RU2321906C1 - Pressure-tube reactor irradiating device for producing cobalt isotopes - Google Patents

Abstract

FIELD: nuclear power engineering; irradiating device section for producing gamma-ray sources from radioactive cobalt.

SUBSTANCE: proposed irradiating device has hanger with load-bearing rod. The latter mounts sections, each incorporating carrying tube with flanges accommodating ampoule boxes holding material being irradiated, and flange locks of boxes. Butt-ends of section tubes have slots and projections; flange locks are made in the form of star; boxes are leak-tight. Section tubes have annular slots. Irradiating device section ampoules can be directly used as internal capsules of enclosed radioactive sources; high degree of safety is ensured in handling radioactive Co-60.

EFFECT: improved temperature conditions, enhanced reliability of section fixation in the course of transport and process operations.

2 cl, 4 dwg

Description

The invention relates to the field of nuclear energy, relates, in particular, to the construction of a link of an irradiation device for nuclear channel reactors and can be used to produce gamma sources from radioactive cobalt.

Currently, radioactive sources obtained during the irradiation of starting materials in accelerators (Bulletin Radntcy-Euroasia No. 1 (7) M., 1993) and nuclear reactors (V.A. Tsykanov, B.V. Samsonov, and Irradiation Technique are widely used). materials in reactors with a high neutron flux.M .: Atomizdat, 1973). Also known are experimental designs of the links of the irradiation device of the BN-600 reactor used to produce radioactive cobalt-60. In these designs, the starting material in the form of tablets is placed in stainless steel ampoules 210 mm long and 8.2 × 0.4 mm in diameter (V.V. Maltsev, A.I. Karpenko, I.A. Chernov, V.V. Golovin, Experience in the production of Co-60 radionuclide in a high-power fast sodium reactor BN-600, conversion in mechanical engineering, No. 3, 2000), (Bulletin Radntcy-Euroasia No. 1 (8) M., 1994) In addition, An irradiation device of a channel-type nuclear reactor is known in which cobalt disks are mounted on an edge (Irradiation device of a channel-type nuclear reactor PM 2218621 (13/16)).

The closest analogue of the claimed technical solution is the irradiation device of a nuclear channel reactor in the form of a rod of an additional absorber with cobalt (SDPK) (Patent No. 2107957, class G21C 7/10). The neutron absorber contains a supporting element on which links with ampoules are fixed, completely filled with cobalt-59 tablets coated with titanium nitride, in contact with the bases. Ampoules are fixed from falling out by flange lock clamping springs.

The disadvantages of the closest analogue are:

- the impossibility of direct use of ampoules with cobalt disks for the production of radioactive sources due to their high surface contamination, because the use of leaky sleeves as canisters leads to direct contact of the ampoules with the reactor coolant and increases the risk of cobalt entering the coolant;

- the difficulty of capturing and disassembling the link SDPK with cobalt in the reactor reactor pools and "hot" chambers;

- the possibility of overheating of the structure due to insufficient heat removal caused by its high hydrodynamic resistance.

The problem solved by the invention is:

- to ensure the direct use of ampoules with cobalt from an irradiation device for the production of sealed radionuclide sources and to reduce the risk of cobalt-60 entering the reactor coolant;

- in accelerating and facilitating the process of disassembling the link of the irradiation device;

- to reduce the risk of overheating of the structure due to an increase in heat removal.

The essence of this invention lies in the fact that in the irradiating device of a nuclear channel reactor for producing cobalt isotopes, including a suspension with a supporting rod, links mounted on it, each of which contains a supporting pipe with flanges and canisters placed in them with ampoules containing irradiated material, and flange stoppers of the canisters, it is proposed to make grooves and protrusions at the ends of the pipe links, flange stoppers to be made in the form of a star, and the canisters are airtight. In addition, it is proposed that inside the pipe links to make ring grooves.

Performing at the ends of the pipes links of grooves and protrusions does not allow the links of the irradiation device to rotate relative to each other and improves the flow conditions of the coolant. The implementation of flange stoppers in the form of a star allows to improve the manufacturability of the disassembly of the irradiation device and increases the area of the flow cross-section for the coolant duct, which leads to a decrease in hydrodynamic resistance. The use of sealed canisters in the links of the irradiation device is an additional barrier from the exit of cobalt-60 to the coolant and reduces the surface contamination of ampoules with cobalt by several orders of magnitude, which allows the ampoules with cobalt from the irradiation device to be sealed in closed radionuclide sources without additional operations. The execution on the inner surface of the supporting pipe of the link of special ring grooves provides easier gripping of the link with technological equipment during its movements.

Figure 1-2 shows a longitudinal section of the irradiation device, figure 3 is a link of the irradiation device, figure 4 is a top view of the link of the irradiation device.

The irradiating device consists of a suspension 1, links 2 with irradiated material mounted on a supporting rod 3, and a guide cone 4, fixing links 2 (Fig.1-2). Suspension 1 is connected to the supporting rod 3 by means of a sleeve 5; the guide cone 4 is connected by means of the bayonet to the supporting rod 3. The finger 6 located on the suspension is used to fix the bearing rod 3 in the bayonet connection of the guide cone 4. Above the links 2 there is a spring clip 7 placed in the glass 8, fixing the links on the supporting rod 3 by pressing to the end of the cone 4.

Link 2 (Fig. 3) of the irradiating device consists of a central carrier pipe 9, to the ends of which are welded upper 10 and lower 11 flanges with six holes for installation of sealed canisters 12. Cases 12 contain sealed ampoules 13 with radioactive cobalt material made in the form of disks 14. To fix the pencil cases in the link, a flange stopper 15 in the form of a star is used, which is welded to the upper part of the carrier pipe. Two grooves 16 are made in the lower part of the pipe, and two protrusions 17 in the upper part. When connecting the links in the irradiation device, the protrusions 17 enter the grooves 16, which fixes the links from rotation relative to each other and ensures a sufficient cross-section for the coolant flow. On the inner side of the supporting pipe of the link of the irradiation device, an annular groove 18 is made, which serves to fix the link during its transportation using special equipment.

Disassembling the irradiation device after irradiation in the reactor is carried out remotely, in the pool under a protective layer of water or in a "hot" chamber. The irradiation device previously unloaded from the reactor into the holding tank case is disassembled in the following sequence:

- remove finger 6;

- acting on the suspension 1, compress the spring clip 7;

- turning the suspension 1 by 90 °, the lower end of the supporting rod 3 is withdrawn from the bayonet connection with the cone 4;

- remove the suspension 1 with a supporting rod 3;

- sequentially remove from the pencil case the spring clip 7, the glass 8, links 2 and the guide cone 4.

The links are transported to a “hot” chamber for extraction of ampoules with cobalt disks. The disassembly of the link is as follows:

- bend the petals of the flange stopper 15;

- pencil cases 12 are removed from the gratings of the link;

- pencil cases 12 are opened and ampoules 13 with cobalt disks 14 are removed from them;

- the extracted ampoules 13 are placed in special devices for storage and (or) transportation.

The proposed technical solution allows you to:

- directly use the ampoules of the link of the irradiating device as internal capsules of sealed radioactive sources;

- increase the degree of safety when handling radioactive Co-60;

- improve temperature conditions during irradiation;

- more reliable to fix the link when performing transport and technological operations.

Claims (2)

1. The irradiating device of a nuclear channel reactor for producing cobalt isotopes, including a suspension with a supporting rod, links mounted on it, each of which contains a supporting pipe with flanges and canisters placed in them with ampoules containing irradiated material, and flange canister stoppers, characterized in that the ends of the pipe links made grooves and protrusions, flange stoppers are made in the form of a star, and pencil cases are airtight. 2. The irradiation device of a nuclear channel reactor for producing cobalt isotopes according to claim 1, characterized in that the ring grooves are made inside the pipe links.

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