A Feasibility Study of Load-Follow Operation Without Boron Adjustment for CPR1000

This paper presents mathematical modeling of dynamic phenomena in large pressurized water reactors to study load-follow capability. One of the main reactor types in China's national nuclear development, CPR1000, uses a mode G control method, with G banks, N banks, R banks, and soluble boron to adjust reactor power changes and the axial power shape. In this paper, a new control mode is adopted that can follow the daily variation of power demand without changing the boron concentration. The control banks are regrouped to realize reactivity/temperature control by M banks and axial offset control by an AO bank. A two-node dynamic core model is constructed, taking into account the coupling coefficient and the mutual influence. The transient parameters are obtained by steady-state calculation of a single channel using the original design and operation parameters of CPR1000. Then, to adopt a control mode without soluble boron adjustment, the optimal control implementation is connected to the core simulation platform. Simulation results show that this optimal control policy can provide the capability for the CPR1000 to follow a daily load curve.