An underwater storage container for the sleeve screws on the upper tube seat of a fuel assembly

Abstract

The present invention relates to the field of nuclear power maintenance technology, and specifically discloses an underwater storage container for sleeve screws on the upper tube seat of a fuel assembly. An underwater storage container for sleeve screws on the upper tube seat of a fuel assembly, the container comprises an extension rod, a storage tank and a support frame, wherein a support frame is provided at the lower end of the extension rod, and the storage tank can be supported and arranged on the support frame; the storage tank comprises a cover plate and a tank body, the tank body is supported and fixed on the support frame, the cover plate is arranged at the upper end of the tank body, and a trumpet mouth with a larger upper part and a smaller lower part is provided on the cover plate, and a short groove is opened at one end on one side of the trumpet mouth, and the size of the groove is larger than the outer diameter of the head of the existing upper tube seat sleeve screw removal tool and smaller than the size of the upper tube seat sleeve screw. An underwater storage container for sleeve screws on the upper tube seat of a fuel assembly described in the present invention can realize the long-term storage of old sleeve screws underwater, and the storage tank can be replaced, and the screws can be ensured to fall into the storage tank by using a large-mouth in and a small-mouth out method.

Description

Technical Field

[0001] The invention belongs to the technical field of nuclear power maintenance, and in particular relates to an underwater storage container for sleeve screws on a tube seat of a fuel assembly. Background Art

[0002] During the single-rod replacement and repair process of a damaged fuel assembly, the upper tube seat sleeve screw of the fuel assembly needs to be removed to remove the upper tube seat of the fuel assembly. The upper tube seat sleeve screw cannot be reused after removal. At the same time, due to its certain radioactivity, a special container is required to achieve its long-term storage underwater. Summary of the invention

[0003] The purpose of the invention is to provide an underwater storage container for the sleeve screws of the upper tube seat of a fuel assembly, so as to solve the problem of storing the sleeve screws of the upper tube seat underwater.

[0004] The technical solution of the present invention is as follows: an underwater storage container for sleeve screws on a fuel assembly tube seat, the container comprising an extension rod, a storage tank and a support frame, wherein the lower end of the extension rod is provided with a support frame, and the storage tank can be supported and set on the support frame; the storage tank comprises a cover plate and a tank body, the tank body is supported and fixed on the support frame, the cover plate is set at the upper end of the tank body, and a trumpet mouth with a larger upper part and a smaller lower part is provided on the cover plate, and a short groove at one end is opened on one side of the trumpet mouth, and the size of the groove is larger than the outer diameter of the head of the existing upper tube seat sleeve screw removal tool and smaller than the size of the upper tube seat sleeve screw.

[0005] The tank body is a cylindrical structure, and a plurality of bosses are arranged on the outer wall of the tank body. The tank body is supported and fixed on the annular support frame by the plurality of bosses.

[0006] The support frame is a cylindrical structure with a certain height, and a plurality of "L"-shaped protrusion structures are provided at its upper end. The "L"-shaped protrusion structure includes an arc segment at the upper end and a vertical segment connected to one side of the arc segment. Grooves are provided on the support frame below the arc segment and on the side of the vertical segment. The boss on the storage tank can be matched and engaged in the groove of the "L"-shaped protrusion structure of the support frame.

[0007] The storage tank comprises a cover plate, a boss and a tank body, wherein the cover plate is fixed to the upper end of the tank body by a nut; the boss is distributed circumferentially on the outer side wall of the tank body and is on the same horizontal plane.

[0008] A positioning pin and a hook are arranged on the cover plate of the storage tank, and existing tools can transport the storage tank as a whole through the positioning pin and the hook.

[0009] The upper end of the extension rod is fixedly connected with a lifting ring, and the extension rod can be used to ensure that the storage tank is below the safety water shielding layer.

[0010] The storage tank is made of stainless steel with good corrosion resistance.

[0011] The side wall of the tank body in the storage tank is provided with a plurality of water flow holes, and the size of the water flow holes is smaller than the size of the sleeve screw of the upper pipe seat.

[0012] The remarkable effect of the present invention is that the underwater storage container for the sleeve screws of the upper tube seat of the fuel assembly described in the present invention can realize the long-term storage of old sleeve screws underwater, and the storage tank can be replaced. The method of large-mouth in and small-mouth out can ensure that the screws fall into the storage tank. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a schematic structural diagram of an underwater storage container for a sleeve screw of a fuel assembly upper tube seat according to the present invention;

[0014] Figure 2 It is a structural schematic diagram of a storage tank in an underwater storage container of a sleeve screw of an upper tube seat of a fuel assembly according to the present invention;

[0015] In the figure: 1. lifting ring; 2. extension rod; 3. storage tank; 4. support frame; 5. cover plate; 6. positioning pin; 7. nut; 8. hook; 9. boss; 10. tank body. DETAILED DESCRIPTION

[0016] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0017] like Figure 1 , Figure 2As shown, an underwater storage container for a sleeve screw on a tube seat of a fuel assembly comprises a lifting ring 1, an extension rod 2, a storage tank 3 and a support frame 4, wherein the upper end of the extension rod 2 is connected with the lifting ring 1, and the lower end of the extension rod 2 is fixedly connected to the annular support frame 4, and a plurality of grooves are provided on the support frame 4, and the storage tank 3 can be supported and fixed on the support frame 4 through a plurality of bosses 9 thereon, wherein the support frame 4 is a cylindrical structure with a certain height, and a plurality of "L"-shaped convex structures are distributed on its upper end, wherein the upper end of the convex structure is an arc segment, and forms an integral structure with the lower end cylinder through a vertical segment on one side, and grooves are opened on the cylinder wall of the support frame 4 below the arc segment and on the side of the vertical segment, and the circumferential positions of the plurality of bosses installed on the side wall of the storage tank 3 match the positions of the grooves on the support frame 4, and the storage tank 3 is placed on the support frame 4, and the storage tank 3 is rotated so that the boss 9 enters the "L"-shaped convex structure and matches The groove engaged with the support frame 4 realizes the stable installation of the storage tank 3 on the support frame 4; the storage tank 3 includes a cover plate 5, a boss 9, and a tank body 10, wherein the tank body 10 is a cylindrical structure, and its outer diameter is slightly smaller than the inner diameter of the support frame 4, and a plurality of bosses 9 are installed on the outer wall of the tank body 10 to match it with the groove on the support frame 4; a plurality of water flow holes are opened on the outer wall of the tank body 10, and the hole diameter is smaller than the size of the upper tube seat sleeve screw; the disc-shaped cover plate 5 is fixed to the upper end of the tank body 10 by a nut 7, and a positioning pin 6 and a hook 8 are fixedly installed on the cover plate 5, and the positioning pin 6 and the hook 8 can be used to realize the overall transportation of the storage tank 3 by using existing tools; a small upper and lower bell mouth is installed on the cover plate 5, and a short groove with a size smaller than the bell mouth is provided on one side of the bell mouth, wherein the size of the short groove is larger than the outer diameter of the head of the upper tube seat sleeve screw removal tool, but smaller than the size of the upper tube seat sleeve screw.

[0018] The specific working process of the underwater storage container for the upper tube seat sleeve screw of the fuel assembly described in the present invention is as follows: before use, the storage tank 3 is installed on the support frame 4, so that the boss 9 falls into the bayonet on the support frame 4,

[0019] Then, the device is transferred and installed at the working position through the lifting ring 1. The length of the extension rod 2 can ensure that the storage tank 3 is below the safe water shielding layer; the screw removal tool carries the upper tube seat sleeve screw that needs to be stored, enters from the bell mouth and moves out from the short slot next to it. Because the size of the sleeve screw is larger than the size of the short slot, it falls into the storage tank 3 at this time; when the storage volume of the storage tank 3 reaches a certain value, it can be replaced as a whole, and the device can be removed from the storage tank 3 as a whole through the cooperation between the special tool and the positioning pin 6 and the hook 8.

Claims

1. An underwater storage container for the sleeve screws of the upper tube seat of a fuel assembly, characterized in that: The container comprises an extension rod (2), a storage tank (3) and a support frame (4), wherein the lower end of the extension rod (2) is provided with a support frame (4), and the storage tank (3) can be supported and arranged on the support frame (4); the storage tank (3) comprises a cover plate (5) and a tank body (10), the tank body (10) is supported and fixed on the support frame (4), the cover plate (5) is arranged at the upper end of the tank body (10), and a trumpet mouth with a larger upper part and a smaller lower part is provided on the cover plate (5), and a short groove is opened on one side of the trumpet mouth, so that The size of the groove is larger than the outer diameter of the head of the existing upper tube seat sleeve screw removal tool and smaller than the size of the upper tube seat sleeve screw; the tank body (10) is a cylindrical structure, and a plurality of bosses (9) are provided on the outer wall of the tank body (10). The tank body (10) is supported and fixed on the annular support frame (4) by the plurality of bosses (9); the support frame (4) is a cylindrical structure with a certain height, and a plurality of "L"-shaped protrusion structures are provided at its upper end. The "L"-shaped protrusion structure includes a circular protrusion at the upper end. The arc segment and the vertical segment connected to one side of the circular segment are provided with grooves on the support frame (4) below the circular segment and on the side of the vertical segment; the boss (9) on the storage tank (3) can be matched and engaged in the groove of the "L"-shaped protrusion structure of the support frame (4); the storage tank (3) comprises a cover plate (5), a boss (9) and a tank body (10), and the cover plate (5) is fixed to the upper end of the tank body (10) by a nut (7); the boss (9) is distributed along the circumferential direction on the outer side wall of the tank body (10) and is on the same horizontal plane; a positioning pin (6) and a lifting hook (8) are provided on the cover plate (5) in the storage tank (3), and the existing tools can transfer the storage tank (3) as a whole through the positioning pin (6) and the lifting hook (8); a lifting ring (1) is fixedly connected to the upper end of the extension rod (2), and the storage tank (3) can be ensured to be below the safety water shielding layer by using the extension rod (2); a plurality of water flow holes are opened on the side wall of the tank body (10) in the storage tank (3), and the size of the water flow holes is smaller than the size of the upper tube seat sleeve screw.

2. The underwater storage container for the upper tube seat sleeve screw of a fuel assembly according to claim 1, characterized in that: The storage tank (3) is made of corrosion-resistant stainless steel.

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