In Russia, work is underway to create a revolutionary nuclear reactor belonging to the fourth generation. We are talking about the BREST reactor, on which enterprises that are part of the state corporation Rosatom are currently working. This promising reactor is being built as part of the Breakthrough project. BREST is a project of fast neutron reactors with a lead coolant, a double-circuit heat transfer to the turbine, as well as supercritical steam parameters. The project has been developed in our country since the late 1980s. The main developer of this reactor is NIKIET named after N. A. Dollezhal (Research and Design Institute of Power Engineering).
Today, nuclear power plants provide Russia with 18% of the electricity it generates. Nuclear energy is very important in the European part of our country, especially in the northwest, where it accounts for 42% of electricity generation. Currently, there are 10 nuclear power plants operating in Russia, which operate 34 power units. Most of them use low-enriched uranium as fuel with a content of the isotope uranium-235 at the level of 2-5%. At the same time, the fuel at the nuclear power plant is not completely consumed, which leads to the formation of radioactive waste.
Russia has already accumulated 18 thousand tons of spent uranium and every year this figure is increasing by 670 tons. In total, there are 345 thousand tons of this waste in the world, of which 110 thousand tons are in the United States. The problem with the processing of these wastes could be solved by a new type of reactor, which would operate in a closed cycle. The creation of such a reactor would help to cope with the leakage of military nuclear technology. Such reactors could be safely supplied to any countries in the world, since in principle it would be impossible to obtain the raw materials necessary for the creation of nuclear weapons on them. But their main advantage would be safety. Such reactors could be started even on old, spent nuclear fuel. According to A. Kryukov, Doctor of Physical and Mathematical Sciences, even rather rough calculations tell us that the reserves of spent uranium accumulated over 60 years of operation of the nuclear industry will be enough for several hundred years of energy generation.
The BREST reactors are a revolutionary project in this direction. This reactor fits well into the context of Vladimir Putin's speech at the Millennium Summit at the UN in September 2000. As part of his report, the Russian president promised the world a new nuclear energy: safe, clean, excluding weapons use. Since that presentation, the work on the implementation of the Breakthrough project and the creation of the BREST reactor has made significant progress.
General view of the BREST-300 reactor
Initially, the BREST unit was designed, which would provide a power unit with a capacity of 300 MW, but later a project appeared with an increased capacity of 1200 MW. At the same time, at this point in time, the developers have concentrated all their efforts on the less powerful reactor BREST-OD-300 (experimental demonstration) in connection with the development of a large volume of new design solutions and plans to test them on a relatively small and cheap project in implementation. In addition, the selected power of 300 MW (electric) and 700 MW (thermal) is the minimum required power to obtain the fuel breeding ratio in the reactor core equal to unity.
Currently, the "Breakthrough" project is being implemented at the site of the enterprise of the state corporation "Rosatom" of the Siberian Chemical Combine (SCC) on the territory of the closed territorial unit (ZATO) Seversk (Tomsk region). This project involves the development of technologies for closing the nuclear fuel cycle, which will be in demand in the nuclear power industry of the future. The implementation of this project in practice provides for the creation of a pilot demonstration power complex consisting of: BREST-OD-300 - a fast neutron reactor with a lead liquid metal coolant with a stationary nuclear fuel cycle and a special module for fabricating / refurbishing fuel for this reactor, as well as a module for reprocessing its spent fuel. It is planned to launch the BREST-OD-300 reactor in 2020.
The general designer of the pilot demonstration energy complex is the St. Petersburg VNIPIET. The reactor is being built by NIKIET (Moscow). Earlier it was reported that the development of the BREST reactor is estimated at 17.7 billion rubles, the construction of a spent nuclear fuel reprocessing module - 19.6 billion rubles, a fabrication module and a fuel refurbishment start-up complex - 26.6 billion rubles. The main task of the power complex being created should be the development of the technology for operating a new reactor, the production of new fuel and the technology for reprocessing spent nuclear fuel. For this reason, the decision to launch the BREST-OD-300 reactor in the power mode in order to generate electricity will be made only after the completion of all research work on the project.
The construction site of the BREST-300 power complex is located in the area of the radiochemical plant of the Siberian Chemical Combine. Work on this site began in August 2014. According to Sergei Tochilin, General Director of SKhK, a vertical leveling has already been carried out here with the excavation of a million cubic meters of soil, cables have been laid, industrial water pipelines have been installed, and other construction work has been completed. Currently, the contractor "Java-Stroy" and the Seversky subcontractor "Spetsteplokhimmontazh" continue the complex of works related to the preparatory period. Today, 400 people work at the construction site, and as the pace of work at the facility increases, the number of builders will grow to 600-700 people. State investments in this project are roughly estimated at 100 billion rubles, according to the press service of the Siberian Chemical Combine.
An experimental demonstration energy complex in the largest in our country closed administrative complex is being built in stages. The first to build a nitride fuel plant is planned to be commissioned in 2017-2018. In the future, the fuel produced at this plant will enter the BREST-300 experimental demonstration reactor, the construction of which will begin in 2016 and will be completed in 2020, this will be the completion of the second stage of the project. The third stage of work envisages the construction of another plant for the reprocessing of spent fuel. The Breakthrough project should be fully operational by 2023. Thanks to the implementation of this ambitious project, about 1.5 thousand new jobs should appear in the city of Seversk. 6-8 thousand workers will directly participate in the construction of the BREST-300 installation.
As the head of the BREST-300 reactor project Andrei Nikolaev said, the experimental demonstration power complex in the city of Seversk will include the BREST-OD-300 reactor plant with a stationary nuclear fuel cycle, as well as a complex for the production of "nuclear fuel of the future." We are talking about nitride fuel for fast reactors. It is assumed that it is on this type of fuel that, starting from the 20s of the XXI century, the entire nuclear power industry will function. It is planned that the experimental BREST-300 reactor will become the world's first fast neutron reactor with a heavy liquid metal coolant. According to the project, spent nuclear fuel in the BREST-300 reactor will be reprocessed and then reloaded into the reactor. A total of 28 tons of fuel will be required for the initial loading of the reactor. At present, the analysis of spent nuclear fuel from the storage facilities of the Siberian Chemical Combine is being carried out - it is possible that a certain amount of products with a plutonium element can be used in the release of fuel for the experimental BREST reactor.
The BREST-300 reactor will have a number of significant advantages in terms of operational safety over any reactor operating today. This reactor will be able to shut down on its own in case of deviation of any parameters. In addition, a fast neutron reactor uses fuel with a lower reactivity margin, and prompt neutron acceleration and the subsequent possibility of an explosion are simply ruled out. Lead, unlike sodium used today as a heat carrier, is passive, and from the point of view of chemical activity, lead is safer than sodium. Dense nitride fuel tolerates temperature conditions and mechanical defects more easily, it is more reliable than oxide fuel. Even the most extreme sabotage accidents with the destruction of external barriers (vessel lids, reactor buildings, etc.) will not be able to lead to radioactive releases that would require evacuation of the population and subsequent long-term alienation of land, as happened during the Chernobyl accident in 1986.
The advantages of the BREST reactor include:
- natural radiation safety in case of all kinds of accidents for external and internal reasons, including sabotage, which does not require evacuation of the population;
- long-term (almost unlimited in time) fuel supply due to the efficient use of natural uranium;
- non-proliferation of nuclear weapons on the planet by eliminating the production during the operation of weapon-grade plutonium and the implementation of on-site technology for dry fuel reprocessing without separation of plutonium and uranium;
- environmental friendliness of energy production and subsequent waste disposal due to a closed fuel cycle with transmutation of long-lived fission products, transmutation and combustion of actinides in a reactor, purification of radioactive waste from actinides, holding and disposal of radioactive waste without violating the natural radiation equilibrium;
- economic competitiveness, which is achieved due to the natural safety of the nuclear power plant and the technology of the implemented fuel cycle, feeding the reactor with only 238U, rejection of complex engineering safety systems, high lead parameters, which ensure the achievement of supercritical parameters of the steam turbine circuit and high efficiency of the thermodynamic cycle, reduction of construction costs.
Project image of the BREST complex. 1 - reactor, 2 - turbine room, 3 - SNF reprocessing module, 4 - fresh fuel fabrication module.
The combination of mononitride fuel, natural qualities of the lead coolant, design solutions of the core and cooling circuits, physical characteristics of a fast reactor brings the BREST reactor to a qualitatively new level of natural safety and makes it possible to ensure stability without triggering active means of emergency protection in very severe accidents, which are insurmountable for any of existing and projected reactors in the world:
- self-propelled gun of all available regulatory bodies;
- shutdown (jamming) of all pumps of the 1st circuit of the reactor;
- shutdown (jamming) of all pumps of the 2nd circuit of the reactor;
- depressurization of the rector's building;
- rupture of steam generator tubes or pipelines of the secondary circuit at any section;
- the imposition of a variety of accidents;
- Unlimited time cooldown at complete power off.
The Breakthrough project being implemented by Rosatom is aimed at creating a new technological platform for the Russian nuclear industry with a closed fuel cycle and solving the problem of spent nuclear fuel and radioactive waste (RW). The result of the implementation of this ambitious project should be the creation of a competitive product that will provide Russian technologies with leadership in the world nuclear energy, and in general in the global energy system for the next 30-50 years.
