Thermal power plants with a closed-feed cycle. This analysis includes a comparison of the available cavitation reserve of feedwater pumps (FWPs) of operating units with that of BREST-OD-300. We established that the number of electric condensate pumps (ECPs) on closed-feed cycle units is equal to the number of FWPs. A preferable system cycle was selected. We used a dynamic model of the BREST-OD-300 power unit to calculate and analyze the mode with failure of the ECP-2 without switching on the reserve pump. Based on the calculation results, we formulated certain characteristics requirements ECP-2 should meet in case their number agrees with that of FWPs. According to the characteristics obtained from the manufacturers, a calculation was made for the same ECP failure mode with an ECP-and-FWP number ratio equal to one. The use of the dynamic model of a power unit makes it possible to assess the reliability of equipment in modes with equipment failure even before the construction of the plant. Based on the study results, it is clear that the number of ECPs of the BREST-OD-300 unit should be no less than the number of FWPs.