“Rosatom started installation of the world's first Generation IV fast reactor BREST-OD-300 in Seversk”.

The containment structure is the outer part of the reactor building. It provides retention of heat-insulating concrete, forms an additional localising barrier of protection, which follows the boundary of the coolant circuit. On its surface, the temperature should not exceed 60 degrees Celsius, and the radiation background is actually equal to the natural background.
A 300 MW power unit based on the BREST-OD-300 fast reactor with lead coolant, which implements the principles of "natural safety", is the key element of the Experimental and Demonstration Energy Complex (EDEC) being created under the Breakthrough Project at the site of the Siberian Chemical Combine in Seversk, Tomsk Region. In addition to the power unit, ODEC will also include facilities of the on-site nuclear fuel cycle - a complex for the production of mixed uranium-plutonium nitride fuel, as well as a module for reprocessing irradiated nuclear fuel.
"Installation of the world's first lead-cooled fast neutron reactor plant - the fourth-generation BREST-OD-300 reactor - has begun. Unlike traditional light-water VVER thermal reactors, the BREST fast reactor has an integral layout. Its reactor vessel is not an all-metal structure like the VVER, but a metal-concrete structure with metal cavities to accommodate the primary circuit equipment. The space between the cavities is gradually filled with concrete filler during construction. In addition, the BREST vessel is larger in size, it can be delivered only in parts, and the final assembly is possible only at the ODEK construction site," commented Vadim Lemekhov, Chief Designer of the BREST-OD-300 reactor unit and General Designer of the Breakthrough Design Branch.
According to the classification adopted by the IAEA, Generation IV nuclear reactors involve the application of various technologies that are united by a common result - higher fuel utilisation efficiency, increased safety, energy efficiency, reduction of spent nuclear fuel, etc.

“The Breakthrough” project implemented by ROSATOM is aimed at achieving a new quality of nuclear power, development, creation and industrial implementation of a closed nuclear fuel cycle based on fast neutron reactors developing large-scale nuclear power.

The advantage of fast reactors is their ability to efficiently use secondary products of the fuel cycle (in particular, plutonium) for power generation. At the same time, having a high reproduction rate, fast reactors can produce more potential fuel than they consume, as well as "afterburning" (i.e. utilising with energy production) highly active transuranic elements (actinides). The BREST-OD-300 reactor will provide itself with the main energy component - plutonium-239, reproducing it from uranium-238 isotope, which in natural uranium ore contains more than 99% (currently, uranium-235 is used for energy production in thermal reactors, the content of which in nature is about 0.7%). Implementation of such technologies will greatly increase the efficiency of natural uranium utilisation, while its share in the world's energy resources is about 86% (coal - 8%, oil - 3%, gas - 3%).