Stability analysis for 220 MWe PHWRs including xenon and iodine equations

The nonlinearity ensuing out of feedback effects becomes important from the point of view of operational dynamics of any nuclear reactor. The multiple equilibrium states available due to nonlinear effects have to be investigated using stability analysis. In the present study, the dynamical characteristics of 220 MWe PHWR is carried out with and without Xenon and Iodine equations. The Eigen analyses for different core irradiations have been worked out in order to investigate the regimes of stability. The analysis is performed with point kinetics model along with fuel and coolant temperature feedbacks. The xenon reactivity feedback is also included in the model. Six delayed neutron precursors have been considered. The control parameter is the fuel temperature coefficient for fixed values of coolant temperature coefficient. Also numerical simulations are performed to support the results obtained by Eigen analysis. (author)