Radioactivity measurement system and radioactivity measurement method

Abstract

This makes it easier to measure objects with complex shapes and prevents the radiation detector from coming into contact with and contaminating the object being measured. [Solution] The radioactivity measurement system 100 includes a dimension measuring device 11 for measuring the dimensions of an object to be measured 201, a radiation detector 31 for detecting radiation from the object to be measured 201, a detector placement device 35 for arranging the radiation detector 31 at an arbitrary location, and a data acquisition device 42 for driving and controlling the radiation detector 31 to collect radiation measurement data. The detector placement device 35 has a detection unit (PSF 32) formed to have a diameter (width) larger than the maximum diameter (width) of the object to be measured 201 based on the dimension information of the object to be measured 201 acquired by the dimension measuring device 11, and the radiation detector 31, which is composed of the detection unit formed in this way, is arranged around the object to be measured 201.

Description

Technical Field

[0001] The present invention relates to a radioactivity measurement system and a radioactivity measurement method.

Background Art

[0002] During the operation of nuclear power plants or in decommissioning measures, a large amount of waste is generated, such as radioactive waste or waste contaminated by radioactivity, along with equipment replacement and facility disassembly. These wastes are classified according to the level of radioactivity concentration, such as the degree of activation or radioactive contamination. Among these, those collectively referred to as low-level radioactive waste are classified into those with relatively high radioactivity concentration, those with relatively low radioactivity concentration, and those with extremely low radioactivity concentration, and are respectively disposed of by in-ground disposal such as medium-depth disposal, shallow in-ground pit disposal, and trench disposal. For high-level radioactive waste with a higher radioactivity concentration than low-level radioactive waste, geological disposal is carried out.

[0003] On the other hand, among the dismantled materials of nuclear power plants, the degree of radiation contamination is sufficiently small compared to the natural radiation level, and the risk to human health can be ignored, so there are some that can be excluded from the regulations regarding radiation protection. These are called clearance items.

[0004] Clearance items do not need to be handled as radioactive substances. Therefore, if the radioactivity concentration is determined to be below the clearance level, they can be removed outside the nuclear power plant. At that time, those that can be reused are reused as resources. Also, those for which reuse is not reasonable can be disposed of in the same way as ordinary industrial waste. The determination of whether it is below the clearance level is carried out by measuring the radiation of the dismantled object to be measured and evaluating the radioactivity from the measurement results.

[0005] One method for measuring and evaluating the radioactivity of dismantled materials is described in Patent Document 1. In the method described in Patent Document 1, the shape of the dismantled material is measured in advance, and based on the shape measurement results, a long PSF is brought close to the surface of the dismantled material to a certain distance. Then, the method described in Patent Document 1 measures the radioactivity by scanning the surface of the dismantled material while maintaining the close distance. The PSF is a scintillation fiber made of plastic (plastic scintillation fiber). This method described in Patent Document 1 can measure the radioactivity of the entire large dismantled material with high accuracy and without missing any hot spots. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2022-70049 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] The prior art described in Patent Document 1 has the following problems: it is desirable to make it easier to measure objects with complex shapes, and there is a possibility that the radiation detector may come into contact with and contaminate the object being measured.

[0008] The amount of clearance material generated is estimated to be tens of thousands of tons per standard light water reactor. Therefore, due to measurement errors in dismantled materials (objects being measured) that exhibit complex shapes, radioactivity evaluations based on radiation measurements may result in a radioactivity concentration higher than the clearance level, even though the material is actually clearance material. In this case, the clearance material is treated as radioactive waste. The conventional technology described in Patent Document 1 uses a long PSF with shape flexibility to measure large dismantled materials, thereby improving the overall efficiency of clearance material processing and disposal by reducing the shredding process when dismantling the clearance material, which is estimated to amount to tens of thousands of tons per reactor. However, clearance dismantled materials generated during decommissioning, etc., include items with complex shapes such as pump casings and valves. The conventional technology described in Patent Document 1 is suitable for detailed measurement of clearance materials with relatively simple shapes such as flat plates and pipes, but it is difficult to measure clearance materials with complex shapes. Therefore, the conventional technology described in Patent Document 1 has the problem that it is desirable to make it easier to measure objects with complex shapes.

[0009] Furthermore, the prior art described in Patent Document 1 involves suspending and moving the radiation detector. This prior art described in Patent Document 1 has the problem that unintended shocks may be applied to the radiation detector, potentially causing it to come into contact with and contaminate the object being measured.

[0010] The present invention was made to solve the aforementioned problems, and its main objective is to provide a radioactivity measurement system and a radioactivity measurement method that facilitates the measurement of objects with complex shapes and prevents the radiation detector from coming into contact with and contaminating the object. [Means for solving the problem]

[0011] To achieve the above objective, the present invention provides a radioactivity measurement system comprising: a dimension measuring device for measuring the dimensions of an object to be measured; a radiation detector for detecting radiation from the object to be measured; a detector placement device for arranging the radiation detector at an arbitrary location; and a data acquisition device for driving and controlling the radiation detector to collect radiation measurement data, wherein the detector placement device is configured to arrange the radiation detector, whose detection unit is formed to have a diameter larger than the maximum diameter of the object to be measured, around the object to be measured based on the dimension information of the object to be measured acquired by the dimension measuring device. Other methods will be described later. [Effects of the Invention]

[0012] According to the present invention, it is possible to make it easier to measure objects with complex shapes, and to prevent the radiation detector from coming into contact with and contaminating the object being measured. [Brief explanation of the drawing]

[0013] [Figure 1] This is a schematic diagram of the entire radioactivity measurement system according to the embodiment. [Figure 2] This is a schematic diagram of the detector arrangement device used in the radioactivity measurement system according to the embodiment. [Figure 3] This is a flowchart showing the operation of the first embodiment of the radioactivity measurement system. [Figure 4A] This is an explanatory diagram (1) of the operation of the first embodiment of the radioactivity measurement system. [Figure 4B] This is an explanatory diagram (2) of the operation of the first embodiment of the radioactivity measurement system. [Figure 4C] This is an explanatory diagram (3) of the operation of the first embodiment of the radioactivity measurement system. [Figure 5] This is a flowchart showing the operation of the second embodiment of the radioactivity measurement system. [Figure 6A] This is an explanatory diagram (1) of the operation of the second embodiment of the radioactivity measurement system. [Figure 6B] This is an explanatory diagram (2) of the operation of the second embodiment of the radioactivity measurement system. [Figure 6C] It is an operation explanatory diagram (3) of the second embodiment of the radioactivity measurement system. [Figure 6D] It is an operation explanatory diagram (4) of the second embodiment of the radioactivity measurement system. [Figure 7] It is a flowchart showing the operation of the third embodiment of the radioactivity measurement system. [Figure 8A] It is an operation explanatory diagram (1) of the third embodiment of the radioactivity measurement system. [Figure 8B] It is an operation explanatory diagram (2) of the third embodiment of the radioactivity measurement system. [Figure 8C] It is an operation explanatory diagram (3) of the third embodiment of the radioactivity measurement system. [Figure 8D] It is an operation explanatory diagram (4) of the third embodiment of the radioactivity measurement system.

Mode for Carrying Out the Invention

[0014] Hereinafter, embodiments of the present invention (hereinafter referred to as "the present embodiment") will be described in detail with reference to the drawings. Note that each figure only schematically shows the present invention to such an extent that it can be sufficiently understood. Therefore, the present invention is not limited only to the illustrated examples. In each figure, common components and similar components are denoted by the same reference numerals, and redundant descriptions thereof are omitted.

[0015] In addition, the prior art described in Patent Document 1 also has the following problems. (1) Measuring corresponding to individual shapes is inefficient, and there is a problem that it is desirable to perform common measurement (shared measurement) on disassembled objects (measurement targets) having complex shapes. (2) There is also a problem that it is desirable to measure radioactivity without cutting the disassembled object (measurement target) according to the size of the detection part of the radiation detector. The present embodiment is also intended to provide a radioactivity measurement system and a radioactivity measurement method that can solve these problems.

[0016] <Configuration of the entire radioactivity measurement system> The overall configuration of the radioactivity measurement system 100 according to this embodiment will be described below with reference to Figure 1. Figure 1 is a schematic diagram of the radioactivity measurement system 100 according to this embodiment.

[0017] As shown in Figure 1, the radioactivity measurement system 100 according to this embodiment includes a dimensional measuring device 11, a dimensional measuring control device 12, a transport device 21, and a transport control device 22. The radioactivity measurement system 100 also includes a radioactivity measuring device 30, a placement control device 41, a data acquisition device 42, and a radioactivity conversion device 43.

[0018] The dimensional measuring device 11 is a component that measures the shape and dimensions of the object to be measured 201 and acquires dimensional information of the object to be measured 201. Here, the object to be measured 201 is assumed to be a dismantled part of a nuclear power plant. The dimensional measuring device 11 can be composed of a stereo camera, a laser rangefinder, an infrared non-contact distance measuring device, etc.

[0019] The dimension measurement control device 12 is a component that controls the operation of the dimension measurement device 11. The dimension measurement control device 12 is electrically connected to the placement control device 41 and outputs the dimension information of the object to be measured 201 acquired by the dimension measurement device 11 to the placement control device 41.

[0020] The transport device 21 is a component that transports the object to be measured 201. The transport control device 22 is a component that controls the operation of the transport device 21. The transport control device 22 causes the transport device 21 to transport the object to be measured 201 from outside to inside the radioactivity measuring device 30, and when the radioactivity measuring device 30 measures the radioactivity of the object to be measured 201, it causes the object to be transported from inside to outside the radioactivity measuring device 30.

[0021] The radioactivity measuring device 30 is a component for measuring the radioactivity of the object to be measured 201. The radioactivity measuring device 30 includes a radiation detector 31 and a detector placement device 35.

[0022] The radiation detector 31 is a component that detects radiation from the object to be measured 201. The radiation detector 31 has a helically arranged PSF 32 that functions as a detection unit, and a PSF support unit 33 that supports the PSF 32. The PSF 32 is a scintillation fiber (plastic scintillation fiber) made of plastic. The PSF 32 is prepared in advance in the PSF feeder 34 and is sent (supplied) from the PSF feeder 34 to the radiation detector 31. It is also possible to configure the radiation detector 31 to use at least one survey meter or the like as the detection unit. However, here, the radiation detector 31 will be described using a helically arranged PSF 32 as the detection unit. The reason for using the PSF 32 as the detection unit is that the PSF 32 can efficiently measure the radioactivity of dismantled materials (object to be measured 201) with various shapes and dimensions and complex shapes. The radioactivity measurement system 100 uses a PSF 32 as the detection unit of the radiation detector 31, enabling it to perform common measurements (standardized measurements) on dismantled objects (objects to be measured 201) with diverse shapes and dimensions and complex forms. Furthermore, the radioactivity measurement system 100 can improve throughput performance by shortening the time required for radioactivity measurement.

[0023] The detector placement device 35 is a component that places the radiation detector 31 in an arbitrary location (for example, around the object to be measured 201 that has been transported into the radioactivity measuring device 30 by the transport device 21). The detector placement device 35 functions as a detector helical placement device that arranges the PSF 32 in a helical manner on the radiation detector 31.

[0024] The placement control device 41 is a component that controls the operation of the detector placement device 35. The data acquisition device 42 is a component that drives and controls the radiation detector 31 to collect radiation measurement data. The radioactivity conversion device 43 is a component that converts the measured values ​​into the radioactivity or radioactivity concentration of the object to be measured 201 based on the radiation measurement data collected by the data acquisition device 42.

[0025] <Configuration of the detector placement device> The configuration of the detector placement device 35 will be described below with reference to Figure 2. Figure 2 is a schematic diagram of the detector placement device 35.

[0026] As shown in Figure 2, the detector placement device 35 includes a support column 301, a support device 302, a diameter variable device 303, and a support section 304.

[0027] The support column 301 is a component that supports the support device 302. In the illustrated example, the support device 302 is supported by a single support column 301, but it may also be supported by multiple support columns. The support column 301 is preferably a sturdy metal rod-shaped member, but other materials (e.g., reinforced plastic) can be used as long as the required strength can be ensured.

[0028] The support device 302 is a component that movably supports the support section 304. The support device 302 moves (rotates) the support section 304 in the direction of arrow A12 around the support column 301 while changing the height of the PSF 32 fed from the PSF feeder 34, thereby arranging (wrapping) the PSF 32 spirally around the periphery (outer circumference) of the support section 304. Such a support device 302 functions as a spiral winding device that winds the PSF 32 spirally.

[0029] The diameter variable device 303 is a component that adjusts (changes) the diameter (width) of the support portion 304. The diameter variable device 303 adjusts (changes) the diameter (width) of the support portion 304 by moving the support portion 304 in the direction of arrow A11. By adjusting (changing) the diameter (width) of the support portion 304, such a diameter variable device 303 functions as a spiral diameter adjustment mechanism that adjusts (changes) the diameter (width) of the PSF 32.

[0030] The support section 304 is a component that supports the PSF 32 around which it is wound. The support section 304 functions as a spiral winding device in which the PSF 32 is arranged (wound) spirally around the support section 304 by the support device 302, which moves (rotates) the support section 304 around the support column 301 in the direction of arrow A12. In the illustrated example, six support sections 304 are shown, but the number of support sections 304 is not limited to six. The more support sections 304 there are, the more they are arranged on a shape that approximates a circle.

[0031] PSF32 is a scintillator material that generates scintillation light through interaction with gamma rays, molded into an optical fiber shape. It measures the incident position and intensity of gamma rays on the fiber from the difference in arrival time of the scintillation light incident on photodetectors placed at both ends of the fiber. PSF32 is available in lengths of approximately 10 to 20 m, and can output gamma ray intensity at intervals of, for example, 10 cm. It also has shape flexibility, such as being bendable like an optical fiber. By arranging the long and shape-flexible PSF32 in a spiral pattern around the outer circumference of the complex-shaped object to be measured 201, it is possible to perform common measurements (standardized measurements) without having to individually address each complex shape. The radioactivity measurement system 100 adjusts the amount of PSF32 sent to the radiation detector 31 by driving and controlling the PSF feeder 34 with the placement control device 41. The radioactivity measurement system 100 also adjusts the placement position of the PSF32 around the support part 304 by driving and controlling the detector placement device 35 with the placement control device 41. This enables the radioactivity measurement system 100 to achieve a helical arrangement of PSF32.

[0032] Furthermore, the radioactivity measurement system 100 includes a dimensional measuring device 11, a dimensional measuring control device 12, a transport device 21, and a transport control device 22 as devices used in the preliminary stage before the radioactivity measurement of the dismantled material (object to be measured 201) by the radioactivity measuring device 30.

[0033] <Operation of the radioactivity measurement system> Here, as an example of the operation of the radioactivity measurement system 100, we will describe three different operation methods, from the first to the third embodiment.

[0034] (First embodiment) First, the operation of the first embodiment of the radioactivity measurement system 100 will be described with reference to Figure 3 and Figures 4A to 4C. Figure 3 is a flowchart showing the operation of the first embodiment of the radioactivity measurement system 100. Figures 4A to 4C are explanatory diagrams of the operation of the first embodiment of the radioactivity measurement system 100, respectively.

[0035] As shown in Figure 3, the radioactivity measurement system 100 measures the shape and dimensions of the object to be measured 201 using the dimensional measuring device 11 (step S105), and obtains dimensional information (diameter (width), height) of the object to be measured 201 (step S110). Figure 4A schematically shows the operation of steps S105 to S110 in Figure 3.

[0036] After step S110, the radioactivity measurement system 100 uses the transport device 21 to transport the object to be measured 201 into the radioactivity measurement device 30 along the arrow B11 shown in Figure 4B (step S115). Figure 4B schematically shows the operation of steps S115 to S125 in Figure 3. In this embodiment, the dimensional measuring device 11 is located outside the radioactivity measurement device 30, so the shape and dimensions of the object to be measured 201 are measured before the object to be measured 201 is transported into the radioactivity measurement device 30. However, the dimensional measuring device 11 can also be located inside the radioactivity measurement device 30. In this case, the dimensional measuring device 11 measures the shape and dimensions of the object to be measured 201 after it has been transported into the radioactivity measurement device 30.

[0037] After step S115, the radioactivity measurement system 100 adjusts the diameter of the support portion 304 of the radiation detector 31 to be larger than the maximum diameter of the object to be measured 201, based on the dimensional information acquired in step S110 by the detector placement device 35 (step S120). At this time, the radioactivity measurement system 100 adjusts the diameter of the support portion 304 of the radiation detector 31 to a diameter that is the maximum diameter of the object to be measured 201 plus a preset dimension.

[0038] After step S120, the radioactivity measurement system 100 uses the PSF feeder 34 and the detector placement device 35 to spirally arrange the PSF 32, which is the detection part of the radiation detector 31, around the support part 304 (outer periphery) (step S125). Figure 4C schematically shows the operation of steps S115 to S125 in Figure 3.

[0039] After step S125, the radioactivity measurement system 100 moves the radiation detector 31, in which the detection unit PSF 32 is arranged in a spiral shape, along the arrow B12 shown in Figure 4C, using the detector placement device 35 to position it around the object to be measured 201 (step S130).

[0040] After step S130, the radioactivity measurement system 100 measures the gamma ray count rate at each location around the object to be measured 201 using the PSF 32 via the radioactivity measuring device 30 (step S135). The gamma ray count rate information at each location is output from the radioactivity measuring device 30 to the data acquisition device 42 and managed by the data acquisition device 42.

[0041] After step S135, the radioactivity measurement system 100 calculates (converts) the radioactivity (Bq) or radioactivity concentration (Bq / g) from the gamma ray count rate information measured in step S135 using the radioactivity conversion device 43 (step S140).

[0042] (Second example) Next, the operation of the second embodiment of the radioactivity measurement system 100 will be described with reference to Figure 5 and Figures 6A to 6D. Figure 5 is a flowchart showing the operation of the second embodiment of the radioactivity measurement system 100. Figures 6A to 6D are explanatory diagrams of the operation of the second embodiment of the radioactivity measurement system 100, respectively.

[0043] In the second embodiment, the diameter of the support portion 304 is pre-set to be larger than the maximum diameter of the expected object to be measured 201 (Figure 4A) (Figure 6A). Then, when an object to be measured 201a smaller than the maximum diameter of the expected object to be measured 201 (Figure 4A) is brought into the radioactivity measuring device 30 (Figure 6B), the radioactivity measuring system 100 arranges the PSF32 around the support portion 304 and adjusts the diameter of the support portion 304. This adjusts the diameter of the PSF32 for the radioactivity measuring system 100 (Figure 6C). After this, the radioactivity measuring system 100 arranges the PSF32 around the object to be measured 201a (Figure 6D).

[0044] As shown in Figure 5, the operation of the second embodiment differs from the operation of the first embodiment (Figure 3) in that it performs steps S126 and S131 instead of step S130.

[0045] The process in step S126 involves adjusting the diameter of the support portion 304 of the radiation detector 31 using the detector placement device 35, thereby adjusting the diameter of the PSF 32 to be close to the maximum diameter of the object to be measured 201a (Figures 6B and 6C).

[0046] Step S131 is the process of positioning the radiation detector 31, whose diameter has been adjusted by the detector positioning device 35, around the object to be measured 201.

[0047] Figure 6A schematically shows the operation of steps S105 to S110 in Figure 5. As described above, in the second embodiment, the diameter of the support portion 304 is predetermined to be larger than the maximum diameter of the object to be measured 201 (Figure 4A).

[0048] Figure 6B schematically shows the operation of steps S115 to S125 in Figure 5. In step S115 of Figure 5, the radioactivity measurement system 100 transports the object to be measured 201 to the radioactivity measurement device 30 along the arrow C11 shown in Figure 6B using the transport device 21.

[0049] Figure 6C schematically shows the operation of step S126 in Figure 5. As shown in Figure 6C, in step S126 of Figure 5, the radioactivity measurement system 100 adjusts the diameter of the support portion 304 of the radiation detector 31 using the detector placement device 35 (see arrow C12). This allows the radioactivity measurement system 100 to adjust the diameter of the PSF 32 to be as close as possible to the maximum diameter of the object to be measured 201a.

[0050] Figure 6D schematically shows the operation of step S131 in Figure 5. The radioactivity measurement system 100 moves the radiation detector 31, in which the PSF 32 is arranged in a spiral pattern, along the arrow C12 shown in Figure 6D, using the detector placement device 35 to position it around the object to be measured 201a.

[0051] (Third embodiment) Next, the operation of the second embodiment of the radioactivity measurement system 100 will be described with reference to Figure 7 and Figures 8A to 8D. Figure 7 is a flowchart showing the operation of the third embodiment of the radioactivity measurement system 100. Figures 8 to 8D are explanatory diagrams of the operation of the third embodiment of the radioactivity measurement system 100, respectively.

[0052] In the third embodiment, the diameter of the support portion 304 is set with a margin to be larger than the maximum diameter of the expected object to be measured 201 (Figure 8A). The margin is set to a degree that eliminates the possibility of interference when the detector placement device 35 is placed around the object to be measured 201. When the object to be measured 201 is brought into the radioactivity measuring device 30, the radioactivity measuring system 100 places the support portion 304 around the object to be measured 201 (Figure 8B). After this, the radioactivity measuring system 100 adjusts the diameter of the PSF 32 by adjusting the diameter of the support portion 304 (Figure 8C). At this time, the radioactivity measuring system 100 sets the diameter of the detector placement device 35 to the length obtained by adding the surface distance from the object to be measured 201, which is to be ensured in order to bring the PSF 32 close to the object to be measured 201 when measuring the radioactivity of the object to be measured 201, to the maximum diameter of the object to be measured 201. To adjust the diameter of the PSF32, the radioactivity measurement system 100 positions the PSF32 around the support part 304 (Figure 8D).

[0053] As shown in Figure 7, the operation of the second embodiment differs from the operation of the first embodiment (Figure 3) in that, instead of processing steps S120 and S130, the processing of steps S121 and S122 is performed between steps S120 and S125.

[0054] Step S121 involves the process of positioning the support portion 304 of the radiation detector 31, which is positioned by the detector positioning device 35 with a diameter larger than the maximum diameter of the object to be measured 201, around the object to be measured 201.

[0055] The process in step S122 involves adjusting the diameter of the support portion 304 using the detector placement device 35 so that it approaches the maximum diameter of the object to be measured 201.

[0056] Figure 8A schematically shows the operation of steps S105 to S110 in Figure 7. As described above, in the third embodiment, the diameter of the support portion 304 is set to a diameter larger than the maximum diameter of the object to be measured 201.

[0057] Figure 8B schematically shows the operation of steps S115 to S125 in Figure 7. In step S115 of Figure 7, the radioactivity measurement system 100 transports the object to be measured 201 to the radioactivity measurement device 30 along arrow D11 shown in Figure 8B using the transport device 21. Then, in step S121 of Figure 7, the radioactivity measurement system 100 positions the support part 304 around the object to be measured 201 along arrow D12 shown in Figure 8B using the transport device 21.

[0058] Figure 8C schematically shows the operation of step S122 in Figure 7. As shown in Figure 8C, in step S122 of Figure 7, the radioactivity measurement system 100 adjusts the diameter of the support portion 304 of the radiation detector 31 using the detector placement device 35 (see arrow D13).

[0059] Figure 8D schematically shows the operation of step S125 in Figure 7. As shown in Figure 8D, in step S125 of Figure 7, the radioactivity measurement system 100 uses the detector placement device 35 to position the PSF 32 around the support 304. This allows the radioactivity measurement system 100 to position the spirally arranged PSF 32 around the object to be measured 201.

[0060] <Main features of the radioactivity measurement system and radioactivity measurement method> The radioactivity measurement system 100 and radioactivity measurement method according to this embodiment can be configured to have the following features.

[0061] (1) As shown in Figure 1, the radioactivity measurement system 100 according to this embodiment comprises a dimensional measuring device 11, a radiation detector 31, a detector placement device 35, and a data acquisition device 42. The dimensional measuring device 11 is a component that measures the dimensions of the object to be measured 201. The radiation detector 31 is a component that detects radiation from the object to be measured 201. The detector placement device 35 is a component that places the radiation detector 31 in an arbitrary location. The data acquisition device 42 is a component that drives and controls the radiation detector 31 to collect radiation measurement data. The detection part of the radiation detector 31 (PSF 32 arranged in a spiral shape) is formed to have a diameter (width) larger than the maximum diameter (width) of the object to be measured 201. The detector placement device 35 places the radiation detector 31, which is composed of the detection part formed in this way, around the object to be measured 201.

[0062] In this embodiment of the radioactivity measurement system 100, a radiation detector 31, in which the detection unit (PSF32) is formed to have a diameter larger than the maximum diameter of the object to be measured 201, is placed around the object to be measured 201. With this embodiment of the radioactivity measurement system 100, the radiation detector 31 can be placed around the dismantled material (object to be measured) in a short time and in an effective manner. Therefore, the radioactivity measurement system 100 in this embodiment can easily measure objects with complex shapes. Furthermore, the radioactivity measurement system 100 in this embodiment can prevent the radiation detector 31 from coming into contact with and contaminating the object to be measured 201.

[0063] Furthermore, the radioactivity measurement system 100 according to this embodiment enables common measurements for dismantled objects (objects to be measured 201) with complex shapes, diverse shapes, and dimensions. In addition, the radioactivity measurement system 100 according to this embodiment can measure radioactivity without cutting the dismantled objects (objects to be measured 201) to match the size of the detection unit (PSF32) of the radiation detector 31.

[0064] Furthermore, if the diameter of the detection unit (PSF32) of the radiation detector 31 is fixed, and the detection unit (PSF32) of the radiation detector 31 is not sufficiently large relative to the dimensions of the dismantled material (object to be measured 201), then it will not be possible to properly position the radiation detector 31 around the dismantled material (object to be measured 201) in a short amount of time. In this case, the measurement of radioactivity will take longer, and the throughput performance will decrease. In contrast, the radioactivity measurement system 100 according to this embodiment has a detection unit (PSF32) of the radiation detector 31 formed to have a diameter larger than the maximum diameter of the object to be measured 201. With this radioactivity measurement system 100 according to this embodiment, the radiation detector 31 can be properly positioned around the dismantled material (object to be measured) in a short amount of time. Therefore, the radioactivity measurement system 100 according to this embodiment can shorten the time required for radioactivity measurement and improve throughput performance. With this radioactivity measurement system 100 according to this embodiment, efficient measurement is possible from the viewpoint of throughput, and the entire processing and disposal of the dismantled material (object to be measured 201) can be carried out efficiently.

[0065] (2) As shown in Figure 1, in the radioactivity measurement system 100 described in item (1) above, the radiation detector 31 is a scintillation fiber type radiation detector in which the detection unit PSF32 (scintillation fiber) is arranged in a spiral shape.

[0066] In this embodiment of the radioactivity measurement system 100, the detection unit, PSF32 (scintillation fiber), is arranged in a spiral shape. In this embodiment of the radioactivity measurement system 100, the radiation detector 31 can accurately measure the shape and dimensions of the object to be measured 201.

[0067] (3) As shown in Figure 2, in the radioactivity measurement system 100 described in item (2) above, the detector arrangement device 35 is a detector helical arrangement device in which PSF32 (scintillation fiber) is arranged in a helical shape.

[0068] The radioactivity measurement system 100 according to this embodiment can arrange PSF32 (scintillation fiber) in a helical shape.

[0069] (4) As shown in Figure 2, in the radioactivity measurement system 100 described in item (3) above, the detector placement device 35 has a diameter variable device 303 that adjusts the diameter of the PSF32 (scintillation fiber) based on dimensional information.

[0070] In this embodiment, the radioactivity measurement system 100 can adjust the diameter of the detection unit, PSF32 (scintillation fiber), to a diameter larger than the maximum diameter of the object to be measured 201.

[0071] (5) As shown in the first embodiment in Figure 3, the radioactivity measurement method according to this embodiment includes a dimensional measurement step (step S105), a detector placement step (steps S115 to S130), and a data acquisition step (step S135) (the same applies to other embodiments). The dimensional measurement step is a step of measuring the dimensions of the object to be measured 201. The detector placement step is a step of placing the radiation detector 31 in an arbitrary location. The data acquisition step is a step of driving and controlling the radiation detector 31 to collect radiation measurement data. The detection part of the radiation detector 31 (PSF 32 arranged in a spiral shape) is formed to have a diameter (width) larger than the maximum diameter (width) of the object to be measured 201. In the detector placement step, the radiation detector 31, which is composed of the detection part formed in this way, is placed around the object to be measured 201 (steps S120 to S125).

[0072] In this embodiment of the radioactivity measurement method, a radiation detector 31, in which the detection unit (PSF32) is formed to have a diameter larger than the maximum diameter of the object to be measured 201, is placed around the object to be measured 201. This radioactivity measurement method according to this embodiment can easily measure objects with complex shapes. Furthermore, this radioactivity measurement method according to this embodiment can prevent the radiation detector 31 from coming into contact with and contaminating the object to be measured 201.

[0073] (6) As shown in the first embodiment in Figure 3, in the radioactivity measurement method of item (5) above, the detector placement step includes steps S120, S125, and S130. Step S120 is a step of adjusting the diameter of the support portion 304 of the radiation detector 31 to a diameter larger than the maximum diameter of the object to be measured 201, based on the dimensional information of the object to be measured 201. Step S125 is a step of arranging the PSF32 (scintillation fiber), which is the detection part of the radiation detector 31, in a spiral shape around the support portion 304 (outer circumference). Step S130 is a step of arranging the radiation detector 31 around the object to be measured 201.

[0074] In this embodiment of the radioactivity measurement method, the diameter of the support portion 304 of the radiation detector 31 is adjusted to be larger than the maximum diameter of the object to be measured 201. Furthermore, in this embodiment of the radioactivity measurement method, the PSF32 (scintillation fiber), which is the detection part of the radiation detector 31, is arranged spirally around the support portion 304, and the radiation detector 31 is positioned around the object to be measured 201. This radioactivity measurement method in this embodiment makes it easier to measure objects with complex shapes. In addition, this embodiment of the radioactivity measurement method prevents the radiation detector 31 from coming into contact with and contaminating the object to be measured 201.

[0075] (7) As shown in the second embodiment in Figure 5, in the radioactivity measurement method of item (5) above, the detector placement step includes steps S120, S125, S126, and S131. Step S120 is a step of adjusting the diameter of the support portion 304 of the radiation detector 31 to a diameter larger than the maximum diameter of the object to be measured 201, based on the dimensional information of the object to be measured 201. Step S125 is a step of arranging the PSF32 (scintillation fiber), which is the detection part of the radiation detector 31, in a spiral shape around the support portion 304. Step S126 is a step of adjusting the diameter of the support portion 304 so that the diameter of the PSF32 approaches the maximum diameter of the object to be measured 201. Step S131 is a step of arranging the radiation detector 31 with the adjusted diameter of the PSF32 around the object to be measured 201.

[0076] The radioactivity measurement method according to this embodiment adjusts the diameter of the support portion 304 of the radiation detector 31 to be larger than the maximum diameter of the object to be measured 201, based on the dimensional information of the object to be measured 201. Then, the radioactivity measurement method according to this embodiment arranges the PSF32 (scintillation fiber), which is the detection part of the radiation detector 31, in a spiral shape around the support portion 304. Subsequently, the radioactivity measurement method according to this embodiment adjusts the diameter of the PSF32 to be closer to the maximum diameter of the object to be measured 201 by adjusting the diameter of the support portion 304, and arranges the radiation detector 31 with the adjusted diameter of the PSF32 around the object to be measured 201. This radioactivity measurement method according to this embodiment can easily measure objects with complex shapes. Furthermore, the radioactivity measurement method according to this embodiment can prevent the radiation detector 31 from coming into contact with and contaminating the object to be measured 201.

[0077] (8) As shown in the third embodiment in Figure 7, in the radioactivity measurement method of item (5) above, the detector placement step includes steps S121, S122, and S125. Step S121 is the step of placing the support portion 304 of the radiation detector 31, which is positioned with a diameter larger than the maximum diameter of the object to be measured 201, around the object to be measured 201. Step S122 is the step of adjusting the diameter of the support portion 304 to be closer to the maximum diameter of the object to be measured 201. Step S125 is the step of arranging the PSF32 (scintillation fiber), which is the detection part of the radiation detector 31, in a spiral shape around the support portion 304.

[0078] In this embodiment of the radioactivity measurement method, a support portion 304 of the radiation detector 31, which has a diameter larger than the maximum diameter of the object to be measured 201, is placed around the object to be measured 201. Then, in this embodiment of the radioactivity measurement method, the diameter of the support portion 304 is adjusted to approach the maximum diameter of the object to be measured 201, and the PSF32 (scintillation fiber) is arranged spirally around the support portion 304. This radioactivity measurement method in this embodiment can easily measure objects with complex shapes. Furthermore, this embodiment of the radioactivity measurement method can prevent the radiation detector 31 from coming into contact with and contaminating the object to be measured 201.

[0079] As described above, the radioactivity measurement system 100 according to this embodiment makes it easier to measure objects with complex shapes and prevents the radiation detector from coming into contact with and contaminating the object.

[0080] The present invention is not limited to the embodiments described above, and includes various modifications. For example, the embodiments described above are described in detail for the purpose of clearly illustrating the present invention, and are not necessarily limited to those having all the configurations described. Furthermore, it is possible to replace some of the configurations of the embodiments with other configurations, and it is also possible to add other configurations to the configurations of the embodiments. In addition, it is possible to add, delete, or replace some of the configurations of each configuration with other configurations. [Explanation of Symbols]

[0081] 11. Dimensional measuring device 12 Dimensional measuring control device 21 Conveying device 22 Conveyance control device 30 Radioactivity measuring device 31. Radiation detector (Scintillation fiber type radiation detector) 32 PSF (Detection Unit) 33 PSF support part 34 PSF feeder 35. Detector placement device (helical detector placement device) 41. Arrangement control device 42 Data acquisition device 43 Radioactivity conversion device 100 Radioactivity Measurement Systems 201 Object to be measured 301 Post 302 Support device (spiral winding device) 303 Diameter Variable Device 304 Support part

Claims

1. A dimensional measuring device for measuring the dimensions of an object, A radiation detector for detecting radiation from the object to be measured, A detector placement device for placing the aforementioned radiation detector at any location, The system includes a data acquisition device that drives and controls the aforementioned radiation detector to collect radiation measurement data, The detector placement device has a detection unit formed to have a diameter larger than the maximum diameter of the object to be measured, based on the dimensional information of the object to be measured acquired by the dimensional measuring device. The radiation detector, which is composed of the detection unit formed in this manner, is placed around the object to be measured. A radioactivity measurement system characterized by the following features.

2. In the radioactivity measurement system according to claim 1, The radiation detector is a scintillation fiber type radiation detector in which the scintillation fibers, which are the detection unit, are arranged in a helical shape. A radioactivity measurement system characterized by the following features.

3. In the radioactivity measurement system according to claim 2, The detector arrangement device is a detector helical arrangement device in which the scintillation fibers are arranged in a helical shape. A radioactivity measurement system characterized by the following features.

4. In the radioactivity measurement system according to claim 3, The detector placement device has a diameter variable device that adjusts the diameter of the scintillation fiber based on the dimensional information. A radioactivity measurement system characterized by the following features.

5. A dimensional measurement process for measuring the dimensions of an object to be measured, A detector placement step involves placing a radiation detector at an arbitrary location, The process includes a data acquisition step of driving and controlling the radiation detector to collect radiation measurement data, In the detector placement step, the detection unit is formed to have a diameter larger than the maximum diameter of the object to be measured, based on the dimensional information of the object to be measured acquired in the dimensional measurement step. The radiation detector, which is composed of the detection unit formed in this way, is then placed around the object to be measured. A method for measuring radioactivity characterized by the following features.

6. In the radioactivity measurement method described in claim 5, The aforementioned detector placement step is, A step of adjusting the diameter of the support portion of the radiation detector to a diameter larger than the maximum diameter of the object to be measured, based on the dimensional information of the object to be measured. The steps include: arranging the scintillation fiber, which is the detection part of the radiation detector, in a spiral shape around the support part; The process includes the step of arranging the radiation detector around the object to be measured. A method for measuring radioactivity characterized by the following features.

7. In the radioactivity measurement method described in claim 5, The aforementioned detector placement step is, A step of adjusting the diameter of the support portion of the radiation detector to a diameter larger than the maximum diameter of the object to be measured, based on the dimensional information of the object to be measured. The steps include: arranging the scintillation fiber, which is the detection part of the radiation detector, in a spiral shape around the support part; The process involves adjusting the diameter of the support portion to bring the diameter of the scintillation fiber closer to the maximum diameter of the object to be measured, The process includes the step of arranging the radiation detector around the object to be measured. A method for measuring radioactivity characterized by the following features.

8. In the radioactivity measurement method described in claim 5, The aforementioned detector placement step is, A step of arranging the support portion of the radiation detector, which has a diameter larger than the maximum diameter of the object to be measured, around the object to be measured, A step of adjusting the diameter of the support portion to be as close as possible to the maximum diameter of the object to be measured, The process includes arranging the scintillation fiber, which is the detection part of the radiation detector, in a spiral shape around the support part. A method for measuring radioactivity characterized by the following features.

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