CONCERNING THE NEUTRON LEVEL AND THE NEUTRON RMS VALUE IN A LINEAR FEEDBACK MODEL OF POINT REACTOR KINETICS WITH ONE GROUP OF DELAYED NEUTRONS AND DRIVEN BY RANDOM REACTIVITY NOISE - APPLICATION OF THE RUNGE-KUTTA-METHOD TO SOLVE A SYSTEM OF STOCHASTIC ORDINARY DIFFERENTIAL-EQUATIONS

A power noise model of point reactor kinetics with instantaneous negat ive reactivity feedback is considered. It is driven by stationary colo ured Gaussian random reactivity noise. The model contains one group of delayed neutrons. They show partially destabilizing effects at interm ediate power states. The neutron steady-state value and the neutron RM S value are obtained as functions of the reactivity excitation strengt h for different power states via computer simulation. The reactivity n oise data are generated by a method based on the Rice formula, and the Langevin equations of the model are directly treated by the Runge-Kut ta method. Results are compared with data obtainable from the Wiener-H ermite functional method in a first-order approximation. (C) 1998 Else vier Science Ltd. All rights reserved.