JP2016050843A - Radiation measuring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radiation measuring device which does not require a mechanism for sliding collimators.SOLUTION: A radiation measuring device includes: a plurality of radiation detectors for inspecting radioactive substances and for identifying positions of the radioactive substances; a shield for shielding the plurality of radiation detectors; a plurality of collimators provided in front of each of the plurality of radiation detectors in order of decreasing view angle from the side of an opening of the shield; and a plurality of radiation detection elements which are provided to each of the plurality of radiation detectors and which are arranged along an optical axis direction of the plurality of collimators.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a radiation measuring apparatus.

  In a radiation measuring apparatus, as one of methods for controlling the radiation measurement range, there is a method that is performed by changing the viewing angle of a collimator used in combination with a radiation detector. A collimator is an instrument for irradiating a radiation detection element with radiation emitted from a certain measurement range by combining with a shield that shields radiation.

  As a technique for changing the viewing angle of the collimator, there is a technique described in Patent Document 1. Patent Document 1 discloses a technique for freely adjusting a viewing angle by mounting a collimator slidably on a small-diameter portion of a detector body and moving the collimator forward and backward to vary the distance from the opening to the radiation detection element. Have been described.

JP 2002-214353 A

  As described above, the conventional technique described in Patent Document 1 is configured to adjust the viewing angle by sliding the collimator. Therefore, a mechanism for sliding the collimator is required, and the radiation measuring apparatus is enlarged. To do.

  Then, an object of this invention is to provide the radiation measuring device which does not require the mechanism for sliding a collimator.

In order to solve the above problems, for example, the configuration described in the claims is adopted.
The present application includes a plurality of means for solving the above problems.
Multiple radiation detectors to investigate radioactive material and identify the location of radioactive material;
A shield for shielding the plurality of radiation detectors;
A plurality of collimators provided on the front side of each of the plurality of radiation detectors in order of increasing viewing angle from the opening side of the shield,
A plurality of radiation detection elements provided in each of the plurality of radiation detectors and disposed along an optical axis direction of the plurality of collimators;
It is characterized by providing.

According to the present invention, since a mechanism for sliding the collimator is unnecessary, the radiation measuring apparatus can be downsized.
Problems, configurations, and effects other than those described above will become apparent from the following description of embodiments.

It is an example of the block diagram which shows the radiation measuring device which concerns on embodiment of this invention. 1 is an example of a block diagram illustrating a configuration of a measurement system according to Embodiment 1. FIG. It is an example of the figure which shows gamma ray energy distribution. It is an example of the figure which shows the gamma ray energy distribution example (1) by the radiation detector for investigation, and the radiation detector for position identification. It is an example of the figure which shows the gamma ray energy distribution example (2) by the radiation detector for investigation, and the radiation detector for position identification. It is an example of the conceptual diagram of the boiling water reactor which shows the example of an application location of a radiation measuring device. 10 is an example of a block diagram illustrating a configuration of a measurement system according to Embodiment 2. FIG. It is an example of the schematic diagram explaining the Eu-154 position identification method. FIG. 9 is an example of a block diagram illustrating a configuration of a measurement system according to a third embodiment. It is an example of the conceptual diagram explaining the visualization by Eu-154 position identification.

  Hereinafter, modes for carrying out the present invention (hereinafter referred to as “embodiments”) will be described in detail with reference to the drawings. The present invention is not limited to the embodiment. In the present specification and drawings, the same components or components having substantially the same function are denoted by the same reference numerals, and redundant description is omitted.

<Radioactive substance detection environment>
The inventors are able to quickly investigate a wide area even in an environment that exists in a nuclear reactor facility, and whose radioactivity distribution is complex and whose radioactivity distribution and geometric conditions may change over time. In addition, various studies were made on a radiation measuring apparatus that can detect radioactive substances contained in fuel debris with high positional resolution. And the radiation measuring device concerning this embodiment was made based on the new knowledge acquired as the examination result. Examples of the reactor facility include facilities such as a reactor containment vessel, a reactor pressure vessel, a reactor pressure suppression chamber, or a torus chamber in a nuclear power plant.

  In recent years, there has been a demand for fuel debris detection technology that can be applied in nuclear reactor facilities such as a reactor containment vessel, a reactor pressure vessel, a reactor pressure suppression chamber, or a torus chamber. As one of methods for estimating the presence or absence of fuel debris, there is a method of measuring specific radiation emitted from fuel debris. Typical examples of the radionuclide include Ce-144 (cerium) and Eu-154 (europium).

  However, Ce-144 has a short half-life (about 239 days). On the other hand, Eu-154 has a long half-life (about 8.6 years) and a relatively large content inside the fuel assembly, and is therefore a promising measurement target for estimating the presence or absence of fuel debris. In order to measure the γ-rays emitted from Eu-154 and Ce-144, it is necessary to apply a radiation detector capable of analyzing nuclides and an analyzer.

  The research area for estimating the presence or absence of fuel debris is a nuclear reactor facility such as a reactor containment vessel, a reactor pressure vessel, a reactor pressure suppression chamber, or a torus chamber. Since this investigation area is wide, it is required to investigate the wide area quickly. On the other hand, in order to improve the accuracy of estimating the presence or absence of fuel debris containing Eu-154 and Ce-144, it is required to perform measurement with high position resolution. These survey areas have high atmospheric dose rates and are difficult for workers to access.

  For this purpose, the investigation device is mounted on an access device such as a crawler, and the investigation at the nuclear reactor facility is advanced by access by the access device. However, there is a possibility that the equipment may break down due to the limit of the weight of the access device and the high atmospheric dose rate. For this reason, the configuration of the investigation device is required to be simple. Therefore, there is a need for a radiation measuring apparatus that can quickly investigate a wide range and can detect Eu-154 and Ce-144 accompanying fuel debris with high position resolution and that is simple in equipment mounted on the access device.

  In the radiation measuring apparatus, the radiation measurement range is controlled by changing the viewing angle of a collimator used in combination with the radiation detector. When measuring a wide range, it is conceivable to increase the viewing angle of the collimator (expand the aperture). Further, when measuring with high position resolution, it is conceivable to reduce the viewing angle of the collimator.

<Radiation measurement apparatus according to an embodiment of the present invention>
[Configuration of radiation measurement equipment]
FIG. 1 is an example of a configuration diagram illustrating a radiation measuring apparatus according to an embodiment of the present invention. The radiation measurement apparatus 10 according to the present embodiment includes, for example, two radiation detectors 11 and 12, a shield 13, two collimators 14 and 15, and two radiation detection elements 16 and 17. And each detection signal of the radiation detectors 11 and 12 is supplied to the measurement system 20 mentioned later by signal cable 18A, 18B with high noise resistance, such as a coaxial cable.

  Of the two radiation detectors 11 and 12, the radiation detector 11 on the opening 13A side of the shield 13 is an investigation radiation detector that investigates radioactive substances. The radiation detector 12 arranged behind the radiation detector 11 (opposite the opening 13A) is a position identification radiation detector that identifies the position of the radioactive substance.

  The radiation measuring apparatus 10 according to the present embodiment is used for the investigation of radioactive substances and the measurement of radioactive substances in a nuclear reactor facility such as a reactor containment vessel, a reactor pressure vessel, a reactor pressure suppression room, or a torus room. Presence or absence of fuel debris is estimated by identifying the position. In the radiation measuring apparatus 10 according to the present embodiment, as a radioactive substance, a radionuclide having a radioactivity half-life longer than a predetermined period (for example, about 8 years), such as Eu-154 (europium), is measured (investigation and position). To be identified). This does not limit Eu-154 as a measurement target.

  Therefore, the investigation radiation detector 11 investigates Eu-154, and the position identification radiation detector 12 identifies the position of Eu-154. The shield 13 is made of a material such as lead, iron, or tungsten, and shields the investigation radiation detector 11 and the position identification radiation detector 12 from radiation incident from outside the viewing angle.

  The collimators 14 and 15 are instruments for guiding the radiation incident on the shield 13 to the radiation detection elements 16 and 17, and provide a viewing angle for measuring a wide range and measuring with high position resolution. The collimator 14 is provided on the front side of the investigation radiation detector 11. The collimator 14 is a wide-aperture investigation collimator having a large viewing angle in order to measure a wide range. The collimator 15 is provided on the front side of the position identification radiation detector 12. The collimator 15 is a narrow aperture position identification collimator having a small viewing angle in order to perform measurement with high position resolution.

  That is, the investigation collimator 14 and the position identification collimator 15 are provided on the front sides of the investigation radiation detector 11 and the position identification radiation detector 12 in descending order of the viewing angle from the opening 13A side of the shield 13. ing. The investigation collimator 14 and the position identification collimator 15 are preferably provided so that their optical axes coincide.

  Here, a taper type is illustrated as a representative example of the shape of the investigation collimator 14. However, the investigation collimator 14 is not limited to the tapered shape. The viewing angle defined by the investigation collimator 14 is indicated by a viewing angle θ1 in FIG. Further, a pinhole type is illustrated as a representative example of the shape of the position identification collimator 15. However, the position identification collimator 15 is not limited to the pinhole type. The viewing angle defined by the position identification collimator 15 is indicated by a viewing angle θ2 in FIG. The viewing angle θ1 and the viewing angle θ2 can be arbitrarily set according to the shapes of the investigation collimator 14 and the position identification collimator 15.

  The radiation detection element 16 is provided in the front part of the investigation radiation detector 11. The radiation detection element 17 is provided in the front part of the position identification radiation detector 12. The radiation detection element 16 and the radiation detection element 17 are arranged along the optical axis direction of the investigation collimator 14 and the position identification collimator 15. The radiation detection element 16 and the radiation detection element 17 are sensors capable of nuclide analysis.

The radiation detection element 16 and the radiation detection element 17 are CdTe, CZT, TlBr, LaBr ₃ (Ce), LaCl ₃ (Ce), LSO, LYSO, GAGG (Ce), LuAG (Pr), NaI (Tl), YAP ( Ce) or GSO. By using such a material, γ rays (γ ray energy: 1274, 1596 keV) radiated from Eu-154 can be measured with high accuracy, which can contribute to improvement in measurement accuracy of Eu-154.

  The radiation measuring apparatus 10 including the investigation radiation detector 11, the position identification radiation detector 12, the shield 13, the investigation collimator 14, the position identification collimator 15, the radiation detection elements 16, 17 and the like is preferably an access device. 30 is used. As the access device 30, various options such as a crawler and a wall surface adsorption type are conceivable.

  The radiation measuring apparatus 10 according to the present embodiment having the above-described configuration employs a configuration in which the radiation detector 11 for investigation and the radiation detector 12 for position identification are shielded by the shield 13, and therefore, under a high dose rate environment. However, the investigation radiation detector 11 and the position identification radiation detector 12 can operate normally. Further, by providing the investigation collimator 14 having a wide opening on the front side of the investigation radiation detector 11, measurement of Eu-154 can be realized in a wide range by the investigation radiation detector 11.

  Further, in the radiation measurement apparatus 10 according to the present embodiment, the radiation detection element 16 and the radiation detection element 17 are arranged along the optical axis direction of the investigation collimator 14, and between the radiation detection element 16 and the radiation detection element 17. A position identification collimator 15 is arranged at the center. Thereby, since the γ-ray transmitted through the radiation detection element 16 and focused by the position identification collimator 15 can be measured by the radiation detection element 17, the position of Eu-154 can be determined with the position resolution determined by the position identification collimator 15. Can be identified.

  Further, in the radiation measuring apparatus 10 according to the present embodiment, the investigation radiation detector 11 and the position identification radiation detector 12 are housed in one shield 13 and a mechanism for adjusting the viewing angle ( This corresponds to a mechanism for sliding the collimator in the prior art). Thereby, size reduction of the radiation measuring apparatus 10 and further simplification of equipment mounted on the access apparatus 30 can be realized.

  Due to the effects described above, the radiation measuring apparatus 10 according to the present embodiment can effectively perform fuel debris in an environment such as a reactor containment vessel, a reactor pressure vessel, a reactor pressure suppression chamber, or a torus chamber in a nuclear power plant. It is possible to estimate the presence or absence of According to the radiation measuring apparatus 10 according to the present embodiment, the radionuclide Eu-154 having a long half-life associated with the fuel debris can be detected with a high position resolution, which can quickly investigate a wide range.

  Moreover, since the radiation measuring device 10 is mounted on the access device 30, it is possible to access an environment where it is difficult for a worker to enter, so that the measurement range of Eu-154 can be dramatically improved and the position of the fuel debris can be estimated. You can save time.

  In the above-described embodiment, two radiation detectors are provided, and two collimators and two radiation detection elements are provided correspondingly. However, the present invention is not limited to this, and the radiation detector, collimator, and A configuration in which three or more radiation detection elements are provided is also possible. For example, a plurality of investigation radiation detectors 11 are provided, and a plurality of investigation collimators 14 having different viewing angles are arranged on the front sides of the plurality of investigation radiation detectors 11 from the opening 13A side of the shield 13 with a viewing angle. The arrangement | positioning arrange | positioned in order with a big can be taken. By adopting this configuration, the radioactive substance can be investigated step by step in descending order of viewing angle. Also, a combination of a survey radiation detector 11 and a position identification radiation detector 12 at a certain viewing angle, or a combination of a survey radiation detector 11 and a position identification radiation detector 12 at another viewing angle. It is also possible to selectively use the viewing angle of the radiation detector 11 for investigation.

[Measurement system configuration]
Next, the gamma ray energy distribution is measured based on the outputs of the investigation radiation detector 11 and the position identification radiation detector 12, and the peak of the radioactive substance, that is, Eu-154 is analyzed from the measurement result. The configuration will be described. Below, the specific Example of a measurement system is described.

(Example 1)
FIG. 2 is an example of a block diagram illustrating the configuration of the measurement system according to the first embodiment. The measurement system 20 receives the outputs of the radiation detector 11 for investigation and the radiation detector 12 for position identification transmitted from the radiation measuring apparatus 10 via signal cables 18A and 18B. As shown in FIG. 2, the measurement system 20 includes a measurement device 21 and an analysis device 23 that process the output of the investigation radiation detector 11, and a measurement device 22 and an analysis device that process the output of the position identification radiation detector 12. 24 and a display device 25.

  The measuring devices 21 and 22 measure the γ-ray energy distribution from the outputs of the investigation radiation detector 11 and the position identification radiation detector 12, respectively. The analysis devices 23 and 24 analyze the peak of Eu-154 from the measurement result of the γ-ray energy distribution by the measurement devices 21 and 22, respectively. The display device 25 displays the measurement result of the γ-ray energy distribution by the measurement devices 21 and 22 and the analysis result of the peak of Eu-154 by the analysis devices 23 and 24.

  FIG. 3 shows the γ-ray energy distribution. As an example, a 662 keV γ-ray peak P11 of Cs-137, a 796 keV γ-ray peak P12 of Cs-134, a 1274 keV γ-ray peak P13 of Eu-154, and a 1596 keV γ-ray peak P14 of Eu-154 are shown. . From this γ-ray energy distribution, the counting rate is calculated as the intensity of the γ-ray peak using the analyzers 23 and 24.

  FIG. 4 shows an example (1) of γ-ray energy distribution by the investigation radiation detector 11 and the position identification radiation detector 12. In FIG. 4, the γ-ray energy distribution by the investigation radiation detector 11 is indicated by a solid line, and the γ-ray energy distribution by the position identification radiation detector 12 is indicated by a broken line. When Eu-154 is within the region of the viewing angle θ1 (see FIG. 1) and outside the region of the viewing angle θ2, the γ-ray peak P13 and the γ-ray peak P14 by Eu-154 are γ by the investigating radiation detector 11. It is confirmed only by the linear energy distribution (solid line), and is not detected by the γ-ray energy distribution (broken line) by the position identifying radiation detector 12.

  FIG. 5 shows an example (2) of γ-ray energy distribution by the investigation radiation detector 11 and the position identification radiation detector 12. 5, as in FIG. 4, the γ-ray energy distribution by the investigation radiation detector 11 is indicated by a solid line, and the γ-ray energy distribution by the position identification radiation detector 12 is indicated by a broken line. When Eu-154 is in the region of the viewing angle θ1 (see FIG. 1) and in the region of the viewing angle θ2, the γ-ray peak P13 and the γ-ray peak P14 by Eu-154 are γ by the investigation radiation detector 11. It is detected by the linear energy distribution (solid line) and the γ-ray energy distribution (broken line) by the position identifying radiation detector 12.

  The measurement system 20 according to the first embodiment described above includes the measurement devices 21 and 22 that respectively measure the γ-ray energy distributions from the outputs of the radiation detector 11 for investigation and the radiation detector 12 for position identification. Γ-rays radiated from 154 (γ-ray energy: 1274, 1596 keV) can be measured. Moreover, by providing the analyzers 23 and 24 for analyzing the output by Eu-154 from the measurement result of the γ-ray energy distribution, and the display device 25 for displaying the γ-ray energy distribution and the analysis results by the analyzers 23 and 24, respectively. The strength of Eu-154 can be visually confirmed, and work efficiency can be improved. Thereby, the measurement accuracy and work efficiency of Eu-154 can be improved.

<Application examples of radiation measurement equipment>
Here, the application part of the radiation measuring apparatus 10 according to the present embodiment when investigating the radioactive substance and identifying the position of the radioactive substance will be specifically described.

  In FIG. 6, the example of an application location of the radiation measuring device 10 is shown. The application location of the radiation measuring apparatus 10 is a general nuclear power plant. Here, as an example, a description will be given using a conceptual diagram of a boiling water reactor.

  The boiling water reactor 40 includes a reactor building 41, a reactor containment vessel 42, a reactor pressure vessel 43, a reactor water recirculation system 44, a reactor pressure suppression chamber 45, a torus chamber 46, a through portion 47, and the like. Has been. In order to confirm the presence / absence of the fuel debris 50 in these facilities, the radiation measuring apparatus 10 includes, for example, the inside of the reactor containment vessel 42, the reactor pressure vessel 43, the reactor pressure suppression chamber 45, or the torus chamber 46. It is mounted on the access device 30 and accessed.

  The access device 30 is controlled by the access device control device 32 via the power cable 31. When accessing, it is performed through the existing penetration part 47 or an intrusion route constructed by construction or the like. The radiation measurement apparatus 10 is connected to the measurement system 20 via signal cables 18A and 18B. Here, as an example, a configuration in which the measurement system 20 is installed in the reactor building 41 is employed, but a configuration in which the measurement system 20 is installed outside the reactor building 41 may be employed.

  The fuel debris 50 is composed of U (uranium) and Pu (plutonium), which are nuclear fuels, fission products, and molten in-core structures. In addition, it is considered that the constituent ratio, shape, and geometric conditions of the elements of the fuel debris 50 vary depending on the location where the fuel debris 50 exists. In order to detect the presence or absence of the fuel debris 50, it is necessary to detect components contained in the fuel debris 50. Components for detection include Ce-144 and Eu-154. However, Ce-144 has a short half-life of about 239 days. On the other hand, Eu-154 has a long half-life of about 8.6 years and a relatively large content inside the fuel assembly. For this reason, in the present embodiment, Eu-154 is set as a measurement target for estimating the presence or absence of the fuel debris 50. This does not limit Eu-154 as a measurement target. Eu-154 has a feature of emitting gamma rays of 123 keV, 723 keV, 873 keV, 1004 keV, and 1274 keV.

  In these facilities, Cs-137, Cs-134, etc. which are fission products, Co-60, Co-58, etc. produced by activation of the reactor internal structure are present as distribution in the background. To do. Here, Cs-137 emits 662 keV gamma rays and has a characteristic of decaying with a half-life of about 30 years. Cs-134 emits gamma rays of 602 keV, 796 keV, 802 keV, and 1365 keV, and has a characteristic of decaying with a half-life of about 2 years. Co-60 emits 1173 keV and 1332 keV gamma rays and has a characteristic of decaying with a half-life of about 5 years. Co-58 mainly emits gamma rays of 511 keV and 811 keV and has a characteristic of decaying with a half-life of about 70 days. In order to detect Eu-154 which is a measurement object in these background environments, the radiation detection element 16 and the radiation detection element 17 which are sensors capable of nuclide analysis are used.

(Example 2)
In the second embodiment, which is another embodiment of the present invention, after investigating the presence or absence of Eu-154 using the investigation radiation detector 11, when the Eu-154 is detected, the radiation detector 12 for position identification is used. It is an example which identifies the position of Eu-154 using.

  FIG. 7 is an example of a block diagram illustrating the configuration of the measurement system according to the second embodiment. In the measurement system 60 according to the second embodiment, the functions of the analysis devices 61 and 62 provided in the subsequent stage of the measurement devices 21 and 22 are different from the functions of the analysis devices 23 and 24 of the first embodiment.

  Specifically, the analysis device 61 uses the output of the investigation radiation detector 11 given through the measuring device 21 and the position information of the access device 30 given from the access device control device 32 to determine the investigation radiation detector 11. It has an Eu-154 investigation algorithm that identifies the presence or absence of Eu-154 at the viewing angle θ1 and outputs the determination result.

  The analysis device 62 uses the output of the position identification radiation detector 12 given through the measuring device 22 and the position information of the access device 30 obtained from the access device control device 32 to determine the viewing angle θ2 of the position identification radiation detector 12. And Eu-154 position identification algorithm for identifying the presence or absence of Eu-154 and outputting the determination result.

  The measurement system 60 according to the second embodiment further includes a control device 63 that controls the analysis devices 61 and 62. The control device 63 includes an Eu-154 investigation and identification process described later. Details of the function of the control device 63 will be described later.

  Next, the Eu-154 position identification method using the Eu-154 survey algorithm and the Eu-154 identification algorithm will be described with reference to FIG. FIG. 8 is an example of a schematic diagram illustrating the Eu-154 position identification method.

  It is assumed that the fuel debris 50 exists with respect to the measurement surface S by the radiation measuring apparatus 10. The measurement range S1 based on the viewing angle θ1 of the investigation radiation detector 11 and the measurement range S2 based on the viewing angle θ2 of the position identification radiation detector 12 are shown on the measurement surface S. In FIG. 8A, since the position where the fuel debris 50 exists is outside the measurement range S2 within the measurement range S1, the analysis device 61 detects Eu-154 based on the Eu-154 investigation algorithm. With this detection as a trigger, the analysis device 62 starts Eu-154 position identification based on the Eu-154 position identification algorithm.

  Here, as an example, the measurement range S2 based on the viewing angle θ2 of the position identification radiation detector 12 is translated in the vertical and horizontal directions indicated by arrows in FIG. 8A. Then, as shown in FIG. 8B, when the fuel debris 50 falls within the measurement range S2, Eu-154 is detected based on the Eu-154 position identification algorithm. Further, the position of the fuel debris 50 is identified from the position information of the access device 30 when Eu-154 is detected.

  The control device 63 sends a command signal for moving the access device 30 within the range of the viewing angle θ1 of the investigation radiation detector 11 after the presence of Eu-154 is confirmed in the analysis result by the Eu-154 investigation algorithm. This is supplied to the access device control device 32. Then, the control device 63 analyzes the output of the position identification radiation detector 12 by the Eu-154 position identification algorithm by the Eu-154 investigation and identification process, and Eu in the range of the viewing angle θ1 of the investigation radiation detector 11. The position of -154 is identified.

  The measurement system 60 according to the second embodiment described above identifies the presence or absence of Eu-154 at the viewing angle θ1 of the investigation radiation detector 11 from the output of the investigation radiation detector 11 and the position information of the access device 30. In addition, the analysis device 61 is provided with an Eu-154 survey algorithm that outputs a determination result. Thereby, since the determination result in the wide range measurement can be obtained during the investigation with the actual machine, the work efficiency can be improved.

  Further, the measurement system 60 according to the second embodiment determines whether Eu-154 exists in the viewing angle θ2 of the position identification radiation detector 12 from the output of the position identification radiation detector 12 and the position information of the access device 30. And the analysis device 62 is provided with an Eu-154 position identification algorithm for outputting the determination result. Thereby, since the determination result in Eu-154 position identification can be obtained during the investigation with an actual machine, work efficiency can be improved.

  Further, after the presence of Eu-154 is confirmed, the access device 30 is moved in the range of the viewing angle θ1, and the output of the radiation detector 12 for position identification is analyzed by the Eu-154 position identification algorithm. The controller 63 is equipped with a Eu-154 survey and identification process for identifying the position. Thereby, it is possible to shift from the determination result in the wide range measurement to the Eu-154 position identification during the investigation with the actual machine, and the determination result in the Eu-154 position identification can be obtained, so that the work efficiency can be improved. it can.

(Example 3)
The third embodiment, which is another embodiment of the present invention, is an example of visualizing the position of Eu-154 by superimposing the analysis results of the Eu-154 identification algorithm and the Eu-154 research algorithm on the image obtained by the research camera. It is.

  FIG. 9 is an example of a block diagram illustrating a configuration of a measurement system according to the third embodiment. The measurement system 70 according to the third embodiment is basically the same as that shown in FIG. 7 except for the configuration including the investigation camera (imaging device) 71, the cable 72, the camera control analysis device 73, and the visualization analysis device 74. It is.

  A general camera can be used as the investigation camera 71. The camera control analysis device 73 controls the investigation camera 71 for photographing and analyzes the output of the investigation camera 71. The visualization analyzing device 74 superimposes the Eu-154 survey algorithm, the Eu-154 position identification algorithm, and the analysis results in the Eu-154 survey and identification process with the output of the survey camera 71 to visualize the position of Eu-154. Has a visualization algorithm.

  FIG. 10 is an example of a conceptual diagram illustrating visualization by Eu-154 position identification. Here, as an example, a pipe 81 having a certain curvature is imaged perpendicularly by the investigation camera 71 with respect to the pipe axis direction. A mesh 82 indicates an area where the radiation measuring apparatus 10 detects the presence or absence of Eu-154. The shading in the pixel represents the intensity of Eu-154, and the intensity of Eu-154 is dark when it is strong. The accuracy of the mesh 82 depends on the measurement region S1 and the measurement region S2 shown in FIG. Further, the mesh 82 including the strength of Eu-154 can be superimposed on an electronic drawing such as CAD data. By displaying the mesh 82 on the display device 25, the worker can visually recognize the survey result in real time with the actual machine.

  The measurement system 70 according to the third embodiment described above superimposes the analysis results of the Eu-154 survey algorithm, the Eu-154 position identification algorithm, and the Eu-154 survey and identification process on the output of the survey camera 71, and Eu- The visualization analysis device 74 includes a visualization algorithm for visualizing the position 154. Then, by displaying the analysis result of the visualization algorithm on the display device 25, the worker can visually recognize the survey result in real time with the actual machine, so that the work efficiency can be improved.

  Further, the analysis result of the visualization algorithm on the electronic drawing showing the investigation area from the analysis result in the Eu-154 investigation algorithm, the Eu-154 position identification algorithm, the Eu-154 investigation and identification process, and the position information of the access device 30. Can be overlapped. Then, by displaying the analysis result of the visualization algorithm on the display device 25, the worker can visually recognize the survey result in real time with the actual machine, so that the work efficiency can be improved.

  In addition, this invention is not limited to above-described embodiment and Example, Various modifications are included. For example, the above-described embodiments and examples are described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations. Further, a part of the configuration of a certain embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of a certain embodiment. Further, it is possible to add, delete, and replace other configurations for a part of the configuration of each embodiment.

DESCRIPTION OF SYMBOLS 10 Radiation measuring device 11 Investigation radiation detector 12 Position identification radiation detector 13 Shield 14 Investigation collimator 15 Position identification collimator 16, 17 Radiation detection element 18A, 18B Signal cables 20, 60, 70 Measurement systems 21, 22 Measuring device 23, 24, 61, 62 Analysis device 30 Access device 32 Access device control device 40 Boiling water reactor 41 Reactor building 42 Reactor containment vessel 43 Reactor pressure vessel 44 Reactor water recirculation system 45 Reactor pressure Suppression chamber 46 Torus chamber 50 Fuel debris 63 Control device 71 Investigation camera 73 Camera control analysis device 74 Visualization analysis device

Claims (10)

Multiple radiation detectors to investigate radioactive material and identify the location of radioactive material;
A shield for shielding the plurality of radiation detectors;
A plurality of collimators provided on the front side of each of the plurality of radiation detectors in order of increasing viewing angle from the opening side of the shield,
A plurality of radiation detection elements provided in each of the plurality of radiation detectors and disposed along an optical axis direction of the plurality of collimators;
A radiation measurement apparatus comprising: Existence of fuel debris that contains radioactive materials by investigating radioactive materials and identifying the location of radioactive materials in nuclear reactor containment vessels, reactor pressure vessels, reactor pressure suppression chambers, or torus chambers The radiation measuring apparatus according to claim 1, wherein the radiation measuring apparatus is estimated. A plurality of measuring devices that respectively measure γ-ray energy distributions based on the outputs of the plurality of radiation detectors;
A plurality of analysis devices for analyzing the peak of the radioactive substance from the measurement results of the plurality of measurement devices;
The radiation measurement apparatus according to claim 1, further comprising: a display device that displays measurement results of the plurality of measurement apparatuses and analysis results of the plurality of analysis apparatuses. The radiation measurement apparatus according to claim 3, wherein the radiation measurement apparatus is mounted on an access device. The analysis device of the system that investigates the radioactive substance among the plurality of analysis devices, from the output of the radiation detector for investigation that investigates the radioactive substance among the plurality of radiation detectors and the position information of the access device, The radiation measurement apparatus according to claim 4, further comprising a survey algorithm that identifies the presence or absence of a radioactive substance at a viewing angle of the survey radiation detector and outputs the result. The analysis device of the system for identifying the position of the radioactive substance among the plurality of analysis apparatuses includes an output of the radiation detector for position identification for identifying the position of the radioactive substance among the plurality of radiation detectors and the position information of the access device. The radiation measurement apparatus according to claim 5, further comprising: a position identification algorithm that identifies the presence or absence of a radioactive substance at a viewing angle of the radiation detector for position identification and outputs the result. A control device for controlling the plurality of analysis devices;
After the presence of the radioactive substance is confirmed in the analysis result by the investigation algorithm, the control device moves the access device at the viewing angle of the investigation radiation detector and outputs the output of the position identification radiation detector. The radiation measurement apparatus according to claim 6, further comprising: an investigation and identification process for analyzing the position identification algorithm and identifying a position of a radioactive substance in a range of a viewing angle of the investigation radiation detector. Investigation camera,
A visualization analysis device having a visualization algorithm that superimposes the investigation algorithm, the identification algorithm, and an analysis result in the investigation and identification process with an output of the investigation camera, and visualizes a position of a radioactive substance,
The radiation measurement apparatus according to claim 7, wherein an analysis result of the visualization algorithm is displayed on the display device. The analysis result of the visualization algorithm is superimposed by superimposing the analysis result of the visualization algorithm on the electronic drawing showing the investigation area from the investigation algorithm, the identification algorithm, and the analysis result in the investigation and identification process and the position information of the access device. The radiation measurement apparatus according to claim 8, wherein a result is displayed on the display device. The plurality of radiation detection elements include CdTe, CZT, TlBr, LaBr ₃ (Ce), LaCl ₃ (Ce), LSO, LYSO, GAGG (Ce), LuAG (Pr), NaI (Tl), YAP (Ce), The radiation measuring apparatus according to claim 1, wherein the radiation measuring apparatus is configured of any one of GSOs.

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