Container for transferring and storing control rod guide cylinder

Abstract

The invention belongs to the technical field of nuclear power station on-site maintenance, and particularly relates to a container for transferring and storing a control rod guide cylinder. Comprising a cover plate and a cylinder, and the cover plate is installed on the cylinder. The cover plate comprises an upper cover plate, a middle lead layer, a lower cover plate, a guide block and a lifting lug, the upper cover plate and the lower cover plate are welded together, the middle lead layer is poured in a cavity between the upper cover plate and the lower cover plate, the lifting lug is arranged at the top of the upper cover plate, and the guide block is arranged at the edge of the side wall of the upper cover plate. The invention has the beneficial effects that the lead layer is poured between the cylinder wall and the cover plate, so that the shielding effect is less than or equal to 2mSv / h, and the radiation dosage taken by operators is effectively reduced; through the upper guide cylinder limiting shaft, the lower guide cylinder limiting shaft and the I-shaped partition plate in the cylinder body, the guide cylinder assembly is effectively protected against radial movement.

Description

Technical Field

[0001] The invention belongs to the technical field of on-site maintenance of nuclear power plants, and in particular relates to a container for transporting and storing control rod guide cylinders. Background Art

[0002] The control rod guide tubes of a nuclear reactor's upper internals are critical components. They allow the reactor's control rod assembly to move up and down within them, providing guidance and positioning. The control rod guide tubes consist of two parts: an upper guide tube and a lower guide tube. These two parts are held together by upper and lower flanges and bolted to the upper internals support plate. When a guide tube fails or exhibits excessive wear, it must be completely replaced. In this case, a specialized storage container is required for the transport and storage of used control rod guide tubes. This device houses at least one set of control rod guide tubes, each equipped with internal guidance and securing features. Summary of the Invention

[0003] The purpose of the present invention is to provide a container for transporting and storing control rod guide cylinders, which is used for transporting and storing control rod guide cylinders after they are disassembled. The device can realize underwater guided loading of control rod guide cylinders, has drainage, sealing and effective radiation shielding functions, and is convenient for transport and on-site storage after being brought ashore.

[0004] The technical solution of the present invention is as follows: A container for transporting and storing control rod guide cylinders comprises a cover plate and a cylinder body, wherein the cover plate is mounted on the cylinder body.

[0005] The cover plate includes an upper cover plate, an intermediate lead layer, a lower cover plate, a guide block and a lifting lug. The upper cover plate and the lower cover plate are welded together, and the intermediate lead layer is poured in the cavity between the upper cover plate and the lower cover plate. A lifting lug is provided on the top of the upper cover plate, and a guide block is provided at the edge of the side wall of the upper cover plate.

[0006] The upper cover plate is a 10 mm thick stainless steel plate, and the lower cover plate is an 8 mm thick stainless steel plate.

[0007] The cylinder is made by welding an inner layer and an outer layer, both of which are rolled up from stainless steel plates, and a lead layer is poured into the cavity between the inner layer and the outer layer.

[0008] The interior of the cylinder is a cavity structure, a positioning seat is provided at the bottom, the bottom is connected to the upper guide cylinder positioning support seat, a guide port is provided in the middle, and an "I"-shaped inner partition is provided on the top.

[0009] The outer edge of the top of the cylinder is connected with a plurality of bolt seats.

[0010] The upper part of the outer wall of the cylinder is provided with a vertical lifting lug.

[0011] The outer wall surface of the cylinder is provided with a horizontal lifting lug.

[0012] A stacking support is provided on the outer side of the transfer cylinder on the outer wall of the cylinder, which is divided into an upper stacking support and a lower stacking support.

[0013] The bottom of the cylinder is provided with a drainage hole leading to the inner cavity of the cylinder.

[0014] The beneficial effects of the present invention are as follows: by pouring a lead layer between the cylinder wall and the cover plate, a shielding effect of ≤2mSv / h is achieved, effectively reducing the radiation dose ingested by the operating personnel; by the upper and lower guide cylinder limit shafts and the "I"-shaped partition in the cylinder body, the guide cylinder assembly is effectively protected from radial movement; a ball valve is installed through a hole leading to the cylinder at the bottom of the device to control the emptying of the radioactive medium (mainly boron-containing water) in the container; by arranging a stable base and a support at the bottom of the device, it is achieved that tipping and rolling will not occur during transportation, and the device can be placed horizontally and stacked on a transport vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 Schematic diagram of the cover;

[0016] Figure 2 This is a cross-sectional view of the interior of the transfer tube;

[0017] Figure 3 This is a schematic diagram of the exterior of the transfer cylinder;

[0018] Figure 4 Schematic diagram of the inner partition;

[0019] Figure 5 It is a schematic diagram of the positioning support seat;

[0020] Figure 6 Schematic diagram of the guide port and positioning seat;

[0021] Figure 7 Schematic diagram of the palletizing lower seat and the palletizing upper seat.

[0022] In the figure: 1 cover plate, 2 cylinder, 3 upper cover plate, 4 middle lead layer, 5 lower cover plate, 6 bolt seat, 7 guide block, 8 lifting lug, 9 outer layer, 10 inner layer, 11 guide mouth, 12 positioning seat, 13 positioning support seat, 14 inner partition, 15 middle stop, 16 vertical lifting lug, 17 stacking lower seat, 18 drainage hole, 19 stacking upper seat, 20 horizontal lifting lug, 21 support positioning plate, 22 support rod. DETAILED DESCRIPTION

[0023] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0024] A container for transporting and storing control rod guide cylinders has an overall cylindrical shape and comprises a cover plate 1 and a cylinder body 2.

[0025] like Figure 1 As shown, the cover plate 1 primarily serves to shield the upper and lower control rod guide cylinder assemblies from radiation and to hold them in place. The cover plate 1 comprises an upper cover plate 3, an intermediate lead layer 4, a lower cover plate 5, guide blocks 7, and lifting lugs 8. The upper cover plate 3 is constructed of 10 mm thick stainless steel, while the lower cover plate 5 is constructed of 8 mm thick stainless steel. The two are welded together. The intermediate lead layer 4 is poured into the cavity between the upper and lower cover plates to effectively shield against radiation.

[0026] like Figure 2 As shown, the cylinder 2 is welded from an inner layer 10 and an outer layer 9. The outer layer 9 is rolled from 10mm thick stainless steel sheet, while the inner layer 10 is rolled from 8mm thick stainless steel sheet. The cavity between the inner and outer layers is cast with a lead layer to effectively shield radiation. Six bolt seats 6 are evenly spaced along the top outer edge of the cylinder 2.

[0027] Cover plate 1 is aligned with cylinder 2 via intermediate stop 15, a boss machined onto cylinder 2. Guide blocks 7 are provided on the outer circumference of cover plate 1, aligning circumferentially with evenly spaced key pins on cylinder 2 to ensure alignment between the six bolt pads 6 of cover plate 1 and cylinder 2. The cover plate 1 and cylinder 2 are ultimately secured together with six bolts, and two rubber seals are placed between them to ensure safe and reliable transportation.

[0028] The cylinder 2 can store a set of control rod guide cylinder assemblies (including upper and lower control rod guide cylinder assemblies), and the upper and lower guide cylinder assemblies are separated by an "I" shaped inner partition 14. Figure 4 As shown, an I-shaped inner partition 14 is welded to the upper inner wall of the cylinder 2. When the entire device is placed horizontally, the inner partition 14 effectively separates the upper and lower guide cylinder assemblies to prevent them from moving radially. The upper guide cylinder is mounted and fixed on the upper guide cylinder positioning support seat 13.

[0029] like Figure 5 As shown, a support and positioning plate 21 is welded to the lower part of the cylinder 2, and a positioning rod 22 is connected to the lower part of the support and positioning plate 21. A circular hole is opened on the support and positioning plate 21, and a trumpet-shaped guide port 11 is provided outside the circular hole. The aperture thereof matches the outer diameter of the lower guide cylinder, as shown in FIG. Figure 6 As shown, the guide opening 11 and positioning seat 12 are welded to the interior of the transfer cylinder 2. The lower guide cylinder passes through the guide opening 11 and is installed in place on the positioning seat 12. The positioning support seat 13 of the upper guide cylinder is welded to the support positioning plate 21. The cover plate is closed, and its lower side presses against the upper surfaces of the upper and lower guide cylinder assemblies, securing the guide cylinder assemblies within the storage cylinder.

[0030] like Figure 2As shown, a drain hole 18 leading to the inner cavity of the cylinder is provided at the bottom of the cylinder. A ball valve is installed at the hole to control the draining of the radioactive medium (primarily boron-containing water) from the container. Three vertical lifting lugs 16 are evenly spaced 120° above the outer wall of the cylinder for lifting the transfer cylinder from the pool. Horizontal lifting lugs 20 are arranged vertically on the outer side of the transfer cylinder 2 to level the upright transfer cylinder for easy transportation and storage.

[0031] like Figure 7 As shown, the outer side of the transfer cylinder is also equipped with stacking supports, which are divided into an upper stacking support 19 and a lower stacking support 17. The upper stacking support 19 and the lower stacking support 17 are symmetrically arranged on the outer side of the cylinder body 2. The lower stacking support 17 has a square groove, and the upper stacking support 19 has a square boss. The square groove and the square boss ensure a tight fit during stacking, ensuring that abnormal situations such as tipping and rolling will not occur during transportation, thus ensuring transportation safety.

[0032] The device has the following functions and features:

[0033] (1) There is a lead layer between the cylinder wall and the cover plate, which can achieve a better shielding radiation effect for the container behind the upper and lower guide cylinder assemblies;

[0034] (2) A guiding and fixing device is provided inside the equipment to guide and fix the control rod guide cylinder assembly;

[0035] (3) Stainless steel is used as the material for the inner and outer shells, which is corrosion-resistant and easy to clean;

[0036] (4) The thickened lead layer of the shell ensures that the radiation level is ≤2mSv / h;

[0037] (5) A drain device for draining the radioactive medium (mainly boron-containing water) inside the container is provided at the bottom of the equipment, which is easy to operate;

[0038] (6) The bottom of the device is equipped with a stable base, which will not tip over or roll over during storage and subsequent transportation. At the same time, there are supports on both sides, which can be placed horizontally or stacked on the transport vehicle.

Claims

1. A container for transporting and storing control rod guide cylinders, characterized by: It includes a cover plate and a cylinder body, wherein the cover plate is installed on the cylinder body; The cover plate includes an upper cover plate, an intermediate lead layer, a lower cover plate, a guide block and a lifting lug. The upper cover plate and the lower cover plate are welded together. The intermediate lead layer is poured into the cavity between the upper cover plate and the lower cover plate. The top of the upper cover plate is provided with a lifting lug, and the side wall edge of the upper cover plate is provided with a guide block. The cylinder is made by welding an inner layer and an outer layer, both of which are rolled up from stainless steel plates, and a lead layer is poured into the cavity between the inner layer and the outer layer.

2. A container for transporting and storing control rod guide cylinders according to claim 1, characterized in that: The upper cover plate is a 10 mm thick stainless steel plate, and the lower cover plate is an 8 mm thick stainless steel plate.

3. A container for transporting and storing control rod guide cylinders according to claim 1, characterized in that: The interior of the cylinder is a cavity structure, a positioning seat is provided at the bottom, the bottom is connected to the upper guide cylinder positioning support seat, a guide port is provided in the middle position, and an "I"-shaped inner partition is provided on the top.

4. A container for transporting and storing control rod guide cylinders according to claim 1, characterized in that: The outer edge of the top of the cylinder is connected with a plurality of bolt seats.

5. The container for transporting and storing control rod guide cylinders according to claim 1, characterized in that: The upper part of the outer wall of the cylinder is provided with a vertical lifting lug.

6. The container for transporting and storing control rod guide cylinders according to claim 1, characterized in that: The outer wall surface of the cylinder is provided with a horizontal lifting lug.

7. The container for transporting and storing control rod guide cylinders according to claim 1, characterized in that: A stacking support is provided on the outer side of the transfer cylinder on the outer wall of the cylinder, which is divided into an upper stacking support and a lower stacking support.

8. The container for transporting and storing control rod guide cylinders according to claim 1, characterized in that: The bottom of the cylinder is provided with a drainage hole leading to the inner cavity of the cylinder.

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