The main theme of this bachelor thesis is a theoretical and computational description of the steam generator. The first chapter deals with a brief description of nuclear power plants. Particular attention is paid to the power plants of the VVER type, which are used in the Czech and Slovak Republic. The theoretical part of this thesis describes the individual components which are important for the operation of a nuclear power plant. The main part of this thesis depicts horizontal and vertical steam generators. Moreover, the PGV-213 type of steam generator that is used in the Dukovany nuclear power plant is more precisely explained. The computation part of this thesis is devoted to the balance and heat calculations of the steam generator. At ...