KR100812536B1 - Nondestructive measurement method of the coating thickness in a triso-coated fuel particle by using the phase contrast x-ray radiography image and apparatus thereof - Google Patents

Abstract

A nondestructive coating thickness measurement method for a TRISO-coated fuel particle by using a phase difference X-ray radiography image and an apparatus thereof are provided to enhance an inspection process of a TRISO-coated fuel particle by measuring the coating thickness nondestructively. A nondestructive coating thickness measurement apparatus for a TRISO-coated fuel particle by using a phase difference X-ray radiography image includes an X-ray shielding cabinet(1). The X-ray shielding cabinet is made of lead for preventing X-ray from leaking. A vibration-preventive system(2) is installed below the X-ray shielding cabinet in order to block external vibration for maintaining precision under micro meters. An X-ray detector(3), made with semiconductor elements, is installed inside the X-ray shielding cabinet and converts X-ray signals to real-time image signals for increasing detecting efficiency. A sample transporter(5) fixes the coated fuel particle on an intended spot with precision. An X-ray generator(6) has a minimum focus size of 0.2~5mum for obtaining a phase difference image. The X-ray generator controller(7) controls the tube voltage, tube current, and focus size of the X-ray generator. A computer system(8) controls the X-ray generator and the X-ray detector and executes a program for coating thickness measurement. A frame grabber converts image signals to digital signals and inputs the digital signals to the computer system. An image monitor displays an X-ray image and a measurement result.

Description

Nondestructive measurement method of the coating thickness in a TRISO-coated fuel particle by using the phase contrast X-ray radiography image and apparatus

1 is an exemplary view showing a schematic configuration of a device for obtaining a phase difference X-ray radiographic image of the coated particle fuel according to the present invention,

FIG. 2 is an exemplary view showing a digital image processing method of measuring a radius and a thickness of each coating layer by extracting a boundary between coating layers of the present invention for a phase difference X-ray image.

3 is a phase difference X-ray radiographic image according to the present invention,

4 is a phase difference X-ray radiographic image according to the present invention and an image representing a center point and a boundary line for the image and expressing the same;

5A is an X-ray image according to the present invention,

5b is an image observed under a microscope after cutting and polishing the center of the coated particle using a destructive ceramic method,

Figure 6a is an image showing the thickness of the coating layer measured by processing the X-ray image according to the present invention,

Figure 6b is an image showing the thickness of the coating layer measured for the image of the cut surface using the ceramography method,

7 is a perspective view showing a coating layer (buffer PyC (pyrolytic carbon) layer, inner PyC layer, SiC layer, outer PyC layer) of the coated particle fuel,

8 is an X-ray radiographic image according to a conventional method.

<Description of the symbols for the main parts of the drawings>

(1): X-ray shielding cabinet (2): Dustproof system

(3): real time X-ray detector (4): coated particle fuel

(5): sample feeder (6): X-ray generator

(7): X-ray generator controller (8): computer system

(9): frame grabber 10: video monitor

(11): TRISO coated particle fuel sample preparation step

(12): phase difference X-ray radiographic digital image acquisition step

(13): Image histogram adjustment step

14: first high frequency image noise removing step

(15): center point extraction step

(16): boundary emphasis step

(17): second step of removing high frequency image noise

18: boundary line extraction step

(19): coating layer radius measuring step

(20): coating layer thickness measurement step

Nondestructive Measurement of TRISO Coated Particle Fuel Coating Layer Thickness Using Retardation X-ray Radiography Image The method and apparatus thereof, in detail, the thickness of the buffer PyC (pyrolytic carbon) layer, the inner PyC layer, the SiC layer, the outer PyC layer, which is a coating layer of TRISO (tri-isotropic) coated particle fuel for hot or ultra high temperature gas furnace Each relates to a method and a device for measuring nondestructively.

In general, TRISO (tri-isotropic) coated particle fuel is used as a fuel for high temperature or ultra high temperature furnaces.

The TRISO (tri-isotropic) coated particle fuel has a buffer PyC (pyrolytic carbon) layer, an inner PyC layer, an SiC layer, and an outer PyC layer as a coating layer as shown in FIG. 7.

Conventionally, in order to measure the coating layer thickness of the coated particle fuel as shown in FIG. 7, a general X-ray radiographic method is used as a destructive cerography method or a non-destructive method.

However, the destructive ceramic method has a problem in that the manufacturing process of the measurement specimen is complicated, the reuse of the measurement specimen is impossible, and radioactive waste is generated during the measurement process.

In addition, the conventional general X-ray radiographic method proposed to improve the disadvantages of the destructive method is a method that depends on the absorption effect of the X-ray to obtain an X-ray image by as closely as possible between the sample and the X-ray detector In this case, there is a disadvantage that the boundary line between the coating layer of the coated particle fuel having a small difference in density and permeation thickness is not clear. 8 is an X-ray radiographic image according to a conventional method.

An object of the present invention for solving the above problems is the value of the boundary region due to the phase change by the refraction of the X-rays at the interface between the coating layers and the interference effect according to the X-ray absorption effect on the coated particle fuel By emphasizing this, by setting the conditions under which the boundary line can acquire a phase difference X-ray radiographic image, the X-ray radiographic image with a clearer boundary line between the coating layers is obtained, and the X-ray obtained by the above process The present invention provides a method and apparatus for automatically extracting a boundary between coating layers for a radiographic image and efficiently measuring the thickness of the coating layer based on the extracted boundary lines.

The present invention, which achieves the object as described above and removes the drawbacks of the prior art, is directed to an apparatus for nondestructively inspecting the coating layer thickness of TRISO coated particle fuel or similar coated particle fuel for high temperature or ultra high temperature gas furnaces. In

An X-ray shielding cabinet made of a lead plate shielding the X-rays so that X-rays do not leak out of the measurement facility;

A dustproof system supporting a lower portion of the X-ray shielding cabinet;

A real-time X-ray detector installed in the X-ray shielding cabinet and configured to semiconductor to increase the measurement efficiency by converting the X-ray signal into a real-time video signal;

A sample transporter installed inside the X-ray shielding cabinet and configured to precisely fix the coated particle fuel in a required position;

An X-ray generator installed in the X-ray shielding cabinet and irradiating X-rays for obtaining a phase difference image on the coated particle fuel;

An X-ray generator controller connected to an X-ray generator installed inside the X-ray shielding cabinet outside the X-ray shielding cabinet and configured to control tube voltage, tube current, and focal size of the X-ray generator;

A frame grabber that converts an image signal of a real-time X-ray detector installed inside the X-ray shielding cabinet into a digital signal and inputs it to a computer system;

A computer system controlling the X-ray generator and the X-ray detector to execute a program for measuring the coating layer thickness by means of a phase difference X-ray radiographic image of the coated particle fuel;

An X-ray image processed by the computer system and a video monitor connected to output the measurement results, characterized in that the device configuration for measuring non-destructive TRISO coated particle fuel coating layer thickness using a phase difference X-ray radiographic image.

The real-time X-ray detector uses a pixel size of 50 μm or less to produce digital X-ray image data in real time.

The X-ray generator uses a device having a focus size of 0.2 ~ 5 μm to obtain a phase difference image. The smaller the focal point is, the better the spatial coherence characteristic of increasing the coherence of X-rays is, and it is very advantageous to acquire the phase difference image by preventing the phenomenon in which the boundary lines are unclearly expressed by the shadow effect. The best results were obtained in the focal section such as.

The X-ray generator controller is configured by controlling the tube voltage of the X-ray generator to 40 to 60 kV, the tube current to 80 to 100 μA and the focal size to 0.2 to 5 μm.

The X-ray detector sets the exposure time to 2 to 6 seconds and the number of accumulated image frames to be 20 to 50 frames.

The coated particle fuel is installed at a position 50 to 70 mm away from the X-ray generator, and the X-ray detector is installed at a position 1000 to 1400 mm away from the coated material fuel.

In the method of non-destructively inspecting the coating layer thickness of TRISO coated particle fuel or similar coated particle fuel for the hot or ultra high temperature gas furnace as described above,

Phase difference X-ray radio with a clear boundary line by emphasizing the value of the boundary area by the phase change caused by the refraction of the X-rays at the interface between the coating layers and the interference effect according to the X-ray absorption effect on the coated particle fuel. A method of acquiring a graphics image, automatically extracting boundary lines between coating layers with respect to the obtained X-ray radiographic image, and nondestructively measuring the thickness of the coating layer based on the extracted boundary lines.

Specifically, a method of acquiring the phase difference X-ray radiographic image, automatically extracting a boundary between coating layers with respect to the obtained X-ray radiographic image, and then measuring the thickness of the coating layer based on the extracted boundary line

Preparing a TRISO coated particle fuel sample which is a measurement target material;

In order to achieve the phase difference effect, a microfocus X-ray generator and an X-ray detector capable of producing digital X-ray image data in real time are installed in the dustproof system, and the coated particle fuel is located at a distance from the X-ray generator. The X-ray detector, and the X-ray generator and the X-ray detector, and the tube voltage, tube current, and X-ray detector of the X-ray generator. Acquiring phase difference X-ray image to set the exposure time, the number of cumulative image frames of:

A histogram adjusting step of processing by a digital image processing technology to increase brightness and contrast of the obtained X-ray image after the step:

Firstly removing high frequency noise included in an image;

Extracting the center point of the coated particle using the center of gravity of the image;

Emphasizing the boundaries between the coating layers;

Secondarily removing the high frequency noise generated in the boundary emphasis process;

Extracting boundary information from an image in which the boundary is highlighted;

Measuring a radius of the coating layer from the boundary information;

And measuring the thickness of the coating layer non-destructively, including measuring the thickness of the coating layer from the radius information.

The phase difference X-ray image acquisition step has a minimum focus size to achieve a phase difference effect. Accurate microfocus X-ray generator with 0.2 to 5 μm, X-ray detector with a pixel size of 50 μm or less capable of producing digital X-ray image data in real time, is installed in the dustproof system and coated particle fuel is generated by X-ray generation. Install the X-ray detector at a distance of 50 to 70 mm from the device, and install the X-ray detector at a distance of 1000 to 1400 mm from the coated fuel, and then operate the X-ray generator and the X-ray detector to generate X-rays. 40 to 60 kV tube voltage, 80 to 100 μA tube current, 2 to 6 seconds exposure time for X-ray detector, 20 to 50 frames for cumulative image frames, X-ray detector and X-ray generation The distance between the devices is set to 1050-1470 mm. If the tube voltage and tube current are set in a low range, the output of the X-rays is lowered, the exposure time and frame rate are increased for proper exposure, and the distance between the X-ray detector and the X-ray generator is set in the low range.

Hereinafter, the configuration and the operation of the embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is an exemplary view showing a schematic configuration of a device for obtaining a phase difference X-ray radiographic image of the coated particle fuel according to the present invention, as shown in the configuration of the present invention is an X-ray shielding cabinet (1), dustproof System (2), real-time X-ray detector (3), sample feeder (5), X-ray generator (6), X-ray generator controller (7), computer system (8), frame grabber (9) ) And a video monitor 10.

The real-time X-ray detector 3 is connected to the frame grabber 9, and the frame grabber 9 is connected to the computer system 8.

The X-ray generator 6 is also connected to an X-ray generator controller 7 and the X-ray generator controller 7 is configured to be connected to a computer system 8.

The video monitor 10 is also an output device connected to the computer system 8.

The dustproof system 2 is provided in the lower part of the X-ray shielding cabinet 1, and inside the X-ray shielding cabinet 1, a real-time X-ray detector 3, a sample feeder 5, X- The line generator 6 and the coated particle fuel 4 to be measured are provided and provided.

Specifically, the X-ray shielding cabinet (1) is a safety cabinet made of a lead plate shielding the X-rays so that X-rays do not leak outside the measurement facility,

The lower part of the X-ray shielding cabinet 1 is provided with a dustproof system 2 so as to block the influence of external vibration in order to maintain the precision of several micrometers or less.

The real-time X-ray detector 3 is made of a semiconductor device and is installed inside the X-ray shielding cabinet 1 to increase the measurement efficiency by converting the X-ray signal into a real-time video signal. The real-time X-ray detector also uses a pixel size of less than 50 μm to produce digital X-ray image data in real time. Since the angle of refraction of the X-ray is small, the smaller the pixel of the X-ray detector is advantageous in order to obtain the phase difference effect due to the interference. Since the spatial resolution due to the refraction of X-rays is about several tens of μm, the phase difference effect can be observed when the pixel size is 50 μm or less. Some semiconductor detectors have a pixel size of about 10 μm, but they are very expensive and have low sensitivity.In the case of X-ray film, they may have a pixel size of 10 μm or less, but data processing is inconvenient. There was such a limitation.

The coated particle fuel 4 is a sample to be measured.

The sample feeder 5 is a device for accurately fixing the coated particle sample in the required position by manipulating a control device outside the cabinet connected to the sample feeder 5 installed inside the cabinet by a tester outside the cabinet.

The X-ray generator 6 is a device having a small focal size of at least 0.2 to 5 μm, which is required for obtaining a phase difference image. The smaller the focal size, the better the spatial coherence characteristic which increases the coherence of X-rays, and it is very advantageous for acquiring the phase difference image by preventing the boundary line from being unclearly expressed by the shadow effect. However, if the focal size is smaller than the lower limit, the X-ray output is very low, so that the exposure time increases and the price of the X-ray generator increases. In addition, when larger than the upper limit value, the spatial coherence characteristic of the X-rays is lowered, thereby reducing the phase difference effect due to interference, thereby limiting the focal size.

The X-ray generator controller 7 is a device for controlling the tube voltage, tube current, and focal size of the X-ray generator 6.

The computer system 8 is a computer system that executes a program that controls the X-ray generator 6 and the X-ray detector 3 and performs coating layer thickness measurement of the coated particle fuel.

The frame grabber 9 converts an image signal of the X-ray detector 3 into a digital signal and inputs the same to the computer system 8.

The image monitor 10 represents an image monitor capable of confirming an X-ray image and a measurement result.

Figure 2 is an exemplary view showing a digital image processing method for measuring the radius and thickness of each coating layer by extracting the boundary between the coating layers of the present invention for the phase difference X-ray image, the phase difference of the coated particle fuel as shown It shows a step-by-step process showing a digital image processing method for measuring the radius and thickness of each coating layer by extracting the boundary line between the coating layers for the X-ray image.

Specific step-by-step process comprises the step (11) of preparing a TRISO coated particle fuel sample to be measured;

Accurate microfocus X-ray generator (6) with a minimum focal size of 0.2 to 5 μm to achieve retardation effects, and an X-ray detector with a sub-50 μm pixel size capable of producing digital X-ray image data in real time (3) Is installed in the dustproof system (table, 2), and the coated particle fuel (4) is installed at a position of 50 to 70 mm away from the X-ray generator (6), and the X-ray detector (3) is placed on the coated material fuel ( 4) After installation at a distance of 1000 to 1400 mm, operate the X-ray generator 6 and the X-ray detector 3 and set the tube voltage of the X-ray generator 6 to 40-60 kV and the tube current. 80 to 100 μA, the exposure time of the X-ray detector 3 to 2 to 6 seconds, the cumulative number of image frames to 20 to 50 frames, and the distance between the X-ray detector 3 and the X-ray generator. (6) is a phase difference X-ray image acquisition step 12, which is set to 1050 ~ 1470 mm:

A histogram adjusting step 13 of processing with a digital image processing technique to increase brightness and contrast of the obtained X-ray image after the step:

Firstly removing the high frequency noise included in the image (14);

Extracting a center point of the coated particle using a center of gravity of the image (15);

Emphasizing the boundary between the coating layers (16);

Secondly removing the high frequency noise generated in the boundary emphasis process;

Extracting boundary line information from the boundary-highlighted image (18);

Measuring (19) the radius of the coating layer from the boundary information;

The thickness of the coating layer is measured 20 from the radius information.

In the phase difference X-ray image acquisition step 12, the coated particle fuel 4 is installed at a position 50 to 70 mm away from the X-ray generator 6 because the distance between the X-ray detector and the object is 1000. It was limited to ˜1400 mm, and the diameter of the coated particle fuel was about 1 mm and the size of the detector was 50 mm. Thus, the proper magnification was set to 21 times.

In addition, in the phase difference X-ray image acquisition step 12, the reason why the X-ray detector 3 is installed at 1000 to 1400 mm from the coated material fuel 4 is that the refractive angle of the X-rays is fine, so that the refractive effect is reduced. To achieve this, the distance between the X-ray detector and the object must be at least 1000 mm. As the distance increases, the effect of refraction increases, but the output density of X-rays decreases, so that the exposure time increases and the size of the shielding cabinet increases, so it is limited to 1000 ~ 1400 mm.

In addition, in the phase difference X-ray image acquisition step 12, the X-ray generator 6 and the X-ray detector 3 are operated and the tube voltage of the X-ray generator 6 is limited to 40 to 60 kV. The reason is that the tube voltage is inversely related to the wavelength of the X-rays. In other words, as the tube voltage increases, the wavelength of the X-ray becomes shorter. The wavelength of X-rays is also related to the retardation effect. That is, since the angle of refraction increases as the wavelength increases and the coherence increases to increase the phase difference effect, the phase difference effect may increase as the tube voltage of the X-ray is lower. However, when the tube voltage of the X-ray is lowered, the transmittance is lowered, which lowers the brightness and contrast characteristics of the X-ray image. The transmittance was lowered at 40 kV or less and the phase difference effect was lowered at 60 kV or more, thereby limiting the tube voltage range as such.

In addition, the reason for limiting the tube current to 80 to 100 μA in the phase difference X-ray image acquisition step 12 is that the X-ray tube current is related to the output and focus size of the X-ray. As the tube current increases, the output increases, but the focal size increases to reduce the phase difference effect. At 80 μA or less, the output was lowered, and at 100 μA or more, the phase difference effect was lowered, thereby limiting the tube current range as such.

In addition, the reason why the exposure time of the X-ray detector 3 is limited to 2 to 6 in the phase difference X-ray image acquiring step 12 is that the exposure time is required for a limited tube voltage / tube current condition, but the X-ray used is The maximum exposure time of the detector was 10 seconds and limited to 2 to 6 seconds or less for stable operation. Correction of the exposure time is made by adjusting the number of frames.

In addition, the reason why the number of cumulative image frames is limited to 20 to 50 frames in the phase difference X-ray image acquisition step 12 requires several minutes of exposure time for proper exposure, and takes 2 to 6 seconds of exposure time per frame. Therefore, the total exposure time was limited to the number of frames to be 40 to 300 seconds.

In addition, in the phase difference X-ray image acquisition step 12, the distance 6 between the X-ray detector 3 and the X-ray generator is limited to 1050 to 1470 mm. The reason is that the X-ray detector and X-ray The distance between the generators is limited to this because it is the sum of the distance '1000-1400 mm' between the X-ray detector and the object mentioned above and the distance 50-70 mm between the object and the X-ray generator.

According to the present invention, the phase difference caused by the refraction of the X-rays at the interface between the coating layers, the phase change due to the refraction of the X-rays, and the interference effect according to the phase difference X-ray image acquisition step 12 As the value of the boundary region is emphasized, a condition for acquiring a phase difference X-ray radiographic image with a clear boundary line is set, thereby obtaining an X-ray radiographic image with a clearer boundary line between coating layers.

The histogram adjusting step 13 automatically analyzes the image quality of the acquired image. To deal with this, the present invention uses a dedicated program that includes all measurement processes from image acquisition to measurement, including histogram adjustment.

In step 14, the high frequency noise included in the image is first removed using a dedicated program including all measurement processes ranging from image acquisition to measurement including a high frequency noise removal function.

Extracting the center point of the coated particle by using the center of gravity of the image 15 extracts the center of gravity using the principle of analyzing the image quality of the obtained image and obtaining the center of gravity. The present invention uses a dedicated program that includes all measurement processes ranging from image acquisition to measurement with center point extraction.

The step 16 of emphasizing the boundaries between the coating layers is to emphasize the boundaries using the differential principle. The present invention uses a dedicated program that includes all the measurement procedures from image acquisition to measurement including these functions.

In step (17), the second step of removing the high frequency noise generated in the boundary emphasis process is repeated to remove the high frequency noise generated in the boundary emphasis process. The present invention uses a dedicated program that includes all of the measurement procedures ranging from image acquisition to measurement.

The step 18 of extracting boundary information from the image in which the boundary is highlighted is a step of analyzing the image quality of the image to determine a threshold value and automatically extracting the position of the boundary based on the image. Use a dedicated program that includes all measurement steps from acquisition to measurement.

The step 19 of measuring the radius of the coating layer from the boundary information is a step of automatically calculating the radius by using the position of the center of gravity and the boundary line obtained in the present invention. Use a dedicated program that includes all measurement steps, from image acquisition to measurement, including calculations.

Step 20 of measuring the thickness of the coating layer from the radius information is a step of automatically calculating the thickness using the previously obtained radius data, the present invention from the image acquisition including the process of automatically calculating the thickness using the radius data Use a dedicated program that includes all the measurement steps leading up to the measurement.

Figure 3 shows a phase difference X-ray radiographic image according to the present invention, the phase difference X-ray radiographic image with a clear boundary line as shown in Figure 3 by performing the steps of the method of Figure 2 with the device configuration of Figure 1 It is possible to improve the coating particle fuel coating layer inspection process by measuring the thickness of the coating layer using this automatically.

Hereinafter is a preferred embodiment of the present invention.

(Example 1)

An X-ray shielding cabinet (1) made of a lead plate shielding the X-rays so that X-rays are not leaked to the outside of the measuring facility according to the present invention; A dustproof system (2) supporting a lower portion of said X-ray shielding cabinet (1); A real-time X-ray detector (3) installed inside the X-ray shielding cabinet (1) and configured of a semiconductor to convert an X-ray signal into a real-time video signal to increase measurement efficiency; A sample feeder (5) installed inside the X-ray shielding cabinet (1) and configured to precisely fix the coated particle fuel (4) in a required position; An X-ray generator (6) installed inside the X-ray shielding cabinet (1) for irradiating X-rays for obtaining a phase difference image to the coated particle fuel (4); An X-ray generator configured to be connected to an X-ray generator 6 installed inside the X-ray shielding cabinet 1 outside to control the tube voltage, tube current, and focal size of the X-ray generator 6. A controller 7; A frame grabber 9 for converting an image signal of a real-time X-ray detector 3 installed inside the X-ray shielding cabinet 1 into a digital signal and inputting it to a computer system 8; A computer system (8) for controlling the X-ray generator (6) and the X-ray detector (3) to execute a program for measuring the coating layer thickness by means of a phase difference X-ray radiographic image of the coated particle fuel. and; After the X-ray image processed by the computer system and the image monitor 10 connected to output the measurement results, the tube voltage 60 kV, tube current 80 uA, focal length 2 um, total exposure time 300 seconds, object and X- The phase difference effect was observed in the X-ray image obtained when the distance between the line generators was 70 mm and the distance between the object and the X-ray detector. Using this image, the boundary line between the coating layers was emphasized and extracted. The radius and the thickness of each coating layer could be measured. These results are shown in FIG. 4, which is a phase difference X-ray radiographic image and an image of the center point and the boundary line extracted from the image.

As a result of comparing the results according to the embodiment with the fracture test, it was confirmed that the fracture test could be replaced by showing a deviation of about 5.7%. These results are shown in FIGS. 5A, 5B, 6A and 6B, where FIG. 5A is an X-ray image according to the present invention, and FIG. 5B is a cutting and polishing of the center of the coated particle using a destructive ceramic method. 6A is an image showing an X-ray image according to the present invention and a thickness of a coating layer measured by treating the same, and FIG. 6B is measured on an image of a cut plane using a ceramic method. Image showing the thickness of the coated layer.

The present invention is not limited to the above-described specific preferred embodiments, and various modifications can be made by any person having ordinary skill in the art without departing from the gist of the present invention claimed in the claims. Of course, such changes will fall within the scope of the claims.

As described above, the present invention improves the coating layer inspection process of the coated particle fuel by non-destructively measuring the thickness of the coating layer during the inspection of the coated particle fuel, and increases the product yield and radioactive waste due to the recycling of the test sample. It is a useful invention that has many effects, such as a reduction in the number of times, and contributes to the improvement of inspection accuracy, and is an invention which is expected to be greatly used in the industry.

Claims (9)

Apparatus for non-destructively testing the coating layer thickness of TRISO coated particle fuel or similar coated particle fuel for hot gas furnace or ultra high temperature gas furnace, An X-ray shielding cabinet (1) made of a lead plate that shields the X-rays so that X-rays do not leak out of the measurement facility; A dustproof system (2) supporting a lower portion of said X-ray shielding cabinet (1); A real-time X-ray detector (3) installed inside the X-ray shielding cabinet (1) and configured of a semiconductor to convert an X-ray signal into a real-time video signal to increase measurement efficiency; A sample feeder (5) installed inside the X-ray shielding cabinet (1) and configured to precisely fix the coated particle fuel (4) in a required position; An X-ray generator (6) installed inside the X-ray shielding cabinet (1) for irradiating X-rays for obtaining a phase difference image to the coated particle fuel (4); An X-ray generator configured to be connected to an X-ray generator 6 installed inside the X-ray shielding cabinet 1 outside to control the tube voltage, tube current, and focal size of the X-ray generator 6. A controller 7; A frame grabber 9 for converting an image signal of a real-time X-ray detector 3 installed inside the X-ray shielding cabinet 1 into a digital signal and inputting it to a computer system 8; A computer system (8) for controlling the X-ray generator (6) and the X-ray detector (3) to execute a program for measuring the coating layer thickness by means of a phase difference X-ray radiographic image of the coated particle fuel; ; TRISO coated particle fuel coating layer thickness nondestructive measuring device using a phase difference X-ray radiographic image, characterized in that the image monitor 10 is connected to output the X-ray image processed by the computer system and the measurement results. The method of claim 1, The real-time X-ray detector is a non-destructive measurement of TRISO coated particle fuel coating layer thickness using a phase difference X-ray radiographic image, characterized in that it has a pixel size of 50 μm or less to produce digital X-ray image data in real time Device. The method of claim 1, The X-ray generator 6 is a non-destructive measuring device of TRISO coated particle fuel coating layer thickness using a phase difference X-ray radiographic image, characterized in that the device having a focal size of 0.2 ~ 5 μm class to obtain a phase difference image . The method of claim 1, The X-ray generator controller 7 is configured to control the tube voltage of the X-ray generator 6 to 40 to 60 kV, the tube current to 80 to 100 μA and the focal size to 0.2 to 5 μm. Non-destructive measuring device of TRISO coated particle fuel coating layer thickness using retardation X-ray radiographic image. The method of claim 1, The X-ray detector 3 has a thickness of TRISO-coated particle fuel coating layer using a phase difference X-ray radiographic image, wherein the exposure time is set to 2 to 6 seconds and the number of accumulated image frames is 20 to 50 frames. Non-destructive measuring device. The method of claim 1, The coated particle fuel 4 is installed at a position 50 to 70 mm away from the X-ray generator 6, and the X-ray detector 3 is positioned at a position 1000 to 1400 mm away from the coated particle 4. TRISO coated particle fuel coating layer thickness nondestructive measurement device using a phase difference X-ray radiographic image, characterized in that the installation. In a method for nondestructively testing the coating layer thickness of TRISO coated particle fuel or similar coated particle fuel for a hot gas furnace or an ultra high temperature gas furnace, Phase difference X-ray radio with a clear boundary line by emphasizing the value of the boundary area by the phase change caused by the refraction of the X-rays at the interface between the coating layers and the interference effect according to the X-ray absorption effect on the coated particle fuel. A phase difference x-ray characterized in that a method of obtaining a imaging image, automatically extracting boundaries between coating layers on the obtained X-ray radiographic image, and measuring the thickness of the coating layer nondestructively based on the extracted boundaries Nondestructive Measurement of TRISO Coated Particle Fuel Coating Layer Thickness Using Radiographic Images. The method of claim 7, wherein The method of acquiring the phase difference X-ray radiographic image, automatically extracting the boundary line between the coating layers with respect to the obtained X-ray radiographic image, and measuring the thickness of the coating layer based on the extracted boundary line, Preparing (11) a TRISO-coated particle fuel sample that is a measurement target material; In order to achieve the phase difference effect, a microfocus X-ray generator 6 and an X-ray detector 3 capable of producing digital X-ray image data in real time are installed in the dustproof system 2 and coated particle fuel 4 ) Is installed at a distance away from the X-ray generator 6, and the X-ray detector 3 is installed at a distance away from the covering material fuel 4, and then the X-ray generator ( 6) and the phase difference X-ray image which operates the X-ray detector 3 and sets the tube voltage of the X-ray generator 6, the tube current, the exposure time of the X-ray detector 3, and the number of accumulated image frames. Obtaining step 12; A histogram adjusting step (13) of processing by a digital image processing technique to increase brightness and contrast of the obtained X-ray image after the step; Firstly removing the high frequency noise included in the image (14); Extracting a center point of the coated particle using a center of gravity of the image (15); Emphasizing the boundary between the coating layers (16); Secondly removing the high frequency noise generated in the boundary emphasis process; Extracting boundary line information from the boundary-highlighted image (18); Measuring (19) the radius of the coating layer from the boundary information; Non-destructive measurement method of TRISO coated particle fuel coating layer thickness nondestructive using a phase difference X-ray radiographic image, comprising the step of measuring the thickness of the coating layer from the radius information (20). The method of claim 8, The phase difference X-ray image acquisition step 12 is capable of producing digital X-ray image data in real time with a precise microfocus X-ray generator 6 having a minimum focus size of 0.2 to 5 μm in order to achieve a phase difference effect. An X-ray detector 3 having a pixel size of 50 μm or less is installed in the dustproof system 2, and the coated particle fuel 4 is installed at a position 50 to 70 mm away from the X-ray generator 6, After the ray detector 3 is installed at a position 1000 to 1400 mm away from the cladding fuel 4, the X-ray generator 6 and the X-ray detector 3 are operated and the X-ray generator ( 6) the tube voltage of 40 to 60 kV, the tube current of 80 to 100 μA, the exposure time of the X-ray detector 3 to 2 to 6 seconds, the number of accumulated image frames to 20 to 50 frames, and the X-ray detector ( 3) and the distance 6 between the X-ray generator is set to 1050 ~ 1470 mm Nondestructive Measurement of TRISO Coated Particle Fuel Coating Layer Thickness Using Retardation X-ray Radiography Image.

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