RU201649U1 - TARGET FOR ACCUMULATION OF ISOTOPES - Google Patents

Abstract

The utility model relates to nuclear technology, namely to the irradiation devices of nuclear reactors, and can be used to obtain radionuclides used in the manufacture of radiopharmaceuticals for diagnostics and therapy in nuclear medicine. The target for the accumulation of target isotopes contains a glass of aluminum alloy, the base of which is made of a monolithic thickness of at least 10 mm. The inner surface of the base of which is made round or conical for a quartz ampoule with the irradiated original parent substance, with a seat for an end cylindrical plug with a diameter smaller than the inner diameter of the glass. The outer surface of the base and the outer surface of the plug are made with cylindrical tips with a diameter smaller than the diameter of the glass. Each tip has a transverse hole. On the outer surface of the glass, an annular groove is made, located below the plug seat, which is welded to the glass. The annular groove is made with a depth equal to half the glass wall thickness. Outside, monolithic with a cylindrical glass, on both sides of the annular groove, at an equal distance from it, two identical protrusions are made in the form of regular hexagonal prisms with a height of at least 10 mm, with outer surfaces parallel to each other and with a distance between opposite faces equal to the outer diameter of the glass. The useful model makes it possible to increase the level of radiation safety in the process of opening and removing the quartz ampoule with the irradiated substance. 1 ill.

Description

The utility model relates to nuclear technology, namely to the irradiation devices of nuclear reactors and can be used to obtain radionuclides used in the manufacture of radiopharmaceuticals for diagnostics and therapy in nuclear medicine.

Currently, various irradiation devices are widely used to activate the initial stable isotopes or their natural mixtures in nuclear reactors [V.A. Tsykanov, B.V. Samsonov “Technique of irradiation in reactors with high neutron flux. M., Atomizdat, 1993.]. Almost all of them contain targets - sealed containers with initial irradiated materials, placed in sealed enclosures to eliminate the risk of release of the resulting radionuclides into the environment during the production of the target isotope.

Known ampoule of the irradiation device of a nuclear reactor [RU 2342716 C1, IPC G21C7 / 10 (2006.01), G21G4 / 04 (2006.01), publ. 12/27/2008], which consists of a body and two covers welded to it. The ampoule is filled with cobalt-59 tablets and zirconium alloy spacers in the form of spring rings. Springs for pressing the spacers to the tablets in the direction of the longitudinal axis of the ampoule are installed in the seats of the ampoule lid.

This device is designed to irradiate the parent material, compressed in the form of pellets, and does not have an inner container, which increases the risk of radionuclides release into the reactor coolant. In addition, the extraction of the irradiated material from the ampoule requires an additional cutting tool, which, under conditions of a high level of ionizing radiation, increases the labor intensity and cost of work and increases the level of contamination of equipment inside the protective box, which in turn leads to an increase in the level of radiation hazard.

Known target for the accumulation of Mo-99 [RU 141375 U1, IPC G21G1 / 00 (2006.01), publ. 06/10/2014], containing a shell, core and end caps. End caps contain cylindrical cavities, and the shell is compressed on the core to contact with it, while the target contains an annular groove on the surface of the plug seat into the shell, which is made before welding.

The disadvantage of such a target is the need for a cutting tool to extract the irradiated material. As a result, the level of emissions into the environment of both the shell and the target isotope radionuclides increases.

Known target for the accumulation of the isotope lutetium-177 [RU 183971 U1, IPC G21G1 / 00 (2006.01), publ. 11.10.2018), selected as a prototype, containing a shell made of an aluminum alloy of a tubular section with a quartz ampoule placed inside it, containing a powder of lutetium-176 nitrate planted on the walls of the ampoule, sealed by welding. The shell made of aluminum alloy is a cylindrical glass with a seat for a cylindrical end cap. The outer surface of the base of the glass is made with a cylindrical tip with a diameter smaller than the diameter of the shell. A transverse hole is made in the cylindrical tip. The inner surface of the base is rounded or conical. A cylindrical end cap with a cylindrical tip with a diameter smaller than the diameter of the shell is welded to the seat of the nozzle with a circular weld. This cylindrical tip also has a transverse hole. On the outer and inner surfaces of the cylindrical nozzle below the plug seat, there are annular grooves located opposite each other and having a depth equal to a quarter of the wall thickness of the cylindrical glass.

Annular grooves on the outer and inner surfaces cylindrical glass provide the process of opening the target after irradiation. After irradiation, the target shell material becomes more brittle, which makes it possible to break the cylindrical glass along the annular grooves and remove the ampoule. However, this target has a completely smooth surface, and the process of opening the target is carried out using manipulators. In this case, it is necessary to squeeze the device with the grips of the manipulator in order to prevent it from turning along its axis and to ensure the vertical position of the device to exclude the possibility of the ampoule falling out of the device during the breaking of the cylindrical glass along the annular grooves. When the cylindrical glass is compressed, it can be crumpled, which leads to the impossibility of removing the quartz ampoule or to its destruction and the ingress of the irradiated target material into the volume of the hot chamber, contamination of it and the ventilation system with radioactive isotopes. Moreover, in conditions of impossibility of fixation in a vertical position, when the irradiation device is opened, the quartz ampoule spontaneously falls out of the internal cavity of the device and is destroyed from impact when falling on the metal surface of the hot chamber for working with radioactive substances.

Thus, this target does not provide the required level of radiation safety for the process of opening the target and removing the quartz ampoule, although it does provide opening of the target without the aid of a cutting tool.

The technical result of the proposed target for the accumulation of target isotopes is to increase the level of radiation safety in the process of opening the quartz ampoule of the irradiation device.

The proposed target for the accumulation of target isotopes, as in the prototype, contains a glass of aluminum alloy, the inner surface of the base of which is made round or conical for a quartz ampoule with the irradiated parent material, with a seat for an end cylindrical plug with a diameter smaller than the inner diameter of the glass, moreover, the outer surface of the base and the outer surface of the plug are made with cylindrical tips with a diameter smaller than the diameter of the glass, transverse holes are made in the tips, and an annular groove is made on the outer surface of the glass, located below the plug seat, which is welded to the glass.

In contrast to the prototype, the base of the glass is made monolithic, at least 10 mm thick. The annular groove is made with a depth equal to half the glass wall thickness. Outside, monolithic with a cylindrical glass, on both sides of the annular groove, at an equal distance from it, two identical protrusions are made in the form of regular hexagonal prisms with a height of at least 10 mm with outer surfaces parallel to each other and with a distance between opposite sides equal to the outer diameter glasses.

In such a target design, the base of the glass is reinforced, and the prism projections act as a weighting agent. The target simplifies the process of opening a quartz ampoule after irradiation, its reliability, as a result, increasing the level of radiation safety.

FIG. 1 shows a proposed target for isotope storage.

The target for the accumulation of isotopes contains a cylindrical glass 1 made of aluminum alloy with a monolithic thickened base 2, which is at least 10 mm of the length of the glass. The inner surface of the base 2 is rounded or conical. Inside the glass 1 there is a quartz ampoule with irradiated material in the form of a metal or a chemical compound of lutetium-176, ytterbium-176, and samarium-152 or stable isotopes of other metals. In the seat of the nozzle 1, a cylindrical plug 3 with a diameter smaller than the inner diameter of the nozzle 1 is welded with a circular welding seam.

The outer surface of the base 2 and the outer surface of the plug 3 are made with identical cylindrical tips 4 located on the same axis, the diameter of which is smaller than the diameter of the glass 1. In the cylindrical tips 4, transverse holes are made 5. On the outer surface of the glass 1 below the seat of the plug 3, an annular groove 6, the depth of which is equal to half of the wall thickness of the glass 1. Outside, monolithic with the cylindrical glass 1, on both sides of the annular groove 6, at an equal distance from it, two identical protrusions are made in the form of a regular hexagonal prism 7 with a height of at least 10 mm, the distance R between the opposite faces of which is equal to the outer diameter of the glass 1, with the outer surfaces of the faces parallel to each other.

Using the tips 5 with holes, it is possible to assemble two or more targets into an irradiation device, while the thickened base of the glass serves as a weighting agent.

As a result of the implementation of the irradiation program, the initially stable isotope turns into a radioactive one. The irradiation process takes place in a sealed quartz ampoule and a sealed target, which eliminates the risk of radionuclides release into the reactor coolant,

After irradiation, the target is placed in an electromechanical device for opening, where it is fixed in a strictly vertical position in a holder with a hexagonal profile in the upper part. The opening device provides the necessary twisting force, which acts strictly in the area reinforced by hexagonal prisms, producing a breaking action of the aluminum alloy glass 1 along the annular groove 6. The lower part of the cylindrical glass 1 with the ampoule is not subjected to any loads and is not destroyed, while maintaining its integrity ampoules, both when opening and removing the ampoule with the irradiated substance.

Claims (1)

A target for the accumulation of target isotopes containing a glass of aluminum alloy, the inner surface of the base of which is made round or conical for a quartz ampoule with the irradiated parent material, with a seat for an end cylindrical plug with a diameter smaller than the inner diameter of the glass, and the outer surface of the base and the outer the surface of the plug is made with cylindrical tips with a diameter smaller than the diameter of the glass, transverse holes are made in the tips, and an annular groove is made on the outer surface of the glass, located below the seat of the plug, which is welded to the glass, characterized in that the base of the glass is made with a monolithic thickness of at least 10 mm, the annular groove is made with a depth equal to half the glass wall thickness, from the outside, monolithic with a cylindrical nozzle on both sides of the annular groove, at an equal distance from it, two identical protrusions are made in the form of regular spines tigonal prisms with a height of at least 10 mm, with outer surfaces parallel to each other and the distance between opposite sides equal to the outer diameter of the glass.

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