than it is today. Fast reactors operating in a closed uranium-plutonium cycle could be the basis for this growth. But, wide adoption of such reactors will be possible if the developers solve the following problems: – safety, ruling out catastrophes such as the Chernobyl accident, is proved convincingly; – economic indicators are no worse than for the light-water reactors competing with them; – a closed fuel cycle (in an integral part of fast reactors), which presupposes radiochemical reprocessing of fuel, does not result in the proliferation of fissioning materials suitable for nuclear bombs; – ecologically safe handling of radioactive wastes will be implemented. The concept of BREST-type reactors should, in the opinion of the developers, solve these problems. It is assumed that 1200 MW(e) BREST-1200 reactors will be the basis of future nuclear power. The technical design of a demonstration BREST-OD-300 reactor with 300 MW electric power and 700 MW thermal power is under development; this reactor should show the structural and conceptual features of BREST-1200 reactors and their fuel cycle. The sodium-cooled fast reactors burning oxide fuel, which have been developed and built thus far, were intended for intense production of excess (more than required by them) plutonium in rapidly developing nuclear power production with plutonium-makeup of thermal reactors. They require the following: – uranium-containing screens surrounding the core, which accumulate weapons-quality plutonium for replenishment of thermal reactors and partially the screens themselves, and a plutonium separation technology; – storage sites for temporary storage of the extracted plutonium. All this creates substantial difficulties for nonproliferation of fissioning materials. The problem of transmutation of long-lived radionuclides was not raised for these reactors. The fire danger of the coolant and the associated safety measures substantially degraded the economics of fast reactors compared with water-cooled reactors. The current situation of nuclear power in Russia makes it possible to change the current view of fast reactors substantially, primarily, to remove the requirement of expanded breeding of plutonium. Approximately four tons of the plutonium contained in the spent fuel from light-water reactors are produced in this country every year. The plutonium which has already been accumulated and the plutonium that will be accumulated in the next 10–15 years will be sufficient to double the capacity of nuclear power in Russia by introducing fast reactors. Consequently, the requirement of expanded plutonium breeding at a high rate can be removed with the new generation of fast reactors, quite simple breeding of fuel, and the developers can concentrate on solving the problems determined by the new requirements for reactors and the closed fuel cycle technology. Atomic Energy, Vol. 89, No. 4, 2000