Method of treatment of radioactive solutions and unit for its implementation

FIELD: physics, nuclear.

SUBSTANCE: offered group of the inventions relates to the devices for processing of radioactive solutions. In the offered method of processing of radioactive solutions before filling of the vessel with the solution in its bottom place an additional vessel from a thin dielectric film is placed. Then the radioactive solution is poured into the vessel, with adding of the substances for treatment process control. After that the solution is exposed to irradiation by unipolar electromagnetic impulses with the power more than 1 MW and with duration less than 1 ns, minimum frequency 1 kHz. The solution is treated within 10-30 minutes, held in the vessel during 1-4 days, then the treated solution is drained and additional vessel is removed for utilization. The offered unit contains a current-conducting housing (1), the central part of which contains electrode (2), designed as a horizontal plate. The plate repeats the housing cross-section shape, but have the sizes 20-30% from the cross-section area of the housing. The unit also contains the generator of unipolar electromagnetic impulses, located outside the housing (3). During the treatment at the bottom of the housing the additional vessel (4) is placed.

EFFECT: simplification of devices for treatment of radioactive solutions with keeping of high quality of cleaning.

2 cl, 1 dwg

 

The invention relates to the field of processing of materials containing radioactive substances, namely, the means of processing of radioactive solutions, and aqueous solutions by electrochemical methods, and can find application in the nuclear industry and waste water treatment.

A known method of purification of liquid waste from ions of heavy metals and radioactive isotopes that are described in the same patent RF №2127459 on CL G21F 9/06, Appl. 25.12.97, publ. 10.03.99.

The known method includes the electrochemical treatment of waste by oxidation of complex compounds of heavy metals and radioactive isotopes on the electrodes using as the cathode gas diffusion electrode, and the anode - narashimha electrode, followed by deposition of isotopes of heavy metals and radioactive ions with collectors and separating the slurry phase from the solution.

The disadvantage of this method is the need for a gas diffusion electrode complex structures.

A method of processing ammonium sulfate radioactive solutions described in the patent of Russian Federation №2271587 on CL G21F 9/16, 9/20, Appl. 06.11.2003, publ. 10.03.2006.

The known method includes galvanomagnetic processing, in which the radioactive solution is passed through vibramicina galanopoulou iron-coke, is the orrection pH of radioactive solutions in two stages with separation of the precipitate after each stage, when this precipitate first-stage adjustment of the pH is mixed with montmorillonite clay, pressed pellets, spend their drying and subsequent calcination to obtain glass ceramics in which the immobilization of sludge containing radionuclides, and the filtrate is first treated in the froth layer for Stripping ammonia and then passed through a natural ion exchanger.

The disadvantage of this method is the complexity of its implementation because of its multi-stage system and a large number of operations.

The known method and device for processing liquid radioactive waste described in the patent of Russian Federation №2116680 "Installation for decontamination of liquid radioactive waste" CL G21F 9/06, Appl. 24.06.94, publ. 27.07.98.

The known method is that in the cavity of the processing chamber with the capacity of the filter loaded polymeric polyelectrolyte hydrogel creates between the chamber walls and capacity filter electric field of 0,001-0,0001/m, using them as electrodes serving of liquid radioactive waste (LRW) for processing by irradiating them with light radiation in the infrared range and spraying their sprinkler on polymer polyelectrolyte hydrogel, before it is controlled by weight saturation to 1:50-1:100, where 1 is the weight of the hydrogel, then subjected to the processed amount of liquid radwaste radiation of the acoustic wave is in the range of 25-45 kHz at a temperature of from 0 to 10°C for intensification of the process of separation LRW water and radioactive waste, that when they settle in the hopper is subjected to a local area heating to reduce the content of moisture and is directed to a container for further processing.

Known device includes a housing in which the camera is to be processed, having a perforated wall, the electrodes to create an electric field, the cavity of the chamber connected to the tank for draining purified water, with the camera placed perforated the capacity of the filter, and the installation is also equipped with emitters of the acoustic waves, the emitters of light waves and heat exchanger, and the chamber is filled polyelectrolyte polymer of the hydrogel, and perforated the capacity of the filter is located in the environment of the hydrogel, also connected by railway with the capacity for discharge of treated water in the upper part of the body is a tube, equipped with a perforated nozzle for spraying the liquid raw on the surface of the processing chamber, and the cavity of the processing chamber and the body cavity is connected to the vacuum unit by means of a branch pipe. At the same time as the acoustic emitters use the emitters of ultrasonic waves, and as electrodes for radiation electric fields use the chamber wall and the perforated wall of the vessel filter.

The disadvantage of this method is the complexity of the process, due to the use is the use of light irradiation, spray, acoustic treatment, heating and so on, which complicates the construction of the installation.

The known method and installation for processing of radioactive solutions, described in the patent of the Russian Federation No. 2319237, Appl. 13.06.2006, publ. 10.03.2008 and selected as a prototype.

The known method is that in the radioactive solution when applying to the processing type of the chemical elements and substances to control the process, the solution was heated and sprayed, then put it under the influence of an electric field in the processing chamber simultaneously with the irradiation of a solution of a unipolar electromagnetic pulses with a capacity of more than 1 MW and a duration less than 1 NS, repetition rate of not less than 1 kHz.

The known apparatus comprises a body placed in it by the electrodes to create an electric field, one of which is the case, the emitter of electromagnetic radiation, a heating device, a device for dispersion of radioactive solution, located in the upper part of the body located outside the casing and connected with it the unipolar generator of electromagnetic pulses with a capacity of over 1 MW, pulse duration of less than 1 NS and a repetition frequency of not less than 1 kHz, the heating device is connected through the pump and nozzle with atomizing device constituting the nozzle block, the second is electrode made in the form of a rod with the needle, located in the Central part of the body that serves as the emitter and connected to the generator.

Known tools provide high quality treatment, however, are very complex, due to the way the need for heating, spraying with careful filtering solution, and device - appropriate devices: device heating, and a spraying device, requiring the use of a filter.

The goal is to simplify processing tools providing high-quality cleaning.

The problem is solved by the fact that:

in the method of processing radioactive solutions, which consists in the fact that the radioactive solution is poured into the container, add the chemical elements and substances to control the process, and then subjecting it to irradiation unipolar electromagnetic pulses with a capacity of more than 1 MW and a duration less than 1 NS, repetition rate of not less than 1 kHz, according to the invention, the irradiation of the solution is carried out using an electrode made in the form of a horizontal plate, before lling solution in its lower part placed additional capacity of thin dielectric films, then pour the solution with the chemical elements and substances for process control processing, handle it in the course the e 10-30 minutes, maintain in capacity within 1-4 days, after which the treated solution is drained and removed the extra capacity, which is subjected to burial;

in an apparatus for handling radioactive solutions containing the body placed in it by the electrodes, one of which is the case, the emitter of electromagnetic radiation located outside the casing and connected with it the unipolar generator of electromagnetic pulses with a capacity of over 1 MW, pulse duration of less than 1 NS and a repetition frequency of not less than 1 kHz, while the second electrode is made in the form of a rod located in the Central part of the body that serves as the emitter and connected to the generator, according to the invention the casing is made of conductive material, the electrode is made in the form of a horizontal plate, the shape of the cross section of the casing and having a size of 20-30% from the sectional area of the casing, which is made with possibility of accommodation in its lower part at the time of treatment and disposal after processing additional capacity of thin dielectric films.

Use in planographic emitter, the shape of the cross section of the hull, but the smaller size allows for more efficient handling of the feed solution, which together with the use in the method of processing the additional capacity of the thin dielectric plait the key at the bottom of the housing, carrying out processing for 10-30 minutes and subsequent storage of the solution in the tank within 1-4 days provides the deposition of additional capacity generated in the process of precipitation, which is then removed together with the additional capacity and landfilled, and enables you to simplify the process and high quality cleaning.

Running in the electrode is in the form of a plate, the shape of the cross section of the body having a size of 20-30% of the sectional area of the housing, makes it possible to increase the size and efficiency of processing, in conjunction with the execution of the body with the possibility of accommodation in its lower part on the processing time and its subsequent removal after the additional processing capacity of the thin dielectric film allows a simpler design of the installation to obtain a high quality.

The technical result - the simplification of the processing of radioactive solutions while providing high quality cleaning.

The inventive method has the novelty in comparison with the prototype, differing from it in such essential characteristics as the electrode is in the form of a flat plate in the shape of the cross section of the casing and having a size of 20-30% of the sectional area of the body, placing at the bottom of the casing installation per the d filling it with a solution of additional capacity of thin dielectric films, the next Bay solution with chemical elements and substances for process control processing, processing it within 10-30 minutes, keeping the body within 1-4 days, discharge of the treated solution and the removal of additional capacity, which is subjected to disposal, providing collectively achieve the specified result.

The inventive installation is new in comparison with the prototype, differing from it in such essential characteristics as the execution of the electrode in the form of a flat plate in the shape of the cross section of the body having a size of 20-30% of the area of its cross section, running the body with locations in its lower part while processing the additional capacity of the thin dielectric film and its removal after processing, provides collectively achieve the specified result.

The applicant unknown solutions having the above salient features that collectively achieve the specified result, he felt, therefore, that the inventive method and installation for processing of radioactive solutions meet the criterion of "inventive step".

The proposed drug for the treatment of radioactive solutions can be widely used in the nuclear industry, and therefore is relevant to the comfort of the criterion of "industrial applicability".

The invention is illustrated in the drawing, which shows a functional diagram of the installation.

The inventive method of processing radioactive solutions is as follows.

Before lling solution in its lower part placed additional capacity of thin dielectric films. Then the radioactive solution is poured into the container, add the chemical elements and substances to control the process. After this, the solution is subjected to irradiation of a unipolar electromagnetic pulses with a capacity of more than 1 MW and a duration less than 1 NS, repetition rate of not less than 1 kHz. The solution process for 10-30 minutes, soak in capacity within 1-4 days, after which the treated solution is drained and removed the extra capacity, which is subjected to disposal.

The inventive system includes a conductive housing 1, in the Central part of which is placed an electrode 2 made in the form of a horizontal plate, the shape of the cross section of the body having a size of 20-30% of the sectional area of the housing, and located outside the housing of the generator 3 unipolar electromagnetic pulse of a power exceeding 1 MW, pulse duration of less than 1 NS and a repetition frequency of at least 1 kHz. While the electrode 2 is connected to one of the terminals of the generator 3 and the housing 1 to the second output of the generator 3. At the time of processing in the lower part of the housing 1 an additional capacity of 4 out of thin dielectric films.

The inventive method and installation are used for handling radioactive solutions as follows.

In case 1 place the additional capacity of 4 of the dielectric thin film, for example, of polyethylene. Pour in the housing 1 of the processed solution, add chemicals, such as acids or alkalis or salts. Then the solution is subjected to a through electrode 2 irradiation for 10-30 minutes unipolar electromagnetic pulses with a capacity of more than 1 MW and a duration less than 1 NS, repetition rate of not less than 1 kHz, obtained from the generator 3.

Irradiation of a solution powerful short pulses with a large area of the electrode leads to the radiolysis of water, which formed a very active reagent hydrated electrons (eaq. The interaction of hydrated electrons from radioactive chemical elements contained in the solution, and with the included chemical reagents causes a change in the chemical composition of the solution and precipitation. While keeping the solution in the installation within 1-4 days resulting from precipitation process are deposited in the additional capacity of 4, which is then removed from the housing 1 and are buried together with the fallout-waste.

As an example of the operation of the plant can p is ivesti the following experience. In the case of a cylindrical shape with a diameter of 120 and a height of 190 mm, made of foil-coated glass was placed additional vessel made of plastic with a diameter of 110 and a height of 160 mm was bathed in an aqueous solution of radioactive137Cs volume of 1 litre.

To the solution was added alkali NaOH in the amount necessary to obtain the pH of a solution is equal to 10.

As an electrode used in a copper plate with a diameter of 30 mm. To the body and the electrode connected to the pulse generator with the following parameters: peak power 2 MW, pulse duration of 1 NS, pulse repetition rate 1 kHz. The processing time is 15 minutes After treatment observed precipitation.

The measured activity value of the aqueous solution in the vessel before treatment was 125 kBq/l, after treatment, after 2 days of 80 kBq/L.

In comparison with the prototype of the proposed processing tools are simpler and reduce the water activity of the solution.

1. The method of processing radioactive solutions, which consists in the fact that the radioactive solution is poured into the container, add the chemical elements and substances to control the process, then subjected to solution irradiation unipolar electromagnetic pulses with a capacity of more than 1 MW and a duration less than 1 NS, repetition rate of not less than 1 kHz, characterized in that blucina solution is carried out using an electrode, made in the form of a horizontal plate, the shape of the hull, before lling solution in its lower part placed additional capacity of thin dielectric films, then pour the solution with the chemical elements and substances to control process, process it within 10-30 minutes, soak in capacity within 1-4 days, after which the treated solution is drained and removed the extra capacity, which is subjected to disposal.

2. Installation for processing of radioactive solutions containing casing is placed in the Central part of the electrode is located outside the housing and connected with it one of the conclusions, and the second output from the generator electrode of a unipolar electromagnetic pulse of a power exceeding 1 MW, pulse duration of less than 1 NS and a repetition frequency of not less than 1 kHz, characterized in that the casing is made of conductive material, the electrode is made in the form of a horizontal plate, the shape of the cross section of the casing and having a size of 20-30% of the sectional area of the housing, which is made with possibility of accommodation in its lower part at the time of treatment and disposal after processing additional proportionate to the capacity of the flexible dielectric film.



 

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