"More productive and safer": Academician of the Russian Academy of Sciences - on work on the creation of a closed nuclear cycle

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- This is a question of the operation of nuclear reactors and methods of handling nuclear waste.

There are two approaches in nuclear power today.

The first is the open nuclear cycle.

This means that the fuel that is placed in the reactor is irradiated and then, at the end of the cycle, stored in special holding pools under water or in a dry form in order to protect the environment from the radioactivity of spent fuel.

I note that the fuel in this case is not recycled, as this is a very complex process.

The second approach is to work in a closed nuclear cycle, which is used by most countries.

In this case, 90% of uranium is processed into energy, and after irradiation and the end of the cycle, the spent fuel is unloaded from the reactor and processed.

• Reactor hall of the fourth power unit of the Beloyarsk nuclear power plant named after I.V.

  Kurchatov in the Sverdlovsk region

• RIA News

• © Pavel Lisitsyn

Obviously, a closed nuclear cycle is economically beneficial, since irradiated uranium can be reused to generate energy.

Scientists are now investigating how many times uranium can be recycled.

At the moment, it has been theoretically shown that natural uranium can be reused (recycled) up to five times.

However, this requires additional costs and an even greater degree of protection against radioactivity.

But the problem with the shortage of uranium raw materials is being solved.

This is a very complex process, so scientists from all over the world are working on research in this area, including the state corporation Rosatom and the Russian Academy of Sciences.

In Russia, such fuel is used at least three times.

In the future, it is possible that uranium will be recycled up to ten times.

However, such technologies have yet to be created: they must meet the requirements of radiation safety and solve the problem of radioactive waste.

Specialists in different countries are working on closing the nuclear cycle: in France, England, Japan and, of course, Russia.

In this case, this problem extends to two types of reactors - thermal and fast.

Worldwide interest in fast reactors has been constantly growing since they appeared in the 1950s, because they are able to provide efficient, safe and sustainable energy production.

Fast reactors, in which the fission of fuel components occurs under the action of fast spectrum neutrons (free neutrons whose kinetic energy is greater than a certain value. -

), expand the fuel base and significantly increase the energy yield of natural uranium compared to thermal neutron reactors.

This level of fuel use extends the lifespan of nuclear power programs by thousands of years and provides significant improvements in nuclear waste management.

Not only the design of the reactors differs, but also the fuel.

It has different purposes.

In particular, MOX fuel appeared during the work of scientists with plutonium.

When the element - uranium-235 - is irradiated, plutonium-239 is formed, which is used in the development of atomic bombs, therefore international agreements are in force in the world to limit the accumulation of plutonium.

This element is very expensive, but also very productive in releasing heat, so it would be simply a sin not to use it in nuclear energy.

• Boris Fyodorovich Myasoedov

• © Press service of GEOKHI

MOX fuel is a mixture containing mainly uranium and a certain amount of plutonium, usually 20-30%, the addition of which depends on the purpose, tasks and properties of the reactor.

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— When we talked about open and closed nuclear fuel cycles, we mentioned that a closed one is a method of spent fuel reprocessing that has been fully completed both in scientific and practical implementation.

Complete fuel recycling solves the problem of waste storage.

Recycling, or the so-called Purex process, consists of many steps.

As a result of processing, plutonium should be separated by 99.99% from the main mass of uranium.

However, when fuel is irradiated in a reactor, not only plutonium is formed, but fission also occurs when new elements are formed.

They are radioactive, and contact with them is dangerous for the environment, in particular for humans.

The problem with radioactive waste today is solved by including it in special preservative matrices.

• Dry Spent Nuclear Fuel Storage (DSSF) at the Zaporozhye NPP in Energodar

• RIA News

In this form, dangerous radioactive isotopes are placed in special ground or underground storage facilities, which are constructed from concrete or other material.

Many of these wastes can remain radioactive for hundreds or even thousands of years.

For example, americium is one of them.

And they need to be stored in conditions where they do not affect the environment.

For example, in Russia, a new magnesium-potassium-phosphate matrix has been proposed for the reliable storage of radioactive waste, which has all the necessary properties.

When waste is included in such a matrix, radionuclides and other components form mineral-like compounds, resembling in properties those formed in the earth.

Metals enclosed in minerals are stored for a very long time.

The domestic matrix has already been tested on real radioactive solutions, which are formed at our radiochemical plants.

There are other options for getting rid of nuclear waste.

In particular, technologies are being developed that make it possible to isolate and fractionate the elements contained in the waste.

A significant part of them refers to platinum elements; in the USA and Russia, palladium is obtained from such waste.

Also, in order not to store the same americium underground for thousands of years, it is transmuted (turned) into shorter-lived and harmless isotopes. 

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The results speak for themselves.

Our country has a very good reputation in the international arena in terms of building new nuclear power plants.

Currently, NPP construction projects are being implemented in China and Turkey.

Earlier, we talked about the domestic technology for separating americium and separating it from other substances.

So, we were the first to come up with such technology.

I consider this an important achievement.

The goal of Russian scientists is to create an innovative Purex process that is more productive and safe in nuclear and economic terms, as well as to reduce the costs, volumes and composition of the resulting radioactive waste.

Now there is also a shortage of uranium raw materials, so Russian scientists are developing a way to extract uranium from sea water.

It is known that billions of tons of uranium are dissolved in the oceans, which is higher than its confirmed reserves on land.

At the same time, the extraction of uranium from sea water can be a safe and sustainable source of it.

• Weakly radioactive nuclide of the chemical element uranium - uranium-238

• Legion Media

• © Phil Degginger

Our Institute is directly involved in solving the above tasks to create new technologies, in the discovery and development of new mineral deposits, including the development of new technologies for the manufacture of nuclear fuel, for example, using microwave radiation (microwave radiation. -

) , as well as for the management of spent fuel, irradiated metal materials and the resulting radioactive waste, for example, using the new mineral-like matrix that I mentioned earlier.

— Knowledge of radiochemistry plays almost the main role in nuclear power engineering.

What is this science and what other areas does it cover?

- The year of birth of radiochemistry is considered to be 1898, when the future Nobel laureates Henri Becquerel and Marie Curie announced the discovery of a new phenomenon, speaking at a meeting of the French Chemical Society.

It was about the radioactive decay of atoms, naturally occurring elements, as well as the possibility of making elements radioactive under certain conditions.

Researchers not only discovered the very phenomenon of radioactive decay, but also isolated the first radioactive element - radium.

This is how radiochemistry was born.

This discovery then excited the whole world.

Before the Second World War, scientists all over the world, including in our country, studied radiation - it turned out that a person, without knowing it, always dealt with radioactivity.

The fact is that cosmic radiation also partially consists of radioactive or excited atoms.

Over time, scientists were able to determine that even non-radioactive material can become radioactive when irradiated with particles that are born during decay or in artificial particle accelerators.

After the 1940s, nuclear reactors became widespread, including in the USSR.

The first nuclear power plant was launched in Russia in 1954 in Obninsk.

Even now, pure enriched uranium or a mixture of uranium and plutonium is used as fuel for such stations.

• Reactor hall of the Obninsk nuclear power plant.

  Reactor AM-1

• RIA News

• © Pavel Bykov

The discovery of radioactive decay made it possible to largely solve the problem of providing mankind with energy.

Nuclear power, fueled by uranium and plutonium, produces an average of 15% of the world's energy.

I'm sure it is

will be

one of the most reliable sources of electricity in the future.

Thanks to the discovery of radioactivity, a new medical direction has also appeared - nuclear medicine.

Radiopharmaceuticals allow targeted delivery of radionuclides to the site of a malignant neoplasm.

This method of cancer treatment is now widely used throughout the world.

Neutron sources (devices that emit neutrons. -

) are used, for example, when searching for oil deposits.

This is a geophysical research method based on the interaction of neutrons with rock matter.

A device containing a neutron source and a detector that registers secondary radiation is lowered into the well.

The latter arises as a result of the interaction of neutrons with the atomic nuclei of the rock.

After irradiation of the rock with neutrons, radioactivity arises in it, the measurement of which provides information about the composition of the rock.

In this way, oil or gas deposits can be found.

Radiochemistry is located at the intersection of several sciences at once: chemistry, physics, mathematics, biology.

If we talk about its role in the development of science in general, then it is also colossal.

• Dmitri Ivanovich Mendeleev

• Gettyimages.ru

• © Sovfoto / Universal Images Group

Initially, Mendeleev's periodic table contained 92 elements, the last of which was uranium.

After the creation of the atomic bomb in the United States in 1945, nuclear reactors began to be used to obtain new transuranium elements that do not exist in nature, but can be obtained artificially.

Such work was carried out not only by American, but also by Soviet scientists.

From 1945 to the 1950s, 18 elements were synthesized in the USSR, five of them for the first time.

Their properties were first studied in Moscow at the Institute of Atomic Energy (NRC Kurchatov Institute), and more recently in Dubna at the Joint Institute for Nuclear Research.

To date, 119 such elements have been discovered in the world.