Nuclear power plant irradiation oversight tube shield container anti-inversion stand

Abstract

The present application belongs to the field of nuclear power plant field maintenance technology, and particularly relates to a nuclear power plant irradiation supervision tube shielding container anti-inverted support, the lock block is an arc structure, two lock blocks are connected and fixed with the upper ring, the upper end of the upper ring is designed with two U-shaped grooves, the upper ring is welded and fixed with the lower ring through the support side plate, the lower ring is welded with one bottom support pipe in each of the four directions of 0 DEG, 90 DEG, 180 DEG and 270 DEG, there are four bottom support pipe extension rods in total, each bottom support pipe extension rod is composed of two round rods with different diameters, the outer surface of the smaller diameter round rod is designed with external threads near the larger diameter round rod, the smaller diameter round rod of the bottom support pipe extension rod is inserted into the bottom support pipe, and the outer surface of the upper ring is welded and fixed with the outer surfaces of the four bottom support pipes through four lateral support rods. The present application can effectively improve the stability and reliability of the vertical placement of the shielding container and solve the problem of vertical placement of the shielding container.

Description

Technical Field

[0001] This invention belongs to the field of nuclear power plant on-site maintenance technology, specifically relating to an anti-tipping support for the shielding container of a nuclear power plant irradiation monitoring tube. It is used to support the vertical placement of the shielding container when the irradiation monitoring tube of the reactor pressure vessel is removed during a nuclear power plant refueling overhaul, preventing the shielding container from tipping over. Background Technology

[0002] During operation, reactor pressure vessels are subjected to high temperatures, high pressures, fluid erosion, corrosion, and neutron irradiation, which cause a decrease in the toughness of the materials and an increase in the ductile-brittle transition temperature. If the operating temperature and pressure exceed the limits, sudden fracture can easily be induced. Therefore, by installing irradiation monitoring tubes in the reactor pressure vessel and conducting periodic sampling tests, the performance changes of the reactor pressure vessel materials are monitored.

[0003] Because the irradiation monitoring tube is highly radioactive, it must be placed in a specialized shielded container to reduce radiation risks. The shielded container is cylindrical in design and must be placed vertically before the irradiation monitoring tube can be inserted into it from directly above. Once vertically positioned, the shielded container must be equipped with anti-tipping supports to prevent it from tipping over during placement without hoisting or other securing measures.

[0004] The existing anti-tipping supports for the irradiation monitoring tube shielding container of nuclear power plants are installed using bolts and clamps. The clamps are fixed to the shielding container by pressure and friction with the outer surface of the shielding container. This method has poor stability, and problems such as support slippage and bolt seizing occur. In addition, the anti-tipping performance is poor, which affects the smooth progress of on-site overhaul work at nuclear power plants.

[0005] Therefore, it is necessary to develop a new anti-tipping support for the shielded container of the nuclear power plant irradiation monitoring tube to solve the problems of poor stability of the anti-tipping support and the tipping of the shielded container. Summary of the Invention

[0006] The purpose of this invention is to provide an anti-tipping support for the shielding container of the nuclear power plant irradiation monitoring tube, which can effectively improve the stability and reliability of the shielding container when placed vertically and solve the problem of vertical placement of the shielding container.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] A tipping prevention support for a nuclear power plant irradiation monitoring tube shielding container is provided. The locking blocks have an arc-shaped structure, and two locking blocks are connected and fixed to an upper ring. The upper end of the upper ring is designed with two U-shaped grooves. The upper ring is welded to the lower ring through a support side plate. A bottom support tube is welded to the lower ring at four directions: 0°, 90°, 180°, and 270°. There are four extension rods for the bottom support tubes. Each extension rod consists of two round rods of different diameters. The outer surface of the smaller diameter round rod is designed with external threads near the larger diameter round rod. The smaller diameter round rod is inserted into the bottom support tube. The outer surface of the upper ring is welded to the outer surface of the four bottom support tubes through the four lateral support rods.

[0009] Each locking block is connected and fixed to the upper ring by two bolts on both sides.

[0010] The two U-shaped grooves of the upper ring are fixed to the two shielding container lifting lugs.

[0011] The upper ring has four bolt holes with internal threads for fixing bolts.

[0012] The upper ring is fixed to the lower ring by welding through six bracket side plates.

[0013] The bottom support tube is a hollow pipe structure.

[0014] The pipe at the outer end of the bottom support tube has internal threads.

[0015] The extended rod of the bottom support tube is a round rod structure.

[0016] The smaller diameter round rod of the bottom support tube extension rod is inserted into the bottom support tube and fixed by threaded connection.

[0017] Insert the four bottom support tube extension rods into the four bottom support tubes and tighten them; remove the four bolts and take off the two locking blocks; place the assembled anti-tipping bracket horizontally on the operating platform; use the reactor building's ring crane to vertically lift the shielding container, and place the shielding container vertically into the anti-tipping bracket from directly above the upper ring; align the shielding container's lifting lugs with the U-shaped groove of the upper ring and insert it; install the two locking blocks and secure them with four bolts; the anti-tipping bracket installation of the shielding container is complete; lift the shielding container to the designated position, loosen the ring crane, carry out the irradiation monitoring tube extraction work, and insert the irradiation monitoring tube into the container; then use the ring crane to lift the shielding container to the operating platform; remove the four bolts and take off the two locking blocks, lift the shielding container vertically, lay it horizontally, and pack it for sealing; reinstall the four bolts and two locking blocks on the upper ring, remove the four bottom support tube extension rods, pack it for sealing, and the work is completed.

[0018] The beneficial effects achieved by this invention are as follows:

[0019] This invention improves the stability and reliability of vertically placed irradiation monitoring tube shielding containers, solving the problem of easy tipping when placed vertically. The anti-tipping bracket is simple and quick to install, and can be pre-assembled and placed on the operating platform, effectively saving overhaul time. The anti-tipping bracket is entirely made of stainless steel, with a simple structure, easy to manufacture, maintain, and clean. It will not pollute the water in the in-core component pool during use, while effectively reducing the risk of foreign objects. Attached Figure Description

[0020] Figure 1 Front view of the support frame to prevent tipping;

[0021] Figure 2 Top view of the support structure to prevent tipping;

[0022] Figure 3 Schematic diagram of the extension rod for the bottom support tube;

[0023] Figure 4 This is a schematic diagram of a shielding container;

[0024] In the diagram: 1—locking block, 2—bolt, 3—upper ring, 4—bracket side plate, 5—lateral support rod, 6—lower ring, 7—bottom support tube, 8—bottom support tube extension rod, 9—shielding container, 10—shielding container lifting lug. Detailed Implementation

[0025] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0026] like Figure 1-3 As shown, the present invention provides an anti-tipping support for a nuclear power plant irradiation monitoring tube shielding container, comprising: a locking block 1, a bolt 2, an upper ring 3, a support side plate 4, a lateral support rod 5, a lower ring 6, a bottom support tube 7, and a bottom support tube extension rod 8. All components are made of stainless steel.

[0027] The locking block 1 has an arc-shaped structure, and there are two of them. Each locking block 1 is connected and fixed to the upper ring 3 by two bolts 2 on both sides.

[0028] The upper end of the upper ring 3 is designed with two U-shaped grooves for fixing to the two shielding container lifting lugs 10; the upper ring 3 is designed with four bolt holes with internal threads for fixing bolts 2; the upper ring 3 is welded to the lower ring 6 through six bracket side plates 4.

[0029] A bottom support tube 7 is welded to each of the four directions of 0°, 90°, 180° and 270° of the lower ring 6; there are a total of 4 bottom support tubes 7. The bottom support tubes 7 are hollow pipe structures, and the pipes at the outer ends of the bottom support tubes 7 are designed with internal threads.

[0030] The bottom support tube extension rod 8 is a round rod structure, with a total of 4 rods; each bottom support tube extension rod 8 consists of 2 round rods of different diameters, and the outer surface of the smaller diameter round rod has an external thread near the larger diameter round rod; the round rod with the smaller diameter can be inserted into the bottom support tube 7 and fixed by threaded connection.

[0031] The outer surface of the upper ring 3 is welded and fixed to the outer surface of the four bottom support tubes 7 by four lateral support rods 5.

[0032] When a nuclear power plant needs to remove the irradiation monitoring tube from the reactor pressure vessel during a refueling overhaul, this anti-tipping bracket is used to support the vertical placement of the shielding vessel.

[0033] 1) Insert the four bottom support tube extension rods 8 into the four bottom support tubes 7 respectively and tighten them; remove the four bolts 2 on the anti-tipping bracket and take off the two locking blocks 1; place the assembled anti-tipping bracket horizontally on the operating platform.

[0034] 2) Use the ring crane of the reactor building to vertically lift the shielding container 9. Place the shielding container 9 vertically into the anti-tipping bracket from directly above the anti-tipping bracket, that is, directly above the upper ring 3. Align the lifting lug 10 of the shielding container with the U-shaped groove of the upper ring 3 and insert it. Install two locking blocks 1 and fix them with four bolts 2. The anti-tipping bracket installation of the shielding container 9 is completed.

[0035] 3) Hoist the shielding container 9 to the designated position, loosen the ring crane, carry out the irradiation monitoring tube extraction work, and put the irradiation monitoring tube into the container. Then use the ring crane to hoist the shielding container 9 to the operating platform.

[0036] 4) Remove the 4 bolts 2, take off the 2 locking blocks 1, lift the shielding container 9 vertically, lay it horizontally, and pack it up.

[0037] 5) Reinstall the 4 bolts and 2 locking blocks on the upper ring 3, remove the 4 bottom support tube extension rods 8, pack and seal them, and the work is finished.

[0038] After assembly, the anti-tipping bracket is installed on the shielding container 9. It is secured to the shielding container's lifting lugs 10 via a U-shaped groove structure and further fixed by locking blocks 1, ensuring a secure bond between the anti-tipping bracket and the shielding container 9 and preventing slippage. This solves the problem of easy slippage in existing anti-tipping brackets. The anti-tipping bracket contacts the ground via a bottom support tube 7 and an extended bottom support tube 8, providing strong support and preventing the shielding container from tipping over. The extended bottom support tube 8 further increases the support area with the ground, improving the anti-tipping performance. Except for the locking blocks 1, bolts 2, and the extended bottom support tube 8, all other components of the anti-tipping bracket are welded together, resulting in high overall strength and good stability. The locking blocks 1, bolts 2, and extended bottom support tube 8 are easy to install, effectively addressing the challenges of overhauling. The extended bottom support tube 8 can be installed when needed and removed when not in use, facilitating the transport and storage of the anti-tipping bracket within the nuclear power plant.

Claims

1. A tipping-proof support for a shielding container of a nuclear power plant irradiation monitoring tube, characterized in that: The locking blocks have an arc-shaped structure. The two locking blocks are connected and fixed to the upper ring. The upper end of the upper ring is designed with two U-shaped grooves. The upper ring is welded to the lower ring through the bracket side plate. A bottom support tube is welded to the lower ring in four directions: 0°, 90°, 180°, and 270°. There are four bottom support tube extension rods in total. Each bottom support tube extension rod consists of two round rods of different diameters. The outer surface of the smaller diameter round rod is designed with external threads near the larger diameter round rod. The round rod with the smaller diameter is inserted into the bottom support tube. The outer surface of the upper ring is welded to the outer surface of the four bottom support tubes through the four lateral support rods.

2. The anti-tipping support for the shielded container of the nuclear power plant irradiation monitoring tube according to claim 1, characterized in that: Each locking block is connected and fixed to the upper ring by two bolts on both sides.

3. The anti-tipping support for the shielded container of the nuclear power plant irradiation monitoring tube according to claim 1, characterized in that: The two U-shaped grooves of the upper ring are fixed to the two shielding container lifting lugs.

4. The anti-tipping support for the shielded container of the nuclear power plant irradiation monitoring tube according to claim 1, characterized in that: The upper ring has four bolt holes with internal threads for fixing bolts.

5. The anti-tipping support for the shielded container of the nuclear power plant irradiation monitoring tube according to claim 1, characterized in that: The upper ring is fixed to the lower ring by welding through six bracket side plates.

6. The anti-tipping support for the shielded container of the nuclear power plant irradiation monitoring tube according to claim 1, characterized in that: The bottom support tube is a hollow pipe structure.

7. The anti-tipping support for the shielded container of the nuclear power plant irradiation monitoring tube according to claim 1, characterized in that: The pipe at the outer end of the bottom support tube has internal threads.

8. The anti-tipping support for the shielded container of the nuclear power plant irradiation monitoring tube according to claim 1, characterized in that: The extended rod of the bottom support tube is a round rod structure.

9. The anti-tipping support for the shielding container of the nuclear power plant irradiation monitoring tube according to claim 1, characterized in that: The smaller diameter round rod of the bottom support tube extension rod is inserted into the bottom support tube and fixed by threaded connection.

10. The anti-tipping support for the shielded container of the nuclear power plant irradiation monitoring tube according to claim 2, characterized in that: Insert the four bottom support tube extension rods into the four bottom support tubes and tighten them; remove the four bolts and take off the two locking blocks; place the assembled anti-tipping bracket horizontally on the operating platform; use the reactor building's ring crane to vertically lift the shielding container, and place the shielding container vertically into the anti-tipping bracket from directly above the upper ring; align the shielding container's lifting lugs with the U-shaped groove of the upper ring and insert it; install the two locking blocks and secure them with four bolts; the anti-tipping bracket installation of the shielding container is complete; lift the shielding container to the designated position, loosen the ring crane, carry out the irradiation monitoring tube extraction work, and insert the irradiation monitoring tube into the container; then use the ring crane to lift the shielding container to the operating platform; remove the four bolts and take off the two locking blocks, lift the shielding container vertically, lay it horizontally, and pack it for sealing; reinstall the four bolts and two locking blocks on the upper ring, remove the four bottom support tube extension rods, pack it for sealing, and the work is completed.

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