A dynamic performance assessment of coordinated control system of small pressurized water reactor based on uncertainty quantification and sensitivity analysis

Parameter uncertainty is an inherent characteristic of control systems. To assess the impact of parameter uncertainty on the system, the dynamic performance assessment with uncertainty quantification and sensitivity analysis is proposed. The input sample set is obtained by Wilks' method and Latin hypercube sampling, then dynamic simulation and statistics are used to realize the uncertainty quantification of output parameters and the identification of key output parameters. The central composite design and second-order polynomial are used to build the agent model for the Sobol's method. Taking the small pressurized water reactor nuclear power plant as an example, a performance assessment platform of coordinated control system is developed through graphical user interface with fast load decrease conditions. The study shows that all the transient safety parameters except reactor core relative power and secondary-side outlet temperature of once-through steam generator (OTSG) satisfy the technical requirements, and the control system has a certain safety margin. Meanwhile, the adjustment time of reactor core relative power and secondary-side outlet temperature of OTSG is highly sensitive to primary-side flowrate of OTSG under the small range of variable load, and sensitive to the opening pressure of the steam dump valve under the large range of variable load.