L.3.2 Activities for prevention and liquidation of accidents.

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New Disaster Environment

ACTIVITIES TO PREVENT AND LIQUIDATE CHEMICAL AND RADIATION ACCIDENTS

1. General characteristics of radiation accidents

A radiation accident is the violation of the limits of safe operation, in which radioactive products or ionizing radiations go beyond the quantities provided for in the norms and it is necessary to interrupt the normal operation of the devices and equipment containing sources of ionizing radiations.

A nuclear reactor is the device in which a controlled chain reaction of nuclear fission of 235U, 233U or 242Plu is maintained. The first nuclear reactor was put into operation in Chicago by the Italian physicist Enrico Fermi on 02.12.1942, and in Russia - in 1954 (with a power of 5 MW).

A nuclear accident is the damage to the heat-separating elements of a nuclear reactor and the accidental exposure of personnel.

The area where the nuclear fuel is located and where the fission chain reactions take place is called the core. Nuclear fuel is stored in tubes called heat separation elements (HSEs). The tubes are made of metal alloys that should not strongly absorb neutrons. The TOEs are placed in a retarder, which serves to slow down the secondary neutrons and increase the efficiency of the fission process.

During operation of the reactor, heat is released at the expense of fission energy, which heats up the TOE. A heat sink system is used to cool the active area. Water, liquid metals or organic liquids are usually used as heat carriers. The heat carrier circulates around the active zone with the help of circulation pumps and removes the heat. To reduce neutron loss, the active zone is surrounded by a reflector. This increases the number of neutrons involved in the fission chain reaction. An important part of the construction of the active zone are the regulating rods. With them, the neutron field is controlled, and if necessary, they are lowered or removed from the active zone. They contain chemical elements absorbing neutrons, for example boron or cadmium (B, Cd). There is always more than the critical mass of uranium in the reactor. But the control rods immersed in the core absorb a large part of the neutrons.

Before starting the reactor, all the rods are completely immersed in the core. Then they are removed from her to such an extent that a critical condition is maintained. When the reactor is shut down, the control rods are again lowered deep into the core. During the operation of the reactors, there is sometimes a danger of an accident.

This can lead to a sudden change in the work regime and to severe consequences. In order to prevent such cases, emergency protection is provided in the reactors. When the power of the reactor exceeds the critical one, the emergency protection is activated automatically and all the regulating rods are lowered into the active zone. This stops the fission chain reaction. Reactors are powerful sources of neutrons and gamma rays that penetrate the core's casing and are hazardous to the health of service personnel.

Therefore, protection of the nuclear reactor is provided by a complex of equipment, reducing the intensity of radiation to the permissible doses. Shielding must attenuate both neutrons and gamma radiation. Since there are no elements in nature that simultaneously weaken both radiations, a combined protection is created from reinforced concrete, steel with the addition of boron-tungsten alloys, etc.

When the coolant passes through the core of the reactor, it is heated and its heat is used to produce steam in so-called steam generators. Water flows through the steam generator, which is partially or completely converted into steam. The steam is released through the turbine which drives the electricity generator. In the condenser, the spent steam is converted into water and again led to the steam generator. According to various criteria such as: type of fuel used, neutron energy, type of moderator, etc., nuclear reactors, about 550 in number in the world, can be classified into the following groups:

A. The energy of neutrons:

-Reactors operating with thermal neutrons;

-Reactors operating with intermediate neutrons;

-Reactors operating with fast neutrons.

B. Nuclear fuel:

-Reactors operating with natural uranium-238, i.e. uranium-235 only 0.71354% of the content of the uranium block;

-Reactors operating with low-enriched uranium, i.e. uranium-235 is 1-2% of the content of the uranium block;

-Reactors operating with highly enriched uranium, i.e. the content of uranium-235 is about 90%;

-Plutonium reactors; -Thorium reactors.

C. Type of retarder:

-Reactors with ordinary or heavy water;

- Graphite reactors;

- Beryllium reactors.

D. Purpose of the reactors:

-Energy reactors intended for obtaining electrical energy;

-Research reactors intended for conducting physical, radiochemical and biophysical research;

- Reactors for obtaining radioactive isotopes;

-Breeder reactors designed for the reproduction of nuclear fuel.

E. Heat removal method:

-Heat carrier only;

-Fuel mixed with coolant;

-Retarder mixed with coolant;

-Fuel retarder - heat carrier.

The main types of reactors for obtaining electricity are:

- the English MAGNOX reactors;

- the American light water reactors "BWR" and "PVR";

- the Russian reactors "VVER" and "RBMK";

- the Canadian "KANDU" reactors.

"Kozloduy" NPP has a total of six reactors of the "VVER" type, of which 4 have a capacity of 440 MW each and two have a capacity of 1000 MW each.

VVER-440 has a vertical thick-walled housing, designed for a pressure of 18 MPa (180 atm). The hull has a diameter of 4.5 meters and a height of 11 meters. The core of the reactor, located in the shell, has a diameter of 2.9 meters and a height of 2.5 meters, and consists of 349 cartridges, 276 of which are operational - filled with nuclear fuel.

The remaining 73 cassettes have control and protection functions. By removing or inserting into the core, they regulate and power the reactor and are used for its emergency shutdown. Each cartridge consists of 126 cylindrical tubes with a length equal to the height of the active zone and are filled with heat-dissipating elements with a diameter of 9.1 mm. Uranium-235 enriched to 3.3% is used as nuclear fuel. Water is used as a heat carrier and neutron retarder. That is why the name of the reactor is derived from there (water-water energy reactor).

2. Classification of nuclear accidents.

According to the International Atomic Energy Agency /IAEA/ at the UN, this can be done on the basis of the scales of space, in which conditions for additional irradiation are created:

Level 1. Consequences are localized only to a single room, laboratory or building in which the relevant nuclear installation or facility is located.

Level 2. Consequences are localized only in the area of the site where the nuclear installation or facility is located.

Level 3. The consequences spread beyond the territory of the site where the nuclear installation or facility is located, creating a danger for the population of that area.

Level 4. Consequences may spread over large spaces distant from the accident site, and transboundary transfer of radioactive materials may be observed.

First degree. It is characterized as an "anomaly" in the functioning of the relevant facility or installation within the permissible limits for its operation. No danger is created for the service personnel.

Second degree. It is characterized as an "incident" in which potential consequences for the safety of the object are possible.

Third degree. It is characterized as a "serious incident" in which there is a possibility of major contamination of the site and exposure of personnel above the specified norms. Expected doses in this case are below 50 mSv (millisieverts) in the whole body (effective or equivalent dose) or below 500 mSv in individual organs Radioactive contamination with liquid radioactive substances can be of the order of several gigabecquerels.

The third degree nuclear accident does not pose a danger to the population living in the vicinity of the site. Individuals can receive doses of several hundred microsieverts from it. It is not necessary to introduce additional measures to protect the population.

Fourth degree. It is characterized as an "accident" within the confines of the nuclear power plant. Partial destruction of the core is possible. Individual personnel may receive effective doses of the order of 1Sv. Minor release of radioactive substances into the environment is possible, in which individuals of the population can receive doses of the order of several millisieverts No additional measures to protect the population need to be introduced.

Fifth degree. It is characterized as an "accident" with a risk to the environment. A significant destruction of the active area is possible. To limit the radiation impact from radioactive products entering the environment, some protective measures must be partially implemented.

Sixth degree. It is characterized as a "severe accident", in which a significant amount of fission products with an activity of the order of several thousand to several tens of thousands of terabecquerels is released. In this case, it is necessary to implement the protection measures provided for in the emergency plan of staff and population.

Seventh degree. It is characterized as a "global emergency", in which it is possible to release large quantities of radioactive substances into the environment, which can spread over large areas. The activity of the radioactive substances released can be of the order of hundreds of thousands of terabecquerels. The radiation effect can to be carried over to neighboring countries.The envisaged protection measures must be put in place, which can cover very large groups of the population.

The classification of accidents as dangerous is defined in the "ORDINANCE on emergency planning and emergency preparedness in case of a nuclear and radiation accident" Adopted by PMS No. 313 of 22.11.2011, promulgated, SG No. 94 of 29.11.2011, in effective from 29.11.2011, amended, No. 57 from 28.07.2015, effective from 28.07.2015, No. 55 from 7.07.2017, effective from 7.07.2017

In order to optimize the requirements for the purposes of emergency planning, objects, facilities and activities are categorized into the following risk categories:

• risk category I - nuclear facilities in which the probable exit events at the site, including

• initial events with a very low probability of occurrence may lead to an accident with severe deterministic effects outside the site;

• risk category II - nuclear facilities, in which the probable exit events at the site may lead to the irradiation of persons outside the site, which necessitates the application of urgent protective measures;

• risk category III - nuclear facilities and sites with radioactive sources, in which probable emergency events at the site may lead to irradiation or radioactive contamination of the environment above the established limits, in which case it is necessary to apply urgent protective measures only within the boundaries of the site;

• risk category IV - activities with nuclear materials and radioactive sources, which may lead to the occurrence of an accident in a place that cannot be predicted and determined in advance, including activities with dangerous sources, illegally acquired;

• risk category V - objects and activities that are not directly related to radioactive sources, but where there is a high probability that, as a result of their activity, radioactive contamination of production and uncontrolled spread of radioactive substances as a result of emergency events will occur, occurred in facilities of risk categories I and II or for other reasons that require the application of protective measures.

3. Emergency response order

Emergency response is taking actions to limit and reduce the consequences of an accident on the health and safety of personnel and the population, the quality of life, material values and the environment, as well as is the basis for restoring normal conditions for social and economic life after the liquidation of the consequences of the accident.

The practical objectives of emergency response are:

1. establishing control over the development of the emergency situation;

2. limitation and/or liquidation of the consequences of the accident;

3. preventing the occurrence of deterministic effects for personnel and the population;

4. timely and appropriate treatment of irradiated persons;

5. reducing the probability of occurrence or limiting, as far as is practically possible, the occurrence of stochastic health effects for the population;

6. prevent or limit, as far as is practicable,

the occurrence of non-radiation risks for personnel and the population, such as the release of

toxic substances in case of fire, explosions, floods, collapses, etc.;

7. preservation, as far as is practically possible, of the property;

8. preparation for the restoration of social and economic life.

The licensee or the holder of the permit maintains constant readiness for actions in case of accidents, keeps an emergency team ready, the members of which are determined in advance with the internal emergency plan. They are equipped with technical, transport and communication means and means of personal protection.

In the event of an emergency situation, the licensee or the permit holder implements the internal emergency plan and, according to an established scheme, notifies the Ministry of Internal Affairs through the Ministry of Internal Affairs and Communications, the chairman of the NRA, as well as the bodies of the executive power, related to the liquidation of the consequences of the emergency situation, including the preservation at the scene of the accident and formation of an operational-investigative group in accordance with the emergency plans.

A person who has registered contamination with radioactive substances on the territory of the country, notifies the chairman of the NRA and the operational duty officer of the Ministry of Internal Affairs and Communications.

Upon receipt of information in the NRA about an existing potential danger of cross-border transmission, the chairman of the NRA notifies the Minister of the Interior through the operational duty officer of the State Security and Defense Ministry - Ministry of the Interior and other competent bodies of the Ministry of the Interior.

For objects of risk categories I and II and in case of cross-border transfer, the Prime Minister by order puts into effect and accordingly terminates the implementation of the external emergency plan at the national level.

Until the implementation of the external emergency plan, the chairman of the National Emergency Committee determines the implementation of urgent measures for the protection of the population, when this is required by the development of the emergency situation.

The bodies of the executive power and the licensee or the permit holder through their emergency teams, early notification and radiation monitoring posts and their specialized laboratories provide data and information about the radiation situation and the development of the emergency situation to the NSHTKC, GDPBZN - MIA and to the NRA in the form, according to the order and within the terms determined by the external emergency plan.

The Ministry of the Interior, through the units that support its activities, carries out an initial assessment, verification and analysis of information, forecasts the development of the emergency situation and determines measures to protect the population together with the Minister of Health, the Minister of Environment and Water and the Chairman of the NRA.

In certain cases, depending on the specifics of the protective measure at the proposal of the Council of Ministers, the Council of Ministers decides on its implementation.

For objects of risk categories III, IV and V, the director of the State Disaster Management Authority - Ministry of Internal Affairs puts into effect the Standard Operating Procedures, included as annexes in the National Disaster Protection Plan, and accordingly terminates their implementation.

Depending on the risk category, the emergency teams implement the emergency plans in compliance with the following requirements:

1. reduction of the time of stay in the places and areas contaminated with radioactive substances;

2. carrying out activities at the greatest possible distance from the radioactive source;

3. use of protective barriers and manipulators when possible;

4. use of individual means of protection.

In order to carry out the activities, the places and areas contaminated with radioactive substances are fenced off, marked and deactivated whenever possible.

The members of the emergency teams constantly monitor their individual radiation doses and upon reaching the established control limits they immediately leave the area of the emergency situation.

Individual monitoring and medical supervision are provided for all members of the emergency teams.

To prevent the spread of radioactive contamination:

1. People, animals, means of transport, materials, technical means and other objects contaminated with radioactive substances shall leave the places and areas contaminated with radioactive substances only after decontamination;

2. Leaving the places and areas contaminated with radioactive substances is permitted when:

a) people and objects contaminated with radioactive substances are isolated in a way that prevents the spread of radioactive substances;

b) the surface contamination of the insulating means does not exceed 20 mSv/h,

c) the power of the equivalent dose at any point of the external surface of the vehicle does not exceed 2 mSv/h, and at the place of the driver and the persons accompanying him - 10 μSv/h;

3. animals contaminated with radioactive substances live in specially designated places.

In cases where it is necessary to carry out urgent life-saving measures, injured persons contaminated with radioactive substances are removed from the places and areas contaminated with radioactive substances, under continuous medical control and individual monitoring.

During the emergency situation, all consequences as well as the effectiveness of the intervention are evaluated and documented.

After the completion of the actions to limit and liquidate the consequences of the emergency situation at the proposal of the National Committee of the Ministers, the Council of Ministers adopts, if necessary, a program for the implementation of long-term protective measures for the population and the environment.

The application of protective measures and any other action to limit, reduce and prevent exposure or the possibility of exposure and the harmful consequences for human health, quality of life, property and the environment in an emergency situation, chronic exposure or previous activities is called INTERVENTION.

The intervention is the basis for restoring normal conditions for social and economic life after liquidation of the consequences of the emergency situation.

The intervention is applied to affect:

1. the source of radioactive pollution - to limit or stop the direct irradiation and discharge of radioactive substances into the environment;

2. the environment - to limit the transfer of radioactive substances to humans;

3. the person - to limit the radiation and effective treatment of irradiated persons.

Intervention is determined based on:

1. the decision-making criteria and intervention levels;

2. the forecast for the development of the emergency situation;

3. the possible results of applying various protective measures;

4. the priority of health and social aspects over economic considerations;

5. other economic, social and psychological factors.

Intervention is only applied when:

1. the benefit of reducing the harmful effects of radiation is sufficient to justify the harm caused by the intervention and its costs, including the social cost;

2. the type, scope and duration of the applied protective measures are optimized so that the benefit of the intervention compared to the harm caused by it is maximized.

The implementation of protective measures is not postponed pending the results of radiation monitoring to confirm the predictions made.

The main types of emergency protective measures that must be implemented immediately in the first hours after the occurrence of a nuclear or radiation emergency are:

1. notification;

2. special treatment (decontamination) of the victims and additional requirements for public and personal hygiene;

3. individual and radiation monitoring;

4. restriction and control of access to places and areas contaminated with

radioactive substances, including limiting the consumption of food products that are potentially contaminated with radioactive substances;

5. protection of respiratory organs;

6. use of protective clothing;

7. concealment;

8. iodine prophylaxis;

9. evacuation.

Long-term protective measures are also applied, the duration of which can be weeks, months or years. The main types of long-term protective measures are:

1. resettlement (temporary or permanent);

2. limiting the consumption of food products and feed contaminated with radioactive substances;

3. decontamination of places and areas contaminated with radioactive substances and property, as well as restriction of their use;

4. restoration works to normalize living conditions in the affected areas.

In case of contamination with radioactive substances as a result of an existing or previous emergency situation or activity:

1. places and areas contaminated with radioactive substances are marked and, if necessary, isolated;

2. continuous individual monitoring is ensured;

3. appropriate intervention is applied taking into account the actual characteristics of the situation;

4. the use of the land and buildings located in the designated places and areas is regulated;

5. the possibility of an increase in the radioactive impact of the population is analysed;

6. radiation monitoring is carried out at different depths below the surface.

If necessary, additional measures are applied to the places and areas where intervention has been implemented, as follows:

1. control of the removed materials contaminated with radioactive substances and their use, including their trade;

2. access control in the territories contaminated with radioactive substances

4. Measures to protect the population in the event of an accident at the NPP.

General measures.

In the event of an accident at Kozloduy NPP and Cherna Voda NPP, as well as in other cases of cross-border transfer of radioactive substances, the following measures are taken:

• the population in the affected areas is informed about the accident and its measures and behavior in the event of radioactive contamination are explained (through the operative on duty of the DG "Fire Safety and Population Protection" - Ministry of the Interior and through the media;

• switches to continuous measurement mode by the radiation control systems;

• ESS forces are put on alert in the affected areas;

• taking urgent protective measures - sheltering the population, iodine prophylaxis, etc.;

• triggering the procedure for emergency, post-election or general evacuation of the population from the emergency planning area, based on the results of the forecast calculations;

• analysis of water, food products, fodder, etc. is carried out. by the relevant competent authorities;

The vital activity of the population and the acquisition of practical skills in the conditions of radioactive contamination are ensured through:

• personal decontamination and additional requirements for public and personal hygiene;

• protection of respiratory organs and use of protective clothing;

• hiding the population;

• use of canned food and feed;

• preference for foods produced before the accident;

• cessation of hunting, fishing and collection of wild mushrooms and fruits;

• application of special decontamination methods in case of inevitable use of contaminated food raw materials;

• transporting food raw materials and products and storing them in closed containers and closed rooms;

• passage of a special regime at the treatment plants.

5. General characteristics of chemical accidents.

Chemically dangerous are practically all objects in which chemical technologies are used to one degree or another. These are primarily chemical, petrochemical and similar plants and enterprises, storage facilities for dangerous chemical substances and oil product warehouses. A significant part of the sites of the non-chemical branches of industry, in the technological processes of which hazardous substances are applied and have chemical transformations, can be counted among the sites with chemical technology. In effect, sites with chemical technologies are potential sources of hazardous substances and environmental pollution and they can be called sites of chemical risk.

The most common poisonous substances in the production sector are: ammonia, sulfuric acid, caustic soda, sulfur oxides, propane-butane, cyanides and other substances.

In the event of an accident at any industrial site, the process of destructive release of its own energy reserve, in which raw materials, intermediate products and production of enterprises participate in an emergency process, create striking factors for the population and the environment, the level of chemical risk is significantly high. In the following, in the concept of chemical technology object (chemical risk object) I will include objects that produce, process, use, transport, contain or emit dangerous substances.

The danger to people and the environment from objects with chemical technologies can also be manifested during their normal functioning. This is related to technological emissions and also to the leakage of hazardous substances. Along with this, and in the cases of radiation accidents and catastrophes, by far the most large-scale and dangerous technological pollution in accidents and accidents in the objects using chemical technologies, especially in the chemically dangerous objects where it is produced, processed, used, transported, stored or chemically dangerous substances, emergency waste and spills are released, often leading to catastrophic consequences.

The safe functioning of chemically hazardous objects depends on many factors: physical and chemical properties of the raw material, the products of production, the nature of the technological process, the construction and reliability of the equipment, the conditions of storage and transportation of the chemical substances, the availability and condition of the control and measuring devices tools and means for automation, the effectiveness of means of emergency protection, etc. In addition, the safety of the production, use, storage and transportation of industrial toxic substances (POS) to a significant extent depends on the level of prevention organization, the timeliness and qualities of planning and warning activities, the preparedness and practical habits of the personnel, the available supervision system of the state of the technical means for emergency protection, as a preventive measure.

Currently, it is accepted as a quantitative measure of the toxicity of POPs to use the values of their concentration and dose of the substances. At the same time, such characteristics as concentration threshold, transmissibility limits, lethal concentration, significance of the toxic dose, which correspond to a certain effect of lesions, are most often used. Threshold is the minimum concentration at which a noticeable physiological effect occurs and the first signs of damage are noticed. Tolerance limit - this is a concentration that a person can withstand for a certain time without suffering persistent damage. An analogy for the tolerance limit is the maximum permissible concentration.

The toxic dose (toxodose) expresses the amount of substances causing a certain toxic effect. In the analysis and assessment of the chemical situation occurring during the spread of POW in the environment, it is accepted that the magnitude of the toxodose is determined as the product of the average concentration of POV in the air during the time of exposure during residence in a contaminated atmosphere (Сt) - in inhalation lesions and the mass of solid and liquid POPs falling into the human skin - in case of skin resorptive lesions.

Classification of industrial toxic chemicals.

Classification of industrial poisonous substances depending on the nature of their toxic action

First group - substances with a poisonous or corrosive effect on the skin and mucous membranes: concentrated acids such as H2SO4 - sulfuric, HNO3 - nitric, HCl - saline, H3PO4 - phosphoric and bases NaOH - sodium, KOH - potassium.

Second group - substances irritating the respiratory organs such as: chlorine, ammonia, sulfur dioxide, sulfur trioxide, phosgene. They cause laryngitis, tracheitis, bronchitis, pneumonia and pulmonary edema.

Third group - blood-poisoning substances, such as benzene, toluene, xylene, hydrogen arsenic, carbon monoxide, amino and nitro derivatives of benzene, etc.

Fourth group - substances acting on the nervous system, such as benzene, hydrogen sulfide, carbon disulfide, methyl alcohol, aniline, nitrobenzene, etc.

Fifth group - substances that inactivate respiratory enzymes and cause oxygen starvation, such as hydrogen cyanide, hydrogen sulfide, etc.

This classification is not fully supported, taking into account that a large part of POPs do not have a specific pronounced toxic effect and exhibit a temporary effect on the mucous membranes, blood circulation, respiratory center, which is why they can hardly be assigned to one or another of the specified five groups.

For this reason, POVs can be grouped into two main groups:

Substances with a general toxic effect;

Substances with an asphyxiating effect.

It is more appropriate to classify POPs based on their degree of toxicity at the same amount. In this regard, POWs can be classified into four groups:

First degree of toxicity - these are extremely dangerous toxic industrial substances with a maximum permissible concentration of the order of hundreds of thousands and millions of mg/l - they include combat poisons;

Second degree of toxicity – dangerously toxic substances with maximum permissible concentrations of the order of thousandths and ten thousandths of mg/l, such as sulfur trioxide, carbon disulfide, acrolein, formaldehyde, nitrobenzene, ethylene oxide, aniline, etc.

Third degree of toxicity – highly toxic substances with maximum permissible concentrations of the order of hundredths of mg/l, such as sulfur dioxide, acetonitrile, various types of alcohol, etc.

The fourth degree of toxicity – moderately toxic substances with maximum permissible concentrations of the order of tenths of tenths of mg/l, such as acetone, methane, ethyl alcohol and others.

With a view to greater security during work, storage and transportation of POW and compliance with safety measures, plants producing these substances are obliged to accompany POW with special emergency cards.

The following must be indicated in the emergency cards:

• the degree of toxicity;

• the main properties of POV;

• overwhelming effect of POV;

• what individual means of protection should be used when eliminating accidents with them;

• how to liquidate the accidents themselves;

• the ways of providing paramedical and medical assistance to the victims;

Each packaging or tank with POW in the storage warehouses and during transportation by means of transport must be accompanied by the corresponding emergency card.

The most common industrial poisons are ammonia and chlorine.

Ammonia is a colorless gas with a sharp suffocating smell, twice lighter than air, forms explosive mixtures. It is soluble in water. Ammonia vapors form a white cloud that rises to a height of 20-30 m. Due to the absorbed moisture from the air, the cloud descends again near the earth's surface.

Ammonia affects the upper respiratory tract and, in greater concentration, the central nervous system. It causes suffocation, severe coughing fits, eye pain, reddened skin with red spots and blisters, dizziness, stomach pain and vomiting. In cases of severe poisoning, heart failure and death may occur.

Chlorine is a highly poisonous gas, with a characteristic pungent, suffocating smell, is non-flammable and has a yellow-green color. It is soluble in water. It quickly evaporates and forms a yellow-green cloud that moves close to the earth's surface and collects in low places and tunnels. To limit chlorine contamination, the leak site is flooded with water, milk of lime, ammonia water and water curtains are created that reduce the spread of vapors. It causes severe irritation of the respiratory tract, excruciating cough, chest pains, burning and tearing of the eyes, on contact it causes burns on the skin. At high concentrations, it can cause pulmonary edema and death.

Accidents involving the release of hazardous chemical substances (HCS) include:

1. release of OHV as a result of leakage or spillage;

2. destruction of the integrity of the main product pipelines for liquid or gaseous chemical substances;

3. fires, explosions and destruction related to the release of dangerous chemical substances;

4. violation of the technological process with the release of dangerous chemical substances;

5. accidents during transport of dangerous chemical substances.

In the event of accidents with the release of dangerous chemical substances, emergency response is carried out by an emergency team according to the order of action for chemical, biological and radiation protection, determined by the instruction.

To eliminate the consequences of accidents and incidents with the release of dangerous chemical substances, the following are carried out:

1. actions to eliminate the consequences by removing the causes and decontamination;

2. neutralization of acid or base spills using decontaminating substances and solutions;

3. elimination of the consequences of accidents with mercury, pesticides and substances of unknown origin;

4. localization of spills of petroleum products by placing containment barriers and limiting environmental pollution.

When substances of unknown composition and origin are discovered, the following is done:

1. reconnaissance and establishment of a safe perimeter;

2. marking of the dangerous (infected) area;

3. providing assistance to the owner (in the case of an unidentified owner, the mayor of the municipality) for safe collection, removal and delivery for destruction of substances in accordance with the Waste Management Act;

4. in the case of an unknown substance, support the sampling;

5. carrying out decontamination of the injured, the staff and the equipment involved in the liquidation of the incident;

6. assisting in the decontamination of the infected site.

6. Main activities in protecting the population from chemical accidents.

One of the main problems in the complex study for forecasting the situation and liquidating the consequences of major chemical accidents with the occurrence of OHP from industrial poisons is the problem of the organization of medical insurance for those affected.

The "treatment on site" system dominates, which ensures the provision of first medical aid in the outbreak, rapid evacuation from the infected area and transport to the designated nearby hospital, where a specialized toxicological hospital is organized on the basis of the therapeutic department and a specialized toxicological team.

Medical insurance under the "on-site" treatment system has the following characteristics:

1. First medical aid, which is given in the outbreak in a certain volume, which, according to the situation and the qualification of the personnel providing the aid, can increase from first medical aid to medical aid. The scope of first medical aid includes the following measures:

a) searching, sorting and carrying out stretcher of all affected from the infected area;

b) interruption of contact with the poison;

c) maintaining the basic life processes - breathing and blood circulation.

2. Transportation of the seriously injured, which must be with sanitary vehicles and with the possibility of conducting intensive resuscitation measures during the evacuation.

3. Specialized hospital treatment of the toxicologically affected, which can only be carried out in a toxicological hospital, providing medical and diagnostic work, which should be carried out according to the type of poisonous substance and the severity of the injury. Therapeutic measures can be carried out in full, which includes: resuscitation, etiopathogenetic, symptomatic and organoprotective treatment.

In addition to medical insurance, a problem with OHP is the hygienic-epidemiological insurance of the people and the affected areas.

Solving it requires:

• Mass training of workers in the threatened enterprise and its adjacent areas in matters of providing first medical aid in the form of self- and mutual aid;

• Express indication of industrial poisons, from the chemical laboratories of the Ministry of Health, the laboratories of the endangered sites and those of the HEI, which must work in close cooperation;

• Development of specific hygiene-preventive measures in case of occurrence of OHP, ways and means for sanitary treatment of the poisoned, prohibition of consumption of drinking water and food products from the infected area without the necessary control; not allowing people into the work premises until the accident is completely eliminated, etc.;

• The availability of means and methods for the disposal and removal of poisonous substances from the contaminated territory, with control over the effect of the decontamination and assessment of the moment for safe work.

ACTIVITIES FOR PREVENTION AND LIQUIDATION OF ACCIDENTS