Secondary neutron source rod manufacturing process

Abstract

The invention discloses a secondary neutron source rod manufacturing process. The secondary neutron source rod manufacturing process comprises the following steps: assembling an inner pipe section; the inner pipe section and the outer shell pipe are assembled, the upper end plug is pressed and plugged into the first end of the outer shell pipe, girth welding is carried out, and then the inner pipe section is installed in the outer shell pipe; installing a lower end plug, pressing and plugging the lower end plug into the second end of the outer cladding tube, and carrying out girth welding; the lower end plug is subjected to helium-filling hole-plugging welding, the outer wrapping shell pipe provided with the lower end plug is installed to a lower end plug helium-filling hole-plugging welding tool, the lower end plug helium-filling hole-plugging welding tool is installed to hole-plugging welding equipment, a welding chamber of the hole-plugging welding equipment is vacuumized, helium with first preset pressure is filled, and helium-filling hole-plugging welding is conducted on the lower end plug. According to the secondary neutron source rod manufacturing process, the flow is simple, the lower end plug is supported and positioned by adopting the lower end plug helium-filling hole-plugging welding tool for helium-filling hole-plugging welding of the lower end plug, the welding efficiency of the lower end plug helium-filling hole-plugging welding can be improved, and the assembling process of a secondary neutron source rod is more convenient.

Description

Technical Field

[0001] This invention relates to the field of nuclear power technology, and more specifically, to a manufacturing process for secondary neutron source rods. Background Technology

[0002] The secondary neutron source rod adopts a double-clad structure design, consisting of an inner tube section 100, a cladding tube 200, an upper plug 300, and a lower plug 400, and is filled with high-pressure helium. The inner tube section 100 is located inside the cladding tube 200, and the upper plug 300 and lower plug 400 seal both ends of the cladding tube 200. A schematic diagram of the specific structure is shown below. Figure 1 As shown in the diagram. The inner tube section 100 consists of an inner shell tube 110, an antimony-beryllium core block 120, an upper end cap 130, and a lower end cap 140, and is filled with high-pressure helium gas. The antimony-beryllium core block 120 is disposed inside the inner shell tube 110, and the upper end cap 130 and lower end cap 140 seal both ends of the inner shell tube 110. A detailed structural diagram is shown below. Figure 2 As shown. In the prior art, the manufacturing process of secondary neutron source rods is complex and the assembly is difficult.

[0003] Therefore, how to reduce the assembly difficulty of secondary neutron source rods and improve their assembly efficiency has become a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a manufacturing process for secondary neutron source rods, so as to reduce the assembly difficulty of secondary neutron source rods and improve the assembly efficiency of secondary neutron source rods.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A manufacturing process for a secondary neutron source rod, the secondary neutron source rod comprising an inner tube section, an outer casing tube, an upper end plug, and a lower end plug, wherein the inner tube section is disposed inside the outer casing tube, and the upper end plug and lower end plug are disposed at both ends of the outer casing tube for sealing the outer casing tube; the manufacturing process for the secondary neutron source rod includes the following steps:

[0007] Assemble the inner tube section, which includes an inner shell tube, an antimony-beryllium core block set inside the inner shell tube, and upper and lower end caps set at both ends of the inner shell tube for sealing the inner shell tube. The inner shell tube is filled with helium.

[0008] Assemble the inner pipe section and the outer shell pipe, insert the upper end plug into the first end of the outer shell pipe and perform circumferential welding, and then install the inner pipe section into the outer shell pipe;

[0009] Install the lower end plug, press the lower end plug into the second end of the outer casing tube and perform circumferential welding;

[0010] The lower end plug is helium-filled and plugged. The outer shell tube with the lower end plug installed is installed onto the lower end plug helium-filled and plugged welding fixture. The lower end plug helium-filled and plugged welding fixture is installed onto the plugging welding equipment. The welding chamber of the plugging welding equipment is evacuated and filled with helium at the first preset pressure. The lower end plug is then helium-filled and plugged.

[0011] Optionally, in the above-mentioned secondary neutron source rod manufacturing process, the helium-filled plug welding fixture for the lower end plug has a positioning channel. One end of the positioning channel is for the outer shell tube with the lower end plug installed to be inserted, and the other end allows the lower end plug to be exposed.

[0012] The lower end helium-filled plugging welding fixture and plugging welding equipment are detachably connected.

[0013] Optionally, in the above-mentioned secondary neutron source rod manufacturing process, the helium-filled plugging and welding fixture at the lower end includes:

[0014] The boss abuts against the cylinder in the welding chamber;

[0015] The lower end plug positioning part is arranged coaxially with the boss, and the lower end plug positioning part is provided with a receiving hole for accommodating the lower end plug.

[0016] Optionally, in the above-mentioned secondary neutron source rod manufacturing process, the step of assembling the inner tube segment includes:

[0017] Install the lower end cap, press the lower end cap into the first end of the inner shell tube and perform circumferential welding;

[0018] Insert the antimony-beryllium core block and then insert it into the inner casing tube with the lower end cap installed.

[0019] Install the upper end cap, press the upper end cap into the second end of the inner shell tube and perform circumferential welding;

[0020] The upper end cap is then filled with helium and plugged with welding.

[0021] Optionally, in the above-mentioned secondary neutron source rod manufacturing process, the step of loading the antimony-beryllium core block specifically includes:

[0022] The inner casing tube with the lower end cap installed is inserted into the glove box of the secondary neutron source, and multiple antimony-beryllium core blocks are inserted into the inner casing tube.

[0023] Optionally, in the above-mentioned secondary neutron source rod manufacturing process, the step of installing the lower head specifically includes:

[0024] The lower end cap is pressed and plugged. The lower end cap is installed on the lower end cap pressing and plugging fixture. The lower end cap pressing and plugging fixture is installed on the pressing and plugging equipment. The inner shell tube is clamped by the clamping equipment. The lower end cap is pressed and plugged into the first end of the inner shell tube by the pressing and plugging equipment.

[0025] The lower end cap is circumferentially welded. After the lower end cap is inserted into the inner shell tube, the circumferential weld between the lower end cap and the inner shell tube is welded using welding equipment.

[0026] Optionally, in the above-mentioned secondary neutron source rod manufacturing process, the lower head plugging tooling and the plugging equipment can be detachably connected.

[0027] Optionally, in the above-mentioned secondary neutron source rod manufacturing process, the lower head plug tooling includes:

[0028] The screw, the push rod of the plugging machine of the plugging equipment has a threaded hole that matches the screw;

[0029] The lower end cap positioning part is connected to the screw, and the lower end cap positioning hole is opened on the lower end cap positioning part.

[0030] Optionally, in the above-mentioned secondary neutron source rod manufacturing process, the hole-plugging welding step of the upper end cap specifically includes:

[0031] Install the inner shell tube with the upper head installed onto the upper head helium-filling and plugging welding fixture. Install the upper head helium-filling and plugging welding fixture into the welding chamber of the plugging welding equipment. Evacuate the welding chamber and fill it with helium at a second preset pressure. Perform helium-filling and plugging welding on the upper head. The second preset pressure is less than the first preset pressure.

[0032] Optionally, in the above-mentioned secondary neutron source rod manufacturing process, both the inner and outer cladding tubes are made of stainless steel.

[0033] As can be seen from the above scheme, the secondary neutron source rod manufacturing process disclosed in this invention has a simple process. The helium filling and plugging welding of the lower end plug uses a lower end plug helium filling and plugging welding fixture to support and position the lower end plug, which can improve the welding efficiency of the lower end plug helium filling and plugging welding, making the processing and assembly of the secondary neutron source rod more convenient and faster, reducing the assembly difficulty of the secondary neutron source rod and improving the assembly efficiency. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0035] Figure 1 This is a schematic diagram of the structure of the secondary neutron source rod disclosed in an embodiment of the present invention;

[0036] Figure 2 This is a schematic diagram of the inner pipe section disclosed in an embodiment of the present invention;

[0037] Figure 3 This is a flowchart of the manufacturing process of the secondary neutron source rod disclosed in an embodiment of the present invention;

[0038] Figure 4 This is a flowchart of the manufacturing process of the inner tube section disclosed in an embodiment of the present invention;

[0039] Figure 5 This is a schematic diagram of the upper end cap structure disclosed in an embodiment of the present invention;

[0040] Figure 6 This is a schematic diagram of the structure of the lower end cap disclosed in an embodiment of the present invention;

[0041] Figure 7 This is a side view of the lower head compression plug tool disclosed in an embodiment of the present invention;

[0042] Figure 8 This is a front view of the lower head compression plug tooling disclosed in an embodiment of the present invention;

[0043] Figure 9 This is a schematic diagram of the structure of the upper end cap helium filling and plugging welding fixture disclosed in an embodiment of the present invention;

[0044] Figure 10 This is a top view of the helium-filled hole-plugging welding fixture disclosed in an embodiment of the present invention;

[0045] Figure 11 This is a side view of the helium-filled hole-plugging welding fixture disclosed in an embodiment of the present invention;

[0046] Figure 12 This is a cross-sectional view of the helium-filled hole-plugging welding fixture disclosed in an embodiment of the present invention;

[0047] Figure 13 This is a schematic diagram of the structure of the lower end plug helium-filled hole plugging welding device disclosed in an embodiment of the present invention.

[0048] Among them, 100 is the inner tube section, 110 is the outer shell tube, 120 is the antimony-beryllium core block, 130 is the upper end cap, 140 is the lower end cap, 200 is the outer shell tube, 300 is the upper end plug, and 400 is the lower end plug;

[0049] 10 is the lower head pressure plug tool, 11 is the screw, 12 is the lower head positioning part, 121 is the lower head positioning hole, 122 is the cutting part, and 13 is the tightening part;

[0050] 20 is the welding fixture for filling the lower end with helium, 21 is the boss, 22 is the positioning part of the lower end plug, 201 is the positioning channel, and 202 is the mounting hole;

[0051] 30 is the welding fixture for plugging holes in the upper head; 31 is the positioning part of the upper head; 301 is the positioning groove.

[0052] 01 is the welding chamber, 02 is the observation window, 03 is the cylinder end flange cover, 04 is the retaining ring, and 05 is the rubber ring. Detailed Implementation

[0053] The core of this invention lies in disclosing a manufacturing process for secondary neutron source rods, so as to reduce the assembly difficulty of secondary neutron source rods and improve the assembly efficiency of secondary neutron source rods.

[0054] like Figure 1 As shown, the secondary neutron source rod includes an inner tube section 100, an outer casing tube 200, an upper end plug 300, and a lower end plug 400. The inner tube section 100 is disposed inside the outer casing tube 200, and the upper end plug 300 and the lower end plug 400 are disposed at both ends of the outer casing tube 200 to seal the outer casing tube 200.

[0055] like Figure 3 As shown in the figure, an embodiment of the present invention discloses a manufacturing process for a secondary neutron source rod, which specifically includes the following steps:

[0056] S10, Assemble the inner pipe section 100;

[0057] like Figure 2 As shown, the inner tube section 100 includes an inner cladding tube 110, an antimony-beryllium core block 120 disposed within the inner cladding tube 110, and upper end caps 130 and lower end caps 140 disposed at both ends of the inner cladding tube 110 for sealing the inner cladding tube 110. The inner cladding tube 110 is filled with helium. The antimony-beryllium core block 120 generates tritium after being activated by irradiation in the reactor. The double-cladding design can reduce the outward permeation of tritium.

[0058] S20, assembling inner pipe section 100 and outer shell pipe 200;

[0059] The upper plug 300 is inserted into the first end of the outer shell tube 200. Then, a sample is taken before welding. Subsequently, the circumferential weld between the upper plug 300 and the outer shell tube 200 is welded. After welding, a sample is taken, and the weld is inspected. X-ray inspection can be used to inspect the weld. Then, a visual inspection is performed to achieve a seal of the upper plug 300. Finally, the inner tube section 100 is installed into the outer shell tube 200.

[0060] S30, Install the lower end plug 400;

[0061] Insert the lower end plug 400 into the second end of the outer shell tube 200, take a sample before welding, and then weld the circumferential weld between the lower end plug 400 and the outer shell tube 200. Take a sample after welding is completed.

[0062] S40. Perform helium-filled plugging welding on the lower end plug 400.

[0063] The outer casing tube 200 with the lower plug 400 installed is installed onto the lower plug helium-filling and plugging welding fixture. The lower plug helium-filling and plugging welding fixture is then installed onto the plugging welding equipment. The welding chamber 01 of the plugging welding equipment is evacuated and filled with helium at a first preset pressure. Helium-filling and plugging welding is then performed on the lower plug 400. The first preset pressure can be specifically determined according to actual needs. In some specific embodiments, the first preset pressure can be selected as 4.5±0.05 MPa. After the plugging welding is completed, the weld and the helium-filling hole are inspected by X-ray, and then the helium filled into the secondary neutron source rod is leak-tested.

[0064] The secondary neutron source rod manufacturing process disclosed in this invention is simple. The helium-filling and plugging welding of the lower end plug 400 is supported and positioned by the lower end plug 400 helium-filling and plugging welding fixture 20, which can improve the welding efficiency of the lower end plug 400 helium-filling and plugging welding, making the processing and assembly of the secondary neutron source rod more convenient and faster, reducing the assembly difficulty of the secondary neutron source rod and improving the assembly efficiency.

[0065] like Figures 10-12 As shown in the embodiment of the present invention, the secondary neutron source rod manufacturing process includes a helium-filled lower plug welding fixture 20 with a positioning channel 201. The positioning channel 201 is a through channel, with one end for inserting the outer casing tube 200 containing the lower plug 400, and the other end allowing the lower plug 400 to protrude. For ease of assembly and disassembly, the lower plug helium-filled lower plug welding fixture 20 is detachably connected to the plugging welding equipment, specifically via a snap-fit ​​connection or a connecting piece connection.

[0066] In some specific embodiments, the lower end helium-filled plugging welding fixture 20 is connected to the plugging welding equipment via a connector, such as... Figures 10-11 As shown, the lower helium-filled plugging welding fixture 20 has mounting holes 202 for screw engagement. The mounting holes 202 are preferably countersunk holes, and multiple countersunk holes are arranged circumferentially along the lower helium-filled plugging welding fixture 20. The lower helium-filled plugging welding fixture 20 is connected to the cylinder by screws, specifically to the cylinder end flange cover 01. It should be noted that the plugging welding equipment includes a welding chamber 01, which has an observation window 02. To ensure the sealing of the welding chamber 01, multiple cylinders are installed within it. The cylinders are designed to ensure a tight connection between the sealing rings (including the retaining ring 04 and the rubber ring 05) and the outer casing tube 200 and inner casing tube 110, making the welding chamber 01 a sealed unit. This allows for the filling of high-pressure helium gas for plugging welding. Specifically, as shown... Figure 13 As shown.

[0067] like Figures 11-13As shown, the lower end plug helium-filling and hole-plugging welding fixture 20 includes a boss 21 and a lower end plug positioning part 22. The boss 21 abuts against the cylinder end flange cover 01 of the welding chamber, and the lower end plug positioning part 22 is coaxially arranged with the boss 21. The lower end plug positioning part 22 has a receiving hole for accommodating the lower end plug 140. Specifically, both the boss 21 and the lower end plug positioning part 22 are cylindrical, and the bottom diameter of the boss 21 is smaller than the bottom diameter of the lower end plug positioning part 22. This arrangement ensures the firmness of the connection between the lower end plug helium-filling and hole-plugging welding fixture 20 and the cylinder end flange cover 01. For ease of installation, a chamfer is provided on the end face of the lower end plug positioning part 22 away from the boss 21.

[0068] like Figure 4 As shown, the secondary neutron source rod manufacturing process disclosed in this embodiment of the invention includes the following steps in step S10:

[0069] S11. Install the lower end cap 140;

[0070] After the lower end cap 140 is inserted into the first end of the inner shell tube 110, a sample is taken before welding. Then, the circumferential weld between the lower end cap 140 and the inner shell tube 110 is welded. After the welding is completed, the weld is inspected, specifically by X-ray inspection, and then a visual inspection is performed. Figure 6 A structural schematic diagram of the lower end cap 140 is provided. In some specific embodiments, the lower end cap 140 includes a disc-shaped structure and a cylindrical structure connected together. A chamfer is provided on the end face of the cylindrical structure away from the disc-shaped structure.

[0071] S12, Load 120 antimony-beryllium core blocks;

[0072] The antimony-beryllium core blocks 120 are loaded into the inner casing tube 110, which has the lower end cap 140 installed. Specifically, the inner casing tube 110 with the lower end cap 140 installed is loaded into the secondary neutron source glove box. The operator inserts their hands into the latex gloves of the glove box, without directly contacting the antimony-beryllium core blocks 120, and loads 376g-401g of the antimony-beryllium core blocks 120 into the open inner tube section 100 through the latex gloves. The number of antimony-beryllium core blocks 120 is approximately 171. It should be noted that this number is only an example and not a limitation. The secondary neutron source glove box is connected to a bellows box, ensuring a negative pressure state inside the glove box, allowing harmful dust to be drawn into the filter through the bellows box. It should be noted that the antimony-beryllium core blocks 120 can also be loaded using installation equipment.

[0073] S13, Install the upper end cap 130;

[0074] The upper end cap 130 is inserted into the second end of the inner shell tube 110 for pre-welding sampling, and then the circumferential weld between the upper end cap 130 and the inner shell tube 110 is welded. Figure 5A structural schematic diagram of the upper head 130 is given. One end of the upper head 130 is a frustum-shaped structure and the other end is a cylindrical structure. A stepped ring is provided between the frustum-shaped structure and the cylindrical structure. The end of the cylindrical structure away from the frustum-shaped structure is provided with a chamfer. At the same time, the upper head 130 has a through helium filling hole.

[0075] S14. Perform helium-filled plugging welding on the upper end cap 130;

[0076] First, pre-welding sampling is performed. Then, the upper end cap 130 is helium-filled and plugged with welding. After welding is completed, the weld seam of the circumferential weld and the helium-filled hole of the helium-filled plug are inspected. This can be done by X-ray inspection. Then, the helium gas is leak-tested, and the assembly and manufacturing of the inner pipe section 100 is completed.

[0077] The secondary neutron source rod manufacturing process disclosed in this embodiment of the invention includes the following steps in step S11:

[0078] S131, Lower end cap 140 pressure plug;

[0079] The lower end cap 140 is installed on the lower end cap pressing fixture 10, and the lower end cap pressing fixture 10 is installed on the pressing equipment. The lower end cap pressing fixture 10 has a lower end cap positioning hole 121 for positioning and supporting the lower end cap 140. The structural schematic diagram of the lower end cap pressing fixture 10 is shown below. Figures 7-8 As shown. The inner shell tube 110 is clamped by a clamping device, and the lower end cap 140 is pressed into the first end of the inner shell tube 110 using a pressing device.

[0080] S132, lower head 140 circumferential weld;

[0081] After the lower end cap 140 is inserted into the inner shell tube 110, the circumferential weld between the lower end cap 140 and the inner shell tube 110 is welded using welding equipment.

[0082] For ease of assembly and disassembly, the lower end cap compression tool 10 is detachably connected to the compression device, specifically via either a threaded connection or a snap-fit ​​connection. In some specific embodiments, a threaded connection is used, such as... Figure 8As shown, the lower end cap pressing fixture 10 includes a screw 11 and a lower end cap positioning part 12. The pressing machine push rod of the pressing equipment has a threaded hole that mates with the screw 11. The lower end cap positioning part 12 is connected to the screw 11, and the upper end cap positioning hole 121 is opened on the lower end cap positioning part 12. To ensure the firmness of the connection between the lower end cap pressing fixture 10 and the pressing machine push rod, the lower end cap pressing fixture 10 also includes a tightening part 13 disposed between the screw 11 and the lower end cap positioning part 12. After the lower end cap pressing fixture 10 is installed onto the pressing machine push rod, the tightening part 13 is installed into the mounting hole of the pressing machine push rod and abuts against the mounting hole circumferentially to achieve tightening. One end of the lower end cap positioning part 12 abuts against the pressing machine push rod.

[0083] like Figures 7-8 As shown, in order to facilitate the use of tools to connect the lower head pressing tool 10 to the pressing machine top rod, a cutting part 122 is provided in the lower head positioning part 12. The cutting part 122 facilitates the use of clamping tools to clamp the lower head pressing tool 10, so as to facilitate the screw 11 of the lower head pressing tool 10 to be screwed into the pressing machine top rod.

[0084] The upper end cap 130 is pressed by the upper end cap pressing tool. The structure of the upper end cap pressing tool is the same as that of the lower end cap pressing tool 10. The upper end cap pressing tool is provided with an upper end cap positioning hole for positioning and supporting the upper end cap 130. In order to share the same pressing equipment, the upper end cap pressing tool and the lower end cap pressing tool 10 have the same external dimensions.

[0085] The secondary neutron source rod manufacturing process disclosed in this invention includes step S14, which specifically comprises: installing the inner cladding tube 110 with the upper end cap 130 installed on it onto the upper end cap helium-filled plugging welding fixture 30; installing the upper end cap helium-filled plugging welding fixture 30 into the welding chamber 01 of the plugging welding equipment; evacuating the welding chamber 01 and filling it with helium at a second preset pressure; and performing helium-filled plugging welding on the upper end cap 130. The second preset pressure is less than the first preset pressure. In some specific embodiments, the second preset pressure can be 1.5 ± 0.05 MPa. It should be noted that the structure of the upper end cap helium-filled plugging welding fixture 30 is the same as that of the lower end plug helium-filled plugging welding fixture 20. The upper end cap helium-filled plugging welding fixture 30 has positioning channels that can position and support the inner cladding tube 110 on which the upper end cap 130 is installed. To facilitate observation of the plugging welding position of the upper head 130, a positioning groove 301 is radially provided on the upper head positioning part 31 of the upper head helium-filled plugging welding fixture 30. The positioning groove 301 facilitates observation of the plugging welding position of the upper head 130 through the observation window 02 of the welding chamber 01 during plugging welding, so as to adjust the distance between the tungsten electrode and the upper head 130.

[0086] The manufacturing process of the secondary neutron source rod disclosed in this invention preferably uses stainless steel for the inner shell tube 110, upper end cap 130, lower end cap 140, outer shell tube 200, upper end plug 300, and lower end plug 400.

[0087] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0088] It should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0089] As indicated in this application and claims, unless the context clearly indicates otherwise, the words "a," "an," "a," and / or "the" are not specifically singular and may include the plural. Generally, the terms "comprising" and "including" only indicate the inclusion of expressly identified steps and elements, which do not constitute an exclusive list, and the method or apparatus may also include other steps or elements. An element defined by the phrase "comprising an..." does not exclude the presence of other identical elements in the process, method, product, or apparatus that includes the element.

[0090] Hereinafter, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature.

[0091] This article uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the core ideas of the present invention. It should be noted that those skilled in the art can make several improvements and modifications to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. A manufacturing process for a secondary neutron source rod, characterized in that, The secondary neutron source rod includes an inner tube section (100), an outer casing tube (200), an upper end plug (300), and a lower end plug (400). The inner tube section (100) is disposed inside the outer casing tube (200), and the upper end plug (300) and the lower end plug (400) are disposed at both ends of the outer casing tube (200) to seal the outer casing tube (200). The manufacturing process of the secondary neutron source rod includes the following steps: Assemble an inner tube section (100), the inner tube section (100) including an inner shell tube (110), an antimony-beryllium core block (120) disposed inside the inner shell tube (110), and an upper end cap (130) and a lower end cap (140) disposed at both ends of the inner shell tube (110) for sealing the inner shell tube (110), the inner shell tube (110) being filled with helium; Assemble the inner tube section (100) and the outer shell tube (200), press the upper end plug (300) into the first end of the outer shell tube (200) and perform circumferential welding, and then install the inner tube section (100) into the outer shell tube (200); Install the lower end plug (400), press the lower end plug (400) into the second end of the outer shell tube (200) and perform circumferential welding; Helium-filled plug welding is performed on the lower end plug (400). The outer shell tube (200) with the lower end plug (400) installed is installed on the lower end plug helium-filled plug welding fixture (20). The lower end plug helium-filled plug welding fixture (20) is installed on the plug welding equipment. The welding chamber (01) of the plug welding equipment is evacuated and filled with helium at a first preset pressure. Helium-filled plug welding is performed on the lower end plug (400).

2. The secondary neutron source rod manufacturing process as described in claim 1, characterized in that, The lower end plug helium filling and plugging welding fixture (20) has a positioning channel (201), one end of which is for the outer shell tube (200) with the lower end plug (400) installed to be inserted, and the other end of which allows the lower end plug (400) to be exposed. The lower end plug helium-filled hole-plugging welding fixture (20) is detachably connected to the hole-plugging welding equipment.

3. The secondary neutron source rod manufacturing process as described in claim 2, characterized in that, The lower end plug helium filling and hole plugging welding fixture (20) includes: A boss (21) abuts against the cylinder of the welding chamber (01); The lower end plug positioning part (22) is coaxially arranged with the boss (21), and the lower end plug positioning part (22) is provided with a receiving hole for accommodating the lower end plug (400).

4. The manufacturing process for the secondary neutron source rod as described in claim 1, characterized in that, The assembly of the inner tube section (100) includes the following steps: Install the lower end cap (140), press the lower end cap (140) into the first end of the inner shell tube (110) and perform circumferential welding; Insert the antimony-beryllium core block (120) into the inner casing tube (110) after the lower end cap (140) is installed; Install the upper end cap (130), press the upper end cap (130) into the second end of the inner shell tube (110) and perform circumferential welding; The upper end cap (130) is helium-filled and plugged with welding.

5. The secondary neutron source rod manufacturing process as described in claim 4, characterized in that, The specific steps of loading the antimony-beryllium core block (120) include: The inner casing tube (110) with the lower end cap (140) installed is inserted into the secondary neutron source glove box, and multiple antimony-beryllium core blocks (120) are inserted into the inner casing tube (110).

6. The secondary neutron source rod manufacturing process as described in claim 4, characterized in that, The steps for installing the lower end cap (140) specifically include: The lower end cap (140) is pressed and plugged. The lower end cap (140) is installed on the lower end cap pressing and plugging fixture (10). The lower end cap pressing and plugging fixture (10) is installed on the pressing and plugging device. The inner shell tube (110) is clamped by the clamping device. The lower end cap (140) is pressed and plugged into the first end of the inner shell tube (110) using the pressing and plugging device. The lower end cap (140) is circumferentially welded. After the lower end cap (140) is pressed into the inner shell tube (110), the circumferential weld between the lower end cap (140) and the inner shell tube (110) is welded using welding equipment.

7. The secondary neutron source rod manufacturing process as described in claim 6, characterized in that, The lower end cap plugging tool (10) is detachably connected to the plugging device.

8. The secondary neutron source rod manufacturing process as described in claim 7, characterized in that, The lower head plug tooling (10) includes: The screw (11) and the push rod of the plugging device have a threaded hole that mates with the screw (11); The lower end cap positioning part (12) is connected to the screw (11), and the lower end cap positioning part (12) is provided with a lower end cap positioning hole (121).

9. The secondary neutron source rod manufacturing process as described in claim 4, characterized in that, The specific steps for plugging and welding the upper end cap (130) include: The inner shell tube (110) with the upper end cap (130) installed is installed on the upper end cap helium-filled plugging welding fixture (30). The upper end cap helium-filled plugging welding fixture (30) is installed in the welding chamber (01) of the plugging welding equipment. The welding chamber (01) is evacuated and filled with helium at a second preset pressure. The upper end cap (130) is then helium-filled plugging welding is performed. The second preset pressure is less than the first preset pressure.

10. The manufacturing process for the secondary neutron source rod as described in any one of claims 1-9, characterized in that, Both the inner casing tube (110) and the outer casing tube (200) are made of stainless steel.

Images