KR102266798B1 - Method and Apparatus for Measuring Gamma Radiation for Determination of Clearance Level of Nuclear Metal Radioactive Waste Having Various Shapes and Densities - Google Patents

Abstract

A method and apparatus for measuring gamma radiation to check whether or not the regulation of nuclear radioactive waste with various shapes and densities has been lifted is presented. According to an embodiment, a gamma radiation measurement method for confirming whether or not the regulation of nuclear radioactive waste is released includes: measuring a shape by 3D modeling the metallic radioactive waste using a 3D scanner; obtaining a correction coefficient by comparing the 3D data obtained through the 3D scanner with an MCNP computer code; obtaining a measured value by measuring the radioactivity of the metal radioactive waste using a gamma radiation measuring unit; reflecting the correction coefficient obtained through the MCNP computer code in the measurement value obtained through the gamma radiation measurement unit; And it can be made including the step of evaluating whether or not the regulation of nuclear power plant metal radioactive waste is released according to the concentration of radioactivity reflected by the correction factor.

Description

Method and Apparatus for Measuring Gamma Radiation for Determination of Clearance Level of Nuclear Metal Radioactive Waste Having Various Shapes and Densities

Embodiments of the present invention relate to a gamma radiation measurement technology and method for confirming whether or not the regulation of nuclear metal radioactive waste having various shapes and densities generated in a nuclear power plant is released, and more particularly, to a nuclear power plant having various shapes and densities. It relates to a method and apparatus for measuring gamma radiation to confirm whether or not the regulation of metal radioactive waste has been lifted.

In the process of dismantling a nuclear power plant, a large amount of metallic radioactive waste is generated. In this case, if the concentration of gamma radiation is below the deregulation level, it can be disposed of as general waste rather than radioactive waste, thereby reducing enormous costs. Therefore, accurate radioactivity measurements are essential to prove that they are below the deregulated values. The generated waste has various sizes, shapes, and densities, and if radioactivity is measured without taking these into account, a large error may occur in the measured value even if it has the same radioactivity.

Since the deregulation standard represents a very low level of 1/100 times that of the ultra-low level standard, this error has a very large effect on the radiometric measurement reliability. If the source of contamination is located inside the metal, the exact location cannot be known, and a lower value than the actual measured value is measured due to the magnetic absorption effect. As a result, it is very difficult to accurately measure the actual radioactivity concentration, so it is necessary to use a conservative approach as much as possible to prove that it is below the deregulation criteria.

Simulation using MCNP computer code is essential to improve the accuracy of radioactivity measurement values and ensure the reliability of measurement results. Using this, the most conservative values can be obtained by deriving correction factors according to the shape, density, and source location of the metal. can

In order to obtain a correction factor according to the shape of the metal radioactive waste, it is important to accurately measure the shape of the metal waste. However, if the operator directly measures it, it is difficult to trust the accuracy of the measurement and there is a risk of radiation exposure, so it is essential to measure it by applying remote-automation technology.

Existing studies on the derivation of radioactive waste correction coefficients mainly consist of measurement studies that vary the density of standardized liquid samples and studies that evaluate the apparent density without considering the shape of the metal waste. No counting studies have been conducted. However, in the case of metal radioactive waste that can be generated in an actual nuclear power plant, since the shape and material are various, research to correct it must be done.

Korean Patent Registration No. 10-1657577 relates to a total gamma radiation measuring device and method for checking the presence or absence of such radioactive contamination. It describes the technology for the device and method that can confirm the final radioactive contamination.

Korean Patent No. 10-1657577

The present invention has been devised to solve the conventional problems as described above, and an object of the present invention is to provide a technique and method for determining whether or not the regulation of nuclear power plant metal radioactive waste having various shapes and densities generated in a nuclear power plant is released. will do

Embodiments of the present invention measure the shape of nuclear metal radioactive waste using a 3D scanner and verify it with the MCNP computer code to accurately measure conservative values, so that nuclear power plant metal radioactivity with various shapes and densities capable of accurate measurement of gamma radiation An object of the present invention is to provide a method and apparatus for measuring gamma radiation for checking whether waste is deregulated.

On the other hand, the technical problems to be achieved in the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned are clearly to those of ordinary skill in the art to which the present invention belongs from the description below. can be understood

A gamma radiation measurement method for determining whether or not the regulation of nuclear power plant metal radioactive waste is released according to an embodiment of the present invention comprises the steps of: measuring a shape by 3D modeling the metal radioactive waste using a 3D scanner; obtaining a correction coefficient by comparing the 3D data obtained through the 3D scanner with an MCNP computer code; obtaining a measured value by measuring the radioactivity of the metal radioactive waste using a gamma radiation measuring unit; reflecting the correction coefficient obtained through the MCNP computer code in the measurement value obtained through the gamma radiation measurement unit; And it can be made including the step of evaluating whether or not the regulation of nuclear power plant metal radioactive waste is released according to the concentration of radioactivity reflected by the correction factor.

Measuring the shape by 3D modeling the metal radioactive waste using the 3D scanner may include: measuring the weight of the metal radioactive waste; 3D modeling the metal radioactive waste using the 3D scanner; and determining the density and metal material of the 3D modeled metal radioactive waste.

In the step of measuring the shape by 3D modeling the metal radioactive waste using the 3D scanner, the 3D modeling using the 3D scanner is measured in an actual size, and when it is determined that the shape of the metal radioactive waste is different from the actual shape This may include calibrating using a reverse engineering program.

Comparing the 3D data obtained through the 3D scanner with the MCNP computer code to obtain a correction coefficient comprises converting the 3D data obtained through the 3D scanner into data having tetrahedral mesh information using a reverse engineering program. converting; comparing the converted data with the calculation of the MCNP computer code; and determining a maximum value of the correction coefficient for self-absorption according to the comparison result.

The step of measuring the radioactivity of the metal radioactive waste using the gamma radiation measuring unit to obtain a measured value includes evaluating the internal characteristics with a standard source, which is a standard certification material (CRM), in advance, and then correcting the measurement efficiency according to the location when measuring the radioactivity. A measured value can be obtained by measuring the radioactivity of the metal radioactive waste by applying a coefficient.

The gamma radiation measuring unit may be formed in a form in which an HPGe semiconductor detector or a NaI(Tl) scintillation detector and a plastic scintillation detector having a high counting rate are combined.

The step of measuring the radioactivity of the metal radioactive waste using the gamma radiation measuring unit to obtain a measured value may include: measuring the radioactivity of the metallic radioactive waste using the gamma radioactivity measuring unit; calculating a counting rate in consideration of the location of the gamma radiation measuring unit and a Minimum Detectable Activity (MDA) value for each nuclide; and obtaining the total radioactivity through the counting rate, and obtaining the radioactivity concentration by reflecting the weight of the metal radioactive waste.

In the case of metal radioactive waste with a similar shape, it can be analyzed by applying shape data within the error range through the database.

According to another embodiment of the present invention, there is provided a gamma radiation measuring device for determining whether or not regulation of nuclear radioactive waste is released, comprising: a shape measuring unit for measuring a shape by 3D modeling of a metallic radioactive waste using a 3D scanner; an MCNP computer code comparison unit that compares 3D data obtained through the 3D scanner with an MCNP computer code to obtain a correction coefficient; a gamma radiation measuring unit for obtaining a measured value by measuring the radioactivity of the metal radioactive waste; a radioactivity concentration calculation unit that reflects the correction factor obtained through the MCNP computer code in the measurement value obtained through the gamma radiation measurement unit; and a deregulation determination unit for evaluating whether or not deregulation of nuclear power plant metal radioactive waste is deregulated according to the concentration of radioactivity to which the correction factor is reflected.

The shape measuring unit may include: a weight measuring unit measuring the weight of the metal radioactive waste; a 3D scanner for 3D modeling the metal radioactive waste; And it may include a density and material determining unit for determining the density and metal material of the 3D modeled metal radioactive waste.

3D modeling using the 3D scanner is measured in actual size, and when it is determined that the shape of the metal radioactive waste is different from the actual shape, it may further include a reverse engineering program correction unit for correcting using a reverse engineering program.

The MCNP computer code comparison unit converts the 3D data obtained through the 3D scanner into data having tetrahedral mesh information using a reverse engineering program, and compares the converted data with the calculation of the MCNP computer code. , it is possible to determine the maximum value of the correction coefficient for self-absorption according to the comparison result.

The gamma radiation measuring unit, after evaluating the internal characteristics with a standard source, which is a standard certified material (CRM) in advance, applies a measurement efficiency correction factor according to the location when measuring the radioactivity to measure the radioactivity of the metal radioactive waste to obtain a measurement value. can

The gamma radiation measuring unit may be formed in a form in which an HPGe semiconductor detector or a NaI(Tl) scintillation detector and a plastic scintillation detector having a high counting rate are combined.

The radioactivity concentration calculation unit measures the radioactivity of the metal radioactive waste using the gamma radiation measurement unit, and the location of the gamma activity measurement unit and the Minimum Detectable Activity (MDA) value for each nuclide. , to obtain the total radioactivity through the counting rate, it is possible to obtain the radioactivity concentration by reflecting the weight of the metal radioactive waste.

According to the embodiments of the present invention, it is possible to replace the method of measuring radioactivity by placing a large amount of radioactive metal waste in an existing hexahedral basket and calculating the apparent density regardless of the shape and material, and a metal having a complex shape Nuclear power plant metal radioactive waste with various shapes and densities that can quickly and accurately determine whether or not to release regulations on metal radioactive waste by measuring its shape using a 3D scanner and verifying it with the MCNP computer code to accurately measure the conservative value. It is possible to provide a method and apparatus for measuring gamma radiation for checking whether or not regulation of

1 is a view schematically showing a gamma radiation measuring device for checking whether or not the regulation of nuclear power plant metal radioactive waste is released according to an embodiment of the present invention.
2 is a block diagram illustrating a gamma radiation measuring device for checking whether or not the regulation of nuclear power plant metal radioactive waste is released according to an embodiment of the present invention.
3 is a flowchart illustrating a gamma radiation measurement method for confirming whether or not regulation of nuclear power plant metal radioactive waste is released according to an embodiment of the present invention.
4 is a view showing an example of a gamma radiation measurement method for confirming whether or not the regulation of nuclear power plant metal radioactive waste is released according to an embodiment of the present invention.
5 is a diagram illustrating an example of a spatial distribution according to an internal position of a gamma radiation measuring unit in three dimensions and two dimensions according to an embodiment of the present invention.
6 is a graph illustrating a change in the minimum detected concentration (MDA) with time according to an embodiment of the present invention.
7 is a graph showing the result of comparing the MCNP computer code and actual measured values for 60Co and 137Cs nuclides according to an embodiment of the present invention.
8 is a diagram illustrating an example of modeling metals of various shapes using a 3D scanner according to an embodiment of the present invention.
9 is a graph illustrating a difference in measured values according to an internal position of an aluminum metal of a standard source according to an embodiment of the present invention.
10 is a graph showing a difference in measured values according to metal materials for 60Co according to an embodiment of the present invention.
11 is a diagram illustrating an example of a database according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. However, the described embodiments may be modified in various other forms, and the scope of the present invention is not limited by the embodiments described below. In addition, various embodiments are provided in order to more completely explain the present invention to those of ordinary skill in the art. The shapes and sizes of elements in the drawings may be exaggerated for clearer description.

1 is a view schematically showing a gamma radiation measuring device for checking whether or not the regulation of nuclear power plant metal radioactive waste is released according to an embodiment of the present invention.

Gamma radiation measurement generally consists of a combination of an HPGe semiconductor detector or NaI(Tl) scintillation detector, which can analyze nuclide due to its excellent resolution, and a plastic scintillation detector with a high counting rate, which ensures sufficient counting rate and performs nuclide analysis at the same time. This is to reduce the measurement time.

In the present invention, a 3D scanner is used for shape measurement for accurate measurement of gamma radiation to check whether or not the regulation of nuclear metal radioactive waste having various shapes and densities has been lifted, and MCNP computation is used to derive correction factors and reliability of the measured values. Using a code, the detector can provide a quick and accurate way to measure using NaI(Tl) and plastic scintillation detectors.

Referring to FIG. 1 , the gamma radiation measuring device for checking whether the regulation of nuclear power plant metal radioactive waste is released according to an embodiment measures the shape of the metal radioactive waste through a 3D scanner 111 and displays the result of the control system 112 . The radioactivity of the metal radioactive waste is measured through the gamma radiation measuring unit 114 , and the result is analyzed through the multi-channel analyzer 115 and then transmitted to the control system 112 .

In addition, the control system 112 may determine whether or not the regulation of the nuclear power plant metal radioactive waste is released, and display the result through the monitor 113 or the like. In this case, the control system 112 may use the MCNP computer code 121 for reliability of the measured value, and may use the Genie-2000 program 122 , the reverse engineering program 123 , and the like. For example, the 3D modeling result is measured in an actual size, and when it is determined that the shape of the metal radioactive waste is different from the actual shape, it can be corrected using the reverse engineering program 123 .

Hereinafter, a gamma radiation measuring device for checking whether or not the regulation of nuclear power plant metal radioactive waste is released according to an embodiment of the present invention will be described.

2 is a block diagram illustrating a gamma radiation measuring device for checking whether or not the regulation of nuclear power plant metal radioactive waste is released according to an embodiment of the present invention.

Referring to FIG. 2 , the gamma radiation measuring device 200 for checking whether or not the regulation of nuclear metal radioactive waste is released according to an embodiment of the present invention includes a shape measuring unit 210 , an MCNP computer code comparing unit 230 , and gamma It may include a radioactivity measuring unit 240 , a radioactivity concentration calculating unit 250 , and a regulatory release determining unit 260 . In addition, according to an embodiment, the reverse engineering program correction unit 220 may be further included. Such a configuration may be included in the gamma radiation measuring device for checking whether the regulation of nuclear power plant metal radioactive waste is released as described in FIG. 1 , and may be included in the control system according to an embodiment. For example, the shape measuring unit 210 may include the 3D scanner described in FIG. 1 or may be included in a control system that has received information from the 3D scanner, the reverse engineering program correction unit 220 , and the MCNP computer code comparison unit 230 . ), the radiation concentration calculating unit 250 and the regulatory release determining unit 260 may be included in the control system described in FIG. 1 , and the gamma radiation measuring unit 240 includes the gamma radiation measuring unit described in FIG. 1 or gamma radiation It may be included in the control system that has received information from the measurement unit.

3 is a flowchart illustrating a gamma radiation measurement method for confirming whether or not regulation of nuclear power plant metal radioactive waste is released according to an embodiment of the present invention.

Referring to FIG. 3 , the method for measuring gamma radiation for determining whether or not the regulation of nuclear power plant metal radioactive waste is released according to an embodiment of the present invention is a 3D model of the metal radioactive waste using a 3D scanner to measure the shape ( 310 ) , Comparing the 3D data obtained through the 3D scanner with the MCNP computer code to obtain a correction factor (320), measuring the radioactivity of the metal radioactive waste using the gamma radiation measuring unit 240 to obtain a measured value (330), the step of reflecting the correction coefficient obtained through the MCNP computer code to the measurement value obtained through the gamma radiation measurement unit 240 (340), and regulation of nuclear metal radioactive waste according to the radiation concentration reflected by the correction coefficient It may include a step 350 of evaluating the presence or absence of release.

The gamma radiation measurement method for confirming whether or not the regulation of nuclear metal radioactive waste is released according to an embodiment of the present invention can be described in more detail with an example of a gamma radiation measuring device for checking whether or not the regulation of nuclear metal radioactive waste is released. have.

In step 310 , the shape measuring unit 210 may measure the shape by 3D modeling the metal radioactive waste using a 3D scanner. If you use a 3D scanner for shape measurement, you can 3D model accurately with real shapes.

The shape measuring unit 210 may further include a weight measuring unit and a density and material determining unit as well as a 3D scanner. In other words, the shape measuring unit 210 includes a weight measuring unit for measuring the weight of the metallic radioactive waste, a 3D scanner for 3D modeling the metallic radioactive waste, and a density for determining the density and metal material of the 3D modeled metallic radioactive waste and a material determining unit. Herein, the shape measuring unit 210 includes not only the 3D scanner but also the weight measuring unit and the density and material determining unit, but the 3D scanner, the weight measuring unit, and the density and material determining unit may be configured in each configuration.

According to an embodiment, the reverse engineering program correction unit 220 may be further included, 3D modeling using a 3D scanner is measured in an actual size, and when it is determined that the shape of the metal radioactive waste is different from the actual shape, the reverse engineering program can be corrected using

In step 320, the MCNP computer code comparison unit 230 may obtain a correction coefficient by comparing the 3D data obtained through the 3D scanner with the MCNP computer code. The MCNP computer code comparison unit 230 converts the 3D data obtained through the 3D scanner into data having tetrahedral mesh information using a reverse engineering program, and compares the converted data with the calculation of the MCNP computer code, The maximum value of the correction coefficient for self-absorption can be determined according to the comparison result. As described above, using 3D data with measured mesh information, it is possible to quickly evaluate the MCNP computer code to which the actual shape is applied.

In step 330 , the gamma radiation measuring unit 240 may measure the radioactivity of the metal radioactive waste to obtain a measured value. Here, the gamma radiation measuring unit 240 may be formed by combining an HPGe meter or a NaI(Tl) meter and a plastic scintillator having a high counting rate. That is, the gamma radiation measuring unit 240 may be formed by combining an HPGe semiconductor detector or a NaI (Tl) scintillation detector and a plastic scintillation detector having a high counting rate.

The gamma radiation measuring unit 240 measures the radioactivity of the metal radioactive waste by applying a measurement efficiency correction factor according to the location when measuring the radioactivity after evaluating the internal characteristics with a standard source, which is a standard certified material (CRM) in advance. can be obtained

In step 340 , the radiation concentration calculating unit 250 may reflect the correction coefficient obtained through the MCNP computer code to the measured value obtained through the gamma radiation measuring unit 240 . More specifically, the radiation concentration calculation unit 250 measures the radioactivity of the metal radioactive waste using the gamma radiation measurement unit 240, and the location of the gamma radiation measurement unit 240 and the minimum detected concentration for each nuclide (MDA: Minimum) After calculating the counting rate considering the Detectable Activity) value, the total radioactivity can be obtained through the counting rate, and the radioactivity concentration can be obtained by reflecting the weight of the metal radioactive waste.

In step 350, the deregulation determination unit 260 may evaluate whether or not the deregulation of the nuclear power plant metal radioactive waste is deregulated according to the radiation concentration reflected by the correction factor. Therefore, it can be measured most conservatively by using the MCNP computer code and the internal characteristics of the gamma radiation measuring unit 240 according to the shape of the metal radioactive waste.

On the other hand, in the case of metal radioactive waste with a similar shape, it can be analyzed by applying shape data within the error range through the database.

4 is a view showing an example of a gamma radiation measurement method for confirming whether or not the regulation of nuclear power plant metal radioactive waste is released according to an embodiment of the present invention.

Referring to FIG. 4 , the gamma radiation measurement method for confirming whether the regulation of nuclear power plant metal radioactive waste is released according to an embodiment of the present invention measures the weight of the metal radioactive waste (411), and uses a 3D scanner to determine the shape After the measurement 412 , the density and metal material of the metal radioactive waste may be determined 413 . And, it is possible to select (414) the metal through the measured value database, and at this time, the reliability of the measured value can be secured through the comparison (416) with the MCNP computer code. Accordingly, the maximum value of the correction coefficient for self-absorption may be determined ( 415 ).

More specifically, after accurately 3D modeling with a real shape using a 3D scanner, the 3D data (3D CAD data) obtained with the 3D scanner is converted into data with tetrahedral mesh information using a reverse engineering program, Data can be compared with the MCNP code using a conversion tool that can be applied to the MCNP code.

In addition, the radioactivity of the metal radioactive waste may be measured ( 421 ) by using the gamma radiation measuring unit. In this case, it can be evaluated by applying a measurement efficiency correction factor according to the measurement location using the internal characteristics of the gamma radiation measurement unit. That is, the total counting rate may be calculated ( 423 ) by considering ( 422 ) the location of the gamma radiation measuring unit and the minimum detected concentration (MDA) value for each nuclide. The total radioactivity can be obtained using the total counting rate. At this time, the total radioactivity can be calculated (424) by reflecting the maximum value of the correction coefficient for self-absorption obtained through comparison with the MCNP computer code. After calculating the radioactivity concentration (525) by reflecting the total radioactivity and the measured weight, it is possible to determine (426) whether or not the regulation of nuclear power plant metal radioactive waste is lifted. That is, by comparing the evaluation value (ie, correction factor) obtained with the MCNP computer code with the measurement value of the radioactivity detector, it is possible to conservatively evaluate whether or not the regulation is lifted.

In this way, by using the 3D data obtained by the 3D scanner, the measurement value measured by the gamma radiation measurement unit, and the correction factor (evaluation value) of the MCNP computer code, it is possible to evaluate whether or not the regulation of radioactive waste from nuclear power plants has been lifted.

On the other hand, in the case of a similar shape among various metal radioactive waste, it is possible to quickly analyze the shape data within the error range through the database.

Hereinafter, the gamma radiation measurement method and apparatus for confirming whether the regulation of nuclear power plant metal radioactive waste is deregulated according to an embodiment of the present invention can be verified through an experiment.

Experiment 1

Since the intensity of radiation is inversely proportional to the square of the distance, the measurement result varies depending on the location of the object to be measured inside the gamma radiation measuring unit (instrument). In this experiment, to confirm this, spatial sensitivity distribution measurement according to the internal position of the instrument can be performed.

5 is a diagram illustrating an example of a spatial distribution according to an internal position of a gamma radiation measuring unit in three dimensions and two dimensions according to an embodiment of the present invention.

Referring to FIG. 5 , in the method for measuring gamma radiation, examples of spatial distribution diagrams according to internal positions of the gamma radiation measuring unit may be expressed as three-dimensional and two-dimensional graphs, respectively. As a result of the measurement, it can be seen that the counting rate decreases as the distance from the center closest to the gamma radiation measurement unit increases.

Experiment 2

Since the standard for deregulation of radioactive waste shows a very low value, it is very important to determine the Minimum Detectable Activity (MDA). Since the minimum detection concentration (MDA) is a function of time, counting rate, and background, it is possible to characterize a measuring instrument that can derive an optimal value depending on the situation if it is appropriately adjusted.

It can be seen that the lower the minimum detection concentration (MDA), the higher the measurement accuracy. If all conditions such as shielding level and measurement area are the same, this becomes a function of time. If the measurement time is lengthened, the reliability of measurement increases, but as the measurement time increases, the working speed decreases, and economic loss may occur accordingly. Therefore, it is necessary to derive the optimal measurement time according to the condition of the waste to be measured.

Therefore, in this experiment, an experiment to measure how the minimum detected concentration (MDA) decreases with time when the conditions for the counting rate and background are the same can be performed.

6 is a graph illustrating a change in the minimum detected concentration (MDA) with time according to an embodiment of the present invention.

Referring to FIG. 6 , the result of the minimum detected concentration (MDA) according to time is shown, and it can be seen that the minimum detected concentration (MDA) decreases exponentially as time increases. This indicates that the minimum detectable concentration (MDA) decreases rapidly at the beginning, so it is not necessary to spend too much time to lower it, and it is only necessary to take the time to maintain 1/10 or less of the deregulation standard, which is the domestic nuclear safety law standard. .

Experiment 3

When a measurement experiment using a radioactive standard is carried out, an error of the source itself and an error of the measured value according to the work skill level of the operator occur. Therefore, it is essential to compare the values with the MCNP computer code to ensure the accuracy of the measured values. At this time, in order to improve the accuracy, the shape of the instrument, the radiation concentration of the source, the shape of the source, and the surrounding shield should be simulated almost like the real thing.

Therefore, in this experiment, we simulate the actual standard source and compare the actual measured value with the value calculated with the MCNP computer code and aim to generate the minimum error.

7 is a graph showing the result of comparing the MCNP computer code and actual measured values for ⁶⁰ Co and ¹³⁷ Cs nuclides according to an embodiment of the present invention.

Referring to FIG. 7 , the measurement results for ⁶⁰ Co and ¹³⁷ Cs nuclides can be compared by performing a measurement experiment after simulating the experimental environment with the MCNP computer code. As a result of the experiment, it can be confirmed that the actual measured value (Experiment) and the value calculated by MCNP (MCNP6 Simulation) are almost identical, and this result shows that the actual measured value is at a reliable level.

Experiment 4

In order to accurately derive the correction factor according to the type of metal, it is very important to accurately measure the shape of the metal radioactive waste. If a worker directly measures this, it takes a long time to measure and there is a risk of exposure, so a method of measuring using remote-automation technology is needed.

Therefore, it aims to accurately measure and 3D modeling metals that can actually occur in nuclear power plants.

8 is a diagram illustrating an example of modeling metals of various shapes using a 3D scanner according to an embodiment of the present invention.

In this experiment, the shape of metal waste that can actually be generated in a nuclear power plant can be modeled using a 3D scanner. As shown in FIG. 8 , the results of modeling various types of metals using a 3D scanner can be shown, and it has been confirmed that the shapes of various metals can be quickly modeled in a short time.

Experiment 5

In general, the radiation concentration of sources inside the metal decreases exponentially. However, the degree of reduction in radiation intensity varies depending on the shape or material of the metal and the location and type of the source, which greatly affects the measurement results. Therefore, it is essential to derive a correction factor for this.

9 is a graph showing the difference in measured values according to the internal position of the aluminum metal of the standard source according to an embodiment of the present invention. And Figure 10 is a graph showing the difference in the measured value according to the metal material for ⁶⁰ Co according to an embodiment of the present invention.

Referring to FIGS. 9 and 10 , graphs in which self-absorption coefficients are derived according to the difference between the position of the source in the metal and the type of metal can be confirmed. As a result of the experiment, it can be confirmed that the higher the self-absorption coefficient is the higher the density of the metal located deep inside the metal, and it can be confirmed ^{that 137} Cs, which is a lower energy region than ⁶⁰ Co, is greatly affected by the self-absorption effect.

11 is a diagram illustrating an example of a database according to an embodiment of the present invention.

11, in the case of metal radioactive waste having a similar shape according to an embodiment, it is possible to provide a database that can be quickly analyzed by applying shape data within an error range.

According to embodiments, when a 3D scanner is used, a complex shape that is difficult for an operator to measure directly can be quickly and accurately measured, thereby improving the accuracy of shape measurement, ensuring worker safety, and economical cost. It may have advantages such as savings.

The device described above may be implemented as a hardware component, a software component, and/or a combination of the hardware component and the software component. For example, devices and components described in the embodiments may include, for example, a processor, a controller, an arithmetic logic unit (ALU), a digital signal processor, a microcomputer, a field programmable array (FPA), It may be implemented using one or more general purpose or special purpose computers, such as a programmable logic unit (PLU), microprocessor, or any other device capable of executing and responding to instructions. The processing device may execute an operating system (OS) and one or more software applications running on the operating system. The processing device may also access, store, manipulate, process, and generate data in response to execution of the software. For convenience of understanding, although one processing device is sometimes described as being used, one of ordinary skill in the art will recognize that the processing device includes a plurality of processing elements and/or a plurality of types of processing elements. It can be seen that can include For example, the processing device may include a plurality of processors or one processor and one controller. Other processing configurations are also possible, such as parallel processors.

The software may comprise a computer program, code, instructions, or a combination of one or more thereof, which configures a processing device to operate as desired or is independently or collectively processed You can command the device. The software and/or data may be any kind of machine, component, physical device, virtual equipment, computer storage medium or device, to be interpreted by or to provide instructions or data to the processing device. may be embodied in The software may be distributed over networked computer systems, and stored or executed in a distributed manner. Software and data may be stored in one or more computer-readable recording media.

The method according to the embodiment may be implemented in the form of program instructions that can be executed through various computer means and recorded in a computer-readable medium. The computer-readable medium may include program instructions, data files, data structures, etc. alone or in combination. The program instructions recorded on the medium may be specially designed and configured for the embodiment, or may be known and available to those skilled in the art of computer software. Examples of the computer-readable recording medium include magnetic media such as hard disks, floppy disks and magnetic tapes, optical media such as CD-ROMs and DVDs, and magnetic such as floppy disks. - includes magneto-optical media, and hardware devices specially configured to store and execute program instructions, such as ROM, RAM, flash memory, and the like. Examples of program instructions include not only machine language codes such as those generated by a compiler, but also high-level language codes that can be executed by a computer using an interpreter or the like.

As described above, although the embodiments have been described with reference to the limited embodiments and drawings, various modifications and variations are possible for those skilled in the art from the above description. For example, the described techniques are performed in a different order than the described method, and/or the described components of the system, structure, apparatus, circuit, etc. are combined or combined in a different form than the described method, or other components Or substituted or substituted by equivalents may achieve an appropriate result.

Therefore, other implementations, other embodiments, and equivalents to the claims are also within the scope of the following claims.

Claims (15)

Measuring the shape by 3D modeling the metal radioactive waste using a 3D scanner;
obtaining a correction coefficient by comparing the 3D data obtained through the 3D scanner with an MCNP computer code;
obtaining a measured value by measuring the radioactivity of the metal radioactive waste using a gamma radiation measuring unit;
reflecting the correction coefficient obtained through the MCNP computer code in the measurement value obtained through the gamma radiation measurement unit; and
Evaluating whether or not the regulation of nuclear power plant metal radioactive waste is lifted according to the radioactivity concentration in which the correction factor is reflected
including,
Measuring the shape by 3D modeling the metal radioactive waste using the 3D scanner,
3D modeling using the 3D scanner is measured in actual size, and if it is determined that the shape of the metal radioactive waste is different from the actual shape, correcting it using a reverse engineering program
A method for measuring gamma radiation to determine whether or not the regulation of nuclear power plant metal radioactive waste has been lifted, including. According to claim 1,
Measuring the shape by 3D modeling the metal radioactive waste using the 3D scanner,
measuring the weight of the metal radioactive waste;
3D modeling the metal radioactive waste using the 3D scanner; and
Determining the density and metal material of the 3D modeled metal radioactive waste
A method for measuring gamma radiation to determine whether or not the regulation of nuclear power plant metal radioactive waste has been lifted, including. delete Measuring the shape by 3D modeling the metal radioactive waste using a 3D scanner;
obtaining a correction coefficient by comparing the 3D data obtained through the 3D scanner with an MCNP computer code;
obtaining a measured value by measuring the radioactivity of the metal radioactive waste using a gamma radiation measuring unit;
reflecting the correction coefficient obtained through the MCNP computer code in the measurement value obtained through the gamma radiation measurement unit; and
Evaluating whether or not the regulation of nuclear power plant metal radioactive waste is lifted according to the radioactivity concentration in which the correction factor is reflected
including,
Comparing the 3D data obtained through the 3D scanner with the MCNP computer code to obtain a correction coefficient,
converting the 3D data acquired through the 3D scanner into data having tetrahedral mesh information using a reverse engineering program;
comparing the converted data with the calculation of the MCNP computer code; and
determining the maximum value of the correction coefficient for self-absorption according to the comparison result;
A method for measuring gamma radiation to determine whether or not the regulation of nuclear power plant metal radioactive waste has been lifted, including. According to claim 1,
Obtaining a measured value by measuring the radioactivity of the metal radioactive waste using the gamma radiation measuring unit,
Obtaining a measured value by measuring the radioactivity of the metal radioactive waste by applying a measurement efficiency correction factor according to location when measuring radioactivity after evaluating the internal characteristics with a standard source, which is a standard certified material (CRM) in advance
A method for measuring gamma radiation to determine whether or not the regulation of nuclear radioactive waste is deregulated. According to claim 1,
The gamma radiation measuring unit,
Combination of HPGe semiconductor detector or NaI(Tl) scintillation detector and plastic scintillation detector with high counting rate
A method for measuring gamma radiation to determine whether or not the regulation of nuclear radioactive waste is deregulated. According to claim 1,
Obtaining a measured value by measuring the radioactivity of the metal radioactive waste using the gamma radiation measuring unit,
measuring the radioactivity of the metal radioactive waste using the gamma radiation measuring unit;
calculating a counting rate in consideration of the location of the gamma radiation measuring unit and a Minimum Detectable Activity (MDA) value for each nuclide; and
Obtaining the total radioactivity through the counting rate, and obtaining the radioactivity concentration by reflecting the weight of the metal radioactive waste
A method for measuring gamma radiation to determine whether or not the regulation of nuclear power plant metal radioactive waste has been lifted, including. According to claim 1,
In the case of metal radioactive waste of similar shape, it is analyzed by applying shape data within the error range through the database.
A method for measuring gamma radiation to determine whether or not the regulation of nuclear radioactive waste is deregulated. a shape measuring unit that measures the shape by 3D modeling the metal radioactive waste using a 3D scanner;
an MCNP computer code comparison unit that compares 3D data obtained through the 3D scanner with an MCNP computer code to obtain a correction coefficient;
a gamma radiation measuring unit for obtaining a measured value by measuring the radioactivity of the metal radioactive waste;
a radioactivity concentration calculation unit that reflects the correction factor obtained through the MCNP computer code in the measurement value obtained through the gamma radiation measurement unit; and
A deregulation determination unit that evaluates whether or not the regulation of nuclear metal radioactive waste has been lifted according to the concentration of radioactivity in which the correction factor is reflected
including,
3D modeling using the 3D scanner is measured in actual size, and when it is determined that the shape of the metal radioactive waste is different from the actual shape, a reverse engineering program correction unit to correct it using a reverse engineering program
Further comprising, a gamma radiation measuring device for checking whether or not the regulation of nuclear power plant metal radioactive waste is released. 10. The method of claim 9,
The shape measuring unit,
a weight measuring unit for measuring the weight of the metal radioactive waste;
a 3D scanner for 3D modeling the metal radioactive waste; and
Density and material determining unit that determines the density and metal material of 3D modeled metal radioactive waste
Including, a gamma radiation measuring device for determining whether or not the regulation of radioactive waste of nuclear power plants has been lifted. delete a shape measuring unit that measures the shape by 3D modeling the metal radioactive waste using a 3D scanner;
an MCNP computer code comparison unit that compares 3D data obtained through the 3D scanner with an MCNP computer code to obtain a correction coefficient;
a gamma radiation measuring unit for obtaining a measured value by measuring the radioactivity of the metal radioactive waste;
a radioactivity concentration calculation unit that reflects the correction factor obtained through the MCNP computer code in the measurement value obtained through the gamma radiation measurement unit; and
A deregulation determination unit that evaluates whether or not the regulation of nuclear metal radioactive waste has been lifted according to the concentration of radioactivity in which the correction factor is reflected
including,
The MCNP computer code comparison unit,
3D data obtained through the 3D scanner is converted into data having tetrahedral mesh information using a reverse engineering program, the converted data is compared with the calculation of the MCNP computer code, and self-absorption according to the comparison result Determining the maximum value of the correction factor for
A gamma radiation measuring device for determining whether or not the regulation of nuclear radioactive waste is released, characterized in that. 10. The method of claim 9,
The gamma radiation measuring unit,
Obtaining a measured value by measuring the radioactivity of the metal radioactive waste by applying a measurement efficiency correction factor according to location when measuring radioactivity after evaluating the internal characteristics with a standard source, which is a standard certified material (CRM) in advance
A gamma radiation measuring device for determining whether or not the regulation of nuclear radioactive waste is released, characterized in that. 10. The method of claim 9,
The gamma radiation measuring unit,
Combination of HPGe semiconductor detector or NaI(Tl) scintillation detector and plastic scintillation detector with high counting rate
A gamma radiation measuring device for determining whether or not the regulation of nuclear radioactive waste is released, characterized in that. 10. The method of claim 9,
The radioactive concentration calculation unit,
The radioactivity of the metal radioactive waste is measured using the gamma radiation measuring unit, and the counting rate is calculated in consideration of the location of the gamma activity measuring unit and the Minimum Detectable Activity (MDA) value for each nuclide. Obtaining the radioactivity and obtaining the radioactivity concentration by reflecting the weight of the metal radioactive waste
A gamma radiation measuring device for determining whether or not the regulation of nuclear radioactive waste is released, characterized in that.

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