Influence of load on turbine and steam generator operation in AP-600

Change of turbine load in the operation of nuclear power plant was necessary to analyse, because it will influence the efficiency and safety of the system. Analysis of turbine and steam generator operation in AP600 nuclear power plant with respect to the change of turbine load was performed to evaluate its performance. The analysis was based on the results of the calculation on the equilibrium of the steam flow at the turbine and steam generator in Rankine cycle, using a computer program which was developed in Basic language. Operation of turbine and steam generator was evaluated during a decrease of load from 100 % to 40 %, which was simulated by closing the regulation valve. The calculation result showed that the decrease of turbine load resulted in the increase of the pressure and temperature of steam generator and reduction in the load of thermal cycle of the reactor fuel. Safety of operation can be ensured when up to 40% reduction in turbine load were applied by using the regulating valve without operating the safety valve. The decrease in efficiency by 30% which is caused by the decrease of turbine load by 40% indicated a good level of efficiency in nuclear power plant