Characteristics and maneuverability of CANDU nuclear power stations operated for base-load and load-following generation

The characteristics and maneuverability of pressurized heavy water nuclear power units operated for base-load and load-following generation are discussed with respect to the requirements of Ontario Hydro. The nuclear generating units of Pickering G.S. 'A' (Units 1-4) and Pickering G.S. 'B' (being designed for Units 5-8), and the turbine-generator-grid of Bruce G .S. 'A' (Units 1-4) were simulated on digital computers. Simulation tests such as normal loading and unloading at various rates, grid frequency upset, and grid islanded cases were conducted with the unit load regulated by three alternative unit power control systems. The results of the simulation show that the necessary flexibility in power maneuvers to meet the load-following requirements in the Ontario Hydro system may be obtained with the CANDU-PHW (Canadian Deuterium Uranium - Pressurized Heavy Water) generating units controlled by an integrated unit load control system which normally operates in a reactor-following-turbine unit control mode. The simulation results also show that the reactor-following-turbine unit control improves the control of many process systems and the overall plant performance.