What is the danger of radioactive waste. Why radioactive waste is dangerous Disposal of radioactive substances

Radioactive waste results from the operation of land-based nuclear installations and shipboard reactors. If radioactive waste is dumped into rivers, seas, oceans, as well as other wastes of human activity, then everything can end sadly. Radioactive exposure that exceeds the natural level is harmful to all living things on land and in water bodies. Accumulating, radiation leads to irreversible changes in living organisms, even deformities in subsequent generations.

Today, there are about 400 nuclear-powered ships operating in the world. They dump radioactive waste directly into the waters of the oceans. The bulk of the waste in this area is generated by the nuclear industry. There are calculations that if nuclear energy will become the main source of energy in the world, the amount of waste can reach thousands of tons per year ... Numerous international organizations actively advocate for a ban on the dumping of radioactive waste into the natural waters of the planet.

But there are other ways to dispose of radioactive waste that do not cause significant damage to the environment.

During the infamous accident at the Mayak Production Association (Ozersk, Chelyabinsk region), a chemical explosion of liquid high-level waste occurred in one of the storage tanks of the radiochemical plant. The main cause of the explosion was insufficient cooling of the waste containers, which were subjected to intense heat and exploded. According to experts, 20 Mci of activity of radionuclides in the tank were involved in the explosion, of which 18 Mki settled on the territory of the object, and 2 Mki scattered on the territory of the Chelyabinsk and Sverdlovsk regions. A radioactive trace was formed, later called the East Ural radioactive trace. The territory subjected to radioactive contamination was a strip up to 20 - 40 km wide and up to 300 km long. The territory on which the introduction of radiation protection measures was required and was assigned the status of radioactively contaminated (with the accepted maximum contamination density of 74 kBq / sq. M or 2 Ci / sq. km for strontium-90), amounted to a rather narrow strip up to 10 km wide and about 105 km.

The density of radioactive contamination of the territory directly at the industrial site reached from tens to hundreds of thousands of Ci per square meter. km for strontium-90. According to the modern international classification, that accident was classified as severe and received an index of 6 on a 7-point system.

For reference:

Federal State Unitary Enterprise "National Operator for Radioactive Waste Management" (FSUE "NO RAO"), created by the order of the state corporation "Rosatom" is the only organization in Russia authorized in accordance with federal law # 190-FZ "On the management of radioactive waste" to carry out activities for the final isolation of radioactive waste and organization of infrastructure for these purposes.

The mission of FSUE "NO RAO" is to ensure the environmental safety of the Russian Federation in the field of final isolation of radioactive waste. In particular, solving the problems of the accumulated Soviet nuclear legacy and newly formed radioactive waste. The enterprise is, in fact, a state production and environmental enterprise, the key goal of which is the final isolation of radioactive waste, taking into account any potential environmental risks.

The first point in Russia for the final isolation of radioactive waste was created in Novouralsk Sverdlovsk region. AT this moment The national operator received a license for the operation of the 1st stage and licenses for the construction of the 2nd and 3rd stages of the facility.

Today FSUE "NO RAO" is also working on the creation of points for the final isolation of radioactive waste of classes 3 and 4 in Ozersk, Chelyabinsk Region, and Seversk, Tomsk Region.

Removal, processing and disposal of waste from 1 to 5 hazard class

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In the 20th century, the non-stop search for the ideal source of energy seemed to be over. This source was the nuclei of atoms and the reactions taking place in them - the active development of nuclear weapons and the construction of nuclear power plants began all over the world.

But the planet quickly faced the problem of processing and destroying nuclear waste. The energy of nuclear reactors carries a lot of dangers, as well as the waste of this industry. Until now, there is no carefully developed processing technology, while the sphere itself is actively developing. Therefore, safety depends primarily on proper disposal.

Definition

Nuclear waste contains radioactive isotopes of certain chemical elements. In Russia, according to the definition given in the Federal Law No. 170 “On the Use of Atomic Energy” (dated November 21, 1995), further use of such waste is not envisaged.

The main danger of materials lies in the radiation of gigantic doses of radiation, which has a detrimental effect on a living organism. The consequences of radioactive exposure are genetic disorders, radiation sickness and death.

Classification map

The main source of nuclear materials in Russia is the sphere of nuclear energy and military developments. All nuclear waste has three degrees of radiation, familiar to many from the course of physics:

• Alpha - radiant.
• Beta - emitting.
• Gamma - emitting.

The former are considered the most harmless, as they give a harmless level of radiation, unlike the other two. True, this does not prevent them from being included in the class of the most hazardous waste.


In general, the classification map of nuclear waste in Russia divides it into three types:

1. Solid nuclear waste. This includes a huge amount of maintenance materials in the energy sector, staff clothing, garbage that accumulates in the course of work. Such waste is burned in kilns, after which the ashes are mixed with a special cement mixture. It is poured into barrels, sealed and sent to storage. The burial is detailed below.
2. Liquid. The process of operation of nuclear reactors is impossible without the use of technological solutions. In addition, this includes water that is used to treat special suits and wash workers. Liquids are carefully evaporated, and then burial occurs. Liquid waste is often recycled and used as fuel for nuclear reactors.
3. Elements of the design of reactors, transport and means of technical control at the enterprise constitute a separate group. Their disposal is the most expensive. To date, there are two ways out: installation of the sarcophagus or dismantling with its partial decontamination and further shipment to the repository for burial.

The map of nuclear waste in Russia also defines low-level and high-level:

• Low-level waste - arise in the course of the activities of medical institutions, institutes and research centers. Here, radioactive substances are used to conduct chemical tests. The level of radiation emitted by these materials is very low. Proper Disposal allows you to turn hazardous waste into normal waste in about a few weeks, after which it can be disposed of as normal waste.
• High-level waste is spent reactor fuel and materials used in military industry to develop nuclear weapons. The fuel at the stations is a special rod with a radioactive substance. The reactor operates for approximately 12-18 months, after which the fuel must be changed. The amount of waste is simply enormous. And this figure is growing in all countries developing the field of nuclear energy. The disposal of high-level waste must take into account all the nuances in order to avoid a catastrophe for the environment and humans.

Recycling and disposal

At the moment, there are several methods for the disposal of nuclear waste. All of them have their advantages and disadvantages, but whatever one may say, they do not completely eliminate the danger of radioactive exposure.

burial

Waste disposal is the most promising method of disposal, which is especially actively used in Russia. First, the process of vitrification or "vitrification" of the waste occurs. The spent substance is calcined, after which quartz is added to the mixture, and this “liquid glass” is poured into special cylindrical steel molds. The resulting glass material is resistant to water, which reduces the possibility of radioactive elements entering the environment.

Finished cylinders are brewed and thoroughly washed, getting rid of the slightest contamination. Then they go to storage for a very long time. long time. The repository is arranged in geologically stable areas so that the repository is not damaged.

Geological disposal is carried out at a depth of more than 300 meters in such a way that for a long time the waste does not need further maintenance.

Burning

Part of the nuclear materials, as mentioned above, is the direct results of production, and a kind of side waste in the energy sector. These are materials exposed to radiation during production: waste paper, wood, clothing, household waste.

All this is burned in specially designed furnaces, which minimize the level of toxic substances in the atmosphere. The ash, among other wastes, is cemented.

Cementing

Disposal (one of the ways) of nuclear waste in Russia by cementing is one of the most common practices. The bottom line is to place irradiated materials and radioactive elements in special containers, which are then filled with a special solution. The composition of such a solution includes a whole cocktail of chemical elements.

As a result, it is practically not exposed to the external environment, which makes it possible to achieve an almost unlimited period. But it is worth making a reservation that such a burial is possible only for the disposal of waste of an average level of danger.

Seal

A long and fairly reliable practice aimed at burying and reducing the amount of waste. It is not applicable to the processing of basic fuel materials, but allows the processing of other wastes. low level danger. This technology uses hydraulic and pneumatic presses with low pressure force.

Reapplication

The use of radioactive material in the field of energy is not fully implemented due to the specific nature of the activity of these substances. Once exhausted, the waste still remains a potential source of energy for reactors.

AT modern world and even more so in Russia, the situation with energy resources is quite serious, and therefore recycling nuclear materials as fuel for reactors no longer seems unbelievable.

Today, there are methods that allow the use of spent raw materials for applications in the energy sector. Radioisotopes contained in the waste are used for food processing and as a "battery" for the operation of thermoelectric reactors.

But while the technology is still in development, and the ideal method of processing has not been found. Nevertheless, the processing and destruction of nuclear waste makes it possible to partially resolve the issue with such garbage, using it as fuel for reactors.

Unfortunately, in Russia, a similar method of getting rid of nuclear debris is practically not being developed.

Volumes

In Russia, all over the world, the volumes of nuclear waste sent for disposal amount to tens of thousands of cubic meters annually. Every year, European storage facilities receive about 45,000 cubic meters of waste, while in the United States, only one landfill in Nevada absorbs such a volume.

Nuclear waste and work related to it abroad and in Russia is the activity of specialized enterprises equipped with high-quality machinery and equipment. At the enterprises, waste is subjected to various methods of treatment described above. As a result, it is possible to reduce the volume, reduce the level of danger, and even use some waste in the energy sector as fuel for nuclear reactors.

The peaceful atom has long proved that everything is not so simple. The energy sector is developing and will continue to develop. The same can be said about the military sphere. But if we sometimes turn a blind eye to the release of other wastes, improperly disposed of nuclear waste can cause a total catastrophe for all mankind. Therefore, this issue needs to be resolved as soon as possible before it is too late.

Radioactive waste has become an extremely acute problem of our time. If at the dawn of the development of energy, few people thought about the need to store waste material, now this task has become extremely urgent. So why is everyone so worried?

Radioactivity

This phenomenon was discovered in connection with the study of the relationship between luminescence and x-rays. AT late XIX century, during a series of experiments with uranium compounds, the French physicist A. Becquerel discovered a hitherto unknown passing through opaque objects. He shared his discovery with the Curies, who studied it closely. It was the world-famous Marie and Pierre who discovered that all uranium compounds, like pure uranium itself, as well as thorium, polonium and radium, have the property. Their contribution has been truly invaluable.

Later it became known that all chemical elements, starting with bismuth, are radioactive in one form or another. Scientists also thought about how the process of nuclear decay could be used to generate energy, and were able to initiate and reproduce it artificially. And to measure the level of radiation, a radiation dosimeter was invented.

Application

In addition to energy, radioactivity received wide application and in other sectors: medicine, industry, scientific research and agriculture. With the help of this property, they learned to stop the spread of cancer cells, make more accurate diagnoses, find out the age of archaeological values, monitor the transformation of substances in various processes, etc. List possible applications Radioactivity is constantly expanding, so it is even surprising that the issue of disposal of waste materials has become so acute only in recent decades. But this is not just garbage that can be easily thrown into a landfill.

radioactive waste

All materials have their own lifespan. This is no exception for elements used in nuclear energy. The output is waste that still has radiation, but no longer has practical value. As a rule, used is considered separately, which can be recycled or applied in other areas. In this case, we are talking simply about radioactive waste (RW), the further use of which is not provided, therefore, they must be disposed of.

Sources and forms

Due to the variety of uses, waste can also have different origin and condition. They are both solid and liquid or gaseous. Sources can also be very different, since in one form or another such waste often occurs during the extraction and processing of minerals, including oil and gas, there are also such categories as medical and industrial RW. There are also natural sources. Conventionally, all these radioactive wastes are divided into low-, medium- and high-level. The United States also distinguishes the category of transuranic radioactive waste.

Options

Enough for a long time it was believed that the disposal of radioactive waste does not require special rules, it was enough to disperse them in the environment. However, later it was discovered that isotopes tend to accumulate in certain systems, such as animal tissues. This discovery changed the opinion about radioactive waste, since in this case the probability of their movement and getting into the human body with food became quite high. Therefore, it was decided to develop some options for how to deal with this type of waste, especially for the high-level category.

Modern technologies make it possible to maximally neutralize the danger posed by radioactive waste by processing them different ways or placed in a safe space for humans.

1. Vitrification. In another way, this technology is called vitrification. At the same time, radioactive waste goes through several stages of processing, as a result of which a rather inert mass is obtained, which is placed in special containers. Then these containers are sent to storage.
2. Synrock. This is another method of radioactive waste neutralization developed in Australia. In this case, a special complex compound is used in the reaction.
3. Burial. At this stage, a search is underway for suitable places in the earth's crust where radioactive waste could be placed. The most promising is the project, according to which the waste material is returned to
4. Transmutation. Reactors are already being developed that can turn highly radioactive waste into less dangerous substances. Simultaneously with the neutralization of waste, they are able to generate energy, so the technologies in this area are considered extremely promising.
5. Removal into outer space. Despite the attractiveness of this idea, it has a lot of drawbacks. First, this method is quite costly. Secondly, there is the risk of a launch vehicle crash, which could be a disaster. Finally, the clogging of outer space with such waste after a while can turn into big problems.

Disposal and storage rules

In Russia, radioactive waste management is regulated primarily by federal law and its commentaries, as well as some related documents, such as the Water Code. According to the Federal Law, all radioactive waste must be buried in the most isolated places, while pollution of water bodies is not allowed, sending into space is also prohibited.

Each category has its own regulations, in addition, the criteria for assigning waste to a particular type and all the necessary procedures are clearly defined. However, Russia has a lot of problems in this area. Firstly, the disposal of radioactive waste may very soon become a non-trivial task, because there are not so many specially equipped storage facilities in the country, and they will be filled pretty soon. Secondly, there is no single system for managing the recycling process, which seriously complicates control.

International projects

Given that the storage of radioactive waste has become the most urgent after the cessation, many countries prefer to cooperate in this matter. Unfortunately, consensus in this area has not yet been achieved, but the discussion of various programs in the UN continues. The most promising projects seem to be to build a large international storage facility for radioactive waste in sparsely populated areas, usually in Russia or Australia. However, the citizens of the latter are actively protesting against this initiative.

Consequences of irradiation

Almost immediately after the discovery of the phenomenon of radioactivity, it became clear that it negatively affects the health and life of humans and other living organisms. The studies that the Curies conducted over several decades eventually led to a severe form of radiation sickness in Maria, although she lived to be 66 years old.

This disease is the main consequence of the effects of radiation on humans. The manifestation of this disease and its severity mainly depend on the total radiation dose received. They can be quite mild, or they can cause genetic changes and mutations, thus affecting the next generations. One of the first to suffer is the function of hematopoiesis, often patients have some form of cancer. At the same time, in most cases, the treatment is quite ineffective and consists only in observing the aseptic regimen and eliminating symptoms.

Prevention

It is quite easy to prevent a condition associated with exposure to radiation - it is enough not to get into areas with its increased background. Unfortunately, this is not always possible, as many modern technologies involve active elements in one form or another. In addition, not everyone carries a portable radiation dosimeter with them to know that they are in an area where prolonged exposure can cause harm. However, there are certain measures to prevent and protect against dangerous radiation, although there are not many of them.

First, it's shielding. Almost everyone who came to x-ray a certain part of the body faced this. If we are talking about the cervical spine or the skull, the doctor suggests putting on a special apron, into which elements of lead are sewn, which does not allow radiation to pass through. Secondly, you can support the body's resistance by taking vitamins C, B 6 and P. Finally, there are special preparations - radioprotectors. In many cases they are very effective.

radioactive waste

radioactive waste (RAO) - waste containing radioactive isotopes of chemical elements and having no practical value.

According to the Russian "Law on the use of atomic energy" (November 21, 1995 No. 170-FZ), radioactive waste (RW) is nuclear materials and radioactive substances, the further use of which is not foreseen. Under Russian law, the import of radioactive waste into the country is prohibited.

Often confused and considered synonymous with radioactive waste and spent nuclear fuel. These concepts should be distinguished. Radioactive waste is materials that are not intended to be used. Spent nuclear fuel is a fuel element containing nuclear fuel residues and many fission products, mainly 137 Cs and 90 Sr , widely used in industry, agriculture, medicine and science. Therefore, it is a valuable resource, as a result of the processing of which fresh nuclear fuel and isotope sources are obtained.

Sources of waste

Radioactive waste is generated in various forms with very different physical and chemical characteristics, such as the concentrations and half-lives of their constituent radionuclides. These wastes can be generated:

• in gaseous form, such as vent emissions from facilities where radioactive materials are processed;
• in liquid form, ranging from scintillation counter solutions from research facilities to high-level liquid waste from spent fuel reprocessing;
• in solid form (contaminated consumables, glassware from hospitals, medical research facilities and radiopharmaceutical laboratories, vitrified waste from fuel processing or spent fuel from nuclear power plants when it is considered waste).

Examples of sources of radioactive waste in human activities:

Work with such substances is regulated sanitary regulations issued by Sanepidnadzor.

• Coal . Coal contains a small number of radionuclides, such as uranium or thorium, but the content of these elements in coal is less than their average concentration in the earth's crust.

Their concentration increases in fly ash, as they practically do not burn.

However, the radioactivity of ash is also very low, it is approximately equal to the radioactivity of black shale and less than that of phosphate rocks, but it represents a known danger, since some fly ash remains in the atmosphere and is inhaled by humans. At the same time, the total volume of emissions is quite large and amounts to the equivalent of 1,000 tons of uranium in Russia and 40,000 tons worldwide.

Classification

Conditionally radioactive waste is divided into:

• low-level (divided into four classes: A, B, C and GTCC (the most dangerous);
• medium active (US legislation does not classify this type of radioactive waste as a separate class, the term is mainly used in European countries);
• highly active.

The US legislation also allocates transuranic radioactive waste. This class includes wastes contaminated with alpha-emitting transuranium radionuclides with half-lives of more than 20 years and concentrations of more than 100 nCi/g, regardless of their form or origin, excluding high-level radioactive waste. Due to the long period of decay of transuranic wastes, their disposal is more thorough than the disposal of low-level and intermediate-level wastes. Also, special attention is paid to this class of waste because all transuranium elements are artificial and the behavior in the environment and in the human body of some of them is unique.

Below is the classification of liquid and solid radioactive waste in accordance with the "Basic Sanitary Rules for Ensuring Radiation Safety" (OSPORB 99/2010).

One of the criteria for such a classification is heat dissipation. In low-level radioactive waste, the heat release is extremely low. In medium-active ones, it is significant, but active heat removal is not required. High-level radioactive waste releases heat so much that they require active cooling.

Radioactive waste management

Initially, it was considered that a sufficient measure was the dispersion of radioactive isotopes in the environment, by analogy with production waste in other industries. At the Mayak plant, in the first years of operation, all radioactive waste was dumped into nearby water bodies. As a result, the Techa cascade of reservoirs and the Techa River itself were polluted.

Later it turned out that due to natural and biological processes, radioactive isotopes are concentrated in various subsystems of the biosphere (mainly in animals, in their organs and tissues), which increases the risks of public exposure (due to the movement of large concentrations of radioactive elements and their possible entry with food in the human body). Therefore, the attitude towards radioactive waste was changed.

1) Protection of human health. Radioactive waste is managed in such a way as to provide an acceptable level of protection of human health.

2) Environmental protection. Radioactive waste is managed in such a way as to ensure an acceptable level of environmental protection.

3) Protection beyond national borders. The management of radioactive waste is carried out in such a way as to take into account possible consequences for human health and the environment beyond national borders.

4) Protection of future generations. Radioactive waste is managed in such a way that the predicted health consequences for future generations do not exceed appropriate levels of consequences that are acceptable today.

5) Burden for future generations. Radioactive waste is managed in such a way as not to impose an undue burden on future generations.

6) National legal structure. Radioactive waste management is carried out within the framework of an appropriate national legal framework that provides for a clear division of responsibilities and the provision of independent regulatory functions.

7) Control over the generation of radioactive waste. The generation of radioactive waste is kept to the minimum practicable level.

8) Interdependence of radioactive waste generation and management. Due account shall be taken of the interdependencies between all stages of radioactive waste generation and management.

9) Installation safety. The safety of radioactive waste management facilities is adequately ensured throughout their lifetime.

Main stages of radioactive waste management

• At storage radioactive waste should be contained in such a way that:
  • ensured their isolation, protection and monitoring of the environment;
  • if possible, actions at subsequent stages (if they are provided) were facilitated.

In some cases, storage may be primarily for technical reasons, such as storing radioactive waste containing primarily short-lived radionuclides for decay and subsequent disposal within authorized limits, or storing high-level radioactive waste prior to disposal in geological formations for the purpose of reduction of heat generation.

• Preliminary processing waste is the initial stage of waste management. This includes collection, chemistry control and decontamination and may include an interim storage period. This step is very important because in many cases the pre-treatment provides the best opportunity to separate the waste streams.

• Treatment management of radioactive waste includes operations whose purpose is to improve safety or economy by changing the characteristics of radioactive waste. Basic processing concepts: volume reduction, removal of radionuclides and composition change. Examples:
  • incineration of combustible waste or compaction of dry solid waste;
  • evaporation, filtration or ion exchange of liquid waste streams;
  • precipitation or flocculation of chemicals.

Capsule for radioactive waste

• Conditioning radioactive waste management consists of those operations in which radioactive waste is formed into a form suitable for movement, transportation, storage and disposal. These operations may include the immobilization of radioactive waste, the placement of waste in containers, and the provision of additional packaging. Common methods of immobilization include solidification of liquid radioactive waste of low and intermediate levels by incorporating it into cement (cementing) or bitumen (bituminization), as well as vitrification of liquid radioactive waste. Immobilized waste, in turn, depending on the nature and concentration, can be packed in various containers, ranging from conventional 200-liter steel drums to containers with a complex design with thick walls. In many cases, processing and conditioning are carried out in close connection with each other.

• burial mainly that radioactive waste is placed in a disposal facility with appropriate security, without the intention of removing it and without providing long-term storage monitoring and maintenance. Safety is mainly achieved through concentration and containment, which involves sequestering suitably concentrated radioactive waste in a disposal facility.

Technology

Intermediate radioactive waste management

Usually in the nuclear industry, intermediate-level radioactive waste is subjected to ion exchange or other methods, the purpose of which is to concentrate radioactivity in a small volume. After processing, a much less radioactive body is completely neutralized. It is possible to use iron hydroxide as a flocculant to remove radioactive metals from aqueous solutions. After absorption of the radioisotopes by iron hydroxide, the resulting precipitate is placed in a metal drum where it is mixed with cement to form a solid mixture. For greater stability and durability, concrete is made from fly ash or furnace slag and Portland cement (as opposed to conventional concrete, which consists of Portland cement, gravel and sand).

Handling of high-level radioactive waste

Removal of low-level radioactive waste

Transportation of flasks with high-level radioactive waste by train, UK

Storage

For temporary storage of high-level radioactive waste, storage tanks for spent nuclear fuel and storage facilities with dry-packed barrels are designed to allow short-lived isotopes to decay before further processing.

Vitrification

Long-term storage of radioactive waste requires conservation of waste in a form that will not react and break down over a long period of time. One way to achieve this state is vitrification (or vitrification). Currently in Sellafield (Great Britain) highly active PAO (purified products of the first stage of the Purex process) are mixed with sugar and then calcined. Calcination involves the passage of waste through a heated rotating tube and aims to evaporate water and denitrogenate fission products to improve the stability of the resulting vitreous mass.

Crushed glass is constantly added to the resulting substance in the induction furnace. As a result, a new substance is obtained, in which, during hardening, the waste is associated with a glass matrix. This substance in a molten state is poured into alloy steel cylinders. Cooling, the liquid solidifies, turning into glass, which is extremely resistant to water. According to the international technological society, it will take about a million years for 10% of this glass to dissolve in water.

After filling, the cylinder is brewed, then washed. After being examined for external contamination, the steel cylinders are sent to underground storage facilities. This state of waste remains unchanged for many thousands of years.

The glass inside the cylinder has a smooth black surface. In the UK, all work is done using high activity chambers. Sugar is added to prevent the formation of the RuO 4 volatile substance containing radioactive ruthenium. In the West, borosilicate glass, identical in composition to pyrex, is added to the waste; in the countries of the former USSR, phosphate glass is usually used. The amount of fission products in glass must be limited, as some elements (palladium, platinum group metals, and tellurium) tend to form metallic phases separately from glass. One of the vitrification plants is located in Germany, where the waste from the activities of a small demonstration processing plant that has ceased to exist is processed.

In 1997, in 20 countries with most of the world nuclear capability, stocks of spent fuel in storage facilities inside the reactors amounted to 148 thousand tons, 59% of which were disposed of. There were 78 thousand tons of waste in external storage facilities, of which 44% was recycled. Taking into account the rate of disposal (about 12 thousand tons annually), the final elimination of waste is still quite far away.

geological burial

Searches for suitable deep final disposal sites are currently underway in several countries; it is expected that the first such storage facilities will become operational after 2010. The international research laboratory in Grimsel, Switzerland deals with issues related to radioactive waste disposal. Sweden is talking about its plans for direct disposal of spent fuel using KBS-3 technology, after the Swedish Parliament deemed it safe enough. Discussions are currently underway in Germany about finding a place for permanent storage of radioactive waste, residents of the village of Gorleben in the Wendland region are protesting vigorously. This place until 1990 seemed ideal for the disposal of radioactive waste due to its proximity to the borders of the former German Democratic Republic. Currently, RW is in temporary storage in Gorleben, the decision on the place of their final disposal has not yet been made. U.S. authorities chose Yucca Mountain, Nevada as the burial site, however this project met with strong opposition and became the subject of heated discussions. There is a project to create an international repository for high-level radioactive waste; Australia and Russia are proposed as possible disposal sites. However, the Australian authorities oppose such a proposal.

There are projects for disposal of radioactive waste in the oceans, among which are disposal under the abyssal zone of the seabed, disposal in the subduction zone, as a result of which the waste will slowly sink to the earth's mantle, and disposal under a natural or artificial island. These projects have obvious advantages and will allow solving international level unpleasant problem of radioactive waste disposal, but despite this, they are currently frozen due to the prohibition of maritime law. Another reason is that in Europe and North America they are seriously afraid of leakage from such a storage, which will lead to an environmental disaster. The real possibility of such a danger has not been proven; however, the bans were tightened after the dumping of radioactive waste from ships. However, in the future, countries that cannot find other solutions to this problem are seriously able to think about the creation of oceanic storage facilities for radioactive waste.

In the 1990s, several options for conveyor disposal of radioactive waste into the bowels were developed and patented. The technology was assumed to be as follows: a large-diameter starting well up to 1 km deep is drilled, a capsule loaded with radioactive waste concentrate weighing up to 10 tons is lowered inside, the capsule must self-heat and melt the earth rock in the form of a “fireball”. After the first “fireball” is deepened, the second capsule should be lowered into the same well, then the third, etc., creating a kind of conveyor.

Reuse of radioactive waste

Another application for isotopes contained in radioactive waste is their reuse. Already, cesium-137, strontium-90, technetium-99 and some other isotopes are used to irradiate food products and ensure the operation of radioisotope thermoelectric generators.

Removal of radioactive waste into space

Sending radioactive waste into space is a tempting idea, since radioactive waste is permanently removed from the environment. However, such projects have significant drawbacks, one of the most important is the possibility of a launch vehicle failure. In addition, the significant number of launches and their high cost make this proposal impractical. The matter is also complicated by the fact that international agreements on this problem have not yet been reached.

Nuclear fuel cycle

Cycle start

Waste initial period from the nuclear fuel cycle - usually resulting from the extraction of uranium, waste rock that emits alpha particles. It usually contains radium and its decay products.

The main by-product of enrichment is depleted uranium, consisting mainly of uranium-238 with less than 0.3% uranium-235. It is stored as UF 6 (waste uranium hexafluoride) and can also be converted to U 3 O 8 . In small quantities, depleted uranium finds use in applications where its extremely high density is valued, such as in the manufacture of keels of yachts and anti-tank shells. Meanwhile, several million tons of waste uranium hexafluoride have accumulated in Russia and abroad, and there are no plans for its further use in the foreseeable future. Waste uranium hexafluoride can be used (along with recycled plutonium) to create mixed oxide nuclear fuel (which may be in demand if the country builds significant quantities of fast neutron reactors) and to dilute highly enriched uranium, which was previously part of nuclear weapons. This dilution, also called depletion, means that any country or group that gets its hands on nuclear fuel will have to repeat a very expensive and complex enrichment process before it can create a weapon.

End of cycle

Substances in which the nuclear fuel cycle has come to an end (mostly spent fuel rods) contain fission products that emit beta and gamma rays. They may also contain actinides that emit alpha particles, which include uranium-234 (234 U), neptunium-237 (237 Np), plutonium-238 (238 Pu) and americium-241 (241 Am), and sometimes even sources neutrons such as californium-252 (252 Cf). These isotopes are produced in nuclear reactors.

It is important to distinguish between the processing of uranium to produce fuel and the processing of used uranium. The used fuel contains highly radioactive fission products. Many of them are neutron absorbers, thus getting the name "neutron poisons". Ultimately, their numbers increase to such an extent that, by trapping neutrons, they stop the chain reaction even when the neutron absorber rods are completely removed.

The fuel that has reached this state must be replaced with fresh, despite the still sufficient amount of uranium-235 and plutonium. Currently, in the US, used fuel is sent to storage. In other countries (in particular, in Russia, Great Britain, France and Japan), this fuel is reprocessed to remove fission products, then, after re-enrichment, it can be reused. In Russia, such fuel is called regenerated. The reprocessing process involves working with highly radioactive substances, and the fission products removed from the fuel are a concentrated form of highly radioactive waste, just like the chemicals used in reprocessing.

To close the nuclear fuel cycle, it is supposed to use fast neutron reactors, which allows processing fuel, which is a waste product of thermal neutron reactors.

On the issue of nuclear proliferation

When working with uranium and plutonium, the possibility of their use in the creation of nuclear weapons is often considered. Active nuclear reactors and stockpiles of nuclear weapons are carefully guarded. However, highly radioactive waste from nuclear reactors may contain plutonium. It is identical to the plutonium used in reactors and consists of 239 Pu (ideal for building nuclear weapons) and 240 Pu (unwanted component, highly radioactive); these two isotopes are very difficult to separate. Moreover, highly radioactive waste from reactors is full of highly radioactive fission products; however, their most of are short-lived isotopes. This means that waste disposal is possible, and after many years the fission products will decay, reducing the radioactivity of the waste and facilitating work with plutonium. Moreover, the unwanted isotope 240 Pu decays faster than 239 Pu, so the quality of weapons raw materials increases over time (despite the decrease in quantity). This causes controversy that, over time, waste storage facilities can turn into a kind of "plutonium mines", from which it will be relatively easy to extract raw materials for weapons. Against these assumptions is the fact that the half-life of 240 Pu is 6560 years, and the half-life of 239 Pu is 24110 years; Pu in a multi-isotope material will halve on its own - a typical conversion of reactor-grade plutonium to weapons-grade plutonium). Therefore, "weapon-grade plutonium mines" will become a problem, if at all, only in the very distant future.

One solution to this problem is to reuse reprocessed plutonium as fuel, such as in fast nuclear reactors. However, the very existence of nuclear fuel reprocessing plants, necessary to separate plutonium from other elements, creates an opportunity for the proliferation of nuclear weapons. In pyrometallurgical fast reactors, the resulting waste has an actinoid structure, which does not allow it to be used to create weapons.

Recycling of nuclear weapons

Waste from the processing of nuclear weapons (unlike their manufacture, which requires raw materials from reactor fuel), does not contain sources of beta and gamma rays, with the exception of tritium and americium. They contain much more actinides that emit alpha rays, such as plutonium-239, which undergoes a nuclear reaction in bombs, as well as some substances with high specific radioactivity, such as plutonium-238 or polonium.

In the past, beryllium and highly active alpha emitters such as polonium have been proposed as nuclear weapons in bombs. Now an alternative to polonium is plutonium-238. For reasons of national security, the detailed designs of modern bombs are not covered in the literature available to the general public.

Some models also contain (RTGs), which use plutonium-238 as a durable source of electrical power to operate the bomb's electronics.

It is possible that the fissile material of the old bomb to be replaced will contain decay products of plutonium isotopes. These include alpha emitting neptunium-236, formed from inclusions of plutonium-240, as well as some uranium-235, obtained from plutonium-239. The amount of this waste from the radioactive decay of the bomb core will be very small, and in any case they are much less dangerous (even in terms of radioactivity as such) than plutonium-239 itself.

As a result of the beta decay of plutonium-241, americium-241 is formed, an increase in the amount of americium is a bigger problem than the decay of plutonium-239 and plutonium-240, since americium is a gamma emitter (its external effect on workers increases) and an alpha emitter, capable of generating heat. Plutonium can be separated from americium in a variety of ways, including pyrometric treatment and extraction with an aqueous/organic solvent. A modified technology for the extraction of plutonium from irradiated uranium (PUREX) is also one of the possible separation methods.

In popular culture

In reality, the impact of radioactive waste is described by the impact of ionizing radiation on the substance and depends on their composition (which radioactive elements are included). Radioactive waste does not acquire any new properties, does not become more dangerous because they are waste. Their greater danger is due only to the fact that their composition is often very diverse (both qualitatively and quantitatively) and sometimes unknown, which complicates the assessment of the degree of their danger, in particular, the doses received as a result of an accident.

see also

Notes

Links

• Safety in handling radioactive waste. General provisions. NP-058-04
• Key Radionuclides and Generation Processes (unavailable link)
• Belgian Nuclear Research Center - Activities (unavailable link)
• Belgian Nuclear Research Center - Scientific Reports (unavailable link)
• International Atomic Energy Agency - Nuclear Fuel Cycle and Waste Technology Program (unavailable link)
• (unavailable link)
• Nuclear Regulatory Commission - Spent Fuel Heat Generation Calculation (unavailable link)

The existence of living organisms on earth (people, birds, animals, plants) largely depends on how the environment in which they live is protected from pollution. Every year, humanity accumulates a huge amount of garbage, and this leads to the fact that radioactive waste becomes a threat to the whole world, if not destroyed.

Now there are already many countries where the problem of environmental pollution, the sources of which are household, industrial waste pay special attention to:

• separate household waste, and then apply methods for its safe processing;
• build waste disposal plants;
• form specially equipped sites for the disposal of hazardous substances;
• create new technologies for the processing of secondary raw materials.

Countries such as Japan, Sweden, the Netherlands and some other states take the issues of radioactive waste disposal and disposal of household waste seriously.

The result of an irresponsible attitude is the formation of giant landfills, where waste products decompose, turning into mountains of toxic garbage.

When was the waste

With the advent of man, waste appeared on Earth. But if the ancient inhabitants did not know what light bulbs, glass, polyethylene and others modern achievements, now scientific laboratories are working on the problem of destroying chemical waste, where talented scientists are involved. It is still not completely clear what awaits the world in hundreds, thousands of years, if waste accumulates.

The first household inventions appeared with the development of glass production. At first, it was produced a little, and no one thought about the problem of waste generation. Industry, keeping pace with scientific achievements began to develop actively by the beginning of the 19th century. Factories that used machinery grew rapidly. Tons of processed coal were thrown into the atmosphere, which polluted the atmosphere due to the formation of acrid smoke. Now industrial giants “feed” rivers, seas and lakes with a huge amount of toxic emissions, natural sources involuntarily become places of their burial.

Classification

In Russia operates The federal law No. 190 of July 11, 2011, which reflects the main Regulations on the collection and management of radioactive waste. The main evaluation criteria by which radioactive waste is classified are:

• Disposable - radioactive waste that does not exceed the risks of radiation exposure and the costs of removal from storage with subsequent burial or handling.
• special - radioactive waste that exceeds the risks of radiation exposure and the costs of subsequent disposal or retrieval.

Radiation sources are dangerous due to their detrimental effect on the human body, and therefore the need to localize active mining is extremely important. Nuclear power plants produce almost no greenhouse gases, but they have another difficult problem. Tanks are filled with spent fuel, they remain radioactive for a long time, and its amount is constantly growing. Back in the 1950s, the first attempts at research were made to solve the problem of radioactive waste. There have been proposals to send them into space, to store them at the bottom of the ocean and other hard-to-reach places.

There are various plans for waste disposal, but decisions on the use of the territories are disputed by public organizations and environmentalists. State scientific laboratories have been working on the problem of destroying the most hazardous waste almost since the advent of nuclear physics.

If successful, this will reduce the generation of radioactive waste from nuclear power plants by up to 90 percent.

What happens in nuclear power plants is that the uranium oxide fuel rod is in a stainless steel cylinder. It is placed in a reactor, uranium decays, releases thermal energy, it drives a turbine and produces electricity. But after only 5 percent of the uranium has undergone radioactive decay, the entire rod becomes contaminated with other elements and must be disposed of.

It turns out the so-called spent radioactive fuel. It is no longer suitable for generating electricity and becomes a waste. The substance contains impurities of plutonium, americium, cerium and other by-products of nuclear decay - this is a dangerous radioactive "cocktail". American scientists are conducting experiments using special apparatus to artificially complete the cycle of nuclear decay.

Waste disposal

The facilities where radioactive waste is stored are not marked on maps, there are no identification marks on the roads, the perimeter is carefully guarded. At the same time, it is forbidden to show the security system to anyone. Dozens of such objects are scattered across the territory of Russia. Here they build storage facilities for radioactive waste. One of these associations processes nuclear fuel. Useful material separated from active waste. They are disposed of, valuable components are again sold.

The requirements of the foreign buyer are simple: he takes the fuel, uses it, and returns the radioactive waste back. They are taken to the plant by rail, robots are engaged in loading, and it is deadly dangerous for a person to approach these containers. Sealed, durable containers are installed in special wagons. A large wagon is turned over, containers with fuel are stacked with special machines, then it is returned to the rails and sent from the nuclear power plant to the point of the enterprise by special trains with alerted railway services, the Ministry of Internal Affairs.

In 2002, demonstrations of the "greens" took place, they protested against the importation of nuclear waste into the country. Russian nuclear scientists believe that they are being provoked by foreign competitors.

Specialized factories process waste of medium and low activity. Sources - everything that surrounds people in ordinary life: irradiated parts of medical devices, parts electronic engineering and other devices. They are shipped in containers. special machines, which deliver radioactive waste by ordinary roads, accompanied by the police. Outwardly, they differ from the standard garbage truck only in color. At the entrance there is a sanitary checkpoint. Here everyone has to change clothes, change shoes.

Only then can you access workplace where it is forbidden to eat, drink alcohol, smoke, use cosmetics and be without overalls.

For employees of such specific enterprises, this is a common job. There is only one difference: if a red light suddenly lights up on the control panel, you must immediately run away: radiation sources cannot be seen or felt. Control devices are installed in all rooms. When everything is in order, the green lamp is on. Work areas are divided into 3 classes.

1 class

Waste is processed here. In the furnace, radioactive waste is turned into glass. It is forbidden for people to enter such premises - it is deadly. All processes are automated. You can enter only in case of an accident in special protective equipment:

• insulating gas mask (special lead protection that absorbs radioactive radiation, shields to protect the eyes);
• special outfit;
• remote means: probes, grippers, special manipulators;

By working in such enterprises and following impeccable precautions, people are not exposed to the danger of exposure to radiation.

Grade 2

From here, the operator controls the furnaces, on the monitor he sees everything that happens in them. The second class also includes rooms where they work with containers. They contain waste of different activity. There are three basic rules here: “stay farther”, “work faster”, “do not forget about protection”!

You can't pick up a waste container with bare hands. There is a risk of serious exposure. Respirators and work gloves are worn only once, when they are removed, they also become radioactive waste. They are burned, the ashes are decontaminated. Each worker always wears an individual dosimeter, which shows how much radiation is collected during the work shift and the total dose, if it exceeds the norm, then the person is transferred to safe work.

3rd grade

It includes corridors and ventilation shafts. There is a powerful air conditioning system. Every 5 minutes the air is completely replaced. A radioactive waste processing plant is cleaner than a good housewife's kitchen. After each transportation, the cars are watered with a special solution. A few people work in rubber boots with a hose in their hands, but the processes are being automated to make them less labor intensive.

2 times a day, the workshop area is washed with water and ordinary washing powder, the floor is covered with plastic compound, the corners are rounded, the seams are well sealed, there are no baseboards and hard-to-reach places that cannot be washed well. After cleaning, the water becomes radioactive, it flows into special holes, and is collected through pipes into a huge container underground. Liquid waste is carefully filtered. The water is purified so that it can be drunk.

Radioactive waste is hidden "under seven locks." The depth of the bunkers is usually 7-8 meters, the walls are reinforced concrete, while the storage is being filled, a metal hangar is installed above it. Containers are used to store very hazardous waste. a high degree protection. Inside such a container is lead, it has only 12 small holes the size of a gun cartridge. Less hazardous waste is placed in huge reinforced concrete containers. All this is lowered into the mines and closed with a hatch.

These containers can later be removed and sent for further processing in order to finally dispose of radioactive waste.

The filled vaults are covered with a special kind of clay, in the event of an earthquake, it will glue the cracks together. The storage facility is covered with reinforced concrete slabs, cemented, asphalted and covered with earth. After that, radioactive waste does not pose a danger. Some of them decay into harmless elements only after 100–200 years. On the secret maps, where the vaults are indicated, there is a signature stamp "keep forever"!

The landfills where radioactive waste is buried are located at a considerable distance from cities, towns and water bodies. Nuclear energy, military programs - problems that concern everyone global community. They consist not only in protecting a person from the influence of radioactive waste generation sources, but also carefully protecting them from terrorists. It is possible that the landfills where radioactive waste is stored can become targets for military conflicts.