A neutron shielding structure applied to target production

Abstract

The application relates to the technical field of isotope production, and particularly discloses a neutron shielding structure applied to target production, wherein a connecting piece is used for connecting a target element and a shielding pipe to form an integral whole; the shielding pipe is a circular pipe structure and is sleeved outside the target element. The neutron shielding structure can be used for neutron shielding in the fields of various reactor elements and isotope production targets, and the integral scheme is simple, easy to produce, reliable in connection, easy to assemble and convenient for automatic production and manufacturing.

Description

Technical Field

[0001] This invention belongs to the field of isotope production technology, specifically relating to a neutron shielding structure used in target production. Background Technology

[0002] Isotope irradiation production is generally carried out in the water-cooled channels of a research reactor. During the irradiation process of producing the target, a specific neutron energy spectrum is required to achieve the best irradiation effect and produce the maximum amount of isotope products. Since the neutron energy spectrum in water-cooled isotope channels is relatively soft, selecting a suitable material as a shielding layer to appropriately harden the channel neutron energy spectrum can improve the conversion rate of isotope production to a certain extent, while simultaneously reducing the heat generated by the target and improving its thermal safety performance.

[0003] Commonly used neutron shielding materials include water, graphite, polyethylene, concrete, stainless steel, and other materials with low atomic numbers or high hydrogen content. These materials occupy a lot of space, and their shielding effect is limited within a certain space. A large amount of shielding material is required to achieve the desired shielding effect.

[0004] For isotope production targets, they are typically placed in irradiation channels of specific sizes for irradiation production. For the sake of neutron economy, the space in these irradiation channels is generally limited. Therefore, employing a neutron shielding scheme that provides better performance within a confined space can benefit the manufacturing, production, and post-processing of isotope targets. Summary of the Invention

[0005] The purpose of this invention is to provide a neutron shielding structure for target production, which produces less waste after target irradiation, facilitates post-processing, and saves space in the irradiation neutron tube.

[0006] The technical solution of the present invention is as follows:

[0007] A neutron shielding structure for target production includes a target element, a connector, and a shielding tube;

[0008] The connector is used to connect the target element and the shielding tube into a whole, so that the whole can be smoothly placed into the corresponding irradiation channel.

[0009] The shielding tube is a circular tube structure and is sleeved on the outside of the target element.

[0010] The connector consists of multiple pins arranged at equal angles to connect the target element and the shielding tube into a whole, allowing this whole to be smoothly placed into the corresponding irradiation channel.

[0011] The thickness of the shielding tube is 0.1 to 1 times the thickness of the target element's casing.

[0012] The shielding tube is made of silver foil.

[0013] The length of the shielding tube exceeds the height of the stacked core blocks in the target element.

[0014] The target element is a solid rod-shaped structure or a ring-shaped structure.

[0015] During irradiation, neutrons in the irradiation channel pass through the shielding tube and are hardened, while isotopic raw materials in the target element undergo fission to produce designated products and generate heat.

[0016] During irradiation, the coolant in the irradiation channel flows through the target element from bottom to top or from top to bottom, carrying away heat.

[0017] The significant advantages of this invention are:

[0018] (1) The neutron shielding structure of the present invention can be used for neutron shielding in various reactor components, isotope production targets and other fields. The overall scheme is simple, easy to produce, reliable in connection, easy to assemble, and convenient for automated production and manufacturing.

[0019] (2) Calculations show that for water-cooled isotope channels with a relatively soft neutron spectrum, using silver foil with a thickness of about 8% of stainless steel can achieve a comparable final neutron shielding effect, achieve appropriate hardening of the neutron spectrum, improve the isotope conversion rate to a certain extent, reduce the heat generation of the target, and improve the thermal safety performance of the target.

[0020] For irradiation channels with limited space, such as when the diameter of the target to be shielded is similar to the diameter of the irradiation channel, the neutron shielding structure adopted in this invention has an absolute advantage over traditional solutions. By using silver foil as the shielding layer, compared with the use of materials containing multiple elements such as stainless steel, the waste generated after the target is irradiated will be reduced from 100% to 5%. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the cross-section of the shielding structure;

[0022] Figure 2 This is a top view of the shielding structure.

[0023] In the figure: 1. Target element; 2. Connector; 3. Shielding tube; 4. Irradiation channel; 5. Upper plug; 6. Inner shell; 7. Outer shell; 8. Lower plug. Detailed Implementation

[0024] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0025] A neutron shielding structure for target production includes a target element 1, a connector 2, and a shielding tube 3.

[0026] The connector 2 is used to connect the target element 1 and the shielding tube 3 into a whole, so that the whole can be smoothly placed into the corresponding irradiation channel 4.

[0027] The shielding tube 3 is a circular tube structure, sleeved on the outside of the target element 1, and is made of silver foil with a thickness of 0.1 to 1 times the shell thickness of the target element 1. Based on the specific neutron distribution in the water-cooled channels and the power distribution of the target element, the length of the shielding tube 3 is appropriately extended to exceed the height of the core block stack in the target element 1, in order to achieve a better shielding effect at both ends of the target element 1, making the power peak of the target element 1 more even compared to when it is not extended.

[0028] During the irradiation process, the neutrons in the irradiation channel 4 pass through the shielding tube 3 and are sufficiently hardened. At the same time, the isotopic raw material in the target element 1 undergoes fission to produce the specified products and generate heat. The coolant in the irradiation channel 4 flows through the target element 1 from bottom to top or from top to bottom, carrying away the heat.

[0029] Example 1

[0030] A neutron shielding structure for target production includes a target element 1, a connector 2, and a shielding tube 3. The target element 1 is a solid rod-shaped structure, including an upper plug, a shell, and a lower plug.

[0031] The connector 2 consists of three pins arranged at equal angles to connect the target element 1 and the shielding tube 3 into a whole, so that this whole can be smoothly placed into the corresponding irradiation channel 4.

[0032] The shielding tube 3 is a circular tube structure made of silver foil. The thickness of the silver foil is 1 / 2 of the thickness of the target shell, and its total length is longer than the height of the core block stack in the target element 1.

[0033] During the irradiation process, the neutrons in the irradiation channel 4 pass through the shielding tube 3 and are sufficiently hardened. At the same time, the isotopic raw material in the target element 1 undergoes fission to produce the specified products and generate heat. The coolant in the channel flows through the target element 1 from bottom to top or from top to bottom, carrying away the heat.

[0034] Example 2

[0035] like Figures 1-2 The diagram illustrates a neutron shielding structure used in target production, comprising a target element 1, a connector 2, and a shielding tube 3. The target element 1 is a ring structure, including an upper plug 5, an inner shell 6, an outer shell 7, and a lower plug 8.

[0036] The connector 2 consists of three pins arranged at equal angles to connect the target element 1 and the shielding tube 3 into a whole, so that this whole can be smoothly placed into the corresponding irradiation channel 4.

[0037] The shielding tube 3 is a circular tube structure made of silver foil. The thickness of the silver foil is 1 / 4 of the thickness of the outer shell 7 of the target element, and its total length is longer than the height of the core block stack in the target element 1.

[0038] During the irradiation process, the neutrons in the irradiation channel 4 pass through the shielding tube 3 and are sufficiently hardened. At the same time, the isotopic raw material in the target element 1 undergoes fission to produce the specified products and generate heat. The coolant in the channel flows through the target element 1 from bottom to top or from top to bottom, carrying away the heat.

[0039] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0040] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A neutron shielding structure for use in target production, characterized in that: Includes target element (1), connector (2), and shielding tube (3); The connector (2) is used to connect the target element (1) and the shielding tube (3) into a whole, so that the whole can be smoothly placed into the corresponding irradiation channel (4); The shielding tube (3) is a circular tube structure and is sleeved on the outside of the target element (1); The connector (2) consists of multiple pins arranged at equal angles to connect the target element (1) and the shielding tube (3) into a whole, so that this whole can be smoothly placed into the corresponding irradiation channel (4). The thickness of the shielding tube (3) is 0.1 to 1 times the thickness of the target element (1) shell; The shielding tube (3) is made of silver foil.

2. The neutron shielding structure for target production as described in claim 1, characterized in that: The length of the shielding tube (3) exceeds the height of the core block stack in the target element (1).

3. The neutron shielding structure for target production as described in claim 1, characterized in that: The target element (1) is a solid rod-shaped structure or a ring-shaped structure.

4. A neutron shielding structure for target production as described in any one of claims 1 to 3, characterized in that: During the irradiation process, the neutrons in the irradiation channel (4) pass through the shielding tube (3) and are hardened, while the isotopic raw materials in the target element (1) undergo fission to produce designated products and generate heat.

5. A neutron shielding structure for target production as described in claim 4, characterized in that: During irradiation, the coolant in the irradiation channel (4) flows from bottom to top or from top to bottom through the target element (1) and carries away heat.

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