Model of IBR-2 power feedback dynamics taking account of slow components

A dynamical model of total feedback is constructed and a procedure for determining the parameters of the dynamics of the slow power-feedback components is investigated. Using the quasistationary equation governing the activity balance, the general effect of power feedback, consisting of the sum of fast and slow components of the reactivity change, is identified. The form of the curves of this effect indicates that the model of dynamic power feedback in IBR-2 for slow processes consists of three components: a proportional link and two slow inertial links (fast and slow links with positive and negative transfer coefficient and time constants of several hours and several tens of hours). The parameters of the dynamics of slow action are determined. The reactivity variation curves obtained according to the model are identical to the measured curves. __________ Translated from Atomnaya énergiya, Vol. 104, No. 4, pp. 198–203, April, 2008.