CN111667939A

CN111667939A - Reactor core assembly and system for producing carbon-14 isotopes

Info

Publication number: CN111667939A
Application number: CN202010425657.8A
Authority: CN
Inventors: 党宇; 陈向阳; 韩宇; 汤春桃; 卢俊强; 付亚茹
Original assignee: Shanghai Nuclear Engineering Research and Design Institute Co Ltd
Current assignee: Shanghai Nuclear Engineering Research and Design Institute Co Ltd
Priority date: 2020-05-19
Filing date: 2020-05-19
Publication date: 2020-09-15

Abstract

The invention provides a reactor core assembly and a system for producing carbon-14 isotopes, the reactor core assembly comprises rods (2, 4) of a cladding structure, cladding tubes (6) are arranged in the rods (2, 4), the cladding tubes (6) cover sealing targets (8) or targets (17), two ends of the cladding tubes (6) are sealed through end plugs (5, 9), and compression springs (7, 15) are arranged between the cladding tubes (6) and the sealing targets (8) or targets (17) and are used for compressing the sealing targets (8) or targets (17). The reactor core assembly is compatible with reactor internals, fuel assemblies and related operation tool interfaces of the pressurized water reactor nuclear power station, can be used for large pressurized water reactor nuclear power stations, has the capacity of loading a large amount of targets, and can flexibly allocate the loading capacity according to actual needs.

Description

Reactor core assembly and system for producing carbon-14 isotopes

Technical Field

The invention relates to the field of in-core components, in particular to the field of carbon-14 isotope production by core operation.

Background

Carbon-14 is a radioactive isotope of carbon, and carbon-14 is used in many applications, such as plant drug research (molecular labeling) in environmental protection, animal drug research in drug development, and biological labeling in healthcare. Natural carbon-14 is very low in reserves and widely distributed in the atmosphere, animals and plants, and is therefore an indispensable way to utilize carbon-14 isotopes through artificial synthesis. Carbon-14 belongs to low-toxicity radioactive nuclide, and the technical feasibility of production and separation by utilizing nuclear power station irradiation is higher. The thermal neutron flux of the nuclear power station is high but not effectively used, and the in-reactor free neutrons are used for carbon-14 industrial production, so that the carbon-14 market gap can be relieved, and the social benefit of the nuclear power station can be greatly increased.

At present, the carbon-14 isotope is produced internationally by adopting modes such as an accelerator or reactor irradiation and the like. For the reactor irradiation mode, as shown in fig. 1, the target material is usually wrapped in a target cylinder, and the target cylinder is placed in the reactor for irradiation. This approach is typically applied to small reactors or pilot stacks with irradiation channels.

The invention discloses a target and a system for a large pressurized water reactor, wherein the assembly is in a rod bundle structure, and the head part is a connecting part and can be matched with an in-reactor component to position the assembly in the reactor. The lower part of the connecting part is connected with a plurality of rods, a target material for producing the carbon-14 isotope is placed in the rods, and the rod bundle of the rod bundle can be inserted into a guide pipe of a reactor fuel assembly and is irradiated when the reactor runs. The assembly comprises a plurality of rods in a single assembly, can be loaded with a large amount of target materials, is used for a large pressurized water reactor, and has the capability of producing the carbon-14 isotope in a large amount. Meanwhile, the number of the rods which are arranged in the nuclear power station can be flexibly adjusted according to the operation requirement of the nuclear power station, and the overlarge influence on the economy of the nuclear power station is avoided.

Disclosure of Invention

The invention aims to provide a core assembly and a system for producing carbon-14 isotopes, and the carbon-14 isotopes can be produced in a pressurized water reactor by using the core assembly.

The reactor core assembly comprises rods (2, 4) of a cladding structure, a cladding tube (6) is arranged in the rods (2, 4), the cladding tube (6) covers a sealing target (8), two ends of the cladding tube (6) are sealed through end plugs (5, 9), and compression springs (7, 15) are arranged between the cladding tube (6) and the sealing target (8) and used for compressing the sealing target (8).

Preferably, the cladding tube (6) is a cylindrical hollow tube, and the material of the cladding tube (6) is stainless steel, zirconium alloy or aluminum alloy.

Preferably, the end plug (5) is connected to the connecting member (1, 3) by a screw.

Preferably, the end plugs (9) are tapered to facilitate insertion of the neutron absorbing rods (2, 4) into the fuel assembly guide tubes.

Preferably, an inner cladding (11) is arranged in the cladding tube (6), the inner cladding (11) is a cylindrical hollow tube, and end plugs (10, 13) seal the inner cladding (11).

Preferably, the inner cladding (11) is made of stainless steel, zirconium alloy or aluminum alloy.

Preferably, the target (12) may Be a pellet, powder or flocculent AlN, Be₃N₂And Si₃N₄，Ca(NO₃)₂And one or more of metallic and non-metallic materials.

Preferably, the compression springs (7, 15) are C-shaped springs or spiral springs.

A core assembly system for producing carbon-14 isotopes, wherein a plurality of core assemblies as claimed in claims 1-8 form a rod bundle structure through interfaces of fuel assemblies and reactor internals inserted by connecting parts (1, 3), and the connecting parts (1, 3) are used for realizing the operation of the core assemblies inside and outside a reactor and in spent fuel pools through handles or barrels.

Preferably, the shape of the connecting member (1, 3) is determined according to the interface between the fuel assembly to be inserted and the internals.

The reactor core assembly for producing the carbon-14 isotope is compatible with reactor internals, fuel assemblies and related operation tool interfaces of a pressurized water reactor nuclear power station, can be used for large pressurized water reactor nuclear power stations, has the capacity of loading a large amount of targets, and can flexibly allocate the loading capacity according to actual needs. The assembly is loaded in a pressurized water reactor nuclear power station, so that the preparation of the carbon-14 isotope in the pressurized water reactor can be realized, the yield of the carbon-14 isotope is improved, the supply problem of the carbon-14 isotope is favorably relieved, and the production cost of the carbon-14 isotope is reduced.

Drawings

FIG. 1 is a schematic view of a target construction;

FIG. 2 is a schematic view of a rod with a carbon-14 target material attached thereto 1;

FIG. 3 is a schematic view 2 of a rod loaded with a carbon-14 target material;

FIG. 4 is a schematic illustration of the containment structure;

FIG. 5 is a schematic view of a double-shelled structure;

FIG. 6 is a schematic view of a hold down spring;

wherein, 2 and 4 are rods, 1 and 3 are connecting parts, 8 is a sealing target material, 5 and 9 are end plugs, 6 is a cladding tube, 11 is an inner cladding, 14 and 18 are end plugs, 17 is a target material, and 7 and 15 are compression springs.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in further detail below.

The specific implementation mode of the reactor core assembly for producing the carbon-14 isotope is as follows:

as shown in fig. 2 and 3, a plurality of rods 2, 4 containing carbon 14 target material are connected into a rod bundle structure through connecting parts 1, 3, and the rods 2, 4 containing target material pass through small holes on the connecting parts. A handle or a cylinder for operation is arranged above the connecting part and is used for realizing the operation of the assembly inside and outside the stack and in the spent fuel pool.

The rods 2, 4 are of double-clad or single-clad construction. The double-cladding structure is shown in figure 4, and is formed by cladding a sealed target material 8 by a cladding tube 6, two ends of the double-cladding structure are sealed by end plugs 5 and 9, and a compression spring 7 is arranged on the double-cladding structure in order to prevent the sealed target material 8 from moving. The shape of the connecting members 1, 3 is determined according to the interface of the fuel assembly and the internals to be inserted.

The cladding tube 6 is a cylindrical hollow tube and is made of metals such as stainless steel, zirconium alloy, aluminum alloy and the like. The outside diameter of the cladding tube 6 is selected according to the outside diameter of the fuel assembly guide tube into which it is inserted. The end plugs 5 connected to the connecting members 1, 3 are provided with threads for fixing the rods 2, 4 to the connecting members 1, 3, but the rods 2, 4 may be connected to the connecting members 1, 3 in other ways. The lower end plug 9 is designed with a conical shape to facilitate insertion of the rods 2, 4 into the fuel assembly guide tubes.

The inner jacket 11 is also a cylindrical hollow tube made of metal such as stainless steel, zirconium alloy, aluminum alloy, and the like. The end plugs 10, 13 seal the inner envelope 11.

The target 12 may be in the form of pellets, powder, flakes, or the like. The material is AlN or Be₃N₂And Si₃N₄， Ca(NO₃)₂And a variety of metallic and non-metallic materials.

The purpose of the compression springs 7, 15 is to compress the target material and prevent the target material from moving during transportation, handling, etc. The compression springs 7, 15 may be C-shaped springs as shown in fig. 4 and 6, or helical springs may be used.

The foregoing embodiments are merely illustrative of the principles and utilities of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or change the above-mentioned embodiments without departing from the spirit and scope of the present invention. Accordingly, it is intended that all equivalent modifications or changes which can be made by those skilled in the art without departing from the spirit and technical spirit of the present invention be covered by the claims of the present invention.

Claims

1. The reactor core assembly for producing the carbon-14 isotope is characterized by comprising rods (2 and 4) of a cladding structure, wherein cladding tubes (6) are arranged in the rods (2 and 4), the cladding tubes (6) are coated with sealing targets (8) or directly coated with the targets (17), two ends of each cladding tube (6) are sealed through end plugs (5 and 9), and compression springs (7 and 15) are arranged between each cladding tube (6) and each target (17) or each sealing target (8) and used for compressing the targets (17) or each sealing target (8).

2. The core assembly for producing a carbon-14 isotope according to claim 1, wherein the cladding tube (6) is a cylindrical hollow tube, and the material of the cladding tube (6) is stainless steel, zirconium alloy, aluminum alloy.

3. The core assembly for producing a carbon-14 isotope according to claim 1, wherein the end plugs (5) are connected by screwing the connection members (1, 3).

4. The core assembly for the production of carbon-14 isotopes as claimed in claim 1, characterised in that said end plugs (9) are provided with a conical shape.

5. The core assembly for producing carbon-14 isotopes as claimed in claim 1, wherein a target (17) or an inner cladding (11) is arranged inside the cladding tube (6), the inner cladding (11) is a cylindrical hollow tube, and end plugs (10, 13) seal the inner cladding (11).

6. The core assembly for the production of carbon-14 isotopes as claimed in claim 5, characterised in that said inner cladding (11) is made of stainless steel, zirconium alloy, aluminium alloy.

7. The core assembly for the production of carbon-14 isotopes as claimed in claim 1, characterised in that said targets (12, 17) can Be pellets, powder or flocculent AlN, Be₃N₂And Si₃N₄，Ca(NO₃)₂And one or more of metallic and non-metallic materials.

8. The core assembly for producing a carbon-14 isotope according to claim 1, wherein the hold-down springs (7, 15) are C-shaped springs or spiral springs.

9. A core assembly system for producing carbon-14 isotopes, characterized in that a plurality of core assemblies as claimed in claims 1-8 form a rod bundle structure through interfaces of fuel assemblies and internals inserted by connecting members (1, 3), and the connecting members (1, 3) are used for realizing the operation of the core assemblies inside and outside the reactor and in spent fuel pools through handles or barrels.

10. The core assembly system for producing a carbon-14 isotope according to claim 9, wherein the shape of the connection members (1, 3) is determined according to the interface of the fuel assembly to be inserted and the internals.