to set the predetermined value in the Pika copper wire removal step to 10 mm, and to process only power cables and power cables with a diameter of 10 mm or more in the Pika copper wire removal step. In this case, if there are cables with a diameter larger than 40 mm, it is preferable to prepare a separate coating stripper that can process cables with a diameter of 40 mm or more so that the Pika copper wire can be removed from such cables as well.

[0085] In addition, the predetermined value used in the cable diameter classification process may be determined based on the constraints of the equipment of a nugget production plant used in the copper nugget production process, for example. For example, if the diameter of cables that can be crushed by a crusher in the nugget production plant is approximately 30 mm or less, the predetermined value may be set to 30 mm, and cables with a diameter larger than 30 mm may not be subject to the copper nugget production process.

[0086] (Control cables, data cables) The control cables and data cables classified by the cable type classification process are turned into miscellaneous nuggets through a miscellaneous nugget production process. Specifically, the miscellaneous nuggets are obtained by cutting the control cables and data cables and separating the coating material from the miscellaneous nuggets. In this miscellaneous nugget production process, for example, the same nugget production plant as that used in the copper nugget production process can be used.

[0087] (If radiation levels are above the standard level) If the radiation level is equal to or higher than the standard value, it is determined that the waste cable 33 cannot be reused without stripping off the coating material of the waste cable 33. Therefore, the coating material with radioactive dust adhering thereto is stripped off, and the radiation level is measured again. If the radiation level of the waste cable 33 after stripping is equal to or lower than the standard value, the cable is processed into Pika copper wire or miscellaneous nuggets. The flow of this process will be described in detail below.

[0088] The discarded cables 33 with radiation levels equal to or higher than the standard value are classified by type in a cable classification process. Specifically, they are classified into power cables, power cables, control cables, and data cables. At this time, "power cables and power cables" may be classified together, and "control cables and data cables" may be classified together.

[0089] (Power cable, power cable) Among the discarded cables 33, the power cables and power cables with radiation levels equal to or higher than the standard value are stripped of their coating in the temporary copper wire extraction process. In this process, the power cables and power cables after the coating is stripped are called temporary copper wires.

[0090] After obtaining the temporary shiny copper wire, the radiation dose of the temporary shiny copper wire is remeasured in a temporary shiny copper wire measurement process. If the radiation dose of the temporary shiny copper wire is less than a predetermined standard value as a result of measuring the radiation dose in the temporary shiny copper wire remeasurement process, the temporary shiny copper wire is determined to be able to be distributed as a shiny copper wire. The temporary shiny copper wire (shiny copper wire) determined to be able to be distributed may be temporarily stored in a storage area for shiny copper wire until it is distributed to the market. On the other hand, if the radiation dose of the temporary shiny copper wire is equal to or greater than the predetermined standard value, the temporary shiny copper wire is determined to be unable to be distributed as a shiny copper wire. The temporary shiny copper wire determined to be unable to be distributed may be temporarily stored in a storage area for radioactive waste in order to be disposed of as radioactive waste.

[0091] The reference value used in the temporary Pika copper wire measuring step is the same as the reference value used in the measuring step.

[0092] (Control cables, data cables) The control and data cables among the discarded cables 33 that have radiation levels equal to or higher than the standard value have their coating stripped from them in a temporary miscellaneous nugget material removal process. In this process, the control and data cables after their coatings have been stripped are called temporary miscellaneous nuggets.

[0093] After obtaining the temporary miscellaneous nugget material, the radiation dose of the temporary miscellaneous nugget material is remeasured in a temporary miscellaneous nugget material measurement process. When the radiation dose of the temporary miscellaneous nugget material is less than the reference value as a result of measuring the radiation dose in the temporary miscellaneous nugget material measurement process, the temporary miscellaneous nugget material can be processed into a miscellaneous nugget and distributed. The temporary miscellaneous nugget material determined as such may be temporarily stored in a miscellaneous nugget storage area until it is processed into a miscellaneous nugget in a temporary miscellaneous nugget material-derived miscellaneous nugget production process and distributed to the market. On the other hand, when the radiation dose of the temporary miscellaneous nugget material is equal to or greater than a predetermined reference value, it is determined that the temporary miscellaneous nugget material cannot be processed into a miscellaneous nugget and distributed. The temporary miscellaneous nugget material determined as such may be temporarily stored in a radioactive waste storage area to be disposed of as radioactive waste.

[0094] The reference value used in the temporary miscellaneous nugget material measuring step is set to be the same as the reference value used in the measuring step.

[0095] (Cable recycling method according to the second embodiment) FIG. 2 shows a flow diagram of a cable recycling method according to the second embodiment. 1, the present embodiment differs from the first embodiment in that a cable type classification process is provided for classifying the waste cables 33 according to the type of cable at the initial stage. The flow after the cable type classification process is similar to that of the first embodiment, and detailed description thereof will be omitted to avoid duplication.

[0096] (Cable recycling system for coating stripping machines) Next, a cable recycling system 1 relating to a coating material stripper will be described with reference to FIG.

[0097] The cable recycling system 1 related to the coating material stripper shown in Figure 3 includes a coating material stripper 30 that strips the outer coating material of a waste cable 33, a stripper exhaust hood 6 that is arranged to cover the coating material stripper 30 and its work area 2, an exhaust gas purification device 3 that is arranged downstream of the stripper exhaust hood 6 and has a metallic exhaust gas purification filter 7 that removes radioactive dust from exhaust gas containing radioactive dust generated in the work area 2 of the coating material stripper 30, and a residual dust removal device 4 that is arranged downstream of the exhaust gas purification device 3 and removes radioactive dust remaining in the purified exhaust gas discharged from the exhaust gas purification device 3.

[0098] The cable recycling system 1 shown in FIG. 3 also includes a suction fan 5 that is provided downstream of the residual dust removal device 4 to suck in air containing radioactive dust within the work area 2, and a pre-duster 31 that removes dust in the exhaust air containing radioactive dust exhausted from the work area 2, provided between the peeler exhaust hood 6 and the exhaust purification device 3. In the following description, the cable recycling system 1 relating to the coating material stripper shown in FIG. 3 will be described in detail.

[0099] (Work area 2) A coating material stripping machine 30 is placed in the work area 2, and an operator 32 inserts a waste cable 33 into an insertion port 30A of the coating material stripping machine 30. The coating material on the outside of the waste cable 33 inserted into the insertion port 30A is stripped by the coating material stripping machine 30. The cable from which the coating material has been stripped becomes the aforementioned shiny copper wire 34, temporary shiny copper wire, or temporary miscellaneous nugget material.

[0100] That is, the coating material stripping machine 30 placed in the work area 2 performs the Pika copper wire removal process, the provisional Pika copper wire removal process, and the provisional miscellaneous nugget material removal process. In detail, in the Pika copper wire removal process, a power cable or a power cable having a radiation dose less than a predetermined reference value and a cable diameter equal to or greater than a predetermined value is inserted into the coating material stripping machine 30 to obtain a Pika copper wire 34 from which the coating material has been stripped. In the provisional Pika copper wire removal process, a power cable or a power cable having a radiation dose equal to or greater than a predetermined reference value is inserted into the coating material stripping machine 30 to obtain a provisional Pika copper wire from which the coating material has been stripped. In the provisional miscellaneous nugget material removal process, a control cable or a data cable having a radiation dose equal to or greater than a predetermined reference value is inserted into the coating material stripping machine 30 to obtain a provisional miscellaneous nugget material from which the coating material has been stripped.

[0101] The structure of the discarded cable 33 differs depending on whether it is a single-core or multiple-core cable, but in the case of a single-core cable, it generally has a form as shown in Fig. 4. That is, as shown in the upper part of Fig. 4, a Pika copper wire 34 serving as a conductor is located in the center, an insulator 35 is arranged to cover the outside of the wire, and a sheath 36 is arranged to cover the outside of the insulator 35. In this case, the part covering the outside of the Pika copper wire 34, i.e., the insulator 35 and the sheath 36, are collectively called the coating material 37. The material of the insulator 35 is generally cross-linked polyethylene, and the material of the sheath 36 is generally vinyl.

[0102] A waste cable 33 is inserted into the insertion port 30A of the coating material stripper 30, and the coating material stripper 30 strips the coating material 37 from the waste cable 33, thereby separating the waste cable 33 into a Pika copper wire 34, an insulator 35, and a sheath 36.

[0103] If radioactive dust is found on the outside of the coating material 37, there is a possibility that the radioactive dust will scatter into the work area 2 where the coating material 37 is peeled off from the waste cable 33 using the coating material peeling machine 30, deteriorating the working environment of the worker 32 working in the work area 2.

[0104] Therefore, it is preferable to provide an exhaust hood 6 so as to cover the work area 2 three-dimensionally, actively suck in the air inside the exhaust hood 6 from the suction port 6A, and discharge the radioactive dust generated inside the work area 2 from the work area 2, thereby improving the work environment inside the work area 2. In addition, since the suction creates a negative pressure inside the work area 2, it is possible to prevent the radioactive dust inside the work area 2 from being released to the outside from unintended places. Note that suction from the exhaust hood 6 can be performed by, for example, a suction fan 5 provided at the rear stage.

[0105] (Preduster 31) The exhaust air AH discharged from the working area 2 is supplied to a pre-duster 31 through an exhaust vent pipe L1. The type of the pre-duster 31 is not particularly limited, but a cyclone, for example, can be used. The pre-duster 31 removes dust particles larger than the fine dust contained in the exhaust air EH, cotton-like debris, and the like.

[0106] Although the pre-duster 31 is not necessarily required, it is preferable to provide it as much as possible in order to prevent clogging of the exhaust gas purification device 3 in the subsequent stage.

[0107] (Exhaust gas purification device 3) The dust-removed exhaust air EH from which dust discharged from the pre-duster 31 has been removed is supplied to the exhaust purification device 3 through the dust-removed exhaust vent pipe L2. An exhaust purification filter 7 is housed inside the exhaust purification device 3. As shown in Figs. 5 to 8, this exhaust purification filter 7 is formed in a cylindrical shape. Although Figs. 5 to 8 show an example of the exhaust purification filter 7 having a cross-sectional shape of a perfect circle, the cross-sectional shape is not limited to this example, and any shape such as an ellipse, a rectangle, or a hexagon may be used. The configuration of the exhaust purification filter 7 is not particularly limited, but it is preferable to use a metal fiber sheet (called a metal fiber sheet, constituting the main filter 14 described later) formed by collecting a plurality of metal fibers into a sheet shape, and a metal mesh member (called a metal mesh member, constituting the shape retention means 15 described later) sandwiched on the upper and lower surfaces of the metal fiber sheet. In addition, as the metal fibers of the metal fiber sheet, stainless steel fibers, tungsten steel fibers, aluminum fibers, nickel fibers, titanium fibers, etc. can be used. Of these metal fibers, it is most preferable to use stainless steel fibers (i.e., stainless steel fibers), and the following description will be given taking as an example a stainless steel fiber sheet using stainless steel fibers as the metal fibers. That is, in the following description, the term "stainless steel fiber sheet" can be read as "metal fiber sheet."

[0108] The stainless steel fiber sheet may be one long stainless steel fiber folded many times into a sheet. A photograph of the stainless steel fiber sheet is shown in FIG. 9. The diameter (fiber diameter) of the stainless steel fiber is preferably about 2 to 5 μm, and the fiber diameter may be selected based on the particle size distribution of the generated dust and the radiation intensity of the dust. In addition, in order to increase the removal rate of radioactive dust in the dust-removed exhaust EH, the porosity of the stainless steel fiber sheet is preferably 65 to 80%. The performance of the exhaust purification filter 7 is preferably such that it has a particle collection rate of 90% or more for dust particles with a particle size of 0.3 μm or more remaining in the dust-removed exhaust EH.

[0109] As described above, by using stainless steel fiber as the material for the exhaust purification filter 7, it is possible to make it less susceptible to deterioration due to radiation emitted from radioactive dust.

[0110] In addition, since there is a risk of exposure during the replacement of the exhaust purification filter 7 to which radioactive dust has adhered, it is preferable to avoid replacing the exhaust purification filter 7 as much as possible. However, since the exhaust purification filter 7 has a main filter and the main filter includes a metal fiber sheet, the frequency of replacing the exhaust purification filter 7 can be reduced. That is, with such an exhaust purification filter 7, even if a large amount of radioactive dust or the like adheres to the exhaust purification filter 7 and the purification ability of the exhaust purification filter 7 decreases, the exhaust purification filter 7 can be regenerated by backwashing using compressed gas PA, so that it is not necessary to replace the exhaust purification filter every time a large amount of radioactive dust or the like adheres to the exhaust purification filter 7, and it is not necessary to replace the filter of the exhaust purification filter 7 for a long period of time. Therefore, it is possible to prevent exposure of workers to radiation during the replacement of the exhaust purification filter 7 and the generation of a large amount of radioactive waste (used exhaust purification filters). In addition, it is also possible to reduce the cost of stopping the purification process of the exhaust EH due to the replacement of the filter and the cost of replacing and disposing of the exhaust purification filter 7.

[0111] Moreover, the exhaust purification filter 7 is particularly excellent at capturing high-dose radioactive dust. Even if sharp fine powder or the like is contained in the dust-removed exhaust EH, the exhaust purification filter 7 is unlikely to be damaged by the fine powder or the like, and from this point of view, the frequency of replacing the exhaust purification filter 7 can be reduced. Furthermore, since the main filter of the exhaust purification filter 7 contains a metal fiber sheet, it is possible to prevent the exhaust purification filter 7 from burning and causing a fire.

[0112] The exhaust purification filter 7 may be a flat stainless steel fiber sheet simply formed into a cylindrical shape, but it is preferable to use a flat stainless steel fiber sheet folded into a bellows shape and formed into a cylindrical shape as shown in FIG. 8 in order to increase the filtration area. As shown in FIG. 8, it is most preferable that the exhaust purification filter 7 is provided with a shape retention means 15 for protecting the main filter 14 on both sides (front and back) of the main filter 14, but the shape retention means 15 may be provided on one side (front or back) of the main filter 14. By providing this shape retention means 15, it becomes easy to maintain the exhaust purification filter 7 in the above-mentioned bellows shape. That is, since the stainless steel fiber sheet constituting the main filter 14 has low shape stability, it is difficult to maintain the bellows shape without the net sheet constituting the shape retention means 15, but by providing the shape retention means 15, the shape stability of the exhaust purification filter 7 is increased and the bellows shape can be maintained. In addition, by providing the shape retention means 15, the strength of the exhaust purification filter 7 is increased, so that the exhaust purification filter 7 is more likely to withstand the pressure of compressed gas applied to the main filter 14 when cleaning the main filter 14.

[0113] Furthermore, by making the exhaust purification filter 7 bellows-shaped, the filtering area is increased, which has the advantage that the amount of exhaust purification processing per unit time can be increased without increasing the size of the container that houses the exhaust purification filter 7 (the container of the exhaust purification device).

[0114] It is preferable that the shape retention means 15 is a mesh sheet so that the dust-removed exhaust EH can reach the main filter 14. Furthermore, if the mesh gaps of the shape retention means 15 are small, the amount of exhaust filtration per unit time decreases and the shape retention means 15 is more likely to become clogged. Therefore, it is preferable that the size of the mesh gaps of the shape retention means 15 is larger than the size of the gaps of the main filter 14. Furthermore, it is preferable to use a material for the shape retention means 15 that is not easily deteriorated by radiation emitted from radioactive dust, and specifically, it is preferable to use stainless steel or the like.

[0115] 10 and 11 show an example of lamination of the main filter 14 and the shape retention means 15 constituting the exhaust purification filter 7. In addition, in FIG. 10 and FIG. 11, the front side and the upper side mean the outside (the side where the container 28 of the exhaust purification device 3 is located) when the exhaust purification filter 7 is attached to the exhaust purification device 3, and the back side and the lower side mean the inside (the side where the inner tube 8 is located) when the exhaust purification filter 7 is attached to the exhaust purification device 3. Since the main filter 14 includes a metal fiber sheet and the shape retention means 15 includes a metal mesh member, it can be said that the exhaust purification filter 7 is a laminate of a metal fiber sheet and a metal mesh member. Note that the main filter 14 may include a material other than the metal fiber sheet, and the shape retention means 15 may also include a material other than the metal mesh member. It is preferable to use a metal fiber sheet (particularly a stainless steel fiber sheet) as the main material of the main filter 14, and it is preferable to use a metal mesh member as the main material of the shape retention means 15. The main filter 14 may be composed of only a metal fiber sheet, and the shape retention means 15 may be composed of only a metal mesh member. In addition, in order to facilitate understanding, the thickness of each layer constituting the exhaust purification filter 7 is exaggerated and shown as being thick in Figures 10 and 11, but the actual thickness of each layer is not limited to these thicknesses.

[0116] In FIG. 10, a three-layer structure is formed in which the shape-retaining means 15 is laminated on the front side US (outside) of the main filter 14 and the shape-retaining means 15 is also laminated on the back side BS (inside) of the main filter 14. From the viewpoint of protecting the main filter 14 and from the viewpoint of forming the main filter 14 into a bellows shape and maintaining the bellows shape, it is most preferable to provide the shape-retaining means 15 on both sides (front side US and back side BS) of the main filter 14 as shown in FIG. 10, but a form in which the shape-retaining means 15 is provided on either one side (front side US or back side BS) of the main filter 14 may also be used. When it is not necessary to protect the main filter 14 and it is not necessary to form the main filter 14 into a bellows shape, the shape-retaining means 15 may not be provided at all. If the shape-retaining means 15 is thin, the function of protecting the main filter 14 may be reduced, and if the shape-retaining means 15 is thick, the ventilation resistance may increase and the exhaust purification processing amount per unit time may be reduced. On the other hand, if the thickness of the main filter 14 is thin, there is a risk that the radioactive dust in the dust-removed exhaust EH may not be sufficiently removed, and if the thickness of the main filter 14 is thick, there is a risk that the airflow resistance increases and the amount of exhaust purification processing per unit time decreases. Note that the thickness of the front side shape retaining means 15U and the thickness of the back side shape retaining means 15B may be the same thickness or different thicknesses.

[0117] The basic structure of the exhaust purification filter 7 shown in Fig. 11 is the same as that of Fig. 10, but differs in that the main filter 14 has a three-layer structure made up of an upper main filter 14U, a middle main filter 14M, and a lower main filter 14D. When using such a three-layer structure, the fiber diameter of the stainless steel fibers in the upper main filter 14U is preferably 6 to 10 µm, the fiber diameter of the stainless steel fibers in the middle main filter 14M is preferably 2 to 5 µm, and the fiber diameter of the stainless steel fibers in the lower main filter 14D is preferably 6 to 10 µm.

[0118] When the main filter 14 has such a layered structure, the metal fibers of the middle-layer main filter 14M, which have a small fiber diameter, can best remove radioactive dust and the like, but have the disadvantage of being weak due to their small fiber diameter. Therefore, by providing the upper-layer main filter 14U and the lower-layer main filter 14D, which are made of metal fibers with a larger fiber diameter than the metal fibers of the middle-layer main filter 14M, the weakness of the fibers of the middle-layer main filter 14M can be compensated for by the strength of the fibers of the upper-layer main filter 14U and the lower-layer main filter 14D. As a result, compared to the case where the main filter 14 is made into a single layer (the fiber diameter of the metal fibers constituting this single layer is assumed to be 2 to 5 μm, the same as the metal fibers of the middle-layer main filter 14M), the strength of the main filter 14 can be increased, the shape stability of the main filter 14 can be improved, and the main filter 14 can be more easily withstood the pressure (pressure due to compressed gas) applied to the exhaust purification filter 7 during backwashing of the exhaust purification filter 7. In particular, since the rear side of the main filter 14 is subjected to the greatest pressure of the compressed gas during backwashing, by increasing the pressure resistance of the lower main filter 14D, damage to the main filter 14 by the compressed gas PA can be prevented.

[0119] Furthermore, when the metal fiber diameter of the upper layer main filter 14U located on the outside of the main filter 14 is large, radioactive dust and the like captured in the gaps of the upper layer main filter 14U located on the outside of the main filter 14 is more easily blown out to the outside of the main filter 14 during backwashing, compared to when the metal fiber diameter of the upper layer main filter 14U located on the outside of the main filter 14 is small. Therefore, there is also the advantage that the cleaning effect during backwashing is improved.

[0120] Furthermore, by forming main filter 14 in a laminated structure, it is possible to reduce variation in performance between main filters 14 when a plurality of main filters 14 are manufactured, and it is possible to stabilize the performance of main filter 14.

[0121] 11 shows an example in which main filter 14 has a three-layer structure, but it may have a four or more layer structure. When using a four or more layer structure, it is preferable to make the fiber diameter of the stainless steel fibers smaller toward the center of main filter 14 in the thickness direction TD, from the viewpoint of protecting the metal fiber layers with small fiber diameters.

[0122] It is preferable that the porosity of the layer in the case where main filter 14 is a single layer is 65 to 80%, and the porosity of each layer in the case where main filter 14 is a multi-layer is 65 to 80%. This porosity can be calculated from the following formulas 1 and 2.

[0123] [Formula 1] P(%) = Main filter layer weight (g / m 2 ) / specific gravity of metal fibers that make up the main filter layer × T (thickness of the main filter layer (cm)) [Formula 2] Porosity (%)=100-P(%)

[0124] The specific gravity of the metal fiber in the above formula 1 is 798 when the metal fiber is stainless steel (SUS316L), for example. In addition, in the case where the main filter is made of a single layer, the "layer of the main filter" in formula 1 refers to that single layer. When the main filter is made of multiple layers and it is desired to find the porosity of each layer of the main filter, it is sufficient to use the basis weight, metal fiber, and thickness of each layer of the main filter. When the main filter is made of multiple layers and it is desired to find the porosity of the entire main filter in a stacked state, it is sufficient to use the basis weight, metal fiber, and thickness of the entire main filter.

[0125] When manufacturing the main filter 14 made up of multiple layers, it is preferable to uniformly stack the metal fibers as raw materials and sinter (compress and fix) the stack.

[0126] It is preferable to provide a cylindrical inner tube 8 inside the exhaust purification filter 7. A punched sheet having a plurality of openings of a predetermined size formed into a cylindrical shape can be used as this inner tube 8. The cross-sectional shape of this inner tube 8 is not particularly limited, and any shape such as a perfect circle as shown in Fig. 7, an ellipse, a rectangle, or a hexagon can be used.

[0127] When the exhaust purification filter 7 is shaped like a bellows as shown in FIG. 8, a peak portion 7X and a valley portion 7Y are generated. When the exhaust purification filter 7 is shaped like a bellows and then cylindrical as shown in FIG. 7 and FIG. 8, an imaginary line IL connecting the multiple valley portions 7Y of the exhaust purification filter 7 becomes a circle in cross section. It is preferable to make the shape of the inner tube 8 the same shape (circular) as this imaginary line IL, and to make the back surface of the multiple valley portions 7Y of the exhaust purification filter 7 contact the surface of the inner tube 8, and it is more preferable to make the back surface of all the valley portions 7Y of the exhaust purification filter 7 contact the surface of the inner tube 8. By making the multiple valley portions 7Y, 7Y contact the inner tube 8 in advance, it is possible to prevent the exhaust purification filter 7 from colliding with the inner tube 8 every time the dust-removed exhaust gas EH passes through the exhaust purification filter 7, and therefore the life of the exhaust purification filter 7 can be extended.

[0128] 5 and 6, the upper and lower ends of the exhaust purification filter 7 and the upper and lower ends of the inner cylinder 8 are respectively sealed, preventing exhaust gas containing radioactive dust from taking a shortcut and entering the purified exhaust passage 13 without passing through the exhaust purification filter 7. The part where the exhaust purification filter 7 and the inner cylinder 8 are sealed is called a seal part 9, and in the embodiment of Fig. 5 and Fig. 6, there is an upper seal part 9A that seals the upper end of the exhaust purification filter 7 and the upper end of the inner cylinder 8, and a lower seal part 9B that seals the lower end of the exhaust purification filter 7 and the lower end of the inner cylinder 8.

[0129] The dust-removed exhaust gas EH flows from the outside to the inside of the cylindrical exhaust gas purification filter 7. In the process in which the dust-removed exhaust gas EH passes through the exhaust gas purification filter 7 from the outside to the inside, radioactive dust particles and the like in the dust-removed exhaust gas EH are captured by the exhaust gas purification filter 7. The purified exhaust gas PEH, which has been purified by passing through the exhaust gas purification filter 7, passes through the opening of the inner cylinder 8 from the outside to the inside and reaches the purified exhaust passage 13. Thereafter, in the embodiment of FIG. 5, the purified exhaust gas PEH moves from the lower side to the upper side of the purified exhaust passage 13, passes through the hole portion of the annular ring of the upper seal portion 9A and the through-hole provided in the mounting plate 10, and reaches the upper part of the exhaust gas purification device 3. Then, it is exhausted from the exhaust gas purification device 3 and sent to the residual dust removal device 4 through the purified exhaust gas vent pipe L3.

[0130] On the other hand, in the process in which the dust-removed exhaust gas EH passes through the exhaust gas purification filter 7 from the outside to the inside, foreign matter such as radioactive dust captured by the exhaust gas purification filter 7 accumulates on the outer surface of the exhaust gas purification filter 7. If the layer of foreign matter such as radioactive dust accumulated on the outer surface becomes thick, the purification processing efficiency of the dust-removed exhaust gas EH decreases, so it is preferable to backwash the exhaust gas purification filter 7 at a specified timing.

[0131] For example, as shown in FIG. 6, compressed gas PA (e.g., compressed air) is injected into the exhaust purification filter 7 from an injection nozzle 11 provided above the exhaust purification filter 7. The compressed gas PA injected from the injection nozzle 11 moves downward, enters the inside of the exhaust purification filter 7 (the purified exhaust passage 13), and then flows in the opposite direction to that in FIG. 5. That is, after passing through the opening of the inner cylinder 8 from the inside to the outside, it passes through the exhaust purification filter 7 from the inside to the outside. As the compressed gas PA passes through the exhaust purification filter 7 in this way, a layer of foreign matter (foreign matter layer) such as radioactive dust that has accumulated on the outer surface of the exhaust purification filter 7 is peeled off, falls below the exhaust purification device 3, and accumulates there. The deposits SD accumulated below the exhaust purification device 3 are periodically discharged to the outside of the exhaust purification device 3.

[0132] It is preferable that the axial direction of the injection nozzle 11 is the same as the axial direction of the exhaust purification filter 7. By making the axial direction of the injection nozzle 11 the same as the axial direction of the exhaust purification filter 7, the gas injected from the injection nozzle 11 reaches the inside of the exhaust purification filter 7 with almost no loss of momentum, which has the advantage of improving the cleaning effect of the exhaust purification filter 7. This improves the cleaning effect (the effect of brushing off radioactive dust adhering to the outer surface of the exhaust purification filter) compared to when the axial direction of the injection nozzle 11 is perpendicular to the axial direction of the exhaust purification filter 7.

[0133] As described above, by backwashing the exhaust purification filter 7 at a prescribed timing, the pressure loss and collection efficiency can be returned to near their initial values, so that the exhaust purification filter 7 does not need to be disposed of as a disposable item, thereby making effective use of global environmental resources and reducing the costs associated with replacing and disposing of the exhaust purification filter 7.

[0134] In addition, while the dust-removed exhaust EH is being purified by the exhaust purification filter 7, backwashing can be performed without stopping the purification process. This is because backwashing is completed in a short time of a few seconds, so there is no need to bother stopping the purification process. In addition, since the lumps of foreign matter such as radioactive dust that are peeled off from the exhaust purification filter 7 during backwashing have a certain weight, even if the dust-removed exhaust EH is flowing toward the exhaust purification filter 7, the lumps of foreign matter such as radioactive dust that are peeled off from the exhaust purification filter 7 are unlikely to reattach to the exhaust purification filter 7 due to the influence of the flow of the dust-removed exhaust EH. If it is desired to reliably prevent the lumps of foreign matter such as radioactive dust that are peeled off from the exhaust purification filter 7 from reattaching to the exhaust purification filter 7, the purification process of the dust-removed exhaust EH may be temporarily stopped before backwashing, and the purification process of the dust-removed exhaust EH may be resumed after the backwashing is completed. However, when this type of treatment is performed, it takes a certain amount of time to switch between the purification process and the cleaning (backwash) process of the dust removal exhaust air EH, which has the disadvantage that the purification process amount of the dust removal exhaust air EH is slightly reduced.

[0135] 12 and 13, it is preferable to provide a plurality of exhaust purification filters 7 inside the exhaust purification device 3, and while one exhaust purification filter 7 is being backwashed, the dust-removed exhaust gas EH is filtered by the other exhaust purification filter 7. For example, in the embodiment of Fig. 12 and 13, a partition wall 29 is provided that divides the internal space 26 of the exhaust purification device 3 into a plurality of small spaces 27, and an exhaust purification filter 7 is provided in each small space.

[0136] Specifically, as shown in FIG. 12, the upper end of the partition wall 29 is fixed to the lower surface of the mounting plate 10 of the exhaust purification device 3, and the partition wall 29 extends downward from there, and the lower end of the partition wall 29 is located near the lower end of the exhaust purification filter 7. In order to prevent the compressed gas PA during backwash from directly colliding with the exhaust purification filter 7 arranged in another small space 27, it is preferable to position the lower end of the partition wall 29 near the lower end of the exhaust purification filter 7. Also, as shown in FIG. 13, this partition wall 29 is attached so as to separate the adjacent exhaust purification filters 7. In addition, as shown in FIG. 13, it is preferable that the partition wall 29 is not abutted against the inner wall of the container 28 of the exhaust purification device 3, and a predetermined gap is provided between the inner wall of the container 28 and the partition wall 29. Similarly, as shown in FIG. 12, it is preferable that the partition wall 29 is not extended further below the lower end of the exhaust purification filter 7, and a predetermined gap is provided below the partition wall 29. This is because, during the exhaust purification process, the dust-removed exhaust air EH that has entered the container 28 of the exhaust purification device 7 passes through each of the gaps and easily enters each of the small spaces 27A, 27B.

[0137] By the partition wall 29 thus attached, the internal space 26 of the exhaust purification device 3 is divided almost equally into two, forming a first small space 27A and a second type space 27B. A first exhaust purification filter 7A is provided in the first small space 27A, and a second exhaust purification filter 7B is provided in the second small space 27B.

[0138] By dividing the internal space 26 of the exhaust gas purification device 3 by the partition wall 29 in this way, it is possible to prevent the compressed gas PA injected from the injection part (nozzle 11) to the exhaust gas purification filter 7 arranged inside one small space 27 from directly colliding with the exhaust gas purification filter 7 arranged in the other adjacent small space 27. As a result, the influence of the compressed gas PA used when backwashing the exhaust gas purification filter 7 arranged in one small space 27 is less likely to reach the exhaust gas purification filter 7 arranged in the other small space 27. In other words, while backwashing the exhaust gas purification filter 7 arranged in some small spaces 27, when purifying the dust-removed exhaust gas EH using the exhaust gas purification filter 7 arranged in the other small space 27, the compressed gas PA is less likely to have an adverse effect on the exhaust gas purification filter 7 during the purification process. Therefore, even while some exhaust gas purification filters 7 are being washed, the other exhaust gas purification filters 7 can perform the exhaust gas purification process as usual, which has the advantage that the efficiency of the exhaust gas purification process in the entire exhaust gas purification device 3 is less likely to decrease.

[0139] 12 and 13 show a state in which exhaust purification processing is performed by the first exhaust purification filter 7A arranged in the first small space 27A while the second exhaust purification filter 7B arranged in the second small space 27B is backwashed. Of course, contrary to the illustrated example, exhaust purification processing may be performed by the second exhaust purification filter 7B while the first exhaust purification filter 7A is backwashed.

[0140] Further, although an example in which only one partition wall 29 is provided is shown in FIG. 11 and FIG. 12, a plurality of partition walls 29 may be provided.

[0141] It has been found that when cleaning the exhaust purification filter 7 as described above, cleaning the exhaust purification filter 7 by applying the compressed gas PA to the inside of the exhaust purification filter 7 is more effective at removing radioactive waste adhering to the exhaust purification filter 7 than cleaning the exhaust purification filter 7 by applying the compressed gas PA to the outside of the exhaust purification filter 7. Therefore, by so-called backwashing the exhaust purification filter 7 as described above, there is an advantage that the exhaust purification filter 7 does not need to be replaced for a longer period of time.

[0142] (Residual dust removal device 4) The residual dust removal device 4 has a residual dust removal filter that removes radioactive dust remaining in the purified exhaust gas PEH. The performance of this residual dust removal filter preferably has a particle collection rate of 99.97% or more for dust particles with a particle size of 0.3 μm remaining in the purified exhaust gas PEH.

[0143] Specifically, the residual dust removal filter may be, for example, a HEPA filter (an air filter with a particle collection rate of 99.97% or more for particles with a diameter of 0.3 μm at the rated air flow rate and an initial pressure loss of 245 Pa or less), or a ULPA filter (an air filter with a particle collection rate of 99.9995% or more for particles with a diameter of 0.15 μm at the rated air flow rate and an initial pressure loss of 245 Pa or less).

[0144] If a dust removal filter is used that does not have a particle collection efficiency of 99.97% or more for dust particles with a particle size of 0.3 μm in the purified exhaust PEH, there is a problem that a large amount of radioactive dust may be mixed into the treated exhaust TEH discharged from the dust removal device 4.

[0145] In addition, by using the residual dust removal filter 25 having a particle collection rate of 99.97% or more for dust particles with a particle size of 0.3 μm remaining in the purified exhaust gas, there is an advantage that almost no radioactive dust is found in the treated exhaust gas after it has passed through the residual dust removal filter 25.

[0146] Furthermore, by providing an exhaust purification filter 7 in front of the residual dust removal filter 25 and capturing most of the radioactive dust present in the dust-removed exhaust EH by this exhaust purification filter 7, it is possible to reduce the frequency of replacing the residual dust removal filter 25. As a result, it is possible to reduce the cost of replacing and disposing of the residual dust removal filter 25.

[0147] (Cable recycling system for cable nugget production plant) 14 shows an example of a cable recycling system 100 related to a cable nugget production plant 99. The cable nugget production plant 99 is a plant that produces nuggets Ng, such as copper nuggets and miscellaneous nuggets, from waste cables 33 and the like, and the cable recycling system 100 is the cable nugget production plant 99 to which mechanisms for purifying exhaust gas, such as an exhaust gas purification device 3 and a residual dust removal device 4, have been added.

[0148] Specifically, the cable nugget production plant 99 performs a copper nugget production process, a miscellaneous nugget production process, and a miscellaneous nugget production process derived from temporary miscellaneous nugget material. In detail, in the copper nugget production process, a power cable or a power cable having a radiation dose less than a predetermined reference value and a cable diameter less than a specified value is input into the cable nugget production plant 99 to obtain a copper nugget CuNg. In the miscellaneous nugget production process, a control cable or a data cable having a radiation dose less than a predetermined reference value is input into the cable nugget production plant 99 to obtain a miscellaneous nugget. In addition, in the miscellaneous nugget production process derived from temporary miscellaneous nugget material, a temporary miscellaneous nugget material having a radiation dose less than a predetermined reference value is input into the cable nugget production plant 99 to obtain a miscellaneous nugget.

[0149] In the following description, details of a cable recycling system 100 related to a cable nugget production plant 99 shown in Fig. 14 will be described. Since Fig. 14 shows a state in which a copper nugget production process is being carried out, the state in which this copper nugget production process is being carried out will be described as an example. Also, since the pre-duster 31, the exhaust purification device 3, the residual dust removal device 4, and the suction fan 5 are the same as those in Fig. 3, their description will be omitted below.

[0150] (Crusher 50) First, power cables, power cables, control cables, data cables, etc. are fed as waste cables 33 into the feed port 50a of the crusher 50. The waste cables 33 fed into the crusher 50 are crushed into small pieces by the crushing section 50d of the crusher 50. The crushed materials consist of copper, coating, iron, etc.

[0151] The crushed material moves on the vibrating conveyor 50e inside the crusher 50 and is discharged from the discharge port 50b. Note that the above-described crusher 50 is merely an example, and the type of the crusher 50 is not particularly limited.

[0152] (Travel Path 52) The crushed material discharged from the discharge port 50b of the crusher 50 is transported to the crusher 54 by a moving path 52. The type of the moving path 52 is not particularly limited, but for example, a belt conveyor as shown in the figure can be used.

[0153] It is preferable to provide a magnetic separator 53 near the moving path 52. In FIG. 14, a suspended magnetic separator 53 is provided above the belt conveyor. By providing this magnetic separator 53, even if the crushed material moving on the belt conveyor contains small iron particles, the magnetic separator 53 can be attracted and removed by the magnets. That is, for example, if the power cable or power cable to be fed into the crusher 50 still has screws or the like attached, iron or the like derived from the screws will be mixed into the crushed material. However, by providing the magnetic separator 53, the iron or the like can be attracted and removed, so that the pre-processing of the power cable or power cable to be fed into the crusher 50 can be simplified. That is, pre-processing for removing screws or the like from each cable is no longer necessary, and each cable can be quickly fed into the crusher 50 in large quantities using a backhoe or the like.

[0154] (Crusher 54) The crushed material carried by the belt conveyor is supplied from a supply port 54a of the crusher 54 to the inside of the crusher 54, and after being crushed inside the crusher 54, is discharged from a discharge port 54b. The type of the crusher 54 is not particularly limited.

[0155] (Miniaturization Equipment 77) The device for reducing the size of the waste cable 33 is referred to as a downsizing device 77. The type of this downsizing device 77 is not particularly limited, but an example is a downsizing device having the crusher 50, the pulverizer 54, and the moving path 52 as described above. A downsizing device having only the crusher 50 and the pulverizer 54 without the moving path 52 may also be used. In this way, the downsizing device 77 may be any device that can reduce the waste cable 33 to the size of a nugget, and the structure of the machine is not particularly limited.

[0156] (Classifier 56) The pulverized material discharged from the pulverizer 54 is supplied to a classifier 56 by compressed air from a blower 55 adjacent to the pulverizer 54. The pulverized material supplied to the classifier 56 is classified into solids and gas inside the classifier 56. That is, light dust in the pulverized material is discharged from the top of the classifier 56 together with the compressed gas sent from the blower 55. On the other hand, relatively heavy solids in the pulverized material, i.e., copper material Cu and coating material Ct, are discharged from the bottom of the classifier 56.

[0157] The type of classifier 56 is not particularly limited, but for example, a cyclone or the like can be used.

[0158] (Sorting machine 57) The copper material Cu and the coating material Ct discharged from the classifier 56 are supplied to a sorter 57, which separates the copper material Cu and the coating material Ct. The type of sorter 57 is not particularly limited, but for example, a wet specific gravity sorter, a dry specific gravity sorter, etc. can be used. In particular, it is preferable to use a wet specific gravity sorter, which has the advantage of not generating radioactive dust in the air.

[0159] In the embodiment shown in FIG. 14, a wet specific gravity sorter is used as the sorter 57. The illustrated wet specific gravity sorter has an inclined portion that is lower on the left side of the drawing and higher on the right side of the drawing. A liquid LQ (water can be cited as a representative example of this liquid. In the following description, the case where water is supplied as the liquid) is supplied from the right side of the drawing to the inclined portion of this wet specific gravity sorter, and a water flow is formed by the supplied water inside the wet specific gravity sorter. The inclined floor surface of the wet specific gravity sorter repeatedly vibrates upward in the inclined direction, and the coating material (light specific gravity) is washed downstream by the water flow, and copper (heavy specific gravity) rises upstream due to friction with the inclined floor surface, and is separated by specific gravity. The copper material Cu, which has a heavy specific gravity, moves upward to the right side of the drawing, then falls by gravity and is supplied to the dehydrator 58. On the other hand, the coating material Ct, which has a light specific gravity, moves downward to the left side of the drawing together with the water, and is supplied to the coating material moving path 65.

[0160] In the embodiment shown in Fig. 16, a dry specific gravity separator is used as the separator 57. The copper material Cu and the coating material Ct supplied to the inlet of the dry specific gravity separator are separated by the difference in specific gravity between the copper material Cu and the coating material Ct using the vibration and the buoyancy of the air while moving on a vibrating deck with many through holes (air flows from below to above the through holes), and the heavy particles (copper material Cu) are discharged from the right side of the drawing, and the light particles (coating material Ct) are discharged from the left side of the drawing.

[0161] When using a dry specific gravity separator, radioactive dust adhering to the copper material Cu or the coating material Ct may be dislodged and scattered by vibration or air as the copper material Cu or the coating material Ct rolls on the deck. Therefore, it is preferable to provide an exhaust hood 64 above the dry specific gravity separator to suck in the radioactive dust and prevent it from spreading.

[0162] As shown in FIG. 16, when a dry specific gravity separator is used, the installation of the dehydrator 58, dryer 59, elevator 60, coating material transport path 65, slag removal device 69, storage tank 67, and draining device 68 can be omitted.

[0163] (Dehydrator 58, dryer 59) The copper material Cu supplied to the dehydrator 58 has water adhering thereto from the wet specific gravity separator, and is dehydrated by the dehydrator 58. Thereafter, the dehydrated material is supplied to the dryer 59 and dried by the dryer 59. The types of the dehydrator 58 and the dryer 59 are not particularly limited.

[0164] (Elevator 60, Magnetic separator 61, Sieve 62) The dried material discharged from the dryer 59 is moved upward by an elevator 60 and supplied to a magnetic separator 61. Impurities other than copper and brass are removed from the dried material by the magnetic separator 61. The dried material is then supplied to a separator 62 (e.g., a vibrating sieve) and sieved to be separated into copper nuggets CuNg and brass C36.

[0165] The brass C36 is used for the outlets and other accessories of the waste cables 33. When the waste cables 33 with the outlets attached are fed into the crusher 50, they are separated by this separation device 62. When the waste cables 33 fed into the crusher 50 do not have outlets or other accessories attached, the installation of this separation device 62 can be omitted.

[0166] The type of the magnetic separator 61 is not particularly limited, but for example, a drum type magnetic separator can be used. The type of the separator 62 is not particularly limited, but for example, a vibrating sieve or other separator can be used.

[0167] (Covering material transport path 65, slag removal device 69, storage tank 67, draining device 68) The coating material supplied to the coating material moving path 65 moves from the right side to the left side of the drawing by the coating material moving path 65. The type of the coating material moving path 65 is not particularly limited, but for example, a coating material moving path such as a screw conveyor can be used.

[0168] The coating material moved by the coating material moving path 65 is supplied to a water draining device 68, where water adhering to the coating material and originating from the wet specific gravity separator is removed. The type of this water draining device 68 is not particularly limited, but for example, a water draining device such as a flexible container bag can be used.

[0169] It is preferable to provide a slag removal device 69 and a storage tank 67 below the coating material transfer path 65. The storage tank 67 is a tank that receives and stores water that falls downward while the coating material is transferred along the coating material transfer path 65. The slag removal device 69 installed between the coating material transfer path 65 and the storage tank 67 is for removing slag contained in the water that falls from the coating material transfer path 65. The type of this slag removal device 69 is not particularly limited.

[0170] (Exhaust purification) In the cable recycling system 100 as described above, if radioactive dust adheres to the waste cables 33, there is a risk that the radioactive dust will scatter during the cable recycling process and pollute the surrounding environment.

[0171] Therefore, it is preferable to prevent the spread of radioactive dust by providing an exhaust hood or the like in places where radioactive dust is likely to scatter. In the cable recycling system 100 shown in Fig. 14, an exhaust box 51 is provided around the inlet 50a of the crusher 50 (on the front and right side of the drawing in Fig. 14). If radioactive dust adheres to the waste cable 33, there is a possibility that the radioactive dust will scatter when the waste cable 33 is fed into the inlet 50a. Therefore, the air around the inlet 50a is sucked in through the suction port 51a of the exhaust box 51 and guided to the pre-duster 31. In addition, if radioactive dust is attached to the crushed material discharged from the crusher 50, the radioactive dust may become detached from the crushed material and scatter inside the crusher 50 as the crushed material moves on the vibrating conveyor 50e inside the crusher 50 toward the discharge port 50b, and the scattered radioactive dust may leak out of the crusher 50 through the discharge port 50b. Therefore, a small exhaust hood 50c is also provided at the discharge port 50b of the crusher 50 to suck in the air in the vicinity of the discharge port 50b and direct it to the pre-duster 31.

[0172] Furthermore, if radioactive dust adheres to the crushed material, there is a possibility that the radioactive dust may fly away when the crushed material is placed on the belt conveyor that is the moving path 52 and moves, so an exhaust hood 63 is provided above the moving path 52 to suck in the air near the moving path 52 and guide it to the dust removal device 4. The reason why the exhaust air from the exhaust hood 63 is guided to the dust removal device 4 instead of the pre-duster 31 is as follows. That is, the crushed material is in a stationary state on the belt conveyor, and it is expected that the amount of radioactive dust scattered from the stationary crushed material is small, and the amount of dust scattered from the stationary crushed material is also expected to be small, so even if the exhaust air is guided to the dust removal device 4, the high-performance filter of the dust removal device 4 is unlikely to become clogged.

[0173] The crushed material moved along the moving path 52 is fed into the crusher 54. If radioactive dust is attached to the crushed material, there is a possibility that the radioactive dust will scatter when the crushed material is fed from the moving path 52 into the crusher 54. For this reason, a small exhaust hood 54c is also provided at the supply port 54a of the crusher 54 so that the air in the vicinity of the supply port 54a of the crusher 54 is also sucked in and led to the pre-duster 31.

[0174] In addition, when the copper material Cu and the coating material Ct discharged from the cyclone are supplied to the sorter 57, if radioactive dust is attached to the copper material Cu and the coating material Ct, the radioactive dust may scatter and pollute the surrounding environment. Therefore, a branch is provided in the piping supplying the sorter 57 to exhaust the exhaust, and the exhaust is led to the pre-duster 31.

[0175] Furthermore, if radioactive dust adheres to the copper material Cu sorted by the sorting machine 57, the radioactive dust may spread in the dehydrator 58 or dryer 59 located downstream of the sorting machine 57, and may contaminate the surrounding environment. Therefore, the dehydrator 58 or dryer 59 is provided with an exhaust hood 64 so that the contaminated air generated by the dehydrator 58 or dryer 59 is guided to the dust removal device 4.

[0176] In addition, since the dehydrator 58 and the dryer 59 are machines arranged in the latter stages in the cable recycling system 100, even if radioactive dust adheres to the copper material Cu supplied to the dehydrator 58 and the dryer 59, the amount is expected to be small. For the same reason, even if dust is mixed in the copper material Cu, the amount is expected to be small. For this reason, the exhaust gas from the exhaust hood 64 is led to the dust removal device 4 instead of the pre-duster 31. That is, this configuration is adopted because it is considered that the high-performance filter of the dust removal device 4 is less likely to become clogged even if the exhaust gas from the exhaust hood 64 is led to the dust removal device 4.

[0177] As described above, it is preferable to provide an exhaust hood in at least one selected from the group consisting of the crusher 50, the pulverizer 54, the moving path 52, the sorter 57, the dehydrator 58 and the dryer 59, and to guide the air containing radioactive dust generated from these devices to the exhaust purification device 3 and the residual dust removal device 4.

[0178] When purifying exhaust gas from at least one of the devices selected from the group consisting of the crusher 50, the pulverizer 54, the moving path 52, the sorter 57, the dehydrator 58, and the dryer 59, providing these devices with the exhaust hood has the advantage of making it easier to exhaust radioactive particles and dust from these devices uniformly. However, if uniform exhaust is not required, the installation of the exhaust hood may be omitted.

[0179] 14, the exhaust gas generated from at least one device selected from the group consisting of the moving path 52, the dehydrator 58, and the dryer 59 is led directly to the residual dust removal device 4, but the present invention is not limited to this. In other words, the exhaust gas generated from at least one device selected from the group consisting of the moving path 52, the dehydrator 58, and the dryer 59 may be supplied to the pre-duster 31.

[0180] (Treatment of liquid from wet specific gravity separator) As described above, when a wet specific gravity separator is used as the separator 57 of the cable recycling system 100, a liquid (e.g., water) is required for the separation. It is preferable to use the liquid by circulating it. A liquid purification treatment system 80 for circulating the liquid will be described below with reference to FIG. 15.

[0181] (Storage tank 67) 14, when a wet specific gravity separator is used as the separator 57, a liquid (for example, water) is used. It is preferable that the water used in the wet specific gravity separator is temporarily stored in a storage tank 67 and then transported to the wet specific gravity separator again for reuse.

[0182] (Blow liquid storage tank 70) The water stored in the storage tank 67 becomes gradually contaminated as dust and radioactive materials attached to the copper material Cu and the coating material Ct dissolve in the water. If this contaminated water is recycled to the wet specific gravity separator without any treatment, there is a risk that the copper material Cu and the coating material Ct fed into the wet specific gravity separator will be contaminated by the recycled water.

[0183] Therefore, it is preferable to transfer the blow water (also called supernatant water; blow water is an example of blow liquid) stored in the storage tank 67 to the blow liquid storage tank 70 and temporarily store it in the blow liquid storage tank 70.

[0184] (Contaminated Liquid Storage Tank 71) The blow water stored in the blow liquid storage tank 70 is transferred to the contaminated liquid storage tank 71 by the pump P2, and is temporarily stored in the contaminated liquid storage tank 71.

[0185] (Purification Equipment 72) The contaminated water (contaminated water is an example of contaminated liquid) stored in the contaminated liquid storage tank 71 is preferably supplied to the purification device 72 and sprayed from the contaminated liquid spraying section 72a of the purification device 72. In addition, it is preferable to provide a freezing coil 72b inside the purification device 72. In this case, it is preferable to position the contaminated liquid spraying section 72a above the freezing coil 72b.

[0186] The type of the contaminated liquid spraying unit 72a is not particularly limited, but may be, for example, a water spray nozzle, etc. The type of the freezing coil 72b is also not particularly limited.

[0187] The contaminated water sprayed from the contaminated liquid spraying unit 72a falls and comes into contact with the outer surface of the freezing coil 72b, and is cooled as it flows down along the outer surface of the freezing coil 72b. Note that a cooling liquid or refrigerant gas is supplied from a chiller unit 75 to the inside of the freezing coil 72b, thereby cooling the freezing coil 72b.

[0188] As the contaminated water flows down the outer surface of the freezing coil 72b, the portion of the contaminated water that does not contain radioactive dust (water that contains no radioactive dust at all, or water that contains so little radioactive dust that it can be considered to contain no radioactive dust at all) adheres to the outer surface of the freezing coil 72b as ice. The remaining portion that does not adhere as ice (for example, water that contains a large amount of radioactive dust) falls to the bottom of the purification device 72, is discharged as impure liquid from the impure liquid discharge port 72c, and is returned to the contaminated liquid storage tank 71. Note that while the contaminated liquid is being supplied, valve B1 is opened and valve B2 is closed.

[0189] By returning the impure liquid to the contaminated liquid storage tank 71 in this way, the degree of contamination of the contaminated water inside the contaminated liquid storage tank 71 gradually increases. Therefore, it is preferable to drive pump P3 at a predetermined timing to transfer the concentrated contaminated water in the contaminated liquid storage tank 71 to the concentrated contaminated liquid storage tank 73. Since the concentrated contaminated water (concentrated contaminated water is an example of concentrated contaminated liquid) temporarily stored in the concentrated contaminated liquid storage tank 73 contains a lot of dust and highly radioactive dust, it is preferable to send it to specialized equipment such as a radioactivity removal device (not shown) at a predetermined timing and purify it with the radioactivity removal device, and to dehydrate and dry the cake generated in the radioactivity removal device and dispose of it in a landfill.

[0190] Meanwhile, as the contaminated water continues to be sprayed from the contaminated liquid spraying unit 72a as described above, ice grows on the surface of the freezing coil 72b. When the ice has grown sufficiently, the operation of the pump P4 is stopped to stop the supply of contaminated water. At the same time, the operation of the chiller unit 75 is stopped to stop cooling the freezing coil 72b. Valve B1 is also closed, and valve B2 is opened.

[0191] Thereafter, the warm water in the defrosting liquid storage tank 74 is supplied to the dissolution promoting liquid spraying unit 72e by the pump P5, and the warm water is sprayed from the dissolution promoting liquid spraying unit 72e. Note that the warm water is a liquid for dissolving the frozen material formed on the outer surface of the freezing coil 72b, and is an example of a dissolution promoting liquid.

[0192] The hot water in the defrosting liquid storage tank 74 is generated by heating the water in the defrosting liquid storage tank 74 with the heater 76. The temperature of the hot water is not particularly limited and can be determined arbitrarily, but the optimal temperature setting is set based on the heater capacity and defrosting time.

[0193] In FIG. 15, in order to make effective use of water resources, the warm water sprayed from the dissolution promoting liquid spraying section 72e is delivered from the defrosting liquid storage tank 74, but warm water may be supplied from an external source separately from this.

[0194] In this manner, the hot water sprayed from the dissolution promoting liquid spraying section 72e falls and comes into contact with the ice formed on the outer surface of the freezing coil 72b, and melts the ice as it flows down the ice and the freezing coil 72b. Water that does not contain radioactive dust, which is produced by the melting of the ice, is discharged from the non-impurity liquid discharge port 72d of the purification device 72 and transferred to the defrosting liquid storage tank 74.

[0195] The water not containing radioactive dust that has been transferred to the defrosting liquid storage tank 74 is returned to the storage tank 67, and then pumped again by the pump P1 to the wet specific gravity separator for reuse.

[0196] (others) As the operation of the wet specific gravity separator and liquid purification treatment system 80 continues, the amount of liquid (liquid to be recycled) used in the wet specific gravity separator gradually decreases because concentrated waste liquid is discarded or volatilized. For this reason, it is preferable to gradually replenish liquid from outside in the liquid purification treatment system 80. This replenishment liquid (referred to as replenishment liquid) is not particularly limited, but examples include city water, tap water, etc.

[0197] Moreover, the path that circulates the liquid used in the wet specific gravity separator and supplies it back to the wet specific gravity separator is called the liquid circulation path. In the example of Fig. 15, the liquid circulation path refers to a path that circulates through the separator 57 (wet specific gravity separator), storage tank 67, blow liquid storage tank 70, contaminated liquid storage tank 71, purification device 72, dissolution promoting liquid storage tank 74, storage tank 67, and separator 57 (wet specific gravity separator) in that order. In Fig. 15, the symbol LR is attached to this series of liquid circulation paths.

[0198] 1: cable recycling system related to coating material stripping machine, 2: working area, 3: exhaust purification device, 4: residual dust removal device, 5: suction fan, 6: exhaust hood, 7: exhaust purification filter, 7A: first exhaust purification filter, 7B: second exhaust purification filter, 7X: peak portion, 7Y: valley portion, 8: inner tube, 9: seal portion, 9A: upper seal portion, 9B: lower seal portion, 10: mounting plate, 11: injection nozzle, 12: compressed gas supply pipe, 13: purified exhaust passage, 14: main filter, 14U: upper layer main filter, 14M: middle layer main filter, 14D: lower layer main filter, 15: shape Holding means, 15U: front side shape holding means (upper side shape holding means), 15D: rear side shape holding means (lower side shape holding means), 16: exhaust air supply port, 17: metal fiber, 18: purified air exhaust port, 24: deposit exhaust port, 25: residual dust removal filter, 26: internal space, 27: small space, 27A: first small space, 27B: second small space, 28: exhaust air purification device container, 29: partition wall, 30: coating material peeling machine, 31: pre-duster, 32: worker, 33: waste cable, 34: Pika copper wire, 35: insulator, 36: sheath, 37: coating material, 50: crusher, 50a: (crusher) inlet, 50b: ( (Crusher) outlet, 51: Exhaust box, 52: Movement path, 53: Magnetic separator, 54: Crusher, 54a: (Crusher) inlet, 54b: (Crusher) outlet, 55: Blower, 56: Classifier, 57: Sorter, 58: Dehydrator, 59: Dryer, 60: Elevator, 61: Magnetic separator, 62: Sieve, 63: (Movement path) exhaust hood, 64: (Dehydrator or dryer) exhaust hood, 65: Covering material movement path, 66: (Dry specific gravity separator) exhaust hood, 67: Storage tank, 68: Draining device, 69: Slag removal device, 70: Blowing liquid storage tank, 71: Contaminated liquid storage tank, 72: Purification device, 72a: Contaminated Liquid spraying section, 72b: freezing coil, 72c: impure liquid outlet, 72d: non-impure liquid outlet, 72e: dissolution promotion liquid spraying section, 73: concentrated contaminated liquid storage tank, 74: dissolution promotion liquid storage tank, 75: chiller unit, 77: miniaturization device, 80: liquid purification processing system, 99: cable nugget production plant, 100: cable recycling system (related to cable nugget production plant), IL: virtual line, AH: exhaust, EH: dust removal exhaust, PEH: purified exhaust, TEH: processed exhaust, PA: compressed gas, SD: deposit, US: front side (upper side), DS: back side (lower side), TD: thickness direction,LR: liquid circulation path, P1: (first) pump, P2: (second) pump, P3: (third) pump, P4: (fourth) pump, P5: (fifth) pump, P6: (sixth) pump, B1: (first) valve, B2: (second) valve, Cu: copper material, Ct: coating material, Ng: nugget, CuNg: copper nugget, C36: brass, LQ: liquid,

Claims

1. A cable recycling method for recycling waste cables from a nuclear facility, comprising the steps of: A measuring step of measuring a radiation dose of the waste cable; a cable diameter classification step of classifying at least one of a power cable and a power source cable among the discarded cables having a radiation dose less than a predetermined reference value according to the size of the diameter; a shiny copper wire extracting step of removing the coating from the cables having a diameter equal to or larger than a predetermined size among the cables classified in the classification step to obtain a shiny copper wire; a copper nugget producing step of pulverizing the cables having a diameter smaller than a predetermined size among the cables classified in the classification step, and separating the pulverized material into a coating material and copper nuggets to obtain copper nuggets, A cable recycling method characterized in that each of the above steps is carried out within the premises of a nuclear facility.

2. A cable recycling method for recycling waste cables from a nuclear facility, comprising the steps of: A measuring step of measuring a radiation dose of the waste cable; and a miscellaneous nugget producing step of pulverizing at least one of a control cable and a data cable among the waste cables having a radiation dose less than a predetermined reference value, and separating the pulverized material into a coating material and a miscellaneous nugget to obtain the miscellaneous nugget, A cable recycling method characterized in that each of the above steps is carried out within the premises of a nuclear facility.

3. After the measuring step, A temporary shiny copper wire extraction process for obtaining a temporary shiny copper wire by stripping a coating material from at least one of a power cable and a power cable among the waste cables having a radiation dose equal to or higher than a predetermined reference value; A temporary copper wire measuring step of measuring the radiation dose of the temporary copper wire, As a result of the provisional shiny copper wire remeasurement process, when the radiation dose of the provisional shiny copper wire is less than a predetermined reference value, the provisional shiny copper wire is judged to be able to be distributed as a shiny copper wire, 3. The cable recycling method according to claim 1, wherein each of the steps is carried out within the premises of a nuclear facility.

4. After the measuring step, a step of removing an outer covering material from at least one of a control cable and a data cable among the waste cables having a radiation dose equal to or higher than a predetermined reference value to obtain a temporary miscellaneous nugget material; a measurement step of measuring a radiation dose of the temporary miscellaneous nugget material; A temporary miscellaneous nugget material-derived miscellaneous nugget producing process includes crushing the temporary miscellaneous nugget material having a radiation dose less than a predetermined reference value as a result of the temporary miscellaneous nugget material measuring process to obtain a miscellaneous nugget, 3. The cable recycling method according to claim 1, wherein each of the steps is carried out within the premises of a nuclear facility.

5. A cable recycling system for recycling waste cables at a nuclear facility, the system being installed on the premises of the nuclear facility, comprising: The cable recycling system comprises: A coating material stripper that strips a coating material from the waste cable; A peeling machine exhaust hood provided in a working area of ​​the coating material peeling machine; an exhaust purification device provided downstream of the peeling machine exhaust hood and including a metallic exhaust purification filter for removing radioactive dust from exhaust gas containing the radioactive dust generated in a working area of ​​the coating material peeling machine; a residual dust removal device provided downstream of the exhaust purification device and configured to remove the radioactive dust remaining in the purified exhaust gas discharged from the exhaust purification device; The residual dust removal device has a residual dust removal filter having a particle collection rate of 99.97% or more for dust particles having a particle size of 0.3 μm remaining in the purified exhaust gas, The waste cable to be supplied to the coating material stripper is Power cables with radiation levels exceeding predetermined standards; Power cables with radiation levels exceeding predetermined standards; Control cables with radiation levels exceeding predetermined standards; Data cables with radiation levels exceeding a predetermined standard value; A power cable whose radiation dose is less than a predetermined standard value and whose diameter is equal to or larger than a predetermined size; and A power cable whose radiation level is less than a predetermined standard value and whose diameter is equal to or larger than a predetermined size; At least one cable selected from the group consisting of A cable recycling system comprising:

6. A cable recycling system for recycling waste cables at a nuclear facility, the system being installed on the premises of the nuclear facility, comprising: The cable recycling system comprises: A miniaturization device for miniaturizing the waste cable; a wet specific gravity separator that separates the small objects reduced in size by the miniaturization device into coating materials and nuggets using a liquid; A dehydrator for dehydrating the separated nuggets; a dryer for drying the dehydrated nuggets; an exhaust purification device including a metallic exhaust purification filter for removing the radioactive dust from exhaust gas containing the radioactive dust exhausted from at least one selected from the group consisting of the miniaturization device, the wet specific gravity separator, the dehydrator, and the dryer; a residual dust removal device provided downstream of the exhaust purification device and configured to remove the radioactive dust remaining in the purified exhaust gas discharged from the exhaust purification device; The residual dust removal device has a residual dust removal filter having a particle collection rate of 99.97% or more for dust particles having a particle size of 0.3 μm remaining in the purified exhaust gas, The waste cable to be supplied to the miniaturization device is A power cable having a radiation dose less than a predetermined standard value and a diameter less than a predetermined size; A power cable having a radiation amount less than a predetermined standard value and a diameter less than a predetermined size; A control cable having a radiation dose below a predetermined reference value; and A data cable whose radiation level is below a predetermined standard value; At least one cable selected from the group consisting of A cable recycling system comprising:

7. A cable recycling system for recycling waste cables at a nuclear facility, the system being installed on the premises of the nuclear facility, comprising: The cable recycling system comprises: A miniaturization device for miniaturizing the waste cable; a dry specific gravity separator for separating the small objects reduced in size by the reduction device into coating materials and nuggets; an exhaust purification device including a metallic exhaust purification filter for removing radioactive dust from exhaust gas containing the radioactive dust exhausted from at least one of the miniaturization device and the dry specific gravity separator; a residual dust removal device provided downstream of the exhaust purification device and configured to remove the radioactive dust remaining in the purified exhaust gas discharged from the exhaust purification device; The residual dust removal device has a residual dust removal filter having a particle collection rate of 99.97% or more for dust particles having a particle size of 0.3 μm remaining in the purified exhaust gas, The waste cable to be supplied to the miniaturization device is A power cable having a radiation dose less than a predetermined standard value and a diameter less than a predetermined size; A power cable having a radiation amount less than a predetermined standard value and a diameter less than a predetermined size; A control cable having a radiation dose below a predetermined reference value; and A data cable whose radiation level is below a predetermined standard value; At least one cable selected from the group consisting of A cable recycling system comprising:

8. A cable recycling system for recycling waste cables at a nuclear facility, the system being installed on the premises of the nuclear facility, comprising: The cable recycling system comprises: A crusher to which the waste cable is supplied and which crushes the supplied waste cable; A crusher for crushing the crushed material crushed by the crusher; A path for moving the crushed material between the crushers; a wet specific gravity separator that separates the pulverized material pulverized by the pulverizer into a coating material and nuggets using a liquid; A dehydrator for dehydrating the separated nuggets; a dryer for drying the dehydrated nuggets; an exhaust purification device including a metallic exhaust purification filter for removing the radioactive dust from exhaust gas containing the radioactive dust exhausted from at least one selected from the group consisting of the crusher, the pulverizer, and the wet specific gravity separator; a residual dust removal device provided downstream of the exhaust purification device and configured to remove the radioactive dust remaining in the purified exhaust gas discharged from the exhaust purification device; The residual dust removal device has a residual dust removal filter having a particle collection rate of 99.97% or more for dust particles having a particle size of 0.3 μm remaining in the purified exhaust gas, The waste cable to be supplied to the crusher is A power cable having a radiation dose less than a predetermined standard value and a diameter less than a predetermined size; A power cable having a radiation amount less than a predetermined standard value and a diameter less than a predetermined size; A control cable having a radiation dose below a predetermined reference value; and A data cable whose radiation level is below a predetermined standard value; At least one cable selected from the group consisting of The exhaust gas containing radioactive dust exhausted from at least one selected from the group consisting of the moving path, the dehydrator, and the dryer is guided to the residual dust removal device without passing through the exhaust gas purification device, and the radioactive dust contained in the exhaust gas is removed by the residual dust removal device. A cable recycling system comprising:

9. The wet specific gravity separator includes: A liquid circulation path is connected to circulate the liquid used in the wet specific gravity separator and supply it to the wet specific gravity separator again, The liquid circulation path includes: a purification device is provided for purifying the used liquid passing through the liquid circulation path; The purification device is a contaminated liquid spraying unit that sprays contaminated liquid, which is a used liquid passing through the liquid circulation path; A freezing coil that freezes a portion of the contaminated liquid sprayed from the liquid spraying unit that does not contain radioactive dust and adheres it to an outer surface; an impure liquid outlet for discharging the remainder of the contaminated liquid sprayed from the liquid spraying unit, the remainder including radioactive dust; a dissolution promoting liquid spraying unit that sprays a dissolution promoting liquid that dissolves the frozen material formed on the outer surface of the freezing coil after the liquid spraying unit stops spraying the liquid; a non-impurity liquid outlet for discharging a liquid not containing radioactive dust dissolved by the dissolution promoting liquid sprayed from the dissolution promoting liquid spraying section; 9. A cable recycling system according to claim 6 or 8, wherein the liquid not containing radioactive dust discharged from the non-impure liquid discharge port is used in the wet specific gravity separator.

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