Now in Russia a new NPP “Brest – OD - 300” is developing which is to become a head in a series of fast reactors cooled by liquid lead or lead-bismuth alloy. Russian abbreviation OD is translated as Pilot-Demonstrational. The ideas are developed to use in this power plant deaeratorless thermal circuit. Such the schemes are widely and successfully used for conventional power plants in Russia.
Deaeratorless thermal schemes are based on the use of direct contact low-pressure reheaters. These reheaters have deaeration ability. Such schemes improve power plants efficiency by 1.5 %. Some other deaerator functions are distributed among other elements of plant. In particular, the presence of an external, independent supply of water, which is available at nuclear power plants and much higher than the supply of water in the deaerator.
Danger of return flow exists for direct-contact low pressure reheaters. But its design allows to eliminate completely the possibility of dangerous return flow. Compliance with safety was verified by calculation and in the operated power plants.