LAUSR

Abstract The purpose of this study is determining the region in the parameter space where the system is either stable or unstable. This work tackles two nonlinear models, one including the impact of the rate of temperature change on reactivity and another not including this term, with the goal to increase the understanding, identifying and associating the physical processes and stability zone. An asymptotic stable region is obtained for both negative and positive values of the rate of temperature change term and for feedback gain value. The stability region size increases with positive rate of the coefficient of temperature change term, whereas it decreases for negative coefficient rate. The results of qualitative analysis are confirmed calculating Lyapunov exponent value for the transient behaviour of the reactor power. The main contribution of this work is the analysis at analytical level carried out to reduced order model non-linear without any reduction in terms.