Today, the world fossil fuel industry has already begun the transition to super-supercritical steam parameters, which allows to increase efficiency and reduce fuel consumption, and the dischargies of harmful substances into the environment. One way to improve the energy efficiency of nuclear power plants is to improve the thermodynamic cycle. The paper presents the results of computer simulation of thermal schemes of nuclear power plants with VVER-1200, BN-1200, and BREST-OD-300 reactors a using steam superheating, as well as steam compression to obtain super supercritical parameters of steam and estimates the efficiency of using these thermal circuits.