Decontamination (decontamination) is the removal of radioactive substances from surfaces or from a mass of various objects of the external environment (buildings, clothes, equipment, water, food products , etc.). The main task of decontamination is to reduce levels of contamination with radioactive substances (see. Isotopes , radioactive) to permissible levels or concentrations. The collection and disposal of radioactive waste is essential (see).
The main methods of decontamination: 1) mechanical (washing with water, wiping with a rag or similar materials, scraping, brushing, cleaning with vacuum cleaners and sandblaster, etc.); 2) physical (diluted with water, etc.); 3) chemical (treatment with acids, alkalis , etc.); 4) physico-chemical (detergents, ion exchange resins, etc.); 5) biological (activated sludge, etc.).Go
Mechanical methods are used to decontaminate surfaces: powders are collected with moistened rags, solutions - with filter paper, etc., and then treated to surfaces with special detergent solutions (Novost powder, etc.). In case of significant residual contamination, mechanical removal of the table, floor, plaster, etc. is carried out.
Decontamination equipment produced in the same ways. Nitric and hydrofluoric acids are used to deactivate stainless steel equipment. Valuable equipment is deactivated with solutions of citric and oxalic acids (0.1–0.2%).
Decontamination of clothing is achieved by multi-stage processing with various detergents with the inclusion of oxalic (citric) acid, Trilon B and other products in the technology of washing.
Hands are treated with brushes with warm water and soap. If contaminated with radioactive thorium or phosphorus , hands should be washed repeatedly with soap with Trilon B, hexametaphosphate or a detergent powder, and if contaminated with radium - kaolin soap.
To remove other radioactive substances, a 1-2% sodium citrate solution or OP-10 wetting agent is used.
Decontamination of water and liquid radioactive waste is carried out using a comprehensive method, including mechanical (filters) and biological (biofilters) cleaning, coagulation and ion exchange filters, as well as evaporation, foaming, etc.
For the decontamination of food used mechanical methods: wash with water, remove the surface layer. With structural contamination of food (for example, vegetables through the root system), decontamination is difficult and ineffective. When contaminated with short-lived isotopes, the products are stored for a period during which the radioactivity is reduced to a safe level due to natural radioactive decay. The level of food contamination is significantly reduced in many processing processes: grinding of grain, production of ghee, etc.
Quality control of decontamination is carried out using dosimetric and radiometric devices.
When carrying out decontamination, it is necessary to follow the rules for working with radioactive substances, including dosimetric control (see) and sanitary treatment (see) of people carrying out these works.Go
Decontamination in the military field is carried out with the aim of preventing or weakening the damaging effects of radioactive substances on the personnel of the troops caught in the zones of radioactive contamination.
Decontamination in field conditions involves the removal of radioactive substances from the surfaces of weapons, military equipment, engineering structures, personal protective equipment, uniforms, shoes, equipment, as well as food and water. The most effective decontamination carried out shortly after radioactive contamination. Depending on the complete removal of radioactive substances, deactivation in the military field conditions may be partial or complete.
Partial decontamination is carried out by troops. It consists in removing the main quantity of radioactive substances from the surfaces of objects and objects with which the personnel is forced to come in contact. Partial decontamination is carried out both on contaminated and non-contaminated areas, using mainly improvised means. From the surface of contaminated objects and objects, radioactive dust is removed by sweeping it with branches, brooms or brushes or wiping wet rags, rags and grass tufts, as well as snow taken from deep layers. Uniforms, bags of gas masks , a cape, camp and other tents are subject to shaking out or vykolachivaniyu sticks. With partial decontamination of mobile military equipment (tanks, armored personnel carriers, etc.) and engineering structures, their internal surfaces are also processed. If there is a water source nearby, the surfaces of objects and objects are washed with water. Partial decontamination of open fortifications consists in removing trenches, trenches, rifle cells from the bottom of the surface layer of the earth, 3-5 cm thick, after sweeping away radioactive dust from vertical and inclined surfaces.
Complete decontamination consists in the complete removal of radioactive substances from all surfaces of military objects and objects or in reducing the contamination with these substances to levels safe for personnel. The effectiveness of the complete decontamination is monitored by dosimetric devices (see. Ionizing radiation dosimeters). Full decontamination is carried out by special units and subdivisions at special treatment points (see) deployed at sites outside the contaminated zone.
The complete removal of radioactive substances from all weapons and military equipment, equipment, footwear, protective clothing, gas masks and other items that do not damage their moistening, is carried out with a water jet or decontamination solutions using special washing equipment. For greater efficiency when washing, use brushes, brooms, rags, etc. Uniform with strong radioactive contamination, which is not reduced when shaking out and knocking out, is subjected to washing in special mechanized laundries .
Food and water when contaminated with radioactive substances undergo only complete deactivation. For water purification using special water treatment equipment containing filter materials that are periodically replaced.
Food contained in solid hermetic containers, are used only after careful processing of containers. Flour, cereal and other products enclosed in soft containers (bags) are moistened, dried, and after the formation of a superficial crust, they are poured into clean sacks, and the crust is destroyed. Meat and fish are thoroughly washed with water. The use of food and water is allowed only after dosimetric control. Personnel involved in the decontamination, undergo sanitary treatment.