An exergy analysis based on the second law of thermodynamics is performed to evaluate the plant and subsystem irreversibility of a nuclear power plant (NPP) with a pressurized water reactor (PWR). The construction of such a system having a maximum reactor core thermal power of 4250 MW is proposed in Turkey and China. This study concentrates on the questions of where and how much of the available work is lost in such a plant. The evaluated exergy destruction of this plant indicates that the reactor pressure vessel including PWR is the most inefficient equipment in the whole NPP, while the turbines take the second place. (C) 2001 Elsevier Science Ltd. All rights reserved.