AFA 3G fuel rod end plug compensation block
By designing the AFA 3G fuel rod end plug compensation block that adapts to the fuel rod shape, the problem of insufficient detection sensitivity and clarity in the existing technology is solved, high-sensitivity defect detection is achieved, and detection is improved through domestic materials and processing. efficiency.
Patent Information
- Application Number
- CN202323577183.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2023-12-27
- Publication Date
- 2024-12-31
- Estimated Expiration
- 2033-12-27
AI Technical Summary
In the existing AFA 3G fuel rod manufacturing technology, there is a lack of compensation block design that meets domestic actual needs, resulting in insufficient sensitivity and clarity in X-ray transmission detection, and a lack of domestic solutions.
A AFA 3G fuel rod end plug compensation block is designed, the main body is a strip-shaped rectangular body, with multiple through holes on the side, the shape of the through hole inner wall is adapted to the shape of the fuel rod, and the center of the weld is ensured through the round table and cylindrical transition design. Align, combine the semi-compensation method to reduce the transillumination thickness and improve sensitivity.
It achieves a good cooperation between the welds of the fuel rod and the compensation block, eliminates scattering and edge corrosion effects, improves the defect detection rate, meets the requirements of high sensitivity, and realizes independent domestic production through domestic materials and processing.
Smart Images
Figure CN222281597U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of nuclear power, and in particular relates to an AFA 3G fuel rod end plug compensation block. Background Art
[0002] In the related technology, the most commonly used type of pressurized water reactor core is the AFA 3G fuel assembly. The fuel rod is one of the most basic units of the fuel assembly. After the upper and lower ends of the AFA 3G fuel rod are welded, X-ray transillumination is required to check its internal quality.
[0003] In the process of industrial X-ray flaw detection, different transillumination methods are used according to the use requirements and detection requirements, generally including: direct transillumination method, full compensation method, and half compensation method. When the transillumination object is a pressurized water reactor nuclear fuel rod, in order to ensure higher sensitivity, clarity and a wider assessment area, the full compensation method will be used. When the full compensation method is used, it is usually necessary to manufacture corresponding compensation blocks according to the external dimensions of the fuel rod. The thickness of the compensation block is determined based on the sensitivity requirements and processing. There are few domestic companies engaged in the manufacture of pressurized water reactor fuel rods, and they have always adopted European standards and their manufacturing methods. AFA 3G fuel rod manufacturing technology also mostly adopts the French RCC-M standard. For this reason, it is necessary to adopt the national standard to design compensation blocks that are more in line with actual use needs. Utility Model Content
[0004] In order to overcome the problems existing in the related art, an AFA 3G fuel rod end plug compensation block is provided.
[0005] According to one aspect of an embodiment of the present disclosure, there is provided an AFA 3G fuel rod end plug compensation block, wherein the main body of the compensation block is a strip-shaped rectangular parallelepiped, and a plurality of through holes are arranged in parallel on the side of the main body, and the inner side of each through hole is adapted to the outer contour of the AFA 3G fuel rod end plug, and for each through hole, the inner wall shape from the front opening to the first position of the through hole is a first cylindrical shape, the inner wall shape from the first position to the second position is a first truncated cone, the inner diameter of the second position is smaller than the inner diameter of the first position, the inner wall shape from the second position to the third position is a second cylindrical shape, the inner wall shape from the third position to the fourth position is a second truncated cone, the inner diameter of the third position is smaller than the inner diameter of the fourth position, and the inner wall shape from the fourth position to the rear opening is a third cylindrical shape;
[0006] When the AFA 3G fuel rod end plug is inserted from the front opening of the corresponding through hole until it is blocked by the inner wall of the through hole and cannot move toward the rear opening of the through hole, the center of the AFA 3G fuel rod weld is located at the center of the compensation block, and the center of the compensation block is opposite to the center of the X-ray head.
[0007] In a possible implementation, the generatrix angle of the first truncated cone is 1 degree greater than the generatrix angle of the inclined plane at the corresponding position of the AFA 3G fuel rod end plug; the generatrix angle of the second truncated cone is 1 degree greater than the generatrix angle of the inclined plane at the corresponding position of the AFA 3G fuel rod end plug.
[0008] In a possible implementation, the manufacturing accuracy of the first frustum and the second frustum are both 0.1 degrees.
[0009] In a possible implementation, the straight line transition portions at the first position, the second position, the third position and the fourth position in each through hole are all rounded.
[0010] In a possible implementation, the roughness of each inner hole is better than Ra0.8.
[0011] The beneficial effects of the present disclosure are: in each through hole of the present disclosure, the first truncated cone and the second truncated cone are used to restrict the inclined surface of the AFA 3G fuel rod end plug, so that when the AFA 3G fuel rod end plug is inserted from the front opening of the corresponding through hole until it is blocked by the inner wall of the through hole and cannot move toward the rear opening of the through hole, the center of the AFA 3G fuel rod weld is located at the center of the compensation block, and the center of the compensation block is directly opposite to the center of the X-ray head, thereby making the fuel rod end plug weld and the compensation block cooperate well, solving the problem of compensating for the thickness change of the radiographic exposure, eliminating the scattered rays and edge erosion effects; compensating and matching the external dimensions of the fuel rod end plug, after radiographic exposure, the image of the fuel rod end plug weld is clear on the film, meeting the sensitivity requirements; defects under the specified sensitivity can be found by using the compensation block, and the defect detection rate is high. BRIEF DESCRIPTION OF THE DRAWINGS
[0012] Figure 1 is a front view of an AFA 3G fuel rod end plug compensation block according to an exemplary embodiment.
[0013] Figure 2 FIG. 4 is a top view of an AFA 3G fuel rod end plug compensation block according to an exemplary embodiment.
[0014] Figure 3 yes Figure 1 AA section view. DETAILED DESCRIPTION
[0015] The utility model is further described in detail below with reference to the accompanying drawings and specific embodiments.
[0016] Figure 1 is a front view of an AFA 3G fuel rod end plug compensation block according to an exemplary embodiment. Figure 2 FIG. 1 is a top view of an AFA 3G fuel rod end plug compensation block according to an exemplary embodiment. Figure 1 and Figure 2 The fuel rod end plug compensation block disclosed in the present invention has a main body that is a strip-shaped rectangular parallelepiped, with a plurality of through holes arranged in parallel on the side of the main body, and the inner side of each through hole is adapted to the outer contour of the AFA 3G fuel rod end plug. When the AFA 3G fuel rod end plug is inserted from the front opening of the corresponding through hole until it is blocked by the inner wall of the through hole and cannot move toward the rear opening of the through hole, the center of the AFA 3G fuel rod weld is located at the center of the compensation block, and the center of the compensation block is opposite to the center of the X-ray head.
[0017] Figure 3 yes Figure 1 The AA section view is as follows: Figure 3 As shown, for each through hole, the inner wall shape from the front opening to the first position of the through hole is a first cylindrical shape, the inner wall shape from the first position to the second position is a first truncated cone shape, the inner diameter of the second position is smaller than the inner diameter of the first position, the inner wall shape from the second position to the third position is a second cylindrical shape, the inner wall shape from the third position to the fourth position is a second truncated cone shape, the inner diameter of the third position is smaller than the inner diameter of the fourth position, and the inner wall shape from the fourth position to the rear opening is a third cylindrical shape;
[0018] In a possible implementation, the generatrix angle of the first truncated cone is 1 degree greater than the generatrix angle of the inclined plane at the corresponding position of the AFA 3G fuel rod end plug; the generatrix angle of the second truncated cone is 1 degree greater than the generatrix angle of the inclined plane at the corresponding position of the AFA 3G fuel rod end plug. The manufacturing accuracy of the first truncated cone and the second truncated cone is 0.1 degree, which facilitates the AFA 3G fuel rod end plug to be installed in the corresponding through hole.
[0019] In order to ensure that the X-ray can vertically penetrate the center of the weld, the present disclosure uses the center of the weld as the center line of the compensation block for design. At the same time, in order to take into account the compensation of the upper end plug hole welding point, the inclination angle of the AFA 3G fuel rod end plug is smaller than the inclination angle of the inner inclination of the adapted through hole, thereby ensuring the full cooperation between the AFA 3G fuel rod end plug and the compensation block. Through dimensional control, the large inclination of the fuel rod end plug is used for positioning. In addition, the present disclosure adopts the compensation block designed by the semi-compensation method. Under the basic requirement of ensuring compensation, the effective penetration thickness is reduced as much as possible, so that the thickness of the compensation block is reduced to meet the sensitivity requirements. Since the sensitivity requirements are met, the defect detection rate is high without considering random events.
[0020] In a possible implementation, to prevent the fuel rod end plug from being scratched by the inner hole of the compensation block after entering the compensation block, the straight transition portions at the first position, the second position, the third position and the fourth position in each through hole are not chamfered but become arc transitions.
[0021] In a possible implementation, the roughness of each inner hole is better than Ra0.8.
[0022] In one possible implementation, the tolerance and accuracy grade of the compensation block are designed using national standards, and the materials and processing are both domestically produced, achieving independent localization.
[0023] In one application example, the upper plug side of each fuel rod is slowly and gently fed into the compensation block in turn. When the fuel rod cannot be fed in any further, the fuel rod reaches the specified cut-off position. At this time, the center of each fuel rod weld is located at the center of the compensation block and is perpendicular to the center of the X-ray head. Select appropriate parameters for transillumination and film evaluation. After the evaluation results come out, the transillumination fuel rods are taken out for circulation.
[0024] The embodiments of the present disclosure have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles of the embodiments, practical applications, or improvements to the technology in the market, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein.
Claims
1. An AFA 3G fuel rod end plug compensation block, characterized in that: The main body of the compensation block is a strip-shaped rectangular parallelepiped, and a plurality of through holes are arranged in parallel on the side of the main body. The inner side of each through hole is adapted to the outer contour of the AFA 3G fuel rod end plug. For each through hole, the inner wall shape from the front opening to the first position of the through hole is a first cylindrical shape, the inner wall shape from the first position to the second position is a first truncated cone, the inner diameter of the second position is smaller than the inner diameter of the first position, the inner wall shape from the second position to the third position is a second cylindrical shape, the inner wall shape from the third position to the fourth position is a second truncated cone, the inner diameter of the third position is smaller than the inner diameter of the fourth position, and the inner wall shape from the fourth position to the rear opening is a third cylindrical shape; When the AFA 3G fuel rod end plug is inserted from the front opening of the corresponding through hole until it is blocked by the inner wall of the through hole and cannot move toward the rear opening of the through hole, the center of the AFA 3G fuel rod weld is located at the center of the compensation block, and the center of the compensation block is opposite to the center of the X-ray head.
2. The AFA 3G fuel rod end plug compensation block according to claim 1, characterized in that: The generatrix angle of the first truncated cone is 1 degree greater than the generatrix angle of the inclined plane at the corresponding position of the AFA 3G fuel rod end plug; the generatrix angle of the second truncated cone is 1 degree greater than the generatrix angle of the inclined plane at the corresponding position of the AFA 3G fuel rod end plug.
3. The AFA 3G fuel rod end plug compensation block according to claim 1, characterized in that: The manufacturing accuracy of the first truncated cone and the second truncated cone is 0.1 degree.
4. The AFA 3G fuel rod end plug compensation block according to claim 1, characterized in that: The straight line transition parts at the first position, the second position, the third position and the fourth position in each through hole are all chamfered.
5. The AFA 3G fuel rod end plug compensation block according to claim 1, characterized in that: The roughness of each inner hole is better than Ra0.8.