The introduction of the bachelor’s thesis briefly presents the principles and classification of nuclear power plants and their importance in today’s energy sector. Special attention is paid to nuclear power plants with pressurized water reactors cooled by light water, which are used in both Czech nuclear power plants and at the same time represent the most widespread type of power reactor in the world. The following part focuses on the description of the secondary steam cycle of a nuclear power plant with a PWR reactor. The main components of this cycle are described in greater detail, namely the steam generator, steam turbine, condenser, and feed-water pump. The thesis also deals with the design of a steam turbine intended to drive the pump and with the subsequent parametric study of suitably selected characteristic turbine parameters. The results were processed using an iterative procedure according to the described methodology. The thermodynamic efficiency of the designed stage reached 84,4%, with a steam mass flow rate of 13 kg/s, a mean blade diameter of 0,5 m, a flow channel height of 76,2 mm, partial admission of 84,5%, and a power output at the coupling with the pump of 509,8 kW at nominal rotational speeds of 5500 min⁻¹.