Jacket tube hydrogenation test device for simulating pressurized water reactor primary loop environment

Abstract

The invention discloses a cladding tube hydrogenation test device for simulating a pressurized water reactor primary loop environment, and relates to the related technical field of cladding tube test equipment. The cladding tube hydrogenation test device comprises a test kettle, wherein the test kettle is provided with a loop water system, a pressurization system and a temperature system; a fuel pellet, a heating element and a gas injection assembly; the fuel pellet and the heating element are arranged in the cladding tube, and the fuel pellet is used for reacting with the test liquid to generate hydrogen; the heating piece is used for heating the interior of the cladding tube; the opening breaking assembly is mounted on the test kettle; and the crevasse assembly is used for crevassing the surface of the cladding tube. According to the technical scheme provided by the invention, the hydrogenation condition of the cladding tube in the pressurized water reactor primary loop environment can be simulated, so that a reference basis is provided for safe operation of a nuclear reactor.

Description

Technical Field

[0001] The invention relates to the technical field related to cladding tube test equipment, and in particular to a cladding tube hydrogenation test device in a simulated pressurized water reactor primary loop environment. Background Art

[0002] As the first safety barrier in the nuclear fuel assembly, the cladding tube is mainly used to contain the radioactive fission products produced during the fission process of the nuclear fuel, prevent the leakage of the products, and ensure the safe operation of the nuclear reactor. Since the cladding tube itself contains hydrogen-containing substances or when the cladding tube is damaged for some reason, the liquid of the nuclear reactor enters the cladding tube and produces hydrogen by zirconium water, uranium water and high temperature decomposition. The hydrogen will be absorbed by the zirconium alloy cladding. The hydride generated by the two will reduce the strength and toughness of the zirconium alloy, and then cause the cladding tube to crack. Therefore, simulating the hydrogenation of the cladding tube in the primary loop environment of a pressurized water reactor is of great significance to the safe operation of the nuclear reactor.

[0003] It should be noted that the above contents are only used to assist in understanding the technical solution of the present invention, and do not constitute an admission that the above contents are prior art. Summary of the invention

[0004] The main purpose of the present invention is to propose a cladding tube hydrogenation test device simulating the primary loop environment of a pressurized water reactor, aiming to simulate the cladding tube hydrogenation situation in the primary loop environment of a pressurized water reactor, thereby providing a reference basis for the safe operation of a nuclear reactor.

[0005] To achieve the above object, the present invention proposes a cladding tube hydrogenation test device in a simulated pressurized water reactor primary loop environment, which is applied to cladding tubes; specifically, the cladding tube hydrogenation test device comprises: A test kettle, wherein the test kettle is provided with a loop water system, a pressurizing system and a temperature system; the loop water system is used to circulate and inject the test liquid into the test kettle, and the pressurizing system and the temperature system are used to control the internal pressure value and the temperature value of the test kettle; A fuel pellet, a heating element and a gas injection assembly; the fuel pellet and the heating element are arranged inside the cladding tube, the fuel pellet is used to react with the test liquid to generate hydrogen; the heating element is used to heat the inside of the cladding tube; the gas injection assembly is connected to the inside of the cladding tube, and the gas injection assembly is used to inject test gas into the inside of the cladding tube; A breaching assembly is installed in the test kettle; the breaching assembly is used to make breaches on the surface of the cladding tube.

[0006] In one embodiment, the test kettle adopts a split structure; specifically, the test kettle includes at least two sections of cylindrical parts, and at least two sections of the cylindrical parts are vertically arranged along a straight line; any two adjacent sections of the cylindrical parts are connected to each other through a connecting component; and each section of the cylindrical part is correspondingly provided with a section of the cladding tube.

[0007] In one embodiment, the connecting assembly includes a connecting ring and a connecting piece; the upper and lower sides of the connecting ring are respectively connected to the ends of the cylindrical piece; the connecting piece is arranged on the annular side of the connecting ring and extends to the annular inner side of the connecting ring; the first end of the connecting piece is used to fix the end of each section of the cladding tube, and the second end of the connecting piece is used to connect to an external power supply device and a gas source device; a power supply channel and a gas channel are provided inside the connecting piece, and the power supply device and the heating element are electrically connected to each other through the power supply channel, and the gas source device and the inside of the cladding tube are connected to each other through the gas channel to form the gas injection assembly.

[0008] In one embodiment, the upper and lower sides of the first end of the connecting member are respectively provided with limiting components, and the limiting components are used to seal and fix the end of each section of the cladding tube to the first end of the connecting member.

[0009] In one embodiment, an end plug is provided at a free end of the cladding tube away from the connecting piece, and the end plug is used to seal the end of the cladding tube.

[0010] In one embodiment, the breaching assembly includes a drill assembly and a jacking assembly disposed on opposite sides of the cylindrical member; The drill assembly comprises a first mounting block and a drill bit component, wherein the first mounting block is fixedly connected to the cylindrical component, and the drill bit component is movably connected to the first mounting block, and the drill bit component is used to drill a hole on the surface of the cladding tube; The jacking assembly includes a second mounting block and a jacking member, wherein the second mounting block is fixedly connected to the cylindrical member, and the jacking member is fixedly connected to the second mounting block, and the jacking member is used to support the cladding tube when the drill bit drills the cladding tube.

[0011] In one embodiment, at least two groups of fixing components are installed on the test kettle, and at least two groups of the fixing components are distributed along the axial linear array of the cladding tube; the fixing components are used to fix and limit the cladding tube; Specifically, each group of the fixing components includes at least two groups of abutment structures, and at least two groups of the abutment structures are distributed in an annular manner around the cylindrical member at equal distances; each group of the abutment structures includes a third mounting block and an abutment member, the third mounting block is fixedly connected to the cylindrical member, the abutment member is slidably connected to the third mounting block, and the abutment member is used to abut against the side of the cladding tube.

[0012] In one embodiment, the heating element comprises a heating rod, and the heating rod is extended along the axial direction of the cladding tube; and the fuel pellet is annularly structured and sleeved on the outer side of the heating rod.

[0013] In one embodiment, the loop water system includes a water inlet pipe installed on the bottom side of the test kettle, and a water outlet pipe installed on the top side of the test kettle; a water circulation device is provided between the water inlet pipe and the water outlet pipe; and / or the temperature system includes a heating jacket mounted on the outside of the test kettle.

[0014] In one embodiment, the cladding tube hydrogenation test device comprises a frame, and the frame is used to install and fix the test kettle through a plurality of supporting members.

[0015] The technical solution of the present invention is to set a loop water system, a pressurizing system and a temperature system in the test kettle, use the loop water system to circulate and inject the test liquid into the test kettle, and use the pressurizing system and the temperature system to control the internal pressure and temperature of the test kettle; and set a heating element inside the cladding tube, and use the heating element to heat the inside of the cladding tube; the combination of the multiple systems can achieve the simulation of the real situation of the cladding tube in the primary loop environment of a pressurized water reactor; then use the gas injection component to inject hydrogen into the inside of the cladding tube until the specified hydrogen amount, so as to achieve the simulation of the primary hydrogenation process of the cladding tube.

[0016] At the same time, considering that in actual operation, there may be some reasons on the surface of the cladding tube that cause the crack to be defective, the liquid in the nuclear reactor can flow into the cladding tube through the crack defect, and reactions such as zirconium water, uranium water and high temperature decomposition occur to generate hydrogen. Based on the above considerations, the present application also sets a fuel pellet in the cladding tube and a crack assembly in the test kettle, wherein the fuel pellet and the real nuclear fuel are made of the same material; the two are combined to simulate the hydrogenation of the cladding tube when the liquid in the nuclear reactor enters the inside of the cladding tube, reacts with the cladding tube and the fuel pellet and decomposes at high temperature to produce a large amount of hydrogen, that is, the secondary hydrogenation of the cladding tube. Specifically, the crack assembly is first used to make a crack on the surface of the cladding tube, so that the test liquid in the test kettle can flow into the inside of the cladding tube through the crack, and react with the fuel pellet and cladding tube inside it and decompose at high temperature to produce a large amount of hydrogen, and then the hydrogen is absorbed by the zirconium alloy in the cladding tube, thereby simulating the process of secondary hydrogenation of the cladding tube.

[0017] By combining the above-mentioned primary hydrogenation situation with the secondary hydrogenation situation, it is possible to simulate the hydrogenation situation of the cladding tube in the primary loop environment of a pressurized water reactor, thereby providing a reference basis for the safe operation of the nuclear reactor. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0019] Figure 1 A first structural schematic diagram of an embodiment of a cladding tube hydrogenation test device provided by the present invention; Figure 2 The second structural schematic diagram of an embodiment of the cladding tube hydrogenation test device provided by the present invention (with the frame and the test kettle hidden); Figure 3 A schematic diagram of the internal structure of a cladding tube in an embodiment of a cladding tube hydrogenation test device provided by the present invention; Figure 4 A schematic diagram of the structure of the connection assembly in one embodiment of the cladding tube hydrogenation test device provided by the present invention; Figure 5 A schematic structural diagram of an end plug in an embodiment of a cladding tube hydrogenation test device provided by the present invention; Figure 6 A schematic diagram of the structure of the breach assembly in one embodiment of the cladding tube hydrogenation test device provided by the present invention; Figure 7 A schematic diagram of the structure of a fixing assembly in one embodiment of a cladding tube hydrogenation test device provided by the present invention.

[0020] Description of reference numerals: 100, cladding tube; 110, fuel pellet; 120, heating element; 130, end plug; 200, test kettle; 210, loop water system; 211, water inlet pipe; 212, water outlet pipe; 220, cylinder-shaped part; 230, connecting assembly; 231, connecting ring; 232, connecting part; 2321, power supply channel; 2322, gas channel; 240, limit assembly; 241, limit ring; 242, locking nut; 250, temperature measuring part; 300, breaching assembly; 310, drill assembly; 311, first mounting block; 312, drill member; 320, jacking assembly; 321, second mounting block; 322, jacking member; 400, fixing assembly; 410, abutting structure; 411, third mounting block; 412, abutting member; 500, frame; 510, support member.

[0021] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0022] The following will be combined with the accompanying drawings in the present invention to clearly and completely describe the technical solution in the present invention. Obviously, what is described is only a part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0023] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0024] In addition, it should be noted that the descriptions of "first", "second", etc. in the present invention are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0025] As the first safety barrier in the nuclear fuel assembly, the cladding tube mainly contains the radioactive fission products produced during the fission process of the nuclear fuel, prevents the leakage of the products, and ensures the safe operation of the nuclear reactor. Since hydrogen is produced during the fission process, the hydrogen will be absorbed by the zirconium alloy in the cladding tube. The hydride generated by the two will reduce the strength and toughness of the zirconium alloy, thereby causing the cladding tube to crack. For the above reasons, there is an urgent need for a test device that can simulate the hydrogenation of the cladding tube in the primary loop environment of a pressurized water reactor, so as to provide a reference for the safe operation of the nuclear reactor.

[0026] In order to solve the above technical problems, the present invention proposes a cladding tube hydrogenation test device simulating a pressurized water reactor primary loop environment.

[0027] See also Figure 1-3In one embodiment of the present invention, the cladding tube hydrogenation test device simulating the primary loop environment of a pressurized water reactor is applied to the cladding tube 100; specifically, the cladding tube hydrogenation test device includes: The test kettle 200 is provided with a loop water system 210, a pressurizing system (not shown in the drawings) and a temperature system (not shown in the drawings); the loop water system 210 is used to circulate and inject the test liquid into the test kettle 200, and the pressurizing system and the temperature system are used to control the internal pressure value and temperature value of the test kettle 200; The fuel pellets 110, the heating element 120 and the gas injection assembly (not shown in the drawings); the fuel pellets 110 and the heating element 120 are arranged inside the cladding tube 100, and the fuel pellets 110 are used to react with the test liquid to generate hydrogen; the heating element 120 is used to heat the inside of the cladding tube 100; the gas injection assembly is connected to the inside of the cladding tube 100, and the gas injection assembly is used to inject the test gas into the inside of the cladding tube 100; The breaching assembly 300 is installed in the test reactor 200 ; the breaching assembly 300 is used to make breaches on the surface of the cladding tube 100 .

[0028] The technical solution of the present invention is to set a loop water system 210, a pressurizing system and a temperature system in the test kettle 200, use the loop water system 210 to circulate and inject the test liquid into the test kettle 200, and use the pressurizing system and the temperature system to control the internal pressure and temperature of the test kettle 200; and set a heating element 120 inside the cladding tube 100, and use the heating element 120 to heat the inside of the cladding tube 100; the combination of the multiple systems can achieve the simulation of the real situation of the cladding tube 100 in the primary loop environment of a pressurized water reactor; then use the gas injection component to inject hydrogen into the inside of the cladding tube 100 until the specified hydrogen amount, so as to achieve the simulation of the primary hydrogenation process of the cladding tube.

[0029] At the same time, considering that in actual operation, there may be some reasons on the surface of the cladding tube 100 that cause defects in the cracks, the liquid in the nuclear reactor can flow into the inside of the cladding tube 100 through the crack defects, and reactions such as zirconium water, uranium water and high-temperature decomposition occur to generate hydrogen. Based on the above considerations, the present application also provides a fuel pellet 110 in the cladding tube 100 and a crack assembly 300 in the test kettle 200, wherein the fuel pellet 110 and the real nuclear fuel are made of the same material; the two are combined to simulate the hydrogenation of the cladding tube when the liquid in the nuclear reactor enters the inside of the cladding tube, reacts with the cladding tube and the fuel pellet, and decomposes at high temperature to produce a large amount of hydrogen, that is, the secondary hydrogenation of the cladding tube 100. Specifically, a breach is first made on the surface of the cladding tube 100 using the breach assembly 300, so that the test liquid in the test kettle 200 can flow into the interior of the cladding tube 100 through the breach, and react with the fuel core blocks 110 and the cladding tube 100 therein and decompose at high temperature to produce a large amount of hydrogen, which is then absorbed by the zirconium alloy in the cladding tube, thereby simulating the secondary hydrogenation process of the cladding tube.

[0030] By combining the above-mentioned primary hydrogenation situation with the secondary hydrogenation situation, it is possible to simulate the hydrogenation situation of the cladding tube in the primary loop environment of a pressurized water reactor, thereby providing a reference basis for the safe operation of the nuclear reactor.

[0031] The cladding tube hydrogenation test device can be used to simulate the high temperature (~300°C, adjustable within a certain range) and high pressure (15.5MPa, adjustable within a certain range) water chemistry (boric acid + lithium hydroxide) environment in the pressure vessel of a pressurized water reactor. The cladding tube 100 is pre-filled with 2MPa helium (pressure adjustable within a certain range) and the cladding tube 100 is equipped with fuel pellets 110 that can simulate the surface temperature of the real fuel pellets 110. The primary hydrogenation and secondary hydrogenation processes of the cladding tube 100.

[0032] It should be noted that the above-mentioned primary hydrogenation and secondary hydrogenation are only descriptive codes for the hydrogenation test of the cladding tube, and there is no necessary connection between the primary hydrogenation and the secondary hydrogenation. In actual operation, the cladding tube 100 can be subjected to a primary hydrogenation test alone, or the cladding tube 100 can be subjected to a secondary hydrogenation test alone, and this application does not impose specific restrictions on them.

[0033] Specifically, refer to the attached Figure 3 The heating element 120 includes a heating rod, which is arranged to extend along the axial direction of the cladding tube 100. In this way, a common heating rod on the market is used as the heating element 120, which has a simple structure and strong practicality. At the same time, the heating rod is extended along the axial direction of the cladding tube 100 to ensure that each area in the axial direction of the cladding tube 100 is heated evenly, so as to ensure the accuracy of the cladding tube hydrogenation test data.

[0034] Specifically, refer to the attached Figure 3The fuel pellet 110 is annularly sleeved on the outside of the heating rod; in this way, the heating rod is sleeved inside the fuel pellet 110, and the heating power of the heating rod is controlled to make the surface temperature of the fuel pellet 110 consistent with the surface temperature of the fuel pile in real operation; and the temperature difference between the outer surface of the fuel pellet 110 and the inner wall of the cladding tube 100 is created, and at the same time, the fuel pellet 110 in the high temperature state reacts with the test liquid / liquid vapor flowing from the rupture of the cladding tube 100 to produce zirconium water, uranium water and high temperature decomposition to generate hydrogen, simulating the high temperature and uranium water hydrogen production share during real operation; in addition, the outer diameter and shape of the fuel pellet 110 can be adjusted to simulate the influence of the swelling degree of the fuel pellet 110 on the hydrogenation process at different burnup depths. If fission products are considered, a certain amount of solid non-radioactive fission elements (isotopes) can also be placed in the fuel pellet 110.

[0035] Specifically, refer to the attached Figure 1 The loop water system 210 includes an inlet pipe 211 installed on the bottom side of the test kettle 200, and an outlet pipe 212 installed on the top side of the test kettle 200; a water circulation device (not shown in the drawings) is provided between the inlet pipe 211 and the outlet pipe 212. With such a configuration, the test liquid flows into the test kettle 200 from the inlet pipe 211 on the bottom side of the test kettle 200, and then is discharged from the outlet pipe 212 on the top side of the test kettle 200. The discharged test liquid is filtered through the water circulation device and then transported back to the inlet pipe 211, thereby forming a loop water system 210. The outlet pipe 212 on the top side of the test kettle 200 can also be used to exhaust gas to adjust the internal gas pressure of the test kettle 200.

[0036] Specifically, the temperature system includes a heating jacket (not shown in the drawings) mounted on the outside of the test kettle 200. With this arrangement, the heating jacket mounted on the outside of the test kettle 200 is used to heat and keep the test liquid inside the test kettle 200 warm to a specified temperature, thereby achieving the purpose of controlling the internal temperature value of the test kettle 200. The structure is simple and the practicability is strong.

[0037] Further, see Attachment Figure 1-2 A temperature measuring element 250 is also installed in the test kettle 200, and the temperature measuring element is electrically connected to the heating sleeve; in this way, the temperature measuring element 250 is used to monitor the internal temperature of the test kettle 200 in real time, and the heating power of the heating sleeve is adjusted and controlled according to the monitored temperature. In order to further improve the temperature control effect, multiple temperature measuring elements 250 can be set for measurement. In this embodiment, the temperature measuring element 250 can be a thermocouple.

[0038] There are many specific structures of the test kettle 200. Figure 1, the test kettle 200 adopts a split structure; specifically, the test kettle includes at least two sections of cylindrical parts 220, and at least two sections of cylindrical parts 220 are arranged vertically along a straight line; any two adjacent sections of cylindrical parts 220 are connected to each other through a connecting assembly 230. In this way, by designing the test kettle 200 as a split structure in which at least two sections of cylindrical parts 220 are arranged vertically along a straight line, it is convenient to place the cladding tube 100 of the long tube structure inside the test kettle 200. At the same time, the connecting assembly 230 is used to seal and connect any two adjacent sections of cylindrical parts 220 to ensure that the test liquid will not leak from the connection between the two sections of cylindrical parts 220. In this embodiment, the test kettle 200 includes three sections of cylindrical parts 220, upper, middle and lower, and each section of the cylindrical part 220 is correspondingly provided with a section of the cladding tube 100.

[0039] Further, see Attachment Figure 4 The connection assembly 230 includes a connection ring 231 and a connection piece 232; the upper and lower sides of the connection ring 231 are respectively connected to the ends of the cylindrical member 220; the connection piece 232 is arranged on the annular side of the connection ring 231 and extends to the annular inner side of the connection ring 231; the first end of the connection piece 232 is used to fix the end of each section of the cladding tube 100, and the second end of the connection piece 232 is used to connect the external power supply device (not shown in the drawings) and the gas source device (not shown in the drawings); the inside of the connection piece 232 is provided with a power supply channel 2321 and a gas channel 2322, through which the power supply device and the heating element 120 are electrically connected to each other, and through the gas channel 2322, the gas source device and the inside of the cladding tube 100 are connected to each other to form a gas injection assembly. In this way, the connection ring 231 is connected as a connecting part of the adjacent two sides of the cylindrical member 220, wherein a sealing layer (not shown in the drawings) is arranged between the connection ring 231 and the cylindrical member 220 to ensure that the test liquid will not leak from the connection between the two sections of the cylindrical member 220. At the same time, considering that the cladding tube 100 is provided with a heating element 120 and a gas injection assembly, both of which need to be interconnected with external power supply equipment and gas source equipment; therefore, a connecting piece 232 is provided. When the end of each section of the cladding tube 100 is fixed to the first end of the connecting piece 232, a power line is used to pass through the power supply channel 2321 to connect the power supply equipment with the heating element 120 inside the cladding tube 100, and a gas pipe is used to pass through the gas channel 2322 to connect the gas source equipment with the inside of the cladding tube 100.

[0040] Furthermore, limit assemblies 240 are respectively provided on the upper and lower sides of the first end of the connecting piece 232, and the limit assemblies 240 are used to seal and fix the end of each section of the cladding tube 100 to the first end of the connecting piece 232; in this way, on the one hand, the end of the cladding tube 100 is fixed to the first end of the connecting piece 232 to ensure that the power cord and the gas pipe mentioned above can be placed into the cladding tube 100 through the power supply channel 2321 and the gas channel 2322 to avoid misalignment between the two; on the other hand, the two are sealed with each other to prevent the test liquid inside the test kettle 200 from flowing into the cladding tube 100 through the connection between the cladding tube 100 and the connecting piece 232, thereby affecting the accuracy of the cladding tube hydrogenation test results.

[0041] Specifically, the limiting assembly 240 includes a limiting ring 241 and a locking nut 242. The limiting ring 241 is formed by a ring structure composed of multiple limiting plates (not shown in the drawings); the annular interior of the limiting ring 241 is used for the cladding tube 100 to pass through; the outside of the limiting ring 241 is provided with a threaded portion; the locking nut 242 is threadedly connected to the limiting ring 241 through the threaded portion to reduce the inner diameter of the limiting ring 241, thereby locking and fixing the cladding tube 100. In this way, the end of the cladding tube 100 is first passed through the limiting ring 241 and the locking nut 242, and then the limiting ring 241 is tightened by using the locking nut 242; since the limiting ring 241 is formed by a ring structure composed of multiple limiting plates, when the locking nut 242 is tightened on the limiting ring 241, the gaps between the multiple limiting plates will continue to shrink, thereby reducing the inner diameter of the limiting ring 241, so that the end of the cladding tube 100 is clamped between the multiple limiting plates, thereby achieving the purpose of locking and fixing the end of the cladding tube 100 to the inner ring of the limiting ring 241.

[0042] Further, see Appendix Figure 5 The free end of the cladding tube 100 away from the connecting piece 232 is provided with an end plug 130, which is used to seal the end of the cladding tube 100. In this way, the end plug 130 is provided at the end of the cladding tube 100 away from the connecting piece 232 to isolate the internal space of the cladding tube 100 from the test kettle 200. The end plug 130 is connected to the cladding tube 100 by welding.

[0043] There are many specific structures of the above-mentioned breach assembly 300. In this embodiment, refer to the attached Figure 6The breaching assembly 300 includes a drill assembly 310 and a jacking assembly 320 which are arranged on opposite sides of the cylindrical member 220; specifically, the drill assembly 310 includes a first mounting block 311 and a drill member 312, the first mounting block 311 is fixedly connected to the cylindrical member 220, the drill member 312 is movably connected to the first mounting block 311, and the drill member 312 is used to drill holes on the surface of the cladding tube 100; the jacking assembly 320 includes a second mounting block 321 and a jacking member 322, the second mounting block 321 is fixedly connected to the cylindrical member 220, the jacking member 322 is fixedly connected to the second mounting block 321, and the jacking member 322 is used to support the cladding tube 100 when the drill member 312 drills the cladding tube 100. In this way, the drill bit 312 and the supporting member 322 are respectively installed on the cylindrical member 220 of the test kettle 200 through the first mounting block 311 and the second mounting block 321; the drill bit 312 is used to make a primary breach on the cladding tube 100, and the size of the breach can be controlled by adjusting the drill diameter of the drill bit 312; the supporting member 322 is located opposite to the drill bit 312, and the supporting member 322 can be used to prevent the cladding tube 100 from radial displacement during the drilling process, thereby affecting the breach quality of the cladding tube 100.

[0044] As a preferred solution of the above embodiment, refer to the attached Figure 7 At least two groups of fixing components 400 are installed on the test kettle 200, and at least two groups of fixing components 400 are distributed along the axial linear array of the cladding tube 100; the fixing components 400 are used to fix and limit the cladding tube 100; in this way, the fixing components 400 are used to fix and limit the cladding tube 100, so that the cladding tube 100 is suspended inside the test kettle 200, avoiding the cladding tube 100 from contacting the inner wall of the test kettle 200 and affecting the test quality.

[0045] Specifically, each set of fixing components 400 includes at least two sets of abutment structures 410, which are equidistantly distributed in an annular manner around the cylindrical member 220; each set of abutment structures 410 includes a third mounting block 411 and abutment members 412, the third mounting block 411 is fixedly connected to the cylindrical member 220, the abutment members 412 are slidably connected to the third mounting block 411, and the abutment members 412 are used to abut against the side of the cladding tube 100. In this way, the cladding tube 100 is clamped and fixed by combining multiple abutment structures 410, so as to achieve the purpose of radial positioning of the cladding tube 100.

[0046] In this embodiment, two groups of fixing components 400 are respectively arranged along the upper and lower positions of the test kettle 200, and each group of fixing components 400 includes four groups of abutment structures 410. The four groups of abutment structures 410 are distributed in an annular shape at equal distances around the cylindrical member 220, that is, two adjacent groups of abutment structures 410 are 90 degrees to each other.

[0047] As a preferred solution of the above embodiment, refer to the attached Figure 1 The cladding tube hydrogenation test device includes a frame 500, and the frame 500 installs and fixes the test kettle 200 through a plurality of supporting members 510. The frame 500 is used to install and fix the test kettle 200, which has a simple structure and strong practicality.

[0048] In other embodiments, a lifting system (not shown in the drawings) is also provided on the frame 500, and the lifting system connects each section of the cylindrical member 220 and the connecting assembly 230. The lifting system can control the lifting and lowering of each section of the cylindrical member 220 and the connecting assembly 230, thereby facilitating the assembly and disassembly of the test kettle 200.

[0049] The following is a general description of the cladding tube hydrogenation test process in combination with the above embodiments: Step 1: Preparation stage; 1) After the test system is assembled, the inside of the cladding tube 100 is cleaned and then pre-filled with 2MPa helium to maintain the pressure (the above 2MPa can be changed according to the actual pre-filled helium pressure in the simulated cladding tube 100); The test system assembly process is as follows: a. The upper, middle and lower cylindrical members 220 of the test kettle 200 are separated from each other; b. The drill bit 312, the supporting member 322 and the abutting member 412 retreat to a safe position so that they cannot interfere with the cladding tube 100; c. The fuel pellet 110 is placed on the heating rod, and then the heating rod with the fuel pellet 110 is placed inside each section of the cladding tube 100, and the end plug 130 is welded at the free end of the cladding tube 100 away from the connecting member 232; d. Place the assembled middle cladding tube 100 in the middle cylindrical member 220, pass the power supply of the heating rod and the thermocouple signal line of the heating rod through the power supply channel 2321 of the connecting member 232 of the connecting assembly 230 and seal it, and connect the upper and lower connecting assemblies 230 to the two ends of the middle cladding tube 100 using their stopper assemblies 240 respectively; f. The connecting ring 231 of the upper and lower connecting components 230 is connected and fixed to the middle cylindrical member 220; g. The upper cladding tube 100 is connected to the upper connection assembly 230 by a stopper assembly 240, and the lower cladding tube 100 is connected to the lower connection assembly 230 by a stopper assembly 240; h. Use the gas control system to inflate and pressure-maintain each section of the assembled cladding tube 100 for leak detection; i. The upper and lower sections of the cylindrical member 220 are connected to the upper and lower side connection components 230; j. Adjust the positions of the thermocouple, the head, the top support member 322 and the abutment member 412 so that each component is in contact with the cladding tube 100; k Use the loop water system 210 to fill the test kettle 200 with water and exhaust the gas in the test kettle 200; 2) Raise the pressure to the test pressure and check for leaks on the test kettle 200; 3) Turn on the heating jacket and heat to the specified test temperature; 4) Turn on the heating rod and heat to the specified test temperature; Step 2: a hydrogenation simulation test; 1) When the cladding tube 100 contains hydrogen during the manufacturing stage of the simulated cladding tube 100, after the gas washing operation inside the cladding tube 100 is completed using the gas control system in step (1) of step one, a helium-hydrogen moderation gas in a specified ratio is flushed into the cladding tube 100 according to the test conditions, and then steps (2), (3), and (4) of step one are executed. After the specified time is reached, the test is stopped.

[0050] 2) When simulating hydrogen evolution of the fuel cladding tube 100 and the fuel pellet 110 during service, after step (1) of step 1 is completed, the gas control system fills the cladding tube 100 with hydrogen at a speed set in the test. When the specified hydrogen volume is reached, the hydrogen injection is stopped. The test is stopped when the test stop condition is met.

[0051] Step 3: Secondary hydrogenation simulation test; 1) After executing step (1) of step 1, when the specified time or condition of the test is reached, the drill bit assembly 310 is controlled to drill holes in the cladding wall until the side wall of the cladding tube 100 is penetrated; this process is fed back by the pressure in the test reactor 200, the pressure change in the cladding tube 100 and the feed distance of the drill bit assembly 312 to provide feedback on the drilling status of the cladding tube 100; 2) After the through hole appears, the test liquid flows into the cladding tube 100, flashes to become gas, and reacts with the inner wall of the cladding tube 100 and the fuel pellets 110 to generate hydrogen, or decomposes into hydrogen under high temperature; 3) The hydrogen produced in the above links will cause secondary hydrogenation in the cladding tube 100. At the same time, the internal components and pressure will be dynamically exchanged and transferred through the primary drilling hole and the primary water loop in the test kettle 200 to restore the conditions for the occurrence of primary breach and secondary hydrogenation in the real reactor. The test will be stopped when the specified time or other test stop conditions are reached.

[0052] Step 4: End of the test: 1) Stop heating.

[0053] 2) After the temperature drops to room temperature, adjust the system pressure to normal pressure.

[0054] 3) Empty the test liquid in the test kettle 200.

[0055] 4) Open the test kettle 200 and take out the cladding tube 100 sample.

[0056] 5) Conducting analysis and research on the cladding tube 100.

[0057] The above are the basic steps of the cladding tube hydrogenation test. When conducting a primary hydrogenation simulation, execute steps one, two and four; when conducting a secondary hydrogenation simulation test, execute steps one, three and four.

[0058] In addition, the following types of research tests can be carried out using this cladding tube test device: a) Try to study the influence of the serious hydrogen absorption position of the cladding tube, such as the distribution and size of the bulge, by prefabricating defects on the inner wall of the cladding tube, such as mechanical scratches, pre-oxidation or removal of the oxide film; b) Try to change the performance of the cladding tube in advance, conduct experiments, and study the conditions required for the complete brittle fracture of the cladding tube in the circumferential direction, such as embrittlement treatment of the cladding tube and prefabrication of defects at the embrittled position, making this position easy to absorb hydrogen, etc.; c) By increasing the annular size of the simulated fuel pellets, the extent to which the swelling of the fuel pellets under different burnup conditions affects the hydrogenation damage of the cladding tube is studied; d) By changing the materials of the cladding tube and the end plug, the hydrogenation characteristics between different materials and components and the welds are studied; e) By improving the inner and outer walls of the cladding tube, research and verify measures to improve the cladding tube's resistance to hydrogenation.

[0059] It should be noted that other contents of the cladding tube hydrogenation test device in a simulated pressurized water reactor primary loop environment disclosed in the present invention are prior arts and will not be described in detail herein.

[0060] The above are only optional embodiments of the present invention, and are not intended to limit the patent scope of the present invention. Any direct / indirect application of the present invention in other related technical fields is included in the patent protection scope of the present invention.

Claims

1. A cladding tube hydrogenation test device simulating a pressurized water reactor primary loop environment, applied to cladding tubes; characterized in that: The cladding tube hydrogenation test device comprises: A test kettle, wherein the test kettle is provided with a loop water system, a pressurizing system and a temperature system; the loop water system is used to circulate and inject the test liquid into the test kettle, and the pressurizing system and the temperature system are used to control the internal pressure value and the temperature value of the test kettle; A fuel pellet, a heating element and a gas injection assembly; the fuel pellet and the heating element are arranged inside the cladding tube, the fuel pellet is used to react with the test liquid to generate hydrogen; the heating element is used to heat the inside of the cladding tube; the gas injection assembly is connected to the inside of the cladding tube, and the gas injection assembly is used to inject test gas into the inside of the cladding tube; A breaching assembly is installed in the test kettle; the breaching assembly is used to make breaches on the surface of the cladding tube.

2. The cladding tube hydrogenation test device according to claim 1, characterized in that: The test kettle adopts a split structure; specifically, the test kettle includes at least two sections of cylindrical parts, and at least two sections of the cylindrical parts are vertically arranged along a straight line; any two adjacent sections of the cylindrical parts are connected to each other through a connecting component; and each section of the cylindrical part is correspondingly provided with a section of the cladding tube.

3. The cladding tube hydrogenation test device according to claim 2, characterized in that: The connecting assembly includes a connecting ring and a connecting piece; the upper and lower sides of the connecting ring are respectively connected to the ends of the cylindrical piece; the connecting piece is arranged on the annular side of the connecting ring and extends to the annular inner side of the connecting ring; the first end of the connecting piece is used to fix the end of each section of the cladding tube, and the second end of the connecting piece is used to connect to an external power supply device and a gas source device; a power supply channel and a gas channel are provided inside the connecting piece, and the power supply device and the heating element are electrically connected to each other through the power supply channel, and the gas source device and the inside of the cladding tube are connected to each other through the gas channel to form the gas injection assembly.

4. The cladding tube hydrogenation test device according to claim 3, characterized in that: Limiting components are respectively provided on the upper and lower sides of the first end of the connecting member, and the limiting components are used to seal and fix the end of each section of the cladding tube to the first end of the connecting member.

5. The cladding tube hydrogenation test device according to claim 3, characterized in that: An end plug is provided at the free end of the cladding tube away from the connecting piece, and the end plug is used to seal the end of the cladding tube.

6. The cladding tube hydrogenation test device according to claim 2, characterized in that: The breaking assembly includes a drill assembly and a jacking assembly arranged on opposite sides of the cylindrical member; The drill assembly comprises a first mounting block and a drill bit component, wherein the first mounting block is fixedly connected to the cylindrical component, and the drill bit component is movably connected to the first mounting block, and the drill bit component is used to drill a hole on the surface of the cladding tube; The jacking assembly includes a second mounting block and a jacking member, wherein the second mounting block is fixedly connected to the cylindrical member, and the jacking member is fixedly connected to the second mounting block, and the jacking member is used to support the cladding tube when the drill bit drills the cladding tube.

7. The cladding tube hydrogenation test device according to claim 2, characterized in that: At least two groups of fixing components are installed on the test kettle, and at least two groups of the fixing components are distributed along the axial linear array of the cladding tube; the fixing components are used to fix and limit the cladding tube; Specifically, each group of the fixing components includes at least two groups of abutment structures, and at least two groups of the abutment structures are distributed in an annular manner around the cylindrical member at equal distances; each group of the abutment structures includes a third mounting block and an abutment member, the third mounting block is fixedly connected to the cylindrical member, the abutment member is slidably connected to the third mounting block, and the abutment member is used to abut against the side of the cladding tube.

8. The cladding tube hydrogenation test device according to claim 1, characterized in that: The heating element comprises a heating rod, and the heating rod is extended along the axial direction of the cladding tube; Furthermore, the fuel core block is in an annular structure and is sleeved on the outer side of the heating rod.

9. The cladding tube hydrogenation test device according to claim 1, characterized in that: The loop water system includes a water inlet pipe installed on the bottom side of the test kettle, and a water outlet pipe installed on the top side of the test kettle; a water circulation device is provided between the water inlet pipe and the water outlet pipe; And / or, the temperature system includes a heating jacket mounted on the outside of the test kettle.

10. The cladding tube hydrogenation test device according to claim 1, characterized in that: The cladding tube hydrogenation test device comprises a frame, and the frame is used to install and fix the test kettle through a plurality of supporting members.

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