Abstract: The process flow of the conventional condensation water precision processing system was introduced. The design features of valveless bypass and conventional bypass were analyzed. Starting from the angle of bypass design in unit thermodynamic system of power station, the security problem of the unit was discussed. The design idea of valveless bypass, the operation mode and the key equipments type selection for the nuclear power station were expounded emphatically.

Key words: nuclear power station, condensation water precision processing, valveless bypass, conventional bypass, boost pump, design feature, equipment type selection