RU93175U1 - IRREGULAR ASSEMBLY FOR PRODUCING RADIOACTIVE MEDICAL ISOTOPES IN AN ATOMIC CHANNEL REACTOR - Google Patents

Abstract

An irradiation assembly for producing radioactive medical isotopes in an atomic channel reactor, consisting of several targets placed in tandem inside a flow-through container with a suspension, characterized in that the targets are equipped with individual suspensions and are formed by glasses installed concentrically with a gap, and the irradiated material is placed in this gap, the targets themselves inside the flow-through container are placed in a protective sealed container equipped with a corrugation and a safety valve.

Description

The utility model relates to the field of nuclear energy, and relates, in particular, to the design of irradiation devices for nuclear channel reactors and can be used to irradiate targets with uranium or another substance to produce radioactive isotopes used in the manufacture of radiopharmaceuticals for diagnosis and therapy in medicine.

Currently, radioactive sources obtained during the irradiation of starting materials in accelerators (Bulletin Radentcy-Euroasia No. 1 (7). M.D993) and nuclear reactors (V.A. Tsykanov, B.V. Samsonov “Irradiation Technique in high neutron flux reactors. M., Atomizdat, 1993.). Also known are the experimental designs of the links of the irradiation devices 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 (V.V. Maltsev, A.I. Karpenko, I.A. Lernov, V.V. Golovin “Experience in the production of Co-60 radionuclide in a fast sodium reactor BN -600 high power. "- Conversion in mechanical engineering, No. 3, 2000. Also known is the irradiating device of a nuclear channel reactor in the form of an additional absorber rod (patent No. 2107957, MKI G21C 7/10). The neutron absorber contains a supporting element on which the links are fixed (targets) with ampoules completely filled with coba tablets ice-59 coated with titanium nitride, in contact with the base. Ampoules were fixed from falling out by stop springs. In the materials of the International scientific and technical conference "Use of the reactor: science and technology. Abstracts of the SSC RF NIIIAIR, Dimitrovgrad, 2001, p.207. described irradiation assembly, consisting of a flowing container and a stack of single crystals of any irradiated material located in it. Water from the cooling system is passed through the container from the bottom up. The container body is made of aluminum, as it slightly weakens the flow of thermal neutrons.

The closest analogue of the claimed utility model is the design of the irradiation assembly presented in the patent for utility model of the Russian Federation No. 38249. The assembly consists of several targets arranged in a stack inside the flow container with irradiated material. In this patent, the target consists of an irradiated material coated with several layers of foil metal, for example, aluminum foil (soft shell). The irradiation assembly is equipped with a suspension unit for its transportation.

The disadvantages of the closest analogue are:

the impossibility of direct use of the irradiated material for the production of radioactive sources due to significant surface contamination, since the use of a soft foil casing does not guarantee against the penetration of the radioactive coolant to the irradiated material;

the possibility of contamination of the reactor coolant with radionuclides that are formed when the target is irradiated with a neutron flux;

the complexity of the assembly, disassembly and transportation of the irradiation device.

The problem solved by the utility model is:

in ensuring the direct use of the irradiated material for the production of sealed radionuclide sources and eliminating the risk of radionuclides entering the reactor coolant;

in accelerating and facilitating the assembly, disassembly, transportation of the irradiation device;

in facilitating the process of disassembling and transporting the irradiated target.

The essence of the claimed utility model consists in the fact that in the irradiation assembly for producing radioactive medical isotopes in an atomic channel reactor consisting of several targets placed in tandem inside a flowing container with a suspension, it is proposed to provide the targets with individual pendants and form them from glasses installed concentrically with a gap and place the irradiated material in this gap, while the targets themselves inside the flowing container should be placed in a protective airtight container equipped with a corrugation, etc. dohranitelnym valve.

This design of the irradiation assembly is significantly superior to that presented in the closest analogue for radiation safety, since it introduced additional protection - a protective container, which eliminates the ingress of radioactive products into the cooling circuit of the reactor if the integrity of the targets is violated. The irradiated material is in a more uniform temperature field, since the temperature of the water is equalized on the protective container due to its high thermal conductivity. The increase in temperature and pressure inside the protective container does not cause its destruction and contamination of the reactor cooling circuit, since the container is equipped with a corrugation, the extension of which leads to an increase in free volume. If the increase in free volume is insufficient, the safety valve is activated. Since the overlying targets rely on the suspensions of the underlying targets, the screening of the neutron flux incident on the targets is significantly reduced. The execution of the target in the form of two glasses of different diameters placed concentrically to each other, simplifies the equipment of the target and the extraction of the irradiated material from it. This design of the target eliminates the spillage of the irradiated material during disassembly, since the outer cup acts as a tray where fallen particles of the irradiated material are collected, which eliminates the need for chemical decontamination.

Graphic material explaining the essence of the utility model is shown in FIGS. 1, 2, where Fig. 1 is a sectional view of an irradiation assembly, and Fig. 2 shows a target structure. The irradiation assembly (FIG. 1) includes a protective container 1 intended for loading irradiation targets 2. A protective container 1 filled with targets 2 is placed in the irradiation container 3, which is made in the form of a tube. In the lower part of the irradiation container 3, a guide cone 4 is fixed with holes 5 for the passage of cooling water. In the upper part of the irradiation container 3 there is a gripper 6 of the suspension unit 7, which is connected to the crane hook (not shown in FIGS. 1, 2). On the wall of the irradiation container 3, holes 8 are made for the intake of cooling water. The protective container in the upper part is equipped with a corrugation 9 and is closed hermetically by a lid 10 in which the safety valve 11 is installed. The protective container 1 is centered in the irradiation container 3 by means of centralizers 12. The target (FIGS. 1, 2) consists of glasses 13, 14 of different diameters, set concentrically. The gap between the side walls of the glasses is filled with irradiated material 15, for example, uranium oxide. The end face of the target is closed by a lid 16, with a welded node of the suspension of the target 17, through which the target is loaded and unloaded with a crane. After irradiating the targets to the desired fluence in the irradiation channel, the irradiation container 3 is removed from the irradiation channel of the reactor and placed in the holding pool, the suspension 7 is removed with a grip 6, and then the sealing cover of the protective container 1. Then the targets 2 are removed and loaded into the transport container. The transport container is sent for processing targets 2 to extract the irradiated material 15.

The proposed technical solution makes it possible to directly use the irradiated material extracted from the targets as ready-made radioactive sources, eliminate the risk of radionuclides entering the reactor coolant, increase the degree of safety when handling radioactive materials, and reliably fix the target with the irradiated material during transport and technological operations.

Claims (1)

An irradiation assembly for producing radioactive medical isotopes in an atomic channel reactor, consisting of several targets placed in tandem inside a flowing container with a suspension, characterized in that the targets are equipped with individual suspensions and are formed by cups mounted concentrically with a gap, and the irradiated material is placed in this gap, in this case, the targets themselves inside the flow container are placed in a protective sealed container equipped with a corrugation and a safety valve.