Introduction  The floating nuclear power plants have the advantages of mobility, flexible layout, less impact from earthquakes and tsunamis, no occupation of land area, and less impact from site conditions. It can effectively support offshore resource development and island energy supply, and is one of the hot topics in nuclear energy utilization today. As the most important equipment in conventional islands, the structural type and parameters of steam turbine generator sets directly affect the operation safety and stability of power plants.

  Method  Based on the ACP100S reactor, this paper discussed the technical scheme of offshore floating nuclear energy platform turbine generator unit from the aspects of turbine exhaust direction, number of shaft systems, back pressure, final stage blades, reheat parameters, reheat stages, and generator cooling method.

  Result  It is recommended to choose a steam turbine consisting of a single shaft, downward exhaust, throttling steam distribution, one single flow high-pressure cylinder module, and one single flow low-pressure cylinder module, with 1200 mm long low-pressure cylinder blades, thermal scheme of 1-stage reheating and 4-stage backheating, single-process condenser, and air-cooled generator.

  Conclusion  The results can provide reference for the subsequent design of floating nuclear power plant systems and related design parameters of steam turbine generator.