Gamma radiation background. Measurement of gamma background in places of residence of the population of rural and urban settlements in the southwestern regions of the Bryansk region. Other uses of radiation

Speaker: Candidate of Medical Sciences, M.V. Kislov (Branch of Bryansk State University in Novozybkov)

Historical information about Novozybkov

It has been considered a city since 1809.

It was first mentioned as the Zybkaya settlement in 1701.

Located in the southwest of the Bryansk region on the Karna River.

The area within the city limits is 31 sq. km. Population - 40,500 people;

The third largest populated area in the region - after Bryansk and Klintsy.

After the accident, the entire territory of the city of Novozybkov was subjected to radioactive contamination:

137Cs - 18.6 Ci/km2, (max - 44.2)

90Sr - 0.25 Ci/km2

State Hydrometeorological Committee data for 1989

The ED of resident training in the first year was approximately 10.0 mSv (1.0 rem).

Radiation gamma background (gamma radiation dose rate)

In May 1986, in the territory of populated areas in the southwestern regions of the Bryansk region, background gamma radiation reached 15,000-25,000 μR/h (150-250 μSv/h).

In Novozybkov:

1991 10 - 150 μR/hour (0.10-1.5 μSv/h),

in the suburban area - 50 - 400 microR/h.

2001 - 20 - 63 μR/hour (0.2 - 0.63 μSv/h),

2006 - 12 - 45 μR/hour (0.12 - 0.45 μSv/h),

2015 - 9 - 41 μR/hour (0.09 - 0.41 μSv/h)

In 1986-1989, in order to reduce the dose of external radiation in populated areas in places where people spent the longest time, decontamination work was carried out, which consisted of:

1. to remove the surface layer of soil,

2. filling the area with “radioactively clean” sand,

3. paving the territory.

Goal of the work

Conduct gamma background measurements in places where people stay in urban and rural settlements in the southwestern regions of the Bryansk region.

Information about the gamma background in the territory of some Russian cities, measurements were carried out in 2012-2015:

Territory of Novozybkov

Results of gamma background measurements on the territory of school No. 9

Results of gamma background measurements in the southwestern regions of the Bryansk region in places where people stay

The territory of the former pioneer camp near the village of Muravinka and Guta, Novozybkovsky district

Generalized data for 2013-2015 yy about GF on the territory of populated areas(μSv/h)

Social problem

In recent years it has become relevant (? ) the problem of forest and peat fires in the southwestern regions of the Bryansk region.

During monitoring gamma background Near and at a distance from fire sources, we did not detect a tendency to increase gamma background.

conclusions

Over the years that have passed since the Chernobyl accident, in the places where the population resides, the gamma radiation background has decreased almost to natural levels.

This is due to:

Physical decay of Chernobyl radionuclides;

Carrying out events:

1. removing the top layer of soil in places where the population stays for a long time;

2. deep plowing,

3. applying a screening road coating,

4. improvement of populated areas.

Gamma radiation poses a rather serious danger to the human body, and to all living things in general.

These are electromagnetic waves with a very short length and high propagation speed.

Why are they so dangerous, and how can you protect yourself from their effects?

About gamma radiation

Everyone knows that atoms of all substances contain a nucleus and electrons that revolve around it. As a rule, the core is a fairly resistant formation that is difficult to damage.

At the same time, there are substances whose nuclei are unstable, and with some influence on them, radiation of their components occurs. This process is called radioactive; it has certain components, named after the first letters of the Greek alphabet:

• gamma radiation.

It is worth noting that the radiation process is divided into two types depending on what exactly is released as a result.

Kinds:

1. Flow of rays with the release of particles - alpha, beta and neutron;
2. Energy radiation – x-ray and gamma.

Gamma radiation is a stream of energy in the form of photons. The process of separation of atoms under the influence of radiation is accompanied by the formation of new substances. In this case, the atoms of the newly formed product have a rather unstable state. Gradually, with the interaction of elementary particles, equilibrium is restored. As a result, excess energy is released in the form of gamma.

The penetrating ability of such a stream of rays is very high. It can penetrate skin, fabrics, and clothing. Penetration through metal will be more difficult. To block such rays, a fairly thick wall of steel or concrete is needed. However, the wavelength of γ-radiation is very small and is less than 2·10−10 m, and its frequency is in the range of 3*1019 – 3*1021 Hz.

Gamma particles are photons with fairly high energy. Researchers claim that the energy of gamma radiation can exceed 10 5 eV. Moreover, the boundary between X-rays and γ-rays is far from sharp.

Sources:

• Various processes in outer space,
• Particle decay during experiments and research,
• The transition of the nucleus of an element from a state of high energy to a state of rest or lower energy,
• The process of deceleration of charged particles in a medium or their movement in a magnetic field.

Gamma radiation was discovered by French physicist Paul Villard in 1900 while conducting research on radium radiation.

Why is gamma radiation dangerous?

Gamma radiation is more dangerous than alpha and beta.

Mechanism of action:

• Gamma rays are able to penetrate through the skin into living cells, resulting in their damage and further destruction.
• Damaged molecules provoke the ionization of new particles of the same type.
• The result is a change in the structure of the substance. The affected particles begin to decompose and turn into toxic substances.
• As a result, new cells are formed, but they already have a certain defect and therefore cannot work fully.

Gamma radiation is dangerous because such human interaction with the rays is not felt by him in any way. The fact is that each organ and system of the human body reacts differently to γ-rays. First of all, cells that can divide quickly are affected.

Systems:

• Lymphatic,
• Heart,
• Digestive,
• Hematopoietic,
• Sexual.

There is also a negative impact at the genetic level. In addition, such radiation tends to accumulate in the human body. At the same time, at first it practically does not appear.

Where is gamma radiation used?

Despite the negative impact, scientists have also found positive aspects. Currently, such rays are used in various spheres of life.

Gamma radiation - application:

• In geological studies, they are used to determine the length of wells.
• Sterilization of various medical instruments.
• Used to monitor the internal state of various things.
• Accurate simulation of spacecraft paths.
• In plant growing, it is used to breed new varieties of plants from those that mutate under the influence of rays.

Gamma particle radiation has found its application in medicine. It is used in the treatment of cancer patients. This method is called “radiation therapy” and is based on the effect of rays on rapidly dividing cells. As a result, when used correctly, it becomes possible to reduce the development of pathological tumor cells. However, this method is usually used when others are already powerless.

Separately, it is worth mentioning its effect on the human brain.

Modern research has established that the brain constantly emits electrical impulses. Scientists believe that gamma radiation occurs at those moments when a person has to work with different information at the same time. Moreover, a small number of such waves leads to a decrease in memory capacity.

How to protect yourself from gamma radiation

What kind of protection exists, and what can you do to protect yourself from these harmful rays?

In the modern world, a person is surrounded by various radiations from all sides. However, gamma particles from space have minimal impact. But what is around is much more dangerous. This especially applies to people working at various nuclear power plants. In this case, protection from gamma radiation consists of applying certain measures.

Measures:

• Do not stay in places with such radiation for a long time. The longer a person is exposed to these rays, the more destruction will occur in the body.
• You should not be where radiation sources are located.
• Protective clothing must be worn. It consists of rubber, plastic with fillers made of lead and its compounds.

It is worth noting that the gamma radiation attenuation coefficient depends on what material the protective barrier is made of. For example, lead is considered the best metal due to its ability to absorb radiation in large quantities. However, it melts at fairly low temperatures, so in some conditions a more expensive metal such as tungsten or tantalum is used.

Another way to protect yourself is to measure the power of gamma radiation in Watts. In addition, power is also measured in sieverts and roentgens.

The rate of gamma radiation should not exceed 0.5 microsieverts per hour. However, it is better if this figure is not higher than 0.2 microsieverts per hour.

To measure gamma radiation, a special device is used - a dosimeter. There are quite a lot of such devices. A device such as the “gamma radiation dosimeter dkg 07d drozd” is often used. It is designed for rapid and high-quality measurement of gamma and X-ray radiation.

Such a device has two independent channels that can measure MED and Dose Equivalent. The DER of gamma radiation is the equivalent dosage power, that is, the amount of energy that a substance absorbs per unit time, taking into account the effect the rays have on the human body. There are also certain standards for this indicator that must be taken into account.

Radiation can negatively affect the human body, but even it has found application in some areas of life.

Video: Gamma radiation

Many people know about the dangers of X-ray examination. There are those who have heard about the danger posed by rays from the gamma category. But not everyone knows what it is and what specific danger it poses.

Among the many types of electromagnetic radiation, there are gamma rays. The average person knows much less about them than about x-rays. But this does not make them any less dangerous. The main feature of this radiation is its short wavelength.

They are similar in nature to light. The speed of their propagation in space is identical to that of light, and is 300,000 km/sec. But due to its characteristics, such radiation has a strong toxic and traumatic effect on all living things.

The main dangers of gamma radiation

The main sources of gamma radiation are cosmic rays. Their formation is also influenced by the decay of atomic nuclei of various elements with a radioactive component and several other processes. Regardless of the specific way in which radiation hits a person, it always has identical consequences. This is a strong ionizing effect.

Physicists note that the shortest waves of the electromagnetic spectrum have the highest energy saturation of quanta. Because of this, the gamma background has gained the reputation of a flow with a large energy reserve.

Its influence on all living things lies in the following aspects:

• Poisoning and damage to living cells. This is due to the fact that the penetrating ability of gamma radiation is particularly high.
• Ionization cycle. Along the path of the beam, the molecules destroyed due to it begin to actively ionize the next portion of molecules. And so on ad infinitum.
• Cell transformation. Cells destroyed in this way cause strong changes in its various structures. The resulting result negatively affects the body, turning healthy components into poisons.
• The birth of mutated cells that are unable to perform their assigned functional duties.

But the main danger of this type of radiation is considered to be the lack of a special mechanism in humans aimed at timely detection of such waves. Because of this, a person can receive a lethal dose of radiation and not even realize it right away.

All human organs react differently to gamma particles. Some systems cope better than others due to reduced individual sensitivity to such dangerous waves.

The worst effect of this effect is on the hematopoietic system. This is explained by the fact that this is where some of the most rapidly dividing cells in the body are present. Also severely affected by such radiation are:

• digestive tract;
• lymph glands;
• genitals;
• hair follicles;
• DNA structure.

Having penetrated the structure of the DNA chain, the rays trigger the process of numerous mutations, disrupting the natural mechanism of heredity. Doctors are not always able to immediately determine the cause of a sharp deterioration in the patient’s well-being. This happens due to the long latent period and the ability of radiation to accumulate harmful effects in cells.

Applications of gamma radiation

Having understood what gamma radiation is, people begin to become interested in the use of dangerous rays.

According to recent studies, with uncontrolled spontaneous exposure to radiation from the gamma spectrum, the consequences do not make themselves felt soon. In particularly advanced situations, radiation can “play out” on the next generation, without having visible consequences for the parents.

Despite the proven danger of such rays, scientists still continue to use this radiation on an industrial scale. Its application is often found in the following industries:

• sterilization of products;
• processing of medical instruments and equipment;
• control over the internal state of a number of products;
• geological work where it is necessary to determine the depth of the well;
• space research, where distance measurements need to be made;
• plant cultivation.

In the latter case, mutations of agricultural crops make it possible to use them for cultivation in countries that were not initially adapted to this.

Gamma rays are used in medicine in the treatment of various oncological diseases. The method is called radiation therapy. It is aimed at maximizing the impact on cells that divide particularly quickly. But in addition to the disposal of such cells harmful to the body, the accompanying healthy cells are killed. Because of this side effect, doctors have been trying for many years to find more effective drugs to fight cancer.

But there are forms of oncology and sarcomas that cannot be gotten rid of by any other method known to science. Then radiation therapy is prescribed in order to suppress the activity of pathogenic tumor cells in a short time.

Other uses of radiation

Today, gamma radiation energy has been studied well enough to understand all the associated risks. But even a hundred years ago, people treated such radiation more disdainfully. Their knowledge of the properties of radioactivity was negligible. Because of this ignorance, many people suffered from diseases unknown to doctors of the past era.

You could find radioactive elements in:

• glazes for ceramics;
• jewelry;
• old souvenirs.

Some “greetings from the past” can be dangerous even today. This is especially true for parts of obsolete medical or military equipment. They are found on the territory of abandoned military units and hospitals.

Radioactive scrap metal also poses a huge danger. It can pose a threat in itself, or it can be found in areas with increased radiation. To avoid hidden exposure from scrap metal items found in a landfill, each item must be inspected with special equipment. It can reveal its real radiation background.

In its “pure form,” gamma radiation poses the greatest danger from the following sources:

• processes in outer space;
• experiments with particle decay;
• transition of the nucleus of an element with a high energy content at rest;
• movement of charged particles in a magnetic field;
• braking of charged particles.

The pioneer in the study of gamma particles was Paul Villard. This French specialist in the field of physical research began talking about the properties of gamma ray radiation back in 1900. An experiment to study the properties of radium prompted him to do this.

How to protect yourself from harmful radiation?

In order for the defense to establish itself as a truly effective blocker, you need to approach its creation in a comprehensive manner. The reason for this is the natural radiation of the electromagnetic spectrum that surrounds a person constantly.

Under normal conditions, sources of such rays are considered relatively harmless, since their dose is minimal. But in addition to the lull in the environment, there are also periodic bursts of radiation. The inhabitants of the Earth are protected from cosmic emissions by the remoteness of our planet from others. But people will not be able to hide from numerous nuclear power plants, because they are distributed everywhere.

The equipment of such institutions is particularly dangerous. Nuclear reactors, as well as various technological circuits, pose a threat to the average citizen. A striking example of this is the tragedy at the Chernobyl nuclear power plant, the consequences of which are still emerging.

To minimize the impact of gamma radiation on the human body at particularly dangerous enterprises, their own safety system was introduced. It includes several main points:

• Time limit for staying near a dangerous object. During the cleanup operation at the Chernobyl Nuclear Power Plant, each liquidator was given only a few minutes to carry out one of the many stages of the overall plan to eliminate the consequences.
• Distance limitation. If the situation allows, then all procedures should be carried out automatically as far as possible from the dangerous object.
• Availability of protection. This is not only a special uniform for a worker in particularly dangerous production, but also additional protective barriers made of different materials.

Materials with increased density and high atomic number act as blockers for such barriers. Among the most common are:

• lead,
• lead glass,
• steel alloy,
• concrete.

• lead plate 1 cm thick;
• concrete layer 5 cm in depth;
• water column 10 cm deep.

All together, this allows us to reduce radiation by half. But you still won’t be able to get rid of it completely. Also, lead cannot be used in high temperature environments. If the room is constantly at high temperature, then fusible lead will not help matters. It must be replaced with expensive analogues:

• tungsten,
• tantalum.

All employees of enterprises where high gamma radiation is maintained are required to wear regularly updated protective clothing. It contains not only lead filler, but also a rubber base. If necessary, the suit is supplemented with anti-radiation screens.

If radiation has covered a large area of ​​the territory, then it is better to immediately hide in a special shelter. If it is not nearby, you can use the basement. The thicker the wall of such a basement, the lower the likelihood of receiving a high dose of radiation.

• - prepare the dosimeter for operation according to the description supplied with the device;
• - place the detector at the measurement location (when measuring on site, the detector is placed at a height of 1 m);
• - take readings from the device and write them down in the table.

Measuring the level of radioactive contamination in the body of animals, machinery, clothing and equipment:

• - select a site for measurements at a distance of 15-20 m from livestock buildings;
• - use the DP-5 device to determine the background on the selected site (D f);
• - measure the dose rate of gamma radiation created by radioactive substances on the surface of the animal’s body (D meas) by placing the detector of the DP-5 device at a distance of 1-1.5 cm from the surface of the animal’s body (screen in position “G”);
• - when establishing radioactive contamination of the skin of animals, examine the entire surface of the body, paying special attention to the places of most likely contamination (limbs, tail, back);
• - contamination of machinery and equipment is checked first of all in those places that people come into contact with during work. Clothing and protective equipment are examined in unfolded form, the places of greatest contamination are found;
• - calculate the radiation dose created by the surface of the measured object using the formula:

D ob = D meas. ? D f/K,

Where, D ob is the radiation dose created by the surface of the object being examined, mR/h; D meas - radiation dose created by the surface of the object together with the background, mR/h; Df - gamma background, mR/h; K is a coefficient that takes into account the screening effect of an object (for the surface of the body of animals it is 1.2; for vehicles and agricultural machinery - 1.5; for personal protective equipment, food containers and pantries - 1.0).

The amount of radioactive contamination obtained in this way is compared with the permissible standard and a conclusion is made about the need for decontamination.

The presence of radioactive substances inside the animal’s body is determined by two measurements: with the detector window of the DP-5 radiometer closed and open. If the readings of the device with the detector window closed and open are the same, the surface being examined is not contaminated with radioactive substances. Gamma radiation passes through the surface under study from the other side (or from the internal tissues of the body). If the readings are higher when the detector window is open than when it is closed, the surface of the body is contaminated with radioactive substances.

The purpose of incoming operational radiation control is to prevent the production of raw materials, the use of which may lead to exceeding the permissible levels of cesium-137 and strontium-90 in food products established by sanitary rules and regulations.

The objects of incoming control are live cattle and all types of raw meat. The procedure for conducting operational radiation monitoring of raw meat and livestock is established taking into account the radiation situation that has developed in the territory of their origin and is carried out in the form of continuous and selective monitoring.

Continuous operational radiological control is carried out when examining raw meat and livestock produced in areas subject to radioactive contamination or suspected of radioactive contamination. Sampling control is carried out during the study of raw meat and livestock produced in areas that have not been subjected to radioactive contamination and are not suspected of radioactive contamination in order to confirm radiation safety and uniformity of batches of raw meat and livestock (in this case, the sample is up to 30% of the volume of the controlled batch).

If raw meat or livestock with radionuclide contents above control levels (CL) are detected, they proceed to continuous operational or full laboratory radiological control.

Radiation monitoring of raw meat and livestock is carried out by assessing the compliance of the measurement results of the specific activity of cesium-137 in the controlled object with the “Control levels”, not exceeding which allows us to guarantee compliance of the controlled products with radiation safety requirements without measuring strontium-90:

(Q/H) Cs-137 + (Q/H) Sr-90 ? 1, where

Q - specific activity of cesium-137 and strontium-90 in the controlled object;

N - specific activity standards for cesium-137 and strontium-90, established by the current rules and regulations for raw meat.

If the measured values ​​of the specific activity of cesium-137 exceed the EC values, then:

To obtain a final conclusion, raw meat is sent to state laboratories, where a full radiological examination is carried out using radiochemical and spectrometric methods;

animals are returned for additional fattening using “clean feed” and (or) drugs that reduce the transfer of radionuclides into the animals’ bodies.

For all types of raw meat and livestock produced in “clean” areas affected by radioactive contamination and subject to radiation control at meat processing plants and farms, four control levels have been introduced:

KU 1 = 100 Bq/kg- for farm animals and raw meat with bone tissue;

KU 2 = 150 Bq/kg- for raw meat, without bone tissue and by-products;

KU 3 = 160 Bq/kg- for cattle raised in the Bryansk region, which suffered the most from the Chernobyl accident (after slaughter, the bone tissue of these animals is subject to mandatory laboratory control for strontium-90 content).

KU 4 = 180 Bq/kg- for commercial and other species of animals.

The assessment of the compliance of the measurement results of the specific activity of cesium-137 with radiation safety requirements is carried out according to the criterion of not exceeding the permissible limit.

The result of measuring the specific activity Q of cesium-137 radionuclide is the measured value Q meas. and error interval?Q.

If it turns out that Q meas.< ?Q, то принимается, что Q изм. = 0, и область возможных значений Q характеризуется соотношением Q ? ?Q.

Raw materials meet radiation safety requirements if, according to the criterion of not exceeding the permissible limit, they satisfy the requirement: (Q ± ?Q) ? KU. Such raw materials enter production without restrictions.

Raw materials do not meet radiation safety requirements if (Q + ?Q) > KU. Raw materials can be recognized as not meeting radiation safety requirements according to the criterion of not exceeding the EC, if?Q ? KU/2. In this case, tests should be carried out in a radiation control laboratory in accordance with the requirements of MUK 2.6.717-98 for food products.

Measuring. To determine the specific activity of cesium-137 in raw meat and animals, it is allowed to use devices that meet the requirements for radiation monitoring equipment included in the State Register and the equipment list of state veterinary laboratories.

A necessary condition for the suitability of measuring instruments for operational monitoring of the specific activity of cesium-137 are:

• - the ability to measure the specific activity of cesium-137 in raw meat or in the body of animals without preparing counting samples;
• - ensuring the measurement error of a “zero activity” sample is no more than?Q ? KU/3 for a measurement time of 100 seconds at an equivalent dose rate of gamma radiation at the measurement site of up to 0.2 μSv/hour.

The specificity of the measured control objects determines special requirements for the choice of measurement geometry and for safety.

Measurement of carcasses, sides, quarters or meat blocks formed from the muscle tissue of one animal is carried out by direct contact of the detector with the object being measured without sampling. To prevent contamination of the detector, it is placed in a protective polyethylene case. The use of the same cover is allowed when measuring only one batch of raw materials. When measuring cuts, offal and poultry, are the objects being measured placed in pallets, boxes or other types of containers to create deep meat blocks? 30 cm. Accordingly, when measuring carcasses of pigs or small livestock, the measured objects should be placed in the form of feet with a total depth “along the meat”? 30 cm. In the same way, provide the required depth when measuring cattle quarters.

When measuring live cattle, half carcasses and hind quarters, the detector is placed in the area of ​​the posterofemoral muscle group at the level of the knee joint between the femur and tibia; when measuring forequarters, the detector is placed in the area of ​​the shoulder blade; When measuring carcasses, sides and hindquarters, the detector is placed in the area of ​​the gluteal muscle group to the left or right of the spine, between the spine, femur and sacrum.

Measurements of gamma radiation background on the school grounds.

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Map of the results of measurements of gamma radiation background in the territory

Secondary school No. ......................................... Novozybkova

1 Characteristics of the territory

1.1. Address, location of the school:

………………………………………………………………………………………………………..

Name of the district, rural settlement, locality, street, number.

1.2. School affiliation: ……………………………………………………………………….

City or district department of education

1.3. Date of construction………………………….....................................................................................................

(year, construction and material from which the school is built, number of floors).

1.4. The measurements were carried out with a DKG-03D “Grach” device, the certified measurement error is 20%.

1.5. Gamma background measurement conditions: ……………………………………………………………..

Date, time of measurement, weather condition.

2. Results of gamma background measurements.

(If an increased gamma background is detected, a description of the site is carried out and its position is noted on the territory diagram).

1. Instrument readings:

The average gamma background value in the house is …….. µSv/h, range – from …… to …… µSv/h.

In the yard – …….. μSv/h.

The highest value of gamma background power is……………. μSv/h.

………………………………………………………………………………………………

Responsible for conducting the survey:

_____________________________________________________________________

(full name and position)

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Memo on measuring gamma radiation background

General information:

It is necessary to correctly understand two important concepts:

1. radiation background of the territory – this is a historically established set of all types of ionizing radiation in a specific territory, formed from natural and artificial sources;

2. radiation gamma background – the level of human exposure to only gamma radiation from natural and artificial sources in a specific area.

Thus, from the above concepts it follows that the “radiation background of the territory” means all types of ionizing radiation (radiation) that affect humans. In the case of applying the concept of “radiation gamma background” – They mean only gamma radiation.

Devices, units of measurement of gamma radiation background.

For measuring radiation gamma backgroundin a specific area apply devices - dosimeters.

Modern dosimetric instruments measureambient dose equivalent rate.Units Sievert per hour (abbreviated Sv/h) or derivatives microSievert per hour (μSv/h is a million times less than a Sievert); milliSievert per hour (mSv/h is 1000 times less than a Sievert). The measured quantity, the ambient dose equivalent rate, allows us to estimate the impact of gamma radiation on the human body without complex mathematical calculations.

In outdated instruments, gamma background is measured in units of " X-ray in an hour" (abbreviated R/h) or derivatives micro-Roentgen per hour (μR/h); milliRoentgen per hour (μR/h). Measured value - mgamma dose rateRadiation is now outdated because it describes the effect of gamma radiation in the air and not on humans.

For gamma radiation, the ratio between the units Roentgen and Sievert is approximately 100:1, that is, 100 Roentgen = 1 Sievert; 100 mR/h = 1 mSv/h; 50 μR/h=0.5 μSv/h orµSv/h.

Natural (natural) values ​​of gamma background on most of our planet are in the range of 0.08 - 0.20 μSv/hour or 8 - 20 μR/hour. There are areas on Earth with a gamma background increased by 2 or more times.

Why do you need to measure gamma background?

A special place is currently occupied by the problem of radiation safety, which determines the prospects for the development of nuclear energy and radiation technologies. The population has ambivalent perceptions of the problems of radiation hazards and radiation risks. These concepts are not comparable. Assessing risks of various natures, including the risk caused by ionizing radiation, is an important aspect of creating optimal living conditions.

For most settlements in Russia, the average value of the natural gamma background in open areas is at an altitude 1 meter from the earth's surface is 5 - 20 μR/h or 0.05 -0.2 μSv/h. The room is somewhat larger. On Earth there are territories with a gamma background increased by 2 or more times. This is due to the structure and chemical composition of the Earth's crust.

If the territory where people live has been subjected to radioactive contamination as a result of a radiation accident or other man-made incidents, then the gamma background value will be higher than the natural level characteristic of this territory. Thus, it is necessary to measure the gamma background in order to identify its increase, develop and carry out measures aimed at ensuring the radiation safety of the population. Such events are carried out by specialists from the radiation safety service of the Ministry of Emergency Situations and Civil Defense of the Russian Federation or from hygiene and epidemiology centers.

Sequence of actions when measuring gamma background

1. Before measuring gamma background, you must carefully read the operating instructions for the dosimeter.

2. Perform an external inspection of the dosimeter. Set the power switch to the off position, open the power compartment cover, and install a battery or more. Close the power compartment cover.

3. Turn on the dosimeter, if necessary, select the operating mode of the device for measuring gamma background. Some dosimeters provide for monitoring the serviceability of the electronic conversion circuit and the dosimeter timer, for which it is necessary to test the device in accordance with the description in the instructions.

4. If the dosimeter is working correctly, it will start taking measurements. Measurements may be accompanied by sound signals.

5. After a certain time, the gamma background values ​​will appear on the device display.With a natural, unmodified background of gamma radiation, the device readings can range from 0.10 to 0.25 μSv/h (10-25 μR/h) depending on the device model, error and measurement location (outdoor or indoors).

6. Gamma background measurements are carried out at height 1 meter from the ground or floor

6. In case of radioactive contamination, the device readings will be several times higher.

7. There may be cases when the dosimeter shows unusually high background gamma values, several times higher than natural levels. In such cases it is necessary:

Step aside 10-20 steps and make sure that the device readings return to normal.

Make sure that the dosimeter is working properly (most devices of this kind have a special self-diagnosis mode).

The normal operation of the dosimeter's electrical circuit can be partially or completely disrupted by short circuits, water, battery leaks, strong external electromagnetic fields, or shock.

If possible, duplicate the measurements using another dosimeter, preferably a different type.

8. If you are sure that you have discovered a source or area of ​​radioactive contamination, you should under no circumstances try to get rid of it yourself (throw it away, bury it or hide it).

Remember! In various regions of our country there are territories that have been subjected to radioactive contamination as a result of a radiation accident or any human actions (removal of industrial waste or radioactive substances to unidentified places).

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