Prediction of thermal efficiency loss in nuclear power plants due to weather conditions in tropical region

Abstract

In this work, the effect of weather condition mainly temperature on the thermal efficiency of a nuclear power plant has been analyzed. Tropical region has been focused where the atmospheric temperature during summer is within the range of 35-45 0C with relative humidity of 50-80%. To evaluate the effect of atmospheric temperature, a simplified thermal hydraulic model of the secondary coolant loop of a VVER-1200 reactor-based nuclear power plant has been developed. This model, which is basically a Rankin cycle, is used to predict the change in overall plant efficiency due to change in condenser pressure. From the derived analytical equations considering the simplified Rankin cycle, it is observed that the overall plant efficiency may reduce from 37.44% to 33.65% for 4 kPa to 15 kPa condenser pressures, respectively, which is highly dependent on the available tertiary coolant water temperature as well as atmospheric temperature conditions. This may result in higher construction and operation costs of nuclear power plants in tropical regions compared to cold countries. A significant increase in the condenser thermal load with regard to condenser pressure is also observed in this study.