RU2134460C1 - Radioactive material disposal method - Google Patents

Abstract

FIELD: disposal of radioactive materials. SUBSTANCE: method may be found useful for liquid and solid materials as well as for those capable of changing their state provided normal heat transfer and escape of gas produced due to radioactive process is ensured. To this end, radioactive material is stored in multilayer system with labyrinth for material outlet so as to eliminate its escape to surrounding water medium. Multilayer enclosure is made in the form of shells joined together so that their open parts are arranged alternately up and down. Inserts placed between shells are loosely joined on one side of adjacent shells and fixed on other side. EFFECT: enlarged functional capabilities. 2 cl, 2 dwg

Description

The technical solution relates to the field of burial of a radioactive substance, which is formed either as a result of a technological process, or is a waste industrial substance, when it is necessary to exclude for a long time the contact of living organisms with the specified substance in order to avoid environmental impact. There is a method of preventing the effects of radiation on living organisms when they place a radioactive substance on the bottom surface of a reservoir, and the thickness of the water layer is chosen sufficient to ensure radiation safety on the surface of the water (1, p. 141),
The disadvantages of the method can be considered:
- activation of the water mass, if neutron radiation is present and its energy is sufficient to excite the nuclei, which will lead to the spread of the activated substance throughout the entire water mass;
- the inability to use for a radioactive substance in a liquid state, because in this case, the entire water volume will be radioactive;
- during the burial of a neutron emitter in an airtight envelope, for example, a fuel rod, the conversion of helium or hydrogen, the pressure inside the envelope will increase, followed by its rupture. The situation is aggravated by heat release, which accelerates the destruction of the shell, and the half-lives of heavy isotopes reach many thousands of years (11, p. 141).

 Any reactor is actually also a repository for the time the assembly is used and there are all of the above factors that are necessary for the implementation of the process. The situation is aggravated by external loads (wind, temperature differences, alternating loads and other complex cases of loading.

The purpose of the technical solution is to provide protection from radioactive substances for a long period of time and to eliminate the effects of any type of radiation on living organisms,
- the possibility of burial of a substance in any form: liquid, solid or changing its state during storage,
- ensuring reliable heat removal and removal of gas formed during nuclear decay.

 This goal is achieved by the fact that the radioactive substance is placed in a multilayer shell, which is made in the form of glasses and conjugate their layers alternately with the open part up and down, while inserts are inserted between the shells that mate with adjacent surfaces of the shells on one - movably, on the other - motionless, and the thickness of the water layer between adjacent shells provides radiation safety on the outer side of the water layer when distributing all the radioactive substance evenly throughout nnemu volume, and an inner shell mounted check valve in a yield of up into an aqueous environment, wherein at least the cup-shaped end inserts mounted in places of contact with the radioactive substance in the inner wall of the shell casing.

 To explain the method, we show a structural diagram of a multilayer shell. In FIG. 1 shows the case when the radioactive substance has a density greater than seawater; in FIG. 2 - the density of the substance is less than the density of water. In both cases, the substance is in liquid form. This condition is valid, because during long-term storage any shells will collapse and crumble due to thermal effects and radiation, if the assembly is significant and its transportation required powerful protection, which helps to improve the quality of thermal insulation.

 The multilayer shell is made of cups 1, which are turned with their open sides alternately in different directions to get a labyrinth to make it difficult for the radioactive substance to enter the open reservoir 2. When the radioactive substance 3 has a density greater than the density of water, the inner cup faces up with its open part (Fig. . 1), when the density of the radioactive substance is less than the density of water, then the inner glass faces the open part down (Fig. 2). On the contact side of the radioactive substance 3 with the wall of the glass 1, a liner 4 is placed, which serves to reduce the integral radiation dose by replacing the volume of the radioactive substance 3 with the liner 4. Between the glasses 1 there are inserts 5 that are fixedly connected, say, to the inner glass 1 and movably with an outside glass. It also serves to enhance the quality of the maze. The outer cup 1 has stops at the bottom 6 for the formation of a single structural assembly, and on top of the eyelets 7 for lowering the assembly after delivery to the place of burial. The inner cavity of the inner glass has a check valve 8 for bleeding gas. Of course, there will be a diffusion of the radioactive substance 3 into the aqueous medium inside the glasses 1, but the release of the substance to the outside, if it takes place after many hundreds of years, will be very insignificant, because after dissolution (diffusion) in the inner glass 1, the solution needs to overcome the gaps between the joints of the glasses 9, the gaps 10 and many. However, there are no forces that would facilitate this process.

Really:
1. The pressure is the same everywhere with the outside.

 2. The temperature is also almost the same for any assembly, because water contact provides heat dissipation, and convective heat transfer will take place more intensively with intense release of thermal energy.

 In addition, each water layer between the glasses 1 in its thickness provides a protection rate on the outer surface of the water layer with the complete dissolution of the radioactive substance throughout the internal volume of the inner shell for a given water layer.

 Therefore, even in the unlikely event that the cup shells 1 begin to break down, the concentration will sharply decrease due to the protective properties of each water layer, which will add pure water in cubic dependence.

 The structural assembly should be installed at the bottom of the sea, with the possibility of descent for measurements and the possibility of installing external emergency caps, the flow should be minimal, and siltation will create a natural protection, which will be additional.

 Thus, all the goals set forth above are achieved. The situation can be improved by filling the internal cavities with oils that will protect the material of the glasses 1 from destruction.

Literature
1. The effect of radiation on materials and parts. Sat articles. Vol. 27. - M.: Main Directorate for the Use of Atomic Energy under the Council of Ministers of the USSR, 1959.

 2. Radiation safety standards (NRB-69). - Atomizdat, 1972.

 3. Palmer Fast neutron reactors. Per. from English. M .: Gosatom.

Claims (2)

 1. The method of burial of a radioactive substance, including placing it in an aqueous medium under a layer of water, which ensures radiation safety on the surface of the water, characterized in that the radioactive substance is placed in a multilayer shell, which is made in the form of glasses and conjugate them alternately with the open part up and down while inserts are placed between the glasses that mate with neighboring glasses movably and motionless from different sides, while the thickness of the aqueous medium between the shells of the glasses provides radiation safety from the outside of the water layer with a uniform distribution of the radioactive substance throughout the internal volume, and the internal cavity of the inner glass is connected by a check valve in the upper part with the medium passing up into the surrounding aqueous medium.  2. The method according to claim 1, characterized in that at least in the inner glass establish a cup-shaped end insert at the points of contact of the radioactive substance with the walls of the glass.

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