The nonlinear stability analysis of a supercritical light water reactor (SCLWR) is presented using a nuclearcoupled thermal-hydraulic reduced-order model. The analytical model is developed by coupling 1. the pointkinetics equations with one group of delayed neutrons, 2. the fuel heat transfer and 3. a 1-D reduced order model which represents the heat absorption phenomenon during the coolant flow. | Progress in Nuclear Energy 117 2019 103051 Contents lists available at ScienceDirect Progress in Nuclear Energy journal homepage locate pnucene On nuclear-coupled thermal-hydraulic instability analysis of Super-Critical- T Light-Water-cooled-reactor SCLWR Subhanker Paul1 Department of Energy and Process Engineering Norwegian University of Science and Technology NTNU Norway ARTICLE INFO ABSTRACT Keywords The nonlinear stability analysis of a supercritical light water reactor SCLWR is presented using a nuclear- Super-critical-light water reactor coupled thermal-hydraulic reduced-order model. The analytical model is developed by coupling 1. the point- Linear stability kinetics equations with one group of delayed neutrons 2. the fuel heat transfer and 3. a 1-D reduced order model Nonlinear stability which represents the heat absorption phenomenon during the coolant flow. Unlike the existing studies which Subcritical hopf are limited to linear stability analysis the primary objective of the work is to present the detailed nonlinear Supercritical hopf Generalized hopf dynamics of the SCLWR system. The said goal is achieved at two levels. The first level is the linear stability Saddle node bifurcation analysis wherein the linear stability boundaries are shown in two sets of parameter space namely the two Globally stable region intrinsic reactivity feedbacks Doppler reactivity feedback and density reactivity feedback and the pseudo- phase-change number and pseudo subcooling number. The parametric effects show the sensitivity of the linear stability boundaries with the system parameters. In the second level to discuss the nonlinear characteristics of the system two types of Hopf bifurcations subcritical and supercritical are studied with the help of first Lyapunov coefficients of the system. Multiple numerical simulations are performed to verify the resultant limit cycle behavior associated with these bifurcations. Moreover the occurrence of the .
