A target arrangement for the production of iridium-192 by irradiation in a research reactor

Abstract

The present application relates to the technical field of isotope irradiation production, in particular to a target material arrangement device suitable for research reactor irradiation production of iridium-192, which adopts the structure provided by the present application and mainly comprises a cladding, a plurality of clamping blocks and iridium sheets, the clamping blocks are arranged on the inner side of the cladding and are arranged in a circle around the central axis of the cladding, and the iridium sheets are arranged on the clamping blocks on the side in contact with the cladding. Through the above structure, the target material in the iridium-192 target material arrangement mode is designed as pure Ir circular sheet. Small-size target material can improve the irradiation uniformity of a single target material and can be used to manufacture a small-size flaw detection source device, thereby increasing the application range of the product. According to the different iridium-191 contents in the target material, the target material is defined as natural target material and high enrichment target material respectively, and the target material arrangement can be adjusted independently according to actual production requirements, which is beneficial to improve the production flexibility of iridium-192.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of isotope irradiation production, in particular to a target material arrangement device suitable for research reactor irradiation production of iridium-192. BACKGROUND

[0002] Iridium is a group VIII transition metal element, with a content of one in ten million in the earth's crust. There are two isotopes of iridium in nature, iridium-191 and iridium-193. Artificial radioactive isotope iridium-192 is obtained by neutron irradiation of stable element iridium-191 and is commonly used in the fields of radiotherapy, industry and scientific research, etc.

[0003] Iridium-192 is widely used in the field of radiotherapy, acting on intracavitary tumors, and can be used to treat various cancers such as cervical cancer, prostate cancer, lung cancer, etc. In radiotherapy, iridium-192 is usually injected or implanted into tumor tissue in the form of seeds or needles. The radioactive decay of iridium-192 can directly destroy cancer cells and reduce the size and volume of tumors.

[0004] Iridium-192 is widely used in the field of industry for non-destructive testing. Industrial non-destructive testing is a method for detecting internal defects or foreign objects in materials, such as metal welded joints, pipes and tanks, etc. In non-destructive testing, iridium-192 radioactive sources can irradiate objects, and then detection equipment is used to detect the reflection and absorption of radiation to determine defects in the material. Because the radiation energy of iridium-192 is moderate and the specific activity of the radioactive source is high, it can be made into a point source greater than 3.7 TBq, which is suitable for gamma radiography of most metal materials. However, the production of iridium-192 in the prior art is low. SUMMARY

[0005] The purpose of the present application is to provide a target material arrangement device suitable for research reactor irradiation production of iridium-192 to solve the above problems in the prior art.

[0006] The present application is achieved by the following technical solutions:

[0007] A target material arrangement device suitable for research reactor irradiation production of iridium-192, comprising a cladding, a plurality of clamping blocks and iridium sheets, the clamping blocks are arranged on the inner side of the cladding and are arranged circumferentially around the central axis of the cladding, and the iridium sheets are arranged on the clamping blocks on the side in contact with the cladding.

[0008] Preferably, one side of the clamping block has a first groove, and the iridium sheet is arranged in the first groove.

[0009] Preferably, a second groove is formed in the length direction of the clamping block on one side of the clamping block, and a protrusion is arranged on the inner side of the cladding, and the protrusion is inlaidly connected with the second groove.

[0010] Preferably, the side of the clamping block away from the shell is provided with a concave arc shape.

[0011] Preferably, the clamping block is provided with four.

[0012] Preferably, the inner diameter of the shell is 0.8 cm, and the outer diameter is 1 cm.

[0013] Preferably, the depth of the first groove is greater than or equal to 0.2 mm.

[0014] Preferably, the included angle of the two side faces of the clamping block adjacent to the second groove is 80 degrees.

[0015] Preferably, the spacing between the upper and lower adjacent iridium sheets is 5 cm.

[0016] Preferably, the side of the clamping block away from the shell is provided with a concave arc shape.

[0017] The technical scheme of the present application has at least the following advantages and beneficial effects:

[0018] The structure provided by the present application mainly includes a shell, a plurality of clamping blocks, and iridium sheets. The clamping blocks are arranged on the inner side of the shell and are arranged around the central axis of the shell. The iridium sheets are arranged on the side of the clamping block that contacts the shell. Through the above structure, the target material in the iridium-192 target material arrangement is designed as a pure Ir circular sheet. Small size target material can improve the irradiation uniformity of a single target material and can be used to manufacture small size flaw detection source devices, increasing the application range of the product. According to the different contents of iridium-191 in the target material, it is defined as natural target material and high enrichment target material, respectively. The target material arrangement can be adjusted independently according to actual production needs, which is beneficial to improve the production flexibility of iridium-192. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to more clearly illustrate the technical scheme of the embodiments of the present application, the following will briefly introduce the drawings needed in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor.

[0020] Figure 1 It is a schematic diagram of the overall structure of the present application.

[0021] Figure 2 It is a schematic diagram of the structure of the clamping block of the present application.

[0022] Figure legend: 1-clamping block, 2-shell, 3-iridium sheet. DETAILED DESCRIPTION

[0023] In order to make the purposes, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. The components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations.

[0024] Please refer to Figure 1-Figure 2 The present application provides a target material arrangement device suitable for research reactor irradiation production of iridium-192, comprising a cladding 2, a plurality of clamping blocks 1 and iridium sheets 3, the clamping blocks 1 are arranged on the inner side of the cladding 2 and are arranged in a circle around the central axis of the cladding 2, and the iridium sheets 3 are arranged on the clamping blocks 1 on the side in contact with the cladding 2.

[0025] Specifically, the cross section of the clamping block 1 is in the shape of a sector, one side of the clamping block 1 has a first groove, the iridium sheet 3 is arranged in the first groove, the side of the clamping block 1 away from the cladding 2 is arranged in an arc shape with a concave shape, and the side adjacent to the cladding 2 is arranged in an arc shape with a convex shape. In this embodiment, the clamping block 1 is provided with four.

[0026] The second groove is formed in the length direction of the clamping block 1 on one side of the clamping block 1, the inner side of the cladding 2 is provided with a protrusion, and the protrusion is embeddedly connected with the second groove.

[0027] In an example embodiment of the present application, the inner diameter of the cladding 2 is 0.8 cm, the outer diameter is 1 cm, the depth of the first groove is greater than or equal to 0.2 mm, the included angle between the two side surfaces of the clamping block 1 adjacent to the second groove is 80 degrees, the interval between the upper and lower adjacent iridium sheets 3 is 5 cm, and the side surfaces of the plurality of clamping blocks 1 away from the cladding 2 are arranged in a circle.

[0028] Secondly, the structure provided by the present application can be used to manufacture a small-size flaw detection source device. It is suitable for high enrichment target material and natural enrichment target material, and can be adjusted independently according to actual production needs, which is beneficial to improve the production flexibility of iridium-192.

[0029] Through the above structure, the arrangement direction of the target material is determined as vertical arrangement, which can effectively reduce the irradiation non-uniformity of a single target material; the radial and longitudinal arrangement interval of the target material is determined, which can effectively avoid the reduction of product activity caused by too dense arrangement of the target material; the arrangement height range of the target material is determined, which can effectively improve the product yield and qualification rate of single irradiation; the positioning mode and fixing mode of the target material are determined, which can effectively improve the qualification rate and safety of single irradiation.

[0030] The target arrangement mode of the application is suitable for the target arrangement mode of the research reactor for producing iridium-192 by irradiation, and the target arrangement mode should be opposite arrangement for expanding the spacing of single-layer targets. The target should be fixed by the cladding 2 and the clamp block 1, and sufficient gap should be reserved for placing the target considering that the target may swell after irradiation.

[0031] The radial and longitudinal spacing between the targets is realized by adopting the design of the special-shaped clamp block 1, so as to avoid the large decrease of the local neutron flux rate due to the too close arrangement of the targets, thereby reducing the yield and specific activity of the target product iridium-192.

[0032] The irradiation height should be selected according to the actual active section height, so as to avoid that the target arrangement height deviates from the active section too much, thereby causing the neutron flux rate to be too low and being difficult to meet the specific activity requirement of the target product iridium-192 after the same irradiation time period.

[0033] In a specific embodiment,

[0034] Embodiment: A target arrangement mode for producing iridium-192 by irradiation is designed according to the application, taking the high-flux research reactor as the application object. The target is designed as a pure Ir circular sheet, and the diameter of a single small sample is 2.7 mm, the thickness is 0.15 mm, and the weight of a single small sample is about 0.02 g.

[0035] Four targets are arranged in a single layer, and the minimum spacing between the cladding 2 and the clamp block 1 is 0.2 mm for placing the target. The aluminum clamp block 1 is a special-shaped cylinder with a central hole, the inner diameter of the clamp block 1 is 0.4 cm, the outer diameter is 0.8 cm, and the central hole is filled with helium. The aluminum cladding 2 is a special-shaped cylinder with a central hole, the inner diameter of the cladding 2 is 0.8 cm, and the outer diameter is 1.0 cm. The clamp block 1 and the cladding 2 jointly function to position and fix the target, and the composition is 6061 aluminum alloy. The active section length of the high-flux research reactor is 1000 mm, the designed irradiation length of the target is 400 mm, and the target is placed at the height of 300-700 mm (taking the bottom of the active section as the starting point). The radial and longitudinal spacing between the targets is realized by adopting the design of the special-shaped clamp block 1, the radial spacing is 7 mm, the longitudinal spacing is 2.3 mm, 86 layers of target arrangement layers are designed, 344 targets can be loaded in total, and the total weight is 6.88 g.

[0036] The central hole K10 of the HFETR fuel element is selected for yield calculation, and the calculation results are as follows:

[0037] Table 1 Calculation results of the specific activity of the irradiation product 192Ir

[0038]

[0039] Table 2 Calculation results of the specific activity of the irradiation product 192Ir

[0040]

[0041] It is calculated that, by using the target arrangement manner of the present application, when the enriched target is used for irradiation production of iridium-192, the average specific activity of iridium-192 is increased from 739 Ci / g to 1284 Ci / g; when the natural target is used for irradiation production of iridium-192, the average specific activity of iridium-192 is increased from 405 Ci / g to 739 Ci / g, which shows that the target arrangement manner can effectively increase the yield of iridium-192.

[0042] The preferred embodiments of the present application have been described above by way of example only, not for limitation of the present application, and various changes and modifications can be made by those skilled in the art based on the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A target arrangement device suitable for producing iridium-192 by irradiation in a research reactor, characterized in that: The invention comprises a cladding (2), a plurality of clamping blocks (1) and an iridium sheet (3), wherein the clamping blocks (1) are arranged on the inner side of the cladding (2) and are arranged circumferentially around the central axis of the cladding (2), and the iridium sheet (3) is arranged on the side of the clamping blocks (1) that contacts the cladding (2); A first groove is formed at one side of the clamping block (1), and the iridium sheet (3) is arranged in the first groove; A second groove is provided on one side of the clamping block (1) along the length direction of the clamping block (1); a protrusion is provided on the inner side of the cladding shell (2), and the protrusion is embedded and connected with the second groove; The included angle between the two side surfaces of the clamping block (1) adjacent to the second groove is 80 degrees.

2. A target arrangement device suitable for producing iridium-192 by irradiation in a research reactor according to claim 1, characterized in that: The side surface of the clamping block (1) away from the enclosure (2) is configured to be an inwardly concave arc.

3. A target arrangement device suitable for producing iridium-192 by irradiation in a research reactor according to claim 2, characterized in that: Four clamping blocks (1) are provided.

4. A target arrangement device suitable for producing iridium-192 by irradiation in a research reactor according to claim 3, characterized in that: The inner diameter of the cladding (2) is 0.8 cm, and the outer diameter is 1 cm.

5. The target arrangement device for producing iridium-192 by irradiation in a research reactor according to claim 4, characterized in that: The depth of the first groove is greater than or equal to 0.2 mm.

6. The target arrangement device for producing iridium-192 by irradiation in a research reactor according to claim 5, characterized in that: The interval between the upper and lower adjacent iridium sheets (3) is 5 cm.

7. A target arrangement device suitable for producing iridium-192 by irradiation in a research reactor according to claim 6, characterized in that: The plurality of clamping blocks (1) are arranged in a circle on a side away from the cladding (2).

Images