Axial power distribution control in pressurized water reactors based on flow rate regulation based on distributed parameters method

The control of axial power distribution is a key challenge in the operation of Pressurized Water Reactors (PWRs). Traditionally, this control has been achieved by adjusting the concentration of soluble boron and moving a select number of control rod banks. In this work, an innovative axial power distribution control method based on flow rate regulation is proposed. This method can reduce the dependence on boron concentration regulation and control rod banks movement, so that the treatment for lots of liquid waste can be avoided, and the structure of reactor cores may become more compact. Different with the lumped parameter system control method, this research introduces a unique PWR core exponential stability condition based on SDLMI from the distributed parameter control theory. Moreover, a distributed parameter state observer is established to provide the feedback of power density, delayed neutron precursor density and ¹³⁵Xe concentration which cannot be measured by sensors directly in PWRs. The numerical experiment shows that the axial power distribution control method based on flow rate regulation can inhibit the power density peak and eliminate hot spots efficiently.