Among all the damaging factors of a nuclear explosion (shock wave, light radiation, electromagnetic pulse, radioactive contamination of the area, ionizing radiation), penetrating radiation is considered to be the most dangerous. This is intense gamma radiation, accompanied by a stream of neutrons that are emitted from the nuclear explosion zone for a short period of time - several tens of seconds. It is the main cause of radiation sickness.
Ionizing radiation
Ionizing radiation, or penetrating radiation, is a stream of photons, elementary particles, atom fission fragments, which is capable of ionizing substances, that is, turning neutral atoms or molecules into ions - positively charged particles.
As a result of this “transformation”, the physicochemical and biological processes in living tissues and materials are violated, the crystal lattice is destroyed, and the molecular structure changes. The radius of damage to penetrating radiation is much smaller than that of light radiation or a shock wave. The most dangerous are the zones located within 2-3 km from the epicenter of the explosion. This is due to the fact that the flows of elementary particles are intensively absorbed by the atmosphere.
The nature of penetrating radiation
To understand what the penetrating radiation of a nuclear explosion is, it is necessary to consider its nature, and for this, turn to the structure of the atom.
Atom is the smallest particle of a chemical element, which consists of a nucleus and electrons rotating around it. The nucleus, in turn, consists of two components - protons and neutrons. The former carry a positive charge, the latter carry a neutral charge. Due to the mass ratio of protons and electrons (with a negative charge), the atom as a whole is electrically neutral.
As a result of the bombardment of an atom of a substance by neutrons, the nucleus splits into two parts with the release of a large amount of energy and the “chipping” of elementary particles. “Breakaway” neutrons, protons bombard other nuclei, and again divide them in half - an uncontrolled nuclear reaction begins.
Thus, penetrating radiation is nothing more than a combination of “breakaway” elementary particles (which did not collide with other nuclei) and a huge amount of energy - electromagnetic or gamma radiation.
The reasons for the change in the structure of the substance
A change in the structure of the substance is the main reason for such a negative effect of ionizing radiation on living tissues and various non-biological materials. This happens as a result of the bombardment of atoms of matter by “split” neutrons. As a result of such an impact, as we have already found out, the nucleus is divided into two parts.
But this happens extremely rarely, because for this, penetrating radiation must have tremendous energy. This and only this is able to divide the core in a stable state.
The main reason for the change in the structure of matter is the knocking out of neutrons from an atom. As a result of this, the mass of the nucleus decreases, electromagnetic equilibrium is disturbed, and in order to restore it, the electron is forced to “leave” its orbit.
The equilibrium is restored, but the atom acquires a positive charge, since the number of its protons has not decreased - the ionization of matter occurs. Obviously, ions are not capable of performing the same functions as atoms. Moreover, molecules become unstable, they decompose into monomers. That is why the effect of penetrating radiation is so fatal to humans.
Radiation sickness
Large doses of ionizing radiation in the vast majority of cases provoke radiation sickness - destruction, damage to tissues by radiation. It can develop as a result of short-term exposure to high doses, or prolonged, less intense exposure. In accordance with this damage can be sharp and secretive. In any case, the disease is detrimental to the human body.
During acute radiation sickness, all body systems, or a specific organ, suffer. Most often, the effect of penetrating radiation is "concentrated" on the rectum. In this case, the disease is accompanied by severe vomiting, nausea, diarrhea and dehydration. Moreover, the body is poisoned by the decay products of cells and molecules. There is general intoxication.
The duration of the latent period of radiation sickness is from several days to a month. During this time, the victim practically does not feel ailments, but then comes the height of the disease. Intoxication occurs, infectious diseases develop, the production of blood cells and bone marrow decreases sharply, extensive hemorrhages and death are observed.
Principles of protection against damaging radiation
The main protection against damaging radiation is time. In the first days after a nuclear explosion, the radiation intensity is much higher than after a few days. This is due to the fact that all substances have different half-lives - first of all, short-lived isotopes (the most dangerous) are divided, and only then the remaining particles. Moreover, for every seven hours, the radiation level decreases tenfold.
Distance is the second protection factor. Double removal from the epicenter of the explosion reduces the level of radiation by 4 times. But the main and most affordable means of protection is shielding - the use of various materials as a barrier to the flow of elementary particles. The best protective properties are lead, steel, concrete, brick, soil. That is why shelters are arranged underground, in the basements of monolithic buildings and structures.
Food Radiation Protection
Protection against penetrating radiation consists not only in creating barriers to the neutron flux and gamma radiation, but also in protecting food from radionuclides. The first thing to do to protect food and water is to place them in a dense shell. It can be a plastic bag, a plastic container, metal containers. This is done so that the decay products could not settle on food, and then get into the body.