Nuclear weapons and their damaging factors. Brief characteristics of the source of nuclear damage

Nuclear weapons are a type of explosive weapon of mass destruction based on the use of intranuclear energy. Nuclear weapons, one of the most destructive means of warfare, are among the main types of weapons of mass destruction. It includes various nuclear weapons (warheads of missiles and torpedoes, aircraft and depth charges, artillery shells and mines equipped with nuclear chargers), means of controlling them and means of delivering them to the target (missiles, aviation, artillery). Lethal effect nuclear weapons based on the energy released during nuclear explosions.

Nuclear explosions are usually divided into air, ground (surface) and underground (underwater). The point at which the explosion occurred is called the center, and its projection on the surface of the earth (water) is called the epicenter of the nuclear explosion.

By air called an explosion, the luminous cloud of which does not touch the surface of the earth (water). Depending on the power of the ammunition, it can be located at an altitude from several hundred meters to several kilometers. There is practically no radioactive contamination of the area during an airborne nuclear explosion (Fig. 17).

Ground (surface) a nuclear explosion is carried out on the surface of the earth (water) or at such a height when the luminous area of ​​the explosion touches the surface of the earth (water) and has the shape of a hemisphere. Its damage radius is approximately 20% less than that of the air.

A characteristic feature of a ground (surface) nuclear explosion- severe radioactive contamination of the area in the area of ​​the explosion and along the trace of the movement of the radioactive cloud (Fig. 18).

Underground (underwater) called an explosion produced underground (underwater). The main damaging factor of an underground explosion is a compression wave propagating in the soil or water (Fig. 19, 20).

Nuclear explosion accompanied by a bright flash and a sharp, deafening sound reminiscent of thunderstorms. In an air explosion, following the flash, a fireball is formed (in the case of a ground explosion, a hemisphere), which quickly increases, rises, cools and turns into a swirling cloud, shaped like a mushroom.

The damaging factors of a nuclear explosion are shock wave, light radiation, penetrating radiation, radioactive contamination and electromagnetic pulse.

Shock wave - one of the main damaging factors of a nuclear explosion, since most of the destruction and damage to structures, buildings, as well as injuries to people are caused by its impact.

Depending on the nature of the destruction at the source nuclear destruction four zones are distinguished: complete, strong, medium and weak destruction.

Basic a method of protection against a shock wave is the use of shelters (shelters).

Light radiation is a stream of radiant energy, including ultraviolet, visible and infrared rays. Its source is a luminous area formed by hot explosion products and hot air.

Light radiation spreads almost instantly and lasts, depending on the power of the nuclear explosion, up to 20 s. It can cause skin burns, damage (permanent or temporary) to people's vision, and fire of flammable materials and objects.

Protection from light radiation can be various items, creating a shadow. Light radiation does not penetrate through opaque materials, so any barrier that can create a shadow protects against the direct action of light radiation and protects against burns. The best results are achieved when using shelters and shelters that simultaneously protect from other damaging factors of a nuclear explosion.

Under the influence of light radiation and a shock wave, fires, combustion and smoldering in the rubble occur in the source of nuclear damage. The set of fires that occur in the source of nuclear damage is usually called mass fires. Fires at the source of nuclear damage continue long time, so they can cause a large number of destruction and cause more damage than the shock wave.

Light radiation is significantly weakened in dusty (smoky) air, fog, rain, and snowfall.

Penetrating radiation - This is ionizing radiation in the form of a stream of gamma rays and neutrons. Its sources are nuclear reactions occurring in the ammunition at the moment of explosion, and radioactive decay fission fragments (products) in the explosion cloud.

The duration of action of penetrating radiation on ground objects is 15-25 s. It is determined by the time the explosion cloud rises to such a height (2-3 km) at which gamma-neutron radiation, absorbed by the air, practically does not reach the earth's surface.

Passing through living tissue, gamma radiation and neutrons ionize molecules that make up living cells, disrupt metabolism and vital functions of organs, which leads to radiation sickness.

As a result of radiation passing through materials environment their intensity decreases. For example, the intensity of gamma rays is reduced by 2 times in steel with a thickness of 2.8 cm, concrete - 10 cm, soil - 14 cm, wood - 30 cm (Fig. 21).

Nuclear pollution. Its main sources are nuclear fission products and radioactive isotopes, formed as a result of the impact of neutrons on the materials from which nuclear weapons are made, and on some elements that make up the soil in the area of ​​the explosion.

In a ground-based nuclear explosion, the glowing area touches the ground. Masses of evaporating soil are drawn inside it and rise upward. As they cool, the vapors of fission products and soil condense. A radioactive cloud is formed. It rises to a height of many kilometers, and then moves at a speed of 25-100 km/h air masses in the direction the wind blows. Radioactive particles falling from the cloud to the ground form a zone radioactive contamination(trace), the length of which can reach several hundred kilometers. In this case, the area, buildings, structures, crops, reservoirs, etc., as well as the air, become infected. Contamination of terrain and objects on the trail of a radioactive cloud occurs unevenly. There are zones of moderate (A), severe (B), hazardous (C) and extremely dangerous (D) pollution.

Moderate pollution zone (zone A)- the first part of the trace from the outside. Its area makes up 70-80% of the entire footprint. External border zones of heavy pollution (zone B, about 10% of the track area) is combined with the inner border of zone A. The outer border zones of hazardous pollution (zone B, 8-10% of the track area) coincides with the inner border of zone B. Extremely hazardous pollution zone (zone D) occupies approximately 2-3% of the track area and is located in zone B (Fig. 22).

Radioactive substances pose the greatest danger in the first hours after deposition, since during this period their activity is greatest.

Electromagnetic pulse is a short-term electromagnetic field that occurs during the explosion of a nuclear weapon as a result of the interaction of gamma rays and neutrons emitted with the atoms of the environment. The consequence of its impact may be the failure of individual elements of radio-electronic and electrical equipment. People can only be harmed if they come into contact with wire lines at the time of the explosion.

Questions and tasks

1. Define and characterize nuclear weapons.

2. Name the types of nuclear explosions and briefly describe each of them.

3. What is called the epicenter of a nuclear explosion?

4. List damaging factors nuclear explosion and describe them.

5. Describe the zones radioactive contamination. In which zone do radioactive substances pose the least danger?

Task 25

Exposure to what damaging factor of a nuclear explosion can cause skin burns, damage to human eyes and fires? Choose the correct answer from the given options:

a) exposure to light radiation;
b) exposure to penetrating radiation;
c) exposure to an electromagnetic pulse.

Task 26

What determines the time of action of penetrating radiation on ground objects? Select the correct answer from the given options:

a) type of nuclear explosion;
b) nuclear charge power;
c) action electromagnetic field arising from the explosion of a nuclear weapon;
d) the time the explosion cloud rises to a height at which gamma-neutron radiation practically does not reach the earth’s surface;
e) the time of propagation of the luminous region that appears during a nuclear explosion, formed by the hot products of the explosion and hot air.

Nuclear weapons is a weapon whose destructive effect is based on the use of intranuclear energy released during a nuclear explosion.

Nuclear weapons are based on the use of intranuclear energy released during chain reactions fission of heavy nuclei of isotopes of uranium-235, plutonium-239 or during thermonuclear reactions of fusion of light nuclei isotopes of hydrogen (deuterium and tritium) into heavier ones.

These weapons include various nuclear munitions (warheads of missiles and torpedoes, aircraft and depth charges, artillery shells and mines) equipped with nuclear chargers, means for controlling them and delivering them to the target.

The main part of a nuclear weapon is a nuclear charge containing a nuclear explosive (NE) - uranium-235 or plutonium-239.

A nuclear chain reaction can only develop if there is a critical mass of fissile material. Before the explosion, nuclear explosives in one ammunition must be divided into separate parts, each of which must be less than critical in mass. To carry out an explosion it is necessary to connect them into a single whole, i.e. create a supercritical mass and initiate the start of the reaction from a special neutron source.

The power of a nuclear explosion is usually characterized by its TNT equivalent.

The use of fusion reactions in thermonuclear and combined ammunition makes it possible to create weapons with virtually unlimited power. Nuclear fusion of deuterium and tritium can be carried out at temperatures of tens and hundreds of millions of degrees.

In reality, in the ammunition this temperature is reached during the nuclear fission reaction, creating conditions for the development of a thermonuclear fusion reaction.

An assessment of the energy effect of the thermonuclear fusion reaction shows that during fusion 1 kg. Helium energy is released from a mixture of deuterium and tritium in 5p. more than when dividing 1 kg. uranium-235.

One of the types of nuclear weapons is neutron ammunition. This is a small-sized thermonuclear charge with a power of no more than 10 thousand tons, in which the main share of energy is released due to the fusion reactions of deuterium and tritium, and the amount of energy obtained as a result of the fission of heavy nuclei in the detonator is minimal, but sufficient to start the fusion reaction.

The neutron component of the penetrating radiation of such a low-power nuclear explosion will have the main damaging effect on people.

For a neutron munition at the same distance from the epicenter of the explosion, the dose of penetrating radiation is approximately 5-10 rubles greater than for a fission charge of the same power.

Nuclear ammunition of all types, depending on their power, are divided into the following types:

1. Ultra-small (less than 1 thousand tons);

2. small (1-10 thousand tons);

3. medium (10-100 thousand tons);

4. large (100 thousand - 1 million tons).

Depending on the tasks solved with the use of nuclear weapons, Nuclear explosions are divided into the following types:

1. air;

2. high-rise;

3. ground (surface);

4. underground (underwater).

Damaging factors of a nuclear explosion

When a nuclear weapon explodes, a colossal amount of energy is released in millionths of a second. The temperature rises to several million degrees, and the pressure reaches billions of atmospheres.

High temperature and pressure cause light radiation and a powerful shock wave. Along with this, the explosion of a nuclear weapon is accompanied by the emission of penetrating radiation, consisting of a stream of neutrons and gamma rays. The explosion cloud contains a huge amount of radioactive fission products of a nuclear explosive, which fall along the path of the cloud, resulting in radioactive contamination of the area, air and objects.

The uneven movement of electric charges in the air, which occurs under the influence of ionizing radiation, leads to the formation of an electromagnetic pulse.

The main damaging factors of a nuclear explosion are:

shock wave - 50% of explosion energy;

light radiation - 30-35% of explosion energy;

penetrating radiation - 8-10% of explosion energy;

radioactive contamination - 3-5% of explosion energy;

electromagnetic pulse - 0.5-1% of explosion energy.

Nuclear weapon- This is one of the main types of weapons of mass destruction. It is capable of incapacitating a large number of people and animals in a short time, and destroying buildings and structures over large areas. The massive use of nuclear weapons is fraught with catastrophic consequences for all humanity, therefore the Russian Federation is persistently and steadily fighting for their ban.

The population must firmly know and skillfully apply methods of protection against weapons of mass destruction, otherwise huge losses are inevitable. Everyone knows the terrible consequences of the atomic bombings in August 1945 of the Japanese cities of Hiroshima and Nagasaki - tens of thousands of dead, hundreds of thousands of injured. If the population of these cities knew the means and methods of protecting themselves from nuclear weapons, were notified of the danger and took refuge in a shelter, the number of victims could be significantly less.

The destructive effect of nuclear weapons is based on the energy released during explosive nuclear reactions. Nuclear weapons include nuclear weapons. The basis of a nuclear weapon is a nuclear charge, the power of the damaging explosion of which is usually expressed in TNT equivalent, i.e., the amount of conventional explosive, the explosion of which releases the same amount of energy as it would be released during the explosion of a given nuclear weapon. It is measured in tens, hundreds, thousands (kilos) and millions (mega) tons.

The means of delivering nuclear weapons to targets are missiles (the main means of delivering nuclear strikes), aviation and artillery. In addition, nuclear land mines can be used.

Nuclear explosions are carried out in the air at various heights, near the surface of the earth (water) and underground (water). In accordance with this, they are usually divided into high-altitude, air, ground (surface) and underground (underwater). The point at which the explosion occurred is called the center, and its projection onto the surface of the earth (water) is called the epicenter of the nuclear explosion.

The damaging factors of a nuclear explosion are shock wave, light radiation, penetrating radiation, radioactive contamination and electromagnetic pulse.

Shock wave– the main damaging factor of a nuclear explosion, since most of the destruction and damage to structures, buildings, as well as injuries to people are, as a rule, caused by its impact. The source of its occurrence is the strong pressure formed in the center of the explosion and reaching billions of atmospheres in the first moments. The area of ​​strong compression of the surrounding layers of air formed during the explosion, expanding, transfers pressure to neighboring layers of air, compressing and heating them, and they, in turn, affect the following layers. As a result, a zone spreads in the air at supersonic speed in all directions from the center of the explosion high pressure. The front boundary of the compressed layer of air is called shock wave front.

The degree of damage to various objects by a shock wave depends on the power and type of explosion, mechanical strength (stability of the object), as well as on the distance at which the explosion occurred, the terrain and the position of objects on it.

The damaging effect of a shock wave is characterized by the magnitude of excess pressure. Overpressure is the difference between the maximum pressure at the shock wave front and normal atmospheric pressure ahead of the wave front. It is measured in newtons per square meter (N/meter squared). This unit of pressure is called Pascal (Pa). 1 N/meter square = 1 Pa (1 kPa * 0.01 kgf/cm square).

With excess pressure of 20 - 40 kPa, unprotected people can suffer minor injuries (minor bruises and contusions). Exposure to a shock wave with an excess pressure of 40 - 60 kPa leads to moderate damage: loss of consciousness, damage to the hearing organs, severe dislocations of the limbs, bleeding from the nose and ears. Severe injuries occur when excess pressure exceeds 60 kPa and are characterized by severe contusions of the entire body, fractures of the limbs, and damage to internal organs. Extremely severe lesions, often fatal, are observed at an excess pressure of 100 kPa.

The speed of movement and the distance over which the shock wave propagates depend on the power of the nuclear explosion; As the distance from the explosion increases, the speed quickly decreases. Thus, when an ammunition with a power of 20 kt explodes, the shock wave travels 1 km in 2 s, 2 km in 5 s, 3 km in 8 s. During this time, a person after the flash can take cover and thereby avoid being hit by the shock wave.

Light radiation is a stream of radiant energy that includes ultraviolet, visible and infrared rays. Its source is a luminous area formed by hot explosion products and hot air. Light radiation spreads almost instantly and lasts, depending on the power of the nuclear explosion, up to 20 s. However, its strength is such that, despite its short duration, it can cause burns to the skin (skin), damage (permanent or temporary) to the organs of vision of people and fire of flammable materials of objects.

Light radiation does not penetrate through opaque materials, so any barrier that can create a shadow protects against the direct action of light radiation and prevents burns. Light radiation is significantly weakened in dusty (smoky) air, fog, rain, and snowfall.

Penetrating radiation is a stream of gamma rays and neutrons. It lasts 10-15 s. Passing through living tissue, gamma radiation ionizes the molecules that make up the cells. Under the influence of ionization, biological processes arise in the body, leading to disruption of the vital functions of individual organs and the development of radiation sickness.

As a result of radiation passing through environmental materials, the radiation intensity decreases. The attenuating effect is usually characterized by a layer of half attenuation, i.e. such a thickness of material, passing through which the radiation is halved. For example, the intensity of gamma rays is reduced by half: steel 2.8 cm thick, concrete 10 cm, soil 14 cm, wood 30 cm.

Open and especially closed cracks reduce the impact of penetrating radiation, and shelters and anti-radiation shelters almost completely protect against it.

Main sources radioactive contamination are fission products of a nuclear charge and radioactive isotopes formed as a result of the influence of neutrons on the materials from which nuclear weapons are made, and on some elements that make up the soil in the area of ​​the explosion.

In a ground-based nuclear explosion, the glowing area touches the ground. Masses of evaporating soil are drawn inside it and rise upward. As they cool, vapors from fission products and soil condense on solid particles. A radioactive cloud is formed. It rises to a height of many kilometers, and then moves with the wind at a speed of 25-100 km/h. Radioactive particles falling from the cloud to the ground form a zone of radioactive contamination (trace), the length of which can reach several hundred kilometers. In this case, the area, buildings, structures, crops, reservoirs, etc., as well as the air, become infected.

Radioactive substances pose the greatest danger in the first hours after deposition, since their activity is highest during this period.

Electromagnetic pulse– these are electric and magnetic fields arising as a result of the influence of gamma radiation from a nuclear explosion on the atoms of the environment and the formation in this environment of a flow of electrons and positive ions. It can cause damage to radio-electronic equipment, disruption of radio and radio-electronic equipment.

The most reliable means of protection against all damaging factors of a nuclear explosion are protective structures. In the field you should take cover behind strong local objects, reverse slopes of heights, and in folds of the terrain.

When operating in contaminated zones, to protect the respiratory organs, eyes and open areas of the body from radioactive substances, respiratory protective equipment (gas masks, respirators, anti-dust fabric masks and cotton-gauze bandages), as well as skin protection products, are used.

The basis neutron ammunition constitute thermonuclear charges that use nuclear fission and fusion reactions. The explosion of such ammunition has a damaging effect, primarily on people, due to the powerful flow of penetrating radiation.

When a neutron munition explodes, the area affected by penetrating radiation exceeds the area affected by the shock wave by several times. In this zone, equipment and structures can remain unharmed, but people will receive fatal injuries.

The source of nuclear destruction is the territory directly exposed to the damaging factors of a nuclear explosion. It is characterized by massive destruction of buildings and structures, rubble, accidents in utility and energy networks, fires, radioactive contamination and significant losses among the population.

The more powerful the nuclear explosion, the larger the source size. The nature of the destruction in the outbreak also depends on the strength of the structures of buildings and structures, their number of storeys and building density. The outer boundary of the source of nuclear damage is taken to be a conventional line on the ground drawn at such a distance from the epicenter (center) of the explosion where the excess pressure of the shock wave is equal to 10 kPa.

The source of nuclear damage is conventionally divided into zones - areas with approximately the same nature of destruction.

Zone of complete destruction- this is an area exposed to a shock wave with an excess pressure (at the outer boundary) of over 50 kPa. All buildings and structures in the zone are completely destroyed, as well as anti-radiation shelters and part of the shelters, continuous rubble is formed, and the utility and energy network is damaged.

Zone of strengths destruction– with excess pressure in the shock wave front from 50 to 30 kPa. In this zone, ground buildings and structures will be severely damaged, local rubble will form, and continuous and massive fires will occur. Most shelters will remain intact; some shelters will have their entrances and exits blocked. People in them can be injured only due to a violation of the sealing of the shelters, their flooding or gas contamination.

Medium Damage Zone excess pressure in the shock wave front from 30 to 20 kPa. In it, buildings and structures will suffer moderate damage. Shelters and basement-type shelters will remain. Light radiation will cause continuous fires.

Light Damage Zone with excess pressure in the shock wave front from 20 to 10 kPa. Buildings will suffer minor damage. Individual fires will arise from light radiation.

Radioactive contamination zone- this is an area that has been contaminated with radioactive substances as a result of their fallout after ground (underground) and low air nuclear explosions.

The damaging effect of radioactive substances is caused mainly by gamma radiation. The harmful effects of ionizing radiation are assessed by the radiation dose (radiation dose; D), i.e. the energy of these rays absorbed per unit volume of the irradiated substance. This energy is measured in existing dosimetric instruments in roentgens (R). X-ray – This is a dose of gamma radiation that creates 1 cubic cm of dry air (at a temperature of 0 degrees C and a pressure of 760 mm Hg) 2.083 billion ion pairs.

Typically, the radiation dose is determined over a period of time called exposure time (the time people spend in the contaminated area).

To assess the intensity of gamma radiation emitted by radioactive substances in a contaminated area, the concept of “radiation dose rate” (radiation level) was introduced. Dose rates are measured in roentgens per hour (R/h), small dose rates are measured in milliroentgens per hour (mR/h).

Gradually, radiation dose rates (radiation levels) decrease. Thus, dose rates (radiation levels) are reduced. Thus, dose rates (radiation levels) measured 1 hour after a ground-based nuclear explosion will decrease by half after 2 hours, by 4 times after 3 hours, by 10 times after 7 hours, and by 100 times after 49 hours. .

The degree of radioactive contamination and the size of the contaminated area of ​​the radioactive trace during a nuclear explosion depend on the power and type of explosion, meteorological conditions, as well as the nature of the terrain and soil. The dimensions of the radioactive trace are conventionally divided into zones (diagram No. 1 p. 57)).

Danger zone. At the outer boundary of the zone, the radiation dose (from the moment radioactive substances fall out of the cloud onto the area until their complete decay is 1200 R, the radiation level 1 hour after the explosion is 240 R/h.

Highly infested area. At the outer boundary of the zone, the radiation dose is 400 R, the radiation level 1 hour after the explosion is 80 R/h.

Moderate infection zone. At the outer boundary of the zone, the radiation dose 1 hour after the explosion is 8 R/h.

As a result of exposure to ionizing radiation, as well as when exposed to penetrating radiation, people develop radiation sickness. A dose of 100-200 R causes radiation sickness of the first degree, a dose of 200-400 R causes radiation sickness of the second degree, a dose of 400-600 R causes radiation sickness. third degree, dose over 600 R – fourth degree radiation sickness.

A single dose of irradiation up to 50 R over four days, as well as multiple irradiation up to 100 R over 10 to 30 days, does not cause external signs of the disease and is considered safe.

Chemical weapons, classification and brief characteristics of toxic substances (CA).

Chemical weapon. Chemical weapons are one of the types of weapons of mass destruction. There have been isolated attempts to use chemical weapons for military purposes throughout the wars. For the first time in 1915, Germany used toxic substances in the Ypres region (Belgium). In the first hours, about 6 thousand people died, and 15 thousand received injuries of varying degrees of severity. Subsequently, the armies of other warring countries also began to actively use chemical weapons.

Chemical weapons are toxic substances and means of delivering them to the target.

Toxic substances are toxic (poisonous) chemical compounds that affect people and animals, contaminating the air, terrain, water bodies and various objects in the area. Some toxins are designed to damage plants. Delivery vehicles include artillery chemical shells and mines (CAP), chemically charged missile warheads, chemical land mines, bombs, grenades and cartridges.

According to military experts, chemical weapons are intended to kill people and reduce their combat and working capacity.

Phytotoxins are intended to destroy cereals and other types of agricultural crops in order to deprive the enemy of the food supply and undermine the military-economic potential.

To a special group chemical weapons One can include binary chemical munitions, which are two containers with different substances - non-toxic in their pure form, but when mixed during an explosion, a highly toxic compound is obtained.

Toxic substances can have different states of aggregation (vapor, aerosol, liquid) and affect people through the respiratory system, gastrointestinal tract or upon contact with skin.

Based on their physiological effects, agents are divided into groups :

Nerve agents - tabun, sarin, soman, V-X. They cause dysfunction nervous system, muscle cramps, paralysis and death;

Agents of skin-blister action – mustard gas, lewisite. Affects the skin, eyes, respiratory and digestive organs. Signs of skin damage are redness (2-6 hours after contact with the agent), then the formation of blisters and ulcers. At a mustard vapor concentration of 0.1 g/m2, eye damage occurs with loss of vision;

Generally toxic agent – hydrocyanic acid and cyanogen chloride. Damage through the respiratory system and when it enters the gastrointestinal tract with water and food. In case of poisoning, severe shortness of breath, a feeling of fear, convulsions, and paralysis appear;

Asphyxiating agent– phosgene. Affects the body through the respiratory system. During the period of latent action, pulmonary edema develops.

Agent of psychochemical action - Bi-Zet. Affects through the respiratory system. Impairs coordination of movements, causes hallucinations and mental disorders;

Irritant agents – chloroacetophenone, adamsite, CS(Ci-Es), SR(C-R). Causes respiratory and eye irritation;

Nerve-paralytic, vesicant, generally poisonous and asphyxiating agents are lethal toxic substances , and agents of psychochemical and irritating action - temporarily incapacitating people.

Nuclear weapons are one of the main types of weapons of mass destruction, based on the use of intranuclear energy released during chain reactions of fission of heavy nuclei of some isotopes of uranium and plutonium or during thermonuclear fusion reactions of light nuclei - isotopes of hydrogen (deuterium and tritium).

As a result of the release of a huge amount of energy during an explosion, the damaging factors of nuclear weapons differ significantly from the effects of conventional weapons. The main damaging factors of nuclear weapons: shock wave, light radiation, penetrating radiation, radioactive contamination, electromagnetic pulse.

Nuclear weapons include nuclear weapons, means of delivering them to the target (carriers) and control means.

The power of a nuclear weapon explosion is usually expressed by TNT equivalent, that is, the amount of conventional explosive (TNT), the explosion of which releases the same amount of energy.

The main parts of a nuclear weapon are: nuclear explosive (NE), neutron source, neutron reflector, explosive charge, detonator, ammunition body.

Damaging factors of a nuclear explosion

The shock wave is the main damaging factor of a nuclear explosion, since most of the destruction and damage to structures, buildings, as well as injuries to people are usually caused by its impact. It is an area of ​​sharp compression of the medium, spreading in all directions from the explosion site at supersonic speed. The front boundary of the compressed air layer is called the shock wave front.

The damaging effect of a shock wave is characterized by the magnitude of excess pressure. Excess pressure is the difference between the maximum pressure at the shock wave front and the normal atmospheric pressure ahead of it.

With excess pressure of 20-40 kPa, unprotected people can suffer minor injuries (minor bruises and contusions). Exposure to a shock wave with an excess pressure of 40-60 kPa leads to moderate damage: loss of consciousness, damage to the hearing organs, severe dislocations of the limbs, bleeding from the nose and ears. Severe injuries occur when excess pressure exceeds 60 kPa. Extremely severe lesions are observed at excess pressure above 100 kPa.

Light radiation is a stream of radiant energy, including visible ultraviolet and infrared rays. Its source is a luminous area formed by hot explosion products and hot air. Light radiation spreads almost instantly and lasts, depending on the power of the nuclear explosion, up to 20 s. However, its strength is such that, despite its short duration, it can cause burns to the skin (skin), damage (permanent or temporary) to people’s organs of vision and fire of flammable materials and objects.

Light radiation does not penetrate through opaque materials, so any barrier that can create a shadow protects against the direct action of light radiation and prevents burns. Light radiation is significantly weakened in dusty (smoky) air, fog, rain, and snowfall.

Penetrating radiation is a stream of gamma rays and neutrons, spreading within 10-15 s. Passing through living tissue, gamma radiation and neutrons ionize the molecules that make up the cells. Under the influence of ionization, biological processes arise in the body, leading to disruption of the vital functions of individual organs and the development of radiation sickness. As a result of the passage of radiation through environmental materials, their intensity decreases. The weakening effect is usually characterized by a layer of half attenuation, that is, such a thickness of material, passing through which the radiation intensity is halved. For example, steel with a thickness of 2.8 cm, concrete - 10 cm, soil - 14 cm, wood - 30 cm, attenuates the intensity of gamma rays by half.

Open and especially closed cracks reduce the impact of penetrating radiation, and shelters and anti-radiation shelters almost completely protect against it.

Radioactive contamination of the area, the surface layer of the atmosphere, airspace, water and other objects occurs as a result of the fallout of radioactive substances from the cloud of a nuclear explosion. The significance of radioactive contamination as a damaging factor is determined by the fact that high levels of radiation can be observed not only in the area adjacent to the explosion site, but also at a distance of tens and even hundreds of kilometers from it. Radioactive contamination of the area can be dangerous for several weeks after the explosion.

Sources of radioactive radiation during a nuclear explosion are: fission products of nuclear explosives (Pu-239, U-235, U-238); radioactive isotopes (radionuclides) formed in soil and other materials under the influence of neutrons, that is, induced activity.

In an area exposed to radioactive contamination during a nuclear explosion, two areas are formed: the explosion area and the cloud trail. In turn, in the area of ​​the explosion, windward and leeward sides are distinguished.

The teacher can briefly dwell on the characteristics of radioactive contamination zones, which, according to the degree of danger, are usually divided into the following four zones:

zone A - moderate infection with an area of ​​70-80 % from the area of ​​the entire explosion trace. The radiation level at the outer boundary of the zone 1 hour after the explosion is 8 R/h;

zone B - severe infection, which accounts for approximately 10 % radioactive trace area, radiation level 80 R/h;

zone B - dangerous contamination. It occupies approximately 8-10% of the explosion cloud footprint; radiation level 240 R/h;

zone G - extremely dangerous infection. Its area is 2-3% of the area of ​​the explosion cloud trace. Radiation level 800 R/h.

Gradually, the level of radiation in the area decreases, approximately 10 times over time intervals divisible by 7. For example, 7 hours after the explosion, the dose rate decreases 10 times, and after 50 hours - almost 100 times.

The volume of air space in which radioactive particles are deposited from the explosion cloud and the upper part of the dust column is usually called the cloud plume. As the plume approaches the object, the radiation level increases due to gamma radiation from radioactive substances contained in the plume. Radioactive particles fall out of the plume, which, falling on various objects, infect them. The degree of contamination of the surfaces of various objects, people’s clothing and skin with radioactive substances is usually judged by the dose rate (radiation level) of gamma radiation near contaminated surfaces, determined in milliroentgens per hour (mR/h).

Another damaging factor of a nuclear explosion is electromagnetic pulse. This is a short-term electromagnetic field that occurs during the explosion of a nuclear weapon as a result of the interaction of gamma rays and neutrons emitted during a nuclear explosion with atoms of the environment. The consequence of its impact may be burnout or breakdown of individual elements of radio-electronic and electrical equipment.

The most reliable means of protection against all damaging factors of a nuclear explosion are protective structures. In open areas and fields, you can use durable local objects, reverse slopes and folds of terrain for shelter.

When operating in contaminated areas, to protect the respiratory organs, eyes and open areas of the body from radioactive substances, it is necessary, if possible, to use gas masks, respirators, anti-dust fabric masks and cotton-gauze bandages, as well as skin protection, including clothing.

Chemical weapons, ways to protect against them

Chemical weapon is a weapon of mass destruction, the action of which is based on the toxic properties of chemicals. The main components of chemical weapons are chemical warfare agents and means of their use, including carriers, instruments and control devices used to deliver chemical munitions to targets. Chemical weapons were prohibited by the 1925 Geneva Protocol. Currently, the world is taking measures to completely ban chemical weapons. However, it is still available in a number of countries.

Chemical weapons include toxic substances (0B) and means of their use. Missiles, aircraft bombs, artillery shells and mines are equipped with toxic substances.

Based on their effect on the human body, 0Bs are divided into nerve paralytic, blister, suffocating, generally poisonous, irritant and psychochemical.

0B nerve agent: VX (Vi-X), sarin. They affect the nervous system when acting on the body through the respiratory system, when penetrating in a vaporous and droplet-liquid state through the skin, as well as when entering the gastrointestinal tract along with food and water. Their durability lasts for more than a day in the summer, and several weeks and even months in the winter. These 0B are the most dangerous. A very small amount of them is enough to infect a person.

Signs of damage are: salivation, constriction of the pupils (miosis), difficulty breathing, nausea, vomiting, convulsions, paralysis.

Gas masks and protective clothing are used as personal protective equipment. To provide first aid to the affected person, a gas mask is put on him and the antidote is injected into him using a syringe tube or by taking a tablet. If 0V nerve agent gets on the skin or clothing, the affected areas are treated with liquid from an individual anti-chemical package (IPP).

0B blister action (mustard gas). They have a multilateral damaging effect. In a droplet-liquid and vapor state, they affect the skin and eyes, when inhaling vapors - the respiratory tract and lungs, when ingested with food and water - the digestive organs. A characteristic feature of mustard gas is the presence of a period of latent action (the lesion is not detected immediately, but after some time - 2 hours or more). Signs of damage are redness of the skin, the formation of small blisters, which then merge into large ones and burst after two to three days, turning into difficult-to-heal ulcers. With any local damage, 0V causes general poisoning of the body, which manifests itself in increased temperature and malaise.

In conditions of using 0B blister action, it is necessary to wear a gas mask and protective clothing. If drops of 0B come into contact with skin or clothing, the affected areas are immediately treated with liquid from the PPI.

0B asphyxiating effect (fosten). They affect the body through the respiratory system. Signs of damage are a sweetish, unpleasant taste in the mouth, cough, dizziness, and general weakness. These phenomena disappear after leaving the source of infection, and the victim feels normal within 4-6 hours, unaware of the damage he has received. During this period (latent action) pulmonary edema develops. Then breathing may sharply worsen, a cough with copious sputum may appear, headache, fever, shortness of breath, palpitations.

In case of defeat, a gas mask is put on the victim, they are taken out of the contaminated area, they are covered warmly and they are provided with peace.

Under no circumstances should you perform artificial respiration on the victim!

0B, generally toxic (hydrocyanic acid, cyanogen chloride). They affect only when inhaling air contaminated with their vapors (they do not act through the skin). Signs of damage include a metallic taste in the mouth, throat irritation, dizziness, weakness, nausea, severe convulsions, and paralysis. To protect against these 0V, it is enough to use a gas mask.

To help the victim, you need to crush the ampoule with the antidote and insert it under the gas mask helmet. In severe cases, the victim is given artificial respiration, warmed up and sent to a medical center.

0B irritant: CS (CS), adamite, etc. Causes acute burning and pain in the mouth, throat and eyes, severe lacrimation, coughing, difficulty breathing.

0B psychochemical action: BZ (Bi-Z). They specifically act on the central nervous system and cause mental (hallucinations, fear, depression) or physical (blindness, deafness) disorders.

If you are affected by 0B irritating and psychochemical effects, it is necessary to treat the infected areas of the body with soapy water, rinse the eyes and nasopharynx thoroughly with clean water, and shake out the uniform or brush it. Victims should be removed from the contaminated area and given medical care.

The main ways to protect the population are to shelter them in protective structures and provide the entire population with personal and medical protective equipment.

Shelters and anti-radiation shelters (RAS) can be used to protect the population from chemical weapons.

When characterizing personal protective equipment (PPE), indicate that they are intended to protect against toxic substances entering the body and onto the skin. Based on the principle of operation, PPE is divided into filtering and insulating. According to their purpose, PPE is divided into respiratory protection (filtering and insulating gas masks, respirators, anti-dust fabric masks) and skin protection (special insulating clothing, as well as regular clothing).

Further indicate that medical protective equipment is intended to prevent injury from toxic substances and provide first aid to the victim. The individual first aid kit (AI-2) includes a set of medicines intended for self- and mutual aid in the prevention and treatment of injuries from chemical weapons.

The individual dressing package is designed for degassing 0V at open areas skin.

In conclusion of the lesson, it should be noted that the duration of the damaging effect of 0V is less than stronger wind and rising air currents. In forests, parks, ravines and narrow streets, 0B persists longer than in open areas.

A nuclear explosion can instantly destroy or disable unprotected people, structures and various material assets.

The main damaging factors of a nuclear explosion are:

Shock wave;

Light radiation;

Penetrating radiation;

Radioactive contamination of the area;

Electromagnetic pulse;

This creates a growing fireball with a diameter of up to several hundred meters, visible at a distance of 100 - 300 km. The temperature of the glowing area of ​​a nuclear explosion ranges from millions of degrees at the beginning of its formation to several thousand at the end and lasts up to 25 seconds. The brightness of light radiation in the first second (80-85% of light energy) is several times greater than the brightness of the Sun, and the resulting fireball during a nuclear explosion is visible for hundreds of kilometers. The remaining amount (20-15%) in the subsequent period of time from 1 to 3 seconds.

Infrared rays are the most damaging, causing instant burns to exposed areas of the body and blinding. The heat may be so intense that it may cause charring or combustion. different material and cracking or melting building materials, which can lead to huge fires within a radius of several tens of kilometers. People who were exposed to the fireball from "Little" Hiroshima at a distance of up to 800 meters were burned so much that they turned to dust.

In this case, the effect of light radiation from a nuclear explosion is equivalent to the massive use incendiary weapons, which is discussed in the fifth section.

The human skin also absorbs the energy of light radiation, due to which it can heat up to high temperature and get burned. First of all, burns occur on open areas of the body facing the direction of the explosion. If you look in the direction of the explosion with unprotected eyes, then eye damage may occur, leading to blindness and complete loss of vision.

Burns caused by light radiation are no different from ordinary burns caused by fire or boiling water; they are stronger the shorter the distance to the explosion and the greater the power of the ammunition. In an air explosion, the damaging effect of light radiation is greater than in a ground explosion of the same power.

The damaging effect of light radiation is characterized by a light pulse. Depending on the perceived light pulse, burns are divided into three degrees. First-degree burns manifest themselves as superficial skin lesions: redness, swelling, and soreness. With second degree burns, blisters appear on the skin. With third degree burns, skin necrosis and ulceration occur.

With an air explosion of ammunition with a power of 20 kt and an atmospheric transparency of about 25 km, first-degree burns will be observed within a radius of 4.2 km from the center of the explosion; with the explosion of a charge with a power of 1 Mt, this distance will increase to 22.4 km. Second degree burns appear at distances of 2.9 and 14.4 km and third degree burns at distances of 2.4 and 12.8 km, respectively, for 20 kt and 1 Mt ammunition.

Light radiation can cause massive fires in populated areas, in forests, steppes, fields.

Any obstacles that do not allow light to pass through can protect against light radiation: shelter, the shadow of a house, etc. The intensity of light radiation strongly depends on meteorological conditions. Fog, rain and snow weaken its effect, and conversely, clear and dry weather favors the occurrence of fires and the formation of burns.

To assess the ionization of atoms in the environment, and therefore the damaging effect of penetrating radiation on a living organism, the concept of radiation dose (or radiation dose) was introduced, the unit of measurement of which is the x-ray (r). Radiation dose 1 r. corresponds to the formation of approximately 2 billion ion pairs in one cubic centimeter of air. Depending on the radiation dose, there are four degrees of radiation sickness.

The first (mild) occurs when a person receives a dose of 100 to 200 rubles. It is characterized by: no vomiting or after 3 hours, once, general weakness, mild nausea, short-term headache, clear consciousness, dizziness, increased sweating, and periodic increases in temperature.

The second (medium) degree of radiation sickness develops when receiving a dose of 200 - 400 r; in this case, signs of damage: vomiting after 30 minutes - 3 hours, 2 times or more, constant headache, clear consciousness, dysfunction of the nervous system, fever, more severe malaise, gastrointestinal upset appear more sharply and faster, the person becomes incompetent. Possible fatalities (up to 20%).

The third (severe) degree of radiation sickness occurs at a dose of 400 - 600 rubles. Characterized by: severe and repeated vomiting, constant headache, sometimes severe, nausea, severe general state, sometimes loss of consciousness or sudden agitation, hemorrhages in the mucous membranes and skin, necrosis of the mucous membranes in the gum area, temperature may exceed 38 - 39 degrees, dizziness and other ailments; Due to the weakening of the body's defenses, various infectious complications appear, often leading to death. Without treatment, the disease ends in death in 20-70% of cases, most often from infectious complications or bleeding.

Extremely severe, at doses over 600 rubles, the primary symptoms appear: severe and repeated vomiting after 20 - 30 minutes for up to 2 or more days, persistent severe headache, consciousness may be confused, without treatment usually ends in death within up to 2 weeks.

In the initial period of ARS, frequent manifestations are nausea, vomiting, and only in severe cases diarrhea. General weakness, irritability, fever, and vomiting are manifestations of both brain irradiation and general intoxication. Important signs of radiation exposure are hyperemia of the mucous membranes and skin, especially in areas of high radiation doses, increased heart rate, increase and then decrease blood pressure up to collapse, neurological symptoms (in particular, loss of coordination, meningeal signs). The severity of symptoms is adjusted with the radiation dose.

The radiation dose can be single or multiple. According to foreign press data, a single irradiation dose of up to 50 r (received over a period of up to 4 days) is practically safe. A multiple dose is a dose received over a period of more than 4 days. A single exposure of a person to a dose of 1 Sv or more is called acute exposure.

Each of these more than 200 isotopes has a different half-life. Fortunately, most fission products are short-lived isotopes, that is, they have half-lives measured in seconds, minutes, hours or days. This means that after a short time (about 10-20 half-lives), the short-lived isotope decays almost completely and its radioactivity will not pose a practical danger. Thus, the half-life of tellurium -137 is 1 minute, i.e. after 15-20 minutes there will be almost nothing left of it.

In an emergency situation, it is important to know not so much the half-life of each isotope, but the time during which the radioactivity of the entire sum of radioactive fission products decreases. There is a very simple and convenient rule that allows you to judge the rate of decrease in the radioactivity of fission products over time.

This rule is called the seven-ten rule. Its meaning is that if the time elapsed after the explosion of a nuclear bomb increases seven times, then the activity of the fission products decreases by 10 times. For example, the level of contamination of the area with decay products an hour after the explosion of a nuclear weapon is 100 conventional units. 7 hours after the explosion (time increased 7 times) the level of pollution will decrease to 10 units (activity decreased 10 times), after 49 hours - to 1 unit, etc.

During the first day after the explosion, the activity of fission products decreases almost 6000 times. And in this sense, time turns out to be our great ally. But over time, the decline in activity is becoming slower. A day after the explosion, it will take a week to reduce activity by 10 times, a month after the explosion - 7 months, etc. However, it should be noted that the decline in activity according to the “seven-ten” rule occurs in the first six months after the explosion. Subsequently, the decline in the activity of fission products occurs faster than according to the “seven to ten” rule.

The amount of fission products formed during the explosion of a nuclear bomb is small in weight terms. Thus, for every thousand tons of explosion power, about 37 g of fission products are formed (37 kg per 1 Mt). Fission products entering the body in significant quantities can cause high levels of radiation and corresponding changes in health status. The amount of fission products formed during an explosion is often estimated not in weight units, but in units of radioactivity.

As you know, the unit of radioactivity is the curie. One curie is the amount of radioactive isotope that gives 3.7-10 10 decays per second - (37 billion decays per second). To imagine the value of this unit, (Recall that the activity of 1 g of radium is approximately 1 curie, and the permissible amount of radium in the human body is 0.1 μg of this element.

Moving from weight units to units of radioactivity, we can say that during the explosion of a nuclear bomb with a power of 10 million tons, decay products are formed with a total activity of the order of 10"15 curies (1000000000000000 curies). This activity constantly, and at first very quickly, decreases, Moreover, its weakening during the first day after the explosion exceeds 6000 times.

Radioactive fallout falls at large distances from the site of a nuclear explosion (significant contamination of the area can be at a distance of about several hundred kilometers). They are aerosols (particles suspended in the air). The sizes of aerosols are very different: from large particles with a diameter of several millimeters to the smallest, not visible to the eye particles measured in tenths, hundredths and even smaller fractions of a micron.

Most of the radioactive fallout (about 60% from a ground explosion) falls in the first day after the explosion. This is local precipitation. Subsequently, the external environment can be additionally polluted by tropospheric or stratospheric precipitation.

Depending on the “age” of the fragments (i.e., the time that has passed since the moment of the nuclear explosion), their isotopic composition also changes. In “young” fission products, the main activity is represented by short-lived isotopes. The activity of “old” fission products is represented mainly by long-lived isotopes, since by this time the short-lived isotopes have already decayed, turning into stable ones. Therefore, the number of isotopes of fission products is constantly decreasing over time. So, a month after the explosion, only 44 isotopes remain, and a year later - 27 isotopes.

According to the age of the fragments, the specific activity of each isotope in the total mixture of decay products also changes. Thus, the isotope of strontium-90, which has a significant half-life (T1/2 = 28.4 years) and is formed during an explosion in small quantities, “outlives” short-lived isotopes, and therefore its specific activity is constantly increasing.

Thus, the specific activity of strontium-90 increases in 1 year from 0.0003% to 1.9%. If a significant amount of radioactive fallout falls, the most severe situation will be during the first two weeks after the explosion. This situation is well illustrated following example: if an hour after the explosion the dose rate of gamma radiation from radioactive fallout reaches 300 roentgens per hour (r/h), then the total radiation dose (without protection) during the year will be 1200 r, of which 1000 r (i.e. almost a person will receive the entire annual radiation dose in the first 14 days. Therefore, the highest levels of infection external environment There will be radioactive fallout in these two weeks.

The bulk of long-lived isotopes are concentrated in the radioactive cloud that forms after the explosion. The height of the cloud rise for a 10 kt munition is 6 km, for a 10 Mt munition it is 25 km.

An electromagnetic pulse is a short-term electromagnetic field that occurs during the explosion of a nuclear weapon as a result of the interaction of gamma rays and neutrons emitted with the atoms of the environment. The consequence of its impact may be burnout and breakdowns of individual elements of radio-electronic and electrical equipment, electrical networks.

The most reliable means of protection against all damaging factors of a nuclear explosion are protective structures. In open areas and fields, you can use durable local objects, reverse slopes and folds of terrain for shelter.

When operating in contaminated areas, special protective equipment should be used to protect the respiratory system, eyes and open areas of the body from radioactive substances.

CHEMICAL WEAPON

Characteristics and combat properties

Chemical weapons are poisonous substances and agents used to kill humans.

The basis of the destructive effect of chemical weapons is toxic substances. They have such high toxic properties that some foreign military experts equate 20 kg of nerve agents in terms of their destructive effect to nuclear bomb, equivalent to 20 Mt of TNT. In both cases, a lesion area of ​​200-300 km may occur.

According to their own damaging properties OBs differ from other combat weapons:

They are capable of penetrating, along with the air, into various structures and military equipment and inflicting defeat on the people in them;

They can maintain their destructive effect in the air, on the ground and in various objects for some, sometimes quite a long time;

Spreading in large volumes of air and on large areas, they inflict defeat on all people within their sphere of action without means of protection;

Agent vapors are capable of spreading in the direction of the wind to significant distances from areas where chemical weapons are directly used.

Chemical munitions are distinguished by the following characteristics:

The durability of the agent used;

The nature of the physiological effects of OM on the human body;

Means and methods of use;

Tactical purpose;

The speed of the oncoming impact;

Explosive action, based on the use of intranuclear energy released during chain reactions of fission of heavy nuclei of some isotopes of uranium and plutonium or during thermonuclear reactions of fusion of hydrogen isotopes (deuterium and tritium) into heavier ones, for example, helium isotope nuclei. Thermonuclear reactions release 5 times more energy than fission reactions (with the same mass of nuclei).

Nuclear weapons include various nuclear weapons, means of delivering them to the target (carriers) and control means.

Depending on the method of obtaining nuclear energy, ammunition is divided into nuclear (using fission reactions), thermonuclear (using fusion reactions), and combined (in which energy is obtained according to the “fission-fusion-fission” scheme). The power of nuclear weapons is measured in TNT equivalent, i.e. a mass of explosive TNT, the explosion of which releases the same amount of energy as the explosion of a given nuclear bomb. TNT equivalent measured in tons, kilotons (kt), megatons (Mt).

Ammunition with a power of up to 100 kt is constructed using fission reactions, and from 100 to 1000 kt (1 Mt) using fusion reactions. Combined ammunition can have a yield of more than 1 Mt. Based on their power, nuclear weapons are divided into ultra-small (up to 1 kg), small (1-10 kt), medium (10-100 kt) and super-large (more than 1 Mt).

Depending on the purpose of using nuclear weapons, nuclear explosions can be high-altitude (above 10 km), airborne (no higher than 10 km), ground-based (surface), underground (underwater).

Damaging factors of a nuclear explosion

The main damaging factors of a nuclear explosion are: shock wave, light radiation from a nuclear explosion, penetrating radiation, radioactive contamination of the area and electromagnetic pulse.

Shock wave

Shock wave (SW)- an area of ​​sharply compressed air, spreading in all directions from the center of the explosion at supersonic speed.

Hot vapors and gases, trying to expand, produce a sharp blow to the surrounding layers of air, compress them to high pressures and densities and heat them to a high temperature (several tens of thousands of degrees). This layer of compressed air represents a shock wave. The front boundary of the compressed air layer is called the shock wave front. The shock front is followed by a region of rarefaction, where the pressure is below atmospheric. Near the center of the explosion, the speed of propagation of shock waves is several times higher than the speed of sound. As the distance from the explosion increases, the speed of wave propagation quickly decreases. At large distances, its speed approaches the speed of sound in air.

The shock wave of medium-power ammunition travels: the first kilometer in 1.4 s; the second - in 4 s; fifth - in 12 s.

The damaging effect of hydrocarbons on people, equipment, buildings and structures is characterized by: velocity pressure; excess pressure in the front of the shock wave movement and the time of its impact on the object (compression phase).

The impact of hydrocarbons on people can be direct and indirect. With direct impact, the cause of injury is an instantaneous increase in air pressure, which is perceived as a sharp blow, leading to fractures, damage internal organs, rupture blood vessels. With indirect exposure, people are affected by flying debris from buildings and structures, stones, trees, broken glass and other items. Indirect impact reaches 80% of all lesions.

With an excess pressure of 20-40 kPa (0.2-0.4 kgf/cm2), unprotected people can suffer minor injuries (minor bruises and contusions). Exposure to hydrocarbons with excess pressure of 40-60 kPa leads to moderate damage: loss of consciousness, damage to the hearing organs, severe dislocations of the limbs, damage to internal organs. Extremely severe injuries, often fatal, are observed at excess pressure above 100 kPa.

The degree of shock wave damage to various objects depends on the power and type of explosion, mechanical strength (stability of the object), as well as on the distance at which the explosion occurred, the terrain and the position of objects on the ground.

To protect against the effects of hydrocarbons, the following should be used: trenches, cracks and trenches, reducing this effect by 1.5-2 times; dugouts - 2-3 times; shelters - 3-5 times; basements of houses (buildings); terrain (forest, ravines, hollows, etc.).

Light radiation

Light radiation is a stream of radiant energy that includes ultraviolet, visible and infrared rays.

Its source is a luminous area formed by hot explosion products and hot air. Light radiation spreads almost instantly and lasts, depending on the power of the nuclear explosion, up to 20 s. However, its strength is such that, despite its short duration, it can cause burns to the skin (skin), damage (permanent or temporary) to the organs of vision of people and fire of flammable materials of objects. At the moment of formation of a luminous region, the temperature on its surface reaches tens of thousands of degrees. The main damaging factor of light radiation is the light pulse.

Light impulse is the amount of energy in calories incident on a unit surface area perpendicular to the direction of radiation during the entire glow time.

The weakening of light radiation is possible due to its screening by atmospheric clouds, uneven terrain, vegetation and local objects, snowfall or smoke. Thus, a thick light weakens the light pulse by A-9 times, a rare one - by 2-4 times, and smoke (aerosol) curtains - by 10 times.

To protect the population from light radiation, it is necessary to use protective structures, basements of houses and buildings, protective properties terrain. Any barrier that can create a shadow protects against the direct action of light radiation and prevents burns.

Penetrating radiation

Penetrating radiation- notes of gamma rays and neutrons emitted from the zone of a nuclear explosion. Its duration is 10-15 s, range is 2-3 km from the center of the explosion.

In conventional nuclear explosions, neutrons make up approximately 30%, and in the explosion of neutron weapons - 70-80% of y-radiation.

The damaging effect of penetrating radiation is based on the ionization of cells (molecules) of a living organism, leading to death. Neutrons, in addition, interact with the nuclei of atoms of some materials and can cause induced activity in metals and technology.

The main parameter characterizing penetrating radiation is: for y-radiation - dose and radiation dose rate, and for neutrons - flux and flux density.

Permissible doses of radiation to the population in war time: single dose - for 4 days 50 R; multiple - within 10-30 days 100 RUR; during the quarter - 200 RUR; during the year - 300 RUR.

As a result of radiation passing through environmental materials, the radiation intensity decreases. The weakening effect is usually characterized by a layer of half weakening, i.e. such a thickness of material, passing through which radiation decreases by 2 times. For example, the intensity of y-rays is reduced by 2 times: steel 2.8 cm thick, concrete - 10 cm, soil - 14 cm, wood - 30 cm.

As protection against penetrating radiation, protective structures are used that weaken its effects from 200 to 5000 times. A pound layer of 1.5 m protects almost completely from penetrating radiation.

Radioactive contamination (contamination)

Radioactive contamination of air, terrain, water areas and objects located on them occurs as a result of the fallout of radioactive substances (RS) from the cloud of a nuclear explosion.

At a temperature of approximately 1700 °C, the glow of the luminous region of a nuclear explosion stops and it turns into a dark cloud, towards which a dust column rises (that’s why the cloud has a mushroom shape). This cloud moves in the direction of the wind, and radioactive substances fall out of it.

Sources of radioactive substances in the cloud are fission products of nuclear fuel (uranium, plutonium), unreacted part of nuclear fuel and radioactive isotopes formed as a result of the action of neutrons on the ground (induced activity). These radioactive substances, when located on contaminated objects, decay, emitting ionizing radiation, which is actually a damaging factor.

The parameters of radioactive contamination are the radiation dose (based on the effect on people) and the radiation dose rate - the level of radiation (based on the degree of contamination of the area and various objects). These parameters are a quantitative characteristic of damaging factors: radioactive contamination during an accident with the release of radioactive substances, as well as radioactive contamination and penetrating radiation during a nuclear explosion.

In an area exposed to radioactive contamination during a nuclear explosion, two areas are formed: the explosion area and the cloud trail.

According to the degree of danger, the contaminated area following the explosion cloud is usually divided into four zones (Fig. 1):

Zone A- zone of moderate infection. It is characterized by a radiation dose until the complete decay of radioactive substances on the outer boundary of the zone - 40 rad and on the inner - 400 rad. The area of ​​zone A is 70-80% of the area of ​​the entire track.

Zone B- an area of ​​heavy infection. The radiation doses at the boundaries are 400 rad and 1200 rad, respectively. The area of ​​zone B is approximately 10% of the area of ​​the radioactive trace.

Zone B— zone of dangerous contamination. It is characterized by radiation doses at the boundaries of 1200 rad and 4000 rad.

Zone G- an extremely dangerous infection zone. Doses at the boundaries of 4000 rad and 7000 rad.

Rice. 1. Scheme of radioactive contamination of the area in the area of ​​a nuclear explosion and along the trail of the cloud movement

Radiation levels at the outer boundaries of these zones 1 hour after the explosion are 8, 80, 240, 800 rad/h, respectively.

Most of the radioactive fallout, causing radioactive contamination of the area, falls from the cloud 10-20 hours after a nuclear explosion.

Electromagnetic pulse

Electromagnetic pulse (EMP) is a set of electric and magnetic fields resulting from the ionization of atoms of the medium under the influence of gamma radiation. Its duration of action is several milliseconds.

The main parameters of EMR are currents and voltages induced in wires and cable lines, which can lead to damage and failure of electronic equipment, and sometimes to damage to people working with the equipment.

In ground and air explosions, the damaging effect of the electromagnetic pulse is observed at a distance of several kilometers from the center of the nuclear explosion.

Most effective protection from electromagnetic pulses is shielding of power supply and control lines, as well as radio and electrical equipment.

The situation that arises when nuclear weapons are used in areas of destruction.

The source of nuclear destruction is the territory within which, as a result of the use of nuclear weapons, mass casualties and death of people, farm animals and plants, destruction and damage to buildings and structures, utility, energy and technological networks and lines, transport communications and other objects.

Nuclear explosion zones

To determine the nature of possible destruction, the volume and conditions for carrying out rescue and other urgent work, the source of nuclear damage is conventionally divided into four zones: complete, severe, medium and weak destruction.

Zone of complete destruction has at the border an excess pressure at the shock wave front of 50 kPa and is characterized by massive irretrievable losses among the unprotected population (up to 100%), complete destruction of buildings and structures, destruction and damage to utility, energy and technological networks and lines, as well as parts of civil defense shelters, the formation of continuous rubble in populated areas. The forest is completely destroyed.

Zone of severe destruction with excess pressure at the shock wave front from 30 to 50 kPa is characterized by: massive irretrievable losses (up to 90%) among the unprotected population, complete and severe destruction of buildings and structures, damage to utility, energy and technological networks and lines, formation of local and continuous blockages in settlements and forests, preservation of shelters and most anti-radiation shelters of the basement type.

Medium Damage Zone with excess pressure from 20 to 30 kPa is characterized by irretrievable losses among the population (up to 20%), medium and severe destruction of buildings and structures, the formation of local and focal debris, continuous fires, preservation of utility and energy networks, shelters and most anti-radiation shelters.

Light Damage Zone with excess pressure from 10 to 20 kPa is characterized by weak and moderate destruction of buildings and structures.

The source of damage in terms of the number of dead and injured may be comparable to or greater than the source of damage during an earthquake. Thus, during the bombing (bomb power up to 20 kt) of the city of Hiroshima on August 6, 1945, most of it (60%) was destroyed, and the death toll was up to 140,000 people.

Personnel of economic facilities and the population falling into zones of radioactive contamination are exposed to ionizing radiation, which causes radiation sickness. The severity of the disease depends on the dose of radiation (exposure) received. The dependence of the degree of radiation sickness on the radiation dose is given in Table. 2.

Table 2. Dependence of the degree of radiation sickness on the radiation dose

In the context of military operations with the use of nuclear weapons, vast territories may be in zones of radioactive contamination, and the irradiation of people may become widespread. To avoid overexposure of facility personnel and the public under such conditions and to increase the sustainability of facility operation National economy In conditions of radioactive contamination in wartime, permissible radiation doses are established. They are:

• with a single irradiation (up to 4 days) - 50 rad;
• repeated irradiation: a) up to 30 days - 100 rad; b) 90 days - 200 rad;
• systematic irradiation (during the year) 300 rad.

Caused by the use of nuclear weapons, the most complex. To eliminate them, disproportionately greater forces and means are required than when eliminating peacetime emergencies.