Nuclear fuel: types and processing. How is spent nuclear fuel stored, and, most importantly, why? Removal of RBMK spent fuel from nuclear power plant sites

Initially, spent fuel was reprocessed solely for the purpose of extracting plutonium for the production of nuclear weapons. Currently, the production of weapons-grade plutonium has practically ceased. Subsequently, the need arose to reprocess fuel from power reactors. One of the goals of reprocessing fuel from power reactors is reuse as a power reactor fuel, including as part of MOX fuel or for the implementation of a closed fuel cycle (CFC). By 2025, it is planned to create a large-scale radiochemical reprocessing plant, which will provide an opportunity to solve the problem of both accumulated fuel and spent fuel unloaded from existing and planned nuclear power plants. At the Zheleznogorsk Gas Chemical Complex it is planned to reprocess both in the experimental demonstration center (ODC) and in large-scale production of spent fuel from pressurized water power reactors VVER-1000 and most waste from channel type reactors RBMK-1000. Regeneration products will be used in the nuclear fuel cycle, uranium - in the production of fuel for thermal neutron reactors, plutonium (together with neptunium) - for fast neutron reactors, which have neutronic properties that provide the possibility of effective closure of the nuclear fuel cycle. At the same time, the rate of reprocessing of RBMK spent fuel will depend on the demand for regeneration products (both uranium and plutonium) in the nuclear fuel cycle. Similar approaches formed the basis of the “Program for the creation of infrastructure and management of spent nuclear fuel for 2011-2020 and for the period until 2030,” approved in November 2011.

In Russia, the Mayak Production Association, founded in 1948, is considered the first enterprise capable of reprocessing spent nuclear fuel. Other large radiochemical plants in Russia are the Siberian Chemical Combine and the Zheleznogorsk Mining and Chemical Combine. Large radiochemical production facilities operate in England (Sellafield plant), in France (Cogema plant (English) Russian) ; production is planned in Japan (Rokkasho, 2010s), China (Lanzhou, 2020), Krasnoyarsk-26 (RT-2, 2020s). The United States has abandoned mass reprocessing of fuel unloaded from reactors and is storing it in special storage facilities.

Technologies

Nuclear fuel is most often a sealed container made of zirconium alloy or steel, often referred to as a fuel element (fuel element). The uranium in them is in the form of small pellets of oxide or (much less commonly) other heat-resistant uranium compounds, such as uranium nitride. The decay of uranium produces many unstable isotopes of other chemical elements, including gaseous ones. Safety requirements regulate the tightness of the fuel rod throughout its service life, and all these decomposition products remain inside the fuel rod. In addition to the decay products, significant amounts of uranium-238, small amounts of unburned uranium-235, and plutonium produced in the reactor remain.

The goal of reprocessing is to minimize the radiation hazard of spent nuclear fuel, safely dispose of unused components, and isolate useful material and ensure their continued use. For this purpose they are most often used chemical methods separation Most simple methods are reprocessing in solutions, but these methods produce the largest amount of liquid radioactive waste, so such methods were popular only at the dawn of the nuclear era. Currently, methods are being sought to minimize the amount of waste, preferably solid waste. They are easier to dispose of by vitrification.

At the heart of all modern technological schemes The reprocessing of spent nuclear fuel (SNF) involves extraction processes, most often the so-called Purex process (from the English Pu U Recovery EXtraction), which consists of the reductive re-extraction of plutonium from a joint extract with uranium and fission products. Specific processing schemes differ in the set of reagents used, the sequence of individual technological stages, and the hardware design.

Plutonium isolated during reprocessing can be used as fuel when mixed with uranium oxide. For fuel, after a sufficiently long campaign, almost two-thirds of the plutonium is in the isotopes Pu-239 and Pu-241 and about a third in Pu-240, due to which it cannot be used to make reliable and predictable nuclear charges(240 isotope is a pollutant).

Notes

1. Safe Danger (Russian). Around the world. vokrugsveta.ru (2003, July). Retrieved December 4, 2013.
2. A.V. Balikhin. On the state and prospects for the development of methods for reprocessing spent nuclear fuel. (Russian) // Integrated use of mineral raw materials. - 2018. - No. 1. - pp. 71-87. - ISSN 2224-5243.
3. infographic (flash) from Guardian
4. Reprocessing plants, world-wide // European Nuclear Society
5. Processing of Used Nuclear Fuel // World Nuclear Association, 2013: “World commercial reprocessing capacity”
6. Status and trends in spent fuel reprocessing // IAEA -TECDOC-1467, September 2005 page 52 Table I Past, current and planned reprocessing capacities in the world
7. The USA wants to reprocess spent nuclear fuel, “Expert” No. 11 (505) (March 20, 2006). Retrieved December 4, 2013. “.. unlike France, Russia and Germany, .. the USA .. preferred to bury it near its gaming center in Las Vegas in Nevada, where more than 10 thousand tons of irradiated fuel have accumulated to date "
8. Plutonium "burning" in LWRs(English) (unavailable link). - “Current reprocessed plutonium (fuel burn-up 35-40 MWd/kg HM) has a fissile content of some 65%, the rest is mainly Pu-240.” Retrieved December 5, 2013. Archived January 13, 2012.
9. PERFORMANCE OF MOX FUEL FROM NONPROLIFERATION PROGRAMS. - 2011 Water Reactor Fuel Performance Meeting Chengdu, China, Sept. 11-14, 2011.

Nuclear fuel is a material used in nuclear reactors to carry out a controlled chain reaction. It is extremely energy-intensive and unsafe for humans, which imposes a number of restrictions on its use. Today we will find out what fuel is nuclear reactor, how it is classified and produced, where it is used.

Progress of the chain reaction

During a nuclear chain reaction, the nucleus is divided into two parts, which are called fission fragments. At the same time, several (2-3) neutrons are released, which subsequently cause the fission of subsequent nuclei. The process occurs when a neutron hits the nucleus of the original substance. Fission fragments have high kinetic energy. Their inhibition in matter is accompanied by the release of a huge amount of heat.

Fission fragments, together with their decay products, are called fission products. Nuclei that share neutrons of any energy are called nuclear fuel. As a rule, they are substances with an odd number of atoms. Some nuclei are fissioned purely by neutrons whose energy is above a certain threshold value. These are predominantly elements with an even number of atoms. Such nuclei are called raw material, since at the moment of capture of a neutron by a threshold nucleus, fuel nuclei are formed. The combination of combustible material and raw material is called nuclear fuel.

Classification

Nuclear fuel is divided into two classes:

1. Natural uranium. It contains fissile uranium-235 nuclei and uranium-238 feedstock, which is capable of forming plutonium-239 upon neutron capture.
2. A secondary fuel not found in nature. This includes, among other things, plutonium-239, which is obtained from fuel of the first type, as well as uranium-233, which is formed when neutrons are captured by thorium-232 nuclei.

From the point of view of chemical composition, there are the following types of nuclear fuel:

1. Metal (including alloys);
2. Oxide (for example, UO 2);
3. Carbide (for example PuC 1-x);
4. Mixed;
5. Nitride.

TVEL and TVS

Fuel for nuclear reactors is used in the form of small pellets. They are placed in hermetically sealed fuel elements (fuel elements), which, in turn, are combined into several hundred fuel assemblies (FA). Nuclear fuel is subject to high requirements for compatibility with fuel rod claddings. It must have a sufficient melting and evaporation temperature, good thermal conductivity, and not greatly increase in volume under neutron irradiation. The manufacturability of production is also taken into account.

Application

Fuel comes to nuclear power plants and other nuclear installations in the form of fuel assemblies. They can be loaded into the reactor both during its operation (in place of burnt-out fuel assemblies) and during a repair campaign. In the latter case, fuel assemblies are replaced in large groups. In this case, only a third of the fuel is completely replaced. The most burned-out assemblies are unloaded from the central part of the reactor, and in their place are placed partially burned-out assemblies that were previously located in less active areas. Consequently, new fuel assemblies are installed in place of the latter. This simple rearrangement scheme is considered traditional and has a number of advantages, the main one of which is ensuring uniform energy release. Of course, this is a conditional scheme that only gives general ideas about the process.

Excerpt

After spent nuclear fuel is removed from the reactor core, it is sent to a cooling pool, which is usually located nearby. The fact is that spent fuel assemblies contain a huge amount of uranium fission fragments. After unloading from the reactor, each fuel rod contains about 300 thousand Curies of radioactive substances, releasing 100 kW/hour of energy. Due to this, the fuel self-heats and becomes highly radioactive.

The temperature of newly unloaded fuel can reach 300°C. Therefore, it is kept for 3-4 years under a layer of water, the temperature of which is maintained in the established range. As it is stored under water, the radioactivity of the fuel and the power of its residual emissions decreases. After about three years, self-heating of the fuel assembly reaches 50-60°C. Then the fuel is removed from the pools and sent for processing or disposal.

Uranium metal

Uranium metal is used relatively rarely as fuel for nuclear reactors. When a substance reaches a temperature of 660°C, a phase transition occurs, accompanied by a change in its structure. Simply put, uranium increases in volume, which can lead to the destruction of fuel rods. In the case of prolonged irradiation at a temperature of 200-500°C, the substance undergoes radiation growth. The essence of this phenomenon is the elongation of the irradiated uranium rod by 2-3 times.

The use of uranium metal at temperatures above 500°C is difficult due to its swelling. After nuclear fission, two fragments are formed, the total volume of which exceeds the volume of that very nucleus. Some fission fragments are represented by gas atoms (xenon, krypton, etc.). Gas accumulates in the pores of the uranium and forms internal pressure, which increases as the temperature increases. Due to an increase in the volume of atoms and an increase in gas pressure, nuclear fuel begins to swell. Thus, this refers to the relative change in volume associated with nuclear fission.

The strength of swelling depends on the temperature of the fuel rods and burnout. With increasing burnup, the number of fission fragments increases, and with increasing temperature and burnup, the internal gas pressure increases. If the fuel has higher mechanical properties, then it is less susceptible to swelling. Uranium metal is not one of these materials. Therefore, its use as fuel for nuclear reactors limits the burnup, which is one of the main characteristics of such fuel.

The mechanical properties of uranium and its radiation resistance are improved by alloying the material. This process involves adding aluminum, molybdenum and other metals to it. Thanks to doping additives, the number of fission neutrons required per capture is reduced. Therefore, materials that weakly absorb neutrons are used for these purposes.

Refractory compounds

Some refractory uranium compounds are considered good nuclear fuel: carbides, oxides and intermetallic compounds. The most common of these is uranium dioxide (ceramics). Its melting point is 2800°C, and its density is 10.2 g/cm 3 .

Since this material does not undergo phase transitions, it is less susceptible to swelling than uranium alloys. Thanks to this feature, the burnout temperature can be increased by several percent. At high temperatures, ceramics do not interact with niobium, zirconium, stainless steel and other materials. Her main drawback lies in low thermal conductivity - 4.5 kJ (m*K), limiting power density reactor. In addition, hot ceramics are prone to cracking.

Plutonium

Plutonium is considered a low-melting metal. It melts at a temperature of 640°C. Due to its poor plastic properties, it is practically impossible to machine. The toxicity of the substance complicates the manufacturing technology of fuel rods. The nuclear industry has repeatedly attempted to use plutonium and its compounds, but they have not been successful. It is not advisable to use fuel for nuclear power plants containing plutonium due to an approximately 2-fold reduction in the acceleration period, which standard reactor control systems are not designed for.

For the manufacture of nuclear fuel, as a rule, plutonium dioxide, alloys of plutonium with minerals, and a mixture of plutonium carbides and uranium carbides are used. Dispersion fuels, in which particles of uranium and plutonium compounds are placed in a metal matrix of molybdenum, aluminum, stainless steel and other metals, have high mechanical properties and thermal conductivity. The radiation resistance and thermal conductivity of the dispersion fuel depend on the matrix material. For example, at the first nuclear power plant, the dispersed fuel consisted of particles of a uranium alloy with 9% molybdenum, which were filled with molybdenum.

As for thorium fuel, it is not used today due to difficulties in the production and processing of fuel rods.

Production

Significant volumes of the main raw material for nuclear fuel - uranium - are concentrated in several countries: Russia, the USA, France, Canada and South Africa. Its deposits are usually located near gold and copper, so all these materials are mined at the same time.

The health of people working in mining is at great risk. The fact is that uranium is a toxic material, and the gases released during its mining can cause cancer. And this despite the fact that the ore contains no more than 1% of this substance.

Receipt

Production of nuclear fuel from uranium ore includes stages such as:

1. Hydrometallurgical processing. Includes leaching, crushing and extraction or sorption recovery. The result of hydrometallurgical processing is a purified suspension of oxyuranium oxide, sodium diuranate or ammonium diuranate.
2. Conversion of a substance from oxide to tetrafluoride or hexafluoride, used to enrich uranium-235.
3. Enrichment of a substance by centrifugation or gas thermal diffusion.
4. Conversion of enriched material into dioxide, from which fuel rod “pellets” are produced.

Regeneration

During operation of a nuclear reactor, fuel cannot be completely burned out, so free isotopes are reproduced. In this regard, spent fuel rods are subject to regeneration for the purpose of reuse.

Today, this problem is solved through the Purex process, consisting of the following stages:

1. Cutting fuel rods into two parts and dissolving them in nitric acid;
2. Cleaning the solution from fission products and shell parts;
3. Isolation of pure compounds of uranium and plutonium.

After this, the resulting plutonium dioxide is used for the production of new cores, and the uranium is used for enrichment or also for the production of cores. Reprocessing nuclear fuel is a complex and expensive process. Its cost has a significant impact on the economic feasibility of using nuclear power plants. The same can be said about the disposal of nuclear fuel waste that is not suitable for regeneration.

Nuclear energy consists of large quantity enterprises for various purposes. The raw materials for this industry are mined from uranium mines. It is then delivered to fuel production plants.

The fuel is then transported to nuclear power plants, where it enters the reactor core. When nuclear fuel reaches the end of its useful life, it is subject to disposal. It is worth noting that hazardous waste appear not only after fuel reprocessing, but also at any stage - from uranium mining to work in the reactor.

Nuclear fuel

There are two types of fuel. The first is uranium mined in mines, respectively, natural origin. It contains raw materials that are capable of forming plutonium. The second is fuel that is created artificially (secondary).

Nuclear fuel is also divided according to chemical composition: metal, oxide, carbide, nitride and mixed.

Uranium mining and fuel production

A large share of uranium production comes from just a few countries: Russia, France, Australia, the USA, Canada and South Africa.

Uranium is the main element for fuel in nuclear power plants. To get into the reactor, it goes through several stages of processing. Most often, uranium deposits are located next to gold and copper, so its extraction is carried out with the extraction of precious metals.

During mining, human health is at great risk, because uranium is a toxic material, and the gases that appear during its mining cause various forms cancer. Although the ore itself contains a very small amount of uranium - from 0.1 to 1 percent. The population living near uranium mines is also at great risk.

Enriched uranium is the main fuel for nuclear power plants, but after its use a huge amount of radioactive waste remains. Despite all its dangers, uranium enrichment is an integral process of creating nuclear fuel.

IN natural form Uranium practically cannot be used anywhere. In order to be used, it must be enriched. Gas centrifuges are used for enrichment.

Enriched uranium is used not only in nuclear energy, but also in weapons production.

Transportation

At any stage of the fuel cycle there is transportation. It is carried out by all available means: by land, sea, air. This is a big risk and a big danger not only for the environment, but also for humans.

During the transportation of nuclear fuel or its elements, many accidents occur, resulting in the release of radioactive elements. This is one of the many reasons why it is considered unsafe.

Decommissioning of reactors

None of the reactors have been dismantled. Even the infamous Chernobyl The whole point is that, according to experts, the cost of dismantling is equal to, or even exceeds, the cost of building a new reactor. But no one can say exactly how much money will be needed: the cost was calculated based on the experience of dismantling small stations for research. Experts offer two options:

1. Place reactors and spent nuclear fuel in repositories.
2. Build sarcophagi over decommissioned reactors.

In the next ten years, about 350 reactors around the world will reach their end of life and must be taken out of service. But since the most suitable method in terms of safety and price has not been invented, this issue is still being resolved.

There are currently 436 reactors operating around the world. Of course, this is a big contribution to the energy system, but it is very unsafe. Research shows that in 15-20 years, nuclear power plants will be able to be replaced by stations that run on wind energy and solar panels.

Nuclear waste

A huge amount of nuclear waste is generated as a result of the activities of nuclear power plants. Reprocessing nuclear fuel also leaves behind hazardous waste. However, none of the countries found a solution to the problem.

Today, nuclear waste is kept in temporary storage facilities, in pools of water, or buried shallowly underground.

The safest method is storage in special storage facilities, but radiation leakage is also possible here, as with other methods.

In fact, nuclear waste has some value, but requires strict compliance with the rules for its storage. And this is the most pressing problem.

An important factor is the time during which the waste is hazardous. Each has its own decay period during which it is toxic.

Types of nuclear waste

When using any nuclear power plant its waste ends up in the environment. This is water for cooling turbines and gaseous waste.

Nuclear waste is divided into three categories:

1. Low level - clothing for nuclear power plant employees, laboratory equipment. Such waste can also come from medical institutions and scientific laboratories. They do not pose a great danger, but require compliance with safety measures.
2. Intermediate level - metal containers in which fuel is transported. Their radiation level is quite high, and those who are close to them must be protected.
3. The high level is spent nuclear fuel and its reprocessing products. The level of radioactivity is rapidly decreasing. Waste high level very little, about 3 percent, but they contain 95 percent of all radioactivity.

LJ user uralochka writes on her blog: I have always wanted to visit Mayak.
It's no joke, this place is one of the most knowledge-intensive enterprises in Russia, here
the first one was launched in 1948 atomic reactor in the USSR, specialists from the Mayak PA were released
plutonium charge for the first Soviet nuclear bomb. Once upon a time it was called Ozersk
Chelyabinsk-65, Chelyabinsk-40, since 1995 it became Ozersk. Here in Trekhgorny,
once Zlatoust-36, a city that is also closed, Ozersk was always called
“Sorokovka” was treated with respect and awe.

Now you can read about a lot of this in official sources, and even more in unofficial ones,
and there was a time when even the approximate location and name of these cities were kept in the strictest
secret. I remember how my grandfather Yakovlev Evgeniy Mikhailovich and I went fishing, and
local questions - where are we from, my grandfather always answered that from Yuryuzan (a neighboring town to Trekhgorny),
and at the entrance to the city there were no signs except the constant “brick”. Grandfather had one of
best friends, his name was Mitroshin Yuri Ivanovich, for some reason I called him nothing else throughout my childhood
like “Vanalize”, I don’t know why. I remember once I asked my grandmother why,
Vanalise, so bald, doesn't have a single hair? Grandmother, then, explained to me in a whisper,
that Yuri Ivanovich served in the “Sorokovka” and eliminated the consequences of a big accident in 1957,
received a large dose of radiation, ruined his health, and his hair no longer grows...

...And now, many years later, I, as a photojournalist, am going to photograph that same RT-1 plant for
agency "Photo ITAR-TASS". Time changes everything.

Ozersk is a restricted city, entry requires passes, my profile was being checked for more than a month and
Everything is ready, you can go. I was met by the press service at the checkpoint, unlike
Ours have a normal computerized system here, enter from any checkpoint, exit like this
from anyone. After that, we drove to the administrative building of the press service, where I left
I was advised to leave my car and my mobile phone, because on the territory of the plant with
Mobile communication devices are prohibited. No sooner said than done, let's go to RT-1. At the factory
We spent a long time at the checkpoint, somehow they didn’t let us through right away with all my photographic equipment, but here it is
It happened. We were given a stern man with a black holster on his belt and white clothes. We met
with the administration, they formed a whole team of guides for us and we moved into the ranks. pass.
Unfortunately, the external territory of the plant and any security systems must be photographed
strictly prohibited, so my camera was in my backpack all this time. This is the frame of me
I filmed it at the very end, this is where the “dirty” territory begins. The division is
really conditional, but it is observed very strictly, this is what allows you not to take it away
radioactive dirt throughout the area.

San. There are separate entrances, women from one entrance, men from the other. Me my companions
They showed me the locker, they said take everything off (absolutely everything), put on rubber flip-flops, close it
locker and move to that window over there. So I did. I'm standing completely naked, in one hand
me the key, into another backpack with a camera, and the woman from the window, which for some reason is located
too low, for my position he asks what my shoe size is. For a long time
I didn’t have to be embarrassed, I was promptly given something like underpants, a light shirt,
overalls and shoes. Everything is white, clean and very pleasant to the touch. Got dressed, attached to
I put a dosimeter tablet in my chest pocket and felt more confident. You can move out.
The guys immediately instructed me not to put the backpack on the floor, not to touch anything unnecessary,
photograph only what is allowed. Yes, no problem - I say, it’s too early for me to have a backpack
throw it away, and I don’t need secrets problems either. This is the place to put on and take off
dirty shoes. The center is clean, the edges are dirty. Conditional threshold of the plant territory.

We traveled around the plant territory on a small bus. External area without special
decoration, blocks of workshops connected by galleries for the passage of personnel and the transfer of chemicals through pipes.
On one side there is a large gallery for collecting clean air from the neighboring forest. This
made so that people in the workshops breathe the outside clean air. RT-1 is only
one of the seven plants of the Mayak PA, its purpose is to receive and reprocess spent nuclear
fuel (SNF). This is the workshop where it all begins; containers with spent nuclear fuel arrive here.
On the right is a carriage with an open lid. Specialists unscrew the top screws with a special
equipment. After this, everyone is removed from this room, the large door is closed.
about half a meter thick (unfortunately, the regime demanded that photographs with it be deleted).
Further work is carried out using cranes that are controlled remotely via cameras. The taps are removed
covers and remove the assemblies with spent fuel.

The assemblies are transferred by cranes to these hatches. Pay attention to the crosses, they are drawn,
to make it easier to position the position of the tap. Under the hatches, the assemblies are immersed in
liquid - condensate (simply put into distilled water). After this assembly on
carts are moved to a nearby pool, which is a temporary warehouse.

I don’t know exactly what it’s called, but the essence is clear - a simple device so as not to
drag radioactive dust from one room to another.

On the left is the same door.

And this is the same adjacent room. Under the feet of the employees there is a swimming pool with a depth of 3.5 to 14
meters filled with condensate. ? You can also see two blocks from the Beloyarsk Nuclear Power Plant, their length is 14 meters.
They are called AMB - “Peaceful Large Atom”.

When you look between the metal plates, you see something like this. Under condensation
an assembly of fuel elements from a shipping reactor is visible.

But these assemblies just came from the nuclear power plant. When the lights were turned off, they glowed with a pale blue glow.
Very impressive. This is the Cherenkov glow; you can read about the essence of this physical phenomenon on Wikipedia.

General view of the workshop.

Go ahead. Transitions between departments along corridors with dim yellow light. Enough underfoot
specific coating, rolled up at all corners. People in white. In general, I immediately went to “Black Mass”
I remembered))). By the way, about the coating, it’s a very reasonable solution, on the one hand it’s more convenient to wash,
nothing will get stuck anywhere, and most importantly, in case of any leak or accident, the dirty floor can be
easy to dismantle.

As they explained to me, further operations with spent nuclear fuel are carried out in indoors in automatic mode.
The whole process was once controlled from these remote controls, but now everything happens from three terminals.
Each of them runs on its own autonomous server, all functions are duplicated. In case of refusal of all
terminals, the operator will be able to complete processes from the remote control.

Briefly about what is happening with spent nuclear fuel. The assemblies are disassembled, the filling is removed, sawn into
parts and placed in a solvent (nitric acid), after which the spent fuel is dissolved
undergoes a whole complex of chemical transformations, from which uranium, plutonium, and neptunium are extracted.
Insoluble parts that cannot be recycled are pressed and glazed. And stored on
the plant area is under constant surveillance. The output after all these processes is formed
ready-made assemblies are already “charged” with fresh fuel, which is produced here. Thus the Lighthouse
carries out a full cycle of working with nuclear fuel.

Department for work with plutonium.

Eight layers of 50 mm leaded glass protect the operator from active elements. Manipulator
connected exclusively by electrical connections, there are no “holes” connecting to the internal compartment.

We moved to the workshop that ships finished products.

The yellow container is intended for transportation of finished fuel assemblies. In the foreground are lids from containers.

The inside of the container is where fuel rods are apparently mounted.

The crane operator controls the crane from any place convenient for him.

On the sides are all-stainless steel containers. As they explained to me, there are only 16 of these in the world.

MOSCOW, November 20 – RIA Novosti. Enterprise of the state corporation "Rosatom" "Mining and Chemical Combine" (GCC, Zheleznogorsk, Krasnoyarsk region) began a pilot reprocessing of spent nuclear fuel (SNF) from Russian nuclear power plants using unique technologies that do not create risks for environment, V industrial scale Such “green” processing will begin at the gas chemical complex after 2020.

At the MCC isotope chemical plant, the world's most modern launch complex of an experimental demonstration center (ODC) for radiochemical processing of spent fuel from nuclear power plant reactors was previously built, which will use the latest, environmentally friendly technologies of the so-called generation 3+. The launch complex will make it possible to develop technological regimes for spent nuclear fuel reprocessing on a semi-industrial scale. In the future, it is planned to create a large-scale plant RT-2 on the basis of the ODC for the regeneration of spent nuclear fuel.

A feature of the technologies that will be used at the ODC will be the complete absence of liquid low-level radioactive waste. Thus, Russian specialists will have a unique opportunity for the first time in the world to prove in practice that recycling nuclear materials possible without harming the environment. According to experts, no other country except Russia currently possesses these technologies. The construction of the center was the most technologically complex project ever. recent history GHC.

The first in the history of the MCC, the spent fuel assembly of the VVER-1000 reactor from the Balakovo NPP, stored at the plant for 23 years, was placed in one of the “hot chambers” of the ODC - a box for remotely controlled work with highly radioactive substances, the corporate publication of the Russian nuclear industry newspaper reported on Monday "Country of Rosatom".

“We are starting to work out the modes (of spent nuclear fuel reprocessing). Now the main thing is to qualitatively develop the technology that will be in basic scheme RT-2 plant,” explained Igor Seelev, director of the isotope chemical plant of the Mining and Chemical Plant, as quoted by the newspaper.

"Green" technologies

First, the so-called thermochemical opening and fragmentation of the spent fuel assembly is carried out. Then voloxidation begins (from the English volume oxidation, volumetric oxidation) - an operation that distinguishes generation 3+ of SNF reprocessing from the previous generation. This technology makes it possible to distill radioactive tritium and iodine-129 into the gas phase and prevent the formation of liquid radioactive waste after dissolving the contents of fuel assembly fragments.

After voloxidation, the fuel is sent for dissolution and extraction. Uranium and plutonium are separated and returned to the fuel cycle in the form of uranium and plutonium dioxides, from which it is then planned to produce mixed oxide uranium-plutonium MOX fuel for fast neutron reactors and REMIX fuel for thermal neutron reactors, which form the basis of modern nuclear energy.

The fission products are conditioned, vitrified and packaged in a protective container. There is no liquid radioactive waste left.

After working out new technology SNF reprocessing is being scaled up for use in the second, full-scale stage of the ODC, which will become the industrial basis of the closed nuclear fuel cycle (CNFC). The construction of the building and the second stage of the ODC is now being completed. It is expected that the experimental demonstration center on an industrial scale will start operating after 2020, and in 2021 the MCC expects to reprocess tens of tons of spent fuel from VVER-1000 reactors, Strana Rosatom reported with reference to the general director of the enterprise, Petr Gavrilov.

In the nuclear fuel cycle, it is believed that due to the expanded reproduction of nuclear fuel, the fuel base of nuclear energy will significantly expand, and it will also be possible to reduce the volume of radioactive waste due to the “burning out” of dangerous radionuclides. Russia, as experts note, ranks first in the world in the technologies for constructing fast neutron reactors, which are necessary for the implementation of the CNFC.

The Federal State Unitary Enterprise "Mining and Chemical Combine" has the status of a federal nuclear organization. MCC is a key enterprise of Rosatom in creating a technological complex of a closed nuclear fuel cycle based on innovative new generation technologies. For the first time in the world, the MCC concentrates three high-tech processes at once - storage of spent nuclear fuel from nuclear power plant reactors, its reprocessing and production of new nuclear MOX fuel for fast neutron reactors.