A CANDU heavy water reactor end face radiation shielding device

Abstract

The present invention discloses a CANDU heavy water reactor end face radiation shielding device, comprising a fuel channel pipe connecting portion and a shielding layer. The fuel channel pipe connecting portion is cylindrical, and the shielding layer is a square flat plate. The shielding layer is fixedly installed at one end of the fuel channel pipe connecting portion. The shielding layer has fitting surfaces on all four sides. One fitting surface of the shielding layer of one shielding device can be seamlessly fitted with another fitting surface of the shielding layer of another shielding device. By mutually splicing individual shielding bodies, overall shielding of the reactor end face is achieved. The shielding device has a simple structure, and workers can quickly complete installation or disassembly without special training, which can effectively reduce labor cost expenditure and reduce safety hazards caused by human errors.

Description

Technical Field

[0001] The present invention relates to the technical field of nuclear radiation protection, and in particular to a CANDU heavy water reactor end face radiation shielding device. Background Art

[0002] The CANDU heavy water reactor, a pressurized tube reactor, features a horizontal core and continuous fuel refueling. Nuclear fuel enters and exits the core through the reactor's end faces, resulting in high radiation dose rates at these locations. Workers working in close proximity to the reactor's end faces for tasks such as replacing feeders, inspecting and measuring reactor channels, and replacing individual fuel channels must maintain prolonged proximity to the reactor's end faces. Therefore, temporary shielding measures are necessary to reduce radiation dose rates in these locations, protect workers, and minimize collective exposure.

[0003] The current temporary shielding method is to use scaffolding to hang lead blankets to shield radiation hotspots and reactor end faces. However, hanging lead blankets has disadvantages such as difficulty in forming comprehensive shielding of the reactor end faces, unsatisfactory overall shielding effects, and high installation doses. In addition, the scaffolding takes up a large space, and temporary dismantling and reinstallation is extremely inconvenient and requires the coordination of multiple trades, which is time-consuming. In addition, the temporary shielding body occupies a large area of ​​the passage at the work site and needs to be dismantled in a timely manner after the work is completed, which is very inconvenient. There are also unstable safety factors, which pose a safety hazard to personnel or equipment. Summary of the Invention

[0004] In response to the deficiencies in the prior art, the present invention aims to provide a CANDU heavy water reactor end face radiation shielding device that can effectively shield radiation from the end face of a pressure tube CANDU heavy water reactor, significantly reduce the radiation dose rate at the work site, and reduce the individual dose of workers and the collective dose of workers in the area.

[0005] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0006] To solve the above-mentioned technical problems, the present invention provides a CANDU heavy water reactor end face radiation shielding device, comprising a fuel channel pipe connection portion and a shielding layer. The fuel channel pipe connection portion is cylindrical, and the shielding layer is a square flat plate. The shielding layer is fixedly installed at one end of the fuel channel pipe connection portion. The shielding layer has a bonding surface on all four sides. One bonding surface of the shielding layer of one shielding device can be seamlessly bonded with another bonding surface of the shielding layer of another shielding device.

[0007] Furthermore, the shielding layer includes a connecting layer and a metal layer, the metal layer is mounted on the connecting layer, and the connecting layer is mounted on one end of the connecting portion of the fuel channel pipe.

[0008] Furthermore, the shielding layer further includes a protective layer, which is installed on a side of the metal layer facing away from the connecting layer.

[0009] Furthermore, the fuel channel pipe connecting portion, the connecting layer and the protective layer are made of engineering plastics.

[0010] Furthermore, the CANDU heavy water reactor end face radiation shielding device further includes a handle, which is installed on a side of the protective layer facing away from the metal layer.

[0011] Furthermore, the material of the metal layer is one of lead, lead alloy, depleted uranium or metal tungsten.

[0012] Furthermore, the fitting surface is perpendicular to the connection surface between the shielding layer and the fuel channel pipe connection portion.

[0013] Furthermore, the fitting surface is arranged at an angle to the connection surface of the shielding layer and the fuel channel pipe connection portion.

[0014] Furthermore, the bonding surface is a stepped surface.

[0015] Furthermore, the fuel channel pipe connecting portion is a cylindrical tube.

[0016] The beneficial effects of the present invention are as follows: a CANDU heavy water reactor end face radiation shielding device provided by the present invention has a fuel channel pipe connection portion that is cylindrical and can be connected to the nuclear fuel channel pipe at the reactor end face; the shielding layer is a square flat plate that is convenient for splicing; the shielding layer is fixedly installed at one end of the fuel channel pipe connection portion; the shielding layer has fitting surfaces on all four sides; one fitting surface of the shielding layer of one shielding device can be seamlessly fitted with another fitting surface of the shielding layer of another shielding device; the overall shielding of the reactor end face is achieved by splicing individual shielding bodies together; the shielding device has a simple structure; staff can quickly complete installation or disassembly without special training, which can effectively reduce labor cost expenditure and reduce safety hazards caused by human errors. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a schematic diagram of the splicing structure of the CANDU heavy water reactor end face radiation shielding device provided in Example 1 of the present invention.

[0018] Figure 2 for Figure 1 Schematic diagram of the enlarged structure at A in the middle;

[0019] Figure 3 This is a schematic structural diagram of the CANDU heavy water reactor end face radiation shielding device provided in the second embodiment of the present invention;

[0020] Figure 4 This is a schematic structural diagram of the CANDU heavy water reactor end face radiation shielding device provided in the third embodiment of the present invention;

[0021] Figure 5 This is a schematic diagram of the splicing structure of the CANDU heavy water reactor end face radiation shielding device provided in Example 3 of the present invention. DETAILED DESCRIPTION

[0022] The present invention will be further described in detail below with reference to the accompanying drawings and specific implementations.

[0023] Example 1

[0024] like Figure 1 and Figure 2 As shown, a CANDU heavy water reactor end face radiation shielding device in this embodiment includes a fuel channel pipe connection portion 1 and a shielding layer 2. The fuel channel pipe connection portion 1 is cylindrical with an inner diameter of 10 to 16 cm and a wall thickness of 0.3 to 0.8 cm. The fuel channel pipe connection portion 1 is made of engineering plastic. In this embodiment, the fuel channel pipe connection portion 1 is a cylindrical tube, but other cross-sectional shapes can also be used according to actual needs. The shielding layer 2 in this embodiment is a square flat plate, fixedly mounted at one end of the fuel channel pipe connection portion 1. The shielding layer 2 has a mating surface on all four sides. One mating surface of the shielding layer 2 of one shielding device can seamlessly mate with the other mating surface of the shielding layer 2 of another shielding device. It is worth noting that in this embodiment, the mating surfaces are stepped surfaces. That is, when in use, the shielding layers 2 of the two shielding devices are connected by a stepped splicing method, which effectively avoids gaps.

[0025] Furthermore, the shielding layer 2 of this embodiment includes a connecting layer 21, a metal layer 22 and a protective layer 23. The metal layer 22 is installed on the connecting layer 21, and the connecting layer 21 is installed on one end of the fuel channel pipe connection part 1. The material of the connecting layer 21 is also engineering plastic. The function of the connecting layer 21 is to fix the metal layer 22 and the fuel channel pipe connection part 1 together, and to prevent the metal layer 22 from colliding with instruments and equipment. The thickness of the connecting layer 21 is usually 0.3 to 0.5 cm. The material of the metal layer 22 of this embodiment is lead. Of course, one of the materials such as lead alloy, depleted uranium or metal tungsten can also be used according to actual needs. The function of the metal layer 22 is mainly to shield the gamma rays generated by the radioactive source. The thickness of the metal shielding layer can be set according to the actual shielding requirements. The thickness of the metal shielding layer of this embodiment can achieve a lead equivalent shielding effect of 1.5 cm. The entire shielding block is a 30*30 cm square design, and the weight of a single shielding device is less than 16 kg. Protective layer 23 is attached to the side of metal layer 22 facing away from connection layer 21. Protective layer 23 protects the metal shielding block and is typically 0.1 to 0.3 mm thick. It is also made of engineering plastic, though other suitable materials can be used as needed. It is worth noting that in this embodiment, connection layer 21, metal layer 22, and protective layer 23 are secured together by bolts.

[0026] Furthermore, the CANDU heavy water reactor end face radiation shielding device further includes a handle, which is mounted on the side of the protective layer 23 facing away from the metal layer 22. The handle facilitates the installation, disassembly and transportation of the CANDU heavy water reactor end face radiation shielding device.

[0027] Example 2

[0028] As another embodiment of the present invention, Figure 3 As shown, unlike the first embodiment, the contact surface of this embodiment is perpendicular to the connection surface between the shielding layer 2 and the fuel channel pipe connection portion 1. That is, when in use, the shielding layers 2 of the two shielding devices are side by side and abut each other. There is a gap between the shielding layers 2 of the two shielding devices, but the two matching shielding devices have the same structure, which facilitates processing and installation.

[0029] Example 3

[0030] As another embodiment of the present invention, Figure 4 and Figure 5 As shown, unlike the first embodiment, the contact surface of this embodiment is angled with the connection surface between the shielding layer 2 and the fuel channel pipe connection portion 1. That is, when in use, the contact surface between the shielding layers 2 of the two shielding devices is an inclined surface, and when installed, the two contact surfaces are connected without a gap.

[0031] The device of the present invention is not limited to the embodiments in the specific implementation manner. As long as a person skilled in the art can derive other implementation manners based on the technical solution of the present invention, they also fall within the scope of technical innovation and protection of the present invention.

Claims

1. A CANDU heavy water reactor end face radiation shielding device, characterized in that: The invention comprises a fuel channel pipe connection part and a shielding layer. The fuel channel pipe connection part is cylindrical, with an inner diameter of 10 to 16 cm and a wall thickness of 0.3 to 0.8 cm. It can be connected to the nuclear fuel channel pipe at the end face of the reactor. Workers can quickly complete installation or disassembly without special training, effectively reducing labor cost expenditure and reducing safety hazards caused by human errors. The shielding layer is a square flat plate. The shielding layer is fixedly installed at one end of the fuel channel pipe connection part. The shielding layer has fitting surfaces on all four sides. One fitting surface of the shielding layer of one shielding device can be seamlessly fitted with another fitting surface of the shielding layer of another shielding device.

2. The CANDU heavy water reactor end face radiation shielding device according to claim 1, characterized in that: The shielding layer includes a connecting layer and a metal layer. The metal layer is installed on the connecting layer. The connecting layer is installed on one end of the fuel channel pipe connecting portion.

3. The CANDU heavy water reactor end face radiation shielding device according to claim 2, characterized in that: The shielding layer further includes a protective layer, which is installed on a side of the metal layer facing away from the connecting layer.

4. The CANDU heavy water reactor end face radiation shielding device according to claim 3, characterized in that: The fuel channel pipe connecting portion, the connecting layer and the protective layer are made of engineering plastic.

5. The CANDU heavy water reactor end face radiation shielding device according to claim 3, characterized in that: The invention also includes a handle, which is installed on a side of the protective layer facing away from the metal layer.

6. The CANDU heavy water reactor end face radiation shielding device according to any one of claims 2 to 5, characterized in that: The material of the metal layer is one of lead, lead alloy, depleted uranium or metal tungsten.

7. The CANDU heavy water reactor end face radiation shielding device according to any one of claims 1 to 5, characterized in that: The affixed surface is perpendicular to a connection surface between the shielding layer and the fuel channel pipe connection portion.

8. The CANDU heavy water reactor end face radiation shielding device according to any one of claims 1 to 5, characterized in that: The fitting surface is arranged at an angle to a connection surface between the shielding layer and the fuel channel pipe connection portion.

9. The CANDU heavy water reactor end face radiation shielding device according to any one of claims 1 to 5, characterized in that: The fitting surface is a stepped surface.

10. The CANDU heavy water reactor end face radiation shielding device according to any one of claims 1 to 5, characterized in that: The fuel channel pipe connecting portion is a cylindrical tube.

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