The main damaging factors of a nuclear explosion are the shock wave (the formation of which consumes 50% of the energy of the explosion), light radiation (35%), penetrating radiation (5%) and radioactive contamination (10%). An electromagnetic pulse and secondary damaging factors are also distinguished.
shock wave- the main factor of the destructive and damaging effect, is a zone of compressed air, which is formed during the instantaneous expansion of gases in the center of the explosion and spreads at great speed in all directions, causing destruction of buildings, structures and damage to people. The range of the shock wave depends on the power and type of explosion, as well as the nature of the terrain. A shock wave consists of a shock wave front, compression and rarefaction zones.
The strength of the shock wave depends on the excess pressure at its front, which is measured by the number of kilogram-forces falling per square centimeter of the surface (kgf / cm 2), or in pascals (Pa): 1 Pa \u003d 0.00001 kgf / cm 2, 1 kgf / cm 2 \u003d 100 kPa (kilopascal).
During the explosions of 13-kiloton bombs in Hiroshima and Nagasaki, the radius of action was expressed approximately in the following figures: a zone of continuous destruction and destruction within a radius of up to 800 - 900 m (overpressure over 1 kg / cm 2) - the destruction of all buildings and structures and almost 100% loss of life; a zone of severe destruction and severe and medium damage to people within a radius of up to 2-2.5 km (overpressure 0.3-1 kg / cm 2); a zone of weak destruction and weak and accidental injuries of people within a radius of up to 3-4 km (overpressure 0.04-0.2 kg / cm 2).
It is also necessary to take into account the "throwing" effect of the shock wave and the formation of secondary projectiles in the form of flying fragments of buildings (bricks, boards, glass, etc.) that injure people.
Under the action of a shock wave on an openly positioned personnel at an overpressure of more than 1 kg / cm 2 (100 kPa), extremely severe, fatal injuries occur (bone fractures, hemorrhages, bleeding from the nose, ears, contusions, barotrauma of the lungs, ruptures of hollow organs, wounds secondary projectiles, the syndrome of prolonged crushing under the ruins, etc.), with a pressure at the front of 0.5-0.9 kg / cm 2 - severe injuries; 0.4-0.5 kg / cm 2 - moderate; 0.2-0.3 kg / cm 2 - light lesions. However, even with an excess pressure of 0.2-0.3 kg / cm2, even severe injuries are possible under the action of the velocity pressure and the propelling action of the shock wave, if the person did not have time to take cover and will be thrown a few meters by the wave or will be injured from secondary projectiles.
During ground and especially underground nuclear explosions, strong vibrations (shaking) of the earth are observed, which can be roughly compared with an earthquake with a force of up to 5-7 points.
The means of protection against the shock wave are various kinds of shelters and shelters, as well as terrain folds, since the front of the shock wave after reflection from the ground runs parallel to the surface and the pressure in the recesses is much less.
Trenches, trenches and shelters reduce losses from the shock wave from 3 to 10 times.
The shock wave radius of more powerful nuclear weapons (more than 20,000 tons of TNT) is equal to the cube root of the ratio of TNT, multiplied by the range of a 20-kiloton bomb. For example, with an increase in the power of the explosion by a factor of 1000, the radius of action increases by a factor of 10 (Table 10).
light emission. From a fireball with an extremely high temperature, a powerful stream of light and heat (infrared) rays of high temperature emanates for 10-20 seconds. Near the fireball, everything (even minerals and metals) melts, turns into a gaseous state and rises with a mushroom cloud. The radius of action of light radiation depends on the power and type of explosion (the largest with an air explosion) and the transparency of the atmosphere (rain, fog, snow sharply reduce the effect due to the absorption of light rays).
Table 9
Approximate ranges of shock wave and light radiation (km)
|
Characteristic |
Explosion power |
|||
|
Zone of complete destruction and death of unprotected people (Rf-100 kPa) | ||||
|
Zone of severe damage, severe and moderate injuries (Rf-30-90 kPa) | ||||
|
Zone of medium and weak destruction, medium and mild injuries (Rf-10-30 kPa) | ||||
|
III degree | ||||
|
II degree | ||||
|
I degree | ||||
Note. Pf - excess pressure on the front of the shock wave. The numerator gives data for air explosions, the denominator - for ground explosions. 100 kPa \u003d 1 kg / cm 2 (1 atm.).
Light radiation causes ignition of combustible substances and massive fires, and in humans and animals, burns of the body of varying severity. In Hiroshima, about 60,000 buildings burned down and about 82% of the affected people had body burns.
The degree of damaging effect is determined by the light pulse, that is, the amount of energy falling on 1 m 2 of the surface of the illuminated body, and is measured in kilojoules per 1 m 2. A light pulse of 100-200 kJ / m 2 (2-5 cal / cm 2) causes a burn of I degree, 200-400 kJ / m 2 (5-10 cal / cm 2) - II, more than 400 kJ / m 2 ( over 10 cal / cm 2) - III degree (100 kJ / m 2).
The degree of damage to materials by light radiation depends on the degree of their heating, which in turn depends on a number of factors: the magnitude of the light pulse, the properties of the material, the coefficient of heat absorption, humidity, combustibility of the material, etc. Dark-colored materials absorb light energy more than light-colored materials . For example, black cloth absorbs 99% of the incident light energy, khaki-colored material - 60%, white cloth - 25%.
In addition, the light pulse causes blinding people, especially at night, when the pupil is dilated. Blinding is more often temporary due to depletion of visual purple (rhodopsin). But at close range, there may be a retinal burn and a more permanent blindness. Therefore, you can not look at the flash of light, you must immediately close your eyes. Currently, there are protective photochromic glasses that lose their transparency from light radiation and protect the eyes.
penetrating radiation. At the time of the explosion, for about 15-20 seconds, as a result of nuclear and thermonuclear reactions, a very powerful stream of ionizing radiation emanates: gamma rays, neutrons, alpha and beta particles. But only gamma rays and neutron flux are related to penetrating radiation, since alpha and beta particles have a short range in air and do not have penetrating power.
The radius of action of penetrating radiation during air explosions of a 20-kiloton bomb is approximately expressed in the following figures: up to 800 m - 100% mortality (dose up to 10,000 R); 1.2 km - 75% mortality (dose up to 1000 R); 2 km - radiation sickness I-II degree (dose 50-200 R). During explosions of thermonuclear megaton munitions, fatal injuries can be within a radius of up to 3-4 km due to the large size of the fireball at the time of the explosion, while the neutron flux becomes of great importance.
The total doses of gamma and neutron exposure of unprotected people in a nuclear focus can be determined from the graphs (Fig. 43).
Especially strongly penetrating radiation is manifested in the explosions of neutron bombs. In the explosion of a neutron bomb with a capacity of 1 thousand tons of TNT equivalent, when the shock wave and light radiation strike within a radius of 130-150 m, the total gamma-neutron radiation is: within a radius of 1 km - up to 30 Gy (3000 rad), 1.2 km -8.5 Gy; 1.6 km - 4 Gy, up to 2 km - 0.75-1 Gy.
Rice. 43. Total dose of penetrating radiation during nuclear explosions.
Various shelters and structures can serve as a means of protection against penetrating radiation. Moreover, gamma rays are more strongly absorbed and retained by heavy materials with a high density, and neutrons are better absorbed by light substances. To calculate the required thickness of protective materials, the concept of a layer of half attenuation is introduced, that is, the thickness of the material, which reduces radiation by a factor of 2 (Table 11).
Table 11
Half attenuation layer (K 0.5). cm
To calculate the protective power of shelters, the formula K s \u003d 2 S / K 0.5 is used
where: K z - protection factor of the shelter, S - thickness of the protective layer, K 0.5 - layer of half attenuation. From this formula it follows that 2 layers of half attenuation reduce radiation by 4 times, 3 layers by 8 times, etc.
For example, a 112 cm earth cover reduces gamma exposure by a factor of 256:
K z \u003d 2 112/14 \u003d 2 8 \u003d 256 (times).
In field shelters, it is required that the protection factor for gamma radiation be equal to 250-1000, that is, an earthen floor with a thickness of 112-140 cm is required.
Radioactive contamination of the area. No less dangerous damaging factor of nuclear weapons is radioactive contamination of the area. The peculiarity of this factor lies in the fact that very large territories are exposed to radioactive contamination, and in addition, its effect lasts for a long time (weeks, months and even years).
So, during a test explosion made by the USA on March 1, 1954 in the South Pacific Ocean in the area of \u200b\u200babout. Bikini (10-megaton bomb), radioactive contamination was noted at a distance of up to 600 km. At the same time, residents of the Marshall Islands (267 people), who were at a distance of 200 to 540 km, and 23 Japanese fishermen on a fishing boat, located at a distance of 160 km from the center of the explosion, were hit.
Sources of radioactive contamination are radioactive isotopes (fragments) formed during nuclear fission, induced radioactivity and the remnants of the unreacted part of the nuclear charge.
Radioactive fission isotopes of uranium and plutonium are the main and most dangerous source of contamination. In a chain reaction of fission of uranium or plutonium, their nuclei are divided into two parts with the formation of various radioactive isotopes. These isotopes subsequently undergo an average of three radioactive decays with the emission of beta particles and gamma rays, turning after that into non-radioactive substances (barium and lead). Thus, in a mushroom cloud there are about 200 radioactive isotopes of 35 elements of the middle part of the periodic table - from zinc to gadolinium.
The most common isotopes among fission fragments are those of yttrium, tellurium, molybdenum, iodine, xenon, barium, lanthanum, strontium, cesium, zirconium, and others. , causing the entire mushroom cloud to become radioactive. Where radioactive dust settles, the terrain and all objects turn out to be contaminated with radioactive substances (contaminated products of a nuclear explosion, PYaV).
Induced radioactivity arises under the action of a neutron flux. Neutrons are able to interact with the nuclei of various elements (air, soil and other objects), as a result of which many elements become radioactive and begin to emit beta particles and gamma rays. For example, sodium becomes a radioactive isotope when it captures a neutron:
11 23 Na + n 1 → 11 24 Na,
which undergoes beta decay with gamma radiation and has a half-life of 14.9 hours: 11 24 Na - 12 24 Mg + ß - + γ.
Of the radioactive isotopes formed during neutron irradiation of soil, manganese-52, silicon-31, sodium-24, and calcium-45 are of the greatest importance.
However, induced radioactivity plays a relatively small role, since it occupies a small area (depending on the power of the explosion within a maximum radius of 2-3 km), and isotopes are formed mainly with a short half-life.
But the induced radioactivity of soil elements and in a mushroom cloud is of great importance in thermonuclear explosions and explosions of neutron bombs, since thermonuclear fusion reactions are accompanied by the emission of a large number of fast neutrons.
The unreacted part of the nuclear charge is the undivided uranium or plutonium atoms. The fact is that the efficiency of the nuclear charge is very low (about 10%), the remaining uranium and plutonium atoms do not have time to undergo fission, the unreacted part is sprayed into tiny particles by the force of the explosion and settles in the form of precipitation from the mushroom cloud. However, this unreacted part of the nuclear charge plays an insignificant role. This is due to the fact that uranium and plutonium have very long half-lives, in addition, they emit alpha particles and are dangerous only when ingested. So, the greatest danger is the radioactive fragments of the fission of uranium and plutonium. The total gamma activity of these isotopes is extremely high: 1 minute after the explosion of a 20-kiloton bomb, it is 8.2 10 11 Ci.
During air nuclear explosions, radioactive contamination of the area in the explosion zone is of no practical importance. This is explained by the fact that the luminous zone does not come into contact with the earth, therefore a relatively small, thin mushroom cloud is formed, consisting of very fine radioactive dust, which rises and infects the atmosphere and stratosphere. Subsidence of RS occurs over large areas over several years (mainly strontium and cesium). There is contamination of the area only within a radius of 800-3000 m, mainly due to induced radioactivity, which quickly (after 2-5 hours) practically disappears.
With ground and low air explosions, the radioactive contamination of the area will be the strongest, since the fireball is in contact with the ground. A massive mushroom cloud is formed, containing a large amount of radioactive dust, which is carried by the wind and settles along the path of the cloud, creating a radioactive trail of the cloud in the form of a strip of earth contaminated with radioactive fallout. Some of the largest particles settle around the stem of the mushroom cloud.
During underground nuclear explosions, very intense contamination is observed near the center of the explosion, part of the radioactive dust was also carried by the wind and settles along the path of the cloud, but the area of the contaminated territory is smaller than in a ground explosion of the same power.
During underwater explosions, a very strong radioactive contamination of a reservoir is observed near the explosion. In addition, radioactive rain falls along the path of the cloud at considerable distances. At the same time, a strong induced, radioactivity of sea water containing a lot of sodium is also noted.
The intensity of radioactive contamination of the area is measured by two methods: the level of radiation in roentgens per hour (R / h) and the dose of radiation in grays (rads) for a certain period of time that personnel can receive in the contaminated area.
In the region of the center of a nuclear explosion, the contaminated area has the shape of a circle somewhat elongated in the direction of the wind. The trace of radioactive fallout along the path of the cloud usually has the shape of an ellipse, the axis of which is directed in the direction of the wind. The width of the trace of radioactive fallout is 5-10 times less than the length of the trace (ellipse).
In a ground explosion of a 10-megaton thermonuclear bomb, the contamination zone with a radiation level of 100 R/h has a length of up to 325 km and a width of up to 50 km, and a zone with a radiation level of 0.5 R/h has a length of more than 1000 km. From this it is clear what vast territories can be contaminated with radioactive fallout.
The start of radioactive fallout depends on the wind speed and can be determined by the formula: t 0 = R/v, where t 0 is the start of fallout, R is the distance from the center of the explosion in kilometers, v is the wind speed in kilometers per hour.
The level of radiation in the contaminated area is constantly decreasing due to the conversion of short-lived isotopes into non-radioactive stable substances.
This decrease occurs according to the rule: with a sevenfold increase in the time elapsed since the explosion, the radiation level decreases by a factor of 10. For example: if after 1 hour the radiation level is equal to 1000 R/h, then after 7 hours - 100 R/h, after 49 hours - 10 R/h, after 343 hours (2 weeks) - 1 R/h.
The level of radiation decreases especially quickly in the first hours and days after the explosion, and then substances with a long half-life remain and the decrease in the level of radiation occurs very slowly.
The exposure dose (gamma rays) to unprotected personnel in the contaminated area depends on the level of radiation, the time spent in the contaminated area, and the rate of decline in the radiation level.
It is possible to calculate the dose of radiation for the period until the complete decay of radioactive substances.
Radioactive fallout infects the area unevenly. The highest levels of radiation are near the center of the explosion and the axis of the ellipse, while away from the center of the explosion and from the axis of the track, the radiation levels will be lower. In accordance with this, the trace of radioactive fallout is usually divided into 4 zones (see p. 251).
The means of protection against radiation sickness in contaminated areas are shelters, shelters, buildings, structures, military equipment, etc., which weaken radiation exposure, and with appropriate sealing (closing doors, windows, etc.), they also prevent the penetration of radioactive dust.
In the absence of shelters, it is necessary to leave the zones of strong and dangerous contamination as soon as possible, that is, to limit the time of exposure of people. The most probable ways of hazardous effects of radioactive substances from a nuclear explosion on people are general external gamma irradiation and contamination of the skin. Internal exposure is not significant in the damaging effect.
Note. It should be added that in Europe there are more than 200 nuclear reactors, the destruction of which can lead to very strong contamination of vast areas of territory with radioactive fallout for a long time. An example of this is the release of radioactive substances from the nuclear reactor accident at Chernobyl.
Nuclear winter. Soviet and American scientists have calculated that a global nuclear missile war could lead to dramatic environmental changes throughout the globe. As a result of hundreds and thousands of nuclear explosions, millions of tons of smoke and dust will be raised into the air to a height of 10-15 km, the sun's rays will not pass, a nuclear night will come, and then a nuclear winter for several years, plants will die, famine may come, everything will be covered with snow. In addition, the earth will be covered with long-lived radioactive fallout. Up to 1 billion people can die in the fire of a nuclear war, up to 2 billion - in a nuclear winter (Yu. M. Svirezhev, A. A. Baev and others).
Electromagnetic impulse and secondary damage factors. During nuclear explosions, due to the ionization of air and the movement of electrons at high speeds, electromagnetic fields arise that create pulsed electrical discharges and currents. An electromagnetic pulse generated in the atmosphere, like lightning, can induce strong currents in antennas, cables, power lines, wires, etc. The induced currents turn off automatic switches, can cause insulation failure, burnout of radio equipment and electrical appliances and electric shock to people. current. The radius of action of an electromagnetic pulse during air explosions with a capacity of 1 megaton is considered to be up to 32 km, with an explosion with a capacity of 10 megatons - up to 115 km.
Secondary damage factors include fires and explosions at chemical and oil refineries, which can cause mass poisoning of people with carbon monoxide or other toxic substances. The destruction of dams and hydraulic structures creates the danger of flood zones in settlements. To protect against secondary damage factors, engineering and technical measures should be taken to protect these structures.
It is necessary to know well the dangers posed by nuclear missile weapons and be able to properly organize the protection of troops and the population.
In a ground-based nuclear explosion, a funnel is formed on the surface of the earth, the dimensions of which depend on the power of the explosion and the type of soil.
The diameter of a funnel formed in dry sandy and clay soils can be determined by the formula:
Where D is the funnel diameter, m;
q is the explosion power, kT.
The program takes only 8 bytes. Therefore, we write it in one line, without addresses:
3; F1/x; ↔; F x y ; 3; eight; ×; S/P.
Operating procedure:
- Enter the explosion power in kT;
- Press V/O, S/P;
- Read in RX the diameter of the funnel in meters.
For example, for a bomb with a TNT equivalent of 1MT, the diameter of the funnel will be 380 m. The depth of the funnel will be approximately 40-60 m.
Just as simply, a seven-byte program solves the inverse problem:
3; eight; ÷; AT; F x 2 ; ×; S/P.
Operating procedure:
- Enter the funnel diameter in meters;
- Press V/O, S/P;
- Calculate the power of the explosion in kT.
The nuclear lesion is characterized by:
a) mass destruction of people and animals;
b) destruction and damage to ground buildings and structures;
c) partial destruction, damage or blockage of protective structures of civil defense;
d) the occurrence of individual, continuous and massive fires;
e) the formation of continuous and partial blockages of streets, driveways, intra-quarter sections;
f) the occurrence of mass accidents on utility networks;
g) the formation of areas and zones of radioactive contamination of the area during a ground explosion.
The radius of destruction by a shock wave, light radiation and penetrating radiation of a ground explosion is somewhat less than with an air one. A characteristic feature of a ground explosion is a strong radioactive contamination of the area both in the area of the explosion and in the direction of the radioactive cloud.
As theoretical studies have shown, the radii of the zones of destruction and damage by the shock wave of nuclear and thermonuclear explosions of various powers are proportional to the cube root of the ratio of TNT equivalents. Therefore, for an approximate comparison of the radii of the zones affected by the shock wave of nuclear explosions of different power, you can use the formula:
where R1 and R1 are the radii of the affected zones, km; q1 and q2 - TNT equivalent, MT.
Let's make a program for calculating the affected areas, based on the data in the table.
| x0 | x1 | x2 | x3 | x4 | x5 | x6 | x7 | x8 | x9 | |
| 0x | P0 | 3 | F1/x | ↔ | F x y | P4 | IP1 | × | IP4 | IP2 |
| 1x | × | IP4 | IP3 | × | IP0 | S/P | BP | 00 |
Before starting, the values R1=3.65 should be entered into the memory registers; R2=7.5; R3=14.
To calculate, enter the TNT equivalent in MT into register X and press C / P. After the end of the calculation, in RT - the radius of the zone of complete destruction in km, in RZ and RY, respectively, the radii of the zones of strong and weak destruction in km, in RX - the initial value of the TNT equivalent in MT.
Literature
- Egorov P.T., Shlyakhov I.A., Alabin N.I. Civil defense. Ed. 2nd. Textbook. - M.: Higher School, 1970, 544 p., ill.
At the beginning of the 20th century, thanks to the efforts of Albert Einstein, mankind first learned that at the atomic level, from a small amount of matter, under certain conditions, a huge amount of energy can be obtained. In the 1930s, work in this direction was continued by the German nuclear physicist Otto Hahn, the Englishman Robert Frisch, and the Frenchman Joliot-Curie. It was they who managed in practice to track the results of the fission of the nuclei of atoms of radioactive chemical elements. The chain reaction process simulated in laboratories confirmed Einstein's theory about the ability of matter in small quantities to release a large amount of energy. Under such conditions, the physics of a nuclear explosion was born - a science that cast doubt on the possibility of the further existence of terrestrial civilization.
The birth of nuclear weapons
Back in 1939, the Frenchman Joliot-Curie realized that exposure to uranium nuclei under certain conditions could lead to an explosive reaction of enormous power. As a result of a nuclear chain reaction, spontaneous exponential fission of uranium nuclei begins, and a huge amount of energy is released. In an instant, the radioactive substance exploded, and the resulting explosion had a huge damaging effect. As a result of the experiments, it became clear that uranium (U235) can be turned from a chemical element into a powerful explosive.
For peaceful purposes, during the operation of a nuclear reactor, the process of nuclear fission of radioactive components is calm and controlled. In a nuclear explosion, the main difference is that a huge amount of energy is released instantly and this continues until the supply of radioactive explosives runs out. For the first time, a person learned about the combat capabilities of the new explosive on July 16, 1945. At the time when the final meeting of the Heads of State of the victors of the war with Germany was taking place in Potsdam, the first test of an atomic warhead took place at the test site in Alamogordo, New Mexico. The parameters of the first nuclear explosion were quite modest. The power of the atomic charge in TNT equivalent was equal to the mass of trinitrotoluene in 21 kilotons, but the force of the explosion and its impact on surrounding objects made an indelible impression on everyone who watched the tests.
Explosion of the first atomic bomb
At first, everyone saw a bright luminous dot, which was visible at a distance of 290 km. from the test site. At the same time, the sound from the explosion was heard within a radius of 160 km. At the place where the nuclear explosive device was installed, a huge crater formed. The funnel from a nuclear explosion reached a depth of more than 20 meters, with an outer diameter of 70 m. On the territory of the test site within a radius of 300-400 meters from the epicenter, the earth's surface was a lifeless lunar surface.
It is interesting to cite the recorded impressions of the participants in the first test of the atomic bomb. “The surrounding air became denser, its temperature instantly rose. Literally a minute later, a huge shock wave swept through the area. At the location of the charge, a huge fireball is formed, after which a mushroom-shaped nuclear explosion cloud began to form in its place. A column of smoke and dust, crowned with a massive nuclear mushroom head, rose to a height of 12 km. Everyone present in the shelter was struck by the scale of the explosion. No one could have imagined the power and strength we faced, ”wrote the head of the Manhattan Project, Leslie Groves, later.
No one, before or since, had at his disposal a weapon of such enormous power. This despite the fact that at that time scientists and the military did not yet have an idea about all the damaging factors of the new weapon. Only the visible main damaging factors of a nuclear explosion were taken into account, such as:
- shock wave of a nuclear explosion;
- light and thermal radiation of a nuclear explosion.
The fact that penetrating radiation and subsequent radioactive contamination during a nuclear explosion is fatal for all living things did not yet have a clear idea. It turned out that these two factors after a nuclear explosion will subsequently become the most dangerous for a person. The zone of complete destruction and devastation is quite small in area in comparison with the zone of contamination of the area by the products of radiation decay. An infected area can have an area of hundreds of kilometers. To the exposure received in the first minutes after the explosion, and to the level of radiation subsequently, contamination of vast territories with radioactive fallout is added. The scale of the catastrophe becomes apocalyptic.
Only later, much later, when atomic bombs were used for military purposes, it became clear how powerful the new weapon was and how severe the consequences of the use of a nuclear bomb would be for people.
The mechanism of atomic charge and the principle of operation
If you do not go into detailed descriptions and technology for creating an atomic bomb, you can briefly describe a nuclear charge in just three phrases:
- there is a subcritical mass of radioactive material (uranium U235 or plutonium Pu239);
- creation of certain conditions for the start of a chain reaction of nuclear fission of radioactive elements (detonation);
- creation of a critical mass of fissile material.
The whole mechanism can be depicted in a simple and understandable drawing, where all parts and details are in strong and close interaction with each other. As a result of the detonation of a chemical or electrical detonator, a detonation spherical wave is launched, compressing the fissile material to a critical mass. The nuclear charge is a multilayer structure. Uranium or plutonium is used as the main explosive. A certain amount of TNT or RDX can serve as a detonator. Further, the compression process becomes uncontrollable.
The speed of the ongoing processes is enormous and comparable to the speed of light. The time interval from the start of detonation to the start of an irreversible chain reaction takes no more than 10-8 s. In other words, it takes only 10-7 seconds to power 1 kg of enriched uranium. This value denotes the time of a nuclear explosion. The reaction of thermonuclear fusion, which is the basis of a thermonuclear bomb, proceeds with a similar speed, with the difference that a nuclear charge sets in motion an even more powerful one - a thermonuclear charge. A thermonuclear bomb has a different principle of operation. Here we are dealing with the reaction of the synthesis of light elements into heavier ones, as a result of which, again, a huge amount of energy is released.
In the process of fission of uranium or plutonium nuclei, a huge amount of energy is generated. At the center of a nuclear explosion, the temperature is 107 Kelvin. Under such conditions, a colossal pressure arises - 1000 atm. Atoms of fissile matter turn into plasma, which becomes the main result of the chain reaction. During the accident at the 4th reactor of the Chernobyl nuclear power plant, there was no nuclear explosion, since the fission of radioactive fuel was carried out slowly and was accompanied only by intense heat release.
The high speed of the processes occurring inside the charge leads to a rapid jump in temperature and an increase in pressure. It is these components that form the nature, factors and power of a nuclear explosion.
Types and types of nuclear explosions
The chain reaction that has started can no longer be stopped. In thousandths of a second, a nuclear charge, consisting of radioactive elements, turns into a plasma clot, torn apart by high pressure. A successive chain of a number of other factors begins that have a damaging effect on the environment, infrastructure facilities and living organisms. The only difference in damage is that a small nuclear bomb (10-30 kilotons) causes less destruction and less severe consequences than a large nuclear explosion with a yield of 100 more megatons.
The damaging factors depend not only on the power of the charge. To assess the consequences, the conditions for detonating a nuclear weapon are important, which type of nuclear explosion is observed in this case. Undermining the charge can be carried out on the surface of the earth, underground or under water, according to the conditions of use, we are dealing with the following types:
- air nuclear explosions carried out at certain heights above the earth's surface;
- high-altitude explosions carried out in the planet's atmosphere at altitudes above 10 km;
- land (surface) nuclear explosions carried out directly above the surface of the earth or above the water surface;
- underground or underwater explosions carried out in the surface thickness of the earth's crust or under water, at a certain depth.
In each individual case, certain damaging factors have their own strength, intensity and characteristics of the action, leading to certain results. In one case, a targeted destruction of the target occurs with minimal destruction and radioactive contamination of the territory. In other cases, one has to deal with large-scale devastation of the area and the destruction of objects, instant destruction of all life occurs, and strong radioactive contamination of vast territories is observed.
An air nuclear explosion, for example, differs from a ground-based detonation method in that the fireball does not come into contact with the earth's surface. In such an explosion, dust and other small fragments are combined into a dust column that exists separately from the explosion cloud. Accordingly, the area of damage also depends on the height of the explosion. Such explosions can be high and low.
The first tests of atomic warheads both in the USA and in the USSR were mainly of three types, ground, air and underwater. Only after the Treaty on the Limitation of Nuclear Tests came into force, nuclear explosions in the USSR, in the USA, in France, in China and in Great Britain began to be carried out only underground. This made it possible to minimize environmental pollution with radioactive products, to reduce the area of exclusion zones that arose near military training grounds.
The most powerful nuclear explosion in the history of nuclear testing took place on October 30, 1961 in the Soviet Union. A bomb with a total weight of 26 tons and a capacity of 53 megatons was dropped in the area of the Novaya Zemlya archipelago from a Tu-95 strategic bomber. This is an example of a typical high air burst, as the explosion occurred at an altitude of 4 km.
It should be noted that the detonation of a nuclear warhead in the air is characterized by a strong effect of light radiation and penetrating radiation. The flash of a nuclear explosion is clearly visible tens and hundreds of kilometers from the epicenter. In addition to powerful light radiation and a strong shock wave diverging around 3600, an air explosion becomes a source of strong electromagnetic disturbance. An electromagnetic pulse generated during an air nuclear explosion within a radius of 100-500 km. able to disable the entire ground electrical infrastructure and electronics.
A striking example of a low air burst was the August 1945 atomic bombing of the Japanese cities of Hiroshima and Nagasaki. Bombs "Fat Man" and "Baby" worked at an altitude of half a kilometer, thereby covering almost the entire territory of these cities with a nuclear explosion. Most of the inhabitants of Hiroshima died in the first seconds after the explosion, as a result of exposure to intense light, heat and gamma radiation. The shock wave completely destroyed the city buildings. In the case of the bombing of the city of Nagasaki, the effect of the explosion was weakened by the features of the relief. The hilly terrain allowed some areas of the city to avoid the direct action of light rays, and reduced the impact force of the blast wave. But during such an explosion, extensive radioactive contamination of the area was observed, which subsequently led to serious consequences for the population of the destroyed city.
Low and high air bursts are the most common modern means of weapons of mass destruction. Such charges are used to destroy the accumulation of troops and equipment, cities and ground infrastructure.
A high-altitude nuclear explosion differs in the method of application and the nature of the action. The detonation of a nuclear weapon is carried out at an altitude of more than 10 km, in the stratosphere. With such an explosion, a bright sun-like flash of large diameter is observed high in the sky. Instead of clouds of dust and smoke, a cloud soon forms at the site of the explosion, consisting of molecules of hydrogen, carbon dioxide and nitrogen evaporated under the influence of high temperatures.
In this case, the main damaging factors are the shock wave, light radiation, penetrating radiation and EMP of a nuclear explosion. The higher the charge detonation height, the lower the shock wave strength. Radiation and light emission, on the contrary, only increase with increasing altitude. Due to the absence of significant movement of air masses at high altitudes, radioactive contamination of territories in this case is practically reduced to zero. Explosions at high altitudes, made within the ionosphere, disrupt the propagation of radio waves in the ultrasonic range.
Such explosions are mainly aimed at destroying high-flying targets. These can be reconnaissance aircraft, cruise missiles, strategic missile warheads, artificial satellites and other space attack weapons.
A ground-based nuclear explosion is a completely different phenomenon in military tactics and strategy. Here, a certain area of the earth's surface is directly affected. Undermining a warhead can be carried out over an object or over water. The first tests of atomic weapons in the United States and in the USSR took place in this form.
A distinctive feature of this type of nuclear explosion is the presence of a pronounced mushroom cloud, which is formed due to the huge volumes of soil and rock particles raised by the explosion. At the very first moment, a luminous hemisphere is formed at the site of the explosion, with its lower edge touching the surface of the earth. During a contact detonation, a funnel is formed at the epicenter of the explosion, where the nuclear charge exploded. The depth and diameter of the funnel depends on the power of the explosion itself. When using small tactical ammunition, the diameter of the funnel can reach two or three tens of meters. When a nuclear bomb is detonated with high power, the dimensions of the crater often reach hundreds of meters.
The presence of a powerful mud and dust cloud contributes to the fact that the bulk of the radioactive products of the explosion falls back to the surface, making it completely contaminated. Smaller dust particles enter the surface layer of the atmosphere and, together with the air masses, scatter over vast distances. If an atomic charge is blown up on the surface of the earth, the radioactive trace from the produced ground explosion can stretch for hundreds and thousands of kilometers. During the accident at the Chernobyl nuclear power plant, radioactive particles that entered the atmosphere fell out along with precipitation on the territory of the Scandinavian countries, which are located 1000 km from the disaster site.
Ground explosions can be carried out to destroy and destroy objects of great strength. Such explosions can also be used if the goal is to create a vast zone of radioactive contamination of the area. In this case, all five damaging factors of a nuclear explosion are in effect. Following the thermodynamic shock and light radiation, an electromagnetic impulse comes into play. The shock wave and penetrating radiation complete the destruction of the object and manpower within the radius of action. Finally, there is radioactive contamination. Unlike the ground-based method of detonation, a surface nuclear explosion lifts huge masses of water into the air, both in liquid form and in a vapor state. The destructive effect is achieved due to the impact of the air shock wave and the large excitement resulting from the explosion. The water raised into the air prevents the spread of light radiation and penetrating radiation. Due to the fact that water particles are much heavier and are a natural neutralizer of the activity of elements, the intensity of the spread of radioactive particles in the air space is negligible.
An underground explosion of a nuclear weapon is carried out at a certain depth. Unlike ground explosions, there is no glowing area here. All the huge impact force is taken by the earth rock. The shock wave diverges in the thickness of the earth, causing a local earthquake. The huge pressure created during the explosion forms a column of soil collapse, going to great depths. As a result of rock subsidence, a funnel is formed at the site of the explosion, the dimensions of which depend on the power of the charge and the depth of the explosion.
Such an explosion is not accompanied by a mushroom cloud. The column of dust that rose at the site of the detonation of the charge has a height of only a few tens of meters. The shock wave converted into seismic waves and local surface radioactive contamination are the main damaging factors in such explosions. As a rule, this type of detonation of a nuclear charge is of economic and applied importance. To date, most nuclear tests are carried out underground. In the 1970s and 1980s, national economic problems were solved in a similar way, using the colossal energy of a nuclear explosion to destroy mountain ranges and form artificial reservoirs.
On the map of nuclear test sites in Semipalatinsk (now the Republic of Kazakhstan) and in the state of Nevada (USA) there are a huge number of craters, traces of underground nuclear tests.
Underwater detonation of a nuclear charge is carried out at a given depth. In this case, there is no light flash during the explosion. A water column 200-500 meters high appears on the surface of the water at the place of explosion, which is crowned with a cloud of spray and steam. The formation of a shock wave occurs immediately after the explosion, causing disturbances in the water column. The main damaging factor of the explosion is the shock wave, which transforms into waves of great height. With the explosion of high-power charges, the height of the waves can reach 100 meters or more. In the future, a strong radioactive contamination is observed at the site of the explosion and in the adjacent territory.
Methods of protection against damaging factors of a nuclear explosion
As a result of the explosive reaction of a nuclear charge, a huge amount of thermal and light energy is generated, which can not only destroy and destroy inanimate objects, but also kill all living things over a large area. In the epicenter of the explosion and in its immediate vicinity, as a result of intense exposure to penetrating radiation, light, thermal radiation and shock waves, all living things die, military equipment is destroyed, buildings and structures are destroyed. With distance from the epicenter of the explosion and over time, the strength of the damaging factors decreases, giving way to the last destructive factor - radioactive contamination.
It is useless to seek salvation for those who have fallen into the epicenter of a nuclear apocalypse. Neither a strong bomb shelter nor personal protective equipment will save here. Injuries and burns received by a person in such situations are incompatible with life. The destruction of infrastructure facilities is total and cannot be restored. In turn, those who found themselves at a considerable distance from the explosion site can count on salvation using certain skills and special methods of protection.
The main damaging factor in a nuclear explosion is the shock wave. The area of high pressure formed at the epicenter affects the air mass, creating a shock wave that propagates in all directions at supersonic speed.
The propagation speed of the blast wave is as follows:
- on flat terrain, the shock wave overcomes 1000 meters from the epicenter of the explosion in 2 seconds;
- at a distance of 2000 m from the epicenter, the shock wave will overtake you in 5 seconds;
- being at a distance of 3 km from the explosion, the shock wave should be expected in 8 seconds.
After the passage of the blast wave, an area of low pressure arises. In an effort to fill the rarefied space, the air goes in the opposite direction. The created vacuum effect causes another wave of destruction. Seeing a flash, before the arrival of the blast wave, you can try to find shelter, reducing the effects of the impact of the shock wave.
Light and heat radiation at a great distance from the epicenter of the explosion lose their strength, so if a person managed to take cover at the sight of a flash, you can count on salvation. Much more terrible is penetrating radiation, which is a rapid stream of gamma rays and neutrons that propagate at the speed of light from the luminous area of the explosion. The most powerful effect of penetrating radiation occurs in the first seconds after the explosion. While in shelter or shelter, there is a high probability of avoiding a direct hit of deadly gamma radiation. Penetrating radiation causes severe damage to living organisms, causing radiation sickness.
If all the above listed damaging factors of a nuclear explosion are of a short-term nature, then radioactive contamination is the most insidious and dangerous factor. Its destructive effect on the human body occurs gradually, over time. The amount of residual radiation and the intensity of radioactive contamination depends on the power of the explosion, terrain conditions and climatic factors. The radioactive products of the explosion, mixed with dust, small fragments and fragments, enter the surface air layer, after which, together with precipitation or independently, they fall to the surface of the earth. The radiation background in the zone of application of nuclear weapons is hundreds of times higher than the natural background radiation, creating a threat to all living things. Being in the territory subjected to a nuclear strike, contact with any objects should be avoided. Personal protective equipment and a dosimeter will reduce the likelihood of radioactive contamination.
Times are turbulent now, with more and more talk of a new Cold War. We want to believe that things will not come to the Third World War, but they decided to tighten up the theory. So, we disassembled a nuclear explosion into five damaging factors and figured out how to survive from each of them. Ready? Flash on the left!
1. Shock wave
Most of the destruction from a nuclear explosion will come from a shock wave rushing at supersonic speeds (more than 350 m/s in the atmosphere). While no one saw, we took a W88 thermonuclear warhead with a yield of 475 kilotons, which is located in the United States, and found out that when it explodes within a radius of 3 km from the epicenter, absolutely nothing and no one will remain; at a distance of 4 km, the buildings will be thoroughly destroyed, and at a distance of 5 km and further, the destruction will be medium and weak. The chances of survival will appear only if you are at least 5 km from the epicenter (and then if you have time to hide in the basement). To independently calculate the radii of damage from an explosion of various capacities, you can use our simulator.
2. Light emission
Causes ignition of combustible materials. But even when you are far from gas stations and warehouses with Moment, you risk getting burns and eye damage. Therefore, hide behind some obstacle like a huge stone block, cover your head with a sheet of metal or other non-combustible thing and close your eyes. After detonating a W88 nuclear bomb at a distance of 5 km, you may not be killed by the shock wave, but the light beam can cause second-degree burns. These are the ones with nasty blisters on the skin. At a distance of 6 km there is a risk of getting first-degree burns: redness, swelling, swelling of the skin - in a word, nothing serious. But the most pleasant thing will happen if you manage to be 7 km from the epicenter: an even tan and survival is guaranteed.
3. Electromagnetic pulse
If you are not a cyborg, you are not afraid of an electromagnetic impulse: it disables only electrical and electronic equipment. Just know that if a mushroom cloud appears on the horizon, it is useless to take a selfie in front of it. The range of the pulse depends on the height of the explosion and the environment and ranges from 3 to 115 km.
4. Penetrating radiation
Despite such a terrible name, the thing is cheerful and harmless. It destroys all living things only within a radius of 2-3 km from the epicenter, where you will be killed by a shock wave anyway.
5. Radioactive contamination
The meanest part of a nuclear explosion. It is a huge cloud consisting of radioactive particles raised into the air by an explosion. The territory of the spread of radioactive contamination is highly dependent on natural factors, primarily on the direction of the wind. If you blow up W88 with a wind of 5 km / h, the radiation will be dangerous at a distance of up to 130 km from the epicenter in the direction of the wind (against the wind, nuclear contamination does not spread further than 3 km). The rate of death from radiation sickness depends on the remoteness of the epicenter, weather, terrain, the characteristics of your body and a bunch of other factors. People infected with radiation can either die instantly or live for years. How this happens depends solely on personal luck and the individual characteristics of the body, in particular on the strength of immunity. Also, patients with radiation sickness are prescribed certain drugs and food to remove radionuclides from the body.
Remember that the one who is warned is armed, and the one who prepares the sled in the summer will survive. Today, we are literally living on the threshold, which has already begun and at any moment you can go into the hottest phase with the use of mass destruction. To protect yourself and your loved ones, you must think in advance where you can hide and survive the atomic bombing of your village.
There is a funny thing on Vott, where, with reference to Google Earth maps, you can compare almost any relevance with the most famous nuclear devices of the "atomic race".
For example, if you select New York on the map and apply the most powerful nuclear bomb created in the USSR to it, it gives the following results:
The damaging factors of an explosion with a power of 100,000 kt (from the smallest to the largest in terms of distance from the epicenter):
Fire Flash Radius: 3.03 km / 1.88 miles
Radiation Radius: 7.49 km / 4.65 miles
blast radius: 12.51 km / 7.77 miles
blast radius: 33.01 km / 20.51 miles
Light damage radius: 77.06 km / 47.88 miles
Whereas when applying the conventional North Korean device,
The damaging factors of an explosion with a power of 6 kt (from the smallest to the largest in terms of distance from the epicenter):
Fire Flash Radius: 0.06 km / 0.04 miles
The maximum size of a nuclear flash; attitude to living objects depends on the height of the detonation.
Shock wave radius: 0.51 km / 0.31 miles
pressure 20 psi; strong structures are destroyed or badly damaged; lethality in this affected area reaches 100%.
Radiation Radius: 1.18 km / 0.73 miles
500 rem / 5 Sv radiation dose; mortality from acute manifestations ranging from 50% to 90%; the time of death is between one hour and several weeks.
blast radius: 1.33 km / 0.83 miles
pressure 4.6 psi; most of the buildings are destroyed; wide range of damage, many dead.
Light damage radius: 1.43 km / 0.89 miles
Third degree burns to unprotected areas of the skin; ignition of flammable materials; with sufficient explosive power, a firestorm is formed.
The main topic was the discussion OFFACKLE”, a plan for nuclear war with the Soviet Union.
Conference transcript (not complete).
Part 1
1. Report by Major General Charles Pearre Cabell, head of intelligence for the US Air Force,
Political information. Soviet agitprop is resting.
Pieces of NSC-68. The CIA is full of cretins.
In the middle of 1952, the USSR will be able to inflict (and most likely strike - it is) unacceptable damage to the United States.
We must prepare.
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2. Three reports. Major General Samuel Egbert Anderson.
Nuclear war scenario.
Soviet aggression.
The defense along the Rhine was most likely unsuccessful.
Defense of Great Britain. Has to be successful.
The three-year occupation of Europe by the Soviets.
And then "Overlord".
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In general, there is not much new.
Who cares - recognized text (English, naturally).
Report from the Strategic Air Command (SAC)- Speech by General Montgomery.
Transcript
Prepared text with illustrations.
What is there.
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Composition of SAK:
3 armies (2nd, 8th, 15th).
67,156 people (military - 60,694, civilians 6,462).
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Aviation:
Total 784
.
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Bombers - 512 (Half ( 256 ) - carriers of nuclear weapons).
heavy - 27 (B-36)
medium - 485 (148 B-50, 337 B-29)
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Note 1. There are a few more B-36s, but they are not combat-ready.
Note 2 - 1800 B-29s are in storage. But after three years, there should be 182 of them.
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Tankers - 77 (all KB-29, "All of these are equipped with the British type refueling system" - so)
Scouts - 62 (all RB-29s). RB-36 and RB-50 have not yet been received.
Fighters - 104 (77 F-82, 27 F-84). The number will soon double.
Transport - 29 (19 C-54, 10 C-97)
With the threat of war, redeployment to advanced bases abroad begins.
7 groups of bombers, 1 - fighters, 1 - reconnaissance and 5 groups of collectors of A-bombs (+1 to Alaska) are scheduled for the transfer.
There is a limited amount of movement on E-day, mostly near staging areas to alert assembly teams.
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Day E + 1 - the first groups decrease.
E+3 - the maximum scale of movements.
E+5 - redeployment completed.
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In England, 8 bases are used.
Assembly Group No. 6 - in Alaska (for B-36).
According to the TROJAN plan, a strike was planned on 70 cities of the USSR.
"OFFTACKLE" - 123 targets.
The intelligence for the bombing is on 60 targets, it is required to conduct aerial reconnaissance of the remaining 63's.
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Location Goal setting:
Several targets are outside the borders of the USSR.
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The first atomic bombing is scheduled for E+6.
Medium bombers strike from British bases, B-36s from Alaska
(at temperatures below -30º, it is impossible to send B-36 through Alaska due to the impossibility of maintenance (there are no hangars of the required sizes).
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In the first strike, 26 targets are hit by medium bombers (from England) and 6 targets by B-36s.
The entire grouping of strategic aviation for the first strike includes 201
British-based medium bomber and 10
B-36 North American based.
Bear 70 A-bombs.
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