Monitoring device and experimental device for neutron poison layer of spent fuel bearing device

Abstract

The invention discloses a monitoring device and an experimental device for a neutron poison layer in a spent fuel bearing device, and relates to the technical field of nuclear chemical engineering, the monitoring device comprises a first support and a second support, the bottoms of the first support and the second support are respectively provided with a moving device, and the first support and the second support are arranged in parallel at an interval; the radiation device is connected to the first support, the radiation end of the radiation device faces the second support, and the radiation end is provided with a first moderation layer; the detection device is connected to the second support, the detection device is provided with a second moderation layer, and a plurality of detectors are sequentially inserted into the second moderation layer. According to the technical scheme, the radiation device and the detection device are supported through the first support and the second support respectively, the radiation device and the detection device can move relatively through the moving device, and the monitoring device can flexibly monitor neutron poison layers at different positions of the spent fuel bearing device.

Description

Technical Field

[0001] This invention relates to the field of nuclear chemical technology, specifically to a monitoring and experimental device for a neutron poison layer in a spent fuel carrier. Background Technology

[0002] In the nuclear energy field, spent fuel storage facilities typically employ a neutron poison layer to absorb neutrons and ensure criticality. However, due to the brittle nature of neutron poison materials, they may fracture under the conditions of spent fuel reprocessing due to corrosion, vibration, or mechanical wear, thereby reducing their neutron absorption capacity. Therefore, measurement methods are needed to monitor the effectiveness of the neutron poison layer.

[0003] Traditional measurements rely solely on simple radiation measurement methods, which cannot accurately determine the location of local failures in the neutron poison layer, thus posing significant potential safety risks. Summary of the Invention

[0004] In view of this, the present invention provides a monitoring device and experimental apparatus for a neutron poison layer in a spent fuel carrier, so as to solve the problem that existing monitoring devices cannot accurately locate the defect location of the neutron poison layer.

[0005] The present invention provides a monitoring device for a subpoison layer in a spent fuel carrier, comprising: The first and second supports each have a movable device at their bottoms, and the first and second supports are arranged side by side with intervals. A radiation device is connected to the first support, with the radiating end of the radiation device facing the second support, and the radiating end is provided with a first moderation layer; A detection device is connected to the second bracket. The detection device has a second moderation layer, in which multiple detectors are sequentially inserted.

[0006] In this invention, a first support and a second support respectively support the radiation device and the detection device. A movable device allows the radiation device and the detection device to move relative to each other, enabling the monitoring device to flexibly monitor the neutron poison layer at different locations on the spent fuel carrier. This improves the applicability and flexibility of the monitoring device, ensuring comprehensive and accurate monitoring of the spent fuel carrier and avoiding situations where certain critical parts cannot be detected due to a fixed location.

[0007] The first moderation layer slows down fast neutrons emitted by the radiation device into slow neutrons. Because slow neutrons have a larger interaction cross-section with the neutron poison, they are more easily absorbed or scattered by the poison, resulting in a more noticeable detectable signal and improving monitoring sensitivity and accuracy. This configuration makes the interaction between neutrons and the neutron poison layer more significant, enabling more effective detection of information related to the neutron poison layer, such as the material integrity of the poison, thus providing a foundation for accurately assessing the performance and state of the neutron poison layer.

[0008] The second moderator layer further slows down neutrons after they have passed through the neutron poison layer, making them easier for detectors to detect. Multiple detectors are used to detect neutrons after they have passed through the neutron poison layer and the second moderator layer. By measuring information such as the neutron count rate, the interaction between neutrons and the neutron poison layer is obtained, and the characteristics of the neutron poison layer are inferred.

[0009] The second moderation layer also acts as a shield against the external environment, effectively absorbing or scattering external neutrons to prevent them from entering the detection device and interfering with measurements. Besides neutrons, other radiation from the external environment (such as gamma rays) can also affect the detector, increasing the background noise of the measurement. The second moderation layer provides some shielding against this environmental radiation, reducing the radiation background around the detector. This allows the detector to more clearly distinguish neutron signals associated with the neutron poison layer when detecting neutrons, further improving the accuracy of the measurement.

[0010] The arrangement and coordinated operation of multiple detector arrays allows for the detection of neutrons from different angles or locations, improving the accuracy and comprehensiveness of detection. This configuration enables the precise detection of various information arising from the interaction between neutrons and the neutron poison layer. Analysis and processing of this information yields detailed data on the neutron poison layer, providing strong technical support for the safe operation and maintenance of spent fuel carrier pylons.

[0011] Optionally, the radiation device includes a neutron radiation source having a radiation end and a circumferential shielding body around the radiation end.

[0012] Optionally, the shielding body is a rectangular frame structure.

[0013] Optionally, the first moderating layer is disposed inside the shield.

[0014] Optionally, a plurality of the detectors are arranged sequentially along the height direction within the collimation and slowing device.

[0015] Optionally, the collimation and slowing device is provided with the second slowing layer on both sides.

[0016] The present invention provides an experimental apparatus for monitoring a neutron poison layer in a spent fuel carrier device, comprising: a radiation device, a simulated carrier device, and a detection device, wherein the simulated carrier device is disposed between the radiation device and the detection device, and the bottom of the simulated carrier device has a moving device; The radiating end of the radiating device faces the simulated support device, and the radiating end is provided with a first moderation layer; The detection device has a second moderation layer, within which multiple detectors are sequentially inserted.

[0017] In this invention, a simulated support device is placed between the radiation device and the detection device, simulating the actual working scenario of a spent fuel support device. By using a moving device at the bottom of the simulated support device to simulate the movement of the radiation device and the detection device along the support device, various parts of the support device can be inspected, thereby helping to identify potential localized problems.

[0018] This monitoring experimental setup provides researchers with the ability to precisely control experimental conditions. Researchers can precisely adjust the intensity of the radiation device, the characteristics of the simulated support device, and the parameters of the detection device according to experimental needs. This precise control helps in in-depth research into various characteristics of the neutron poison layer. For example, by changing the intensity of the radiation device, researchers can study the response of the neutron poison layer under different neutron fluxes, thereby better understanding and optimizing the performance of the spent fuel support measurement device. Similarly, by changing the thickness of the moderator layer in front of the radiation device or the detection device, researchers can study the response of the neutron poison layer under different neutron energies, thus better understanding and optimizing the performance of the spent fuel support measurement device. Furthermore, by changing the distribution parameters of the neutron poison layer through splicing, researchers can study the response of the measurement device to different neutron poison layer distributions, thereby better verifying the performance of the measurement device.

[0019] Optionally, the simulated support device includes a body layer and a boron carbide layer connected to the front and / or back of the body layer.

[0020] Optionally, the boron carbide layer has removable multiple boron carbide sheets.

[0021] Optionally, the bottom of the radiation device, the simulation support device, and the detection device has a device support body, the device support body has a first track, the radiation device and the detection device are set on the first track, and the first track is used to adjust the distance between the radiation device and the detection device; The device support also has a second track, which is perpendicular to the first track, and the position of the simulated bearing device is adjusted by the second track. Attached Figure Description

[0022] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0023] Figure 1 This is a front view of a specific embodiment of the monitoring device for a subpoison layer in a spent fuel carrier provided by an embodiment of the present invention; Figure 2 This is a front view of a specific embodiment of the experimental apparatus for monitoring the subpoison layer in a spent fuel carrier provided in this invention. Figure 3 for Figure 2 The diagram shows a perspective view of an experimental setup for monitoring the subpoison layer in a spent fuel carrier.

[0024] Explanation of reference numerals in the attached figures: 1. First support; 2. Second support; 3. Radiation device; 301. Neutron radiation source; 302. First moderation layer; 303. Shielding structure; 4. Detection device; 401. Detector; 402. Second moderation layer; 5. Simulated load-bearing device; 501. Body layer; 502. Boron carbide layer; 6. First track; 7. Second track; 8. Equipment support. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0027] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0028] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0029] Example 1 like Figure 1 As shown, this is a specific embodiment of the monitoring device for the subpoison layer in the spent fuel carrying device provided in this embodiment, including: a first support 1 and a second support 2, the first support 1 and the second support 2 are arranged side by side with intervals, and a carrying device for spent fuel is adapted to be arranged between the first support 1 and the second support 2.

[0030] like Figure 1 As shown in this embodiment, a radiation device 3 is connected to the first support 1, with the radiating end of the radiation device 3 facing the second support 2. The radiating end is provided with a first moderator layer 302. The function of the first moderator layer 302 is to slow down the fast neutrons emitted by the radiation device 3 into slow neutrons. Because the interaction cross-section between slow neutrons and neutron poison is larger, they are more easily absorbed or scattered by the neutron poison, thus generating a more obvious detectable signal, which is beneficial to improving the sensitivity and accuracy of monitoring. This configuration makes the interaction between neutrons and the neutron poison layer more significant, enabling more effective detection of relevant information about the neutron poison layer, such as the material integrity of the neutron poison, providing a basis for accurately assessing the performance and state of the neutron poison layer.

[0031] like Figure 1 As shown, in this embodiment, a detection device 4 is connected to the second support 2. The detection device 4 has a second moderation layer 402, and multiple detectors 401 are sequentially inserted into the second moderation layer 402. The detectors 401 can be of various types, such as gas detectors 401, semiconductor detectors 401, and scintillator detectors 401, for testing. In this embodiment, a He-3 neutron proportional counter tube of the gas detector type 401 is selected for measurement.

[0032] The second moderation layer 402 further slows down the neutrons after they have passed through the neutron poison layer, making them easier for the detector 401 to detect. Multiple detectors 401 are used to detect neutrons after they have passed through the neutron poison layer and the second moderation layer 402. By measuring information such as the neutron count rate, the results of the interaction between the neutrons and the neutron poison layer are obtained, and the characteristics of the neutron poison layer are inferred.

[0033] The second moderation layer 402 also serves as a shielding structure against the external environment, effectively absorbing or scattering these external neutrons to prevent them from entering the detection device 4 and interfering with measurements. Besides neutrons, other radiation from the external environment (such as gamma rays) may also affect the detector 401, increasing the background noise of the measurement. The second moderation layer 402 provides some shielding against this environmental radiation, reducing the radiation background around the detector 401. This allows the detector 401 to more clearly distinguish neutron signals associated with the neutron poison layer when detecting neutrons, further improving the accuracy of the measurement.

[0034] like Figure 1 As shown in this embodiment, the bottoms of the first support 1 and the second support 2 are each equipped with a movable device. This movable device allows the radiation device 3 and the detection device 4 to move relative to each other, enabling the monitoring device to flexibly monitor the neutron poison layer at different locations on the spent fuel carrier. This improves the applicability and flexibility of the monitoring device, ensuring comprehensive and accurate monitoring of the spent fuel carrier and avoiding situations where certain critical parts cannot be detected due to a fixed location.

[0035] In this embodiment, by arranging and cooperating with an array of multiple detectors 401, neutrons can be detected from different angles or positions, improving the accuracy and comprehensiveness of detection. This setup enables precise detection of various information arising from the interaction between neutrons and the neutron poison layer. Through analysis and processing of this information, detailed data on the neutron poison layer can be obtained, providing strong technical support for the safe operation and maintenance of spent fuel carrier devices.

[0036] like Figure 1 As shown, in some embodiments, the radiation device 3 includes a neutron radiation source 301, which has a radiating end and a circumferential shield 303. The shield 303 effectively reduces stray neutrons in the air except in the collimating direction, ensuring radiation safety for personnel and the environment. Specifically, the neutron radiation source 301 can be an Am-Be neutron radiation source 301, a Cf-252 neutron radiation source 301, etc. This embodiment uses an Am-Be neutron radiation source 301 with an emissivity of 1.35E+5n / s.

[0037] like Figure 1 As shown, in some embodiments, the shielding body 303 is a rectangular frame structure. Specifically, the shielding body 303 may be constructed from modular boron-containing polyethylene, thereby fixing the radiation source within the shielding body 303.

[0038] like Figure 1 As shown, in some embodiments, the first moderating layer 302 is disposed inside the shield 303. The first moderating layer 302 is detachably connected and can be configured with different thicknesses, specifically using high-density polyethylene material. This configuration better accommodates the adjustment of monitored variables.

[0039] like Figure 1 As shown, in some embodiments, a plurality of detectors 401 are sequentially arranged along the height direction within the collimation and slowing-down device. Further, the plurality of detectors 401 within the collimation and slowing-down device are arranged horizontally. The second slowing-down layer 402 is detachably disposed on both sides of the collimation and slowing-down device, allowing the thickness of the second slowing-down layer 402 to be changed as needed.

[0040] Example 2 like Figure 2 , Figure 3 As shown, this is a specific implementation of the experimental device for monitoring the toxic layer in a spent fuel carrier device provided in this embodiment. It includes: a radiation device 3, a simulated carrier device 5, and a detection device 4. The simulated carrier device 5 is disposed between the radiation device 3 and the detection device 4. Placing the simulated carrier device 5 between the radiation device 3 and the detection device 4 can simulate the actual working scenario of the spent fuel carrier device.

[0041] like Figure 2 , Figure 3 As shown, in this embodiment, the simulated support device 5 has a moving device at its bottom. This moving device allows the simulated radiation device 3 and detection device 4 to move along the support device, enabling the detection of various parts of the support device and helping to identify potential local problems.

[0042] like Figure 2 , Figure 3 As shown, in this embodiment, the radiating end of the radiating device 3 faces the simulated support device 5, and the radiating end is provided with a first moderation layer 302. The detection device 4 has a second moderation layer 402, and a plurality of detectors 401 are sequentially inserted in the second moderation layer 402.

[0043] In this embodiment, the intensity of the radiation device 3, the characteristics of the simulated bearing device 5, and the parameters of the detection device 4 can be precisely adjusted according to experimental requirements.

[0044] like Figure 2 , Figure 3 As shown, in some embodiments, the simulated support device 5 includes a body layer 501 and a boron carbide layer 502 connected to the front and back sides of the body layer 501. The boron carbide layer 502 is used to simulate the neutron poison layer of the support device 5.

[0045] like Figure 2 , Figure 3 As shown, in some embodiments, the boron carbide layer 502 has removable multiple boron carbide sheets. During experiments, by removing parts of the boron carbide, it can be used to simulate the destruction of a localized neutron poison layer in the carrier device 5.

[0046] like Figure 2 , Figure 3 As shown, in some embodiments, the bottom of the radiation device 3, the simulation support device 5, and the detection device 4 has a device support body 8, and the device support body 8 has a first track 6. The radiation device 3 and the detection device 4 are arranged on the first track 6, and the first track 6 is used to adjust the distance between the radiation device 3 and the detection device 4.

[0047] like Figure 2 , Figure 3 As shown, in some embodiments, the device support 8 also has a second track 7, which is perpendicular to the first track 6. The second track 7 is used to adjust the position of the simulated support device 5. Specifically, the second track 7 can be a slide rail, on which a slide table is slidably mounted. The simulated support device 5 is connected to the slide table, thereby enabling the simulated support device 5 to slide along the second track 7.

[0048] In some embodiments, the second track 7 has a drive device connected to the slide table, which drives the slide table to move along the second track 7. Specifically, the drive device uses a PLC control unit to control the servo motor to simulate the overall movement of the support device 5.

[0049] After the experimental device for monitoring the neutron poison layer in the spent fuel carrier provided in this embodiment is assembled, the PLC control device and the neutron detector 401 are powered on, and the host computer software is used for control and debugging. After confirming that the equipment is in good operating condition, the test is started.

[0050] When in use, open the host computer software to preheat the equipment and fix the position of the radiation device 3.

[0051] First, the relevant tests are completed by changing the position and thickness of the second moderation layer 402 in the detection device 4.

[0052] Secondly, the distance between the radiation device 3 and the simulated support device 5 is changed to complete the corresponding test.

[0053] Then, a second moderation layer 402 of different thicknesses is added to the front end of the neutron radiation source 301 to complete another round of testing.

[0054] Based on these experimental variables, cross-tests were conducted. Through this series of tests, the selection of relative position and moderating layer thickness was determined under fixed optimal experimental conditions.

[0055] The equipment was rearranged according to the above test conditions.

[0056] Remove the neutron radiation source 301, turn on the detector 401 and test the host computer software for measurement. Use the PLC control device to control the simulated carrier device 5 to move on the second track 7 at a speed of 0.5 m / s. Record a set of measurement values ​​at 60s intervals as the background count rate test value.

[0057] The neutron radiation source 301 was reinstalled, and the detector 401 was turned on to test the host computer software for measurement. The PLC control device was used to control the simulated carrier device 5 to move on the second orbit 7 at a speed of 0.5 m / s. A set of measurement values ​​was recorded at 60s intervals as the initial source term count rate test value.

[0058] By moving a boron carbide plate spliced ​​on the boron carbide layer 502, a crack with a size of 10mm×300mm is created. The PLC control device controls the simulated bearing device 5 to move on the second track 7 at a speed of 0.5m / s. A set of measurement values ​​is recorded at 60s intervals as real-time source term count rate test values.

[0059] By changing the size of the cracks generated in the boron carbide layer 502 to 20mm×300mm and 50mm×300mm respectively, the real-time source term count rate was measured and given. By calculating the rate of change between the real-time measured value and the initial measured value, and observing whether the host computer software outputs an alarm signal when a specific crack size is generated, it can be determined whether the neutron poison is in a deactivated state when the crack is generated.

[0060] Turn off the equipment after the test is completed.

[0061] The experimental apparatus for monitoring the neutron poison layer in a spent fuel carrier device provided in this embodiment places the simulated carrier device 5 between the radiation device 3 and the detection device 4. By simulating the body layer 501 and the boron carbide layer 502 (simulating the neutron poison layer) of the simulated carrier device 5, as well as the relative positional relationship between each device, the actual working scenario of the spent fuel carrier device is simulated, so that the experiment can be carried out under near-real conditions, ensuring the reliability and effectiveness of the experimental results.

[0062] The moving device at the bottom of the simulated support device 5 can simulate the movement of the radiation device 3 and the detection device 4 along the support device, enabling the experiment to detect various parts of the support device. By detecting data changes in different parts, it is helpful to discover potential local problems and gain a comprehensive understanding of the performance of the support device.

[0063] The first moderator layer 302 at the emitting end of the radiation device 3 slows down the emitted neutrons, making them more likely to interact with the simulated neutron poison layer. After interaction, the neutrons reach the detection device 4, where the second moderator layer 402 further slows them down, facilitating detection by multiple detectors 401. The multiple detectors 401 work collaboratively to acquire relevant information about the neutrons, providing data support for analyzing the characteristics of the neutron poison layer.

[0064] The experimental apparatus for monitoring the neutron poison layer in a spent fuel carrier device provided in this embodiment allows for precise adjustment of the parameters of the radiation device 3 and the detection device 4 according to experimental requirements. This flexibility enables the experiment to simulate various real-world scenarios, study the performance of the neutron poison layer under different conditions, and provide theoretical basis and data support for the design, optimization, and safe operation of actual spent fuel carrier devices.

[0065] The experimental apparatus for monitoring the neutron poison layer in a spent fuel carrier device provided in this embodiment uses a first track 6 on the device support 8 to adjust the distance between the radiation device 3 and the detection device 4, thereby changing the distance neutrons travel in the air and simulating neutron propagation under different real-world scenarios. A second track 7, perpendicular to the first track 6, connects to the simulated carrier device 5 via a slide rail and a sliding table. This allows adjustment of the simulated carrier device 5's position, enabling it to receive neutron radiation at different locations and comprehensively simulating the working state of the actual carrier device at different positions. The drive device uses a PLC control program to control the servo motor's movement, precisely driving the sliding table to move along the second track 7, achieving precise adjustment of the simulated carrier device 5's position to meet different experimental requirements.

[0066] Although embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations all fall within the scope defined by the present invention.

Claims

1. A monitoring device for a subpoison layer in a spent fuel carrier, characterized in that, include: The first support (1) and the second support (2) each have a moving device at their bottom, and the first support (1) and the second support (2) are arranged side by side with intervals. A radiation device (3) is connected to the first support (1), with the radiation end of the radiation device (3) facing the second support (2), and the radiation end is provided with a first moderation layer (302). The detection device (4) is connected to the second bracket (2). The detection device (4) has a second moderation layer (402), and multiple detectors (401) are sequentially inserted in the second moderation layer (402).

2. The monitoring device for the subpoison layer in a spent fuel carrier according to claim 1, characterized in that, The radiation device (3) includes a neutron radiation source (301) having a radiation end and a shield (303) circumferentially distributed around the radiation end.

3. The monitoring device for the subpoison layer in a spent fuel carrier according to claim 2, characterized in that, The shield (303) is a rectangular frame structure.

4. The monitoring device for the subpoison layer in a spent fuel carrier according to claim 3, characterized in that, The first moderating layer (302) is disposed inside the shield (303).

5. The monitoring device for a subpoison layer in a spent fuel carrier according to any one of claims 1-4, characterized in that, Multiple detectors (401) are arranged sequentially along the height direction within the collimation and slowing device.

6. The monitoring device for a subpoison layer in a spent fuel carrier according to claim 5, characterized in that, The collimation and slowing device has a second slowing layer (402) distributed on both sides.

7. An experimental device for monitoring the toxic layer in a spent fuel carrier, characterized in that, include: The device includes a radiation device (3), a simulation support device (5), and a detection device (4), wherein the simulation support device (5) is disposed between the radiation device (3) and the detection device (4), and the bottom of the simulation support device (5) has a moving device. The radiating end of the radiating device (3) faces the simulated support device (5), and the radiating end is provided with a first moderation layer (302). The detection device (4) has a second moderation layer (402), and multiple detectors (401) are sequentially inserted in the second moderation layer (402).

8. The experimental apparatus for monitoring the subpoison layer in a spent fuel carrier device according to claim 7, characterized in that, The simulated support device (5) includes a body layer (501) and a boron carbide layer (502) connected to the front and / or back of the body layer (501).

9. The experimental apparatus for monitoring the subpoison layer in a spent fuel carrier device according to claim 8, characterized in that, The boron carbide layer (502) has removable multiple boron carbide sheets.

10. The experimental apparatus for monitoring the subpoison layer in a spent fuel carrier according to any one of claims 7-9, characterized in that, The bottom of the radiation device (3), the simulation support device (5) and the detection device (4) has a device support body (8), and the device support body (8) has a first track (6). The radiation device (3) and the detection device (4) are set on the first track (6), and the distance between the radiation device (3) and the detection device (4) is adjusted by the first track (6). The equipment support (8) also has a second track (7), which is perpendicular to the first track (6). The second track (7) is used to adjust the position of the simulated bearing device (5).

Images