Evaluation method for nuclear irradiation of robot in containment

Abstract

The invention relates to the technical field of nuclear radiation, and provides a method for evaluating nuclear irradiation of a robot in a containment vessel, which comprises the following steps: dividing the space in the containment vessel into a plurality of voxels, and obtaining the total concentration of various radionuclides in each voxel; based on the volume of each voxel, the distance between each voxel and the robot and the total concentration of various radionuclides in each voxel, calculating a first nuclear irradiation dose of each voxel to the robot; and summing the plurality of first nuclear radiation doses to obtain the total nuclear radiation dose of the robot at the current position. According to the method for evaluating nuclear irradiation of the robot in the containment, the total nuclear irradiation dose of the robot at the current position can be calculated, whether the robot can normally work in a high-radiation environment after an accident or not can be evaluated according to the relation between the total nuclear irradiation dose and the preset value, the evaluation method is simple and feasible, and the evaluation efficiency is improved. And the accuracy is high.

Description

Technical Field

[0001] The invention relates to the field of nuclear radiation technology, and in particular to a method for evaluating nuclear radiation of a robot in a containment shell. Background Art

[0002] Nuclear safety has always been a topic of great concern. Once a nuclear accident occurs in a nuclear power plant, radioactive materials originally contained in closed containers and loops may leak into the containment. As the accident progresses, radioactive materials may spread to the external environment, affecting the environment and public safety. In order to deal with the accident reasonably, robots are needed to detect the accident environment. Therefore, it is necessary to reasonably evaluate the radiation dose received by the robot in the radiation field to ensure that the robot can work normally in the high radiation field environment after the accident.

[0003] Currently, experimental methods are usually used to evaluate the radiation dose received by robots in radiation fields. However, the experimental method is time-consuming and labor-intensive, and the experimental conditions are difficult to achieve real accident conditions. At the same time, radioactive experiments are extremely risky. Therefore, it is crucial to provide a new method for evaluating the nuclear radiation exposure of robots. Summary of the invention

[0004] The present invention provides a method for evaluating nuclear radiation of a robot in a containment shell, so as to solve the defects of the prior art that the evaluation of nuclear radiation of a robot by a test method is time-consuming, labor-intensive and has high risks.

[0005] The present invention provides a method for evaluating nuclear radiation exposure of a robot in a containment shell, comprising: dividing the space in the containment shell into a plurality of voxels, and obtaining the total concentration of various radioactive nuclides in each voxel; calculating the first nuclear radiation dose of each voxel to the robot based on the volume of each voxel, the distance between each voxel and the robot, and the total concentration of various radioactive nuclides in each voxel; and summing a plurality of the first nuclear radiation doses to obtain the total nuclear radiation dose received by the robot at the current position.

[0006] According to a method for evaluating nuclear radiation of a robot in a containment shell provided by the present invention, the step of dividing the space in the containment shell into a plurality of volume elements comprises: dividing the space in the containment shell into a plurality of said volume elements according to three dimensions: the axial length of the containment shell, the radius of the containment shell and the azimuth angle.

[0007] According to a method for evaluating nuclear exposure of a robot in a containment shell provided by the present invention, the step of calculating the first nuclear exposure dose of each voxel to the robot based on the volume of each voxel, the distance between each voxel and the robot, and the total concentration of various radioactive nuclides in each voxel includes: establishing a cylindrical coordinate system with the center of the bottom surface of the containment shell as the circle point and the axial length, radius and azimuth of the containment shell as coordinates; obtaining the first coordinates of the contour of each voxel in the cylindrical coordinate system, and calculating the volume of each voxel based on the first coordinates.

[0008] According to a method for evaluating nuclear exposure of a robot in a containment shell provided by the present invention, the step of calculating the first nuclear exposure dose of each voxel to the robot based on the volume of each voxel, the distance between each voxel and the robot, and the total concentration of various radioactive nuclides in each voxel also includes: calculating the second coordinates of the center point of each voxel based on the various first annotations; obtaining the third coordinates of the robot at the current position; and calculating the distance between the robot and each voxel based on the second coordinate and the third coordinate.

[0009] According to a method for evaluating nuclear radiation exposure of a robot in a containment shell provided by the present invention, the step of calculating the first nuclear radiation dose of each voxel to the robot based on the volume of each voxel, the distance between each voxel and the robot, and the total concentration of various radioactive nuclides in each voxel also includes: obtaining the concentration of various radioactive nuclides in each voxel; calculating the second nuclear radiation dose of each radioactive nuclide to the robot based on the concentration, the volume of each voxel, and the distance between each voxel and the robot; and summing multiple second nuclear radiation doses to obtain the first nuclear radiation dose of each voxel to the robot.

[0010] A method for evaluating nuclear radiation exposure of a robot in a containment shell provided by the present invention also includes: obtaining the working time of the robot at the current position; and calculating the first nuclear radiation dose of each voxel to the robot based on the working time, the volume of each voxel, the distance between each voxel and the robot, and the total concentration of radioactive nuclides in each voxel.

[0011] According to a method for assessing nuclear irradiation of a robot in a containment shell provided by the present invention, the step of obtaining the total concentration of various radioactive nuclides in each voxel includes: obtaining concentration data of various radioactive nuclides in each voxel that changes with time.

[0012] According to a method for evaluating nuclear radiation exposure of a robot in a containment shell provided by the present invention, the method further includes: before calculating the first nuclear radiation dose, selecting a nuclear accident condition that needs to be evaluated and obtaining a radioactive source item leaked into the containment shell.

[0013] According to a method for evaluating nuclear radiation exposure of a robot in a containment shell provided by the present invention, the method further comprises: evaluating the nuclear radiation exposure of the robot based on the relationship between the total nuclear radiation dose and a preset value.

[0014] According to a method for evaluating nuclear radiation exposure of a robot in a containment shell provided by the present invention, the method further includes: when the total nuclear radiation dose is greater than or equal to a preset value, determining that the robot cannot work normally; when the total nuclear radiation dose is less than the preset value, determining that the robot can work normally.

[0015] The method for evaluating nuclear radiation exposure of a robot in a containment shell provided by the present invention can calculate the total nuclear radiation dose received by the robot at the current position. According to the relationship between the total nuclear radiation dose and a preset value, it can be evaluated whether the robot can work normally in a high radiation environment after an accident. The evaluation method is simple and feasible and has a high accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 The present invention provides a flowchart of a method for evaluating nuclear irradiation of a robot in a containment shell.

[0018] Figure 2 It is a division diagram of voxels.

[0019] Reference numerals: 1. Body element. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] Combine the following Figure 1 and Figure 2 The present invention describes a method for evaluating nuclear irradiation of a robot in a containment shell.

[0022] like Figure 1As shown, in an embodiment of the present invention, a method for evaluating nuclear irradiation of a robot in a containment shell comprises the following steps: Step 100: Divide the space in the containment into multiple voxels 1, and obtain the total concentration of various radioactive nuclides in each voxel 1; Step 200: Calculate the first nuclear radiation dose of each voxel 1 to the robot based on the volume of each voxel 1, the distance between each voxel 1 and the robot, and the total concentration of radioactive nuclides in each voxel 1; Step 300: Sum multiple first nuclear radiation doses to obtain the total nuclear radiation dose received by the robot at the current position.

[0023] Specifically, after a nuclear accident occurs, the reactor loop leaks radioactive nuclides into the containment. In this embodiment, the radioactive nuclides include: rare gases, such as Kr and Xe; alkali metals, such as Cs; and halogens, such as I and Br. The concentration of radioactive nuclides in different places in the containment is different. When the robot is located at different positions, the nuclear radiation dose it receives is also different. In this embodiment, the space in the containment is divided into a plurality of voxels 1. There are many ways to divide the voxels 1, such as dividing the space in the containment into a plurality of cylinders with different radii, or dividing the space in the containment into a plurality of voxels 1 according to the three dimensions of the axial length of the containment, the radius of the containment, and the azimuth angle. The total concentration of various radioactive nuclides in each voxel 1 is obtained, and based on each voxel 1, the distance between each voxel 1 and the robot, and the total concentration of radioactive nuclides in each voxel 1, the first nuclear radiation dose of each voxel 1 to the robot is calculated, and the first nuclear radiation dose of each voxel 1 is summed to obtain the total nuclear radiation dose received by the robot at the current position. If the total nuclear radiation dose is greater than or equal to the preset value, it indicates that the robot cannot work normally in the current nuclear radiation environment; if the total nuclear radiation dose is less than the preset value, it indicates that the robot can work normally in the current nuclear radiation environment.

[0024] The method for evaluating nuclear radiation exposure of a robot in a containment shell provided in an embodiment of the present invention can calculate the total nuclear radiation dose received by the robot at the current position. According to the relationship between the total nuclear radiation dose and the preset value, it can be evaluated whether the robot can work normally in the high radiation environment after the accident. The evaluation method is simple and feasible, and has a high accuracy.

[0025] like Figure 2 As shown, in an embodiment of the present invention, the step of dividing the space inside the containment shell into a plurality of volume elements 1 includes: dividing the space inside the containment shell into a plurality of volume elements 1 according to three dimensions: the axial length of the containment shell, the radius of the containment shell, and the azimuth angle.

[0026] Specifically, the containment is approximated as a cylinder, with the center of the bottom of the cylinder as the origin, the axial length of the cylinder, the radius of the cylinder and the azimuth as coordinates, and a cylindrical coordinate system is established, such as Figure 2 As shown, is the axial direction of the cylinder, is the radial direction of the cylinder, is the azimuth, and the coordinates of any point on the cylinder are expressed as ( , , ). The space inside the containment is divided into two parts according to the axial length of the cylinder. , radial length of cylinder and azimuth The three dimensions are divided into a plurality of voxels 1, and the more the number of divided voxels 1 is, the higher the calculation accuracy is.

[0027] The calculation formula for the second nuclear radiation dose received by the robot at any position in the containment is: . (Formula 1) in: The second radiation dose to the robot caused by the radiation released by various radionuclides in the containment, Gy; is the duration of radioactive exposure of the robot in the containment, s; is the concentration of radionuclide i in volume element j, Bq / m3; is the air kerma rate constant corresponding to the specific gas environment of radionuclide i in the containment, (Gy / s)·(Bq / m2)-1; is the volume of element j in the containment, m3; is the distance from voxel j to the robot’s location, m. In the above formula, It is a fixed value, and its value is related to the quality and energy of the rays released by the radioactive nuclides and the density and composition of the gas in the space.

[0028] According to the above formula, the second nuclear radiation dose of a radioactive nuclide can be calculated when the robot is at any position in the containment, and the second nuclear radiation doses of various radioactive nuclides are accumulated to obtain the first nuclear radiation dose of each first body element 1 to the robot, and the total nuclear radiation dose can be obtained by summing up multiple first nuclear radiation doses. When the total nuclear radiation dose is greater than or equal to the preset value, it indicates that the robot cannot work normally in the containment.

[0029] In the embodiment of the present invention, the method for calculating the volume of each voxel 1 is: obtaining each first coordinate of the contour of the voxel 1 in the cylindrical coordinate system, and calculating the volume of the voxel 1 based on the first coordinates.

[0030] Specifically, suppose that voxel 1 is The first coordinate in the direction is , , then voxel 1 is in The range in direction is , accordingly, it can be determined that voxel 1 is The range in direction is , the azimuth range is , then the volume of the voxel It can be expressed as .

[0031] The distance from each voxel 1 to the robot's position in the containment shell The calculation method is as follows: The second coordinate of the center point of voxel j is expressed as ,in , , ; Assume that the third coordinate of the robot at its current position is , at this time, the distance from the volume element j to the point where the robot is located in the containment shell It can be expressed as: According to Formula 1, the total nuclear radiation dose received by the robot at a certain position in the containment is related to the working time of the robot in the containment. The longer the working time, the greater the total nuclear radiation dose received.

[0032] Specifically, the robot's work in the containment is not limited to a certain position. During the entire working time, it may need to work in multiple positions. Therefore, after the robot's position changes, the total nuclear radiation dose received by the robot at this position can be calculated according to Formula 1 according to the above method.

[0033] According to the above method, the total nuclear radiation dose of the robot at each position can be calculated according to the working time of the robot in each position in actual work. By adding up the total nuclear radiation dose of each position, it can be found how long the robot can work in the containment under the current accident conditions, so as to better evaluate and guide the robot's work in a high radiation environment.

[0034] In one embodiment of the present invention, the formula 1 It can be a fixed value, that is, when the concentration of various radioactive nuclides in the containment shell does not change, the robot is placed in the containment shell to calculate the nuclear radiation dose received by the robot.

[0035] In another embodiment of the present invention, in Formula 1 It can also be a variable, that is, when a nuclear accident occurs in the reactor and radionuclides begin to leak into the containment, the robot is placed in the containment. At this time, the concentration of various radionuclides in the containment increases with time. In this embodiment, when the total concentration of various radionuclides in each volume element is obtained, the concentration data of radionuclides in each volume element 1 that changes with time can be obtained. For example, when the radionuclides are not leaking, the robot is located in the containment. When the radionuclides begin to leak into the containment, the robot starts working. At this time, the working time of the robot is equal to the time for the radionuclides to diffuse into the containment. The concentration of various radionuclides in each volume element 1 at this time can be obtained based on the time.

[0036] In an embodiment of the present invention, the evaluation method further includes: before calculating the first nuclear irradiation dose, selecting a nuclear accident condition that needs to be evaluated and obtaining a radioactive source item leaked into the containment.

[0037] Specifically, based on the nuclear accident source term analysis and assessment procedure, the nuclear accident conditions that need to be evaluated are selected for the design parameters of a specific reactor type, and the radioactive source terms that leak from the reactor loop into the containment after a nuclear accident are calculated.

[0038] Compared with the experimental method, the method for evaluating nuclear radiation exposure of a robot in a containment provided by an embodiment of the present invention can quickly and efficiently calculate the radiation dose received by the robot in the radiation field, and evaluate whether the robot can work normally in the high-radiation environment after the accident; at the same time, different radiation field distribution results caused by different nuclear accidents can be simulated, and the nuclear radiation dose received by the robot at any position in the containment can be calculated, so that the work of the robot under different working conditions can be evaluated, and the applicability is stronger.

[0039] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for assessing nuclear irradiation of a robot in a containment shell, characterized in that: include: Dividing the space within the containment into a plurality of volume elements, and obtaining the total concentration of various radionuclides in each volume element; Calculate the first nuclear irradiation dose of each voxel to the robot based on the volume of each voxel, the distance between each voxel and the robot, and the total concentration of various radionuclides in each voxel; The plurality of first nuclear radiation doses are summed to obtain a total nuclear radiation dose received by the robot at the current position.

2. The method for evaluating nuclear irradiation of a robot in a containment shell according to claim 1, characterized in that: The step of dividing the space within the containment into a plurality of volume elements comprises: The space inside the containment shell is divided into a plurality of volume elements according to the three dimensions of the axial length of the containment shell, the radius of the containment shell and the azimuth angle.

3. The method for evaluating nuclear irradiation of a robot in a containment shell according to claim 1, characterized in that: The step of calculating the first nuclear irradiation dose of each voxel to the robot based on the volume of each voxel, the distance between each voxel and the robot, and the total concentration of various radionuclides in each voxel comprises: A cylindrical coordinate system is established with the center of the bottom surface of the containment shell as a circle point and the axial length, radius and azimuth angle of the containment shell as coordinates; The first coordinates of the contour of each voxel in the cylindrical coordinate system are obtained, and the volume of each voxel is calculated based on the first coordinates.

4. The method for evaluating nuclear irradiation of a robot in a containment shell according to claim 3, characterized in that: The step of calculating the first nuclear irradiation dose of each voxel to the robot based on the volume of each voxel, the distance between each voxel and the robot, and the total concentration of various radionuclides in each voxel further includes: Based on the first annotations, calculate the second coordinates of the center point of each voxel; Obtaining a third coordinate of the robot at the current position; The distance between the robot and each voxel is calculated based on the second coordinate and the third coordinate.

5. The method for evaluating nuclear irradiation of a robot in a containment shell according to claim 4, characterized in that: The step of calculating the first nuclear irradiation dose of each voxel to the robot based on the volume of each voxel, the distance between each voxel and the robot, and the total concentration of various radionuclides in each voxel further includes: Obtain the concentration of various radionuclides in each voxel; calculating a second nuclear irradiation dose of each radionuclide to the robot based on the concentration, the volume of each voxel, and the distance between each voxel and the robot; The plurality of the second nuclear radiation doses are summed to obtain a first nuclear radiation dose of each voxel to the robot.

6. The method for evaluating nuclear irradiation of a robot in a containment shell according to claim 1, characterized in that: Also includes: Obtaining the working time of the robot at the current position; Based on the working time, the volume of each voxel, the distance between each voxel and the robot, and the total concentration of radioactive nuclides in each voxel, a first nuclear irradiation dose of each voxel to the robot is calculated.

7. The method for evaluating nuclear irradiation of a robot in a containment shell according to claim 1, characterized in that: The step of obtaining the total concentration of various radionuclides in each voxel comprises: Obtain the concentration data of various radionuclides in each element over time.

8. The method for evaluating nuclear irradiation of a robot in a containment shell according to claim 1, characterized in that: The evaluation method also includes: Before calculating the first nuclear irradiation dose, a nuclear accident condition that needs to be evaluated is selected to obtain a radioactive source item leaking into the containment.

9. The method for evaluating nuclear irradiation of a robot in a containment shell according to claim 1, characterized in that: The evaluation method also includes: Based on the relationship between the total nuclear radiation dose and the preset value, the nuclear radiation condition of the robot is evaluated.

10. The method for evaluating nuclear irradiation of a robot in a containment shell according to claim 9, characterized in that: The evaluation method also includes: When the total nuclear radiation dose is greater than or equal to a preset value, determining that the robot cannot work normally; When the total nuclear radiation dose is less than the preset value, it is determined that the robot can work normally.

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