Application of radioactivity. Use of radioactivity for peaceful purposes

The phenomenon of radioactivity and its use in science, industry and medicine

Prepared by: student

School No. 26, Vladimir

Khrupolov K.

Another mystery of nature

The late 19th and early 20th centuries were exceptionally rich in breathtaking discoveries and inventions that people could only dream of. The idea of ​​the possibility of obtaining inexhaustible energy contained in an insignificant amount of matter lived in the recesses of human thought.

A famous scientist of that time was Becquerel, who set himself the goal of unraveling the nature of the mysterious glow of certain substances under the influence of solar radiation. Becquerel amasses a huge collection of glowing chemicals and natural minerals.

Goal of the work

• Study of the concept of radioactivity, its discovery.

• Find out how radioactive isotopes are used in science, industry and medicine.

• Determine the value of the phenomenon of radioactivity in the world.

Radioactivity phenomenon

Radioactivity is the ability of some atomic nuclei to spontaneously transform into other nuclei with the emission of various types of radioactive radiation and elementary particles.

How to use the phenomenon of radioactivity?

Application of radioactivity in medicine

Radiotherapy is the use of strong radiation to kill cancer cells.

Radioactive iodine accumulates in the thyroid

gland, determines dysfunction and

used in the treatment of Graves' disease.

Sodium-labeled saline solution measures the speed of blood circulation and determines the patency of the blood vessels of the extremities.

Radioactive phosphorus measures blood volume and treats erythremia.

Applications of radioactivity in industry

One example of this is the following method for monitoring piston ring wear in internal combustion engines. By irradiating the piston ring with neutrons, they cause nuclear reactions in it and make it radioactive. When the engine operates, particles of ring material enter the lubricating oil. By examining the level of radioactivity in the oil after a certain time of engine operation, ring wear is determined. Powerful gamma radiation from radioactive drugs is used to examine the internal structure of metal castings in order to detect defects in them.

Application of radioactivity in agriculture

Irradiation of plant seeds with small doses of gamma rays from radioactive drugs leads to a noticeable increase in yield. “Tagged atoms” are used in agricultural technology. For example, to find out which phosphorus fertilizer is better absorbed by a plant, various fertilizers are labeled with radioactive phosphorus P. By then examining plants for radioactivity, it is possible to determine the amount of phosphorus they have absorbed from different types of fertilizer.

Discovery of the phenomenon of radioactivity.

The discovery of the phenomenon of radioactivity can be considered one of the most outstanding discoveries of modern science. It was thanks to him that man was able to significantly deepen his knowledge of the structure and properties of matter, understand the laws of many processes in the Universe, and solve the problem of mastering nuclear energy.

The potential for great science

Until the discovery of radioactivity, scientists believed that they knew all physical phenomena and had nothing to discover.

Is it possible that there is something else in the world unknown to mankind?

Slide 2

Radioactivity is the transformation of atomic nuclei into other nuclei, accompanied by the emission of various particles and electromagnetic radiation. Hence the name of the phenomenon: in Latin radio - radiate, activus - effective. This word was coined by Marie Curie. When an unstable nucleus - a radionuclide - decays, one or more high-energy particles fly out of it at high speed. The flow of these particles is called radioactive radiation or simply radiation.

Slide 3

Types of radioactive radiation

When powerful sources of radiation appeared in the hands of researchers, millions of times stronger than uranium (these were preparations of radium, polonium, actinium), it was possible to become more familiar with the properties of radioactive radiation. Ernest Rutherford, the spouses Maria and Pierre Curie, A. Becquerel, and many others took an active part in the first studies on this topic. First of all, the penetrating ability of the rays was studied, as well as the effect on the radiation of the magnetic field. It turned out that the radiation is not uniform, but is a mixture of “rays”. Pierre Curie discovered that when a magnetic field acts on radium radiation, some rays are deflected while others are not. It was known that a magnetic field deflects only charged flying particles, positive and negative in different directions. Based on the direction of deflection, we were convinced that the deflected ?-rays were negatively charged. Further experiments showed that there was no fundamental difference between cathode and ?-rays, which meant that they represented a flow of electrons. Deflected rays had a stronger ability to penetrate various materials, while non-deviated rays were easily absorbed even by thin aluminum foil - this is how, for example, the radiation of the new element polonium behaved - its radiation did not penetrate even through the cardboard walls of the box in which the drug was stored. When using stronger magnets, it turned out that the ?-rays are also deflected, only much weaker than the ?-rays, and in the other direction. It followed from this that they were positively charged and had a significantly greater mass (as they later found out, the mass of?-particles is 7740 times greater than the mass of the electron). This phenomenon was first discovered in 1899 by A. Becquerel and F. Giesel. Later it turned out that?-particles are the nuclei of helium atoms (nuclide 4He) with a charge of +2 and a mass of 4 units. When, in 1900, the French physicist Paul Villar (1860-1934) studied the deviation?-and? -rays, he discovered in the radiation of radium a third type of rays that do not deviate in the strongest magnetic fields; this discovery was soon confirmed by Becquerel. This type of radiation, by analogy with alpha and beta rays, was called gamma rays; the designation of different radiations with the first letters of the Greek alphabet was proposed by Rutherford. Gamma rays turned out to be similar to X-rays, i.e. they are electromagnetic radiation, but with shorter wavelengths and therefore more energy. All these types of radiation were described by M. Curie in her monograph “Radium and Radioactivity”. Instead of a magnetic field, an electric field can be used to “split” radiation, only the charged particles in it will not be deflected perpendicular to the lines of force, but along them - towards the deflection plates. For a long time it was unclear where all these rays come from. Over the course of several decades, through the work of many physicists, the nature of radioactive radiation and its properties were clarified, and new types of radioactivity were discovered.? Alpha rays are emitted mainly by the nuclei of the heaviest and therefore less stable atoms (they are located after lead in the periodic table). These are high energy particles. Is it common to see multiple groups? -particles, each of which has a strictly defined energy. So, almost everything? -particles emitted from 226Ra nuclei have an energy of 4.78 MeV (megaelectron volts) and a small fraction? -particles with an energy of 4.60 MeV. Another radium isotope, 221Ra, emits four groups? -particles with energies of 6.76, 6.67, 6.61 and 6.59 MeV. This indicates the presence of several energy levels in nuclei; their difference corresponds to the energy emitted by the nucleus? -quanta. “Pure” alpha emitters are also known.

Slide 4

The effect of radioactive radiation on humans

Radioactive radiation of all types (alpha, beta, gamma, neutrons), as well as electromagnetic radiation (X-rays) have a very strong biological effect on living organisms, which consists in the processes of excitation and ionization of atoms and molecules that make up living cells. Under the influence of ionizing radiation, complex molecules and cellular structures are destroyed, which leads to radiation damage to the body. Therefore, when working with any source of radiation, it is necessary to take all measures to protect people who may be exposed to radiation. However, a person can be exposed to ionizing radiation at home. The inert, colorless, radioactive gas radon can pose a serious danger to human health. As can be seen from the diagram shown in Fig. 5, radon is a product of the decay of radium and has a half-life T = 3.82 days. Radium is found in small quantities in soil, stones, and various building structures. Despite the relatively short lifetime, the concentration of radon is continuously replenished due to new decays of radium nuclei, so radon can accumulate in enclosed spaces. Once in the lungs, radon emits ?-particles and turns into polonium, which is not a chemically inert substance. What follows is a chain of radioactive transformations of the uranium series (Fig. 5). According to the American Commission on Radiation Safety and Control, the average person receives 55% of ionizing radiation from radon and only 11% from medical care. The contribution of cosmic rays is approximately 8%. The total radiation dose that a person receives during his life is many times less than the maximum permissible dose (MAD), which is established for people in certain professions who are subject to additional exposure to ionizing radiation.

Slide 5

Application of radioactive isotopes

One of the most outstanding studies carried out using “tagged atoms” was the study of metabolism in organisms. It has been proven that in a relatively short time the body undergoes almost complete renewal. The atoms that make it up are replaced by new ones. Only iron, as experiments on isotope studies of blood have shown, is an exception to this rule. Iron is part of the hemoglobin of red blood cells. When radioactive iron atoms were introduced into food, it was found that the free oxygen released during photosynthesis was originally part of water, not carbon dioxide. Radioactive isotopes are used in medicine both for diagnosis and for therapeutic purposes. Radioactive sodium, injected in small quantities into the blood, is used to study blood circulation; iodine is intensively deposited in the thyroid gland, especially in Graves' disease. By observing radioactive iodine deposition using a meter, a diagnosis can be made quickly. Large doses of radioactive iodine cause partial destruction of abnormally developing tissues, and therefore radioactive iodine is used to treat Graves' disease. Intense cobalt gamma radiation is used in the treatment of cancer (cobalt gun). No less extensive are the applications of radioactive isotopes in industry. One example of this is the following method for monitoring piston ring wear in internal combustion engines. By irradiating the piston ring with neutrons, they cause nuclear reactions in it and make it radioactive. When the engine operates, particles of ring material enter the lubricating oil. By examining the level of radioactivity in the oil after a certain time of engine operation, ring wear is determined. Radioactive isotopes make it possible to judge the diffusion of metals, processes in blast furnaces, etc. Powerful gamma radiation from radioactive preparations is used to study the internal structure of metal castings in order to detect defects in them. Radioactive isotopes are increasingly used in agriculture. Irradiation of plant seeds (cotton, cabbage, radishes, etc.) with small doses of gamma rays from radioactive drugs leads to a noticeable increase in yield. Large doses of radiation cause mutations in plants and microorganisms, which in some cases leads to the appearance of mutants with new valuable properties (radio selection). This is how valuable varieties of wheat, beans and other crops were developed, and highly productive microorganisms used in the production of antibiotics were obtained. Gamma radiation from radioactive isotopes is also used to control harmful insects and for food preservation. “Tagged atoms” are widely used in agricultural technology. For example, to find out which phosphorus fertilizer is better absorbed by the plant, various fertilizers are labeled with radioactive phosphorus 15 32P. By then examining the plants for radioactivity, it is possible to determine the amount of phosphorus they have absorbed from different types of fertilizer. An interesting application of radioactivity is the method of dating archaeological and geological finds by the concentration of radioactive isotopes. The most commonly used method of dating is radiocarbon dating. An unstable isotope of carbon appears in the atmosphere due to nuclear reactions caused by cosmic rays. A small percentage of this isotope is found in the air along with the regular stable isotope. Plants and other organisms take up carbon from the air and accumulate both isotopes in the same proportions as in the air. After the plants die, they stop consuming carbon and the unstable isotope, as a result of β-decay, gradually turns into nitrogen with a half-life of 5730 years. By accurately measuring the relative concentration of radioactive carbon in the remains of ancient organisms, the time of their death can be determined.

Slide 6

Applications of radioactivity.

1. Biological actions. Radioactive radiation has a detrimental effect on living cells. The mechanism of this action is associated with the ionization of atoms and the decomposition of molecules inside cells during the passage of fast charged particles. Cells in a state of rapid growth and reproduction are especially sensitive to the effects of radiation. This circumstance is used to treat cancer tumors. For therapy purposes, radioactive drugs emitting g-radiation are used, since the latter penetrate into the body without noticeable weakening. When radiation doses are not too high, cancer cells die, while no significant damage is caused to the patient’s body. It should be noted that radiotherapy for cancer, like x-ray therapy, is by no means a universal remedy that always leads to a cure. Excessively large doses of radioactive radiation cause severe diseases in animals and humans (the so-called radiation sickness) and can lead to death. In very small doses, radioactive radiation, mainly a-radiation, has, on the contrary, a stimulating effect on the body. This is associated with the healing effect of radioactive mineral waters containing small amounts of radium or radon.2. Luminous compounds. Luminescent substances glow under the influence of radioactive radiation (cf. § 213). By adding a very small amount of radium salt to a luminescent substance (for example, zinc sulfide), permanently luminous paints are prepared. These paints, when applied to watch dials and hands, sights, etc., make them visible in the dark.3. Determining the age of the Earth. The atomic mass of ordinary lead, mined from ores that do not contain radioactive elements, is 207.2. As can be seen from Fig. 389, the atomic mass of lead formed as a result of the decay of uranium is 206. The atomic mass of lead contained in some uranium minerals turns out to be very close to 206. It follows that these minerals did not contain lead at the time of formation (crystallization from a melt or solution) ; all the lead present in such minerals accumulated as a result of the decay of uranium. Using the law of radioactive decay, it is possible to determine its age based on the ratio of the amounts of lead and uranium in a mineral (see exercise 32 at the end of the chapter). The age of minerals of various origins containing uranium determined by this method is measured in hundreds of millions of years. The age of the oldest minerals exceeds 1.5 billion years. The age of the Earth is usually considered to be the time that has passed since the formation of the solid earth's crust. Many measurements based on the radioactivity of uranium, as well as thorium and potassium, place the Earth's age at more than 4 billion years.

Slide 7

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Introduction………………………………………………………………………………3

Application of radioactive sources in various

spheres of human activity……………………………………………………….3

Chemical industry

Urban economy

Medical industry

Radiation sterilization of products and materials

Production of radioisotope pacemakers

Pre-sowing irradiation of seeds and tubers

Radioisotope diagnostics (introduction of a radioactive drug into the body)

Radioactive waste, problems of their disposal…………………..8

Lack of development of the method………………………………………………………...12

Pressure from external circumstances………………………………………………………..13

Decision making and technological complexity of the problem………………………...13

Uncertainty of the concept………………………………………………………...14

References……………………………………………………….16

Introduction

Currently, it is difficult to find a branch of science, technology, industry, agriculture and medicine where sources of radioactivity (radioactive isotopes) are not used. Artificial and natural radioactive isotopes are a powerful and subtle tool for creating sensitive methods of analysis and control in industry, a unique tool for medical diagnosis and treatment of malignant tumor diseases, and an effective means of influencing various substances, including organic ones. The most important results were obtained using isotopes as radiation sources. The creation of installations with powerful sources of radioactive radiation made it possible to use it to monitor and control technological processes; technical diagnostics; therapy of human diseases; obtaining new properties of substances; converting the decay energy of radioactive substances into heat and electricity, etc. Most often for these purposes, isotopes such as ⁶⁰CO, ⁹⁰Sr, ¹³⁷Cs and plutonium isotopes are used. To prevent sources from depressurizing, they are subject to strict requirements for mechanical, thermal and corrosion resistance. This provides a guarantee of maintaining tightness throughout the entire period of operation of the source.

The use of radioactive sources in various fields of human activity.

Chemical industry

Radiation-chemical modification of polyamide fabric to give it hydrophilic and antistatic properties.

Modification of textile materials to obtain wool-like properties.

Obtaining cotton fabrics with antimicrobial properties.

Radiation modification of crystal to produce crystal products of various colors.

Radiation vulcanization of rubber-fabric materials.

Radiation modification of polyethylene pipes to increase heat resistance and resistance to aggressive environments.

Hardening of paint and varnish coatings on various surfaces.

Wood industry

As a result of irradiation, soft wood acquires a significantly low ability to absorb water, high stability of geometric dimensions and higher hardness (production of mosaic parquet).

Urban economy

Radiation treatment and disinfection of wastewater.

Medical industry

Radiation sterilization of products and materials

The range of radiation-sterilizable products includes over a thousand items, including disposable syringes, blood service systems, medical instruments, suture and dressing materials, various prostheses used in cardiovascular surgery, traumatology and orthopedics. The main advantage of radiation sterilization is that it can be carried out continuously at high throughput. Suitable for sterilization of finished products packaged in transport containers or secondary packaging, and also applicable for sterilization of thermolabile products and materials.

Production of radioisotope pacemakers with power supplies based on ²³⁸Pu. Implanted into the human body, they are used to treat various heart rhythm disorders that are not amenable to medication. The use of a radioisotope power source increases their reliability, increases their service life to 20 years, and returns patients to normal life by reducing the number of repeated operations to implant a pacemaker.

Agriculture and food industry

Agriculture is an important area of ​​application of ionizing radiation. To date, in agricultural practice and agricultural scientific research, the following main areas of use of radioisotopes can be distinguished:

Irradiation of agricultural objects (primarily plants) with a low dose in order to stimulate their growth and development;

Application of ionizing radiation for radiation mutagenesis and plant selection;

Using the method of radiation sterilization to combat insect pests of agricultural plants.

Pre-sowing irradiation of seeds and tubers(wheat, barley, corn, potatoes, beets, carrots) leads to improved sowing qualities of seeds and tubers, acceleration of plant development processes (precocity), and increases plant resistance to adverse environmental factors.

In the field of breeding, mutagenesis research is being carried out. The goal is to select macromutations for the development of high-yielding varieties. Radiation mutants of interest have already been obtained for more than 50 crops.

The use of ionizing radiation to sterilize insect pests in elevators and granaries can reduce crop losses by up to 20%.

Known that ionizing γ-radiation prevents the germination of potatoes and onions, is used for disinfestation of dried fruits, food concentrates, slows down microbiological spoilage and extends the shelf life of fruits, vegetables, meat, and fish. The possibility of accelerating the aging processes of wines and cognac, changing the rate of fruit ripening, and removing the unpleasant odor of medicinal waters has been identified. In the canning industry (fish, meat and dairy, vegetables and fruit), sterilization of canned food is widely used. It should be noted that a study of irradiated food products showed that γ-irradiated products are harmless.

We examined the use of radioisotopes specific to individual industries. In addition, radioisotopes are used throughout industry for the following purposes:

Measuring levels of liquid melts;

Measurement of densities of liquids and pulps;

Counting items on a container;

Measuring the thickness of materials;

Measuring ice thickness on aircraft and other vehicles;

Measurement of density and moisture content of soils;

Non-destructive γ-flaw detection of product materials.

Radioisotope therapeutic devices, as well as clinical radioisotope diagnostics, have found clinical use directly in medical practice.

γ-therapeutic devices for external γ-irradiation have been mastered. These devices have significantly expanded the possibilities of remote γ -therapy of tumors through the use of static and mobile irradiation options.

Various options and methods of radiation treatment are used for individual tumor locations. Persistent five-year cures for stages 1, 2 and 3 were obtained, respectively, in

90-95, 75-85 and 55-60% of patients. The positive role of radiation therapy in the treatment of cancer of the breast, lung, esophagus, oral cavity, larynx, bladder and other organs is also well known.

Radioisotope diagnostics (introduction of a radioactive drug into the body) has become an integral part of the diagnostic process at all stages of disease development or assessment of the functional state of a healthy organism. Radioisotope diagnostic studies can be reduced to the following main sections:

Determination of radioactivity of the whole body, its parts, individual organs in order to identify the pathological condition of the organ;

Determination of the speed of movement of a radioactive drug through individual areas of the cardiovascular system;

Study of the spatial distribution of a radioactive drug in the human body for visualization of organs, pathological formations, etc.

The most important aspects of diagnosis include pathological changes in the cardiovascular system, timely detection of malignant neoplasms, assessment of the state of the bone, hematopoietic and lymphatic systems of the body, which are difficult to access objects for research using traditional clinical and instrumental methods.

Nay labeled with ¹³y has been introduced into clinical practice for the diagnosis of thyroid diseases; NaCe labeled with ²⁴Na for studying local and general blood flow;

Na₃PO₄, labeled with ³³P to study the processes of its accumulation in pigmented skin formations and other tumor formations.

The diagnostic method in neurology and neurosurgery using the isotopes ⁴⁴Tc, ¹³³Xe and ¹⁶⁹Y has gained leading importance. It is necessary for a more precise diagnosis of brain diseases, as well as diseases of the cardiovascular system. In nephrology and urology, radioactive drugs containing ¹³¹Y, ¹⁹⁷Hg,

¹⁶⁹Yb, ⁵¹Cr and ¹¹³Yn. Thanks to the introduction of radioisotope examination methods, early morbidity of the kidneys and other organs has improved.

The scientific and applied applications of p/isotopes are very wide. Let's look at a few:

Of practical interest is the use of radioisotope power plants (RPUs) with electrical power from several units to hundreds of watts. The greatest practical application has been found in radioisotope thermoelectric generators, in which the conversion of radioactive decay energy into electrical energy is carried out using thermoelectric converters; such power plants are characterized by complete autonomy, the ability to operate in any climatic conditions, a long service life and operational reliability.

Radioisotope power supplies provide operation in systems of automatic weather stations; in navigation equipment systems in remote and uninhabited areas (electric power supply to lighthouses, directional signs, navigation lights).

Thanks to the positive experience of using them in low temperature conditions, it became possible to use them in Antarctica.

It is also known that isotope power plants with ²¹ºPo were used on vehicles moving on the surface of the Moon (lunar rovers).

The use of r/a isotopes in scientific research cannot be overestimated, since all practical methods follow from positive results in research.

In addition, it is worth mentioning such very narrow specializations as pest control in ancient objects of art, as well as the use of natural radioactive isotopes in radon baths and mud during spa treatment.

At the end of their service life, radioactive sources must be delivered in the prescribed manner to special plants for processing (conditioning) with subsequent disposal as radioactive waste.

Radioactive waste, problems of their disposal

The problem of radioactive waste is a special case of the general problem of environmental pollution by human waste. But at the same time, the pronounced specificity of radioactive waste requires the use of specific methods to ensure safety for humans and the biosphere.

The historical experience of handling industrial and household waste was formed in conditions when awareness of the danger of waste and programs for its neutralization was based on direct sensations. The capabilities of the latter ensured the adequacy of awareness of the connections between influences directly perceived by the senses and the upcoming consequences. The level of knowledge made it possible to present the logic of the mechanisms of the impact of waste on humans and the biosphere, which corresponded quite accurately to real processes. The practically developed traditional ideas about methods of waste disposal have historically been joined by qualitatively different approaches developed with the discovery of microorganisms, forming not only empirically, but also scientifically grounded methodological support for the safety of humans and their habitat. In medicine and social management systems, corresponding sub-sectors were formed, for example, sanitary and epidemiological affairs, municipal hygiene, etc.

With the rapid development of chemistry and chemical production, new, previously unknown elements and chemical compounds, including those that do not exist in nature, appeared in industrial and household waste in massive quantities. In scale, this phenomenon has become comparable to natural geochemical processes. Humanity has found itself faced with the need to reach another level of problem assessment, where, for example, accumulative and delayed effects, methods for identifying exposure dosages, the need to use new methods and special highly sensitive equipment for detecting danger, etc. must be taken into account.

A qualitatively different danger, although similar to the chemical one in some of its characteristics, was brought to humans by "radioactivity" , as a phenomenon that is not directly perceived by human senses, is not destroyed by methods known to mankind, and is still generally insufficiently studied: the discovery of new properties, impacts and consequences of this phenomenon cannot be ruled out. Therefore, when forming general and specific scientific and practical tasks “to eliminate the danger of radioactive waste” and, in particular, when solving these problems, constant difficulties arise, showing that the traditional formulation does not accurately reflect the real, objective nature of the “radwaste problem”. However, the ideology of such a statement is widespread in legal and non-legal documents of a national and interstate nature, which, as can be assumed, cover a wide range of modern scientific views, directions, research and practical activities; take into account the developments of all well-known domestic and foreign organizations dealing with the “radwaste problem”.

Decree of the Government of the Russian Federation dated October 23, 1995 No. 1030 approved the Federal Target Program “Management of Radioactive Waste and Spent Nuclear Materials, Their Recycling and Disposal for 1996-2005.”

Radioactive waste is considered in it “as substances (in any state of aggregation), materials, products, equipment, objects of biological origin that are not subject to further use, in which the content of radionuclides exceeds the levels established by regulations. The Program has a special section “State of the Problem”, containing a description of specific objects and public areas where “radioactive waste management” occurs, as well as general quantitative characteristics of the “radwaste problem” in Russia.

“The large amount of accumulated unconditioned radioactive waste, the insufficiency of technical means to ensure the safe handling of this waste and spent nuclear fuel, the lack of reliable storage facilities for their long-term storage and (or) disposal increase the risk of radiation accidents and create a real threat of radioactive contamination of the environment and over-irradiation population and personnel of organizations and enterprises whose activities involve the use of atomic energy and radioactive materials.”

The main sources of high-level radioactive waste (RAW) are nuclear energy (spent nuclear fuel) and military programs (plutonium from nuclear warheads, spent fuel from transport reactors of nuclear submarines, liquid waste from radiochemical plants, etc.).

The question arises: should radioactive waste be considered simply as waste or as a potential source of energy? The answer to this question determines whether we want to store them (in an accessible form) or bury them (that is, make them inaccessible). The generally accepted answer now is that radioactive waste is indeed waste, with the possible exception of plutonium. Plutonium can theoretically serve as a source of energy, although the technology for generating energy from it is complex and quite dangerous. Many countries, including Russia and the United States, are now at a crossroads: to “launch” plutonium technology using plutonium released during disarmament, or bury this plutonium? Recently, the Russian government and Minatom announced that they want to reprocess weapons-grade plutonium together with the United States; this means the possibility of developing plutonium energy.

For 40 years, scientists have been comparing options for disposal of radioactive waste. The main idea is that they must be placed in such a place that they cannot enter the environment and harm humans. This ability to harm radioactive waste is retained for tens and hundreds of thousands of years. Irradiated nuclear fuel, which we extract from the reactor contains radioisotopes with half-lives from several hours to a million years (half-life is the time during which the amount of radioactive substance is halved, and in some cases new radioactive substances appear). But the overall radioactivity of waste decreases significantly over time. For radium, the half-life is 1620 years, and it is easy to calculate that after 10 thousand years about 1/50 of the original amount of radium will remain. The regulations of most countries provide for waste safety for a period of 10 thousand years. Of course, this does not mean that after this time, radioactive waste will no longer be dangerous: we are simply shifting further responsibility for radioactive waste to distant posterity. To do this, it is necessary that the places and form of burial of this waste be known to posterity. Note that the entire written history of mankind is less than 10 thousand years old. The challenges that arise during the disposal of radioactive waste are unprecedented in the history of technology: people have never set themselves such long-term goals.

An interesting aspect of the problem is that it is necessary not only to protect people from waste, but at the same time to protect waste from people. During the period allotted for their burial, many socio-economic formations will change. It cannot be ruled out that in a certain situation, radioactive waste may become a desirable target for terrorists, targets for attack in a military conflict and so on. It is clear that, thinking about millennia, we cannot rely on, say, government control and protection - it is impossible to foresee what changes may occur. It may be best to make the waste physically inaccessible to humans, although, on the other hand, this would make it difficult for our descendants to take further security measures.

It is clear that not a single technical solution, not a single artificial material can “work” for thousands of years. The obvious conclusion is that the natural environment itself must isolate waste. Options were considered: burying radioactive waste in deep oceanic depressions, in bottom sediments of the oceans, in polar caps; send them to space; put them in deep layers of the earth's crust. It is now generally accepted that the optimal way is to bury waste in deep geological formations.

It is clear that solid radioactive waste is less prone to penetration into the environment (migration) than liquid radioactive waste. Therefore, it is assumed that liquid radioactive waste will first be converted into solid form (vitrified, converted into ceramics, etc.). However, in Russia, injection of liquid highly active radioactive waste into deep underground horizons is still practiced (Krasnoyarsk, Tomsk, Dimitrovgrad).

Currently, the so-called "multi-barrier" or “deeply echeloned” burial concept. The waste is first contained by a matrix (glass, ceramics, fuel pellets), then a multi-purpose container (used for transport and disposal), then a sorbent fill around the containers, and finally by the geological environment.

So, we will try to bury radioactive waste in deep geological fractions. At the same time, we were given a condition: to show that our burial will work, as we plan, for 10 thousand years. Let's now see what problems we will encounter along this path.

The first problems arise at the stage of selecting sites for study.

In the USA, for example, not a single state wants it. So that a national burial site is located on its territory. This led to the fact that, through the efforts of politicians, many potentially suitable areas were crossed off the list, not on the basis of a scientific approach, but as a result of political games.

What does it look like in Russia? Currently, in Russia it is still possible to study areas without feeling significant pressure from local authorities (if you do not involve burial near cities!). I believe that as the real independence of the regions and subjects of the Federation increases, the situation will shift towards the situation of the United States. There is already a sense of Minatom’s inclination to shift its activities to military sites over which there is practically no control: for example, the Novaya Zemlya archipelago (Russian test site No. 1) is supposed to be used for the creation of a burial site, although in terms of geological parameters this is far from the best place, which will be discussed later .

But let’s assume that the first stage is over and the site has been selected. It is necessary to study it and give a forecast for the functioning of the burial for 10 thousand years. Here a new problem appears.

Lack of development of the method.

Geology is a descriptive science. Certain branches of geology deal with predictions (for example, engineering geology predicts the behavior of soils during construction, etc.), but never before has geology been tasked with predicting the behavior of geological systems for tens of thousands of years. From many years of research in different countries, doubts even arose whether a more or less reliable forecast for such periods is even possible.

Let us imagine, however, that we managed to develop a reasonable plan for studying the site. It is clear that it will take many years to implement this plan: for example, Mount Yaka in Nevada has been studied for more than 15 years, but a conclusion about the suitability or unsuitability of this mountain will not be made earlier than in 5 years. At the same time, the disposal program will come under increasing pressure.

Pressure from external circumstances.

During the Cold War, waste was ignored; they accumulated, were stored in temporary containers, were lost, etc. An example is the Hanford military facility (analogous to our “Beacon”), where there are several hundred giant tanks with liquid waste, and for many of them it is not known what is inside. One sample costs 1 million dollars! There, in Hanford, buried and “forgotten” barrels or boxes of waste are discovered about once a month.

In general, over the years of development of nuclear technology, a lot of waste has accumulated. Temporary storage facilities at many nuclear power plants are close to filling, and at military complexes they are often on the verge of failure due to old age or even beyond this point.

So, the burial problem requires urgent solutions. Awareness of this urgency is becoming increasingly acute, especially since 430 power reactors, hundreds of research reactors, hundreds of transport reactors of nuclear submarines, cruisers and icebreakers continue to continuously accumulate radioactive waste. But people with their backs to the wall don't necessarily come up with the best technical solutions and are more likely to make mistakes. Meanwhile, in decisions related to nuclear technology, errors can be very costly.

Let's finally assume that we spent 10-20 billion dollars and 15-20 years studying a potential site. It's time to make a decision. Obviously, there are no ideal places on Earth, and any place will have positive and negative properties from the point of view of burial. Obviously, you will have to decide whether the positive properties outweigh the negative ones, and whether these positive properties provide sufficient security.

Decision making and technological complexity of the problem

The disposal problem is technically extremely complex. Therefore, it is very important to have, firstly, high-quality science, and secondly, effective interaction (as they say in America - “interface”) between science and decision-making politicians.

The Russian concept of underground isolation of radioactive waste and spent nuclear fuel in permafrost rocks was developed at the Institute of Industrial Technology of the Russian Ministry of Atomic Energy (VNIPIP). It was approved by the State Environmental Expertise of the Ministry of Ecology and Natural Resources of the Russian Federation, the Ministry of Health of the Russian Federation and Gosatomnadzor of the Russian Federation. Scientific support for the concept is provided by the Department of Permafrost Science at Moscow State University. It should be noted that this concept is unique. As far as I know, no country in the world is considering the issue of burying radioactive waste in permafrost.

The main idea is this. We place heat-generating waste in the permafrost and separate it from the rocks with an impenetrable engineered barrier. Due to heat release, the permafrost around the burial begins to thaw, but after some time, when the heat release decreases (due to the decay of short-lived isotopes), the rocks will freeze again. Therefore, it is enough to ensure the impermeability of engineering barriers for the period when the permafrost thaws; After freezing, migration of radionuclides becomes impossible.

Uncertainty concept

There are at least two serious problems with this concept.

First, the concept assumes that frozen rocks are impenetrable to radionuclides. At first glance, this seems reasonable: all water is frozen, ice is usually motionless and does not dissolve radionuclides. But if you carefully study the literature, it turns out that many chemical elements migrate quite actively in frozen rocks. Even at temperatures of 10-12ºC, non-freezing, so-called film, water is present in the rocks. What is especially important is that the properties of the radioactive elements that make up radioactive waste, from the point of view of their possible migration in permafrost, have not been studied at all. Therefore, the assumption that frozen rocks are impermeable to radionuclides is without any basis.

Secondly, even if it turns out that permafrost is indeed a good insulator of radioactive waste, it is impossible to prove that the permafrost itself will last long enough: let us recall that the standards provide for disposal for a period of 10 thousand years. It is known that the state of permafrost is determined by climate, with the two most important parameters being air temperature and the amount of precipitation. As you know, air temperatures are rising due to global climate change. The highest rate of warming occurs at the middle and high latitudes of the northern hemisphere. It is clear that such warming should lead to thawing of ice and reduction of permafrost.

Calculations show that active thawing can begin within 80-100 years, and the rate of thawing can reach 50 meters per century. Thus, the frozen rocks of Novaya Zemlya can completely disappear in 600-700 years, and this is only 6-7% of the time required to isolate the waste. Without permafrost Carbonate rocks of Novaya Zemlya have very low insulating properties with respect to radionuclides.

The problem of storage and disposal of radioactive waste (RAW) is the most important and unresolved problem of nuclear energy.

No one in the world yet knows where and how to store high-level radioactive waste, although work in this direction is underway. So far we are talking about promising, and by no means industrial technologies for enclosing highly active radioactive waste in refractory glass or ceramic compounds. However, it is unclear how these materials will behave under the influence of radioactive waste contained in them for millions of years. Such a long shelf life is due to the huge half-life of a number of radioactive elements. It is clear that their release to the outside is inevitable, because the material of the container in which they will be enclosed does not “live” that much.

All technologies for processing and storing radioactive waste are conditional and questionable. And if nuclear scientists, as usual, dispute this fact, then it would be appropriate to ask them: “Where is the guarantee that all existing storage facilities and burial grounds are not already carriers of radioactive contamination, since all observations of them are hidden from the public?”

There are several burial grounds in our country, although they try to keep silent about their existence. The largest is located in the Krasnoyarsk region near the Yenisei, where waste from most Russian nuclear power plants and nuclear waste from a number of European countries are buried. When carrying out scientific research work on this storage facility, the results turned out to be positive, but recently observations have shown a violation of the ecosystem of the Yenisei River, that mutant fish have appeared, and the structure of the water in certain areas has changed, although the data of scientific examinations is carefully hidden.

In the world, the disposal of high-level radioactive waste has not yet been carried out; there is only experience in their temporary storage.

Bibliography

1. Vershinin N.V. Sanitary and technical requirements for sealed radiation sources.

In the book. "Proceedings of the Symposium". M., Atomizdat, 1976

2. Frumkin M. L. et al. Technological foundations of radiation processing of food products. M., Food industry, 1973

3. Breger A. Kh. Radioactive isotopes – sources of radiation in radiation-chemical technology. Isotopes in the USSR, 1975, No. 44, pp. 23-29.

4. Pertsovsky E. S., Sakharov E. V. Radioisotope devices in the food, light and pulp and paper industries. M., Atomizdat, 1972

5. Vorobyov E.I., Pobedinsky M.N. Essays on the development of domestic radiation medicine. M., Medicine, 1972

6. Selection of a site for the construction of a radioactive waste storage facility. E.I.M., TsNIIatominform, 1985, No. 20.

7. Current state of the problem of radioactive waste disposal in the USA. Nuclear technology abroad, 1988, No. 9.

8. Heinonen Dis, Disera F. Disposal of nuclear waste: processes occurring in underground storage facilities: IAEA Bulletin, Vienna, 1985, vol. 27, no. 2.

9. Geological studies of sites for the final disposal of radioactive waste: E.I.M.: TsNIIatominform, 1987, No. 38.

10. Bryzgalova R.V., Rogozin Yu.M., Sinitsyna G.S. et al. Assessment of some radiochemical and geochemical factors that determine the localization of radionuclides during the burial of radioactive waste in geological formations. Proceedings of the 6th CMEA Symposium, vol. 2, 1985.

radiation particle irradiation radon

People have learned to use radiation for peaceful purposes, with a high level of safety, which has made it possible to raise almost all industries to a new level.

Producing energy using nuclear power plants. Of all branches of human economic activity, energy has the greatest impact on our lives. Heat and light in homes, traffic flows and the operation of industry - all this requires energy. This industry is one of the fastest growing. Over 30 years, the total capacity of nuclear power units has increased from 5 thousand to 23 million kilowatts.

Few people doubt that nuclear energy has taken a strong place in the energy balance of humanity.

Let's consider the use of radiation in flaw detection. X-ray and gamma flaw detection are one of the most common uses of radiation in industry to control the quality of materials. The X-ray method is non-destructive, so that the material being tested can then be used for its intended purpose. Both X-ray and gamma flaw detection are based on the penetrating ability of X-ray radiation and the characteristics of its absorption in materials.

Gamma radiation is used for chemical transformations, for example, in polymerization processes.

Perhaps one of the most important developing industries is nuclear medicine. Nuclear medicine is a branch of medicine associated with the use of achievements of nuclear physics, in particular radioisotopes, etc.

Today, nuclear medicine makes it possible to study almost all human organ systems and is used in neurology, cardiology, oncology, endocrinology, pulmonology and other areas of medicine.

Using nuclear medicine methods, the blood supply to organs, bile metabolism, kidney, bladder, and thyroid function are studied.

It is possible not only to obtain static images, but also to overlay images obtained at different points in time to study dynamics. This technique is used, for example, in assessing heart function.

In Russia, two types of diagnostics using radioisotopes are already actively used - scintigraphy and positron emission tomography. They allow you to create complete models of organ function.

Doctors believe that at low doses, radiation has a stimulating effect, training the human biological defense system.

Many resorts use radon baths, where the level of radiation is slightly higher than in natural conditions.

It has been noticed that those who take these baths have improved performance, calmed the nervous system, and healed injuries faster.

Research by foreign scientists suggests that the incidence and mortality from all types of cancer are lower in areas with a higher natural background radiation (most sunny countries include these).

Radiation, radioactivity and radio emission are concepts that even sound quite dangerous. In this article you will learn why some substances are radioactive and what that means. Why is everyone so afraid of radiation and how dangerous is it? Where can we find radioactive substances and what does this threaten us with?

Radioactivity concept

By radioactivity I mean the “ability” of atoms of certain isotopes to split and thereby create radiation. The term “radioactivity” did not appear immediately. Initially, such radiation was called Becquerel rays, in honor of the scientist who discovered it while working with an isotope of uranium. We now call this process the term “radioactive radiation.”

In this rather complex process, the original atom is transformed into an atom of a completely different chemical element. Due to the ejection of alpha or beta particles, the mass number of the atom changes and, accordingly, this moves it according to D.I. Mendeleev’s table. It is worth noting that the mass number changes, but the mass itself remains almost the same.

Based on this information, we can slightly rephrase the definition of the concept. So, radioactivity is also the ability of unstable atomic nuclei to independently transform into other, more stable and stable nuclei.

Substances - what are they?

Before we talk about what radioactive substances are, let's generally define what is called a substance. So, first of all, it is a type of matter. It is also logical that this matter consists of particles, and in our case these are most often electrons, protons and neutrons. Here we can already talk about atoms, which consist of protons and neutrons. Well, molecules, ions, crystals, and so on are made from atoms.

The concept of a chemical substance is based on the same principles. If it is impossible to isolate a nucleus in matter, then it cannot be classified as a chemical substance.

About radioactive substances

As mentioned above, in order to exhibit radioactivity, an atom must spontaneously decay and turn into an atom of a completely different chemical element. If all the atoms of a substance are unstable enough to decay in this way, then you have a radioactive substance. In more technical language, the definition would sound like this: substances are radioactive if they contain radionuclides, and in high concentrations.

Where are radioactive substances located in D.I. Mendeleev’s table?

A fairly simple and easy way to find out whether a substance is radioactive is to look at D.I. Mendeleev’s table. Everything that comes after the lead element are radioactive elements, as well as promethium and technetium. It is important to remember which substances are radioactive, because it can save your life.

There are also a number of elements that have at least one radioactive isotope in their natural mixtures. Here is a partial list of them, showing some of the most common elements:

• Potassium.
• Calcium.
• Vanadium.
• Germanium.
• Selenium.
• Rubidium.
• Zirconium.
• Molybdenum.
• Cadmium.
• Indium.

Radioactive substances include those that contain any radioactive isotopes.

Types of radioactive radiation

There are several types of radioactive radiation, which will be discussed now. Alpha and beta radiation have already been mentioned, but this is not the entire list.

Alpha radiation is the weakest radiation and is dangerous if particles enter directly into the human body. Such radiation is produced by heavy particles, and that is why it is easily stopped even by a sheet of paper. For the same reason, alpha rays do not travel more than 5 cm.

Beta radiation is stronger than the previous one. This is radiation from electrons, which are much lighter than alpha particles, so they can penetrate several centimeters into human skin.

Gamma radiation is realized by photons, which quite easily penetrate even further to the internal organs of a person.

The most powerful radiation in terms of penetration is neutron radiation. It is quite difficult to hide from it, but in fact it does not exist in nature, except perhaps in close proximity to nuclear reactors.

Impact of radiation on humans

Radioactively hazardous substances can often be fatal to humans. In addition, radiation exposure has an irreversible effect. If you are exposed to radiation, you are doomed. Depending on the extent of the damage, a person dies within a few hours or over many months.

At the same time, it must be said that people are continuously exposed to radioactive radiation. Thank God it's weak enough to be fatal. For example, watching a football match on television, you receive 1 microrad of radiation. Up to 0.2 rad per year is generally the natural radiation background of our planet. 3rd gift - your portion of radiation during dental x-rays. Well, exposure to more than 100 rads is already potentially dangerous.

Harmful radioactive substances, examples and warnings

The most dangerous radioactive substance is Polonium-210. Due to the radiation around it, a kind of luminous blue “aura” is even visible. It is worth saying that there is a stereotype that all radioactive substances glow. This is not at all true, although there are such variants as Polonium-210. Most radioactive substances are not at all suspicious in appearance.

Livermorium is currently considered the most radioactive metal. Its isotope Livermorium-293 takes 61 milliseconds to decay. This was discovered back in 2000. Ununpentium is slightly inferior to it. The decay time of Ununpentia-289 is 87 milliseconds.

Another interesting fact is that the same substance can be both harmless (if its isotope is stable) and radioactive (if the nuclei of its isotope are about to collapse).

Scientists who studied radioactivity

Radioactive substances were not considered dangerous for a long time, and therefore were freely studied. Unfortunately, sad deaths have taught us that caution and increased levels of safety are needed with such substances.

One of the first, as already mentioned, was Antoine Becquerel. This is a great French physicist, to whom belongs the fame of the discoverer of radioactivity. For his services, he was awarded membership in the Royal Society of London. Because of his contributions to this field, he died quite young, at the age of 55. But his work is remembered to this day. The unit of radioactivity itself, as well as craters on the Moon and Mars, were named in his honor.

An equally great person was Marie Skłodowska-Curie, who worked with radioactive substances together with her husband Pierre Curie. Maria was also French, albeit with Polish roots. In addition to physics, she was engaged in teaching and even active social activities. Marie Curie is the first woman to win the Nobel Prize in two disciplines: physics and chemistry. The discovery of such radioactive elements as Radium and Polonium is the merit of Marie and Pierre Curie.

Conclusion

As we see, radioactivity is a rather complex process that does not always remain under human control. This is one of those cases where people can find themselves completely powerless in the face of danger. This is why it is important to remember that truly dangerous things can be very deceptive in appearance.

You can most often find out whether a substance is radioactive or not once it has been exposed to it. Therefore, be careful and attentive. Radioactive reactions help us in many ways, but we should also not forget that this is a force practically beyond our control.

In addition, it is worth remembering the contribution of great scientists to the study of radioactivity. They passed on to us an incredible amount of useful knowledge that now saves lives, provides entire countries with energy and helps treat terrible diseases. Radioactive chemicals are a danger and a blessing to humanity.