Device for preventing cross-section high temperature oxidation and swelling deformation of small size plate element sample
By designing a device to prevent high-temperature oxidation and swelling deformation of small-sized plate component samples, and using long and short clamping slides and tightening screws to clamp the sample cross-section, the problem of oxidation and fission gas leakage in high-temperature experiments was solved, thus improving the accuracy and reliability of experimental results.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- NUCLEAR POWER INSTITUTE OF CHINA
- Filing Date
- 2023-06-02
- Publication Date
- 2026-07-14
AI Technical Summary
Existing small-sized plate-shaped nuclear fuel element samples are prone to cross-section oxidation and expansion and deformation due to the leakage of fission gas during high-temperature experiments, which affects the accuracy of experimental results.
A device for preventing high-temperature oxidation and swelling deformation of small-sized plate component samples was designed. It adopts a structure of long and short clamping slides and a tightening screw. The sample cross section is completely clamped by moving the slides through the tightening screw, thereby reducing the leakage of oxidation and cracking gases.
It effectively reduces cross-sectional oxidation and fission gas leakage caused by high-temperature heating, and improves the accuracy and reliability of the evaluation of the microstructure and performance of nuclear fuel elements after irradiation.
Smart Images
Figure CN116735309B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of nuclear fuel element irradiation technology, specifically to a device for preventing high-temperature oxidation and swelling deformation of small-sized plate element samples. Background Technology
[0002] Plate-type nuclear fuel elements are a typical type of fuel element used in experimental reactors. They are formed in one piece through a rolling process, and the fuel plate consists of three parts: an upper cladding, a core, and a lower cladding. During reactor operation, neutron irradiation, high temperature and pressure, and corrosive coolant have a significant impact on the fuel element. During operation within the reactor, the fuel core generates a large amount of inert fission gas, which exists in cracks, gaps between the core and cladding, or large pores, and diffuses, migrates, and accumulates, exerting significant pressure on the cladding and causing fuel swelling. Under over-design-base accidents and loss-of-coolant accidents, the fuel core temperature rises sharply, releasing large amounts of fission gas and causing a rapid increase in pressure. This leads to blistering, localized rupture, and excessive swelling on the upper cladding surface, blocking coolant flow channels between fuel plates and triggering more severe accidents. Therefore, studying and analyzing the effects of fission gas on blistering, volume swelling, and crack propagation behavior of plate elements is extremely important, providing crucial experimental data for practical engineering applications.
[0003] Currently, the samples used in high-temperature bubbling experiments for fuel elements are small-sized samples cut from plate-type fuel elements. Sampling and cutting damages the sample cross-section, creating numerous defects. During the heating process, a large amount of fission gas that should diffuse, migrate, and accumulate to the sample surface overflows from the cross-section, causing swelling and deformation. Simultaneously, the cross-section is easily oxidized, exacerbating the swelling and making it difficult to achieve the expected results in the high-temperature bubbling experiment, thus affecting the experimental outcomes.
[0004] To improve and solve the above problems, a device specifically designed to prevent high-temperature oxidation and swelling deformation of small-sized plate component samples was developed. Long and short clamping slips are used to cover the sample cross-section to mitigate the problems of cross-sectional swelling and oxidation. Summary of the Invention
[0005] The purpose of this invention is to provide a device for preventing high-temperature oxidation and swelling deformation of small-sized plate component samples, so as to improve and overcome the above-mentioned deficiencies and problems of existing experimental devices and technologies.
[0006] The technical solution of the present invention is as follows: A device for preventing high-temperature oxidation and swelling deformation of small-sized plate component samples, comprising a sample loading plane base, a rectangular sample positioning grid, a long clamping slide, a short clamping slide, a tightening screw, a slide fixing pin, a sample groove, an L-shaped sample loading fixing seat, a slide rail, and a threaded through hole;
[0007] The sample slot is located inside the rectangular sample positioning grid. An L-shaped sample fixing seat is provided at the upper left corner of the sample loading plane base 1. The rectangular sample positioning grid is hollow and has slide rails on its four sides. The long and short clamping plates are both inside the rectangular sample positioning grid and are located near the rectangular sample positioning grid frame diagonally opposite the L-shaped sample fixing seat. The sliding fixing pin is connected to the long and short clamping plates that pass through the slide rails, fixing the long and short clamping plates in the rectangular sample positioning grid. The tightening screw is connected to the long and short clamping plates near the threaded through hole 22 on the rectangular sample positioning grid.
[0008] The sample groove is parallel to the surface of the sample loading plane base.
[0009] The rectangular sample positioning grid has slide rails at different positions on all four sides.
[0010] The slide rail has a fixed length, which limits the sliding range of the long and short pressing slides.
[0011] The tightening screw is adapted to the size of the threaded through hole.
[0012] The long and short clamping slides each have two locking pin ports at their two ends.
[0013] The size of the locking pin for fixing the slider is compatible with the pin opening size at the ends of the long and short clamping sliders.
[0014] The sample well is adapted to the size of the sample to be tested.
[0015] The L-shaped sample mounting holder has threaded through holes on the two sides of a rectangular sample positioning grid in the diagonal direction.
[0016] The device described above is made of high-temperature resistant ceramic material.
[0017] In the rectangular sample positioning grid, the right-angle end formed by the corresponding opposite sides of the long and short pressing slides is aligned with the L-shaped sample mounting and fixing bracket.
[0018] The entire device operates within a radiation-shielded glove box.
[0019] The significant advantage of this invention lies in the fact that by tightening the screw, the long and short clamping slides within the rectangular sample positioning slot are moved to completely press and cover the cross-section of the fuel element sample placed in the sample slot. This effectively reduces cross-sectional swelling caused by high-temperature heating, reduces the contact area between air and the sample cross-section to prevent oxidation of the cross-section and the leakage of fission gases from the cross-section, thereby increasing the probability of fission gases migrating and accumulating in the shallow surface layer of the sample. This improves the accuracy and reliability of the microstructure and performance evaluation results of nuclear fuel elements after irradiation. The invention has a simple structure and is stable and reliable. Attached Figure Description
[0020] Figure 1 This is a schematic diagram of the structure of the present invention.
[0021] Figure 2 This is a top view of the present invention.
[0022] In the figure: 1. Sample loading plane base; 2. Rectangular sample positioning grid; 3. Long clamping slide; 4. Short clamping slide; 5. Tightening screw; 6. Slide fixing pin; 7. Sample groove; 11. L-shaped sample loading fixing seat; 21. Slide rail (slide groove); 22. Threaded through hole. Detailed Implementation
[0023] To more clearly describe the present invention, the following description is provided in conjunction with the accompanying drawings and specific embodiments.
[0024] The device for preventing high-temperature oxidation and swelling deformation of small-sized plate component samples includes a sample loading plane base 1, a rectangular sample positioning grid 2, a long clamping slide 3, a short clamping slide 4, a tightening screw 5, a slide fixing pin 6, a sample groove 7, an L-shaped sample loading fixing seat 11, a slide rail (slide groove) 21, and a threaded through hole 22.
[0025] The sample slot 7 is parallel to the surface of the sample loading plane base 1 and located inside the rectangular sample positioning grid 2 with four sides. An L-shaped sample loading fixing seat 11 is provided at the upper left corner of the surface of the sample loading plane base 1. The sample slot 7 is used to fix the rectangular sample positioning grid 2 when loading the sample. The rectangular sample positioning grid 2 is hollow, with the sample slot 7 in the middle and parallel to the surface of the sample loading plane base 1. Slide rails (slide grooves) 21 are opened at different positions on the four sides of the grid. The long pressing slide 3 and the short pressing slide 4 are both inside the rectangular sample positioning grid 2, respectively close to the rectangular sample positioning grid 2 frame diagonally opposite to the L-shaped sample loading fixing seat 11. The sliding fixing pin 6 is connected to the end bayonet of the long and short pressing slides 3 and the short pressing slide 4 that pass through the slide rail (slide groove) 21, and fixes them in the rectangular sample positioning grid 2. The tightening screw 5 is connected to the frame close to the long pressing slide 3 and the short pressing slide 4 through the threaded through hole 22 on the rectangular sample positioning grid 2.
[0026] Furthermore, the right-angle end of the rectangular sample positioning frame 2, which is formed by the opposite side frame of the long pressing slide 3 and the short pressing slide 4, is aligned with the "L"-shaped sample fixing bracket 11.
[0027] Furthermore, the slide rails (grooves) 21 on the four sides of the rectangular sample positioning grid 2 are fixed in length, limiting the sliding range of the long pressing slide 3 and the short pressing slide 4.
[0028] Furthermore, the tightening screw 5 is sized to match the threaded through hole 22.
[0029] Furthermore, the size of the pin 6 for fixing the slide plate is adapted to the pin opening size at the ends of the long pressing slide plate 3 and the short pressing slide plate 4.
[0030] Furthermore, the size of the sample slot 7 in the rectangular sample positioning grid 2 in the diagonal direction of the "L"-shaped sample fixing card seat 11 is adapted to the size of the sample to be tested.
[0031] Furthermore, the rectangular sample positioning grid 2 in the diagonal direction of the “L”-shaped sample fixing bracket 11 has two threaded through holes 22 on each of its two sides.
[0032] Furthermore, each of the two ends of the long pressing slide 3 and the short pressing slide 4 has two locking pin openings.
[0033] Furthermore, the device is made of high-temperature resistant ceramic material.
[0034] Furthermore, the sample installation process of the device was carried out in a radiation-shielded glove box.
[0035] After neutron irradiation, the plate-shaped element is transferred to the hot chamber. The area to be observed and tested is disassembled and cut into small rectangular samples with both long and wide sides ranging from 20mm to 30mm. The samples are placed in shielded lead containers and transported to a radioactive shielded glove box. The device is placed flat on the operating platform in the radioactive shielded glove box, and the right-angle ends formed by the corresponding opposite sides of the rectangular sample positioning frame 2 (long clamping sliders 3 and short clamping sliders 4) are checked to align with the L-shaped sample mounting bracket 11. The operator uses tweezers to remove the rectangular sample from the shielded lead container and place it in the sample slot 7. The position is adjusted to ensure that the sample is level with the base 1. Then, using tweezers or a small robotic arm, the four tightening screws 5 are rotated to contact the long clamping sliders 3 and short clamping sliders 4 and move them into the sample positioning slot. This ensures that the long clamping sliders 3 and short clamping sliders 4 cooperate with the frame of the rectangular sample positioning frame 2 to completely clamp and cover the cross-section of the fuel element sample placed in the sample slot, so that the sample and the rectangular sample positioning frame 2 can move together as a whole. The entire unit was then transported via a special transport container to the high-temperature bubbling test device for fuel elements for further testing.
Claims
1. A device for preventing high-temperature oxidation and swelling deformation of the cross-section of small-sized plate component samples, characterized in that: Includes a sample loading plane base (1), a rectangular sample positioning grid (2), a long clamping slide (3), a short clamping slide (4), a tightening screw (5), a slide fixing pin (6), a sample groove (7), an L-shaped sample loading fixing seat (11), a slide rail (21), and a threaded through hole (22); The sample slot (7) is located inside the rectangular sample positioning grid (2). An L-shaped sample fixing seat (11) is provided at the upper left corner of the sample loading plane base (1). The rectangular sample positioning grid (2) is hollow. Slide rails (21) are opened on the four sides of the rectangular sample positioning grid (2). The long pressing slide (3) and the short pressing slide (4) are both inside the rectangular sample positioning grid (2), respectively close to the rectangular sample fixing seat (11) at the diagonal direction. The sample positioning grid (2) frame, the sliding fixing pin (6) is connected to the long pressing slide (3) and the short pressing slide (4) passing through the slide rail (21), and the long pressing slide (3) and the short pressing slide (4) are fixed in the rectangular sample positioning grid (2). The tightening screw (5) is connected to the frame of the rectangular sample positioning grid (2) near the long pressing slide (3) and the short pressing slide (4) through the threaded through hole (22) on the rectangular sample positioning grid (2). In the rectangular sample positioning grid (2), the right-angle end formed by the opposite side frame of the long pressing slide (3) and the short pressing slide (4) is aligned with the L-shaped sample fixing seat (11); The sample groove (7) is parallel to the surface of the sample loading plane base (1); The rectangular sample positioning grid (2) has slide rails (21) at different positions on its four sides; The slide rail (21) has a fixed length, which limits the sliding range of the long pressing slide (3) and the short pressing slide (4); Take the rectangular sample out of the shielded lead container and place it in the sample slot (7). Adjust the position to ensure that the rectangular sample is level with the sample loading base (1). Then, use tweezers or a small robot to rotate the four tightening screws (5) to make them contact the long pressing slide (3) and the short pressing slide (4) and move them into the sample slot (7). Ensure that the long pressing slide (3) and the short pressing slide (4) cooperate with the frame of the rectangular sample positioning grid (2) to completely press and cover the rectangular sample section placed in the sample slot (7), so that the rectangular sample and the rectangular sample positioning grid (2) become a whole that moves together.
2. The device for preventing high-temperature oxidation and swelling deformation of small-sized plate component samples according to claim 1, characterized in that: The tightening screw (5) is sized to match the threaded through hole (22).
3. The device for preventing high-temperature oxidation and swelling deformation of small-sized plate component samples according to claim 1, characterized in that: The long pressing slide (3) and the short pressing slide (4) each have two pin holes at their two ends.
4. The device for preventing high-temperature oxidation and swelling deformation of small-sized plate component samples according to claim 3, characterized in that: The pin (6) for fixing the slide plate is adapted to the pin opening size of the ends of the long pressing slide plate (3) and the short pressing slide plate (4).
5. The device for preventing high-temperature oxidation and swelling deformation of small-sized plate component samples according to claim 1, characterized in that: The sample well (7) is adapted to the size of the sample to be tested.
6. The device for preventing high-temperature oxidation and swelling deformation of small-sized plate component samples according to claim 1, characterized in that: L-shaped sample mounting holder (11) and rectangular sample positioning grid (2) with threaded through holes (22) on both sides.
7. The device for preventing high-temperature oxidation and swelling deformation of small-sized plate component samples according to claim 1, characterized in that: The device described above is made of high-temperature resistant ceramic material.
8. The device for preventing high-temperature oxidation and swelling deformation of small-sized plate component samples according to claim 1, characterized in that: The entire device operates within a radiation-shielded glove box.