Abstract
Nuclear power plant can be a key pillar of a country’s energy supply. In their operation, it is necessary to follow the efficient use of the primary energy source. Using the thermodynamic analysis of energy and exergy flows in a nuclear power plant, we calculated the energy and exergy efficiency. With comparison of final electrical energy and internal energy of nuclear fuel we hand the energy efficiency for chosen power station. This has significant meaning. However, a nuclear power plant is an example of power station, that operates generally on principle of heat transfer. At that irreversibility and thus loss of exergy occur, so a clearer and more meaningful picture of the efficient use of nuclear fuel is shown by exergy efficiency. This is describing relationship between exergy of output electric current and exergy of nuclear fuel. The main goal of our research work was to observe the energy and exergy flows and their loses on the built model of the nuclear power plant. Based on the findings, we gave energy and exergy efficiency for individual assembly and the whole plant. By comparing the two efficiency evaluation criteria, we researched where deviations occur between energy and exergy efficiency. The essence of such an analysis is the data that clearly show us the places where we lose energy or exergy. With such knowledge, we can discuss on theoretical possibilities of improvements on individual assemblies of power station, which would upgrade the existing efficiency of the entire nuclear power plant. For the set model in our research, the energy efficiency was found to be 33.7% and the exergy efficiency 46.8%.