Radiation hazardous objects
Classification of radiation hazardous objects.
The radiation-dangerous object (RDO) - an object which is stored, processed, used or
transported radioactive substance in an accident in which or destruction can occur
exposure to ionizing radiation or radioactive contamination of humans, farm animals and
plants, objects of economy and surrounding natural environment.
The radiation-dangerous objects include: nuclear power plants for different purposes;
enterprises for the reprocessing of irradiated fuel, and temporary storage of radioactive
waste; research organizations with research reactors or particle accelerators; sea vessels
from power plants; storage of nuclear weapons; landfills, where testing of nuclear
warheads.
According to the potential radiation hazard is established four categories of objects:
Category I - radiation facilities, in an accident the possible radiation exposure to the
population and the need for its protection measures;
Category II are objects in an accident in which radiation exposure is limited to the
territory of the sanitary protection zone;
Category III are objects whose radiation exposure is limited to the territory of the object;
Category IV includes objects from the effects of radiation is limited to the premises
where the works with sources of radiation.
Nuclear weapon- this is one of the main types of weapons of mass destruction. It is able
to briefly incapacitate large numbers of people and animals, destroying buildings and
facilities over large areas.
A variety of nuclear weapons is the neutron. It is able to quickly defeat a large number of
troops and military equipment in the vast area.
Nuclear weapons include nuclear, thermonuclear neutron or ammunition and means of
their application.
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Radiation (laser and accelerator) weapon - kind of directed energy weapons based on
the use of electromagnetic radiation of high-energy lasers. Striking effect of RW is
determined mainly by thermomechanical and shock - impulsive laser beam on the target.
One of its type- combat laser gun (CLG).
The radiation safety. 1. Ionizing radiation and types of radiation. 2. Radiation Safety
Principles. 3. Classification of radiation hazardous objects.
1. Ionizing radiation and types of radiation. Ionizing radiation -radiation is the
interaction with the substance which leads to the formation of this substance ions of
opposite signs.
Ionizing radiation called these types of radiant energy that getting into a particular
environment or penetrating through them, make them ionization. These properties are
radioactive radiation, high-energy radiation, X-rays and others.
Types of radiation.Radiation impact on personnel and the population in the zone of
radioactive contamination is characterized by the values of external and internal
exposure of people.
An external radiation refers to direct human exposure to ionizing radiation from sources
located outside the body, mainly on the sources of gamma rays and neutrons.
Internal exposure occurs due to ionizing radiation from sources located within the
person. These sources are formed in critical (most sensitive) organs and tissues. Internal
exposure is due to sources of alpha, beta and gamma radiation.
Radiation Safety Principles.
Radiation safety is an integral part of the overall safety, ensuring safe working conditions
for workers and the public by using different sources of ionizing radiation. Radiation
safety is ensured by a complex of organizational and technical measures aimed at the
creation and maintenance of working conditions of staff and the livelihoods of people
who rule out the possibility of exceeding the dose limits and reduce the actual radiation
doses to a minimum practicable the International Commission on Radiological Protection
is used to protect the population of the valuation method.
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The principle of justification applies at the stage of decision-making by the authorized
bodies in the design of new radiation sources and radiation facilities, licensing,
development and approval of rules of hygiene and radiation safety standards, as well as
the changing conditions of operation
The principle of optimization of maintenance at the lowest possible and achievable
level of both individual (below the limits established by the HN) and collective doses,
taking into account social and economic factors
The principle of valuation provided by all persons, on which depends the level of
human exposure and provides not exceed the established by the Law of the Republic of
Kazakhstan dated April 23, 1998 № 219-I «On Radiation Safety of the Population" and
HN individual dose limits exposure of citizens from all sources of ionizing radiation.
Radiation danger of war:

existence of large stockpiles of nuclear weapons;

reduce the "nuclear threshold";

states not included in the system of collective "nuclear security";

extensive development of nuclear energy
Radiation hazard peacetime:
 widespread use in all areas of the sources of ionizing radiation;
 the presence of radiation destabilized areas;
 unsolved problem of nuclear waste;
 the problem of terrorism
Classification of ionizing radiation:
By the presence of the rest mass:
1. Electromagnetic (have no rest mass)
- X-ray,
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- Gamma radiation.
2. Сorpuscular:
(have a rest mass)
-β-particles
-protons,
- a-particles
- Neutrons
- Mesons, etc.
Alpha particles () –
Flux of nuclei of helium atoms, with a strong ionizing, provide a high density of
ionization range in air is 5-11 cm, in biological tissues penetrate to a depth of 0.1 mm;
Beta particles ( -,  +) –
The flux of electrons with a negative or positive charge -1 +1. Range in air up to 10-20 m
in biological tissues penetrate to a depth of 5-7 cm
Gamma radiation ()-
Electromagnetic radiation, similar to X-rays, consisting of the gamma-ray energy photons (no rest mass, so have great penetrating density of various materials and
biological tissues.
Flux of neutrons (n) - flux of neutral particles
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Fast
neutrons
with
energies
of
1-10
MeV
also have great penetrating power.
Natural sources of ionizing radiation
1 cosmic
2. background radiation from construction materials
3. additional (smoking, soil, fertilizers, etc.)
Medical sources of ionizing radiation
1. radiodiagnosis
2. radionuclide diagnosis
Industrial sources of ionizing radiation
1. nuclear power engineering
2. occupational exposure
3. testing of nuclear weapons
Medical exposure
The widespread use of ionizing radiation in the treatment of cancer.
In this case, patients often develop general and local radiation reaction, which largely
determine the prognosis.
In Russia now operates about 400 radioactive facilities (nuclear power plants, plants for
reprocessing, radioactive waste, nuclear facilities of the Ministry of Defense of Russia,
etc.). Every year the number of people exposed to ionizing radiation.
Radiobiological effects
Stochastic –
The severity is independent of dose (malignant tumors, leukemia, etc.)
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Nonstochastic (deterministic) - there is a threshold dose, the severity of symptoms
depends on the dose (radiation sickness, radiation cataract, fetal abnormalities)
Stochastic effects
The main remote somatic effect is an increased frequency of cancer with a fatal and
non-fatal among the exposed population, the occurrence of which will occur within a few
decades (first 50 years) after exposure. In addition, non-fatal cancers will cause the
associated physical and psychological effects, which can significantly reduce the quality
of life.
hereditary
effects are a result of irradiation of the gonads in individuals reproductive age .
Fundamentals of biological action
Stages
1. Physical
2. Physicochemical
3. Chemical
4. Biological
Molecular level
theory of indirect action of radiation - the impact on the liquid medium, in particular
water, which occupies about 80% of the mass of the cell.
The irradiation of water formed ions and free radicals (superoxide anion radical O 2,
hydroxyl radical NO and hydroperoxide radical H2O2).
Oxygen effect
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reflected in the injury increased in the presence of oxygen radicals, which reacts with
water radicals and hydrated electrons, forming oxidizing radicals.
Any hypoxia, lack of oxygen during irradiation reduces the radiosensitivity of 2-2.5 times
The cellular level - the structural and metabolic hypothesis by A.M.Kuzin violation of
the fundamental processes of cellular metabolism - the synthesis of DNA (replication),
RNA (transcription), protein (translation),
Form of radiation cell death
Reproductive
-
proliferating
cells
(chromosome aberrations, etc.)
Interphase - nonproliferating and proliferating out of mitosis (necrosis and apoptosis)
Levels of recovery post-radiation damage
Molecular (chemical repair) - due to the thiol groups of bioactive substances
Intracellular (excision repair mechanism) – Defects DNA breaks (up to 90% of all
breaks)
System - a compensatory response of the immune system (inclusion of proliferation
through cytokines)
Law-Bergonie Tribondeau
radiosensitive tissues is directly proportional to the proliferative activity and inversely
proportional to the degree of differentiation of its constituent cells.
In accordance with this rule, the degree of radiosensitivity of mammalian tissues
are as follows:
lipoid,
myeloid,
germinative, and intestinal surface epithelium,
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muscle,
nerve,
cartilage and bone tissue.
Effects of a nuclear explosion
Radiation
1. Penetrating radiation
2. Radioactive contamination
Non-radiation of a nuclear explosion:
1.blast wave
2.luminous radiation
3.electromagnetic pulse
Blast wave
Cutting range of compressed and heated air, extending in all directions from the center of
the explosion.
Destruction of people:
effect of excess pressure, dynamic pressure of heated air ("throwing action");
effect of "secondary projectiles" (flying at high speed broken glass, rubble collapsing
buildings, falling trees, etc.).
Luminous radiation
It is the fluw of radiant energy, including ultraviolet, visible and infrared radiation.
Length of radiation depends on the caliber of ammunition, ranging from 1 to 30 seconds.
In such a short duration of light emission are people openly placed on the ground, can be
burned I - IV degree burns to the retina, cornea and eyelids, as well as temporary
blindness.
Electromagnetic pulse
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arises from the ionization of the air and the emergence of powerful electromagnetic fields
in electrical circuits (antenna, cable, power lines, etc.) create the momentum of the
induced current, which can cause insulation failure and electric shock, as well as the
explosion of cathode ray tubes and injuries caused by broken glass.
Penetrating radiation
is the flux of neutrons and gamma rays, which are having an effect at the time of the
explosion
and
during
the
next
short
period
of
time.
With increasing distance from ground zero change in the ratio between the dose of
gamma and neutron radiation in the predominance of gamma radiation, since neutrons
are distributed in the air at a shorter distance.
Nuclear accident - a dangerous event for uncontrolled chain reaction in a nuclear reactor
(the emergence of local centers of criticality), which leads to damage in the core and
release of radionuclides
Radiation accident - threatening event, caused by partial or complete opening of the
working reactor, in which air is driven in combined cycle gas and solid phases,
contaminated with radionuclides
Classification of radiation accidents
1-3 levels - the incident;
Level 4 - accident within the NPP;
Level 5 - an accident risk to the environment (Fukushima, Japan, 2011);
Level 6 - severe accident (city Windscale, UK, 1957);
Level 7 - global accident (Chernobyl, USSR, 1986).
Radiation damage are factors in the contaminated areas
 (in
descending
order
of
importance):
uniform external gamma irradiation of the body;
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 external beta-irradiation of exposed skin, conjunctival and mucous membranes;
 emission of radionuclides, which can enter the body by inhalation or oral route
Factors radiation hazard
In the early period (several days) after the accident the biggest danger incorporation
mixture of radioactive isotopes of iodine.
In later periods (years after the accident) to the fore the internal exposure of the body by
entering a long-lived radionuclides 137Cs, 90Sr.
Inhalation of radioactive substances
About 25% got in the respiratory particles exhaled radionuclides.
Radioactive substances can enter the body in different ways: inhalation, dermal and oral
Ingestion of radioactive substances
Absorption of highly soluble radionuclides are:
mainly in the small intestine;
radioactive substances less absorbed in the stomach
Percutaneous delivery of radioactive substances
Most radioactive substances do not penetrate intact skin. radioactive substances
penetration through the skin depends on: the density of pollution on the area of
contaminated sites solubility in water and lipids,the physiological state of the skin.
Removal of radionuclides from the body
Elimination pathway:
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• through the kidneys
• gastrointestinal (including bile) with saliva,milk through the lungs.
Preventive measures
To reduce the inhalation of radioactive substances - the use of respirators.
When you are in the contaminated areas - skin protection.
For the prevention of nutritional products revenues nuclear explosion must be avoided
consumption of water and food, the level of contamination exceeds safe.
Control the level of contamination of water and food
Partial decontamination with soap and water to the skin
First-aid
Wear a respirator or gas mask;
Sweep up the dust from the clothes and shoes
Rinse mouth, wash the eye and nasal cavity with water from the flask;
Take a pill radioprotector.
Radioprotectors - this medication or prescription drugs which injected into the body
before exposure is high protective effect
Classification radioprotectors
Short-duration (duration: 30 min)
Short-duration (duration: 30 min)
Iodine preparations
Potassium iodide.
When prophylactic use thyroid absorption of radioactive iodine can be reduced by 95 97%. Tincture of iodine - used in milk or water (44 drops 1 time a day, or 22 drops 2
times a day after meals ½ cup liquid)
Methods for measuring ionizing radiation
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 Ionization
 Chemical
 Photographic
 Scintillation
 Fluorescent
Dosimeters
I Designed to detect, signal and measuring ionizing radiation and measure radiation
levels on the ground
II Used to monitor the doses. Drives doses are used for diagnostics radiation injury of the
wounded and sick
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